105 research outputs found

    Nanocrystallization and Amorphization Induced by Reactive Nitrogen Sputtering in Iron and Permalloy

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    Thin films of iron and permalloy Ni80Fe20 were prepared using an Ar+N2 mixture with magnetron sputtering technique at ambient temperature. The nitrogen partial pressure, during sputtering process was varied in the range of 0 to 100%, keeping the total gas flow at constant. At lower nitrogen pressures RN2<33% both Fe and NiFe, first form a nanocrystalline structure and an increase in nitrogen partail pressure results in formation of an amorphous structure. At intermediate nitrogen partial pressures, nitrides of Fe and NiFe were obtained while at even higher nitrogen partial pressures, nitrides themselves became nanocrystalline or amorphous. The surface, structural and magnetic properties of the deposited films were studied using x-ray reflection and diffraction, transmission electron microscopy, polarized neutron reflectivity and using a DC extraction magnetometer. The growth behavior for amorphous film was found different as compared with poly or nanocrystalline films. The soft-magnetic properties of FeN were improved on nanocrystallization while those of NiFeN were degraded. A mechanism inducing nanocrystallization and amorphization in Fe and NiFe due to reactive nitrogen sputtering is discussed in the present article.Comment: 13 Pages, 15 Figure

    Effect of differential heat treatments on antibacterial activity of fermented goat milk

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    The present study was conducted to evaluate the effect of three different temperatures on the antibacterial potential of fermented goat milk.Goat milk is one of the naturalfoods to complete perfection.Bioactive peptides, the specific protein fragments that have a positive impact on body functions, can be produced during milk fermentation. Thanks to the starter cultures’ proteolytic activity.Fresh pooled goat milk sample collected was divided into four lots. One set was used for raw milk analysis and the remaining three were subjected to heat treatment at three different timetemperature combinations namely;72°C for 15 sec, 85°C for 10 min, and 121° C for 15 min. These samples were cooled immediately to 42ºC, inoculated with 0.04 % DVS yogurt culture,incubated at 42º C for 4 hrs, and then stored at 5±2°C for 21 days for storage studies. The analysis was carried out at 7-day intervals. An agar well diffusion assay was performed to assess the inhibitory activity ofWater-soluble peptide extracts (WSPE) of these samples against Bacillus cereus ATCC 10876, Escherichia coli NCIM 2685, Salmonella enterica ATCC 6017, and Staphylococcus aureus ATCC 25923. The milk that was heated to 85°C for 10 min before fermentation showed the highest antibacterial activity against E.coli during the 7th and 14th day of storage, withthe zone of inhibition measuredat 17±0.433mm and 21±0.55mm respectively.Thus, it can be concluded that milk heated at 85°C for 10 min had better antibacterial activity than the other two treatments

    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&nbsp;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

    Oleic acid is an endogenous ligand of TLX/NR2E1 that triggers hippocampal neurogenesis

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    Altres ajuts: Cancer Prevention and Research Institute of Texas (CPRIT), Core Facility Support Award (CPRIT-RP180672, R1313, 1R01GM138781-01); NIH (CA125123, RR024574); Eunice Kennedy Shriver National Institute of Child Health & Human Development of the NIH (P50HD103555); BCM start-up funds; Albert and Margaret Alkek Foundation; McNair Medical Institute; Robert and Janice McNair Foundation; BCM Seed Funding (1P20CA221731-01A1); National Institute of General Medical Sciences (R01 GM120033); Cynthia and Antony Petrello Endowment; Mark A. Wallace Endowment; McKnight Foundation; Dana Foundation; BCM Computational and Integrative Biomedical Research Center seed grant.Neural stem cells, the source of newborn neurons in the adult hippocampus, are intimately involved in learning and memory, mood, and stress response. Despite considerable progress in understanding the biology of neural stem cells and neurogenesis, regulating the neural stem cell population precisely has remained elusive because we have lacked the specific targets to stimulate their proliferation and neurogenesis. The orphan nuclear receptor TLX/NR2E1 governs neural stem and progenitor cell self-renewal and proliferation, but the precise mechanism by which it accomplishes this is not well understood because its endogenous ligand is not known. Here, we identify oleic acid (18:1ω9 monounsaturated fatty acid) as such a ligand. We first show that oleic acid is critical for neural stem cell survival. Next, we demonstrate that it binds to TLX to convert it from a transcriptional repressor to a transcriptional activator of cell-cycle and neurogenesis genes, which in turn increases neural stem cell mitotic activity and drives hippocampal neurogenesis in mice. Interestingly, oleic acid-activated TLX strongly up-regulates cell cycle genes while only modestly up-regulating neurogenic genes. We propose a model in which sufficient quantities of this endogenous ligand must bind to TLX to trigger the switch to proliferation and drive the progeny toward neuronal lineage. Oleic acid thus serves as a metabolic regulator of TLX activity that can be used to selectively target neural stem cells, paving the way for future therapeutic manipulations to counteract pathogenic impairments of neurogenesis

    Novel Decapeptides that Bind Avidly and Deliver Radioisotope to Colon Cancer Cells

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    The rapidly growing field of targeted tumor therapy often utilizes an antibody, sometimes tagged with a tumor-ablating material such as radioisotope, directed against a specific molecule.This report describes the discovery of nine novel decapeptides which can be radioactively labeled, bind to, and deliver (32)P to colon cancer cells. The decapeptides vary from one another by one to three amino acids and demonstrate vastly different binding abilities. The most avidly binding decapeptide can permanently deliver very high levels of radioisotope to the adenocarcinoma cancer cell lines at an efficiency 35 to 150 times greater than to a variety of other cell types, including cell lines derived from other types of cancer or from normal tissue.This experimental approach represents a new example of a strategy, termed peptide binding therapy, for the potential treatment of colorectal and other adenocarcinomas

