Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulator...Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.展开更多
In this editorial,we offer our perspective on the groundbreaking study entitled“Hypoxia and inflammatory factor preconditioning enhances the immunosup-pressive properties of human umbilical cord mesenchymal stem cell...In this editorial,we offer our perspective on the groundbreaking study entitled“Hypoxia and inflammatory factor preconditioning enhances the immunosup-pressive properties of human umbilical cord mesenchymal stem cells”,recently published in World Journal of Stem Cells.Despite over three decades of research on the clinical application of mesenchymal stem cells(MSCs),only a few therapeutic products have made it to clinical use,due to multiple preclinical and clinical challenges yet to be addressed.The study proved the hypoxia and inflammatory factor preconditioning led to higher immunosuppressive effects of MSCs without damaging their biological characteristics,which revealed the combination of inflammatory factors and hypoxic preconditioning offers a promising approach to enhance the function of MSCs.As we delve deeper into the intricacies of pretreat-ment methodologies,we anticipate a transformative shift in the landscape of MSC-based therapies,ultimately contributing to improved patient outcomes and advancing the field as a whole.展开更多
This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The p...This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The parameters of delamination index along with coating damage index were extracted through electrochemical impedance spectroscopy(EIS) tests to determine how Zr may affect the corrosion protection of duplex PEO/epoxy coated samples. Pull-off adhesion tests were also accomplished to form a better understanding of Zr-enhanced PEO coating’ function. According to the obtained results, the presence of Zr can reduce the damage to the coating system by almost twice.展开更多
The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregna...The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregnating fresh scallops with 0.2 g/100 m L konjac glucomannan(KGM),carrageenan(CA),and sodium alginate(SA)before the drying and rehydration process.After rehydration,the KGM treated samples had better water retention and the highest betaine content.The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids(FAA)and inosine monophosphate(IMP).What’s more,a total of 77 volatile compounds were detected,with a maximum of 15 esters.The highest proportion in the four groups was eugenol,followed by n-hexadecanoic acid,methyl hexadecanoate etc.The SA group had no significant contribution in terms of quality and taste.The samples pretreated with KGM had the best quality,and those pretreated by CA had the best flavor.展开更多
A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sam...A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sample pretreatment and reduced sample treatment time. Recovery of the quinolones was between 92% - 101% for spiked honey samples. The limit of detection was 0.22 - 3.78 ng/mL (signal/noise ratio = 3). There was good linear correlation between HPLC peak area and concentration of the quinolones, with a linear range of 1.0 - 100.0 ng/mL and correlation coefficients >0.9997. The method proposed was validated for detecting quinolones in honey samples.展开更多
Hemicellulose and lignin are not reasonably utilized during the dissolved pulp preparation process.This work aimed to propose a process for the co-production of dissolving pulp,furfural,and lignin from eucalyptus.High...Hemicellulose and lignin are not reasonably utilized during the dissolved pulp preparation process.This work aimed to propose a process for the co-production of dissolving pulp,furfural,and lignin from eucalyptus.High-grade dissolving pulp was prepared from eucalyptus using a combination of extremely low acid(ELA)pretreatment,Kraft cooking,and elementary chlorine-free(ECF)bleaching.The obtained pre-hydrolysate was catalytic conversion into furfural in a biphasic system,and lignin during Kraft cooking and ECF was recovered.The process condition was discussed as well as the mass flow direction.The results showed that ELA pretreatment could effectively remove 80.1%hemicellulose.Compared with traditional hydrothermal pretreatment,the ELA pretreatment significantly increased the xylose yield from 5.05 to 14.18 g/L at 170℃ for 2 h,which had practical significance for furfural production.The 82.7%furfural yield and 82.9%furfural selectivity were obtained from xylose-rich pre-hydrolysate using NaCl as a phase modifier in a biphasic system with 4-methyl-2-pentanone(MIBK)as an organic phase by ion exchange resin catalysts at 190℃ for 2 h.Subsequently,the pretreated eucalyptus was subjected to Kraft cooking,and the optimal alkali amount was 14%.Then,the Kraft pulp was bleached using the O-D1-EP-D_(2) sequence,and dissolving pulp was obtained with an ISO brightness of 86.0%,viscosity of 463 mL/g,andα-cellulose content of 95.4%.The Kraft lignin which has a potential application was investigated by 2D-HSQC NMR and 31P NMR.The results showed that the S/G ratio of Kraft lignin was 1.93,and the content of phenolic hydroxyl groups was 2.53 mmol/g.Moreover,based on the above proposed process,30.5 g dissolving pulp,5.5 g furfural,and 21.2 g lignin per 100 g eucalyptus chips(oven dry)were produced.This research will provide new catalysis and pulping technical routes for dissolving pulp,furfural,and Kraft lignin products,which are in great demand in the chemical industry.展开更多
