Search

Abstract Background Accumulating studies have highlighted the significant role of circulating metabolomics in the etiology of reproductive system disorders. However, the causal effects between genetically determined metabolites (GDMs) and reproductive diseases, including primary ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), and abnormal spermatozoa (AS), still await thorough clarification. Methods With the currently most comprehensive genome-wide association studies (GWAS) data of metabolomics, systematic two-sample Mendelian randomization (MR) analyses were conducted to disclose causal associations between 1,091 blood metabolites and 309 metabolite ratios with reproductive disorders. The inverse-variance weighted (IVW) method served as the primary analysis approach, and multiple effective MR methods were employed as complementary analyses including MR-Egger, weighted median, constrained maximum likelihood (cML-MA), contamination mixture method, robust adjusted profile score (MR-RAPS), and debiased inverse-variance weighted method. Heterogeneity and pleiotropy were assessed via MR-Egger intercept and Cochran’s Q statistical analysis. Outliers were detected by Radial MR and MR-PRESSO methods. External replication and metabolic pathway analysis were also conducted. Results Potential causal associations of 63 GDMs with POI were unearthed, and five metabolites with strong causal links to POI were emphasized. Two metabolic pathways related to the pathogenesis of POI were pinpointed. Suggestive causal effects of 70 GDMs on PCOS were detected, among which 7 metabolites stood out for strong causality with elevated PCOS risk. Four metabolic pathways associated with PCOS mechanisms were recognized. For AS, 64 GDMs as potential predictive biomarkers were identified, particularly highlighting two metabolites for their strong causal connections with AS. Three pathways underneath the AS mechanism were identified. Multiple assessments were conducted to further confirm the reliability and robustness of our causal inferences. Conclusion By extensively assessing the causal implications of circulating GDMs on reproductive system disorders, our study underscores the intricate and pivotal role of metabolomics in reproductive ill-health, laying a theoretical foundation for clinical strategies from metabolic insights.

BackgroundSecond-trimester abortion is a critical issue in infertile women with polycystic ovary syndrome (PCOS) treated with assisted reproductive technology (ART), cervical incompetence (CI) may play a role. Although previous studies have revealed an association between PCOS and CI in women undergoing ART with fresh embryo transfer, the associated risk factors in frozen embryo transfer cycles are still unknown. The primary objective of this study is to examine the impact of CI on the occurrence of second-trimester abortion in women with PCOS undergoing frozen embryo transfer.MethodsThis retrospective cohort study included patients who underwent frozen-thawed embryo transfer and experienced second-trimester abortion between January 2012 and January 2020 from the Reproductive Medical Center of the First Affiliated Hospital of Zhengzhou University. Logit-transformed propensity score matching (PSM) was used to assess covariates. Patients were classified into the PCOS and non-PCOS groups. The PCOS group was further divided into two subgroups: the CI group and non-CI group.ResultsAfter case matching with PSM, 278 patients were included: 139 each in the PCOS group and non-PCOS groups. More miscarriages were attributed to CI in the PCOS group compared with the control group (20.14% vs. 10.07%). Subsequently, in the PCOS group, CI and non-CI subgroup analyses revealed a higher transfer cleavage-stage embryo incidence in the CI group than in the blastocysts group (p=0.001). Moreover, the between-group miscarriage-related gestational age varied significantly (p=0.039). Binary logistic regression analysis revealed that cleavage embryo transfer (p= 0.047) was associated with increased CI risk in the PCOS group, besides, increasing the number of transferred embryos did not impact the occurrence of CI in patients with PCOS.ConclusionCI independently predicted a higher risk of second-trimester abortion in patients with PCOS during the frozen embryo transfer cycle. What’s more, increasing the number of transferred embryos did not affect the incidence of CI in the PCOS group.

