细菌在翻译过程中,mRNA受到损伤(如缺失终止密码子)时会使翻译提前终止,导致核糖体熄火,细菌自身会启动核糖体拯救途径。由tmRNA-SmpB介导的反式翻译系统是结核分枝杆菌中的核糖体拯救途径,对结核分枝杆菌的生长繁殖有重大影响。为探究...细菌在翻译过程中,mRNA受到损伤(如缺失终止密码子)时会使翻译提前终止,导致核糖体熄火,细菌自身会启动核糖体拯救途径。由tmRNA-SmpB介导的反式翻译系统是结核分枝杆菌中的核糖体拯救途径,对结核分枝杆菌的生长繁殖有重大影响。为探究分枝杆菌中反式翻译途径的启动及其功能特点,本研究选取耻垢分枝杆菌为实验菌株,分别以mCherry和egfp作为报告基因,通过在报告基因3′端添加大肠埃希菌终止子序列,构建能在菌体中反映反式翻译表达的报告体系,并初步探究该体系中报告基因的动态表达特点。结果显示,相比正常表达mCherry的对照菌株,实验菌株中表达的错误mCherry蛋白很快被水解,菌体颜色均明显浅于前者,增强绿色荧光蛋白(enhanced green fluorescent protein,EGFP)定量检测数据也显示错误EGFP水平显著低于正常表达的EGFP水平,表明两种反式翻译报告体系均构建成功。报告基因的动态表达数据显示,蛋白出现翻译异常时,耻垢分枝杆菌可在蛋白翻译过程中快速启动反式翻译途径,并于40～45h将不成熟错误蛋白完全水解。本研究构建的反式翻译报告体系可为后续开展分枝杆菌反式翻译途径的功能研究及抗结核药物筛选提供帮助。展开更多
The current ulcerative colitis （UC） treatment algorithm involves a step-up therapeutic strategy, mainly aiming at inducing and maintaining its clinical remission. Although this therapeutic strategy may seem to be co...The current ulcerative colitis （UC） treatment algorithm involves a step-up therapeutic strategy, mainly aiming at inducing and maintaining its clinical remission. Although this therapeutic strategy may seem to be cost-efficient and reduce the risk of side effects, recent trials and case reports have shown that top-down therapy using infliximab induces a rapid clinical response, enhances patient quality of life, promotes mucosal healing, reduces surgeries and indirect cost of treatment for patients with severe UC. Moreover, since long-term treatment with infliximab is safe and well tolerated, early aggressive top-down therapeutic strategy may be a more effective approach, at least in a subgroup of severe extensive UC patients.展开更多
How do auditors react to insider trading in client firms？ This paper examines the effects of insider trading on the audit report date. Insiders tend to urge managers to manage earnings to make more profits through tr...How do auditors react to insider trading in client firms？ This paper examines the effects of insider trading on the audit report date. Insiders tend to urge managers to manage earnings to make more profits through trading their own firm＇s shares. If auditors play an important role in monitoring managers, they may pay more attention to insider trading, which may delay the filing of audit reports. We find that the more the insiders trade their stocks, the longer the audit report lag is. In addition, to address the effectiveness of auditors＇ efforts to prevent managers from earnings management, we test whether an extra effort by auditors can reduce aggressive accounting. We also find that auditors deter aggressive accounting by stretching report lag in response to insider trading, implying that auditors＇ efforts weaken insiders＇ opportunistic behavior. This study contributes to the literature by providing evidence that insider trading is a significant determinant of the audit report lag. We suggest that auditors are interested in insiders＇ activity and it can enhance the quality of accounting information.展开更多
Virus-induced gene silencing is regarded as a powerful and efficient tool for the analysis of gene function in plants because it is simple, rapid and transformation-free. It has been used to perform both forward and r...Virus-induced gene silencing is regarded as a powerful and efficient tool for the analysis of gene function in plants because it is simple, rapid and transformation-free. It has been used to perform both forward and reverse genetics to identify plant functional genes. Many viruses have been developed into virus-induced gene silencing vectors and gene functions involved in development, biotic and abiotic stresses, metabolism, and cellular signaling have been reported. In this review, we discuss the development and application of virus-induced gene silencing in plant functional genomics.展开更多
Antivenom is the most effective method currently available for the treatment of poisonous snake bite. Allergic reactions to antivenom have been reported in the past. Here we shared a case of allergic re- actions to an...Antivenom is the most effective method currently available for the treatment of poisonous snake bite. Allergic reactions to antivenom have been reported in the past. Here we shared a case of allergic re- actions to antivenom in an old male patient who was bitten twice by the same snake （probably same one） at the same biting site within a month whereas the patient did not show any allergic disorder in the first bitten. Envenomations twice in a short period time by the same kind of snake are very rare. Physician should be alert to the occurrence of allergic reactions in treating this type of patients with antivenom. The skin allergy test has a certain value in predicting the allergic response before the second use of antivenom. Desensitization may reduce the incidence of allergic reactions, but this is insufficient. Rather than non-lgE-mediated immediate hypersensitivity, patients receiving the second treatment of antivenom may develop IgE-mediated immediate hypersensitivity. Once happened, the antivenom treatment should be stopped promptly and anti-allergy treatment should be given immediately.展开更多
