98 research outputs found

    Measurement Analysis of Specific Absorption Rate in Human Body Exposed to a Base Station Antenna by Using Finite Difference Time Domain Techniques

    Get PDF
    The system analysis of specific absorption rate (SAR) in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works. The objectives of this work are to evaluate the knowledge and awareness about SAR among human body and mobile base station. The paper investigates the electromagnetic wave absorption inside a human body. The human body has been identified using dataset based on 2D object considering different electrical parameters.The SAR convinced inside the human body model exposed to a radiating base station antenna (BSA) has been considered for multiple numbers of carrier frequencies and input power of 20 W/carrier at GSM 900 band.The distance (R) of human body from BSA is varied in the range of 0.1 m to 5.0 m. For the number of carrier frequency equal to one and R = 0.1 m,the concentrated value of whole-body average SAR obtained by FDTD technique is found to be 0.68 W/kg which decreases either with increase of R or decrease of number of carrier frequencies. Safety distance for general public is found to be 1.5 m for number of carrier frequencies equal to one.The performance accuracy of this analysis meets the high level condition by comparing with the relevant system development in recent time

    Research on Self-balancing Two Wheels Mobile Robot Control System Analysis

    Get PDF
    The paper presents the research on self-balancing two-wheels mobile robot control system analysis with experimental studies. The research problem in this work is to stabilize the mobile robot with self-control and to carry the sensitive things without failing in a long span period. The main objective of this study is to focus on the mathematical modelling of mobile robot from laboratory scale to real world applications. The numerical expression with mathematical modelling is very important to control the mobile robot system with linearization. The fundamental concepts of dynamic system stability were utilized for maintaining the stability of the constructed mobile robot system. The controller design is also important for checking the stability and the appropriate controller design is proportional, integral,and derivative – PID controller and Linear Quadratic Regulator (LQR). The steady state error could be reduced by using such kind of PID controller.The simulation of numerical expression on mathematical modeling was conducted in MATLAB environments. The confirmation results from the simulation techniques were applied to construct the hardware design of mobile robot system for practical study. The results from simulation approaches and experimental approaches are matched in various kinds of analyses. The constructed mobile robot system was designed and analyzed in the control system design laboratory of Yangon Technological University (YTU)

    A mixed methods evaluation of Advanced Life Support in Obstetrics (ALSO) and Basic Life Support in Obstetrics (BLSO) in a resource-limited setting on the Thailand-Myanmar border [version 1; peer review: 2 approved]

    Get PDF
    Background: Short emergency obstetric care (EmOC) courses have demonstrated improved provider confidence, knowledge and skills but impact on indicators such as maternal mortality and stillbirth is less substantial. This manuscript evaluates Advanced Life Support in Obstetrics (ALSO) and Basic Life Support (BLSO) as an adult education tool, in a protracted, post-conflict and resource-limited setting. Methods: A mixed methods evaluation was used. Basic characteristics of ALSO and BLSO participants and their course results were summarized. Kirkpatrick’s framework for assessment of education effectiveness included: qualitative data on participants’ reactions to training (level 1); and quantitative health indicator data on change in the availability and quality of EmOC and in maternal and/or neonatal health outcomes (level 4), by evaluation of the post-partum haemorrhage (PPH) related maternal mortality ratio (MMR) and stillbirth rate in the eight years prior and following implementation of ALSO and BLSO. Results: 561 Thailand-Myanmar border health workers participated in ALSO (n=355) and BLSO (n=206) courses 2008-2020. Pass rates on skills exceeded 90% for both courses while 50% passed the written ALSO test. Perceived confidence significantly improved for all items assessed. In the eight-year block preceding the implementation of ALSO and BLSO (2000-07) the PPH related MMR per 100,000 live births was 57.0 (95%CI 30.06-108.3)(9/15797) compared to 25.4 (95%CI 11.6-55.4)(6/23620) eight years following (2009-16), p=0.109. After adjustment, PPH related maternal mortality was associated with birth before ALSO/BLSO implementation aOR 3.825 (95%CI 1.1233-11.870), migrant (not refugee) status aOR 3.814 (95%CI 1.241-11.718) and attending ≀four antenatal consultations aOR 3.648 (95%CI 1.189-11.191). Stillbirth rate per 1,000 total births was 18.2 (95%CI 16.2-20.4)(291/16016) before the courses, and 11.1 (95%CI 9.8-12.5)(264/23884) after, p=0.038. Birth before ALSO/ BLSO implementation was associated with stillbirth aoR 1.235 (95%CI 1.018-1.500). Conclusions: This evaluation suggests ALSO and BLSO are sustainable, beneficial, EmOC trainings for adult education in protracted, post-conflict, resource-limited settings