Abstract Background Agar-like zona pellucida (ZP) is the most common type of abnormal ZP, and is one of the causes of low fertility or infertility. However, the molecular mechanism of agar-like ZP is unclear. Single-cell RNA-sequencing (scRNA-seq) analysis was used to assess the cellular and molecular landscape of oocytes with agar-like ZP. Methods Human metaphase I (MI) oocytes were collected from four patients with agar-like ZP and four healthy donors. Total RNA was isolated, cDNA was synthesized, and libraries were generated and subsequently sequenced on a HiSeq 2500 instrument. The scRNA-seq data were analyzed with R software. Results We identified 1320 genes that were differentially expressed between agar-like ZP oocytes and healthy donor oocytes. Gene Ontology term enrichment results showed that the genes downregulated in agar-like ZP oocytes were significantly related to extracellular matrix organization, while the genes upregulated in agar-like ZP oocytes were significantly related to the regulation of response to DNA damage stimulus. The Kyoto Encyclopedia of Genes and Genomes enrichment results showed that genes were enriched in the ECM-receptor interaction pathway and focal adhesion pathway. Other signaling pathways important in oocyte development were also enriched, such as PI3K-Akt. Differential expression analysis identified UBC, TLR4, RELA, ANXA5, CAV1, KPNA2, CCNA2, ACTA2, FYN and ITGB3 as genetic markers of oocytes with agar-like ZP. Conclusions Our findings suggest that agar-like ZP oocytes exhibit significant downregulation of genes involved in the ECM-receptor interaction signaling pathway and focal adhesion pathway, which could lead to aberrant ZP formation, while the upregulated genes were significantly related to regulation of the response to DNA damage stimulus. Agar-like ZP formation may interfere with the normal exchange of signals between oocytes and perivitelline granulosa cells, thereby preventing cumulus cells from participating in oocyte DNA damage repair and causing MI arrest.

Abstract Sarcopenia (low muscle mass, i.e., quantity) is associated with poor clinical outcomes in patients with acute-on-chronic liver failure (ACLF). In this study, we aimed to illustrate the clinical prognostic value of myosteatosis (muscle fat infiltration) for short-term mortality in patients with ACLF. We retrospectively enrolled consecutive patients with ACLF between January 2019 and January 2022. Computed tomography-based body composition analysis was performed at the third lumbar vertebral level to determine skeletal muscle radiation attenuation. Fine and Gray’s competing risk regression model, with liver transplantation as a competing risk, was used to assess the factors associated with 90-day mortality. A total of 431 patients with ACLF were included. Myosteatosis and sarcopenia were observed in 261 (60.6%) and 87 (20.2%) patients, respectively. Competitive risk regression showed that age (HR 1.021, 95% CI 1.000–1.043, P = 0.042), APASL ACLF Research Consortium (AARC) score (HR 1.498, 95% CI 1.312–1.710, P

The flow field structure for aero-engine combustor is one of the most important factors for combustion performance. To investigate how the rotating direction of dual-axial swirlers affects the flow field and combustion characteristics, particle image velocimetry (PIV) experiments were conducted in the primary combustion and intermediate zones. Additionally, planar laser induced fluorescence (PLIF) was used to map the distribution of kerosene and OH in the primary combustion zone. The results show that the swirling jets in co-swirl exhibit greater jet momentum, resulting in a longer primary recirculation zone and a larger deflection angle of the primary jets. This ultimately leads to a higher recirculation rate compared to counter-swirl. The primary jets define the boundary of the flow field structure. The rotating direction primarily affects the flow field structure upstream of the primary jets, exerts a relatively weaker influence on the intermediate zone, which is mainly affected by the deflection direction of the primary jets, and essentially has no impact on the dilution jets. Co-swirl has a relatively stable flow field than counter-swirl, whereas the flow field in counter-swirl is more chaotic, featuring a greater number of vortex cores in the primary recirculation zone. The coupling between the primary and swirling jets affects the mass transfer direction in the intermediate zone, which is reflected in the fact that the mass transfer is from top-left to bottom-right in co-swirl, while it is in the opposite direction in counter-swirl. OH is predominantly found in the swirling shear layers, the primary and secondary combustion zones, whereas kerosene is mainly concentrated in the shear layers of swirling jets. The kerosene distribution in co-swirl shows a larger and more concentrated expansion angle compared to counter-swirl. In contrast, the OH distribution downstream of counter-swirl is broader, with more intense combustion due to enhanced kerosene decomposition and fuel-air mixing. The smaller primary recirculation zone in counter-swirl forces the primary combustion zone to extend downstream, leading to a more intense reaction in the secondary recirculation zone.

