Background Kurtosis reflecting noise's temporal structure is an effective metric for evaluating noise-induced hearing loss (NIHL), and its threshold is still unclear. Objective To explore the energy range of kurtosis and the threshold of NIHL induced by kurtosis in this energy rangeMethods Using cross-sectional design, 4631 noise-exposed workers in manufacturing industry were selected. The hearing loss and noise exposure data of each worker were collected. Logistic regression model was used to establish the dose-response relationship between noise exposure and hearing loss and estimate the range of energy effects. Restricted cubic spline model was utilized to analyze the dose-response relationship curves of kurtosis to noise-induced hearing loss (NIHI) and high-frequency noise-induced hearing loss (HFNIHL) under different 8 h equivalent sound levels (L_{EX,8 h}), as well as to estimate the kurtosis effect threshold. Results The logistic regression model analysis showed that the prevalence of NIHI and HFNIHL increased significantly with increase of L_{EX,8 h} for steady noise; when L_{EX,8 h} of non-steady noise was 80-100 dB(A), the risk of hearing loss increased with an increase in kurtosis (P<0.05). The restricted cubic spline model showed that when L_{EX,8 h} of non-steady noise was 0-80 dB(A) or >100 dB(A), there was no significant relationship between kurtosis and NIHI or HFNIHL. When L_{EX,8 h} was 80-100 dB(A), there was a significant nonlinear dose-response relationship between kurtosis and NIHL or HFNIHL (P <0.001), and kurtosis > 28.08 exerted effect in elevating NIHI or HFNIHL. Conclusion The effect threshold of kurtosis on NIHL is 28.08 when non-steady noise levels are in the range of 80-100 dB(A). The effect threshold of kurtosis needs further verification.

BACKGROUND:Aerobic exercise can suppress liver fibrosis in diabetic mice.However,the specific mechanism is yet to be elucidated.OBJECTIVE:To investigate the protective effect and mechanism of aerobic exercise on liver fibrosis in db/db mice via the transforming growth factor-β/Smad signaling pathway.METHODS:8-week-old male db/db mice and age-matched m/m mice were randomly divided into m/m control group,m/m+exercise group,db/db control group,and db/db+exercise group,with 10 mice in each group.Mice in the exercise group were subjected to a 12-week aerobic exercise.After the exercise,fasting blood glucose levels were measured in mice,and glucose tolerance and insulin tolerance tests were conducted.Mouse liver was extracted to calculate liver index and mouse eyeballs were taken to collect blood sample and detect biochemical indicators.Masson,oil red O and Hematoxylin-eosin staining were used to detect and analyze the pathological changes in mouse liver tissues.Immunohistochemistry was used to determine the protein expression levels of transforming growth factor-β1 and p-Smad3.Western blot analysis was applied to determine the protein expression levels of transforming growth factor-β1,Smad3,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen.RESULTS AND CONCLUSION:Compared with the m/m group and m/m+exercise group,body mass,liver mass,liver index,fasting blood glucose,triglycerides,total cholesterol,low-density lipoprotein and creatine kinase levels were significantly increased(P<0.01),but the high-density lipoprotein level significantly decreased(P<0.01)in the db/db group;the protein expressions of transforming growth factor-β1,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen significantly increased(P<0.01)in the db/db group;the area under curve of glucose and insulin tolerance tests significantly increased(P<0.01)in the db/db group;and pathological staining of the liver in the db/db group showed extensive infiltration of inflammatory cells,increased lipid droplets,and significant fibrosis.In the db/db+exercise group,aerobic exercise could significantly reduce body mass,liver mass,liver index,fasting blood glucose,triglycerides,total cholesterol,low-density lipoprotein and creatine kinase levels(P<0.05 or P<0.01),and increase high-density lipoprotein level(P<0.05).Similarly,a marked decrease was observed in the protein expression levels of transforming growth factor-β1,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen(P<0.05 or P<0.01)in the db/db+exercise group.In addition,the area under the curve of glucose tolerance and insulin tolerance tests significantly decreased(P<0.01,P<0.05),and pathological changes in liver tissues were significantly improved.In conclusion,aerobic exercise can attenuate liver fibrosis in diabetic mice,which may be related to the regulation of the transforming growth factor-β1/Smad signaling pathway.

