In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic...In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.展开更多
Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PT...Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.展开更多
Background:Chimeric antigen receptor T(CAR-T)cell therapy has achieved marked therapeutic success in ameliorating hematological malignancies.However,there is an extant void in the clinical guidelines concerning the mo...Background:Chimeric antigen receptor T(CAR-T)cell therapy has achieved marked therapeutic success in ameliorating hematological malignancies.However,there is an extant void in the clinical guidelines concerning the most effective chemotherapy regimen prior to chimeric antigen receptor T(CAR-T)cell therapy,as well as the optimal timing for CAR-T cell infusion post-chemotherapy.Materials and Methods:We employed cell-derived tumor xenograft(CDX)murine models to delineate the optimal pre-conditioning chemotherapy regimen and timing for CAR-T cell treatment.Furthermore,transcriptome sequencing was implemented to identify the therapeutic targets and elucidate the underlying mechanisms governing the treatment regimen.Results:Our preclinical in vivo evaluation determined that a combination of cyclophosphamide and fludarabine,followed by the infusion of CD19 CAR-T cells five days subsequent to the chemotherapy,exerts the most efficacious therapeutic effect in B-cell hematological malignancies.Concurrently,RNA-seq data indicated that the therapeutic efficacy predominantly perturbs tumor cell metabolism,primarily through the inhibition of key mitochondrial targets,such as C-Jun Kinase enzyme(C-JUN).Conclusion:In summary,the present study offers critical clinical guidance and serves as an authoritative reference for the deployment of CD19 CAR-T cell therapy in the treatment of B-cell hematological malignancies.展开更多
Grain size influences the yield and quality of rice(Oryza sativa L.),and grain length is one of the component traits of grain size.In this study,a near-isogenic line LB3 with long grain size was constructed using japo...Grain size influences the yield and quality of rice(Oryza sativa L.),and grain length is one of the component traits of grain size.In this study,a near-isogenic line LB3 with long grain size was constructed using japonica rice cultivar 02428,with short grain size,as the recipient parent and indica rice cultivar ZYX,with long grain size,as the donor parent,by multi-generation backcrossing and selfing.BSA-seq was used for preliminary QTL mapping and InDel markers were developed to fine map the locus.The major QTL,tentatively named qGL10,for grain length was located in a 128.45 kb region of chromosome 10.Combined with haplotype analysis of rice varieties,expression pattern analysis of candidate genes suggested LOC_Os10g39130(OsMADS56)as a candidate gene.Sequence alignment of OsMADS56 in 02428 and LB3 revealed that there were 15 SNPs in the promoter region and four in the coding region.Further haplotype analysis suggested that SNP9(G/A)located in the TGTCACA motif might account for the different expression levels of OsMADS56 in 02428 and LB3.These results lay a foundation for the application of qGL10 in molecular breeding of new rice varieties.展开更多
Bacterial leaf streak(BLS),caused by Xanthomonas oryzae pv.oryzicola(Xoc),is a bacterial disease affecting rice production in Asia and Africa,whose severity is expected to increase with climate change.Identification o...Bacterial leaf streak(BLS),caused by Xanthomonas oryzae pv.oryzicola(Xoc),is a bacterial disease affecting rice production in Asia and Africa,whose severity is expected to increase with climate change.Identification of new quantitative-trait loci(QTL)or resistance genes for BLS resistance is essential for developing resistant rice.A genome-wide association study to identify QTL associated with BLS resistance was conducted using phenotypic and genotypic data from 429 rice accessions.Of 47 QTL identified,45 were novel and two co-localized with previously reported QTL or genes conferring BLS resistance.qBLS6.2 on chromosome 6 explained the greatest phenotypic variation.Combined analysis of differential expression and annotations of predicted genes near qBLS6.2 based on haplotype and disease phenotype identified OsBLS6.2(LOC_Os06g02960)as a candidate gene for qBLS6.2.OsBLS6.2 knockout plants showed higher resistance to Xoc than wild-type plants.Many other candidate genes for resistance to Xoc were identified.展开更多
Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ c...Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.展开更多
BACKGROUND： Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke, as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischem...BACKGROUND： Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke, as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischemia. However, the mechanisms of homocysteine remain unclear Several reports have addressed the effects of homocysteine on ischemic stroke. OBJECTIVE： To analyze the effects of homocysteine on apoptosis, intracellular superoxide dismutase （SOD） activity, and malondialdehyde content in tissue surrounding hematoma in rats with cerebral hemorrhage, and to determine the action pathway of malondialdehyde following cerebral hemorrhage. DESIGN, TIME AND SETTING： The randomized, controlled, animal experiment was performed at the Laboratory of Molecular Biology, Hospital Affiliated to Luzhou Medical College, China from April 2007 to April 2008. MATERIALS： In situ apoptosis detection kit （Roche, Mannheim, Germany）, SOD detection kit and malondialdehyde detection kit （Nanjing Jiancheng Bioengineering Institute, China）, and homocysteine （Sigma, St Louis, MO, USA） were used in the present study. METHODS： A total of 75 Sprague Dawley rats were equally and randomly assigned to sham surgery model, and homocysteine groups. Autologous blood was infused into the caudate putamen of rats to establish models of cerebral hemorrhage in model and homocysteine groups. Homocysteine was injected directly into the brain through the skull at the hematoma hemisphere at 30 minutes after model induction in the homocysteine group. MAIN OUTCOME MEASURES： At 6, 12, 24, and 72 hours, as well as 1 week, post-surgery, neurological deficits were observed in each group. Brain water content was measured using the dry-wet weight method. Cell apoptosis in tissue surrounding the hematoma was detected utilizing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL）. SOD activity and malondialdehyde content in tissue surrounding the hematoma were respectively measured using the xanthine oxidase and thiobarbituric acid methods. RESULTS： Neurological function was similar between model and homocysteine groups following cerebral hemorrhage （P 〉 0.05）. Brain water content was increased at 12 hours post-surgery, peaked at 3 days, and remained unchanged at 7 days in the model group. Brain edema was not significantly aggravated following homocysteine intervention （P 〉 0.05）, but SOD activity significantly decreased and malondialdehyde content significantly increased （P 〈 0.05）. The number of apoptotic cells increased in rats with cerebral hemorrhage at 12 hours （P 〈 0.05）, and numbers peaked at 72 hours following model establishment （P〈 0.05）. The time of peak value was identical between model and homocysteine groups. Brain water content was negatively associated with SOD activity （rmodel group =-0.448, P 〈 0.05; rhomocysteine group =-0.612, P 〈 0.05）, but was positively associated with malondialdehyde content （rmodel group = 0.542, P 〈 0.05; rhomocysteine group = 0.684, P 〈 0.05） in brain tissues surrounding the hematoma following surgery in model and homocysteine groups. CONCLUSION： Homocysteine aggravates neurological dysfunction and brain edema in rats with cerebral hemorrhage. The mechanisms of action are likely associated with production of oxygen-free radical and cellular apoptosis following cerebral hemorrhage.展开更多
Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficien...Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.展开更多
Objective： Although many clinical studies on skip lymphatic metastasis in non-small cell lung cancer have been reported, the risk factors for skip lymphatic metastasis are still controversy and debatable. This study ...Objective： Although many clinical studies on skip lymphatic metastasis in non-small cell lung cancer have been reported, the risk factors for skip lymphatic metastasis are still controversy and debatable. This study investigated, by multivariate logistic regression analysis, the clinical features of skip metastasis to mediastinal lymph nodes （N2） in non-small cell lung cancer 0NISCLC） patients. Methods： We collected the clinicopathological data of 256 pN2-NSCLC patients who underwent lobectomy plus systemic lymph node dissection in Fujian Medical University Union Hospital. The cases in the present study were divided into two