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Background: Depression and anxiety symptoms among medical students are often a concern. The Patient Health Questionnaire-Four (PHQ-4), an important tool for depression and anxiety screening, is commonly used and easy to administer. This study aimed to assess and update the longitudinal measurement invariance and psychometric properties of the simplified Chinese version. Methods: A three-wave longitudinal survey was conducted among healthcare students using the PHQ-4. Structural validity was based on one-factor, two-factor, and second-order factor models, construct validity was based on the Self-Rated Health Questionnaire (SRHQ), Sleep Quality Questionnaire (SQQ), and Rosenberg Self-Esteem Scale (RSES), and longitudinal measurement invariance (LMI), internal consistency, and test–retest reliability were based on structural consistency across three time points. Results: The results of the confirmatory factor analysis indicated that two-factor model was the best fit, and LMI was supported at three time points. Inter-factor, factor-total, and construct validity correlations of the PHQ-4 were acceptable. Additionally, Cronbach's alpha, McDonald's omega, and the intraclass correlation coefficient demonstrated acceptable/moderate to excellent reliability of the PHQ-4. Conclusions: This study adds new longitudinal evidence that the Chinese version of the PHQ-4 has promising LMI and psychometric properties. Such data lends confidence to the routine and the expanded use of the PHQ-4 for routine screening of depression and anxiety in Chinese healthcare students. [ABSTRACT FROM AUTHOR]

Aconitine is a crucial toxic component in Chinese herbal medicines such as Aconitum, Aconitum coreanum, and Aconitum soongaricum. The poisoning symptoms of the central nervous system and cardiovascular system caused by it are relatively common in China, and there are many studies on cardiovascular system diseases caused by aconitine. However, the specific mechanism of neurotoxicity induced by aconitine is still unclear. This study explored the effect and mechanism of mitochondrial calcium uniporter on mitochondrial energy metabolism disorder in aconitine poisoning hippocampal neurons. The results showed that after treatment with 400μmol/L aconitine, mitochondrial energy metabolism was abnormal in rat hippocampal neuron cells, the expression of MCU in mitochondria was up-regulated, calcium overload in mitochondria, ATP production decreased, and mitochondrial membrane potential Changes, increased expression of the apoptosis gene Cleaved-Caspase-3. After treatment with the MCU agonist spermine, mitochondrial energy metabolism was significantly abnormal, and cell apoptosis was increased considerably. However, pretreatment with calcium ion channel inhibitor Ruthenium Red (RR) effectively promoted the generation of ATP, thereby improving mitochondrial energy metabolism disorders and reducing cell apoptosis. These results suggest that aconitine induces mitochondrial energy metabolism dysfunction in hippocampal neurons, which may be related to the increased expression of MCU. [Display omitted] • Aconitine affects mitochondrial energy metabolism by inducing mitochondrial calcium overload and inhibiting ATP production. • Aconitine induces mitochondrial energy metabolism disorder by enhancing MCU signaling pathway. • Aconitine increases the apoptosis of HT22 cells by enhancing the MCU signaling pathway. [ABSTRACT FROM AUTHOR]

Background: Kidney dysfunction frequently occurred after orthotopic liver transplantation (OLT). Chronic renal disease (CKD) is a complicated problem and is associated with increased mortality. The aim of this study is to find the risk factors for the incidence of CKD at 1 year after OLT in China. Methods: From January 2017 to December 2017, we retrospectively assessed 280 recipients in our single center. Chronic renal failure was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 for 3 months, regardless of the presence or absence of structural kidney damage. Cox proportional hazard model was used to identify the factors to the incidence of CKD after liver transplantations. Kaplan–Meier plots with log-rank test were presented to evaluate patient survival time in those with and without CKD. Results: With a median follow-up of 17.4 months, 48 patients developed CKD after liver transplantations, representing 17.1% of the cohort. The cox-regression model showed that recipients age (HR = 1.097, P < 0.01), AKI (HR = 1.542, P < 0.01) and MELD score (HR = 1.077, P < 0.01) were significantly associated with the development of post-transplant CKD at 1 year. Recipient survival at 1 year was significantly worse in recipients with CKD compared to those without CKD (P < 0.01) after adjustment by age and gender. Conclusion: Our findings suggested that age, AKI and MELD score were associated with the incidence of CKD 1 year after OLT in a Chinese cohort. Recipients with CKD were associated with worse survival. [ABSTRACT FROM AUTHOR]

