173 research outputs found

    Heat Transfer Modeling and Analysis of Solar Thermo-chemical Reactor for Hydrogen Production from Water

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    AbstractA solar thermo-chemical reactor is modeled and analyzed for the solar thermal dissociation of zinc oxide into zinc and oxygen involved in the thermo-chemical cycle for hydrogen production. The reactor consists of a cavity surrounded by a rotating insulation layer made of alumina. The granular zinc oxide particles are fed into the cavity and are directly exposed to the solar radiation entering the cavity through a quartz window. A three dimensional numerical model coupling the multiphase particle dynamics in gravitational field, multiphase heat transfer, k-ɛ turbulence model, discrete ordinates radiation model, Arrhenius reaction rate model is developed. The cavity temperature and oxygen molar flow rate at the outlet of the reactor which is the indicator of the reaction rate has been validated with a 10kW reactor prototype. An energy balance study of thermal performance parameters including the various losses occurring from the reactor and efficiency is also done. The major losses were contributed by re-radiation (46%) and sensible heating of reactor components (35.5%), while the minor losses were contributed by convection by argon (1%) and conduction through insulation (2%).The thermal efficiency of the reactor is calculated to be 15.5%

    Influence of Reinforcements and Heat Treatment on Mechanical and Wear Properties of Al 7075 based Hybrid Composites

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    AbstractA new class of hybrid composite Al 7075 alloy reinforced with fly ash particulates and E-glass short fibers has been formed. Hardness, tensile strength and wear properties of the composites have been evaluated and validated. Significant improvement in the properties was been observed with addition of reinforcements. Further, properties of heat treated composites were enhanced when compared to as cast composites. Artificial Neural Network modelling has been carried out for validation of the experimental results, by using MATLAB software. The modelling results revealed that experimental values were convincingly accurate with an error within 10% in training, testing and validation

    Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity

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    A common complication associated with diabetes is painful or painless diabetic peripheral neuropathy (DPN). The mechanisms and determinants responsible for these peripheral neuropathies are poorly understood. Using both streptozotocin (STZ)-induced and transgene-mediated murine models of type 1 diabetes (T1D), we demonstrate that Transient Receptor Potential Vanilloid 1 (TRPV1) expression varies with the neuropathic phenotype. We have found that both STZ- and transgene-mediated T1D are associated with two distinct phases of thermal pain sensitivity that parallel changes in TRPV1 as determined by paw withdrawal latency (PWL). An early phase of hyperalgesia and a late phase of hypoalgesia are evident. TRPV1-mediated whole cell currents are larger and smaller in dorsal root ganglion (DRG) neurons collected from hyperalgesic and hypoalgesic mice. Resiniferatoxin (RTX) binding, a measure of TRPV1 expression is increased and decreased in DRG and paw skin of hyperalgesic and hypoalgesic mice, respectively. Immunohistochemical labeling of spinal cord lamina I and II, dorsal root ganglion (DRG), and paw skin from hyperalgesic and hypoalgesic mice reveal increased and decreased TRPV1 expression, respectively. A role for TRPV1 in thermal DPN is further suggested by the failure of STZ treatment to influence thermal nociception in TRPV1 deficient mice. These findings demonstrate that altered TRPV1 expression and function contribute to diabetes-induced changes in thermal perception

    Preclinical formulation for the pharmacokinetics and efficacy of GBO-006, a selective polo like kinase 2 (PLK2) inhibitor for the treatment of triple negative breast cancer

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    GBO-006 was shown to be a highly specific and selective PLK2 inhibitor that promoted mitotic arrest in various cancer cell lines, subsequently resulting in their apoptotic death. Intraperitoneal alternate day dosing of GBO-006 using 100 % DMSO as formulation showed significant tumor regression in xenograft models, demonstrating proof of concept of PLK2 inhibition in vivo. These studies necessitated the development of a suitable and GRAS (generally considered as safe) preformulation for pharmacokinetic and efficacy studies. GBO-006 possesses challenging physicochemical and biopharmaceutical properties like poor solubility in aqueous media, low permeability and a crystalline nature. Different methods like cosolvency, complexation and micellar solubilization were employed to improve the solubility of GBO-006. A strategy of co-solvency is used to solubilize the GBO-006 up to 10 mg/mL. A formulation with 20 % DMSO, 40 % PEG 400, 30 % of 100 mM citrate buffer (pH 3.0) and 10 % solutol displayed clear solution without any visual precipitation of the drug even after 2 weeks of storage. GBO-006 showed moderate clearance in rat and high systemic clearance in mouse and dog. It showed poor oral bioavailability across all species. Intraperitoneal dosing of GBO-006 demonstrated the linear exposure. GBO-006 showed significant inhibition of tumor progression

    An In Vivo Functional Screen Uncovers miR-150-Mediated Regulation of Hematopoietic Injury Response

