BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastroint...BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastrointestinal symptoms in patients with uremia undergoing hemodialysis.METHODS We retrospectively selected 98 patients with uremia who underwent regular hemo-dialysis treatment in the blood purification center of our hospital from December 2022 to December 2023.The gastrointestinal symptoms and scores of each dimension were evaluated using the Gastrointestinal Symptom Grading Scale(GSRS).Patients were divided into gastrointestinal symptoms and no gastrointestinal symptom groups according to whether they had gastrointestinal symptoms.The factors that may affect gastrointestinal symptoms were identified by single-factor analysis.Multiple logistic regression analysis was performed to identify independent risk factors for gastrointestinal symptoms.RESULTS Gastrointestinal symptoms included indigestion,constipation,reflux,diarrhea,abdominal pain,and eating disorders,and the total average GSRS score was 1.35±0.47.This study showed that age,number of tablets,dialysis time,glucocorticoid,parathyroid hormone(PTH),combined diabetes mellitus and C-reactive protein(CRP)were independent risk factors for gastrointestinal symptoms in patients with uremia undergoing hemodialysis,whereas body mass index(BMI),hemoglobin(Hb),and urea clearance index were independent protective factors(P<0.05).CONCLUSION Gastrointestinal symptoms are mostly mild in patients with uremia undergoing hemodialysis,most commonly including dyspepsia,eating disorders,and gastroesophageal reflux.The independent influencing factors mainly include the BMI,age,number of pills taken,dialysis time,urea clearance index,Hb,use of glucocorticoids,and thyroid hormone level.PTH,CRP,and diabetes are clinically related factors influencing the occurrence of gastrointestinal symptoms,and targeted prevention can be performed.展开更多
The fracture toughness of SA508-Ⅲ steel was studied in the temperature range from room temperature to 320℃ using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the...The fracture toughness of SA508-Ⅲ steel was studied in the temperature range from room temperature to 320℃ using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the conditional fracture toughness （JQ） of the steel first decreased and then increased with increasing test temperature. The maximum and minimum values of do were 517.4 kJ/m^2 at 25℃ and 304.5 kJ/m^2 at 180℃, respectively. Dynamic strain aging （DSA） was also observed to occur when the temperature exceeded 260℃ with a certain strain rate. Both the dislocation density and the number of small dislocation cells effectively increased because of the occurrence of DSA; as a consequence, crack propagation was more strongly inhibited in the steel. Simultaneously, an increasing number of fine carbides precipitated under high stress at temperatures greater than 260℃. Thus, the deformation resistance of the steel was improved and the Jo was enhanced.展开更多
Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. Thi...Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. This study examined 375 plasma samples from patients with HIV-1 who were infected with the CRF07_BC strain, including 104 drug-naive participants and 271 in whom antiretroviral therapy(ART) had failed. Only one participant in the drug-naive group had a drug-resistance mutation(M46L), compared with 31.73% of those in whom ART had failed. Further analysis showed that 19.56% of strains contained mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors(NNRTIs) alone, 0.74% were resistant to nucleoside reverse transcriptase inhibitors(NRTIs) alone, and 11.44% were dual-resistant to both NRTIs and NNRTIs. The most common mutation in the ART-failure group was M184V(35.88%), K103N(45.01%), Y181C(17.33%), and G190S/A(15.88%). The percentages of HIV-1 strains resistant to lamivudine, emtricitabine, efavirenz, etravirine, and nevirapine were 10.70%, 10.70%, 28.04%, 7.75%, and 26.20%, respectively. To explore site variants possibly related to drug resistance, variations in the ancestor/consensus CRF07_BC sequences from the therapy-naive and ART-failure groups were compared, and seven mutations at six positions were identified as being significantly differently distributed between the two groups(p<0.05). Detailed sequence data will provide information on CRF07_BC genetic characterizations, and improve our understanding of antiretroviral susceptibility and the evolution of drug-resistance mutations. This will be valuable in developing and implementing local public-health approaches for HIV drug-resistance prevention and treatment.展开更多
SA508-Ⅲ steel was charged with different hydrogen(H) contents using a high-pressure thermal charging method to study the effects of H content on the tensile properties and evaluate the H embrittlement behavior of the...SA508-Ⅲ steel was charged with different hydrogen(H) contents using a high-pressure thermal charging method to study the effects of H content on the tensile properties and evaluate the H embrittlement behavior of the steel. The results indicate that the ultimate tensile strength remains nearly unchanged with the addition of H. In contrast, the yielding strength slightly increases, and the elongation significantly decreases with increasing H content, especially at concentrations exceeding 5.6 × 10-6. On the basis of fractographic analysis, it is clear that the addition of H changes the fracture mode from microvoid coalescence to a mixture of river patterns and dimples. Carbides are strong traps for H; thus, the H atoms easily migrate in the form of Cottrell atmosphere toward the carbides following moving dislocations during tensile deformation. In addition, stress-induced H atoms accumulate at the interface between carbides and the matrix after necking under three-dimensional stress, which weakens the interfacial bonding force. Consequently, when the local H concentration reaches a critical value, microcracks occur at the interface, resulting in fracture.展开更多
