BACKGROUND:An ideal scaffold material needs appropriate degradation rate and certain mechanical properties, but the traditional colagen sponge scaffold has rapid degradation velocity and low mechanical strength, which is easy to colapse and difficult to maintain its natural form. Traditional cross-linking methods also have the problems of cytotoxicity or colagen denaturation, severely limiting the application of colagen. OBJECTIVE:To design a new cross-linking method for colagen and to optimize the self-assembly process so as to develop a colagen sponge scaffold with good mechanical properties and resistance to degradation. METHODS:Colagens were modified by self-assembly technology to prepare colagen fibrils which were then freeze-dried into fibrilar colagen sponges. Meanwhile, we optimized the conditions of self-assembly by using orthogonal experiment based on univariate analysis of the effect of initial colagen mass concentration, final phosphate concentration and pH value on the conversion yield of colagen self-assembly. RESULTS AND CONCLUSION:We optimized the conditions of self-assembly revealed that the optimum conditions to prepare colagen fibrils were determined as pH=8.0, initial colagen concentration=2 mg/mL, and final concentration of phosphate=15 mmol/L. The results of scanning electron microscope showed that fibrilar colagen sponges were characterized by refined porous structure which was connected by colagen fibrils. In addition, the fibrilar colagen sponges showed better equilibrium-sweling ratio, water retaining property and mechanical strength compared with unmodified colagen spondages (P < 0.05), to solve the problems in rapid degradation.

Objective To investite the effect of endotoxin pretreatment on lung injury induced by hepatic ischemia reperfusion in rabbits and its mechanism. Method Forty-eight New Zealand white rabbits were randomly divided into4 groups with 12 rabbits each group:routine control group,pretreatment control group,ischemia reperfusion group (IR group), and preperfusion group( LPS + IR group). Rabbits of routine control group received operative dissector only, and those of pretreatment control group received pretratment of daily intraabdominal injection of lipopo|ysaccharide(O.5,0.5,and 1.0 mg/kg,respectively)in the 3 days before operative dissector.Livers of IR group were rendered and ischeraic for 30 minutes, and repeffused for up to 4 hours. Rabbits of LPS +IR group received the preueaunent before heretic ischemia repeffusion. Four hours after reperfusion, serum endotoxin,tumor necrosis factor-α(TNF-α), wet/dry ratio and broncho-alveolar lavage fluid protein content of lung,malondialdehyde(MDA) and mpenrxide dismutase(SOD) in lung homogenate, lung injury ratio, and activity of Nuclear factor-kB(NF-kB) in alveolar macrophage wene examined. Differences within the groups were analyzed using One way ANOVA. Results Between the two control groups,there were no significant differences in all indexes(P>0.05). The TNF-α[ (48.31±5.31)pg/ml vs.(56.47±5.09)pg/ml, P<0.01],wet/dry ratio [(4.98±0.33)vs. (5.22±0.31), P = 0.03],broncho-alveolar hvage fluid protein content[(0.68±0.11)g/L vs. (0.76±0.10)g/L, P =0.04],MDA[(0.86±0.06)nmol/mg vs. (0.93±0.07)nmol/mg, P =0.02],lung injury ra-tio[(13.4±4.3)% vs. (17.4±4.1)%, P = 0.03],and the activity of NF-gB[(5.82±1.12)OD/mm2 vs.(7.40±1.26)OD/mm2, P<0.01] in alveolar macrophage of the LPS+ IB group were all significantly lower than those of IB group, while the SOD[ (90.30±7.38 )U/rag vs. (84.44±7.90 )U/rag, P = 0.04]of LPS + IR group was significantly higher than that of IR group. Conclusions Endotoxin pretrealment may ameliorate the lung injury induced by hepatic isehernia reperfusion. The mechanism may be that endotoxin pretreatment deoreases production of serum TNF-α and the activity of NF-kB in alveolar maerophage.