BACKGROUND:Aerobic exercise can suppress liver fibrosis in diabetic mice.However,the specific mechanism is yet to be elucidated.OBJECTIVE:To investigate the protective effect and mechanism of aerobic exercise on liver fibrosis in db/db mice via the transforming growth factor-β/Smad signaling pathway.METHODS:8-week-old male db/db mice and age-matched m/m mice were randomly divided into m/m control group,m/m+exercise group,db/db control group,and db/db+exercise group,with 10 mice in each group.Mice in the exercise group were subjected to a 12-week aerobic exercise.After the exercise,fasting blood glucose levels were measured in mice,and glucose tolerance and insulin tolerance tests were conducted.Mouse liver was extracted to calculate liver index and mouse eyeballs were taken to collect blood sample and detect biochemical indicators.Masson,oil red O and Hematoxylin-eosin staining were used to detect and analyze the pathological changes in mouse liver tissues.Immunohistochemistry was used to determine the protein expression levels of transforming growth factor-β1 and p-Smad3.Western blot analysis was applied to determine the protein expression levels of transforming growth factor-β1,Smad3,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen.RESULTS AND CONCLUSION:Compared with the m/m group and m/m+exercise group,body mass,liver mass,liver index,fasting blood glucose,triglycerides,total cholesterol,low-density lipoprotein and creatine kinase levels were significantly increased(P<0.01),but the high-density lipoprotein level significantly decreased(P<0.01)in the db/db group;the protein expressions of transforming growth factor-β1,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen significantly increased(P<0.01)in the db/db group;the area under curve of glucose and insulin tolerance tests significantly increased(P<0.01)in the db/db group;and pathological staining of the liver in the db/db group showed extensive infiltration of inflammatory cells,increased lipid droplets,and significant fibrosis.In the db/db+exercise group,aerobic exercise could significantly reduce body mass,liver mass,liver index,fasting blood glucose,triglycerides,total cholesterol,low-density lipoprotein and creatine kinase levels(P<0.05 or P<0.01),and increase high-density lipoprotein level(P<0.05).Similarly,a marked decrease was observed in the protein expression levels of transforming growth factor-β1,p-Smad3,α-smooth muscle actin,type I collagen and type III collagen(P<0.05 or P<0.01)in the db/db+exercise group.In addition,the area under the curve of glucose tolerance and insulin tolerance tests significantly decreased(P<0.01,P<0.05),and pathological changes in liver tissues were significantly improved.In conclusion,aerobic exercise can attenuate liver fibrosis in diabetic mice,which may be related to the regulation of the transforming growth factor-β1/Smad signaling pathway.

Objective:To determine the content of the released nickel ion through the 7 extraction media to extract the Ni-Ti wires and to plot the curve of the released nickel ion so as to identify a leaching medium that can be substituted for blood for in vitro Ni release evaluation. Methods:The release of Ni through microwave digestion/inductively coupled plasma mass spectrometry (ICP-MS) in the goat serum was determined. Because of the high content of Ni release, it could be determined by diluting the extraction medium, and other extraction media could be determined directly. Ni release standard curves were plotted by the release amount and different time point variables. Though the different extraction media Ni release curves confirm the specificity of extraction media instead of blood.Results:By analyzing the Ni release curves of seven leaching media, it was found that none of these seven extraction media was suitable for the evaluation of Ni release in in vitro leaching media. Considering the safety of the leaching medium and the simplicity of preparation, hydrochloric acid solution was chosen as the leaching medium, but the concentration needed to be diluted accordingly. Finally, a hydrochloric acid solution was created as an alternative to blood for the in vitro study of Ni release from Ni-Ti alloy cardiovascular products, with a volume fraction of 0.005%. Conclusions:The in vitro leaching medium that can replace blood was found to be hydrochloric acid for the time being, but its concentration was too high, resulting in too much Ni release as well, which deviated from the actual situation. Therefore, the hydrochloric acid solution was diluted step by step, and the Ni release curve was examined until it was close to the clinical release level, and the actual concentration was determined, thus laying a solid foundation for the subsequent evaluation of the safety and risk.

Objective To investigate the effect of erythroid differentiation associated gene(EDAG)on hematopoietic stem/progenitor cells(HSPCs)under chronic inflammation.Methods In this study,EDAG-/-and wild type(WT)mice were divided into the experiment group and control group.An infectious chronic inflammation model was established via multiple intraperitoneal injections of Listeria monocytogenes(LM),while a sterile chronic inflammation model was generated via multiple intraperitoneal injections of polyinosinic-polycytidylic acid[Poly(I∶C)].The effect of EDAG on HSPCs was explored under chronic inflammation conditions.Results In the LM repeated infection model,EDAG deletion led to a decrease in HSPCs and long-term hematopoietic stem cells(LT-HSCs)in mice as well as a significant bias towards myeloid differentiation in peripheral blood.Similarly,EDAG knockout also resulted in reduced numbers of HSPCs and decreased colony-forming ability in aseptic chronic inflammation models.Conclusion EDAG deficiency accelerates HSPC depletion in young mice under chronic inflammation,indicating strong protection of EDAG against HSPC damage induced by chronic inflammation.

