How calling emerges and develops during COVID-19: a qualitative study of medical students.

INTRODUCTION: The presence of calling in medicine has been shown to be related to a preponderance of positive outcomes among medical students. However, only a few studies examined the antecedents of calling. Of this group, little is known about how a calling emerges and develops in a crisis situation. This study examines the processes underlying the emergence and development of calling when confronted with COVID-19. METHODS: Semi-structured interviews were conducted with medical students (N = 28) from China from February to March 2020. Medical students reported their experiences about the emergence of calling, its antecedents, and its outcomes in the context of the COVID-19 pandemic. Interviews were transcribed and analyzed using a thematic analysis approach. RESULTS: Four main themes were identified: (1) the definition of calling, (2) the trajectories of calling development, (3) the factors leading to the emergence of calling, and (4) the outcomes of the emergence of calling. Medical students conceptualized calling as both self- and other-oriented regarding serving the common good. Three calling paths were revealed: significantly enhanced, growing out of nothing, and remaining unchanged. Work sense-making and identity formation interact to facilitate the emergence of calling. The emergence of a calling affects career and study-related outcomes. DISCUSSION: Our findings advance the concept of how the calling of medical students emerges and develops in response to life events through work sense-making and identity formation. Academic institutions and medical educators could leverage these events to facilitate calling discernment among medical students.

Decoding the biological properties and transcriptomic landscapes of human natural killer cells derived from bone marrow and umbilical cord blood.

Longitudinal studies have highlighted allogeneic natural killer (NK) cell-based cytotherapy for cancer immunosurveillance and immunotherapy, yet the deficiency of systematic and detailed comparison of NK cells from candidate sources including umbilical cord blood (UC) and bone marrow (BM) largely hinders the large-scale application. Herein, we isolated resident NK cells (rUC-NK, rBM-NK) from mononuclear cells (MNC), and analyzed the corresponding expanded NK cell counterparts (eUC-NK, eBM-NK). Then, the eUC-NK and eBM-NK were turned to multifaceted bioinformatics from the aspects of gene expression profiling and genetic variations. The percentages of total or activated NK cells in rBM-NK group were approximate 2-fold higher over those in the rUC-NK group, respectively. Instead, the proportion of total NK cells in eUC-NK was higher than that in the eBM-NK group, and in particular, the CD25+ memory-like NK cell subset. Furthermore, eUC-NK and eBM-NK manifested multidimensional similarities and diversities in gene expression pattern and genetic spectrum, whereas both eUC-NK and eBM-NK exhibited effective tumor killing capacity. Collectively, we dissected the cellular and transcriptomic signatures of NK cells generated from UC-MNC and BM-MNC, which supplied new literature for further exploring the characteristics of the indicated NK cells and would benefit the clinical application for cancer immunotherapy in future.

A study of starch resources with high-amylose content from five Chinese mutant banana species.

Investigation on staple crop starch of new species has been becoming the research focus of scholars at present. Based on this, the physicochemical properties and microstructural characteristics of starches isolated from Chinese mutant Musa acuminata Colla acuminata and double balbisiana (MA), Musa double acuminata cv. Pisang Mas (MAM), Musa acuminata cv. Pisang Awak (MAA), and Musa Basjoo Siebold (MBS), and Musa double acuminata and balbisiana-Prata (MAP) were investigated. Results exhibited that all starches exhibited high content of amylose (34.04-42.59%). According to the particle size, they were divided into medium (MA, MAM) (14.54-17.71 µm) and large (MAA, MBS, MAP) (23.01-23.82 µm) group. The medium group with A-type crystallization showed higher peak viscosity (PV), final viscosity, gel fracturability and gel hardness. For large group with B-type crystallization, the compact particle morphology, higher degree of crystallinity, short range order, gelatinization enthalpy, pasting temperature, lower porosity, water absorption capacity (WAC) and oil absorption capacity were found. In addition, the medium group with higher PV and gel hardness could be used as food thickening or gelling agents. The large group with higher Rc, short-range order, lower porosity and WAC could be potential to become raw material for resistant starch. All results showed the amylose content, had significant effect on the microstructure and physicochemical properties of starch samples. Outcomes in this investigation might provide a basis of theoretical application for industrial food production.

Multifaceted characterization of the biological and transcriptomic signatures of natural killer cells derived from cord blood and placental blood.

