Influence of Microstructure on Mechanical Properties of Snow

Snow, being composed of ice grains of varying shapes, sizes, orientations, etc., has been treated as a particulate material. The mechanical properties of snow have been described in terms of microstructural parameters. A set of variables, which characterise the microstructure of snow at the granular level, has been chosen and quantified following the techniques of quantitative stereology for section plane. The data of quasi-static tests, e.g. constant strain-rate creep tests, have been analysed to determine the Young's modulus and compactive viscosity and the same have been correlated with the microstructural parameters. Inspite of scatter, definite trends are discernible. Considering the fact that deformation of snow is associated with translation and rotation of constituent grains in such a way as to attain the most stable configuration, the concept of fabric reconstruction, which is characterised by the concentration of normals (to the tangent plane at the point of grain contact) in the direction of the applied load, has been examined. The results demonstrated the occurrence of fabric reconstruction during the process of deformation. Finally, a dimensionless quantity, called the microstructural index (I), has been proposed to adequately represent the influence of microstructure

Evaluation of serum lipid profile in cases of pre-eclampsia and eclampsia

Background: According to the current knowledge, rise in the serum triglyceride level is a major contributor in the pathogenesis of preeclampsia and eclampsia. The present study was designed to compare the changes in lipid profile in normal pregnancy, pre-eclampsia & eclampsia cases.Methods: A case control study was done consisting of total 100 study subjects, 75 already diagnosed pre-eclamptic & eclamptic women and 25 normotensive pregnant women. Age range was 18-35 years, gestational age 28 weeks to term were included. Serum Total Cholesterol (TC), triglyceride and HDL-cholesterol by enzymatic colorimetric method were done.Results: Results showed that level of serum triglycerides in mild pre-eclampsia (156.22 ± 66.5 mg/dl), severe pre-eclampsia (168.30 ± 68.1 mg/dl) & eclampsia (224.89 ± 84.40 mg/dl) as compared to normal pregnant women (130.95 ± 44.64 mg/dl) was increased significantly (P <0.05). Other parameters TC, HDL-C, LDL-C were not changed significantly.Conclusions: The findings of the present study are consistent with previous studies, suggesting increased levels of serum triglyceride as an important factor in the pathological process of preeclampsia & eclampsia. This may help in developing strategies for prevention or early diagnosis of the disorder

Thermodynamics predicts how confinement modifies hard-sphere dynamics

We study how confining the equilibrium hard-sphere fluid to restrictive one- and two-dimensional channels with smooth interacting walls modifies its structure, dynamics, and entropy using molecular dynamics and transition-matrix Monte Carlo simulations. Although confinement strongly affects local structuring, the relationships between self-diffusivity, excess entropy, and average fluid density are, to an excellent approximation, independent of channel width or particle-wall interactions. Thus, thermodynamics can be used to predict how confinement impacts dynamics.Comment: 4 pages, 4 figure

Morphology of the Esophageal Hiatus: Is It Different in 3 Types of Hiatus Hernias?

Background/aimsThe esophageal hiatus is formed by the right crus of the diaphragm in the majority of subjects. Contraction of the hiatus exerts a sphincter-like action on the lower esophageal sphincter (LES). The aim is to study the hiatal anatomy (using CT scan imaging) and function (using high-resolution manometry [HRM]), and esophageal motor function in patients with sliding and paraesophageal hiatal hernia.MethodsWe assessed normal subjects (n = 20), patients with sliding type 1 hernia (n = 18), paraesophageal type 2 hernia (n = 19), and mixed type 3 hernia (n = 19). Hernia diagnosis was confirmed on the upper gastrointestinal series. The hiatal morphology was constructed from the CT scan images. The LES pressure and relaxation, percent peristalsis, bolus pressure, and hiatal squeeze pressure were assessed by HRM.ResultsThe CT images revealed that the esophageal hiatus is formed by the right crus of the diaphragm in all normal subjects and 86% of hernia patients. The hiatus is elliptical in shape with a surface area of 1037 mm2 in normal subjects. The hiatal dimensions were larger in patients compared to normal subjects. The HRM revealed impaired LES relaxation and higher bolus pressure in patients with paraesophageal compared to the sliding hernia. The hiatal pinch on HRM was recognized in significantly higher number of patients with sliding as compared to paraesophageal hernia.ConclusionsUsing a novel approach, we provide details of the esophageal hiatus in patients with various kinds of hiatal hernia. Impaired LES relaxation in paraesophageal hernia may play a role in its pathophysiology and genesis of symptoms

Accuracy of computerized tomography in determining hepatic tumor size in patients receiving liver transplantation or resection

Computerized tomography (CT) of liver is used in oncologic practice for staging tumors, evaluating response to treatment, and screening patients for hepatic resection. Because of the impact of CT liver scan on major treatment decisions, it is important to assess its accuracy. Patients undergoing liver transplantation or resection provide a unique opportunity to test the accuracy of hepatic-imaging techniques by comparison of finding of preoperative CT scan with those at gross pathologic examination of resected specimens. Forty-one patients who had partial hepatic resection (34 patients) or liver transplantation (eight patients) for malignant (30 patients) or benign (11 patients) tumors were evaluable. Eight (47%) of 17 patients with primary malignant liver tumors, four (31%) of 13 patients with metastatic liver tumors, and two (20%) of 10 patients with benign liver tumors had tumor nodules in resected specimens that were not apparent on preoperative CT studies. These nodules varied in size from 0.1 to 1.6 cm. While 11 of 14 of these nodules were 1.0 cm. These results suggest that conventional CT alone may be insufficient to accurately determine the presence or absence of liver metastases, extent of liver involvement, or response of hepatic metastases to treatment

Transition Metal Chemistry of Oxime Containing Ligands: Part III-Complexes of Fe(II), Co(II) & Ni(II) with Pyridine-2-aldoxime & 6-Methylpyridine-2-aldoxime

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