Objective: To investigate the clinical effect of percutaneous transhepatic bile duct drainage guided by ultrasound. Methods: From June 2016 to June 2018, 100 patients with obstructive jaundice in Lishui Central Hospital were treated with ultrasound-guided percutaneous transhepatic bile duct drainage.The success rate and postoperative complications of the patients were analyzed. Results: Among 100 cases, 98 cases were successful, 2 cases failed, and the failure rate was 2%.The success rate of one-time catheterization in 0.5-2.0 cm patients with intrahepatic bile duct diameter(98.91%) was significantly higher than that in intrahepatic bile duct diameter 0.3-0.4 cm patients(87.50%), compared with two different diameter puncture catheterization, the difference was statistically significant(χ²=12.369, P<0.05). All 98 cases with successful puncture were followed up after operation (P<0.05), and there was no statistically significant difference between the two groups(P<0.05). The drainage tube was removed in 2 cases, bile duct infection was found in 2 cases, the remaining patients were unobstructed, and there were no obvious complications. Conclusion Ultrasound-guided percutaneous transhepatic catheterization and drainage for the treatment of obstructive jaundice caused by malignant tumor is simple, reliable, safe and effective, and has a certain clinical value.It is worthy of popularizing and application.

Objective:To understand the 10-year risk of ischemic cardiovascular disease (ICVD) in hypertensive patients in communities in Shenzhen, and to provide baseline data for the comprehensive implementation of community-based hypertension health management measures based on ICVD risk assessment.Methods:From July 2017 to June 2018, 200 community health service centers in 10 districts of Shenzhen were selected by multi-stage random sampling to investigate hypertensive patients in communities aged≥35. After the patients who met the inclusion criteria signed the informed consent form, the demographic characteristics, physical examination, and laboratory tests were conducted. The absolute risk of ICVD in 10 years was evaluated by using the ICVD risk assessment module from the Shenzhen community health service information system. According to the China 10-year risk for ICVD score tables, recommended by the Chinese cardiovascular disease prevention guidelines, the risk grade of ICVD was estimated and analyzed. In addition, the relative risk was used to eliminate the influence of gender and age, and the single sample t-test was used for comparisons with the larger population. Results:30 015 hypertensive patients from communities were investigated, including 16 165 (53.86%) males and 13 850 (46.14%) females, aged 35-102 years, with a median age of 59.0. 6 405 (21.34%), 5 771 (19.23%) and 17 839 (59.43%) were at high, medium and low risk of ICVD, respectively. The absolute risk was 3.77%, 95% CI (3.72%-3.82%). The risk grades of ICVD in 10 years was different as per gender, age, marital status, population type， smoking, family history of hypertension, history of diabetes mellitus, systolic blood pressure, body mass index, and total cholesterol level, P values were all<0.001. The risk grades of ICVD in males, married patients, floating populations, having a total cholesterol <5.20 mmol/L, non-smokers, non-diabetics, and having a family history of hypertension were lower than that of other characteristics, and increased with age, systolic blood pressure, and body mass index. Further analysis of 15 652 patients aged 35-59 years old showed that the 10-year risk of ICVD in patients with hypertension in communities was slightly higher than that of the larger population, and the relative risk was 1.27, 95% CI (1.25-1.28), t=37.648, P<0.001. In males, relative risk was 0.94, 95% CI (0.93-0.95), t= 9.906, P<0.001, and there were no significant trend changes among age groups. In females, relative risk was 2.05, 95% CI (2.01-2.09), t=72.207, P<0.001, and increased with age. Conclusion:The 10-year risk of ICVD in hypertensive patients is often at a high level in Shenzhen, so it is necessary to carry out the risk assessment of ICVD in the community. The effect of community hypertension health management on reducing the risk of ICVD may vary between genders. The risk of ICVD in male patients is lower than that of males in the larger population, but in female patients it is still much higher.

Objective To investigate the influence of type 2 diabetes mellitus(T2DM)on cognitive function and the effective connectivity with in the default mode network(DMN)in the brain.Methods A total of 93 hospitalized patients diagnosed with T2DM were enrolled in this study as T2DM group from The First Affiliated Hospital of Guangzhou University of Chinese Medicine during September 2021 to December 2022.Simultaneously,108 healthy individuals were recruited from the community as normal control(NC)group.The cognitive functions were evaluated in the two groups.A random dynamic causal modeling approach was employed to analyze the effective connectivity within DMN in both groups.Additionally,Pearson correlation analysis was performed to examine the association between differential connectivity,clinical indicators,and cognitive scores in both groups.Results In comparison to the NC group,T2DM individuals exhibited statistically significant reductions in scores in the auditory verbal learning test(AVLT)for immediate recall and the digit symbol substitution test(DSST)(P＜0.05).Additionally,they displayed a notable decrease in effective connectivity from the left lateral parietal cortex(LLPC)to the posterior cingulate cortex(PCC),as well as from the LLPC to the right lateral parietal cortex(RLPC)within the DMN(P＜0.05).Pearson correlation analysis unveiled a negative association between HbA1c levels and the strength of effective connectivity from LLPC to PCC.Conversely,a positive correlation was observed between AVLT(immediate)scores and the strength of effective connectivity from LLPC to PCC and LLPC to RLPC.Additionally,DSST scores displayed a positive correlation with the strength of effective connectivity from LLPC to PCC(P＜0.05).Conclusion Patients with T2DM display compromised effective connectivity from LLPC to PCC and LLPC to RLPC within the DMN network,and this alteration may associated with cognitive impairment.

