An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been...An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been confirmed by comparing the calculated spinning sideband patterns for powdered crystalline dimethyl sulfone at different exchange rates with experimentally measured spectra at various temperatures.展开更多
In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illic...In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites(methamphetamine,amphetamine,morphine,codeine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone)and cotinine(COT)in wastewater samples.The analysis was performed by loading 2 m L of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step(5%methanol)to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection(LOD)and limit of quantification(LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and250 ng/L,except for that of COT.The intra-and inter-day precisions were<10.45%and 25.64%,respectively,and the relative recovery ranged from 83.74%to 162.26%.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental results of identical samples analyzed using off-line SPE.The difference rate was between 19.91%and-20.44%,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.展开更多
Ulcerative colitis(UC)is a chronic and non-specific inflammatory bowel disease(IBD).Huanglian Ganjiang decoction(HGD),derived from ancient book Beiji Qianjin Yao Fang,has demonstrated efficacy in treating UC patients ...Ulcerative colitis(UC)is a chronic and non-specific inflammatory bowel disease(IBD).Huanglian Ganjiang decoction(HGD),derived from ancient book Beiji Qianjin Yao Fang,has demonstrated efficacy in treating UC patients traditionally.Previous research established that the compatibility of cold herb Coptidis Rhizoma+Phellodendri Chinensis Cortex(CP)and hot herb Angelicae Sinensis Radix+Zingiberis Rhizoma(AZ)in HGD synergistically improved colitis mice.This study investigated the compatibility mechanisms through which CP and AZ regulated inflammatory balance in colitis mice.The experimental colitis model was established by administering 3%dextran sulphate sodium(DSS)to mice for 7 days,followed by CP,AZ and CPAZ treatment for an additional 7 days.M1/M2 macrophage polarization levels,glucose metabolites levels and pyruvate dehydrogenase kinase 4(PDK4)expression were analyzed using flow cytometry,Western blot,immunofluorescence and targeted glucose metabolomics.The findings indicated that CP inhibited M1 macrophage polarization,decreased inflammatory metabolites associated with tricarboxylic acid(TCA)cycle,and suppressed PDK4 expression and pyruvate dehydrogenase(PDH)(Ser-293)phosphorylation level.AZ enhanced M2 macrophage polarization,increased lactate axis metabolite lactate levels,and upregulated PDK4 expression and PDH(Ser-293)phosphorylation level.TCA cycle blocker AG-221 and adeno-associated virus(AAV)-PDK4 partially negated CP’s inhibition of M1 macrophage polarization.Lactate axis antagonist oxamate and PDK4 inhibitor dichloroacetate(DCA)partially reduced AZ’s activation of M2 macrophage polarization.In conclusion,the compatibility of CP and AZ synergistically alleviated colitis in mice through M1/M2 macrophage polarization balance via PDK4-mediated glucose metabolism reprogramming.Specifically,CP reduced M1 macrophage polarization by restoration of TCA cycle via PDK4 inhibition,while AZ increased M2 macrophage polarization through activation of PDK4/lactate axis.展开更多
Photocatalytic oxygen reduction for hydrogen peroxide(H_(2)O_(2))synthesis presents a green and costeffective production method.However,achieving highly selective H_(2)O_(2)synthesis remains challenging,necessitating ...Photocatalytic oxygen reduction for hydrogen peroxide(H_(2)O_(2))synthesis presents a green and costeffective production method.However,achieving highly selective H_(2)O_(2)synthesis remains challenging,necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative by-products.Herein,we report for the visible light-driven simultaneous co-photocatalytic reduction of O2to H_(2)O_(2)and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride(CNRb).The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h^(-1)for H_(2)O_(2)generation and photooxidation rate of 3.75 mM h^(-1)for furfuryl alcohol to furoic acid,achieving a remarkable solar-to-chemical conversion(SCC)efficiency of up to 2.27%.Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical formation.This is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2adsorption and reinforce the capability to extract protons,thereby triggering a high selective redox product formation.This study holds great potential in precisely regulating reactive radical processes at the atomic level,thereby paving the way for efficient synthesis of H_(2)O_(2)coupled with biomass valorization.展开更多
Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the p...Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.展开更多
Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the prim...Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the primary factor leading to the failure of radiotherapy.Histone modifications in cancer cells are known to play a pivotal role in regulating radiosensitivity by modulating chromatin structure,either by loosening or tightening it.Here,we provide a comprehensive summary of the link between aberrant histone modifications and radiation resistance across various cancer and normal tissue cells.Furthermore,we discuss the regulatory mechanisms of histone modifications and the enzymes on the recruitment of proteins that recognize histone modifications.Consequently,these processes substantially affect the radiosensitivity of tumors.In addition to cancer cells,we highlight the intricate interplay between histone modification and radiosensitivity,both within and beyond the cancer cells.Meanwhile,various drugs targeting histone modifications emerge as a promising therapeutic strategy to overcome radioresistance of tumors as well as radioprotection.The combination of histone modification inhibitors with radiotherapy presents a novel approach to enhance cancer treatment outcomes in clinical practice.Nevertheless,the underlying mechanisms through which histone modifications influence cancer radiosensitivity require further elucidation to identify novel targets for radiotherapeutic intervention.展开更多
The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of ...The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of a new TMT TiSe_(3)single crystal by using a high-pressure and high-temperature technique.The crystal structure of TiSe_(3)was determined by measuring the single-crystal x-ray diffraction and selected area electron diffraction.The 1D chain-like structure along the b-axis is formed by the TiSe_(6)prisms which share their tops and bottoms with each other.TiSe_(3)is a narrow band gap semiconductor with electron-type carriers under ambient conditions identified by the electrical and Hall effect measurements.It exhibits a pressure-induced semiconductor-to-metal transition around 4 GPa.As the pressure further increases to~6 GPa,a pressure-induced Lifshitz transition occurs,as indicated by the electrical transport measurements,high-pressure crystal structure characterizations,and electronic band structure calculations.展开更多
The microstructure of twinning as well as the phase boundary between 1:5 H and 2:17 R phase in Fe-rich Sm_(2)Co_(17)-type magnets was characterized at atomic scale using nanobeam diffraction and highresolution STEM-HA...The microstructure of twinning as well as the phase boundary between 1:5 H and 2:17 R phase in Fe-rich Sm_(2)Co_(17)-type magnets was characterized at atomic scale using nanobeam diffraction and highresolution STEM-HAADF imaging,and the reason for the dramatic increase of coercivity during slow cooling was investigated based on the microchemistry analysis.The twinning relationship in the 2:17 R phase originates from ordered substitution of Sm atoms by Co-Co atomic pairs on every three(3033)and(3033)planes,leading to formation of two corresponding equivalent twin variants.The basal plane of the 2:17 R phase,the 1:3 R platelet phase across the 2:17 R cell and the 1:5 H cell boundary phase between two adjacent 2:17 R cells all can act as effective twin boundary.The cell boundary phase is precipitated along the pyramidal habit plane,and a fully coherent phase boundary(PB)is formed between the 1:5 H and 2:17 R phases with the orientation relationship to be PB//(1121)1:5 H//(1011)_(2):17 R.The phase boundary may either be parallel to or intersect with the pyramidal planes occupied by Co-Co atomic pairs.The substantial increase of coercivity during slow cooling is ascribed to the development of large gradient of the elements concentration within the cell boundary phase,resulting in large gradient of domain wall energy,and thus the pinning strength of the cell boundary phase against magnetic domain wall motion is significantly enhanced.展开更多
Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)ev...Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)even at trace level(nmol/mol)are usually involved in cell construction and further H_(2)production,which would cause degradation of the catalysts and shorten the lifetime of the fuel cells.Moreover,the highly reactive SCs could cause varied species and concentrations of them in complex matrices,so online rather than offline analysis of SCs in H_(2)would be preferred.In this context,we developed a new system combining online cryogenic preconcentration of nine SCs and subsequent determination by GC-SCD(sulfur chemiluminescent detector),with the correlation coefficients of the calibration curves higher than 0.999,calculated limits of detection no higher than 0.050 nmol/mol,analytical time around 30 min per sample,and satisfactory precision and accuracy(RSD<5%and SD<15%).The analytical performance was much better than or at least comparable to the previously reported and the developed system was successfully applied for real sample analysis.展开更多
