Theoretical investigation of the scanning tunneling microscopy of Majorana bound states in topological superconductor vortices.

Scanning tunneling microscopy (STM) is an indispensable tool in detecting Majorana bound states (MBSs) in vortices of topological superconductors. By reducing the computational complexity via non-uniform grids, we systematically study the tunnel coupling as well as the temperature dependence of the differential conductance of MBSs in two dimensional devices. Numerical results show that the conductance peak approaches the quantized value 2e 2/h in strong coupling limit at low temperatures which are characteristic features of MBSs. More interestingly, a conductance local minimum in the spatially scanning is observed when the STM tip is placed at the vortex center. The dip structure can be enhanced with increased temperature or enlarged vortex size. We ascribe this observation to the sensitivity of the Andreev reflection processes of carriers at the vortex center where the thermal energy could be comparable to the vanishing pair potential. We also investigate the STM of two-vortex systems where the hybridization of the vortices can lead to oscillatory behavior of the state energy. With small inter-vortex distances, the original MBSs in vortices can merge into topologically trivial states and the conductance peak can be significantly suppressed.

Uptake of referrals for women with positive perinatal depression screening results and the effectiveness of interventions to increase uptake: a systematic review and meta-analysis.

AIMS: Perinatal depression threatens the health of maternal women and their offspring. Although screening programs for perinatal depression exist, non-uptake of referral to further mental health care after screening reduces the utility of these programs. Uptake rates among women with positive screening varied widely across studies and little is known about how to improve the uptake rate. This study aimed to systematically review the available evidence on uptake rates, estimate the pooled rate, identify interventions to improve uptake of referral and explore the effectiveness of those interventions. METHODS: This systematic review has been registered in PROSPERO (registration number: CRD42019138095). We searched Pubmed, Web of Science, Cochrane Library, Ovid, Embase, CNKI, Wanfang Database and VIP Databases from database inception to January 13, 2019 and scanned reference lists of relevant researches for studies published in English or Chinese. Studies providing information on uptake rate and/or effectiveness of interventions on uptake of referral were eligible for inclusion. Studies were excluded if they did not report the details of the referral process or did not provide exact uptake rate. Data provided by observational studies and quasi-experimental studies were used to estimate the pooled uptake rate through meta-analysis. We also performed meta-regression and subgroup analyses to explore the potential source of heterogeneity. To evaluate the effectiveness of interventions, we conducted descriptive analyses instead of meta-analyses since there was only one randomised controlled trial (RCT). RESULTS: Of 2302 records identified, 41 studies were eligible for inclusion, including 39 observational studies (n = 9337), one quasi-experimental study (n = 43) and one RCT (n = 555). All but two studies were conducted in high-income countries. The uptake rates reported by included studies varied widely and the pooled uptake rate of referral was 43% (95% confidence intervals [CI] 35-50%) by a random-effect model. Meta-regression and subgroup analyses both showed that referral to on-site assessment or treatment (60%, 95% CI 51-69%) had a significantly higher uptake rate than referral to mental health service (32%, 95% CI 23-41%) (odds ratio 1.31, 95% CI 1.13-1.52). The included RCT showed that the referral intervention significantly improved the uptake rate (p ＜ 0.01). CONCLUSIONS: Almost three-fifths of women with positive screening results do not take up the referral offers after perinatal depression screening. Referral to on-site assessment and treatment may improve uptake of referral, but the quality of evidence on interventions to increase uptake was weak. More robust studies are needed, especially in low-and middle-income countries.

Health system responsiveness in Hong Kong: a comparison between South Asian and Chinese patients' experiences.

OBJECTIVES: Health system responsiveness is related to the way and the environment in which individuals are treated during their health system interaction. Generally, patients who are members of ethnic minority (EM) groups encounter more challenges in receiving healthcare services and bear a disproportionate burden of diseases compared with most counterparts. We aimed to compare the health system responsiveness perceived by South Asian (SA) EM people with that of local Chinese people in Hong Kong. STUDY DESIGN: The cross-sectional survey sample comprised 575 SA and 494 Chinese individuals. The health system responsiveness module of the World Health Survey 2002 was used for data collection. METHODS: We used propensity score weighting method to balance the two groups. Simple and multiple regressions were used to compare the perceived outpatient and inpatient health system responsiveness between SA and Chinese participants, respectively, before and after adjustment for demographics. All estimates were accompanied by 95% confidence intervals, and two-sided tests were conducted with significance concluded by a P value < 0∙05. RESULTS: Compared with the Chinese participants, the SA participants reported generally lower health system responsiveness for outpatient and inpatient services. The top three mean score difference (SA-Chinese) for outpatient care included autonomy (-0.78, P < 0.001), communication (-0.67, P < 0.001), and choice (-0.53, P < 0.001), and the top three mean score difference for inpatient care included communication (-0.90, P < 0.001), autonomy (-0.82, P < 0.001), and choice (-0.61, P < 0.01). In addition, SA participants also experienced lower responsiveness in access to community support (-0.81, P < 0.001) during hospitalization but perceived higher quality of basic amenities (0.29, P < 0.001) and confidentiality (0.44, P < 0.01) in outpatient settings. CONCLUSION: SA participants in an urbanized Chinese-oriented society reported generally lower health system responsiveness compared with the local Chinese group; however, SA participants perceived higher confidentiality and quality of basic amenities in their outpatient experience. Concerted efforts from healthcare providers and policymakers are required to improve the existing healthcare system for users of members of EM groups.