• Design a SIR N model for capturing spatiotemporal characteristics of spreading risks. • Reveal the relation between spreading risk and the network topology of human movement. • Construct a resilient strategy to control and contain the spreading risk of contagious diseases. Spreading risks of contagious diseases have threatened human lives and disrupted the global economy. Protecting humanity from contagious diseases, such as coronavirus, is a critical task of our time. Unlike other types of risks, the spreading of contagious diseases could be enhanced by human movements. As human movements are inherently dynamic and heterogenous, it brings challenges in analyzing the spreading on a large scale. Here, we combine network theory and epidemiology models to construct a SIR N model for capturing spatiotemporal characteristics of spreading risks. With mean-field theory and Lyapunov theorem, our model reveals the relation between spreading risk and the network topology of human movement. The model allows us to construct a resilient strategy to control and contain the risk. The approach is tested retrospectively with coronavirus cases in China and the United States. Our results adequately interpret the historical trends and justify the resilience of nations' strategies. The model demonstrates a pattern of resilience in dynamic networks, which could shed light on handling contagious risks. [ABSTRACT FROM AUTHOR]

To identify sources of heavy metal(loid) (HM) contamination in agricultural soils of Huzhou, surface soil samples were sampled from 89 different agricultural regions in 2012. Concentrations of heavy metal(loid)s, along with pH, total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM), were determined. Ecological risk was then assessed using a modified Hakanson ecological risk index, and the sources of contamination were determined using principal component analysis (PCA). Mean concentrations of heavy metal(loid)s were 10.26, 23.21, 83.75, 22.81, 0.25, 61.86, 33.03, and 0.15 mg kg−1for As, Cu, Zn, Ni, Cd, Cr, Pb, and Hg, respectively. Cu, Zn, Ni, Cr, Cd, Hg, and Pb were correlated positively with TP and there were obvious positive correlations among Cu, Zn, Ni, Cr, and Cd. Risk index (RI) values varied from 39 to 1246 with a mean value of 137. Enrichment of Pb, Zn, Cu, and especially Cd can be attributed to excessive use of nitrogen and phosphorus fertilizers containing heavy metals, as well to surface irrigation and natural soil formation. While the ecological risk of most agricultural soils in Huzhou is low, it is recommended that the use of phosphate and nitrogen fertilizers be restricted and production technology be improved to reduce the heavy metal(loid) concentrations. Results suggest that the Chinese environmental quality standard for soil should be revised to better address heavy metal(loid) contamination. [ABSTRACT FROM AUTHOR]

The carbonate chemistry in river-dominated marginal seas is highly heterogeneous, and there is ongoing debate regarding the definition of atmospheric CO 2 source or sink. On this basis, we investigated the carbonate chemistry and air-sea CO 2 fluxes in a hotspot estuarine area: the Changjiang Estuary during winter and summer. The spatial characteristics of the carbonate system were influenced by water mixing of three end-members in winter, including the Changjiang freshwater with low total alkalinity (TA) concentration, the less saline Yellow Sea Surface Water with high TA, and the saline East China Sea (ECS) offshore water with moderate TA. While in summer with increased river discharge, the carbonate system was regulated by simplified two end-member mixing between the Changjiang freshwater and the ECS offshore water. By performing the end-member mixing model on DIC variations in the river plume region, significant biological addition of DIC was found in winter with an estimation of −120 ± 113 μmol kg−1 caused by wintertime organic matter remineralization from terrestrial source. While this biological addition of DIC shifted to DIC removal due to biological production in summer supported by the increased nutrient loading from Changjiang River. The p CO 2 dynamics in the river plume and the ECS offshore were both subjected to physical mixing of freshwater and seawater, whether in winter and summer. In the inner estuary without horizontal mixing, the p CO 2 dynamics were mainly influenced by biological uptake in winter and temperature in summer. The inner estuary, the river plume, and the ECS offshore were sources of atmospheric CO 2 , with their contributions varying seasonally. The Changjiang runoff enhanced the inner estuary's role as a CO 2 source in summer, while intensive biological uptake reduced the river plume's contribution. [Display omitted] • Mixing of end-members drove the variation of carbonate system among seasons. • Winter biological DIC addition and summer DIC removal occurred in the rive plume. • The important role of freshwater inputs in CO 2 emissions from the Changjiang estuary. [ABSTRACT FROM AUTHOR]