By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coe...By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coercivity is enhanced from 1.42 to 1.86 T,while further addition leads to a reduction in remanence and coercivity.The analyses of phase composition reveal that Ti mainly exists in the form of metallic Ti alloy,and part of Ti combines with B to form the TiB2 phase after the liquid phase sintering process.This process results in a consumption of B in the local Nd-Fe-B composition system and a change of the grain boundary component,which contributes to the formation process of the RE_(6)(Fe,M)_(14) phase after the annealing process.Therefore,with the modification of grain boundary and composition system,the intergranular addition of Pr-Cu-Ti induces the generation of continuous thin grain boundary phases.It promotes the intergrain exchange decoupling,increasing the coercivity in the annealed magnet.While the excess addition results in the segregation of TiB_(2),as well as the precipitation of TiB_(2) into the Nd-Fe-B phase,which leads to structural defects.Thus,the further effort for the addition alloy with Ti to reduce the deterioration of the microstructure will lead to further improvement in magnetic properties.展开更多
Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and in...Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.展开更多
Cyclic 3’,5’-adenosine monophosphate(cAMP)and cyclic 3’,5’-guanosine monophosphate(cGMP)are considered as potential biomarkers for Yin-Yang disharmony in traditional Chinese medicine.However,phosphodiesterase-medi...Cyclic 3’,5’-adenosine monophosphate(cAMP)and cyclic 3’,5’-guanosine monophosphate(cGMP)are considered as potential biomarkers for Yin-Yang disharmony in traditional Chinese medicine.However,phosphodiesterase-mediated ex vivo degradation of these molecules in biological samples may result in their underestimation.In the present study,a ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)method was developed for determination of cAMP and cGMP in rat plasma,with special consideration of their stability ex vivo.Following precipitation of proteins from plasma samples with 0.4 M perchloric acid,the analytes were chromatographed on a Shimadzu Shimpack-XR-ODS II column with 2.5 mM ammonium acetate and methanol in gradient mode.The MS/MS detection was performed using multiple reaction monitoring in the positive electrospray ionization mode.The lower limit of quantification was 0.27 ng/mL for cAMP and 0.37 ng/mL for cGMP.The method was used to determine the plasma cAMP and cGMP levels in normal and Yin deficiency diabetic rats treated with or without Rehmannia glutinosa.The developed method may be useful for evaluating the regulatory effects of Chinese herbal medicine on the levels of cAMP and cGMP in the body.展开更多
Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structu...Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as （1）. 24-hydroperoxycycloart-25- en-3β-ol; （2）. cycloart-25-en-3β 24-diol; （3）. 25-hydroperoxycycloart-23-en-3β-ol; （4）. cycloart-23-en-3β, 25-diol; （5）. cycloart-23, 25-dien-3β-ol; and （6）. cycloart-24-en-3β-ol by spectroscopic （MS, 1D and 2D NMR） data analysis. Cycloartane derivatives are widely distributed the alga. All these compounds that have been isolated alga for the first time. in terrestrial plants, but only few were obtained in from terrestrial plants, were found in the marine alga for the first time.展开更多
Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead...Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead to poor contact with anode/cathode and the operation failure of full cells.Herein,the dual-interlayers are constructed as the fast interfacial ion-migration channel by using Ti_(3)C_(2)T_(x)(MXene,Txis-O,-OH,-F) with trace ionic liquid(IL),which promote the intimate contact between LLZTO and anode/cathode and suppress Li-dendrites growth.Notably,IL can wet the cathode to promote intimate interface contact and be decomposed into some inorganic compounds(such as Li3N,LiF,and Li2Sx),resulting in reduced interfacial resistance and fast Li-ion transportation.Consequently,in the prepared Li-symmetric cell,the interfacial resistance on the anode side plunges to 33.1 Ω cm^(-2),and stably maintains over 1000 h without short circuit at 0.05 mA cm^(-2).The full cell of Li|LiFePO4delivers a high initial capacity of 158.52 mA h g^(-1)and outstanding retention of 90.18% after 100 cycles at 60℃ and 0.2 C.Our work provides an efficient strategy to design dual-interlayers between LLZTO and anode/cathode for the interfacial modification to enhance the performance of solid garnet batteries.展开更多
To investigate a possible therapeutic mechanism of cell therapy in the field of cerebral palsy using granulocyte-colony stimulating factor（G-CSF）-mobilized peripheral blood mononuclear cells（m PBMCs）,we compared t...To investigate a possible therapeutic mechanism of cell therapy in the field of cerebral palsy using granulocyte-colony stimulating factor（G-CSF）-mobilized peripheral blood mononuclear cells（m PBMCs）,we compared the expression of inflammatory cytokines and neurotrophic factors in PBMCs and m PBMCs from children with cerebral palsy to those from healthy adult donors and to cord blood mononuclear cells donated from healthy newborns.No significant differences in expression of neurotrophic factors were found between PBMCs and m PBMCs.However,in cerebral palsy children,the expression