National biological standards for antibiotics are critical components of the antibiotic quality control system and serve as reference materials for measuring and calibrating the biological activity of antibiotics. This article systematically reviews the classification, definition of potency units, and current research status of commercially available national antibiotic biological standards in China. At present, these standards can be categorized based on chemical structure, number of components, and development methods. The definition of potency units has evolved from an early “arbitrarily assigned unit” to “being represented by the mass of the antibiotic salt” and, more recently, to the current mainstream approach of “being represented by the mass of the active ingredient”. This evolution reflects a shift in quality control philosophy from primarily biological analysis to a system dominated by chemical analysis supplemented by biological methods. Current research focuses on optimizing potency determination methods, studying the unification of content and potency, and implementing dual quality control of both the potency and the ratio/content of active components in multi-component antibiotics. For complex multi-component antibiotics, the microbiological assay based on biological activity remains irreplaceable in quality control. Future efforts should emphasize further method optimization, ensuring batch-to-batch consistency of standards, and advancing precision quality control as key research priorities for antibiotic biological standards.

Objective To explore the effect of training weights on energy expenditure(EE)among young males during squatting.Methods Twenty young males with strength training experience≥1 year were recruited and performed 3 sets of squats,with 5 repetitions per set,at 40%1RM,60%1RM and 80%1RM,respectively,with an interval of at least 72 hours.Oxygen uptake(VO2),heart rate,blood lactate,and the mechanical work on the barbell during squat exercises were measured before,during,and after each sets.Moreover,one-way repeated-measures ANOVA was used to compare EE differenc-es between different training weights,and two-way ANOVA was employed to examine the weight×method effect on metabolic equivalent(MET)values.Meanwhile,Pearson's correlation analysis was conducted to examine the correlation between EE and barbell mechanical work.Results(1)Training weight has significant effects on the total energy expenditure and EE during excess post-exercise oxy-gen consumption(EPOC)stage(P<0.001),while a significant increase was observed in the glycolytic EE only at 80%1RM and the aerobic EE with no less than 60%1RM(P<0.01 and P<0.05).(2)The percentage of EPOC-stage and glycolytic EE in the total energy expenditure was significantly higher than the aerobic EE(P<0.01),while that of aerobic EE at 40%1RM and 60%1RM was significantly higher than at 80%1RM(P<0.01).(3)Total energy expenditure(r=0.65,P<0.001)and EPOC-stage EE(r=0.68,P<0.001)showed moderate correlation with the mechanical work done.(4)Aerobic EE was significantly lower than the mechanical work done during squatting(P<0.001).Moreover,the MET values of squats calculated using aerobic EE during exercise at 40%-80%1RM was 2.42±0.54,2.89±0.87 and 2.7±0.56,while the MET ones calculated using the total energy expenditure reached 14.99±2.94,20.52±4.51 and 28.57±6.88.Conclusions Only EPOC-stage and glycolytic EE elevate with the increase of weight.Moreover,EE and the MET value scalculated using VO2 dur-ing exercise may under estimate the actual intensity of squat.Meanwhile,the accuracy of EE estima-tion may be improved by introducing the mechanical work.

Objective To explore the effect of training weights on energy expenditure(EE)among young males during squatting.Methods Twenty young males with strength training experience≥1 year were recruited and performed 3 sets of squats,with 5 repetitions per set,at 40%1RM,60%1RM and 80%1RM,respectively,with an interval of at least 72 hours.Oxygen uptake(VO2),heart rate,blood lactate,and the mechanical work on the barbell during squat exercises were measured before,during,and after each sets.Moreover,one-way repeated-measures ANOVA was used to compare EE differenc-es between different training weights,and two-way ANOVA was employed to examine the weight×method effect on metabolic equivalent(MET)values.Meanwhile,Pearson's correlation analysis was conducted to examine the correlation between EE and barbell mechanical work.Results(1)Training weight has significant effects on the total energy expenditure and EE during excess post-exercise oxy-gen consumption(EPOC)stage(P<0.001),while a significant increase was observed in the glycolytic EE only at 80%1RM and the aerobic EE with no less than 60%1RM(P<0.01 and P<0.05).(2)The percentage of EPOC-stage and glycolytic EE in the total energy expenditure was significantly higher than the aerobic EE(P<0.01),while that of aerobic EE at 40%1RM and 60%1RM was significantly higher than at 80%1RM(P<0.01).(3)Total energy expenditure(r=0.65,P<0.001)and EPOC-stage EE(r=0.68,P<0.001)showed moderate correlation with the mechanical work done.(4)Aerobic EE was significantly lower than the mechanical work done during squatting(P<0.001).Moreover,the MET values of squats calculated using aerobic EE during exercise at 40%-80%1RM was 2.42±0.54,2.89±0.87 and 2.7±0.56,while the MET ones calculated using the total energy expenditure reached 14.99±2.94,20.52±4.51 and 28.57±6.88.Conclusions Only EPOC-stage and glycolytic EE elevate with the increase of weight.Moreover,EE and the MET value scalculated using VO2 dur-ing exercise may under estimate the actual intensity of squat.Meanwhile,the accuracy of EE estima-tion may be improved by introducing the mechanical work.

