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Samuel M Cohen 《Toxicological sciences》2004,80(2):225-229
An approach to the evaluation of carcinogenic risk resulting from exposure to a given chemical is presented in place of a reliance on two-year rodent bioassays. An emphasis is placed on evaluation of the potential DNA reactivity or increased cell proliferation that can be produced by a chemical. The special cases of immunosuppressive and estrogenic chemicals are considered. These evaluations are proposed to involve a combination of in vitro assays, computerized models, and short-term (up to 13 weeks) bioassays in rodents. The emphasis is on mechanistic understanding and evaluation of the dose response and relevance to humans. 相似文献
44.
目的:探讨护理风险预警机制在慢性乙型肝炎肝衰竭病人护理中的应用效果。方法:选取2018年1月—2019年12月我院收治的104例慢性乙型肝炎肝衰竭病人,按照病人入院顺序,并采用单双号抽签方式分为对照组和观察组,各52例。对照组给予常规护理干预,观察组临床护理中引入护理风险预警机制,对比两组肝功能指标、并发症发生情况、护理满意度、护理质量评分、护理缺陷评分及住院时间。结果:干预后,两组肝功能指标均有所改善,且观察组下降幅度较对照组大(P<0.001);观察组与对照组并发症发生率分别为7.69%、25.00%,观察组与对照组总满意度分别为96.15%、76.92%,观察组病人护理质量评分高于对照组,护理缺陷评分及住院时间低于对照组,差异均有统计学意义(P<0.05)。结论:将护理风险预警机制用于慢性乙型肝炎肝衰竭病人的临床护理中,有利于改善病人肝功能指标,减少并发症及护理缺陷,提高护理满意度,提升护理质量,缩短病人住院时间。 相似文献
45.
糖皮质激素性高眼压(GIOH)是一种由糖皮质激素引起的高眼压。长期处于GIOH状态,可能会导致视神经损害和视野缺损,最终发展成糖皮质激素性青光眼(GIG),可能致盲。糖皮质激素主要通过介导糖皮质激素受体(GR)发挥生物学作用,同时还涉及到转化生长因子(TGF)-β、Wnt、Rho等因素在GIOH的形成中的作用。深入探讨GIOH小梁网的病理改变及相关分子机制对于理解GIOH的发病机制和治疗提供了重要的理论依据。因此文章就GIOH小梁网的病理改变及相关分子机制进行综述,旨在为进一步研究GIOH的病理机制及治疗提供理论依据。 相似文献
46.
In this study, the autolytic clinker microsphere with clinker as core and polyvinyl pyrrolidone (PVP) as coating film was prepared. Pretreatment of clinker with silane coupling agent was firstly processed during the preparation. To investigate the autolytic mechanism, the microstructures of the autolytic clinker microsphere at different curing ages were observed using environmental scanning electron microscopy (ESEM), equipped with an energy dispersive spectrometer (EDS). The autolytic stages were also identified based on the microstructural evolution. The influence of pretreatment degree on autolytic behavior was also studied by measurements of micro-morphology and isothermal calorimetry. Experimental results indicated that the compressive strength recovery of specimens was increased by 15–19% due to the addition of autolytic clinker microspheres. The recovery of compressive strength was also improved with the increase of pH value. The improvements in compressive strength recovery of specimens with microspheres were in the range of 15–19%, 15–31%, 25–36%, and 29–50% with the pH value of 7, 8, 10, and 12, respectively. It was also found that inner damage of cement-based matrix had greater recovery when pre-cracked specimens were cured in alkaline environments. 相似文献
47.
Yu Gao Long Dong Liang Huang Zhong Huang Faliang Li Haijun Zhang Shaowei Zhang 《Materials》2022,15(10)
Magnesia-based refractory is widely used in high-temperature industries; its easy hydration is, however, a key concern in refractory processing. Understanding the hydration mechanism of MgO will help in solving its hydration problem. Herein, the hydration behavior of (MgO)n (n = 1–6) at the molecular level and the effect mechanisms of several anti-hydration agents on the hydration of (MgO)4 were investigated with first-principles calculations. The results indicated that the following: (1) The smaller the (MgO)n cluster size, the more favorable the hydration of MgO and the tendency to convert into Mg(OH)2 crystal; (2) Anti-hydration agents can coordinate with the unsaturated Mg atom of (MgO)4 to form a bond, increasing the coordination number of Mg, thus reducing its activity when reacting with H2O; (3) The greater the number of −COOH groups and the longer the chain length in the anti-hydration agents, the better its effect of inhibiting the hydration of MgO. These findings could enhance the understanding of the mechanism of hydration of MgO and provide theoretical guidance for the design of novel anti-hydration agents. 相似文献
48.
寡转移性非小细胞肺癌( NSCLC)不同于广泛转移的晚期 NSCLC,针对寡转移灶局部治疗可获得潜在治愈的可能。立体定向放射治疗( SBRT)作为有效的局部治疗手段,联合化疗、络氨酸激酶抑制剂( TKIs)、免疫检查点抑制剂( ICIs)、抗血管生成等可以为晚期 NSCLC病人带来生存获益。该文回顾了 SBRT在寡转移性 NSCLC的研究,从 SBRT对寡转移性 NSCLC的治疗效果、 SBRT联合 TKIs和 SBRT联合 ICIs的临床研究进展展开综述。 相似文献
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Seung-Jin Park Yea Eun Kang Jeong-Hwan Kim Jong-Lyul Park Seon-Kyu Kim Seung-Woo Baek In Sun Chu Shinae Yi Seong Eun Lee Young Joo Park Eun-Jae Chung Jin Man Kim Hye Mi Ko Je-Ryong Kim Seung-Nam Jung Ho-Ryun Won Jae Won Chang Bon Seok Koo Seon-Young Kim 《Clinical and experimental otorhinolaryngology》2022,15(2):183