Factors Affecting Infection Control Behaviors to Prevent COVID-19: An Online Survey of Nursing Students in Anhui, China in March and April 2020.

BACKGROUND The pandemic of coronavirus disease 2019 (COVID-19) has become a major public health challenge all over the world. People's knowledge, attitudes, and preventive behaviors about diseases affect the degree of adherence to control measures. This study aimed to survey the affecting factors of COVID-19 prevention behavior among nursing students in China. MATERIAL AND METHODS Six-hundred thirteen nursing students in Anhui, China participated in an online survey from March 30 to April 5, 2020. The survey collected demographic information, electronic health (eHealth) literacy, COVID-19-related knowledge, attitudes, and prevention behavior data using descriptive analysis and multinomial logistic regression to analyze the data. RESULTS The mean age of study participants was 20.88 years, of which 31.8% were male (n=613). Television (84.9%) and WeChat (79.6%) were the major sources of their information. Nursing students had good knowledge (14.68±2.83), had positive attitudes (4.03±0.59), had good practices (3.92±0.65), and had basic eHealth literacy (30.45±6.90). Nursing students with higher eHealth literacy (odds ratio [OR]=0.89, P<0.01), good knowledge (OR=0.89, P<0.01), and positive attitudes (OR=0.24, P<0.01) took more preventive behaviors. Students living in the countryside (OR=0.09, P<0.01) and of a young age (OR=1.51, P<0.05) seldom took preventive actions. Men, compared with women, were less likely to take preventive measures. (OR=1.44, P<0.05). CONCLUSIONS Good eHealth literacy, good knowledge, and a positive attitude were the most important variables that affected the prevention behavior against COVID-19. Targeted health education should be conducted for male students and students living in the countryside by providing reliable and effective online sources.

Differentiation of rat adipose-derived mesenchymal stem cells into corneal-like epithelial cells driven by PAX6.

Corneal integrity, transparency and vision acuity are maintained by corneal epithelial cells (CECs), which are continuously renewed by corneal limbal stem cells (LSCs). Deficiency of CECs and/or LSCs is associated with numerous ocular diseases. Paired box (PAX)6 is an eye development-associated transcription factor that is necessary for cell fate determination and differentiation of LSCs and CECs. In the present study, the PAX6 gene was introduced into adipose-derived rat mesenchymal stem cells (ADMSCs) to investigate whether PAX6-transfected cells were able to transdifferentiate into corneal-like epithelial cells and to further verify whether the cells were suitable as a cell source for corneal transplantation. The ADMSCs were isolated from the bilateral inguinal region of healthy Sprague Dawley rats. The characteristics of ADMSCs were identified using flow cytometric analysis. After subculture, ADMSCs underwent transfection with recombinant plasmid containing either PAX6-enhanced green fluorescent protein (EGFP) complementary (c)DNA or EGFP cDNA (blank plasmid group), followed by selection with G418 and determination of the transfection efficiency. Subsequently, the morphology of the ADMSCs and the expression profiles of corneal-specific markers CK3/12 and epithelial-specific adhesion protein were determined. E-cadherin was detected using immunofluorescence staining and western blot analysis at 21 days following transfection. An MTT cell proliferation and a colony formation assay were performed to assess the proliferative activity and clonogenicity of PAX6-transfected ADMSCs. Finally, the PAX6-expressing ADMSCs were transplanted onto the cornea of a rabbits with limbal stem cell deficiency (LSCD). At 21 days after transfection, the ADMSCs with PAX6 transfection exhibited a characteristic flagstone-like appearance with assembled corneal-like epithelial cells, and concomitant prominent expression of the corneal-specific markers cytokeratin 3/12 and E-cadherin. Furthermore, the proliferation and colony formation ability of PAX6-overexpressing ADMSCs was significantly retarded. The transplantation experiment indicated that PAX6-reprogramed ADMSCs attached to and replenished the damaged cornea via formation of stratified corneal epithelium. Taken together, these results suggested that conversion of ADMSCs into corneal-like epithelium may be driven by PAX6 transfection, which makes ADMSCs a promising cell candidate for the treatment of LSCD.

Structural evolutions and hereditary characteristics of icosahedral nano-clusters formed in Mg70Zn30 alloys during rapid solidification processes.

