Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.

Objective To investigate the basic situation of nuclear medicine diagnostic and treatment institutions in Shanghai, understand the development level and distribution characteristics of nuclear medicine in Shanghai, and assess the current status of nuclear medicine development in Shanghai. Methods Using questionnaires, on-site verification, and retrieval of information system records, a survey was carried out on nuclear medicine department staff, equipment, and personal radiation exposure levels of workers in Shanghai. Results As of December 2023, there were 48 nuclear medicine diagnostic and treatment institutions in Shanghai, including 32 (66.7%) tertiary hospitals. Of these, 24 (50%) hospitals performed ¹³¹I therapy, and 9 (18.8%) hospitals conducted ¹³¹I treatment for thyroid cancer. There were 681 nuclear medicine radiation workers, with an average annual effective dose from external radiation of 0.54 mSv. There were 137 pieces of nuclear medicine equipment, including 56 SPECT/CT, 42 PET/CT, 8 PET/MRI, 25 thyroid function meters, and 6 cyclotrons. In 2023, the total radioactivity of radionuclides used in Shanghai was 1.2 × 10⁸ MBq, with 3.4 × 10⁷ MBq of ¹⁸F, 7.4 × 10⁷ MBq of ^99mTc, and 1.2 × 10⁷ MBq of ¹³¹I. The total annual number of nuclear medicine diagnostic and treatment procedures performed was 247 826 and the application frequency was 10.0 procedures per thousand population. Conclusion Clinical nuclear medicine in Shanghai has developed rapidly, achieving the Level I healthcare standard as defined in the UNSCEAR 2008 report. Enhancing occupational protection for radiation workers is a critical issue that requires particular attention in the next phase of development.

Objective The biomechanical model for the musculoskeletal system of a human knee joint was established using a numerical simulation method.The kinematic and dynamic information captured during jumping motion simulated by the human dynamic model was used as driven data of the knee biomechanical model,followed by further analysis of the stress field distribution characteristics of the meniscus under different thermal-force coupling knee brace conditions.Methods Based on computed tomography and magnetic resonance imaging of the subject,a realistic human knee model,including bone,articular cartilage,meniscus,ligaments and peripheral soft tissues of the knee joint,was constructed.Furthermore,two gaits,namely taking-off and landing-on,of jumping motion with an increased risk of meniscus injuries were selected according to mechanical features in full-cycle jumping motion.Subsequently,the stress field characteristics of the knee meniscus under four different thermal-force coupling knee braces were analyzed,the changes of the peak stress of the meniscus and its stress concentration area were discussed,and the protective efficacy and mechanical basis of meniscal injuries and wearing knee braces were explored.Results The anterior part of the medial knee meniscus was a vulnerable area under concentrated stress.Under the knee brace thermal-force coupling condition,the stress concentration area of the medial meniscus was transferred from its narrow and weak anterior part to its wide and thick middle part,and the peak stress was also significantly reduced.The peak stress on the medial meniscus and that on the lateral meniscus were similar,indicating that the two parts of the meniscus bore the external load evenly,and the meniscus stress concentration area decreased.Conclusions Thermal-force coupling knee braces have good protective effects against knee meniscus injury.The numerical simulation provides theoretical support and technical guidance for the design of multifunctional thermal knee braces.

OBJECTIVE:To systematically evaluate the efficacy of transcranial direct current stimulation on the motor function of patients with Parkinson's disease,and to compare the efficacy of transcranial direct current stimulation at different targets on the motor function of patients with Parkinson's disease,so as to provide a theoretical basis for the target selection of transcranial direct current stimulation in clinical practice. METHODS:Cochrane Library,PubMed,Web of Science,CNKI,VIP,WanFang Data were retrieved for randomized controlled trials on the improvement of motor function in patients with Parkinson's disease by transcranial direct current stimulation published from the database inception to January 2023.The keywords were"Parkinson,transcranial direct current stimulation"in English and Chinese.The quality of the included studies was evaluated using the Cochrane 5.1.0 risk of bias assessment tool and the PEDro scale.Meta-analysis of outcome indicators was performed using RevMan 5.4 and Stata 17.0 software. RESULTS:Fifteen randomized controlled trials were finally included,and the PEDro scale showed that all were high-quality or very high-quality studies.Meta-analysis showed that transcranial direct current stimulation significantly improved Unified-Parkinson Disease Rating Scale part III score[mean difference(MD)=-2.49,95%confidence interval(CI):-4.42 to-0.55,P<0.05),step frequency score(MD=0.07,95%CI:0.03-0.11,P<0.05)and step speed score(MD=0.02,95%CI:0.00-0.05,P<0.05),but not for Berg Balance Scale scores(MD=2.57,95%CI:-0.74 to 5.87,P>0.05).Network Meta-analysis probability ranking:In terms of Unified-Parkinson Disease Rating Scale part III scores,the probability ranking results of target stimulation efficacy were dorsal lateral prefrontal cortex(52.4%)>primary motor cortex(45.8%)>central point of the brain(1.8%)>conventional rehabilitation(0%);in terms of gait frequency scores,the probability probability ranking results of target stimulation efficacy were cerebellum(50.1%)>central point of the brain(45.8%)>dorsal lateral prefrontal cortex(3.9%)>primary motor cortex(0.2%)>conventional rehabilitation(0%);in terms of gait speed scores,the probability ranking results of target stimulation efficacy were cerebellum(64.8%)>dorsal lateral prefrontal cortex(23.8%)>central point of the brain(9.4%)>primary motor cortex(1.7%)>conventional rehabilitation(0.4%);in terms of Berg Balance Scale scores,the probability ranking results of target stimulation efficacy were cerebellum(77.4%)>dorsal lateral prefrontal cortex(20.7%)>central point of the brain(0.7%)>conventional rehabilitation(0.2%). CONCLUSION:Transcranial direct current stimulation significantly improves motor function of patients with Parkinson's disease,with better motor coordination in the dorsolateral prefrontal cortex and better walking and balance in the cerebellum.

