1.Analysis of related factors for preschool children s safety seat use in a district of Beijing
HU Jiangong, ZHAO Yingying, HE Chao, YOU Kai,PENG Tao
Chinese Journal of School Health 2026;47(1):42-45
Objective:
To understand the allocation and use of safety seats for preschool children and explore its related factors, so as to provide a scientific reference for promoting the usage of safety seats.
Methods:
A stratified random cluster sampling method was used to select 3 143 parents of preschool children aged 3 to 6 from six kindergartens in Shunyi District, Beijing from January 3 to 10, 2022. An online questionnaire survey was conducted to collect and evaluate the equipment and use of child safety seats in different characteristics of preschool children, as well as their scores of health beliefs. Multiple factor Logistic regression analysis was used to investigated the related factors of safety seat configuration and use.
Results:
The equipping rate and usage rate of safety seats for preschool children were 66.56% and 58.45%, respectively. The proportion of equipped and used safety seats for preschool children in core families (69.52%, 62.23%) were higher than that in large families (64.35%, 55.62%), only child families ( 72.39 %, 64.87%) were higher than non only child families (61.49%, 52.86%), and urban families (71.63%, 63.04%) were higher than rural families (52.31%, 45.51%) ( χ 2=9.23, 13.86; 41.72, 46.44; 101.96 ,76.97,all P <0.05) . As the educational level of parents ( χ 2 trend =154.23,98.76) and annual income of the family ( χ 2 trend =155.78,127.69) rised, the reporting rates of the equipped and used child safety seats in the family also increased(all P <0.05 ). There were statistically significant differences in the scores of different dimensions of health beliefs for the provision ( t =-20.22-18.16) and use ( t =24.32-24.17) of safety seats for preschool children(all P <0.05). After adjusting for child sex, child age, family annual income, parental education level, family type, whether the child was an only child, and place of residence,multivariate Logistic regression analysis showed that preschool children with higher perceived susceptibility score( OR =1.11, 1.08), higher self efficacy score( OR =1.23, 1.33), and higher suggestive factors score( OR =1.08, 1.12) were more likely to have and use safety seats in their families, while preschool children with higher perceived impairments score( OR =0.82, 0.80) were less likely to have and use safety seats in their families (all P <0.05).
Conclusions
The installation rate of child safety seats needs to be improved, and there is also a certain gap in their use after installation. Parents of preschool children should improve susceptibility and self efficacy to safety seat equipment and use, and perceptual barriers should be reduced.
2.Quality Evaluation of Gegen Qinlian Tablets Based on HPLC Multi-component Quantification Combined with Chemical Pattern Recognition and TOPSIS Analysis
Ping QIN ; Yingying LU ; Wenming ZHANG ; Zifang FENG ; Lihong GU ; Chenjie XIA ; Minmin HU ; Xiaowei CHEN ; Zhenhua BIAN ; Xiwan LU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(6):217-224
ObjectiveTo establish a high-performance liquid chromatography(HPLC) for the quantitative analysis of multiple components in Gegen Qinlian tablets, and to comprehensively evaluate the quality of samples from different manufacturers by integrating chemical pattern recognition and technique for order preference by similarity to ideal solution(TOPSIS), in order to provide a reference basis for quality evaluation and control of Gegen Qinlian tablets. MethodsHPLC was employed to determine the contents of 10 components in 28 batches of Gegen Qinlian tablets collected from 6 manufacturers, and taking the detection results as variables, SIMCA 14.1 and SPSS 26.0 were employed for cluster analysis(CA), principal component analysis(PCA), and orthogonal partial least squares-discriminant analysis(OPLS-DA) to identify key components affecting the quality. Then, TOPSIS analysis was employed to rank the quality of Gegen Qinlian tablets from the 6 manufacturers and establish a comprehensive quality evaluation method. ResultsA quantitative method for Gegen Qinlian tablets was established. After methodological validation, the method was found to be stable and reliable, and could be used for the quantitative analysis of this preparation. The contents of 3′-hydroxy puerarin, puerarin, 3′-methoxy puerarin, daidzein, coptisine hydrochloride, epiberberine, jatrorrhizine hydrochloride, berberine hydrochloride, palmatine hydrochloride and baicalin in 28 batches of samples were 3.58-7.35, 24.88-42.32, 4.20-9.36, 4.33-7.60, 2.52-6.44, 0.93-4.10, 0.58-3.05, 10.68-22.92, 0.82-4.82, 11.73-60.16 