176 research outputs found
Stability and evolution of electromagnetic solitons in relativistic degenerate laser plasmas
The dynamical behaviors of electromagnetic (EM) solitons formed due to
nonlinear interaction of linearly polarized intense laser light and
relativistic degenerate plasmas are studied. In the slow motion approximation
of relativistic dynamics, the evolution of weakly nonlinear EM envelope is
described by the generalized nonlinear Schr{\"o}dinger (GNLS) equation with
local and nonlocal nonlinearities. Using the Vakhitov-Kolokolov criteria, the
stability of an EM soliton solution of the GNLS equation is studied. Different
stable and unstable regions are demonstrated with the effects of soliton
velocity, soliton eigenfrequency, as well as the degeneracy parameter
, where is the Fermi momentum and the electron
mass, and is the speed of light in vacuum. It is found that the stability
region shifts to an unstable one and is significantly reduced as one enters
from the regimes of weakly relativistic to ultrarelativistic
degeneracy of electrons. The analytically predicted results are in
good agreement with the simulation results of the GNLS equation. It is shown
that the standing EM soliton solutions are stable. However, the moving solitons
can be stable or unstable depending on the values of soliton velocity, the
eigenfrequency or the degeneracy parameter. The latter with strong degeneracy
can eventually lead to soliton collapse.Comment: 9 pages, 5 figure
Role of intravenous tranexamic acid on cesarean blood loss: A prospective randomized study
Background: Postpartum hemorrhage (PPH) is a major cause of maternal mortality globally. Tranexamic acid, an anti‑fibrinolytic agent, is a novel approach to prevent this dreadful complication. This study aims to document the efficacy of intravenous (IV) tranexamic acid in reducing blood loss during and after cesarean section (CS).Materials and Methods: In this prospective, randomized, placebo‑controlled, open‑label study, 100 mothers scheduled for elective CS were randomly selected and divided into two groups (study and control) of 50 each. The study group received 1 g IV tranexamic acid and the control group received IV placebo. Following delivery, all mothers received 10 units of oxytocin in 500 mL of normal saline.Results: The mean intraoperative and postpartum blood loss were significantly lower in the study group than the control group: 499.11 ± 111.2 ml and 59.93 ± 12.5 ml versus 690.85 ± 198.41 ml and 110.06 ± 13.47ml, respectively (P < 0.001). Total blood loss was 30% less in the study group (P < 0.001). Six mothers had PPH in the control group while none in the study group had PPH. The difference between the preoperative and postoperative hemoglobin values was significantly less in the study group than the control group, 0.26 ± 0.22 g% versus 0.99 ± 0.48 g% (P < 0.001).There was no significant difference with respect to other hematologic parameters. There was no added adverse effect or need for NICU admission in the study group.Conclusion: Preoperative IV tranexamic acid significantly reduced blood loss during elective CS without any significant adverse effects.Keywords: Anti‑fibrinolytics; blood‑loss; cesarean delivery; postpartum hemorrhage; Tranexamic aci
Hybrid Inductive Power Transfer and Wireless Antenna System for Biomedical Implanted Devices
In this paper, we present a hybrid system consisting of a novel microstrip antenna that can be designed to resonate at various frequencies within the ultra-high frequency (UHF) band (e.g., 415 MHz, 905 MHz, and 1300 MHz), combined with a pair of high frequency (HF) coils (13.56 MHz). The system is designed to be fabricated on an FR4 substrate layer, and it provides a compact solution for simultaneous wireless power transfer (WPT) and multi-band wireless communication, to be utilized in implanted medical devices. The external antenna/coil combination (EX) will be located outside the body on the skin layer. The EX has 79.6mm-diameter. The implanted hybrid combination (IM) has 31.5mm-diameter. The antenna is designed such that by varying the position of a shorting pin the resonance frequency can be changed among three frequencies; therefore, the same design can be used for various applications. The system was designed using numerical simulation tools, and then it was fabricated and measured. The design was optimized while the performance of the system was numerically simulated at various depths inside a layered body model. Furthermore, the insertion loss (S21) and transmission efficiency (η) for both antenna and coil pairs at different depths were studied through simulation and measurements. The system provides a good solution for the combination of power transfer and multi-band data communication
Nursing Personnel Planning for Rural Hospitals in Burdwan District, West Bengal, India, Using Workload Indicators of Staffing Needs
Lack of appropriate human resources planning is an important factor in
the inefficient use of the public health facilities. Workforce
projections can be improved by using objective methods of staffing
needs based on the workload and actual work undertaken by workers, a
guideline developed by Peter J. Shipp in collaboration with
WHO\u2014Workload Indicators of Staffing Need (WISN). A
cross-sectional study was carried out to estimate the nursing stuff
requirement for the rural hospitals and provide a quantitative
description of imbalances, if there is any, in the allocation at the
district level during 2011. The average WISN turns out to be 0.35 for
entire district, which means only 35% of the required nurses is
available or 65% understaffed. So, there is an urgent need for more
allocations and deployment of staff so that workload can be tackled and
evenly distributed among all nursing personnel
Variants in Hormone Biosynthesis Genes and Risk of Endometrial Cancer.
