Induced charges in a Thomas-Fermi metal: insights from molecular simulations

We study the charge induced in a Thomas-Fermi metal by an ion in vacuum, using an atomistic description employed in constant-potential molecular dynamics simulations, and compare the results with the predictions from continuum electrostatics. Specifically, we investigate the effects of the Thomas-Fermi screening length $l_{TF}$ and the position $d$ of the ion with respect to the surface on the induced charge distribution in a graphite electrode. The continuum predictions capture most of the features observed with the atomistic description (except the oscillations due to the atomic sites of the graphite lattice), provided that $d$ and $l_{TF}$ are larger than the inter-atomic distances within the electrode. At large radial distance from the ion, the finite $l_{TF}$ case can be well approximated by the solution for a perfect metal using an effective distance $d+l_{TF}$. This requires a careful definition of the effective interface between the metal and vacuum for the continuum description. Our atomistic results support in particular an early analytical prediction [Vorotyntsev and Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008] for a single charge at the interface between a Thomas-Fermi metal and a polarizable medium, which remains to be tested in atomistic simulations with an explicit solvent

Depression and anxiety in asthma patients attending a tertiary care centre in north Kerala: a cross-sectional study

Background: Asthma is a common chronic non-communicable disease that causes substantial burden to people, often causing a reduced quality of life, not only due to its physical effects, but also its psychological and social effects. Objectives were to assess the prevalence of depression and anxiety in patients with stable asthma in a tertiary care centre. to assess the relationship between bronchial asthma symptom control and degree of depression and anxiety. To assess the quality of life in asthma patients.Methods: It was a cross-sectional study conducted in govt. medical college, Kannur for 1 year duration. The 150 patients with stable asthma, attending the outpatient clinic of department of chest diseases, satisfying inclusion criteria were included in the study. The socio demographic details and the relevant clinical details were collected using the socio demographic proforma. Spirometry was done for all patients. Quality of life of these patients was assessed with standardized asthma quality of life questionnaire-Malayalam version. For psychological status, (HADS) 23 scale was used.Results: We found 33 patients (22%) to have depression and 33 (22%) patients to have anxiety among stable asthma patients. AQLQ scores were assessed and obtained a median of 4.92, interquartile range of 5.0. The median AQLQ scores among patients with no anxiety and depression was 5.56. The median AQLQ score among patients with depression and anxiety was 3.400. There was significant correlation between the control of asthma with AQLQ score.Conclusions: Depression and anxiety is substantially related to quality of life, and hospitalization in asthma patients.

Islet-Like Cell Aggregates Generated from Human Adipose Tissue Derived Stem Cells Ameliorate Experimental Diabetes in Mice

BACKGROUND: Type 1 Diabetes Mellitus is caused by auto immune destruction of insulin producing beta cells in the pancreas. Currently available treatments include transplantation of isolated islets from donor pancreas to the patient. However, this method is limited by inadequate means of immuno-suppression to prevent islet rejection and importantly, limited supply of islets for transplantation. Autologous adult stem cells are now considered for cell replacement therapy in diabetes as it has the potential to generate neo-islets which are genetically part of the treated individual. Adopting methods of islet encapsulation in immuno-isolatory devices would eliminate the need for immuno-suppressants. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we explore the potential of human adipose tissue derived adult stem cells (h-ASCs) to differentiate into functional islet like cell aggregates (ICAs). Our stage specific differentiation protocol permit the conversion of mesodermic h-ASCs to definitive endoderm (Hnf3β, TCF2 and Sox17) and to PDX1, Ngn3, NeuroD, Pax4 positive pancreatic endoderm which further matures in vitro to secrete insulin. These ICAs are shown to produce human C-peptide in a glucose dependent manner exhibiting in-vitro functionality. Transplantation of mature ICAs, packed in immuno-isolatory biocompatible capsules to STZ induced diabetic mice restored near normoglycemia within 3-4 weeks. The detection of human C-peptide, 1155±165 pM in blood serum of experimental mice demonstrate the efficacy of our differentiation approach. CONCLUSIONS: h-ASC is an ideal population of personal stem cells for cell replacement therapy, given that they are abundant, easily available and autologous in origin. Our findings present evidence that h-ASCs could be induced to differentiate into physiologically competent functional islet like cell aggregates, which may provide as a source of alternative islets for cell replacement therapy in type 1 diabetes

