Aqueous zinc-ion batteries are promising due to inherent safety,low cost,low toxicity,and high volumetric capacity.However,issues of dendrites and side reactions between zinc metal anode and the electrolyte need to be...Aqueous zinc-ion batteries are promising due to inherent safety,low cost,low toxicity,and high volumetric capacity.However,issues of dendrites and side reactions between zinc metal anode and the electrolyte need to be solved for extended storage and cycle life.Here,we proposed that an electrolyte additive with an intermediate chelation strength of zinc ion—strong enough to exclude water molecules from the zinc metal-electrolyte interface and not too strong to cause a significant energy barrier for zinc ion dissociation—can benefit the electrochemical stability by suppressing hydrogen evolution reaction,overpotential growth,and den-drite formation.Penta-sodium diethylene-triaminepentaacetic acid salt was selected for such a purpose.It has a suitable chelating ability in aqueous solutions to adjust solvation sheath and can be readily polarized under electrical loading conditions to further improve the passivation.Zn||Zn symmetric cells can be stably operated over 3500 h at 1 mA cm^(-2).Zn||NH4V4O10 full cells with the additive show great cycling stability with 84.6%capacity retention after 500 cycles at 1 A g^(-1).Since the additive not only reduces H2 evolution and corrosion but also modifies Zn2+diffusion and deposition,highlyreversible Zn electrodes can be achieved as verified by the experimental results.Our work offers a practical approach to the logical design of reliable electrolytes for high-performance aqueous batteries.展开更多
Iron is essential for all organisms including microbial,cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overloa...Iron is essential for all organisms including microbial,cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic haemochromatosis, thalassaemia intermedia and ex-thalassaemia transplanted patients who are safely treated with venesection. Iron chelating drugs can override normal regulatory pathways, correct iron imbalance and minimise iron toxicity. The use of iron chelating drugs as main, alternative or adjuvant therapy is in progress in many conditions, especially those with non established or effective therapies.展开更多
Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·...Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity.展开更多
Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this sys...Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this system will cause many problems such as high hygroscopicity,Li+migration,pinholes and so on,which hinder PSC from maintaining high efficiency and stability for long-term.In this work,an effective strategy is demonstrated to improve the performance and stability of PSC by replacing t BP with 12-crown-4.The chelation of 12-crown-4 with Li+not only improves the doping effect of Li-TFSI,but also perfectly solves the problems caused by the Li-TFSI/tBP system.The PSC based on this strategy achieved a champion power conversion efficiency(PCE)over 21%,which is significantly better than the pristine device(19.37%).More importantly,the without encapsulated device based on Li-TFSI/12-crown-4 still maintains 87%of the initial PCE even after 60 days exposure in air,while the pristine device only maintains 22%of the initial PCE under the same aging conditions.This strategy paves a novel way for constructing efficient and stable PSCs.展开更多
[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,conc...[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.展开更多
Traditional risk factors for cardiovascular disease can only assess risks for groups of people. New parameters of arterial stiffness are more reliable for predicting cardiovascular outcomes for individuals with and wi...Traditional risk factors for cardiovascular disease can only assess risks for groups of people. New parameters of arterial stiffness are more reliable for predicting cardiovascular outcomes for individuals with and without a cardiovascular history. The objective of this study was to assess the effects of Magnesium-EDTA chelation therapy using new methods and parameters such as pulse wave velocity (PWV), central blood pressure (SBPao) and endothelial function (Aix). We followed 43 patients with an abnormal PWV and SBPao, setting them up in two groups. The 21 patients in Group A had already been diagnosed with cardiovascular disease. The other 22 patients in Group B also showed abnormal PWV, SBPao and Aix, but showed no cardiovascular symptoms. Each patient in Groups A and B received one Mg-EDTA treatment per week. The total treatment plan consisted of 25 Mg-EDTA chelation treatments according to the standard protocol of IBCMT. After 25 Mg-EDTA chelation sessions, PWV and SBPao improved significantly in all patients of Groups A and B. In addition, Aix improved significantly in these patients, but remained abnormal. Group C included 18 asymptomatic patients with normal PWV or SBPao. Aix was abnormal in this group, but to a much lesser extent than Groups A and B. The 18 asymptomatic patients of Group C did not receive Mg-EDTA treatment. Observation showed no significant changes in all three parameters of arterial stiffness. The results of this study indicate that a course of treatment with Magnesium-EDTA chelation therapy significantly lowers cardiovascular risks. We conclude that Mg-EDTA chelation therapy improves PWV as an indicator of arterial stiffness, SBPao (central blood pressure) as an indicator of aortic elasticity and Aix (augmented aortic index) as an indicator of endothelial functioning. These improvements in PWV, SBPao and Aix demonstrate that atherosclerosis is a dynamic and (partially) reversible process.展开更多
