Doping of gallium nitride using disilane

The silicon doping of n-type GaN using disilane has been demonstrated for films grown on sapphire substrates by low pressure organometallic vapor phase epitaxy. The binding energy of an exciton bound to a neutral Si donor has been determined from low temperature (6K) photoluminescence spectra to be 8.6 meV. Nearly complete activation of the Si impurity atom in the GaN lattice has been observed.     

The effect of leukotriene D4 on the patency of nasal passage in the guinea pig

BACKGROUND: Demodex folliculorum has been reported in rosacea in a number of clinical studies. As the Demodex mite is also present in many healthy individuals, it has been suggested that the mite may have a pathogenic role only when it is present in high densities. Moreover, some authors have proposed that a mite density above 5/cm2 may be a criterion for the diagnosis of inflammatory rosacea. In this study, the possible role of D. folliculorum and the importance of mite density in rosacea were investigated using a skin surface biopsy technique. METHODS: Thirty-eight patients with rosacea and 38 age-and-sex-matched healthy subjects entered the study. With the skin surface biopsy technique, we obtained samples from three facial sites. We then determined the mite positivities, the mean mite counts in both study groups, the mean mite densities at each facial site and in the rosacea subgroups, and the mite densities above 5/cm2. RESULTS: The mean mite count in the rosacea group (6,684) was significantly higher than that in controls (2,868; p < 0.05). The cheek was the most frequently and heavily infested facial region. Ten rosacea patients and five normal subjects had mite densities over 5/cm2; the difference was not statistically significant (p > 0.05). CONCLUSIONS: Rosacea is a disease of multifactorial origin, and individual properties may modify the severity of the inflammatory response to Demodex. We suggest that a certain mite density is not an appropriate criterion in the diagnosis of the disease; nevertheless, large numbers of D. folliculorum may have an important role in the pathogenesis of rosacea, together with other triggering factors.     

Expansion of natural (NK1+) T cells that express alpha beta T cell receptors in transporters associated with antigen presentation-1 null and thymus leukemia antigen positive mice

Thymic selection of natural killer-1+ natural T cells that express alpha beta T cell receptors requires a conserved beta 2-microglobulin-associated molecule, presumably CD1d, displayed by CD4+8+ thymocytes. Here we demonstrate that positive selection of natural T cells occurs independent of transporters associated with antigen presentation-1 (TAP-1) function. Moreover, natural T cells in TAP-1o/o mice are numerically expanded. Several H-2 class Ib molecules function in a TAP-independent manner, suggesting that if expressed in TAP-1o/o thymocytes, they could play a role in natural T cell development. Of these class Ib molecules, H-2TL is expressed by TAP-1o/o thymocytes. Moreover, we find that thymi of TL+ mice congenic or transgenic for H-2T18 also have a numerically expanded natural T cell repertoire compared with TL- mice. This expansion, as in TAP-1o/o thymi, is evident in each of the limited T cell receptor V beta chains expressed by natural T cells, suggesting that TL and CD1d impact similar repertoires. Thus TL, in addition to CD1d, plays a role in natural T cell development.     

Comparison of the effects of the dipeptidyl peptidase inhibitors captopril, ramipril, and enalapril on water intake and sodium appetite of Sprague-Dawley rats.

Two experiments were performed with rats to study the effects of different inhibitors of angiotensin I (Ang I) converting enzyme on water intake and sodium appetite. Subcutaneous administration of low doses of either enalapril or ramipril, like captopril, was dipsogenic. Acute administration of ramipril also enhanced the drinking response to peripherally administered Ang I. Higher doses inhibited the drinking response to Ang I, administered acutely peripherally or centrally. Data provide behavioral evidence that enalapril and ramipril inhibit brain converting enzyme activity and are considerably more potent than captopril. All 3 compounds, administered chronically in food, induced an appetite for NaCl solution. Enalapril and ramipril were more potent than captopril. Plasma renin activity was increased by each of these inhibitors, but the magnitude of the increase was not clearly related to the amount of NaCl consumed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characteristics of thirst and sodium appetite in mice (Mus musculus).

