299 research outputs found

    Impact of Portlandite on Alkali-Silica Reaction of Pyrex Glass and Blastfurnace Slag Aggregate

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    In this study, it is investigated the effect of Ca ion on dissolution and reaction products in alkaline environment using Pyrex glass showing ASR expansion and blast furnace slag fine aggregate suppressing ASR. It is reported that Ca plays a role in the dissolution and polymerization of silica, and is therefore an important factor in ASR. For each sample, calculation of dissolution rate and analysis of solid phase product by 29Si MAS NMR and XRD/Rietveld analysis, and liquid phase analysis by ICP-AES were performed. As a result, it was confirmed that addition of Ca has an influence on dissolution behavior of PG and BFS. In the reaction of PG, addition of Ca promotes the polymerization reaction of silica and increases the amount of N-S-H which has expandable and contributes to deterioration mechanism. On the other hand, in BFS, the dissolved silica did not polymerize and N-S-H did not form. It was suggested that the difference in ASR reactivity between PG and BFS is due to the difference in the reaction behavior

    MHD Mixed Convection Micropolar Fluid Flow through a Rectangular Duct

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    Mixed convection flow through a rectangular duct with at least one of the sides of the walls of the rectangle being isothermal under the influence of transversely applied magnetic field has been analyzed numerically in this study. The governing differential equations of the problem have been transformed into a system of nondimensional differential equations and then solved numerically. The dimensionless velocity, microrotation components, and temperature profiles are displayed graphically showing the effects of various values of the parameters present in the problem. The results showed that the flow field is notably influenced by the considered parameters. It is found that increasing the aspect ratio increases flow reversal, commencement of the flow reversal is observed after some critical value, and the applied magnetic field increases the flow reversal in addition to flow retardation. The microrotation components flow in opposite direction; also it is found that one component of the microrotation will show no rotational effect around the center of the duct

    BIODEGRADATION OF POLYNUCLEAR AROMATIC HYDROCARBONS USING INDIGENOUS STRAINS OF BACTERIA FOR SUSTAINABLE SOIL DEVELOPMENT

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    16S rRNA gene sequence analyses of the four isolates from a former industrial site (OC1, OC2, OC3, and OC4) were assigned to the genus, Enterobacter (OC1) and Pseudomonas (OC2, OC3, and OC4). The degradation and growth behaviour of the four isolates were investigated on naphthalene, fluoranthene, pyrene and chrysene. All the strains utilized naphthalene, fluoranthene, chrysene but pyrene partially, as sole sources of carbon and energy. The time course studies using relative concentration> 100, >115, > 89 and> 12 ppm for naphthalene, fluoranthene, pyrene and chrysene respectively, resulted in rapid exponential increases in cell numbers and concomitant disappearance of the test substrates. Naphthalene was degraded between the range of 25 and 99%, while chrysene degradation ranged between 35 and 69%, pyrene 4 -21% and fluoranthene 7 -19 %. Our results suggest that contaminated, former industrial sites contain a capable microbial community that may be used for bioremediation of the site for sustainable soil developmen

    Lutein Has a Positive Impact on Brain Health in Healthy Older Adults: A Systematic Review of Randomized Controlled Trials and Cohort Studies

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    A previous systematic review revealed that lutein intake leads to improved cognitive function among older adults. However, the association between lutein intake and brain health remains unclear. Methods: We searched the Web of Science, PubMed, PsycInfo, and Cochrane Library for research papers. The criteria were (1) an intervention study using oral lutein intake or a cross-sectional study that examined lutein levels and the brain, (2) participants were older adults, and (3) brain activities or structures were measured using a brain imaging technique (magnetic resonance imaging (MRI) or electroencephalography (EEG)). Results: Seven studies using MRI (brain activities during rest, cognitive tasks, and brain structure) and two studies using EEG were included. We mainly focused on MRI studies. Three intervention studies using MRI indicated that 10 mg lutein intake over 12 months had a positive impact on healthy older adults’ brain activities during learning, resting-state connectivity, and gray matter volumes. Four cross-sectional studies using MRI suggested that lutein was positively associated with brain structure and neural efficiency during cognitive tasks. Conclusion: Although only nine studies that used similar datasets were reviewed, this systematic review indicates that lutein has beneficial effects on healthy older adults’ brain health

