Soil microbial biomass is an important indicator to measure the dynamic changes of soil carbon pool.It is of great signifi cance to understand the dynamics of soil microbial biomass in plantation for rational manageme...Soil microbial biomass is an important indicator to measure the dynamic changes of soil carbon pool.It is of great signifi cance to understand the dynamics of soil microbial biomass in plantation for rational management and cultivation of plantation.In order to explore the temporal dynamics and infl uencing factors of soil microbial biomass of Keteleeria fortunei var.cyclolepis at diff erent stand ages,the plantation of diff erent ages(young forest,5 years;middle-aged forest,22 years;mature forest,40 years)at the Guangxi Daguishan forest station of China were studied to examine the seasonal variation of their microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN)by chloroform fumigation extraction method.It was found that among the forests of diff erent age,MBC and MBN diff ered signifi cantly in the 0–10 cm soil layer,and MBN diff ered signifi cantly in the 10–20 cm soil layer,but there was no signifi cant diff erence in MBC for the 10–20 cm soil layer or in either MBC or MBN for the 20–40 cm soil layer.With increasing maturity of the forest,MBC gradually decreased in the 0–10 cm soil layer and increased fi rstly and then decreased in the 10–20 cm and 20–40 cm soil layers,and MBN increased fi rstly and then decreased in all three soil layers.As the soil depth increased,both MBC and MBN gradually decreased for all three forests.The MBC and MBN basically had the same seasonal variation in all three soil layers of all three forests,i.e.,high in the summer and low in the winter.Correlation analysis showed that MBC was signifi cantly positively correlated with soil organic matter,total nitrogen,and soil moisture,whereas MBN was signifi cantly positively correlated with soil total nitrogen.It showed that soil moisture content was the main factor determining the variation of soil microbial biomass by Redundancy analysis.The results showed that the soil properties changed continuously as the young forest grew into the middle-aged forest,which increased soil microbial biomass and enriched the soil nutrients.However,the soil microbial biomass declined as the middle-age forest continued to grow,and the soil nutrients were reduced in the mature forest.展开更多
Multilevel inverters are preferred solutions for photovoltaic(PV)applications because of lower total harmonic distortion(THD),lower switching stress and lower electromagnetic interference(EMI).In order to reduce the l...Multilevel inverters are preferred solutions for photovoltaic(PV)applications because of lower total harmonic distortion(THD),lower switching stress and lower electromagnetic interference(EMI).In order to reduce the leakage current in the single-phase low-power PV inverters,a five-level transformer-less inverter is proposed in this paper.A total of eleven switches are required,while six of them only withstand a quarter of the dc-bus voltage,so the costs for them are low.Another four switches are turned on or off at the power line cycle,the switching losses for them are ignored.In addition,the flying-capacitors(FCs)voltages are only a quarter of the dc-bus voltage,and they are balanced at the switching frequency,which further reduces the system investment.The experimental results based on a 1 kW prototype show that the proposed modulation strategy can balance the FCs voltages at Vdc/4 very well.And the leakage current can be reduced to about 27 mA under both active and reactive operations,which satisfies the VDE 0126-1-1 standard.展开更多
Objective: Diagnosis of patients with negative prostate biopsy and persistent suspicion of prostate cancer remains a serious problem. In this study, we investigated the application of optimizing prostate biopsy for pa...Objective: Diagnosis of patients with negative prostate biopsy and persistent suspicion of prostate cancer remains a serious problem. In this study, we investigated the application of optimizing prostate biopsy for patients who need repeat prostate biopsy. Methods: In this prospective, non-randomized phase-I clinical trial, the prostate cancer detection rate of initial detection scheme was compared with optimizing prostate biopsy scheme. The number of punctures of initial detection scheme was the same as that of optimizing prostate biopsy scheme. The puncture direction of optimizing prostate biopsy was a 45° angle to the sagittal plane from front, middle, and back. The two cores from each lateral lobe were horizontally inwardly inclined 45°. Results: A total of 45 patients with initial negative biopsy for cancer were received the optimizing prostate biopsy scheme. The cancer detection rate was 17.8%(8/45), and prostate intraepithelial neoplasm(PIN) was 6.7%(3/45). The patients receiving repeat transrectal prostate biopsies were pathologically diagnosed as lower Gleason grade prostate cancers. Conclusion: The cancer detection rate of repeat biopsy prostate cancer is lower than that of initial biopsy. Our study showed that the optimizing prostate biopsy is important to improve the detection rate of repeat transrectal prostate biopsies patients.展开更多
