The willingness for dietary and behavioral changes in frontline epidemic prevention workers after experiencing the outbreak of COVID-19 in China: a cross-sectional study

BACKGROUND@#The 2019 novel coronavirus disease (COVID-19) has had a massive impact on public health, resulting in sudden dietary and behavioral habit changes. Frontline epidemic prevention workers play a pivotal role against COVID-19. They must face high-risk infection conditions, insufficient anti-epidemic material supplies, mental pressure, and so on. COVID-19 seriously affects their dietary and behavioral habits, and poor habits make them more susceptible to COVID-19. However, their baseline dietary and behavioral habits before COVID-19 and their willingness to change these habits after the outbreak of COVID-19 remain unclear for these workers in China. This study aimed to explore the baseline dietary and behavioral habits of frontline workers and their willingness to change these habits after the outbreak of the epidemic; in addition, susceptible subgroups were identified by stratified analyses as targets of protective measures to keep them from being infected with COVID-19.@*METHODS@#A cross-sectional study was conducted through an online questionnaire using a sample of 22,459 valid individuals living in China, including 9402 frontline epidemic prevention workers.@*RESULTS@#Before COVID-19, 23.9% of the frontline epidemic prevention workers reported a high-salt diet, 46.9% of them reported a high frequency of fried foods intake, and 50.9% of them smoked cigarettes. After the outbreak of COVID-19, 34.6% of them expressed a willingness to reduce salt intake, and 43.7% of them wanted to reduce the frequency of pickled vegetables intake. A total of 37.9% of them expressed a willingness to decrease or quit smoking, and 44.5% of them wanted to increase sleep duration. Significant differences in the baseline dietary and behavioral habits and the willingness to change their habits were observed between frontline epidemic prevention workers and other participants. Among the frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19, frontline epidemic prevention experience was a promoting factor for adopting worse dietary and behavioral habits, including those in the high-salt intake subgroup (OR, 2.824; 95% CI, 2.341-3.405) and the 11-20 cigarettes/day subgroup (OR, 2.067; 95% CI, 1.359-3.143).@*CONCLUSIONS@#The dietary and behavioral habits of frontline epidemic prevention workers were worse than that those of other participants before COVID-19. They had a greater willingness to adopt healthy dietary and behavioral habits after experiencing the outbreak of COVID-19. However, frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19 continued in engage in these poor habits. Dietary and behavioral intervention policies should be drafted to protect their health, especially frontline epidemic prevention workers with poor habits at baseline.

Screening of new virulence genes of high virulence Klebsiella pneumoniae by Tn-seq / 中华微生物学和免疫学杂志

Objective:To construct a transposon mutation library and screen new virulence genes of hypervirulent Klebsiella pneumoniae(hvKp). Methods:The transposon mutation library was constructed and treated with human serum. The changes in the abundance of the genes of library mutant strains were analyzed by Transposon sequencing (Tn-seq). Besides, KEGG (kyoto encyclopedia of genes and genomes) annotation and enrichment analysis were performed on the screened genes.Results:A total of 405 genes were screened out according to the abundance of the genes in the library treated with human serum was 20% lower than that without treated, and 351 genes, 86.7% of these genes were conserved in HS11286, NJST258_1, NTUH-K2044 and RJF293. Ten genes existed in strains NTUH-K2044 and RJF293 with high virulence, while these genes were absent in HS11286 and NJST258_1 with low virulence. The mutants with genes such as glycosyl transferase gene wzy, aggregator protein gene wzi and capsule transporter gene wza, which belong to the capsule polysaccharide gene clusters, could not be detected after serum treatment. The abundance of iron carriers gene clusters such as aerobacterin and salmonellin in each library changed less than one time. KEGG annotation results showed that most annotated genes were involved in amino acid metabolism, cofactor and vitamin metabolism, carbohydrate metabolism, etc. Conclusions:Tn-seq is a reliable method to screen functional genes. In this study, 405 candidate virulence genes of hvKp were successfully screened out, providing an experimental basis for further research on the function and regulation mechanism of new virulence genes of hvKp.

