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991.
随着社会的发展,健康的概念已扩展为生理健康、心理健康以及良好的社会适应能力。同时随着生活节奏的加快,日益激烈的竞争,人们的心理压力也逐渐增加,更多的心理问题和身心疾病也相继出现。与健康关系密切的护理工作已经成为卫生保健行业中压力最大的职业之一。此文从护理的职业压力表现、压力源以及怎样去适应等方面进行了探讨,希望能让护士的职业压力受到社会的关注。 相似文献
992.
The non-uniform corrosion of steel bars is the main factor affecting the durability of concrete. The cracking pattern of concrete due to corrosion is closely related to the distribution of the corrosion products. Research on the thickness distribution of the rust layer and the cracking pattern of concrete under different influencing factors is of great significance in the prediction of the service life of existing reinforced concrete structures and the avoidance of the premature cracking of the reinforced concrete structures to be built. This paper studies the thickness distribution of the rust layer on the surface of single and multiple corroded reinforcements under non-uniform corrosion. The electrochemical analysis of the electrified corrosion process was carried out by using the finite element analysis software, and the distribution of the current density was obtained. The effects of geometric parameters, steel bar position, and steel bar spacing and shape on the corrosion expansion cracking pattern were studied. The results indicated that as the position of the steel bar differed, the crack pattern of the concrete changed, depending on the number of corrosion peaks (i.e., the maximum thickness of the rust layer). In terms of the corner-located steel, the number of corrosion peaks varied in the cases of different geometrical parameters (i.e., the diameter of the steel bar and the distance between the steel bars and the stainless steel wire). Nevertheless, the critical corrosion degrees of the side-located and corner-located steel bars, with respect to the cracking of the outer concrete surface, were basically the same. Additionally, the ribbed steel bar presented a lower critical corrosion degree than that of the plain steel bar, while little influence was exhibited with the varying angles of the rib. 相似文献
993.
Surface cracking is a major issue in amino resin-based flame-retardant coatings, which can be reduced by mixing flexible resins into the coatings. In this study, flexible waterborne polyurethane (WPU) was added into a melamine-modified, urea-formaldehyde, resin-based intumescent flame retardant (MUF-IFR) coating. A molecular chain of WPU was inserted into the MUF network and formed a WPU/MUF-semi-IPN structure. The cracking resistance of the coating was gradually enhanced with the increase in WPU content. When the WPU content exceeded 25% of the total resin, there were no cracks in the coatings after crack-resistance tests. The coatings before and after toughening showed good transparency on wood surfaces. The influence of WPU on char formation and flame retardant properties were explored by TGA, SEM, and cone calorimetry. The results showed that the decomposition of WPU occurred before char formation, which decreased the integrity of the coating and damaged the compactness of the char. Therefore, the addition of WPU reduced the expansion height and the barrier capacity of the char as well as the flame retardant properties of the coating. When the amount of WPU was 25% of the total resin, compared to the non-WPU coating, the average heat release rate in 300 s (AveHRR300s) and the total heat release at 300 s (THR300s) of the samples were increased by 45.8% and 35.7%, respectively. However, compared to the naked wood, the peak heat release rate (pHRR1), AveHRR300s, and THR300s of the samples with the coating containing 25% WPU were decreased by 64.2%, 39.0%, and 39.7%, respectively. Therefore, the thermal stability of WPU affected char formation. The amount of WPU added should be chosen to be the amount that was added just before the coating cracked. 相似文献
994.
Wuqiang He Feng Liu Liming Tan Zhihui Tian Zijun Qin Lan Huang Xiangyou Xiao Guowei Wang Pan Chen Baogang Liu 《Materials》2022,15(12)
Thermo-mechanical process of nickel-based oxide dispersion strengthened (ODS) superalloys is critical to produce desired components. In this study, an efficient method of consolidating powder is introduced to optimize the preparation process, microstructure and properties of nickel-based ODS superalloys. The influences of consolidation temperature, strain rate and ball milling time on the hardness of nickel-based superalloys were studied. The relationship among process, microstructure and hardness was established, the nanoparticles strengthening and grain boundary strengthening in nickel-based ODS superalloys were discussed. The results indicate that long ball milling time, moderately low consolidation temperature and high strain rates are beneficial to improving properties of nickel-based superalloys. Moreover, dispersion strengthening of nanoparticles and grain boundary strengthening play important roles in enhancing nickel-based ODS superalloys. 相似文献
995.
加味桃核承气汤含药血清对胰岛素诱导兔血管平滑肌细胞增殖的抑制作用 总被引:2,自引:0,他引:2
目的:探讨加味桃核承气汤含药血清对胰岛素诱导兔血管平滑肌细胞增殖的抑制作用。方法:采用兔主动脉平滑肌细胞株(SMC),以胰岛素(RI)诱导SMC增殖,制备桃核承气汤不同配伍组方含药血清,MTT法观察各组对RI诱导SMC增殖的抑制作用,以罗格列酮及美迪康作为对照组,探讨各组在糖尿病大血管病变发生与发展中可能的作用。结果:RI诱导SMC增殖试验确定RI终浓度为300mu/L;加味桃核承气汤含药血清对RI诱导SMC增殖的抑制作用试验显示,活血 泻热通下组、桃核承气汤组、罗格列酮组增殖抑制作用十分显著(P<0.01),以活血 泻热通下组抑制率最高(39.8%)。美迪康组、泻热通下组及益气养阴组增殖抑制作用不明显(P>0.05)。结论:加味桃核承气汤可能通过抑制RI诱导SMC增殖作用抗糖尿病动脉粥样硬化所致的大血管病变,本方抑制平滑肌细胞增殖的有效成份可能存在于活血 泻热通下组中。 相似文献
996.