Banxia Xiexin Decoction(BXXXD),a traditional herbal formula,has been used to treat ulcerative colitis(UC)clinically.In this study,chemical compounds and putative targets of BXXXD and UC related therapeutic targets wer...Banxia Xiexin Decoction(BXXXD),a traditional herbal formula,has been used to treat ulcerative colitis(UC)clinically.In this study,chemical compounds and putative targets of BXXXD and UC related therapeutic targets were screened from multiple databases.The protein-protein interaction(PPI)was conducted using String database,and 31 candidate targets were screened from CytoNCA database.The Database for Annotation,Visualization and Integrated Discovery(DAVID)and Metascape database were used for Kyoto Encyclopedia of Genes and Genomes(KEGG)channel and Gene Ontology(GO)enrichment analysis respectively,and the enrichment analysis results were visualized by OmicShare platform.Meanwhile,the interaction network among Chinese herbs,active compounds,candidate targets and pathways was built by Cytoscape 3.7.2 software,and the potential compounds of BXXXD in the treatment of UC were screened.Finally,molecular docking technology was used to verify the putative key compounds.Combined with literature research,5 key compounds for the treatment of UC were identified,which are mainly involved in TNF signaling pathway,cancer signaling pathway,inflammatory bowel disease(IBD),Toll-like receptor signaling pathway,and NF-κB signaling pathway.This study provides a scientific basis for BXXXD as an effective alternative therapeutic agent for UC from a new perspective,and also provides a feasible method for basic chemical research and pharmacological research of BXXXD.展开更多
Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component c...Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component catalysts for the cycloaddition of CO_(2)and epoxides,and their catalytic activities are obviously higher than those of their binary analogues.Further studies revealed that the halide anions(Cl^(–),Br^(–),I^(–))and the metal complexes influenced the catalytic activity,and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction.A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields(55%—99%)with high selectivity(>99%)at 30℃and 1 bar CO_(2),whereas internal epoxides required higher both reaction temperatures(60—120℃)and catalyst loading(2 mol%)for high yields.The catalyst was recyclable for four times without noticeable loss of catalytic activity.Based on the results of kinetic studies and in℃situ IR reactions,a plausible reaction mechanism was proposed.展开更多
Comprehensive Summary Four heterometallic rare earth(Ⅲ)-cobalt(Ⅱ)complexes(rare earth=Y(1),Sm(2),Nd(3),La(4))stabilized by an o-phenylenediamine-bridged tris(phenolato)ligand(L)have been synthesized and characterize...Comprehensive Summary Four heterometallic rare earth(Ⅲ)-cobalt(Ⅱ)complexes(rare earth=Y(1),Sm(2),Nd(3),La(4))stabilized by an o-phenylenediamine-bridged tris(phenolato)ligand(L)have been synthesized and characterized.In these tetranuclear complexes,one polydentate L coordinates to one rare earth(Ⅲ)ion,and one cobalt(Ⅱ)ion,respectively,while two rare earth ions are bridged by four acetate groups.These complexes were applied in the copolymerization of cyclohexene oxide and CO_(2),which showed good activity(TON up to 440)and high poly(cyclohexene carbonate)selectivity(>99%).Kinetic studies determined the equation as rate=k[CHO]1[CO_(2)]0[initiator]1,which proves a first-order dependence on initiator concentrations and implies a synergistic mechanism with rare earth and cobalt ions cooperating in epoxide ring-opening and chain propagation.展开更多
In the present study,we aimed to investigate the chemical constituents and analgesic activity of Aconitum kusnezoffii Reichb. The isolation and purification of components were achieved by a series of chromatography, i...In the present study,we aimed to investigate the chemical constituents and analgesic activity of Aconitum kusnezoffii Reichb. The isolation and purification of components were achieved by a series of chromatography, including silica gel, Sephadex LH-20 and HPLC. By using spectroscopic analysis, their structures were identified. Using PDE-4A as analgesic target, moleculardocking was conducted between isolated compounds by using Schrodinger software. Neoline is a typical non-ester diterpene alkaloid. It was studied by using the mouse torsion body method and hot plate method. A total of 12 diterpene alkaloids were obtainedand identified as Mesaconitine(1), Bewutine (2), Bewudine (3), Songoramine (4), Songorine (5), Neoline (6), Talasamine (7), isotalatizidine (8), Hokbusine A (9), Mesaconine (10), 8-OEt-14-benzoylmesaconine (11), 8-Methoxy-14-benzoyl-beiwutinine (12).Compounds 9 and 12 were isolated from Aconitum kusnezoffii Reichb. for the first time. Twelve diterpenealkaloids could act on the analgesic target. Neoline is a typical non-ester diterpene alkaloid. It had significant analgesic effect. Diterpene alkaloids were the main components of Aconitum kusnezoffiiReichb., and they had good analgesic activity.展开更多
