[Objective]To explore a new type of internal fixation system for the fixation of femoral intertrochanteric fracture.[Method]According to femoral tuberosity anatomical shape,anatomical locked hook-plate internal fixation system(ALHP) was designed,its biomechanical properties was examined and ALHP was applied for the clinical treatment of intertrochanteric fracture of the aged patients.[Result]Twenty-seven cases of intertrochanteric fracture were fixed with ALHP and followed up from 1.5 to 2 years,with an average time was 1.8 years.According to Sanders functional sores:the good and excellent rate was 100%.[Conclusion]Anatomy type locked hook-plate internal fixation system possesses reasonable design and produces firm fixation for intertrochanteric fracture.It can offer the elderly patients early exercises and reduce the incidence of complication.

A total of 3499 cases of influenza A (H1N1) were included in this study for analysis.Epidemiological and clinical data of these cases were input into EpiData software and analyzed by SPSS software. Throat swabs were collected from the cases and detected for nucleic acid of influenza A ( H1N1 )virus using real-time polymerase chain reaction (RT-PCR) with fluorescence quantitative method, and time of viral excretion and clinical features of the cases were analyzed. Results showed that 0. 37% of the cases were in-apparent and asymptomatic and the most common symptom of the cases was fever (86. 77% ).Throat swabs converted to negative on the sixth day of onset in average, and no factors related to the time of conversion was found with logistic regression analysis.

Objective:To assess the effect of Bolus materials(a material has the same effect with tissue)on dose distribution of electron beam radiotherapy on chest wall after surgery for breast cancer.Methods:Radiotherapy model of chest wall after modified radical mastectomy for breast cancer was constructed in this study.Based on the 6 MeV electron beam phase space file(PSF),which came from the International Atomic Energy Agency(IAEA)official website,and the Geant4 Monte Carlo software package,the research calculated the dose distributions of the electron beam radiotherapy of 5 kinds of different materials included water,polystyrene,polylactic acid,glycerol and silica-gel in Bolus materials,and compared the differences of the dose distributions between chest wall and lung tissue.Results:The Bolus materials have a relatively minor effect on the depth of maximum dose(dmax)of electron beams on the chest wall.The dmax maximum difference that was caused by Bolus with 10mm thickness only was 2mm.The Bolus materials with 10mm thickness have a notable effect on dose distribution,particularly in the posterior edge of the chest wall and shallow lung tissue.The order of Bolus materials corresponding to the dose in the posterior edge of the chest wall,from large to small,was polystyrene,water,polylactic acid,silica-gel and glycerol.For Bolus materials with 5 mm thickness and 10 mm thickness,the dose differences were approximate 8%and 15%,respectively.In shallow lung tissue,the corresponding Bolus materials with doses from large to small were water,polystyrene,polylactic acid,silica-gel and glycerol.For Bolus materials with 5 mm thickness and 10 mm thickness,the maximum dose differences were approximate 50%and 70%,respectively.Conclusion:The effect of Bolus materials has larger effect on the dose distribution of electron beam radiotherapy on the chest wall.The reasonable selection of Bolus materials is contributed to ensure the dose of target region,and minimize dose deposition of lung tissue.

Objective: To analyze the influencing factors of acute gastroenteritis outbreaks caused by norovirus in Beijing from 2014 to 2018. Methods: Data of acute gastroenteritis events caused by norovirus in Beijing from April 2014 to March 2018 were collected. Unconditional logistic regression model was conducted to identify the risk factors of the outbreaks. Results: A total of 765 acute gastroenteritis epidemics caused by norovirus were reported in Beijing, in which 85.88% (657/765) were cluster events and 14.12% (108/765) were outbreaks. Among the outbreaks, 70.37% (76/108) were reported in 2017; 84.26% (91/108) were reported in winter and spring; 88.89% (96/108) were reported in kindergartens, primary or secondary schools; 81.48% (88/108) were through person-to-person transmission; 93.52% (101/108) were caused by norovirus GⅡ infection. The risk of outbreaks in suburban and out suburb area were 1.84 times (95%CI: 1.13-3.02) and 3.78 times (95%CI: 1.62-8.82) as high as that in urban area, respectively. The risks of outbreaks in primary, secondary schools and other institutions were 6.26 times (95%CI: 3.53-11.10), 14.98 times (95%CI: 6.23-36.01) and 8.71 times (95%CI: 3.07-24.71) as high as that in kindergartens, respectively. The risk of outbreak in which patients having lower hospital visiting rate than the median rate of all events was 2.29 times than that in the context of having higher hospital visiting rate (95%CI:1.42-3.68). The risk of foodborne outbreak was 14.55 times as high as that transmitted through person-to-person (95%CI: 3.15-67.07). Conclusion Measures such as strengthening the prevention and control of norovirus outbreaks in suburbs, primary schools, secondary schools and other institutions, promoting patients to visit the hospital actively, improving the management of foodborne events and kitchen workers should be taken to reduce the incidence of acute gastroenteritis outbreaks caused by norovirus.

