Human-induced landslide on a high cut slope: a case of repeated failures due to multi-excavation

The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and then a geological model at different failure stages is proposed. The geological analysis shows that the excavation-induced repeated failures are related to the exposure of the weak bedding plane and the toe unloading of the cut slope, Numerical modeling is conducted based on a sequential method, taking into account the main failure stages of cut slope. The simulation results fairly coincide with the practical phenomena observed in field. It is shown that the decrease in normal stress of displaced mass on cut slope will induce the increase in shear stress in bedding planes and that at the toe of the cut slope. The released stress leads to repeated gravitational instabilities of cut slope due to the decrease in normal stress and the increase in shear stress along the bedding planes of mudstone.

Repeated Failure in Reward Pursuit Alters Innate Drosophila Larval Behaviors

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown,although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit(RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference,which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tbh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tbh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.

Pituitary Suppression before Frozen Embryo Transfer Is Beneficial for Patients Suffering from Idiopathic Repeated Implantation Failure

Long-term gonadotropin-releasing hormone agonist（Gn RHa） administration before in vitro fertilization（IVF）/intracytoplasmic sperm injection（ICSI） in infertile women with endometriosis or adenomyosis significantly enhanced the chances of pregnancy in both fresh and frozen embryo transfer cycles. We hypothesized that long-term Gn RHa treatment might also be beneficial for the idiopathic repeated implantation failure（RIF） patients. In the 21 patients receiving Gn RHa and hormone replacement therapy（G-HRT） protocols for frozen embryo transfer, their data were compared with those of the 56 of frozen/fresh cycles they had previously undergone（previous protocols）. Comparison showed that the finial results were significantly better with G-HRT protocols than with their previous protocols, with pregnancy rate, clinical pregnancy rate, implantation rate and on-going pregnancy rate being 70%, 60%, 40% and 38% respectively with G-HRT protocols, against 17%, 11%, 6.3% and 5% with previous protocols. The results showed that hormonally controlled endometrial preparation with prior Gn RHa suppression could be used for patients who had experienced repeated failures of IVF treatment despite having morphologically optimal embryos, and the treatment may help increase the receptivity of the endometrium in these patients.

Preimplantation genetic testing for aneuploidy improves clinical outcomes in patients with repeated implantation failure

Objective:The objective of this study is to study whether preimplantation genetic testing for aneuploidy(PGT-A)improves the clinical outcomes of infertile patients with repeated implantation failure(RIF)undergoing frozen-thawed embryo transfer.Methods:This is a retrospective analysis of clinical pregnancy,live birth,miscarriage rates,and obstetric and perinatal outcomes of women with RIF with or without PGT-A.Statistical analyses of categorical data were performed using propensity score matching(PSM),χ^(2)test,and Student’s t test.Results:We enrolled 466 patients with RIF,of which,209 were in the RIF-PGT-A group.The rate of euploid blastocysts was significantly associated with age and day 5 or 6 blastocysts.There were significant differences between the RIF-PGT-A group and the RIF-non-PGT-A group across several parameters.After PSM,positive serum human chorionic gonadotropin(56.9%and 33.9%,P<0.01),clinical pregnancy(49.5%and 31.2%,P<0.01),live birth(43.1%and 25.7%,P<0.01),and fetal heart rates(50.0%and 29.8%,P<0.01)per transfer were significantly higher in the RIF-PGT-A group.Conclusion:Elective single-embryo transfer PGT-A can minimize the risk of obstetric and perinatal outcomes,especially fetal body weight,in women with RIF.Additionally,PGT-A can significantly improve pregnancy and live birth rates.