A series of o-phenylenediamine bridged tris(phenolate)ligand-stabilized rare-earth metal complexes were synthesized and characterized.Lanthanum(complex 1),neodymium(complex 2^(tBu)),and yttrium(complex 3)complexes sta...A series of o-phenylenediamine bridged tris(phenolate)ligand-stabilized rare-earth metal complexes were synthesized and characterized.Lanthanum(complex 1),neodymium(complex 2^(tBu)),and yttrium(complex 3)complexes stabilized by ligand of buiky tert-butyl substituents are mononuclear,whereas neodymium complexes 2^(Me)and 2^(C1)bearing smaller methyl and chloro substituents are dinuclear,respectively.They were applied in the alternating copolymerization of CO_(2)and cyclohexene oxide.The addition of benzyl alcohol is beneficial to improving yields(up to 86%)and selectivity of poly(carbonate)(up to 99%).Stoichiometric reaction of benzyl alcohol with rare-earth metal complexes 1 and 2^(tBu)results in formation of complexes 4 and 5 as dinuclear complexes with benzyl alcohol coordination,which was confirmed via single crystal X-ray diffraction analysis,and nuclear magnetic resonance(NMR)spectroscopy(for 4).Complex 5 shows equally good activity and selectivity of that of complex 2^(tBu)and benzyl alcohol,consolidating that complex 5 is indeed generated during polymerization.The neodymium tris(phenolate)5 is one of the few examples of rare-earth metal complex as a single-component initiator for copolymerization of epoxide and CO_(2).Matrix-assisted laser desorption ionization-time of flight(MALDI-TOF)mass spectrometry analysis proves benzyloxy group as the chain end.^(1)H NMR monitoring suggests that the insertion of CO_(2)may be the first step in the growth of the polymer chain.展开更多
The reactivities of benzoxazine functionalized amine bridged bis(phenol)s LnH_(2)(n=1—3)with rare earth metal complexes were explored,founding that both the aryl substituents of the ligand and the rare earth metals h...The reactivities of benzoxazine functionalized amine bridged bis(phenol)s LnH_(2)(n=1—3)with rare earth metal complexes were explored,founding that both the aryl substituents of the ligand and the rare earth metals have profound influences on reaction outcomes.展开更多
Sequential addition of L-lactide(LA) followed by ε-caprolactone(CL), and simultaneous addition of both monomers, afforded random LA/CL copolymers in the presence of lanthanide aryloxides under mild conditions. Transe...Sequential addition of L-lactide(LA) followed by ε-caprolactone(CL), and simultaneous addition of both monomers, afforded random LA/CL copolymers in the presence of lanthanide aryloxides under mild conditions. Transesterification was proved to play a predominant role in random copolymer formation. Moreover, treatment of poly(L-lactide) with ε-CL led to random copolymer formation, which provides a new strategy not only to prepare random LA/CL copolymers, but also to directly modify PLLA.展开更多
In this study,we demonstrated the label-free continuous separation and enrichment of Bacillus subtilis populations based on length using viscoelastic microfluidics.B.subtilis,a gram-positive,rod-shaped bacterium,has b...In this study,we demonstrated the label-free continuous separation and enrichment of Bacillus subtilis populations based on length using viscoelastic microfluidics.B.subtilis,a gram-positive,rod-shaped bacterium,has been widely used as a model organism and an industrial workhorse.B.subtilis can be arranged in different morphological forms,such as single rods,chains,and clumps,which reflect differences in cell types,phases of growth,genetic variation,and changing environmental factors.The ability to prepare B.subtilis populations with a uniform length is important for basic biological studies and efficient industrial applications.Here,we systematically investigated how flow rate ratio,poly(ethylene oxide)(PEO)concentration,and channel length affected the length-based separation of B.subtilis cells.The lateral positions of B.subtilis cells with varying morphologies in a straight rectangular microchannel were found to be dependent on cell length under the co-flow of viscoelastic and Newtonian fluids.Finally,we evaluated the ability of the viscoelastic microfluidic device to separate the two groups of B.subtilis cells by length(i.e.,1-5μm and>5μm)in terms of extraction purity(EP),extraction yield(EY),and enrichment factor(EF)and confirmed that the device could separate heterogeneous populations of bacteria using elasto-inertial effects.展开更多
As an antibiotic,tetracycline has been widely used against bacterial infection or as feed additives for growth promotion,which may lead to the enrichment of antibiotic residues in animals or their products.Therefore,t...As an antibiotic,tetracycline has been widely used against bacterial infection or as feed additives for growth promotion,which may lead to the enrichment of antibiotic residues in animals or their products.Therefore,the detection of tetracycline is closely related to human health.The morphological transformation of CoOOH nanoflakes induced by tetracycline was monitored by scanning electron microscope images,dark-field light scattering images and optical spectra,which found that tetracycline could decompose CoOOH nanoflakes into small nanoparticles with low light scattering signal.As a result,the reduced light scattering of CoOOH nanoflakes was proportional to the increased concentration of tetracycline in the range of 1.0-250μmol/L,and the limit of determination(LOD)was 0.23μmol/L(3σ/k).Most foreign substances did not interfere in the analysis of tetracycline.Furthermore,the concentration of tetracycline in different milk samples detected with the standard addition method was so low that it accorded with the safety regulation,which was similar to the detection result with high-performance liquid chromatography(HPLC).展开更多