Objective:To analyze the influencing factors of thyroid volume in children aged 8 - 10 in Yunnan Province, and provide scientific basis for improving iodine deficiency disorders monitoring.Methods:From March to July 2020, in 129 counties (cities, districts) under the jurisdiction of Yunnan Province, each county (city, district) was divided into 5 sampling areas based on east, west, south, north, and middle. One township was selected from each area, and 40 non-boarding children aged 8 - 10 from one primary school were selected from each township (age balanced, half male and half female) as survey subjects. One random urine sample and household edible salt samples were collected for urine iodine and salt iodine testing, and physical examination and thyroid volume measurement were conducted for children. The influencing factors of thyroid volume were analyzed using Pearson correlation.Results:A total of 24 934 urine samples were collected from children, with a median urine iodine of 233.2 μg/L. A total of 24 933 household edible salt samples were collected from children, the median salt iodine was 24.17 mg/kg, and the qualified rate of iodized salt was 96.63% (24 003/24 839); A total of 24 937 children were examined of their thyroid gland, with a median thyroid volume of 2.62 ml and a goiter rate of 1.12% (280/24 937). Among them, there were 12 410 boys and 12 527 girls, with thyroid volumes of 2.61 and 2.64 ml, respectively. The thyroid volume of boys was positively correlated with age, height, weight, body mass index, body surface area, and salt iodine ( r = 0.15, 0.21, 0.26, 0.18, 0.25, 0.03, P < 0.001). The thyroid volume of girls was positively correlated with age, height, weight, body mass index, and body surface area ( r = 0.17, 0.26, 0.28, 0.17, 0.27, P < 0.001). Conclusion:Children aged 8 - 10 in Yunnan Province are at an iodine excess level; the age, weight, height, body mass index, and body surface area are influencing factors of thyroid volume.

Objective:To investigate the difference in the radiation sensitivity of hematopoietic stem and progenitor cells (HSPCs) derived from fetal liver and bone marrow.Methods:HSPCs from fetal liver of 14.5 d embryo or bone marrow of 8 week-old mice were isolated to receive a single dose of 5 or 10 Gy irradiation in vitro using a 60Co irradiator. Twelve hours later, the cell apoptosis, mitochondrial reactive oxygen species (ROS) level, colony formation ability and DNA damage in HSPCs were detected. Freshly isolated HSPCs were injected into lethally irradiated CD45.1 + C57BL/6J mice (4.5 Gy+ 5 Gy with an interval of 30 min) Chimerism rate, lineage constitution, and cell cycle were analyzed 12 weeks after transplantation. Results:Compared with bone marrow HSPCs after irradiation, the percentage of apoptosis in fetal liver HSPCs was significantly higher ( t=16.21, 12.27, P<0.05), the level of ROS was dramatically elevated ( t=68.72, 18.89, P<0.05). At 10 Gy, fetal liver HSPCs could not form colonies at all ( t=12.41, 15.67, 9.46, P<0.05). γ-H2AX immunofluorescence staining showed that the DNA damage of fetal liver HSPCs was more severe after irradiation, and the number of Foci formed was significantly higher than that of bone marrow HSPCs ( t=2.27, 2.03, P< 0.05), which indicated that fetal liver HSPCs were more sensitive to radiation. The chimerism rate of transplanted fetal liver HSPCs was lower than that of bone marrow cells ( t=5.84, P<0.05) with a higher proportion of myeloid lineage, suggesting that fetal liver HSPCs had lower in vivo reconstitution capacity than bone marrow HSPCs and were more prone to myeloid differentiation. The cell cycle of bone marrow HSPCs from transplanted chimeric mice was examined, and the proportion of S-phase was significantly higher in the fetal liver group than that in the bone marrow group ( t=2.89, P<0.05). Mitochondrial stress results showed that fetal liver HSPCs had higher basal respiratory capacity ( t=39.19, P<0.05), proton leakage ( t=6.64, P<0.05), ATP production ( t=9.33, P<0.05), and coupling efficiency ( t=7.10, P<0.05) than bone marrow c-Kit + cells, while respiratory reserve capacity ( t=5.53, P< 0.05) was lower than that of bone marrow c-Kit + cells. Conclusions:HSPCs derived from fetal liver display higher radiosensitivty compared with bone marrow HSPCs, laying the foundation for an in-depth illustration of the effects of radiation on hematopoietic stem cells at different developmental stages.

