592 research outputs found

    Dogs as a source of Salmonella spp. in apparently healthy dogs in the Valencia Region. Could it be related with intestinal lactic acid bacteria?

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    Altres ajuts: Banco Santander (ES), FUSPBS-PPC 15/2016Although salmonellosis is considered one of the most important food-borne zoonotic diseases in Europe, close contact between dogs and their owners can also be a potential source of Salmonella spp. for humans. This study assessed the prevalence and antimicrobial resistance of Salmonella spp. in apparently healthy dogs in the Valencian Region, eastern Spain. Moreover, a macroscopic comparison of lactic acid bacteria in both Salmonella -positive and Salmonella -negative dogs was carried out. Of a total of 325 dogs sampled, 6 (1.85%) were positive for Salmonella spp. with 3 different serotypes, Havana (3), Mikawasima (2) and monophasic Typhimurium (1). All isolates were susceptible to all antimicrobials tested except monophasic S. Typhimurium, which was resistant to ampicillin. Finally, macroscopic results revealed that lactic acid bacteria had higher heterogeneity in the Salmonella -negative dogs than in the Salmonella -positive dogs. Although the results in our study showed a low prevalence of Salmonella spp., raw food has been suggested as a risk factor for bacteria in dog faeces. Public awareness campaigns on good hygiene practices, especially after handling canine faeces or raw food, are necessary. Furthermore, to reduce the potential transmission of bacteria, dogs should be fed food that has been properly cooked, as raw or undercooked food can be a source of zoonotic pathogens. Moreover, further studies must be performed to determine the relationship between lactic acid bacteria and Salmonella spp. in dog faeces

    Design of a Multimode MIMO Antenna Using the Theory of Characteristic Modes

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    In this communication, the design procedure of a multimode Multiple-Input Multiple-Output (MIMO) antenna is presented. The antenna consists of a metallic ring antenna operating with different orthogonal modes, whose performance in a MIMO system is similar to traditional antenna arrays. Thus, a compact MIMO antenna is obtained, which is very suitable for mobile terminals. A modal analysis of the antenna is carried out first by means of the Theory of Characteristic Modes, in order to identify the different radiating modes of the antenna. Then a set of feeding configurations is proposed so as to excite these modes. As the modes must operate in the same frequency band, a loading technique is used in the antenna in order to shift the resonance frequency of the modes to the proper band

    Effect of the Front and Back Illumination on Sub-Terahertz Detection Using n-Channel Strained-Silicon MODFETs

