951 research outputs found

    Solar System Using Parabolic Trough Collector for Water Desalination Unit

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    In this research, a parabolic trough solar collector was used for brackish water desalination. The aim of this research was to investigate the desalination characteristics of this solar system under variable operation parameters and to determine the most efficient design configuration. The experiments were performed on a locally fabricated parabolic trough collector composed of mirror collector, solar energy absorption system, steam-brine separation vessel, heat exchanger, electrical panel, and sun tracking device. The efficiency of the system was tested by changing the main parameters, namely, solar collector slope angle, brackish water feed flow rate, heat exchanger, incident angle, ambient temperature, and receiver temperature. The results showed that the maximum distilled water was 10.4 Lt/(5 hrs. (11:00 am to 16:00 pm)). This water production was achieved at feed water flow rate 4.8 Lt/hr, the incident angles were in the range of 10o to 54o, the ambient temperature was in the range of 30-32 oC, collector efficiency was in the range of 48-38%. In conclusion, this system proved to be promising and can be further developed to achieve better results

    Petrochemistry, petrogenesis and classification of Um Huqab, Garf and El-Mueilha granitic masses, Southeastern Desert, Egypt

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    The granitic masses of Um Huqab, Garf and El-Mueilha Southeastern Desert, Egypt, and belonging to synorogenic, late- and post-orogenic cycles are examined. Petrochemical characters based on major elements data of 13 newly analysed samples are clarified. Behaviour of major elements is discussed and chemical and modal classifications are presented based on normative feldspars and modal composition. Petrographical and petrochepiical data suggest a magmatic origin for the examined granitic rocks. El-Mueilha granitic mass suffered along the peripheral parts, as well as along faults leading to albitization

    Psychological Contract and its Impact on the Organizational Citizenship Behaviors- an Applied Study from Bahrain

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    The present paper aims to investigate the impact of psychological contract on the organizational citizenship behaviors within governmental business context. The study encompasses workers from the governmental service sector in Bahrain. 280 questionnaires were randomly distributed to the employees of different specialties. Simple and multiple regressions were used to analyze the data and test hypotheses. The results showed that the psychological contract used dimensions positively affected the organizational citizenship behaviors at the organization under study. Furthermore, there were no significant differences in the responses of the participants due to demographic variables, such as gender, age, qualification, position title, and professional experience

    Association of HLA (Class I & II) and Susceptibility to Hydatid Cyst Disease

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    Background: Hydatid cyst disease is a parasitic zoonotic disease caused by genus Echinococcus. This disease believed to has genetic background in it's aetiopathogenesis course . The aim of this study is to shed light on the possible correlation between HLA-class I (A,B,C) & HLA-class II (DR & DQ) antigens and the susceptibility to this disease. Patients & Methods: Fifty patient with hydatid cyst disease before undergoing surgical operation were investigated for HLA. Class I and class II by using microlymphocytotoxicity test. The results were compared with 115 healthy control. Results: Significant increased trend of HLA-A28 and A-11, -B18 and B-35, -DR3 and DR-11 (P<0.001, P<0.01) in patients with this disease as compared with healthy control. On the other hand, increased trend of HLA-28 (P<0.01) in patients with hydatid disease especially in those with a cyst location in liver. Conclusions: High frequency of HLA-A11 and –A28, B18 and –B35, -DR3 and –DR11 antigens may play major role in susceptibility to hydatid disease. HLA-A28 could be the most related antigen to this disease and acting as genetic marker that could in one way or another play crucial role in susceptibility especially in cases of hydatid disease in liver

    Assessment of strategies for switching patients from olanzapine to risperidone: A randomized, open-label, rater-blinded study

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    <p>Abstract</p> <p>Background</p> <p>In clinical practice, physicians often need to change the antipsychotic medications they give to patients because of an inadequate response or the presence of unacceptable or unsafe side effects. However, there is a lack of consensus in the field as to the optimal switching strategy for antipsychotics, especially with regards to the speed at which the dose of the previous antipsychotic should be reduced. This paper assesses the short-term results of strategies for the discontinuation of olanzapine when initiating risperidone.</p> <p>Methods</p> <p>In a 6-week, randomized, open-label, rater-blinded study, patients with schizophrenia or schizoaffective disorder, on a stable drug dose for more than 30 days at entry, who were intolerant of or exhibiting a suboptimal symptom response to more than 30 days of olanzapine treatment, were randomly assigned to the following switch strategies (common risperidone initiation scheme; varying olanzapine discontinuation): (i) abrupt strategy, where olanzapine was discontinued at risperidone initiation; (ii) gradual 1 strategy, where olanzapine was given at 50% entry dose for 1 week after risperidone initiation and then discontinued; or (iii) gradual 2 strategy, where olanzapine was given at 100% entry dose for 1 week, then at 50% in the second week, and then discontinued.</p> <p>Results</p> <p>The study enrolled 123 patients on stable doses of olanzapine. Their mean age was 40.3 years and mean (± standard deviation (SD)) baseline Positive and Negative Syndrome Scale (PANSS) total score of 75.6 ± 11.5. All-cause treatment discontinuation was lowest (12%) in the group with the slowest olanzapine dose reduction (gradual 2) and occurred at half the discontinuation rate in the other two groups (25% in abrupt and 28% in gradual 1). The relative risk of early discontinuation was 0.77 (confidence interval 0.61–0.99) for the slowest dose reduction compared with the other two strategies. After the medication was changed, improvements at endpoint were seen in PANSS total score (-7.3; <it>p </it>< 0.0001) and in PANSS positive (-3.0; <it>p </it>< 0.0001), negative (-0.9; <it>p </it>= 0.171) and anxiety/depression (-1.4; <it>p </it>= 0.0005) subscale scores. Severity of movement disorders and weight changes were minimal.</p> <p>Conclusion</p> <p>When switching patients from olanzapine to risperidone, a gradual reduction in the dose of olanzapine over 2 weeks was associated with higher rates of retention compared with abrupt or less gradual discontinuation. Switching via any strategy was associated with significant improvements in positive and anxiety symptoms and was generally well tolerated.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00378183</p