Endometrial MicroRNA Signature during the Window of Implantation Changed in Patients with Repeated Implantation Failure

Background： At present, a diagnostic tool with high specificity for impaired endometrial receptivity, which may lead to implantation failure, remains to be developed. We aimed to assess the different endometrial microRNA （miRNA） signatures for impaired endometrial receptivity by microarray analysis. Methods： A total of 12 repeated implantation failure （RIF） patients and I0 infertile patients, who conceived and delivered after one embryo transfer attempt, were recruited as RIF and control groups, respectively. Endometrial specimens from the window of implantation （WOI） were collected from these two groups. MiRNA microarray was conducted on seven and five samples from the RIF and control groups, respectively. Comparative, functional, and network analyses were performed for the microarray results. Quantitative real-time polymerase chain reaction （PCR） was performed on other samples to validate the expression of specific miRNAs. Results： Compared with those in the control group, the expression levels of 105 miRNAs in the RIF group were found to be significantly up- or down-regulated （at least 2-fold） by microarray analysis. The most relevant miRNA functional sets of these dysregulated miRNAs were miR-30 family, human embryonic stern cell regulation, epithelial-mesenchymal transition, and miRNA tumor suppressors by tool for annotations ofmicroRNA analysis. Network regulatory analysis found 176 miRNA-mRNA interactions, and the top 3 core miRNAs were has-miR-4668-5p, has-miR-429, and has-miR-5088. Expression levels of the 18 selected miRNAs in new samples by real-time PCR were found to be regulated with the same trend, as the result ofmicroarray analysis. Conclusions： There is a significant different expression of certain miRNAs in the WOI endometrium for RIF patients. These miRNAs may contribute to impaired endometrial receptivity.

Clinical Observations of Sequential Therapy with Chinese Medicine and Hysteroscopic Mechanical Stimulation of the Endometrium in Infertile Patients with Repeated Implantation Failure Undergoing Frozen-Thawed Embryo Transfer

Objectives： To investigate the clinical effect of sequential therapeutic intervention Yupei Qisun [compensating for weakness by invigorating Kidney （Shen） and Spleen （Pi） in advance] in Chinese medicine （CM） and hysteroscopic endometrial mechanical stimulation on the treatment of infertile patients with repeated implantation failure （RIF）; and to study the differences in patients＇ endometrial thickness and type on the day of embryo transfer, serum hormone levels on embryo transfer day and clinical pregnancy outcomes. Methods： In the clinical study, 168 frozen-thawed embryo transfer （FET） cycles for couples with RIF conforming to the research protocol were randomly divided into three groups： a CM group with 56 cycles （CM combined with FET）, a hysteroscopy group with 55 cycles （hysteroscopic endometfial mechanical stimulation）, and a control group with 57 cycles （conventional FET）. Differences in endometrial thickness on the embryo transfer day, levels of serum estradiol （E2） and progesterone （P） on the embryo transfer day, the E2/P ratio on the embryo transfer day, biochemical and clinical pregnancy rates, implantation rate, abnormal pregnancy rate and other indices were compared among the three groups. Results： Endometrial thickness, E2 and P levels, and the EJP ratio on embryo transfer day and other factors had no significant differences among groups. The biochemical pregnancy, clinical pregnancy, and implantation rates of the CM and hysteroscopy groups were significantly higher than the control group （P〈0.05）, and there were no significant differences between these two groups. The abnormal pregnancy rate had no significant difference among the three groups. Conclusions： Sequential therapy of Yupei Qisun could significantly improve the clinical outcomes of RIF-FET cycles, being equivalent to hysteroscopic endometrial mechanical stimulation, and provided a reliable method to treat such infertile couples.

The number and cytotoxicity and the expression of cytotoxicity-related molecules in peripheral natural killer(NK)cells do not predict the repeated implantation failure(RIF)for the in vitro fertilization patients

Natural killer(NK)cells are thought to play a key role in the successful establishment of a pregnancy by facilitating immunological adaptation of the semi-allogeneic developing embryo.The aim of this study was to explore the cell number,immunophenotypic characteristics,and activities of peripheral blood NK cells in women with repeated implantation failure(RIF).Peripheral blood was obtained from 27 women with RIF and 11 healthy,fertile controls during the middle luteal phase of the menstrual cycle.CD3^-CD56^+NK cells were quantified and analyzed by flow cytometry for the expression of cytolytic molecules(granzyme B,granulysin,and perforin)as well as cell surface receptors responsible for NK cell activation or inhibition(NKG2D,NKp30,NKp46,CD158a,CD158b).NK cytotoxicity was measured at three effector-to-target cell ratios.Women with RIF and fertile controls did not differ significantly in the percentage of circulating CD3CD56t NK cells,or in the proportions of these cells that expressed granzyme B,granulysin,or perforin.The two groups also did not differ significantly in the proportions of NK cells expressing the receptors NKG2D,NKp30,NKp46,CD158a or CD158b.General linear model analysis showed that NK cytotoxicity increased with effector-to-target cell ratio.However,NK cytotoxicity did not differ significantly between patients with RIF and fertile controls.These results suggest that RIF is not associated with significant alterations in the number or function of peripheral blood NK cells.