An 87-year-old woman with primary open-angle glaucoma presented to our hospital. Although the combined cataract and minimally invasive glaucoma surgeries (MIGS) were an appropriate surgical option, the presence of ban...An 87-year-old woman with primary open-angle glaucoma presented to our hospital. Although the combined cataract and minimally invasive glaucoma surgeries (MIGS) were an appropriate surgical option, the presence of band keratopathy made it difficult to perform ab interno glaucoma surgery in her right eye (OD);therefore, the corneal opacity was removed using ethylenediaminetetraacetic acid (EDTA) chelation procedure. One month after chelation, microhook ab interno trabeculotomy and cataract surgery were performed successfully. Clear intraoperative visualization of the angle structures is critical for the success of these MIGS procedures. In glaucomatous eyes that require MIGS, EDTA chelation is a good neoadjuvant therapy for coexisting band keratopathy.展开更多
Ethylene Diamine Tetra Acetic Acid (EDTA) chelation therapy has been considered a definitive alternative therapy for by-pass surgery in atherosclerotic cardiovascular disease for more than four decades. It is a relati...Ethylene Diamine Tetra Acetic Acid (EDTA) chelation therapy has been considered a definitive alternative therapy for by-pass surgery in atherosclerotic cardiovascular disease for more than four decades. It is a relatively inexpensive method believed to restore blood flow in atherosclerotic vessels. However, the benefits of chelation therapy yet remain controversial in the treatment of ischemic heart disease. We observed the effect of EDTA chelation therapy on exercise tolerance in 13 volunteering patients receiving conventional treatment for established symptomatic coronary heart disease. Each patient received 30 weekly infusions of EDTA followed by monthly 12 boosters according to the ACAM protocol (American College for Advancement in Medicine). This was in addition to the conventional therapies they received from their respective physician in hospital. Stress ECG, echocardiography and coronary angiogram findings were obtained at the beginning of treatment. The distance that a patient could walk on level ground at moderate speed and the number of steps he/she can climb up on a staircase until he/she begins to feel either chest pain or breathlessness were the two clinical parameters of exercise tolerance recorded to grade angina. Liver and renal functions were tested at 1st, 5th, 10th, 15th and 30th infusions. Of the 13 patients, 11 showed improvement in angina grading whilst 2 experienced no effect. One patient improved from angina grade IV to I, 6 from grade III to I, 1 from grade III to II and 3 from grade II to I. A statistically significant reduction in the mean score (p = 0.002) was noticed at 6th month of treatment when compared to that of the first month. A significant 1.7 fold increase (p = 0.009) in the mean SGPT level was observed at the 30th infusion when compared to the pre-treatment values. The SGOT level showed no significant change (p = 0.664). None of the patients showed clinical features of hepato-cellular damage. The mean serum creatinine level showed a trend for reduction (p = 0.083) with treatment. The recognized side effects of intravenous EDTA chelation therapy such as liver damage, renal damage, hypersensitivity, symptomatic hypocalcaemia, and thrombophlebitis were not encountered. Thus, EDTA chelation therapy as prescribed by the ACAM protocol seems safe and effective in improving exercise tolerance in ischemic heart disease when administered concurrently with conventional therapy.展开更多
Adherence to thalassemia treatment including chelation drugs is influenced by numerous factors. This study aims to explore beliefs about iron chelation therapy and adherence to this medication in Jordanian children wi...Adherence to thalassemia treatment including chelation drugs is influenced by numerous factors. This study aims to explore beliefs about iron chelation therapy and adherence to this medication in Jordanian children with thalassemia major. In this descriptive cross-sectional study, seventy three patients were selected conveniently to complete the study instruments. Participants reported high adherence to their chelation therapy (88.1%). The majority (87.6%) expressed necessity for chelation therapy. However, 42.18% of the participants expressed their concerns about the therapy in which 57.9% of them showed concerns about dependency on medicine and 46.4% of them revealed concerns about the long-term effect of medicine. Overall, about 12.9% of the participants recorded correct and complete answers about thalassemia and its treatment. Knowledge about thalassemia and concerns about chelation were not significantly associated with adherence to the chelation therapy (r = 0.32, p = 0.19;r = 0.29, p = 0.25, respectively). However, there was a significant positive relationship between beliefs about the necessity of the therapy and adherence to it (r = 0.38, p = 0.03). In conclusion, Jordanian children showed proper adherence to their chelation therapy. Health care professionals should discuss patients’ concerns about chelation therapy which might increase patients’ adherence to their therapy.展开更多
The influence of methionine supplementation on the efficacy of common antidotes to lead poisoning, calcium disodium ethylenediaminetetraacetate （CaNa<sub>2</sub>EDTA） and D-penicillamine （DPA）, was inv...The influence of methionine supplementation on the efficacy of common antidotes to lead poisoning, calcium disodium ethylenediaminetetraacetate （CaNa<sub>2</sub>EDTA） and D-penicillamine （DPA）, was investigated in rats. The animals were given lead acetate （0.1% in drinking water） for 12 weeks and thereafter treated with CaNa<sub>2</sub>EDTA, DPA （0.3mmol/kg, intraperitoneally）, DL-methionine （1.34 mmol/kg, intragastrically）, or the combination of a chelating agent and methionine for 3 days. While chelating agents enhanced the urinary excretion of Pb, methionine increased the fecal excretion of Pb significantly. Treatment with the combination of a chelating agent and methionine did not potentiate the effect of each antidote. However, methionine supplementation increased the efficacy of both chelating agents in reducing the hepatic and renal Pb burden but not the blood Pb level. The Pb-induced inhibition of blood δ-aminolevulinic acid dehydratase activity and the increase in urinary excretion of δ-aminolevulinic acid were reversed to a certain extent by CaNa<sub>2</sub>EDTA, DPA, and methionine but the combination did not improve their individual performances. The beneficial effects of methionine may be attributed to its ability to increase the bioavailability of glutathione （GSH）, useful in chelating Pb and counteracting the toxic effects, as evidenced by restoration of the Pb-induced decrease in hepatic GSH level by treatment with methionine. Methionine may be useful as a supportive therapy in chelation of Pb. （c）1989 Academic Press. Inc.展开更多
