جستجوی مقالات مرتبط با کلیدواژه « شیمی » در نشریات گروه « پزشکی »

Tamoxifen is a group of drugs of selective estrogen receptor modulators, and is one of the drugs effective in the prevention and treatment of some cancers (such as breast cancer). In this study, the interaction of tamoxifen with DNA is investigated experimentally. Also, the electronic structure (at atomic scale) of the molecular system of tamoxifen was theoretically investigated, using atom in molecule (AIM) theory.

First, in the experimental section of this study, the interaction of Tamoxifen with DNA were investigated by UV-ViS technique and hydrodynamic method (Viscometry). In addition, the analysis of the experimental results shows the obvious effect of concentration on the mechanism of how the tamoxifen molecule binds to DNA. Then, in the theoretical part of this research, using computational biophysical chemistry methods, some properties of tamoxifen molecular system, such as electronic Density of States (DOS), boundary orbital’s energy (HOMO/LUMO), Electrostatic Potential Energy (EPS) and electronic contour maps of the electron density and its Laplacian, will be calculated.

This article is a meta-analysis with animal sample.

 Result of the UV-ViS spectroscopy technique and viscometry indicated hyperchromism and hypochromism effect. In addition, the result were depend on the concentration of the drug and affected the kind of binding of Tamoxifen to DNA. the analysis of computational studies on the drug tamoxifen suggests that the mechanism of the local charge/energy distribution in the molecular system of tamoxifen plays an important role in how this drug binds to DNA.

 Based on the experimental results of UV-ViS technique and viscometry, as well as the electronic/vibrational properties of the tamoxifen molecular system, it was defined that the Tamoxifen interacts significantly with all the binding sites of DNA.

The aim of this study was to determine the co-authorship condition of chemistry researchers in University of Yazd in Web of Science database. This scientometric study was performed to visualize the co-authorship networks. For data description، Spss and Ravar- matrix software were used and Ucinet and Net draw software were applied to analyze the data. The density of co-authorship network was 0. 0288 and the results showed that researchers who had high frequency had strong correlations among the faculty members of Yazd University، too. In general، It can be concluded that there are no many connections between relationships that constitute co-authorship network among faculty members of Yazd University and there is not a high coherence among their co-authorship networks.

Dental composite resins، as the name implies، are composite materials composed of organic and inorganic elements. The main components of dental composites are polymers، organic and inorganic filers، an initiator and an activator. In addition، some elements، referred to as silanes، are added to the surface of non-organic phases or fillers of composite resins for a stable bond between the two organic and inorganic phases. The aim of this study was to review the chemical structure of dental composites with a special emphasis on nano-composites and new composites. Review Report: This review was carried out by running a search in various databases including Pubmed and ISI Web of Science from 1987 to 2010 using the key words dental composites، nano-composite and chemical structure. In the recent decade، major changes have taken place in the chemical structure of dental composites; these changes include fluoride- and calcium phosphate-releasing nano-composites and use of nano-molecular processes to construct tooth enamel by using nano-rods، nano-spheres and amelogenin. With a proper knowledge of changes in the chemical structure of dental composites، clinical behavior of these materials can be evaluated more properly. It appears that new changes are going to have important effects on the clinical behavior of newly introduced composites; however، further research is required in this respect.

Gastric cancer is one of the most common cancers in Iran and is one of the most frequent causes of death due to cancer. Despite progresses in treatment, it still causes much mortalities and its treatment is still a matter of debate in the world. This study was performed with the aim of investigating the factors affecting prognosis, the survival rate and effect of different treatments on survival in gastric adenocarcinoma patients. This analytical case series study was conducted on 47 gastric or cardia adenocarcinoma patient referring to Shahid-Ramezanzadeh Radiation Center from 2004 to 2009 and were selected by accessible sampling. Data was extracted from patient's records and follow up was conducted through telephone contacts. Kaplan-Meier curves and SPSS 13 software were used for data analysis. Two-year and three-year survival of patients were 50% and 30%, respectively. Mean survival rate was 29.9 months and mean disease free survival rate was 12.95 months. Survival rate revealed a significant relation with disease stage (p=0.046), performed therapies (p=0.027) and surgical margin. Patients who had received a combination of surgery, chemotherapy and radiation therapy had the best survival. Survival had no relation with type of adenocarcinoma, tumor location or grade and chemotherapy regimen. Age, gender, surgery type, tumor location or grade and chemotherapy regimen do not affect survival, but the disease stage, performed therapies and surgical margin affect it. It seems that a combination of surgery, chemotherapy and radiation therapy would provide the best effect on patent's survival.

Abu Bakr Mohammad Ibn Zakaria Razi, known in the western literature as Rhazes, wasborn in 865 CE in Reyy, a township south of modern Tehran. In his youth, he pursued thecraft of goldsmith and was lead gradually to the art of Alchemy. He excelled in this art such that his genial contributions and historic discoveries helped convert the superstitionshrouded alchemy into the experiment-based rational chemistry. Rhazes is also credited for a scientific classification of minerals, purification of oils and the first description of chemical reduction. Rhazes was the first to produce colored glass and synthesis of paints.