Instead of running away, she stood to attention with arms akimbo and gave a serious smile. The giant wooden basket on her back almost made her fall as she tried to straighten her body. When I raised the camera, Yang J...Instead of running away, she stood to attention with arms akimbo and gave a serious smile. The giant wooden basket on her back almost made her fall as she tried to straighten her body. When I raised the camera, Yang Jiaxiu was walking along a narrow, muddy mountain path in a virgin fir forest, carrying about 50 kilograms of water. She twisted her body to pour the water into a large tank when she finally arrived at her house. Then the Miao woman put down the展开更多
三水醋酸钠(CH3COONa·3H2O)经过添加增稠剂和成核剂后具有广阔的应用前景,而其热物性参数影响着蓄热器的设计计算。T-history曲线法(Temperature History Method)简单实用,方便快捷。经水浴实验后,求得混合材料的固态导热系数为0.7...三水醋酸钠(CH3COONa·3H2O)经过添加增稠剂和成核剂后具有广阔的应用前景,而其热物性参数影响着蓄热器的设计计算。T-history曲线法(Temperature History Method)简单实用,方便快捷。经水浴实验后,求得混合材料的固态导热系数为0.77 W/(m·℃),液态导热系数为1.12 W/(m·℃),相变潜热为247.6 k J/kg,与利用差示扫描量热法(Differential Scanning Calorimetry)测得混合材料在循环过程中的相变潜热值误差维持在7.2%内,能够满足实际使用要求。展开更多
BACKGROUND Chronic hepatitis B is a highly heterogeneous disease that can be divided into four phases: Immune tolerant(IT), immune active(IA), inactive carrier(IC) and hepatitis B envelope antigen(HBeAg)-negative hepa...BACKGROUND Chronic hepatitis B is a highly heterogeneous disease that can be divided into four phases: Immune tolerant(IT), immune active(IA), inactive carrier(IC) and hepatitis B envelope antigen(HBeAg)-negative hepatitis(ENEG).AIM To investigate the immune status of natural killer(NK) and T cells in different phases of chronic hepatitis B.METHODS The frequency, phenotype and function of circulating NK cells, as well as nonantigen-specific and hepatitis B virus(HBV)-specific T cell responses were detected by flow cytometry in healthy and HBV-infected subjects.RESULTS The ability of NK cells to produce IFN-γ was markedly attenuated in HBVinfected patients overall but was less compromised in IC patients. Patients in the IT and IA phases also displayed significantly lower TNF-α production compared to healthy subjects. NK cells were phenotypically activated in the IA and ENEGphases, as evidenced by the upregulation of NKp44 in CD56^(bright) NK cells and CD69 in CD56^(dim) NK cells. Furthermore, global T-cells from the ENEG phase displayed a proinflammatory cytokine profile with upregulated IFN-γ and TNF-αexpression, while this profile was suppressed in IT and IA patients. Finally, core and S antigen-specific T cell responses were significantly stronger after in vitro expansion in the IC phase compared to other phases.CONCLUSION Our findings demonstrate the changes in immune response pattern during the natural history of HBV infection. Both NK and T cells are functionally impaired in the IT and IA phases. With the spontaneous clearance of HBeAg and hepatitis B surface antigen decline, NK cell cytokine production and HBV-specific T responses are partially restored in IC phase, and the ENEG phase is dominated by nonantigen-specific T cell responses.展开更多
Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populati...Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter(“miasmata”). Notable Roman and medieval scholars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century microbiology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious historical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid-20th century work of Wells, Riley and Mills who proved how expiratory aerosols(their “droplet nuclei”)could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th century “Great Acceleration” of an increasingly hypermobile human population repeatedly infected by different strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chemistry are accelerating human awareness of current environmental challenges. As such, the “anthropause”lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be preserved in the Anthropocene stratal record.展开更多
Background: Gastric cancer is the third most incident malignancy and the fifth leading cause of death in the world. In Brazil, it is the fourth most common tumour in men and the fifth in women. Familial aggregation of...Background: Gastric cancer is the third most incident malignancy and the fifth leading cause of death in the world. In Brazil, it is the fourth most common tumour in men and the fifth in women. Familial aggregation of this tumour is being studied and discussed by experts. Aim: Determine the frequency of family history of cancer in patients with gastric cancer, suggesting familial aggregation or increased risk for hereditary cancer syndromes. Methods: This is a retrospective cross-sectional study carried out from January 2011 to March 2015 at the Department of Abdominal and Pelvic Surgery of the Brazilian National Cancer Institute (INCA). Data were collected from electronic medical records and analyzed using SPSS Statistics? version 20. Results: 873 patients with gastric adenocarcinoma were analyzed. A family history of cancer was reported by 451 patients (51.6%), which reported cancer in 878 relatives, of which 110 (12.6%), reported having more than three relatives with any type of cancer. The most prevalent malignancies among these relatives were gastric cancer (21.3%) and breast cancer (9.5%). Conclusion: Most of the patients had cancer family history, being gastric cancer the most common. The high percentage of cancer family history confirms the importance of collecting this information, whose lack reflects professional negligence, as family history study can serve as a low-cost tool, favoring prevention and early diagnosis, situations where morbidity and mortality are smaller, thus reducing health costs and assistance and preserving lives.展开更多