Background:Angiotensin-converting enzyme inhibitors(ACEi)and angiotensin-II receptor blockers(ARB),the most commonly prescribed antihypertensive medications,counter renin-angiotensin-aldosterone system(RAAS)activation...Background:Angiotensin-converting enzyme inhibitors(ACEi)and angiotensin-II receptor blockers(ARB),the most commonly prescribed antihypertensive medications,counter renin-angiotensin-aldosterone system(RAAS)activation via induction of angiotensin-converting enzyme 2(ACE2)expression.Considering that ACE2 is the functional receptor for SARS-CoV-2 entry into host cells,the association of ACEi and ARB with COVID-19 outcomes needs thorough evaluation.Methods:We conducted retrospective analyses using both unmatched and propensity score(PS)-matched cohorts on electronic health records(EHRs)to assess the impact of RAAS inhibitors on the risk of receiving invasive mechanical ventilation(IMV)and 30-day mortality among hospitalized COVID-19 patients.Additionally,we investigated the immune cell gene expression profiles of hospitalized COVID-19 patients with prior use of antihypertensive treatments from an observational prospective cohort.Results:The retrospective analysis revealed that there was no increased risk associated with either ACEi or ARB use.In fact,the use of ACEi showed decreased risk for mortality.Survival analyses using PS-matched cohorts suggested no significant relationship between RAAS inhibitors with a hospital stay and in-hospital mortality compared to non-RAAS medications and patients not on antihypertensive medications.From the analysis of gene expression profiles,we observed a noticeable up-regulation in the expression of 1L1R2(an anti-inflammatory receptor)and RETN(an immunosuppressive marker)genes in monocytes among prior users of ACE inhibitors.Conclusion:Overall,the findings do not support the discontinuation of ACEi or ARB treatment and suggest that ACEi may moderate the COVID-19 hyperinflammatory response.展开更多
This study explored the combined use of the O-arm and real-time navigation during spinal fixation. The clinical data for 60 patients undergoing spinal fixation, at Beijing Tsinghua Chang Gung Hospital between May 5, 2...This study explored the combined use of the O-arm and real-time navigation during spinal fixation. The clinical data for 60 patients undergoing spinal fixation, at Beijing Tsinghua Chang Gung Hospital between May 5, 2015 and May 1, 2017, were retrospectively analyzed. Pre-, intra-, and postoperative imaging findings were assessed. The patients were classified into the occipitocervical fusion(32 cases) and thoracic/lumbar/sacral spine fixation(28 cases, including 6 cases of percutaneous pedicle screw) groups. Lesion resections were performed microscopically. An O-arm, combined with real-time navigation, was used to assess spinal fixation. Efficacy was evaluated using operative times, X-ray times, screw positioning, and complications. Within the occipitocervical fusion group, 182 screws were placed in the cervical spine and 96 in the occipital bone. However, 6 screws penetrated the bone cortex and were adjacent to the vertebral arteries, based on O-arm three-dimensional imaging; therefore, the precision rate was 96.7%. Within the thoracic/lumbar/sacral spine fixation group, 148 pedicle screws were implanted, with 4 initially outside the vertebral body,yielding a precision rate of 97.3%. Ten percutaneous pedicle screws were implanted and well positioned. O-arm scans were performed 3 times/patient, with an average of 20–30 min/time. Screw implantation times were 5–7 min(cervical spine), 8–10 min(thoracic spine), and 6–8 min(lumbar spine). Intraoperative O-arm scans, combined with real-time navigation technology, allow real-time observation of screw angles and depths, improving the accuracy and safety of posterior screw fixations and reducing the radiation dose and frequency experienced by patients and surgeons.展开更多
文摘BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastrointestinal symptoms in patients with uremia undergoing hemodialysis.METHODS We retrospectively selected 98 patients with uremia who underwent regular hemo-dialysis treatment in the blood purification center of our hospital from December 2022 to December 2023.The gastrointestinal symptoms and scores of each dimension were evaluated using the Gastrointestinal Symptom Grading Scale(GSRS).Patients were divided into gastrointestinal symptoms and no gastrointestinal symptom groups according to whether they had gastrointestinal symptoms.The factors that may affect gastrointestinal symptoms were identified by single-factor analysis.Multiple logistic regression analysis was performed to identify independent risk factors for gastrointestinal symptoms.RESULTS Gastrointestinal symptoms