BACKGROUND:Orthodontic treatment to move the mandibular second molar in place of the missing first molar is a good method for preserving natural teeth.However,molars often exhibit mesial tipping when using clear aligners.The impact of attachments and overcorrection on the molar mesialization with clear aligners is unclear.OBJECTIVE:To investigate the effects of attachments and overcorrection on displacement and biomechanics of the mandibular second molar mesialization.METHODS:A finite element model with the left mandibular first molar missing was constructed using a volunteer's cone-beam CT and intraoral scan data.The experiment was divided into four groups based on the position of attachments on the left mandibular second molar:without attachment,buccal attachment,lingual attachment,and buccal-lingual attachment,with overcorrection degrees(0°,1°,2°,3°,and 4°)for each group,totaling 20 models.The calculation and analysis of the displacement trends and stress were performed using Abaqus software.RESULTS AND CONCLUSION:(1)Mesial tipping and intrusion of the molar,distal tipping of the canines and permolars,and linguaing of the incisors occurred during molar mesialization.(2)The displacement of molars increased when attachments were used,with the maximum displacement occurring when buccal-lingual attachments were applied.Molars tended to tip towards the side without attachments when attachments were designed unilaterally.However,the inclination of molars did not decrease when attachments were used.(3)Molars exhibited reduced mesial tipping and intrusion,approaching overall movement,and the stress of periodontal ligament was relieved and more evenly distributed during overcorrection treatment,and this effect became more pronounced with increased degrees of overcorrection.(4)Attachments can enhance the effectiveness of overcorrection,with the best performance observed when buccal-lingual attachments are used.Using attachments and overcorrection together helps control molar mesial tipping and intrusion,but overall molar movement is not achieved.

Objective:To assess the status of undernutrition and appropriate catch-up growth in extremely preterm infants within 24 months of corrected age (CA).Methods:A retrospective cohort study was conducted. A total of 422 extremely preterm infants born at Shenzhen Maternity and Child Healthcare Hospital, Women and Children's Medical Center, Southern Medical University from January 2017 to December 2022 and followed up until 24 months of CA were enrolled. The extremely preterm infants were grouped by gestational age at birth (<25, 25-26, 27 weeks), birth weight (<500, 500-749, 750-999,≥1 000 g), weight for gestational age (large for gestational age (LGA), appropriate for gestational age (AGA), small for gestational age (SGA)) and sex. Weight data within 24 months of CA were collected every 3 months. Nutritional insufficiency, growth rate, and achievement of adequate catch-up growth were analyzed during the period from 0 to 24 months of CA. Z-score method was used to analyze data. Fenton 2013 preterm growth charts (Fenton 2013) were used before 40 weeks of corrected gestational age, and World Health Organization child growth standards (2009) fitted Z-scores were applied from 40 weeks of CA. Changes in weight Z-scores of extremely preterm infants from 0 to 24 months of CA were observed and compared, the occurrence of moderate to severe malnutrition and growth retardation was determined, nutritional insufficiency was assessed, and growth rate as well as the achievement of appropriate catch-up growth were analyzed. The Lambda-mu-sigma method combined with the Z-score fitting model was used to fit and analyze the distribution characteristics of weight percentiles in extremely preterm infants. The Chi-square test was used to compare differences among groups.Results:A total of 422 extremely preterm infants were included, with a gestational age at birth of 26.3(25.4, 27.2) weeks and a birth weight of (880±177) g. Among them, 238 were males and 184 were females; 36 cases (8.5%) were LGA, and 16 cases (3.8%) were SGA. During follow-up within 24 month of CA, 89 cases (21.1%) developed moderate to severe malnutrition. When compared separately among different birth weight and gestational age at birth groups, there had both statistically differences in the incidence of moderate to severe malnutrition ( χ2=42.94 and 9.17, both P<0.05). The incidence was the highest in the birth weight of CA<500 g group and the <25 weeks gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks gestational age at birth group in their respective groups. Growth retardation occurred in 5.2% (22/422). However, there had statistically differences in the incidence of growth retardation among different birth weight and gestational age at birth groups, in each grouped time interval ( χ2=21.61 and 4.30, both P<0.05). The proportions of rapid growth were relatively high in the 0-3 months and 3-6 months of CA groups, which were 96 cases (27.4%) and 98 cases (26.6%), respectively. Overall, appropriate catch-up growth was achieved in 341 cases (80.8%) from 0 to 24 months of CA. There had statistically differences in the completion rate of appropriate catch-up growth among different birth weight and gestational age at birth groups ( χ2=23.65 and 7.08, both P<0.05). The completion rate was the highest in the birth weight of CA<500 g group and the <25 weeks of gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks of gestational age at birth group. Conclusions:The lower the birth weight and gestational age of extremely preterm infants, the higher the incidence of moderate to severe malnutrition and the lower the achievement rate of adequate catch-up growth within 24 months of CA. The period of 0-6 months of CA is the critical window for catch-up in extremely preterm infants.