BACKGROUND: Perinatal blood including umbilical cord blood and placental blood are splendid sources for allogeneic NK cell generation with high cytotoxicity of combating pathogenic microorganism and malignant tumor. Despite the generation of NK cells from the aforementioned perinatal blood, yet the systematical and detailed information of the biological and transcriptomic signatures of UC-NKs and P-NKs before large-scale clinical applications in disease remodeling is still largely obscure. METHODS: Herein, we took advantage of the "3IL"-based strategy for high-efficient generation of NK cells from umbilical cord blood and placental blood (UC-NKs and P-NKs), respectively. On the one hand, we conducted flow cytometry (FCM) assay and coculture to evaluate the subpopulations, cellular vitality and cytotoxic activity of the aforementioned NK cells. On the other hand, with the aid of RNA-SEQ and multiple bioinformatics analyses, we further dissected the potential diversities of UC-NKs and P-NKs from the perspectives of transcriptomes. RESULTS: On the basis of the "3IL" strategy, high-efficient NKs were generated from mononuclear cells (MNCs) in perinatal blood. P-NKs revealed comparable ex vivo expansion but preferable activation and cytotoxicity upon K562 cells over UC-NKs. Both of the two NKs showed diversity in cellular vitality and transcriptome including apoptotic cells, cell cycle, gene expression profiling and the accompanied multifaceted biological processes. CONCLUSIONS: Our data revealed the multifaceted similarities and differences of UC-NKs and P-NKs both at the cellular and molecular levels. Our findings supply new references for allogeneic NK cell-based immunotherapy in regenerative medicine and will benefit the further exploration for illuminating the underlying mechanism as well.

Sexually transmitted infections and semen quality from subfertile men with and without leukocytospermia.

BACKGROUND: The role of sexually transmitted infections (STIs) in semen parameters and male infertility is still a controversial area. Previous studies have found bacterial infection in a minority of infertile leukocytospermic males. This study aims to investigate the prevalence of STIs in semen from subfertile men with leukocytospermia (LCS) and without leukocytospermia (non-LCS) and their associations with sperm quality. METHODS: Semen samples were collected from 195 men who asked for a fertility evaluation. Infection with the above 6 pathogens was assessed in each sample. Sperm quality was compared in subfertile men with and without LCS. RESULTS: The LCS group had significantly decreased semen volume, sperm concentration, progressive motility, total motility and normal morphology. The infection rates of Ureaplasma urealyticum (Uuu), Ureaplasma parvum (Uup), Mycoplasma hominis (MH), Mycoplasma genitalium (MG), Chlamydia trachomatis (CT), herpes simplex virus-2 (HSV-2) and Neisseria gonorrhoeae (NG) were 8.7 %, 21.0 %, 8.2 %, 2.1 %, 3.6 %, 1.0 and 0 %, respectively. The STI detection rates of patients with LCS were higher than those of the non-LCS group (52.3 % vs. 39.3 %), although there was no statistically significant difference between the two groups (P = 0.07). All semen parameters were not significantly different between LCS with STIs and without STIs, except the semen volume in the MG-infected patients with LCS was significantly lower than that in the noninfected group. CONCLUSIONS: LCS was associated with a reduction in semen quality, but was not associated with STIs.

Circulating exosomal miR-125a-5p as a novel biomarker for cervical cancer.

Exosomal microRNAs (miRs/miRNAs) have been reported to be associated with cervical cancer. The aim of the present study was to investigate circulating exosomal miRNA as a biomarker for cervical cancer diagnosis. In the present study, samples from 6 patients with cervical cancer and 6 healthy control subjects were retrieved for exosomal RNA-sequencing. The results revealed that a total of 39 miRNAs were differentially expressed between patients with cervical cancer and healthy controls (P<0.001; fold-change >2.0). Exosomal miR-125a-5p was further quantified in plasma from 60 subjects, which included 22 healthy individuals and 38 patients with cervical cancer. miR-16a-5p served as the reference miRNA for quantitative PCR analysis of exosomal miR-125a-5p in patients with cervical cancer and healthy individuals. The results revealed that exosomal miR-125a-5p expression levels in the patients with cervical cancer were significantly lower than those in the healthy controls (P<0.001). Receiver operating characteristic (ROC) curve analyses were performed and the results revealed that the level of plasma exosomal miR-125a-5p was a potential marker for differentiating between non-cervical cancer and cervical cancer, with an ROC area under the curve of 0.7129. At the cut-off value of 2.537 for miR-125a-5p, cervical cancer diagnostic sensitivities and specificities were 59.1 and 84.2%, respectively. The present study provides confirmation that exosomal miR-125a-5p could potentially serve as a biomarker for cervical cancer diagnosis. The present study involved only a small number of clinical samples; more samples are required to support the conclusions of the present study.