Stromal cell decidualization and embryo implantation: a vulnerable step leading to successful pregnancy

Endometrial stromal cell decidualization is a crucial step in endometrial remodeling during pregnancy.Decidualization is controlled by orchestrated ovarian hormones,followed by the activation of various downstream signaling pathways.Accumulating evidence has shown multiple functions of decidualized endometrial stromal cells during embryo implantation,including tissue remodeling,antioxidative stress,angiogenesis,and immune tolerance.The distinct secretomes of decidualized stromal cells also reveal their intensive interactions with epithelial,endothelial,and immune cells.However,aberrant decidualization leads to pregnancy failures,such as recurrent pregnancy loss and repeated implantation failure.This review aimed to provide an overview of the molecular mechanisms underlying the divergent functions of decidualized endometrial stromal cells and their potential clinical applications.Moreover,the use of single-cell RNA sequencing data further enhances our understanding of these biological processes.This review discusses decidualization-related signaling pathways that serve as potential therapeutic targets for treating implantation failure in in vitro fertilization and provides novel approaches to investigate the underlying causes of female infertility.

Endometrial Collagen Fibril Hyperplasia is Associated with Implantation Failure in Women Undergoing IVF-ET

Objective To analyse the effects of controlled ovarian hyperstimulation （ COH） on the endometrial expression of collagen fibril （CF） during the peri-implantation period in patients undergoing IVF, and its relation to endometrial receptivity （ER） in repeated implantation failure（RIF）. Methods Peripheral blood and endometrial biopsies were obtained from 45 infertile women on days 5, 7 or 9 after oocytes retrieval or ovulation in a stimulated cycle （SC） and natural cycle （NC） respectively. CF was assayed by transmission electron microscope and quantified by modified Masson dyeing. The outcome of subsequent embryo transfer（ET） was observed. Results Levels of both E2 and progesterone were higher in the peripheral blood in SC than in NC. Also the expression of CF in the stroma in each secretory phase was increased significantly in SC （P 〈O.05）. After embryo transferring, expression levels of CF in the pregnancy group dropped between the mid- and late-secretory phase, but no change in the non-pregnancy group. In the same term, all patients undergone endometrial curettage had higher pregnancy rate than those without. Conclusion Imbalance of production and degradation of endometrial CF in the secretory phase resulting from COH may be the cause of defective ER and implantation failure in some RIF patients. Endometrial curettage may improve implantation rate by inducing appropriate CF hyperplasia and degradation.

Use of biological and chemical molecules in regulating embryo implantation and endometrial receptivity

This review summarizes the drugs and chemicals that may modulate embryo implantation.Non-hormonal molecules,including aspirin,improved endometrial blood flow,while low molecular weight heparin,vitamin E,sildenafil,and atosiban modulated the expression of endometrial genes.Hormonal factors,including human chorionic gonadotropin and growth hormones,can regulate the expression of endometrial receptivity markers.Other immunomodulatory molecules,including granulocyte colony-stimulating factor,peripheral blood mononuclear cells,autologous platelet-rich plasma,and intralipid and intravenous immunoglobulins,may improve implantation rate by modulating endometrial immune functions.Medicinal extracts of the Chinese herbs Paeonia lactiflora and Perilla frutescens increased the expression of leukemia inhibitory factors in endometrial epithelial cells.Recently,the use of the commercially available Library of Pharmacologically Active Compounds with a high-throughput screening method has provided an approach to screen for compounds that may potentially enhance or suppress embryo implantation.Whether these biomedical findings translate into clinical effects that enhance or suppress embryo implantation requires further investigation.