34 research outputs found

    Prediction of Heat Transfer Coefficient of Pool Boiling Using Back propagation Neural Network

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    Artificial neural network (ANN), in comparison with empirical correlations, has recently received more attention. The present paper includes predictive modeling of heat transfer coefficient for binary mixtures in pool boiling for hydrocarbon compounds, using Back propagation techniques through Multilayer Perceptron, one of the types of the artificial neural networks. To train and learn the system, predictive neural network was found, which is capable of understanding and predicting the preset output which is heat transfer coefficient. The principle operation of such neural networks is based on the experimental data collected from some researchers [1-4]. A new ANN model is proposed using five inputs (mole fraction, temperature difference, heat flux, density and viscosity) to predict the heat transfer coefficient. The prediction using ANN shows 0.0026 AARE (Absolute Average Relative Error) with most widely known correlations namely those of Calus, Fujita and Thome which have given 0.086, 0.066 and 0.038 respectively

    Novel Conserved-region T-cell Mosaic Vaccine With High Global HIV-1 Coverage Is Recognized by Protective Responses in Untreated Infection

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    An effective human immunodeficiency virus type 1 (HIV-1) vaccine is the best solution for halting the acquired immune deficiency syndrome epidemic. Here, we describe the design and preclinical immunogenicity of T-cell vaccine expressing novel immunogens tHIVconsvX, vectored by DNA, simian (chimpanzee) adenovirus, and poxvirus modified vaccinia virus Ankara (MVA), a combination highly immunogenic in humans. The tHIVconsvX immunogens combine the three leading strategies for elicitation of effective CD8+ T cells: use of regions of HIV-1 proteins functionally conserved across all M group viruses (to make HIV-1 escape costly on viral fitness), inclusion of bivalent complementary mosaic immunogens (to maximize global epitope matching and breadth of responses, and block common escape paths), and inclusion of epitopes known to be associated with low viral load in infected untreated people (to induce field-proven protective responses). tHIVconsvX was highly immunogenic in two strains of mice. Furthermore, the magnitude and breadth of CD8+ T-cell responses to tHIVconsvX-derived peptides in treatment-naive HIV-1+ patients significantly correlated with high CD4+ T-cell count and low viral load. Overall, the tHIVconsvX design, combining the mosaic and conserved-region approaches, provides an indisputably better coverage of global HIV-1 variants than previous T-cell vaccines. These immunogens delivered in a highly immunogenic framework of adenovirus prime and MVA boost are ready for clinical development

    HIV-1 remission following CCR5Δ32/Δ32 haematopoietic stem cell transplantation

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    HIV-1 cure remains elusive with only one reported case a decade ago. Termed the “Berlin Patient”, the individual underwent 2 allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) procedures using a donor with a homozygous mutation in the HIV coreceptor CCR5 (CCR5Δ32/Δ32) to treat his acute myeloid leukemia. Total body irradiation was given with each HSCT. Critically, it is unclear which treatment or patient parameters contributed to this only documented case of long term HIV remission. Here we show that HIV-1 remission may be possible with a less aggressive and toxic approach. An HIV-1-infected adult underwent allo-HSCT for Hodgkin’s Lymphoma using cells from a CCR5Δ32/Δ32 donor. He experienced mild gut graft versus host disease. Antiretroviral therapy was interrupted 16 months after transplantation. HIV-1 remission has been maintained through a further 18 months. Plasma HIV-1 RNA has been undetectable at <1 copy/ml along with undetectable HIV-1 DNA in peripheral CD4 T lymphocytes. Quantitative viral outgrowth assay from peripheral CD4 T lymphocytes shows no reactivatable virus using a total of 24 million resting CD4 T cells. CCR5-tropic, but not CXCR4-tropic viruses were identified in HIV-1 DNA from CD4 T cells of the patient prior to transplant. CD4 T cells isolated from peripheral blood post-transplant did not express CCR5 and were only susceptible to CXCR4-tropic virus ex vivo. HIV-1 Gag-specific CD4 and CD8 T cell responses were lost after transplantation whilst Cytomegalovirus (CMV)-specific responses were detectable. Likewise, HIV-1-specific antibodies and avidities fell to levels comparable to those in the Berlin patient following transplantation. Although at 18 months post-treatment interruption it is premature to conclude that this patient has been cured, these data suggest that single allo-HSCT with homozygous CCR5Δ32 donor cells may be sufficient to achieve HIV-1 remission with reduced intensity conditioning and no irradiation, and the findings further support the development of HIV remission strategies based on preventing CCR5 expression.NIHR AmFA

    The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

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    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Cosmic Consequences of Kaniadakis and Generalized Tsallis Holographic Dark Energy Models in the Fractal Universe

