Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N ferti...Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 （control）, 100, 200, 300, or 350 kg N ha^-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates （300 and 350 kg N ha^-1） showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha^-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice.展开更多
分离新型鸭源微RNA病毒进行全基因组测序并进行遗传进化分析。对本实验室2021年不同来源的种鸭和肉鸭病料进行PCR检测,初步确定存在一种未知分类的新型微RNA病毒感染。取病死鸭病料组织处理后接种SPF鸡胚分离病毒,设计引物对分离到的病...分离新型鸭源微RNA病毒进行全基因组测序并进行遗传进化分析。对本实验室2021年不同来源的种鸭和肉鸭病料进行PCR检测,初步确定存在一种未知分类的新型微RNA病毒感染。取病死鸭病料组织处理后接种SPF鸡胚分离病毒,设计引物对分离到的病毒进行PCR检测,通过重叠PCR方法进行全基因组扩增测序。将分离病毒各蛋白氨基酸序列两两比对,同时选取GenBank数据库中微RNA病毒代表毒株序列绘制系统进化树,并对主要蛋白P1、2C、3D序列比对分析。结果显示:共分离到三株微RNA病毒,分别命名为21101株、21016株和21075株(GenBank登录号:OQ927377~OQ927379)。基因组长度分别为7445、7445和7447 bp,均包含一个编码2141个氨基酸的开放阅读框(ORF),可划分为P1、P2、P3三个部分,符合微RNA病毒序列特征。基于全基因组序列遗传进化分析发现,三株分离病毒与本实验室前期分离的Duck/FC22/China/2017(GenBank登录号:MN102111)毒株及上海兽医研究所分离的Duck/AH15/CHN/2015(GenBank登录号:MT681985)位于同一分支,与鸭甲型肝炎病毒(Duck hepatitis A virus,DHAV)遗传距离最近。分离的三株鸭源微RNA病毒进行全基因组测序及遗传进化分析发现,与目前已知的两株微RNA毒株为同一类新型鸭源微RNA病毒。展开更多
基金Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-413-3)National Natural Science Foundation of China (No.30390080)National Basic Research Program of China (No.2005CB121108)
文摘Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 （control）, 100, 200, 300, or 350 kg N ha^-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates （300 and 350 kg N ha^-1） showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha^-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice.
基金supported by the Natural Science Foundation of Hunan Province(2021JJ30399)the Key Project of Health Commission of Hunan Province(202104122479),China。
文摘目的:黑色素瘤具有高度恶性和异质性。开发特定的黑色素瘤预后预测模型对提高患者的生存率和选择治疗策略至关重要。最近,铁死亡已被证明是一种由过度脂质过氧化诱导的铁依赖性程序性细胞死亡形式。然而,铁死亡相关基因(ferroptosis-related genes,FRGs)与黑色素瘤预后的相关性仍不清晰。本研究评估FRGs在黑色素瘤中的作用,开发一种新的预后模型,旨在为黑色素瘤的个性化治疗及疗效改善提供新思路。方法:首先通过系统地表征癌症基因组图谱(The Cancer Genome Atlas,TCGA)-皮肤黑色素瘤(skin cutaneous melanoma,SKCM)中73个FRGs的遗传改变和mRNA表达。同时通过反转录聚合酶链反应和蛋白质印迹法验证筛选的特定靶基因。随后使用TCGASKCM队列构建多基因特征模型。根据特征模型将黑色素瘤患者分为高风险和低风险组,对铁死亡相关的特征模型与免疫特征、免疫治疗的疗效或药物反应进行相关分析。结果:通过分析TCGA-SKCM数据集中的黑色素瘤样本,发现FRGs在基因变异和拷贝数变异方面表现出高频率,这些变化显著影响了基因的表达。此外,与正常皮肤组织相比,在黑色素瘤组织中发现了30个显著差异表达的基因。随后使用LASSO Cox回归方法构建的FRGs相关预后模型成功识别了13个与患者总体生存预后相关的FRGs,并通过外部数据集验证了该模型的有效性。最后,功能富集和免疫响应结果分析进一步表明高风险和低风险组之间存在免疫细胞浸润、突变负担和低氧状态的显著差异,且该模型能有效预测免疫治疗响应和药物敏感性。结论:本研究建立了一种强预后预测模型,可为黑色素瘤患者的靶向治疗和免疫治疗提供新的方向。
文摘分离新型鸭源微RNA病毒进行全基因组测序并进行遗传进化分析。对本实验室2021年不同来源的种鸭和肉鸭病料进行PCR检测,初步确定存在一种未知分类的新型微RNA病毒感染。取病死鸭病料组织处理后接种SPF鸡胚分离病毒,设计引物对分离到的病毒进行PCR检测,通过重叠PCR方法进行全基因组扩增测序。将分离病毒各蛋白氨基酸序列两两比对,同时选取GenBank数据库中微RNA病毒代表毒株序列绘制系统进化树,并对主要蛋白P1、2C、3D序列比对分析。结果显示:共分离到三株微RNA病毒,分别命名为21101株、21016株和21075株(GenBank登录号:OQ927377~OQ927379)。基因组长度分别为7445、7445和7447 bp,均包含一个编码2141个氨基酸的开放阅读框(ORF),可划分为P1、P2、P3三个部分,符合微RNA病毒序列特征。基于全基因组序列遗传进化分析发现,三株分离病毒与本实验室前期分离的Duck/FC22/China/2017(GenBank登录号:MN102111)毒株及上海兽医研究所分离的Duck/AH15/CHN/2015(GenBank登录号:MT681985)位于同一分支,与鸭甲型肝炎病毒(Duck hepatitis A virus,DHAV)遗传距离最近。分离的三株鸭源微RNA病毒进行全基因组测序及遗传进化分析发现,与目前已知的两株微RNA毒株为同一类新型鸭源微RNA病毒。