Objective: To investigate the associations between childhood obesity and performance of six minute walk test (6MWT), providing evidence for exercise tolerance assessment and exercise intervention strategies for children and adolescents. Methods: From March 2021 to December 2023, a cohort study was conducted among students recruited from a primary and secondary school in Chongqing, a total of 709 valid samples were included. The 6MWT was used to assess exercise tolerance, with vital signs measured before and after the test. Anthropometric indicators, including height, weight, and waist circumference, were measured using standardized procedures. Generalized additive models (GAM) and restricted cubic spline (RCS) regression were employed to analyze the nonlinear relationships between obesity related indicators and six minute walk distance (6MWD). Results: The mean 6MWD of participants was (602.59±70.73)m. GAM showed that after adjusting for confounding factors, body mass index (BMI) and weight had non linear relationships with 6MWD [effective degrees of freedom were 1.55 and 7.13 respectively], and overweight/obesity was associated with a decrease in 6MWD ( β =-18.65) (all P <0.01). Further RCS regression analysis showed that both BMI and weight showed an "inverted U shaped" non linear relationship with 6MWD in the overall population and sex stratified subgroups; the 6MWD of females was lower than that of males, and it showed a significant downward trend with the increase of BMI or weight (all P <0.05). Conclusion Body weight and BMI in children and adolescents have an important impact on 6MWD, and obesity in children and adolescents is markedly associated with decline in exercise tolerance.

目的 探讨应激性高血糖比率（SHR）与大动脉粥样硬化型脑梗死患者卒中后认知功能障碍（PSCI）的相关性。方法 连续性筛选2023年7月1日—2024年6月30日在北京京煤集团总医院住院的大动脉粥样硬化型脑梗死患者，共计1 222例纳入分析。根据SHR的三分位数水平，将患者分为3组：低值组（0.175~0.764，n=408），中值组（0.765~0.905，n=407）及高值组（0.906~2.760，n=407）。采用单因素分析比较两组间相关指标的差异，采用单因素及多因素Logistic回归分析，找出PSCI发生的独立危险因素；使用限制性三次样条（RCS）来阐明SHR水平与PSCI发生的关联，并进行阈值效应分析。结果 所有随访的患者中，PSCI发生率为16.3%（199/1 222）；高值组患者的年龄、平均动脉压（MAP）、入院时NIHSS评分、出院时MRS评分及PSCI发生率均增高，同时，MMSE评分及高学历占比显著降低（P均<0.05）；在校正相关因素后，除年龄大、高低密度脂蛋白水平、高同型半胱氨酸水平、高血清肌酐、合并糖尿病病史及出院高MRS评分外，高SHR（OR=5.19，95%CI 3.15~8.55，P<0.001）是PSCI发生的独立危险因素；SHR与PSCI发生率呈“倒V”型的非线性关系（Pfor overall<0.001，Pfor nonlinear<0.001），且两者之间的关联存在阈值效应（Pfor likelihood test<0.001），即当SHR<1.28时，SHR和PSCI为正向关联（OR=93.26，95%CI 27.23~319.42），当SHR>1.28时，SHR和PSCI为负向关联（OR=0.08，95%CI 0.02~0.41）。结论 在大动脉粥样硬化型脑梗死患者中，PSCI发生率较高；SHR与PSCI的发生呈“倒V”型的非线性关系。