Objective:To understand the radiation protecton awareness of clinical staff for patients, and to provide strategies and suggestions for promoting the justification of medical exposure.Methods:From June to September 2023, 1 430 physicians or technicians from 10 tertiary hospitals, 9 secondary hospitals and 8 primary hospitals in Shanghai were selected by multi-stage stratified random sampling method to conduct a questionnaire survey about radiation-related cognition through a combination of offline and online survey. The contents of the questionnaire included the characteristics of the respondents, the training of radiation protection, the self-awareness of patients on radiation protection, the actual cognition of the basic knowledge of ionizing radiation, the cognition of the dose caused by different types of the radiological examinations, and the ways to access knowledge of ionizing radiation. SPSS software was used for statistical analysis.Results:A total of 1 229 valid questionnaires were received, of which 82.10% respondents belonged to the clinical department and 17.90% belonged to the radiology department. 58.37% of the respondents in clinical department have received radiation-related training, and 98.64% in radiology department have done so. The overall mastery of radiation protection-related knowledge in radiology department was better than in clinical department, and the difference was statistically significant ( χ2=39.58, P<0.05). Most of the respondents tended to underestimate the radiation dose to patients from CT scans, and the proportion of the respondents who underestimated the CT doses to different sites was all greater than 45%. Logistic regression analysis showed that the contributing factors affecting radiation protection cognition are a combination of technical titles, radiation protection training to a varing degree, the level of medical institutions and their majors (95% CI of the OR values did not include 1, χ2=5.66-28.26, P<0.05). Conclusions:Most clinical staff have realized the importance of controlling the radiation dose in radiological examinations, but there is less understanding of the dose magnitude caused by different radiological examinations. Education and training are the best way to improve the awareness of ionizing radiation. Radiation protection training should be integrated into general medical education or standardized training for physicians.

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.

OBJECTIVE: To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR. METHODS: Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 ⁵ hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining. RESULTS: The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). CONCLUSION Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.
Rats ; Male ; Humans ; Animals ; Root Resorption/therapy* ; Rats, Sprague-Dawley ; Osteoclasts ; Tooth Movement Techniques ; Stem Cells

Hepatocellular carcinoma(HCC) is one of the most common malignancies of the digestive system,which is prone to be associated with microvascular or macrovascular invasion. Among them,HCC with inferior vena cava tumor thrombus(IVCTT) or right atrium tumor thrombus(RATT) is rare and has a poor prognosis. However,surgical treatment of HCC with IVCTT and (or) RATT is rarely reported and summarized. The review described the classification of HCC tumor thrombus with IVCTT and (or) RATT, summarized the progress of surgical approaches and surgical operations,and introduced a case of thrombectomy after pushing from the outer surface of the atrium,rendering the RATT to the inferior vena cava under non-cardiopulmonary bypass. The review also proposed the prospective treatments for HCC with IVCTT or RATT,providing clinical guidance to hepatobiliary surgeons.

Hepatocellular carcinoma(HCC) is one of the most common malignancies of the digestive system,which is prone to be associated with microvascular or macrovascular invasion. Among them,HCC with inferior vena cava tumor thrombus(IVCTT) or right atrium tumor thrombus(RATT) is rare and has a poor prognosis. However,surgical treatment of HCC with IVCTT and (or) RATT is rarely reported and summarized. The review described the classification of HCC tumor thrombus with IVCTT and (or) RATT, summarized the progress of surgical approaches and surgical operations,and introduced a case of thrombectomy after pushing from the outer surface of the atrium,rendering the RATT to the inferior vena cava under non-cardiopulmonary bypass. The review also proposed the prospective treatments for HCC with IVCTT or RATT,providing clinical guidance to hepatobiliary surgeons.

Objective:To construct back propagation (BP) neural network model to predict the dose required for 131I therapy for hyperthyroidism and to calculate the personalized dose plan for patients. Methods:A complete set of data of patients treated for hyperthyroidism radioaiodine was collected from the nuclear medicine departments of several medical colleges in Shanghai, including history, examination result, treatment course, etc. As a result, a prediction model was established. The predicated result for BP neural network, radial basis function (RBF) neural network and Support Vector Machine (SVM) were compared by means of small sample data. The optimal model was selected to predict administrated dose and to finally test the accuracy of the model.Results:The average errors in BP neural network, RBF neural network and SVM model based on small samples were 5.53%, 7.09% and 9.64%, respectively. After comparison, BP neural network was selected to build the prediction model. 30 cases of data were selected by random sampling to verify the BP neural network. The mean error, mean square error, minimum error and maximum error of the prediction result were 7.22%, 0.053, 0.57% and 13.78%, respectively.Conclusions:In this study, a neural network prediction method was proposed to provide a more accurate dose for patients in need of radioiodine therap for hyperthyroidism, and to reduce the possibility of radiation damage or the unsatisfactory therapeutic effect caused by insufficient dose. It has clinical practical significance in providing the reference for clinicians to evaluate the administrated dose.