[Discussion on the application status and method improvement of gas chromatography in occupational health inspection standards in China].

As a rapid, accurate and efficient analytical technique, gas chromatography is widely used in the detection of volatile organic compounds and inorganic small molecule toxins, and it is the main analytical method in the national testing standards for occupational health. The existing effective national standards of gas chromatography for the detection of some substances have low column efficiency, high toxicity of reagents, poor correlation of the standard curve and low desorption efficiency and other problems, some of which can be solved through method improvement. At the same time, with the use of new materials and new processes, new types of toxic substances are emerging, and there are still many occupational disease hazards of limited value without supporting detection methods, gas chromatography can be applied to the detection of some toxic substances to better complement the vacancy of China's occupational health detection methods. This paper analyzes the current situation of the application of gas chromatography in occupational health testing standards, discusses the improvement of some of these methods, and helps to promote the application and development of gas chromatography in occupational health testing.

[Effect of preimplantation genetic testing for aneuploidies on pregnancy outcome in patients with unexplained recurrent spontaneous abortion].

Objective: To investigate the effect of preimplantation genetic testing for aneuploidies (PGT-A) on pregnancy outcome and perinatal outcome of single live birth in patients with unexplained recurrent spontaneous abortion (URSA). Methods: The clinical data of 351 cycles of the first transfer of a blastocyst through whole embryo freezing in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from 2019 to 2021 were retrospectively analyzed. According to whether PGT-A was performed before the transfer, the patients were divided into two groups: the PGT-A group (160 cycles) and the control group (191 cycles) were treated with in vitro fertilization/intracytoplasmic sperm microinjection (IVF/ICSI). To adjust for confounding factors, propensity score matching (PSM) was carried out in a 1∶1 ratio between the two groups of patients. After matching, 98 patients in the PGT-A group and 98 patients in the control group were compared for pregnancy outcome and perinatal outcome of singleton live births. Results: Before PSM, the female age in the PGT-A group was (33.6±4.0) years, lower than that in the control group (34.5±4.5) years (P=0.049). Male age in the PGT-A group was (33.6±4.1) years, lower than that in the control group (35.3±5.1) years (P<0.001). There were statistically significant differences between the two groups in infertility factors, female body mass index (BMI), years of infertility, number of spontaneous abortions, basal follicle stimulating hormone (FSH), endometrial thickness on the day of transfer and the percentage of high-quality blastocysts (all P values<0.05); After PSM, there was a statistically significant difference in fertilization methods and infertility factors between the two groups (P<0.05), while other differences were not statistically significant (all P values>0.05); There were statistically significant differences between the two groups in implant rate [63.3% (62 cycles) vs. 49.0% (48 cycles), P=0.044], clinical pregnancy rate [63.3% (62 cycles) vs. 49.0% (48 cycles), P=0.044], and live birth rate [42.9% (42 cycles) vs. 28.6% (28 cycles), P=0.037]. There was no statistically significant difference in perinatal outcomes between the PGT-A group and the control group in obtaining single birth live births (P>0.05). Conclusion: Compared with conventional IVF/ICSI assisted pregnancy, PGT-A assisted pregnancy significantly improves implantation rate, clinical pregnancy rate, and live birth rate in URSA patients. PGT-A improves the pregnancy outcomes in URSA patients but not perinatal outcomes in patients with singleton live births.

[The effect of chronic endometritis on the clinical outcomes of patients with failure of first embryo transfer].

