Research on early warning model of the hearing loss of workers exposed to noise / 中华劳动卫生职业病杂志

Objective: To explore the change of hearing threshold of workers exposed to noise, establish an individual-based hearing loss early warning model, accurately and differentiated the health of workers exposed to noise. Methods: In September 2019, all physical examination data of 561 workers exposed to noise from an enterprise were collected since their employment. Three indicators of average hearing threshold of the better ear, namely, at high frequency, 4000 Hz and speech frequency, were constructed. The generalized estimating equation (GEE) was used to adjust gender and age and establish the warning model of each indicator. Finally, sensitive indicators and warning models were screened according to AUC and Yoden index. Results: Among the 561 workers exposed to noise, 26 (4.6%) workers had hearing loss. The sensitivity indicators were the average hearing threshold at speech frequency ≥20 dB, high frequency ≥30 dB and 4000 Hz ≥25 dB. The AUC of each index was 0.602, 0.794 and 0.804, and the Youden indexes were 0.204, 0.588 and 0.608, respectively. In GEE of hearing loss warning models, high-frequency hearing threshold ≥20 dB and 4000 Hz hearing threshold ≥25 dB were the optimal models, with AUC of 0.862. Conclusion: Combined with the changes of individual hearing threshold over the years, can accurately assess the risk of individual hearing loss of workers exposed to noise.

Imaging classification and analysis of the diagnosis and treatment of infected pancreatic necrosis:a report of 126 cases / 中华外科杂志

Objective: To explore the clinical characteristics of various types of infected pancreatic necrosis(IPN) and the prognosis of different treatment methods in the imaging classification of IPN proposed. Methods: The clinical data of 126 patients with IPN admitted to the Department of Pancreatic and Biliary Surgery, the First Affiliated Hospital of Harbin Medical University from December 2018 to December 2021 were analyzed retrospectively. There were 70 males(55.6%) and 56 females(44.4%), with age(M(IQR)) of 44(17)years (range: 12 to 87 years). There were 67 cases(53.2%) of severe acute pancreatitis and 59 cases (46.8%) of moderately severe acute pancreatitis. All cases were based on the diagnostic criteria of IPN. All cases were divided into Type Ⅰ(central IPN)(n=21), Type Ⅱ(peripheral IPN)(n=23), Type Ⅲ(mixed IPN)(n=74) and Type Ⅳ(isolated IPN)(n=8) according to the different sites of infection and necrosis on CT.According to different treatment strategies,they were divided into Step-up group(n=109) and Step-jump group(n=17). The clinical indicators and prognosis of each group were observed and analyzed by ANOVA,t-test,χ2 test or Fisher exact test,respectively. Results: There was no significant difference in mortality, complication rate and complication grade in each type of IPN(all P>0.05). Compared with other types of patients, the length of stay (69(40)days vs. 19(19)days) and hospitalization expenses(323 000(419 000)yuan vs. 60 000(78 000)yuan) were significantly increased in Type Ⅳ IPN(Z=-4.041, -3.972; both P<0.01). The incidence of postoperative residual infection of Type Ⅳ IPN was significantly higher than that of other types (χ2=16.350,P<0.01). There was no significant difference in the mortality of patients with different types of IPN between different treatment groups. The length of stay and hospitalization expenses of patients in the Step-up group were significantly less than those in the Step-jump group(19(20)days vs. 33(35)days, Z=-2.052, P=0.040;59 000(80 000)yuan vs. 122 000(109 000)yuan,Z=-2.317,P=0.020). Among the patients in Type Ⅳ IPN, the hospitalization expenses of Step-up group was significantly higher than that of Step-jump group(330 000(578 000)yuan vs. 141 000 yuan,Z=-2.000,P=0.046). The incidence of postoperative residual infection of Step-up group(17.4%(19/109)) was significantly lower than that of Step-jump group(10/17)(χ2=11.980, P=0.001). Conclusions: Type Ⅳ IPN is more serious than the other three types. It causes longer length of stay and more hospitalization expenses. The step-up approach is safe and effective in the treatment of IPN. However, for infected lesions which are deep in place,difficult to reach by conventional drainage methods, or mainly exhibit "dry necrosis", choosing the step-jump approach is a more positive choice.