Objective To investigate the quality control and protection level of medical electron linear accelerators in Shanghai, China. Methods The startified random sampling method was used to cover tertiary, secondary and ungraded hospitals, and a total of 30 medical electron linear accelerators in 15 hospitals were tested for quality control and protection level according to relevant standards. Results Five medical electron linear accelerators failed the quality control test, with an overall inspection pass rate of 83.3% and a re-inspection pass rate of 100%. The pass rate of flatness of square X-ray irradiation field (5 cm × 5 cm)-(30 cm × 30 cm) was 83.3%, the pass rate of symmetry of square X-ray irradiation field was 96.7%, and other indices were qualified. All medical electron linear accelerator rooms passed the protection test. Conclusion The protection of medical electron linear accelerator rooms in Shanghai meets the requirements of national standards, and some indices do not meet the requirements of national standards in the preliminary inspection. The quality control of medical electron linear accelerators should be further strengthened to ensure the treatment effect of patients.

Objective To evaluate the accuracy of bioelectrical impedance analysis(BIA)in measurement of appendicular skeletal muscle mass(ASM)of adults.Methods A total of 836 adults aged 18-42 years were recruited in Guangzhou using a convenient sampling method from April 2021 to September 2022.ASM was measured using BIA and Dual-energy X-ray absorptiometry(DXA).Using DXA as the standard method,the consistency between the BIA and DXA measurements was evaluated by intra-class correlation coefficients(ICCs)and Bland-Altman analysis in logarithmically transformed data,in order to evaluate the accuracy of BIA in ASM measurement.Receiver operating characteristic curve was plotted to evaluate the diagnostic value of BIA for screening low muscle mass.Results A total of 774 individuals were included for analysis finally.ICCs for ASM measured by BIA and DXA were 0.774 and 0.667 in males and females,respectively.Mean ratios(limits of Agreement)of ASM were 0.94(0.80-1.10)and 0.91(0.78-1.05)in males and females,respectively.Area under curve of BIA for screening low muscle mass were 0.91 and 0.94 in males and females,respectively.The optimal cut-off values of Z-score by BIA for males and females were-0.57 and-0.66,respectively.Sensitivity and specificity for males were 82.5%and 86.0%,while being 86.8%and 93.8%,for females.Conclusion BIA shows a moderate consistency with DXA for measuring ASM in adults.Furthermore,BIA yields a good diagnostic value in identifying low muscle mass in adults aged 18-42 years.