Objective: To investigate the effect of chronic endometritis (CE) on the clinical outcomes of patients with failure of first embryo transfer. Methods: A total of 5 605 cycles of frozen-thawed single blastocyst transfer in the reproductive center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to June 2021 were retrospectively collected. After the failure of first embryo transfer, all patients underwent hysteroscopy, and when necessary, endometrial pathology and immunohistochemistry were combined to diagnose CE. Patients were divided into two groups: non-CE group (5 033 cycles) and CE treatment group (572 cycles). The main outcome was live birth rate and the secondary outcomes included clinical pregnancy rate and early abortion rate. The quantitative data were represented by Median (Q1, Q3). The rank sum test was used for comparison between groups. The factors related to live birth rate were analyzed by binary logistic regression model. Results: The incidence of CE was 10.21% (572 cycles) in patients with the failure of first embryo transfer. The maternal age in the non-CE group was 31.0 (29.0, 34.0) years old, and that in the CE treatment group was 31.0 (29.0, 34.0) years old (P<0.001). There was a statistically significant difference in endometrial preparation between the two groups (P=0.010). The endometrial thickness in the CE group was 9.0 (8.2, 10.3) mm on progesterone transformation day, which was higher than that of [9.5 (8.6, 11.0) mm] in the non-CE group (P<0.001). There was no significant difference in clinical pregnancy rate (60.3% (3 035 cycles) vs 63.1% (361 cycles), P=0.193), early abortion rate (17.1% (520 cycles) vs 20.5% (74 cycles), P=0.112) and live birth rate (49.2% (2 477 cycles) vs 49.3% (282 cycles), P=0.969) between the non-CE group and the CE treatment group. The maternal age, endometrial thickness on progesterone transformation day and blastocyst grade were related factors of the live birth rate, and the OR(95%CI) were 0.94 (0.93-0.96), 1.10 (1.06-1.14) and 2.07 (1.84-2.32)), respectively (all P<0.001). Compared with the non-CE group, the CE treatment group did not affect the live birth rate after transplantation, the aOR (95%CI) was 0.99 (0.82-1.18), P=0.882. Conclusions: For patients who underwent the failure of first embryo transfer, hysteroscopy is recommended before single frozen blastocyst transfer, and if necessary, combined with immunohistochemical screening for CE. After standardized treatment, CE patients could obtain similar clinical pregnancy rate, early miscarriage rate and live birth rate as non-CE patients.

[Research progress and application prospect of stem cells in inflamed dental tissues on periodontal bone regeneration].

Tissue engineering has become a research hotspot regarding periodontal bone regeneration in recent years. Generally, stem cells used in periodontal tissue engineering are derived from healthy dental tissues, while restricted due to the strict indication of tooth extraction and limited sources. Stem cells in inflamed dental tissues mainly derive from inflamed pulp, periapical and periodontal tissues. Stem cells in inflamed dental tissues are abundant and retain most of the basic characteristics of stem cell compared with the ones derived from healthy dental tissues, which can be a promising source of stem cells for periodontal bone regeneration. In this review, we summarize the current application and prospect of stem cells in inflamed dental tissues on periodontal bone regeneration, and then discuss their feasibility as seed cells, in order to provide a reference for future research and clinical application of stem cells in inflamed dental tissues.

Increased Expression of Efflux Pump norA Drives the Rapid Evolutionary Trajectory from Tolerance to Resistance against Ciprofloxacin in Staphylococcus aureus.

The intensively intermittent use of antibiotics promotes the rapid evolution of tolerance, which may lead to resistance acquisition in the following evolutionary trajectory. In addition to directly exporting antibiotics as an instant resistance strategy, efflux pumps are overexpressed in tolerant strains. To investigate how efflux pumps participate in resistance development from tolerance to resistance, we performed in vitro evolutional experiments against the antibiotic ciprofloxacin in norA efflux pump mutants of Staphylococcus aureus. These experiments demonstrated that overexpression of norA rapidly facilitated the development of ciprofloxacin resistance from tolerance to resistance through elevated spontaneous mutations. The generated resistance mutations were further fixed in the population by increasing survival ability. The observed Ser80Phe and Glu84Lys mutations in the topoisomerase IV ParC (GrlA in S. aureus) may be responsible for tolerant strains to develop resistance to ciprofloxacin since it has been reported that such mutations disrupt the water-metal ion bridge between quinolones and ParC. MepA and Sav1866 are related to the same antibiotic (ciprofloxacin) susceptibility as NorA, and they also contributed to resistance development against ciprofloxacin. MgrA positively regulated NorA expression and the development of ciprofloxacin resistance. Importantly, blocking the evolutionary pathway by coadministering ciprofloxacin with the efflux pump inhibitor reserpine effectively delayed the resistance acquisition in an in vitro experiment. This study illustrated the role of efflux pumps in the evolutionary trajectory from tolerance to resistance. The delayed resistance development caused by the efflux pump inhibitor illuminates a possible strategy for postponing the resistance acquisition from tolerance to resistance by disrupting efflux pumps.

[Effect of dNLR and LIPI scores on the prognosis of elderly patients with non-surgical treatment of non-small cell lung cancer].

