Morphological, optical and photovoltaic characteristics of MoSe2/SiOx/Si heterojunctions.

This work reports the effect of different processing parameters on the structural and morphological characteristics of MoSe2 layers grown by chemical vapour deposition (CVD), using MoO3 and Se powders as solid precursors. It shows the strong dependence of the size, shape and thickness of the MoSe2 layers on the processing parameters. The morphology of the samples was investigated by field emission scanning electron microscopy (FESEM) and the thickness of the deposited layers was determined by atomic force microscopy (AFM). Raman and photoluminescence (PL) spectroscopies were used to confirm the high quality of the MoSe2 layers. Surface composition was examined by photoelectron spectroscopy (XPS). Moreover, the MoSe2/SiOx/Si heterojunctions exhibit diode behaviour, with a rectification ratio of 10, measured at ±2.0 V, which is due to the p-i-n heterojunctions formed at the p-Si/SiOx/MoSe2 interface. A photovoltaic effect was observed with a short circuit current density (Jsc), open circuit voltage (VOC) and efficiency of -0.80 mA/cm2, 1.55 V and 0.5%, respectively. These results provide a guide for the preparation of p-i-n heterojunctions based on few-layer MoSe2 with improved photovoltaic response.

The methamphetamine burn patient.

Early aggressive fluid resuscitation has significantly decreased the morbidity and mortality associated with volume losses from large burns. Although most patients are adequately resuscitated using the Parkland formula, we noted increased fluid requirements for shock resuscitation in patients involved in methamphetamine laboratory explosions. Because predominant users are young healthy individuals in their 20s and 30s, we had not anticipated burn shock resuscitation failures in this patient group. We reviewed our experience with burn patients with documented methamphetamine use to determine whether this patient group presents new dilemmas to the burn surgeon. A 2-year retrospective study of 30 patients (15 methamphetamine users, 15 controls) revealed that the methamphetamine burn patient requires two to three times the standard Parkland formula resuscitation. In this study, methamphetamine burns larger than 40% TBSA had a 100% mortality.

Repeat prescribing: which diagnoses, which drugs?

Background-Repeat prescribing should be limited to drugs which are to be prescribed on a long-term basis to patients whose conditions are stable. Early studies were based on small sample sizes. The definition of repeat prescribing has not been consistent and interpractice variation in repeat prescribing has not been described.Aims-To describe the diagnostic categories and anatomical groups associated with repeat prescriptions; to describe interpractice variation associated with repeat prescribing and to describe the repeat to consultation ratio for the most frequently prescribed diagnoses and drugs.Method-Doctors from a stratified quota sample of 22 Northern Ireland practices recorded their perceived diagnosis for every consultation and for every repeat prescription over a 2-week period.Results-The diagnostic categories significantly associated with repeat prescriptions were digestive, cardiovascular, neurological, psychiatric and metabolic ( p < 0.0001). The anatomical drug categories significantly associated with repeat prescriptions were gastrointestinal drugs, cardiovascular drugs, central nervous system drugs, dressings and appliances (p < 0.0001). There was wide interpractice variation in repeat prescribing (both overall and for individual anatomical groups) and associated diagnoses. High repeat to consultation ratios were recorded for ranitidine, temazepam and diazepan.Conclusions-Wide interpractice variation in repeat prescribing and associated diagnoses revealed poor consensus among practices. Therefore, the approach to the management of common conditions - whether to consult or issue a repeat prescription - was not uniform. The implications of these findings require further research. Commonly occurring diagnoses and drugs had unacceptably high repeat to consultation ratios. Copyright (c) 2000 John Wiley & Sons, Ltd.

Mutational analysis of the engrailed homeodomain recognition helix by phage display.

