944 research outputs found

    Exploration of Cd1−xZnxSe as a window layer for CIGS based solar cell with PEDOT: PSS as back surface field layer

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    This research investigates the potential of Cd _1−x Zn _x Se thin film for photovoltaic applications. The electrical behavior of CIGS based solar cell is examined with the novel Cd _1−x Zn _x Se as buffer layer material by Solar Cell Capacitance Simulator (SCAPS). The tunability of Cd _1−x Zn _x Se facilities to reduce the defects between absorber and buffer layer by determining the ideal conduction band offset. It is revealed that cross-over occurs between the p-type absorber and the metal back contact if the metal work function is below 4.6 eV. In this research, a thin PEDOT: PSS back surface (BSF) layer was integrated which enhances the device efficiency from 22.5 percent to 28.32% while retaining the metal work function at 5.1 eV. The trade-off between the use of metal having higher work function and inclusion of heavily doped BSF layer is one of the important findings of this research. These findings pave the way for Cd _1−x Zn _x Se to be commercially used as a buffer layer material for CIGS solar cell

    Amphotericin B Nano-Assemblies Circumvent Intrinsic Toxicity and Ensure Superior Protection in Experimental Visceral Leishmaniasis with Feeble Toxic Manifestation

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    In spite of its high effectiveness in the treatment of both leishmaniasis as well as a range of fungal infections, the free form of the polyene antibiotic amphotericin B (AmB) does not entertain the status of the most preferred drug of choice in clinical settings. The high intrinsic toxicity of the principal drug could be considered the main impedance in the frequent medicinal use of this otherwise very effective antimicrobial agent. Taking into consideration this fact, the pharma industry has introduced many novel dosage forms of AmB to alleviate its toxicity issues. However, the limited production, high cost, requirement for a strict cold chain, and need for parenteral administration are some of the limitations that explicitly compel professionals to look for the development of an alternate dosage form of this important drug. Considering the fact that the nano-size dimensions of drug formulation play an important role in increasing the efficacy of the core drug, we employed a green method for the development of nano-assemblies of AmB (AmB-NA). The as-synthesized AmB-NA manifests desirable pharmacokinetics in the treated animals. The possible mechanistic insight suggested that as-synthesized AmB-NA induces necrosis-mediated cell death and severe mitochondrial dysfunction in L. donovani promastigotes by triggering depolarization of mitochondrial membrane potential. In vivo studies demonstrate a noticeable decline in parasite burden in the spleen, liver, and bone marrow of the experimental BALB/c mice host. In addition to successfully suppressing the Leishmania donovani, the as-formed AmB-NA formulation also modulates the host immune system with predominant Th1 polarization, a key immune defender that facilitates the killing of the intracellular parasite

    Enhanced DASS-CARE 2.0: a blockchain-based and decentralized FL framework

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    The emergence of the Cognitive Internet of Medical Things (CIoMT) during the COVID-19 pandemic has been transformational. The CIoMT is a rapidly evolving technology that uses artificial intelligence, big data, and the Internet of Things (IoT) to provide personalized patient care. The CIoMT can be used to monitor and track vital signs, such as temperature, blood pressure, and heart rate, thus giving healthcare providers real-time information about a patient’s health. However, in such systems, the problem of privacy during data processing or sharing remains. Therefore, federated learning (FL) plays an important role in the Cognitive Internet of Medical Things (CIoMT) by allowing multiple medical devices to securely collaborate in a distributed and privacy-preserving manner. On the other hand, classical centralized FL models have several limitations, such as single points of failure and malicious servers. This paper presents an enhancement of the existing DASS-CARE 2.0 framework by using a blockchain-based federated learning framework. The proposed solution provides a secure and reliable distributed learning platform for medical data sharing and analytics in a multi-organizational environment. The blockchain-based federated learning framework offrs an innovative solution to overcome the challenges encountered in traditional FL. Furthermore, we provide a comprehensive discussion of the advantages of the proposed framework through a comparative study between our DASS-CARE 2.0 and the traditional centralized FL model while taking the aforementioned security challenges into consideration. Overall, the performance of the proposed framework shows significant advantages compared to traditional methods

    First Search for Axion-Like Particles in a Storage Ring Using a Polarized Deuteron Beam

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    Based on the notion that the local dark-matter field of axions or axion-like particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we performed the first experiment to search for ALPs using a storage ring. For that purpose, we used an in-plane polarized deuteron beam stored at the Cooler Synchrotron COSY, scanning momenta near 970 MeV/c. This entailed a scan of the spin precession frequency. At resonance between the spin precession frequency of deuterons and the ALP-induced EDM oscillation frequency there will be an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and consequently the spin precession frequency were ramped to search for a vertical polarization change that would occur when the resonance is crossed. At COSY, four beam bunches with different polarization directions were used to make sure that no resonance was missed because of the unknown relative phase between the polarization precession and the axion/ALP field. A frequency window of 1.5-kHz width around the spin precession frequency of 121 kHz was scanned. We describe the experimental procedure and a test of the methodology with the help of a radiofrequency Wien filter located on the COSY ring. No ALP resonance was observed. As a consequence an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.Comment: 25 pages, 24 figures, 7 tables, 67 reference

    Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990-2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

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    10.1016/S2352-3018(21)00152-1LANCET HIV810E633-E65

    Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

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    Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)

    Design of an efficient thulium-doped fiber amplifier for dual-hop earth to satellite optical wireless links

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    Optical wireless communication (OWC) links enable high-speed data transmission between earth stations and satellites. The propagation of optical signals through the atmosphere suffer from atmospheric attenuation and turbulence due to rain, fog, snow, clouds, and wind. The impact of these impairments on propagation of optical signals becomes more pronounced in the case of deep space links. Therefore, optical amplifiers of high output power and gain are extremely useful in deep space links to achieve error free transmission by improving the link budget. In this paper, we propose the design of an efficient Thulium-doped fiber amplifier (TDFA) as booster as well as an in-line based on dual-stage pumping scheme for employment in a dual-hop earth to satellite OWC Link. The pumping scheme, length of Thulium-doped fiber (TDF), and Tm3+ concentration in the proposed design of TDFA are optimized in such a way so that high output power and gain are achieved for booster and in-line stages, respectively. Output power and gain of 4.6 W and 18.8 dB, respectively are achieved for signal power of 0 dBm at 1807.143 nm when TDFA is used as booster amplifier. Similarly, gain and output power of 66.6 dB and 1.5 W, respectively are achieved for signal power of −35 dBm at 1807.143 nm when TDFA is used as in-line amplifier. A noise figure (NF) of 4.4 dB is achieved for signal wavelength of 1807.143 nm and power of 0 dBm. Finally, the system level performance of the designed TDFA is investigated using bit error rate (BER) metric for a dual-hop earth to satellite OWC wavelength division multiplexed (WDM) transmission system of four quadrature phase shift keying (QPSK) modulated optical signals with an aggregate data rate of 104 Gbps. The BER results showed different possible ranges of error-free transmission at the forward error correction (FEC) limit of 10-4 for different values of atmospheric attenuation

    Safety and efficacy of intraperitoneal drain placement after emergency colorectal surgery. An international, prospective cohort study