Background and objective: Atrioesophageal fistula (AEF) is a rare but devastating complication with high mortality post atrial fibrillation (AF) ablation. The purpose of current study was to determine the epidemiology, clinical features, pathogenesis, and management of AEF after AF ablation. Methods and results: Patients with diagnosed AEF were included and retrospectively analyzed according to the registry of 11 centers in China from January 2010 to December 2019. A total of 16 AEF cases were identified from 44 794 patients who received a left atrial ablation procedure (0.035% per procedure). The interval from procedure to clinical onset of AEF averaged 18.3 days (3‐39 days). The fever ranked the most common symptom, occurred in 14 of the 16 cases, followed by neurological deficits (n = 11), chest pain (n = 5), and hematemesis (n = 4). Patients undergoing surgical repair had a better prognosis compared to those receiving nonsurgical management ([4 of 8] 50.0% vs [8 of 8] 100%, P <.05) with an overall mortality rate of 75.0%. Conclusion: AEF is highly characterized by varied manifestations. Early diagnosis and urgent surgical repair are vital to those patients and associated with improved survival rates. [ABSTRACT FROM AUTHOR]

Background: Data on management of maternal arrhythmia among Chinese were limited. Radiofrequency catheter ablation (RFCA) proved to be a reliable treatment choice for sustained tachyarrhythmia but it has rarely been performed during pregnancy due to radiation exposure. Objective: To investigate the incidence of idiopathic sustained maternal arrhythmia and the feasibility of RFCA in the pregnant patients without fluoroscopy. Methods: From January of 2015 to December of 2018, the medical records on pregnancy‐related admissions in Beijing Anzhen Hospital (Beijing, China) were retrospectively analyzed. Patients who had sustained tachyarrhythmia episodes without structural heart disease were identified. Catheter ablation was performed in those with drug resistant and severely frequent tachyarrhythmia under the guidance of electroanatomical mapping system and intracardiac echocardiography catheter (ICE), if appropriate. Results: During the study period, 12 584 consecutive pregnant women were admitted for pregnancy‐related reasons, 156 (1.2%) of them were identified as sustained maternal tachyarrhythmia. Twenty‐eight patients (age 21‐37 years) received catheter ablation because the arrhythmias were drug resistant and severely frequent. The RFCA was successfully performed in all patients with zero fluoroscopy after 72.4 ± 24.7 min. Transseptal puncture was performed in 11 patients under the guidance of ICE. In a median of 37 (interquartile range [IQR]: 34‐39) weeks' pregnancy, 28 healthy fetuses were delivered. No cardiac‐related adverse event occurred during delivery. During later follow‐up, all patients were free of arrhythmia, and all the infants were well developed. Conclusion: Sustained maternal tachyarrhythmia is not uncommon in the clinical practice. To those with drug resistant and severely frequent arrhythmia, RFCA with zero fluoroscopy could be safely performed with acceptable efficacy. [ABSTRACT FROM AUTHOR]

We reported genomic profiling, clinical characterization, and treatment efficacy of available therapeutic agents in the largest multicenter cohort of patients with FH-deficient renal cell carcinoma (RCC) to date. First-line combination therapy with an immune checkpoint inhibitor plus a tyrosine kinase inhibitor (ICI/TKI) was associated with more favorable outcomes in comparison to other first-line therapies, including bevacizumab plus erlotinib and TKI monotherapy, suggesting ICI/TKI combinations could be promising in advanced FH-deficient RCC. Further randomized studies in larger data sets are needed for independent validation of these findings. FH-deficient renal cell carcinoma (RCC) is a rare and exceptionally aggressive RCC subtype. There is currently limited understanding of the molecular alterations, pathogenesis, survival outcomes, and systemic therapy efficacy for this cancer. To perform a retrospective multicenter analysis of molecular profiling and clinical outcomes for patients with FH-deficient RCC, with an emphasis on treatment response to first-line immune checkpoint inhibitor plus tyrosine kinase inhibitor (ICI/TKI) versus bevacizumab plus erlotinib (Bev/Erlo) combination therapy in patients with advanced disease. The study included 77 cases of FH-deficient RCC from 15 centers across China. Clinical characteristics, molecular correlates, 18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging, and treatment outcomes were analyzed. A total of 77 patients were identified, including 70 cases with a germline FH alteration (hereditary leiomyomatosis RCC syndrome [HLRCC]-associated RCC) and seven patients with somatic FH loss. Recurrent pathogenic alterations were found in NF2 (six/57, 11%), CDH1 (six/57, 11%), PIK3CA (six/57, 11%), and TP53 (five/57, 8.8%). Sixty-seven patients were evaluable for response to first-line systemic therapy with Bev/Erlo (n = 12), TKI monotherapy (n = 29), or ICI/TKI (n = 26). ICI/TKI combination therapy was associated with more favorable overall survival on systemic treatment (hazard ratio [HR] 0.19, 95% confidence interval [CI] 0.04–0.90) and progression-free survival on first-line therapy (HR 0.22, 95% CI 0.07–0.71) compared to Bev/Erlo combination therapy. The main limitation is the retrospective study design. We described the genomic characteristics of FH-deficient RCC in an Asian population and observed a favorable response to ICI/TKI combinational therapy among patients with advanced disease. This real-world study provides evidence supporting the antitumour activity of combining molecular targeted therapy plus immunotherapy for kidney cancer deficient in fumarate hydratase. Further studies are needed to investigate the efficacy of this combination strategy in this rare cancer. [ABSTRACT FROM AUTHOR]