Chemotherapy can induce a robust T cell antitumor immune response by triggering immunogenic cell death(ICD),a process in which tumor cells convert from nonimmunogenic to immunogenic forms.However,the antitumor immune ...Chemotherapy can induce a robust T cell antitumor immune response by triggering immunogenic cell death(ICD),a process in which tumor cells convert from nonimmunogenic to immunogenic forms.However,the antitumor immune response of ICD remains limited due to the low immunogenicity of tumor cells and the immunosuppressive tumor microenvironment.Although autophagy is involved in activating tumor immunity,the synergistic role of autophagy in ICD remains elusive and challenging.Herein,we report an autophagy amplification strategy using an ion-chelation reaction to augment chemoimmunotherapy in cancer treatments based on zinc ion(Zn^(2+))-doped,disulfiram(DSF)-loaded mesoporous silica nanoparticles(DSF@Zn-DMSNs).Upon pH-sensitive biodegradation of DSF@Zn-DMSNs,Zn2+and DSF are coreleased in the mildly acidic tumor microenvironment,leading to the formation of toxic Zn2+chelate through an in situ chelation reaction.Consequently,this chelate not only significantly stimulates cellular apoptosis and generates damage-associated molecular patterns(DAMPs)but also activates autophagy,which mediates the amplified release of DAMPs to enhance ICD.In vivo results demonstrated that DSF@Zn-DMSNs exhibit strong therapeutic efficacy via in situ ion chelation and possess the ability to activate autophagy,thus enhancing immunotherapy by promoting the infiltration of T cells.This study provides a smart in situ chelation strategy with tumor microenvironment-responsive autophagy amplification to achieve high tumor chemoimmunotherapy efficacy and biosafety.展开更多
Glyphosate-based herbicides are widely used around the world, making it likely that most humans have significant exposure. Because of habitual exposure, there are concerns about toxicity including neurotoxicity that c...Glyphosate-based herbicides are widely used around the world, making it likely that most humans have significant exposure. Because of habitual exposure, there are concerns about toxicity including neurotoxicity that could result in neurological, psychiatric, or cognitive impairment. We recently found that a single injection of glyphosate inhibits long-term potentiation, a cellular model of learning and memory, in rat hippocampal slices dissected 1 day after injection, indicating that glyphosate-based herbicides can alter cognitive function. Glyphosate-based herbicides could adversely affect cognitive function either indirectly and/or directly. Indirectly, glyphosate could affect gut microbiota, and if dysbiosis results in endotoxemia(leaky gut), infiltrated bacterial by-products such as lipopolysaccharides could activate pro-inflammatory cascades. Glyphosate can also directly trigger pro-inflammatory cascades. Indeed, we observed that acute glyphosate exposure inhibits long-term potentiation in rat hippocampal slices. Interestingly, direct inhibition of long-term potentiation by glyphosate appears to be similar to that of lipopolysaccharides. There are several possible measures to control dysbiosis and neuroinflammation caused by glyphosate. Dietary intake of polyphenols, such as quercetin, which overcome the inhibitory effect of glyphosate on long-term potentiation, could be one effective strategy. The aim of this narrative review is to discuss possible mechanisms underlying neurotoxicity following glyphosate exposure as a means to identify potential treatments.展开更多
Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed highe...Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.展开更多
This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instan...This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.展开更多
Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of thi...Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.展开更多
Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work inves...Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work investigates on PFP for the degradation of CIP to understand the formation mechanism and stability of iron complexes under ultraviolet(UV)-light illumination.A comparison was made with the UV-photocatalysis(UV/TiO_2)process where CIP doesn't form a complex.In PFP,the optimal dose of Fe^(2+)and H_2O_2were found to be 1.25 and10 mmol/L with pH of 3.5.An optimal TiO_2dose of 1.25 g/L was determined in the UV/TiO_2process.Maximum CIP removal and mineralization efficiency of 93.1%and 47.3%were obtained in PFP against 69.7%and 27.6%in the UV/TiO_2process.The mass spectra could identify seventeen intermediate products including iron-CIP complexes in PFP,and only seven intermediate products were found in the UV/TiO_2process with a majority of common products in both the processes.The proposed mechanism supported by the mass spectra bridged the routes of CIP cleavage in the PFP and UV/TiO_2process,and the decomposition pathway of Fe^(3+)-CIP chelate complexes in PFP was also elucidated.Both in PFP and UV/TiO_2processes,the target site of HO~·radical attack was the secondary-N atom present in the piperazine ring of the CIP molecule.The death of Escherichia coli bacteria was 55.7%and 66.8%in comparison to the control media after 45 min of treatment in PFP and UV/TiO_2process,respectively.展开更多
