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聚酰胺—胺树枝状聚合物(PAMAM)作为一种新型超支化大分子聚合物,因其出色的化学和生物学特性,一直被众学者称之为“人工蛋白”。 PAMAM的特点是存在内部空腔,并含有大量的反应性末端基团,这些结构使得PAMAM可以被用作仿生大分子,模拟天然有机基质在牙体组织表面进行仿生矿化,即PAMAM作为有机模板调控矿物质成核以及晶体的生长,以此来建造比传统的异体材料更加理想的牙体修复材料。本文就 PAMAM 诱导牙体硬组织仿生矿化的研究进展作一综述。  相似文献   
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Hepatitis E virus (HEV) is the most common cause of acute liver failure (LF) and one of the most common factors causing acute injury in acute-on-chronic LF (ACLF). When HEV-related LF occurs, a series of changes take place in both the intrahepatic environment and extrahepatic microenvironment. The changed types and distribution of immune cells (infiltrating macrophages and increased lymphocytes) in liver tissue, as well the increased proinflammatory cytokines and chemokines in the blood, indicate that the occurrence and progression of HEV-related LF are closely related to immune imbalance. The clinical features and immune reaction in the body during HEV-related acute LF (ALF) and ACLF are complicated. This review highlights recent progress in elucidating the clinical manifestations of HEV-associated ALF and ACLF and discusses the corresponding systemic immune changes and possible regulatory mechanisms.  相似文献   
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Microglia, the innate immune cells of the CNS, perform critical inflammatory and noninflammatory functions that maintain normal neural function. For example, microglia clear misfolded proteins, elaborate trophic factors, and regulate and terminate toxic inflammation. In Alzheimer’s disease (AD), however, beneficial microglial functions become impaired, accelerating synaptic and neuronal loss. Better understanding of the molecular mechanisms that contribute to microglial dysfunction is an important objective for identifying potential strategies to delay progression to AD. The inflammatory cyclooxygenase/prostaglandin E2 (COX/PGE2) pathway has been implicated in preclinical AD development, both in human epidemiology studies and in transgenic rodent models of AD. Here, we evaluated murine models that recapitulate microglial responses to Aβ peptides and determined that microglia-specific deletion of the gene encoding the PGE2 receptor EP2 restores microglial chemotaxis and Aβ clearance, suppresses toxic inflammation, increases cytoprotective insulin-like growth factor 1 (IGF1) signaling, and prevents synaptic injury and memory deficits. Our findings indicate that EP2 signaling suppresses beneficial microglia functions that falter during AD development and suggest that inhibition of the COX/PGE2/EP2 immune pathway has potential as a strategy to restore healthy microglial function and prevent progression to AD.  相似文献   
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To examine the knowledge level, behaviors, and psychological status of the Chinese population during the COVID-19 pandemic, and to explore the differences between urban and rural areas.We carried out a cross-sectional survey of the knowledge, behaviors related to COVID-19, and mental health in a probability sample of 3001 community residents in 30 provinces or districts across China from February 16–23, 2020. Convenience sampling and a snowball sampling were adopted. We used General Anxiety Disorder (GAD), the 9-item Patient Health Questionnaire (PHQ-9), and knowledge and behaviors questionnaire of community residents regarding COVID-19 designed by us to investigate the psychological status, disease-related knowledge, and the behavior of Chinese urban and rural residents during the