A mangiferin aglycon derivative J99745 has been identified as a potent xanthine oxidase(XOD) inhibitor by previous in vitro study. This study aimed to evaluate the hypouricemic effects of J99745 in experimental hyperu...A mangiferin aglycon derivative J99745 has been identified as a potent xanthine oxidase(XOD) inhibitor by previous in vitro study. This study aimed to evaluate the hypouricemic effects of J99745 in experimental hyperuricemia mice, and explore the underlying mechanisms. Mice were orally administered 600 mg/kg xanthine once daily for 7 days and intraperitoneally injected 250 mg/kg oxonic acid on the 7 th day to induce hyperuricemia. Meanwhile, J99745(3, 10, and 30 mg/kg), allopurinol(20 mg/kg) or benzbromarone(20 mg/kg) were orally administered to mice for 7 days. On the 7 th day,uric acid and creatinine in serum and urine, blood urea nitrogen(BUN), malondialdehyde(MDA) content and XOD activities in serum and liver were determined. Morphological changes in kidney were observed using hematoxylin and eosin(H&E) staining. Hepatic XOD, renal urate transporter 1(URAT1), glucose transporter type 9(GLUT9), organic anion transporter 1(OAT1) and ATP-binding cassette transporter G2(ABCG2) were detected by Western blot and real time polymerase chain reaction(PCR). The results showed that J99745 at doses of 10 and 30 mg/kg significantly reduced serum urate, and enhanced fractional excretion of uric acid(FEUA). H&E staining confirmed that J99745 provided greater nephroprotective effects than allopurinol and benzbromarone. Moreover, serum and hepatic XOD activities and renal URAT1 expression declined in J99745-treated hyperuricemia mice. In consistence with the ability to inhibit XOD, J99745 lowered serum MDA content in hyperuricemia mice. Our resultssuggest that J99745 exerts urate-lowering effect by inhibiting XOD activity and URAT1 expression, thus representing a promising candidate as an anti-hyperuricemia agent.展开更多
Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environment...Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients（e.g.,phosphorus（P））.In this study,ferrihydrite/goethite-humic acid（FH/GE–HA）complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity（Q（max））decreased in the order of FH（22.17 mg/g）〉FH-HA（5.43 mg/g）〉GE（4.67 mg/g）〉GE-HA（3.27 mg/g）.After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.展开更多
A hybrid spectrum sensing and geolocation database framework is proposed to tackle the discovery of spatial-temporal spectrum hole in cognitive radio networks.We first analyze the advantages and disadvantages of spect...A hybrid spectrum sensing and geolocation database framework is proposed to tackle the discovery of spatial-temporal spectrum hole in cognitive radio networks.We first analyze the advantages and disadvantages of spectrum sensing-based and geolocation database-based approaches respectively,which motivate us to further propose a hybrid protocol framework by effectively integrating the benefits of both spectrum sensing and geolocation database.Specifically,in the proposed hybrid approach,the goal is to maximize the utilization of spatialtemporal spectrum hole while satisfying the protection constraints for the primary users.Analytical and numerical results demonstrate the superior performance of the proposed hybrid approach over the existing spectrum sensing only and geolocation database only approaches,in terms of interference-free throughput.This article serves as a fundamental framework for advancing the design of hybrid approaches for spatial-temporal spectrum hole discovery.展开更多