Aiming at the dual-mode round combustor model of kerosene fuel, the combustor mode transition test under different conical strut choking ratios was carried out. The monotonicity, sensitivity and stability of the wall pressure as a controlled parameter are analyzed, and the variation law of the mode transition boundary and the choking ratio of the conical strut is studied. The research indicated that at Δx = 30 mm downstream of the kerosene injector, the wall pressure exhibited good monotonicity, high sensitivity, and relatively good stability, making it most suitable as the controlled parameter for fuel flow rate. When the choking ratio was 0.00, 0.22, and 0.26, the equivalent ratios corresponding to the mode transition boundaries were 0.667, 0.64, and 0.51, respectively. As the choking ratio of the conical strut increased, the equivalent ratio corresponding to the mode transition boundary decreased. The variation curves of the corrected wall pressure ratio and equivalent ratio at Δx = 30 mm and Δx = 60 mm downstream of the kerosene injector also exhibited an approximate parallel relationship, with the mode transition boundary corresponding to corrected wall pressure ratios of 0.0278 and 0.028, respectively.

Abstract Background Recent studies about the effect of gonadotropin (Gn) dose on the clinical outcomes of IVF are still controversial, and no studies have analyzed the relationship between Gn dose and embryo quality. Since AMH is a strong predictor of oocyte quality, we aim to evaluate the relationship between total Gn dose and embryo quality and clinical outcomes at different AMH levels in IVF cycles. Methods A total of 12,588 patients were enrolled in the retrospective study. The included cycles were categorized by serum AMH levels (AMH ≤ 1 ng/ml, 1 ng/ml 5 ng/ml), total Gn dosage ( 5 ng/ml group and AMH ≤ 1 ng/ml group. The blastocyst formation rate and high-quality blastulation rate had a negative relationship with Gn does for women aged 5 ng/ml group (P

Feline panleukopenia virus (FPV), a globally pervasive and highly pathogenic pathogen, has garnered significant attention recently due to the cross-species transmission of its variants. Despite the vast body of research conducted on FPV, studies exploring its evolutionary history, dynamics, and the factors driving its evolution remain scarce. The pathogenicity of strains with the prevalent mutations (A91S and I101T) in the VP2 protein has also not been fully elucidated. This study conducted a comparative analysis of FPV VP2 sequences sourced from Xinjiang province in China, other provinces in China, and other countries. It was confirmed that the evolutionary rate of FPV approached that of RNA viruses, at approximately 1.13 × 10−4 substitutions/site/year. The study reconstructed molecular models of the VP2 protein with the A91S and I101T mutations and used viral strains carrying these mutations to perform the animal regression experiment. It was confirmed that isolates with the A91S and I101T mutations could cause typical leukopenia and acute enteritis symptoms, suggesting that the mutant strains still possess certain pathogenicity. This is the first study to report on the evolutionary dynamics of FPV in Xinjiang, China, and it emphasized the importance of continuously monitoring FPV evolutionary dynamics.

Abstract In view of the long calculation cycle, high processing test and cost of the traditional aero-engine combustion chamber design process, which restricts the engine optimization design cycle, this paper innovatively proposes a surrogate model for the performance of aero-engine combustion chambers based on the POD-Hierarchical-Kriging method. Through experiments, the predicted results of the POD-Hierarchical-Kriging model are compared and analyzed with the calculated results of the one-dimensional program, and the root mean square error of the predicted values of combustion efficiency and total pressure loss is 0.0064% and 0.1995%, respectively. The accuracy of the POD-Hierarchical-Kriging model is compared with the cubic polynomial model, the basic Kriging model and the Hierarchical-Kriging model. It verifies the feasibility and accuracy of the POD-Hierarchical-Kriging model for the prediction of performance of aero-engine combustion chambers. The global sensitivity analysis method is applied to obtain the influence effect of design variables on the performance. Then, a multi-objective optimization method based on the NSGA-II algorithm is studied, and finally the optimal set of Pareto solutions is obtained and analyzed, which can be used to guide the optimal design of aero-engine combustion chambers and accelerate the progress of aero-engine development.

