1,482 research outputs found

    The role of non-thermal plasma technique in NOx treatment : a review

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    Non-thermal plasma (NTP) has been introduced over the past several years as a promising method for nitrogen oxide (NOx) removal. The intent, when using NTP, is to selectively transfer input electrical energy to the electrons, and to not expend this in heating the entire gas stream, which generates free radicals through collisions, and promotes the desired chemical changes in the exhaust gases. The generated active species react with the pollutant molecules and decompose them. This paper reviews and summarizes relevant literature regarding various aspects of the application of NTP technology on NOx removal from exhaust gases. A comprehensive description of available scientific literature on NOx removal using NTP technology is presented, including various types of NTP, e.g. dielectric barrier discharge, corona discharge and electron beam. Furthermore, the combination of NTP with catalyst and adsorbent for better NOx removal efficiency is presented in detail. The removal of NOx from both simulated gases and real diesel engines is also considered in this review paper. As NTP is a new technique and is not yet commercialized, there is a need for more studies to be performed in this field

    Increased interferon alpha receptor 2 mRNA levels is associated with renal cell carcinoma metastasis

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    <p>Abstract</p> <p>Background</p> <p>Interferon-α (IFN-α) is one of the central agents in immunotherapy for renal cell carcinoma (RCC) and binds to the IFN-α receptor (IFNAR). We investigated the role of IFNAR in RCC.</p> <p>Methods</p> <p>We quantified IFNAR mRNA expression in paired tumor and non-tumor samples from the surgical specimens of 103 consecutive patients with RCC using a real-time reverse transcription polymerase chain reaction (RT-PCR), and IFNAR2 protein using Western blotting.</p> <p>Results</p> <p>The absolute level of IFNAR1 and IFNAR2 mRNAs in tumor and non-tumor tissues did not correlate with the malignant and metastatic profiles. The relative yields of the PCR product from the tumor tissue to that from the corresponding non-tumor tissue (T/N) for the expression of IFNAR mRNAs were calculated. While the T/N ratio of IFNAR1 did not correlate with any factor, a high T/N ratio of IFNAR2 correlated with poor differentiation (<it>P </it>< 0.05), local invasion (<it>P </it>< 0.001), and metastasis (<it>P </it>< 0.0001). By multivariate analysis, a high T/N ratio of IFNAR2 predicted a shortened overall survival in all cases (<it>P </it>< 0.05) and a shorter disease-free survival in those without metastasis (M0; 68 cases, <it>P </it>< 0.05). Impressively, patients with a poorer response to IFN-α treatment had a higher IFNAR2 T/N ratio than those who had a good response (P < 0.05). IFNAR2c protein expression was higher in the primary tumors in patients with metastases (M1; 35 cases) compared to those without ( P < 0.0001).</p> <p>Conclusion</p> <p>IFNAR2 is associated with the progression of RCC.</p

    Developmental effects of endocrine-disrupting chemicals in wildlife and humans.

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    Large numbers and large quantities of endocrine-disrupting chemicals have been released into the environment since World War II. Many of these chemicals can disturb development of the endocrine system and of the organs that respond to endocrine signals in organisms indirectly exposed during prenatal and/or early postnatal life; effects of exposure during development are permanent and irreversible. The risk to the developing organism can also stem from direct exposure of the offspring after birth or hatching. In addition, transgenerational exposure can result from the exposure of the mother to a chemical at any time throughout her life before producing offspring due to persistence of endocrine-disrupting chemicals in body fat, which is mobilized during egg laying or pregnancy and lactation. Mechanisms underlying the disruption of the development of vital systems, such as the endocrine, reproductive, and immune systems, are discussed with reference to wildlife, laboratory animals, and humans

    Increased serum hepcidin-25 level and increased tumor expression of hepcidin mRNA are associated with metastasis of renal cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Hepcidin has an important role in iron metabolism. We investigated whether hepcidin was involved in renal cell carcinoma (RCC).</p> <p>Methods</p> <p>We measured serum hepcidin-25 levels in 32 patients by liquid chromatograpy (LC)-mass spectrometry (MS)/MS, and assessed hepcidin mRNA expression in paired tumor and non-tumor tissue samples from the surgical specimens of 53 consecutive patients with RCC by real-time reverse transcription polymerase chain reaction.</p> <p>Results</p> <p>The serum hepcidin-25 level was higher in patients with metastatic RCC than nonmetastatic RCC (<it>P </it>< 0.0001), and was positively correlated with the serum interleukin-6 and C-reactive protein levels (<it>P </it>< 0.001). Expression of hepcidin mRNA was lower in tumor tissues than in non-tumor tissues (<it>P </it>< 0.0001). The serum hepcidin-25 level was not correlated with the expression of hepcidin mRNA in the corresponding tumor tissue specimens from 32 patients. Hepcidin mRNA expression in tumor tissue was correlated with metastatic potential, but not with histological differentiation or tumor stage. Kaplan-Meier analysis showed that over expression of hepcidin mRNA was related to shorter overall survival in RCC patients. Univariate analysis (Cox proportional hazards model) showed that the hepcidin mRNA level was an independent prognostic factor for overall survival.</p> <p>Conclusion</p> <p>Our findings suggest that a high serum hepcidin-25 level may indicate the progression of RCC, and that upregulation of hepcidin mRNA expression in tumor tissue may be related to increased metastatic potential.</p