Objective:To provide evidence for clinical diagnosis, prevention and control of group A rotavirus (RVA) diarrhea, the clinical characteristics of RVA diarrhea in children in Beijing from 2011 to 2018 were analyzed.Methods:From January 2011 to December 2018, 4 819 stool samples from children under 5 years old with diarrhea were collected monthly from 3 hospitals in Beijing. General information, clinical characteristics and other information of children were collected. RVA was detected by enzyme-linked immunosorbent assay (ELISA), genotype was identified by multiple semi-nested RT-PCR. The Vesikari clinical severity score was used to define the severity of diarrhea in children. Dichotomous unconditional logistic regression was used to analyze clinical symptoms and other differences between RVA positive and negative cases. Chi-square and Fisher direct probability tests were used to compare the composition among different groups.Results:A total of 4 819 fecal samples were collected, 953 were positive for RVA, the positive detection rate was 19.78%. The positive rate of RVA was high in the younger age group, and the incidence was high in winter and spring. RVA-positive children had more risk on diarrhea ≥5 times a day, vomiting symptoms, fever, mild dehydration, and Vesikari score ≥11. The positive rate of RVA in watery stool samples (26.13%, 214/819) and infectious diarrhea cases (42.20%, 265/628) was the highest respectively. There were no significant differences in clinical symptoms, clinical diagnoses and fecal traits among children with different RVA genotypes.Conclusions:The clinical symptoms of RVA diarrhea were severe in children. RVA genotype did not affect the clinical symptoms. Stool traits (watery stools) and Vesikari score can assist physicians in diagnosing RVA diarrhea.

Objective:To understand the gene characteristics of Sapovirus from diarrhea cases in diarrhoeal disease clinics in Beijing.Methods:In 2019, stool samples were collected from diarrhea cases in diarrhoeal disease clinics in Beijing. The samples were used for the detection of nucleic acid of Sapovirus with real-time RT-PCR. Different RT-PCR methods were used for the partial gene segment amplification in the capsid protein VP1 region and the polymerase RdRp region, and sequencing was conducted for amplified positive products. The sequences were aligned with software BioEdit 7.0.9.0 and analyzed with software Mega 6.06.Results:The overall detection rate of Sapovirus was 2.89% (44/1 522), the detection rate in children under 5 years old was 3.34% (18/539) and 2.64% (26/983) in children aged ≥5 years. The capsid protein VP1 region was sequenced in 23 strains belonging to 8 genotypes (GⅠ.2 had 6 strains, GⅠ.1 and GⅡ.3 had 5 strains, respectively, GⅠ.3 and GⅡ.5 had 2 strains, respectively, GⅠ.5, GⅡ.1 and GⅣ.1 had 1 strain, respectively). A total of 16 strains were detected in the cases aged ≥5 years, and the proportion of GⅠ.2 was highest (37.50%, 6/16), and 7 strains were detected in the cases under 5 years old, the proportions of GⅠ.1 and GⅡ.3 were highest (both 42.86%, 3/7); The internal similarity of each genotype was 95.5%-100.0%, and the similarity with the 51 reference strains of human or sewage sources in different years and different countries was 92.2%-100.0%. The polymerase RdRp region was sequenced in 25 strains belonging to 8 genotypes (GⅡ.P3 had 9 strains, GⅠ.P3 had 4 strains, GⅠ.P1, GⅠ.P2 and GⅡ.P1 had 3 strains, respectively, GⅠ.P5, GⅡ.P5 and GⅣ.P1 had 1 strain, respectively). Fifteen strains were detected in the cases aged ≥5 years, and GⅡ.P3 had the highest proportion (40.00%, 6/15). Ten strains were detected in the cases under 5 years old, and the proportions of GⅠ. P1, GⅡ.P1 and GⅡ.P3 were highest (all 30.00%, 3/10); The internal similarity of each genotype was 94.0%-100.0%, and the similarity with the 39 reference strains of human or sewage sources in different years and different countries was 90.2%-99.1%.Conclusions:Sapovirus is one of the pathogens among diarrhea cases in Beijing. The main genome is GⅠ and GⅡ, and the genotypes are diverse and dispersed. The main genotypes of diarrhea cases in people aged ≥5 years and less than 5 years are different.