Soybean mosaic virus(SMV) is one of the most devastating viral pathogens of soybean(Glycine max(L.) Merr). In total, 22 Chinese SMV strains(SC1–SC22) have been classified based on the responses of 10 soybean cultivar...Soybean mosaic virus(SMV) is one of the most devastating viral pathogens of soybean(Glycine max(L.) Merr). In total, 22 Chinese SMV strains(SC1–SC22) have been classified based on the responses of 10 soybean cultivars to these pathogens. However, although several SMVresistance loci in soybean have been identified, no gene conferring SMV resistance in the resistant soybean cultivar(cv.) Kefeng No.1 has been cloned and verified. Here, using F_(2)-derived F_(3)(F_(2:3)) and recombinant inbred line(RIL) populations from a cross between Kefeng No.1 and susceptible soybean cv. Nannong 1138-2, we localized the gene in Kefeng No.1 that mediated resistance to SMV-SC3 strain to a 90-kb interval on chromosome 2. To study the functions of candidate genes in this interval, we performed Bean pod mottle virus(BPMV)-induced gene silencing(VIGS). We identified a recombinant gene(which we named R_(SC3)K) harboring an internal deletion of a genomic DNA fragment partially flanking the LOC100526921 and LOC100812666 reference genes as the SMV-SC3 resistance gene.By shuffling genes between infectious SMV DNA clones based on the avirulent isolate SC3 and virulent isolate 1129, we determined that the viral protein P3 is the avirulence determinant mediating SMV-SC3 resistance on Kefeng No.1. P3 interacts with RNase proteins encoded by R_(SC3)K, LOC100526921, and LOC100812666. The recombinant R_(SC3)K conveys much higher anti-SMV activity than LOC100526921 and LOC100812666, although those two genes also encode proteins that inhibit SMV accumulation, as revealed by gene silencing in a susceptible cultivar and by overexpression in Nicotiana benthamiana. These findings demonstrate that R_(SC3)K mediates the resistance of Kefeng No.1 to SMV-SC3 and that SMV resistance of soybean is determined by the antiviral activity of RNase proteins.展开更多
目的探讨脱氧胆酸盐两性霉素B在重症侵袭性真菌感染患者体内药代动力学(pharmacokinetics,PK)特点及目标靶值并分析其PK变化的影响因素。方法选取从2018年11月—2022年11月在东南大学附属中大医院重症医学科就诊并接受脱氧胆酸盐两性霉...目的探讨脱氧胆酸盐两性霉素B在重症侵袭性真菌感染患者体内药代动力学(pharmacokinetics,PK)特点及目标靶值并分析其PK变化的影响因素。方法选取从2018年11月—2022年11月在东南大学附属中大医院重症医学科就诊并接受脱氧胆酸盐两性霉素B输入治疗的重症侵袭性真菌病患者。用药从1 mg/d开始逐渐累加至50 mg/d,持续静脉泵入6 h,在用药第7、14天采集给药前及给药后1、3、6、9、12 h的外周血2 mL,采用液相色谱与串联质谱联用(liquid chromatography tandem mass spectrometry,LC-MS/MS)法测定血浆中两性霉素B的浓度。观察两性霉素B的PK特点并采用线性回归法,分析影响其PK变化的影响因素。结果共纳入12例重症侵袭性真菌病患者,对比正常受试者中得到的脱氧胆酸盐两性霉素B的药代动力学参数,重症侵袭性真菌感染(invasive fungal infection,IFI)患者体内两性霉素B的谷浓度(Cmin)、清除率(clearance,CL)、半衰期(t_(1/2))和浓度时间曲线下面积(area under concentration-time curve,AUC)均高于健康受试者(均P<0.05),而血药浓度峰值(Cmax)(1.63±0.77)mg/L未见明显差异。更快的两性霉素B剂量累加速度相比于正常累加组无明显的不良反应发生率(均P>0.05)变化,并且其Cmax和表观分布容积(apparent volume of distribution,Vd)更高。单因素分析显示实时APACHEⅡ评分可能是两性霉素B峰浓度的影响因素(P=0.008)。结论重症IFI患者体内两性霉素B的谷浓度、CL、半衰期(t_(1/2))、和AUC均高于健康受试者,但Cmax两组未见明显差异,实时APACHEⅡ评分可能是影响两性霉素B峰浓度的影响因素。更快的两性霉素B药物累加速度未表现出明显的即刻不良反应发生率的增加,并且存在更高的药效浓度。展开更多
Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due ...Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory species.In this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present forests.In the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from 1965.Factors that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree analysis.The coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory layer.The abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always different.Although the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH increased.The findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was multidimensional.Functional group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession.展开更多