included indigestion,constipation,reflux,diarrhea,abdominal pain,and eating disorders,and the total average GSRS score was 1.35±0.47.This study showed that age,number of tablets,dialysis time,glucocorticoid,parathyroid hormone(PTH),combined diabetes mellitus and C-reactive protein(CRP)were independent risk factors for gastrointestinal symptoms in patients with uremia undergoing hemodialysis,whereas body mass index(BMI),hemoglobin(Hb),and urea clearance index were independent protective factors(P<0.05).CONCLUSION Gastrointestinal symptoms are mostly mild in patients with uremia undergoing hemodialysis,most commonly including dyspepsia,eating disorders,and gastroesophageal reflux.The independent influencing factors mainly include the BMI,age,number of pills taken,dialysis time,urea clearance index,Hb,use of glucocorticoids,and thyroid hormone level.PTH,CRP,and diabetes are clinically related factors influencing the occurrence of gastrointestinal symptoms,and targeted prevention can be performed.
基金financially supported by the Major State Basic Research Development Program of China (No. 2011CB610506)the National Natural Science Foundation of China (Nos. 51371044 and 51171039)the Fundamental Research Fund for the Central Universities of China (No. N130410001)
文摘The fracture toughness of SA508-Ⅲ steel was studied in the temperature range from room temperature to 320℃ using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the conditional fracture toughness （JQ） of the steel first decreased and then increased with increasing test temperature. The maximum and minimum values of do were 517.4 kJ/m^2 at 25℃ and 304.5 kJ/m^2 at 180℃, respectively. Dynamic strain aging （DSA） was also observed to occur when the temperature exceeded 260℃ with a certain strain rate. Both the dislocation density and the number of small dislocation cells effectively increased because of the occurrence of DSA; as a consequence, crack propagation was more strongly inhibited in the steel. Simultaneously, an increasing number of fine carbides precipitated under high stress at temperatures greater than 260℃. Thus, the deformation resistance of the steel was improved and the Jo was enhanced.
基金supported by the Chinese Government AIDS Program (grant number 2008ZX001-016)the China 4th Global Fund AIDS Program (grant number CHN-405-G05-H)a Sichuan Provincial Health Department research project (number 120154)
文摘Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. This study examined 375 plasma samples from patients with HIV-1 who were infected with the CRF07_BC strain, including 104 drug-naive participants and 271 in whom antiretroviral therapy(ART) had failed. Only one participant in the drug-naive group had a drug-resistance mutation(M46L), compared with 31.73% of those in whom ART had failed. Further analysis showed that 19.56% of strains contained mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors(NNRTIs) alone, 0.74% were resistant to nucleoside reverse transcriptase inhibitors(NRTIs) alone, and 11.44% were dual-resistant to both NRTIs and NNRTIs. The most common mutation in the ART-failure group was M184V(35.88%), K103N(45.01%), Y181C(17.33%), and G190S/A(15.88%). The percentages of HIV-1 strains resistant to lamivudine, emtricitabine, efavirenz, etravirine, and nevirapine were 10.70%, 10.70%, 28.04%, 7.75%, and 26.20%, respectively. To explore site variants possibly related to drug resistance, variations in the ancestor/consensus CRF07_BC sequences from the therapy-naive and ART-failure groups were compared, and seven mutations at six positions were identified as being significantly differently distributed between the two groups(p<0.05). Detailed sequence data will provide information on CRF07_BC genetic characterizations, and improve our understanding of antiretroviral susceptibility and the evolution of drug-resistance mutations. This will be valuable in developing and implementing local public-health approaches for HIV drug-resistance prevention and treatment.
基金financially supported by the Major State Basic Research Development Program of China (No. 2011CB610506)the National Natural Science Foundation of China (Nos. 51371044 and 51171039)the Fundamental Research Fund for the Central Universities, China (No. N130410001)
文摘SA508-Ⅲ steel was charged with different hydrogen(H) contents using a high-pressure thermal charging method to study the effects of H content on the tensile properties and evaluate the H embrittlement behavior of the steel. The results indicate that the ultimate tensile strength remains nearly unchanged with the addition of H. In contrast, the yielding strength slightly increases, and the elongation significantly decreases with increasing H content, especially at concentrations exceeding 5.6 × 10-6. On the basis of fractographic analysis, it is clear that the addition of H changes the fracture mode from microvoid coalescence to a mixture of river patterns and dimples. Carbides are strong traps for H; thus, the H atoms easily migrate in the form of Cottrell atmosphere toward the carbides following moving dislocations during tensile deformation. In addition, stress-induced H atoms accumulate at the interface between carbides and the matrix after necking under three-dimensional stress, which weakens the interfacial bonding force. Consequently, when the local H concentration reaches a critical value, microcracks occur at the interface, resulting in fracture.
