9,462 research outputs found

    A Review on Adverse Health Effects of Laboratory Volatile Solvents

    Get PDF
    The main objective of this review is to describe the health effects of commonly used laboratory volatile solvents in institutional laboratories. The most commonly used laboratory solvents such as petroleum ether, methanol, diethyl ether, benzene, acetone, mercury, etc. are having moderate to severe health effects on user. The mode of exposure and duration exposure of volatile solvents has greater effect on user. In a laboratory, when students/ researcher doing experiment unknowingly they are getting exposed with volatile solvents which has grater health (adverse) effect. The severity of the adverse effect varies based on type of exposure and duration exposure. The undesired effects of laboratory volatile solvents are sometime irreversible and may cause life-threatening problems

    Spontaneous pneumomediastinum: a rare complication of idiopathic pulmonary fibrosis.

    No full text
    An 89-year-old woman with idiopathic pulmonary fibrosis (IPF) and a previous right mastectomy and implant for breast cancer presented with worsening breathlessness. There was no history of cough, haemoptysis, chest pain or fever. The chest radiograph (CXR, Fig. A) showed extensive fibrotic changes in both lungs consistent with the known diagnosis of IPF. A computerised tomo - graphy (CT) scan of the thorax revealed marked pneumo - mediastinum (black arrows) extending throughout the length the mediastinum (Fig. B). No subcutaneous emphysema was noted and no obvious cause for the pneumomediastinum was identifiable. There was no history of trauma or evidence to suggest pulmonary or mediastinal infection from gas-forming organisms. There was also no recent history of tracheobronchial or oesophageal interventions and a barium swallow excluded an oesophageal rupture. A diagnosis of spontaneous pneumomediastium (SPM) was made. The patient was managed conservatively. Her dyspnoea gradually improved and she was discharged home

    Characterisation of GNSS Space Service Volume

    Get PDF
    There is increasing demand for navigation capability for space vehicles. The idea to extend the application of Global Navigation Satellite Systems (GNSS) from terrestrial to space applications by the use of main beam and side lobe signals has been shown to be feasible. In order to understand the performance and the potential space applications GNSS can support, this paper characterises the Space Service Volume (SSV) in terms of the four parameters of minimum received power, satellite visibility, pseudorange accuracy and Geometric Dilution of Precision (GDOP). This new definition enables the position errors to be estimated. An analytical methodology is proposed to characterise minimum received power for the worst location. Satellite visibility and GDOP are assessed based on grid points at different height layers (to capture the relationship between height and visibility) for single and multiple GNSS constellations, the former represented by BeiDou III (BDS III) and the latter, BDS III in various combinations with GPS, GLONASS and GALILEO. Additional simulation shows that GNSS can potentially support lunar exploration spacecraft at the Earth phasing orbit. This initial assessment of SSV shows the potential of GNSS for space vehicle navigation

    A breath-hold R2 mapping pulse sequence detects a decrease in myocardial ferritin iron after one-week of iron chelation

    Get PDF
    Oral Abstract Session XI – New CMR Methods Applied to Human Imaging: O69Intracellular ferritin iron is evidently in equilibrium with the cytosolic iron pool that can change rapidly with iron chelation. This study demonstrates the feasibility of quantitatively detecting short-term changes in myocardial iron produced by iron-chelating therapy using RR2 measurement.postprintThe 13th Annual Scientific Sessions of the Society for Cardiovascular Magnetic Resonance (SCMR), Phoenix, AZ., 21-24 January 2010. In Final Program of the 13th Annual Scientific Sessions of SCMR, 2010, p. 29, abstract no. O6

    Transition probabilities for general birth-death processes with applications in ecology, genetics, and evolution

    Full text link
    A birth-death process is a continuous-time Markov chain that counts the number of particles in a system over time. In the general process with nn current particles, a new particle is born with instantaneous rate λn\lambda_n and a particle dies with instantaneous rate μn\mu_n. Currently no robust and efficient method exists to evaluate the finite-time transition probabilities in a general birth-death process with arbitrary birth and death rates. In this paper, we first revisit the theory of continued fractions to obtain expressions for the Laplace transforms of these transition probabilities and make explicit an important derivation connecting transition probabilities and continued fractions. We then develop an efficient algorithm for computing these probabilities that analyzes the error associated with approximations in the method. We demonstrate that this error-controlled method agrees with known solutions and outperforms previous approaches to computing these probabilities. Finally, we apply our novel method to several important problems in ecology, evolution, and genetics

    Iron Status and Analysis of Efficacy and Safety of Ferric Carboxymaltose Treatment in Patients with Inflammatory Bowel Disease

    Get PDF
    Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels 60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Base

    Transportability of Overall Survival Estimates From US to Canadian Patients With Advanced Non-Small Cell Lung Cancer With Implications for Regulatory and Health Technology Assessment.