mg·g-1, respectively. Among them, puerarin, berberine hydrochloride and baicalin all met the limit requirements for this preparation specified in the 2025 edition of the Pharmacopoeia of the People's Republic of China. CA and PCA clustered the 28 batches of samples into 5 categories, PCA extracted 2 principal components with a cumulative variance contribution rate of 90.588%, and OPLS-DA screened out 4 differential markers with variable importance in the projection(VIP) values>1.0, namely baicalin, 3′-hydroxy puerarin, coptisine hydrochloride and palmatine hydrochloride, which might be the main components affecting the quality of Gegen Qinlian tablets. TOPSIS analysis showed that the comprehensive score of each evaluation index(Ci) values of different manufacturers were different. Among them, the Ci of manufacturer B was ranked higher, indicating potentially superior quality, while the Ci of manufacturer A was ranked lower, suggesting potentially inferior quality. ConclusionThis study establishes a quantitative method for Gegen Qinlian tablets, and the content uniformity of the same manufacturer is good, while there are differences in the contents of active components among different manufacturers. Through the chemical pattern recognition analysis, it is found that the content differences of Gegen Qinlian tablets may be related to baicalin, 3′-hydroxy puerarin, coptisine hydrochloride and palmatine hydrochloride.
3.Feasibility of deep learning reconstruction algorithm combined with adual-low protocol for thoracoabdominal aortic CT angiography
Yingying HU ; Yunpeng GAO ; Yan CHEN ; Nanxue LIANG ; Yue LIN ; Tongxi LIU ; Peiyao ZHANG ; Hongliang SUN
Chinese Journal of Radiology 2025;59(10):1149-1154
Objective:To investigate the feasibility of deep learning reconstruction (DLR) algorithm combined with a dual-low protocol (low radiation dose and low contrast medium dose) for thoracoabdominal aortic CT angiography (CTA).Methods:This cross-sectional study prospectively enrolled 56 patients suspected of aortic diseases who underwent aortic CTA at China-Japan Friendship Hospital from June 2023 to June 2024. All patients were randomly divided into two groups: Group A (28 cases) underwent CTA with a tube voltage of 100 kVp, automatic tube current modulation (noise index=10), and a contrast agent dose of 80 ml (flow rate 5 ml/s), with images reconstructed using the three-dimensional adaptive iterative dose reduction algorithm (AIDR). Group B (28 cases) underwent CTA with a tube voltage of 80 kVp, automatic tube current modulation (noise index=25), and a contrast agent dose of 40 ml (flow rate 3.5 ml/s), with images reconstructed using either the deep learning reconstruction algorithm-Advanced intelligent Clear-IQ Engine (AiCE subgroup) or the AIDR (AIDR subgroup). Two physicians evaluated the image quality of the three groups subjectively and objectively. Objective evaluation metrics included CT values, image noise (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) at the ascending aorta, carina-level descending aorta, celiac trunk-origin abdominal aorta, and common iliac bifurcation abdominal aorta carina. Subjective evaluation metrics included image quality and noise scores. Comparisons among the three datasets (Group A, AiCE subgroup, AIDR subgroup) were performed using one-way ANOVA or the Kruskal-Wallis test, with appropriate post-hoc tests for pairwise comparisons.Results:No significant differences were observed in CT values of the ascending aorta, descending aorta, and abdominal aorta between Group A and the AiCE subgroup or the AIDR subgroup ( P0.05). However, significant overall differences were found in SD, SNR, and CNR values for the ascending aorta, descending aorta, and abdominal aorta ( P0.05). Pairwise comparisons revealed that, except for no significant differences in SD, SNR, and CNR values of the ascending and descending aorta between Group A and the AiCE subgroup, and no significant difference in SNR values of the ascending and abdominal aorta between Group A and the AIDR subgroup ( P0.05), all other intergroup comparisons showed statistically significant differences ( P0.05). Significant overall differences were also observed in image quality and noise scores between Group A and the AiCE and AIDR subgroups ( P0.05). Except for no significant differences in image quality and noise scores between Group A and the AiCE subgroup ( P0.05), all other pairwise comparisons showed statistically significant differences ( P0.05). Conclusions:The application of deep learning reconstruction algorithm combined with a dual-low protocol in thoracoabdominal aortic CTA can reduce radiation dose and contrast agent dose while maintaining diagnostic image quality, demonstrating significant clinical value for widespread adoption.