Effects of cyclosporine A on proliferation, invasion and migration of HTR-8/SVneo human extravillous trophoblasts.

As shown in our previous study, cyclosporine A (CsA) promotes the proliferation, invasion and migration of villous trophoblasts, thus improving embryo implantation. In addition, the incidence of preeclampsia (PE) is decreased in patients with recurrent spontaneous abortion (RSA) and repeated implantation failure (RIF) treated with CsA during the first trimester. Abnormal function of extravillous trophoblasts (EVTs) in early pregnancy is recognized as the pathogenetic mechanism of PE. EVTs share homology and function with pre-villous trophoblasts and villous trophoblasts; thus, we hypothesized that CsA may have the same regulatory effect on EVTs. In this study, we investigated the effects of CsA on HTR-8/SVneo trophoblasts in the extravillous layer and explored the underlying mechanisms. QPCR and Western blot (WB) analyses were performed to detect expression alterations in relevant proliferation and invasion proteins in response to different concentrations of CsA. We used an Affymetrix IVT expression microarray to examine the target genes of CsA in preeclamptic placentas versus normal placentas. Our results showed that certain concentrations of CsA could promote the proliferation, invasion and migration of HTR8/SVneo cells. CsA was also found to promote the expression of titin, MMP9, EGFR, and PRR15. TRAIL may be a target gene for CsA-mediated regulation of EVTs. CONCLUSIONS: By promoting the expression of related proteins and regulating the functions of HTR8/SVneo cells, CsA can promote vascular recasting and placental function, which may affect the pathogenesis of PE.

Cognitive Bias, Entrepreneurial Emotion, and Entrepreneurship Intention.

Although numerous studies have explored the factors influencing entrepreneurial activity, there is a lack of a theoretical basis for linking these factors to entrepreneurship behavioral intention. The current study uses the theory of self-regulating attitude to construct a theoretical model of examining the relationship among cognitive bias, entrepreneurial emotion, and entrepreneurship intention. A total of 312 valid samples were collected from college students at a Chinese university. The bootstrapping method was used to test the multi-mediation hypotheses. Our research found that positive entrepreneurial emotion plays a mediating role in the relationship between optimism and entrepreneurship intention, whereas negative entrepreneurial emotion plays a mediating role in the relationship between overconfidence and entrepreneurship intention. These findings underline the importance of a correct understanding of cognitive bias and entrepreneurial emotion in the process of entrepreneurship.

Guanxi HRM Practice and Employees' Occupational Well-Being in China: A Multi-Level Psychological Process.

Chinese employees may experience and respond to guanxi human resource management (HRM) practice (e.g., recruiting, selecting, inducting and appraising employees based on personal relationships). Little has been done to examine the linkage between guanxi HRM practice and employees' occupational well-being. This study investigates the psychological process of how guanxi HRM practice affects employees' occupational well-being. The theoretical model of this study proposes that employee psychological safety mediates the relationship between guanxi HRM practice and occupational well-being, while collectivistic team culture moderates the relationship between guanxi HRM practice and psychological safety. Multi-level data from 297 employees nested within 42 teams support all hypotheses. This study reveals the cross-level effects of guanxi HRM practice and providing practical suggestions for future research on psychologically safe and healthy work environments.

Bridging the Gap between Affective Well-Being and Organizational Citizenship Behavior: The Role of Work Engagement and Collectivist Orientation.

Workplace well-being has received considerable attention over the past decade. Relative to the positive relationship between affective well-being and in-role performance, the relationship between affective well-being and extra-role performance has received little empirical attention. The purpose of this study was to examine the relationships among affective well-being, work engagement, collectivist orientation, and organizational citizenship behavior. Specifically, we tested this model with a sample of 264 employees from a telecom company in China. We found that: (1) affective well-being was the positive predictor of organizational citizenship behavior (B = 0.482, p < 0.001); (2) work engagement mediated the relationship between employee affective well-being and organizational citizenship behavior (indirect effect = 0.330, p < 0.001); and (3) collectivist orientation moderated the relationship between affective well-being and work engagement (B = 0.113, p < 0.01) and affective well-being and organizational citizenship behavior (B = 0.084, p < 0.05). Our discussion highlights the benefits of understanding the role of work engagement and cultural values with regard to the relationship between affective well-being and organizational citizenship behavior.

What Drives the Trickle-Down Effect of Calling Orientation From Supervisors to Subordinates? The Perspective of Social Learning Theory.

