Objective To understand the individual radiation dose levels and changes of occupational external exposure among radiation workers in a steel group from 2020 to 2023, and to provide a basis for strengthening radiation protection in the group. Methods According to the Specifications for individual monitoring of occupational external exposure (GBZ 128-2019), individual monitoring was conducted using a thermoluminescent dosimeter, with each monitoring cycle lasting 90 days, totaling four cycles per year. Individual monitoring data of occupational external exposure among radiation workers in the steel group from 2020 to 2023 were collected for statistical analysis. Results A total of 5889 monitoring records were collected from radiation workers across 37 affiliated units of the steel group during the period of 2020-2023. The average annual effective dose was 0.150 mSv, the maximum annual effective dose was 3.84 mSv, and 0.3% monitored workers showed annual effective doses exceeding 1 mSv. The average annual effective dose in 2023 was 0.146 mSv, which was lower than in 2020 but higher than in 2021 and 2022 (Z = −6.657 to 14.129, P < 0.001). The number of monitored workers in industrial and medical sectors accounted for 86.9% and 13.1%, respectively. Their average annual effective doses were 0.152 mSv and 0.140 mSv, respectively, and the difference was statistically significant (Z = −7.969, P < 0.001). In the industrial sector, the average annual effective dose for the monitored workers in industrial radiography was significantly higher than other occupations (Z = −8.094, P < 0.001). There was a significant difference in average annual effective dose among workers of different occupational categories in the medical sector (H = 67.040, P < 0.001). The average annual effective doses were relatively high for diagnostic radiology and nuclear medicine. Additionally, the average annual effective doses for male and female radiation workers were 0.150 mSv and 0.152 mSv, respectively (P > 0.05). Conclusion The average annual effective dose of radiation workers in the steel group was at low levels for four consecutive years, which meet the requirements of the national standard. However, to maintain the individual radiation dose levels of radiation workers as low as reasonably achievable, it remains necessary to strengthen radiation protection management in the steel group.

AIM: To evaluate the visual quality of patients after modified design aspheric balance curve(ABC)with intraocular lens(IOL)implantation, and to analyze the influencing factors of clinical IOL selection and guide the patient's IOL selection plan. METHODS: A prospective case-control study was conducted in 67 patients(74 eyes)with simple cataract underwent phacoemulsification and foldable aspheric IOL implantation, and 23 eyes in the observation group were implanted with modified design IOL(HOYA Vivinex XY1 group), the control group was implanted with 51 eyes of traditional design IOL(Tecnis ZCB00 group with 27 eyes, IQ SN60WF group with 24 eyes). The uncorrected visual acuity, the best corrected visual acuity, total ocular spherical aberration(SA)and coma under different pupil diameters(3, 4, 5, 6mm), and different pupil diameters(3, 4, 5mm)were measured 1wk and 1mo after operation, the modulation transfer function(MTF)curve, objective scattering index(OSI), intraocular scattered light value Log(s)and contrast sensitivity were obtained. Statistical analysis was performed on the obtained data.RESULTS: The uncorrected visual acuity and best corrected visual acuity at 1wk and 1mo after operation in the three groups were significantly improved compared with those before operation, there was no significant difference among groups(P>0.05). The difference of total ocular spherical aberration was statistically significant among the three groups with 5 and 6mm pupil diameter 1wk after operation(P=0.045, 0.037)and there were differences among three groups in pupil diameter of 6mm at 1mo after operation(P=0.042). Comparing the total ocular coma aberration, there were differences among the three groups at 1wk and 1mo after the operation at the pupil diameter of 5 and 6 mm(P<0.05). With the increase of pupil diameter at 1wk and 1mo after operation, the total ocular spherical aberration in the HOYA Vivinex XY1 group was lower than that in the other two groups. The MTF values of the Vivinex XY1 group were higher than those that of the control group at each spatial frequency, there was no significant difference among groups(P>0.05), and there were no statistical differences in objective scattering index, intraocular scattered light value Log(s)and contrast sensitivity among the three groups(P>0.05).CONCLUSION:The improved design of the modified Vivinex IOL can reduce the total ocular spherical aberration and coma, improve the visual quality, and provide a new method for the selection of aspheric IOL.