of interleukin-6 was significantly increased in m PBMCs as compared to PBMCs,and the expression of interleukin-3 was significantly decreased in m PBMCs as compared to PBMCs.In healthy adults,the expression levels of both interleukin-1βand interleukin-6 were significantly increased in m PBMCs as compared to PBMCs.The expression of brain-derived neurotrophic factors in m PBMC from cerebral palsy children was significantly higher than that in the cord blood or m PBMCs from healthy adults.The expression of G-CSF in m PBMCs from cerebral palsy children was comparable to that in the cord blood but significantly higher than that in m PBMCs from healthy adults.Lower expression of pro-inflammatory cytokines（interleukin-1β,interleukin-3,and-6）and higher expression of anti-inflammatory cytokines（interleukin-8 and interleukin-9）were observed from the cord blood and m PBMCs from cerebral palsy children rather than from healthy adults.These findings indicate that m PBMCs from cerebral palsy and cord blood mononuclear cells from healthy newborns have the potential to become seed cells for treatment of cerebral palsy.展开更多
In this study, a new parameter, S phase cell percentage （S fraction） normalized BrdU （SFN-BrdU） incorporation rate, was introduced to detect $ arrest. The results showed a positive linear correlation between the B...In this study, a new parameter, S phase cell percentage （S fraction） normalized BrdU （SFN-BrdU） incorporation rate, was introduced to detect $ arrest. The results showed a positive linear correlation between the BrdU incorporation rate and the S fraction in unperturbed 16HBE cells. Theoretical analysis indicated that only S arrest could result in a decrease in the SFN-BrdU incorporation rate. Additionally, the decrease in SFN-BrdU incorporation rate and the activation of DNA damage checkpoints further demonstrated that S arrest was induced by diethyl sulfate treatment of 16HBE cells. In conclusion, $FN-BrdU incorporation rate can be used to detecting S arrest.展开更多
Objective To investigate the role of autophagy in MnC l2-induced apoptosis in human bronchial epithelial 16 HBE cells.Methods Cell proliferation was measured by MTT assay.Mitochondrial membrane potential（MMP） and ap...Objective To investigate the role of autophagy in MnC l2-induced apoptosis in human bronchial epithelial 16 HBE cells.Methods Cell proliferation was measured by MTT assay.Mitochondrial membrane potential（MMP） and apoptosis were measured by flow cytometry.Autophagic vacuoles were detected by fluorescence microscopy.Cellular levels of apoptosis and autophagy-related proteins were measured by western blotting.Results 16 HBE cell proliferation was inhibited by Mn Cl2 in a dose-and time-dependent manner.Mn Cl2-induced 16 HBE cell growth inhibition was related to MMP depolarization prior to the induction of apoptosis.Our data revealed that Mn Cl2-induced apoptosis in 16 HBE cells was mediated by decreased expression of Bcl-2 and increased levels of cleaved caspase-3.It was observed that when we exposed 16 HBE cells to MnCl2 in a dose-dependent manner,the formation of autophagic vacuoles and the levels of LC-3B-II were elevated.RNA interference of LC3 B in these Mn Cl2-exposed cells demonstrated that MMP loss and apoptosis were enhanced.Additionally,the pan-caspase inhibitor Z-VAD-FMK increased the cellular levels of Bcl-2 and decreased apoptosis,but did not affect the cellular levels of LC3 B in Mn Cl2-treated 16 HBE cells.Conclusion Mn Cl2 dose-and time-dependently inhibits 16 HBE cell proliferation and induces MMP loss and apoptosis.Autophagy acts in a protective role against Mn Cl2-induced apoptosis in 16 HBE cells.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant No.29674006。
文摘An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been confirmed by comparing the calculated spinning sideband patterns for powdered crystalline dimethyl sulfone at different exchange rates with experimentally measured spectra at various temperatures.
基金supported by the National Key Research and Development Program of China(Grant No.:2018YFC0807402)the National Natural Science Foundation of China(Grant No.:82073810)。
文摘In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites(methamphetamine,amphetamine,morphine,codeine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone)and cotinine(COT)in wastewater samples.The analysis was performed by loading 2 m L of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step(5%methanol)to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection(LOD)and limit of quantification(LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and250 ng/L,except for that of COT.The intra-and inter-day precisions were<10.45%and 25.64%,respectively,and the relative recovery ranged from 83.74%to 162.26%.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental results of identical samples analyzed using off-line SPE.The difference rate was between 19.91%and-20.44%,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.
基金supported by the National Natural Science Foundation of China(Nos.82374325 and 82074322)GDAS'ProjectofScience and Technology Development(No.2022GDASZH-2022010110).