T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防...T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防伪加密要求偏低,对于不确定度的覆盖不全面,对新技术的支持略有不足,这些需要在今后的实践中加以修正,以便更好地服务于计量行业的发展。展开更多
Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be...Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.展开更多
文摘Instead of running away, she stood to attention with arms akimbo and gave a serious smile. The giant wooden basket on her back almost made her fall as she tried to straighten her body. When I raised the camera, Yang Jiaxiu was walking along a narrow, muddy mountain path in a virgin fir forest, carrying about 50 kilograms of water. She twisted her body to pour the water into a large tank when she finally arrived at her house. Then the Miao woman put down the
文摘三水醋酸钠(CH3COONa·3H2O)经过添加增稠剂和成核剂后具有广阔的应用前景,而其热物性参数影响着蓄热器的设计计算。T-history曲线法(Temperature History Method)简单实用,方便快捷。经水浴实验后,求得混合材料的固态导热系数为0.77 W/(m·℃),液态导热系数为1.12 W/(m·℃),相变潜热为247.6 k J/kg,与利用差示扫描量热法(Differential Scanning Calorimetry)测得混合材料在循环过程中的相变潜热值误差维持在7.2%内,能够满足实际使用要求。
基金Supported by National Science Fund of China(NSFC)No.30771911National Science and Technology Major Project No.2012ZX10002007-003
文摘BACKGROUND Chronic hepatitis B is a highly heterogeneous disease that can be divided into four phases: Immune tolerant(IT), immune active(IA), inactive carrier(IC) and hepatitis B envelope antigen(HBeAg)-negative hepatitis(ENEG).AIM To investigate the immune status of natural killer(NK) and T cells in different phases of chronic hepatitis B.METHODS The frequency, phenotype and function of circulating NK cells, as well as nonantigen-specific and hepatitis B virus(HBV)-specific T cell responses were detected by flow cytometry in healthy and HBV-infected subjects.RESULTS The ability of NK cells to produce IFN-γ was markedly attenuated in HBVinfected patients overall but was less compromised in IC patients. Patients in the IT and IA phases also displayed significantly lower TNF-α production compared to healthy subjects. NK cells were phenotypically activated in the IA and ENEGphases, as evidenced by the upregulation of NKp44 in CD56^(bright) NK cells and CD69 in CD56^(dim) NK cells. Furthermore, global T-cells from the ENEG phase displayed a proinflammatory cytokine profile with upregulated IFN-γ and TNF-αexpression, while this profile was suppressed in IT and IA patients. Finally, core and S antigen-specific T cell responses were significantly stronger after in vitro expansion in the IC phase compared to other phases.CONCLUSION Our findings demonstrate the changes in immune response pattern during the natural history of HBV infection. Both NK and T cells are functionally impaired in the IT and IA phases. With the spontaneous clearance of HBeAg and hepatitis B surface antigen decline, NK cell cytokine production and HBV-specific T responses are partially restored in IC phase, and the ENEG phase is dominated by nonantigen-specific T cell responses.
基金supported by the Spanish Research Council (CSIC, Project COVID19 CSIC 202030E226)the Generalitat de Catalunya (SGR41)。
文摘Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter(“miasmata”). Notable Roman and medieval scholars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century microbiology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious historical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid-20th century work of Wells, Riley and Mills who proved how expiratory aerosols(their “droplet nuclei”)could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th century “Great Acceleration” of an increasingly hypermobile human population repeatedly infected by different strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chemistry are accelerating human awareness of current environmental challenges. As such, the “anthropause”lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be preserved in the Anthropocene stratal record.
文摘Background: Gastric cancer is the third most incident malignancy and the fifth leading cause of death in the world. In Brazil, it is the fourth most common tumour in men and the fifth in women. Familial aggregation of this tumour is being studied and discussed by experts. Aim: Determine the frequency of family history of cancer in patients with gastric cancer, suggesting familial aggregation or increased risk for hereditary cancer syndromes. Methods: This is a retrospective cross-sectional study carried out from January 2011 to March 2015 at the Department of Abdominal and Pelvic Surgery of the Brazilian National Cancer Institute (INCA). Data were collected from electronic medical records and analyzed using SPSS Statistics? version 20. Results: 873 patients with gastric adenocarcinoma were analyzed. A family history of cancer was reported by 451 patients (51.6%), which reported cancer in 878 relatives, of which 110 (12.6%), reported having more than three relatives with any type of cancer. The most prevalent malignancies among these relatives were gastric cancer (21.3%) and breast cancer (9.5%). Conclusion: Most of the patients had cancer family history, being gastric cancer the most common. The high percentage of cancer family history confirms the importance of collecting this information, whose lack reflects professional negligence, as family history study can serve as a low-cost tool, favoring prevention and early diagnosis, situations where morbidity and mortality are smaller, thus reducing health costs and assistance and preserving lives.
文摘T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防伪加密要求偏低,对于不确定度的覆盖不全面,对新技术的支持略有不足,这些需要在今后的实践中加以修正,以便更好地服务于计量行业的发展。
基金financially supported by the Fourth Term of"333 Engineering"Program of Jiangsu Province(Grant No.BRA2011116)Youth Foundation of Jiangsu Province(Grant No.BK2012095)Special Program for Hadal Science and Technology of Shanghai Ocean University(Grant No.HAST-T-2013-01)
文摘Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.