In this study,the effects of intermetallic compounds(Mg_(17)Al_(12)and Al_(8)Mn_(5))on the Mg-Al layered double hydroxide(LDH)formation mechanism and corrosion behavior of an in-situ LDH/Mg(OH)_(2)steam coatings on AZ...In this study,the effects of intermetallic compounds(Mg_(17)Al_(12)and Al_(8)Mn_(5))on the Mg-Al layered double hydroxide(LDH)formation mechanism and corrosion behavior of an in-situ LDH/Mg(OH)_(2)steam coatings on AZ80 Mg alloy were investigated.Citric acid(CA)was used to activate the alloy surface during the pretreatment process.The alloy was first pretreated with CA and then subjected to a hydrothermal process using ultrapure water to produce Mg-Al-LDH/Mg(OH)_(2)steam coating.The effect of different time of acid pretreatment on the activation of the intermetallic compounds was investigated.The microstructure and elemental composition of the obtained coatings were analyzed using FE-SEM,EDS,XRD and FT-IR.The corrosion resistance of the coated samples was evaluated using different techniques,i.e.,potentiodynamic polarization(PDP),electrochemical impedance spectrum(EIS)and hydrogen evolution test.The results indicated that the CA pretreatment significantly influenced the activity of the alloy surface by exposing the intermetallic compounds.The surface area fraction of Mg_(17)Al_(12)and Al_(8)Mn_(5)phases on the surface of the alloy was significantly higher after the CA pretreatment,and thus promoted the growth of the subsequent Mg-Al-LDH coatings.The CA pretreatment for 30 s resulted in a denser and thicker LDH coating.Increase in the CA pretreatment time significantly led to the improvement in corrosion resistance of the coated AZ80 alloy.The corrosion current density of the coated alloy was lower by three orders of magnitude as compared to the uncoated alloy.展开更多
Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmac...Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmaceuticals and other chemical compounds in Flint River(Madison County,AL)and Flint Creek(Morgan County,AL).Along the Flint River,samples were taken at three sites:Winchester Road,Brian Fork,and Hobbs Road.Similarly,along Flint Creek,samples were taken at three sites:Vaughn Bridge,Mean Bridge and Red Bank Bridge.At each site,samples were taken at four locations:upland from the water,along the banks of the water,at the deposition sediment of the water,and within the surface water itself.Samples were collected and analyzed for the presence of and concentration of chemical compounds by Waypoint Analytical Laboratory using proprietary High-Pressure LC/MS/MS(Liquid Chromatography and Dual Mass Spectroscopy)methods.Between 14 and 26 chemical compounds were identified at each site,adding up to a total of 548 chemical compounds between Flint River and Flint Creek.The chemical compounds and their concentrations were recorded and then sorted into four categories:pharmaceuticals and personal care products(PPCPs),VOCs(Volatile Organic Compounds),petroleum compounds,and CECs(Contaminants of Emerging Concern).Between both Flint River and Flint Creek,PPCPs were the largest category of contaminants,comprising of 46%of compounds identified.This study demonstrates that Flint River and Flint Creek are potentially hazardous to Madison County and Morgan County residents,as trace concentrations of pharmaceuticals in drinking water can cause several health issues.展开更多
Selective surface dissolution was found to be important in spodumene flotation. In this study, we proposed to introduce ultrasound into the pretreatment process to accelerate particle vibration and cavitation, as well...Selective surface dissolution was found to be important in spodumene flotation. In this study, we proposed to introduce ultrasound into the pretreatment process to accelerate particle vibration and cavitation, as well as the migration of mineral surface components to solution. Micro-flotation results showed that the flotation recovery of spodumene can be 86.08% by ultrasound pretreatment, but only 39.30% by traditional mechanical agitation pretreatment. Compared with traditional mechanical agitation, ultrasonic pretreatment can shorten the pretreatment process, reduce the dosage of agents, reduce the mechanical agitation speed, and improve the efficiency of the pretreating process. Inductively coupled plasma analysis showed that, in the ultrasonic system, the amount of Li, Al, and Si species in the solution was twice as much as those in the traditional preprocessing system. Moreover, the scanning electron microscope results demonstrated a larger surface dissolution area in the ultrasonic system. X-Ray photoelectron spectroscopy results showed that the atomic concentration of Si species on the spodumene surface decreased, whereas the relative atomic concentrations of Li and Al species increased, indicating that the ultrasound effect strengthened the selective dissolution of elements on the mineral surface.The high-resolution spectra of O 1s showed that more collectors are adsorbed on the mineral surface treated by ultrasonic pretreatment.展开更多