Abstract Background Peutz Jeghers syndrome (PJS) is an autosomal dominant genetic disorder caused by STK11 mutation with a predisposition to gastrointestinal polyposis and cancer. PJS patients suffer poor quality of life and are highly concerned about whether deleterious mutations transmit to their offspring. Therefore, this study aimed to propose feasible clinical management and provide effective preimplantation genetic testing for monogenic defect (PGT-M) strategies to protect offspring from inheriting the disease. Methods A hospital-based clinical retrospective analysis reviewing the clinical characteristics and fertility aspects was first conducted on 51 PJS patients at the First Affiliated Hospital of Zhengzhou University between January 2016 and March 2021. Among the 51 patients, the PGT-M strategy was further carried out in 4 couples, which started with a biopsy of the trophectoderm cells of embryos and whole genome amplification using multiple displacement amplification. Thereafter, single nucleotide polymorphism linkage analyses based on karyomapping were performed with copy number variations of the embryos identified simultaneously. Finally, prenatal diagnosis was used to verify the validity of the PGT-M results. Results A comprehensive management flowchart adopted by the multidisciplinary team model was formulated mainly focusing on clinical genetic and gastrointestinal aspects. Under the guidelines of this management, 32 embryos from 4 PJS pedigrees were diagnosed and 2 couples successfully conceived healthy babies free of the STK11 pathogenic mutation. Conclusions Our comprehensive management could help affected families avoid having children with PJS through preimplantation genetic testing and provide meaningful guidance for multidisciplinary clinical practice on PJS.

Helicobacter pylori FabX, a dehydrogenase/isomerase flavoprotein, is required for unsaturated fatty acid synthesis. Here, the authors characterize FabX substrate recognition and catalytic mechanism, and reveal that it contains an atypical [4Fe-4S] cluster, which is essential and participates in the catalytic cycle.

Background and aimsThe progressive and generalized loss of skeletal muscle mass, strength and physical function is defined as sarcopenia. Sarcopenia is closely related to the prognosis of patients. Accurate diagnosis and adequate management of sarcopenia are crucial. The psoas muscle mass index taken at the third lumbar vertebra (L3-PMI, cm2/m2) is one of the established methods for evaluating skeletal muscle mass. However, the cutoff values of L3-PMI for diagnosis of sarcopenia are not yet to be clarified in Asian populations. We attempted to establish reference values for low L3-PMI that would be suitable for defining sarcopenia in the Northern Chinese population.MethodsThis was a retrospective, multicenter cross-sectional study. A search of abdominal CT imaging reports was conducted in four representative cities in northern China. Transverse CT images were measured using the analysis software Slice-O-Matic. Low psoas muscle index was defined as the 5th percentile or mean-2SD of the study group.Results1,787 healthy individuals in the study were grouped by age. The sex and number of people in each group were similar. L3-PMI had a negative linear correlation with age, and a strong correlation with the skeletal muscle index taken at the third lumbar vertebrae (L3-SMI, cm2/m2). The L3-PMI reference values in males were 5.41 cm2/m2 for 20–29 years, 4.71 cm2/m2 for 30–39 years, 4.65 cm2/m2 for 40–49 years, 4.10 cm2/m2 for 50–59 years and 3.68 cm2/m2 for over 60 years by using 5th percentile threshold. Similarly, the reference values in females were 3.32, 3.40, 3.18, 2.91, and 2.62 cm2/m2. When using mean-2SD as the reference, the values for each age group were 4.57, 4.16, 4.03, 3.37, and 2.87 cm2/m2 for males and 2.79, 2.70, 2.50, 2.30, and 2.26 cm2/m2 for females, respectively.ConclusionWe defined the reference values of age-specific low skeletal muscle mass when simply evaluated by L3-PMI. Further studies about the association of sarcopenia using these reference values with certain clinical outcomes or diseases are needed.

Abstract Sarcopenia is a well-recognized factor affecting the prognosis of chronic liver disease, but its impact on acute decompensation underlying chronic liver disease is unknown. This study evaluated the impact of sarcopenia on short-term mortality in patients with acute-on-chronic liver failure (ACLF). One hundred and seventy-one ACLF patients who underwent abdominal CT between 2015 and 2019 were retrospectively included in this study. Skeletal muscle index at the third lumbar vertebrae (L3-SMI) was used to diagnose sarcopenia.The ACLF patients in this study had a L3-SMI of 41.2 ± 8.3 cm2/m2 and sarcopenia was present in 95/171 (55.6%) patients. Body mass index (BMI), cirrhosis, and higher serum bilirubin were independently associated with sarcopenia. Following multivariate Cox regression analysis, cirrhosis (hazard ratio (HR) 2.758, 95%CI 1.323–5.750), serum bilirubin (HR 1.049, 95%CI 1.026–1.073), and international normalized ratio (INR) (HR 1.725, 95%CI 1.263–2.355) were associated with 3-month mortality (P

