Hemophilia is a hereditary coagulation disorder, in which patients often suffer from joint dysfunction due to recurrent joint bleeding, with the knee joint being particularly susceptible to involvement, thereby significantly impairing their ability to walk.Gait analysis, as an objective, quantitative, and comprehensive assessment tool, can be employed to accurately evaluate the walking function of patients and provide a scientific basis for the rehabilitation management of individuals with hemophilia.With the deepening of medical research, the role of gait analysis in the rehabilitation management of hemophilia is increasingly being recognized.This review article summarizes the application of gait analysis in the rehabilitation management of hemophilia, including changes in gait parameters, kinematic and kinetic characteristics of joints in patients with hemophilia, as well as the relationships between these parameters and the severity of the disease and treatment outcomes in hemophilia patients, exploring the role of gait analysis in the rehabilitation management of hemophilia to better apply it in clinical practice.

OBJECTIVES: To compare the clinical effect on Bell's facial palsy in the acute stage between the staging comprehensive treatment with acupuncture-moxibustion and western medication. METHODS: Sixty patients with Bell's facial palsy in the acute stage were randomly divided into an observation group and a control group, with 30 cases in each one. The patients in the control group were administered orally with prednisone acetate tablets and methylcobalamin tablets until the 28th day of illness. In the observation group, the staging comprehensive treatment with acupuncture-moxibustion was adopted. On the affected side, Qianzheng (EX-HN 16), Yifeng (TE 17), Sibai (ST 2), Yangbai (GB 14), Jiache (ST 6), Dicang (ST 4) and Touwei (ST 8), etc. were stimulated. In the acute stage (Day 1 to 7 of illness), the routine acupuncture and the point-toward-point needle insertion were delivered, no any manipulation was exerted at acupoints, and the needles were retained for 30 min. In the subacute stage (Day 8 to 14 of illness), on the base of the treatment as the acute stage, the depth of needle insertion was adjusted at a part of acupoints and the even needling technique was operated by twisting needle. Besides, electroacupuncture (EA) was attached to Qianzheng (EX-HN 16) and Dicang (ST 4), with continuous wave of low intensity and high frequency, 100 Hz, for 20 min. In the recovery stage (Day 15 to 28 of illness), on the base of the treatment as the subacute stage, the heavy stimulation of acupuncture was given, in which, the sticking and lifting needle techniques were delivered after the needles were inserted from Sibai (ST 2) toward Dicang (ST 4), and from Dicang (ST 4) toward Jiache (ST 6), separately; warm needling was operated at Yifeng (TE 17), and EA changed to stimulate the acupoints with the intermittent wave of high intensity and low frequency, 2 Hz, for 30 min. Acupuncture-moxibustion was given once every other day until the end of the 28th day of illness. The level of House-Brackmann facial nerve function rating scale (H-B grade),the score of Sunnybrook facial nerve grading system (Sunnybrook), the score of facial disability index (FDI), the temperature difference in the infrared thermal imaging facial area and electromyogram (EMG) situation of the affected muscle group were observed before and after treatment in the two groups. Using musculoskeletal ultrasound,the facial nerve diameter was detected and the clinical effect was compared between the two groups. RESULTS: After treatment, the level of H-B grade, Sunnybrook score, the scores of physical function and social life function in FDI were improved when compared with those before treatment in the patients of either group (P<0.01, P<0.05), and the results of these evaluations in the observation group were better than those of the control group (P<0.05). After treatment, the temperature difference of the frontal area, the eye area, the zygomatic area and the mouth corner was declined in comparison with that before treatment in the two groups (P<0.05), and the temperature difference in each area in the observation group was lower than that of the control group (P<0.05).The root mean square (RMS) of the frontal muscle group, the zygomatic muscle group and the orbicularis muscle group on the affected side increased in comparison with that before treatment in the two groups (P<0.01), and RMS of the observation group was higher than that of the control group (P<0.05) after treatment. Before treatment, the diameter of the facial nerve on the affected side was larger than that on the healthy side (P<0.01), and after treatment, the diameter on the affected side was reduced when compared with that before treatment in the two groups (P<0.01); the diameter of the facial nerve on the affected side in the observation group was smaller than that of the control group (P<0.05), while, the diameter on the affected side was larger when compared with the healthy side in the control group (P<0.05). The total effective rate of the observation group was 93.3% (28/30), higher than that of the control group (83.3% [25/30], P<0.05). CONCLUSIONS The staging comprehensive treatment with acupuncture-moxibustion is clearly effective on Bell's facial palsy in the acute stage, which affirms the effectiveness of acupuncture-moxibustion for the acute stage of Bell's facial palsy in comparison with conventional western medication.