Chlorhexidine-grafted coating to improve antibacterial property of the micro/nanoporous titanium surfaces / 中华口腔医学杂志

Objective@#To investigate the antibacterial properties and the osteoblast-compatibility of chlorhexidine (CHX)-modified porous titanium.@*Methods@#Smooth pure titanium specimen with diameter of 10.0 mm and thickness of 1.5 mm treated with alkali heat method were set as control group. Those with covalent conjugation of aminosilane were set as silane group, and those with CHX grafted by glutaraldehyde were set as CHX group. Scanning electron microscope (SEM) was used to observe the surface morphology and element compositions were detected by X-ray photoelectron spectroscopy. Hydrophilicity was analyzed by surface water contact angle test (n=6), while surface amino/imine groups quantification were performed through acid orangeⅡ(n=5) and the CHX was quantified by optical densitometric method (n=5). Live/dead bacterial staining, the morphology of adherent bacteria by SEM, plate counting method and inhibition zone method were executed to evaluate the antibacterial property of the samples. Osteoblast compatibility was evaluated by methyl thiazolyl tetrazolium. Cell-bacterial co-culture was conducted to evaluated the cell viability on the samples under the circumstance with bacteria.@*Results@#After CHX grafting, pores on the titanium surface were decreased, while the atom ratio of C, N, Cl increased and the water contact angle decreased to 37.5°±4.0°. The density of CHX on the surface was (5.07±0.39) μg/cm2. The results of live/dead bacterial staining and the morphology of adherent bacteria showed that only little dead bacterial (bacterial wall rupture) adherent on the surface of CHX group, which proved that the modified surface could inhibit bacteria adhesion and even destroyed bacteria; the plate counting displayed sporadic colonies and a transparent inhibition zone could be observed, which demonstrated that CHX group could suppress bacteria multiplication from surrounding environment. When incubating for 1 and 3 days, the cell viability of CHX group showed no significant difference from that of control group (P>0.05) ; when incubating for 5 days, the value of cell viability of CHX group was 0.547±0.087, and this was significantly lower than that of the control group (0.751±0.056) (P<0.05), demonstrating a slight inhibition of cell proliferation by CHX. The results of bacteria-cell co-culture for 3 days showed that a mass of bacteria adhered on the surface of the control group while considerable cells adhered on the surface of CHX group and exhibited a good shape.@*Conclusions@#Porous titanium surface grafted by CHX showed an excellent antibacterial properties and allowed cell adhesion in bacterial circumstance, providing immediate implantation options for patients with bad oral health.

Application of nanodrug carriers in the prevention and treatment of infection around orthopedic prosthesis / 生物医学工程学杂志

Despite the continuous improvement in perioperative use of antibiotics and aseptic techniques, the incidence of infection continues to rise as the need for surgery increasing and brings great challenges to orthopedic surgery. The rough or porous structure of the prosthesis provides an excellent place for bacterial adhesion, proliferation and biofilm formation, which is the main cause of infection. Traditional antibiotic therapy and surgical debridement are difficult to determine whether the infected focus have been removed completely and whether the infection will recur. In recent years, nanotechnology has shown obvious advantages in biomaterials and drug delivery. Nano drug carriers can effectively achieve local antimicrobial therapy, prevent surgical infection by local sustained drug release or intelligent controlled drug release under specific stimuli, and reduce the toxic side effects of drugs. The unique advantages of nanotechnology provide new ideas and options for the prevention and treatment of periprosthetic infection. At present, the application of nano-technology in the prevention and treatment of infection can be divided into the addition of nano-drug-loaded materials to prosthesis materials, the construction of drug-loaded nano-coatings on the surface of prosthesis, the perfusable nano-antimicrobial drug carriers, and the stimulation-responsive drug controlled release system. This article reviews the methods of infection prevention and treatment in orthopaedic surgery, especially the research status of nanotechnology in the prevention and treatment of periprosthetic infection.

Preparation of Biological Functional Magnetic Nanoparticles and Study on the Effect of Guiding Endothelial Progenitor Cells In Vitro / 生物医学工程学杂志

Coprecipitation method was used to prepare triiron tetroxide magnetic nanoparticles enclosed in L-DOPA, and then EDC was used to activate the carboxyl group of L-DOPA after the nanoparticles were synthesized. The carboxyl group of L-DOPA formed amide bond with specific amino on the aptamer by dehydration condensation reaction. The surfaces of magnetic nanoparticles were modified with aptamer and L-DOPA. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (SEM), magnetic measurement (VSM) and other testing methods were used to detect the magnetic nanoparticles in different stages. The endothelial progeni-tor cells (EPCs) were cocultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface-modified magnetic nanoparticles to endothelial progenitor cells (EPCs) was evaluated under an applied magnetic field and simulated dynamic blood flow condition. The results showed that the prepared magnetic nanoparticles had good magnetic response, good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles could combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directionally guided on to a stent surface under the magnetic field in the dynamic flow environment.