ObjectiveAbdominal adipose is closely related to many endocrine and metabolic diseases. The aim of this study was to analyze the distribution of abdominal adipose tissue in a healthy population in northern China determined by abdominal computed tomography (CT).MethodsData for this study were obtained from a multicenter, retrospective, cross-sectional study that collected abdominal CT scans of 1787 healthy individuals from 4 representative cities in northern China. Areas of visceral adipose tissue (VATA) and subcutaneous adipose tissue (SATA) were obtained by measuring CT images at the level of the 3rd lumbar vertebra. Visceral adipose tissue index (VATI) and subcutaneous adipose index (SATI) were obtained by normalizing the square of height to analyze the distribution of the above indexes and visceral obesity among different body mass index (BMI), gender and age.ResultsThe mean age of this healthy population was 45.3 ± 15.2 years and the mean BMI was 23.5 ± 3.2 kg/m2, with 902 men and 885 women. Compared with women, men had a significantly higher median VATA (120.9 vs. 67.2 cm2), VATI (39.1 vs. 25.6 cm2/m2) and a significantly higher percentage of visceral adiposity (VATA ≥ 100 cm2) (60.8 vs. 30.4%), while women had significantly higher SATA (116.9 vs. 146.7 cm2) and SATI (38.8 vs. 55.8 cm2/m2) than men. Whether men or women, VATI was positively correlated with age. Interestingly, SATI was weakly positively correlated with age in women, while SATI was weakly negatively correlated with age in men. In persons with a normal BMI, the proportion of visceral adiposity increases with age, whereas in men with a normal BMI, the proportion of visceral adiposity decreases after the age of 60 years but remains >50%.ConclusionsThe distribution of abdominal visceral and subcutaneous adipose tissue parameters measured by CT differed among gender, age, and BMI. Even men and women with normal BMI have a high proportion of visceral obesity.

Type 3 hereditary hemochromatosis (HH) is a rare form of HH characterized by genetic mutation in the TFR2 gene. Clinical features reported in patients with type 3 HH include abnormal liver function, liver fibrosis, cirrhosis, diabetes, hypogonadism, cardiomyopathy, and skin pigmentation. Since its original description in 2000, 33 pathogenic TFR2 mutations associated with HH have been described until now. Here, we first reported a Chinese pedigree of TFR2-related hemochromatosis with a novel compound heterozygous mutation c.1288G > A (p.G430R)/c.960T > A (p.Y320X). Interestingly, different phenotypes were reported although the proband and his sister shared the same gene mutation. This inconsistency between genotypes and phenotypes indicates multifactorial etiology contributing to the development of HH. Our report broadens the mutation spectrum of the TFR2 gene associated with HH.

Abstract Background To assess the dynamic changes in clinical and CT characteristics of COVID-19 patients with different epidemiology histories. Methods Fifty-three discharged COVID-19 patients were enrolled at Beijing YouAn Hospital, Capital Medical University, between January 21 and March 10, 2020. Spearman correlation analysis was performed between CT scores and laboratory indicators. Patients were divided into the Wuhan group (lived in or with travel to Wuhan, numbering 30 cases) and non-Wuhan group (close contacts or unknown exposure, totaling 23 cases). The CT and laboratory findings were compared between and within groups during the clinical process. Results Fever (88.7%), cough (64.2%), fatigue (34%), and abnormal laboratory indicators, including lymphopenia, reduced albumin, albumin/globulin (A/G), and elevated C-reactive protein (CRP), were mainly observed. Subpleural ground-glass opacities (86.8%) were usually detected at admission. The CT scores were highly correlated with lymphocytes, CRP, albumin, and A/G at initial and follow-ups (all p

