Objective To evaluate the radiation dose levels induced by secondary neutrons at different locations inside proton therapy treatment rooms, and analyze the distribution characteristics of neutron energy spectra by combining experimental measurements with simulations, and to provide a theoretical basis and technical support for radiation protection design and management in proton therapy. Methods Multiple representative measurement points were established in the treatment rooms of two hospital-based proton therapy centers. The DIAMON neutron spectrometer was employed to perform in-situ measurements of secondary neutron doses and energy spectra. Three-dimensional simulation models of treatment rooms were constructed using the FLUKA code to simulate the generation and transport of secondary neutrons. Results Measurements showed that the neutron dose was highest near the target region, reaching up to 4293.750 µSv/h. The doses at the maze entrance were the next highest, ranging from 422.091 to 489.268 µSv/h, while the doses in the middle section of the maze ranged from 2.860 to 6.727 µSv/h. The neutron energy spectra exhibited a triple-peak pattern. Conclusion Significant accumulation of secondary neutrons was observed near the target and in the maze regions during proton therapy, with intermediate-energy neutrons being the dominant dose contributor. The consistency between measurements and simulations validated the reliability of the model, which can provide a basis for optimizing treatment room shielding and controlling occupational exposure for staff.

OBJECTIVE: To explore the effectiveness of free paraumbilical perforator flaps in repairing skin and soft tissue defects in children. METHODS: Between February 2018 and March 2024, 12 children with skin and soft tissue defects were treated with the free paraumbilical perforator flaps. There were 7 boys and 5 girls with an average age of 6.3 years (range, 2-12 years). The defects located on the upper limbs in 6 cases, lower limbs in 5 cases, and neck in 1 case. The causes of wounds included 7 cases of electrical burns, 1 case of thermal burn, 2 cases of scar release and excision due to scar contraction after burns, 1 case of scar ulcer at the amputation stump after severe burns, and 1 case of skin necrosis after a traffic accident injury. The size of defects after debridement ranged from 7.0 cm×4.0 cm to 18.0 cm×10.0 cm. According to the defect size, 11 cases were repaired with unilateral paraumbilical perforator flaps centered on the umbilicus, among which 3 cases with larger defects were designed as "L"-shaped flaps along the lateral and lower ends of the perforator; the donor sites were directly closed. One case with extensive defect after scar excision and release was repaired with bilateral expanded paraumbilical perforator flaps; the donor sites were repaired with autologous split-thickness skin grafts. The size of flaps ranged from 9.0 cm×4.0 cm to 20.0 cm×11.0 cm. Postoperatively, analgesia and sedation were provided, and the blood supply of the flaps was observed. RESULTS: All operations were successfully completed. The operation time was 4-7 hours, with an average of 5.0 hours. After postoperative analgesia and sedation, the visual analogue scale (VAS) score for pain in all children was less than or equal to 3, and there was no non-cooperation due to pain. All flaps and skin grafts survived completely, and the wounds healed by first intention. Ten children underwent 1-4 times of flap de-fatting, finger separation, and trimming. All children were followed up 6-48 months (mean, 26.6 months). No obvious swelling of the flaps occurred, and the texture was soft. At last follow-up, among the 6 children with upper limb defects, 2 had upper limb function grade Ⅳ and 4 had upper limb function grade Ⅴ according to the Carroll upper limb function assessment method. The 4 children with lower limb defects had no limitation of joint movement. The neck flexion and rotation in the 1 child with neck defect significantly improved when compared with that before operation. The 1 child with residual ulcer at the amputation stump could wear a prosthesis and move without limitation, and no new ulcer occurred. Linear scars were left at the donor sites, and no abdominal wall hernia was formed. CONCLUSION The free paraumbilical perforator flap has abundant blood supply and can be harvested in large size. It can be used to repair skin and soft tissue defects in children and has the advantages of short operation time, minimal injury, high safety, and minimal impact on the growth and development of children.