Objective: To investigate the effects of derived neutrophil to lymphocyte ratio (dNLR) and lung immune prognostic index (LIPI) score on the overall survival (OS) of non-surgical elderly non-small cell lung cancer (NSCLC) patients. Methods: Clinical and pathological data of NSCLC patients in Hebei General Hospital from January 2014 to June 2018 were collected retrospectively. The dNLR value was calculated based on the results of blood routine before treatment, and the optimal cut-off value of dNLR was obtained by ROC curve. The patients were divided into low dNLR level group and high dNLR level group based on the optimal dNLR cut-off value. The groups were classified as good, intermediate and poor based on the LIPI score consisting of lactate dehydrogenase (LDH) and dNLR tested before treatment. The Kaplan-Meier method and Log rank test were used for survival analysis, and the Cox risk proportional regression model was used for analysis of prognostic influences. Results: The area under the ROC curve for dNLR predicting prognosis in non-surgical elderly NSCLC patients was 0.591 (95% CI: 0.491, 0.692; P=0.093). The optimal cut-off value for dNLR predicting prognosis in elderly NSCLC patients was 2.515, with a sensitivity of 45.5% and a specificity of 81.8%. The gender, BMI, pathological type and degree of tumor differentiation were associated with dNLR levels (P<0.05). The median survival times were 16 and 10 months for patients in the low dNLR level group (dNLR<2.51) and high dNLR level group (dNLR≥2.51), respectively (P<0.001), and 15, 10 and 6 months for patients with good, intermediate and poor LIPI scores, respectively (P<0.001). The age, gender, smoking, pathological type, tumor differentiation, clinical stage, BMI, dNLR level, LDH level and LIPI scores were all associated with patient prognosis (P<0.05), and age≥76 years, tumor differentiation and clinical stage Ⅲ and Ⅳ were independent factors influencing patient prognosis (P<0.05). Conclusion: No matter what treatment measures are taken, dNLR level and LIPI score are related to patients' prognosis, and non-surgical elderly NSCLC patients with high dNLR level and poor LIPI score before treatment have worse prognoses.

[Determination of phenyl glycidyl ether in workplace air by solvent desorption gas chromatography].

Objective: To establish a solvent desorption gas chromatographymethod for the determination of phenyl glycidyl ether (PGE) . Methods: From October to December 2020, PGE in the air of workplace was collected with carbon tube and desorbed by 25% acetone-carbon disulfide. The target toxicant was separated with the gas chromatography (GC) column and analyzed with flame ionization detector (FID), and quantified by peak area. Results: The linear range of PGE in the air of workplace was 10.0-1109.0 µg/ml, the linear equation was y=1.156x-4.328, with a correlation coefficient of 0.9997. The limit of detection was 3.0 µg/ml. The lower limit of quantification was 10.0 µg/ml. The intar-batch and inter-batch precisionswere 4.9%-6.4% and 6.2%-6.9%, respectively. The recovery rate was ranged from 97.2%-98.8%, the average collection efficiency was 100%, and the average extraction efficiency was 90.1%. The samples could be stored at 4 ℃ for 7 d. Conclusion: This method has high precision and good accuracy, and it is applicable for the determination of PGE in workplace air.

[Prognosis factors for death within 90 days of discharge in patients with acute kidney injury requiring continuous renal replacement therapy after surgery for Stanford type A acute aortic dissection].

Objective: To investigate the prognosis factors for death within 90 days after discharge in patients with acute kidney injury(AKI) treated requiring continuous renal replacement therapy(CRRT) undergoing surgery for acute Standford type A aortic dissection. Methods: The clinic data of 126 patients undergoing CRRT for postoperative AKI after acute type A aortic dissection surgery in the Center for Cardiac Intensive Care, Beijing Anzhen Hospital from July 2016 to February 2019 were analyzed retrospectively. There were 83 males and 43 females, aging (52.9±11.2) years(range: 25 to 70 years). The patients' demographic characteristics, disease-related information, perioperative data, laboratory indexes during CRRT, complications, and survival information within 90 days after discharge were recorded. Independent prognosis factors for death within 90 days of discharge were determined by Kaplan-Meier survival analysis, univariate and multifactorial Cox regression analysis. Results: Totally 57 of 126 patients(45.2%) died over the first 90 days after discharge. Kaplan-Meier survival analysis and univariate Cox regression analysis showed that there were significant differences between the non-survival and survival group including ≥65 years old, high lactate values 12 hours after CRRT, pulmonary infection, liver dysfunction, presence of permanent neurological complications, and postoperative ejection fraction(EF)<45%. Multifactorial Cox regression analysis revealed that ≥65 years old(HR=2.14, 95%CI: 1.09 to 4.21, P=0.03), high lactate values 12 hours after CRRT(HR=1.13, 95%CI: 1.06 to 1.20, P=0.01) and postoperative EF<45%(HR=2.21, 95%CI: 1.09 to 4.51, P=0.03) were independent prognosis factors for patients' death within 90 days after hospital discharge. Conclusions: ≥65 years old, high lactate values 12 hours after CRRT and postoperative EF<45% are independent prognosis factors for death within 90 days after discharge in patients undergoing CRRT for AKI after acute type A aortic dissection surgery. Proper identification and management of prognosis factors could be beneficial to improve patients' outcomes.