An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfor...An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfortunately,current iron-based therapeutic strategies often lack effectiveness and can elicit off-target toxicities.We report here a dual-therapeutic prodrug,DOXjade,that allows for iron chelation chemo-photothermal cancer therapy.This prodrug takes advantage of the clinically approved iron chelator deferasirox(ExJade®)and the topoisomerase 2 inhibitor,doxorubicin(DOX).Loading DOXjade onto ultrathin 2D Ti_(3)C_(2) MXene nanosheets produces a construct,Ti_(3)C_(2)-PVP@DOXjade,that allows the iron chelation and chemotherapeutic functions of DOXjade to be photo-activated at the tumor sites,while potentiating a robust photothermal effect with photothermal conversion efficiencies of up to 40%.Antitumor mechanistic investigations reveal that upon activation,Ti_(3)C_(2)-PVP@DOXjade serves to promote apoptotic cell death and downregulate the iron depletion-induced iron transferrin receptor(TfR).A tumor pH-responsive iron chelation/photothermal/chemotherapy antitumor effect was achieved both in vitro and in vivo.The results of this study highlight what may constitute a promising iron chelation-based phototherapeutic approach to cancer therapy.展开更多
Background:One of the most pervasive complications of burn injury is wound progression,characterized by continuous tissue destruction in untreated wounds,which leads to wound infection,inflammation,oxidative stress an...Background:One of the most pervasive complications of burn injury is wound progression,characterized by continuous tissue destruction in untreated wounds,which leads to wound infection,inflammation,oxidative stress and excessive scar formation.We determined whether additional tissue destruction could be attenuated with Livionex formulation(LF)lotion,which contains a metal-chelating agent and reduces inflammation in burn wounds.Methods:We subjected male Sprague Dawley rats to a 2%total body surface area(TBSA)burn using a brass comb model and topically applied LF lotion(containing ethylenediaminetetraacetic acid and methyl sulfonyl methane)to the affected area every 8 hours over 3 days.Inflammatory cytokine levels,cell apoptosis and wound healing were compared in LF lotion-treated and untreated rats.Statistical analysis was performed using a one-way analysis of variance in conjunction with Tukey’s post-hoc test.Results:Serum inflammatory cytokines were not detectable after 3 days,suggesting that small burn wounds induce only an immediate,localized inflammatory response.Microscopy revealed that LF lotion improved burn site pathology.Deoxynucleotidyl transferase biotin-d-UTP nick-end labeling staining showed reduced cell death in the LF-treated samples.LF lotion prevented the spread of tissue damage,as seen by increased amounts of Ki-67-positive nuclei in the adjacent epidermis and hair follicles.Tumor necrosis factor-alpha,interleukin-6 and inducible nitric oxide synthase levels in LF-treated skin sections from burned rats were comparable to the levels observed in unburned control sections,indicating that LF lotion reduces inflammation in and around the burn site.Conclusions:These results establish LF lotion as a therapeutic agent for reducing inflammatory stress,cell death and tissue destruction when applied immediately after a burn injury.Further studies of LF lotion on large TBSA burns will determine its efficacy as an emergency treatment for reducing long-term morbidity and scarring.展开更多
Protein kinase substrate phage (PKS phage) was constructed by fusing the substrate recognition consensus sequence of cAMP-dependent protein kinase (cAPK) with bacteriophage minor coat protein g3p and by dis-playing it...Protein kinase substrate phage (PKS phage) was constructed by fusing the substrate recognition consensus sequence of cAMP-dependent protein kinase (cAPK) with bacteriophage minor coat protein g3p and by dis-playing it on the surface of filamentous bacteriophage fd. Phosphorylation in vitro by cAPK showed a unique labelled band of approximately 60 ku, which was consistent with the molecular weight of the PKS-g3p fusion protein. Some weakly phosphorylated bands for both PKS phage and wild-type phage were also observed. Phage display random 15-mer peptide library phosphorylated by cAPK was selected with ferric (Fe3+ ) chelalion affinity resin. After 4 rounds of screening, phage clones were picked out to determine the displayed peptide sequences by DNA sequencing. The results showed that 5 of 14 sequenced phages displayed the cAPK recognition sequence motif (R)RXS/T. Their in vitro phosphorylation analyses revealed the specific labelled bands corresponding to the positive PKS phages with and without the展开更多
Nitrogen-containing compounds are ubiquitously found in the fields of organic chemistry,pharmaceuticals,agrochemicals,medicinal chemistry and functional materials.The C-H bond amination reaction is one of the most str...Nitrogen-containing compounds are ubiquitously found in the fields of organic chemistry,pharmaceuticals,agrochemicals,medicinal chemistry and functional materials.The C-H bond amination reaction is one of the most straightforward protocols in the CN bond formation,showing"step"and"atomic"economy.As a catalyst for C-H amination reaction,copper exhibits its unique catalytic properties due to easily accessible oxidation states.The research progress of copper-catalyzed C-H amination in recent years is summarized.At the same time,reaction mechanisms are also briefly described in representative aminations to provide insights for the development prospects of highly practical and more environmentally benignprocesses.展开更多
基金This work is financially supported by National Natural Science Foundation of China(NSFC-No.52173257 and 52372064).