Humans ; Facial Paralysis/therapy* ; Moxibustion ; Acupuncture Therapy ; Bell Palsy/therapy* ; Face

Background Permethrin is a commonly used pyrethroid insecticide and has been found to be potentially neurotoxic. Microglia are innate immune cells in the central nervous system and are involved in the development of a range of neurodegenerative diseases. Objective To observe possible toxic effects of permethrin on human microglia clone 3 (HMC3) in vitro and explore associated mechanism. Methods HMC3 were treated with 0, 10, 25, and 55 μmol·L⁻¹ permethrin for 72 h. Cell cycle and apoptosis were measured using flow cytometry. Cyclin-dependent kinase 1 (CDK1), cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin B2 (CCNB2), cellular tumor antigen p53 (p53), factor-related apoptosis (FAS), caspase 3 (CASP3), and H2A histone family member X (H2AX) were detected by quantitative real-time PCR (qPCR). The differential genes and enrichment pathways of HMC3 after 0 and 25 μmol·L⁻¹ permethrin treatment was analyzed by RNA sequencing. HMC3 was treated by 0, 10, 25, and 55 μmol· L⁻¹ permethrin for 72 h. The content of nitric oxide (NO) in the supernatant was detected using Griess reagent. The secretion level of interleukin-6 (IL-6) was detected by enzyme linked immunosorbent assay (ELISA). The mRNA expression levels of mitogen-activated protein kinase (MAPK) pathway (including MAPK1, MAPK8, and MAPK14), interleukin-1β (IL-1β), IL-6, and matrix metalloproteinase (MMP) families (including MMP1, MMP2, MMP3, and MMP9) were detected by qPCR. The protein expressions of phosphorylated p38 mitogen-activated protein kinase (p-p38), phosphorylated extracellular signal-regulated kinase (p-ERK), IL-1β, IL-6, and MMP1 were detected by Western blot. Results HMC3 was arrested in G2/M phase after 0, 10, 25, and 55 μmol·L⁻¹ permethrin treatment for 72 h, of which there was a statistically significant difference between the 55 μmol·L⁻¹ permethrin treatment group and the control group (P<0.01), and the mRNA expression of CDKN1A was up-regulated according to the qPCR (P<0.05). There was no statistically significant difference in the proportions of apoptosis between the groups (P＞0.05). The RNA sequencing showed that the differential genes were enriched in the MAPK pathway, and the mRNA expressions of MAPK1, MAPK8, and MAPK14 were up-regulated after the permethrin treatment at 55 μmol·L⁻¹ compared to the control group by qPCR (P<0.05). The Western blot revealed that, compared to the control group, the levels of p-p38 and p-ERK were increased after the 10 μmol·L⁻¹ permetrin treatment (P<0.05), the p-ERK level was increased after the 25 μmol·L⁻¹ permetrin treatment (P<0.05), and the p-p38 level was up-regulated after the 55 μmol·L⁻¹ permetrin treatment (P<0.05). The secretion of NO in the supernatant of HMC3 increased after permetrin treatment compared to the control group (P<0.05), the mRNA and protein expressions and the secretion of IL-6 showed an upward trend, the mRNA and protein expressions of IL-1β were up-regulated (P<0.05), and the mRNA and protein expressions of MMP1 were up-regulated in the 25 and 55 μmol·L⁻¹ permethrin groups (P<0.05). Conclusion Permethrin inhibits HMC3 cell proliferation in vitro, induces cell cycle arrest, activates MAPK pathway, and promotes the expression of inflammatory factors IL-1β and MMP1, which may be one of the mechanism of neurotoxicity induced by permethrin.