Objective: The aim of this study was to investigate whether it was necessary to increase the number of cores at initial prostate biopsy with patients of prostate-specific antigen(PSA) ≥ 20 ng/mL and to explore an app...Objective: The aim of this study was to investigate whether it was necessary to increase the number of cores at initial prostate biopsy with patients of prostate-specific antigen(PSA) ≥ 20 ng/mL and to explore an appropriate individualized transrectal ultrasonograhpy(TRUS)-guided prostate biopsy for the detection of prostate cancer in men suspicious of prostate cancer. Methods: A total of 115 patients with PSA ≥ 20 ng/mL and suspicious of prostate cancer were prospectively randomized to perform TRUS-guided biopsy. Patients were randomized to a "6 + X" cores or a "10 + X" cores protocol. The primary end point was cancer detection rate. Secondary end points were cancer characteristics, rate of complications and the level of pain experienced by patients during TRUS-guided prostate biopsy. Results: Preoperative variables were similar in both groups. The overall prostate cancer detection rate was 73.9%. The "10 + X" cores strategy increased cancer detection rate only 9.7% in patients with PSA ≥ 20 ng/mL but < 50 ng/mL, while there was no difference between the two strategies for cancer detection in patients with PSA ≥ 50.1 ng/mL. The number of extended biopsy cores and pain score of extended biopsy in prostate cancer patients increased significantly(P < 0.001). Conclusion: Our findings suggest that there is no significant advantage in using extended biopsy protocol in all patients with PSA ≥ 20 ng/mL.展开更多
[Objectives] This study was conducted to evaluate the toxicity risk of prochloraz-manganese chloride complex to environmental organisms. [Methods] The acute toxicity tests of prochloraz-manganese chloride complex on 8...[Objectives] This study was conducted to evaluate the toxicity risk of prochloraz-manganese chloride complex to environmental organisms. [Methods] The acute toxicity tests of prochloraz-manganese chloride complex on 8 common environmental organisms, such as Coturnix coturnix japonica, Apis mellifera L., Eisenia foetida, Bombyx mori, Trichogramma japonicum, Brachydanio rerio, Daphnia magna Straus and Scenedesmus obliquus were carried out. [Results] Prochloraz-manganese chloride complex to D. magna EC50(48 h): 1.11 mg a.i./L, with a 95% confidence limit of 1.00-1.26 mg a.i./L;B. rerio LC50(96 h): 2.84 mg a.i./L, with a 95 % Confidence limit of 2.43-3.48 mg a.i./L;S. obliquus ErC50(72 h): 1.88×10^-2 mg a.i./L, with a 95% confidence limit of 1.70×10^-2-2.16×10^-2 mg a.i./L;C. coturnix LD50(168 h): 1.01×10^3 mg a.i./kg body weight, with a 95% confidence limit of 7.87×10^2-1.27×10^3 mg a.i./kg body weight;T. japonicum LR50(24 h): 2.53×10^-3 mg a.i./cm^2, with a 95% confidence limit of 2.14×10^-3-2.99×10^-3 mg a.i./cm^2;B. mori LC50(96 h): 2.03×10^2 mg a.i./L, with a 95% confidence limit of 1.79×10^2-2.30×10^2 mg a.i./L;A. mellifera(peroral) LD50(48 h)>100 μg a.i./bee;A. mellifera(contact) LD50(48 h)>100 μg a.i./bee;E. foetida LC50(14 d)>1.00×10^2 mg a.i./kg dry soil. According to the Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media for Pesticide Registration, prochloraz-manganese chloride complex had low toxicity to A. mellifera, C. coturnix, B. mori and E. foetida, medium toxicity to D. magna and B. rerio, and high toxicity and low risk to S. obliquus and T. japonicum. [Conclusions] This study provides a data basis for the toxicity and environmental safety evaluation of the agent.展开更多
Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the obj...Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the objective of this study was to determine the effects of green manure interplantation on soil fertility and plant growth of Eucalyptus plantation in a short term.A field experiment of one year was established to investigate the green manure growth,forest soil nutrients and Eucalyptus plant growth inter-planted with two legume species(Tephrosia candida,TC and Sesbania cannabina,SC)at south subtropical China.Legumes were inter-planted in linear among the tree space of Eucalyptus stand.Result showed that the green manure inter-plantation increased soil organic matter by 9.66%of TC and 18.44%of SC.Soil available nitrogen,phosphorus and potassium were improved significantly by the legume treatments as well.The increment of height and diameter at breast height of Eucalyptus during the experiment was significant in legume treatments.Thus,the timber volume increment was improved significantly by 46.81%of TC and 35.47%of SC compared with the control treatment.Therefore,the inter-plantation of legume green manure under the Eucalyptus plantation is effective to improve soil fertility and tree growth.Such a measure is potential and referenced for the sustainable forest management.展开更多
Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial...Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial cell(BMEC)dysfunction via the miR-9/Hes1 axis remain unknown.Therefore,the current study aimed to determine the effects of EXOs on BMEC proliferation,migration,and death via the miR-9/Hes1 axis.Methods:Immunofluorescence,quantitative real-time polymerase chain reaction,cell counting kit-8 assay,wound healing assay,calcein-acetoxymethyl/propidium iodide staining,and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs.Results:EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions.The overexpression of miR-9 promoted BMEC prolifera-tion and migration and reduced cell death under hypoxic conditions.Moreover,miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death.Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death.Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice.Meanwhile,EXO treatment improved cerebrovascular alterations.Conclusion:NSC-derived EXOs can promote BMEC proliferation and migra-tion and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions.Therefore,EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.展开更多
文摘Soil microbial biomass is an important indicator to measure the dynamic changes of soil carbon pool.It is of great signifi cance to understand the dynamics of soil microbial biomass in plantation for rational management and cultivation of plantation.In order to explore the temporal dynamics and infl uencing factors of soil microbial biomass of Keteleeria fortunei var.cyclolepis at diff erent stand ages,the plantation of diff erent ages(young forest,5 years;middle-aged forest,22 years;mature forest,40 years)at the Guangxi Daguishan forest station of China were studied to examine the seasonal variation of their microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN)by chloroform fumigation extraction method.It was found that among the forests of diff erent age,MBC and MBN diff ered signifi cantly in the 0–10 cm soil layer,and MBN diff ered signifi cantly in the 10–20 cm soil layer,but there was no signifi cant diff erence in MBC for the 10–20 cm soil layer or in either MBC or MBN for the 20–40 cm soil layer.With increasing maturity of the forest,MBC gradually decreased in the 0–10 cm soil layer and increased fi rstly and then decreased in the 10–20 cm and 20–40 cm soil layers,and MBN increased fi rstly and then decreased in all three soil layers.As the soil depth increased,both MBC and MBN gradually decreased for all three forests.The MBC and MBN basically had the same seasonal variation in all three soil layers of all three forests,i.e.,high in the summer and low in the winter.Correlation analysis showed that MBC was signifi cantly positively correlated with soil organic matter,total nitrogen,and soil moisture,whereas MBN was signifi cantly positively correlated with soil total nitrogen.It showed that soil moisture content was the main factor determining the variation of soil microbial biomass by Redundancy analysis.The results showed that the soil properties changed continuously as the young forest grew into the middle-aged forest,which increased soil microbial biomass and enriched the soil nutrients.However,the soil microbial biomass declined as the middle-age forest continued to grow,and the soil nutrients were reduced in the mature forest.
基金the National Natural Science Foundation of China Under Grant 51977069the Innovative Talents of“High-Level Talent Gathering Project”of Hunan Province,China Under Grant 2018RS3048+1 种基金the Natural Science Foundation for Distinguished Young Scholars of Hunan Province,China Under Grant 2020JJ2007the First Key Research and Talents Preprogram of Changsha,Hunan Province,China Under Grant kq2004020.