Objective:To study the effect of sevoflurane pretreatment before one-lung ventilation on pulmonary compliance, oxygenation function and systemic inflammatory response.Methods:104 patients who accepted one-lung ventila...Objective:To study the effect of sevoflurane pretreatment before one-lung ventilation on pulmonary compliance, oxygenation function and systemic inflammatory response.Methods:104 patients who accepted one-lung ventilation operation in Mianyang Central Hospital between April 2014 and December 2015 were selected and randomly divided into the sevoflurane group who accepted sevoflurane pretreatment combined with routine anesthesia and the control group who accepted routine anesthesia, and the pulmonary compliance and oxygenation function parameters during one-lung ventilation as well as the contents of inflammatory mediators in serum and the contents of inflammation regulation molecules in alveolar lavage fluid were determined.Results: At T1, T2 and T3, Cdyn and PaO2/FiO2 levels of sevoflurane group were significantly higher than those of control group, and serum ICAM-1, IL-6, IL-8 and TNF-α contents were significantly lower than those of control group while IL-10 contents were significantly higher than those of control group;after operation, AQP-1, p38MAPK, TLR4 and NF-κB contents in collapsed alveolar lavage fluid of sevoflurane group were significantly lower than those of control group.Conclusion: Sevoflurane pretreatment before one-lung ventilation can improve the pulmonary compliance and oxygenation function, and inhibit the activation of inflammatory response.展开更多
A new method of pretreatment of corn straw with Phanerochaete chrysosporium combined with pyrolysis was proposed to improve the quality of bio-oil.The characterization results demonstrated that microbial pretreatment ...A new method of pretreatment of corn straw with Phanerochaete chrysosporium combined with pyrolysis was proposed to improve the quality of bio-oil.The characterization results demonstrated that microbial pretreatment was an effective method to decrease the lignin,which can achieve a maximum removal rate of 44.19%.Due to the destruction of biomass structure,the content of alkali metal and alkaline earth metal is reduced.Meanwhile,the depolymerized biomass structure created better pyrolysis conditions to promote the pyrolysis efficiency,increase the average decomposition rate of pyrolysis and reduce the residue.In fast pyrolysis,because of the enrichment of cellulose and the removal of lignin,the contents of acids,linear carbonyls,furans,and sugars increased while the contents of phenols decreased.As for the catalytic pyrolysis,due to the hydrocarbon pool reaction and shape selection deoxidation of ZSM-5 catalyst,the total hydrocarbon and aromatics contents can significantly increase up to 34.37%and 30.59%,respectively,with 3 weeks of pretreatment.And the the low molecular content of bio-oil increased after pretreatment,which can significantly benefit the entry of primary pyrolysis steam into the catalyst pores to improve the catalytic efficiency and hydrocarbon contents.This method provides a new treatment idea for high-quality utilization of biomass.展开更多
The effects of sulfuric acid-associated mechanical pretreatment on the hydrolysis behavior of pine sawdust were investigated in this study.Sulfuric acid could act as an acidic catalyst to depolymerize holocellulose th...The effects of sulfuric acid-associated mechanical pretreatment on the hydrolysis behavior of pine sawdust were investigated in this study.Sulfuric acid could act as an acidic catalyst to depolymerize holocellulose through cleavage of the glycosidic bonds,the dissociation energies of which were supplied by the impact of a ball on pine sawdust,during milling.The destruction of glycosidic and hydrogen bonds in pine sawdust resulted in a decrease of crystallinity and an increase of water solubility.The sulfuric acid could promote the hydrolysis of holocellulose and its hydrolysis products.It also destroyed the chemical linkages between holocellulose and lignin during ball milling.The cleavage of chemical linkages with holocellulose made lignin more difficult to hydrolyze in subcritical water,and higher activation energy was needed to hydrolyze pretreated pine sawdust at higher reaction temperatures.It also led to the formation of glucose char and aromatic-linked polymer char from the hydrolysis products of holocellulose.展开更多
