Background: Recent literature has explored the role of human chorionic gonadotropin (hCG) triggering in frozen embryo transfer (FET) cycles with natural endometrial preparation. Despite this, the impact of hCG triggering on pregnancy outcomes following endometrial preparation with mild stimulation (mST) using Letrozole and Gonadotropins remains inadequately characterized. This study aimed to elucidate the effects of hCG-trigger on pregnancy outcomes in mST-FET cycles.
View Article and Find Full Text PDFOur study probed the differences in ion channel gene expression in the endometrium of women with Recurrent Implantation Failure (RIF) compared to fertile women. We analyzed the relative expression of genes coding for T-type Ca2+, ENaC, CFTR, and KCNQ1 channels in endometrial samples from 20 RIF-affected and 10 control women, aged 22-35, via microarray analysis and quantitative real-time PCR. Additionally, we examined DNA methylation in the regulatory region of KCNQ1 using ChIP real-time PCR.
View Article and Find Full Text PDFResearch Question: Are TUBB8 gene variations present in Iranian infertile women with oocyte maturation arrest or embryo cleavage arrest?
Design: TUBB8 gene variations were investigated by polymerase chain reaction sequencing on blood samples from 16 women with oocyte maturation arrest and 12 women with cleavage arrest, collectively referred to as the experimental cohort, as well as 56 fertile women as the control group. The Exome Sequencing Project and dbSNP databases and the Genome Aggregation Database were used to search the frequency of corresponding variants. PolyPhen and SIFT were used to conduct in-silico analysis of gene variations and Align-GVGD was used to predict the effect of missense variants on proteins.
Objective: Genomic imprinting is an epigenetic phenomenon that plays a critical role in normal development of embryo. Using exogenous hormones during assisted reproductive technology (ART) can change an organism hormonal profile and subsequently affect epigenetic events. Ovarian stimulation changes gene expression and epigenetic pattern of imprinted genes in the organs of mouse fetus.
View Article and Find Full Text PDFBackground: Intraindividual copy number variation (CNV) origin is largely unknown. They might be due to aging and/or common genome instability at the preimplantation stage while contribution of preimplantation in human intraindividual CNVs occurrence is unknown. To address this question, we investigated mosaicism and its origin in the fetuses of natural conception.
View Article and Find Full Text PDFVitrification affects fertilization ability and developmental competence of mammalian oocytes. This effect may be more closely associated with an intracellular calcium rise induced by cryoprotectants. The present study aimed to assess whether addition of Ethylene Glycol Tetraacetic acid (EGTA) to vitrification solution could improve quality and developmental competence of in vitro matured ovine oocytes.
View Article and Find Full Text PDFThis study aimed to determine the optimum concentration of trehalose in solutions used for vitrification of in vitro matured (IVM) ovine oocytes. IVM oocytes were randomly divided into four experimental (vitrified) and one control (fresh) groups. Experimental groups were treated with different concentrations (0.
View Article and Find Full Text PDFBackground: OBJECTIVE: This paper reports results from studies on modifications of histone marks in transcriptional regulatory regions of H19, Igf2 and Mest genes in vitrified-warmed and cultured mouse embryos.
Materials And Methods: Non vitrified and vitrified-warmed 8-cell embryos were cultured in Ham's F10+10% BSA into blastocyst stage in two experimental groups. Gene expression level was assessed by quantitative PCR and histone modifications were evaluated by ChIP assay method.
Objectives: Vitrification is increasingly used in assisted reproductive technology (ART) laboratories worldwide. In this study the effect of vitrification on the expression and modifications of H3 histones of Igf2 and Oct4 was investigated in blastocysts cultured from vitrified and non-vitrified two-cell embryos.
Materials And Methods: In this experimental study, two-cell embryos were cultured in KSOM medium to reach the blastocyst stage.
Background: Peripheral nerve injury is a common lesion in clinical practice and transplantation is one of the most common approaches to its treatment. While nerve graft is used for restoring the defected nerve using autologous or allogenic tissues, Schwann cells are considered as an alternative source. In this study, bone marrow stromal cells (BMSCs) were induced to transdifferentiate into Schwann-like cells (SLCs) using progesterone.
View Article and Find Full Text PDFWe propose a set of design rules with a model Hamiltonian that allows electrons to form attracting pairs through the exploitation of a new combination of resonant band alignment and Coulombic repulsion. The pair bands and single particle bands in various lattices are calculated and compared in energy, and regions of net attraction are identified. This work provides guidelines for the construction of molecular systems, nanocrystals, and nanoparticle arrays with the potential for superconductivity.
View Article and Find Full Text PDFVitrification of embryos is a routine procedure in many IVF laboratories. The effect of vitrification on gene expression and some modifications of H3 histone in H19 and MEST imprinted genes in blastocysts produced in vitro from non-vitrified and vitrified two-cell embryos was investigated. The expression level of the chosen imprinted genes increased significantly (P < 0.
