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81.
利用3-异氰基丙基三乙氧基硅烷(ICPTES)与联萘二酚合成联萘酚单硅酯,首次在酸性条件下利用联萘酚单硅酯与1,2-三乙氧基硅基乙烷(BTSE)作为共同硅源,以阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和聚环氧乙烷-聚环氧丙烷-聚环氧乙烷三嵌段共聚物P123为共模板剂,合成出粒径3~5 μm,平均孔径约5 nm的新型联萘酚杂化介孔硅胶。应用于联萘类衍生物的分离研究,结果显示该固定相机械强度较好,在15 min内对5种联萘类衍生物能够达到基线分离,并且对联萘类衍生物的分离性能优于商品化硅胶柱。 相似文献
82.
不同致癌能力镍化合物的致突变效应 总被引:3,自引:0,他引:3
张桥 《中华劳动卫生职业病杂志》1989,7(5):296-299
Ni_3S_2,NiSA,NiSC,NiSO_4与NiCl_2等五种镍合物是具有不同致癌能力的化合物。在V_(79)细胞株基因突变试验系统中,这五类化合物能诱发HGPGT 与Na/k ATP ase 酶位点突变,其强弱程度与在动物致癌试验结果所见是一致的。提示这些镍化合物可能是通过致突变机制作用的致癌物。亦可以利用基因突变试验来预测其致癌性。这五种镍化合物可在V_(79)细胞株和SHE 细胞诱发SCE 与微核形成,但其作用强弱与其致癌能力不相一致。表明利用这类试验预测镍化合物的致癌性是不适宜的。 相似文献
83.
Beata Olas 《Nutrients》2022,14(11)
Apitherapy is a form of alternative therapy that relies on the use of bee products, i.e., honey, royal jelly, propolis, pollen, and bee venom (known as apitoxin), for the prevention and treatment of various diseases. Various in vitro and in vivo studies suggest that these products may be effective in the prophylaxis and treatment of cardiovascular diseases (CVDs). This mini-review of papers identified in various electronic databases describes new aspects of the bioactivity of certain bee products, viz. bee pollen, royal jelly, bee venom, propolis, and bee bread, as natural interesting products for the prevention and treatment of common CVDs. 相似文献
84.
85.
Toxicity of Organotin Compounds to Activated Sludge 总被引:3,自引:0,他引:3
Athanasios S. Stasinakis Nikolaos S. Thomaidis Themistokles D. Lekkas 《Ecotoxicology and environmental safety》2001,49(3):275-280
Inhibition of respiration rate of activated sludge heterotrophic microorganisms was determined for tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), and triphenyltin (TPhT). TBT, DBT, and TPhT exhibit similar acute toxicity to activated sludge, while MBT is less toxic. The effect of various experimental parameters, such as sludge age, concentrations of suspended solids, and exposure time, on toxicity was investigated. An increase in sludge age or in the concentration of suspended solids reduces the observed inibition. Longer exposure seems to increase the inhibition of TBT, DBT, and TPhT during the first hours of exposure, while later the inhibition remains constant. In the case of MBT, 24 h after exposure, the respiration rate was similar to that of the control biomass. 相似文献
86.
胃癌危险性不同人群膳食硝酸盐、亚硝酸盐及维生素C摄入量 总被引:5,自引:0,他引:5
本文研究福建省长乐县胃癌危险性不同的人群膳食硝酸盐(NO_3~-)、亚硝酸盐(NO_2~-)及维生素C摄入量。胃癌死亡率较高的漳港乡居民NO_3~-摄入量(132.75mg/日)明显高于死亡率居中的首占乡(84.65mg/日)(P<0.05),但与死亡率较低的梅花乡(113.12mg/日)无显著性差异。NO_2~-摄入量漳港乡显著高于首占乡和梅花乡(3.36mg/日对0.21和0.73mg/日)(P<0.01)。首占乡居民维生素C摄入量(56.13mg/日)明显低于漳港乡(123.09mg/日)和梅花乡(105.90mg/日)(P<0.01)。维生素C摄入量与NO_2~-摄入量的摩尔比值三个乡分别为3.22、3.30和4.33,与胃癌死亡率呈相反平行关系。结果提示:NO_3~-和NO_2~-可能是该地区胃癌高发的因素之一。 相似文献
87.