Objective To study the feasibility of clinical application of an individualized customized material. Methods Five batches of individualized customized materials were randomly selected, from which 10 cm × 11 cm samples were intercepted for experimental analysis. Among them, 10 cm × 10 cm materials were selected to perform dosimetric analysis and HU change analysis before and after irradiation with a radiotherapy dose for breast cancer of 50 Gy as the irradiation basis. The center Point 1 on the lower surface of the individualized material and the center Point 2 of the solid water volume were selected for dosimetric analysis before and after the sample is irradiated. After reaching a sufficient amount of irradiation, the 1 cm × 10 cm materials intercepted in the center position and the remaining 1 cm × 10 cm materials after the first sampling were sent to the material science laboratory for analysis of physical properties of density, viscosity, hardness, and tear strength. Results In the comparative analysis of HU values before and after exposure, after receiving 50 Gy dose irradiation, the difference rate of HU value was 5.252%, which was close to the expected 5% difference rate in clinical medicine. In the dosimetric analysis of Point 1 and Point 2, the dose in the irradiated samples was significantly higher than that in the unirradiated samples; the dose in Point 1 increased by 3.742%, and the dose in Point 2 increased by 2.039%. Before and after irradiation, except for the physical density which showed a significant difference, there was no significant difference in viscosity, hardness, and tear strength. Conclusion The individualized customized material can meet the requirements of routine clinical medicine.

【Objective】 To establish gas chromatography for the determination of tributyl phosphate(TBP) residues in human prothrombin complex and then verify it. 【Methods】 Acid modified polyethylene glycol(PEG)(20M) capillary column was used with n-hexane as solvent. The chromatographic parameters were as follows: gasification chamber temperature at 220 ℃, column temperature at 155 ℃, detector temperature at 220 ℃, column flow rate at 2.0 mL/min, carrier gas as N2, detector as FID, and collection time for 10min. The accuracy, repeatability, linearity, specificity, intermediate precision, detection limit, quantitative limit, range and durability were verified. 【Results】 The verification results showed that the method had good specificity. The linear regression correlation coefficient of standard curve was 0.999 90. The recovery rate were 98.4%, 97.5% and 95.7% when the concentration at 50%, 100%(30μg/mL) and 150%, respectively, with an average recovery of 97.2% and a relative deviation of 2.15%. When the concentration was 100%, the repeatability was 2.08%, and the relative deviation of intermediate precision was 1.63%. The detection limit was 0.255 μg/mL, and the quantitative limit was 0.511 μg/mL. After changing capillary chromatographic columns with different batch numbers but the same types and manufacturer, the applicability test of the system met the requirements, and the method had good durability. 【Conclusion】 This method can be used for the determination of TBP residues of human prothrombin complex in laboratory.

In recent years, peptide self-assembly has received much attention because of its ability to form regular and ordered structures with diverse functions. Self-assembled peptides can form aggregates with defined structures under specific conditions. They show different characteristics and advantages (e.g., good biocompatibility and high stability) compared with monomeric peptides, which form the basis for potential application in the fields of drug delivery, tissue engineering, and antiseptics. In this paper, the molecular mechanisms, types and influencing factors of forming self-assembled peptides were reviewed, followed by introducing the latest advances on fibrous peptide hydrogels and self-assembled antimicrobial peptides. Furthermore, the challenges and perspectives for peptide self-assembly technology were discussed.
Drug Delivery Systems ; Hydrogels ; Peptides ; Tissue Engineering

