398 research outputs found
Post-COVID-19 Effects on Female Fertility: An In-Depth Scientific Investigation
This study aimed to comprehensively investigate the post-COVID-19 effects on
female fertility in patients with a history of severe COVID-19 infection. Data
were collected from 340 patients who had previously experienced severe COVID-19
symptoms and sought medical assistance at private clinics and fertility centers
in various provinces of Iraq. A comparative control group of 280 patients, who
had not contracted COVID-19 or had mild cases, was included. The study assessed
ovarian reserve, hormonal imbalances, and endometrial health in the
post-recovery phase. The findings revealed a significant decrease in ovarian
reserve, hormonal disturbances, and endometrial abnormalities among patients
with a history of severe COVID-19 infection compared to the control group. This
in-depth investigation sheds light on the potential long-term impacts of severe
COVID-19 on female fertility. The results emphasize the need for further
research and targeted interventions to support women affected by post-COVID-19
fertility issues. Understanding these effects is crucial for providing
appropriate medical care and support to women on their reproductive journey
after recovering from severe COVID-19
Inhibition Effect of Hydrazine-Derived Coumarin on a Mild Steel Surface in Hydrochloric acid
In this work, economy novel hydrazine-derived coumarin 4-(6-methylcoumarin)acetohydrazide (MCA) were synthesized, characterized, and tested as an inhibitor for the corrosion of a surface of mild steel in an acidic environment through weight loss and Scanning electron microscopy (SEM) techniques. Results showed that the synthesized inhibitor can inhibit the corrosion of mild steel surface in a 1 M hydrochloric acid environment. The corrosion inhibition efficiency of MCA increases with increasing MCA concentration and decreases with increasing temperature. SEM analysis showed the formation of a film as a protective layer from MCA molecules on the surface of mild steel. Adsorption of the MCA molecules on the mild steel surface in the presence of hydrochloric acid environment was obeyed Langmuir isotherm. The density functional theory (DFT) calculations were used to study the relationship between molecular structure and inhibition efficiency and they found in good agreement
The effect of magnetic field direction on thermoelectric and thermomagnetic coefficients of undoped single crystalline InSb at room temperature
Thermoelectric and thermomagnetic coefficients were calculated for n-type undoped InSb single crystals through a temperature range from 10°C up to 80°C and magnetic fields from -0.6T to 0.6T. The thermoelectric Seebeck coefficient varied only with the temperature gradient, while the thermomagnetic Nernst coefficient varied with both the temperature gradient and the magnetic field. This paper also investigated the effects of the incident angle of magnetic field on the InSb sample surface with regard to the values of thermoelectric and thermomagnetic coefficients; the results showed that thermoelectric and thermomagnetic coefficients were independent of magnetic field direction
IDEFIX: a versatile performance-portable Godunov code for astrophysical flows
Exascale super-computers now becoming available rely on hybrid
energy-efficient architectures that involve an accelerator such as Graphics
Processing Units (GPU). Leveraging the computational power of these machines
often means a significant rewrite of the numerical tools each time a new
architecture becomes available. To address these issues, we present Idefix, a
new code for astrophysical flows that relies on the Kokkos meta-programming
library to guarantee performance portability on a wide variety of architectures
while keeping the code as simple as possible for the user. Idefix is based on a
Godunov finite-volume method that solves the non-relativistic HD and MHD
equations on various grid geometries. Idefix includes a wide choice of solvers
and several additional modules (constrained transport, orbital advection,
non-ideal MHD) allowing users to address complex astrophysical problems. Idefix
has been successfully tested on Intel and AMD CPUs (up to 131 072 CPU cores on
Irene-Rome at TGCC) as well as NVidia and AMD GPUs (up to 1024 GPUs on Adastra
at CINES). Idefix achieves more than 1e8 cell/s in MHD on a single NVidia V100
GPU and 3e11 cell/s on 256 Adastra nodes (1024 GPUs) with 95% parallelization
efficiency (compared to a single node). For the same problem, Idefix is up to 6
times more energy efficient on GPUs compared to Intel Cascade Lake CPUs. Idefix
is now a mature exascale-ready open-source code that can be used on a large
variety of astrophysical and fluid dynamics applications.Comment: 18 pages, 18 figures, 3 tables, accepted for publication in Astronomy
& Astrophysic
Semi-Automatic segmentation of multiple mouse embryos in MR images
