Laparoscopy is non-inferior to open surgery for rectal cancer: A systematic review and meta-analysis.

BACKGROUND: Laparoscopic surgery has been endorsed by clinical guidelines for colon cancer, but not for rectal cancer on account of unapproved oncologic equivalence with open surgery. AIMS: We started this largest-to-date meta-analysis to comprehensively evaluate the safety and efficacy of laparoscopy in the treatment of rectal cancer compared with open surgery. MATERIALS & METHODS: Both randomized and nonrandomized controlled trials comparing laparoscopic proctectomy and open surgery between January 1990 and March 2020 were searched in PubMed, Cochrane Library and Embase Databases (PROSPERO registration number CRD42020211718). The data of intraoperative, pathological, postoperative and survival outcomes were compared between two groups. RESULTS: Twenty RCTs and 93 NRCTs including 216,615 patients fulfilled the inclusion criteria, with 48,888 patients received laparoscopic surgery and 167,727 patients underwent open surgery. Compared with open surgery, laparoscopic surgery group showed faster recovery, less complications and decreased mortality within 30 days. The positive rate of circumferential margin (RR = 0.79, 95% CI: 0.72 to 0.85, p < 0.0001) and distal margin (RR = 0.75, 95% CI: 0.66 to 0.85 p < 0.0001) was significantly reduced in the laparoscopic surgery group, but the completeness of total mesorectal excision showed no significant difference. The 3-year and 5-year local recurrence, disease-free survival and overall survival were all improved in the laparoscopic surgery group, while the distal recurrence did not differ significantly between the two approaches. CONCLUSION: Laparoscopy is non-inferior to open surgery for rectal cancer with respect to oncological outcomes and long-term survival. Moreover, laparoscopic surgery provides short-term advantages, including faster recovery and less complications.

Decidual stromal cell-derived exosomes deliver miR-22-5p_R-1 to suppress trophoblast metabolic switching from mitochondrial respiration to glycolysis by targeting PDK4 in unexplained recurrent spontaneous abortion.

INTRODUCTION: Studies have shown that EMT (epithelial-mesenchymal transition) and energy metabolism influence each other, and it is unclear whether the trophoblast energy metabolism phenotype is dominated by glycolysis or mitochondrial respiration, and the relationship between trophoblast energy metabolism and EMT is still unclear. METHODS: Exosomes were isolated from the DSC of URSA patients and their miRNA profile was characterized by miRNA sequencing. Wound healing assays and transwell assays were used to assess the invasion and migration ability of trophoblasts. Mitochondrial stress and glycolysis stress test were used to evaluate energy metabolism phenotype of trophoblast. Luciferase reporter assays, qRT-PCR and WB were conducted to uncover the underlying mechanism. Finally, animal experiments were employed to explore the effect of DSC-exos on embryo absorption in mice. RESULTS: Our results showed that URSA-DSC-exos suppressed trophoblast EMT to reduce their migration and invasion, miR-22-5p_R-1 was the most upregulated miRNAs. URSA-DSC-exos can suppress trophoblast MGS (metabolic switch from mitochondrial respiration to glycolysis) and inhibit trophoblast migration and invasion by transferring miR-22-5p_R-1. Mechanistically, miR-22-5p_R-1 suppress trophoblast MGS and inhibit trophoblast EMT by directly suppressing PDK4 expression at the post-transcriptional level. Furthermore, in vivo experiment suggested that URSA-DSC-exos aggravated embryo absorption in mice. Clinically, PDK4 and EMT molecule were aberrant in villous of URSA patients, and negative correlations were found between miR-22-5p_R-1 and PDK4. DISCUSSION: Our findings indicated that URSA-DSC-exos induced MGS obstacle playing an important role in intercellular communication between trophoblast and DSC, illuminating a novel mechanism in DSC regulation of trophoblasts and their role in URSA.

Comprehensive machine learning-based preoperative blood features predict the prognosis for ovarian cancer.

