BACKGROUND:It has been found that internal factors such as anatomical structure,hormone level and neuromuscular function of athletes are closely related to the risk of anterior cruciate ligament injuries,and external factors such as the material of the playing field also become one of the risk factors affecting the occurrence of non-contact anterior cruciate ligament injuries,but they are relatively under-attended in the current studies. OBJECTIVE:To explore effects of artificial turf versus natural grass on the biomechanical performance of the lower limbs in young females during jump-landing. METHODS:According to the test needs,artificial turf and natural grass in accordance with the standards of GB/T 20033.3-2006 and GB/T 19995.1-2005 were leveled and fixed on two three-dimensional force measuring platforms.Twenty-one young females were voluntarily recruited and completed the jump-landing task on the artificial turf and natural grass.Subjects stood on the steps and then jumped forward,jumped down to the force measuring platform and immediately jumped with full force to the force measuring platform again.The two landings were required to fall to the two force measuring platforms,and the whole jumping action was considered successful without any pause.The kinematic,kinetic and electromyographic data of the lower limbs during the landing process were collected synchronously to compare and analyze the differences between the two. RESULTS AND CONCLUSION:In terms of kinetics,posterior and vertical ground reaction force at the initial landing moment during jump-landing on the natural grass were significantly lower than those on the artificial turf(P＜0.05,P＜0.01),as well as at the peak ground reaction force moment(P＜0.05,P＜0.05).Additionally,the knee flexion moment when jump-landing on the natural grass was higher than that on the artificial turf(P＜0.01).In terms of electromyography,within 100 ms after the initial landing moment,the electromyography activity levels of medial femoris muscle,lateral femoris muscle and anterior tibialis muscle when jump-landing on the natural grass were significantly lower than those on the artificial turf(P＜0.05,P＜0.01,P＜0.05).To conclude,compared with the natural grass,jump-landing on the artificial turf leads to an change in biomechanical performance that will cause an increase in anterior cruciate ligament tension.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.

Objective To investigate the effectiveness and safety of volumetric modulated arc therapy (VMAT) hypofractionated radiotherapy and intensity modulated conformal radiotherapy technique (IMRT) conventional fractionated radiotherapy after breast cancer radical operation.Methods Eighty-five patients with breast cancer modified radical operation admitted and treated in this hospital from March 1,2021 to De-cember 30,2021 were selected as the research subjects and divided into the VMAT group (n=41) and the IM-RT group (n=42) according to the random number table method.The VMAT group adopted the hypofrac-tionated radiotherapy,with the single fractionated dose of 2.9 Gy/frequency and radiotherapeutic total dose of 43.5 Gy/15 frequencies;the IMRT group adopted the IMRT conventional fractionated radiotherapy,with the single fractionated dose of 2.0 Gy/frequency and radiotherapeutic total dose of 50.0 Gy/25 frequencies.The planning target region V95,V110,conformity index,homogeneity index,treatment time,V5,V20,V30,average dose (Dmean) in the affected side lung,humeral head Dmean and heart V30,Dmean were compared between the two groups.Meanwhile,local recurrence,distant metastasis,disease-free survival and acute and chronic radiation injury were compared between the two groups.Results Compared with the IMRT group,V95 in the VMAT was higher,V110 and homogeneity index were lower,the treatment time was shorter,V5 in the affected lung,Dmean and Dmean in the affected humeral head were lower,V30 in the affected lung was higher,heart V30 in the left side breast cancer was lower,heart Dmean in the right side breast cancer was lower,and the differences were statistically significant (P<0.05).All patients survived without local relapse.The distant metastasis rate and disease free survival rate had no statistical difference between the two groups (P>0.05).Follow up lasted for 12 months,the incidence rates of grade Ⅰ-Ⅱ acute radiodermatitis,radiation esophagitis,chronic radioder-matitis and radiation pneumonia had no statistical differences between the two groups (P>0.05).The inci-dence rate of grade Ⅰ-Ⅱ shoulder dysfunction in the VMAT group was lower than that in the IMRT group with statistical difference (P<0.05).No grade Ⅱ and above acute and chronic radiation injury in the two groups occurred.Conclusion VMAT hypofractionated radiotherapy after breast cancer radical operation is safe and effective.