pandemic.The average score of anxiety and depression among urban residents was 9.15 and 11.25, respectively, while the figures in rural areas were 8.69 and 10.57, respectively. There was a statistically significant difference in the levels of anxiety (P < .01) and depression (P < .01). Urban participants reported significantly higher levels of knowledge regarding COVID-19 in all aspects (transmission, prevention measures, symptoms of infection, treatment, and prognosis) (P < .01), compared to their rural counterparts. While a majority of respondents in urban areas obtained knowledge through WeChat, other apps, and the Internet (P < .01), residents in rural areas accessed information through interactions with the community (P < .01). Urban residents fared well in exchanging knowledge about COVID-19 and advising others to take preventive measures (P < .01), but fared poorly in advising people to visit a hospital if they displayed symptoms of the disease, compared to rural residents (P < .01). Regression analysis with behavior showed that being female (OR = 2.106, 95%CI = 1.259–3.522), aged 18 ≤ age < 65 (OR = 4.059, 95%CI = 2.166–7.607), being satisfied with the precautions taken by the community (OR = 2.594, 95%CI = 1.485–4.530), disinfecting public facilities in the community (OR = 2.342, 95%CI = 1.206–4.547), having knowledge of transmission modes (OR = 3.987, 95%CI: 2.039, 7.798), symptoms (OR = 2.045, 95%CI = 1.054–4.003), and outcomes (OR = 2.740, 95%CI = 1.513–4.962) of COVID-19, and not having anxiety symptoms (OR = 2.578, 95%CI = 1.127–5.901) were positively associated with affirmative behavior in urban areas. Being married (OR = 4.960, 95%CI = 2.608–9.434), being satisfied with the precautions taken by the community (OR = 2.484, 95%CI = 1.315–4.691), screening to ensure face mask wearing before entering the community (OR = 8.809, 95%CI = 2.649–19.294), and having knowledge about precautions (OR = 4.886, 95%CI = 2.604–9.167) and outcomes (OR = 2.657, 95%CI = 1.309–5.391) were positively associated with acceptable conduct in rural areas.The status of anxiety and depression among urban residents was more severe compared to those living in rural areas. There was a difference in being positively associated with constructive behaviors between rural and urban areas.  相似文献   
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  目的  评估磁共振弥散加权成像(DWI)结合三维乳腺数字化断层摄影(DBT)钙化分数对于钙化征象在乳腺良恶性病变诊断的应用价值。  方法  回顾性分析我院118例行乳腺DWI检查和DBT检查的患者,DBT检查发现有钙化征象,其中乳腺癌患者51例,病理类型包括:浸润性导管癌、浸润性导管癌、导管原位癌、髓样癌、浸润性小叶癌、黏液腺癌;乳腺良性病变67例,病理类型包括:纤维腺瘤、腺病、导管内乳头状瘤。对所有患者DBT图像的钙化征象进行钙化评分并且测量相应病变区域的表观扩散系数(ADC)值,分析ADC值、钙化分数及二者联合在乳腺含钙化病变的诊断效能。  结果  乳腺癌组ADC值低于乳腺良性病变组,差异有统计学意义(P < 0.05);钙化分数高于良性病变组,差异有统计学意义(P < 0.05)。ADC值对诊断乳腺良恶性病变的曲线下面积(AUC)为0.853,钙化分数对诊断乳腺良恶性病变的AUC值为0.855,采用Delong检验得出两种方法对诊断乳腺含钙化病变的良恶性诊断效能一致,差异无统计学意义(P=0.625)。两种方法(钙化分数+ADC值)的Logistic回归分析显示,两种方法相结合的AUC值为0.903,具有很高的诊断效能。将ROC曲线(钙化分数、ADC值、两种方法结合的预测概率)经两两Delong检验结果显示,两种方法结合的ROC与单一ROC的差异有统计学意义(P=0.041、0.022)。  结论  DWI与DBT钙化分数对于钙化征象在乳腺良恶性病变的鉴别诊断效能无差别,两种方法相结合的诊断效能显著高于单一方法,为乳腺含钙化病灶的诊断与鉴别诊断中提供了更加可靠的依据。   相似文献   
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目的运用360度评价对我院住培学员的岗位胜任力进行评价,对学员岗位胜任力的现状进行探讨分析。方法使用问卷调查表分别从专业基地教学主任、学员指导教师、同专业学员及学员本人的角度,对2017级222名住培学员的岗位胜任力进行360度评价,利用SPSS22.0对数据进行统计分析。结果连续两年的测评,住院学员8类岗位胜任力的自评和他评得分低于满分,学员在临床基本能力、医患沟通能力、掌握与运用医学知识、团队合作能力4项内容的评分,差异有统计学意义(P<0.05);同时学员在临床基本能力、医生职业精神与素质、医患沟通能力、掌握与运用医学知识、团队合作能力5项内容的评分较上一年相比,差异也有统计学意义(P<0.05)。结论调查结果提示360度评价可帮助住培学员提高岗位胜任力,后续培训应围绕调查结果和以岗位胜任力为导向来调整与设置,需增加人文属性内容的培训以及再量化培训测评内容、指标和进一步完善考评反馈机制。  相似文献   
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