Objective:To investigate the effect of sevoflurane pretreatment on cerebral oxygen saturation, pulmonary compliance and systemic stress response in patients with one-lung ventilation. Methods:A total of 70 patients wi...Objective:To investigate the effect of sevoflurane pretreatment on cerebral oxygen saturation, pulmonary compliance and systemic stress response in patients with one-lung ventilation. Methods:A total of 70 patients with lung cancer who accepted the selective pulmonary lobectomy in our hospital between January 2012 and December 2015 were collected and divided into observation group and control group (n=35) according to the single-blind randomized control method. After general anesthesia induction, the control group received air/oxygen mixed ventilation, and the observation group received sevoflurane pretreatment for 30 min and received one-lung ventilation after that. Immediately after anesthesia induction (T0), 30 min after sevoflurane pretreatment (T1), 60 min after sevoflurane pretreatment (T2) and at chest wall suture after operation (T3), the cerebral oxygen saturation monitor was used to determine the left and right regional cerebral oxygen saturation (rSO2);end-expiratory airway blocking method and related indexes were used to calculate the contralateral pulmonary static compliance (Cst) and pulmonary dynamic compliance (Cdyn);the RIA method was used to determine serum stress hormone levels.Results:At T0, differences in cerebral oxygen saturation, pulmonary compliance and systemic stress response were not statistically significant between two groups of patients;at T1, T2 and T3, left and right rSO2 levels of observation group were higher than those of control group, Cst and Cdyn levels were significantly higher than those of control group, and serum epinephrine (E), norepinephrine (NE), cortisol (Cor) and angiotensinⅡ (AngⅡ) levels were lower than those of control group.Conclusion:Sevoflurane pretreatment can promote the intraoperative cerebral oxygen saturation and pulmonary compliance, and reduce systemic stress response in patients with one-lung ventilation.展开更多
A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated durin...A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated during the study.The experimental results show that for aperture diameters of 0.4,0.6,or 0.8 mm smaller apertures provide more complete filtration.Rotations of 12,20,28,or 40 r/min show that higher speeds give more efficient filtration.Suspended solids decreased in both particle size and concentration after the filtration.The separated slime can be directly reused as a fuel.Efficient filtration pretreatment systems for coal mine drainage were investigated and the economic feasibility is analyzed in this article.展开更多
Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,...Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.展开更多
Background: In developed countries, colon cancer is the second most prevalent cancer, only exceeded by prostate cancer in men and breast cancer in women. After Hepatocellular carcinoma, breast cancer, bladder cancer, ...Background: In developed countries, colon cancer is the second most prevalent cancer, only exceeded by prostate cancer in men and breast cancer in women. After Hepatocellular carcinoma, breast cancer, bladder cancer, lung cancer, Non-Hodgkin Lymphoma and brain tumors, colon cancer is the 7<sup>th</sup> most common cancer in Egypt, in both sexes, representing 3.47% and 3%, in both male and female cancers, respectively. Aim of the Work: The aim of this study was to evaluate the prognostic and predictive significance of pretreatment Neutrophil/lymphocytes ratio (NLR), in terms of disease-free survival (DFS) and recurrence, in high-risk stage II and stage III Colorectal cancer patients who underwent curative resection. Patients and Methods: We retrospectively evaluated 103 patients, who were submitted to upfront surgery as first therapeutic option in curative intent, between January 2017 and December 2018. Pretreatment Neutrophil/lymphocytes ratio (NLR), as well as demographics, clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were conducted to identify prognostic factors associated with disease free survival (DFS) and recurrence. Results: The cutoff point of Neutrophils/lymphocytes ratio (NLR) was calculated with Kaplan-Meier curves and log-rank test to 3. This study revealed that neutrophils/lymphocytes ratio (NLR) was significantly associated with disease free survival (p as no difference in efficacy between both chemotherapy regimens FOLFOX and XELOX in both high-risk stage II and stage III colon cancer regarding disease free survival & the toxicity profile associated with each regimen and its grades between patients. Conclusion: Our study suggests that preoperative Neutrophils/lymphocytes ratio (NLR) more than 3 may be an independent prognostic marker for TTR (time to recurrence) in high-risk stage II and stage III colon cancer patients.展开更多
基金supported by the National Natural Science Foundation of China (Nos.51974064,52174239,and 52374259)the Open Project of the Key Laboratory of Solid Waste Treatment and Resource Utiliza-tion of the Ministry of Education,China (No.23kfgk02).