PURPOSE: Significant advancements in improving ovarian cancer (OC) outcomes have been limited over the past decade. To predict prognosis and improve outcomes of OC, we plan to develop and validate a robust prognosis signature based on blood features. METHODS: We screened age and 33 blood features from 331 OC patients. Using ten machine learning algorithms, 88 combinations were generated, from which one was selected to construct a blood risk score (BRS) according to the highest C-index in the test dataset. RESULTS: Stepcox (both) and Enet (alpha = 0.7) performed the best in the test dataset with a C-index of 0.711. Meanwhile, the low RBS group possessed observably prolonged survival in this model. Compared to traditional prognostic-related features such as age, stage, grade, and CA125, our combined model had the highest AUC values at 3, 5, and 7 years. According to the results of the model, BRS can provide accurate predictions of OC prognosis. BRS was also capable of identifying various prognostic stratifications in different stages and grades. Importantly, developing the nomogram may improve performance by combining BRS and stage. CONCLUSION: This study provides a valuable combined machine-learning model that can be used for predicting the individualized prognosis of OC patients.

Decidual stromal cells-derived exosomes incurred insufficient migration and invasion of trophoblast by disturbing of ß-TrCP-mediated snail ubiquitination and degradation in unexplained recurrent spontaneous abortion.

BACKGROUND: Exosomes released from decidual stromal cells (DSC-exos) play a crucial role in facilitating the epithelial-mesenchymal transition (EMT) of trophoblasts and insufficient trophoblasts EMT are associated with URSA (unexplained recurrent spontaneous abortion). However, the mechanisms underlying DSC-exos inducing EMT is not completely understood. METHODS: DSC-exos of normal pregnant women (N-DSC-exos) and URSA patients (URSA-DSC-exos) were extracted and characterized. Characterization of the isolated DSC-exos was performed using with TEM (transmission electron microscopy), NTA (nanoparticle tracking analysis), and WB (western blot) techniques. Subsequently, these DSC-exos were co-cultured with trophoblasts cell lines (HTR-8/SVneo). The influence of both N-DSC-exos and URSA-DSC-exos on trophoblasts proliferation, invasion and migration, as well as on the expression of EMT-related proteins, was evaluated through a series of assays including CCK8 assays, wound healing assays, transwell assays, and western blot, respectively. Then rescue experiments were performed by ß-TrCP knockdown or ß-TrCP overexpressing trophoblasts with snail-siRNA transfection or ß-TrCP overexpressing Lentivirus infection, respectively. Finally, animal experiments were employed to explore the effect of N-DSC-exos on embryo absorption in mice. RESULTS: We found increased ß-TrCP expression in the villus of URSA patients when compared to the normal pregnant women, alongside reduction in the levels of both snail and N-cadherin within URSA patients. N-DSC-exos can promote the EMT of the trophoblast by inhibiting ß-TrCP-mediated ubiquitination and degradation of transcription factor snail. Moreover the capacity to promote EMT was found to be more potent in N-DSC-exos than URSA-DSC-exos. Down-regulation of snail or overexpression of ß-TrCP can reverse the effects of N-DSC-exos on trophoblast. Finally, in vivo experiment suggested that N-DSC-exos significantly reduced the embryo resorption rate of spontaneous abortion mouse model. CONCLUSIONS: Our findings indicate that URSA-DSC-exos caused insufficient migration and invasion of trophoblast because of disturbing of ß-TrCP-mediated ubiquitination and degradation of EMT transcription factor snail. Elucidating the underlying mechanism of this dysregulation may shed light on the novel pathways through which DSC-exos influence trophoblast function, thereby contributing to our understanding of their role in URSA.

Effect of Annealing Temperature on Mechanical Properties and Work Hardening of Nickel-Saving Stainless Steel.

Compared to Cr-Ni stainless steel, nickel-saving stainless steel is a low-cost austenitic stainless steel. We studied the deformation mechanism of stainless steel at various annealing temperatures (850 °C, 950 °C, and 1050 °C). The grain size of the specimen increases with increasing annealing temperature while the yield strength decreases, which follows the Hall-Petch equation. When plastic deformation occurs, dislocation increases. However, the deformation mechanisms can vary between different specimens. Stainless steel with smaller grains is more likely to transform into martensite when deformed. While twinning occurs when the grains are more prominent, the deformation results in twinning. The phase transformation during plastic deformation relies on the shear, so the orientation of the grains is relevant before and after plastic deformation.