文摘Aqueous zinc-ion batteries are promising due to inherent safety,low cost,low toxicity,and high volumetric capacity.However,issues of dendrites and side reactions between zinc metal anode and the electrolyte need to be solved for extended storage and cycle life.Here,we proposed that an electrolyte additive with an intermediate chelation strength of zinc ion—strong enough to exclude water molecules from the zinc metal-electrolyte interface and not too strong to cause a significant energy barrier for zinc ion dissociation—can benefit the electrochemical stability by suppressing hydrogen evolution reaction,overpotential growth,and den-drite formation.Penta-sodium diethylene-triaminepentaacetic acid salt was selected for such a purpose.It has a suitable chelating ability in aqueous solutions to adjust solvation sheath and can be readily polarized under electrical loading conditions to further improve the passivation.Zn||Zn symmetric cells can be stably operated over 3500 h at 1 mA cm^(-2).Zn||NH4V4O10 full cells with the additive show great cycling stability with 84.6%capacity retention after 500 cycles at 1 A g^(-1).Since the additive not only reduces H2 evolution and corrosion but also modifies Zn2+diffusion and deposition,highlyreversible Zn electrodes can be achieved as verified by the experimental results.Our work offers a practical approach to the logical design of reliable electrolytes for high-performance aqueous batteries.
文摘Iron is essential for all organisms including microbial,cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic haemochromatosis, thalassaemia intermedia and ex-thalassaemia transplanted patients who are safely treated with venesection. Iron chelating drugs can override normal regulatory pathways, correct iron imbalance and minimise iron toxicity. The use of iron chelating drugs as main, alternative or adjuvant therapy is in progress in many conditions, especially those with non established or effective therapies.
基金funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program。
文摘Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity.
基金the National Natural Science Foundation of China(22175029 and 62104031)the Sichuan Science and Technology Program(2019YJ0162)+3 种基金the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices(KFJJ202109)the Natural Science Foundation of Shenzhen Innovation Committee(JCYJ20210324135614040)the Technical Field Funds of 173 Project(2021-JCJQ-JJ-0663)the Fundamental Research Funds for the Central Universities of China(ZYGX2021J010 and Y030202059018023)for financial support。
文摘Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this system will cause many problems such as high hygroscopicity,Li+migration,pinholes and so on,which hinder PSC from maintaining high efficiency and stability for long-term.In this work,an effective strategy is demonstrated to improve the performance and stability of PSC by replacing t BP with 12-crown-4.The chelation of 12-crown-4 with Li+not only improves the doping effect of Li-TFSI,but also perfectly solves the problems caused by the Li-TFSI/tBP system.The PSC based on this strategy achieved a champion power conversion efficiency(PCE)over 21%,which is significantly better than the pristine device(19.37%).More importantly,the without encapsulated device based on Li-TFSI/12-crown-4 still maintains 87%of the initial PCE even after 60 days exposure in air,while the pristine device only maintains 22%of the initial PCE under the same aging conditions.This strategy paves a novel way for constructing efficient and stable PSCs.
基金Supported by Youth Fund of National Natural Science Foundation of China(31801673)Talent Development Fund of Anhui Academy of Agricultural Sciences(17F1205)+2 种基金Youth Innovation Fund of President of Anhui Academy of Agricultural Sciences(17B1220)Team Building Project of Anhui Academy of Agricultural Sciences(18C1225)Youth Fund of Natural Science Foundation of Anhui Province(1808085QC94)
文摘[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.
文摘Traditional risk factors for cardiovascular disease can only assess risks for groups of people. New parameters of arterial stiffness are more reliable for predicting cardiovascular outcomes for individuals with and without a cardiovascular history. The objective of this study was to assess the effects of Magnesium-EDTA chelation therapy using new methods and parameters such as pulse wave velocity (PWV), central blood pressure (SBPao) and endothelial function (Aix). We followed 43 patients with an abnormal PWV and SBPao, setting them up in two groups. The 21 patients in Group A had already been diagnosed with cardiovascular disease. The other 22 patients in Group B also showed abnormal PWV, SBPao and Aix, but showed no cardiovascular symptoms. Each patient in Groups A and B received one Mg-EDTA treatment per week. The total treatment plan consisted of 25 Mg-EDTA chelation treatments according to the standard protocol of IBCMT. After 25 Mg-EDTA chelation sessions, PWV and SBPao improved significantly in all patients of Groups A and B. In addition, Aix improved significantly in these patients, but remained abnormal. Group C included 18 asymptomatic patients with normal PWV or SBPao. Aix was abnormal in this group, but to a much lesser extent than Groups A and B. The 18 asymptomatic patients of Group C did not receive Mg-EDTA treatment. Observation showed no significant changes in all three parameters of arterial stiffness. The results of this study indicate that a course of treatment with Magnesium-EDTA chelation therapy significantly lowers cardiovascular risks. We conclude that Mg-EDTA chelation therapy improves PWV as an indicator of arterial stiffness, SBPao (central blood pressure) as an indicator of aortic elasticity and Aix (augmented aortic index) as an indicator of endothelial functioning. These improvements in PWV, SBPao and Aix demonstrate that atherosclerosis is a dynamic and (partially) reversible process.
文摘An 87-year-old woman with primary open-angle glaucoma presented to our hospital. Although the combined cataract and minimally invasive glaucoma surgeries (MIGS) were an appropriate surgical option, the presence of band keratopathy made it difficult to perform ab interno glaucoma surgery in her right eye (OD);therefore, the corneal opacity was removed using ethylenediaminetetraacetic acid (EDTA) chelation procedure. One month after chelation, microhook ab interno trabeculotomy and cataract surgery were performed successfully. Clear intraoperative visualization of the angle structures is critical for the success of these MIGS procedures. In glaucomatous eyes that require MIGS, EDTA chelation is a good neoadjuvant therapy for coexisting band keratopathy.