文摘Banxia Xiexin Decoction(BXXXD),a traditional herbal formula,has been used to treat ulcerative colitis(UC)clinically.In this study,chemical compounds and putative targets of BXXXD and UC related therapeutic targets were screened from multiple databases.The protein-protein interaction(PPI)was conducted using String database,and 31 candidate targets were screened from CytoNCA database.The Database for Annotation,Visualization and Integrated Discovery(DAVID)and Metascape database were used for Kyoto Encyclopedia of Genes and Genomes(KEGG)channel and Gene Ontology(GO)enrichment analysis respectively,and the enrichment analysis results were visualized by OmicShare platform.Meanwhile,the interaction network among Chinese herbs,active compounds,candidate targets and pathways was built by Cytoscape 3.7.2 software,and the potential compounds of BXXXD in the treatment of UC were screened.Finally,molecular docking technology was used to verify the putative key compounds.Combined with literature research,5 key compounds for the treatment of UC were identified,which are mainly involved in TNF signaling pathway,cancer signaling pathway,inflammatory bowel disease(IBD),Toll-like receptor signaling pathway,and NF-κB signaling pathway.This study provides a scientific basis for BXXXD as an effective alternative therapeutic agent for UC from a new perspective,and also provides a feasible method for basic chemical research and pharmacological research of BXXXD.
基金the National Key R&D Program of China(2022YFF0709802)the National Natural Science Foundation of China(22271205)PAPD is gratefully acknowledged.
文摘Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component catalysts for the cycloaddition of CO_(2)and epoxides,and their catalytic activities are obviously higher than those of their binary analogues.Further studies revealed that the halide anions(Cl^(–),Br^(–),I^(–))and the metal complexes influenced the catalytic activity,and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction.A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields(55%—99%)with high selectivity(>99%)at 30℃and 1 bar CO_(2),whereas internal epoxides required higher both reaction temperatures(60—120℃)and catalyst loading(2 mol%)for high yields.The catalyst was recyclable for four times without noticeable loss of catalytic activity.Based on the results of kinetic studies and in℃situ IR reactions,a plausible reaction mechanism was proposed.
基金financial support from the National Natural Science Foundation of China(21871198)the Major Research Project of the Natural Science of the Jiangsu Higher Education Institutions(19KJA360005 and 19KJA320007),and PAPD.
文摘Comprehensive Summary Four heterometallic rare earth(Ⅲ)-cobalt(Ⅱ)complexes(rare earth=Y(1),Sm(2),Nd(3),La(4))stabilized by an o-phenylenediamine-bridged tris(phenolato)ligand(L)have been synthesized and characterized.In these tetranuclear complexes,one polydentate L coordinates to one rare earth(Ⅲ)ion,and one cobalt(Ⅱ)ion,respectively,while two rare earth ions are bridged by four acetate groups.These complexes were applied in the copolymerization of cyclohexene oxide and CO_(2),which showed good activity(TON up to 440)and high poly(cyclohexene carbonate)selectivity(>99%).Kinetic studies determined the equation as rate=k[CHO]1[CO_(2)]0[initiator]1,which proves a first-order dependence on initiator concentrations and implies a synergistic mechanism with rare earth and cobalt ions cooperating in epoxide ring-opening and chain propagation.
基金National Natural Science Foundation of China(Grant No.30973628)the National Science and Technology Major Project of China(Grant No.SQ2018ZX090301)
文摘In the present study,we aimed to investigate the chemical constituents and analgesic activity of Aconitum kusnezoffii Reichb. The isolation and purification of components were achieved by a series of chromatography, including silica gel, Sephadex LH-20 and HPLC. By using spectroscopic analysis, their structures were identified. Using PDE-4A as analgesic target, moleculardocking was conducted between isolated compounds by using Schrodinger software. Neoline is a typical non-ester diterpene alkaloid. It was studied by using the mouse torsion body method and hot plate method. A total of 12 diterpene alkaloids were obtainedand identified as Mesaconitine(1), Bewutine (2), Bewudine (3), Songoramine (4), Songorine (5), Neoline (6), Talasamine (7), isotalatizidine (8), Hokbusine A (9), Mesaconine (10), 8-OEt-14-benzoylmesaconine (11), 8-Methoxy-14-benzoyl-beiwutinine (12).Compounds 9 and 12 were isolated from Aconitum kusnezoffii Reichb. for the first time. Twelve diterpenealkaloids could act on the analgesic target. Neoline is a typical non-ester diterpene alkaloid. It had significant analgesic effect. Diterpene alkaloids were the main components of Aconitum kusnezoffiiReichb., and they had good analgesic activity.