Isolation and proteomic profiling of urinary exosomes from patients with colorectal cancer.

Exosomes in the body fluid are effective cell-derived membranous structures transferring various molecules to mediate intercellular communication. The expression of protein in the urinary exosomes from the colorectal cancer (CRC) patients could reflect the characteristics of tumorigenesis. The urinary exosomes with globular membrane structure, the size of 30 ~ 100 nm and positive expression of CD9, CD63 and CD81 were successfully isolated from 9 CRC patients and 3 heathy adults using the density gradient ultracentrifugation. Proteome profiles revealed by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) indicated that several proteins were differentially expressed among different stages of CRC. Compared with normal controls, 67 proteins in CRC urinary exosomes were upregulated and 74 proteins were downregulated. The bioinformatics analysis revealed the decreased proteins were related to ESCRT III complex disassembly. The CHMP family was further determined to be the hub of interaction network of proteins enriched in ESCRT signaling. The significant decrease of CHMP4A, CHMP4B, CHMP2A, CHMP2B and CHMP1B were respectively found in the total CRC group and distant metastasis group compared with NC group. Moreover, the CEACAM family also showed significant aberrant changes in the urinary exosomes of CRC patients. The CEACAM7 and CEACAM1 were increased in the CRC patients compared with healthy individuals (P < 0.05). Significant changes of proteomic profile could be found in the urinary exosomes in the CRC patients. The differential expressed urinary exosomes derived proteins showed potential usage in diagnosis and prognosis of CRC.

Antiphosphatidylserine/prothrombin antibodies (aPS/PT) and risk of obstetric anti-phospholipid syndrome.

OBJECTIVE: Assessment of the prevalence of anti-phosphatidylserine-prothrombin antibodies (aPS/PT) with OAPS and SN-OAPS in Chinese patients. METHODS: This retrospective study proceeded at Ren Ji Hospital, Shanghai, China, from January 2019 to January 2020. Two hundred eleven OAPS, 68 SN-OAPS, 81 disease controls, and 30 healthy donors were enrolled. IgM and IgG aPS/PT, IgM/IgG - aCL, and IgM/ IgG/ anti-ß2GPI antibodies were tested by ELISA while LAC was tested by clotting assays. All the patients were followed up and tested at least twice over 12 weeks apart. RESULTS: Thirty-three OAPS (15.64%) and 31 SN-OAPS (45.59%) were positive for aPS/PT. aPS/PT IgM showed a high Youden index (.813), which classified OAPS and SN-OAPS patients from healthy controls and other autoimmune diseases. aPS/PT showed a stronger relationship with LAC. Of the 25 OAPS women positive for IgM aPS/PT, 19 (79%) LAC were positive, while of the eight women positive for IgG aPS/PT, 100% were found LAC positive. CONCLUSION: aPS/PT antibody showed an efficient diagnostic value for Chinese patients with OAPS and SN-OAPS, which could be a potential risk predictor for obstetric complications.

Effect of low dose aspirin application during pregnancy on fetal congenital anomalies.

BACKGROUND: With the extensive use of aspirin in obstetrics and reproductive medicine, concerns of potentially related congenital anomalies have been raised in previous studies. However, there is a lack of evidence concerning the safety of application of aspirin during pregnancy in Chinese population, especially during the first trimester. PATIENTS AND METHODS: We retrospectively included a total of 2,763 patients with 2,856 fetuses (2670 singleton births and 93 pairs of twins), among whom 1,684 took low dose aspirin (LDA) during pregnancy (the LDA group) and the other 1,079 were not exposed to LDA (the control group). The primary outcome was the rate of fetal congenital anomalies, and was compared between the LDA group and the control group. We also conducted logistic regression to examine the potential risk factors of congenital abnormalities. RESULTS: The average daily dose of LDA taken was 67.6 mg. The rate of congenital anomalies was comparable between the two groups, suggesting low teratogenicity of LDA application during pregnancy (3.3% vs. 2.8%; P = 0.421). The duration of LDA exposure and the time of LDA exposure showed no association with congenital anomalies. A previous history of fetal congenital anomalies was associated with an increased risk of the recurrence of congenital anomalies in the siblings (adjusted OR = 3.00, 95% CI: 1.00-8.60; P = 0.041). CONCLUSION: Exposure to LDA during pregnancy did not increase the risk of congenital anomalies in the fetus, suggesting that it was safe to apply LDA during pregnancy. A history of previous fetal abnormalities was found to be an independent risk factor of congenital anomalies. Our study suggests that LDA can be safely applied during pregnancy without increasing risks of congenital anomalies.

