Acute toxicity of 30 pharmaceutically active compounds to freshwater planarians,Dugesia japonica

Pharmaceutically active compounds are produced worldwide and consumed in large quantities, so these chemicals are frequently detected in limnic environments posing potential ecological risks. Thirty pharmaceutically active compounds were selected for examination of their acute toxicity for freshwater planarians (Dugesia japonica). Among the 30 compounds tested, diclofenac, mefenamic acid, naproxen, propranolol HCl, and diphenhydramine HCl had a 48-h nominal LC₅₀ below10 mg L^?1, and for 18 chemicals, it exceeded 100 mg L^?1. The 96-h nominal LC₅₀ was below 10 mg L^?1 for diclofenac, mefenamic acid, naproxen, propranolol HCl, diltiazem HCl, diphenhydramine HCl, hydroxyzine HCl, and triprolidine HCl, and for 15 chemicals, it exceeded 100 mg L^?1. Among different therapeutic groups, analgesics were most toxic to planarians, and antibiotics were least toxic. Antihistamines and beta blockers varied in their acute toxicity to planarians. At the current environmental levels, none of the tested pharmaceutically active compounds may have acutely harmful impacts on aquatic invertebrates. To answer the question whether chronic, long-term exposure to pharmaceutically active compounds may entail ecological risks for aquatic ecosystems, further investigations with different end points in multiple species tests are needed.     

孕鼠PFOS暴露对糖皮质激素水平及胎鼠生长发育的影响

为探究孕期全氟辛烷磺酸(PFOS)暴露与母源糖皮质激素(GC)水平、胎鼠生长发育之间的关系,将孕期为12 d(GD12)的24只SD雌性大鼠,随机分为4组给予不同剂量的PFOS(0,5,10,20 mg·kg-1),连续灌胃7 d,在GD19时对孕鼠和胎鼠的体重、胎鼠肝脏系数和肝脏生化指标、孕鼠血清的生化指标和GC水平、胎盘11β-羟基类固醇脱氢酶2(11β-HSD2)的酶学活性和胰岛素样生长因子-1(IGF-1)的mRNA表达水平分别进行检测。结果表明,与对照组相比:PFOS 20 mg·kg-1组,母鼠体重、胎鼠体重和体长显著下降(P0.001);PFOS 20 mg·kg-1组,胎鼠肝脏脏器系数低于对照组(P0.001);PFOS 10 mg·kg-1组,胎鼠肝脏中的酶活性(ALT、AST和ALP等)显著升高(P0.001);PFOS 20 mg·kg-1组,孕鼠血清GC水平升高(P0.05);胎盘IGF-1的mRNA表达水平随PFOS剂量升高而降低;胎盘11β-HSD2的活性随PFOS剂量升高而降低。研究表明,孕期暴露PFOS可以导致胎鼠肝脏毒性,降低胎盘11β-HSD2氧化活性导致GC浓度升高,进而影响胎鼠的生长发育。     

新冠疫情下的保险业及保险连接证券市场

2019年底爆发的新型冠状病毒疫情已经给全世界造成了深远的影响,沉重打击了各国经济,人类生产、生活方式都发生重大变化.即使已经过去半年,目前的情况仍不明朗,每天仍有大量人员被确诊,全球经济前景充满不确定性.通过观察疫情对保险业的影响,认为在政策推动和需求增加的情况下,保险业未来的业务范围会向大流行病扩展.计算保险连接证...     

The aryl receptor inhibitor epigallocatechin-3-gallate protects INS-1E beta-cell line against acute dioxin toxicity

The aim of this research was to investigate the mechanism(s) underlying the acute toxicity of dioxin in pancreatic beta cells and to evaluate the protective effects of epigallocatechin-3-gallate (EGCG), the most abundant of the green tea’s catechins and a powerful inhibitor of the aryl hydrocarbon receptor (AhR). Using the insulin-secreting INS-1E cell line we have explored the effect of 1 h exposure to different concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), alone or in the presence of EGCG, on: (a) cell survival; (b) cellular ultrastructure; (c) intracellular calcium levels; (d) mitochondrial membrane potential; (e) glucose-stimulated insulin secretion and (f) activation of MAP kinases. Our results demonstrate that TCDD is highly toxic for INS-1E cells, suggesting that pancreatic beta cells should be considered a relevant and sensitive target for dioxin acute toxicity. EGCG significantly protects INS-1E cells against TCDD-induced toxicity in terms of both cell survival and preservation of cellular ultrastructure. The mechanism of this protective effect seems to be related to: (a) the ability of EGCG to preserve the mitochondrial function and thus to prevent the TCDD-induced inhibition of glucose-stimulated insulin secretion and (b) the ability of EGCG to inhibit the TCDD-induced activation of selected kinases, such as e.g. ERK 1/2 and JNK. Our results clearly show that EGCG is able to protect pancreatic beta cells against dioxin acute toxicity and indicate the mitochondrion as the most likely target for this beneficial effect.     

两种不同构型b射线颗粒物分析仪线性关系的有效性评价

为评价导流锥式同时采样-测量β射线颗粒物分析仪的测量准确度,以分步采样-测量β射线颗粒物分析仪采样分析作为参比方法,使用2类构型的仪器对环境空气中可吸入颗粒物PM₁₀和细颗粒物PM_2.5进行长期平行比对监测.本文依据EN 16450标准对比对数据线性关系进行有效性评价,建立了修正的线性方程,导出了方法间不确定度评价式,结果表明导流锥式同时采样-测量结构和分步采样-测量结构的β射线颗粒物分析仪之间存在有效的线性关系.通过仪器内置修正参数浓度斜率、浓度截距修正后,在较宽浓度跨度范围（0~250μg/m³）内和足够多的比对数据（n>100）条件下,两种不同结构的仪器监测PM₁₀和PM_2.5的比对斜率、截距和相关系数（参比方法作为X轴）均能满足EPA CFR 40part53的要求.     

Prenatal evaluation of fetal renal function based on serum beta2-microglobulin assessment

The relationship between fetal renal function (FRF) and fetal serum beta₂-microglobulin (B2MG) was investigated by comparing its value in 112 unaffected fetuses with that of 23 fetuses presenting with urinary tract malformations (UTM). Fetal serum level of B2MG was totally unrelated to gestational age; its value increased in cases of severe impairment of FRF but was similar to controls in all mild uropathies (p<0.05). Evaluating serum B2MG could be beneficial in fetuses with severe renal damage, but is of no use in unilateral UTM since only the global FRF is tested and not the function of each single kidney. Copyright © 2001 John Wiley & Sons, Ltd.     

MPC-9604型流气式四路低本底α、β计数器效率研究

简述了MPC-9604型流气式四路低本底α、β计数器效率校准的基本原理,研究了α源各铺样质量与探测效率的关系。     

The Effect of UV-B Irradiation on the Biodegradability of Poly-β-Hydroxybutyrate (PHB) and Poly-ɛ-Caprolactone (PCL)

The biodegradability of poly--hydroxybutyrate and poly--caprolactone in soil compostage before and after irradiation of the polymers for 192, 425, and 600 h in a Weather-Ometer was examined. The biodegradability tests were done in soil compostage at pH 7.0, 9.0, and 11.0 to assess the influence of this parameter on degradation. The rate of degradation was directly proportional to the soil alkalinity. Poly--hydroxybutyrate showed the greatest weight loss and aging in a Weather-Ometer did not significantly increase the biodegradation, except when the polymer was aged for 425 h and buried in soil compostage of pH 11.0.