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    [EN] Plasma waves in semiconductor gated 2-D systems can be used to efficiently detect Terahertz (THz) electromagnetic radiation. This work reports on the response of a strained-Si Modulation-doped Field-Effect Transistor (MODFET) under front and back sub-THz illumination. The response of the MODFET has been characterized using a two-tones solid-state continuous wave source at 0.15 and 0.30 THz. The DC drain-to-source voltage of 500-nm gate length transistors transducing the sub-THz radiation (photovoltaic mode) exhibited a non-resonant response in agreement with literature results. Two configurations of the illumination were investigated: (i) front side illumination in which the transistor was shined on its top side, and (ii) back illumination side where the device received the sub-THz radiation on its bottom side, i.e., on the Si substrate. Under excitation at 0.15 THz clear evidence of the coupling of terahertz radiation by the bonding wires was found, this coupling leads to a stronger response under front illumination than under back illumination. When the radiation is shifted to 0.3 THz, as a result of a lesser efficient coupling of the EM radiation through the bonding wires, the response under front illumination was considerably weakened while it was strengthened under back illumination. Electromagnetic simulations explained this behavior as the magnitude of the induced electric field in the channel of the MODFET was considerably stronger under back illumination.This research was funded by the Ministerio de Ciencia, Investigacion y Universidades of Spain andFEDER (ERDF: European Regional Development Fund) under the Research Grants numbers RTI2018-097180-B-100 and TEC2016-78028-C3-3-P and FEDER/Junta de Castilla y Leon Research Grant number SA256P18. Also by Conselleria d'Educacio, lnvestigacio, Cultura i Esport, Generalitat Valenciana (Spain) through the grant AIC0/2019/018. The APC received no external funding.Delgado-Notario, JA.; Calvo-Gallego, J.; Velázquez-Pérez, JE.; Ferrando Bataller, M.; Fobelets, K.; Meziani, YM. (2020). Effect of the Front and Back Illumination on Sub-Terahertz Detection Using n-Channel Strained-Silicon MODFETs. Applied Sciences. 10(17):1-9. https://doi.org/10.3390/app10175959S191017Lewis, R. A. (2019). A review of terahertz detectors. Journal of Physics D: Applied Physics, 52(43), 433001. doi:10.1088/1361-6463/ab31d5Dragoman, D., & Dragoman, M. (2004). Terahertz fields and applications. Progress in Quantum Electronics, 28(1), 1-66. doi:10.1016/s0079-6727(03)00058-2Mittleman, D. M. (2017). Perspective: Terahertz science and technology. Journal of Applied Physics, 122(23), 230901. doi:10.1063/1.5007683Pawar, A. Y., Sonawane, D. D., Erande, K. B., & Derle, D. V. (2013). Terahertz technology and its applications. Drug Invention Today, 5(2), 157-163. doi:10.1016/j.dit.2013.03.009Federici, J., & Moeller, L. (2010). Review of terahertz and subterahertz wireless communications. Journal of Applied Physics, 107(11), 111101. doi:10.1063/1.3386413Federici, J. F., Schulkin, B., Huang, F., Gary, D., Barat, R., Oliveira, F., & Zimdars, D. (2005). THz imaging and sensing for security applications—explosives, weapons and drugs. Semiconductor Science and Technology, 20(7), S266-S280. doi:10.1088/0268-1242/20/7/018Dyakonov, M., & Shur, M. (1993). Shallow water analogy for a ballistic field effect transistor: New mechanism of plasma wave generation by dc current. Physical Review Letters, 71(15), 2465-2468. doi:10.1103/physrevlett.71.2465Dyakonov, M., & Shur, M. (1996). Detection, mixing, and frequency multiplication of terahertz radiation by two-dimensional electronic fluid. IEEE Transactions on Electron Devices, 43(3), 380-387. doi:10.1109/16.485650Tauk, R., Teppe, F., Boubanga, S., Coquillat, D., Knap, W., Meziani, Y. M., … Shur, M. S. (2006). Plasma wave detection of terahertz radiation by silicon field effects transistors: Responsivity and noise equivalent power. Applied Physics Letters, 89(25), 253511. doi:10.1063/1.2410215Rumyantsev, S. L., Fobelets, K., Veksler, D., Hackbarth, T., & Shur, M. S. (2008). Strained-Si modulation doped field effect transistors as detectors of terahertz and sub-terahertz radiation. Semiconductor Science and Technology, 23(10), 105001. doi:10.1088/0268-1242/23/10/105001Javadi, E., Delgado-Notario, J. A., Masoumi, N., Shahabadi, M., Velázquez-Pérez, J. E., & Meziani, Y. M. (2018). Continuous Wave Terahertz Sensing Using GaN HEMTs. physica status solidi (a), 215(11), 1700607. doi:10.1002/pssa.201700607Delgado-Notario, J. A., Clericò, V., Diez, E., Velázquez-Pérez, J. E., Taniguchi, T., Watanabe, K., … Meziani, Y. M. (2020). Asymmetric dual-grating gates graphene FET for detection of terahertz radiations. APL Photonics, 5(6), 066102. doi:10.1063/5.0007249Lewis, R. A. (2014). A review of terahertz sources. Journal of Physics D: Applied Physics, 47(37), 374001. doi:10.1088/0022-3727/47/37/374001Delgado-Notario, J., Velazquez-Perez, J., Meziani, Y., & Fobelets, K. (2018). Sub-THz Imaging Using Non-Resonant HEMT Detectors. Sensors, 18(2), 543. doi:10.3390/s18020543Gaspari, V., Fobelets, K., Velazquez-Perez, J. E., Ferguson, R., Michelakis, K., Despotopoulos, S., & Papavassilliou, C. (2004). Effect of temperature on the transfer characteristic of a 0.5 μm-gate Si:SiGe depletion-mode n-MODFET. Applied Surface Science, 224(1-4), 390-393. doi:10.1016/j.apsusc.2003.08.066Fobelets, K., Jeamsaksiri, W., Papavasilliou, C., Vilches, T., Gaspari, V., Velazquez-Perez, J. E., … König, U. (2004). Comparison of sub-micron Si:SiGe heterojunction nFETs to Si nMOSFET in present-day technologies. Solid-State Electronics, 48(8), 1401-1406. doi:10.1016/j.sse.2004.01.017Delgado Notario, J. A., Javadi, E., Calvo-Gallego, J., Diez, E., Velázquez, J. E., Meziani, Y. M., & Fobelets, K. (2016). Sub-Micron Gate Length Field Effect Transistors as Broad Band Detectors of Terahertz Radiation. International Journal of High Speed Electronics and Systems, 25(03n04), 1640020. doi:10.1142/s0129156416400206Sakowicz, M., Łusakowski, J., Karpierz, K., Grynberg, M., Gwarek, W., Boubanga, S., … Studart, N. (2010). A High Mobility Field-Effect Transistor as an Antenna for sub-THz Radiation. doi:10.1063/1.3295528Knap, W., Teppe, F., Meziani, Y., Dyakonova, N., Lusakowski, J., Boeuf, F., … Shur, M. S. (2004). Plasma wave detection of sub-terahertz and terahertz radiation by silicon field-effect transistors. Applied Physics Letters, 85(4), 675-677. doi:10.1063/1.177503