文摘Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.
基金National Natural Science Foundation of China,No.82172196,No.82372507,and No.81971891.
文摘In this editorial,we offer our perspective on the groundbreaking study entitled“Hypoxia and inflammatory factor preconditioning enhances the immunosup-pressive properties of human umbilical cord mesenchymal stem cells”,recently published in World Journal of Stem Cells.Despite over three decades of research on the clinical application of mesenchymal stem cells(MSCs),only a few therapeutic products have made it to clinical use,due to multiple preclinical and clinical challenges yet to be addressed.The study proved the hypoxia and inflammatory factor preconditioning led to higher immunosuppressive effects of MSCs without damaging their biological characteristics,which revealed the combination of inflammatory factors and hypoxic preconditioning offers a promising approach to enhance the function of MSCs.As we delve deeper into the intricacies of pretreat-ment methodologies,we anticipate a transformative shift in the landscape of MSC-based therapies,ultimately contributing to improved patient outcomes and advancing the field as a whole.
文摘This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The parameters of delamination index along with coating damage index were extracted through electrochemical impedance spectroscopy(EIS) tests to determine how Zr may affect the corrosion protection of duplex PEO/epoxy coated samples. Pull-off adhesion tests were also accomplished to form a better understanding of Zr-enhanced PEO coating’ function. According to the obtained results, the presence of Zr can reduce the damage to the coating system by almost twice.
基金funded by the National Key R&D Program of China(2020YFD0900900)。
文摘The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregnating fresh scallops with 0.2 g/100 m L konjac glucomannan(KGM),carrageenan(CA),and sodium alginate(SA)before the drying and rehydration process.After rehydration,the KGM treated samples had better water retention and the highest betaine content.The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids(FAA)and inosine monophosphate(IMP).What’s more,a total of 77 volatile compounds were detected,with a maximum of 15 esters.The highest proportion in the four groups was eugenol,followed by n-hexadecanoic acid,methyl hexadecanoate etc.The SA group had no significant contribution in terms of quality and taste.The samples pretreated with KGM had the best quality,and those pretreated by CA had the best flavor.
文摘A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sample pretreatment and reduced sample treatment time. Recovery of the quinolones was between 92% - 101% for spiked honey samples. The limit of detection was 0.22 - 3.78 ng/mL (signal/noise ratio = 3). There was good linear correlation between HPLC peak area and concentration of the quinolones, with a linear range of 1.0 - 100.0 ng/mL and correlation coefficients >0.9997. The method proposed was validated for detecting quinolones in honey samples.
基金This research was funded by the National Natural Science Foundation of China(No.21978104)the Program for the National Key Research and Development Program of China(No.2021YFC2101601).
文摘Hemicellulose and lignin are not reasonably utilized during the dissolved pulp preparation process.This work aimed to propose a process for the co-production of dissolving pulp,furfural,and lignin from eucalyptus.High-grade dissolving pulp was prepared from eucalyptus using a combination of extremely low acid(ELA)pretreatment,Kraft cooking,and elementary chlorine-free(ECF)bleaching.The obtained pre-hydrolysate was catalytic conversion into furfural in a biphasic system,and lignin during Kraft cooking and ECF was recovered.The process condition was discussed as well as the mass flow direction.The results showed that ELA pretreatment could effectively remove 80.1%hemicellulose.Compared with traditional hydrothermal pretreatment,the ELA pretreatment significantly increased the xylose yield from 5.05 to 14.18 g/L at 170℃ for 2 h,which had practical significance for furfural production.The 82.7%furfural yield and 82.9%furfural selectivity were obtained from xylose-rich pre-hydrolysate using NaCl as a phase modifier in a biphasic system with 4-methyl-2-pentanone(MIBK)as an organic phase by ion exchange resin catalysts at 190℃ for 2 h.Subsequently,the pretreated eucalyptus was subjected to Kraft cooking,and the optimal alkali amount was 14%.Then,the Kraft pulp was bleached using the O-D1-EP-D_(2) sequence,and dissolving pulp was obtained with an ISO brightness of 86.0%,viscosity of 463 mL/g,andα-cellulose content of 95.4%.The Kraft lignin which has a potential application was investigated by 2D-HSQC NMR and 31P NMR.The results showed that the S/G ratio of Kraft lignin was 1.93,and the content of phenolic hydroxyl groups was 2.53 mmol/g.Moreover,based on the above proposed process,30.5 g dissolving pulp,5.5 g furfural,and 21.2 g lignin per 100 g eucalyptus chips(oven dry)were produced.This research will provide new catalysis and pulping technical routes for dissolving pulp,furfural,and Kraft lignin products,which are in great demand in the chemical industry.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51601108 and 52071191)the Natural Science Foundation of Shandong Province(ZR2020ME011).