ObjectiveTo develop a novel precision rehabilitation service model for structural problems in rural rehabilitation services for persons with disabilities in China, such as shortages of professional resources, imprecise assessment and lack of service continuity, guided by International Classification of Functioning, Disability and Health (ICF) and supported by digital technologies. MethodsUsing ICF as an analytical tool and rural disability rehabilitation services as the application scenario, this study adopted a problem-oriented approach focused on current service challenges. Through literature review, situation analysis and strategy exploration, elements of body functions and structures, activities and participation, environmental factors, and digital technologies were organically integrated to form systematic solutions. ResultsA precision rehabilitation service model developed for rural persons with disabilities was constructed based on ICF and integrated with digital technologies such as the Internet of Things, big data and telerehabilitation. The model encompassed three dimensions: precise assessment of body functions, precise matching of intervention modalities and precise adjustment of environmental factors. An implementation pathway for digital technology-empowered precision rehabilitation in rural areas was proposed. ConclusionThe digitally empowered precision rehabilitation service model based on ICF is helpful for addressing the challenges of equity and precision in rural rehabilitation services in China, promoting access fairer, more accessible and systematically continuous rehabilitation services.

Objective: To investigate the effects of clinical routine X-ray irradiation dose (average irradiation dose: 29.7±0.54 Gy) on the function, apoptosis, activation state and mitochondrial function of platelets during in vitro storage, so as to provide experimental evidence for optimizing platelet irradiation strategies. Methods: A paired experimental design was adopted. Platelets were collected from 12 healthy donors, and each sample was equally divided into the irradiated group and the control group (non-irradiated). All samples were stored for 5 days under standard platelet preservation conditions (22±2℃, continuous oscillation). Flow cytometry was used to detect platelet count, apoptosis rate (Annexin V+ positive rate), activation markers (CD62P, PAC-1, CD42b) and reactive oxygen species (ROS) level. Meanwhile, mitochondrial-specific probes were used to evaluate changes in mitochondrial count, membrane potential and adenosine triphosphate (ATP) content. Additionally, transmission electron microscopy (TEM) was employed to observe the ultrastructure of platelets, with a focus on mitochondrial morphology, platelet membrane integrity and granule distribution. Results: Within 5 days of storage, the platelet count was (841±89.16)×10 /L in the irradiated group and (824.5±92.88)×10 /L in the control group, with no statistically significant difference between the two groups (P=0.54). The apoptosis rate was (4.94±1.39) % in the irradiated group and (5.50±0.83) % in the control group, showing no significant difference (P=0.31). For activation indicators, the CD62P expression rate was (24.32±7.57) % in the irradiated group versus (25.21±8.13) % in the control group (P=0.43). The PAC-1 positive rates were (12.15±4.43) % and (11.75±3.40) % in the irradiated group and control group, respectively (P=0.44). The CD42b expression rates were (12.14±4.43) % and (11.75±3.4) % in the two groups, respectively (P=0.47). The ROS levels were (31.98±8.1) % and (30.64±5.89) % in the two groups, respectively (P=0.45). No significant differences were found in the above indicators. For mitochondrial function indicators, the mitochondrial count was (55.88±11.49) % in the irradiated group and (53.5±7.24) % in the control group (P=0.57). The ATP contents were (42.45±5.29) % and (41.58±9.50) % in the irradiated group and control group, respectively (P=0.77). The relative membrane potential values were (59.53±10.89) % and (57.49±6.54) % in the two groups, respectively (P=0.47). No significant difference were observed on the mitochondrial function-related indicators. TEM further confirmed that the ultrastructure of platelets in the irradiation group was intact, the mitochondrial morphology was normal, and no pathological changes such as swelling or vacuolization were observed. Conclusion: This study evaluated the impact of conventional-dose X-ray irradiation on platelet storage quality, confirming that this dose does not significant impair platelet count, apoptosis rate, activation status, or mitochondrial function. This finding provides important experimental evidence for the clinical promotion of X-ray irradiation technology and suggests its potential as a safe alternative to γ irradiation. Future studies could further expand the sample size and extend the observation period to verify the effects of X-ray irradiation on long-term platelet storage and post-transfusion in vivo survival rate.