文摘Ulcerative colitis(UC)is a chronic and non-specific inflammatory bowel disease(IBD).Huanglian Ganjiang decoction(HGD),derived from ancient book Beiji Qianjin Yao Fang,has demonstrated efficacy in treating UC patients traditionally.Previous research established that the compatibility of cold herb Coptidis Rhizoma+Phellodendri Chinensis Cortex(CP)and hot herb Angelicae Sinensis Radix+Zingiberis Rhizoma(AZ)in HGD synergistically improved colitis mice.This study investigated the compatibility mechanisms through which CP and AZ regulated inflammatory balance in colitis mice.The experimental colitis model was established by administering 3%dextran sulphate sodium(DSS)to mice for 7 days,followed by CP,AZ and CPAZ treatment for an additional 7 days.M1/M2 macrophage polarization levels,glucose metabolites levels and pyruvate dehydrogenase kinase 4(PDK4)expression were analyzed using flow cytometry,Western blot,immunofluorescence and targeted glucose metabolomics.The findings indicated that CP inhibited M1 macrophage polarization,decreased inflammatory metabolites associated with tricarboxylic acid(TCA)cycle,and suppressed PDK4 expression and pyruvate dehydrogenase(PDH)(Ser-293)phosphorylation level.AZ enhanced M2 macrophage polarization,increased lactate axis metabolite lactate levels,and upregulated PDK4 expression and PDH(Ser-293)phosphorylation level.TCA cycle blocker AG-221 and adeno-associated virus(AAV)-PDK4 partially negated CP’s inhibition of M1 macrophage polarization.Lactate axis antagonist oxamate and PDK4 inhibitor dichloroacetate(DCA)partially reduced AZ’s activation of M2 macrophage polarization.In conclusion,the compatibility of CP and AZ synergistically alleviated colitis in mice through M1/M2 macrophage polarization balance via PDK4-mediated glucose metabolism reprogramming.Specifically,CP reduced M1 macrophage polarization by restoration of TCA cycle via PDK4 inhibition,while AZ increased M2 macrophage polarization through activation of PDK4/lactate axis.
基金National Natural Science Foundation of China(22309032,22109120,and 62104170)Guangdong Basic and Applied Basic Research Foundation(2022A1515011737)+2 种基金Science and Technology Program of Guangzhou(2023A04J1395)GDAS’Project of Science and Technology Development(2021GDASYL-20210102010)Zhejiang Provincial Natural Science Foundation of China(LY23F040001)。
文摘Photocatalytic oxygen reduction for hydrogen peroxide(H_(2)O_(2))synthesis presents a green and costeffective production method.However,achieving highly selective H_(2)O_(2)synthesis remains challenging,necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative by-products.Herein,we report for the visible light-driven simultaneous co-photocatalytic reduction of O2to H_(2)O_(2)and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride(CNRb).The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h^(-1)for H_(2)O_(2)generation and photooxidation rate of 3.75 mM h^(-1)for furfuryl alcohol to furoic acid,achieving a remarkable solar-to-chemical conversion(SCC)efficiency of up to 2.27%.Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical formation.This is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2adsorption and reinforce the capability to extract protons,thereby triggering a high selective redox product formation.This study holds great potential in precisely regulating reactive radical processes at the atomic level,thereby paving the way for efficient synthesis of H_(2)O_(2)coupled with biomass valorization.
基金supported by the financial support of the National Science Fund for Distinguished Young Scholars of China(No.52025014)the National Natural Science Foundation of China(Nos.52101109 and 52171090)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LD24E010003 and LZJWY23E090001)the Natural Science Foundation of Ningbo(Nos.2023J410).
文摘Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.
基金supported by the National Natural Science Foundation of China(82404200 and 82473574)Projects from Sichuan Province(2024ZYD0126,China)+1 种基金Key Innovation Project from Tibet Province(XZ202501ZY0131,China)Sichuan Science and Technology Program(MZGC20240002,China).
文摘Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the primary factor leading to the failure of radiotherapy.Histone modifications in cancer cells are known to play a pivotal role in regulating radiosensitivity by modulating chromatin structure,either by loosening or tightening it.Here,we provide a comprehensive summary of the link between aberrant histone modifications and radiation resistance across various cancer and normal tissue cells.Furthermore,we discuss the regulatory mechanisms of histone modifications and the enzymes on the recruitment of proteins that recognize histone modifications.Consequently,these processes substantially affect the radiosensitivity of tumors.In addition to cancer cells,we highlight the intricate interplay between histone modification and radiosensitivity,both within and beyond the cancer cells.Meanwhile,various drugs targeting histone modifications emerge as a promising therapeutic strategy to overcome radioresistance of tumors as well as radioprotection.The combination of histone modification inhibitors with radiotherapy presents a novel approach to enhance cancer treatment outcomes in clinical practice.Nevertheless,the underlying mechanisms through which histone modifications influence cancer radiosensitivity require further elucidation to identify novel targets for radiotherapeutic intervention.