ObjectiveTo explore the possible mechanism of Changweiqing （肠胃清） in the treatment of colorectal cancer. MethodsHCT 116 cancer cells were used to prepare intestinal cancer cells with silenced polypyrimidine region binding protein 3 （PTBP3） gene and stably transfected cells with overexpressed PTBP3 gene. Stably transfected cells with silenced PTBP3， stably transfected cells with overexpressed PTBP3 and untransfected cancer cells were injected into the armpit of 72 nude mice to construct three different subcutaneous transplanted tumor models of colorectal cancer cells， including the silenced model， the overexpressed model and the control model， with 24 mice per model. Mice of each transplanted tumor modelwere randomly divided into Changweiqing （CWQ） group， oxaliplatin （OXA） group and normal saline （NS） group， with 8 mice in each group. The CWQ groups were given intragastric administration of 35.9625 g/kg of Changweiqing oral liquid and were intraperitoneally injected with 0.2ml of normal saline； the NS groups were given 0.5ml of normal saline by gavage， and intraperitoneal injection of 0.2ml of normal saline； the OXA groups were intraperitoneally injected with 5 mg/kg （0.2 ml） of oxaliplatin and given 0.5ml of normal saline by gavage. Each group was given intragastric administration once a day and intraperitoneal injection three times a week. After 31 days， the weight of subcutaneous tumors in each group was measured， and the tumor inhibition rate of the groups in each model were measured. Immunohistochemistry and other methods were used to detect the expression level of cell proliferation cell nuclear antigen Ki67 and apoptosis index. Real-time PCR and Western Blot were used to detect mRNA and protein expressions of PTBP3， signal transducer and activator of transcription 3 （STAT3） splicing isoform α （STAT3α）， STAT3 splicing isoform β （STAT3β）， B-cell lymphoma/leukemia-2 （Bcl-2） splicing isoform α （Bcl-2α）， and Bcl-2 splicing isoform β （Bcl-2β） in subcutaneous tumor cells in each group. ResultsFor all three transplanted tumor models， the weight of the subcutaneous tumors and Ki67 expression level of subcutaneous tumor tissue in all CWQ groups and OXA groups were lower than those of the corresponding NS groups， while the apoptosis level were higher （P＜0.05 or P＜0.01）. The mRNA and protein expressions of PTBP3， STAT3α， and Bcl-2α in the subcutaneous tumor tissues of the silenced model CWQ group and the overexpressed model CWQ group were lower than those of the corresponding NS groups， while the mRNA and protein expression levels of STAT3β and Bcl-2β were higher （P＜0.05 or P＜0.01）. All there groups of silenced model had lower subcutaneous tumor weight， Ki67 expression level， and mRNA and protein expression levels of PTBP3， STAT3α， and Bcl-2α in subcutaneous tumor tissue， as well as higher apoptosis level and mRNA and protein expression levels of STAT3β and Bcl-2β than those in all groups of control model； all groups of overexpressed model had higher subcutaneous tumor weight， Ki67 expression level， and mRNA and protein expression levels of PTBP3， STAT3α， and Bcl-2α ， while lower apoptosis level and mRNA and protein expression levels of STAT3β and Bcl-2β than those in all control model groups （P＜0.05 or P＜0.01）. In the control model， compared with the NS group， The tumor inhibition rate of all OXA groups was higher than that of corresponding CWQ groups， respectively. Compared to that of each control model group， the tumor inhibition rate was positive value of each silenced model group， and negative value of each overexpressed model group. ConclusionPTBP3 can promote the proliferation and inhibit apoptosis of intestinal cancer cells， upregulate the expression of STAT3α and Bcl-2α， and downregulate the expression of STAT3β and Bcl-2β in intestinal cancer cells. The meachnism of action of Changweiqing in the treatment of colorectal cancer maybe related to the inhibition of PTBP3， and regulation of the expression of STAT3α， STAT3β， Bcl-2α， and Bcl-2β.