Humans ; Perforator Flap/transplantation* ; Child ; Male ; Female ; Soft Tissue Injuries/surgery* ; Child, Preschool ; Plastic Surgery Procedures/methods* ; Burns/surgery* ; Umbilicus/surgery* ; Skin Transplantation/methods* ; Skin/injuries* ; Cicatrix/surgery* ; Treatment Outcome

Objective:To explore various factors influencing speech recognition ability in patients with age-related hearing loss（ARHL） and to investigate the correlation between speech recognition ability and cognitive function. Methods:This case-control study enrolled 150 ARHL patients（experimental group） and 132 normal-hearing controls. Participants underwent relevant assessments of auditory function, cognitive function, and tinnitus severity. Various statistical analyses were performed to evaluate the results. Results:①The PBmax and MoCA scores were significantly lower in the ARHL group compared to the control group（P<0.05）. ②PBmax in the ARHL group was significantly influenced by multiple factors（P<0.05）. ③Negative correlations were observed between PBmax in the ARHL group and age, degree of hearing loss, duration of the disease, duration of the worst hearing loss, smoking status, and tinnitus severity（P<0.05）, while positive correlations were found between PBmax and education level, occupation type, frequency of verbal communication, and cognitive function level（P<0.05）. ④Higher education level, frequent verbal communication, and high cognitive function level were protective factors for PBmax in ARHL patients（P<0.05）, whereas the other factors were independent risk factors（P<0.05）. ⑤A significant correlation was found between PBmax and MoCA scores in the ARHL group, and this correlation between cognitive function and speech recognition ability remained significant across different degrees of hearing loss（<0.05）. Conclusion:Speech recognition ability in ARHL patients is influenced by multiple factors. Cognitive function demonstrates a robust, bidirectional association with speech recognition ability, even after adjusting for hearing loss severity.
Humans ; Case-Control Studies ; Middle Aged ; Male ; Female ; Aged ; Speech Perception ; Cognition ; Presbycusis/physiopathology* ; Adult ; Hearing Loss

The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that evade immunity elicited by vaccination has posed a global challenge to the control of the coronavirus disease 2019 (COVID-19) pandemic. Therefore, developing countermeasures that broadly protect against SARS-CoV-2 and related sarbecoviruses is essential. Herein, we have developed a lipid nanoparticle (LNP)-encapsulated mRNA (mRNA-LNP) encoding the full-length Spike (S) glycoprotein of SARS-CoV-2 (termed RG001), which confers complete protection in a non-human primate model. Intramuscular immunization of two doses of RG001 in Rhesus monkey elicited robust neutralizing antibodies and cellular response against SARS-CoV-2 variants, resulting in significantly protected SARS-CoV-2-infected animals from acute lung lesions and complete inhibition of viral replication in all animals immunized with low or high doses of RG001. More importantly, the third dose of RG001 vaccination elicited effective neutralizing antibodies against current epidemic XBB and JN.1 strains and similar cellular response against SARS-CoV-2 Omicron variants (BA.1, XBB.1.16, and JN.1) were observed in immunized mice. All these results together strongly support the great potential of RG001 in preventing the infection of SARS-CoV-2 variants of concern (VOCs).

Objective:To analyze the cost and structural impact of the new technology"transhysteroscopic mechanical rotary excision of abnormal uterine tissues"on the DRG group of"surgery for intrauterine lesions"under the DRG payment method,and to provide clinical data for supporting the development of the exclusion policy for the new technology and new items.Methods:Cases in which transhysteroscopic mechanical rotary excision of abnormal uterine tissues was used in the gynecology day unit of the Peking Union Medcial College Hospital from March 2022 to November 2023,which were paid for under the DRG group of"surgery for intrauterine pathology",were retrospectively analyzed for the impact of the new technology on the cost and structure of the cases.Results:The price of"transhysteroscopic mechanical rotary excision of abnormal uterine tissues"in the Beijing Medical Service Price Item Specification is 8 000 yuan(Class C out-of-pocket expenses),which is higher than the payment standard of 6 866 yuan for the NE19 group,and the use of this new technology significantly increased the total hospitalization medical cost,the out-of-pocket ratio of the patients and the surgical cost,which led to an increase in the burden of the patients and the loss of the hospitals.Conclusion:"Transhysteroscopic mechanical rotary excision of abnormal uterine tissue"has the advantages of improving patients'prognosis and accelerating recovery,shortening operation time,avoiding intraoperative thermal injuries,and shortening the learning curve of doctors,etc.Policy makers should take into account cost control,patients'prognosis and the development of medical technology,scientifically and prudently formulate the exclusion policy of the new technology,reasonably determine the payment standard,and make good use of the exclusion policy and the payment standard.