The homeodomain (HD) is a ubiquitous protein fold that confers DNA binding function on a superfamily of eukaryotic gene regulatory proteins. Here, the DNA binding of recognition helix variants of the HD from the engrailed gene of Drosophila melanogaster was investigated by phage display. Nineteen different combinations of pairwise mutations at positions 50 and 54 were screened against a panel of four DNA sequences consisting of the engrailed consensus, a non-specific DNA control based on the lambda repressor operator OR1 and two model sequence targets con-taining imperfect versions of the 5'-TAAT-3' consensus. The resulting mutant proteins could be divided into four groups that varied with respect to their affinity for DNA and specificity for the engrailed consensus. The altered specificity phenotypes of several mutant proteins were confirmed by DNA mobility shift analysis. Lys50/Ala54 was the only mutant protein that exhibited preferential binding to a sequence other than the engrailed consensus. Arginine was also demonstrated to be a functional replacement for Ala54. The functional combinations at 50 and 54 identified by these experiments recapitulate the distribution of naturally occurring HD sequences and illustrate how the engrailed HD can be used as a framework to explore covariation among DNA binding residues.

Repeat prescribing management--a cause for concern?

BACKGROUND: No existing studies of repeat prescribing management have been carried out on statistically adequate samples permitting an extrapolation of results with regard to the population of general practitioners (GPs). AIM: To provide adequate regional evidence of the quality of repeat prescribing management for the profession and its administrators, and to test a scoring system for quality assurance in repeat prescribing practice. METHOD: A semi-structured questionnaire was administered by one observer to a statistically representative population sample of Northern Ireland's general practices to investigate the extent to which they adopted recommended procedures for the management of repeat prescribing. Responses to 26 of these questions were used to score the quality of management. The subjects were a random sample of 57 practices stratified for number of partners, geographical area, and fundholding status. RESULTS: The main outcome measures were the percentage adoption of recommended procedures at the time of repeat prescription issue and at the review consultation, use of computing for repeat prescribing and the effects of fundholding; and quality assurance scores. During issue of repeats, essential checks are often omitted; the potential of computerization for improving management is often not realized. At review consultation, the opportunities for quality assurance are often missed. Fundholders manage repeat prescribing significantly better than non-fundholders, but in neither group is the mean management score exemplary. CONCLUSION: We have identified and quantified serious deficiencies in repeat prescribing management in a representative sample large enough to permit extrapolation to the regional population of GPs. In response, we have devised guidelines that GPs might use to address this problem. We have tested and proved a scoring system for repeat prescribing evaluation.

Antibiotic prescribing for respiratory tract infections in general practice.

OBJECTIVES: (1) To describe interpractice variation in diagnosis of respiratory infections at consultation. (2) To test the hypotheses that: (a) The decision to prescribe an antibiotic in respiratory infection is influenced by the diagnosis, the perceived certainty of diagnosis, and whether or not a consultation takes place. (b) The choice of antibiotic is influenced by the diagnosis. DESIGN: A regional survey of prescribing and associated morbidity in general practice, over a 2-week period in April 1994. SETTING: Stratified quota sample of 22 Northern Ireland practices. RESULTS: There was wide interpractice variation in diagnosis of common respiratory infections at consultation, especially tonsillitis (5.0-157.5/1000 consultations). Overall, different diagnoses predicted the decision to prescribe an antibiotic at different levels (coryza 42.3%, tonsillitis 84.8%), but there was wide interpractice variation in the decision to prescribe for most diagnoses. With the exception of coryza and sinusitis, the perceived certainty of diagnosis did not significantly influence the decision to prescribe. The decision to prescribe was not significantly influenced by whether or not a consultation took place. Overall, broad spectrum penicillins were the therapeutic group most frequently prescribed for a given diagnosis with the exception of tonsillitis (phenoxymethylpenicillin) and sinusitis (tetracyclines), but there was wide interpractice variation in choice of antibiotic. CONCLUSIONS: Little consensus exists among practices regarding rational prescribing decisions in respiratory illness. The absence of a consultation was no deterrent to antibiotic prescribing. At one extreme, it is suggested that some practices are avoiding consultations for respiratory infections. There is wide variation in choice of antibiotic, despite existing guidelines.

The use of angiotensin converting enzyme inhibitors in general practice--appropriate or inappropriate?

