56 research outputs found

    Enhancement of spin to charge conversion efficiency at the topological surface state by inserting normal metal spacer layer in the topological insulator based heterostructure

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    We report efficient spin to charge conversion (SCC) in the topological insulator (TI) based heterostructure (BiSbTe1.5Se1.5/Cu/Ni80Fe20BiSbTe_{1.5}Se_{1.5}/Cu/Ni_{80}Fe_{20}) by using spin-pumping technique where BiSbTe1.5Se1.5BiSbTe_{1.5}Se_{1.5} is the TI and Ni80Fe20Ni_{80}Fe_{20} is the ferromagnetic layer. The SCC, characterized by inverse Edelstein effect length (λIEE\lambda_{IEE}) in the TI material gets altered with an intervening Copper (Cu) layer and it depends on the interlayer thickness. The introduction of Cu layer at the interface of TI and ferromagnetic metal (FM) provides a new degree of freedom for tuning the SCC efficiency of the topological surface states. The significant enhancement of the measured spin-pumping voltage and the linewidth of ferromagnetic resonance (FMR) absorption spectra due to the insertion of Cu layer at the interface indicates a reduction in spin memory loss at the interface that resulted from the presence of exchange coupling between the surface states of TI and the local moments of ferromagnetic metal. The temperature dependence (from 8K to 300K) of the evaluated λIEE\lambda_{IEE} data for all the trilayer systems, TI/Cu/FM with different Cu thickness confirms the effect of exchange coupling between the TI and FM layer on the spin to charge conversion efficiency of the topological surface state

    Effect of ondansetron on the analgesic efficacy of tramadol used for postoperative analgesia: a randomised controlled study

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    Background: Ondansetron is used to reduce tramadol induced postoperative nausea and vomiting  (PONV). Studies on patient-controlled analgesia (PCA) found that ondansetron reduces the analgesic  efficacy of tramadol. Drug requirement in PCA and in conventional intravenous analgesia without PCA  device may differ. This study evaluated the effect of ondansetron on analgesic efficacy of tramadol for postoperative analgesia without a PCA device.Methods: A prospective, randomised, placebo-controlled, double-blind parallel group study was  conducted on 126 euthyroid patients of ASA I and II, aged between 30 and 65 years undergoing  hemithyroidectomy under general anaesthesia. Patients were divided into group O and group C. At the time of closure of strap muscles, patients in group O received tramadol 1.5 mg/kg IV and ondansetron 0.1 mg/kg (diluted to 4 ml) IV and those in group C received tramadol 1.5 mg/kg IV and normal saline 4 ml IV. Duration of analgesia, pain score (VAS), PONV and sedation scores were analysed.Results: Duration of analgesia was longer in group C compared with group O (164.1 min vs. 76.3 min, p < 0.05). Postoperative VAS score was higher in group O (p < 0.001). Group C showed higher PONV and sedation score.Conclusion: Ondansetron reduces the duration and quality of analgesia of tramadol administered  conventionally without a PCA device.Keywords: ondansetron, pain, postoperative nausea and vomiting, sedation, tramado

    Overview of Chatbots with special emphasis on artificial intelligence-enabled ChatGPT in medical science

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    The release of ChatGPT has initiated new thinking about AI-based Chatbot and its application and has drawn huge public attention worldwide. Researchers and doctors have started thinking about the promise and application of AI-related large language models in medicine during the past few months. Here, the comprehensive review highlighted the overview of Chatbot and ChatGPT and their current role in medicine. Firstly, the general idea of Chatbots, their evolution, architecture, and medical use are discussed. Secondly, ChatGPT is discussed with special emphasis of its application in medicine, architecture and training methods, medical diagnosis and treatment, research ethical issues, and a comparison of ChatGPT with other NLP models are illustrated. The article also discussed the limitations and prospects of ChatGPT. In the future, these large language models and ChatGPT will have immense promise in healthcare. However, more research is needed in this direction

    Single locus genotyping to track Leishmania donovani in the Indian subcontinent: Application in Nepal

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    Background We designed a straightforward method for discriminating circulating Leishmania populations in the Indian subcontinent (ISC). Research on transmission dynamics of visceral leishmaniasis (VL, or Kala-azar) was recently identified as one of the key research priorities for elimination of the disease in the ISC. VL in Bangladesh, India, and Nepal is caused by genetically homogeneous populations of Leishmania donovani parasites, transmitted by female sandflies. Classical methods to study diversity of these protozoa in other regions of the world, such as microsatellite typing, have proven of little use in the area, as they are not able to discriminate most genotypes. Recently, whole genome sequencing (WGS) so far identified 10 different populations termed ISC001-ISC010. Methodology / Principle findings As an alternative to WGS for epidemiological or clinical studies, we designed assays based on PCR amplification followed by dideoxynucleotide sequencing for identification of the nonrecombinant genotypes ISC001 up to ISC007. These assays were applied on 106 parasite isolates collected in Nepal between 2011 and 2014. Combined with data from WGS on strains collected in the period 2002–2011, we provide a proof-of-principle for the application of genotyping to study treatment outcome, and differential geographic distribution. Conclusions / Significance Our method can aid in epidemiological follow-up of visceral leishmaniasis in the Indian subcontinent, a necessity in the frame of the Kala-azar elimination initiative in the region