Several ancient apple varieties and a wild apple variety grown in Croatia were analysed for the polyphenol content and compared to two varieties grown in USA. In the flesh, flavanols, dihydrochalcones and phenolic acids (24 to 137, 23 to 109, 3 to 238 mg kg−1 of fresh weight (FW), respectively) were found. Peel contained flavanols, dihydrochalcones, phenolic acids, flavonols and anthocyanins (65 to 690, 21 to 141, 0 to 107, 205 to 1223, 0 to 213 mg kg−1 FW, respectively). The wild apple was characterized by much higher flavanol and phenolic acid content in the flesh (301 and 734 mg kg−1 FW, respectively) while the peel was similar to other apples. The polyphenol profile was similar to apples from USA. The varieties Zimnjara, Lještarka and Adamova zvijezda could be highlighted as sources of polyphenols. Varieties are categorized by the content of dihydrochalcones and flavanols in the flesh (whether that content is high or low), and by the relative portion of phenolic acids and flavanols in the flesh (high phenolic acid proportion, lower flavanol proportion and vice versa). There was not observed to be as strong a pattern for categorizing differences in the peel. 相似文献
88.
Solder/Cu joints are important components responsible for interconnection in microelectronics. Construction of the solder/Cu joints through liquid/solid (L/S) reactions accompanies the formation of the Cu–Sn intermetallic compounds (IMCs) at the joint interface. The Cu6Sn5 IMC exhibits remarkable distinctions in thickness and morphology upon increasing the L/S reaction time. Effects of the initial characteristics of thickness and morphology on the growth kinetics of Cu6Sn5 during subsequent isothermal aging were investigated. SAC305 solder was reflowed on a Cu electroplated layer at 265 °C for 1 to 60 min to produce the Cu6Sn5 IMC with different thickness and morphology at the SAC305/Cu interface. The as-fabricated SAC305/Cu joint samples were aged at 200 °C for 72 to 360 h to investigate the growth kinetics of Cu6Sn5. The results show that the initial characteristics of thickness and morphology significantly influenced the growth kinetics of Cu6Sn5 during the subsequent solid/solid (S/S) reaction. A prolonged L/S reaction time of 60 min (L/S-60) produced a scallop-type Cu6Sn5 IMC with a larger grain size and a thicker thickness, which reduced the quantity of fast diffusion path (grain boundary) and the magnitude of concentration gradient, thus slowing down the growth rate of Cu6Sn5. According to the growth kinetics analysis, the growth rate constant of Cu6Sn5 could be remarkably reduced to 0.151 µm/h0.5 for the L/S-60 sample, representing a significant reduction of 70 % compared to that of the L/S-1 sample (0.508 µm/h0.5 for L/S reaction time of 1 min). 相似文献
89.
磺脲类降糖药继发性失效2型糖尿病患者血清瘦素水平的变化 总被引:2,自引:1,他引:2
目的 观察磺脲类(SU)降糖药继发性失效2型糖尿病(T2DM)患者血清瘦素水平,探讨瘦素水平与其他代谢指标的相关性.方法 选择60例磺脲类降糖药继发性失效T2DM患者(SFS组)、30例血糖控制良好的T2DM患者(WCP组)和20例健康志愿者(NC组).采用酶联免疫吸附法(ELISA法)检测3组受检者的瘦素水平,同时检测生化指标、胰岛素水平等,并进行相关性分析.结果 WCP组患者血清瘦素水平[(10.2±3.6)ng/ml]与NC组[(6.6±2.3)ng/ml]比较,SFS组患者血清瘦素水平[(14.8±3.9)ng/ml]与WCP组比较,差异均有统计学意义(P<0.05);WCP组及SFS组患者的空腹胰岛素水平[分别为(16.5±7.2)μU/L和(17.5±7.5)μU/L]、胰岛素抵抗指数(HOMA-IR)[分别为(4.1±2.9)和(4.3±2.9)]与NC组[分别为(13.9±6.8)μU/L和(2.7±1.6)]比较,差异均有统计学意义(P<0.05).相关性分析显示,SFS组患者血清瘦素水平与空腹血糖、餐后2 h血糖、糖化血红蛋白、体质指数、空腹胰岛素、HOMA-IR、三酰甘油及低密度脂蛋白胆固醇水平呈正相关(P<0.05),与高密度脂蛋白胆固醇水平呈负相关(P<0.05).结论 瘦素和胰岛素抵抗相互作用,可能在磺脲类降糖药继发性失效发病中起重要作用. 相似文献
90.
目的:观察天参益智方(TSYZ)对慢性铝中毒痴呆模型大鼠的空间探索学习记忆功能的改善作用,并对该中药复方进行最大给药量急性毒性实验研究。方法:以慢性铝中毒法复制痴呆动物模型,随机将动物模型分为5组,即模型组,天参益智方高、中、低剂量组,阳性对照组,另设正常对照组,用水迷宫法对其空间探索学习记忆能力进行检测。结果:慢性铝中毒痴呆模型组大鼠在安全岛象限的搜索时间及搜索距离显著延长,天参益智方高剂量组的搜索时间及搜索距离显著低于模型组。结论:天参益智方对慢性铝中毒痴呆大鼠的学习记忆能力有明显的改善作用,且无明显毒性。 相似文献