Metal-insulator transition in the In/Si(111) surface

The metal-insulator transition observed in the In/Si(111)-4x1 reconstruction is studied by means of ab initio calculations of a simplified model of the surface. Different surface bands are identified and classified according to their origin and their response to several structural distortions. We support the, recently proposed [New J. of Phys. 7 (2005) 100], combination of a shear and a Peierls distortions as the origin of the metal-insulator transition. Our results also seem to favor an electronic driving force for the transition.Comment: Presented in the 23 European Conference in Surface Science, Berlin, September 2005. Submitted to Surface Science (proceedings of the conference) in August 200

Fibrinogen storage disease without hypofibrinogenemia associated with estrogen therapy

BACKGROUND: Cytoplasmic inclusion bodies within hepatocytes may have different etiologies, including the Endoplasmic Reticulum Storage Diseases (ERSDs). ERSD is a pathological condition characterized by abnormal accumulation of proteins destined for secretion in the endoplasmic reticulum of hepatocytes; it may be congenital (primary) or acquired (secondary). Fibrinogen storage disease is a form of ERSD. CASE PRESENTATION: We present a case of fibrinogen storage disease secondary to estrogen replacement therapy. Its causal relationship to the drug is shown by histological, immunohistochemical and ultrastructural studies of paired liver biopsies obtained during and after the drug therapy. CONCLUSION: The liver biopsies of patients with idiopathic liver enzyme abnormalities should be carefully evaluated for cytoplasmic inclusion bodies and, although rare, fibrinogen deposits

Chronic insulin treatment of diabetes does not fully normalize alterations in the retinal transcriptome

<p>Abstract</p> <p>Background</p> <p>Diabetic retinopathy (DR) is a leading cause of blindness in working age adults. Approximately 95% of patients with Type 1 diabetes develop some degree of retinopathy within 25 years of diagnosis despite normalization of blood glucose by insulin therapy. The goal of this study was to identify molecular changes in the rodent retina induced by diabetes that are not normalized by insulin replacement and restoration of euglycemia.</p> <p>Methods</p> <p>The retina transcriptome (22,523 genes and transcript variants) was examined after three months of streptozotocin-induced diabetes in male Sprague Dawley rats with and without insulin replacement for the later one and a half months of diabetes. Selected gene expression changes were confirmed by qPCR, and also examined in independent control and diabetic rats at a one month time-point.</p> <p>Results</p> <p>Transcriptomic alterations in response to diabetes (1376 probes) were clustered according to insulin responsiveness. More than half (57%) of diabetes-induced mRNA changes (789 probes) observed at three months were fully normalized to control levels with insulin therapy, while 37% of probes (514) were only partially normalized. A small set of genes (5%, 65 probes) was significantly dysregulated in the insulin-treated diabetic rats. qPCR confirmation of findings and examination of a one month time point allowed genes to be further categorized as prevented or rescued with insulin therapy. A subset of genes (Ccr5, Jak3, Litaf) was confirmed at the level of protein expression, with protein levels recapitulating changes in mRNA expression.</p> <p>Conclusions</p> <p>These results provide the first genome-wide examination of the effects of insulin therapy on retinal gene expression changes with diabetes. While insulin clearly normalizes the majority of genes dysregulated in response to diabetes, a number of genes related to inflammatory processes, microvascular integrity, and neuronal function are still altered in expression in euglycemic diabetic rats. Gene expression changes not rescued or prevented by insulin treatment may be critical to the pathogenesis of diabetic retinopathy, as it occurs in diabetic patients receiving insulin replacement, and are prototypical of metabolic memory.</p

Photoelectron diffraction of C6H8/Si(001): A model case for photoemission study of organic molecules adsorbed on silicon surfaces

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Dependence on the deposition conditions in the adsorption of C6H8 molecules on a Si(100)-2×1 surface

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