    Gastric adenocarcinoma in a patient re-infected with H. pylori after regression of MALT lymphoma with successful anti-H. pylori therapy and gastric resection: a case report

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    BACKGROUND: Helicobacter pylori (H. pylori) has been etiologically linked with primary gastric lymphoma (PGL) and gastric carcinoma (GC). There are a few reports of occurrence of both diseases in the same patient with H. pylori infection. CASE PRESENTATION: We report a patient with PGL in whom the tumor regressed after surgical resection combined with eradication of H. pylori infection. However, he developed GC on follow up; this was temporally associated with recrudescence / re-infection of H. pylori. This is perhaps first report of such occurrence. CONCLUSIONS: Possible cause and effect relationship between H. pylori infection and both PGL and GC is discussed. This case also documents a unique problem in management of PGL in tropical countries where re-infection with H. pylori is supposed to be high

    High monocytic MDSC signature predicts multi-drug resistance and cancer relapse in non-Hodgkin lymphoma patients treated with R-CHOP

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    IntroductionNon-Hodgkin Lymphoma (NHL) is a heterogeneous lymphoproliferative malignancy with B cell origin. Combinatorial treatment of rituximab, cyclophsphamide, hydroxydaunorubicin, oncovin, prednisone (R-CHOP) is the standard treatment regimen for NHL, yielding a complete remission (CR) rate of 40-50%. Unfortunately, considerable patients undergo relapse after CR or initial treatment, resulting in poor clinical implications. Patient’s response to chemotherapy varies widely from static disease to cancer recurrence and later is primarily associated with the development of multi-drug resistance (MDR). The immunosuppressive cells within the tumor microenvironment (TME) have become a crucial target for improving the therapy efficacy. However, a better understanding of their involvement is needed for distinctive response of NHL patients after receiving chemotherapy to design more effective front-line treatment algorithms based on reliable predictive biomarkers.MethodsPeripheral blood from 61 CD20+ NHL patients before and after chemotherapy was utilized for immunophenotyping by flow-cytometry at different phases of treatment. In-vivo and in-vitro doxorubicin (Dox) resistance models were developed with murine Dalton’s lymphoma and Jurkat/Raji cell-lines respectively and impact of responsible immune cells on generation of drug resistance was studied by RT-PCR, flow-cytometry and colorimetric assays. Gene silencing, ChIP and western blot were performed to explore the involved signaling pathways.ResultsWe observed a strong positive correlation between elevated level of CD33+CD11b+CD14+CD15- monocytic MDSCs (M-MDSC) and MDR in NHL relapse cohorts. We executed the role of M-MDSCs in fostering drug resistance phenomenon in doxorubicin-resistant cancer cells in both in-vitro, in-vivo models. Moreover, in-vitro supplementation of MDSCs in murine and human lymphoma culture augments early expression of MDR phenotypes than culture without MDSCs, correlated well with in-vitro drug efflux and tumor progression. We found that MDSC secreted cytokines IL-6, IL-10, IL-1β are the dominant factors elevating MDR expression in cancer cells, neutralization of MDSC secreted IL-6, IL-10, IL-1β reversed the MDR trait. Moreover, we identified MDSC secreted IL-6/IL-10/IL-1β induced STAT1/STAT3/NF-κβ signaling axis as a targeted cascade to promote early drug resistance in cancer cells.ConclusionOur data suggests that screening patients for high titre of M-MDSCs might be considered as a new potential biomarker and treatment modality in overcoming chemo-resistance in NHL patients

    Dendritic cells and antigen trapping technology — A revolution in vaccine/immunotherapy strategy

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    491-504Vaccines based on dendritic cells—the immune system’s key responders to foreign invaders— grabbed the spotlight of this decade. Scientists have devised a dozen different ways to make dendritic cell vaccines. They have linked dendritic cells with all kinds of antigens, including peptides derived from gene mutations, tumor/pathogen RNA, viral vectors, and with whole pathogen/tumor lysate. And they are adding cytokines such as granulocyte macrophage colony stimulating factor or interleukin 4 during dendritic cell growth or maturation or at the site of vaccination to try to boost response. We are still learning the best way to generate the dendritic cells, load them with the antigen and send them to the right place in the body, and use of the biological stage of development of dendritic cells that is best suited to stimulate a response. In the present review attempts have been made to present a comprehensive synopsis of the history, development and ramifications of evolving knowledge on dendritic cell biology and the prospects for being developed as a rational immunotherapeutic tool. Further clinical studies are warranted
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