Objective: To explore the distribution characteristics and influencing factors of adverse reactions in whole blood donation in Jinan, Shandong, so as to provide evidence for the prevention and control of such adverse reactions in this region. Methods: A retrospective analysis was conducted on whole blood donors and adverse reaction cases in Jinan during 2023. To explore influencing factors of adverse reactions, univariate and multivariate logistic regression analyses were used to examine the relationships between adverse reactions and factors such as gender, age, donation organization mode, donation frequency, donation volume, time slot, and health examination results. Results: A total of 122 961 whole blood donations were recorded in Jinan in 2023. Donation-related adverse reactions occurred in 2 054 cases, with an incidence rate of 1.67%. Univariate analysis revealed significant differences in the incidence of adverse reactions across donor characteristics: the rate was higher in females (2.35%, 921/39 192) than in males (1.35%, 1 133/83 769), donors aged 18-25 years had the highest incidence (3.48%, 1 799/51 733), the incidence in group donations (3.13%, 1,737/55 534) was significantly higher than in individual donations (0.47%, 317/67 427), and insufficient blood collection was closely associated with adverse reactions (all P<0.001). Multivariate logistic regression analysis identified group donation, female gender, and a pulse rate of 81-99 beats per minute as risk factors for adverse reactions (all P<0.001), while systolic blood pressure of 116-139 mmHg and diastolic blood pressure of 76-89 mmHg were protective factors (all P<0.05). Compared to younger and lower-weight donor groups, older and higher-weight donors had a significantly lower risk of adverse reactions (all P<0.05). Donors giving 400 mL had a higher risk than those giving 200 mL (P<0.001). In addition, compared with the donation time slot of 7:00-8:59, the risk of adverse reactions was significantly higher during 9:00-16:59, with the time slot of 13:00-14:59 showing the most prominent risk (all P<0.05). However, no statistically significant difference was observed between the time slot of 17:00-20:59 and that of 7:00-8:59 (P>0.05). The primary clinical manifestation of adverse reactions was donation-related vasovagal reaction, with mental tension being the leading precipitating factor, accounting for 69.08% (1 419/2 054) of cases. Conclusion: The occurrence of adverse reactions in whole blood donation in the Jinan is influenced by multiple factors, including donor demographic characteristics, donation organization mode, physiological indicators, and time of donation. It is recommended to enhance the identification and intervention for high-risk groups, and optimize donation processes and service models to reduce the incidence of adverse reactions, thereby ensuring donor safety and blood quality.

BackgroundThe violent aggressive behaviors of patients with schizophrenia usually have the characteristics of suddenness， unpredictability， high severity， and great difficulty in prevention. Early identification and accurate assessment of their risk of violent aggression have significant clinical significance. ObjectiveTo construct a predictive model for the violence risk in hospitalized patients with schizophrenia， to identify the key factors influencing the occurrence of violent behavior in these patients， so as to provide references for clinical precise quantitative assessment and early intervention. MethodsA total of 200 patients with schizophrenia who were hospitalized at Taiyuan Psychiatric Hospital from March 2022 to September 2024 and met the diagnostic criteria of the International Classification of Diseases， eleventh edition （ICD-11） were collected to form the modeling cohort. They were randomly divided into a training set （n=140） and a test set （n=60） at a ratio of 7∶3. Based on the least absolute shrinkage and selection operator （LASSO） regression algorithm， the feature variables were screened and dimension-reduced. The support vector machine （SVM） from machine learning was selected for model training and prediction. The discrimination efficacy of the model was evaluated by the area under the receiver operating characteristic （ROC） curve （AUC）， accuracy， precision， sensitivity， specificity， F1 value， and Brier value. ResultsLASSO regression screening identified 16 feature variables. Pearson correlation analysis revealed a positive correlation between prior violent behavior frequency and clinical psychiatric symptom scores （r=0.580， P<0.01）， a positive correlation between hospitalization compliance and current disease status （r=0.550， P=0.003）， and a positive correlation between educational level and family per capita monthly income （r=0.367， P<0.01）. The SVM model achieved an AUC of 0.853， accuracy of 0.800， precision of 0.810， sensitivity of 0.895， specificity of 0.636， F1 value of 0.850， and Brier value of 0.168. ConclusionThe SVM model has a relatively high level of applicability and overall predictive performance in the assessment of violent risk in schizophrenia patients， which is helpful for the early identification of violent risks in such patients. ［Funded by Specialized Research Project for Enhancing the Competence of Health Professionals in Taiyuan City （number， Y2023006）］

