142 research outputs found

    Charged-Higgs phenomenology in the Aligned two-Higgs-doublet model

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    The alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents. In addition to the usual fermion masses and mixings, the aligned Yukawa structure only contains three complex parameters, which are potential new sources of CP violation. For particular values of these three parameters all known specific implementations of the model based on discrete Z_2 symmetries are recovered. One of the most distinctive features of the two-Higgs-doublet model is the presence of a charged scalar. In this work, we discuss its main phenomenological consequences in flavour-changing processes at low energies and derive the corresponding constraints on the parameters of the aligned two-Higgs-doublet model.Comment: 46 pages, 19 figures. Version accepted for publication in JHEP. References added. Discussion slightly extended. Conclusions unchange

    Effect of Wood-fiber geometry size on Mechanical Properties of Wood-fiber From Neolamarckia Cadamba Species Reinforced Polypropylene Composites

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    Using natural wood-fiber as reinforcement in commercial thermoplastics is gaining momentum due to its high specific properties and renewable resources. In this study, the effect of wood particle geometry size on mechanical properties of thermoplastics composite was investigated. The wood species that has been chosen is Kelempayan species (Neolamarckia cadamba) and reinforced with polypropylene using fiber geometry size of 75 and 250? m. Thermoplastic composites were produced from two types of ratio (30:70 and 10:90) between wood-fiber and polypropylene. Static bending and tensile strength were tested. The result showed that wood-fiber from 75? m geometry sizes with ratio of 30:70 between wood-fiber and polypropylene was most suitable in producing thermoplastic composites. The geometry sizes of wood particle as well as the ratio between wood-fiber and polypropylene were found to influence the mechanical properties of the thermoplastic composites

    Chemical Composition of Small Diameter Wild Acacia Mangium Species

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    Acacia mangium is an exotic species grows wildly and widely planted in Malaysia, as an effort for reforestation and also known to be used in pulp and paper industries. The objectives of this study is to determine 5 chemical composition (extractives, holocellulose, α-cellulose, hemicellulose and lignin) in 2 different parts (wood and bark) from 3 different portions (bottom, middle and top) of small diameter wild Acacia mangium. Samples were collected from Jeli, approximately 10 kilometers from Universiti Malaysia Kelantan (UMK), Jeli Campus, Kelantan with diameter around 5-8 cm. Samples were then grounded using laboratory grade mill into powder form for chemical composition analysis. All analyses were done according to Technical Association of the Pulp and Paper Industry (TAPPI) standard method, except for hemicellulose which is the data collected through equation. All the data and results were statistically analyzed using two-way ANOVA and Tukey’s Post Hoc test. Results acquired reveals that extractives content was highest in bark part from bottom portion (15.03%). Highest holocellulose percentage can be found in wood part of top portion (85.99%) and the highest of α-cellulose content is in wood partfrom top portion (49.84%), meanwhile the highest of hemicellulose content can be found in wood part from top portion (36.15%). Lignin percentage is the highest in bark part of bottom portion (31.18%). This study has determined small diameter wild Acacia mangium as a useful alternative resource in pulp and paper industries

    Effect of Torrefaction Process on Crystallinity Index Properties of Empty Fruit Bunch’s Biochar

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    The effect of torrefaction process on crystallinity index (CrI) properties from biomass material which is empty fruit bunch’s biochar had been identified in this study. There are three major torrefaction parameters for biomass material which is particle size, holding temperature and residence time was determined. The investigation on the empty fruit bunch’s biochar had been done by X-ray diffraction (XRD). There was decreasing pattern for CrI occurred as the holding temperature increased from 200 to 300°C and residence time increased from 30 to 90 minutes, but there are no significant affected by the particle size parameter. This shows that the empty fruit bunch’s biochar cellulose crystallinity is reduced as the cellulose become completely amorphous

    Capsule Endoscopy: A Valuable Tool in the Follow-Up of People With Celiac Disease on a Gluten-Free Diet

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    OBJECTIVES: Traditional celiac disease guidelines recommend follow-up endoscopy and duodenal biopsies at 6–12 months after commencing a gluten-free diet (GFD). However, histology may remain abnormal even 1–2 years later. We evaluated the role of capsule endoscopy in patients with celiac disease after treatment with a GFD. METHODS: Twelve adult patients with newly diagnosed celiac disease were prospectively enrolled. All patients had baseline symptom assessment, celiac serology (tissue transglutaminase antibody, tTG), and capsule endoscopy. Twelve months after commencing a GFD, patients underwent repeat symptom assessment, celiac serology, upper gastrointestinal endoscopy, and capsule endoscopy. RESULTS: At baseline, capsule endoscopy detected endoscopic markers of villous atrophy in the duodenum and extending to a variable distance along the small intestine. On the basis of small bowel transit time, the mean±s.e.m. percentage of small intestine with villous atrophy was 18.2±3.7%. After 12 months on a GFD, repeat capsule endoscopy demonstrated mucosal healing from a distal to proximal direction, and the percentage of small intestine with villous atrophy was significantly reduced to 3.4±1.2% (P¼0.0014) and this correlated with improvement in the symptom score (correlation 0.69, P¼0.01). There was a significant improvement in symptom score (5.2±1.0 vs. 1.7±0.4, P¼0.0012) and reduction in immunoglobulin A–tTG levels (81.5±10.6 vs. 17.5±8.2, P¼0.0005). However, 42% of subjects demonstrated persistent villous abnormality as assessed by duodenal histology. CONCLUSIONS: After 12 months on a GFD, patients with celiac disease demonstrate an improvement in symptoms, celiac serology, and the extent of disease as measured by capsule endoscopy. Mucosal healing occurs in a distal to proximal direction. The extent of mucosal healing correlates with improvement in symptoms. Duodenal histology does not reflect the healing that has occurred more distally.Ilmars Lidums, Edward Teo, John Field and Adrian G. Cummin