Objective The biomechanical performance of Ilizarov fixator models with different configurations for humeral shaft defect was compared,so as to provide a biomechanical basis for selecting the appropriate circular external fixation structure for the clinical treatment of humeral shaft defects using Ilizarov technology.Methods Based on CT data of the humerus from a healthy volunteer,the external fixators with three configurations,namely,hybrid frame,semi-ring frame and 90° fan frame were established.The finite element method was used to simulate the displacement and stress distribution under different loading conditions,and the finite element results were validated by biomechanical tests.Results Finite element analysis results:in terms of displacement,under compression,tensile and torque conditions,the displacement of 90° fan model was smaller than that of hybrid and semi-ring models.In terms of stress,the 90° fan model had the smallest displacement under tensile condition.In compression and torque tests,the semi-annular model had the lowest stress.Biomechanical test results:the semi-ring model exhibited the smallest displacement under axial compression,but there was no significant difference between the three models(P＞0.05).Conclusions The semi-ring and 90° fan frames can achieve a similar stability as the traditional hybrid frame through the strategy of'reducing the ring and increasing the stem'.The unilateral structure of the 90° fan frame has the advantages of small size,light weight,and structural stability,as well as a small impact on the shoulder and elbow joints,which makes it more valuable in clinical applications.

Objective The biomechanical performance of Ilizarov fixator models with different configurations for humeral shaft defect was compared,so as to provide a biomechanical basis for selecting the appropriate circular external fixation structure for the clinical treatment of humeral shaft defects using Ilizarov technology.Methods Based on CT data of the humerus from a healthy volunteer,the external fixators with three configurations,namely,hybrid frame,semi-ring frame and 90° fan frame were established.The finite element method was used to simulate the displacement and stress distribution under different loading conditions,and the finite element results were validated by biomechanical tests.Results Finite element analysis results:in terms of displacement,under compression,tensile and torque conditions,the displacement of 90° fan model was smaller than that of hybrid and semi-ring models.In terms of stress,the 90° fan model had the smallest displacement under tensile condition.In compression and torque tests,the semi-annular model had the lowest stress.Biomechanical test results:the semi-ring model exhibited the smallest displacement under axial compression,but there was no significant difference between the three models(P＞0.05).Conclusions The semi-ring and 90° fan frames can achieve a similar stability as the traditional hybrid frame through the strategy of'reducing the ring and increasing the stem'.The unilateral structure of the 90° fan frame has the advantages of small size,light weight,and structural stability,as well as a small impact on the shoulder and elbow joints,which makes it more valuable in clinical applications.

Objective:To evaluate the effects of nasal endoscopy in curettage of large mandibular cyst.Methods:20 cases of large mandibular cyst admitted to Xianyang Hosptial of Yan'an University from January 2022 to December 2023 were included.The curet-tage of mandibular cyst was performed under general anesthesia through intraoral incision by nasal endoscopy-assisted illumination and enlargement of the lesion area during the operation.The application effects were evaluated from the aspects of surgical incision length,nerve injury and cyst recurrence.Results:During operation,the surgical filed of view was clear and the operation was suc-ceeded in all cases.There was no complication in and after the nasal endoscopy-assisted curettage,no cyst recurrence was observed during 1-year follow-up.Conclusion:Nasal endoscopy-assisted curettage of large mandibular cyst is effective and safe.