Intakes of water and NaCl solution were examined in mice following treatment with agents that stimulate or mimic components of the renin-angiotensin-aldosterone system. Injections of angiotensin II or isoproterenol produced little water intake compared with robust responses to either intracellular dehydration or extracellular dehydration induced by treatment with polyethylene glycol. In studies on appetite for NaCl solution, mice exhibited no spontaneous preference for NaCl solution over water and did not change this preference during treatment with deoxycorticosterone acetate, a sodium-deficient diet, or after adrenalectomy. Plasma concentrations of aldosterone were increased in intact mice fed a sodium-deficient diet but not eliminated by adrenalectomy. Acute treatment with furosemide in combination with a sodium-deficient diet stimulated an appetite for NaCl solution. Chronic oral administration of an angiotensin I converting enzyme inhibitor failed to induce a NaCl appetite. Findings show that mice are refractory to the induction of water or NaCl intake by stimuli of the renin-angiotensin-aldosterone system, highly effective in rats, suggesting that there may be major differences among rodents in hormonal determinants of behaviors related to hydromineral homeostasis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Immediate ipsilateral fibular transfer in a large tibial defect using a ring fixator. A case report

A 57-year-old man with monoclonal gamma-globulinemia was admitted because of edema and proteinuria. A renal biopsy specimen showed lobular glomerulonephritis associated with deposition of material that was positive for IgG, C3, C1q, fibrin, kappa light chain, and lambda light chain but was not stained by Congo red. Glomeruli showed massive electron-dense deposits with two kinds of unusual, highly organized crystalline structures in the mesangial matrix and peripheral capillary loops. Clinically, the patient had nephrotic syndrome, microscopic hematuria, and hypertension. No Bence-Jones protein or cryoglobulin was found in the urine or serum. Immunoelectrophoresis of blood and urine revealed increased IgG-lambda paraprotein, but no free light chains were found. This case was not associated with amyloidosis, systemic lupus erythematosus, light chain deposition disease, cryoglobulinemia, or multiple myeloma. Immunotactoid glomerulopathy was diagnosed. Treatment with oral prednisone was effective for the management of nephrotic syndrome and renal dysfunction. Glomerular deposition of two kinds of microtubular structure in immunotactoid glomerulopathy has rarely been reported.     

Central injection in rats of alpha-melanocyte-stimulating hormone analog: effects on food intake and brain Fos

Lateral cerebroventricular (LCVT) administration of the alpha-MSH agonist analog Nle4DPhe7alpha-MSH (NDP-MSH) inhibited food intake in food-deprived rats, but did not inhibit water intake in water-deprived rats. When NDP-MSH was administered into the fourth ventricle (4CVT), comparable suppressions of food intake were observed. LCVT and 4CVT administration of NDP-MSH also reduced spontaneous 24 h food intake. LCVT injection of NDP-MSH greatly attenuated food intake stimulated in sated rats by acute CVT administration of neuropeptide Y (NPY). These and other data suggest that alpha-MSH is an important endogenous regulator of food intake, possibly acting downstream of NPY. In an attempt to assess further the sites of action of NDP-MSH, a qualitative mapping study of Fos-like immunoreactive (Fos-ir) neurons was performed following LCVT administration of NDP-MSH. LCVT injection of NDP-MSH induced Fos-ir in several forebrain regions including cortex, striatum, bed nucleus of the stria terminalis, paraventricular nucleus of the hypothalamus and arcuate nucleus. The combination of NPY and NDP-MSH did not produce obvious antagonism or cancellation of effects in any region examined. Thus, the site(s) of action of NDP-MSH on food intake remain to be clarified.     

First-pass versus second-pass parsing processes in a Wernicke's and a Broca's aphasic: electrophysiological evidence for a double dissociation

The present paper is a first attempt to integrate the classical brain lesion behavioral impairment approach of functional neuroanatomy and the electrophysiological brain mapping approach in the domain of syntactic processing. In a group of normal age-matched controls we identified three electrophysiological components previously observed in correlation with language comprehension processes: an early left anterior negativity normally seen in correlation with syntactic first-pass parsing processes (ELAN), a centroparietal negativity seen in correlation with processes of lexical-semantic integration (N400), and a late centroparietal positivity observed in correlation with secondary syntactic processes of reanalysis and repair (P600). The early left anterior negativity was absent in a patient with an extended lesion in the anterior part of the left hemisphere sparing the temporal lobe, although the late centroparietal positivity and the centroparietal N400 were present. In a patient with a left temporal-parietal lesion the early left anterior negativity was found to be present, whereas the N400 component was absent. These findings suggest that first-pass parsing and secondary processes are subserved by distinct brain systems.