    BRF1 accelerates prostate tumourigenesis and perturbs immune infiltration

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    BRF1 is a rate-limiting factor for RNA Polymerase III-mediated transcription and is elevated in numerous cancers. Here, we report that elevated levels of BRF1 associate with poor prognosis in human prostate cancer. In vitro studies in human prostate cancer cell lines demonstrated that transient overexpression of BRF1 increased cell proliferation whereas the transient downregulation of BRF1 reduced proliferation and mediated cell cycle arrest. Consistent with our clinical observations, BRF1 overexpression in a Pten-deficient mouse (Pten BRF1 ) prostate cancer model accelerated prostate carcinogenesis and shortened survival. In Pten BRF1 tumours, immune and inflammatory processes were altered, with reduced tumoral infiltration of neutrophils and CD4 positive T cells, which can be explained by decreased levels of complement factor D (CFD) and C7 components of the complement cascade, an innate immune pathway that influences the adaptive immune response. We tested if the secretome was involved in BRF1-driven tumorigenesis. Unbiased proteomic analysis on BRF1-overexpresing PC3 cells confirmed reduced levels of CFD in the secretome, implicating the complement system in prostate carcinogenesis. We further identify that expression of C7 significantly correlates with expression of CD4 and has the potential to alter clinical outcome in human prostate cancer, where low levels of C7 associate with poorer prognosis

    The Physical Conditions of Emission-Line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations

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    We present rest-frame optical emission-line flux ratio measurements for five z>5z>5 galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and post-processing steps to the NIRSpec pipeline reduction products in order to ensure reliable relative flux calibration of emission lines that are closely separated in wavelength, despite the uncertain \textit{absolute} spectrophotometry of the current version of the reductions. Compared to z3z\sim3 galaxies in the literature, the z>5z>5 galaxies have similar [OIII]λ\lambda5008/Hβ\beta ratios, similar [OIII]λ\lambda4364/Hγ\gamma ratios, and higher (\sim0.5 dex) [NeIII]λ\lambda3870/[OII]λ\lambda3728 ratios. We compare the observations to MAPPINGS V photoionization models and find that the measured [NeIII]λ\lambda3870/[OII]λ\lambda3728, [OIII]λ\lambda4364/Hγ\gamma, and [OIII]λ\lambda5008/Hβ\beta emission-line ratios are consistent with an interstellar medium that has very high ionization (log(Q)89\log(Q) \simeq 8-9, units of cm~s1^{-1}), low metallicity (Z/Z0.2Z/Z_\odot \lesssim 0.2), and very high pressure (log(P/k)89\log(P/k) \simeq 8-9, units of cm3^{-3}). The combination of [OIII]λ\lambda4364/Hγ\gamma and [OIII]λ\lambda(4960+5008)/Hβ\beta line ratios indicate very high electron temperatures of 4.1<log(Te/K)<4.44.1<\log(T_e/{\rm K})<4.4, further implying metallicities of Z/Z0.2Z/Z_\odot \lesssim 0.2 with the application of low-redshift calibrations for ``TeT_e-based'' metallicities. These observations represent a tantalizing new view of the physical conditions of the interstellar medium in galaxies at cosmic dawn.Comment: Accepted for publication in AAS Journals. 14 pages, 6 figures, 3 table

    The effectiveness of a low-intensity problem-solving intervention for common adolescent mental health problems in New Delhi, India: protocol for a school-based, individually randomized controlled trial with an embedded stepped-wedge cluster randomized controlled recruitment trial

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    Background Conduct, anxiety and depressive disorders account for over 75% of the adolescent mental health burden globally. The current protocol will test a low-intensity problem-solving intervention for school-going adolescents with common mental health problems in India. The protocol also tests the effects of a classroom-based sensitization intervention on the demand for counselling services in an embedded recruitment trial. Methods We will conduct a two-arm individually randomized controlled trial in six Government-run secondary schools in New Delhi. The targeted sample is 240 adolescents in grades 9-12 with persistent, elevated mental health symptoms and associated impact. Participants will receive either a brief problem-solving intervention delivered over 3 weeks by lay counsellors (intervention), or enhanced usual care comprised of problem-solving booklets (control). Self-reported adolescent mental health symptoms and idiographic problems will be assessed at 6 weeks (co-primary outcomes) and again at 12 weeks post-randomization. In addition, adolescent-reported impact of mental health difficulties, perceived stress, mental wellbeing and clinical remission, as well as parent-reported adolescent mental health symptoms and impact scores, will be assessed at 6 and 12 weeks post-randomization. We will also complete a parallel process evaluation, including estimations of the costs of delivering the interventions. An embedded recruitment trial will apply a stepped-wedge, cluster (class)-randomized controlled design in 70 classes across the six schools. This will evaluate the added impact of a classroom-based sensitization intervention over school-level recruitment sensitization activities on the primary outcome of referral rate into the host trial (i.e. the proportion of adolescents referred as a function of the total sampling frame in each condition of the embedded recruitment trial). Other outcomes will be the proportion of referrals eligible to participate in the host trial, proportion of self-generated referrals, and severity and pattern of symptoms among referred adolescents in each condition. Power calculations were undertaken separately for each trial. A detailed statistical analysis plan will be developed separately for each trial prior to unblinding. Discussion Both trials were initiated on 20 August 2018. A single research protocol for both trials offers a resource-efficient methodology for testing the effectiveness of linked procedures to enhance uptake and outcomes of a school-based psychological intervention for common adolescent mental health problems
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