4.Epidemiological characteristics of influenza in Beijing, 2023‒2024
Lu ZHANG ; Ying SUN ; Li ZHANG ; Chunna MA ; Jiaojiao ZHANG ; Jia LI ; Jiaxin MA ; Yingying WANG ; Xiaodi HU ; Daitao ZHANG ; Wei DUAN
Shanghai Journal of Preventive Medicine 2025;37(10):821-825
ObjectiveTo understand the epidemic characteristics of influenza in Beijing from 2023 to 2024, and to provide a scientific basis for the prevention and control of influenza. MethodsData on influenza-like illness (ILI) from secondary level and above hospitals, etiology surveillance data, and influenza clusters outbreaks data from 2023‒2024 were used to analyze the epidemic trend and pathogenic characteristics of influenza. Furthermore, an influenza comprehensive index was used to categorize the epidemic intensity at the severity level. ResultsA total of 2 065 857 ILI cases were reported in 2023‒2024 epidemic season, and the percentage of ILI was 3.67%. The age group of 5‒14 years accounted for the highest proportion of ILI (30.48%). A total of 41 766 throat swabs from ILI were detected, with a positive rate of 17.28%.A (H3N2) (51.86%) and B Victoria (41.93%) were the most prevalent subtypes of influenza virus. Clustered influenza outbreaks occurred mainly in primary schools (57.78%) and middle schools (35.55%), mainly caused by the influenza A (H3N2) subtype (85.93%). According to the influenza comprehensive index (I), the period of influenza activity and above (I>0.5) lasted for a total of 37 weeks, accounting for 71.15% of the entire influenza season. ConclusionCompared with previous years, the epidemic level of influenza in Beijing was increased in 2023‒2024, and the peak time became earlier. The comprehensive index method can objectively evaluate the level of influenza epidemic and provide suggestions for the future prevention and control of influenza in Beijing.
5.Prevalence and risk factors of olfactory dysfunction among the elderly in China:a populational based study
Shuting YU ; Wenwen DIAO ; Xiaoli ZHU ; Huijing HE ; Yaoda HU ; Guangliang SHAN ; Xingming CHEN ; Yingying ZHU
Chinese Archives of Otolaryngology-Head and Neck Surgery 2025;32(9):570-574
OBJECTIVE Aimd to investigate the prevalence of olfactory dysfunction among healthy elderly individuals in China using a large sample size and to explore its correlations with demographic and other factors.METHODS A total of 5 258 participants who aged 60 and above underwent the T&T olfactometer test and completed questionnaires.The prevalence of olfactory dysfunction was reported,and logistic regression analyses were performed to assess the associations between olfactory dysfunction and other factors.RESULTS The overall prevalence of olfactory dysfunction in the study was 26.5%.Independent risk factors for olfactory dysfunction included advanced age,rural residence(OR=1.88,95%CI:1.60-2.22,P<0.01),current smoking(OR=1.45,95%CI:1.15-1.83,P<0.01),and self-reported olfactory dysfunction(OR=10.12,95%CI:8.44-12.14,P<0.01).In contrast,female gender(OR=0.70,95%CI:0.58-0.85,P<0.01)and high educational attainment were independently associated with a lower prevalence of olfactory dysfunction.CONCLUSION The prevalence of olfactory dysfunction among individuals aged 60 and above increased with age.Male gender,rural residence,low educational attainment,current smoking,and self-reported decline in olfactory function were independently associated with olfactory dysfunction.