基金supported by National Natural Science Foundation of China(81573645,81202538 and 81673422)CAMS Innovation Fund for Medical Sciences(CIFMS,2016-I2M-3-007)National Science and Technology Major Projects for "Major New Drugs Innovation and Development"(2013ZX09508104and 2013ZX09402203)
文摘A mangiferin aglycon derivative J99745 has been identified as a potent xanthine oxidase(XOD) inhibitor by previous in vitro study. This study aimed to evaluate the hypouricemic effects of J99745 in experimental hyperuricemia mice, and explore the underlying mechanisms. Mice were orally administered 600 mg/kg xanthine once daily for 7 days and intraperitoneally injected 250 mg/kg oxonic acid on the 7 th day to induce hyperuricemia. Meanwhile, J99745(3, 10, and 30 mg/kg), allopurinol(20 mg/kg) or benzbromarone(20 mg/kg) were orally administered to mice for 7 days. On the 7 th day,uric acid and creatinine in serum and urine, blood urea nitrogen(BUN), malondialdehyde(MDA) content and XOD activities in serum and liver were determined. Morphological changes in kidney were observed using hematoxylin and eosin(H&E) staining. Hepatic XOD, renal urate transporter 1(URAT1), glucose transporter type 9(GLUT9), organic anion transporter 1(OAT1) and ATP-binding cassette transporter G2(ABCG2) were detected by Western blot and real time polymerase chain reaction(PCR). The results showed that J99745 at doses of 10 and 30 mg/kg significantly reduced serum urate, and enhanced fractional excretion of uric acid(FEUA). H&E staining confirmed that J99745 provided greater nephroprotective effects than allopurinol and benzbromarone. Moreover, serum and hepatic XOD activities and renal URAT1 expression declined in J99745-treated hyperuricemia mice. In consistence with the ability to inhibit XOD, J99745 lowered serum MDA content in hyperuricemia mice. Our resultssuggest that J99745 exerts urate-lowering effect by inhibiting XOD activity and URAT1 expression, thus representing a promising candidate as an anti-hyperuricemia agent.
基金supported by the National Natural Science Foundation of China(Nos.41171198,41403079)the China Postdoctoral Science Foundation(No.2013M542238)+1 种基金the Chongqing Special Postdoctoral Science Foundation(No.Xm2014023)the Fundamental Research Funds for the Central Universities(No.XDJK2015B035)
文摘Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients（e.g.,phosphorus（P））.In this study,ferrihydrite/goethite-humic acid（FH/GE–HA）complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity（Q（max））decreased in the order of FH（22.17 mg/g）〉FH-HA（5.43 mg/g）〉GE（4.67 mg/g）〉GE-HA（3.27 mg/g）.After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.
基金supported by the National Nat-ural Science Foundation of China(61172062 and 61301160)Jiangsu Province Natural Science Foundation(BK2011116)the National Basic Research Program of China(2009CB320400)
文摘A hybrid spectrum sensing and geolocation database framework is proposed to tackle the discovery of spatial-temporal spectrum hole in cognitive radio networks.We first analyze the advantages and disadvantages of spectrum sensing-based and geolocation database-based approaches respectively,which motivate us to further propose a hybrid protocol framework by effectively integrating the benefits of both spectrum sensing and geolocation database.Specifically,in the proposed hybrid approach,the goal is to maximize the utilization of spatialtemporal spectrum hole while satisfying the protection constraints for the primary users.Analytical and numerical results demonstrate the superior performance of the proposed hybrid approach over the existing spectrum sensing only and geolocation database only approaches,in terms of interference-free throughput.This article serves as a fundamental framework for advancing the design of hybrid approaches for spatial-temporal spectrum hole discovery.