    S1P lyase regulates DNA damage responses through a novel sphingolipid feedback mechanism

    Get PDF
    The injurious consequences of ionizing radiation (IR) to normal human cells and the acquired radioresistance of cancer cells represent limitations to cancer radiotherapy. IR induces DNA damage response pathways that orchestrate cell cycle arrest, DNA repair or apoptosis such that irradiated cells are either repaired or eliminated. Concomitantly and independent of DNA damage, IR activates acid sphingomyelinase (ASMase), which generates ceramide, thereby promoting radiation-induced apoptosis. However, ceramide can also be metabolized to sphingosine-1-phosphate (S1P), which acts paradoxically as a radioprotectant. Thus, sphingolipid metabolism represents a radiosensitivity pivot point, a notion supported by genetic evidence in IR-resistant cancer cells. S1P lyase (SPL) catalyzes the irreversible degradation of S1P in the final step of sphingolipid metabolism. We show that SPL modulates the kinetics of DNA repair, speed of recovery from G2 cell cycle arrest and the extent of apoptosis after IR. SPL acts through a novel feedback mechanism that amplifies stress-induced ceramide accumulation, and downregulation/inhibition of either SPL or ASMase prevents premature cell cycle progression and mitotic death. Further, oral administration of an SPL inhibitor to mice prolonged their survival after exposure to a lethal dose of total body IR. Our findings reveal SPL to be a regulator of ASMase, the G2 checkpoint and DNA repair and a novel target for radioprotection

    Mouse SPNS2 Functions as a Sphingosine-1-Phosphate Transporter in Vascular Endothelial Cells

    Get PDF
    Sphingosine-1-phosphate (S1P), a sphingolipid metabolite that is produced inside the cells, regulates a variety of physiological and pathological responses via S1P receptors (S1P1–5). Signal transduction between cells consists of three steps; the synthesis of signaling molecules, their export to the extracellular space and their recognition by receptors. An S1P concentration gradient is essential for the migration of various cell types that express S1P receptors, such as lymphocytes, pre-osteoclasts, cancer cells and endothelial cells. To maintain this concentration gradient, plasma S1P concentration must be at a higher level. However, little is known about the molecular mechanism by which S1P is supplied to extracellular environments such as blood plasma. Here, we show that SPNS2 functions as an S1P transporter in vascular endothelial cells but not in erythrocytes and platelets. Moreover, the plasma S1P concentration of SPNS2-deficient mice was reduced to approximately 60% of wild-type, and SPNS2-deficient mice were lymphopenic. Our results demonstrate that SPNS2 is the first physiological S1P transporter in mammals and is a key determinant of lymphocyte egress from the thymus

    Anthropogenic interferences lead to gut microbiome dysbiosis in Asian elephants and may alter adaptation processes to surrounding environments

    Get PDF
    Human activities interfere with wild animals and lead to the loss of many animal populations. Therefore, efforts have been made to understand how wildlife can rebound from anthropogenic disturbances. An essential mechanism to adapt to environmental and social changes is the fluctuations in the host gut microbiome. Here we give a comprehensive description of anthropogenically induced microbiome alterations in Asian elephants (n = 30). We detected gut microbial changes due to overseas translocation, captivity and deworming. We found that microbes belonging to Planococcaceae had the highest contribution in the microbiome alterations after translocation, while Clostridiaceae, Spirochaetaceae and Bacteroidia were the most affected after captivity. However, deworming significantly changed the abundance of Flavobacteriaceae, Sphingobacteriaceae, Xanthomonadaceae, Weeksellaceae and Burkholderiaceae. These findings may provide fundamental ideas to help guide the preservation tactics and probiotic replacement therapies of a dysbiosed gut microbiome in Asian elephants. More generally, these results show the severity of anthropogenic activities at the level of gut microbiome, altering the adaptation processes to new environments and the subsequent capability to maintain normal physiological processes in animals

    Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

    Get PDF
    Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection
    • 

    corecore