    Longitudinally extensive transverse myelitis with AQP4 antibodies revealing ovarian teratoma.

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    Paraneoplastic myelitis is a rare inflammatory disorder most frequently associated with solid tumors or lymphoproliferative disorders. Patients often harbor onconeuronal antibodies and their prognosis is usually poor. Here we report a 42-year old woman with longitudinally extensive transverse myelitis and aquaporin-4 (AQP4) antibodies that led to the diagnosis of ovarian teratoma. After tumor removal and immune therapy (including corticosteroids, plasma exchange, intravenous immunoglobulins and rituximab) the patient progressively improved achieving complete recovery. Histological study of the teratoma demonstrated neural tissue containing AQP4 expressing cells and intense inflammatory infiltrates, providing evidence for a possible paraneoplastic link between both disorders

    Contactin-associated protein-2 antibodies in non-paraneoplastic cerebellar ataxia

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    Background Relatively few studies have searched for potentially pathogenic antibodies in non-paraneoplastic patients with cerebellar ataxia. Methods and Results We first screened sera from 52 idiopathic ataxia patients for binding of serum IgG antibodies to cerebellar neurons. One strong-binding serum was selected for immunoprecipitation and mass spectrometry, which resulted in the identification of contactin-associated protein 2 (CASPR2) as a major antigen. CASPR2 antibodies were then found by a cell-based assay in 9/88 (10%) ataxia patients, compared to 3/144 (2%) multiple sclerosis or dementia controls (p=0.011). CASPR2 is strongly expressed in the cerebellum, only partly in association with voltage-gated potassium channels. Conclusions Prospective studies are now needed to see whether identification of CASPR2 antibodies has relevance for the diagnosis and treatment of idiopathic cerebellar ataxia

    Intestinal fungi contribute to development of alcoholic liver disease

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    This study was supported in part by NIH grants R01 AA020703, U01 AA021856 and by Award Number I01BX002213 from the Biomedical Laboratory Research & Development Service of the VA Office of Research and Development (to B.S.). K.H. was supported by a DFG (Deutsche Forschungsgemeinschaft) fellowship (HO/ 5690/1-1). S.B. was supported by a grant from the Swiss National Science Foundation (P2SKP3_158649). G.G. received funding from the Yale Liver Center NIH P30 DK34989 and R.B. from NIAAA grant U01 AA021908. A.K. received support from NIH grants RC2 AA019405, R01 AA020216 and R01 AA023417. G.D.B. is supported by funds from the Wellcome Trust. We acknowledge the Human Tissue and Cell Research (HTCR) Foundation for making human tissue available for research and Hepacult GmbH (Munich, Germany) for providing primary human hepatocytes for in vitro analyses. We thank Dr. Chien-Yu Lin Department of Medicine, Fu-Jen Catholic University, Taiwan for statistical analysis.Peer reviewedPublisher PD