    Characterization of Diesel Degrading Bacterial Species from Contaminated Tropical Ecosystem

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    The bacterial diversity in a diesel contaminated tropical soil was investigated using diesel oxidation in gradient cultures dynamics (pH and OD) of the pure cultures. The diesel dependent growths of these isolates were assessed for 15 days by monitoring the gradient fluxes in the pH and Optical density OD of the media. Results showed an increase in OD as well as fluctuations in pH values. The mean OD data obtained was 0.515- 1.187 with pH of 6.95- 7.2. From the morphological and biochemical characterization and comparison with respect to the standard references, the isolates S1P1, S3P3, S2P2, S2P1,and S3P2 were presumably the members of the genera Bacillus, Pseudomonas and Mycobacterium species. From the study, it was apparent that the tropical ecosystems contained unique organisms with the ability to deal with diesel contaminatio

    Evaluating the diesel biodegradation potential of wild microfungi isolat-ed from decaying wood in Nigeria

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    We evaluated the potentials of pure wild microfungi isolated from decaying wood in utilizing diesel as source of carbon/energy and monitoring of their physiological responses via OD and pH gradient fluxes. The fungi diversity was obtained by conventional enrichment culture methods. Pure cultures of tentative fungal species namely: SC1, SC2, SC3, YI and Y2 were tested for their ability to utilize diesel oil as carbon and energy source. From the cultur-al, morphological and biochemical characterization and comparison with respect to the standard reference of fungi, the wild microfungi tentatively named as SC1, SC2, SC3, YI and Y2 were seemingly the members of Penicil-lum, Aspergillus, Mucor, Candida and Cryptococcus species. The diesel de-pendent growth of the pure microfungi was assessed by monitoring the flux-es in the pH and Optical density OD of the minimal media slurry for 288 hours. There were fluctuations in OD as well as pH values for the different microfungi. The mean pH data 5.90 ± 0.01-7.01± 0.01 and the OD 0.349± 0.001 -1.232 ± 0.002 were obtained. The ability of our fungal isolates to tol-erate diesel and grow in it, suggests that the isolates can be employed as bioremediation agent

    BCAA catabolism in brown fat controls energy homeostasis through SLC25A44.

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    Branched-chain amino acid (BCAA; valine, leucine and isoleucine) supplementation is often beneficial to energy expenditure; however, increased circulating levels of BCAA are linked to obesity and diabetes. The mechanisms of this paradox remain unclear. Here we report that, on cold exposure, brown adipose tissue (BAT) actively utilizes BCAA in the mitochondria for thermogenesis and promotes systemic BCAA clearance in mice and humans. In turn, a BAT-specific defect in BCAA catabolism attenuates systemic BCAA clearance, BAT fuel oxidation and thermogenesis, leading to diet-induced obesity and glucose intolerance. Mechanistically, active BCAA catabolism in BAT is mediated by SLC25A44, which transports BCAAs into mitochondria. Our results suggest that BAT serves as a key metabolic filter that controls BCAA clearance via SLC25A44, thereby contributing to the improvement of metabolic health

    TGF-β-dependent reprogramming of amino acid metabolism induces epithelial–mesenchymal transition in non-small cell lung cancers