Ne uroprotection of meteorin against oxygen-glucose deprivation-induced injury in cultured astrocytes / 医学研究生学报

Objective The expression and neuroprotective effect of meteorin in neurons and astrocytes after cerebral infarc-tion have yet to be clarified.This study was to investigate the expression and location of meteorin in the rat model of middle cerebral ar -tery occlusion (MCAO) and its neuroprotective effect against oxygen -glucose deprivation (OGD)-induced injury in cultured neurons or astrocytes. Methods Forty-two healthy adult male SD rats were randomly divided into 6 groups of equal number:sham operation and 6 h, 12 h, 24 h, 3 d, and 7 d MCAO.The cortical tissue was harvested for determination of the expression and location of meteorin by Western blot and immunohistochemistry as well as the meteorin expression in the neurons and astrocytes subjected to OGD. The neuroprotective effect of meteorin on the neurons and astrocytes was e-valuated by CCK8 and PI/Hoechst33342 staining. Results Com-pared with the sham operation group, the expression of meteorin was decreased after MCAO and reached the lowest level at 3 days ( P (0.78), and OGD+PBS (0.60) as compared with the sham control ( 1.51) (P0.05).Concerning the effect of meteorin intervention on the OGD-induced injury of the astrocytes, the A value was significantly reduced in OGD (1.24 ±0.17), OGD+meteorin (1.51 ±0.30), and OGD+PBS (1.23 ±0.16) in comparison with the sham control (2.43 ±0.12) (P<0.01), lower in the OGD and OGD+PBS groups than in the OGD+meteorin group ( P<0.05) . Conclusion Meteorin is mainly expressed in the neurons and astrocytes after MCAO and it promotes the survival of the astrocytes with OGD-induced injury.

Effect of dopamine on the activity of matrix metalloproteinases and degradation of dentin collagen / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the inhibition effect of dopamine on the activity of matrix metalloproteinases (MMP) and the effect of dopamine on degradation of dentin collagen for its potential use in caries treatment and dentin adhesive.</p><p><b>METHODS</b>In the experiment of MMP activity test, 2.0 g/L dopamine + 1.0 g/L highly purified collagenase type VIII from Clostridium histolyticum served as the experimental group, and deionized water + 1.0 g/L highly purified collagenase type VIII from Clostridium histolyticum served as the negative control group, and 2% chlorhexidine + 1.0 g/L highly purified collagenase type VIII from Clostridium histolyticum served as the positive control group, and the mixture volume ratio of the two ingredients in every group was 1:9. After 15 minutes, the enzyme activity of each sample was tested by MMP activity colerimetric quantitative detection kits, and the test was repeated 5 times in each group. In the experiment of collagen degradation, the dentin slices were demineralized with 37% phosphoric acid for 1 min. In sequence, 2 dentin slices were used to observe the morphology, and the remaining 30 dentine slices were randomly divided into three groups (n = 10) according to random number table: the negative control ones were stored in 100 µl deionized water and 900 µl collagenase (7 days, 37 °C), the positive control ones were stored in 100 µl chlorhexidine and 900 µl collagenase (7 days, 37 °C) and the experimental specimens were stored in 100 µl dopamine and 900 µl collagenase (7 days, 37 °C). The degraded collagen was investigated by assaying hydroxyproline. The framework of collagen was evaluated with field emission scanning electron microscope (FE-SEM).</p><p><b>RESULTS</b>The statistical results of completely random design ANOVA showed that the MMP activity and the amount of degraded collagen of the negative control group [(0.089 ± 0.011) µmol · min⁻¹ · mg⁻¹ and (2 837 ± 201) µg/cm²] were significantly higher than those of the positive control group [(0.038 ± 0.006) µmol · min⁻¹ · mg⁻¹ and (1 288 ± 172) µg/cm²] and the experimental group [(0.030 ± 0.009) µmol · min⁻¹ · mg⁻¹ and (1 389 ± 255) µg/cm²] (P < 0.05). SEM observation indicated that the structural integrity of the collagen network on dentin still existed in experiment samples and positive control groups, however, collagen fibrils were destructed and the structural integrity disappeared in the negative control groups.</p><p><b>CONCLUSIONS</b>Dopamine may inhibit MMP activity and reduce the amount of degraded collagen.</p>