基金the National Key R&D Program of China(Grant Nos.2023YFA1406100 and 2024YFA1400066)the Open Research Fund of Beijing National Laboratory for Condensed Matter Physics(Grant No.2023BNLCMPKF002)+6 种基金supported by the National Natural Science Foundation of China(Grant Nos.52288102 and 52090020)the S&T Program of Hebei(Grant No.225A1102D)the Open Projects from the State Key Laboratory of Metastable Materials Science and Technology,Yanshan University(Grant No.202301)carried out at the Synergetic Extreme Condition User Facility(SE-CUF)of the Chinese Academy of Sciencessupport from the Analytical Instrumentation Center(Grant No.SPST-AIC10112914)School of Physical Science and Technology(SPST),ShanghaiTech Universitysupported by the Double First-Class Initiative Fund of ShanghaiTech University.
文摘The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of a new TMT TiSe_(3)single crystal by using a high-pressure and high-temperature technique.The crystal structure of TiSe_(3)was determined by measuring the single-crystal x-ray diffraction and selected area electron diffraction.The 1D chain-like structure along the b-axis is formed by the TiSe_(6)prisms which share their tops and bottoms with each other.TiSe_(3)is a narrow band gap semiconductor with electron-type carriers under ambient conditions identified by the electrical and Hall effect measurements.It exhibits a pressure-induced semiconductor-to-metal transition around 4 GPa.As the pressure further increases to~6 GPa,a pressure-induced Lifshitz transition occurs,as indicated by the electrical transport measurements,high-pressure crystal structure characterizations,and electronic band structure calculations.
基金Project supported by Zhejiang Province Public Welfare Technology Application Research Project(LGC20E010002)National Natural Science Foundation of China(51877094)。
文摘The microstructure of twinning as well as the phase boundary between 1:5 H and 2:17 R phase in Fe-rich Sm_(2)Co_(17)-type magnets was characterized at atomic scale using nanobeam diffraction and highresolution STEM-HAADF imaging,and the reason for the dramatic increase of coercivity during slow cooling was investigated based on the microchemistry analysis.The twinning relationship in the 2:17 R phase originates from ordered substitution of Sm atoms by Co-Co atomic pairs on every three(3033)and(3033)planes,leading to formation of two corresponding equivalent twin variants.The basal plane of the 2:17 R phase,the 1:3 R platelet phase across the 2:17 R cell and the 1:5 H cell boundary phase between two adjacent 2:17 R cells all can act as effective twin boundary.The cell boundary phase is precipitated along the pyramidal habit plane,and a fully coherent phase boundary(PB)is formed between the 1:5 H and 2:17 R phases with the orientation relationship to be PB//(1121)1:5 H//(1011)_(2):17 R.The phase boundary may either be parallel to or intersect with the pyramidal planes occupied by Co-Co atomic pairs.The substantial increase of coercivity during slow cooling is ascribed to the development of large gradient of the elements concentration within the cell boundary phase,resulting in large gradient of domain wall energy,and thus the pinning strength of the cell boundary phase against magnetic domain wall motion is significantly enhanced.
基金the financial support to this work by Sichuan Science and Technology,China(Nos.2019ZDZX0035&2018TZDZX0008)the Ministry of Education through the 111 Project(No.B17030).
文摘Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)even at trace level(nmol/mol)are usually involved in cell construction and further H_(2)production,which would cause degradation of the catalysts and shorten the lifetime of the fuel cells.Moreover,the highly reactive SCs could cause varied species and concentrations of them in complex matrices,so online rather than offline analysis of SCs in H_(2)would be preferred.In this context,we developed a new system combining online cryogenic preconcentration of nine SCs and subsequent determination by GC-SCD(sulfur chemiluminescent detector),with the correlation coefficients of the calibration curves higher than 0.999,calculated limits of detection no higher than 0.050 nmol/mol,analytical time around 30 min per sample,and satisfactory precision and accuracy(RSD<5%and SD<15%).The analytical performance was much better than or at least comparable to the previously reported and the developed system was successfully applied for real sample analysis.