groups： skip metastasis （N2 skip＋） and non- skip metastasis （N2 skip-）. A retrospective analysis of clinical pathological features of two groups was performed, rib determine an independent factor, multivariate logistic regression analysis was used to identify possible risk factors. Results： A total of 256 pN2-NSCLC patients were recruited. The analysis results showed that gender, pathologic types, surgery, pleural involvement, smoking history, age, tumor stages, and differentiation were not statistical significant factors impacting on skip metastasis in pN2-NSCLC （P〉0.05）, whereas tumor size was an independent factor for skip metastasis （P=0.02）. Conclusions： The rate of skip lymphatic metastasis increases in pN2-NSCLC patients, in accompany with an increased tumor size.展开更多
Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its com...Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its composition,the specific active ingredients in AR that act on NK cells are not clear yet.Cell membrane chromatography(CMC)is mainly used to screen the active ingredients in a complex system of herbal medicines.In this study,a new comprehensive two-dimensional(2D)NK-92MI CMC/C18 column/time-of-flight mass spectrometry(TOFMS)system was established to screen for potential NK cell activators.To obtain a higher column efficiency,3-mercaptopropyltrimethoxysilane-modified silica was synthesized to prepare the NK-92MI CMC column.In total,nine components in AR were screened from this system,which could be washed out from the NK-92MI/CMC column after 10 min,and they showed good affinity for NK-92MI/CMC column.Two representative active compounds of AR,isoastragaloside Ⅰ and astragaloside IV,promoted the killing effect of NK cells on K562 cells in a dose-dependent manner.It can thus suggest that isoastragaloside Ⅰ and astragaloside Ⅳ are the main immunomodulatory components of AR.This comprehensive 2D NK-92MI CMC analytical system is a practical method for screening immune cell activators from other herbal medicines with immunomodulatory effects.展开更多
基金The Guangdong Basic and Applied Basic Research Foundation(2022A1515010730)National Natural Science Foundation of China(32001647)+2 种基金National Natural Science Foundation of China(31972022)Financial and moral assistance supported by the Guangdong Basic and Applied Basic Research Foundation(2019A1515011996)111 Project(B17018)。
文摘In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.
基金supported by the Natural Science Research Project of Anhui Province University, No.2023AH040394 (to TY)Hefei Comprehensive National Science Center Leading Medicine and Frontier Technology Research Institute Project, No.2023IHM01073 (to TY)the Natural Science Foundation of Anhui Province, Nos.2308085QH258 (to JW), 2008085MH246 (to TY)。
文摘Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.
基金National Natural Science Foundation of China(No.82370164)Sanming Project of Medicine in Shenzhen(No.SZSM202011004)Shenzhen Science and Technology Innovation Commission(JCYJ20180307150419435 and JCYJ20210324123004011).
文摘Background:Chimeric antigen receptor T(CAR-T)cell therapy has achieved marked therapeutic success in ameliorating hematological malignancies.However,there is an extant void in the clinical guidelines concerning the most effective chemotherapy regimen prior to chimeric antigen receptor T(CAR-T)cell therapy,as well as the optimal timing for CAR-T cell infusion post-chemotherapy.Materials and Methods:We employed cell-derived tumor xenograft(CDX)murine models to delineate the optimal pre-conditioning chemotherapy regimen and timing for CAR-T cell treatment.Furthermore,transcriptome sequencing was implemented to identify the therapeutic targets and elucidate the underlying mechanisms governing the treatment regimen.Results:Our preclinical in vivo evaluation determined that a combination of cyclophosphamide and fludarabine,followed by the infusion of CD19 CAR-T cells five days subsequent to the chemotherapy,exerts the most efficacious therapeutic effect in B-cell hematological malignancies.Concurrently,RNA-seq data indicated that the therapeutic efficacy predominantly perturbs tumor cell metabolism,primarily through the inhibition of key mitochondrial targets,such as C-Jun Kinase enzyme(C-JUN).Conclusion:In summary,the present study offers critical clinical guidance and serves as an authoritative reference for the deployment of CD19 CAR-T cell therapy in the treatment of B-cell hematological malignancies.