文摘Ethylene Diamine Tetra Acetic Acid (EDTA) chelation therapy has been considered a definitive alternative therapy for by-pass surgery in atherosclerotic cardiovascular disease for more than four decades. It is a relatively inexpensive method believed to restore blood flow in atherosclerotic vessels. However, the benefits of chelation therapy yet remain controversial in the treatment of ischemic heart disease. We observed the effect of EDTA chelation therapy on exercise tolerance in 13 volunteering patients receiving conventional treatment for established symptomatic coronary heart disease. Each patient received 30 weekly infusions of EDTA followed by monthly 12 boosters according to the ACAM protocol (American College for Advancement in Medicine). This was in addition to the conventional therapies they received from their respective physician in hospital. Stress ECG, echocardiography and coronary angiogram findings were obtained at the beginning of treatment. The distance that a patient could walk on level ground at moderate speed and the number of steps he/she can climb up on a staircase until he/she begins to feel either chest pain or breathlessness were the two clinical parameters of exercise tolerance recorded to grade angina. Liver and renal functions were tested at 1st, 5th, 10th, 15th and 30th infusions. Of the 13 patients, 11 showed improvement in angina grading whilst 2 experienced no effect. One patient improved from angina grade IV to I, 6 from grade III to I, 1 from grade III to II and 3 from grade II to I. A statistically significant reduction in the mean score (p = 0.002) was noticed at 6th month of treatment when compared to that of the first month. A significant 1.7 fold increase (p = 0.009) in the mean SGPT level was observed at the 30th infusion when compared to the pre-treatment values. The SGOT level showed no significant change (p = 0.664). None of the patients showed clinical features of hepato-cellular damage. The mean serum creatinine level showed a trend for reduction (p = 0.083) with treatment. The recognized side effects of intravenous EDTA chelation therapy such as liver damage, renal damage, hypersensitivity, symptomatic hypocalcaemia, and thrombophlebitis were not encountered. Thus, EDTA chelation therapy as prescribed by the ACAM protocol seems safe and effective in improving exercise tolerance in ischemic heart disease when administered concurrently with conventional therapy.
文摘Adherence to thalassemia treatment including chelation drugs is influenced by numerous factors. This study aims to explore beliefs about iron chelation therapy and adherence to this medication in Jordanian children with thalassemia major. In this descriptive cross-sectional study, seventy three patients were selected conveniently to complete the study instruments. Participants reported high adherence to their chelation therapy (88.1%). The majority (87.6%) expressed necessity for chelation therapy. However, 42.18% of the participants expressed their concerns about the therapy in which 57.9% of them showed concerns about dependency on medicine and 46.4% of them revealed concerns about the long-term effect of medicine. Overall, about 12.9% of the participants recorded correct and complete answers about thalassemia and its treatment. Knowledge about thalassemia and concerns about chelation were not significantly associated with adherence to the chelation therapy (r = 0.32, p = 0.19;r = 0.29, p = 0.25, respectively). However, there was a significant positive relationship between beliefs about the necessity of the therapy and adherence to it (r = 0.38, p = 0.03). In conclusion, Jordanian children showed proper adherence to their chelation therapy. Health care professionals should discuss patients’ concerns about chelation therapy which might increase patients’ adherence to their therapy.
文摘The influence of methionine supplementation on the efficacy of common antidotes to lead poisoning, calcium disodium ethylenediaminetetraacetate （CaNa<sub>2</sub>EDTA） and D-penicillamine （DPA）, was investigated in rats. The animals were given lead acetate （0.1% in drinking water） for 12 weeks and thereafter treated with CaNa<sub>2</sub>EDTA, DPA （0.3mmol/kg, intraperitoneally）, DL-methionine （1.34 mmol/kg, intragastrically）, or the combination of a chelating agent and methionine for 3 days. While chelating agents enhanced the urinary excretion of Pb, methionine increased the fecal excretion of Pb significantly. Treatment with the combination of a chelating agent and methionine did not potentiate the effect of each antidote. However, methionine supplementation increased the efficacy of both chelating agents in reducing the hepatic and renal Pb burden but not the blood Pb level. The Pb-induced inhibition of blood δ-aminolevulinic acid dehydratase activity and the increase in urinary excretion of δ-aminolevulinic acid were reversed to a certain extent by CaNa<sub>2</sub>EDTA, DPA, and methionine but the combination did not improve their individual performances. The beneficial effects of methionine may be attributed to its ability to increase the bioavailability of glutathione （GSH）, useful in chelating Pb and counteracting the toxic effects, as evidenced by restoration of the Pb-induced decrease in hepatic GSH level by treatment with methionine. Methionine may be useful as a supportive therapy in chelation of Pb. （c）1989 Academic Press. Inc.
基金the National Natural Science Foundation of China(Grant No.81730102,32271384)Shanghai Basic Research Program(Grant No.20JC1411702)Shanghai Science and Technology Program(Grant No.20ZR1456100).