文摘In this study,the effects of intermetallic compounds(Mg_(17)Al_(12)and Al_(8)Mn_(5))on the Mg-Al layered double hydroxide(LDH)formation mechanism and corrosion behavior of an in-situ LDH/Mg(OH)_(2)steam coatings on AZ80 Mg alloy were investigated.Citric acid(CA)was used to activate the alloy surface during the pretreatment process.The alloy was first pretreated with CA and then subjected to a hydrothermal process using ultrapure water to produce Mg-Al-LDH/Mg(OH)_(2)steam coating.The effect of different time of acid pretreatment on the activation of the intermetallic compounds was investigated.The microstructure and elemental composition of the obtained coatings were analyzed using FE-SEM,EDS,XRD and FT-IR.The corrosion resistance of the coated samples was evaluated using different techniques,i.e.,potentiodynamic polarization(PDP),electrochemical impedance spectrum(EIS)and hydrogen evolution test.The results indicated that the CA pretreatment significantly influenced the activity of the alloy surface by exposing the intermetallic compounds.The surface area fraction of Mg_(17)Al_(12)and Al_(8)Mn_(5)phases on the surface of the alloy was significantly higher after the CA pretreatment,and thus promoted the growth of the subsequent Mg-Al-LDH coatings.The CA pretreatment for 30 s resulted in a denser and thicker LDH coating.Increase in the CA pretreatment time significantly led to the improvement in corrosion resistance of the coated AZ80 alloy.The corrosion current density of the coated alloy was lower by three orders of magnitude as compared to the uncoated alloy.
基金supported by the U.S.Department of Agriculture National Institute of Food and Agriculture’s Capacity Building Grant Program[#2017-2021-38821-26426].
文摘Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmaceuticals and other chemical compounds in Flint River(Madison County,AL)and Flint Creek(Morgan County,AL).Along the Flint River,samples were taken at three sites:Winchester Road,Brian Fork,and Hobbs Road.Similarly,along Flint Creek,samples were taken at three sites:Vaughn Bridge,Mean Bridge and Red Bank Bridge.At each site,samples were taken at four locations:upland from the water,along the banks of the water,at the deposition sediment of the water,and within the surface water itself.Samples were collected and analyzed for the presence of and concentration of chemical compounds by Waypoint Analytical Laboratory using proprietary High-Pressure LC/MS/MS(Liquid Chromatography and Dual Mass Spectroscopy)methods.Between 14 and 26 chemical compounds were identified at each site,adding up to a total of 548 chemical compounds between Flint River and Flint Creek.The chemical compounds and their concentrations were recorded and then sorted into four categories:pharmaceuticals and personal care products(PPCPs),VOCs(Volatile Organic Compounds),petroleum compounds,and CECs(Contaminants of Emerging Concern).Between both Flint River and Flint Creek,PPCPs were the largest category of contaminants,comprising of 46%of compounds identified.This study demonstrates that Flint River and Flint Creek are potentially hazardous to Madison County and Morgan County residents,as trace concentrations of pharmaceuticals in drinking water can cause several health issues.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFC2903202)the National Natural Science Foundations of China (Nos. 51974366, 52174267, 52174270 and 52004250)+2 种基金the China Postdoctoral Science Foundation (No. 2020M680100 and 2020TQ0279)the Postdoctoral Research Grant in Henan Province (No. 202003025)the State Key Laboratory of Mineral Processing and Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources。
文摘Selective surface dissolution was found to be important in spodumene flotation. In this study, we proposed to introduce ultrasound into the pretreatment process to accelerate particle vibration and cavitation, as well as the migration of mineral surface components to solution. Micro-flotation results showed that the flotation recovery of spodumene can be 86.08% by ultrasound pretreatment, but only 39.30% by traditional mechanical agitation pretreatment. Compared with traditional mechanical agitation, ultrasonic pretreatment can shorten the pretreatment process, reduce the dosage of agents, reduce the mechanical agitation speed, and improve the efficiency of the pretreating process. Inductively coupled plasma analysis showed that, in the ultrasonic system, the amount of Li, Al, and Si species in the solution was twice as much as those in the traditional preprocessing system. Moreover, the scanning electron microscope results demonstrated a larger surface dissolution area in the ultrasonic system. X-Ray photoelectron spectroscopy results showed that the atomic concentration of Si species on the spodumene surface decreased, whereas the relative atomic concentrations of Li and Al species increased, indicating that the ultrasound effect strengthened the selective dissolution of elements on the mineral surface.The high-resolution spectra of O 1s showed that more collectors are adsorbed on the mineral surface treated by ultrasonic pretreatment.