Long-read assembly of major histocompatibility complex and killer cell immunoglobulin-like receptor genome regions in cynomolgus macaque.

BACKGROUND: The major histocompatibility complex (MHC) and the killer cell immunoglobulin-like receptors (KIR) are key regulators of immune responses. The cynomolgus macaque, an Old World monkey species, can be applied as an important preclinical model for studying human diseases, including coronavirus disease 2019 (COVID-19). Several MHC-KIR combinations have been associated with either a poor or good prognosis. Therefore, macaques with a well-characterized immunogenetic profile may improve drug evaluation and speed up vaccine development. At present, a complete overview of the MHC and KIR haplotype organizations in cynomolgus macaques is lacking, and characterization by conventional techniques is hampered by the extensive expansion of the macaque MHC-B region that complicates the discrimination between genes and alleles. METHODS: We assembled complete MHC and KIR genomic regions of cynomolgus macaque using third-generation long-read sequencing approach. We identified functional Mafa-B loci at the transcriptome level using locus-specific amplification in a cohort of 33 Vietnamese cynomolgus macaques. RESULTS: This is the first physical mapping of complete MHC and KIR gene regions in a Vietnamese cynomolgus macaque. Furthermore, we identified four functional Mafa-B loci (B2, B3, B5, and B6) and showed that alleles of the Mafa-I*01, -B*056, -B*034, and -B*001 functional lineages, respectively, are highly frequent in the Vietnamese cynomolgus macaque population. CONCLUSION: The insights into the MHC and KIR haplotype organizations and the level of diversity may refine the selection of animals with specific genetic markers for future medical research.

Effect of early inflammatory reaction on ovarian reserve after laparoscopic cystectomy for ovarian endometriomas.

This study aimed to investigate the effect of early inflammatory reaction on ovarian reserve of patients with ovarian endometriomas after laparoscopic cystectomy. Our retrospective case series included 112 patients with ovarian endometriomas that underwent the laparoendoscopic single-site cystectomy. Interleukin-6 (IL-6), hs-CRP, tumour necrosis factor-α (TNF-α), interleukin-17A (IL-17A) and AMH level were detected during perioperative and postoperative period. In our study, ovarian endometriomas with low AMH group were found having higher level of IL-6 than the normal AMH group in the preoperative status. On the 3rd day after operation, the change of AMH level was inversely proportional to the IL-6 level. During the follow-up within one year, it was found that the bilateral nature of the cyst and the postoperative IL-6 increased level were the risk factors for AMH not returning to baseline level. Our results suggested that inflammatory reaction is indeed involved in the damage of ovarian reserve during laparoscopic cystectomy. Hence, the negative impact of inflammatory injury should be fully considered before operation, especially young women with bilateral ovarian endometriomas.Impact StatementWhat is already known on this subject? Ovarian reserve in women always was reduced after the laparoscopic cystectomy. It is reported that it may be related to the use of energy instruments, haemostatic methods or the size of cysts in minimally invasive surgery.What do the results of this study add? Inflammatory reaction is indeed involved in the damage of ovarian reserve during LESS cystectomy. Interleukin-6 (IL-6) may act as the most main inflammatory factor aggravating damage of the ovarian reserve. Moreover, increased IL-6 level after surgery and bilateral cyst burden are the two risk factors for AMH not returning to baseline level within one year after surgery.What are the implications of these findings for clinical practice and/or further research? In clinic, the negative impact of inflammatory injury on ovarian reserve should be fully considered before operation, especially young women with bilateral ovarian endometriomas. Moreover, this is also the clinical basis for further study on the mechanism of inflammatory ovarian injury or the method of blocking the inflammatory response to reduce the damage of ovarian reserve after surgery.