文摘细菌在翻译过程中,mRNA受到损伤(如缺失终止密码子)时会使翻译提前终止,导致核糖体熄火,细菌自身会启动核糖体拯救途径。由tmRNA-SmpB介导的反式翻译系统是结核分枝杆菌中的核糖体拯救途径,对结核分枝杆菌的生长繁殖有重大影响。为探究分枝杆菌中反式翻译途径的启动及其功能特点,本研究选取耻垢分枝杆菌为实验菌株,分别以mCherry和egfp作为报告基因,通过在报告基因3′端添加大肠埃希菌终止子序列,构建能在菌体中反映反式翻译表达的报告体系,并初步探究该体系中报告基因的动态表达特点。结果显示,相比正常表达mCherry的对照菌株,实验菌株中表达的错误mCherry蛋白很快被水解,菌体颜色均明显浅于前者,增强绿色荧光蛋白(enhanced green fluorescent protein,EGFP)定量检测数据也显示错误EGFP水平显著低于正常表达的EGFP水平,表明两种反式翻译报告体系均构建成功。报告基因的动态表达数据显示,蛋白出现翻译异常时,耻垢分枝杆菌可在蛋白翻译过程中快速启动反式翻译途径,并于40～45h将不成熟错误蛋白完全水解。本研究构建的反式翻译报告体系可为后续开展分枝杆菌反式翻译途径的功能研究及抗结核药物筛选提供帮助。
文摘The current ulcerative colitis （UC） treatment algorithm involves a step-up therapeutic strategy, mainly aiming at inducing and maintaining its clinical remission. Although this therapeutic strategy may seem to be cost-efficient and reduce the risk of side effects, recent trials and case reports have shown that top-down therapy using infliximab induces a rapid clinical response, enhances patient quality of life, promotes mucosal healing, reduces surgeries and indirect cost of treatment for patients with severe UC. Moreover, since long-term treatment with infliximab is safe and well tolerated, early aggressive top-down therapeutic strategy may be a more effective approach, at least in a subgroup of severe extensive UC patients.
文摘How do auditors react to insider trading in client firms？ This paper examines the effects of insider trading on the audit report date. Insiders tend to urge managers to manage earnings to make more profits through trading their own firm＇s shares. If auditors play an important role in monitoring managers, they may pay more attention to insider trading, which may delay the filing of audit reports. We find that the more the insiders trade their stocks, the longer the audit report lag is. In addition, to address the effectiveness of auditors＇ efforts to prevent managers from earnings management, we test whether an extra effort by auditors can reduce aggressive accounting. We also find that auditors deter aggressive accounting by stretching report lag in response to insider trading, implying that auditors＇ efforts weaken insiders＇ opportunistic behavior. This study contributes to the literature by providing evidence that insider trading is a significant determinant of the audit report lag. We suggest that auditors are interested in insiders＇ activity and it can enhance the quality of accounting information.
基金supported by the National Transgenic Research Projects of China (Grant No. 2009ZX08009-026B)
文摘Virus-induced gene silencing is regarded as a powerful and efficient tool for the analysis of gene function in plants because it is simple, rapid and transformation-free. It has been used to perform both forward and reverse genetics to identify plant functional genes. Many viruses have been developed into virus-induced gene silencing vectors and gene functions involved in development, biotic and abiotic stresses, metabolism, and cellular signaling have been reported. In this review, we discuss the development and application of virus-induced gene silencing in plant functional genomics.
文摘Antivenom is the most effective method currently available for the treatment of poisonous snake bite. Allergic reactions to antivenom have been reported in the past. Here we shared a case of allergic re- actions to antivenom in an old male patient who was bitten twice by the same snake （probably same one） at the same biting site within a month whereas the patient did not show any allergic disorder in the first bitten. Envenomations twice in a short period time by the same kind of snake are very rare. Physician should be alert to the occurrence of allergic reactions in treating this type of patients with antivenom. The skin allergy test has a certain value in predicting the allergic response before the second use of antivenom. Desensitization may reduce the incidence of allergic reactions, but this is insufficient. Rather than non-lgE-mediated immediate hypersensitivity, patients receiving the second treatment of antivenom may develop IgE-mediated immediate hypersensitivity. Once happened, the antivenom treatment should be stopped promptly and anti-allergy treatment should be given immediately.