AIMS: To evaluate the pattern of prescribing of angiotensin-converting enzyme (ACE) inhibitors in general practice, related to the primary clinical diagnosis and concomitant medication. DESIGN: A descriptive survey of general practitioners' prescribing habits, presumptive diagnosis and patient demography over a period of 2 weeks in April 1994. SETTING: A stratified quota sample of 22 practices in Northern Ireland. RESULTS: The major clinical indication for the use of ACE inhibitors was essential hypertension (61.5%) with only a minority usage (19.9%) in congestive heart failure. Co-prescription of drugs with potential for interaction with angiotensin-converting enzyme inhibitors was not uncommon (16.7%). Of the 353 patients with a diagnosis of congestive heart failure, only 64 (18.1%) were receiving ACE inhibitors. The dosages used were lower than recommended for this indication. A significantly higher proportion of elderly patients with heart failure were prescribed hypnotic drugs (14.7% versus 8.3%; p<0.001) and had the co-existence of insomnia (11.8% versus 6.9%; p<0.001) compared to patients without heart failure. CONCLUSIONS: ACE inhibitors were underused in the treatment of congestive heart failure, and were often prescribed in suboptimal dosages. The frequent concurrent prescription of hypnotics and the co-existence of insomnia in heart failure may reflect this therapeutic strategy.

Peripheral vasodilators and the management of peripheral vascular disease and Raynaud's syndrome in general practice.

There is no convincing evidence that peripheral vasodilators produce any significant improvement in exercise tolerance in patients with peripheral vascular disease, and these drugs may do more harm than good. In the treatment of severe Raynaud's syndrome, however, thymoxamine, prazosin or nifedipine is recommended. A descriptive study was carried out, firstly, to determine why these drugs are prescribed in general practice, and secondly, to describe the drug choices in the treatment of both Raynaud's syndrome and peripheral vascular disease in a representative sample of 22 practices in Northern Ireland. Of those patients prescribed peripheral vasodilators 69.6% were diagnosed as peripheral vascular disease, claudication or atherosclerosis. Over three-quarters of peripheral vasodilators prescribed were repeat prescriptions. Of those with Raynaud's syndrome only half were treated appropriately, and certainty of diagnosis did not guarantee appropriate treatment. Peripheral vasodilators accounted for the majority (51.5%) of items prescribed for peripheral vascular disease. A minority of patients with peripheral vascular disease (20.3%) were prescribed aspirin, and a smaller minority (4.4%) had undergone amputation. Peripheral vasodilators were prescribed unnecessarily and inappropriately. Measures to promote evidence-based treatment of both Raynaud's syndrome and peripheral vascular disease in general practice need to be taken.

Research methodology: Coding perceived morbidity in general practice--an evaluation of the Read Classification and the International Classification of Primary Care (ICPC).

OBJECTIVES: To evaluate the Read Classification and the International Classification of Primary Care (ICPC). METHODS: The Read Classification was used to code the diagnoses for 3474 patient encounters, in a pilot sample of three volunteer practices (11 general practitioners), and the ICPC was used to code 21,416 patient encounters in a stratified quota sample of 22 practices (59 general practitioners), in a survey aiming to relate prescribing to perceived diagnosis. RESULTS/EXPERIENCE: The Read Classification was found to be a detailed and exhaustive classification of medical diagnoses, but it was more time consuming to use than the ICPC, due to the complexity of the classification, the over-use of alpha characters compared to the ICPC, and the mixing of alpha characters with numeric digits within the codes. Encoding, decoding and statistical analysis were found to be more straightforward using the ICPC compared with the Read Classification. The ICPC was found to be deficient in 40 important diagnoses, and these are listed. CONCLUSION: The Read Classification was of limited value in this drug utilization survey, in that the design of the code reduced its utility in statistical analyses. The ICPC was an efficient code, which met the criteria of exclusiveness, usefulness and hierarchy. The classification is not exhaustive enough to prevent loss of information as a result of coding, but the authors' amendments virtually eliminated this problem.