Lysosome Biogenesis and Autophagy

Lysosomes degrade biological components acquired by endocytosis, the major cellular pathway for internalization of extracellular material, and macroautophagy. This chapter presents an overview of these two major degradative intracellular pathways, and highlights the emerging cross talks between them, in healthy and diseased conditions. The pathways to lysosomes include the biosynthetic transport routes, endocytic pathways, and the autophagy pathways. The central actors of the autophagy process are the ATG genes. Based on their organization in complexes and interactions, the ATG genes have been divided into many functional clusters that compose the core autophagy machinery. Cross talk between the endocytic and autophagic pathways occurs at many levels: transcriptional regulation, protein sharing, and compartmental connections. The chapter focuses on the fusion and fission events between compartments of the endolysosomal system and autophagic membranes, respectively. Lysosome-related disorders are caused by mutations in genes encoding for proteins that directly affect lysosomal functioning, including lysosomal hydrolases and lysosomal membrane proteins

A Rare Case of Huge Unilocular Autoamputated Extra-ovarian Dermoid Cyst

Ovarian dermoid cysts are one of the commonest benign, pelvic tumours. However, presence of dermoid cysts at extra-ovarian locations is very rare. The extra-ovarian dermoid cysts can be of ovarian origin or may also originate from non-ovarian sites like omentum, retroperitoneum, mediastinum, etc. We report one such rare case of extra-ovarian dermoid cyst observed in a 70-year-old postmenopausal woman at department of Gynaecology of our hospital. Her ultrasonographic observations showed a large well defined cystic lesion predominantly in the left adnexa extending into the midline with internal echoes within, which was later confirmed with MRI. Following this, she underwent a total abdominal hysterectomy with vertical midline incision. Intraoperatively, she was found to have a large tumour of 3.25kg (28cm x 26cm x 11cm) with adhesion to the omentum on its anterior upper and posterior aspects. The surface of the oval mass was smooth with few adherent lobules of fat in some areas. Its gross cut section showed a thick walled uniloculated cyst with yellow areas and thick creamy white fluid. Cyst wall had a bony hard area and two balls of hair were also noted in side. The pedicle of the tumour seen to arise from the left side broad ligament close to left ovary. Uterus was atretic with an intramural fibroid. The dermoid appears to be derived from its autoamputation from one of the pelvic organs; probably ovary. It is unique in its size and vastness occupying the major part of the lower half of the abdominal cavity

Induced charges in a Thomas–Fermi metal: insights from molecular simulations

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Electrical noise in electrolytes: a theoretical perspective

Seemingly unrelated experiments such as electrolyte transport through nanotubes, nano-scale electrochemistry, NMR relaxometry and surface force balance measurements, all probe electrical fluctuations: of the electric current, the charge and polarization, the field gradient (for quadrupolar nuclei) and the coupled mass/charge densities. The fluctuations of such various observables arise from the same underlying microscopic dynamics of the ions and solvent molecules. In principle, the relevant length and time scales of these dynamics are encoded in the dynamic structure factors. However, modelling the latter for frequencies and wavevectors spanning many orders of magnitude remains a great challenge to interpret the experiments in terms of physical processes such as solvation dynamics, diffusion, electrostatic and hydrodynamic interactions between ions, interactions with solid surfaces, etc. Here, we highlight the central role of the charge–charge dynamic structure factor in the fluctuations of electrical observables in electrolytes and offer a unifying perspective over a variety of complementary experiments. We further analyze this quantity in the special case of an aqueous NaCl electrolyte, using simulations with explicit ions and an explicit or implicit solvent. We discuss the ability of the standard Poisson–Nernst–Planck theory to capture the simulation results, and how the predictions can be improved. We finally discuss the contributions of ions and water to the total charge fluctuations. This work illustrates an ongoing effort towards a comprehensive understanding of electrical fluctuations in bulk and confined electrolytes, in order to enable experimentalists to decipher the microscopic properties encoded in the measured electrical noise

Endometrial stromal sarcoma

Endometrial stromal sarcoma (ESS) is a rare malignant tumor of the endometrium, occurring in the age group of 40–50 years. This is a case of low-grade ESS presenting as rapid enlargement of a fibroid uterus. Because of her secondary infertility, she was planned for myomectomy. However, due to the high degree of suspicion of a sarcomatous change in the fibroid, in view of rapid enlargement of uterus within the last 4 months, we planned for a preoperative endometrial aspiration. It showed low-grade ESS, which was later confirmed by histopathology examination of total hysterectomy specimen. As surgery was the main treatment for ESS, because of the proper preoperative diagnosis, we could plan the treatment accordingly. Despite the rarity of the tumor, one has to consider the possibility of ESS in cases with presentation of rapid enlargement of a fibroid uterus