178 research outputs found

    The thermo-mechanical degradation of ethylene vinyl acetate used as a solar panel adhesive and encapsulant

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    The thermal ageing of an Ethylene-vinyl Acetate (EVA) polymer used as an adhesive and encapsulant in a photovoltaic module has been investigated. The EVA is used to bond the silicon solar cells to the front glass and backing sheet and to protect the photovoltaic materials from the environment and mechanical damage. Using a range of experimental techniques, including Dynamic Mechanical Analysis, Differential Scanning Calorimetry and Thermo-Gravimetric analysis, it was possible to show a link between changes in mechanical properties with both the transient temperature and the degree of long-time thermal ageing. Importantly, it was possible to show that the ageing related property changes were likely due to long term structural changes rather than any modification of the chemistry of the material

    The Role of Liposomal CpG ODN on the Course of L. major Infection in BALB/C Mice

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    "nBackground: Historically, leishmanization is the most effective protective measure against Cutaneous Leishmaniasis (CL), CL lesion induced by leishmanization sometimes takes a long time to heal. Ma­nipulation of leishmanization inoculums needed to induce a mild and acceptable CL lesion. The aim of this study was to explore if liposomal form of CpG ODN (Cytosin phosphate Guanin Oligodeoxynu­cleotides) mixed with Leishmania major   would induce a milder lesion size in Balb/c mice."nMethods: This study was performed in Biotechnology Research Center, Mashhad, and Center for Re­search and Training in Skin Diseases and Leprosy, Tehran, Iran during 2008-2009.  mice were subcutaneously (SC) inoculated with L. major mixed with liposomal form of CpG ODN, or L. major plus free CpG ODN, or L. major mixed with empty liposomes or L. major in PBS. The lesion onset and the size of lesion were recorded; the death rate was also monitored. "nResult: Footpad thickness was significantly (P<0.01) smaller, death rate was also significantly (P<0.05) lower in the mice received L. major mixed with liposomal CpG ODN or free CpG ODN than control groups received L. major in PBS or L. major plus liposomes, also mice which received L. ma­jor mixed with CpG ODN in soluble form showed a significantly (P < 0.001) smaller lesion size than control groups."nConclusion: CpG ODN seems to be an appropriate immunopotentiator mixed with Leishmania stabi­late in leishmanization

    OPTIma:simplifying calorimetry for proton computed tomography in high proton flux environments

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    Objective. Proton computed tomography (pCT) offers a potential route to reducing range uncertainties for proton therapy treatment planning, however the current trend towards high current spot scanning treatment systems leads to high proton fluxes which are challenging for existing systems. Here we demonstrate a novel approach to energy reconstruction, referred to as ‘de-averaging’, which allows individual proton energies to be recovered using only a measurement of their integrated energy without the need for spatial information from the calorimeter. Approach. The method is evaluated in the context of the Optimising Proton Therapy through Imaging (OPTIma) system which uses a simple, relatively inexpensive, scintillator-based calorimeter that reports only the integrated energy deposited by all protons within a cyclotron period, alongside a silicon strip based tracking system capable of reconstructing individual protons in a high flux environment. GEANT4 simulations have been performed to examine the performance of such a system at a modern commercial cyclotron facility using a σ ≈ 10 mm beam for currents in the range 10–50 pA at the nozzle. Main results. Apart from low-density lung tissue, a discrepancy of less than 1% on the Relative Stopping Power is found for all other considered tissues when embedded within a 150 mm spherical Perspex phantom in the 10–30 pA current range, and for some tissues even up to 50 pA. Significance. By removing the need for the calorimeter system to provide spatial information, it is hoped that the de-averaging approach can facilitate clinically relevant, cost effective and less complex calorimeter systems for performing high current pCTs

    Using Combined Descriptive and Predictive Methods of Data Mining for Coronary Artery Disease Prediction: a Case Study Approach

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    Heart disease is one of the major causes of morbidity in the world. Currently, large proportions of healthcare data are not processed properly, thus, failing to be effectively used for decision making purposes. The risk of heart disease may be predicted via investigation of heart disease risk factors coupled with data mining knowledge. This paper presents a model developed using combined descriptive and predictive techniques of data mining that aims to aid specialists in the healthcare system to effectively predict patients with Coronary Artery Disease (CAD). To achieve this objective, some clustering and classification techniques are used. First, the number of clusters are determined using clustering indexes. Next, some types of decision tree methods and Artificial Neural Network (ANN) are applied to each cluster in order to predict CAD patients. Finally, results obtained show that the C&RT decision tree method performs best on all data used in this study with 0.074 error. All data used in this study are real and are collected from a heart clinic database

    Antifungal susceptibility testing of <i>Candida </i>species isolated from the immunocompromised patients admitted to ten university hospitals in Iran

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    Abstract Background Antifungal susceptibility testing is a subject of interest in the field of medical mycology. The aim of the present study were the distributions and antifungal susceptibility patterns of various Candida species isolated from colonized and infected immunocompromised patients admitted to ten university hospitals in Iran. Methods In totally, 846 Candida species were isolated from more than 4000 clinical samples and identified by the API 20 C AUX system. Antifungal susceptibility testing was performed by broth microdilution method according to CLSI. Results The most frequent Candida species isolated from all patients was Candida albicans (510/846). The epidemiological cutoff value and percentage of wild-type species for amphotericin B and fluconazole in Candida albicans, Candida tropicalis, Candida glabrata and Candida krusei were 0.5 μg/ml (95%) and 4 μg/ml (96%); 1 μg/ml (95%) and 8 μg/ml (95%); 0.5 μg/ml (99%) and 19 μg/ml (98%); and 4 μg/ml (95%) and 64 μg/ml (95%), respectively. The MIC90 and epidemiological cutoff values to posaconazole in Candida krusei were 0.5 μg/ml. There were significant differences between infecting and colonizing isolates of Candida tropicalis in MIC 90 values of amphotericin B, and isolates of Candida glabrata in values of amphotericin B, caspofungin, and voriconazole (P < 0.05). Conclusions Our findings suggest that the susceptibility patterns of Candida species (colonizing and infecting isolates) in immunocompromised patients are not the same and acquired resistance was seen in some species

    The epidemiology of Candida species isolated from urinary tract infections

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    Candida spp. are members of a genus, including closely related fungal species that cause a variety of infections. Objectives: The aim of this study was the isolation of various Candida species from vulvovaginitis and urethra of patients in Neyshabur, Northeast Iran from 2013 to 2015. Methods: This descriptive-analytical and cross-sectional study was performed to identify Candida spp. causing vulvovaginitis and Urinary Tract Infection (UTI) at a referral laboratory in Neyshabur district, Khorasan Razavi Province. A total of 451 vaginal and midstream urine samples were collected. Ten micro-liters of each specimen was cultured on CHROM agar plates and then incubated at 37°C for 24 to 48 hours, aerobically. Candida species were identified based on colony morphology, germ tube production and micro-morphology on corn meal agar including 1% Tween 80. Results: The mean age of the patients was 34.7_16.3. Candida albicans was the predominant species isolated. Moreover, age groups of 21 to 30 and 0 to 1 years were the most and the least infected individuals. Moreover, Candida spp. were significantly morecommon in females compared to males (P value 103. Conclusions: In this study, C. albicans was the most common species isolated from patients with vulvovaginitis and UTI, and significantly more common amongst females compared to males. The prevalence of candida spp. had significantly declined from 2013 to 2015. Moreover, the candida spp. counts were mostly higher than 103cfu/mL
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