Intracellular Lipid Accumulation Drives the Differentiation of Decidual Polymorphonuclear Myeloid-Derived Suppressor Cells via Arachidonic Acid Metabolism.

Decidual polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are essential to immune tolerance during pregnancy. A reduction in the number of these cells is associated with unexplained recurrent pregnancy loss (URPL). In our previous study, we reported that PMN-MDSCs are a group of mature neutrophils that are activated by the decidua microenvironment. In the present study, we show that the decidua microenvironment induces substantial lipid accumulation in neutrophils during their differentiation to PMN-MDSCs. Lower levels of lipid accumulation are detected in PMN-MDSCs from URPL patients, and the amount of lipid in the PMN-MDSCs is positively correlated with the proportion of PMN-MDSCs. Next, we demonstrate that decidua-derived IL6 with the presence of arachidonic acid upregulates fatty acid-binding protein 5 (FABP5) via the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Fy -60ABP5 then continuously stimulates intracellular lipid accumulation. Increased intracellular lipid accumulation mediates arachidonic acid metabolism, a pathway that is significantly activated by the induction of the decidua microenvironment, to stimulate the synthesis of prostaglandin E2 (PGE2) and finally induce the differentiation of PMN-MDSCs. To summarize, decidua-derived IL6 facilitates the differentiation of PMN-MDSCs from neutrophils via the pSTAT3/FABP5/PGE2 pathway. Defects in the process may result in impaired differentiation and dysfunction of PMN-MDSCs in URPL. These findings enhance our understanding of the physiological mechanisms of immune tolerance in pregnancy and provide therapeutic options for URPL.

Prophylactic effect of tenofovir on viral reactivation in immunocompromised pregnant women living with hepatitis B virus.

The appropriate prophylaxis for hepatitis B virus reactivation (HBVr) during gestation for immunocompromised pregnant women has yet to be determined. The prophylactic efficacy and safety of tenofovir disoproxil fumarate (TDF) in hepatitis B surface antigen (HBsAg)-positive patients and the HBVr risk in hepatitis B core antibody (HBcAb)-positive patients during gestation were investigated. Eligible pregnant women were diagnosed with rheumatic diseases and were administered prednisone (≤10 mg daily) with permitted immunosuppressants at screening. HBsAg-positive participants were instructed to take TDF; those unwilling to take TDF were followed up as the control group. Propensity score matching was applied to control for differences in confounding factors between the HBcAb-positive and uninfected groups. Hepatopathy, maternal, pregnancy, and safety outcomes were documented as endpoints. A cohort of 1292 women was recruited from 2017 to 2020, including 58 HBsAg-positive patients (29 in each group). A total of 120 pairs in the HBcAb-positive and noninfection groups were analyzed. Among HBsAg-positive patients, 6 (20.7%) cases of hepatitis flare (hazard ratio [HR]: 7.44; 95% confidence interval [CI]: 1.50-36.89; p = 0.014) and 12 (41.4%) cases of HBVr (HR: 8.71; 95% CI: 2.80-27.17; p < 0.001) occurred in the control group, while 0 occurred in the TDF prophylaxis group. The HBV level at delivery was the lowest (1.6 log10 IU/ml) for those who received TDF during the pregestation period with a good safety profile. More adverse maternal outcomes were observed in the control group (odds ratio: 0.19, 95% CI: 0.05-0.77, p = 0.021), including one death from fulminant hepatitis and two cases of vertical transmission. No HBVr was recorded in HBcAb-positive participants. Among immunocompromised pregnant women, prophylactic TDF during pregestation was necessary for HBsAg-positive women, whereas regular monitoring was recommended for HBcAb-positive women.

Prognostic analysis of antibody typing and treatment for antiphospholipid syndrome-related recurrent spontaneous abortion.