Despite an increase in research on calling orientation, few studies have investigated its antecedents. Drawing on social learning theory, we hypothesized that subordinates' perceptions of their supervisor's role modeling mediate the relationship between supervisor's and subordinates' calling orientations. Supervisor's organizational status is supposed to augment the trickle-down process for calling orientation. We used multilevel modeling to test these hypotheses in a sample of 738 subordinates nested in 77 work teams in Chinese firm. We found that supervisor's calling orientation was positively related to subordinate's calling orientation and that the relationship was fully mediated by subordinates' perceptions of role modeling. Additionally, the relationship between supervisor's calling orientation and subordinates' calling orientation via role modeling was moderated by supervisor's organizational status at the second stage.

Von Hippel-Lindau gene expression on the human fallopian tube epithelium during the menstrual cycle.

The Von Hippel-Lindau gene (VHL) is a tumor suppressor gene, which is widely expressed in kidney, lung, breast, ovary, and cervix. VHL gene mutations can induce VHL disease and tumorigenesis. However, whether this gene is expressed in the human fallopian tube has not been evaluated. The objectives of this study were to investigate whether the VHL gene is expressed in human fallopian tube, and to investigate its expression changes during the menstrual cycle. Twenty­seven patients undergoing abdominal hysterectomy with adnexectomy for benign uterine disease were enrolled in the study. Human fallopian tubes were divided into proliferative stage (n=14) and secretory stage (n=13) according to the stage of the menstrual cycle they were isolated from. The expression of the VHL gene and protein was studied by reverse transcription-polymerase chain reaction (RT-PCR), western blotting and immunohistochemistry, respectively. The results revealed positive expression of the VHL protein in the cytoplasm of ciliated cells of the human fallopian tube. The mRNA and protein expression of VHL in the fallopian tubes was higher in the proliferative compared to the secretory phase of the menstrual cycle, but this difference was not significant (P>0.05). Overall, this study presents data on the VHL mRNA and protein expression in the human fallopian tube, which may be relevant to the process of differentiation of ciliated and secretory cells.

Comparison of the outcome of conventional in vitro fertilization and intracytoplasmic sperm injection in moderate male infertility from ejaculate.

OBJECTIVE: To evaluate whether couples with moderate male infertility should be treated with conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). PATIENTS AND METHODS: A total of 249 couples with moderate male infertility undergoing their first IVF/ICSI cycle were enrolled in the study. The couples were divided into two groups according to the results of semen analysis: moderate oligozoospermia (O group) and moderate oligoasthenozoospermia (OA group). Sibling oocytes were randomized into groups to be inseminated either by conventional IVF or ICSI. Fertilization rate, embryo quality, implantation rate, and clinical pregnancy rate were examined. RESULTS: There was no difference in the fertilization, implantation, and pregnancy rates between conventional IVF and ICSI in either the O group or OA group (p > 0.05). Additionally, in the OA group, the good quality embryo rate was similar after IVF or ICSI (p > 0.05). However, in the O group, the good quality embryo rate was significantly higher after ICSI than after IVF (p < 0.05). CONCLUSIONS: Couples with moderate oligozoospermia or moderate oligoasthenozoospermia did not influence the major indices of IVF. Because of the uncertainties concerning the safety of ICSI, couples with moderate oligozoospermia or moderate oligoasthenozoospermia need not be subjected to this procedure.

Von Hippel-Lindau gene expression in human endometrium during menstrual cycle.

The von Hippel­Lindau (VHL) gene is a tumor suppressor gene, which is widely expressed in the kidney, lung, breast, eye, ovary and cervix. Mutations of the VHL gene are able to induce VHL disease and tumorigenesis. However, it has yet to be evaluated whether the VHL gene is expressed in the human endometrium. The objective of the present study was to investigate whether the VHL gene is expressed in the human endometrium and to identify changes in expression levels during the menstrual cycle. A total of 35 human endometrial tissue samples in the proliferative (n=17) and secretory phase (n=18) were subjected to the present study. VHL gene expression levels were assessed using Western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). It was observed that the expression of VHL mRNA in the human endometrium decreased from the proliferative to secretory phase (P<0.05). Levels of VHL protein in the proliferative phase were higher than those in the secretory phase (P<0.05). In conclusion, the present study revealed that the VHL gene is expressed in the normal human endometrium, and its expression levels change during the different periods of the menstrual cycle.

Pathological changes of testicular tissue in normal adult mice: A retrospective analysis.