【Objective】 To study the application effect of gel adsorbent tank in the production of human prothrombin complex concentrate(PCC). 【Methods】 Six batches of PCC were produced from 1000 L cryoprecipitated plasma, using the same gel twice for adsorption within the tank.The number of gel repeated application was examined by retrospective confirmation, and the adsorption rate, specific activity and residue of finished virus inactivation reagent were determined before and after adsorption. 【Results】 All 6 batches of PPC, produced by the same gel, satisfied quality criteria. Both PPC solution and the gel presented good color. The average activities of coagulation Factors Ⅱ, Ⅶ, Ⅸ and Ⅹ of six batches of PCC were 118.2%, 157.0%, 140.5% and 176.8%, respectively. The The adsorption capacity of coagulation factor Ⅱ, Ⅸ and Ⅹ were both 100% in the first and second adsorption, while coagulation factor Ⅶ were 75% and 81%, respectively. The average specific activity of coagulation factor Ⅸ was 0.7 IU/mg. The average residues of polysorbate 80 and tributyl phosphate products were 0 μg/mL and 33 μg/mL, respectively. The same batch of gel can be repeatedly used up to 6 times during the PCC process. 【Conclusion】 The gel adsorption tank presents good application value in the production of PCC, which can realize process amplification and automatic control.

Objective To explore the dosimetric differences of radiotherapy plan for cervical cancer with 4 different fluence smoothing (FS) parameters using Monaco treatment planning system (Monaco TPS). Methods Fifteen patients with ⅠB2 stage cervical cancer in our hospital were enrolled in this study. And a 2 Volumetric Modulated Arc Therapy (VMAT) plan for each patient were completed by Monaco 5.11 TPS according to the X-Ray Voxel Monte Carlo (XVMC) method. For each plan was optimized by FS function, with the level of Off, Low, Medium and High. To compare the difference of plan optimization time, conformity index (CI), Homogeneity index (HI), D_mean, D_min, D_2% of PTV，dose to the organ at risk (OAR)，the number of Segments# and MU#，estimated total delivery time (ETDT), quantum Efficiency (QE) of the plans, the formation of Segments# with the same angle and verification of inserting 729 two-dimensional matrix into PTW octavius 4D module of different FS function levels, with the precondition of the Prescription isodose curve covering 95% of the target area. The data was analysed by multivariate factor analysis with the application of SPSS, and P < 0.05 was considered as statistically significant. And the Planned revenue score of different FS levels was also calculated. Results Except for the D_min of PTV (the lowest value is (32.09 ± 0.26) Gy for the Off group, and the highest value is (35.98 ± 0.42) Gy for the High group), V₄₀ of the rectum (the lowest value in the Medium group is 55.88% ± 2.02%, and the highest value in the High group was 61.90% ± 2.98%) and bladder (the lowest value was 45.01% ± 2.08% in the Medium group, and the highest value is 50.45% ± 1.98% in the High group), the V₂₀ (the lowest value High group was 49.05% ± 1.98%, the highest value Off group was 56.52% ± 1.75%) of femoral head (P < 0.05), there was no significant difference of the dose assessment results for PTV and OARs in 4 different FS function levels. In the High level, the ETDT, QE and MU# were showed better than other groups evidently, however, the number of Segments# showed no significant difference. The plan validation results was increased with the improvement of FS function level, and the level of High was considered to be the optimal. To compare the score of overall benefits of the plan, the level of Medium (−17.18 ± 0.05) got the highest score, and the Low group (−17.58 ± 0.05) and the High group (−17.42 ± 0.06) have similar scores, and Off group (−18.81 ± 0.08) has the lowest score. Conclusion Different FS levels of the Monaco 5.11 TPS can optimize the radiotherapy plan for cervical cancer, but the level of Medium is considered to be the most applicable.

