In order to restore a degraded alkaline grassland, the local government implemented a large restoration project using fences in Changling county, Jilin province, China, in 2000. Grazing was excluded from the protected...In order to restore a degraded alkaline grassland, the local government implemented a large restoration project using fences in Changling county, Jilin province, China, in 2000. Grazing was excluded from the protected area, whereas the grazed area was continuously grazed at 8.5 dry sheep equivalent（DSE）/hm2. In the current research, soil and plant samples were taken from grazed and fenced areas to examine changes in vegetation and soil properties in 2005, 2006 and 2008. Results showed that vegetation characteristics and soil properties improved significantly in the fenced area compared with the grazed area. In the protected area the vegetation cover, height and above- and belowground biomass increased significantly. Soil pH, electrical conductivity and bulk density decreased significantly, but soil organic carbon and total nitrogen concentration increased greatly in the protected area. By comparing the vegetation and soil characteristics with pre-degraded grassland, we found that vegetation can recover 6 years after fencing, and soil pH can be restored 8 years after fencing. However, the restoration of soil organic carbon, total nitrogen and total phosphorus concentrations needed 16, 30 and 19 years, respectively. It is recommended that the stocking rate should be reduced to 1/3 of the current carrying capacity, or that a grazing regime of 1-year of grazing followed by a 2-year rest is adopted to sustain the current status of vegetation and soil resources. However, if N fertilizer is applied, the rest period could be shortened, depending on the rate of application.展开更多
Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture ...Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture （CA） is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world＇s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.展开更多
HIV reverse transcriptase(RT)inhibitors are the important components of highly active antiretroviral therapies(HAARTs)for anti-HIV treatment and pre-exposure prophylaxis in clinical practice.Many RT inhibitors and the...HIV reverse transcriptase(RT)inhibitors are the important components of highly active antiretroviral therapies(HAARTs)for anti-HIV treatment and pre-exposure prophylaxis in clinical practice.Many RT inhibitors and their combination regimens have been approved in the past ten years,but a review on their drug discovery,pharmacology,and clinical efficacy is lacking.Here,we provide a comprehensive review of RT inhibitors(tenofovir alafenamide,rilpivirine,doravirine,dapivirine,azvudine and elsulfavirine)approved in the past decade,regarding their drug discovery,pharmacology,and clinical efficacy in randomized controlled trials.Novel RT inhibitors such as islatravir,MK-8504,MK-8507,MK8583,IQP-0528,and MIV-150 will be also highlighted.Future development may focus on the new generation of novel antiretroviral inhibitors with higher bioavailability,longer elimination half-life,more favorable side-effect profiles,fewer drug–drug interactions,and higher activities against circulating drug-resistant strains.展开更多
Three plasmid expression vectors containing modified hepatitis B surface antigen (HBsAg) carrying pres epitopes were constructed. Transient expression after in vitro transfection in COS-M6 cells showed that under the ...Three plasmid expression vectors containing modified hepatitis B surface antigen (HBsAg) carrying pres epitopes were constructed. Transient expression after in vitro transfection in COS-M6 cells showed that under the transcriptional control of the human cytomegalovirus (CMV) immediate early promoter, fusion genes expressed the modified HBV envelope proteins which were efficiently secreted into culture medium and presented HBsAg, preS1 and preS2 antigenicity. DNA-based immunization with these plasmids carrying pres sequences induced anti-HBs antibody in BALB/c mice. The titers of anti-HBs antibody were higher than those appeared in mice immunized with plasmid carrying S gene only. DNA injection with plasmids containing preS1 sequences elicited also high titers of anti-preS1 antibody. Moreover, the antipreS1 antibodies were found to appear earlier than anti-HBs antibodies.展开更多
The authors regret that the trade name“Acriptega”should be replaced by“Kocitaf”in this article,because the“Acriptega”represents the antiviral regimen of TDFþFTCþDTG,and the“Kocitaf”represents the TAF...The authors regret that the trade name“Acriptega”should be replaced by“Kocitaf”in this article,because the“Acriptega”represents the antiviral regimen of TDFþFTCþDTG,and the“Kocitaf”represents the TAFþFTCþDTG regimen.Although it does not affect the conclusion,it is an obvious error.The authors apologize for any inconvenience caused to the journal and readers.展开更多
