Quantum chemical analysis of the structures of MgSO4 hydrates

Magnesium sulfate salts can form hydrated compounds with up to seven degree of hydration with an energy exchange of the order of 2.8GJ/m3 [1]. In addition, this salt is abundant in nature and thus this material is a potential candidate for storing energy in seasonal heat storage systems. One of the main issues in using this material for seasonal heat storage system is its slow kinetics and low extent of water take-up under normal atmospheric conditions [2]. In addition, the salt undergoes considerable changes in its crystalline structure during hydration and dehydration, and often they encounter the formation of cracks and pores in the crystal structure [3]. This significantly affects the efficiency of the salt in storing energy and also reusability of the material. A molecular level investigation is necessary to understand the process of hydration and dehydration in detail. Presence of an extensive network of hydrogen bonds in MgSO4.7H2O crystal is identified by Allan Zalkin et al [4]. Significant delocalization of hydrogen atoms within the hydrogen bonds are reported in the study. The 7th water molecule in a hepta-hydrate crystal is captured in the interstitial space within the crystals due to coulombic forces and they are very easily removable. Thus modeling a stable molecule of magnesium sulfate hepta hydrate is difficult. So we undertake the hexa hydrated magnesium sulfate to study the equilibrium molecular structure. The hydrogen bonds present in the structure, which stabilizes the molecule, is a focus of attention in this study. In addition, we report Natural Bond Orbital (NBO) [5] charges of Mg and S as a function of degree of hydration in this study. The NBO analysis gives information about electronic occupations in the molecule. In addition, the variation of the natural charges give information about the nature of inters atomic interactions involved in the hydration process of magnesium sulfates. The hydration process is accompanied by a considerable amount of energy exchange with the surroundings. In addition, significant changes in the crystal structure are predicted to happen during hydration. The binding of a water molecule on a slab of magnesium sulfate will resemble the hydration phenomena of a real crystal. Maslyuk et al [6] have performed such an analysis on kieserite structures and found the influence of hydrogen bonds during hydration. A similar study has done towards the last part of this account, which gives important information about hydration process of magnesium sulfate crystal

A combined case of gastric lipoma and inflammatory fibroid polyp: Case report and review of the literature

An unusual case of gas trio lipoma combined with inflammatory pseudotumor (inflammatory fibrous polyp) is presented along with a brief discussion of a pertinent literature

Catechol-O-methyltransferase gene Val108/158Met polymorphism in bipolar disorder

Backgrounds: Although several studies have tested the association between bipolar disorder (BD) and the Val108 (H, high-activity allele)/158Met (L, low-activity allele) polymorphism of the catechol-O-methyltransferase (COMT) gene, most of the results showed no significant association. However, an association between the H or L allele and bipolar disorder (BD), particularly, between L allele and rapid-cycling form has been reported; it has also been suggested that the variation in the COMT gene modifies the course of BD and there is a tendency for the L allele amongst the female patients. In this study, the researchers aimed to evaluate the association between BD and COMT gene H/L polymorphism considering the influence of gender in a group of Turkish patients. Method: One hundred and thirty-five BD patients (71 male and 64 female) and 171 controls were included. Polymerase chain reaction-based endonuclease digestion method was used. Results: Genotypic distribution in patients and controls were in Hardy-Weinberg equilibrium. No significant difference was found in genotypic and allelic frequencies between patients and controls. However, female patients had H allele more frequently than male patients and female healthy controls. Females had more depressive and less manic episodes than males. Number of total episodes was associated with H allele in all patients. Conclusion: Distribution of COMT genetic polymorphism was not significantly different between the patients and controls. However, it has been found an association of H allele with female patients and number of episodes among all patients. © 2011 Elsevier GmbH. All rights reserved

Adenosine Deaminase, Nitric Oxide, Superoxide Dismutase, and Xanthine Oxidase in Patients with Major Depression: Impact of Antidepressant Treatment

Background: There has been much evidence in recent years that free oxygen radicals and nitric oxide (NO) may play an important role in the pathophysiology of neuropsychiatric disorders. In this study, we aimed to investigate whether NO, xanthine oxidase (XO), superoxide dismutase (SOD), and adenosine deaminase (ADA) levels are associated with major depression (MD) and to evaluate the impact of antidepressant treatments on NO, SOD, ADA and XO levels in MD. Methods: Thirty-six patients who were diagnosed as MD according to DSM-IV criteria and 20 healthy controls were included. The serum levels of NO, XO, SOD, and ADA were measured by spectrophotometric methods both in patients and controls. Patients were treated with antidepressant drugs for 8 weeks. All patients were assessed by Hamilton Depression Rating Scale (HDRS) both before and after antidepressant treatment. Results: ADA and XO levels of the patients were significantly higher than the controls. SOD level of the patients was significantly lower than the controls. Although NO levels of the patients were higher than the controls, the difference was not statistically significant. There was no correlation between HDRS and the parameters studied (SOD, ADA, XO, and NO) of the patients. After 8 weeks of antidepressant treatment, ADA and SOD activities were increased, whereas NO and, XO levels decreased significantly. Conclusions: ADA, XO, and SOD activity may have a pathophysiological role in MD and may predict prognosis of MD. Activity of these enzymes may be used to monitor effects of the antidepressant treatment. © 2007 IMSS