Abstract Background To assess whether preimplantation genetic testing for aneuploidy with next generation sequencing (NGS) outweighs single nucleotide polymorphism (SNP) array in improving clinical outcomes. Methods A retrospective analysis of the clinical outcomes of patients who underwent PGT-A treatment in a single center from January 2013 to December 2017.A total of 1418 couples who underwent PGT-A treatment were enrolled, of which 805 couples used NGS for PGT-A, while the remaining 613 couples used SNP array for PGT-A. Clinical pregnancy rate, miscarriage rate and healthy baby rate were compared between the MALBAC-NGS-PGT-A and MDA-SNP-PGT-A groups. Results After testing karyotypes of 5771 biopsied blastocysts, 32.2% (1861/5771) were identified as chromosomally normal, while 67.8% were chromosomally abnormal. In terms of clinical outcomes, women in the MALBAC-NGS-PGT-A group had a significantly higher clinical pregnancy rate (50.5% vs 41.7%, p = 0.002) and healthy baby rate (39.6% vs 31.4%, p = 0.003), and a lower miscarriage rate (15.5% vs 22.8%, p = 0.036). Conclusion This is the largest study reporting the extensive application of NGS-based PGT-A, whilst comparing the clinical outcomes of MALBAC-NGS-PGT-A and MDA-SNP-PGT-A. The results provide greater evidence supporting the wider use of NGS in PGT-A, not only for its lower cost but also for its improved clinical outcomes compared to SNP-based PGT-A.

ObjectiveThe use of psoas muscle index (PMI) in acute-on-chronic liver failure (ACLF) has not been reported, and the aim of this study was to evaluate the predictive value of PMI for the prognosis of patients with ACLF.MethodsIn this study, male ACLF patients who underwent abdominal CT between 2015 and 2019 in our center were included to analyze the association between PMI and 1-year mortality in male ACLF patients, and subgroup analyses were performed according to age stratification (≤ 40 and >40 years).ResultsWe included 116 male patients with confirmed ACLF, with a mean PMI of 5.98 ± 1.68 cm2/m2 and a 1-year mortality of 51.7% (60). Univariate COX regression analysis showed that PMI was a protective factor [hazard ratio (HR), 0.851, 95%CI: 0.734–0.987] for 1-year mortality in male patients with ACLF. Nevertheless, multivariate analysis did not find an independent relationship between PMI and 1-year mortality. Subgroup analysis by age found that adjusted for MELD score, PMI was independently associated with 1-year mortality in young (age ≤ 40 years) male patients with ACLF (HR 0.689, 95% CI: 0.496–0.958). While no effect of PMI on 1-year mortality in non-young (age > 40 years) male ACLF patients was found. Correlation analysis found that there was no significant correlation between PMI and age in young (age ≤ 40 years) male ACLF patients, but, PMI decreased with age (r = −0.246, P < 0.05) in non-young (age > 40 years) male ACLF patients.ConclusionPMI was found to be associated with 1-year mortality in male ACLF patients, especially in patients younger than 40 years, PMI predict 1-year mortality independent of MELD score.

It is well known that the transfer of embryos at the blastocyst stage is superior to the transfer of embryos at the cleavage stage in many respects. However, the rate of blastocyst formation remains low in clinical practice. To reduce the possibility of wasting embryos and to accurately predict the possibility of blastocyst formation, we constructed a nomogram based on range of clinical characteristics to predict blastocyst formation rates in patients with different types of infertility. We divided patients into three groups based on female etiology: a tubal factor group, a polycystic ovary syndrome group, and an endometriosis group. Multiple logistic regression was used to analyze the relationship between patient characteristics and blastocyst formation. Each group of patients was divided into a training set and a validation set. The training set was used to construct the nomogram, while the validation set was used to test the performance of the model by using discrimination and calibration. The area under the curve (AUC) for the three groups indicated that the models performed fairly and that calibration was acceptable in each model.

Calcium is a crucial factor in regulating the biological behavior of cells. The imbalance of calcium homeostasis in cytoplasm will cause abnormal behavior of cells and the occurrence of diseases. In intracytoplasmic sperm injection (ICSI) cycle, the dysfunction of oocyte activation caused by insufficient release of Ca2+ from endoplasmic reticulum is one of the main reasons for repeated fertilization failure. Calcium ionophore (A23187) is a highly selective calcium ionophore, which can form stable complex with Ca2+ and pass through the cell membrane at will, effectively increasing intracellular Ca2+ levels. It has been reported that calcium ionophore (A23187) can activate oocytes and obtain normal embryos. However, there are few studies on unfertilized oocytes after calcium ionophore (A23187) rescue activation in ICSI cycle. The purpose of this study was to analyze the effects of calcium ionophore (A23187) rescue activation on the activation of unfertilized oocytes, embryonic development potential, embryonic development timing and chromosomal aneuploidy, and to compare and analyze the clinical data of patients with calcium ionophore (A23187) activation in clinical application. The results showed that a certain proportion of high-quality blastocysts with normal karyotype could be obtained after calcium ionophore (A23187) rescue activation of unfertilized oocytes, and it did not have a significant effect on the timing of embryo development. In clinical practice, direct activation with calcium ionophore (A23187) after ICSI was better than rescue activation the next day. In conclusions, the studies on the effectiveness and safety of calcium ionophore (A23187) rescue activation for oocytes with ICSI fertilization failure can enable some patients to obtain usable, high-quality embryos during the first ICSI cycle.

