复合核苷氧钒配合物(VRC)的合成及对RNA酶的抑制效应

运用改进的有机溶剂助溶法合成了复合核苷氧钒配合物（VRC）——一种强的核糖核酸酶（RNAase)抑制剂，并经紫外差谱、红外光谱、顺磁共振光谱研究了核苷与氧钒离子在不同pH值和不同金属/核苷比中的结合及结合方式。实验结果表明，用本法制备的VRC在保护核糖核酸免受核糖核酸酶的降解方面与国外同类产品具有同样的效能，与蛋白类的核糖核酸酶抑制剂RNAasin相比，可在较高的温度下发挥核糖核酸酶抑制剂的作用。     

Effect of Lanthanum（ Ⅲ ） on Cytosolic Free Calcium in Isolated Rabbit Mature Osteoclasts

Theformationandresorptionofboneismain tainedbytheinteractionsofosteoblasts(OBs)withos teoclasts(OCs),andafunctionalimbalancebetween themmaycausethelossofbonemass.OCsaremulti nucleatedcellsformedbythefusionofmononuclear progenitorsofthemonocyte macrophagef…     

金属及合金的无切削点滴分析

一般分析金属及合金都是把要分析的东西削下来一部份,用酸溶解,再在所得的溶液中检出所含的金属。当然,经过切削取样,金属就改变了它的外貌,甚至使它失去使用价值,所以需要一种不损坏样品表面的分析方法。不久以前,点滴分析的创始者H.A.塔那那也夫发明了无切削点滴分析,解决了这一问题。无切削分析的原理是把适当的溶剂(一般都是酸)两三滴,滴到样品表面上,使之溶解,然后取所得溶液进行点滴分析。所以无切削点滴分析实     

分析用特效试剂研究中存在的问题

总结过去三十多年国内外特效试剂研究中存在的问题,找出我们应该解决的问题和解决的途径,对于走自己的道路研制特效试剂是有帮助的。下面提出几点看法。一、原有试剂的改进过去三四十年中提出了许多特效试剂,但是其中能站得住脚的为数不多。一种好的试剂要具备许多条件。有些试剂,甚至是应用普遍的试剂,由     

混合配体络合物稳定常数的电位法测定

测定混合配体络合物MAB的稳定常数时多用标准碱溶液对含金属离子M及两配体酸H_mA和H_nB的溶液体系(以下简称M-A-B体系)进行pH滴定。在滴定过程中,该体系有下列关系:     

Effects of Lanthanum on Formation and Bone-Resorbing Activity of Osteoclast-Like Cells

The effect of La3 on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant-acid phosphatase-positive ［TRAP( )］ multi-nucleated cells and measuring the number and surface area of bone resorption pits with photomicrography and image analysis. The formation and morphological characteristics of osteoclast-like cells and bone resorption pits were observed under a phase contrast inverted microscope. La3 promotes the formation of osteoclast-like cells at the concentration of 1.00×10-8mol·L-1 compared with the control group(P<0.01), whereas no significant change in cell number is observed at higher concentrations(1.00×10-5, 1.00×10-6 and 1.00×10-7 mol·L-1)(P>0.05). La3 at the concentration of 1.00×10-8mol·L-1 also increases the number and surface area of the resorption pits(P<0.01), but inhibits the bone-resorbing activity dose-dependently(P<0.01)at higher concentrations(1.00×10-5, 1.00×10-6 and 1.00×10-7 mol·L-1). These findings suggest that La3 may promote or inhibit the formation and bone-resorbing activity of osteoclast-like cells depending on its concentration.     

Effects of Lanthanum on Bone Resorbing Activity of Rabbit Mature Osteoclasts Co-Cultured with Osteoblasts

The effects of lanthanum (Ⅲ) on the bone resorbing activity of rabbit mature osteoclasts (OCs) in the presence of osteoblasts (OBs) were studied in vitro by measuring the number and area of absorption pits. La(Ⅲ) at concentrations ranging from 1.00×10-5 to 1.00×10-8 mol·L-1 show no effect on mature OC number (P＞0.05). In the OC-OB co-culture systems without La(Ⅲ), osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not (P＞0.05). Under the OC-OB not-in-contact condition, the effect of La(Ⅲ) on the bone-resorbing activity of OCs was similar to that of La(Ⅲ) in the absence of OBs (P＞0.05). However, while OCs were in direct contact with OBs, the inhibitory effects of La(Ⅲ) on OCs' bone-resorbing activity decreased at the concentrations of 1.00×10-5, 1.00×10-6 and 1.00×10-7 mol·L-1, and the promotion effects increased at 1.00×10-8 mol·L-1 (P＜0.05). The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La(Ⅲ).     

Gadolinium induced apoptosis of human embryo liver L02 cell line by ROS-mediated AIF pathway

Gd3+ complexes have a variety of medical applications.In order to shed light on the mechanism of hepatotoxicity of Gd3+ compounds,we investigated the effects of GdCl3 on human embryo liver cell strand (L02 cells).The experimental results showed that long-time exposure to GdCl3 resulted in L02 cell apoptosis.The incubation of L02 cells with GdCl3 first induced increase in cellular reactive oxygen species (ROS) and decrease in mitochondrial inner membrane potential (?ψm).It later resulted in the activation of poly (ADP-ribose) polymerase (PARP) and the release of mitochondrial apoptosis-inducing factor (AIF).The activation of caspase 3,however,was not observed.Antioxidants could significantly reduce GdCl3-induced decrease of Δψm,release of AIF,and cell apoptosis.Although GdCl3 caused a significant increase in cell membrane permeability in L02,the change of cell membrane permeability was unlikely to be involved in GdCl3-induced cell apoptosis.Overall,our experimental results suggested that GdCl3 induced apoptosis of human embryo liver L02 cell line by ROS-mediated AIF pathway.     

祝贺《化学试剂》创刊三十周年

编者按:时值<化学试剂>创刊三十周年,本刊名誉主编、编委会主任、中国科学院院士王夔教授为我刊发来了深情寄语,表达了对<化学试剂>创刊三十年深切的关注.     

沉淀色谱分析法

苏联分析化学家Е.Н.Гапон及Т.Б. Гапон承继了М.С.Двет的色谱分析研究的光辉事业,在1948年提出一个重要的方法——沉淀色谱分析(注1)。这个方法给无机化合物的色谱分析开辟了一条新的道路。自从Двет提出了色谱分析以后,四十馀年来,色谱分析曾经成功地用於生物化学上,有机分析上,有机化合物分离上,以至有机化学工业上,只是色谱分析如何用於无机分析中,这个问题,始终得不到很好解决。主要原因是由於一