To investigate the structural evolution and hereditary mechanism of icosahedral nano-clusters formed during rapid solidification, a molecular dynamics (MD) simulation study has been performed for a system consisting of 107 atoms of liquid Mg70Zn30 alloy. Adopting Honeycutt-Anderson (HA) bond-type index method and cluster type index method (CTIM-3) to analyse the microstructures in the system it is found that for all the nano-clusters including 2~8 icosahedral clusters in the system, there are 62 kinds of geometrical structures, and those can be classified, by the configurations of the central atoms of basic clusters they contained, into four types: chain-like, triangle-tailed, quadrilateral-tailed and pyramidal-tailed. The evolution of icosahedral nano-clusters can be conducted by perfect heredity and replacement heredity, and the perfect heredity emerges when temperature is slightly less than Tm then increase rapidly and far exceeds the replacement heredity at Tg; while for the replacement heredity, there are three major modes: replaced by triangle (3-atoms), quadrangle (4-atoms) and pentagonal pyramid (6-atoms), rather than by single atom step by step during rapid solidification processes.

Crystallization characteristics in supercooled liquid zinc during isothermal relaxation: A molecular dynamics simulation study.

The crystallization characteristics in supercooled liquid Zn during isothermal relaxation were investigated using molecular dynamics simulations by adopting the cluster-type index method (CTIM) and the tracing method. Results showed that the crystallization process undergo three different stages. The size of the critical nucleus was found to be approximately 90-150 atoms in this system; the growth of nuclei proceeded via the successive formation of hcp and fcc structures with a layered distribution; and finally, the system evolved into a much larger crystal with a distinct layered distribution of hcp and fcc structures with an 8R stacking sequence of ABCBACAB by adjusting all of the atoms in the larger clusters according to a certain rule.

Emerging role of adipokines in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by multisystem organ involvement and unclear pathogenesis. Several adipokines synthesized in the adipose tissue, including leptin, adiponectin, resistin, and chemerin, have been explored in autoimmune rheumatic diseases, especially SLE, and results suggest that these mediators may be implicated in the pathogenesis of SLE. However, the current results are controversial. In this review, we will briefly discuss the expression and possible pathogenic role of several important adipokines, including leptin, adiponectin, resistin, and chemerin in SLE.

Subclinical atherosclerosis in patients with systemic lupus erythematosus: A systemic review and meta-analysis.

OBJECTIVE: Systemic lupus erythematosus (SLE) is associated with increased risk of cardiovascular disease. Carotid intima media thickness (CIMT) and carotid plaques are both frequently used to identify populations at higher cardiovascular risk. A systematic literature search and meta-analysis were performed to evaluate CIMT and carotid plaques difference between SLE patients and normal controls. METHODS: The literatures comparing markers of cardiovascular risk (CIMT and prevalence of carotid plaques) in SLE and controls were systematically searched in PubMed, EMBASE and Cochrane databases. The overall mean CIMT difference and pooled odds ratio (OR) for the prevalence of carotid plaques between SLE patients and control groups were calculated by fixed-effects or random-effect model analysis. Meta-regression was performed to explore the potential influencing factors. Publication bias was examined by a funnel plot and Egger's test. RESULTS: A total of 80 studies (6085 SLE patients and 4794 controls) were included in the final analysis, 71 studies with data on CIMT (4814 cases and 3773 controls) and 44 studies reporting on the prevalence of carotid plaques (4417 cases and 3528 controls). As compared to controls, SLE patients showed a higher CIMT (WMD: 0.07 mm; 95%CI: 0.06, 0.09; P<0.001), and an increased prevalence of carotid plaques (OR: 2.45; 95%CI: 2.02, 2.97; P<0.001). Meta-regression models showed that traditional cardiovascular risk factors (age, HDL and triglyceride of SLE patients) and lupus related risk factors (as expressed by duration, ESR, SLEDAI and steroids) had a significant influence on CIMT, steroids and triglyceride had significant influence on the prevalence of carotid plaques. CONCLUSIONS: Our findings support the current evidence base for an increased cardiovascular burden in SLE patients and support the use of CIMT and carotid plaques in observational studies in SLE patients. The findings are of importance to design more specific prevention and treatment strategies.

Histopathology of melanosis coli and determination of its associated genes by comparative analysis of expression microarrays.