OBJECTIVE: To determine the efficacy of antibody typing and treatment on live birth rate in Chinese patients with antiphospholipid syndrome (APS)-related recurrent spontaneous abortion (RSA). METHODS: A retrospective study analyzed 4542 Chinese patients who experienced spontaneous abortion, of whom 314 had APS (272 primary and 42 secondary). Type of antibodies was tested. Anticoagulant and anti-inflammatory treatments were adopted according to the titer and type of antibodies. The incidence of repeated abortion and placental dysfunction, gestational age, and mean weight of the fetuses were recorded. RESULTS: Among the patients with APS-related RSA, primary APS accounted for the largest proportion. The proportion of antibody classification was as follows: ß2-glycoprotein 1 (ß2GP1)-IgM (151, 48.08%), lupus anticoagulant (LAC) (36, 11.46%), anticardiolipin (aCL)-IgM (32, 10.19%), ß2GP1-IgM and aCL-IgM (29, 9.23%), and aCL-IgG (16, 5.09%). After treatment, the negative conversion of antibody, including ß2GP1-IgM and LAC, significantly improved pregnancy outcomes. There was no significant difference in pregnancy outcomes between the other antibody titers. CONCLUSION: The combination of anticoagulant and anti-inflammatory treatment led to a higher live birth rate in the treatment of APS-related RSA, highlighting the potential of antibody typing in providing clinical guidance for the treatment of APS-related RSA.

Low-dose aspirin treatment improves endometrial receptivity in the midluteal phase in unexplained recurrent implantation failure.

OBJECTIVE: To compare endometrial receptivity in patients with and without unexplained recurrent implantation failure (URIF) and the benefits of low-dose aspirin treatment in women with URIF. METHODS: A retrospective study was conducted at Ren Ji Hospital, Shanghai, from January 2014 to January 2017. Endometrial thickness, pulsatility index (PI), resistive index (RI), and systolic-to-diastolic ratio (S/D) values of endometrial and uterine perfusion were recorded and compared between women with and without URIF. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive accuracy of the risk of URIF. Ultrasonography examination was repeated after 2 months of treatment with low-dose aspirin. RESULTS: PI, RI, and S/D values for endometrial blood flow were significantly higher in URIF patients than the control group (P < 0.001). The predictive indexes were 0.833, 0.857, and 0.839, respectively. Differences between the groups for endometrial thickness and impedance of uterine perfusion were not significant (P > 0.05). After low-dose aspirin treatment, endometrial and uterine arterial blood flow resistance in URIF patients was significantly lower than before treatment (P < 0.05). CONCLUSION: URIF patients had inappropriate endometrial blood flow. Doppler parameters are promising for predicting women at high risk of URIF. Low-dose aspirin treatment can improve endometrial receptivity.

Low-dose aspirin improves blood perfusion of endometrium of unexplained recurrent biochemical pregnancy loss.

OBJECTIVE: To assess the differences in Doppler parameters of endometrial receptivity in unexplained recurrent biochemical pregnancy loss (URBPL) and the therapeutic effect of low-dose aspirin (LDA). METHODS: A retrospective study was conducted at Ren Ji Hospital, Shanghai, PR China, from January 2017 to January 2019. Doppler parameters of endometrium and uterus were recorded as the evaluation of the endometrial receptivity. Receiver operating characteristic (ROC) curve was managed to predict the risk of URBPL. Ultrasonography tests were repeated after 2 months of treatment with LDA. RESULTS: Biochemical pregnancies did not correlate with maternal age. The resistance of endometrial perfusion (pulsatility index, resistive index, and systolic-to-diastolic ratio) was significantly higher in URBPLs (P < 0.001) and had predictive values (0.739, 0.779, and 0.760, respectively). Endometrial thickness and impedance to uterine blood flow showed no statistically significant difference (P > 0.05). After treatment with LDA, patients with URBPL improved the blood perfusion of endometrium significantly (P < 0.01). CONCLUSION: There was no relation between BPL and maternal age. Patients with URBPL had inappropriate endometrial blood velocity. Doppler indices are capable of predicting the risk of URBPL. LDA exerts the therapeutic effect on improving blood perfusion of endometrium in URBPL.

Management of heparin resistance due to antithrombin deficiency in a Chinese pregnant woman: a case report.