基金supported by the Guangdong Provincial Key R&D Program(2021B0707010010)the Key R&D Program of Guangzhou Science and Technology Project(202103000083).
文摘Grain size influences the yield and quality of rice(Oryza sativa L.),and grain length is one of the component traits of grain size.In this study,a near-isogenic line LB3 with long grain size was constructed using japonica rice cultivar 02428,with short grain size,as the recipient parent and indica rice cultivar ZYX,with long grain size,as the donor parent,by multi-generation backcrossing and selfing.BSA-seq was used for preliminary QTL mapping and InDel markers were developed to fine map the locus.The major QTL,tentatively named qGL10,for grain length was located in a 128.45 kb region of chromosome 10.Combined with haplotype analysis of rice varieties,expression pattern analysis of candidate genes suggested LOC_Os10g39130(OsMADS56)as a candidate gene.Sequence alignment of OsMADS56 in 02428 and LB3 revealed that there were 15 SNPs in the promoter region and four in the coding region.Further haplotype analysis suggested that SNP9(G/A)located in the TGTCACA motif might account for the different expression levels of OsMADS56 in 02428 and LB3.These results lay a foundation for the application of qGL10 in molecular breeding of new rice varieties.
基金the Open Project(2020)of Guangdong Key Laboratory of New Technology in Rice Breeding,the Natural Science Foundation of Guangdong Province,China(2019A1515011825)the Special Rural Revitalization Funds of Guangdong Province(Seed Industry Revitalization Project)(2022-NPY-00-006).
文摘Bacterial leaf streak(BLS),caused by Xanthomonas oryzae pv.oryzicola(Xoc),is a bacterial disease affecting rice production in Asia and Africa,whose severity is expected to increase with climate change.Identification of new quantitative-trait loci(QTL)or resistance genes for BLS resistance is essential for developing resistant rice.A genome-wide association study to identify QTL associated with BLS resistance was conducted using phenotypic and genotypic data from 429 rice accessions.Of 47 QTL identified,45 were novel and two co-localized with previously reported QTL or genes conferring BLS resistance.qBLS6.2 on chromosome 6 explained the greatest phenotypic variation.Combined analysis of differential expression and annotations of predicted genes near qBLS6.2 based on haplotype and disease phenotype identified OsBLS6.2(LOC_Os06g02960)as a candidate gene for qBLS6.2.OsBLS6.2 knockout plants showed higher resistance to Xoc than wild-type plants.Many other candidate genes for resistance to Xoc were identified.
文摘Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.
文摘BACKGROUND： Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke, as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischemia. However, the mechanisms of homocysteine remain unclear Several reports have addressed the effects of homocysteine on ischemic stroke. OBJECTIVE： To analyze the effects of homocysteine on apoptosis, intracellular superoxide dismutase （SOD） activity, and malondialdehyde content in tissue surrounding hematoma in rats with cerebral hemorrhage, and to determine the action pathway of malondialdehyde following cerebral hemorrhage. DESIGN, TIME AND SETTING： The randomized, controlled, animal experiment was performed at the Laboratory of Molecular Biology, Hospital Affiliated to Luzhou Medical College, China from April 2007 to April 2008. MATERIALS： In situ apoptosis detection kit （Roche, Mannheim, Germany）, SOD detection kit and malondialdehyde detection kit （Nanjing Jiancheng Bioengineering Institute, China）, and homocysteine （Sigma, St Louis, MO, USA） were used in the present study. METHODS： A total of 75 Sprague Dawley rats were equally and randomly assigned to sham surgery model, and homocysteine groups. Autologous blood was infused into the caudate putamen of rats to establish models of cerebral hemorrhage in model and homocysteine groups. Homocysteine was injected directly into the brain through the skull at the hematoma hemisphere at 30 minutes after model induction in the homocysteine group. MAIN OUTCOME MEASURES： At 6, 12, 24, and 72 hours, as well as 1 week, post-surgery, neurological deficits were observed in each group. Brain water content was measured using the dry-wet weight method. Cell apoptosis in tissue surrounding the hematoma was detected