1,170 research outputs found

    DEVELOPMENT OF AN AUTOMATED BATCH-PROCESS SOLAR WATER DISINFECTION SYSTEM

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    One of the shortcomings of solar disinfection of water (SODIS) is the absence of a feedback mechanism indicating treatment completion. This work presents the development of an automated batch-process water disinfection system aimed at solving this challenge. Locally sourced materials in addition to an Arduinomicro processor were used to control the algorithm of the water disinfection system. A comparison of solar radiation sensing accuracy of the system to the Campbell Stokes instrument using student’s t-test showed no significance difference between the two data sets at p=0.05. Test conducted with Escherichia Coli spiked water shows that a 6 log reduction in CFU/ml was achieved within 15 minutes for an average global solar irradiance of 400 W/m2. The system disinfected 11 litres of water in a day for solar radiation of 8.5 MJ/m2/day and Escherichia coli concentration not exceeding 106 CFU/ml.  http://dx.doi.org/10.4314/njt.v36i1.3

    CP properties of symmetry-constrained two-Higgs-doublet models

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    The two-Higgs-doublet model can be constrained by imposing Higgs-family symmetries and/or generalized CP symmetries. It is known that there are only six independent classes of such symmetry-constrained models. We study the CP properties of all cases in the bilinear formalism. An exact symmetry implies CP conservation. We show that soft breaking of the symmetry can lead to spontaneous CP violation (CPV) in three of the classes.Comment: 14 pages, 2 tables, revised version adapted to the journal publicatio

    Serum hormonal levels in HIV/AIDS infected male subjects on antiretroviral therapy (ART) in Nnewi, Nigeria

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    This study was designed to assess the serum hormonal levels (Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Testosterone, Estrogen, Progesterone, Prolactin and Cortisol) in symptomatic HIV/AIDS male subjects on ART. A total of 411 participants aged between 17 and 58 (43 ±10) years were randomly recruited for the study. The participants were staged and grouped as follows: symptomatic HIV/AIDS male subjects on ART (n= 139), symptomatic HIV/AIDS male subjects not on ART (n= 136) and HIV seronegative subjects (n= 136). Blood samples were collected from the participants for the determination of HIV status by immunochromatography and HIV confirmation by Western Blot. Enzyme Linked Immunosorbent assay (ELISA) was used to assay for FSH, LH, Testosterone, Estrogen, Progesterone, Prolactin and Cortisol levels. Their results showed significant rise in FSH, LH in HIV seropositive participants on ART compared respectively to those not on ART and the HIV seropositive subjects (p< 0.05). On the other hand, the Estrogen, Progesterone, Prolactin and Cortisol were all raised in symptomatic HIV seropositive participants not on ART compared respectively to the symptomatic HIV seroposive on ART and the HIV seronegative groups(p< 0.05). The testosterone levels significantly decreased in both symptomatic HIV infected subjects on ART and those not on ART compared with the HIV seronegative controls (p< 0.05). The relevance of HIV infection on the serum hormonal status is that HIV infection causes hypogonadism as well as primary testicular failure in symptomatic HIV participants not on ART. Also, HIV infection causes hyperprolactinaemia,hyperprogesteronaemia and hypercortisolism in symptomatic HIV  participants not on ART

    Copper-based water repellent and antibacterial coatings by aerosol assisted chemical vapour deposition

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    The adhesion and proliferation of bacteria on solid surfaces presents a major challenge in both healthcare and industrial applications. In response to this problem, an effective and simple method is reported to fabricate superhydrophobic antibacterial copper coated polymer films via aerosol assisted chemical vapor deposition (AACVD). The material is characterized using a range of techniques including electron microscopy, water contact angle measurement and elemental mapping. The antibacterial activity of the modified film is tested against the Gram-negative bacterium, Escherichia coli, and the Gram-positive bacterium, Staphylococcus aureus and the film shows highly significant antibacterial activity against both bacteria (>4 log reduction in bacterial numbers) in 15 min and 60 min, respectively. In addition, all the CVD modified samples results in a significant reduction in bacterial cell adhesion compared to the control materials. Thus, we report a new film type that has dual mode of action-the superhydrophobicity helps limit cell adhesion combined with a cytotoxic copper induced bacteria kill

    The association between attention-deficit/hyperactivity disorder and retinal nerve fiber/ganglion cell layer thickness measured by optical coherence tomography: a systematic review and meta-analysis