Untreated individuals with antithrombin (AT) deficiency are at higher risk of thrombosis and adverse pregnancy outcomes. The present recommendations are mostly empirical for treating patients with AT deficiency during pregnancy because of the absence of guidelines. We report a rare case of heparin resistance due to AT deficiency in a pregnant 32-year-old Chinese woman. We also reviewed the English medical literature for AT deficiency and its association with thromboembolism and treatment. This patient suffered two early miscarriages because of thrombosis due to AT deficiency. The patient was administered the combination of adequate low molecular weight heparin with fresh frozen plasma and warfarin because of her heparin resistance. She delivered a healthy female newborn without any adverse effects of the anticoagulation therapy. Our findings suggest that the combination of adequate low molecular weight heparin with fresh frozen plasma and warfarin is effective for preventing thrombus during pregnancy.

Effect of low-molecular-weight heparins on anti-Xa peak levels and adverse reactions in Chinese patients with recurrent spontaneous abortion: a single-center, observational study.

OBJECTIVE: To compare three commonly used low-molecular-weight heparins (LWMHs) in the treatment of recurrent spontaneous abortion (RSA) by evaluating the anti-Xa peak levels and adverse reactions. METHODS: In this single-center, observational study, we enrolled 310 patients with RSA in whom anti-Xa levels were measured during pregnancy. Patients were divided into three groups according to the LMWH they used: the nadroparin group, enoxaparin group and dalteparin group. We compared the peak anti-Xa levels and the coagulation status of each group, and analyzed the incidence of adverse reactions, including local allergy, liver and renal dysfunction, and the impact on platelet. RESULTS: Patients in the enoxaparin group had a higher anti-Xa peak level than those in the nadroparin group (0.80 ± 0.22 IU/ml vs. 0.61 ± 0.24 IU/ml; P <  0.0001), although most patients in the three groups reached the target concentration of anti-Xa. Furthermore, patients in the enoxaparin group had a more stable anti-Xa levels during pregnancy. In addition, patients in the nadroparin group had a higher rate of local allergy than those in the enoxaparin group (60.5% vs. 42.5%; P = 0.004) and those in the dalteparin group (60.5% vs. 33.3%; P = 0.002). Further examination by the type of local allergy indicated a dramatic difference in pruritus and induration between the nadroparin group and the other two groups. No difference was found in the incidence of liver and renal dysfunction and thrombocytopenia. CONCLUSION: Compared with nadroparin and daltepatin, enoxaparin showed a better performance regarding anti-Xa levels and the incidence of adverse reactions in the treatment of RSA.

Effect of Welding Peak Temperature on Microstructure and Impact Toughness of Heat-Affected Zone of Q690 High Strength Bridge Steel.

The effect of peak temperature (TP) on the microstructure and impact toughness of the welding heat-affected zone (HAZ) of Q690 high-strength bridge steel was studied using a Gleeble-3500 thermal simulation testing machine. The results show that the microstructure of the inter critical heat-affected zone (ICHAZ) was ferrite and bainite. The microstructure of fine grain heat-affected zone (FGHAZ) and coarse grain heat-affected zone (CGHAZ) was lath bainite (LB) LB, lath martensite (LM), and granular bainite (GB), but the microstructure of FGHAZ was finer. With the increase in peak temperature, the content of LB and GB decreased, the content of LM increased, and the lath bundles of LM and LB gradually became coarser. With the increase in peak temperature, the grain size of the original austenite increased significantly, and the impact toughness decreased significantly. When the peak temperature was 800 °C, the toughness was the best. For CGHAZ, the peak temperature should be less than 1200 °C to avoid excessive growth of grain and reduction of mechanical property.

Study on Kinetics of Transformation in Medium Carbon Steel Bainite at Different Isothermal Temperatures.

Ultra-fine carbide-free bainitic (UCFB) steel, also known as nano-bainite (NB) steel, is composed of bainitic ferrite laths with nanoscale thickness and carbon-rich film-like retained austenite located between laths. The bainite transformation kinetic model can accurately describe the bainite transformation kinetics in conventional austempering (CA) processes based on the shear mechanism combined with the dilatometer test. UCFB steels with medium and high carbon composition are designed in this work to systematically study the transformation kinetics of bainite, and the evolution of its microstructure and properties, and reveal the influence of heat treatment processes on the microstructure and properties the UCFB steels. The results show that the activation energy for BF nucleation decreases during the CA process and isothermal transformation temperature decreases. The bainite transformation is first nucleated at the grain boundaries, and then nucleated at the newly formed bainitic ferrite/austenite interface.