Objective:To explore the differences in dynamic spontaneous brain activity in individuals with subjective cognitive decline (SCD) and its correlation with spatial navigation ability in SCD subjects.Methods:A total of 72 SCD subjects(SCD group) and 67 normal controls (NC group) matched for age, gender and education level were recruited from September 2020 to February 2023 at the Affiliated Drum Tower Hospital, Medical School of Nanjing University. All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) examinations, spatial navigation tests and cognitive function assessments. The rs-fMRI time series were segmented using a sliding time window method, and statistical analyses were carried out using SPSS 26.0 software to compare the differences in the dynamic amplitude of low frequency fluctuation (dALFF) between the two groups. Correlation analysis was conducted between dALFF values in different brain regions and scale scores and spatial navigation tests.Results:Compared with the NC group, the dALFF variability in the right precuneus(0.119±0.021, 0.130±0.031) and left cuneus(0.143±0.034, 0.156±0.032) in SCD group decreased ( t=-3.41, -3.12, P<0.05, FDR corrected), and the dALFF variability in the right middle occipital gyrus(0.146±0.023, 0.137±0.020) and right angular gyrus(0.148±0.025, 0.139±0.026) increased ( t=4.51, 3.36, both P<0.05, FDR corrected). The temporal variability of dALFF in the right precuneus in SCD group was negatively correlated with egocentric spatial navigation ( r=-0.341, P=0.025), delayed allocentric spatial navigation ( r=-0.286, P=0.035) and memory function ( r=-0.332, P=0.009). The temporal variability of dALFF in the left middle occipital gyrus was positively correlated with language function ( r=0.339, P=0.015) and visuospatial function ( r=0.343, P=0.008) in SCD group. Conclusions:The temporal variability of dALFF in the right precuneus and the left middle occipital gyrus may be the neurobiological basis of cognitive decline and spatial navigation impairment in SCD subjects, and it can be used as a potential imaging marker for early identification of SCD patients.

Objective:To systematically appraise and summarize existing evidence on enteral nutrition in patients receiving radiotherapy for head and neck cancer.Methods:Based on the 6S Pyramid of Evidence-based Resources, a systematic search was conducted to identify guidelines, expert consensuses, and evidence summaries related to enteral nutrition for radiotherapy patients with head and neck cancer published from January 2018 to September 2023. The search covered relevant websites of guidelines, websites of academic societies, and databases (in Chinese and English). Literature screening, quality assessment, and data extraction were performed independently by the researchers.Results:A total of 19 studies were included, consisting of 10 guidelines, 7 expert consensuses, and 2 evidence summaries. Four aspects and 67 items of best evidence on organizational management, nutritional screening and assessment, enteral nutritional intervention programs, and monitoring and follow-up were summarized.Conclusion:This study summarized the best evidence for enteral nutrition in patients receiving radiotherapy for head and neck cancer, which can inform the standardized nutritional management and promote the translation of evidence-based knowledge into practice.

{L-End}Objective To investigate the current status of academic procrastination, psychological resilience, and emotional intelligence among undergraduate nursing students in Hebei Province. {L-End}Methods A total of 2 121 undergraduate nursing students from seven medical universities in Hebei Province were selected as the research subjects using a convenient sampling method. The Academic Procrastination Scale, Psychological Resilience Scale, and Emotional Intelligence Scale were used to investigate their academic procrastination, psychological resilience, and emotional intelligence. {L-End}Results The median score for academic procrastination among undergraduate nursing students was 62.5 points. The scores for psychological resilience and emotional intelligence were (79.9±10.1) and (100.7±11.6) points, respectively. The results of the multiple logistic regression analysis showed that students from urban areas experienced more severe academic procrastination than those from rural areas (P<0.05). Students with indifferent family relationships experienced more severe academic procrastination than those with close family relationships (P<0.05). Higher grade levels, lower scores in psychological resilience, and lower scores in emotional intelligence were associated with more severe academic procrastination among these nursing students (all P<0.05). {L-End}Conclusion The overall degree of academic procrastination among undergraduate nursing students in Hebei Province is at a moderate level. The level of psychological resilience and emotional intelligence can negatively affect the degree of academic procrastination among these undergraduate nursing students.

Objective: Subthreshold attention-deficit/hyperactivity disorder (ADHD) has been suggested to be a “morbid condition” which also needs medical attention. Methods: The present study recruited 89 children with subthreshold ADHD (sADHD), 115 children with diagnosed ADHD (cADHD), and 79 healthy controls (HC) to explore the clinical manifestation, executive functions (EFs) of sADHD, and the caregiver strain. The clinical manifestation was evaluated through clinical interviews and parent-reports. Executive functions were assessed both experimentally and ecologically. Caregiver strain was measured by a parent-reported questionnaire. Results: For the clinical manifestation, both sADHD and cADHD indicated impairments when compared with HC. The comorbidities and the scaled symptoms indicated that the externalizing behaviors were relatively less serious in sADHD than cADHD, whereas the internalizing behaviors between two groups were comparable. For ecological EFs, sADHD scored between cADHD and HC in inhibition and working memory. For experimental EFs, sADHD was comparable to cADHD in inhibition, shifting, and was worse than cADHD in verbal working memory. For the caregiver strain, all scores of sADHD were between that in cADHD and that in HC. Conclusion Our present findings supported the suggestion of subthreshold ADHD as “morbid condition,” which should be treated with caution in clinical practice, especially for the internalizing behaviors and some key components of EFs.