Melanosis coli (MC) refers to the condition characterized by abnormal brown or black pigmentation deposits on the colonic mucosa. However, the histopathological findings and genes associated with the pathogenesis of melanosis coli remain to be fully elucidated. The present study aimed to examine the histopathological features and differentially expressed genes of MC. This involved performing hematoxylin and eosin staining, specific staining and immunohistochemistry on tissues sections, which were isolated from patients diagnosed with MC. DNA expression microarray analysis, western blotting and immunofluorescence assays were performed to analyze the differentially expressed genes of melanosis coli. The results demonstrated that the pigment deposits in MC consisted of lipofuscin. A TUNEL assay revealed that a substantial number of apoptotic cells were present within the macrophages and superficial lamina propria of the colonic epithelium. Expression microarray analysis revealed that the significantly downregulated genes were CYP3A4, CYP3A7, UGT2B11 and UGT2B15 in melanosis coli. Western blotting and immunofluorescence assays indicated that the expression of CYP3A4 in the normal tissue was higher than in the MC tissue. The results of the present study provided a comprehensive description of the histopathological characteristics and pathogenesis of MC and for the first time, to the best of our knowledge, demonstrated that the cytochrome P450­associated genes were significantly downregulated in melanosis coli. This novel information can be used to assist in further investigations of melanosis coli.

Fully human HER2/cluster of differentiation 3 bispecific antibody triggers potent and specific cytotoxicity of T lymphocytes against breast cancer.

The use of a bispecific antibody (BsAb) is a promising and highly specific approach to cancer therapy. In the present study, a fully human recombinant single chain variable fragment BsAb against human epidermal growth factor receptor (HER)2 and cluster of differentiation (CD)3 was constructed with the aim of developing an effective treatment for breast cancer. HER2/CD3 BsAb was expressed in Chinese hamster ovary cells and purified via nickel column chromatography. Flow cytometry revealed that the HER2/CD3 BsAb was able to specifically bind to HER2 and CD3­positive cells. HER2/CD3 BsAb was able to stimulate T-cell activation and induce the lysis of cultured SKBR­3 and BT474 cells in the presence of unstimulated T lymphocytes. HER2/CD3 BsAb efficiently inhibited the growth of breast cancer tissue by activating and inducing the proliferation of tumor tissue infiltrating lymphocytes. Therefore, HER2/CD3 BsAb is a potent tool which may be a suitable candidate for the treatment of breast cancer.

Mesenchymal stem cell-mediated suppression of hypertrophic scarring is p53 dependent in a rabbit ear model.

INTRODUCTION: Mesenchymal stem cells (MSCs) are considered to play important roles in wound repair and tissue remodeling. Hypertrophic scar (HTS) is a cutaneous condition characterized by deposits of excessive amount of collagen after an acute skin injury. However, currently there is little knowledge about the direct relationship between MSCs and HTS. METHODS: The hypertrophic scar model was established on rabbit ears. MSCs were isolated from rabbit femur bone marrow and transplanted through ear artery injection. Hypertrophic scar formation was examined using frozen-section analysis, hematoxylin and eosin (HE) staining, Masson's trichrome staining, and scar elevation index. The role of p53 in the MSCs-mediated anti-scarring effect was examined by gene knockdown using p53 shRNA. RESULTS: In this study, MSCs engraftment through ear artery injection significantly inhibited the hypertrophic scarring in a rabbit ear hypertrophic scar model, while this anti-scarring function could be abrogated by p53 gene knockdown in MSCs. Additionally, we found that MSCs down-regulated the expression of TGF-ß receptor I (TßRI) and alpha-smooth muscle actin (α-SMA) at both mRNA and protein levels in a paracrine manner, and this down-regulation was rescued by p53 gene knockdown. Moreover, our results showed that MSCs with p53 gene knockdown promoted the proliferation of fibroblasts through increasing nitric oxide (NO) production. CONCLUSIONS: These results suggest that MSCs inhibit the formation of HTS in a p53 dependent manner through at least two mechanisms: inhibition of the transformation of HTS fibroblast to myofibroblast; and inhibition of the proliferation of fibroblasts through inhibition of NO production.

[Preparation of polyclonal antibody of human endothelial-overexpressed lipopolysaccharide-associated factor 1].

OBJECTIVE: To prepare the polyclonal antibody of human endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1), and to determine the expression of EOLA1 in human umbilical vein endothelial cell (HUVEC). METHODS: The protein samples (sample 1 and 2) expressing EOLA1 were purified and renatured. The protein concentrations were determined with bicinchoninic acid assay. The protein samples were identified with peptide mass fingerprinting (PMF) analysis. Protein sample with higher coincidence rate of amino acid sequence with theoretic protein was used to inoculate 4 mice; another 4 mice inoculated with adjuvant were used as control. Serum was isolated from collected mice blood. Polyclonal antibody of EOLA1 was purified with saturated ammonium sulfate precipitation, and was determined with ELISA for the titer (data were denoted by absorbance value). The expression of EOLA1 in HUVEC was determined with Western blot. RESULTS: The concentration of protein sample 1 and 2 was respectively 0.124 16 mg/mL and 0.132 15 mg/mL. According to PMF analysis, the coincidence rate of amino acid sequence between protein samples and theoretic protein were 32% (protein sample 1) and 24% (protein sample 2). The polyclonal antibody of EOLA1 with titer more than 1:10 000 was obtained from mice inoculated with protein sample 1. The expression of EOLA1 protein in HUVEC was determined with polyclonal antibody of EOLA1. CONCLUSIONS: The polyclonal antibody of EOLA1 can be prepared by inoculating mice with EOLA1 prokaryotic expressing protein, which can be used for determination of EOLA1 protein.

