106 research outputs found

    Efficacy of progestin-primed ovarian stimulation in women with polycystic ovary syndrome undergoing in vitro fertilization: a systematic review and meta-analysis

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    Polycystic ovary syndrome (PCOS) is a common endocrinopathy causing infertility in childbearing women. Progestin-primed ovarian stimulation (PPOS) protocol has recently been used for infertile women. However, whether PPOS provides a significant benefit over gonadotropin-releasing hormone (GnRH) analogue protocols in PCOS is still controversial. The objective of this systematic review is to investigate the efficacy of PPOS in patients with PCOS during in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). We searched Medline, Embase, Google Scholar, ClinicalTrials, and Cochrane Central Register of Controlled Trials from inception to April 1, 2023. Randomized controlled trials (RCTs) and observational studies comparing the efficacy between PPOS and conventional GnRH analogue protocols in patients with PCOS in English were included. The primary outcomes included live birth rate, the incidence of moderate or severe ovarian hyperstimulation syndrome (OHSS), and the number of metaphase II oocytes. The pooled estimates were calculated using the random-effects models as odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CIs). Three RCTs and six cohort studies involving 2289 patients were included. Results from RCTs suggest that PPOS leads to no significant difference in the risk of OHSS, the number of metaphase II oocytes, or the rate of live birth when compared to GnRH analogue protocols. The pooling estimates of cohort studies showed consistent results. Additionally, in cohort studies, PPOS required a higher dose of Gn and tended to improve the implantation rate, clinical pregnancy rate, and ongoing pregnancy rate. For subgroup analyses, the higher implantation rate, clinical pregnancy rate, and ongoing pregnancy rate were found in PPOS compared to the GnRH agonist short protocol. However, the certainty of the evidence for the outcomes was generally low. Overall, There is currently no evidence to support that PPOS could reduce the risk of OHSS, increase oocyte maturation, or improve pregnancy outcomes in women with PCOS undergoing IVF/ICSI when compared to GnRH analogue protocols. Considering its efficiency and safety, this protocol could be a patient-friendly and viable alternative for PCOS patients, especially when frozen-thawed embryo transfer is planned. Future high-quality randomized trials with children’s long-term safety and cost-effective analyses are still required.System Review RegistrationNPLASY (202340059). https://inplasy.com/inplasy-2023-4-0059

    dRecQ4 Is Required for DNA Synthesis and Essential for Cell Proliferation in Drosophila

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    Background: The family of RecQ DNA helicases plays an important role in the maintenance of genomic integrity. Mutations in three of the five known RecQ family members in humans, BLM, WRN and RecQ4, lead to disorders that are characterized by predisposition to cancer and premature aging. Methodology/Principal Findings: To address the in vivo functions of Drosophila RecQ4 (dRecQ4), we generated mutant alleles of dRecQ4 using the targeted gene knock-out technique. Our data show that dRecQ4 mutants are homozygous lethal with defects in DNA replication, cell cycle progression and cell proliferation. Two sets of experiments suggest that dRecQ4 also plays a role in DNA double strand break repair. First, mutant animals exhibit sensitivity to gamma irradiation. Second, the efficiency of DsRed reconstitution via single strand annealing repair is significantly reduced in the dRecQ4 mutant animals. Rescue experiments further show that both the N-terminal domain and the helicase domain are essential to dRecQ4 function in vivo. The N-terminal domain is sufficient for the DNA repair function of dRecQ4. Conclusions/Significance: Together, our results show that dRecQ4 is an essential gene that plays an important role in no

    Uif, a Large Transmembrane Protein with EGF-Like Repeats, Can Antagonize Notch Signaling in Drosophila

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    <div><h3>Background</h3><p>Notch signaling is a highly conserved pathway in multi-cellular organisms ranging from flies to humans. It controls a variety of developmental processes by stimulating the expression of its target genes in a highly specific manner both spatially and temporally. The diversity, specificity and sensitivity of the Notch signaling output are regulated at distinct levels, particularly at the level of ligand-receptor interactions.</p> <h3>Methodology/Principal Findings</h3><p>Here, we report that the <em>Drosophila</em> gene <em>uninflatable</em> (<em>uif</em>), which encodes a large transmembrane protein with eighteen EGF-like repeats in its extracellular domain, can antagonize the canonical Notch signaling pathway. Overexpression of Uif or ectopic expression of a neomorphic form of Uif, Uif*, causes Notch signaling defects in both the wing and the sensory organ precursors. Further experiments suggest that ectopic expression of Uif* inhibits Notch signaling <em>in cis</em> and acts at a step that is dependent on the extracellular domain of Notch. Our results suggest that Uif can alter the accessibility of the Notch extracellular domain to its ligands during Notch activation.</p> <h3>Conclusions/Significance</h3><p>Our study shows that Uif can modulate Notch activity, illustrating the importance of a delicate regulation of this signaling pathway for normal patterning.</p> </div