[Establishment of a deep learning-based visual model for intelligent recognition of Oncomelania hupensis].

OBJECTIVE: To establish a deep learning-based visual model for intelligent recognition of Oncomelania hupensis, the intermediate host of Schistosoma japonicum, and evaluate the effects of different training strategies for O. hupensis image recognition. METHODS: A total of 2 614 datasets of O. hupensis snails and 4 similar snails were generated through field sampling and internet capture, and were divided into training sets and test sets. An intelligent recognition model was created based on deep learning, and was trained and tested. The precision, sensitivity, specificity, accuracy, F1 score and Youden index were calculated. In addition, the receiver operating characteristic (ROC) curve of the model for snail recognition was plotted to evaluate the effects of "new learning", "transfer learning" and "transfer learning + data enhancement" training strategies on the accuracy of the model for snail recognition. RESULTS: Under the "transfer learning + data enhancement" strategy, the precision, sensitivity, specificity, accuracy, Youden index and F1 score of the model were 90.10%, 91.00%, 97.50%, 96.20%, 88.50% and 90.51% for snail recognition, which were all higher than those under both "new learning" and "transfer learning" strategies. There were significant differences in the sensitivity, specificity and accuracy of the model for snail recognition under "new learning", "transfer learning" and "transfer learning + data enhancement" training strategies (all P values < 0.001). In addition, the area under the ROC curve of the model was highest (0.94) under the "transfer learning + dataenhancement" training strategy. CONCLUSIONS: This is the first visual model for intelligent recognition of O. hupensis based on deep learning, which shows a high accuracy for snail image recognition. The "transfer learning + data enhancement" training strategy is helpful to improve the accuracy of the model for snail recognition.

Dentine sialophosphoprotein signal in dentineogenesis and dentine regeneration.

Dentineogenesis starts on odontoblasts, which synthesise and secrete non-collagenous proteins (NCPs) and collagen. When dentine is injured, dental pulp progenitors/mesenchymal stem cells (MSCs) can migrate to the injured area, differentiate into odontoblasts and facilitate formation of reactionary dentine. Dental pulp progenitor cell/MSC differentiation is controlled at given niches. Among dental NCPs, dentine sialophosphoprotein (DSPP) is a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING) family, whose members share common biochemical characteristics such as an Arg-Gly-Asp (RGD) motif. DSPP expression is cell- and tissue-specific and highly seen in odontoblasts and dentine. DSPP mutations cause hereditary dentine diseases. DSPP is catalysed into dentine glycoprotein (DGP)/sialoprotein (DSP) and phosphoprotein (DPP) by proteolysis. DSP is further processed towards active molecules. DPP contains an RGD motif and abundant Ser-Asp/Asp-Ser repeat regions. DPP-RGD motif binds to integrin αVß3 and activates intracellular signalling via mitogen-activated protein kinase (MAPK) and focal adhesion kinase (FAK)-ERK pathways. Unlike other SIBLING proteins, DPP lacks the RGD motif in some species. However, DPP Ser-Asp/Asp-Ser repeat regions bind to calcium-phosphate deposits and promote hydroxyapatite crystal growth and mineralisation via calmodulin-dependent protein kinase II (CaMKII) cascades. DSP lacks the RGD site but contains signal peptides. The tripeptides of the signal domains interact with cargo receptors within the endoplasmic reticulum that facilitate transport of DSPP from the endoplasmic reticulum to the extracellular matrix. Furthermore, the middle- and COOH-terminal regions of DSP bind to cellular membrane receptors, integrin ß6 and occludin, inducing cell differentiation. The present review may shed light on DSPP roles during odontogenesis.

The morphological and histological study of chicken left ovary during growth and development among Hy-line brown layers of different ages.