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    We investigate the recently proposed holographic dark energy models with the apparent horizon as the IR cutoff by assuming Kaniadakis and generalized Tsallis entropies in the fractal universe. The implications of these models are discussed for both the interacting (Γ=3Hb2ρm) and noninteracting (b2=0) cases through different cosmological parameters. Accelerated expansion of the universe is justified for both models through deceleration parameter q. In this way, the equation of state parameter ωd describes the phantom and quintessence phases of the universe. However, the coincidence parameter r~=Ωm/Ωd shows the dark energy- and dark matter-dominated eras for different values of parameters. It is also mentioned here that the squared speed of sound gives the stability of the model except for the interacting case of the generalized Tsallis holographic dark energy model. It is mentioned here that the current dark energy models at the apparent horizon give consistent results with recent observations

    Analysis of baryon to entropy ratio in Ricci inverse gravity

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    This letter is devoted to investigate the matter-antimatter asymmetry through baryogenesis (and generalized gravitational baryogenesis interaction) in the realm of f(R, A) theory of gravity also known as Ricci inverse gravity, where R is the curvature scalar and A is the anti-curvature scalar. Baryogensis (baryon to entropy ratio ηBS=ηβηβˉS\frac{\eta_{_B}}{S}=\frac{\eta_{_\beta}-\eta_{\bar{\beta}}}{S} ) is a theoretical process that took place in the early history of the universe producing supremacy of matter over anti-matter, where S is entropy of universe and ηβ(ηβˉ)\eta_{_\beta}(\eta_{\bar{_\beta}}) is the baryon (anti-baryon) number. In this article, we inspect the consequences of CPviolating\mathcal{C}\mathcal{P}-violating interactions proportional to ν(R+A)\partial_{\nu}(R+A) and νf(R+A)\partial_{\nu}f(R+A) . We take f(R,A)=R+αAf(R,A)=R+\frac{\alpha}{A} as specific model to analyze the phenomenon of baryogenesis and generalized gravitational baryogenesis. Our outcomes show that f(R, A) gravity can come up consistently and significantly to the phenomenon of gravitational baryogenesis. We compare our results with latest astrophysical data of baryon to entropy ratio, which exhibits outstanding compatibility with the observational bounds

    Compatibility of big bang nucleosynthesis in some modified gravities

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    This paper is devoted to investigate the implications of Einstein-Aether and modified Hořava–Lifshitz theories of gravity to the formation of light elements in the early universe named as big bang nucleosynthesis. We choose different models from these theories for a detailed investigation of big bang nucleosynthesis epoch and compare it with the observational bounds. That is, we compare the deviation of freeze-out temperature TfT_{_f} with the Λ\Lambda CDM paradigm and use observational bounds on ΔTfTf\left| \frac{\Delta T_{_f}}{T_{_f}}\right| to inspect constraints on the involved free parameters of these models. We apply Chi-square test on the Hubble parameter H in each model to analyze the compatibility of model parameters with the observations and find consistent results. We find that chosen models of Einstein-Aether gravity and modified Hořava–Lifshitz gravity can satisfy big bang nucleosynthesis constraints and thus constitute a viable cosmology since they can be source for dark energy sector and late-time accelerated expansion

    <i>k</i>-Essence Inflation Evading Swampland Conjectures and Inflationary Parameters

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    In this paper, we study the inflationary scenario in the realm of k-essence model and swampland conjectures. Taking into account three models of Chaplygin gas, such as generalized, modified, and generalized cosmic Chaplygin gas models, we discuss the equation of state (EoS) parameter ω, slow roll parameters (ϵ(ϕ),η(ϕ)), curvature perturbation (Ps), tensor to scalar ratio (r), and scalar spectral index (ns). As regards the k-essence model, the coupling function as a function of scalar field L(ϕ) is used. We investigate the swampland conjecture and then find the value of ζ(ϕ), i.e., bound of second conjecture for these three models by unifying swampland conjecture and k-essence. We plot the EoS parameter ω, inflationary parameters plane r−ns and bound of swampland conjecture ζ(ϕ)−ϕ, which determine that the values of ω−1 for each model, r, are r0.0094,r≤0.0065,r≤0.0067, and ranges for ns are [0.934,0.999],[0.9,0.999],[0.9,0.992] for generalized, modified, and generalized cosmic Chaplygin gas models, respectively, and compare their compatibility with the Planck data from 2018. Furthermore, we determine the bound for swampland conjecture as ζ(ϕ)≤0.992,ζ(ϕ)≤0.964,ζ(ϕ)≤0.964 for generalized, modified and generalized cosmic Chaplygin gas models, respectively
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