6.Exploration of the application of vehicle-mounted 5G remote mobile robotic surgical system in thyroid surgery
Meng WANG ; Wen TIAN ; Qingqing HE ; Guolou LI ; Jian ZHU ; Xiaodong MA ; Wei WEI ; Qiongqiong TAN ; Jinzhi HU ; Yingying WANG ; Peng ZHOU ; Gang WANG ; Yixin LIU ; Hejun WANG ; Yu LIU ; Lihu LIU
International Journal of Surgery 2025;52(1):28-32
Objective:To investigate the feasibility and safety of implementing a domestic vehicle-mounted remote mobile robotic surgical system in thyroid surgery applications, integrated with 5G communication technology.Methods:Using the main system located on the vehicle-mounted mobile robot operating platform of the 960th Hospital of PLA Joint Logistics Support Force and the slave system of Weifang Traditional Chinese Hospital, the remote radical thyroidectomy 5G communication technology, and analyze the clinical and information transmission data of two female patients who underwent remote mobile robot thyroid cancer surgery on October 21, 2024 at Weifang Traditional Chinese Medicine Hospital.Results:The remote radical thyroidectomy was conducted by the robosurgeons utilizing a vehicle-mounted mobile robotic surgical system, and the procedure was successfully completed without necessitating intermediate open surgery. The operation durations for patient 1 and patient 2 were 135 minutes and 108 minutes, respectively, with 7 and 13 lymph nodes dissected, respectively. The average delay in surgical data transmission was recorded at 61.9 milliseconds, with no instances of signal interruption or frame loss. The procedure proceeded smoothly, without any jamming, and the audio and video transmissions were consistently clear. Follow up for 21 days after surgery showed no complications such as hoarseness, skin damage, or lymphatic fistula.Conclusion:The implementation of a vehicle-mounted remote mobile robotic surgery system for thyroid surgery has demonstrated safety and feasibility. Furthermore, the utilization of the 5G network offers rapid data transmission and minimal latency, closely approximating the therapeutic efficacy of traditional robotic thyroidectomy.
7.The correlation between KRAS, NRAS, BRAF, PIK3 CA mutations and clinical characteristics in elderly colorectal cancer patients
Wenrong JIANG ; Su WANG ; Li DING ; Yingying SUN ; Yingxin MIAO ; Hu ZHAO ; Shiwen WANG
Chinese Journal of Geriatrics 2025;44(4):465-471
Objective:To investigate the correlation between mutations in KRAS, NRAS, BRAF, and PIK3 CA and the clinical characteristics of elderly colorectal cancer(CRC)patients. Methods:Paraffin-embedded tissue samples were obtained from 191 elderly CRC patients who consulted at Huadong Hospital, affiliated to Fudan University, between January 2022 and July 2023.Following deoxyribonucleic acid(DNA)extraction, the amplification refractory mutation system polymerase chain reaction(ARMS-PCR)was employed to detect the mutation profiles of KRAS, NRAS, BRAF, and PIK3 CA.Concurrently, serum samples collected prior to radical resection were analyzed for carcinoembryonic antigen(CEA), carbohydrate antigen 19-9(CA19-9), and carbohydrate antigen 72-4(CA72-4)using electrochemical luminescence.A comparative analysis of the clinical characteristics and preoperative serological tumor marker concentrations among patients with different gene mutations was conducted to elucidate their correlation. Results:A total of 191 elderly CRC patients were enrolled in the study, with ages ranging from 60 to 94 years(mean age 72.1±7.8 years), including 112 males.The mutation rate of KRAS, NRAS, BRAF, and PIK3 CA, as determined by combined detection, was found to be 49.21%(94/191)among elderly CRC patients. KRAS exhibited the highest mutation rate at 35.08%, with statistically significant differences observed in gender, primary site, degree of differentiation, and neurovascular invasion between patients with and without KRAS mutations( P<0.05 for all comparisons).The BRAF mutation rate was 8.90%, and significant differences in gender, age, primary site, and degree of differentiation were also noted between patients with and without BRAF mutations( P<0.05 for all).The mutation rates for NRAS and PIK3 CA were 2.62% and 5.24%, respectively, with no statistically significant differences in the clinical characteristics of patients across different groups( P>0.05 for all).Additionally, the proportion of patients over the age of 90 in the double mutation group was significantly higher( P<0.01).Significant differences in serum CA19-9 concentrations were observed among the various mutation types( P<0.05). Conclusions:There are notable differences in age, gender, primary site, degree of differentiation, and neurovascular invasion among elderly CRC patients with varying mutation statuses of KRAS, NRAS, BRAF, and PIK3 CA.Patients with double mutations exhibited higher concentrations of CA19-9 in preoperative serum.
