337 research outputs found

    Effect of membrane properties on the performance of batch reverse osmosis (RO): The potential to minimize energy consumption

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    Efforts to improve the performance of RO desalination include new membranes and new system configurations. Batch RO is an innovative configuration which helps to minimize Specific Energy Consumption (SEC) at high recovery. However, there is a lack of experimental studies regarding the performance of different membranes in batch RO. In this study, we tested four 8-in. RO membranes of different permeabilities in a free-piston batch RO system to assess how membrane properties affect performance. Tests were conducted with brackish feed water containing 1000–5000 mg/L of NaCl, at recovery of 0.8. Performance in terms of SEC, permeate quality and salt rejection was quantified. SEC and salt rejection varied considerably from low-permeability to high-permeability membranes. For the lowest permeability membrane rejection was >95 %, whereas for the higher permeability membranes it was only 82–96 %. SEC with high-permeability membranes was approximately 25–29 % lower than with the lowest permeability membrane. Using a verified model, we predict that on increasing the permeability from 5 to 20 L/m2/h/bar, hydraulic SEC would go down further by 17–28 % using ultra high-permeability membranes. Though this study shows the potential for SEC reduction, it also underlines the limitations of current commercial membranes and therefore the need for membranes with even higher permeability

    Ameliorating the effect of Zingiber officinale (ginger) hydroethanolic extract on scopolamine-induced memory impairment in adult male rats

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    Background and aims: The spice Zingiber officinale or ginger possesses antioxidant and neuroprotective effects. In this study we hypothesized that treatment with hydroethanolic extract of ginger (50, 100 and 200 mg/kg, p.o) would have an effect on the scopolamine-induced memory impairment in rats. Methods: In this experimental study, 64 male Wistar rats were divided into eight groups (8 rats in each group): normal saline, scopolamine (1 mg/kg), ginger extract (50, 100 and 200 mg/kg), or scopolamine (1 mg/kg) plus ginger extract (50, 100 and 200 mg/kg). Memory impairment was induced with a single injection of scopolamine (1 mg/kg, i.p). Cognitive functions were evaluated using passive avoidance learning (PAL) task. Retention test was carried out 24 hours after training, and the latency of entering the dark compartment step-through latency (STL) and the total time in the dark compartment (TDC) were recorded. All statistical analysis was carried out at 5% level of significance using SPSS version 21. The data were analyzed by ANOVA followed by Tukey’s test. Results: The time latency in scopolamine-treated group was lower than control (p<0.001). Treatment of the animals by 100 and 200 mg/kg of ginger extract before the training trial increased the time latency at 24 h after the training trial (p<0.01). Also, administration of extract at doses of 100 and 200 mg/kg in scopolamine received groups before retention trials, increased the time latency than the scopolamine only treated groups (p<0.001). Conclusion: The results revealed that the ginger hydroethanolic extract attenuated scopolamine-induced memory impairment

    Histological characterisation of the skin of the Paraechinus hypomelas, Brandt, 1836 (Erinaceidae: Eulipotyphla)

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    Background: The current study represents the first description of the histological characterisations of the normal skin of Brandt’s hedgehog (paraechinus hypomelas). Materials and methods: Skin samples were collected from abdomen, back, nostril and cloacal regions. Results: The skin consisted of 3 layers including epidermis, dermis and hypodermis. The epidermis was covered by a layer of keratinised squamous epithelium mainly in the back region, but the skin keratinisation was present with a little amount or may was absent in other regions. Histologically, the total thickness of skin was maximum on the back and minimum on the cloacal regions. The epidermis consisted of 4 layers and stratum lucidum was absent in all regions. Beneath the epidermis, the dermis layer was constituted of dense connective tissue in which the hair follicles, sweat glands, sebaceous glands, arrector pilli muscles and blood vessels were present. The sweat and sebaceous glands were more populated in the nostril region. The hair follicles were located in the epidermal and dermal regions. Vibrissae were only in the nostrils region and characterised from other hairs by their large and well innervated hair follicle which was surrounded by the blood sinus. Conclusions: The present findings show that in Brandt’s hedgehog (paraechinus hypomelas) the back and cloacal regions have thickest and thinnest skin respectively as compared to the nostril and abdominal regions. In addition, sebaceous and sweat glands were mainly populated in the nostril regio

    Report of a new mutation and frequency of connexin 26 gene (GJB2) mutations in patients from three provinces of Iran

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    Autosomal recessive and sporadic non-syndromic hearing loss (ARSNSHL) is the major form of hereditary deafness. Mutations in the GJB2 gene encoding the gap-junction protein Connexin 26 have been identified to be highly associated with ARSNSHL. In this study we have analyzed 196 deaf subjects from 179 families having one or more deaf children in 3 proviences of Iran, including Kordestan, Khuzestan and Golestan. The nested PCR prescreening strategy and direct sequencing technique were used to detect the mutations in coding exon of the gene. Altogether 3 GJB2 recessive mutations including 35delG, 167delT and V27I+E114G, were identified in 23 of 179 families (12.8). Fourteen of 179 families were observed to have GJB2 mutation in both alleles (7.8). A novel variant (R159H) also was found in a deaf family from Khuzestan. Four polymorphisms V27I, E114G, S86T and V153 I also were detected in 7 families. A polymorphism(S86T) was seen in the whole population studied. Our data indicated that the rate of connexin 26 mutations is different in this three Irainian population and is lower than the high frequency of 35delG (26) reported from Gilan province in the north of Iran