The outbreak of the COVID-19 pandemic has caused negative impacts on people's lifestyles, as well as considerable indirect social impacts, which has even overshadowed the direct impact of virus infection itself. This study is aimed at examining the changes in physical health-related indexes of Chinese college students before and after the COVID-19 lockdown. The data of this study are from the National Physical Health Testing Program, covering 43 college students (male: 22) from a class of a Chinese university. Paired t -tests were performed on the physical health test data separately collected in November 2019 before the COVID-19 pandemic and October 2020 after the COVID-19 lockdown was lifted. As shown by the test results, compared to the prelockdown data, college students had an increased body mass index (BMI) (0.43 (SD 0.94) P = 0.004), decreased vital capacity (VC) (-128.98 (SD 310.13) ml P = 0.009), and lowered performance in the 800/1000 m endurance (-6.21 (SD 8.81) points P < 0.001) and standing long jump tests (-2.44 (SD 7.37) points P = 0.036) after the lockdown, and the differences in these regards all were significant. In addition, for the students in the overweight/obese group, their pre- and postlockdown physical fitness test results were found to have no statistically significant difference (P > 0.05), but the students in the control group showed a significantly increased BMI, as well as significantly decreased vital capacity and performance in the 800/1000 m endurance and standing long jump tests (P < 0.05). The findings of this study are expected to help government departments and policymakers better understand the impacts of school closures and online learning on the physical health of adolescents, while providing a basis for the formulation of measures that are aimed at reversing adolescents' physical health decline. [ABSTRACT FROM AUTHOR]

Background: Drug-resistant tuberculosis (TB) continues to be a public health threat. There are few studies on transmission and genotyping of MDR-TB family households in China. This study aimed to investigate transmission of multidrug-resistant tuberculosis (MDR-TB) within family households by deletion-targeted multiplex polymerase chain reaction (DTM-PCR), mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) genotyping.Methods: Among 993 MDR-TB patients registered from Wuhan Institute for Tuberculosis Control, drug resistance and the time interval between the index patients and secondary patients were analyzed in 49 MDR-TB patients from 23 families, in which 22 MDR-TB strains from 11 families who had matched strains were genotyped by DTM-PCR and standard 24-loci MIRU-VNTR genotyping method.Results: The time interval between the index patients and the secondary patients ranged from half a month to 110 months. Thirteen secondary patients developed active MDR-TB within two years and accounted for 50% (13/26) of all secondary patients. Among eleven pairs of MDR-TB families, six pairs had identical genotypes, the cluster rate was 54.5% (12/22); three pairs had a single MIRU-VNTR locus variation. If a single MIRU-VNTR locus variation was tolerated in the cluster definition, the cluster rate raised to 81.8% (18/22).Conclusions: The family households of MDR-TB patients are at risk for infection of MDR-TB. To reduce transmission, MDR-TB patients should be diagnosed earlier and promptly treated in an effective manner, meanwhile, the close family contacts should be screened for TB infection. [ABSTRACT FROM AUTHOR]