    Impact of Modifier Oxides on Mechanical and Radiation Shielding Properties of B2O3-SrO-TeO2-RO Glasses (Where RO = TiO2, ZnO, BaO, and PbO)

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    The influence of modifier oxides (TiO2, ZnO, BaO, and PbO) on the mechanical and radiation shielding properties of boro-tellurate glasses is investigated. Samples with a composition of B2O3-SrO-TeO2-RO (RO represents the modifier oxides) were fabricated using the melt quench method, and their physical, mechanical, and radiation attenuation parameters were reported. For this aim, Monte Carlo simulation was employed to predict the radiation attenuation parameters, while the Makishima-Mackenzie model was adopted to determine the mechanical properties. The tightly packed structure with better cross-linkage density is possessed by the Ti-containing glass (SBT-Ti) system among the titled glass batch. The higher Poisson and micro-hardness values of the SBT-Ti glass indicate its structure’s reduced free volume and better compactness. For the glass with PbO, the linear and mass attenuation coefficients are highly increased compared to those glasses doped with TiO2, ZnO, and BaO. The thinner half-value layer was reported at 0.015 MeV, taking values 0.006, 0.005, 0.004, and 0.002 for samples with TiO2, ZnO, BaO, and PbO, respectively. SBT-Pb sample (with PbO) has a thinner HVL compared to other fabricated glass samples. The fabricated glasses’ thickness (Deq) equivalent to 1 cm of lead (Pb) was reported. The results demonstrated that Deq is high at low energy and equals 11.62, 8.81, 7.61, 4.56 cm for SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb glass samples, respectively. According to the Deq results, the fabricated glasses have a shielding capacity between 30 and 43% compared to the pure Pb at gamma-ray energy of 1.5 MeV. At high energy (8 MeV), the transmission factor values for a thickness of 1 cm of the fabricated samples reach 88.68, 87.83, 85.95, and 83.11% for glasses SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb, respectively. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The authors acknowledge the support of Taif University Researchers Supporting Project number (TURSP-2020/127), Taif University, Taif, Saudi Arabia

    The presence of tumour-associated lymphocytes confers a good prognosis in pancreatic ductal adenocarcinoma: an immunohistochemical study of tissue microarrays

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    Background Tumour-associated lymphocytes (TALs) have been linked with good prognosis in several solid tumours. This study aimed to evaluate the prognostic significance of CD3, CD8 and CD20 positive lymphocytes in pancreatic ductal adenocarcinoma. Methods After histological re-evaluation of the tumours of 81 patients who underwent surgical resection for exclusively pancreatic ductal adenocarcinoma, tissue micro-arrays (TMA) were constructed and immunohistochemistry was performed for CD3, CD8 and CD20. The number of lymphocytes within specific tumour compartments (i.e. stromal and intratumoural) was quantified. X-tile software (Yale School of Medicine, CT, USA) was used to stratify patients into 'high’ and 'low’ for each of the lymphocytes stained and their association with survival. Receiver operating curves (ROC) were constructed to evaluate the association between the TALs, alone and in combination, with clinicopathological features. Results CD3 and CD8 positive lymphocytes were associated with grade of tumour differentiation. The presence of intratumoural CD3 positive cells was associated with improved survival (p = 0.028), and intratumoural and stromal CD3 in combination also correlated with improved survival (p = 0.043). When CD20 positive lymphocyte levels were high, survival improved (p = 0.029) and similar results were seen for CD20 in combination with intratumoural CD3 (p = 0.001) and stromal CD8 (p = 0.013). Conclusions This study has shown a correlation between the presence of TALs and survival in pancreatic ductal adenocarcinoma

    Endothelial cells regulate p53-dependent apoptosis of neural progenitors after irradiation

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    Endothelial cells represent an important component of the neurogenic niche and may regulate self-renewal and differentiation of neural progenitor cells (NPCs). Whether they have a role in determining the apoptotic fate of NPCs after stress or injury is unclear. NPCs are known to undergo p53-dependent apoptosis after ionizing radiation, whereas endothelial cell apoptosis after irradiation is dependent on membrane acid sphingomyelinase (ASMase) and is abrogated in sphingomyelin phosphodiesterase 1 (smpd1)- (gene that encodes ASMase) deficient mice. Here we found that p53-dependent apoptosis of NPCs in vivo after irradiation was inhibited in smpd1-deficient mice. NPCs cultured from mice, wild type (+/+) or knockout (−/−), of the smpd1 gene, however, demonstrated no difference in apoptosis radiosensitivity. NPCs transplanted into the hippocampus of smpd1−/− mice were protected against apoptosis after irradiation compared with those transplanted into smpd1+/+ mice. Intravenous administration of basic fibroblast growth factor, which does not cross the blood–brain barrier, known to protect endothelial cells against apoptosis after irradiation also attenuated the apoptotic response of NPCs. These findings provide evidence that endothelial cells may regulate p53-dependent apoptosis of NPCs after genotoxic stress and add support to an important role of endothelial cells in regulating apoptosis of NPCs after injury or in disease

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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