文摘Chemotherapy can induce a robust T cell antitumor immune response by triggering immunogenic cell death(ICD),a process in which tumor cells convert from nonimmunogenic to immunogenic forms.However,the antitumor immune response of ICD remains limited due to the low immunogenicity of tumor cells and the immunosuppressive tumor microenvironment.Although autophagy is involved in activating tumor immunity,the synergistic role of autophagy in ICD remains elusive and challenging.Herein,we report an autophagy amplification strategy using an ion-chelation reaction to augment chemoimmunotherapy in cancer treatments based on zinc ion(Zn^(2+))-doped,disulfiram(DSF)-loaded mesoporous silica nanoparticles(DSF@Zn-DMSNs).Upon pH-sensitive biodegradation of DSF@Zn-DMSNs,Zn2+and DSF are coreleased in the mildly acidic tumor microenvironment,leading to the formation of toxic Zn2+chelate through an in situ chelation reaction.Consequently,this chelate not only significantly stimulates cellular apoptosis and generates damage-associated molecular patterns(DAMPs)but also activates autophagy,which mediates the amplified release of DAMPs to enhance ICD.In vivo results demonstrated that DSF@Zn-DMSNs exhibit strong therapeutic efficacy via in situ ion chelation and possess the ability to activate autophagy,thus enhancing immunotherapy by promoting the infiltration of T cells.This study provides a smart in situ chelation strategy with tumor microenvironment-responsive autophagy amplification to achieve high tumor chemoimmunotherapy efficacy and biosafety.
基金supported by MH101874 (to CFZ)MH122379 (to CFZ)the Taylor Family Institute for Innovative Psychiatric Research and the Bantly Foundation (to CFZ)。
文摘Glyphosate-based herbicides are widely used around the world, making it likely that most humans have significant exposure. Because of habitual exposure, there are concerns about toxicity including neurotoxicity that could result in neurological, psychiatric, or cognitive impairment. We recently found that a single injection of glyphosate inhibits long-term potentiation, a cellular model of learning and memory, in rat hippocampal slices dissected 1 day after injection, indicating that glyphosate-based herbicides can alter cognitive function. Glyphosate-based herbicides could adversely affect cognitive function either indirectly and/or directly. Indirectly, glyphosate could affect gut microbiota, and if dysbiosis results in endotoxemia(leaky gut), infiltrated bacterial by-products such as lipopolysaccharides could activate pro-inflammatory cascades. Glyphosate can also directly trigger pro-inflammatory cascades. Indeed, we observed that acute glyphosate exposure inhibits long-term potentiation in rat hippocampal slices. Interestingly, direct inhibition of long-term potentiation by glyphosate appears to be similar to that of lipopolysaccharides. There are several possible measures to control dysbiosis and neuroinflammation caused by glyphosate. Dietary intake of polyphenols, such as quercetin, which overcome the inhibitory effect of glyphosate on long-term potentiation, could be one effective strategy. The aim of this narrative review is to discuss possible mechanisms underlying neurotoxicity following glyphosate exposure as a means to identify potential treatments.
基金funded by Jiangsu Shuang Chuang Tuan Dui program (JSSCTD202147)Jiangsu Shuang Chuang Ren Cai program (JSSCRC2021541)+1 种基金Young Elite Scientists Sponsorship Program by CAST (2022QNRC001)the Initiation Funds of Yangzhou University for Distinguished Scientists
文摘Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.
基金granted by the National Key R&D Program of China (2021YFD21001005)National Natural Science Foundation of China (31972102,32101980)+1 种基金Special key project of Chongqing technology innovation and application development (cstc2021jscx-cylhX0014)Chongqing Technology Innovation and Application Development Special Project (cstc2021jscx-tpyzxX0014)。
文摘This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.
文摘Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.
基金supported by the Indian Institute of Guwahati (India), for providing the research fellowship to Mr. Ardhendu Sekhar Giri
文摘Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work investigates on PFP for the degradation of CIP to understand the formation mechanism and stability of iron complexes under ultraviolet(UV)-light illumination.A comparison was made with the UV-photocatalysis(UV/TiO_2)process where CIP doesn't form a complex.In PFP,the optimal dose of Fe^(2+)and H_2O_2were found to be 1.25 and10 mmol/L with pH of 3.5.An optimal TiO_2dose of 1.25 g/L was determined in the UV/TiO_2process.Maximum CIP removal and mineralization efficiency of 93.1%and 47.3%were obtained in PFP against 69.7%and 27.6%in the UV/TiO_2process.The mass spectra could identify seventeen intermediate products including iron-CIP complexes in PFP,and only seven intermediate products were found in the UV/TiO_2process with a majority of common products in both the processes.The proposed mechanism supported by the mass spectra bridged the routes of CIP cleavage in the PFP and UV/TiO_2process,and the decomposition pathway of Fe^(3+)-CIP chelate complexes in PFP was also elucidated.Both in PFP and UV/TiO_2processes,the target site of HO~·radical attack was the secondary-N atom present in the piperazine ring of the CIP molecule.The death of Escherichia coli bacteria was 55.7%and 66.8%in comparison to the control media after 45 min of treatment in PFP and UV/TiO_2process,respectively.
基金supported by the National Natural Science Foundation of China(Grant No.11904239,Y.W.W)the Creative Research Initiative of National Research Foundation of Korea(NRF)(CRI project No.2018R1A3B1052702,J.S.K.)+1 种基金Initial support for the work in Austin came from the National Institutes of Health(CA 68682 to J.L.S.)with subsequent funding from the Robert A.Welch Foundation(F-0018 to J.L.S.)supported by Brain Pool Program through the funded by the Ministry of Science and ICT(Grant No.2020H1D3A1A02080172,M.L.).