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    Epithelial–mesenchymal transition (EMT)—a fundamental process in embryogenesis and wound healing—promotes tumor metastasis and resistance to chemotherapy. While studies have identified signaling components and transcriptional factors responsible in the TGF-β-dependent EMT, whether and how intracellular metabolism is integrated with EMT remains to be fully elucidated. Here, we showed that TGF-β induces reprogramming of intracellular amino acid metabolism, which is necessary to promote EMT in non-small cell lung cancer cells. Combined metabolome and transcriptome analysis identified prolyl 4-hydroxylase α3 (P4HA3), an enzyme implicated in cancer metabolism, to be upregulated during TGF-β stimulation. Further, knockdown of P4HA3 diminished TGF-β-dependent changes in amino acids, EMT, and tumor metastasis. Conversely, manipulation of extracellular amino acids induced EMT-like responses without TGF-β stimulation. These results suggest a previously unappreciated requirement for the reprogramming of amino acid metabolism via P4HA3 for TGF-β-dependent EMT and implicate a P4HA3 inhibitor as a potential therapeutic agent for cancer

    Initial experience of transumbilical laparoendoscopic single-site surgery of partial adrenalectomy in patient with aldosterone-producing adenoma

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    <p>Abstract</p> <p>Background</p> <p>Laparoscopic single-site surgery has recently emerged in the field of urology and this minimally-invasive surgery has resulted in a further reduction in morbidity compared with traditional laparoscopy. We present our initial experience with laparoendoscopic single-site surgery of partial adrenalectomy (LESS-PA) to treat aldosterone-producing adenomas.</p> <p>Case presentation</p> <p>A 60-year-old woman was diagnosed with aldosterone-producing macroadenomas in the left adrenal and aldosterone-producing microadenomas in the right adrenal. A two-step operation was planned. The first step involved transumbilical LESS-PA for the left adrenal tumors. A multichannel port was inserted through the center of the umbilicus and the left adrenal gland was approached using bent instruments according to standard traditional laparoscopic procedures. The tumors were resected using an ultrasonic scalpel, and the resected site was coagulated using a vessel sealing instrument and then sealed with fibrin glue. Operative time was 123 minutes and blood loss was minimal. The patient was discharged from hospital within 72 hours. Her right adrenal microadenomas will be treated in the next several months.</p> <p>Conclusions</p> <p>Although our experience is limited, LESS-PA appears to be safe and feasible for treating aldosterone-producing adenomas. More cases and comparisons with the multiport technique are needed before drawing any definite conclusions concerning the technique.</p

    Cellular immunity in children with successful immunoprophylactic treatment for mother-to-child transmission of hepatitis B virus

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    Background: The administration of hepatitis B immunoglobulin followed by hepatitis B vaccine can result in a protective efficacy of almost 90% in mother-to-child transmission of hepatitis B virus (HBV). However, little is known about immunity against HBV infection in children after immunoprophylactic treatment. We tried to assess the association between T-cell responses and viremia in children after successful prophylactic treatment. Methods: Thirteen children and their 8 HBV carrier mothers (8 families), who were positive for human leukocyte antigen (HLA)-A24, were enrolled in this study. All of the 13 children received immunoprophylactic treatment and became negative for hepatitis B surface antigen (HBsAg) after birth. HBV-specific cytotoxic T lymphocyte (CTL) responses were evaluated using IFNγ - enzyme-linked immunosorbent spot (ELISPOT) and major histocompatibility complex class I peptide pentamer assays. Serum HBV DNA was measured by real-time PCR. Results: Significant HBV-specific T-cell responses were detected in 2 (15%) of the 13 children by ELISPOT. However, the frequency of HLA-A24-HBV-specific CTLs was very low in both HBV carrier mothers and children using pentamers. Of the 13 children, 4 (31%) were positive for serum HBV DNA. However, the levels of serum HBV DNA were 100 copies/ml or less. One of the 2 children in whom significant HBV-specific CTL responses were detectable was positive for serum HBV DNA. Conclusions: HBV core and polymerase-specific T-cell responses were detected and a low-dose viremia was observed in children after successful immunoprophylaxis treatment. Although the presence of viremia was not related to HBV-specific T-cell responses, CTLs might play a role in the control of HBV infection in children born to HBsAg-positive mothers after immunoprophylactic treatment. </p
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