    What is the optimum time to start antiretroviral therapy in people with HIV and tuberculosis coinfection? A systematic review and meta-analysis

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    Background: HIV and tuberculosis are frequently diagnosed concurrently. In March 2021, World Health Organization recommended that antiretroviral therapy (ART) should be started within two weeks of tuberculosis treatment start, at any CD4 count. We aimed to assess whether earlier ART improved outcomes in people with newly diagnosed HIV and tuberculosis. Methods: We did a systematic review by searching nine database for for trials that compared earlier ART to later ART initiation in people with HIV and tuberculosis. We included studied published from database inception to 12 March 2021. We compared ART within four weeks vs. ART more than four weeks after TB treatment, and ART within two weeks vs. ART between two and eight weeks, and stratified analysis by CD4 count. The main outcome was death; secondary outcomes included IRIS and AIDS-defining events. We used random effects meta-analysis to pool effect estimates. Results: 2468 abstracts were screened, from which we identified nine trials. Among people with all CD4 counts, there was no difference in mortality by earlier ART (≤ 4 week) vs. later ART (> 4 week) (risk difference [RD] 0%; 95% confidence interval [CI] -2% to +1%). Among people with CD4 count ≤50 cells/mm3, earlier ART (≤4 weeks) reduced risk of death (RD -6%; -10% to -1%). Among people with all CD4 counts earlier ART (≤4 weeks) increased the risk of IRIS (RD +6%, 95% CI +2% to +10%) and reduced the incidence of AIDS defining events (RD -2%, 95% CI -4% to 0%). Results were similar when trials were restricted to the five trials which permitted comparison of ART within two weeks to ART between two and eight weeks. Discussion: Earlier ART did not alter risk of death overall among people living with HIV who had TB disease. Trials were conducted between 2004 and 2014, before recommendations to treat HIV at any CD4 count or to rapidly start ART in people without TB. No trials included children or pregnant women. No trials included integrase inhibitors in ART regimens. For logistical and patient preference reasons, earlier ART initiation for everyone with TB and HIV may be preferred to later ART

    Exploring the feasibility of engaging Traditional Birth Attendants in a prevention of Mother to Child HIV Transmission program in Lilongwe, Malawi

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    ObjectiveTo investigate the willingness of Traditional Birth Attendants (TBAs) to provide single dose antiretroviral prophylaxis to infants born to mothers with HIV and the feasibility of providing the TBAs with antiretroviral medication.Design2 focus groups with a total of 17 registered TBAs.SettingLilongwe, MalawiMethodsTBAs were recruited by local health workers and participated in focus groups assessing their attitudes towards participation in a PMTCT program.ResultsTBAs were willing to participate in this prevention of mother-to-child HIV transmission (PMTCT) program and helped identify barriers to their participation.ConclusionsGiven appropriate support and training, TBAs’ participation in PMTCT programs could be an additional way to deliver medication to mothers and neonates who might otherwise miss crucial doses of medication

    Opinions on integrating couple counselling and female sexual reproductive health services into Voluntary Medical Male Circumcision services in Lilongwe, Malawi

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    Background Couples HIV Counselling and Testing (CHCT) has been found to be potentially beneficial than individual HIV Counselling and Testing for prevention and treatment of HIV. However, there are few health care opportunities for men and women to access health services together, leading to underutilization of CHCT service. Integrating female Sexual and Reproductive Health (SRH) services into male-dominated service could be more effective than trying to integrate men's health services into female-dominated health services. A potential site for male-female service integration could be Voluntary Medical Male Circumcision (VMMC) centers. Methodology We conducted a qualitative study in Lilongwe, Malawi between June to August 2018. Twenty VMMC clients, 20 peers and 20 VMMC providers completed individual in-depth interviews to share their opinions on what they thought about integrating CHCT and other SRH Services into VMMC services. These proposed SRH services include family planning, cervical cancer screening, sexually transmitted infection management and pre-exposure prophylaxis (PrEP). Content analysis was used to analyze the results. Results All participants were receptive to integration of CHCT, and most accepted the integration of SRH services into VMMC Services. Most VMMC clients, peers and care providers said that CHCT integration would help couples to know their HIV status, prevent HIV transmission, encourage healthy relationships, and provide a chance for women to participate in VMMC counselling and wound care. However, integration of other services, such as family planning and cervical cancer screening, drew mixed opinions among participants. Most VMMC clients, peers and providers felt that integration of services would promote male involvement and increase men's knowledge in feminine sexual reproductive health services. A few providers expressed concerns over service integration, citing reasons such as overcrowding, work overload, gender mixing, and lack of provider capacity and space. Most participants supported integrating PrEP with VMMC Services and felt that PrEP would complement VMMC in HIV prevention. Few providers, peers and VMMC clients felt the addition of PrEP to VMMC services would lead to high-risk sexual activity that would then increase the risk for HIV acquisition. A few participants recommended community sensitization when integrating some of sexual reproductive health services into VMMC Services to mitigate negative perceptions about VMMC services and encourage service uptake among couples Conclusion Most participants service providers, VMMC clients and Peers were receptive to integrating SRH services, particularly HIV prevention services such as CHCT and PrEP, into male dominated VMMC services. Adequate community sensitization is required when introducing other SRH services into VMMC services
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