基金supported by the National Key Basic Research Program of China (2011CB403203)the Strategic Science and Technology Guide Project of Chinese Academy of Sciences (XDA05050401)
文摘In order to restore a degraded alkaline grassland, the local government implemented a large restoration project using fences in Changling county, Jilin province, China, in 2000. Grazing was excluded from the protected area, whereas the grazed area was continuously grazed at 8.5 dry sheep equivalent（DSE）/hm2. In the current research, soil and plant samples were taken from grazed and fenced areas to examine changes in vegetation and soil properties in 2005, 2006 and 2008. Results showed that vegetation characteristics and soil properties improved significantly in the fenced area compared with the grazed area. In the protected area the vegetation cover, height and above- and belowground biomass increased significantly. Soil pH, electrical conductivity and bulk density decreased significantly, but soil organic carbon and total nitrogen concentration increased greatly in the protected area. By comparing the vegetation and soil characteristics with pre-degraded grassland, we found that vegetation can recover 6 years after fencing, and soil pH can be restored 8 years after fencing. However, the restoration of soil organic carbon, total nitrogen and total phosphorus concentrations needed 16, 30 and 19 years, respectively. It is recommended that the stocking rate should be reduced to 1/3 of the current carrying capacity, or that a grazing regime of 1-year of grazing followed by a 2-year rest is adopted to sustain the current status of vegetation and soil resources. However, if N fertilizer is applied, the rest period could be shortened, depending on the rate of application.
基金supported by the National Natural Science Foundation of China (40771132)the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD15B06)+3 种基金the Australian Center for International Agricultural Research (CIM-1999-094)the Education Department of Gansu Province, China (0802-07)the Research Fund for the Doctoral Program of Higher Education of China (20106202120004)the Gansu Provincial Key Laboratory of Aridland Crop Science
文摘Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture （CA） is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world＇s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.
基金This work was funded by the National Nature Science Foundation of China(31871324,81730064,31571368,China)the Hunan Youth Elite Project(2018RS3006,China)the National Science and Technology Major Project(2018ZX10715004,China).
文摘HIV reverse transcriptase(RT)inhibitors are the important components of highly active antiretroviral therapies(HAARTs)for anti-HIV treatment and pre-exposure prophylaxis in clinical practice.Many RT inhibitors and their combination regimens have been approved in the past ten years,but a review on their drug discovery,pharmacology,and clinical efficacy is lacking.Here,we provide a comprehensive review of RT inhibitors(tenofovir alafenamide,rilpivirine,doravirine,dapivirine,azvudine and elsulfavirine)approved in the past decade,regarding their drug discovery,pharmacology,and clinical efficacy in randomized controlled trials.Novel RT inhibitors such as islatravir,MK-8504,MK-8507,MK8583,IQP-0528,and MIV-150 will be also highlighted.Future development may focus on the new generation of novel antiretroviral inhibitors with higher bioavailability,longer elimination half-life,more favorable side-effect profiles,fewer drug–drug interactions,and higher activities against circulating drug-resistant strains.
文摘Three plasmid expression vectors containing modified hepatitis B surface antigen (HBsAg) carrying pres epitopes were constructed. Transient expression after in vitro transfection in COS-M6 cells showed that under the transcriptional control of the human cytomegalovirus (CMV) immediate early promoter, fusion genes expressed the modified HBV envelope proteins which were efficiently secreted into culture medium and presented HBsAg, preS1 and preS2 antigenicity. DNA-based immunization with these plasmids carrying pres sequences induced anti-HBs antibody in BALB/c mice. The titers of anti-HBs antibody were higher than those appeared in mice immunized with plasmid carrying S gene only. DNA injection with plasmids containing preS1 sequences elicited also high titers of anti-preS1 antibody. Moreover, the antipreS1 antibodies were found to appear earlier than anti-HBs antibodies.
文摘The authors regret that the trade name“Acriptega”should be replaced by“Kocitaf”in this article,because the“Acriptega”represents the antiviral regimen of TDFþFTCþDTG,and the“Kocitaf”represents the TAFþFTCþDTG regimen.Although it does not affect the conclusion,it is an obvious error.The authors apologize for any inconvenience caused to the journal and readers.