Objective:To investigate the correlation between peri-coronary fat attenuation index (FAI) and plaque formation in patients with myocardial bridge (MB) of the left anterior descending artery (LAD) using coronary computed tomography angiography (CCTA) and to develop an optimal predictive model to explore the potential application of FAI in the primary prevention of MB related atherosclerosis.Methods:In this retrospective study, prediction models associated with perivascular fat inflammation were developed and validated using both logistic regression and machine learning (ML) algorithm. A training dataset was collected from 253 patients who underwent ≥2 coronary computed tomography angiography (CCTA) with ≥3 months intervals from one tertiary hospital from January 2007 to April 2021 and had baseline CCTA showing no plaques in LAD MB. The median follow-up time was 3.2 years. According to the same criteria, a total of 75 LAD MB patients from four other hospitals were included to form an independent external validation dataset, with a median follow-up time of 1.8 years. Receiver operating characteristic (ROC) curve analysis with integrated discrimination improvement (IDI) and category net reclassification index (NRI) were used to compare the performance of the predictive models.Results:62 patients (24.5%) in the training dataset had proximal plaque formation in LAD MB, while 22 patients (29.3%) in the external validation dataset had plaque formation during the follow-up period. Baseline FAI within the longitudinal distance equal to 30 mm proximal to the MB entrance was an independent predictor ( OR=1.068, P=0.046). According to the model results, ROC curves were plotted. The AUC of Model 1 was 0.822, and the AUCs of Model 2 and 1 were 0.821 and 0.591 in the training dataset. After the DeLong test, the AUC of Model 1 was superior to that of Model 2 ( Z=2.839, P=0.005) and Model 1 ( Z=6.124, P<0.001). These findings were further validated in the external validation dataset, where ML-model 3 yielded the best predictive performance, outperforming the logistic regression-based Model 2 (categorical NRI=0.359, P=0.048; IDI=0.108, P=0.046). Conclusion:FAI measured within the 30 mm proximal to the entrance of MBs due to its prone to plaque development is an independent predictor for atherosclerotic plaque formation. The ML-prediction model based on a decision tree algorithm combines FAI, MB anatomical features, and patient risk factors, which is beneficial for patients undergoing routine CCTA examination to identify inflamed coronary arteries in advance and guide the clinical adoption of more targeted preventive treatment, including anti-inflammatory treatment.

Objective This study aimed to investigate the regulatory effect of electroacupuncture(EA)intervention on the protein kinase B(Akt)/mammalian target of rapamycin(mTOR)/hypoxia-inducible factor 1α(HIF-1α)signaling pathway in the hippocampal tissue of Alzheimer's disease(AD)model mice and its effect on astrocytic glycolytic function,further exploring how EA ameliorates AD-related cognitive impairment.Methods Eighteen APP/PS1 mice were randomly divided into model,EA,and sham EA groups(n=6)using the random number table method.Six wild-type C57BL/6J mice served as the control group.The EA group received EA stimulation at acupoints"Shenshu"(BL23),"Baihui"(GV20),and"Zusanli"(ST36)(administered every other day,20 min per session,for 4 weeks).The sham EA group received identical needle insertions at the same acupoints without electrical stimulation.The control and model groups were only restrained.Cognitive function was assessed using the Morris water maze and Y-maze spontaneous alternation tests.Hippocampal morphology was observed via hematoxylin and eosin staining.Hippocampal β-amyloid peptide 1-42(Aβ1-42)deposition was detected using immunohistochemistry.HIF-1α protein expression,the p-Akt/Akt,and p-mTOR/mTOR ratios were measured using Western blotting.Pyruvate kinase M2(PKM2)and lactate dehydrogenase A(LDHA)activities were quantified using enzyme-linked immunosorbent assay.Hexokinase(HK)activity and L-lactate content were determined using a colorimetric assay.Co-localization of LDHA with the astrocyte marker glial fibrillary acidic protein was quantitatively analyzed using immunofluorescence double-labeling combined with Pearson's correlation coefficient.Results Compared with the control group,the model group mice exhibited cognitive decline,as shown by prolonged escape latency(P<0.01),reduced number of platform crossings,lower time spent in the target quadrant,and decreased spontaneous alternation accuracy(P<0.01).The hippocampal neurons showed cell body swelling,deeper nuclear staining,enlarged intercellular spaces,and increased average optical density of Aβ1-42(P<0.01).The p-Akt/Akt and p-mTOR/mTOR ratios,as well as HIF-1α protein expression,were elevated(P<0.01).PKM2,LDHA,HK,and L-lactic acid levels were significantly increased(P<0.01),and the co-localization coefficient of LDHA with astrocytes was enhanced.Compared to the model group,the EA group of mice showed improved cognitive function.The hippocampal neurons had more intact structures,with a more uniform cell distribution.The average optical density of Aβ1-42 decreased(P<0.01),and the p-Akt/Akt and p-mTOR/mTOR ratios,as well as HIF-1α protein expression,decreased(P<0.01).PKM2,LDHA,HK,and L-lactic acid levels decreased(P<0.05),and the co-localization coefficient of LDHA with astrocytes significantly decreased(P<0.01).No significant improvement was observed in any of the indicators in the sham EA group compared with the EA group.Conclusion EA at"Shenshu"(BL23),"Baihui"(GV20),and"Zusanli"(ST36)ameliorates cognitive dysfunction in AD model mice.The underlying mechanism may involve suppressing the overactivation of the hippocampal Akt/mTOR/HIF-1α signaling pathway,thereby downregulating key glycolytic enzyme activities and reducing abnormal lactate accumulation.Furthermore,the astrocytic glycolytic metabolic pathway may constitute a key therapeutic target for this intervention.

