Effect of Sodium Chloride on Efficiency of Cisplatinum Dissolved in Dimethyl Sulfoxide: An In Vitro Study

Cisplatinum (Cispt) is an anti-cancer drug with a low level of solubility. One of Cispt’s solvents is dimethyl sulfoxide (DMSO) which can be substituted with chlorine of drug as Cispt’s solvent. Applying such a solvent in biological studies is impossible due to intense reduction in activity. On the other hand, it is specified that Cispt’s stability is increased in aqueous media by increasing sodium chloride (NaCl) concentration up to 0.9 %. Consequently, we intended to study the effect of DMSO on cytotoxicity of Cispt in presence of sodium. MTT assay was employed to study cytotoxicity effect of Cispt + NaCl + DMSO and Cispt + DMSO on G-292 cell line. Cytotoxicity in dilutions of 300 and 9 (p < 0.01) of Cispt in Cispt + NaCl + DMSO formulation was equal to 78 and 7 %. These values were estimated 79 and 18 % for Cispt + DMSO formulation and 79 and 24 % for free drug. IC50 values demonstrated reduction of 45 % in cytotoxicity of Cispt in Cispt + DMSO formulation. Studying chemical structure of Cispt and Cispt dissolved in DMSO showed that NaCl cannot inhibit inactivating effect of DMSO on Cispt and effect of this solvent on Cispt is independent from presence of NaCl. Results represented that using NaCl does not result in stability and keeping cytotoxicity properties of Cispt in DMSO. Findings suggest more studies for using DMSO as a solvent of Cispt.     

信息系统中软件修改管理问题

软件的修改管理问题是信息系统开发中的一个重要问题,该问题也是软件工业中所面临的十分重要的挑战。因此,现代的软件修改管理工具,或着称为配置控制工具,必须能对影响软件开发中的各种修改进行有效的管理。本文就此问题进行了探讨。     

An Investigation into the Parameters Affecting Preparation of Polybutyl Cyanoacrylate Nanoparticles by Emulsion Polymerization

Emulsion polymerization was used to synthesize poly butyl cyanoacrylate nanoparticles in presence of steric stabilizer dextran 70. Nanoparticles were characterized by particle size analysis, scanning electron microscopy and light microscopy. Polymerization factors affecting particle size and distribution such as dextran 70, polysorbate 80 (PS 80) and H⁺ concentration, polymerization time and temperature, and sonication were studied. Distinct concentrations of stabilizer were needed to produce proper nanoparticles. In this case, the appropriate value was 2 % of total volume. At pH 4 significant decrease in production efficiency demonstrated the substantial effect of H⁺ concentration on nanoparticles. Furthermore significant increases in particle size and distribution was observed at 50 °C compared to room temperature. 0.001 % (v/v) PS 80 represented notable influence on size and distribution. In addition, shaped nanoparticles were obtained by altering polymerization time from 5.5 h to 18 h. Finally, nanoparticle features were influenced by different factors. Appropriate manipulating of such factors can lead to obtaining desirable nanoparticles.     

Effects of temperature and effective strain on the flow behavior of Ti–6Al–4V

In this study, the hot backward extrusion of Ti–6Al–4V alloy is considered by finite element analysis and experiments. The effects of reduction and initial billet temperature on the force required for extrusion, on the maximum strain produced and on the formation of surface cracks are discussed. The simulation results show that the increase of temperature at high reduction is considerable and that can be reached 150 °C in the billet and punch interface. Moreover, the maximum strain is predicted at the interface of billet and punch. The study shows that the temperature rise and plastic deformation may induce surface cracks.     

Fabrication of multi-layer polymeric micro-sieve having narrow slot pores with conventional ultraviolet-lithography and micro-fabrication techniques

Fast detection of waterborne pathogens is important for securing the hygiene of drinking water. Detection of pathogens in water at low concentrations and minute quantities demands rapid and efficient enrichment methods in order to improve the signal-to-noise ratio of bio-sensors. We propose and demonstrate a low cost and rapid method to fabricate a multi-layer polymeric micro-sieve using conventional lithography techniques. The micro-fabricated micro-sieves are made of several layers of SU-8 photoresist using multiple coating and exposure steps and a single developing process. The obtained micro-sieves have good mechanical properties, smooth surfaces, high porosity (≈40%), and narrow pore size distribution (coefficient of variation < 3.33%). Sample loading and back-flushing using the multi-layer micro-sieve resulted in more than 90% recovery of pathogens, which showed improved performance than current commercial filters.     

Choronic effects of Lamotrigine on liver function in adult male rats

A number of newly developed antiepileptic drugs are currently in use, among them Lamotrigine (LTG) is more common. Despite the extensive use of this drug, it has not been possible to predict the side effects especially the hepatotoxic reactions after long-term treatment. The present study was designed to find out alterations in the activities of liver enzymes after chronic exposure of rats to different dose of LTG. Adults male (Wistar) rats were treated orally with LTG [5 mg/kg body weight or 25 mg/kg body wt.] for 60 days. After the experimental period, auto analyzer carried out liver function tests. The liver histopathology was obtained after scarifying the rats. There was a significant increase in the level of ALP, AST, ALT and bilirubin at therapeutic dose of LTG. The increase level of these enzymes and bilirubin at toxic dose were much higher and significant. However, the total protein and albumin significantly decreased at toxic dose of LTG. Elevation of liver enzymes and bilirubin after chronic exposure of rats to high dose of LTG reflects hepatocellular damage that may lead to hepatitis. It is concluded that regular liver function and drug monitoring should follow the treatment with LTG.