  Objective  To investigate the predictive value of albumin-bilirubin (ALBI) score combined with liver function index and carcinoembryonic antigen (CEA) for liver metastasis of colorectal cancer.  Methods  We retrospectively analyzed the clinical data of patients with colorectal cancer who underwent surgical treatment in the Second Hospital & Clinical Medical Hospital, Lanzhou University from January 2016 to July 2021 and were followed up for 24 months. According to the follow-up results, the enrolled patients were divided into liver metastasis group and non-liver metastasis group, and were randomly divided into modeling group and validation group by a ratio of 2∶1. The risk factors of liver metastasis in the patients with colorectal cancer were analyzed. Lasso-Logistic regression was used to construct the prediction model. Bootstrap method was used for internal verification. Receiver operating characteristic curve, calibration curve and clinical decision curve were used to evaluate the reliability of the prediction model. Finally, a nomogram was drawn to show the prediction results.  Results  A total of 195 patients who met the inclusion and exclusion criteria were enrolled, including 130 in the modeling group and 65 in the validation group. Through Lasso regression variable screening and Logistic regression analysis, the results showed that ALBI score(OR=8.062, 95% CI: 2.545-25.540), alanine transaminase (ALT) (OR=1.037, 95% CI: 1.004-1.071) and CEA (OR=1.025, 95% CI: 1.008-1.043) were independent predictors of liver metastasis in colorectal cancer. The area under curve (AUC) of the combined prediction of liver metastasis of colorectal cancer in the modeling group was 0.921, the sensitivity was 78%, the specificity was 95%, the C-index was 0.921, the H-L fitting curve χ²=0.851, P=0.654, and the slope of the calibration curve was close to 1, suggesting that the accuracy of the model was high, and the DCA curve showed that the model had good clinical application value. For the data of the modeling group, the Bootstrap method was used for internal verification of 1000 resamplings. The accuracy was 0.869, the kappa consistency was 0.709, and the AUC was 0.913. When ALBI score, ALT and CEA were used to diagnose liver metastasis of colorectal cancer alone, the AUC of CEA was the largest (0.897), and the combination of the three had the highest efficacy in the diagnosis of liver metastasis of colorectal cancer. In the validation group, the AUC, sensitivity, specificity, C-index of the combined prediction of liver metastasis of colorectal cancer were 0.918, 85.0%, 95.6%, 0.918, respectively, and H-L fitting curve χ²=0.586, P=0.746.  Conclusions  ALBI score, ALT and CEA have certain predictive value for liver metastasis of colorectal cancer. The combined diagnosis of liver metastasis of colorectal cancer has high efficacy, and the risk prediction model constructed has a good predictive effect.

ObjectiveThis study aimed to evaluate the clinical efficacy of Ruyi Zhenbaowan（RYZBW）in the treatment of initial and early knee osteoarthritis （KOA） through a prospective multicenter，randomized，double-blind，and placebo-parallel controlled trial. MethodFrom October 13^th， 2021 to December 25^th， 2021， 240 KOA subjects meeting the acceptance criteria were enrolled in 15 sub-centers including Wangjing Hospital， Chinese Academy of Chinese Medical Sciences， and they were randomly divided into observation group and control group， with 120 cases in each group. The intervention measures for the observation group were RYZBW + health education， and the intervention measures for the control group were RYZBW placebo + health education. The intervention period in both groups was four weeks， and they were followed up for four weeks after the intervention. The primary outcome measure was the total score of Western Ontario and McMaster University Osteoarthritis Index score （WOMAC score）， and the secondary outcome measures were the response rate of visual scale （VAS） pain score， WOMAC sub item scores （joint pain， joint stiffness， and joint function）， quality of life （SF-12） score， and traditional Chinese medicine （TCM） syndrome score. Result（1） Efficacy evaluation. The marginal model results showed that the observation group was better than the control group in improving the WOMAC total score and WOMAC pain score in the treatment of KOA with RYZBW， and the difference was statistically significant （P<0.05）. There was no significant difference between the two groups in improving VAS score response rate， WOMAC function score， WOMAC stiffness score， SF12-PCS （quality of life-physical health） score， SF12-MCS （quality of life-mental health） score， and TCM syndrome score. （2） Subgroup analysis. ① In terms of VAS score response rate， the response rate of the observation group was higher than that of the control group for subjects with baseline VAS score of （4， 5］， and the difference was statistically significant （P<0.05）. ② In terms of TCM syndrome score， for subjects aged ［56， 60］ and ［61， 65］， the decrease in total TCM syndrome score in the observation group was better than that in the control group， and the difference was statistically significant （P<0.05）. ConclusionTibetan medicine RYZBW has good clinical efficacy in improving WOMAC total score， VAS score response rate， WOMAC pain score， WOMAC function score， and TCM syndrome score for patients with initial and early KOA， which can fill the lack of Tibetan medicine RYZBW in the treatment of KOA and make a demonstration study for the inheritance and development of ethnic medicine.