Mouse testicular experimental models are widely used in the study of andrology, reproductive toxicology and pharmacology. Under physiological conditions, a normal adult mouse is usually considered to have normal testes. However, whether normal adult mouse testes exhibit pathological changes has not been evaluated. The objective of this study was to investigate the pathological changes of testicular tissues in normal adult mice. A retrospective analysis of 720 adult male Kunming mice, used in previous studies as controls, was performed. Bilateral testicular tissues were stained with hematoxylin and eosin for pathological examinations. Among the 720 mice, nine had abnormal testes, an incidence of 1.3%. The nine mice with abnormal testes included two with microrchidia (22.2%) while the others had a normal testicular size. The observed pathological changes associated with microrchidia were seminiferous epithelial vacuolation, spermatogenesis arrest at the spermatocyte stage and the absence of sperm in all tubules. In other abnormal testes, pathological alterations included seminiferous epithelial vacuolation, severe hypospermatogenesis and symplasts composed of collapsed spermatids in tubules. The results demonstrate that normal adult male mice exhibit testicular pathological changes. Therefore, the possibility of abnormal testes in normal adult mice must be considered when using mice to establish a testicular experimental model.

Expression of PPAR-γ in adipose tissue of rats with polycystic ovary syndrome induced by DHEA.

The objective of this study was to investigate the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) in adipose tissue of the rat model of polycystic ovary syndrome (PCOS), induced by dehydroepiandrosterone (DHEA). Sixteen sexually immature Sprague-Dawley female rats were randomly assigned to the DHEA (n=8) or control (n=8) group. Adipose tissue was collected from the two rat groups following subcutaneous injection of DHEA in the DHEA group and a standard laboratory diet in the control group for 20 consecutive days. Reverse transcription polymerase chain reaction and western blot analysis were performed to detect expression of PPAR-γ at the mRNA and protein level in the adipose tissue. Both PPAR-γ mRNA and protein levels were decreased in the adipose tissue of DHEA­induced PCOS rats compared to the control group. This decrease was significant (P<0.01). These results suggest that the pathogenesis of PCOS, which shares a number of common features with hyperandrogenemia, may involve the lipid metabolism pathway through inhibition of PPAR-γ.

Expression of toll-like receptor 4 in maternal monocytes of patients with gestational diabetes mellitus.

Toll-like receptors (TLRs) are pattern recognition receptors and play an important role in innate immune responses and the occurrence of inflammatory disease. TLR4 is a member of the TLR family and its activation is capable of inducing inflammatory responses, reflecting a relationship between the innate and adaptive immune systems. However, whether TLR4 is expressed in patients with gestational diabetes mellitus (GDM) has not been elucidated. The aim of the present study was to investigate whether TLR4 is expressed in maternal peripheral blood monocytes of patients with GDM. A case-control study, using standard quantitative polymerase chain reaction and western blotting, was performed to assess the TLR4 expression in 30 females with GDM and 32 healthy pregnant females at similar gestational ages. Serum tumor necrosis factor (TNF)-α levels were assessed using ELISA in all the females. The TLR4 expression levels in the maternal peripheral blood monocytes and the serum TNF-α levels were increased in females with GDM compared with healthy pregnant females (P<0.05). Additionally, there was a positive correlation between the TLR4 expression level in peripheral blood monocytes and serum TNF-α levels in all the females. These results indicate that TLR4-mediated release of inflammatory cytokines may represent one factor leading to increased glucose levels in patients with GDM. In addition, TLR4 may be involved in the pathogenesis of GDM.

Outcome of conventional IVF and ICSI on sibling oocytes in moderate ligoasthenozoospermia.

OBJECTIVE: To evaluate the outcomes of patients with moderate oligoasthenozoospermia treated with conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). METHODS: A total of 99 couples with moderate oligoasthenozoospermia undergoing their first IVF/ICSI cycle were included in the study. Sibling oocytes were randomized to be inseminated either by conventional IVF or ICSI. Fertilization rate, cleavage rate, embryo quality, implantation rate, and clinical pregnancy rate were examined. RESULTS: There was no difference in the fertilization rate, cleavage rate, implantation rate, and pregnancy rate between conventional IVF and ICSI (P>0.05). The good quality embryo rate was significant difference between after IVF and after ICSI (P<0.05). CONCLUSIONS: Couples with moderate oligoasthenozoospermia did not influence the major indices of IVF and the uncertainties concerning the safety of ICSI, couples with moderate oligoasthenozoospermia need not be subjected to ICSI.