Formation and evolution of metastable bcc phase during solidification of liquid Ag: a molecular dynamics simulation study.

On the basis of the quantum Sutton-Chen potential, the rapid solidification processes of liquid silver have been studied by molecular dynamics simulation for four cooling rates. By means of several analysis methods, the competitions and transitions between microstructures during the cooling processes have been analyzed intensively. It is found that there are two phase transitions in all simulation processes. The first one is from liquid state to metastable (transitional) body-centered cubic (bcc) phase. The initial crystallization temperature T(ic) increases with the decrease of the cooling rate. The second one is from the transitional bcc phase to the final solid phase. This study validates the Ostwald's step rule and provides evidence for the prediction that the metastable bcc phase forms first from liquid. Further analyses reveal that the final solid at 273 K can be a mixture of hexagonal close-packed (hcp) and face-centered cubic (fcc) microstructures with various proportions of the two, and the slower the cooling rate is, the higher proportion the fcc structure occupies.

[The mid- or long-term clinical results of prosthetic disc nucleus replacement in the treatment of lumbar disc disease].

OBJECTIVE: To evaluate the mid- or long-term clinical results and the factors that influence the outcomes of prosthetic disc nucleus (PDN) replacement in the treatment of lumbar disc disease. METHODS: Thirty-four patients who underwent the PDN replacement from March 2002 to October 2003 were followed for an average of 52.6 months (range from 48 to 66 months). Twenty patients were discogenic low back pain, 14 patients were lumbar disc herniation. The follow-up results were evaluated by using the Oswestry disability index (ODI) and the visual analogue scales (VAS) through direct examinations and questionnaires. ODI was 58.4% preoperatively, and VAS was 7.4. Radiography was also used to measure the range of motion (ROM) and disc height of the operative segment, and findings were compared with those on preoperative radiographs. RESULTS: Twelve months after operation, a significant proportion of patients recovered from low back pain or leg pain, ODI decreased to averaged 18.2%. VAS decreased to 1.8, the average increase of the postoperative disc height was 17.6%, ROM was 9.2 degrees. At the final followup, all patients with deteriorated leg radicular symptoms improved, ODI increased from 18.2% 12 months after operation to averaged 31.2%. Low back pain became more serious in 18 patients. VAS increased from 1.8 to 3.1, the average decrease of the postoperative to preoperative disc height was 13.5%, ROM decreased to 6.8 degrees. The rate of degeneration or breakages of the end plates was 64.7% (22/34), implant device migrations were observed in 25 patients. CONCLUSIONS: The mid- or long-term outcome of PDN replacement in the treatment of degenerative lumbar disc disease is not as encouraging as that of the short-term follow-up. It is neither effective in term of restoration of the intervertebral disc height nor increase of the ROM of the operative segment, complication rates are significantly higher, and inferior results are to be expected. The selection of suitable surgical candidates and determination of valid indications for operative treatment are very important.

Formation mechanism of critical nucleus during nucleation process of liquid metal sodium.

To deeply understand the formation mechanism of a critical nucleus during the nucleation process of liquid metal sodium, a system consisting of 10 000 Na atoms has been simulated by using molecular dynamics method. The evolutions of nuclei are traced directly, adopting the cluster-type index method. It is found that the energies of clusters and their geometrical constraints interplay to form the favorable microstructures during the nucleation process. The nucleus can be formed through many different pathways, and the critical size of the nucleus would be different for each pathway. It is also found that the critical nucleus is nonspherical and may include some metastable structures. Furthermore, the size of the cluster and its internal structure both play a crucial role in determining whether it is a critical nucleus, and this is in agreement with the simulations by computing the free energy of the Lennard-Jones system [D. Moroni, P. R. ten Wolde, and P. G. Bolhuis, Phys. Rev. Lett. 94, 235703 (2005)].