Objective:To evaluate the effect of emodin on liver injury in a mouse model of intestinal ischemia-reperfusion (I/R) and the role of heme oxygenase-1-mediated autophagy.Methods:Twenty-four SPF-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 18-22 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (Sham group), I/R group, emodin group (E group) and emodin plus HO-1 inhibitor Zinc Protoporphyrin Ⅸ (ZnPP) group (ES group). The intestinal I/R injury model was established by clamping the superior mesenteric artery for 45 min followed by 120 min of reperfusion. Emodin 40 mg/kg dissolved in 5% methylcellulose sodium was given by gastric gavage once a day for 5 days before ischemia in E group. Emodin 40 mg/kg dissolved in 5% methylcellulose sodium was given by gastric gavage once a day for 5 days before intestinal I/R, and ZnPP 7.5 mg/kg was injected via the tail vein at 12 h before ischemia in ES group. Orbital venous blood samples were collected at the end of reperfusion for determination of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations. Then the mice were sacrificed, and liver tissues were obtained for microscopic examination of the pathological changes (after HE staining) and for determination of the activity of superoxide dismutase (SOD), content of malondialdehyde (MDA), expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) mRNA (by fluorescent quantitative polymerase chain reaction), the expression of HO-1, autophagy-related protein Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) (by Western blot). The LC3-Ⅱ/Ⅰ ratio was calculated. Results:Compared with Sham group, the activity of SOD was significantly decreased, the content of MDA and serum ALT and AST concentrations were increased, the expression of IL-6 and TNF-α mRNA and HO-1 was up-regulated, the expression of Beclin1 was down-regulated, the LC3-Ⅱ/Ⅰ ratio was decreased ( P<0.05), and the pathological changes of liver tissues were found in I/R group. Compared with I/R group, the activity of SOD was significantly increased, the content of MDA and serum ALT and AST concentrations were decreased, the expression of IL-6 and TNF-α mRNA was down-regulated, the expression of HO-1 and Beclin1 was up-regulated, the LC3-Ⅱ/Ⅰ ratio was increased ( P<0.05), and the pathological changes of liver tissues were significantly attenuated in E group ( P<0.05). Compared with E group, the activity of SOD was significantly decreased, the content of MDA and serum ALT and AST concentrations were increased, the expression of IL-6 and TNF-α mRNA was up-regulated, the expression of HO-1 and Beclin1 was down-regulated, the LC3-Ⅱ/Ⅰ ratio was decreased ( P<0.05), and the pathological changes of liver tissues were aggravated in ES group. Conclusions:Emodin can alleviate liver injury induced by intestinal I/R in mice, and the mechanism may be related to the activation of HO-1-mediated autophagy.

【Objective】 To evaluate the dietary quality with the dietary balance index (DBI_16) and the association between dietary quality and bone mass among middle-aged and elderly people in Gansu Province so as to provide evidence for improving dietary quality and bone health status of Gansu population. 【Methods】 Based on the information of the type and quantity of food intake and the bone mass of middle-aged and elderly people aged 35 years and above collected by the Gansu Project in the Regional Ethnic Cohort Study in Northwest China, DBI_16 was used to evaluate the intake level of cereals, vegetables, fruits, milk, beans, fish and shrimp, eggs and other foods, and the degree of inadequate, excessive and unbalanced dietary intake of the participants. Multiple linear regression was used to evaluate the associations of three component indexes of DBI_16, high bound score (DBI_HBS), low bound score (DBI_LBS), diet quality distance (DBI_DQD), and seven single indexes of DBI_16 with bone mass. 【Results】 Analyses of the dietary and bone mass data of 11,840 participants showed that 44.8% of participants consumed excessive amounts of cereals compared to the dietary recommendation. 96.3%, 90.6%, 90.1%, 71.9%, 95.1% and 60.3% of participants’ intake of vegetables, fruits, milk, soybeans, fish and shrimp, and eggs, respectively, were inadequate. 47.7% participants consumed less than 10 types of food. 2.3% participants’ DBI_LBS levels were appropriate. 54.7% participants’ DBI_HBS levels were appropriate. Only 1.2% participants’ DBI_DQD reached a balanced level. The bone mass level in the study population was (2.5±0.6) kg [(2.8±0.5) kg for men and (2.3±0.5) kg for women]. After adjusting for sociodemographic characteristics, lifestyle, total dietary energy intake and body mass index, DBI_LBS and DBI_DQD were negatively associated with bone mass [β and 95% CI was -0.002 01 (-0.003 62--0.000 40) and -0.001 76 (-0.003 09--0.000 43), respectively]. 【Conclusion】 Dietary intake imbalance is common among middle-aged and elderly people in Gansu Province, and the more severe the dietary intake imbalance, the lower the bone mass level.