Chicken ovaries are known to develop asymmetrically and only the left ovary fully develops. Although both have been greatly investigated, a gap in scientific reports is still felt between 2-mo-old and sexual maturity. In this study, we aimed at investigating the changes in components that occur during growth to analyze the morphohistological correlation between the left ovary and the follicle development at different age stages in Gallus domesticus. The ovaries were harvested from 60 chickens aged 1 and 3-wk-old, 1, 2, 3, and 4-mo-old (n = 10 per age group), then fixed in AAF solution. Hematoxylin-and Eosin protocol was used to stain the tissue for microscopic observations. Results revealed that the left ovary exhibited an ovarian tissue, a site of follicular growth that displayed various shapes from smooth to greatly indented as the follicles differentiated. Atretic follicles at various regression stages were noticed frequently as the chicks grew in age from 3-wk-old onward along with their differentiation. Rete ovarii, remnants from the male homologs were observed throughout the whole study showing epoöphoron, connecting rete, and gland-like structures that tend to diminish with age. The feature of the left ovary is closely related to the follicular developmental stage, and the bigger and differentiated the follicles are, the more indented and irregular its epithelium appears. Atresia is a normal physiological process that we observed throughout the whole study. Also that, rete ovarii do not spontaneously arise in the ovary but it develops and grows in juvenile chicken as well as in adult ones.

[Spatio-temporal patterns of Oncomelania hupensis snail habitats in Suzhou, Wuxi and Changzhou cities along the Taihu Lake region].

OBJECTIVE: To investigate the spatio-temporal distribution characteristics of Oncomelania hupensis snail habitats in three cities of Suzhou, Wuxi and Changzhou along the Taihu Lake region, so as to provide technical supports for establishing a sensitive and highly effective surveillance and forecast system for schistosomiasis. METHODS: Snail distribution data were collected from Suzhou, Wuxi and Changzhou cities from 1950 to 2018, and the changing trend for snail habitats were described over years. In addition, the clusters of snail habitats were detected using Kernel density analysis and SaTScan space-time scan analysis. RESULTS: The number of snail habitats appeared a single-peak distribution in Suzhou, Wuxi and Changzhou cities from 1950 to 2018, which peaked in 1970 and then declined rapidly. There were 62.68% of snail habitats eliminated within 10 years after identification, of which 38.24% were eliminated at the year of identification. Kernel density analysis and SaTScan space-time scan analysis revealed that high-density clusters of snail habitats were mainly distributed in Kunshan City, Wuzhong District and Xiangcheng District from 1970 to 1980, and in Yixing City in 1990; since then, the clusters gradually shrank, and overall appeared a move from northeast to west of Taihu Lake. A total of 4 new clusters were detected after 1970, as revealed by space-time scanning of snail habitats. In current snail habitats, emerging snail habitats are mainly identified in Huqiu District (Dongzhu Town), Wuzhong District (Guangfu Town), Taicang City (Shaxi Town) and Jintan District, and re-emerging snail habitats are scattered in 7 districts. CONCLUSIONS: The distribution of snail habitats are spatio-temporal aggregation in Suzhou, Wuxi and Changzhou cities. The monitoring and prediction of emerging and re-emerging snail habitats are the key points in the future.

[Determination of Cyclohexene in workplace air by Solvent desorption gas chromatography].

Objective: To establish a solvent desorption gas chromatography method for determination of cyclohexene in workplace air. Methods: Cyclohexene in the air of workplace was collected with carbon tube and desorbed by carbon disulfide. The target toxicant was separated with the GC column and analyzed with FID detector, identified by retention time, and quantified by peak area. Results: The linear range of cyclohexene in the air of workplace was 0.77~4 050.00 µg/ml, with a correlation coefficient of 0.9999. The limit of detection was 0.23 µg/ml. The lower limit of quantification was 0.77 µg/ml. The minimum detectable concentration was 0.15 mg/m(3) under1.5 L sampling volume and 1.0 ml extraction solution volume. The within-run precision of different cyclohexene concentrations was 0.62%~1.9% and the between-run precisions was 1.5%~3.5%; The average extraction efficiency was 96.4%; Penetration capacity (100 mg of carbon tube) was 29.4 mg; The average collection efficiency was 100%; The samples could be stored for 7 days at room temperature. When placed in 4 ℃ refrigerator, the samples could be stored for 14 days. The potential coexistence of cyclohexane, hexane, benzene, toluene and ethylbenzene with cyclohexene in the air did not interfere with the results of determination. Conclusion: This method has high sensitivity, precision, accuracy and lower limit of detection and it is applicable for determination of cyclohexene in workplace air.

[Physiological and pathological effects of nitric oxide and nitric oxide synthase in oral cavity].