基金Project supported by the National Natural Science Foundation of China(21871198)the Major Research Project of the Natural Science of the Jiangsu Higher Education Institutions(19KJA360005)the Open Research Fund of State Key Laboratory of Rare-Earth Resource Utilization(CIAC)and PAPD。
文摘A series of o-phenylenediamine bridged tris(phenolate)ligand-stabilized rare-earth metal complexes were synthesized and characterized.Lanthanum(complex 1),neodymium(complex 2^(tBu)),and yttrium(complex 3)complexes stabilized by ligand of buiky tert-butyl substituents are mononuclear,whereas neodymium complexes 2^(Me)and 2^(C1)bearing smaller methyl and chloro substituents are dinuclear,respectively.They were applied in the alternating copolymerization of CO_(2)and cyclohexene oxide.The addition of benzyl alcohol is beneficial to improving yields(up to 86%)and selectivity of poly(carbonate)(up to 99%).Stoichiometric reaction of benzyl alcohol with rare-earth metal complexes 1 and 2^(tBu)results in formation of complexes 4 and 5 as dinuclear complexes with benzyl alcohol coordination,which was confirmed via single crystal X-ray diffraction analysis,and nuclear magnetic resonance(NMR)spectroscopy(for 4).Complex 5 shows equally good activity and selectivity of that of complex 2^(tBu)and benzyl alcohol,consolidating that complex 5 is indeed generated during polymerization.The neodymium tris(phenolate)5 is one of the few examples of rare-earth metal complex as a single-component initiator for copolymerization of epoxide and CO_(2).Matrix-assisted laser desorption ionization-time of flight(MALDI-TOF)mass spectrometry analysis proves benzyloxy group as the chain end.^(1)H NMR monitoring suggests that the insertion of CO_(2)may be the first step in the growth of the polymer chain.
基金support fromtheNational Natural Science Foundation of China(21871198)the Major Research Project of the Natural Science of the Jiangsu Higher Education Institutions(19KJA360005),and PAPD.
文摘The reactivities of benzoxazine functionalized amine bridged bis(phenol)s LnH_(2)(n=1—3)with rare earth metal complexes were explored,founding that both the aryl substituents of the ligand and the rare earth metals have profound influences on reaction outcomes.
基金supported by the National Natural Science Foundation of China (21402138, 21674070)the Major Research Project of the Natural Science of the Jiangsu Higher Education Institutions (14KJA150007)+1 种基金the Project of Scientific and Technologic Infrastructure of Suzhou (SZS201708)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Sequential addition of L-lactide(LA) followed by ε-caprolactone(CL), and simultaneous addition of both monomers, afforded random LA/CL copolymers in the presence of lanthanide aryloxides under mild conditions. Transesterification was proved to play a predominant role in random copolymer formation. Moreover, treatment of poly(L-lactide) with ε-CL led to random copolymer formation, which provides a new strategy not only to prepare random LA/CL copolymers, but also to directly modify PLLA.
基金This work was supported by an Australian Research Council(ARC)Discovery Project Grant(DP200102269)to ML and AKCPL acknowledges support from the Overseas Research Program for Outstanding Young and Middle-aged College Students and Principals of Jiangsu Province,the Scientific Research and Innovation Team of Suqian University(2021td07)+3 种基金the Suqian Science&Technology Project(Z2020136)AKC was supported by an Australian Research Council(ARC)DECRA fellowship(DE180100929)HL was supported by International Macquarie University Research Excellence Scholarships(iMQRES)for graduate studyDY was supported by an Alfred Deakin Postdoctoral Research Fellowship from Deakin University.
文摘In this study,we demonstrated the label-free continuous separation and enrichment of Bacillus subtilis populations based on length using viscoelastic microfluidics.B.subtilis,a gram-positive,rod-shaped bacterium,has been widely used as a model organism and an industrial workhorse.B.subtilis can be arranged in different morphological forms,such as single rods,chains,and clumps,which reflect differences in cell types,phases of growth,genetic variation,and changing environmental factors.The ability to prepare B.subtilis populations with a uniform length is important for basic biological studies and efficient industrial applications.Here,we systematically investigated how flow rate ratio,poly(ethylene oxide)(PEO)concentration,and channel length affected the length-based separation of B.subtilis cells.The lateral positions of B.subtilis cells with varying morphologies in a straight rectangular microchannel were found to be dependent on cell length under the co-flow of viscoelastic and Newtonian fluids.Finally,we evaluated the ability of the viscoelastic microfluidic device to separate the two groups of B.subtilis cells by length(i.e.,1-5μm and>5μm)in terms of extraction purity(EP),extraction yield(EY),and enrichment factor(EF)and confirmed that the device could separate heterogeneous populations of bacteria using elasto-inertial effects.