View Article and Find Full Text PDFBackground: The aim of this study is to investigate the effect of ISM1 culture medium on embryo development, quality and outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles. This study compares culture medium commonly used in the laboratory setting for oocyte recovery and embryo development with a medium from MediCult. We have assessed the effects of these media on embryo development and newborn characteristics.
View Article and Find Full Text PDFNatural photosynthetic complexes accomplish the rapid conversion of photoexcitations into spatially separated electrons and holes through precise hierarchical ordering of chromophores and redox centers. In contrast, organic photovoltaic (OPV) cells are poorly ordered, utilize only two different chemical potentials, and the same materials that absorb light must also transport charge; yet, some OPV blends achieve near-perfect quantum efficiency. Here we perform electronic structure calculations on large clusters of functionalized fullerenes of different size and ordering, predicting several features of the charge generation process, outside the framework of conventional theories but clearly observed in ultrafast electro-optical experiments described herein.
View Article and Find Full Text PDFObjective: The appropriate interaction between a blastocyst and the endometrium is essential for successful implantation. Numerous factors, including hormone receptors (progesterone receptor), cytokines [leukemia inhibitory factors (LIF)], and adherence molecules such as E-cadherin are involved in the cross-talk that occurs between the embryo and endometrium. Studies show that a lack of these genes impact endometrial receptivity.
View Article and Find Full Text PDFThe collection of charge carriers is a fundamental step in the photovoltaic conversion process. In disordered organic films, low mobility and disorder can make collection the performance-limiting step in energy conversion. We derive two analytic relationships for carrier collection efficiency in organic photovoltaics that account for the presence or absence of carrier-selective electrodes.
View Article and Find Full Text PDFWe use a one-dimensional tight binding model with an impurity site characterized by electron-vibration coupling, to describe electron transfer and localization at zero temperature, aiming to examine the process of polaron formation in this system. In particular we focus on comparing a semiclassical approach that describes nuclear motion in this many vibronic-states system on the Ehrenfest dynamics level to a numerically exact fully quantum calculation based on the Bonca-Trugman method [J. Bonča and S.
View Article and Find Full Text PDFWe have studied the electron transfer occurring in the photosystem I (PSI) reaction center from the special pair to the first iron-sulfur cluster. Electronic structure calculations performed at the DFT level were employed to determine the on-site energies of the fragments comprising PSI, as well as the charge transfer integrals between neighboring pairs. This electronic Hamiltonian was then used to compute the charge transfer dynamics, using the stochastic surrogate Hamiltonian approach to account for the coherent propagation of the electronic density but also for its energy relaxation and decoherence.
View Article and Find Full Text PDFThe aim of this study was to determine if laser zona thinning could improve the rates of pregnancy and implantation for vitrified-warmed embryo transfer at the cleavage stage. A total of 400 vitrified-warmed embryo transfer cycles were randomly assigned to either the test group or the control group. The zona pellucida of vitrified-warmed embryos in the patients of the control group was untreated, whereas in the test group it was partially thinned by laser just before embryo transfer.
View Article and Find Full Text PDFPurpose: The objective of this retrospective study was to evaluate the efficacy of vitrification and slow freezing for the cryopreservation of human cleavage stage embryos in terms of post-warming survival rate, post-warming embryo morphology and clinical outcomes.
Methods: The embryos of 305 patients at cleavage stages were cryopreserved either with vitrification (153 patients) or slow-freezing (152 patients) methods. After warming; the survival rate, post-warmed embryo morphology, clinical pregnancy and implantation rates were evaluated and compared between the two groups.
Bone marrow stromal cells (BMSCs) were reported to transdifferentiate into Schwann cells by a two-stage protocol, using beta-mercaptoethanol and retinoic acid (BME-RA) as preinducers (preinduction stage: PS) and platelet derived growth factor (PDGF), basic fibroblast growth factor (bFGF), forskolin (FSK) and heregulin (HRG) as inducers (induction stage: IS). In this study, six groups were used, group one was used as control (PS: BME-RA; IS: PDGF, bFGF, FSK and HRG). In group 2, the preinducer was similar to group 1, and in the induction stage, progesterone replaced HRG.
View Article and Find Full Text PDFElectrochemical impedance spectroscopy has been applied to the analysis of the behavior of monolayers of dioleoyl phosphatidylcholine (DOPC) on a mercury electrode. Experiments were carried out in electrolytes KCl and NaCl (0.1 mol dm(-3)) and Mg(NO3)2 (0.
View Article and Find Full Text PDFNanotechnology
February 2005
A great step forward in science and technology was made when it was discovered that lattice mismatch can be used to grow highly ordered, artificial atom-like structures called self-assembled quantum dots. Several groups have in the meantime successfully demonstrated useful infrared photodetection devices which are based on this technology. The new physics is fascinating, and there is no doubt that many new applications will be found when we have developed a better understanding of the underlying physical processes, and in particular when we have learned how to integrate the exciting new developments made in nanoscopic addressing and molecular self-assembly methods with semiconducting dots.
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