Objective: To determine the current prevalence of health risk behaviors among college students in Henan Province, and to conduct an in depth analysis of the impact of cumulative ecological risks on health risk behaviors, so as to provide scientific basis for promoting healthy development of adolescents. Methods: Using a multi stage stratified cluster sampling method, 9 743 college students from six universities in Henan Province were included as the research subjects from April to June 2023. A questionnaire survey was conducted using the College Student Cumulative Ecological Risk Scale and the China Urban Adolescent Health Related Behavior Survey Questionnaire (University Version). Data were analyzed by descriptive statistical analysis, Chi square test and binary Logistic regression. Results: The reporting rates of unhealthy eating behavior, unhealthy weight loss behaviors, lack of physical activity, daily risk behaviors, negative emotions, current smoking behavior current drinking behaviors, Internet addiction emotions and dangerous sexual behaviors among college students in Henan Province were 40.2%, 39.5%, 76.0%, 13.7%, 28.1%, 11.3%, 12.7%, 5.9% and 2.2%, respectively. The reporting rates of negative emotions, current smoking behaviors, current drinking behaviors, dangerous sexual behaviors and daily risk behaviors of college students were higher in boys than in girls ( χ 2=44.00, 995.20, 902.49, 121.95, 103.09, P <0.05). In terms of reporting rates of unhealthy diet, unhealthy weight loss and lack of exercise behavior, girls were higher than boys ( χ 2=107.59, 13.01, 145.83, P <0.05). Cumulative ecological risk was positively correlated with overall health risk behaviors. For every unit increase in the cumulative ecological risk index, the risk of health risk behaviors among college students increased by 48%. Conclusions The prevalence of health risk behaviors among college students is relatively common. It should adrocate for a healthy lifestyle, reduce the cumulative ecological risk and the occurrence of health risk behaviors to promote the healthy development of adolescents.

Objective:To investigate the epidemiology of pathogens of acute respiratory tract infection (ARTI) in children in Guangzhou area.Methods:A total of 13 610 hospitalized children with ARTI in Guangzhou Women and Children′s Medical Center from January 2018 to December 2021 were enrolled. Throat swab specimens were collected, and fluorescent quantitative polymerase chain reaction (PCR) was performed to detect 11 respiratory pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV), human rhinovirus (HRV), human bocavirus (HBoV), human metapneumovirus (HMPV), enterovirus (EV), influenza A virus (IFA), influenza B virus (IFB), Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP). Grouping according to age (< one year group, one to < three years group, three to < six years group, six to 14 years group) and season. Chi-square test was used for statistical analysis. Results:At least one pathogen was detected in 6 331 cases among 13 610 patients, and the overall positive rate was 46.52%. The detection rates from high to low were as follows: RSV (13.75%(1 872/13 610)), ADV (4.82%(656/13 610)), PIV (4.82%(656/13 610)), MP (4.54%(618/13 610)), HRV (3.39%(462/13 610)), HBoV (2.64%(359/13 610)), HMPV (2.59%(352/13 610)), EV (1.76%(239/13 610)), IFA (1.29%(176/13 610)), IFB (0.90%(122/13 610)) and CP (0.30%(41/13 610)). The positive rate of viral detection showed significant differences among different age groups ( χ2=49.91, P<0.001), and the highest positive rate was in the age group of one to