基金Project supported by Major Project of"Science and Technology Innovation 2025"in Ningbo(2018B10086)Major project of"Inner Mongolia Science and Technology"(2019ZD020)+3 种基金Zhejiang Province Public Welfare Technology Application Research Project(LGG21E010007)Major Scientific and Technological Re search and Development Projects in Jiangxi Province(20203ABC28W006)Kunpeng Project in Zhejiang Province,National Natural Science Foundation of China(52101238)Ningbo Top Talent Program。
文摘By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coercivity is enhanced from 1.42 to 1.86 T,while further addition leads to a reduction in remanence and coercivity.The analyses of phase composition reveal that Ti mainly exists in the form of metallic Ti alloy,and part of Ti combines with B to form the TiB2 phase after the liquid phase sintering process.This process results in a consumption of B in the local Nd-Fe-B composition system and a change of the grain boundary component,which contributes to the formation process of the RE_(6)(Fe,M)_(14) phase after the annealing process.Therefore,with the modification of grain boundary and composition system,the intergranular addition of Pr-Cu-Ti induces the generation of continuous thin grain boundary phases.It promotes the intergrain exchange decoupling,increasing the coercivity in the annealed magnet.While the excess addition results in the segregation of TiB_(2),as well as the precipitation of TiB_(2) into the Nd-Fe-B phase,which leads to structural defects.Thus,the further effort for the addition alloy with Ti to reduce the deterioration of the microstructure will lead to further improvement in magnetic properties.
文摘Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.
基金financially supported by the National Natural Science Foundation of China(No.J1103606)。
文摘Cyclic 3’,5’-adenosine monophosphate(cAMP)and cyclic 3’,5’-guanosine monophosphate(cGMP)are considered as potential biomarkers for Yin-Yang disharmony in traditional Chinese medicine.However,phosphodiesterase-mediated ex vivo degradation of these molecules in biological samples may result in their underestimation.In the present study,a ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)method was developed for determination of cAMP and cGMP in rat plasma,with special consideration of their stability ex vivo.Following precipitation of proteins from plasma samples with 0.4 M perchloric acid,the analytes were chromatographed on a Shimadzu Shimpack-XR-ODS II column with 2.5 mM ammonium acetate and methanol in gradient mode.The MS/MS detection was performed using multiple reaction monitoring in the positive electrospray ionization mode.The lower limit of quantification was 0.27 ng/mL for cAMP and 0.37 ng/mL for cGMP.The method was used to determine the plasma cAMP and cGMP levels in normal and Yin deficiency diabetic rats treated with or without Rehmannia glutinosa.The developed method may be useful for evaluating the regulatory effects of Chinese herbal medicine on the levels of cAMP and cGMP in the body.
基金Supported by the National High-Tech R&D Program (863 Program) (Nos. 2001AA620403, 2003AA620403 and 2002AA217081) the State Major Basic Research Development Program of China (973 Program, No. 2002CB41240)+1 种基金 the Major Program of CAS (No. KJCX315-215) NSFC(Nos. 40176038, 30171106, and 30530080) and the International Cooperation Projects of BMBF-CNCBD
文摘Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as （1）. 24-hydroperoxycycloart-25- en-3β-ol; （2）. cycloart-25-en-3β 24-diol; （3）. 25-hydroperoxycycloart-23-en-3β-ol; （4）. cycloart-23-en-3β, 25-diol; （5）. cycloart-23, 25-dien-3β-ol; and （6）. cycloart-24-en-3β-ol by spectroscopic （MS, 1D and 2D NMR） data analysis. Cycloartane derivatives are widely distributed the alga. All these compounds that have been isolated alga for the first time. in terrestrial plants, but only few were obtained in from terrestrial plants, were found in the marine alga for the first time.
基金financially supported by the National Natural Science Foundation of China(NSFC)(52172096)。
文摘Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead to poor contact with anode/cathode and the operation failure of full cells.Herein,the dual-interlayers are constructed as the fast interfacial ion-migration channel by using Ti_(3)C_(2)T_(x)(MXene,Txis-O,-OH,-F) with trace ionic liquid(IL),which promote the intimate contact between LLZTO and anode/cathode and suppress Li-dendrites growth.Notably,IL can wet the cathode to promote intimate interface contact and be decomposed into some inorganic compounds(such as Li3N,LiF,and Li2Sx),resulting in reduced interfacial resistance and fast Li-ion transportation.Consequently,in the prepared Li-symmetric cell,the interfacial resistance on the anode side plunges to 33.1 Ω cm^(-2),and stably maintains over 1000 h without short circuit at 0.05 mA cm^(-2).The full cell of Li|LiFePO4delivers a high initial capacity of 158.52 mA h g^(-1)and outstanding retention of 90.18% after 100 cycles at 60℃ and 0.2 C.Our work provides an efficient strategy to design dual-interlayers between LLZTO and anode/cathode for the interfacial modification to enhance the performance of solid garnet batteries.