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    Purpose: Retinal nerve fiber/ganglion cell layer (RNFL/GCL) thickness measured using optical coherence tomography has been proposed as an ocular biomarker for children with attention-deficit/hyperactivity disorder (ADHD), but findings varied in different studies. This study aims to determine the association between RNFL/GCL thickness and ADHD in children by systematic review and meta-analysis. / Methods: We performed a literature search in Embase, PubMed, Medline, Web of Science, and PsycINFO for relevant articles published up to February 29, 2020. All studies with original data comparing RNFL/GCL thickness in ADHD and healthy children were included. The Newcastle Ottawa Scale was used to assess bias risk and quality of evidence. Pooled estimates of the differences in thickness of RNFL or GCL between ADHD and healthy subjects were generated using meta-analysis with a random-effect model due to significant inter-study heterogeneity. Sensitivity analysis was also performed. / Results: We identified four eligible studies involving a total of 164 ADHD and 150 control subjects. Meta-analysis revealed that ADHD in children was associated with a reduction in global RNFL thickness (SMD, − 0.23; 95% CI − 0.46, − 0.01; p = 0.04). The global GCL thickness was examined in two studies with 89 ADHD and 75 control subjects, but the pooled difference in global GCL thickness between ADHD children and controls was not statistically significant (SMD, − 0.34; 95% CI − 1.25, 0.58; p = 0.47). / Conclusion: Existing evidence suggests a possible association between ADHD and RNFL thinning in children. In view of the limited number of reports, further studies in large cohorts should be warranted

    Impact of Snoring on Telomere Shortening in Adolescents with Atopic Diseases

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    Atopic diseases can impose a significant burden on children and adolescents. Telomere length is a cellular marker of aging reflecting the impact of cumulative stress exposure on individual health. Since elevated oxidative stress and inflammation burden induced by chronic atopy and snoring may impact telomere length, this study aimed to investigate whether snoring would moderate the relationship between atopic diseases and telomere length in early adolescence. We surveyed 354 adolescents and their parents. Parents reported the adolescents’ history of atopic diseases, recent snoring history as well as other family sociodemographic characteristics. Buccal swab samples were also collected from the adolescents for telomere length determination. Independent and combined effects of atopic diseases and snoring on telomere length were examined. Among the surveyed adolescents, 174 were reported by parents to have atopic diseases (20 had asthma, 145 had allergic rhinitis, 53 had eczema, and 25 had food allergy). Shorter TL was found in participants with a history of snoring and atopic diseases (β = −0.34, p = 0.002) particularly for asthma (β = −0.21, p = 0.007) and allergic rhinitis (β = −0.22, p = 0.023). Our findings suggest that snoring in atopic patients has important implications for accelerated telomere shortening. Proper management of atopic symptoms at an early age is important for the alleviation of long-term health consequences at the cellular level

    Elevated expression of artemis in human fibroblast cells is associated with cellular radiosensitivity and increased apoptosis

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    Copyright @ 2012 Nature Publishing GroupThis article has been made available through the Brunel Open Access Publishing Fund.Background: The objective of this study was to determine the molecular mechanism(s) responsible for cellular radiosensitivity in two human fibroblast cell lines 84BR and 175BR derived from two cancer patients. Methods: Clonogenic assays were performed following exposure to increasing doses of gamma radiation to confirm radiosensitivity. γ-H2AX foci assays were used to determine the efficiency of DNA double strand break (DSB) repair in cells. Quantitative-PCR (Q-PCR) established the expression levels of key DNA DSB repair proteins. Imaging flow cytometry using Annexin V-FITC was used to compare artemis expression and apoptosis in cells. Results: Clonogenic cellular hypersensitivity in the 84BR and 175BR cell lines was associated with a defect in DNA DSB repair measured by the γ-H2AX foci assay. Q-PCR analysis and imaging flow cytometry revealed a two-fold overexpression of the artemis DNA repair gene which was associated with an increased level of apoptosis in the cells before and after radiation exposure. Over-expression of normal artemis protein in a normal immortalised fibroblast cell line NB1-Tert resulted in increased radiosensitivity and apoptosis. Conclusion: We conclude elevated expression of artemis is associated with higher levels of DNA DSB, radiosensitivity and elevated apoptosis in two radio-hypersensitive cell lines. These data reveal a potentially novel mechanism responsible for radiosensitivity and show that increased artemis expression in cells can result in either radiation resistance or enhanced sensitivity.This work was supported in part by The Vidal Sassoon Foundation USA. This article is made available through the Brunel Open Access Publishing Fund
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