Objective To study the dosimetry effect of D_w and D_m middle and lower esophageal cancer in Monaco treatment planning system (TPS). Methods 30 patients with T₃N₀M₀StageⅡa middle and lower esophageal cancer were selected for experiment. For each patient, optimize the plan using dose to water (D_w) and dose to medium (D_m) dose calculation mode, then rescale prescription dose to 95% volume of PTV. Compare the difference in the two mode, conformity index (CI), Homogeneity index (HI), Mean dose (D_mean), Minimum dose (D_min), Maximum dose (D₂), Dose to Organ at risk (OAR), MU, Optimization time, photon usage, and QA results of MatriXX and Arc Check. Use SPSS for multivariate analysis. Results In the dose evaluation of the middle and lower esophageal cancer cases under different dose calculation methods, the spinal cord, trachea, V₂₀ of the whole lung, and D₂ of the liver have significant dosimetric differences, the dose value, the sequential dose results were compared as (37.92 ± 1.11)/(35.85 ± 1.08), (59.91 ± 1.43)/(60.25 ± 0.98), (22.52 ± 1.75)/(21.38 ± 2.01), (42.89 ± 0.52)/(41.73 ± 0.58). In the comparison of dose cloud distribution, the difference is mainly located in the cavity and the inner wall of the lung in the target area, the dose in the target cavity in the D_w group is higher than that in the D_m group. The dose in the inner and outer walls of the lung cavity in the D_w group are slightly adducted than that in the D_m group, especially in the central area.Dose QA of MartiXX (3%-3 mm) and Arc Check (2%-2 mm) with different dose calculation methods of 60 plans of 30 cases have all passed clinical requirements. D_m Group is better than D_w group. Conclusion It is recommended to use D_m dose calculation method for Monaco 5.11 TPS in the condition of treatment planning for middle and lower esophageal cancer.

Objective: To understand the infection status and genetic characteristics of Norovirus from foodborne diseases in sentinel hospital of Ma′anshan city. Methods: The 911 stool samples and epidemiological data of the patients with foodborne disease were collected from three hospitals of Ma′anshan city during January 2015 to June 2018. The G Ⅰ and G Ⅱ Norovirus were detected by real-time reverse transcription PCR. Some of the positive specimens were amplified by conventional reverse transcription PCR, and the PCR products were sequenced for sequence alignment and phylogenetic analysis. Results: The positive rate of Norovirus was 14.7% (134/911), in which 7 strains were G Ⅰ, 124 strains were G Ⅱ and 3 strains were mixed infection. Norovirus can be detected throughout the year, with high positive rate from December to April of the next year [24.4%(20/82)-45.3%(24/53)]. The 78 males (15.5%) and 55 females (13.7%) were positive for Norovirus (χ²=0.58,P=0.448). There was no significant difference in different age groups (χ²=9.55, P=0.089). A total of 79 strains were successfully sequenced, 4 strains were G Ⅰ group(5.1%), 75 strains were G Ⅱ group (94.9%). The predominant strains were GⅡ.17 and GⅡ.4, aud the number were 35 and 15 respectively. The predominant strains were different in different years. The main strain was GⅡ.17 in 2015 (30, 68.2%),GⅡ.4 in 2016 (5/9) and 2017 (8/16), but GⅡ.3 in 2018 (3/6). Conclusion Norovirus diarrhea was popular in Ma′anshan city throughout the year,especially in winter and spring. The prevalent strain was GⅡ,genotypes were diversified distribution,the dominant strains were GⅡ.17 and GⅡ.4. The predominant strains were different in different years.

Objective: To compare laparoscopic cholecystectomy (LC) with or without percutaneous transhepatic gallbladder drainage (PTGD) for acute severe cholecystitis. Methods: According to the predefined inclusion and exclusion criteria, 23 articles were selected for this meta-analysis. All patients were treated with LC with or without PTGD. A meta-analysis was used to analyze the clinical efficacy. Results: Compared with LC, all the surgical indicators of LC with PTGD were significantly better than LC alone (all P≤0.05), including the operation time: 95%CI(-27.24, -9.27); intraoperative blood loss: 95%CI(-50.25, -40.19); postoperative hospital stay: 95%CI(-3.63, -0.64); rates of conversion to open abdomen: OR=0.48, 95%CI(0.32, 0.74); rates of incision infection: OR=0.49, 95%CI(0.25, 0.99); drainage tube indwelling time: 95%CI(-2.07, -1.19); gastrointestinal function recovery time: 95%CI(-1.73, -0.77); rates of bile leakage: OR=0.23, 95%CI(0.12, 0.44); and rates of complications: OR=0.36, 95%CI(0.27, 0.48). Conclusion Compared with LC alone, PTGD+ LC is the preferred treatment for acute severe cholecystitis.