Hydrogen peroxide preconditioning enhances the therapeutic efficacy of Wharton's Jelly mesenchymal stem cells after myocardial infarction / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Exposure of cells to sublethal concentrations of hydrogen peroxide (H2O2) can alleviate subsequent oxidative stress-induced apoptosis. We assessed the effects of H2O2 preconditioning on the therapeutic potential of human umbilical cord Wharton's Jelly mesenchymal stem cells (WJ-MSCs) in a murine model of myocardial infarction.</p><p><b>METHODS</b>WJ-MSCs were incubated in the media for 2 hours with or without 200 µmol/L H2O2. Mice underwent left anterior descending coronary artery ligation, and received injection of phosphate buffered saline, 1×10(6) WJ-MSCs, or 1×10(6) H2O2 preconditioned WJ-MSCs 3 hours later via tail vein. Echocardiography was performed 0, 7, 14 and 28 days after surgery, and the mice were euthanized on day 28 for histological analysis. In vitro cytokine concentrations in the WJ-MSC cell supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The effect of WJ-MSC cell supernatant on the migration and proliferation of endothelial cells were observed by transwell migration and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide (MTT) assays.</p><p><b>RESULTS</b>Echocardiographic measurements revealed a significant improvement in the left ventricular contractility of the WJ-MSCs-H2O2 group compared to the WJ-MSCs group. Histological analysis revealed increased neovascularization and reduced myocardial fibrosis in the WJ-MSCs-H2O2 group compared to the WJ-MSCs group. Pretreatment of WJ-MSCs with H2O2 increased the secretion of interleukin-6 (IL-6) into the cell culture supernatant by approximately 25-fold. The culture supernatant from WJ-MSCs-H2O2 significantly increased the migration and proliferation of endothelial cells; these effects could be blocked using an anti-IL-6 antibody.</p><p><b>CONCLUSIONS</b>This study demonstrates that H2O2 preconditioning significantly enhanced the therapeutic potential of WJ-MSCs, possibly by stimulating the production of IL-6 by WJ-MSCs, which may cause migration and proliferation of endothelial cells and increase neovascularization.</p>

Short-term medication of L-carnitine before intracytoplasmic sperm injection for infertile men with oligoasthenozoospermia / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the pregnancy promoting effect of L-carnitine combined with intracytoplasmic sperm injection (ICSI) in treating male infertility with oligoasthenozoospermia.</p><p><b>METHODS</b>We assigned 129 patients with oligoasthenozoospermia to receive 2 weeks of oral L-carnitine followed by ICSI (medication group, n = 42) and ICSI alone (control group, n = 87). We compared the sperm concentration and motility, the percentage of grade a + b sperm, and sperm deformity before and after L-carnitine medication, as well as the rates of fertilization, cleavage, available embryo and clinical pregnancy between the two groups.</p><p><b>RESULTS</b>The percentage of grade a + b sperm was significantly increased after L-carnitine medication as compared with the baseline ([13.5 +/- 10.7] % vs [9.6 +/- 7.2] %, P<0.05), and so was the rate of available embryo in the medication group after ICSI in comparison with that of the control group (77.50% vs 69.04%, P<0.05).</p><p><b>CONCLUSION</b>Short-term medication of L-carnitine can improve sperm quality and raise the success rate of ICSI.</p>

TNF-α and IL-1RA polymorphisms and silicosis susceptibility in Chinese workers exposed to silica particles: a case-control study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the association of TNF-α and IL-1RA SNPs with the risk of silicosis in Chinese workers exposed to silica particles.</p><p><b>METHODS</b>Case-control study design was used to enroll 68 silicotic patients induced by silica particles and 68 healthy workers matched for length of silica particle exposure as controls. Both cases and controls were from the same company in southwest China, and each of them was requested to complete a questionnaire. Blood samples were drawn for genomic DNA extraction from each participant. The genotyping of TNF-α (-238 and -308) and IL-1RA (+2018) was performed using polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) and SYBR green-based quantitative polymerase chain reaction (qPCR), respectively. Unconditional logistic regression model was used to estimate odds ratios (ORs) and their 95% confidential intervals (CI) for SNPs.</p><p><b>RESULTS</b>No significant differences were found between cases and controls in particles exposure length, body mass index (BMI), and status of smoking and alcohol consumption except for age (P=0.001) and blood type (P=0.042). The frequencies of TNF-α (-238) and IL-1RA (+2018) genotypes in cases were significantly different from those in controls, (P=0.001 and P=0.002, respectively), while a borderline significant difference was found in the frequencies of TNF-α (-308) between cases and controls (P=0.063). The variants of three SNPs increased the risk of silicosis in the Chinese workers exposed to silica particles. The adjusted ORs of TNF-α (-308), TNF-α (-238) and IL-1RA (+2018) were 2.8 (95% CI: 1.1-7.5), 20.9 (95% CI: 1.8-236.4) and 4.0 (95% CI: 1.6-10.1), respectively.</p><p><b>CONCLUSION</b>It is suggested that cytokine polymorphisms of TNF-α (-238, -308) and IL-1RA (+2018) are associated with the risk of silicosis in the Chinese workers exposed to silica particles. Further independent studies on the interaction between SNPs and exposure to silica particles with a larger sample size are therefore warranted.</p>

Impact of body mass index on outcome of in vitro fertilization-embryo transfer in patients with polycystic ovarian syndrome / 上海第二医科大学学报

Objective To compare the clinical outcomes of in vitro fertilization-embryo transfer(IVF-ET) in polycystic ovary syndrome(PCOS) patients with different body mass index(BMI).MethodsEighty-seven PCOS patients who received IVF-ET were classified into four groups according to BMI: group A,BMI0.05).ConclusionThe doses of gonadotropins are increased in PCOS patients with increasing BMI.The number of usable embryo is significant decreased in PCOS patients with BMI≥25 kg/m2.

Performance of underground heat storage system in a double-film-covered greenhouse / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2 degrees C, 4.6 degrees C and 2.0 degrees C higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.