    Antibacterial Modification of Cellulosic Materials

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    The proliferation of bacteria on the surfaces of cellulosic materials during their use and storage can have negative effects on the materials themselves and on consumers. People’s demands for materials with antibacterial properties have been satisfied in recent years because of the emergence of various antibacterial compounds. This paper reviews recent research and development progress in antibacterial modification of cellulosic fibers using various biocides such as N-halamines, quaternary ammonium salts, chitosan, triclosan, and nanoparticles composed of noble metals and metal oxides. Antibacterial mechanisms and treating methods for antibacterial cellulosic materials are also involved in this paper

    Estimating Non-market environmental benefits of the Conversion of Cropland to Forest and Grassland Program: A choice modeling approach

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    The non-market values of the environmental benefits derived from the Conversion of Cropland to Forest and Grassland Program (also known as the Grain for Green Program and the Sloped Land Conversion Program) in the Loess Plateau region of North West Chin

    Nano‐engineered nickel catalysts supported on 4‐channel α‐Al 2

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    A nickel (Ni) nanoparticle catalyst, supported on 4-channel α-Al2O3 hollow fibers, was synthesized by atomic layer deposition (ALD). Highly dispersed Ni nanoparticles were successfully deposited on the outside surfaces and the inside porous structures of hollow fibers. The catalyst was employed to catalyze the dry reforming of methane (DRM) reaction and showed a methane reforming rate of 2040 Lh-1gNi-1 at 800°C. NiAl2O4 spinel was formed when Ni nanoparticles were deposited on alpha-alumina substrates by ALD, which enhanced the Ni-support interaction. Different cycles (two, five, and ten) of Al2O3 ALD films were applied on the Ni/hollow fiber catalysts to further improve the interaction between the Ni nanoparticles and the hollow fiber support. Both the catalyst activity and stability were improved with the deposition of Al2O3 ALD films. Among the Al2O3 ALD coated catalysts, the catalyst with five cycles of Al2O3 ALD showed the best performance

    Pore-neck resistance to light gases in a microporous BTESE-derived silica: A comparison of membrane and xerogel powder

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    A supported membrane and a xerogel derived from 1,2-bis(triethoxysilyl)ethane (BTESE) under the same conditions were characterized by a gas uptake technique and membrane permeation method, respectively, to investigate the transport mechanism inside the pores. The results indicated that the transport in both materials was governed by repulsive necks, with more adsorptive gases experiencing stronger restrictions. Furthermore, on the basis of a comparison between the two samples, the similarity of activation energies for spherical gases provided positive evidence for the commonly used assumption of pore network equivalence between xerogels and membranes derived under the same conditions. Finally, the neck dimensions in both materials were evaluated by the GT-based model, and a mean value of approximately 2.90 angstrom (center-to-center distance) was obtained

    Recent Advanced Development of Acid-Resistant Thin-Film Composite Nanofiltration Membrane Preparation and Separation Performance in Acidic Environments

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    Membrane filtration technology has attracted extensive attention in academia and industry due to its advantages of eco-friendliness related to environmental protection and high efficiency. Polyamide thin-film composite nanofiltration (PA TFC NF) membranes have been widely used due to their high separation performance. Non-acid-resistant PA TFC NF membranes face tremendous challenges in an acidic environment. Novel and relatively acid-resistant polysulfonamide-based and triazine-based TFC NF membranes have been developed, but these have a serious trade-off in terms of permeability and selectivity. Hence, how to improve acid resistance of TFC NF membranes and their separation performance in acidic environments is a pivotal issue for the design and preparation of these membranes. This review first highlights current strategies for improving the acid resistance of PA TFC NF membranes by regulating the composition and structure of the separation layer of the membrane performed by manipulating and optimizing the construction method and then summarizes the separation performances of these acid-resistant TFC NF membranes in acidic environments, as studied in recent years
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