8.Value of half-dose 18F-FDG deep-inhaled breath-hold total-body PET/CT in improvement of poor alignment of tumor lesions in thoracic and upper abdominal regions
Jin JIA ; Keqing YUAN ; Meng LIU ; Yingying HU ; Wei FAN ; Chao ZHOU ; Weiguang ZHANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(5):281-287
Objective:To evaluate the value of deep-inhaled breath-hold (DIBH)-30s scanning with total-body PET/CT under half-dose injection mode in improving the poor alignment of thoracic and upper abdominal tumors.Methods:Forty-six patients (28 males, 18 females, age (57.3±11.4) years) who underwent half-dose 18F-FDG total-body DIBH-30s PET/CT examination because of suspect or confirmed thoracic and upper abdominal tumors in Sun Yat-Sen University Cancer Center between October 2022 and February 2023 were analyzed retrospectively. SUV, standard deviation (SD) and signal-to-noise ratio (SNR) of the liver and mediastinal blood pool in free breath (FB)-8min, FB-30s and DIBH-30s PET images were measured; SUV of lesions, metabolic tumor volume (MTV) and tumor-to-background ratio (TBR) in DIBH-30s and FB-8min images were also measured; maximum diameter of contraposition offset and offset rate in coronal, transverse and sagittal directions of lesions in DIBH-30s and FB-8min images were calculated. Five-point Likert scale was used to score the overall image quality, image noise level and diagnostic confidence of fused images. Kruskal-Wallis rank sum test, Nemenyi test or Mann-Whitney U test was used to compare the parameters of different groups. Results:Among the 46 patients, 38 successfully completed breath-holding collection, and 80 lesions were detected, including 37 in the lungs and 43 in the livers. The liver SUV max (3.40(3.15, 3.63), 3.44(3.06, 3.70)) and SD (0.36(0.32, 0.41), 0.35(0.30, 0.40)) in DIBH-30s group and FB-30s group were higher than those (SUV max: 2.73(2.45, 2.92), SD: 0.15(0.13, 0.17)) in FB-8min group ( H values: 49.79, 85.27, χ2 values: 3.26-3.65, all P<0.001). The SUV max and the SD of mediastinal blood pool in DIBH-30s group and FB-30s group were also higher ( H values: 9.31, 59.73, χ2 values: 2.13-2.75, all P<0.01), while SNR liver and SNR med in those 2 groups were lower ( H values: 87.90, 54.11, χ2 values: 3.36-5.47, all P<0.001). The image noise scores of DIBH-30s group and FB-30s group were lower than the score of FB-8min group (3(3, 3) vs 3(3, 4) vs 5(5, 5); H=93.02, χ2 values: 2.13, 2.23, all P<0.001). The overall image quality score and diagnostic confidence score of DIBH-30s group were higher than those of FB-30s group and FB-8min group ( H values: 70.13, 24.22, χ2 values: 2.11-2.48, all P<0.001). The SUV and TBR of lesions in DIBH-30s group were higher than those of FB-8min group ( Z values: from -3.82 to -2.44, all P<0.05), while the MTV, contraposition offset and offset rate were lower than those of FB-8min group ( Z values: from -6.20 to -3.18, all P<0.001). Conclusions:DIBH-30s scanning with total-body PET/CT can make the focus alignment more accurate, which is suitable for short-time collection or low drug administration activity. It has a unique value in improving the poor focus alignment of chest and upper abdomen tumors.