We investigated the risk associated with variants in three genes involved in estrogen biosynthesis, CYP11A1, CYP17A1, and CYP19A1, in the population-based case-control study of Estrogen, Diet, Genetics, and Endometrial Cancer. This study was conducted in New Jersey in 2001-2006 with 417 cases and 402 controls. For CYP11A1, there was no association between the number of [TTTTA]( n ) repeats (D15S520) and risk. For CYP17A1, risk was somewhat lower among women with the C/C genotype at T-34C (rs743572) (adjusted OR = 0.65, 95% CI 0.41-1.02). For CYP19A1, risk was lower among women homozygous for the 3-bp deletion (rs11575899) in exon 4 (adjusted OR = 0.44, 95% CI 0.26-0.76), while the number of [TTTA]( n ) repeats was not significantly related to risk: the adjusted OR for n = 7/7 repeats versus n \u3e 7/\u3e7 repeats was 0.81 (95% CI 0.54-1.23). In stratified analyses, results for CYP19A1 were stronger among women with higher (\u3e or =27.4) body mass index: for the homozygous deletion, OR = 0.30 (95% CI 0.15-0.62); for the n = 7/7 genotype, OR = 0.49 (95% CI 0.26-0.93). The interaction between the n = 7/7 genotype and BMI was statistically significant (p = 0.01). The insertion/deletion variant in CYP19A1 appears to be related to risk of endometrial cancer; risk associated with variants in this gene may vary according to BMI
Vitamin D Receptor Gene Haplotypes and Polymorphisms and Risk of Breast Cancer: A Nested Case-Control Study
Observational and experimental studies suggest that vitamin D may influence breast cancer etiology. Most known effects of vitamin D are mediated via the vitamin D receptor (VDR). Few polymorphisms in the VDR gene have been well studied in relation to breast cancer risk and results have been inconsistent
Sun Exposure, Vitamin D Receptor Genetic Variants, and Risk of Breast Cancer in the Agricultural Health Study
Background: Epidemiologic evidence suggests a negative relation between sunlight exposure and breast cancer risk. The hypothesized mechanism is sunlight-induced cutaneous synthesis of vitamin D
Quantitative single cell monitoring of protein synthesis at subcellular resolution using fluorescently labeled tRNA
We have developed a novel technique of using fluorescent tRNA for translation monitoring (FtTM). FtTM enables the identification and monitoring of active protein synthesis sites within live cells at submicron resolution through quantitative microscopy of transfected bulk uncharged tRNA, fluorescently labeled in the D-loop (fl-tRNA). The localization of fl-tRNA to active translation sites was confirmed through its co-localization with cellular factors and its dynamic alterations upon inhibition of protein synthesis. Moreover, fluorescence resonance energy transfer (FRET) signals, generated when fl-tRNAs, separately labeled as a FRET pair occupy adjacent sites on the ribosome, quantitatively reflect levels of protein synthesis in defined cellular regions. In addition, FRET signals enable detection of intra-populational variability in protein synthesis activity. We demonstrate that FtTM allows quantitative comparison of protein synthesis between different cell types, monitoring effects of antibiotics and stress agents, and characterization of changes in spatial compartmentalization of protein synthesis upon viral infection
The Bangladesh Risk of Acute Vascular Events (BRAVE) Study: objectives and design.