文摘An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfortunately,current iron-based therapeutic strategies often lack effectiveness and can elicit off-target toxicities.We report here a dual-therapeutic prodrug,DOXjade,that allows for iron chelation chemo-photothermal cancer therapy.This prodrug takes advantage of the clinically approved iron chelator deferasirox(ExJade®)and the topoisomerase 2 inhibitor,doxorubicin(DOX).Loading DOXjade onto ultrathin 2D Ti_(3)C_(2) MXene nanosheets produces a construct,Ti_(3)C_(2)-PVP@DOXjade,that allows the iron chelation and chemotherapeutic functions of DOXjade to be photo-activated at the tumor sites,while potentiating a robust photothermal effect with photothermal conversion efficiencies of up to 40%.Antitumor mechanistic investigations reveal that upon activation,Ti_(3)C_(2)-PVP@DOXjade serves to promote apoptotic cell death and downregulate the iron depletion-induced iron transferrin receptor(TfR).A tumor pH-responsive iron chelation/photothermal/chemotherapy antitumor effect was achieved both in vitro and in vivo.The results of this study highlight what may constitute a promising iron chelation-based phototherapeutic approach to cancer therapy.
基金supported by grants from Livionex Flow through NIH SBIR Phase I,NIAMS(R43 AR062419)the Army,Navy,NIH,Air Force,VA and Health Affairs to support the AFIRM II effort,under Award No.W81XWH-13-2-0054+2 种基金The US Army Medical Research Acquisition Activity,820 Chandler Street,Fort Detrick MD 21702–5014 is the awarding and administering acquisition office.Opinions,interpretations,conclusions and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense.Support was also provided,in part,by National Institute of Environmental Health Sciences(P30 ES006676)National Institute of General Medical Sciences(P50 GM060338 to DNH and R01 GM112936 to CCF)Shriners Hospitals for Children(84202 to AE and 80500 to DNH).
文摘Background:One of the most pervasive complications of burn injury is wound progression,characterized by continuous tissue destruction in untreated wounds,which leads to wound infection,inflammation,oxidative stress and excessive scar formation.We determined whether additional tissue destruction could be attenuated with Livionex formulation(LF)lotion,which contains a metal-chelating agent and reduces inflammation in burn wounds.Methods:We subjected male Sprague Dawley rats to a 2%total body surface area(TBSA)burn using a brass comb model and topically applied LF lotion(containing ethylenediaminetetraacetic acid and methyl sulfonyl methane)to the affected area every 8 hours over 3 days.Inflammatory cytokine levels,cell apoptosis and wound healing were compared in LF lotion-treated and untreated rats.Statistical analysis was performed using a one-way analysis of variance in conjunction with Tukey’s post-hoc test.Results:Serum inflammatory cytokines were not detectable after 3 days,suggesting that small burn wounds induce only an immediate,localized inflammatory response.Microscopy revealed that LF lotion improved burn site pathology.Deoxynucleotidyl transferase biotin-d-UTP nick-end labeling staining showed reduced cell death in the LF-treated samples.LF lotion prevented the spread of tissue damage,as seen by increased amounts of Ki-67-positive nuclei in the adjacent epidermis and hair follicles.Tumor necrosis factor-alpha,interleukin-6 and inducible nitric oxide synthase levels in LF-treated skin sections from burned rats were comparable to the levels observed in unburned control sections,indicating that LF lotion reduces inflammation in and around the burn site.Conclusions:These results establish LF lotion as a therapeutic agent for reducing inflammatory stress,cell death and tissue destruction when applied immediately after a burn injury.Further studies of LF lotion on large TBSA burns will determine its efficacy as an emergency treatment for reducing long-term morbidity and scarring.
文摘Protein kinase substrate phage (PKS phage) was constructed by fusing the substrate recognition consensus sequence of cAMP-dependent protein kinase (cAPK) with bacteriophage minor coat protein g3p and by dis-playing it on the surface of filamentous bacteriophage fd. Phosphorylation in vitro by cAPK showed a unique labelled band of approximately 60 ku, which was consistent with the molecular weight of the PKS-g3p fusion protein. Some weakly phosphorylated bands for both PKS phage and wild-type phage were also observed. Phage display random 15-mer peptide library phosphorylated by cAPK was selected with ferric (Fe3+ ) chelalion affinity resin. After 4 rounds of screening, phage clones were picked out to determine the displayed peptide sequences by DNA sequencing. The results showed that 5 of 14 sequenced phages displayed the cAPK recognition sequence motif (R)RXS/T. Their in vitro phosphorylation analyses revealed the specific labelled bands corresponding to the positive PKS phages with and without the
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21938001,21961160741,22078072)the Special Innovation Project of Guangdong Provincial Department of Education(No.2021KTSCX082)+2 种基金the Science and Technology Plan Project of Maoming City(Nos.2020581,2021009,2021012)the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110346)the Scientific Research Foundation of Guangdong University of Petrochemical Technology(Nos.517152,2019rc053).
文摘Nitrogen-containing compounds are ubiquitously found in the fields of organic chemistry,pharmaceuticals,agrochemicals,medicinal chemistry and functional materials.The C-H bond amination reaction is one of the most straightforward protocols in the CN bond formation,showing"step"and"atomic"economy.As a catalyst for C-H amination reaction,copper exhibits its unique catalytic properties due to easily accessible oxidation states.The research progress of copper-catalyzed C-H amination in recent years is summarized.At the same time,reaction mechanisms are also briefly described in representative aminations to provide insights for the development prospects of highly practical and more environmentally benignprocesses.