Objective:To understand the epidemiological characteristics and clinical features of rotavirus-, norovirus-, adenovirus-and astrovirus-associ ated acute gastroenteritis in children under 5 years old in Beijing from Octorber, 2015 to March, 2017.Methods:In the intestinal clinic of 6 hospitals in 6 districts of Beijing, information and stool samples of the first 30 patients with acute gastroenteritis who are under the age of 5 years are collected monthly.Rotavirus, norovirus, adenovirus and astrovirus are identified by PCR.Descriptive epidemiological method was used to describe the epidemiological characteristics of diarrhea caused by rotavirus, norovirus, adenovirus and astrovirus in Beijing. One-way analysis of variance was used to analyze the Vesikari clinical severity score of of acute gastroenteritis caused by each virus. Unconditional logistic regression analysis was used to analysis the associated factors of clinical features.Results:Of the 2 052 samples, 709 (34.6%) were non-mixed infections: the positive rate of rotavirus, norovirus, adenovirus and astrovirus were 20.0%, 7.5%, 4.2% and 2.9%, respectively. A total of 135 cases (6.6%) were mixed infection. The mean and standard deviation of Vesikari clinical severity score was 8.0±3.1 for rotavirus associated acute gastroenteritis, which was significantly higher than norovirus (6.4±2.4, P<0.001), adenovirus (6.2±2.1, P<0.001) and astrovirus (6.1±2.0, P<0.001). The comparison of clinical features showed that compared with astrovirus, the children under 5 years old infected with rotavirus were more likely to have a diarrhea ≥5 days ( OR=3.334), have vomiting ≥3 times within one day ( OR=8.788), have vomiting≥1 day ( OR=3.963), have a Vesikari clinical severity score ≥11 severe cases ( OR=13.194). Norovirus infected cases were prone to have vomiting≥3 times in 1 day ( OR=5.710).Adenovirus infected cases were prone to have a diarrhea≥5 days ( OR=2.616). When using rotavirus as a reference, children under 5 years of age were less likely to develop fever≥38.4 ℃ after infection with norovirus ( OR=0.397) or adenovirus ( OR=0.280). Conclusions:The results of this study showed that the characteristics of acute gastroenteritis caused by different viruses are different. The clinical symptoms caused by rotavirus are more serious. Children under 24 months of age are at high risk of rotavirus infection. Effective preventive measures such as vaccination should be taken as soon as possible.