Quantum interference of Josephson current in topological Anderson insulator junctions.

We investigate the critical supercurrent in Josephson junctions consisting of topological Anderson insulators (TAIs) via the Matsubara Green's function formalism. Our numerical results show that the disorder-induced edge states display distinct differences in dominating normal and supercurrent transport in the TAI phase. Unlike the hallmark of the TAI phase which exhibits a quantized conductance plateau, the critical supercurrent over the disorder strength exhibits a peak structure where the maximum value is reached at the weak-disorder boundary of the TAI phase. Although the magnitude of the averaged critical supercurrent is suppressed with increasing disorder strength, periodic oscillations of the supercurrent on an external magnetic flux survive in the TAI phase. These findings indicate that the supercurrent quantum interference effect can be an effective probe in detecting the emergence of disorder-induced edge state in TAIs.

Prevalence of S282T mutation in different genotypes of hepatitis C virus from DAA-treated naïve Chinese patients who were chronically infected with HCV.

OBJECTIVE: Although direct-acting antiviral agents (DAAs) for treating hepatitis C virus (HCV) infection have not yet been approved for clinical application at present in China, the development trend is irresistible. DAAs-containing therapeutic regimens have been approved and others are also under development worldwide. In vitro studies have shown that S282T mutation in the NS5B region of HCV is involved in DAAs resistance. The aim of this study was to investigate naturally occurring resistance mutation of S282T in different genotypes of HCV from DAA-treated naïve Chinese patients who were chronically infected with HCV. PATIENTS AND METHODS: 250 Chinese patients chronically infected with HCV were enrolled in this study. All subjects were naïve to DAAs. Direct sequencing of HCV NS5B region was performed in all enrolled patients. RESULTS: 70.4% (176/250) cases were infected with HCV genotype 1b, 19.2% (47/250) were 2a, 4.0% (11/250) were 6a, 3.6% (10/250) were 3b, 1.6% (4/250) were 1a and 1.2% (3/250) were 3a. Genotype 4, 5 and 7 were not observed. The S282T mutation was not found in any of the cases. CONCLUSIONS: The results showed that the S282T mutation was not prevalent in DAA-treated naïve Chinese patients who were chronically infected with HCV.

The productions of atrial natriuretic peptide and arginine vasopressin in small cell lung cancer with brain metastases and their associations with hyponatremia.

OBJECTIVE: Hyponatremia is one of the most frequently encountered electrolyte disorder in small cell lung cancer (SCLC) patients. It was shown that some SCLC cell lines could produce atrial natriuretic peptide (ANP) and arginine vasopressin (AVP). The aim of the study was to assess the secretion of ANP, AVP and their relative contributions to hyponatremia in SCLC patients, especially in patients with brain metastases. PATIENTS AND METHODS: In total, 194 SCLC patients including 51 patients with brain metastases were collected. The levels of ANP and AVP were measured with radioimmunoassay kits. And then their associations with serum sodium were investigated. The progression-free survival (PFS) was compared between the hyponatremia group and the normal serum sodium group. RESULTS: Serum sodium was negatively correlated with the plasma levels of ANP (r=-0.171, p=0.017) and AVP (r = -0.244, p=0.001) in all SCLC patients. In the brain metastatic subgroup, there was also a negative correlation between serum sodium and ANP (r=-0.399, p=0.004), while there was no correlation between serum sodium and AVP (r=-0.232, p=0.101). The occurrence rate of hyponatremia (serum sodium values below 135 mmol/l) in patients with brain metastases (21/51, 41.18%) was higher than that in patients without brain metastases (37/143, 25.87%) (p=0.040). The progression-free survival (PFS) in the hyponatremia group was significantly shorter than that in patients of the group without hyponatremia (p=0.010). Moreover, compared with patients which regained normal serum sodium after the treatment, the PFS of patients still with hyponatremia after the treatment was significantly shorter (p=0.049). CONCLUSIONS: ANP might play a leading role in the formation of hyponatremia of SCLC patients with brain metastases. Correcting hyponatremia timely and appropriately could improve SCLC patients' prognosis.

[Nested case-control study on associated factors for anemia during pregnancy].