Nitric oxide (NO) is a short-lived free radical which is not only involved in regulating many physiological processes of the body, but also closely related to many diseases. Nitric oxide synthase (NOS) is the key enzyme for NO production. NOS exists as three distinct isoforms, the endothelial NOS (eNOS), neuronal NOS (nNOS) and inducible NOS (iNOS). It has been found that nNOS and eNOS were expressed in normal pulp tissues, periodontal tissues and salivary glands, and the NO produced from nNOS and eNOS was involved in their physiological functions. NO and iNOS are involved in the occurrence and development of pulpitis, periodontitis, salivary gland disease and oral cancer. This review focuses on the physiological and pathological effects of NO and different subtypes of NOS in oral cavity.

[Discussion on the consistency of detection methods of main indexes of workplace air, ambient air and indoor air].

Major air pollutants include particulate matter, ozone, sulfur dioxide and nitrogen dioxide, etc. Recent posts have confirmed that air pollution has a variety of adverse health effects on people's health.For professional people, because of occupational hazards of these major atmospheric pollutants also exist in the workplace, is likely to suffer from the double hazards of occupational hazards and air pollutants in the workplace, if similar pollutants are present in the home, the daily exposure concentration of the occupational population may be significantly higher than that of the general population. Exposure limits and testing methods for major atmospheric pollutants (particulate matter or dust, ozone, sulfur dioxide and nitrogen dioxide) are set by relevant standards in workplace air, ambient air and indoor air. However, due to different places and different management departments, there are differences in the detection methods of the same indicators, which brings difficulties to estimate the total daily exposure level. The purpose of this paper is to discuss the "consistency" of the detection method of relevant pollutants in the air, in order to provide scientific basis for estimating the daily exposure level of pollutants in different populations.

[Consideration of surgeons participating in 2019 coronavirus disease emergency medical rescue].

As a newly epidemic, 2019 coronavirus disease (COVID-19) with a concentrated outbreak poses a great challenge to medical treatment. The severe and critical patients are complex complicatied with the psychological problems, and the medical staff are overworked and under tremendous psychological pressure. The surgeon participated in emergency medical rescue could provide professional treatment for the patients combined with surgical diseases, as well as specialized training for the non-surgeon crew, to reduce surgical-related mortality. With the advantages of good team consciousness, strong aseptic concept and good psychological quality, the surgeons can quickly adapt to and carry out rescue work under the premise of good self-protection. Surgeons need to develop critical care management concepts and focus on the critical care support equipment. Some suggestions are put forward for the standardized training of resident surgeons to cultivate compound talents. It is hoped that this article can lead to the thinking of how to participate in the emergency medical rescue of infectious diseases among surgeons and provide some enlightenment for future surgical education.

LINC00511 accelerates the proliferation of cardiomyocytes after myocardial ischemia/reperfusion injury by absorbing miRNA-515-5p.

OBJECTIVE: The aim of this study was to clarify the role of LINC00511 in regulating the proliferative ability of cardiomyocytes undergoing ischemia/reperfusion (I/R) injury by absorbing miRNA-515-5p. MATERIALS AND METHODS: Adult male C57BL/6 mice were subjected to I/R injury, and I/R model was constructed in vivo. Primary cardiomyocytes were isolated from 1-2 days-old male mice and treated with H2O2 to establish the I/R model in vitro. The relative expression level of LINC00511 was determined after ligation of the anterior descending coronary artery (LAD) in mice or H2O2 induction in primary cardiomyocytes for different time points, respectively. The regulatory effect of LINC00511 on the viability of H2O2-treated cardiomyocytes was assessed. Subsequently, the interaction between LINC00511 and miRNA-515-5p was evaluated by Dual-Luciferase Reporter Gene Assay. Furthermore, the viability and 5-Ethynyl-2'-deoxyuridine (EdU)-positive rate influenced by LINC00511/miRNA-515-5p were examined. RESULTS: LINC00511 was gradually downregulated with the prolongation of I/R procedures in mice or H2O2 treatment in primary cardiomyocytes. The overexpression of LINC00511 significantly elevated the viability and EdU-positive rate in H2O2-treated cardiomyocytes. LINC00511 could bind to miRNA-515-5p. Meanwhile, there was a negative correlation between the levels of LINC00511 and miRNA-515-5p. In addition, the overexpression of miRNA-515-5p reversed the promoting effect of LINC00511 on the proliferative ability of H2O2-treated cardiomyocytes. CONCLUSIONS: LINC00511 accelerates the proliferation of cardiomyocytes after I/R by targeting miRNA-515-5p.