文摘Multilevel inverters are preferred solutions for photovoltaic(PV)applications because of lower total harmonic distortion(THD),lower switching stress and lower electromagnetic interference(EMI).In order to reduce the leakage current in the single-phase low-power PV inverters,a five-level transformer-less inverter is proposed in this paper.A total of eleven switches are required,while six of them only withstand a quarter of the dc-bus voltage,so the costs for them are low.Another four switches are turned on or off at the power line cycle,the switching losses for them are ignored.In addition,the flying-capacitors(FCs)voltages are only a quarter of the dc-bus voltage,and they are balanced at the switching frequency,which further reduces the system investment.The experimental results based on a 1 kW prototype show that the proposed modulation strategy can balance the FCs voltages at Vdc/4 very well.And the leakage current can be reduced to about 27 mA under both active and reactive operations,which satisfies the VDE 0126-1-1 standard.
基金Supported by grants from the Pudong New Area Medical Health System Outstanding Young Talent Training Plan(No.PWRq2013-17)Zhoupu Hospital of Pudong New District(No.ZP-XM-2012B-22)
文摘Objective: Diagnosis of patients with negative prostate biopsy and persistent suspicion of prostate cancer remains a serious problem. In this study, we investigated the application of optimizing prostate biopsy for patients who need repeat prostate biopsy. Methods: In this prospective, non-randomized phase-I clinical trial, the prostate cancer detection rate of initial detection scheme was compared with optimizing prostate biopsy scheme. The number of punctures of initial detection scheme was the same as that of optimizing prostate biopsy scheme. The puncture direction of optimizing prostate biopsy was a 45° angle to the sagittal plane from front, middle, and back. The two cores from each lateral lobe were horizontally inwardly inclined 45°. Results: A total of 45 patients with initial negative biopsy for cancer were received the optimizing prostate biopsy scheme. The cancer detection rate was 17.8%(8/45), and prostate intraepithelial neoplasm(PIN) was 6.7%(3/45). The patients receiving repeat transrectal prostate biopsies were pathologically diagnosed as lower Gleason grade prostate cancers. Conclusion: The cancer detection rate of repeat biopsy prostate cancer is lower than that of initial biopsy. Our study showed that the optimizing prostate biopsy is important to improve the detection rate of repeat transrectal prostate biopsies patients.
基金Supported by Pudong New Area Medical Health System Outstanding Young Talent Training Plan(No.PWRq2013-17)Pudong New District Zhoupu Hospital of Shanghai(No.ZP-XM-2012B-22)
文摘Objective: The aim of this study was to investigate whether it was necessary to increase the number of cores at initial prostate biopsy with patients of prostate-specific antigen(PSA) ≥ 20 ng/mL and to explore an appropriate individualized transrectal ultrasonograhpy(TRUS)-guided prostate biopsy for the detection of prostate cancer in men suspicious of prostate cancer. Methods: A total of 115 patients with PSA ≥ 20 ng/mL and suspicious of prostate cancer were prospectively randomized to perform TRUS-guided biopsy. Patients were randomized to a "6 + X" cores or a "10 + X" cores protocol. The primary end point was cancer detection rate. Secondary end points were cancer characteristics, rate of complications and the level of pain experienced by patients during TRUS-guided prostate biopsy. Results: Preoperative variables were similar in both groups. The overall prostate cancer detection rate was 73.9%. The "10 + X" cores strategy increased cancer detection rate only 9.7% in patients with PSA ≥ 20 ng/mL but < 50 ng/mL, while there was no difference between the two strategies for cancer detection in patients with PSA ≥ 50.1 ng/mL. The number of extended biopsy cores and pain score of extended biopsy in prostate cancer patients increased significantly(P < 0.001). Conclusion: Our findings suggest that there is no significant advantage in using extended biopsy protocol in all patients with PSA ≥ 20 ng/mL.