Objective:To understand the epidemiological characteristics and clinical features of rotavirus-, norovirus-, adenovirus-and astrovirus-associ ated acute gastroenteritis in children under 5 years old in Beijing from Octorber, 2015 to March, 2017.Methods:In the intestinal clinic of 6 hospitals in 6 districts of Beijing, information and stool samples of the first 30 patients with acute gastroenteritis who are under the age of 5 years are collected monthly.Rotavirus, norovirus, adenovirus and astrovirus are identified by PCR.Descriptive epidemiological method was used to describe the epidemiological characteristics of diarrhea caused by rotavirus, norovirus, adenovirus and astrovirus in Beijing. One-way analysis of variance was used to analyze the Vesikari clinical severity score of of acute gastroenteritis caused by each virus. Unconditional logistic regression analysis was used to analysis the associated factors of clinical features.Results:Of the 2 052 samples, 709 (34.6%) were non-mixed infections: the positive rate of rotavirus, norovirus, adenovirus and astrovirus were 20.0%, 7.5%, 4.2% and 2.9%, respectively. A total of 135 cases (6.6%) were mixed infection. The mean and standard deviation of Vesikari clinical severity score was 8.0±3.1 for rotavirus associated acute gastroenteritis, which was significantly higher than norovirus (6.4±2.4, P<0.001), adenovirus (6.2±2.1, P<0.001) and astrovirus (6.1±2.0, P<0.001). The comparison of clinical features showed that compared with astrovirus, the children under 5 years old infected with rotavirus were more likely to have a diarrhea ≥5 days ( OR=3.334), have vomiting ≥3 times within one day ( OR=8.788), have vomiting≥1 day ( OR=3.963), have a Vesikari clinical severity score ≥11 severe cases ( OR=13.194). Norovirus infected cases were prone to have vomiting≥3 times in 1 day ( OR=5.710).Adenovirus infected cases were prone to have a diarrhea≥5 days ( OR=2.616). When using rotavirus as a reference, children under 5 years of age were less likely to develop fever≥38.4 ℃ after infection with norovirus ( OR=0.397) or adenovirus ( OR=0.280). Conclusions:The results of this study showed that the characteristics of acute gastroenteritis caused by different viruses are different. The clinical symptoms caused by rotavirus are more serious. Children under 24 months of age are at high risk of rotavirus infection. Effective preventive measures such as vaccination should be taken as soon as possible.

Objective To investigate the rotavirus contamination in commercial oysters in Beijing. Methods Between February 2014 and March 2015, a total of 280 oysters were collected in a large aquatic market in Beijing, and 5 oysters per stall were collected and classified as one sample.The samples were processed using three kinds of methods:direct treatment, PEG ( polyethylene glycol) 8 000 precipitation and proteinase K digestion-PEG 8 000 precipitation.Group A rotaviruses were detected by real time RT-PCR, and G/P genotyping was performed using the semi-nested RT-PCR.The VP7 and VP4 genes of positive samples were amplified, sequenced, and the phylogenetic tree was constructed using the maximum likelihood method with MEGA software ( version 6.06 ) .Results The detection rates of group A rotaviruses of three methods (direct treatment, PEG 8 000 precipitation and proteinase K digestion-PEG 8 000 precipitation) were 3.57%(2/56), 7.14%(4/56) and 5.38% (3/56), respectively.Rotaviruses were detected in 8 oysters samples ( 14.29%) , which were collected during autumn and winter . The G/P genotype combination included G9/P[8] (2 strains) and G9/P[N] (6 strains).The VP7 genes of 3 strains and the VP4 gene of one strain were sequenced successfully, and the phylogenetic analyses demonstrated that these strains had the highest similarity to those G9/P[8] strains prevailing in recent years in China.Conclusion Group A rotaviruses were detected in some commercial oysters during autumn and winter in Beijing, indicating a risk of foodborne illness.

Objective:To investigate the contamination of ball lettuce sold by norovirus and rotavirus in Beijing.Methods:From November 2015 to October 2016, 54 samples were collected at a market stall in Beijing. The potentially existing viruses were eluted and concentrated from the ball lettuce leaves using centrifugation and direct methods corresponding to three kinds of eluants. Norovirus and rotavirus were detected by real time RT-PCR. The partial VP1 gene of norovirus was amplified by semi-nested RT-PCR. The PCR product was sequenced directly, the sequence alignment was performed using the BioEdit 7.0.9.0 software, the phylogenetic tree was constructed with the MEGA 6.06 software.Results:Among 54 pieces of ball lettuce, rotavirus was detected negative, and the detection rate of norovirus was 11.11% (6/54). Of these NoV-positive specimens, 3 (50.0%) were NoV GII, 1 (16.7%) was NoV GI, and 2 (33.33%) were a mix of NoV GI and GII, The detection rates in spring, summer, autumn and winter were 8.3% (1/12), 0.0% (0/8), 28.6% (4/14) and 5.0% (1/20), respectively. One strain was sequenced successfully and identified as GII.3 genotype. The strain shares 100.0% nucleotide identity with strain KY348698 isolated from human in Guangdong in 2014.Conclusions:Human norovirus contamination existed in some ball lettuce sold in Beijing, eating raw unwashed ball lettuce may indicate a risk of viral acute gastroenteritis.