utilizing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL）. SOD activity and malondialdehyde content in tissue surrounding the hematoma were respectively measured using the xanthine oxidase and thiobarbituric acid methods. RESULTS： Neurological function was similar between model and homocysteine groups following cerebral hemorrhage （P 〉 0.05）. Brain water content was increased at 12 hours post-surgery, peaked at 3 days, and remained unchanged at 7 days in the model group. Brain edema was not significantly aggravated following homocysteine intervention （P 〉 0.05）, but SOD activity significantly decreased and malondialdehyde content significantly increased （P 〈 0.05）. The number of apoptotic cells increased in rats with cerebral hemorrhage at 12 hours （P 〈 0.05）, and numbers peaked at 72 hours following model establishment （P〈 0.05）. The time of peak value was identical between model and homocysteine groups. Brain water content was negatively associated with SOD activity （rmodel group =-0.448, P 〈 0.05; rhomocysteine group =-0.612, P 〈 0.05）, but was positively associated with malondialdehyde content （rmodel group = 0.542, P 〈 0.05; rhomocysteine group = 0.684, P 〈 0.05） in brain tissues surrounding the hematoma following surgery in model and homocysteine groups. CONCLUSION： Homocysteine aggravates neurological dysfunction and brain edema in rats with cerebral hemorrhage. The mechanisms of action are likely associated with production of oxygen-free radical and cellular apoptosis following cerebral hemorrhage.
文摘Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.
文摘Objective： Although many clinical studies on skip lymphatic metastasis in non-small cell lung cancer have been reported, the risk factors for skip lymphatic metastasis are still controversy and debatable. This study investigated, by multivariate logistic regression analysis, the clinical features of skip metastasis to mediastinal lymph nodes （N2） in non-small cell lung cancer 0NISCLC） patients. Methods： We collected the clinicopathological data of 256 pN2-NSCLC patients who underwent lobectomy plus systemic lymph node dissection in Fujian Medical University Union Hospital. The cases in the present study were divided into two groups： skip metastasis （N2 skip＋） and non- skip metastasis （N2 skip-）. A retrospective analysis of clinical pathological features of two groups was performed, rib determine an independent factor, multivariate logistic regression analysis was used to identify possible risk factors. Results： A total of 256 pN2-NSCLC patients were recruited. The analysis results showed that gender, pathologic types, surgery, pleural involvement, smoking history, age, tumor stages, and differentiation were not statistical significant factors impacting on skip metastasis in pN2-NSCLC （P〉0.05）, whereas tumor size was an independent factor for skip metastasis （P=0.02）. Conclusions： The rate of skip lymphatic metastasis increases in pN2-NSCLC patients, in accompany with an increased tumor size.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82073814,81973291,82122066,and 82003909)the Rising-Star Program of Shanghai Science and Technology Committee(Grant No.:19QA1411500).
文摘Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its composition,the specific active ingredients in AR that act on NK cells are not clear yet.Cell membrane chromatography(CMC)is mainly used to screen the active ingredients in a complex system of herbal medicines.In this study,a new comprehensive two-dimensional(2D)NK-92MI CMC/C18 column/time-of-flight mass spectrometry(TOFMS)system was established to screen for potential NK cell activators.To obtain a higher column efficiency,3-mercaptopropyltrimethoxysilane-modified silica was synthesized to prepare the NK-92MI CMC column.In total,nine components in AR were screened from this system,which could be washed out from the NK-92MI/CMC column after 10 min,and they showed good affinity for NK-92MI/CMC column.Two representative active compounds of AR,isoastragaloside Ⅰ and astragaloside IV,promoted the killing effect of NK cells on K562 cells in a dose-dependent manner.It can thus suggest that isoastragaloside Ⅰ and astragaloside Ⅳ are the main immunomodulatory components of AR.This comprehensive 2D NK-92MI CMC analytical system is a practical method for screening immune cell activators from other herbal medicines with immunomodulatory effects.