Radiotherapy uses high-energy X-rays or other particles to destroy cancer cells and medical practitioners have used this approach extensively for cancer treatment (Hachadorian et al., 2020). However, it is accompanied by risks because it seriously harms normal cells while killing cancer cells. The side effects can lower cancer patients' quality of life and are very unpredictable due to individual differences (Bentzen, 2006). Therefore, it is essential to assess a patient's body damage after radiotherapy to formulate an individualized recovery treatment plan. Exhaled volatile organic compounds (VOCs) can be changed by radiotherapy and thus used for medical diagnosis (Vaks et al., 2012). During treatment, high-energy X-rays can induce apoptosis; meanwhile, cell membranes are damaged due to lipid peroxidation, converting unsaturated fatty acids into volatile metabolites (Losada-Barreiro and Bravo-Díaz, 2017). At the same time, radiotherapy oxidizes water, resulting in reactive oxygen species (ROS) that can increase the epithelial permeability of pulmonary alveoli, enabling the respiratory system to exhale volatile metabolites (Davidovich et al., 2013; Popa et al., 2020). These exhaled VOCs can be used to monitor body damage caused by radiotherapy.
Breath Tests/methods* ; Exhalation ; Humans ; Quality of Life ; Respiratory System/chemistry* ; Volatile Organic Compounds/analysis*

Objective:To compare the diagnostic efficiency of colloidal gold dipstick method (PTH dipstick method) with that of doctors’ experience method based on nano-carbon method for rapid identification of parathyroid gland in thyroidectomy of thyroid cancer.Methods:From March to July 2020, 90 patients underwent thyroid surgery in the Friendship Hospital, Capital Medical University participated in the experimental study, and 155 samples underwent empirical judgment, parathyroid dipstick and pathological examination. All operations were performed by senior specialists. SPSS statistics 17.0 software was used for statistical analysis.Results:Seventy-four cases of parathyroid gland confirmed by both pathology and empirical judgment, and 81 cases of non-parathyroid gland confirmed by pathology; 130 cases of parathyroid glands confirmed by both PTH dipstick method and pathology, and 22 cases of non-parathyroid glands confirmed by pathology. The accuracy rate of PTH dipstick method was 85.53% which was much higher than that of empirical judgment method (47.74%). The data were statistically significant ( χ2=49.14, P<0.05). The sensitivity of PTH method was 95.89%, the specificity of PTH method was 75.94%, and the Youden index was 0.7183. The sensitivity of empirical judgment method was 81.3%, the specificity of empirical judgment method was 47.74%, and the Youden index was 0.2904. Conclusions:The diagnostic efficiency of the PTH method is higher than that of empirical judgment method to identify parathyroid gland in thyroid surgery. The two methods can be used together to increase the protection of parathyroid gland during operation.

Alzheimer's disease （AD） is a common degenerative disease of the central nervous system in the elderly， with memory impairment and behavioral changes as the main clinical manifestations. Modern research has demonstrated that many herbs with both medicinal and edible values have anti-oxidation and anti-aging activities. In addition， these herbs are naturally safe and play a role in disease prevention and health care. The 110 medicinal and edible herbs announced by the National Health Commission of the People's Republic ofChina in 2021 were studied. The relevant papers published in the last five years were searched against CNKI， VIP， Wanfang Data， PubMed and other databases. The effects， mechanism， and active ingredients of the medicinal and edible herbs against Alzheimer's disease were summarized. The results showed that more than 30 herbs including Ginseng Radix et Rhizoma， Curcumae Longae Rhizoma， Astragali Radix， Corni Fructus， Gastrodiae Rhizoma， Angelicae Sinensis Radix， Cistanches Herba， Croci Stigma， Glycyrrhizae Radix et Rhizoma， Ganoderma and their active ingredients were effective in the prevention and treatment of Alzheimer's disease. Among them， ten herbs that met the requirements were screened out for analysis. The medicinal and edible herbs and their active ingredients can act on multiple targets and treat Alzheimer's disease via multiple signaling pathways such as nuclear factor-κB （NF-κB）， mitogen-activated protein kinase 5 （MEK5）/extracellular signal-regulated kinase 5 （ERK5）， cytochrome C （CytC） and cysteine aspartate-specific protease （Caspase）-3/（Caspase）-9， Wnt/β-catenin， and brain-derived neurotrophic factor （BDNF）/tyrosine kinase receptor B （TrkB）/phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）， thus improving learning， cognitive ability， and memory ability. Most of the medicinal and edible herbs have the tropism to the heart， spleen， liver， and kidney meridians and tonifying effect.