Objective: To investigate theoptimal idarucizumab (dabigatran antagonist) usage strategy for patients with acute pericardial tamponade receiving uninterrupted dabigatran during catheter ablation for atrial fibrillation (AF). Methods: Ten patients presenting acute pericardial tamponade while receiving uninterrupted dabigatran during catheter ablation for AF in Beijing Anzhen Hospital from January 2019 to July 2020 were enrolled and retrospectively analyzed. A "wait and see" strategy of idarucizumab was carried out for all patients; in brief, idarucizumab was applied following pericardiocentesis, comprehensive evaluation of bleeding and hemostasis. Results: There were five males, five paroxysmal AF, and the average age of the patients was 64.0 ± 9.8 years. Among the 10 patients, four were treated with dabigatran 110 mg, six were treated with dabigatran 150 mg, and one was simultaneously given clopidogrel. The average time from pericardial tamponade to the last dose of dabigatran was 8.2 ± 3.4 h. All patients underwent pericardiocentesis successfully, and the average drainage volume was 322.5 ml (220.0 ± 935.0 ml). For reversal anticoagulation, six patients received protamine, and five patients received idarucizumab. Of the five patients who were treated with idarucizumab, four presented exact hemostasis, except for one patient who underwent continuous drainage and finally received surgery repair. The average time to restart anticoagulation was 1.1 ± 0.3 days after the procedure, and no rebleeding, embolism or deaths were observed. Conclusion: The "wait and see" strategy of idarucizumab for acute pericardial tamponade during the perioperative period of catheter ablation for AF may be safe and feasible. [ABSTRACT FROM AUTHOR]

Little is known about Epstein-Barr virus (EBV)-associated intrahepatic cholangiocarcinoma (EBVaICC) because of its rarity. We aimed to comprehensively investigate the clinicopathology, tumor immune microenvironment (TIME) and genomic landscape of this entity in southern China. We evaluated 303 intrahepatic cholangiocarcinomas (ICCs) using in situ hybridization for EBV. We compared clinicopathological parameters between EBVaICC and nonEBVaICC, and we analyzed EBV infection status, tumor-infiltrating lymphocytes (TILs) and genomic features of EBVaICC by immunohistochemistry, double staining, nested PCR, multiplex immunofluorescence staining, fluorescence in situ hybridization and whole-exome sequencing. EBVaICC accounted for 6.6% of ICCs and was associated with EBV latency type I infection and clonal EBV isolates. Patients with EBVaICC were more often female and younger, with solitary tumors, higher HBV infection rates and less frequent cirrhosis; the lymphoepithelioma-like (LEL) subtype was more common in EBVaICC. EBVaICC was associated with a significantly larger TIME component than nonEBVaICC. The LEL subtype of EBVaICC – associated with a significantly increased density and proportion of CD20+ B cells and CD8+ T cells – was associated with significantly higher 2-year survival rates than conventional EBVaICC and nonEBVaICC. Both PD-1 and PD-L1 in TILs, and PD-L1 in tumor cells, were overexpressed in EBVaICC. High PD-L1 expression in tumor cells and high CD8+ TIL densities were significantly more common in EBVaICC than in nonEBVaICC. Seven genes (MUC4 , DNAH1, GLI2 , LIPE , MYH7 , RP11-766F14.2 and WDR36) were mutated in at least 3 patients. EBVaICC had a different mutational pattern to liver fluke-associated cholangiocarcinoma and HBV-associated ICC. EBVaICC, as a subset of ICC, has unique etiological, clinicopathological and genetic characteristics, with a significantly larger TIME component. Paradoxically, patients with EBVaICC could be candidates for immune checkpoint therapy. Epstein-Barr virus (EBV) is associated with a subtype of intrahepatic cholangiocarcinoma, with unique clinicopathological and genetic characteristics. The tumor immune microenvironment is also different in this tumor subtype and patients with EBV-associated intrahepatic cholangiocarcinoma may respond well to immune checkpoint inhibitors. [Display omitted] • EBVaICC accounted for 6.6% of ICCs and was associated with EBV latency type I infection and clonal EBV isolates. • EBVaICChas unique characteristics related to etiology, clinicopathology and molecular genetics. • Both PD-1 and PD-L1 in tumor-infiltrating lymphocytes and PD-L1 in tumor cells are overexpressed in EBVaICC. • Patients with EBVaICC may respond well to immune checkpoint inhibitors. • The lymphoepithelioma-like subtype of EBVaICC is related to favorable survival. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is common in abdominal solid organ transplant recipients and a cause of morbidity and mortality in this population. However, the outcomes of catheter ablation (CA) in transplant recipients with AF remain unclear. This study aimed to elucidate the outcomes of CA in renal and hepatic transplant recipients. Methods and Results: Between 2015 and 2019, 14 transplant recipients (nine with kidney transplantation and five with liver transplantation) were enrolled from among 10,741 AF patients and underwent CA at Anzhen Hospital. Another 56 patients matched by age, sex, and AF type were selected as the control group (four controls for each transplant recipient). During a mean follow‐up of 30.0 ± 13.3 months after the initial procedure, 10 (71.4%) of the transplant patients, compared to 41 (73.2%) of the control patients, remained free from AF recurrence (p = 1.000). A repeated procedure was performed in one transplant patient and in six control subjects. Consequently, 11 (78.6%) of the transplant patients, compared to 46 (82.1%) of controls, were in sinus rhythm after the repeated ablation (p =.715). Notably, Kaplan–Meier analysis did not demonstrate any significant differences in the atrial arrhythmia‐free rate after the initial and repeated procedure between the two groups. Vascular complications were identified in one transplant patient and two control subjects, while no life‐threatening complications were observed in either group. There was no transient allograft dysfunction in transplant recipients after CA. Conclusion: CA is safe and effective in abdominal solid transplant recipients, and maybe an optimal therapeutic strategy for this group. [ABSTRACT FROM AUTHOR]