在急性、亚急性创伤性深静脉血栓形成大鼠模型中,动态检测并比较分析血管内皮纤溶、凝血相关基因的表达变化和差异,探讨其在创伤性深静脉血栓形成中的作用和意义。分别取150只SD大鼠建立急性、亚急性血栓形成模型。急性血栓模型组采用直接钳夹股静脉 双后肢石膏固定、亚急性组采用定量击打双侧大腿 双后肢石膏固定的方式造模。根据深静脉血栓形成过程中不同的生物学状态,将实验动物分为正常对照、创伤即刻、血栓形成初始期、血栓形成高峰期、血栓消退、血栓不消退和血栓不形成7组。采用Genechip Rat Genome4302.0芯片,测定股静脉RNA表达情况,运用基因芯片数据分析方法(倍数变化分析)筛选出差异性表达基因。重点分析血管内皮纤溶、凝血相关基因在两种模型中的变化和差异。结果显示:内皮细胞抗凝和纤溶功能相关基因如ThbdN、os及Plat等基因的表达变化与创伤性深静脉血栓形成关系密切。内皮细胞抗凝和纤溶功能的减弱是创伤性深静脉血栓形成的重要因素之一。这一机制在血管直接受损的急性血栓模型中更显著。 相似文献
997.
MMP-2与TIMP-2在神经胶质瘤侵袭中的作用及其意义 总被引:3,自引:0,他引:3
目的分析MMP-2、TIMP-2的表达与神经胶质瘤恶性程度和侵袭性之间的关系。方法采用免疫组化S-P法,测定76例不同级别神经胶质瘤和10例正常脑组织中,MMP-2和TIMP-2蛋白表达。结果MMP-2蛋白表达水平与神经胶质瘤的恶性程度呈正相关系(P<0.01);在神经胶质瘤中MMP-2与TIMP-2蛋白表达水平之间呈明显的负相关系。结论MMP-2的表达与神经胶质瘤的恶性程度正相关系;MMP-2与TIMP-2之间的平衡失调与神经胶质瘤的恶性程度和侵袭性密切相关,两者之间协同作用在神经胶质瘤的侵袭中有重要的意义。 相似文献
998.
目的:探讨清炎颗粒治疗肾盂肾炎的作用机制。方法:采用孙建实方法改进造模,除空白组正常喂养外,治疗组给予清炎颗粒,模型组给予生理盐水,对照组给予至灵胶囊灌胃,分别喂养至3,7,15,30,60 d处死。取胸腺称重,计算胸腺指数,并取肾做病理分析。结果:清炎颗粒能提高不同时段小鼠的胸腺指数,并减轻相应时段的病理改变。结论:清炎颗粒通过提高小鼠的免疫功能来达到治疗肾盂肾炎的目的。 相似文献
999.
目的:探讨MMP-9、PCNA在鼻内翻性乳头状瘤(SNIP)发病及其复发和恶变中的作用。方法:选取40例SNIP及10例鼻腔鼻窦鳞状细胞癌(SCC)组织蜡块,全部标本分为4组,即良性SNIP组、复发SNIP组、恶变SNIP组及SCC组。利用免疫组织化学染色技术检测MMP-9、PCNA在各组中的表达情况。结果:MMP-9、PCNA在良性SNIP组、复发SNIP组、恶变SNIP组及SCC组中的表达逐渐增强,经秩和检验两两比较,显示MMP-9的表达在良性SNIP组与复发SNIP组,良性SNIP组与恶变SNIP组,良性SNIP组与SCC组之间均有显著性差异,复发SNIP组与恶变SNIP组,复发SNIP组与SCC组,恶变SNIP组与SCC组之间无明显差异;PCNA的表达在各组间差异无显著性。结论:MMP-9、PCNA的表达参与SNIP的发病,并在其复发和恶变中起重要作用,可能是SNIP复发和恶变的早期事件之一。 相似文献
1000.
Junwei Han Yang Yang Xiangmei Li Jiashuo Wu Yuqi Sheng Jiayue Qiu Qian Wang Ji Li Yalan He Liang Cheng Yan Zhang 《Molecular oncology》2022,16(11):2153
The processes of cancer initiation, progression, and response to therapy are affected by the sex of cancer patients. Immunotherapy responses largely depend on the tumor microenvironment (TME), but how sex may shape some TME features, remains unknown. Here, we analyzed immune infiltration signatures across 19 cancer types from 1771 male and 1137 female patients in The Cancer Genome Atlas to evaluate how sex may affect the tumor mutational burden (TMB), immune scores, stromal scores, tumor purity, immune cells, immune checkpoint genes, and functional pathways in the TME. Pan‐cancer analyses showed higher TMB and tumor purity scores, as well as lower immune and stromal scores in male patients as compared to female patients. Lung adenocarcinoma, lung squamous carcinoma, kidney papillary carcinoma, and head and neck squamous carcinoma showed the most significant sex biases in terms of infiltrating immune cells, immune checkpoint gene expression, and functional pathways. We further focused on lung adenocarcinoma samples in order to identify and validate sex‐specific immune cell biomarkers with prognostic potential. Overall, sex may affect the tumor microenvironment, and sex‐specific TME biomarkers may help tailor cancer immunotherapy in certain cancer types. 相似文献