    Impact of Liver Inflammation on Bile Acid Side Chain Shortening and Amidation

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    Bile acid (BA) synthesis from cholesterol by hepatocytes is inhibited by inflammatory cytokines. Whether liver inflammation also affects BA side chain shortening and conjugation was investigated. In human liver cell lines (IHH, HepG2, and HepaRG), agonists of nuclear receptors including the farnesoid X receptor (FXR), liver X receptor (LXR), and peroxisome proliferator-activated receptors (PPARs) did not affect the expression of BA-related peroxisomal enzymes. In contrast, hepatocyte nuclear factor 4? (HNF4?) inhibition down-regulated acyl-CoA oxidase 2 (ACOX2). ACOX2 was repressed by fibroblast growth factor 19 (FGF19), which was prevented by extracellular signal-regulated kinase (ERK) pathway inhibition. These changes were paralleled by altered BA synthesis (HPLC-MS/MS). Cytokines able to down-regulate cholesterol-7?-hydroxylase (CYP7A1) had little effect on peroxisomal enzymes involved in BA synthesis except for ACOX2 and bile acid-CoA:amino acid N-acyltransferase (BAAT), which were down-regulated, mainly by oncostatin M (OSM). This effect was prevented by Janus kinase (JAK) inhibition, which restored BA side chain shortening and conjugation. The binding of OSM to the extracellular matrix accounted for a persistent effect after culture medium replacement. In silico analysis of four databases (n = 201) and a validation cohort (n = 90) revealed an inverse relationship between liver inflammation and ACOX2/BAAT expression which was associated with changes in HNF4? levels. In conclusion, BA side chain shortening and conjugation are inhibited by inflammatory effectors. However, other mechanisms involved in BA homeostasis counterbalance any significant impact on the serum BA profile

    Microwave tomography: an algorithm for cylindrical geometries

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    The letter presents an efficient algorithm in cylindrical coordinates for microwave diffraction tomography. In comparison with algorithms in cartesian co-ordinates, the mechanical rotation of the object is avoided and higher-quality images are obtained with similar processing time.Peer ReviewedPostprint (published version

    Hepatic wound repair

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    BACKGROUND: Human chronic liver diseases (CLDs) with different aetiologies rely on chronic activation of wound healing that represents the driving force for fibrogenesis progression (throughout defined patterns of fibrosis) to the end stage of cirrhosis and liver failure. ISSUES: Fibrogenesis progression has a major worldwide clinical impact due to the high number of patients affected by CLDs, increasing mortality rate, incidence of hepatocellular carcinoma and shortage of organ donors for liver transplantation. BASIC SCIENCE ADVANCES: Liver fibrogenesis is sustained by a heterogeneous population of profibrogenic hepatic myofibroblasts (MFs), the majority being positive for alpha smooth muscle actin (alphaSMA), that may originate from hepatic stellate cells and portal fibroblasts following a process of activation or from bone marrow-derived cells recruited to damaged liver and, in a method still disputed, by a process of epithelial to mesenchymal transition (EMT) involving cholangiocytes and hepatocytes. Recent experimental and clinical data have identified, at tissue, cellular and molecular level major profibrogenic mechanisms: (a) chronic activation of the wound-healing reaction, (b) oxidative stress and related reactive intermediates, and (c) derangement of epithelial-mesenchymal interactions. CLINICAL CARE RELEVANCE: Liver fibrosis may regress following specific therapeutic interventions able to downstage or, at least, stabilise fibrosis. In cirrhotic patients, this would lead to a reduction of portal hypertension and of the consequent clinical complications and to an overall improvement of liver function, thus extending the complication-free patient survival time and reducing the need for liver transplantation. CONCLUSION: Emerging mechanisms and concepts related to liver fibrogenesis may significantly contribute to clinical management of patients affected by CLDs
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