基金supported by the National Key R&D Program of China (2021YFD1201604)Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP)+1 种基金the Core Technology Development for Breeding Program of Jiangsu Province (JBGS-2021-014)China Agriculture Research System of MOF and MARA (No. CARS-04)。
文摘Soybean mosaic virus(SMV) is one of the most devastating viral pathogens of soybean(Glycine max(L.) Merr). In total, 22 Chinese SMV strains(SC1–SC22) have been classified based on the responses of 10 soybean cultivars to these pathogens. However, although several SMVresistance loci in soybean have been identified, no gene conferring SMV resistance in the resistant soybean cultivar(cv.) Kefeng No.1 has been cloned and verified. Here, using F_(2)-derived F_(3)(F_(2:3)) and recombinant inbred line(RIL) populations from a cross between Kefeng No.1 and susceptible soybean cv. Nannong 1138-2, we localized the gene in Kefeng No.1 that mediated resistance to SMV-SC3 strain to a 90-kb interval on chromosome 2. To study the functions of candidate genes in this interval, we performed Bean pod mottle virus(BPMV)-induced gene silencing(VIGS). We identified a recombinant gene(which we named R_(SC3)K) harboring an internal deletion of a genomic DNA fragment partially flanking the LOC100526921 and LOC100812666 reference genes as the SMV-SC3 resistance gene.By shuffling genes between infectious SMV DNA clones based on the avirulent isolate SC3 and virulent isolate 1129, we determined that the viral protein P3 is the avirulence determinant mediating SMV-SC3 resistance on Kefeng No.1. P3 interacts with RNase proteins encoded by R_(SC3)K, LOC100526921, and LOC100812666. The recombinant R_(SC3)K conveys much higher anti-SMV activity than LOC100526921 and LOC100812666, although those two genes also encode proteins that inhibit SMV accumulation, as revealed by gene silencing in a susceptible cultivar and by overexpression in Nicotiana benthamiana. These findings demonstrate that R_(SC3)K mediates the resistance of Kefeng No.1 to SMV-SC3 and that SMV resistance of soybean is determined by the antiviral activity of RNase proteins.
文摘目的探讨脱氧胆酸盐两性霉素B在重症侵袭性真菌感染患者体内药代动力学(pharmacokinetics,PK)特点及目标靶值并分析其PK变化的影响因素。方法选取从2018年11月—2022年11月在东南大学附属中大医院重症医学科就诊并接受脱氧胆酸盐两性霉素B输入治疗的重症侵袭性真菌病患者。用药从1 mg/d开始逐渐累加至50 mg/d,持续静脉泵入6 h,在用药第7、14天采集给药前及给药后1、3、6、9、12 h的外周血2 mL,采用液相色谱与串联质谱联用(liquid chromatography tandem mass spectrometry,LC-MS/MS)法测定血浆中两性霉素B的浓度。观察两性霉素B的PK特点并采用线性回归法,分析影响其PK变化的影响因素。结果共纳入12例重症侵袭性真菌病患者,对比正常受试者中得到的脱氧胆酸盐两性霉素B的药代动力学参数,重症侵袭性真菌感染(invasive fungal infection,IFI)患者体内两性霉素B的谷浓度(Cmin)、清除率(clearance,CL)、半衰期(t_(1/2))和浓度时间曲线下面积(area under concentration-time curve,AUC)均高于健康受试者(均P<0.05),而血药浓度峰值(Cmax)(1.63±0.77)mg/L未见明显差异。更快的两性霉素B剂量累加速度相比于正常累加组无明显的不良反应发生率(均P>0.05)变化,并且其Cmax和表观分布容积(apparent volume of distribution,Vd)更高。单因素分析显示实时APACHEⅡ评分可能是两性霉素B峰浓度的影响因素(P=0.008)。结论重症IFI患者体内两性霉素B的谷浓度、CL、半衰期(t_(1/2))、和AUC均高于健康受试者,但Cmax两组未见明显差异,实时APACHEⅡ评分可能是影响两性霉素B峰浓度的影响因素。更快的两性霉素B药物累加速度未表现出明显的即刻不良反应发生率的增加,并且存在更高的药效浓度。
基金supported by the Natural Science Foundation of Yunnan Province(Grant No:202301AT070356)the Open Fund of the Key Laboratory of Tropical Forest Ecology,Chinese Academy of Sciences,National Science Foundation of China(Grant No.32061123003)+1 种基金the Joint Fund of the National Natural Science Foundation of China-Yunnan Province(Grant No.U1902203)the Field Station Foundation of the Chinese Academy of Sciences.
文摘Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory species.In this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present forests.In the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from 1965.Factors that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree analysis.The coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory layer.The abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always different.Although the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH increased.The findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was multidimensional.Functional group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession.