基金supported by the Research Fund of Hanyang University(HY-2012)
文摘To investigate a possible therapeutic mechanism of cell therapy in the field of cerebral palsy using granulocyte-colony stimulating factor（G-CSF）-mobilized peripheral blood mononuclear cells（m PBMCs）,we compared the expression of inflammatory cytokines and neurotrophic factors in PBMCs and m PBMCs from children with cerebral palsy to those from healthy adult donors and to cord blood mononuclear cells donated from healthy newborns.No significant differences in expression of neurotrophic factors were found between PBMCs and m PBMCs.However,in cerebral palsy children,the expression of interleukin-6 was significantly increased in m PBMCs as compared to PBMCs,and the expression of interleukin-3 was significantly decreased in m PBMCs as compared to PBMCs.In healthy adults,the expression levels of both interleukin-1βand interleukin-6 were significantly increased in m PBMCs as compared to PBMCs.The expression of brain-derived neurotrophic factors in m PBMC from cerebral palsy children was significantly higher than that in the cord blood or m PBMCs from healthy adults.The expression of G-CSF in m PBMCs from cerebral palsy children was comparable to that in the cord blood but significantly higher than that in m PBMCs from healthy adults.Lower expression of pro-inflammatory cytokines（interleukin-1β,interleukin-3,and-6）and higher expression of anti-inflammatory cytokines（interleukin-8 and interleukin-9）were observed from the cord blood and m PBMCs from cerebral palsy children rather than from healthy adults.These findings indicate that m PBMCs from cerebral palsy and cord blood mononuclear cells from healthy newborns have the potential to become seed cells for treatment of cerebral palsy.
基金supported by the National Nature Science Foundation of China(Nos.81370079 and 81001253)the Beijing Natural Science Foundation(No.7132122)
文摘In this study, a new parameter, S phase cell percentage （S fraction） normalized BrdU （SFN-BrdU） incorporation rate, was introduced to detect $ arrest. The results showed a positive linear correlation between the BrdU incorporation rate and the S fraction in unperturbed 16HBE cells. Theoretical analysis indicated that only S arrest could result in a decrease in the SFN-BrdU incorporation rate. Additionally, the decrease in SFN-BrdU incorporation rate and the activation of DNA damage checkpoints further demonstrated that S arrest was induced by diethyl sulfate treatment of 16HBE cells. In conclusion, $FN-BrdU incorporation rate can be used to detecting S arrest.
基金supported by National Natural Science Foundation of China(Nos.81370079 and 81001253)Beijing Natural Science Foundation(No.7132122)
文摘Objective To investigate the role of autophagy in MnC l2-induced apoptosis in human bronchial epithelial 16 HBE cells.Methods Cell proliferation was measured by MTT assay.Mitochondrial membrane potential（MMP） and apoptosis were measured by flow cytometry.Autophagic vacuoles were detected by fluorescence microscopy.Cellular levels of apoptosis and autophagy-related proteins were measured by western blotting.Results 16 HBE cell proliferation was inhibited by Mn Cl2 in a dose-and time-dependent manner.Mn Cl2-induced 16 HBE cell growth inhibition was related to MMP depolarization prior to the induction of apoptosis.Our data revealed that Mn Cl2-induced apoptosis in 16 HBE cells was mediated by decreased expression of Bcl-2 and increased levels of cleaved caspase-3.It was observed that when we exposed 16 HBE cells to MnCl2 in a dose-dependent manner,the formation of autophagic vacuoles and the levels of LC-3B-II were elevated.RNA interference of LC3 B in these Mn Cl2-exposed cells demonstrated that MMP loss and apoptosis were enhanced.Additionally,the pan-caspase inhibitor Z-VAD-FMK increased the cellular levels of Bcl-2 and decreased apoptosis,but did not affect the cellular levels of LC3 B in Mn Cl2-treated 16 HBE cells.Conclusion Mn Cl2 dose-and time-dependently inhibits 16 HBE cell proliferation and induces MMP loss and apoptosis.Autophagy acts in a protective role against Mn Cl2-induced apoptosis in 16 HBE cells.