During recent decades, Bangladesh has experienced a rapid epidemiological transition from communicable to non-communicable diseases. Coronary heart disease (CHD), with myocardial infarction (MI) as its main manifestation, is a major cause of death in the country. However, there is limited reliable evidence about its determinants in this population. The Bangladesh Risk of Acute Vascular Events (BRAVE) study is an epidemiological bioresource established to examine environmental, genetic, lifestyle and biochemical determinants of CHD among the Bangladeshi population. By early 2015, the ongoing BRAVE study had recruited over 5000 confirmed first-ever MI cases, and over 5000 controls "frequency-matched" by age and sex. For each participant, information has been recorded on demographic factors, lifestyle, socioeconomic, clinical, and anthropometric characteristics. A 12-lead electrocardiogram has been recorded. Biological samples have been collected and stored, including extracted DNA, plasma, serum and whole blood. Additionally, for the 3000 cases and 3000 controls initially recruited, genotyping has been done using the CardioMetabochip+ and the Exome+ arrays. The mean age (standard deviation) of MI cases is 53 (10) years, with 88 % of cases being male and 46 % aged 50 years or younger. The median interval between reported onset of symptoms and hospital admission is 5 h. Initial analyses indicate that Bangladeshis are genetically distinct from major non-South Asian ethnicities, as well as distinct from other South Asian ethnicities. The BRAVE study is well-placed to serve as a powerful resource to investigate current and future hypotheses relating to environmental, biochemical and genetic causes of CHD in an important but under-studied South Asian population.The Gates Cambridge Trust has supported Dr Chowdhury. Epidemiological fieldwork in BRAVE has been supported by grants to investigators at the Cardiovascular Epidemiology Unit, University of Cambridge. The Cardiovascular Epidemiology Unit is underpinned by programme grants from the British Heart Foundation (RG/13/13/30194), the UK Medical Research Council (MR/L003120/1), and the UK National Institute of Health Research Cambridge Biomedical Research Centre. BRAVE has received support for genetic assays from the European Research Council (ERC-2010-AdG-20100317), European Commission Framework 7 (Grant Agreement number: 279233), and the Cambridge British Heart Foundation Centre for Excellence in Cardiovascular Science; We would like to acknowledge the contributions of the following individuals: Cardiology Research Group in Bangladesh Mohammad Afzalur Rahman, Mohammad Abdul Kader Akanda, M Atahar Ali, Mir Jamal Uddin, SM Siddiqur Rahman, Amal Kumar Choudhury, Md. Mamunur Rashid, Nazir Ahmed Chowdhury, Mohammad Abdullahel Baqui, Kajal Kumar Karmoker, Mohammad Golam Azam; Setting up/implementation of fieldwork in Bangladesh Abbas Bhuiya, Susmita Chowdhury, Kamrun Nahar, Neelima Das, Proshon Roy, Sumona Ferdous, Taposh Kumar Biswas, Abu Sadat Mohammad Sayed Sharif, Ranjit Shingha, Rose Jinnath Tomas, Babulal Parshei, Mabubur Rahman, Mohammad Emon Hossain, Akhirunnesa Mily, AK Mottashir Ahmed, Sati Chowdhury, Sushila Roy, Dipak Kanti Chowdhury, Swapan Kumar Roy; Epidemiological/statistical support in Cambridge Stephen Kaptoge, Simon Thompson, Angela Wood, Narinder Bansal, Anna Ramond, Clare Oliver-Williams, Marinka Steur, Linda O’Keeffe, Eleni Sofianopoulou, Setor Kunutsor, Donal Gorman, Oscar H Franco, Malcolm Legget, Pinal Patel, Marc Suhrcke, Sylvaine Bruggraber, Jonathan Powell; Data management Matthew Walker, Steve Ellis, Shawkat Jahangir, Habibur Rahman, Rifat Hasan Shammi, Shafqat Ullah, Mohammad Abdul Matin and Administration Beth Collins, Hannah Lombardi, Binder Kaur, Rachel Henry, Marilena Papanikolaou, Robert Smith, Abdul Wazed, Robert Williams, Julie Jenkins, Keith Hoddy.This is the final published version of the article. It was originally published in the European Journal of Epidemiology (Chowdhury R, et al., European Journal of Epidemiology, 2015, doi:10.1007/s10654-015-0037-2). The final version is available at http://dx.doi.org/10.1007/s10654-015-0037-
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