Objective:To evaluate the value of peripheral blood systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), carcinoembryonic antigen (CEA), D-dimer, and albumin (ALB) alone or their combination in the diagnosis of early-onset colorectal cancer (EOCRC).Methods:From January 1, 2023 to November 30, 2024, 104 patients with EOCRC (EOCRC group) hospitalized at Renmin Hospital of Wuhan University were enrolled. During the same period, by simple random sampling method, 104 patients with benign colorectal polyps (benign polyp group) and 104 healthy individuals for health examinations (healthy control group) from outpatient department were enrolled. The peripheral blood parameters (including neutrophil count, lymphocyte count, CEA, and others) and pathological characteristics of EOCRC (including TNM stage, tumor differentiation grade, and depth of invasion) were collected. The relationship between peripheral blood parameters and EOCRC pathological features were analyzed. Receiver operating characteristic curves (ROC) were plotted, and the area under the curve (AUC) was calculated to evaluate the diagnostic value. Multivariate logistic regression analysis was performed to analyze the peripheral blood parameters which independently correlated with EOCRC and a combined diagnostic model was established. Simple random sampling method was used to divide the subjects in the negative control group (healthy control group + benign polyp group) and positive group (EOCRC group) into a training set (218 cases) and a validation set (94 cases) at a ratio of 7∶3, and the diagnostic performance of the combined diagnostic model in the training and validation sets was assessed. Hosmer-Lemeshow test and calibration curve were used to evaluate the fit and consistency of the model. Independent sample t-test, one-way ANOVA, Mann-Whitney U test and Kruskal-Wallis H test were used for statistical analysis. Results:EOCRC group had the highest levels of SII(744.03 (473.01, 1 246.28), 437.77 (342.28, 607.47), 497.31 (385.76, 721.63)×10 9/L), NLR(2.42 (1.76, 3.94), 1.96 (1.54, 2.52), 1.91 (1.55, 2.75)), CEA (3.58 (1.96, 20.85), 1.31 (0.95, 1.93), 1.21 (0.76, 2.11) μg/L) and D-dimer (0.36 (0.20, 0.90), 0.19 (0.12, 0.28), 0.18 (0.12, 0.30) mg/L), and the lowest levels of LMR(3.51±1.56, 4.38±1.37, 4.72±1.84) and ALB(42.40 (39.90, 44.70), 44.57 (42.83, 46.25), 44.95 (43.10, 46.58) g/L) than benign polyp group and healthy control group, and the differences were statistically significant ( H=31.18, 16.21, 76.72 and 47.72, F=15.40, H=34.19; all P<0.001). In EOCRC patients, there were statistically significant differences in SII and LMR between patients with different tumor invasion depth ( Z=-2.48, t=2.31; both P<0.05), in CEA between patients with different TNM stage, with or without lymph node metastasis and distant metastasis( Z=-2.68, -2.50 and -2.65; all P<0.05), in D-dimer between patients with different TNM stage, differentiation grade, invasion depth, and with or without lymph node metastasis and distant metastasis ( Z=-2.50, -2.60, -2.06, -2.14 and -3.33; all P<0.05), and in ALB between patients with or without distant metastasis ( Z=-2.52, P=0.012).The AUC of combination of SII, NLR, LMR, CEA, D-dimer, and ALB in differential diagnosis of the healthy control group and the EOCRC group was 0.914 (95% confidence interval (95% CI): 0.870 to 0.958, P<0.001), and the AUC of the combination in differential diagnosis of the benign polyp group and the EOCRC group was 0.904 (95% CI: 0.857 to 0.950, P<0.001). The results of multivariate logistic regression analysis revealed that SII, NLR, LMR, CEA, and ALB were all independently correlated with EOCRC (all P<0.05). The diagnostic model for EOCRC was established by the combination of SII, NLR, LMR, CEA, and ALB, and the AUC of the model in the training set and validation set was 0.911 and 0.883, respectively. The Hosmer-Lemeshow goodness-of-fit test indicated good model fit ( P=0.437). Calibration curve analysis showed strong consistency between predicted probabilities and actual probabilities, and the mean absolute error was 0.015. Conclusions:SII, NLR, LMR, CEA, D-dimer, and ALB all demonstrate diagnostic value in the diagnosis of EOCRC. The combined diagnostic model based on SII, NLR, LMR, CEA, and ALB demonstrates excellent diagnostic performance, which may serve as an adjunctive diagnostic approach for EOCRC.