Glucocorticoids coordinately regulate type I collagen pro alpha 1 promoter activity through both the glucocorticoid and transforming growth factor beta response elements: a novel mechanism of glucocorticoid regulation of eukaryotic genes.

Glucocorticoids have previously have shown to decrease Type I collagen synthesis in vivo and in fibroblast cell culture. Several studies have demonstrated that glucocorticoids decrease Type I procollagen gene expression. These latter studies have included uridine incorporation into pro alpha 1 (I) and pro alpha 2 (I) mRNAs and nuclear run-off experiments. Using the ColCat 3.6 plasmid, which contains part of the 5' flanking region of the pro alpha 1 (I) collagen gene and the reporter gene, chloramphenicol acetyltransferase, the present studies demonstrate by stable transfection of fetal rat skin fibroblasts that dexamethasone down regulates the promoter activity of the pro alpha 1 (I) collagen gene. The glucocorticoid-mediated down-regulation of procollagen gene expression was demonstrated using the ColCat 3.6, 2.4, 1.7, or 0.9 plasmid. In addition, competitive oligonucleotide transfection experiments and site specific mutation of the glucocorticoid response element (GRE) in the whole ColCat 3.6 plasmid did not eliminate the effect. The possibility existed that another cis-element in the 5' flanking region of the pro alpha 1 (I) collagen gene was also required for the collagen glucocorticoid-mediated down-regulation of procollagen gene expression, since TGF-beta has been shown to stimulate in a decrease of transforming growth factor-beta (TGF-beta) secretion into the media. Gel mobility studies demonstrated that glucocorticoid treatment of rat skin fibroblasts decreased glucocorticoid receptor binding to the GRE and TGF-beta activator protein to the TGF-beta element which were brought back to control values by coordinate exogenous TGF-beta treatment. Thus the interaction of these TGF-beta molecules with cellular membrane receptors and subsequent transduction is dramatically decreased resulting in less signals to regulate collagen gene expression. These data indicate that glucocorticoids coordinately regulate procollagen gene expression through both the GRE and TGF-beta elements. Depression of procollagen gene expression by glucocorticoids through the TGF-beta element is mediated by decreased TGF-beta secretion, possibly involving a secondary effect on regulatory protein(s) encoded by noncollagenous protein gene(s). The present studies provide the basis for a novel mechanism of glucocorticoid-mediator regulation of eukaryotic genes containing the TGF-beta element.

Hemoptysis as a presentation of mild hemophilia A in an adult.

It is not unusual for mild hemophilia A to escape detection into adolescent years and it is often detected following dental extractions or other mild trauma. The present report describes a patient shown to have only 8 to 9 percent factor VIII activity at age 30 years. The presentation of recurrent mild hemoptysis with upper respiratory tract infections is unusual and of interest in the differential diagnosis of hemoptysis.

Asthma in the Navy and Marine Corps.

Today, asthma is an increasing health problem in young Americans. In some cases, it can be quite difficult to diagnose. Many individuals enter military service each year with undiagnosed asthma, which subsequently limits their performance of duty. We review the patterns of asthma in children and young adults and relate this to Navy and Marine Corps personnel. We also review the current evaluation of this disease in the U.S. Navy Medical Department and suggest future improvements in this evaluation.

Intrathoracic osteosarcoma diagnosed by CT scan and pleural biopsy.

Osteosarcoma rarely presents as a primary lesion in the chest, whereas pulmonary metastases are common. The diagnosis of primary intrathoracic osteosarcoma has invariably been by thoracotomy or autopsy. We present a case of a densely calcified, primary intrathoracic osteosarcoma where diagnosis was made antemortem by pleural biopsies and computed tomography scan.

Torulopsis glabrata fungemia in a diabetic patient.

We have presented a case of a stable diabetic outpatient who had an acute illness that proved to be Torulopsis glabrata fungemia responsive to amphotericin B therapy. Her only apparent additional predisposition was a nonobstructing renal calculus. Fungemia with this organism in an outpatient is most unusual. T glabrata should be an additional consideration in outpatient as well as inpatient illnesses, especially in diabetic women.