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    SummaryHematopoietic stem and progenitor cells are often undesired targets of chemotherapies, leading to hematopoietic suppression requiring careful clinical management. Whether microRNAs control hematopoietic injury response is largely unknown. We report an in vivo gain-of-function screen and the identification of miR-150 as an inhibitor of hematopoietic recovery upon 5-fluorouracil-induced injury. Utilizing a bone marrow transplant model with a barcoded microRNA library, we screened for barcode abundance in peripheral blood of recipient mice before and after 5-fluorouracil treatment. Overexpression of screen-candidate miR-150 resulted in significantly slowed recovery rates across major blood lineages, with associated impairment of bone marrow clonogenic potential. Conversely, platelets and myeloid cells from miR-150 null marrow recovered faster after 5-fluorouracil treatment. Heterozygous knockout of c-myb, a conserved target of miR-150, partially phenocopied miR-150-forced expression. Our data highlight the role of microRNAs in controlling hematopoietic injury response and demonstrate the power of in vivo functional screens for studying microRNAs in normal tissue physiology

    JNK associated leucine zipper protein functions as a docking platform for Polo like kinase 1 and regulation of the associating transcription factor Forkhead box protein K1

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    JLP (JNK associated Leucine zipper protein) is a scaffolding protein that interacts with various signaling proteins associated with coordinated regulation of cellular process such as endocytosis, motility, neurite outgrowth, cell proliferation and apoptosis. Here we identified Polo like kinase 1 (PLK1) as a novel interaction partner of JLP through mass spectrometric approaches. Our results indicate that JLP is phospho-primed by PLK1 on Thr 351, which is recognized by the PBD of PLK1 leading to phosphorylation of JLP at additional sites. SILAC and quantitative LC-MS/MS analysis was performed to identify PLK1 dependent JLP interacting proteins. Treatment of cells with the PLK1 kinase inhibitor BI2536 suppressed binding of the Forkhead box protein K1 (FOXK1) transcriptional repressor to JLP. JLP was found to interact with PLK1 and FOXK1 during mitosis. Moreover, knockdown of PLK1 affected the interaction between JLP and FOXK1. FOXK1 is a known transcriptional repressor of the CDK inhibitor p21/WAF1 and knockdown of JLP resulted in increased FOXK1 protein levels and a reduction of p21 transcript levels. Our results suggest a novel mechanism by which FOXK1 protein levels and activity are regulated by associating with JLP and PLK1

    Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: A greenhouse trial.

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    An in vitro study was undertaken to evaluate the compatibility of indigenous plant growth promoting rhizobacteria (PGPR) with commonly used inorganic and organic sources of fertilizers in tea plantations. The nitrogenous, phosphatic and potash fertilizers used for this study were urea, rock phosphate and muriate of potash, respectively. The organic sources of fertilizers neem cake, composted coir pith and vermicompost were also used. PGPRs such as nitrogen fixer; Azospirillum lipoferum, Phosphate Solubilizing Bacteria (PSB); Pseudomonas putida, Potassium Solubilizing Bacteria (KSB); Burkholderia cepacia and Pseudomonas putida were used for compatibility study. Results were indicated that PGPRs preferred the coir pith and they proved their higher colony establishment in the formulation except Azospirillum spp. that preferred vermicompost for their establishment. The optimum dose of neem cake powder

    Requirement of argininosuccinate lyase for systemic nitric oxide production

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    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases

    Master Transcription Factor Reprogramming Unleashes Selective Translation Promoting Castration Resistance and Immune Evasion in Lethal Prostate Cancer

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    Signaling rewiring allows tumors to survive therapy. Here we show that the decrease of the master regulator microphthalmia transcription factor (MITF) in lethal prostate cancer unleashes eukaryotic initiation factor 3B (eIF3B)-dependent translation reprogramming of key mRNAs conferring resistance to androgen deprivation therapy (ADT) and promoting immune evasion. Mechanistically, MITF represses through direct promoter binding eIF3B, which in turn regulates the translation of specific mRNAs. Genome-wide eIF3B enhanced cross-linking immunoprecipitation sequencing (eCLIP-seq) showed specialized binding to a UC-rich motif present in subsets of 5\u27 untranslated regions. Indeed, translation of the androgen receptor and major histocompatibility complex I (MHC-I) through this motif is sensitive to eIF3B amount. Notably, pharmacologic targeting of eIF3B-dependent translation in preclinical models sensitizes prostate cancer to ADT and anti-PD-1 therapy. These findings uncover a hidden connection between transcriptional and translational rewiring promoting therapy-refractory lethal prostate cancer and provide a druggable mechanism that may transcend into effective combined therapeutic strategies. SIGNIFICANCE: Our study shows that specialized eIF3B-dependent translation of specific mRNAs released upon downregulation of the master transcription factor MITF confers castration resistance and immune evasion in lethal prostate cancer. Pharmacologic targeting of this mechanism delays castration resistance and increases immune-checkpoint efficacy. This article is featured in Selected Articles from This Issue, p. 2489
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