基金the National Natural Science Foundation of China(No.21405123)the Innovation and Entrepreneurship Project of Southwest University(20172902008)+1 种基金the College of Pharmaceutical Sciences Innovation and Entrepreneurship Project of Southwest University(YX2017-CXYB-10)the Open Funding Project of the State Key Laboratory of Bioreactor Engineering.
文摘As an antibiotic,tetracycline has been widely used against bacterial infection or as feed additives for growth promotion,which may lead to the enrichment of antibiotic residues in animals or their products.Therefore,the detection of tetracycline is closely related to human health.The morphological transformation of CoOOH nanoflakes induced by tetracycline was monitored by scanning electron microscope images,dark-field light scattering images and optical spectra,which found that tetracycline could decompose CoOOH nanoflakes into small nanoparticles with low light scattering signal.As a result,the reduced light scattering of CoOOH nanoflakes was proportional to the increased concentration of tetracycline in the range of 1.0-250μmol/L,and the limit of determination(LOD)was 0.23μmol/L(3σ/k).Most foreign substances did not interfere in the analysis of tetracycline.Furthermore,the concentration of tetracycline in different milk samples detected with the standard addition method was so low that it accorded with the safety regulation,which was similar to the detection result with high-performance liquid chromatography(HPLC).
文摘Background:Angiotensin-converting enzyme inhibitors(ACEi)and angiotensin-II receptor blockers(ARB),the most commonly prescribed antihypertensive medications,counter renin-angiotensin-aldosterone system(RAAS)activation via induction of angiotensin-converting enzyme 2(ACE2)expression.Considering that ACE2 is the functional receptor for SARS-CoV-2 entry into host cells,the association of ACEi and ARB with COVID-19 outcomes needs thorough evaluation.Methods:We conducted retrospective analyses using both unmatched and propensity score(PS)-matched cohorts on electronic health records(EHRs)to assess the impact of RAAS inhibitors on the risk of receiving invasive mechanical ventilation(IMV)and 30-day mortality among hospitalized COVID-19 patients.Additionally,we investigated the immune cell gene expression profiles of hospitalized COVID-19 patients with prior use of antihypertensive treatments from an observational prospective cohort.Results:The retrospective analysis revealed that there was no increased risk associated with either ACEi or ARB use.In fact,the use of ACEi showed decreased risk for mortality.Survival analyses using PS-matched cohorts suggested no significant relationship between RAAS inhibitors with a hospital stay and in-hospital mortality compared to non-RAAS medications and patients not on antihypertensive medications.From the analysis of gene expression profiles,we observed a noticeable up-regulation in the expression of 1L1R2(an anti-inflammatory receptor)and RETN(an immunosuppressive marker)genes in monocytes among prior users of ACE inhibitors.Conclusion:Overall,the findings do not support the discontinuation of ACEi or ARB treatment and suggest that ACEi may moderate the COVID-19 hyperinflammatory response.
基金Supported by the Beijing Tsinghua Changgung Hospital Fund(No.12015C1045)
文摘This study explored the combined use of the O-arm and real-time navigation during spinal fixation. The clinical data for 60 patients undergoing spinal fixation, at Beijing Tsinghua Chang Gung Hospital between May 5, 2015 and May 1, 2017, were retrospectively analyzed. Pre-, intra-, and postoperative imaging findings were assessed. The patients were classified into the occipitocervical fusion(32 cases) and thoracic/lumbar/sacral spine fixation(28 cases, including 6 cases of percutaneous pedicle screw) groups. Lesion resections were performed microscopically. An O-arm, combined with real-time navigation, was used to assess spinal fixation. Efficacy was evaluated using operative times, X-ray times, screw positioning, and complications. Within the occipitocervical fusion group, 182 screws were placed in the cervical spine and 96 in the occipital bone. However, 6 screws penetrated the bone cortex and were adjacent to the vertebral arteries, based on O-arm three-dimensional imaging; therefore, the precision rate was 96.7%. Within the thoracic/lumbar/sacral spine fixation group, 148 pedicle screws were implanted, with 4 initially outside the vertebral body,yielding a precision rate of 97.3%. Ten percutaneous pedicle screws were implanted and well positioned. O-arm scans were performed 3 times/patient, with an average of 20–30 min/time. Screw implantation times were 5–7 min(cervical spine), 8–10 min(thoracic spine), and 6–8 min(lumbar spine). Intraoperative O-arm scans, combined with real-time navigation technology, allow real-time observation of screw angles and depths, improving the accuracy and safety of posterior screw fixations and reducing the radiation dose and frequency experienced by patients and surgeons.