Objective: To explore the related factors of anemia during pregnancy and provide scientific evidence for the primary prevention of anemia during pregnancy. Methods: The pregnant women (≤12 pregnant weeks) who received the first pregnancy care in a local medical institution in Hunan province from June 2013 to November 2014 were included in this cohort study, and for them anemia had been excluded by physical examination. Baseline survey and follow up till childbirth were conducted for them. A queue-based nested case-control study (1 ∶ 2) was conducted (380 pregnant women with anemia detected in this study as case group, 760 pregnant women without anemia randomly selected and matched by age, habitual residence during pregnancy as control group. And t test, χ(2) test and logistic regression analysis were conducted to identify related factors of anemia during pregnancy. Results: Multivariate logistic regression analysis indicated that low family annual income level (net income) (OR=2.08, 95%CI: 1.22-3.59), low educational level (OR=2.09, 95%CI: 1.22-3.59), pre-pregnancy perm/hair dye (OR=2.23, 95%CI: 1.63-3.05), early pregnancy vomiting (OR=2.51, 95%CI: 1.56-4.03) were the risk factors for anemia during pregnancy. Intake of vitamin and trace element supplements (OR=0.69, 95%CI: 0.50-0.94), frequent meat, fish, shrimp, egg intakes (OR=0.68, 95%CI: 0.49-0.92), frequent soy milk, milk intakes (OR=0.51, 95%CI: 0.27-0.95) were the protective factors for anemia during pregnancy. Conclusion: A number of factors, such as family annual income level, education level, poisonous and harmful material contact, pregnancy reaction, nutrition, are related to the incidence of anemia during pregnancy, it is necessary to take preventive measures to reduce the incidence of anemia during pregnancy.

Imperatorin shows selective antitumor effects in SGC-7901 human gastric adenocarcinoma cells by inducing apoptosis, cell cycle arrest and targeting PI3K/Akt/m-TOR signalling pathway.

PURPOSE: The main purpose of the present study was to determine the anticancer properties of imperatorin - a naturally occurring coumarin compound - against SGC-7901 human gastric adenocarcinoma cells and the mouse fibroblast cell line 3T3 (normal cell line). METHODS: Imperatorin effects on apoptosis induction, cell cycle phase distribution and PI3K/Akt/m-TOR signalling pathways were studied. MTT cell viability assay examined the compound's cytotoxic potential, while inverted phase contrast microscopy and fluorescence microscopy techniques were used to study morphological changes induced in SGC-7901 cells by imperatorin. Flow cytometry examined its effects on cell cycle progression while Western blot assay was used to study changes in protein expressions of PI3K/Akt/m-TOR pathway. RESULTS: Imperatorin induced a dose-dependent growth inhibition of the SGC-7901 gastric cancer cells with an IC50 value 62.6 µM, while in case of normal 3T3 mouse fibroblast cells, the drug did not show significant toxicity (IC50 value 195.8 µM), indicating that the drug selectively induced cytotoxicity in gastric cancer cells. The cells became rounded up, shrunken in size and got detached from the monolayer attached to well surface. Cells treated with 10, 75 and 175 µM imperatorin indicated that they began to emit yellow or red fluorescence which is an indication of early or late apoptosis respectively. Imperatorin also induced significant DNA fragmentation along with increasing the fraction of sub-G1 cells, indicating a sub-G1 cell cycle arrest. CONCLUSION: Imperatorin could prove an important lead molecule for the treatment of gastric cancer and deserves further research in vivo against more cell lines.

Short communication: Distribution of recessive genetic defect carriers in Chinese Holstein.

In dairy cattle, 4 important recessive hereditary diseases exist: complex vertebral malformation (CVM), bovine leukocyte adhesion deficiency (BLAD), citrullinemia (CTLN), and deficiency of uridine monophosphate synthase (DUMPS). Holstein Associations in developed countries have established monitoring systems for such disorders in Holstein bulls for decades. Over the past decades, China has continuously imported Holstein semen and embryos, mainly from North America but also from Europe. The dissemination of such genetic defects was undetermined until now, although efforts were taken to develop molecular techniques and detect carriers for CVM and BLAD in small populations of Chinese dairy cattle. Thus, herein we extensively screened 732 proven bulls participating in artificial insemination programs and 136 young bulls entering progeny test from 15 bull stations in China for CVM, BLAD, CTLN, and DUMPS. The proportion of carriers of the defects was found to be 7.72, 1.38, 0.23, and 0.12%, respectively. Given our findings, early diagnostic and monitoring systems on recessive inherited disorders among proven and young bulls entering the national genetic improvement programs for dairy cattle of China should be established immediately, in which a series of measures will be taken to prevent further spreading of such disorders and gradually eliminate them in the dairy cattle population in China.

Detection of quantitative trait loci affecting milk production traits on bovine chromosome 6 in a Chinese Holstein population by the daughter design.

Fourteen microsatellite markers with a coverage of 63.5 cM on bovine chromosome 6 were selected, and 26 sire families with 2,260 daughters were analyzed for mapping quantitative trait loci (QTL) affecting 5 milk production traits in a Chinese Holstein population. In the analyses across 26 families and within the largest significant families with a one-QTL model fitted, a QTL near BMS470 was detected that affected fat yield at the 5% experiment-wide significance level. When a 2-QTL model was fitted in the across-family analysis, it was found that there might exist 2 QTL affecting the 3 yield traits, although the exact or empirical thresholds for the significance testing were unknown. In all analyses, the results for milk yield and protein yield were generally consistent, which might have resulted from the same genetic background for milk and protein yield.