基金Supported by Hunan Scientific and Technological Innovation Planning Project(2019NK4170)Fund for Hunan Province Double First-Class Applied Discipline Plant Protection。
文摘[Objectives] This study was conducted to evaluate the toxicity risk of prochloraz-manganese chloride complex to environmental organisms. [Methods] The acute toxicity tests of prochloraz-manganese chloride complex on 8 common environmental organisms, such as Coturnix coturnix japonica, Apis mellifera L., Eisenia foetida, Bombyx mori, Trichogramma japonicum, Brachydanio rerio, Daphnia magna Straus and Scenedesmus obliquus were carried out. [Results] Prochloraz-manganese chloride complex to D. magna EC50(48 h): 1.11 mg a.i./L, with a 95% confidence limit of 1.00-1.26 mg a.i./L;B. rerio LC50(96 h): 2.84 mg a.i./L, with a 95 % Confidence limit of 2.43-3.48 mg a.i./L;S. obliquus ErC50(72 h): 1.88×10^-2 mg a.i./L, with a 95% confidence limit of 1.70×10^-2-2.16×10^-2 mg a.i./L;C. coturnix LD50(168 h): 1.01×10^3 mg a.i./kg body weight, with a 95% confidence limit of 7.87×10^2-1.27×10^3 mg a.i./kg body weight;T. japonicum LR50(24 h): 2.53×10^-3 mg a.i./cm^2, with a 95% confidence limit of 2.14×10^-3-2.99×10^-3 mg a.i./cm^2;B. mori LC50(96 h): 2.03×10^2 mg a.i./L, with a 95% confidence limit of 1.79×10^2-2.30×10^2 mg a.i./L;A. mellifera(peroral) LD50(48 h)>100 μg a.i./bee;A. mellifera(contact) LD50(48 h)>100 μg a.i./bee;E. foetida LC50(14 d)>1.00×10^2 mg a.i./kg dry soil. According to the Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media for Pesticide Registration, prochloraz-manganese chloride complex had low toxicity to A. mellifera, C. coturnix, B. mori and E. foetida, medium toxicity to D. magna and B. rerio, and high toxicity and low risk to S. obliquus and T. japonicum. [Conclusions] This study provides a data basis for the toxicity and environmental safety evaluation of the agent.
基金The authors are grateful forfinancial support from Guangxi Zhuang Autonomous Region(AA17204087-11)Aids in sampling from the members of National Dongmen Forest Farm of Guangxi Zhuang Autonomous Region are appreciated.
文摘Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the objective of this study was to determine the effects of green manure interplantation on soil fertility and plant growth of Eucalyptus plantation in a short term.A field experiment of one year was established to investigate the green manure growth,forest soil nutrients and Eucalyptus plant growth inter-planted with two legume species(Tephrosia candida,TC and Sesbania cannabina,SC)at south subtropical China.Legumes were inter-planted in linear among the tree space of Eucalyptus stand.Result showed that the green manure inter-plantation increased soil organic matter by 9.66%of TC and 18.44%of SC.Soil available nitrogen,phosphorus and potassium were improved significantly by the legume treatments as well.The increment of height and diameter at breast height of Eucalyptus during the experiment was significant in legume treatments.Thus,the timber volume increment was improved significantly by 46.81%of TC and 35.47%of SC compared with the control treatment.Therefore,the inter-plantation of legume green manure under the Eucalyptus plantation is effective to improve soil fertility and tree growth.Such a measure is potential and referenced for the sustainable forest management.
基金Program of Natural Science Foundation of Shanghai,Grant/Award Number:21ZR1453800 and 22ZR1452400Program of National Natural Science Foundation of China,Grant/Award Number:82370057+3 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:22120220562Program of Shanghai Municipal Health Commission,Grant/Award Number:20204Y0384Program of National Key Research and Development Project of China,Grant/Award Number:2023YFC2509500。
文摘Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial cell(BMEC)dysfunction via the miR-9/Hes1 axis remain unknown.Therefore,the current study aimed to determine the effects of EXOs on BMEC proliferation,migration,and death via the miR-9/Hes1 axis.Methods:Immunofluorescence,quantitative real-time polymerase chain reaction,cell counting kit-8 assay,wound healing assay,calcein-acetoxymethyl/propidium iodide staining,and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs.Results:EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions.The overexpression of miR-9 promoted BMEC prolifera-tion and migration and reduced cell death under hypoxic conditions.Moreover,miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death.Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death.Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice.Meanwhile,EXO treatment improved cerebrovascular alterations.Conclusion:NSC-derived EXOs can promote BMEC proliferation and migra-tion and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions.Therefore,EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.