    Characterization of an engineered human purine nucleoside phosphorylase fused to an anti-her2/neu single chain Fv for use in ADEPT

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    Abstract Background Antibody Directed Enzyme Prodrug Therapy (ADEPT) can be used to generate cytotoxic agents at the tumor site. To date non-human enzymes have mainly been utilized in ADEPT. However, these non-human enzymes are immunogenic limiting the number of times that ADEPT can be administered. To overcome the problem of immunogenicity, a fully human enzyme, capable of converting a non-toxic prodrug to cytotoxic drug was developed and joined to a human tumor specific scFv yielding a fully human targeting agent. Methods A double mutant of human purine nucleoside phosphorylase (hDM) was developed which unlike the human enzyme can cleave adenosine-based prodrugs. For tumor-specific targeting, hDM was fused to the human anti-HER2/neu single chain Fv (scFv), C6 MH3B1. Enzymatic activity of hDM with its natural substrates and prodrugs was determined using spectrophotomeric approaches. A cell proliferation assay was used to assess the cytotoxicity generated following conversion of prodrug to drug as a result of enzymatic activity of hDM. Affinity of the targeting scFv, C6 MH3B1 fused to hDM to Her2/neu was confirmed using affinity chromatography, surface plasmon resonance, and flow-cytometry. Results In vitro hDM-C6 MH3B1 binds specifically to HER2/neu expressing tumor cells and localizes hDM to tumor cells, where the enzymatic activity of hDM-C6 MH3B1, but not the wild type enzyme, results in phosphorolysis of the prodrug, 2-fluoro-2'-deoxyadenosine to the cytotoxic drug 2-fluoroadenine (F-Ade) causing inhibition of tumor cell proliferation. Significantly, the toxic small drug diffuses through the cell membrane of HER2/neu expressing cells as well as cells that lack the expression of HER2/neu, causing a bystander effect. F-Ade is toxic to cells irrespective of their growth rate; therefore, both the slowly dividing tumor cells and the non-dividing neighboring stromal cells that support tumor growth should be killed. Analysis of potential novel MHCII binding peptides resulting from fusion of hDM to C6 MH3B1 and the two mutations in hDM, and of the structure of hDM compared to the wild-type enzyme suggests that hDM-C6 MH3B1 should exhibit minimal immunogenicity in humans. Conclusion hDM-C6 MH3B1 constitutes a novel human based protein that addresses some of the limitations of ADEPT that currently preclude its successful use in the clinic

    Endothelins are vascular-derived axonal guidance cues for developing sympathetic neurons

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    During development, sympathetic neurons extend axons along a myriad of distinct trajectories, often consisting of arteries, to innervate one of a large variety of distinct final target tissues. Whether or not subsets of neurons within complex sympathetic ganglia are predetermined to innervate select end-organs is unknown. Here we demonstrate in mouse embryos that the endothelin family member Edn3 (ref. 1), acting through the endothelin receptor EdnrA (refs 2, 3), directs extension of axons of a subset of sympathetic neurons from the superior cervical ganglion to a preferred intermediate target, the external carotid artery, which serves as the gateway to select targets, including the salivary glands. These findings establish a previously unknown mechanism of axonal pathfinding involving vascular-derived endothelins, and have broad implications for endothelins as general mediators of axonal growth and guidance in the developing nervous system. Moreover, they suggest a model in which newborn sympathetic neurons distinguish and choose between distinct vascular trajectories to innervate their appropriate end organs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62906/1/nature06859.pd

    An adjuvant free mouse model of oral allergenic sensitization to rice seeds protein

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    <p>Abstract</p> <p>Background</p> <p>Rice is commonly known as a staple crop consumed worldwide, though with several rice proteins being reported for allergic properties in clinical studies. Thus, there is a growing need for the development of an animal model to better understand the allergenicity of rice proteins and the immunological and pathophysiological mechanisms underlying the development of food allergy.</p> <p>Methods</p> <p>Groups of BALB/c mice were sensitized daily with freshly homogenized rice flour (30 mg or 80 mg) without adjuvant by intragastric gavage. In addition, the mice were challenged with extracted rice flour proteins at several time points intragastrically. Hypersensitivity symptoms in mice were evaluated according to a scoring system. Vascular leakage, ELISA of rice protein-specific IgE, histopathology of small intestine, and passive cutaneous anaphylaxis were conducted on challenged mice.</p> <p>Results</p> <p>An adjuvant free mouse model of rice allergy was established with sensitized mice showing increased scratching behaviors and increased vascular permeability. Rice protein-specific IgE was detected after eighteen days of sensitization and from the fifth challenge onwards. Inflammatory damage to the epithelium in the small intestine of mice was observed beyond one month of sensitization. Passive cutaneous anaphylaxis results confirmed the positive rice allergy in the mouse model.</p> <p>Conclusions</p> <p>We introduced a BALB/c mouse model of rice allergy with simple oral sensitization without the use of adjuvant. This model would serve as a useful tool for further analysis on the immunopathogenic mechanisms of the various rice allergens, for the evaluation of the hypersensitivity of rice or other cereal grains, and to serve as a platform for the development of immunotherapies against rice allergens.</p
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