Objective:Evaluation of ultrasound-guided radiofrequency of hyperthermia combined with recombinant human adenovirus H101 for the treatment of hepatocellular carcinoma (HCC).Methods:In vitro cell therapy experiments, luciferase/red fluorescent protein/lentivirus mediated McA-RH7777 cells were conducted and divided into 4 groups. Each group was repeatedly treated for 6 times: (1) recombinant human adenovirus type 5 H101 [(multiplicity of infection, MOI)=0.2]+ RFH group, heated at 42℃ for 30 min; (2) recombinant human adenovirus type 5 H101 alone (MOI=0.2); (3) RFH alone, heated at 42℃ for 30 min; (4) control group: physiological saline group. Twenty-four nude rats weighing 180-220 g were selected to establish a nude rat model of orthotopic HCC. They were divided into 4 groups with 6 rats in each group: (1) H101+ RFH combined treatment group: RFH electrode needles were punctured to the center of the tumor in the liver of nude rats under ultrasound guidance, and H101 was directly injected through the electrode injection end. RFH was delivered to the tumor at a temperature of 42℃ for 30 min; (2) H101 treatment group: MOI=0.2; (3) RFH treatment group; (4) sham surgery group. Fluorescence microscopy imaging was used to evaluate the viability of cells in vitro experiments. For in vivo validation, ultrasound imaging was used to follow up the tumor size. Tumor gross specimens and pathological changes were also evaluated.Results:Twenty-four hours after treatment, the survival rate of cells in the H101+ RFH group was the lowest under fluorescence microscopy. The results of MTS quantitative analysis showed that the relative absorbance of mezzanine in the H101+ RFH group cells was lower than that in the H101 group alone [(25.00±2.27)% vs. (69.50±4.53)%], the RFH group alone [(25.00±2.27)% vs. (92.83±1.66)%], and the control group [(25.00±2.27)% vs. 100%], with statistical significance (all P<0.001). The number of apoptotic cells in the H101+ RFH group was higher than that in the H101 group alone [(54.5±3.1)% vs. (25.2±1.4)%], the RFH group alone [(54.5±3.1)% vs. (5.7±0.6)%], and the control group [(54.5±3.1)% vs. (3.9±0.5)%], all of which showed statistically significant differences (all P<0.001). The relative tumor volume of nude rats in the H101+ RFH combination treatment group was smaller than that in the H101 treatment group (0.776±0.127 vs. 1.312±0.188), RFH treatment group (0.776±0.127 vs. 1.893±0.571), and sham surgery group (0.776±0.127 vs. 1.977±0.590), all of which had statistical significance (all P<0.001). The number of apoptotic cells in nude rats in the H101+ RFH combination treatment group was higher than that in the H101 treatment group [(49.85±4.00%)% vs. (22.70±0.65)%], the RFH treatment group [(49.85±4.00% vs. (5.36±0.84)%], and the sham surgery group [(49.85±4.00)% vs. (5.96±0.78)%], all of which showed statistically significant differences (all P<0.001). Conclusion:Ultrasound guided RFH combined with recombinant human adenovirus H101 has a promoting effect on the treatment of HCC.

Background Individual monitoring of occupational external exposure is an essential part of the occupational health management of radiation workers, and is an important basis for the evaluation of individual absorbed dose and the diagnosis of occupational radiation diseases. Continuous participation of monitoring service providers in intercomparison is a fundamental quality assurance for routine monitoring, which can identify problems and improve them in time. Objective Taking the Laboratory of Radiation Protection in Shanghai Institute of Preventive Medicine as an example, to evaluate the performance of an individual occupational external dose monitoring system in the laboratory, identify influencing factors of the monitoring results, and provide a basis for improving the quality of daily monitoring by analyzing the process and results of a national intercomparison of individual dose monitoring. Methods According to the Testing criteria of personnel dosimetry performance for external exposure (GBZ 207-2016), and the relevant requirements of Class II (photon) inspection, a total of 20 groups of blind sample dosimeters were measured for four consecutive years from 2018 to 2021. The radiation energy source of each group was identified, and related personal dose equivalent H_p(10), the uncertainty of measurement results, and the deviation between the reported value and the reference value were calculated. The national intercomparison process and results of individual dose monitoring were also analyzed. Results The energy sources of the blind samples in the tested laboratory for four years were N100 or Cs-137. The reported dose values of the blind samples were 0.57-4.61 mSv, the combined uncertainties were 0.043-0.365 mSv, the expanded uncertainties (k=2) were 0.09-0.73 mSv, and the relative expanded uncertainties (k=2) were 13.8%-16.4%. The single-group performance ∣P_i∣ of 20 sets of blind samples in the four years was ≤0.10, the yearly comprehensive performance of 5 sets of blind samples was ≤0.10, and the yearly Q score of the test report was >15 points. The laboratory achieved excellent results in the national intercomparison of individual dose monitoring in four consecutive years, except the Q value not reaching full score. Conclusion The laboratory exhibits standardized data processing of individual dose monitoring, generates accurate and reliable results, and meets the requirements of relevant national standards; but it should continue to participate in the national intercomparison of individual dose monitoring, strengthen the angular response research of energy identified dosimeter, improve the monitoring ability of low-dose X-rays, analyze the key points of reducing the uncertainty of measurement results, and continuously improve the monitoring ability.