文摘Objective:To study the effect of sevoflurane pretreatment before one-lung ventilation on pulmonary compliance, oxygenation function and systemic inflammatory response.Methods:104 patients who accepted one-lung ventilation operation in Mianyang Central Hospital between April 2014 and December 2015 were selected and randomly divided into the sevoflurane group who accepted sevoflurane pretreatment combined with routine anesthesia and the control group who accepted routine anesthesia, and the pulmonary compliance and oxygenation function parameters during one-lung ventilation as well as the contents of inflammatory mediators in serum and the contents of inflammation regulation molecules in alveolar lavage fluid were determined.Results: At T1, T2 and T3, Cdyn and PaO2/FiO2 levels of sevoflurane group were significantly higher than those of control group, and serum ICAM-1, IL-6, IL-8 and TNF-α contents were significantly lower than those of control group while IL-10 contents were significantly higher than those of control group;after operation, AQP-1, p38MAPK, TLR4 and NF-κB contents in collapsed alveolar lavage fluid of sevoflurane group were significantly lower than those of control group.Conclusion: Sevoflurane pretreatment before one-lung ventilation can improve the pulmonary compliance and oxygenation function, and inhibit the activation of inflammatory response.
基金supported by the Natural Science Fund Program of China (No.52306043)the Science and Technology Project of Jiangsu Province (Nos.BE2022604&BE2021701)+2 种基金the Youth Talent Promotion Project of Jiangsu Provincial Association for Science and Technology (No.JSTJ-2022-046)the Inner Mongolia Major Science and Technology Project (No.2021ZD0022)the State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering (China) (Nos.2022-K25&2022-K37).
文摘A new method of pretreatment of corn straw with Phanerochaete chrysosporium combined with pyrolysis was proposed to improve the quality of bio-oil.The characterization results demonstrated that microbial pretreatment was an effective method to decrease the lignin,which can achieve a maximum removal rate of 44.19%.Due to the destruction of biomass structure,the content of alkali metal and alkaline earth metal is reduced.Meanwhile,the depolymerized biomass structure created better pyrolysis conditions to promote the pyrolysis efficiency,increase the average decomposition rate of pyrolysis and reduce the residue.In fast pyrolysis,because of the enrichment of cellulose and the removal of lignin,the contents of acids,linear carbonyls,furans,and sugars increased while the contents of phenols decreased.As for the catalytic pyrolysis,due to the hydrocarbon pool reaction and shape selection deoxidation of ZSM-5 catalyst,the total hydrocarbon and aromatics contents can significantly increase up to 34.37%and 30.59%,respectively,with 3 weeks of pretreatment.And the the low molecular content of bio-oil increased after pretreatment,which can significantly benefit the entry of primary pyrolysis steam into the catalyst pores to improve the catalytic efficiency and hydrocarbon contents.This method provides a new treatment idea for high-quality utilization of biomass.
基金supported by the National Natural Science Foundation of China(22078225)the Natural Science Foundation of Zhejiang Province(LGF22E080025 and LHY22E080005)。
文摘The effects of sulfuric acid-associated mechanical pretreatment on the hydrolysis behavior of pine sawdust were investigated in this study.Sulfuric acid could act as an acidic catalyst to depolymerize holocellulose through cleavage of the glycosidic bonds,the dissociation energies of which were supplied by the impact of a ball on pine sawdust,during milling.The destruction of glycosidic and hydrogen bonds in pine sawdust resulted in a decrease of crystallinity and an increase of water solubility.The sulfuric acid could promote the hydrolysis of holocellulose and its hydrolysis products.It also destroyed the chemical linkages between holocellulose and lignin during ball milling.The cleavage of chemical linkages with holocellulose made lignin more difficult to hydrolyze in subcritical water,and higher activation energy was needed to hydrolyze pretreated pine sawdust at higher reaction temperatures.It also led to the formation of glucose char and aromatic-linked polymer char from the hydrolysis products of holocellulose.