Objective:To investigate the repair effect of autologous costal cartilage combined with silicone prosthesis on injection rhinoplasty.Methods:From July 2016 to July 2019, 28 patients who were dissatisfied with the appearance of injectable rhinoplasty and required surgical repair were treated in our hospital. Among them, 26 patients were injected with hyaluronic acid as filler, and 2 patients were unknown filler. On the basis of thoroughly cleaning the filler and releasing the adhesive tissue, the method of autogenous costal cartilage combined with silicone prosthesis was adopted: the costal cartilage was taken to support the nasal tip, and the silicone prosthesis was used to fill the nasal dorsum. The incidence of complications was observed postoperatively, and the score of each patient before and 6 months after operation was evaluated by ROE questionnaire.Results:No postoperative complications such as skin infection and necrosis, prosthesis deformation and displacement, and pneumothorax were observed in all the patients, and the incision healing was smooth. All patients were followed up for 6-18 months. Among the 6 questions on the preoperative and postoperative ROE questionnaire, except for question 2, the difference between the the two was statistically significant ( t=7.58, P<0.05). Conclusions:The use of autologous costal cartilage combined with silicone prosthesis can effectively repair injection-type rhinoplasty, which can not only achieve satisfactory postoperative results, but also reduce surgical complications. It is easy to operate and worthy of choice in clinical practice.

Objective:To study the effect of different doses of 60Co γ-ray ionizing radiation on mitochondrial function in mouse hematopoietic stem and progenitor cells (HSPCs). Methods:C57BL/6 mice were divided into control group, 1 Gy irradiation group and 4.5 Gy irradiation group. The mitochondrial functions were detected at 12 h and 24 h after irradiation, including ROS level, membrane potential, mitochondrial structure, and mitochondrial stress. Bone marrow c-Kit + cells received a single 15 Gy irradiation in vitro, after 24 h, mitochondrial function was detected. Results:It was found that mice leukocytes ( t=12.41, 18.31, 16.48, 14.16, 19.08, 20.25, P<0.05), red blood cells ( t=4.81, 6.62, P<0.05) and platelets ( t=4.33, 6.68, P<0.05) were significantly reduced. The numbers of bone marrow colony formation unit ( t=16.27, 55.66, 17.06, 43.75, P<0.05), and HSPCs ( t=5.16, 11.55, P<0.05) were decreased dose-dependently post-irradiation. Under 1 Gy irradiation, the mitochondrial function and mitochondrial basal metabolic index of HSPCs ( t= 7.36, 3.68, 4.58, 3.15, 3.15, P<0.05) were enhanced at 24 h post-irradiation. Under 4.5 Gy irradiation, mitochondrial number, mitochondrial membrane potential ( t=12.29, 10.46, P<0.05), maximal respiration and spare respiratory capacity were decreased ( t=7.81, 5.78, 6.70, 5.83, P<0.05), ROS level was increased ( t=4.63, 4.12, P<0.05). The basal respiration and oxidative phosphorylated ATP production were reduced at 12 h after irradiation ( t=8.48, 3.80, P<0.05); and the proton leakage was increased ( t=6.57, P<0.05) and coupling efficiency was reduced ( t=11.43, P<0.05) at 24 h after irradiation. In cultured c-Kit + cells, the level of ROS ( t=11.30, P<0.05) and the maximum respiration and spare respiratory capacity were increased ( t=4.25, 3.44, P<0.05) while the mitochondrial membrane potential was decreased ( t=34.92, P<0.05) significantly. Conclusions:A method for systematically assessing mitochondrial function in HSPCs was established, and the effect of ionizing radiation on mitochondrial function of HSPCs was clarified, laying a foundation for further revealing the mechanism of ionizing radiation-induced mitochondrial damage in HSPCs.

Objective:To investigate the therapeutic effect of conjoint fascia sheath suspension and levator palpebrae muscle shortening on congenital severe blepharoptosis.Methods:From June 2014 to December 2018, 30 cases (40 eyes) of congenital severe ptosis were treated in Ningbo First Hospital and Shaoxing Women and Children＇s Hospital. All patients were corrected by conjoint fascia sheath suspension and levator palpebrae muscle shortening. Six months after operation, the distance between the middle point of upper eyelid margin and corneal reflex point was measured to evaluate the correction effect of blepharoptosis; the improvement of upper eyelid appearance was evaluated by 5-point Likert scale (LS), and the incidence of complications was counted.Results:Thirty patients (40 eyes) were followed up for 6-12 months. Correction effect showed that preoperative marginal reflex distance (MRD) was (0.10±0.05) and postoperative MRD was (3.80±0.55); the difference was statistically significant ( t=0.95, P<0.05); 38 eyes (95%) were corrected and 2 eyes (5%) were undercorrected; appearance of upper eyelid showed that preoperative LS was (0.50±0.05) and postoperative LS (3.80±0.55); the difference was statistically significant ( t=0.98, P<0.05). Only one case was complicated with keratitis caused by improper early nursing after incomplete closure exposure, and the patient was cured by sealing the eyes combined with drug conservative treatment. Conclusions:Combined conjoint fascial sheath suspension and levator palpebrae shortening in the treatment of severe blepharoptosis has significant effect, with the advantages of simple operation, small surgical trauma, low recurrence rate, low incidence of complications, high predictability of surgical results and high satisfactory rate of patients.