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective To compare the stress magnitude and distribution of the restorations,remaining tooth tissues,and bonding interfaces of endodontically mandibular first molar with different buccolingual residual tooth tissue thicknesses in two different restorations.Methods The finite element method was used to model the restorations of mandibular first molars with different buccolingual residual tissue thicknesses after root canal treatment.The vertical and oblique loads were applied to record the stress magnitude and distribution of restorations,residual tissues,and bonding interfaces of the different restorations.Results Three different models of mandibular first molar were designed based on the amount of buccal and glossal side dental tissue.Based on this simulation of the dental preparation of FO and EC and the preparation of the prosthesis,generating 6 different groups:FO repair in A1 group,thickness of the buccal tooth tissue is 2mm;A2 group was repaired by FO,thickness of the buccal tooth tissue is 3mm;A3 Group was performed with FO repair,thickness of the buccal and lingual remaining tooth tissue is 4mm;In B1 group,with EC repair,thickness of buccal tooth tissue is 2mm;In B2 group with EC repair,thickness of buccal tooth tissue is 3mm;In B3 group,using EC repair,thickness of remaining dental tissue on buccal and lingual side was 4mm.Results Two loading modes,the restoration such as effect force distribution are concentrated around the loading point,dentin effect force are concentrated in the tooth neck,the full coverage of high embedded group restoration-dental resin interface maximum main stress(MPS)is concentrated in the hole wall and shaft wall Angle,the pulp cavity setting crown group restoration-dental resin interface MPS focus in the bottom wall angle of the pulp cavity setting hole type.In the model of tooth tissue thickness in the same buccal-lingual side,except that the peak effect force of the restoration was greater than the peak of the full coverage crown,the peak of the observed index of the full coverage crown was greater than that of the whole cavity.Conclusion Endocrown can better protect the tooth tissue after root canal treatment,and it is recommended to choose endocrown for restoration after root canal treatment.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective To standardize and enhance the cleanliness of hospital floor and cleaning tools,significantly re-duce the influence of the predisposing factors that easily cause hospital-acquired infectious events,and reduce the possibility of such events due to inadequate cleaning and hygiene practices.Methods This study used Guangdong Second Provincial General Hospital as the research subject,cleaning tools were washed using both traditional manual disinfection and centralized mechanical cleaning and disinfection methods.Relevant experimental data were collected and compared to determine which method was more effective in terms of cleaning quality and optimal utilization of human resources.Results The bacterial colony count of floor tow-els treated with centralized mechanical cleaning and disinfection[(2.34±0.78)cfu/cm2]was significantly lower than that of the traditional manual cleaning group[(32.34±15.63)cfu/cm2].Similarly,the bacterial colony count on the floor cleaned with me-chanically centralized disinfected towels[(4.75±1.58)cfu/cm2]was much lower than that of the traditional manual disinfection group[(17.74±10.21)cfu/cm2)].Additionally,the bacterial colony count on door handles treated with centralized mechanical disinfection[(2.8±1.2)cfu/cm2]was significantly lower than that of the manual method[(10.1±5.7)cfu/cm2].Conclusion The centralized mechanical cleaning and disinfection method significantly mitigates the risk of hospital-acquired infections caused by insufficient disinfection of cleaning tools,while improving both the efficiency and quality of sanitation processes.