文摘Objective:To investigate the effect of sevoflurane pretreatment on cerebral oxygen saturation, pulmonary compliance and systemic stress response in patients with one-lung ventilation. Methods:A total of 70 patients with lung cancer who accepted the selective pulmonary lobectomy in our hospital between January 2012 and December 2015 were collected and divided into observation group and control group (n=35) according to the single-blind randomized control method. After general anesthesia induction, the control group received air/oxygen mixed ventilation, and the observation group received sevoflurane pretreatment for 30 min and received one-lung ventilation after that. Immediately after anesthesia induction (T0), 30 min after sevoflurane pretreatment (T1), 60 min after sevoflurane pretreatment (T2) and at chest wall suture after operation (T3), the cerebral oxygen saturation monitor was used to determine the left and right regional cerebral oxygen saturation (rSO2);end-expiratory airway blocking method and related indexes were used to calculate the contralateral pulmonary static compliance (Cst) and pulmonary dynamic compliance (Cdyn);the RIA method was used to determine serum stress hormone levels.Results:At T0, differences in cerebral oxygen saturation, pulmonary compliance and systemic stress response were not statistically significant between two groups of patients;at T1, T2 and T3, left and right rSO2 levels of observation group were higher than those of control group, Cst and Cdyn levels were significantly higher than those of control group, and serum epinephrine (E), norepinephrine (NE), cortisol (Cor) and angiotensinⅡ (AngⅡ) levels were lower than those of control group.Conclusion:Sevoflurane pretreatment can promote the intraoperative cerebral oxygen saturation and pulmonary compliance, and reduce systemic stress response in patients with one-lung ventilation.
基金support through Special Basic Research Fund of China Central University(No.2011QH01)Innovative Experiment Projects for Undergraduates
文摘A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated during the study.The experimental results show that for aperture diameters of 0.4,0.6,or 0.8 mm smaller apertures provide more complete filtration.Rotations of 12,20,28,or 40 r/min show that higher speeds give more efficient filtration.Suspended solids decreased in both particle size and concentration after the filtration.The separated slime can be directly reused as a fuel.Efficient filtration pretreatment systems for coal mine drainage were investigated and the economic feasibility is analyzed in this article.
基金Supported by the Technological Project of Heilongjiang Province"the Open Competition Mechanism to Select the Best Candidates"(2022ZXJ05C01-03)。
文摘Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.
文摘Background: In developed countries, colon cancer is the second most prevalent cancer, only exceeded by prostate cancer in men and breast cancer in women. After Hepatocellular carcinoma, breast cancer, bladder cancer, lung cancer, Non-Hodgkin Lymphoma and brain tumors, colon cancer is the 7<sup>th</sup> most common cancer in Egypt, in both sexes, representing 3.47% and 3%, in both male and female cancers, respectively. Aim of the Work: The aim of this study was to evaluate the prognostic and predictive significance of pretreatment Neutrophil/lymphocytes ratio (NLR), in terms of disease-free survival (DFS) and recurrence, in high-risk stage II and stage III Colorectal cancer patients who underwent curative resection. Patients and Methods: We retrospectively evaluated 103 patients, who were submitted to upfront surgery as first therapeutic option in curative intent, between January 2017 and December 2018. Pretreatment Neutrophil/lymphocytes ratio (NLR), as well as demographics, clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were conducted to identify prognostic factors associated with disease free survival (DFS) and recurrence. Results: The cutoff point of Neutrophils/lymphocytes ratio (NLR) was calculated with Kaplan-Meier curves and log-rank test to 3. This study revealed that neutrophils/lymphocytes ratio (NLR) was significantly associated with disease free survival (p as no difference in efficacy between both chemotherapy regimens FOLFOX and XELOX in both high-risk stage II and stage III colon cancer regarding disease free survival & the toxicity profile associated with each regimen and its grades between patients. Conclusion: Our study suggests that preoperative Neutrophils/lymphocytes ratio (NLR) more than 3 may be an independent prognostic marker for TTR (time to recurrence) in high-risk stage II and stage III colon cancer patients.