Objective: To investigate the feasibility and safety of wire‐guided pericardial access without contrast. Methods: From January 2014 to February 2019, patients who received epicardial mapping and ablation of ventricular tachycardia in the Beijing Anzhen Hospital were entered into the current study. They were divided into contrast‐guided access group or wire‐guided access group according to the pericardial puncture technique used. The baseline variables, procedure parameters, complications were collected and compared. Results: During the study period, a consecutive of 73 patients received epicardial access. The initial 32 patients received contrast‐guided puncture with success achieved in 30 patients, the remaining 41 patients underwent wire‐guided puncture with success achieved in 40 patients (30/32 and 40/41, P =.581). Fluoroscopy time (4.45 ± 0.52 and 4.38 ± 0.46 minutes, P =.891) and access time (5.14 ± 0.58 and 5.34 ± 0.50 minutes, P =.657) were comparable between the two groups. Inadvertent right ventricular puncture occurred more commonly in the contrast‐guided group (5/32 and 1/41, P =.038). Though more pericardial effusions (2/32 and 1/41, P =.575), tamponade (2/32 and 1/41, P =.575), and surgical repair (1/32 and 0/41, P =.432) occurred in the contrast‐guided group, they reached no statistical difference. Conclusion: Wire‐guided pericardial puncture exhibits better safety and similar success rates to contrast‐guided technique with a trend towards less complications. [ABSTRACT FROM AUTHOR]

In southern China, the silver pheasant (Lophura nycthemera) is a widespread species due to complex topography and sufficient habitats and food resources. We investigated the microsatellite and mitochondrial DNA control region sequence of 115 individuals from 7 locations in China to study population dynamics of the silver pheasant during the Pleistocene. The neutrality test and mismatch distribution analyses showed that population expansion began in the interglacial period (76,053 years ago), and the latest common ancestor appeared approximately 970,300 years ago. Most populations exhibited a high level of genetic diversity as well as gene flow. Results of phylogenetic trees and network and STRUCTURE analyses provided insights into the weak population structure of this species. The weak phylogeographic and complex historical expansion population of the silver pheasant during the interglacial period could probably be related to its complex topography and the sufficient amount of suitable habitats and food resources in southern China. [ABSTRACT FROM AUTHOR]

Otolith microchemistry allows reconstructing the life histories and understanding the habitat uses of fishes. In this study, the relationship of Sr:Ca ratios and salinity from various environments, i.e. freshwater of the Min River, brackish water of the estuary and seawater of the coastal marine (Fujian Province, China), were built, revealing a significant positive correlation (p < 0.05). A total of 29 adult Chinese gizzard shad Clupanodon thrissa were collected in 2017–2020 for otolith (sagitta) microchemistry. The specimens were only collected from the Min River and the estuary, with none from the coastal marine regions despite same efforts input. The results confirmed that all 29 individuals hatched in either freshwater or brackish water. Four contingents were recognized based on various life histories, including three migratory contingents (Types A-C, N = 26) and one freshwater residential contingent (Type D, N = 3). The three migratory contingents were the freshwater-brackish migratory contingent (Type A, N = 12), the brackish-freshwater migratory contingent (Type B, N = 10) and the brackish-variable migratory contingent (Type C, N = 4). Only a small proportion of C. thrissa individuals (N = 4) migrated to seawater habitat during the first few months of lifetime, and most individuals preferred freshwater habitat during the first year. There were no significant differences between life history pattern and sex (p = 1.00), and between the number of fish migratory times crossing different habitats and age (p = 0.84). The lower reaches of the Min River and the estuary are confirmed to be important spawning grounds for C. thrissa , based on otolith microchemistry of this study and gonad histology of a previous examination. The findings have significant implications for the Min River and the estuary protection and fishery stock management. [ABSTRACT FROM AUTHOR]