<p>Abstract</p> <p>Background</p> <p>The motivation behind this paper is to aid the automatic phenotyping of mouse embryos, wherein multiple embryos embedded within a single tube were scanned using Magnetic Resonance Imaging (MRI).</p> <p>Results</p> <p>Our algorithm, a modified version of the simplex deformable model of Delingette, addresses various issues with deformable models including initialization and inability to adapt to boundary concavities. In addition, it proposes a novel technique for automatic collision detection of multiple objects which are being segmented simultaneously, hence avoiding major leaks into adjacent neighbouring structures. We address the initialization problem by introducing balloon forces which expand the initial spherical models close to the true boundaries of the embryos. This results in models which are less sensitive to initial minimum of two fold after each stage of deformation. To determine collision during segmentation, our unique collision detection algorithm finds the intersection between binary masks created from the deformed models after every few iterations of the deformation and modifies the segmentation parameters accordingly hence avoiding collision.</p> <p>We have segmented six tubes of three dimensional MR images of multiple mouse embryos using our modified deformable model algorithm. We have then validated the results of the our semi-automatic segmentation versus manual segmentation of the same embryos. Our Validation shows that except paws and tails we have been able to segment the mouse embryos with minor error.</p> <p>Conclusions</p> <p>This paper describes our novel multiple object segmentation technique with collision detection using a modified deformable model algorithm. Further, it presents the results of segmenting magnetic resonance images of up to 32 mouse embryos stacked in one gel filled test tube and creating 32 individual masks.</p
Role of activating transcription factor 4 in the hepatic response to amino acid depletion by asparaginase
The anti-leukemic agent asparaginase activates the integrated stress response (ISR) kinase GCN2 and inhibits signaling via mechanistic target of rapamycin complex 1 (mTORC1). The study objective was to investigate the protective role of activating transcription factor 4 (ATF4) in controlling the hepatic transcriptome and mediating GCN2-mTORC1 signaling during asparaginase. We compared global gene expression patterns in livers from wildtype, Gcn2 -/-, and Atf4 -/- mice treated with asparaginase or excipient and further explored selected responses in livers from Atf4 +/- mice. Here, we show that ATF4 controls a hepatic gene expression profile that overlaps with GCN2 but is not required for downregulation of mTORC1 during asparaginase. Ingenuity pathway analysis indicates GCN2 independently influences inflammation-mediated hepatic processes whereas ATF4 uniquely associates with cholesterol metabolism and endoplasmic reticulum (ER) stress. Livers from Atf4 -/- or Atf4 +/- mice displayed an amplification of the amino acid response and ER stress response transcriptional signatures. In contrast, reduction in hepatic mTORC1 signaling was retained in Atf4 -/- mice treated with asparaginase
Transcription factor ATF4 directs basal and stress-induced gene expression in the unfolded protein response and cholesterol metabolism in the liver
Disturbances in protein folding and membrane compositions in the endoplasmic reticulum (ER) elicit the unfolded protein response (UPR). Each of three UPR sensory proteins-PERK (PEK/EIF2AK3), IRE1, and ATF6-is activated by ER stress. PERK phosphorylation of eIF2 represses global protein synthesis, lowering influx of nascent polypeptides into the stressed ER, coincident with preferential translation of ATF4 (CREB2). In cultured cells, ATF4 induces transcriptional expression of genes directed by the PERK arm of the UPR, including genes involved in amino acid metabolism, resistance to oxidative stress, and the proapoptotic transcription factor CHOP (GADD153/DDIT3). In this study, we characterize whole-body and tissue-specific ATF4-knockout mice and show in liver exposed to ER stress that ATF4 is not required for CHOP expression, but instead ATF6 is a primary inducer. RNA-Seq analysis indicates that ATF4 is responsible for a small portion of the PERK-dependent UPR genes and reveals a requirement for expression of ATF4 for expression of genes involved in oxidative stress response basally and cholesterol metabolism both basally and under stress. Consistent with this pattern of gene expression, loss of ATF4 resulted in enhanced oxidative damage, and increased free cholesterol in liver under stress accompanied by lowered cholesterol in sera
Multilayered Heater Nanocryotron: A Superconducting-Nanowire-Based Thermal Switch
We demonstrate a multilayer nanoscale cryogenic heater-based switch (M-hTron) that uses a normal-metal heater overlapping a thin-film superconductor separated by a thin insulating layer. The M-hTron eliminates leakage current found in three-terminal superconducting switches and applies heat locally to the superconductor, reducing the energy required to switch the device. Modeling using the energy-balance equations and the acoustic mismatch model demonstrates reasonable agreement with experiment. The M-hTron is a promising device for digital superconducting electronics that require high fan-out and offers the possibility of enhancing readout for superconducting-nanowire single-photon detectors
- …