20 research outputs found

    Magnetocaloric effect and piezoresponse of engineered ferroelectric-ferromagnetic heterostructures

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    This study reports the magnetocaloric effect (MCE) and piezoresponse of integrated ferroelectric-ferromagnetic heterostructures of PbZr0.52Ti0.48O3 (PZT) (5 nm)/Bi-Sr-Ca-Cu-2-O-x (BSCCO) (5 nm)/La0.67Sr0.33MnO3 (LSMO) (40 nm)/MgO (0 01). Magnetic and pizoresponse behavior of the heterostructures are found to be governed by magneto-electric coupling and induced lattice strains. In addition, a maximum MCE is studied using Maxwell equations from both Field Cooled (FC) and Zero Field Cooled (ZFC) magnetization data. Maximum MCE entropy change (vertical bar Delta s vertical bar) of 42.6 mJkg(-1)K(-1) (at 258 K) and 41.7 mJkg(-1)K(-1) (at 269 K) are found corresponding to FC and ZFC data, respectively. The variation in maximum entropy change and corresponding temperatures for FC and ZFC data revealed that the application of a magnetic field can significantly contribute towards tuning of the MCE. Interestingly, these multilayered structures are found to sustain MCE over a broad temperature range, which makes them attractive for improved solid-state energy conversion devices

    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

    Integration of Motion Capture and EMG data for Classifying the Human Motions

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    Three dimensional motion capture facility is a powerful tool for quantitative and qualitative assessment of multijoint external movements. Electro-myograph (EMG) signals give the physiologic information of muscles while doing motions. In this paper, our objective is to integrate these two different bio-medical data together and to extract precise and accurate feature information for classifying the human motions. When both forms of data are integrated and analyzed together, the information achieved will be immensely useful to quantify the complex human motions for medical reasons or sport performances. These biological quantifications of biomechanical data, are useful for gait analysis and several orthopedic applications, such as joint mechanics, prosthetic designs, and sports medicines. The different dimensionality reduction approaches such Integral of Absolute value and Weighted Singular Value Decomposition are used to extract the preliminary features from EMG and motion capture data respectively. On combining these feature vectors, fuzzy clustering such as Fuzzy c-means (FCM) is performed on these vectors that are mapped as the points in multi-dimensional feature space. We get the degree of memberships with every cluster for each mapped point. This extracted information is used as the final feature vectors for classifying the human motions. information achieved will be immensely useful to quantify the complex human motions for medical reasons or sport performances. These biological measuring of biomechanical data, are useful for gait analysis and several orthopedic applications, such as joint mechanics, prosthetic designs, and sports medicines. 1

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    Not AvailableCatla catla is the fastest growing Indian major carp and one of the major aquaculture species in South Asia. A monoclonal antibody (MAb) designated B8 MAb was produced against nylon wool-enriched thymus mononuclear cells of C. catla. This MAb did not show reactivity with macrophage and epithelial cell lines derived from catla thymus in cellular ELISA. In flow cytometric analysis of gated lymphocytes, the percentage of B8 positive (B8+) cells in thymus (n = 10, 500–600 g) was determined to be 77.7 %. Similarly, the percentage of B8+ cells in kidney, spleen and blood (n = 5) was 15.08, 1.1 and 32.17 %, respectively. Western blotting of reduced membrane proteins showed that B8 MAb reacted with a polypeptide having a molecular weight of 168.2 kDa. In indirect immunoperoxidase test, B8+ cells appeared to be lymphoid cells with a high nucleus to cytoplasmic ratio. B8 reactive cells were densely packed in central region of thymus whereas, a few cells were found to be positive in kidney and spleen sections. B8 MAb also reacted with a significant population of lymphocytes in blood smears. Considering the economic importance of C. catla, this MAb should be a useful tool for studying immune response of this fish species.Not Availabl

    Oculometric Feature Changes During Acute Hypoxia in a Simulated High-Altitude Airdrop Scenario

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    BACKGROUND: Severe acute hypoxia results in a rapid deterioration of cognitive functioning and thus poses a risk for human operations in high altitude environments. This study aimed at investigating the effects of oxygen system failure during a high-altitude high-opening (HAHO) parachute jump scenario from 30,000 ft (9144 m) on human physiology and cognitive performance using a noncontact eye-tracking task. METHODS: Nine healthy male volunteers (ages 27–48) were recruited from the Norwegian Special Operations Commandos. Eye-tracking data were collected to derive information on cognitive performance in the context of rapid dynamic changes in pressure altitude while performing a modified King-Devick test. The baseline data was collected at 8000 ft (2438 m) while breathing 100% oxygen during decompression. For every test, the corresponding arterial blood gas analysis was performed. RESULTS: The study subjects endured severe hypoxia, which resulted in significant prolongations of fixation time (range: 284.1–245.6 ms) until 23,397 ft (131 m) and fixation size (range: 34.6–32.4 mm) until 25,389 ft (7739 m) as compared to the baseline (217.6 ± 17.8 ms and 27.2 ± 4.5 mm, respectively). The increase in the saccadic movement and decrease in the saccadic velocity was observed until 28,998 ft and 27,360 ft (8839 and 8339 m), respectively. DISCUSSION: This is the first study to investigate cognitive performance from measured oculometric variables during severe hypobaric hypoxia in a simulated high-altitude airdrop mission scenario. The measurement of altered oculometric variables under hypoxic conditions represents a potential avenue to study altered cognitive performance using noncontact sensors that can derive information and serve to provide the individual with a warning from impending incapacitation
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