    Get PDF
    IMPORTANCE: The external validity of survival outcomes derived from clinical practice data from US patients with advanced non-small cell lung cancer (NSCLC) is not known and is of potential importance because it may be used to support regulatory decision-making and health technology assessment outside of the US. OBJECTIVE: To evaluate whether overall survival (OS) estimates for a selected group of patients with advanced NSCLC from a large US clinical practice database are transportable to Canadian patients receiving the same systemic therapies. DESIGN, SETTING, AND PARTICIPANTS: This retrospective multicenter cohort study used transportability analysis to assess whether adjustment for pretreatment characteristics of eligible patient cohorts could reliably approximate OS estimated from US-based samples to Canadian populations. A total of 17 432 eligible adult patients who were diagnosed de novo with advanced NSCLC on or after January 1, 2011, were included in the analysis and followed up until September 30, 2020. Because data on race and ethnicity were available in the US database but not the Canadian database and because racial and ethnic distribution was likely to be similar between US and Canadian patients, these characteristics were not analyzed. EXPOSURES: Initiation of platinum-doublet chemotherapy or pembrolizumab monotherapy as first-line systemic treatment for advanced NSCLC. MAIN OUTCOMES AND MEASURES: OS measured from the time of initiation of the respective treatment regimen. RESULTS: Among 17 432 eligible patients, 15 669 patients from the US and 1763 patients from Canada were included in the analysis. Of those, 11 863 patients (sample size-weighted estimates of mean [SD] age, 68.0 [9.3] years; 6606 [55.7%] male; 10 100 from the US and 1763 from Canada) were included in the subset of patients with complete data for baseline covariates. A total of 13 532 US patients received first-line chemotherapy, and 2137 received first-line pembrolizumab monotherapy. Of those, 8447 patients (62.4%) in the first-line chemotherapy group and 1653 patients (77.3%) in the first-line pembrolizumab group had complete data on baseline covariates for outcome model estimation. A total of 1476 Canadian patients who received first-line chemotherapy and 287 patients who received first-line pembrolizumab monotherapy were identified from the target population. After standardization to baseline patient covariates in the Canadian cohorts, transported OS estimates revealed a less than 5% mean absolute difference from the observed OS in the target population (0.56% over 60 months of follow-up in the first-line chemotherapy group and 4.54% over 30 months of follow-up in the first-line pembrolizumab group). Negative control analysis using a mismatched outcome model revealed a 6.64% discrepancy and an incompatible survival curve shape. The results were robust to assumptions of random missingness for baseline covariates, to unadjusted differences in baseline metastases and comorbidities, and to differences in the standard of care between the US and Canada related to administration of second-line anti-programmed cell death 1 ligand 1 immunotherapy for patients who initiated first-line chemotherapy. CONCLUSIONS AND RELEVANCE: The results of this cohort study suggest that, under specific circumstances, OS estimates from US clinical practice data can be adjusted using baseline clinical characteristics to closely approximate OS in selected groups of Canadian patients with advanced NSCLC. These results may have implications for regulatory decision-making and health technology assessment in target populations outside of the US

    Nano-cathodoluminescence reveals the effect of electron damage on the optical properties of nitride optoelectronics and the damage threshold

    Get PDF
    Nano-cathodoluminescence (Nano-CL) reveals optical emission from individual InGaN quantum wells for applications in optoelectronic devices. We show the luminescent intensity decays over time with exposure to the electron beam for energies between 80 and 200 keV. Measurements of the CL intensity over time show an exponential decline in intensity, which we propose is due to the formation of nitrogen Frenkel defects. The measured CL damage decreases with reductions in the electron accelerating voltage and we suggest that the electron induced structural damage may be suppressed below the proposed damage threshold. The electron beam induced damage leads to a non-radiative region that extends over the measured minority carrier diffusion length. Nano-CL may thus serve as a powerful technique to study III-nitride optoelectronics.This work was carried out with the support of the United Kingdom Engineering and Physical Sciences Research Council under Grant Nos. EP/NO17927/1 and EP/J003603/1. R. Oliver acknowledges funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement number 279361 (MACONS) and the from the Royal Academy of Engineers/Leverhulme Trust senior research fellowship
    corecore