The drug resistance situation and clinical distribution of multi-drug resistance Acinetobacter baumannii in a general hospital in 2014 / 国际检验医学杂志

Objective To investigate the drug resistance situation and clinical distribution of multi‐drug resistance Acinetobacter baumannii(MDRAB) ,in order to provide references for clinical treatment and prevention of MDRAB infection .Methods The de‐partments ,types of specimens ,time of infection ,gender and age of patients with Acinetobacter baumannii(AB)infection from Janu‐ary to December 2014 were retrospectively analysed ,and drug resistance rates of MDRAB were analysed as well .Results A total of 123 strains of MDRAB were isolated ,which accounted for 44 .73% of all strains of AB .The antibacterial resistance rates were over 90% for MDRAB against 12 out of 15 common antibacterial agents ,while the antibacterial resistance rate for MDRAB against mi‐nocycline was relatively low(19 .23% ) .Distribution of AB and MDRAB infection concentrated to certain departments ,which shown that intensive care unit(ICU) ,departments of respiratory medicine and neurosurgery were the major departments of infection .The strains of AB and MDRAB isolated from sputum specimens accounted for 84 .00% and 93 .50% respectively .There was no signifi‐cant differences of MDRAB infection among 12 Months in 2014 .There was no statistically significant differences in constituent ratio of MDRAB infection and non‐MDRAB infection between patients in different gender and between patients in different age groups . Conclusion MDRAB strains are seriously resistant to commonly used antibacterial agents ,while minocycline could still be a signifi‐cant antibacterial agent for clinical treatment of MDRAB infection .Strengthening infection management in ICU and departments of respiratory medicine and neurosurgery ,and infection management of respiratory tract and wound could have significance for reduc‐ing the risk of MDRAB infection .

Risk factors for multidrug-resistant Acinetobacter baumannii infection / 中国感染控制杂志

Objective To evaluate risk factors for multidrug-resistant Acinetobacter baumannii (MDRAB)infec-tion,so as to provide reference for making preventive and control measures of MDRAB infection.Methods Clinical data of patients with Acinetobacter baumannii (A.baumannii )infection in a hospital between April 2011 and Sep-tember 2012 were surveyed,distribution and specimen sources of A.baumannii and MDRAB were analyzed,and risk factors of MDRAB were assessed.Results Of 236 isolates of A.baumannii,74 (31.36%)were MDRAB .The isolation rate of MDRAB in intensive care unit and neurosurgery department was up to 60.00%(27/45)and 58.06%(18/31)respectively;MDRAB were mainly isolated from wound (45.45%),respiratory tract (34.27%),and urinary tract (17.65%).Univariate analysis revealed that difference in length of hospital stay,use of serum albumin,fiberbronchoscopy, coma days,tracheotomy,use of ventilator,incisional drainage,urinary catheterization,use of carbapenems,and antimicro-bial days in different groups were statistically different (P <0.05).Multivariate logistic regression analysis revealed that tracheotomy(OR95%CI :1.152-7.187),use of ventilator(OR95%CI :1.263 -7.664)were independent risk factors for MDRAB infection.Conclusion Tracheotomy and use of ventilator play an important role in the producing and sprea-ding of MDRAB ,management on drug-resistant bacteria is important in reducing MDRAB infection.

Progress in researches of in-vivo re-endothelialization at the site of implanting cardiovascular devices / 生物医学工程学杂志

Restenosis and thrombus at the site of implanting cardiovascular devices remains a significant problem in the practice of interventional cardiology. Recently, lots of studies reveal that endothelial impairment was considered as one of the most important mechanisms contributing to restenosis. The method of accelerating endothelial regeneration at the injury site could prevent restenosis and thrombus, so such methods are of importance for improving the effectiveness of interventional therapy for atherosclerosis. This paper summarized the progress in researches in-vivo re-endothelialization at the site of intravascular stent.