Background: Multiple pregnancies are one of the major safety concerns of in vitro fertilization (IVF) due to the increased risk of maternal and neonatal complications. Single embryo transfer is the most effective way to reduce the risk of multiple pregnancies. Selection of the embryo and optimization of the implantation environment are crucial to retain the success rate when the number of transferred embryos is diminished. Fresh embryo transfer with supra-physiological levels of hormones has been suggested to have an adverse effect on implantation. Elective frozen embryo transfer has been suggested to result in a higher rate of live birth than fresh embryo transfer. However, there is still a lack of evidence from randomized clinical trials comparing the efficacy and safety between frozen and fresh single blastocyst transfers.Methods/design: We are conducting a randomized controlled trial in women aged 20-35 undergoing their first cycle of IVF with or without intracytoplasmic sperm injection. After ovarian stimulation with a gonadotropin-releasing hormone antagonist protocol, women who obtain four or more embryos on day 3 of the embryo culture are randomized into two parallel groups: a single fresh blastocyst transfer group and a single frozen blastocyst transfer group (all blastocysts vitrified and a deferred frozen blastocyst transfer). The primary outcome is singleton live birth.Discussion: The results of this study will provide evidence for the efficacy and safety of the strategy of elective frozen single blastocyst transfer in women with a good prognosis.Trial Registration: Chinese Clinical Trial Registry, ChiCTR-IOR-14005405 . Registered on 30 Oct 2014. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether the common variant rs2305957 spanning PLK4 (Polo-like kinase 4) confers risk to embryo development in Northern Chinese Han (CHN) women.Design: Genetic association study.Setting: University hospital.Patient(s): A total of 2,015 infertile women who underwent in vitro fertilization (IVF), 530 women with early recurrent miscarriage (ERM), and 600 fertile control women in the CHN population.Intervention(s): Genotyping of rs2305957 was performed by means of high-resolution melting analysis.Main Outcome Measure(s): Blastocyst formation, implantation, early miscarriage, and live birth rates in infertile women; genotype distribution at rs2305957 in ERM case and control subjects.Result(s): In the first cohort of this study, infertile women with AA genotype had a lower blastocyst formation rate than those with AG or GG genotype. No significant differences were observed in implantation rate, early miscarriage rate, or live birth rate among AA, AG, and GG subgroups. In the second cohort, common variant rs2305957 was related to ERM. Genotype frequency differences were also significant in both additive model and dominant model.Conclusion(s): Common variant rs2305957 is associated with blastocyst formation and ERM in CHN women. Further investigations of PLK4 gene during embryo development could be worthwhile. [ABSTRACT FROM AUTHOR]

Computerized ionospheric tomography (CIT) technique allows reconstructing the 3-dimensional and even 4-dimensional state of the ionosphere in terms of electron content. It is typically denoted as an inverse problem. Due to the unevenly distributed measurements collected from ground receivers, together with limited cut-off elevation angle and density of observations, the normal matrix of the inverse problem becomes sparse, which makes it difficult to solve and potentially unstable. The main methods to resolve the problem are the constraint algorithms during the process of the electron density inversion. A new approach is proposed for CIT that aims to mitigate the ill-posed problem and improve the precision of ionospheric electron density (IED) resolution by using constrained least squares. In this method, a new scheme of constructing parameter weight matrices in both horizontal and vertical directions is designed using the correlation of IED among those neighboring voxels, which helps to add the information needed in CIT, and the ill-posed problem is efficiently resolved. The accuracy and feasibility of the additional constraints in CIT algorithms are verified by numerical simulation tests. Finally, this newly developed method of constrained least squares is used to effectively perform the tomographic reconstruction of IED distribution over southeast China. [ABSTRACT FROM AUTHOR]