Objective:To develop an ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses and to test its reliability and validity.Methods:The initial questionnaire was constructed through literature review, group discussion, Delphi expert consultation, and pilot-testing based on the theory of knowledge, attitude and practice. Convenience sampling was used to select 301 ICU nurses from Class Ⅲ Grade A hospitals in Honghe Hani and Yi Autonomous Prefecture, Beijing City, Yantai City, Wuhan City, and Xi'an City from January to February 2024 to examine the reliability and validity of the questionnaire.Results:The ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses consisted of three dimensions of knowledge, attitude, and practice with a total of 52 items. In the two rounds of consultation, the expert authority coefficients were all 0.871, and Kendall's harmony coefficient was 0.186 and 0.161, respectively ( P<0.01) . Exploratory factor analysis extracted three common factors with a cumulative variance contribution rate of 74.989%. The split-half reliability of the questionnaire was 0.835, and the Cronbach's α coefficient was 0.979, and the Cronbach's α coefficients for knowledge, attitude, and practice dimensions were 0.976, 0.989, and 0.972, respectively. The content validity index at the questionnaire level was 0.996, and the content validity index at the item level was 0.800 to 1.000. Conclusions:The ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses has good reliability and validity, and can be used as a tool to assess the knowledge, attitude and practice of nurses towards ICU acquired dysphagia.

Objective:To develop an ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses and to test its reliability and validity.Methods:The initial questionnaire was constructed through literature review, group discussion, Delphi expert consultation, and pilot-testing based on the theory of knowledge, attitude and practice. Convenience sampling was used to select 301 ICU nurses from Class Ⅲ Grade A hospitals in Honghe Hani and Yi Autonomous Prefecture, Beijing City, Yantai City, Wuhan City, and Xi'an City from January to February 2024 to examine the reliability and validity of the questionnaire.Results:The ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses consisted of three dimensions of knowledge, attitude, and practice with a total of 52 items. In the two rounds of consultation, the expert authority coefficients were all 0.871, and Kendall's harmony coefficient was 0.186 and 0.161, respectively ( P<0.01) . Exploratory factor analysis extracted three common factors with a cumulative variance contribution rate of 74.989%. The split-half reliability of the questionnaire was 0.835, and the Cronbach's α coefficient was 0.979, and the Cronbach's α coefficients for knowledge, attitude, and practice dimensions were 0.976, 0.989, and 0.972, respectively. The content validity index at the questionnaire level was 0.996, and the content validity index at the item level was 0.800 to 1.000. Conclusions:The ICU-acquired Swallowing Disorders Knowledge, Attitude and Practice Questionnaire for Nurses has good reliability and validity, and can be used as a tool to assess the knowledge, attitude and practice of nurses towards ICU acquired dysphagia.