Objective: To systematically evaluate the association between random urinary electrolyte levels and hypertension among children and adolescents in Guizhou Province, so as to provide evidence for region specific dietary guidance and interventions. Methods: In 2023, a total of 2 480 children and adolescents aged 6 to 17 years were recruited from a nine-year coherent style school in Guizhou Province in a children health cohort, with follow ups conducted in 2024 and 2025. Random urine samples were collected to measure urinary sodium, potassium, calcium, and chloride, and the urinary sodium to potassium ratio (Na/K) was calculated. The diagnosis of hypertension was based on the criteria established by the Chinese Guidelines for Hypertension Prevention and Treatment (2024 revised edition) and relevant research. Linear mixed models and multinomial Logistic regression were used to assess the associations of urinary electrolytes with systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and the risk of hypertension. Results: At baseline, SBP, DBP, and MAP were 102.33 (94.33, 110.33), 61.33 (56.33, 67.00) and 75.22 (69.67, 81.33)mmHg among children and adolescents, respectively. After adjusting for potential confounders and two follow-ups, higher urinary Na/K ratio was positively associated with higher of SBP ( β=0.054, 95%CI =0.028- 0.081 ) and MAP ( β=0.038, 95%CI =0.010-0.066), as well as higher risks of hypertension ( OR=1.248, 95%CI =1.006-1.548) (all P <0.05). Higher of urinary chloride levels were positively associated with higher of SBP ( β=0.088, 95%CI = 0.009- 0.167), whereas higher of urinary potassium (SBP: β=-0.062, 95%CI =-0.096 to -0.028; MAP: β=-0.041, 95%CI = -0.078 to -0.005) and calcium levels (SBP: β=-0.036, 95%CI =-0.065 to -0.007) were negatively associated with blood pressure (all P < 0.05 ). Conclusion The urinary Na/K, as a comprehensive electrolyte marker, more stably reflects sodium load and excretory pressure in children and adolescents, and may serve as an early predictor of hypertension risk.

ObjectiveThis paper aims to analyze the damage degree of muscle tone in rats with spasticity of cerebral apoplexy （SCA） and the expression of Nestin and β-catenin in the M1 region of the cerebral cortex， thereby investigating the action mechanism of different doses of Shaoyao Gancaotang on rats with SCA. MethodsThe rats were randomly divided into a blank group， a model group， a positive control group （baclofen， 5.25 mg·kg^-1）， and low， medium， and high-dose groups of Shaoyao Gancaotang （2.1， 4.2， 8.4 g·kg^-1）， with nine rats in each group. A rat model with SCA was established by using a modified phrenic nerve block combined with intraventricular injection of anhydrous ethanol. Following behavioral scoring to confirm model validity， drug interventions were conducted. Neurological deficits and muscle tone were evaluated by behavioral assessments. The open field test was used to measure locomotor distance. Transmission electron microscopy was employed to examine the synaptic structures. Skeletal muscle adenosine triphosphate （ATP）ase staining was used to analyze myofibrillar changes. Hematoxylin and eosin （HE） staining was used to observe the histomorphological changes. Immunohistochemistry， Real-time polymerase chain reaction （Real-time PCR）， and Western blot were employed to detect mRNA levels and protein expressions of Nestin and β-catenin in the M1 region of the cerebral cortex. ResultsCompared with the blank group， rats in the model group exhibited significantly increased neurological deficit scores （P<0.01）， markedly elevated muscle tone scores （P<0.01）， substantially reduced locomotor distance （P<0.01）， prominent structural swelling and blurring， severe destruction of cerebral cortical cells， a significant increase in the proportion of skeletal muscle ATPase type Ⅰ fibers （P<0.01）， a significant decrease in mRNA levels and protein expression of Nestin （P<0.01）， and a significant increase in mRNA levels and protein expression of β-catenin （P<0.01）. Compared with the model group， the Shaoyao Gancaotang group exhibited reduced neurological deficit scores and muscle tone scores in rats with SCA （P<0.01） and increased locomotor distance （P<0.01）. Transmission electron microscopy revealed clearer and more intact synaptic structures in the rats from the Shaoyao Gancaotang group， with increased vesicle numbers and improved morphology. HE staining revealed intact neuronal cell structures with regular arrangement and reduced vacuolated cells in the rats from Shaoyao Gancaotang. ATPase staining result indicated a decreased proportion of type Ⅰ muscle fibers in the rats from the Shaoyao Gancaotang group （P<0.01）. Real-time PCR results demonstrated increased mRNA expressions of Nestin and β-catenin in the rats from the Shaoyao Gancaotang group （P<0.01）. Immunohistochemistry and western blot analyses indicated elevated protein expressions of Nestin and β-catenin in rats with SCA from the Shaoyao Gancaotang group （P<0.05， P<0.01）. ConclusionShaoyao Gancaotang may improve neurological function impairment and limb spasticity in model rats with SCA by regulating the proliferation and differentiation of neural stem cells in the cerebral cortex M1 region.