9.Biomimetic dual-cell membrane nanoprobes employed for bimodal fluorescence-MR imaging of pancreatic cancer
Yanqi ZHONG ; Yingying MA ; Wenzheng LU ; Heng ZHANG ; Yuxi GE ; Peng WANG ; Jing ZHAO ; Jianying QIAN ; Jingxiao CHEN ; Shudong HU
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(2):88-93
Objective:To construct fused cancer cell/neutrophil membrane-coated polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNP@FMs) and explore the potential for targeted pancreatic cancer fluorescence imaging and MRI.Methods:Cancer cell membranes fused with neutrophil membranes were encapsulated on the surface of polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNPs) to prepare PMNP@FMs. The morphology, structure, and MRI performance of the product were characterized. The cytotoxicity of PMNP@FMs towards human pancreatic cancer cells (PANC-1) and normal human pancreatic ductal epithelial cells (hTERT-HPNE) was evaluated using cell counting kit (CCK)-8, and in vivo toxicity was assessed in healthy mice. PANC-1 pancreatic cancer xenograft nude mouse models were established for in vivo fluorescence imaging and MRI. Data were analyzed using the independent-sample t test, repeated measures analysis of variance and the least significance difference method. Results:PMNP@FMs exhibited a core-shell structure with a diameter of (112.81±8.64) nm, negative surface charge, and good dispersibility. The T 1 relaxivity of PMNPs was 18.81±0.22, which was 4.1 times higher than that of gadopentetate dimeglumine (Gd-DTPA) (4.55±0.24; t=75.54, P<0.001). Co-culture of PMNPs and PMNP@FMs with hTERT-HPNE and PANC-1 cells for 24 h resulted in cell viability above 90% within the concentration range of 0-500 μg/ml. PMNP@FMs did not affect mouse survival and showed no apparent organ damage. In vivo fluorescence imaging and MRI revealed that PMNP@FMs accumulated highly in tumors and reached the peak 24 h post intravenous administration (relative MR signal: 1.35±0.01, fluorescence intensity: (1.20±0.25)×10 10), surpassing the peak observed in the control group (1.22±0.01, (3.87±0.50)×10 9;F values: 11.03-188.01, t values: 18.20, 5.64, all P<0.05), with hepatic metabolism being the primary route of clearance. Conclusion:PMNP@FMs demonstrate a potential for targeted pancreatic cancer fluorescence imaging and MRI, offering promising prospect for precise diagnosis of early-stage pancreatic cancer.
10.Effect of influenza vaccination on influenza cluster epidemic in primary and secondary schools in Beijing in surveillance during 2023-2024
Yingying WANG ; Ying SUN ; Jia LI ; Wei DUAN ; Chunna MA ; Jiaojiao ZHANG ; Jiaxin MA ; Lu ZHANG ; Xiaodi HU ; Daitao ZHANG ; Li ZHANG
Chinese Journal of Epidemiology 2025;46(9):1580-1585
Objective:To analyze the effect of influenza vaccination on influenza cluster epidemic in primary and secondary schools in Beijing during the 2023-2024 surveillance season and provide evidence for the improvement of influenza vaccination strategies.Methods:The incidence data of influenza cluster epidemic and influenza vaccination coverage in the schools in Beijing during 2023-2024 were collected. Descriptive epidemiological methods were used to analyze cluster epidemic characteristics, and χ2 test was used to compare incidence differences between groups, and OR value and vaccine effectiveness [VE=(1- OR)×100%] were calculated. A negative binomial regression model was used to evaluate the association between school vaccination rates and cluster epidemic risk. Joinpoint regression was used to analyze trends in relative risk ( RR) with increasing vaccination coverage and to determine the optimal vaccination threshold. Results:A total of 126 influenza cluster epidemic were reported in 115 primary and secondary schools in Beijing during 2023-2024 with the median size of 15 case, the average attack rate was 36.26% (2 033/5 607). The epidemics mainly occurred in urban area (70, 55.56%). Primary schools were the main setting (78, 61.90%), and influenza A(H3N2) was the predominant subtype (108, 85.71%). The overall influenza vaccination coverage in the primary and secondary students was 54.26%, while the average vaccination in classes affected by the epidemics was 58.57%. The overall protection rate was 47.62%, the protection rate was higher in primary schools (49.65%) than in secondary schools (46.60%). The protection rates against influenza A(H1N1)pdm09 (80.93%) and influenza B (Victoria lineage) (81.65%) were significantly higher than that against influenza A(H3N2) (44.19%). When school vaccination coverage reached ≥76.00%, the epidemic risk decreased by 52.82%.Conclusions:Even the match between influenza vaccine strains and circulating strains is suboptimal, increasing influenza vaccination coverage in schools can effectively reduce the risk for influenza cluster epidemic. In the future, measures such as policy guidance and public health education should be taken to further improve vaccination coverage, thereby establishing herd immunity and reducing the transmission risk of influenza in schools.


Result Analysis
Print
Save
E-mail