Many manufacturers today are striving to offer high value-added product-service offerings (PSO) due to increasing competitions and environmental concerns. Modularization of PSO can improve design efficiency and quickly response to customer’s personalized requirements. However, research has rarely been conducted on the PSO modularization schemes evaluation which is critical to the success of the whole modularization. There are also no proper evaluation criteria for such heterogeneous form of hybrid solution. Therefore, in order to select reasonable modularization scheme of PSO, an approach based on fuzzy TOPSIS with integrated weights is proposed in this paper. Integration of subjective weight and objective weight helps to avoid underestimating or overestimating weigh of evaluation criteria, while the fuzzy TOPSIS approach provides a structure of multi-criteria decision-making (MCDM) under uncertain environment. A case study of compressor rotor service is used to validate the feasibility and effectiveness of the proposed method.

Large eddy simulations of a stratified swirling flow of a Cambridge swirl burner for both nonreacting and reacting cases are conducted using a finite rate chemistry approach represented by a partially stirred reactor model. The large eddy simulation predictions are compared with experimental measurements for velocity, temperature, and concentrations of major species. The agreement is found in overall trend of velocity prediction, but temperature and concentration of major species show slight discrepancies in the central region. Two reduced chemical mechanisms are examined in the present paper with the objective of assessing their capabilities in predicting swirling flame characteristics, and the distinct difference using two mechanisms is found in CO distribution profiles, which is considered the consequence of different kinetics of CO-CO2 equilibrium. Flow structures are qualitatively and quantitatively analyzed with numerical results. Large-scale vortex structures and precession motions are observed in both nonreacting and reacting cases. Frequency of vortex shedding is identified from the point data of instantaneous velocity in the discharging stream-induced shear layer. On this basis, the intensity and frequency of precession motion are shown to be enhanced in the presence of combustion. Large-scale wrinkling of the flame surface is resolved and characterized in the flame zone, and the effect of mixture stratification is then further discussed.

The characteristic of the spray within combustion chamber is one of the determining factors that affect the performance and exhaust gas emissions of an aero-engine. Recently, the holography technique has been successfully applied to spray atomization measurement due to its significant advances. In this article, an atmospheric test rig of pressure-swirl nozzle is built. The kerosene spray generated at the atmospheric condition and in an aero-engine combustor is measured. The Sauter mean diameter of the spray droplets is obtained. In addition, the theoretical analysis of film formation and sheet breakup processes are conducted. Comparison of theoretical analysis and experimental results on the spray atomization of a pressure-swirl nozzle is presented.

The development of high-performance aeroengine combustion chambers strongly depends on the accuracy and reliability of efficient numerical models. In the present work, a reacting solver with a steady laminar flamelet model and spray model has been developed in OpenFOAM and the solver details are presented. The solver is firstly validated by Sandia/ETH-Zurich flames. Furthermore, it is used to simulate nonpremixed kerosene/air spray combustion in an aeroengine combustion chamber with the RANS method. A comparison with available experimental data shows good agreement and validates the capability of the new developed solver in OpenFOAM.

The principal features of primary zone determine the performance parameters of the whole combustion chamber, such as the pollutant emissions and combustion efficiency. In this work, flow field and major species concentration measurements are conducted in the primary zone of an aero-engine combustion chamber. The operating conditions such as air inlet temperature, chamber pressure, and air-to-fuel ratio are chosen to replicate the realistic operating conditions. The velocity field and streamlines are obtained by particle imaging velocimetry technology. The concentrations of major species are acquired by a spontaneous Raman scattering system. This article validates the feasibility of two laser diagnostic measurement techniques and presents the initial results under realistic aero-engine conditions.