    Probing the charged Higgs boson at the LHC in the CP-violating type-II 2HDM

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    We present a phenomenological study of a CP-violating two-Higgs-doublet Model with type-II Yukawa couplings at the Large Hadron Collider (LHC). In the light of recent LHC data, we focus on the parameter space that survives the current and past experimental constraints as well as theoretical bounds on the model. Once the phenomenological scenario is set, we analyse the scope of the LHC in exploring this model through the discovery of a charged Higgs boson produced in association with a W boson, with the former decaying into the lightest neutral Higgs and a second W state, altogether yielding a b\bar b W^+W^- signature, of which we exploit the W^+W^- semileptonic decays.Comment: 37 pages, 16 figures; v2 updated treatment of LHC constraint

    Effects of Dietary Restriction on Cancer Development and Progression

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    The effects of caloric restriction on tumor growth and progression are known for over a century. Indeed, fasting has been practiced for millennia, but just recently has emerged the protective role that it may exert toward cells. Fasting cycles are able to reprogram the cellular metabolism, by inducing protection against oxidative stress and prolonging cellular longevity. The reduction of calorie intake as well as short- or long-term fasting has been shown to protect against chronic and degenerative diseases, such as diabetes, cardiovascular pathologies, and cancer. In vitro and in vivo preclinical models showed that different restriction dietary regimens may be effective against cancer onset and progression, by enhancing therapy response and reducing its toxic side effects. Fasting-mediated beneficial effects seem to be due to the reduction of inflammatory response and downregulation of nutrient-related signaling pathways able to modulate cell proliferation and apoptosis. In this chapter, we will discuss the most significant studies present in literature regarding the molecular mechanisms by which dietary restriction may contribute to prevent cancer onset, reduce its progression, and positively affect the response to the treatments

    Differential baseline and response profile to IFN-γ gene transduction of IL-6/IL-6 receptor-α secretion discriminate primary tumors versus bone marrow metastases of nasopharyngeal carcinomas in culture

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    <p>Abstract</p> <p>Background</p> <p>Understanding of immunobiology of bone marrow metastases (designated BM-NPC) <it>versus </it>primary tumors (P-NPC) of the nasopharynx is far from complete. The aim of this study was to determine if there would be differences between cultured P-NPCs and BM-NPCs with respect to (i) constitutive IL-6 and the IL-6 receptor gp80 subunit (IL-6Rα) levels in the spent media of nontransduced cells, and (ii) IL-6 and IL-6Rα levels in the spent media of cells transduced with a retroviral vector containing the <it>IFN-γ </it>gene.</p> <p>Methods</p> <p>A panel of NPC cell lines were transduced with the <it>IFN-γ </it>gene through a retroviral vector. Four clonal sublines were isolated <it>via </it>limiting dilution methods. Cytofluorometric analysis was performed for the detection of cell surface antigens of HLA class I, HLA class II and ICAM-1. ELISA was used to assay for IFN-γ, IL-6 and IL-6Rα in the spent media of cultured cell lines.</p> <p>Results</p> <p>Our results showed that in day 3 culture supernatants, low levels of soluble IL-6 were detected in 5/5 cultured tumors derived from P-NPCs, while much higher constitutive levels of IL-6 were detected in 3/3 metastasis-derived NPC cell lines including one originated from ascites; the difference was significant (<it>p </it>= 0.025). An inverse relationship was found between IL-6Rα and IL-6 in their release levels in cultured P-NPCs and metastasis-derived NPCs. In <it>IFN-γ</it>-transduced-P-NPCs, IL-6 production increased and yet IL-6Rα decreased substantially, as compared to nontransduced counterparts. At variance with P-NPC cells, the respective ongoing IL-6 and IL-6Rα release patterns of BM-NPC cells were not impeded as much following <it>IFN-γ </it>transduction. These observations were confirmed by extended kinetic studies with representative NPC cell lines and clonal sublines. The latter observation with the clonal sublines also indicates that selection for high IL-6 or low IL-6Rα producing subpopulations did not occur as a result of <it>IFN-γ</it>-transduction process. P-NPCs, which secreted constitutively only marginal levels of IFN-γ (8.4 ~ 10.5 pg/ml), could be enhanced to produce higher levels of IFN-γ (6.8- to 10.3-fold increase) after <it>IFN-γ </it>transduction. Unlike P-NPCs, BM-NPCs spontaneously released IFN-γ at moderate levels (83.8 ~ 100.7 pg/ml), which were enhanced by 1.3- to 2.2-fold in the spent media of their <it>IFN-γ</it>-transduced counterparts.</p> <p>Conclusion</p> <p>Our results showed that cultured P-NPCs and BM-NPCs could be distinguished from one another on the basis of their differential baseline secretion pattern of IFN-γ, IL-6 and IL-6Rα, and their differential response profiles to <it>IFN-γ </it>gene transfer of the production of these three soluble molecules. These results suggest that the IL-6 and IFN-γ pathways in a background of genetic instability be involved in the acquisition of metastatic behaviour in BM-NPCs.</p
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