Objective To investigate the intrauterine growth characteristics of twins and birthweight discordant twins (discordant twins ).MethodsTotal of 1010 twin pregnancies (2020 fetuses) with complete delivery records from the Department of Obstetrics and Gynecology,the First and Third Affiliated Hospital of SUN Yat-sen University between January 1,2000 and July 31,2010 were studied retrospectively.One handred and ninteen cases (238 fetuses) with intrapair birthweight difference ≥25％ were determined as the discordant twins group,and the other 891 cases (1782 fetuses) with intrapair birthweight difference ＜ 25％ were identified as the concordant twins group.The singleton control group included 4042 singleton pregnancies in the same period.Results ( 1 ) Comparison of clinical data between the twins groups:the birthweight of larger-twin,smaller-twin and intrapair birthweight difference in the discordant twins group and the concordant twins group were ( 2090± 827 ) g,( 1392 ± 592 ) g,( 33.9 ±9.3 ) ％,and ( 2408 ± 543 ) g,( 2191 ± 505 ) g,( 8.9 ± 6.5 ) ％,respectively,with significant differences (P＜0.01).The incidence of discordant twins was 11.78％ (119/1010).Compared with the concordant twins group,the discordant twins group bad higher proportion of monochorionic twins,and higher prevalence of pregnancy complications such as late miscarriage,abnormal umbilical insertion,twin-twin transfusion syndrome and hypertensive disorders in pregnancy ( P ＜ 0.05 ).( 2 ) The characteristics of twin birthweight distribution:① In all the 2020 twins,80.05％ (1617/2020) fetuses had birthweight below the 50th percentile of the singleton control group,while 23.71％ (479/2020) feeuses got birthweight below the 10th percentile of the singleton control group.② After 19th gestational week,the 50th and 90th percentile of all twins' birthweight were lower than those of singletons.After 38th gestational week,the birthweight of singletons kept increasing and reached its peak at 41 th week,while the birthweight of twins reached its peak at 38th week,followed by a decline at 39 weeks,which was even lower than the 10th percentile of the singleton control group.③ The distribution of birthweight of larger- and smaller-twin in the discordant twins group:65 (54.6％,65/119) larger-twins and one (0.8％,1/119) smaller-twin had birthweight above the 50th percentile of all twins,while 5 (4.2％,5/119) larger-twins and 97 ( 81.5％,97/119 ) smaller-twins got birthweight below the 10th percentile of all twins.Conclusions ( 1 ) The patterns of birthweight curves for each gestational week are different between twins and singletons.In order to evaluate the growth of twins, birthweight reference for twins shoull be employed.( 2 ) According to the reference of twins birthweight,the most discordant twins are complicated with fetal growth restriction at least in one twin.

Objective To understand the infection status, epidemiological characteristics and genetic evolution of adenovirus in children with diarrhea in Tianjin. Methods A total of 1609 fecal specimens were collected from hospitalized children with diarrhea from July 2017 to July 2018 in Tianjin Children's Hospital. Viral nucleic acid was extracted and amplified by the hexon gene fragment. Positive specimens were used for nucleic acid sequence determination and sequence alignment and phylogenetic tree analysis with known sequences in GenBank. Rotavirus in the stool specimens was detected by gold standard method, and campylobacter was detected by latex agglutination method. Bocavirus, Norovirus and Clostridium difficile were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Results A total of 69 specimens with adenoviruses were detected in 1609 cases, with a positive rate of 4.3％, in which 82.6％adenovirus-positive children were between 7 and 48 months old. The positive rate of adenovirus peaked in the summer and autumn, and the differences of this value among seasons were statistical significance (χ2=11.467,P=0.009). In these cases, the mixed infection rate of adenovirus was 26.1％(18/69), in which 7 cases were mixed with Norovirus, 7 cases were mixed with rotavirus and 4 cases were mixed with Clostridium difficile. A total of 39 adenovirus-positive PCR products were randomly selected for gene sequence detection, and 7 adenovirus genotypes were detected. Results showed that these viruses were mainly the type 41 enteric adenovirus (46.1％, 18/39), followed by type 31, type 3 and type 7 non-intestinal adenovirus, while types 1, 5 and 6 were relatively rare. Conclusions There are diverse types of adenovirus in children with diarrhea in Tianjin. The adenovirus-infected diarrhea mostly happen in summer and autumn, and is common in children.

Histiocytic necrotic lymphadenitis is known as Kikuchi-Fujimoto disease (KFD).KFD is a systemic disease,which is characterized by fever,necrotizing lymphadenopathy and leukopenia.However,involvement of the central and peripheral nervous system is rare.It can present as aseptic meningitis,encephalomyelitis,peripheral neuropathy,cerebellar ataxia and tremor,which makes it difficult to be differentiated with other nervous system diseases.Our review summarizes the clinical manifestations and differential diagnoses of KFD involving nervous system in order to reduce misdiagnoses and mistreatments.

On account of the problem that traditional C-arm X-ray apparatus cannot provide precise route guidance for minimally invasive surgeries, we designed and developed a laser positioning and navigation system based on C-arm X-ray apparatus, which can achieve precise positioning function and reduce the exposure of doctors and patients to radiation in minimally invasive surgeries under the linear guidance of a laser beam. Furthermore, this system can enhance the refinement level of surgical operation in minimally invasive surgeries.
Cone-Beam Computed Tomography ; Humans ; Minimally Invasive Surgical Procedures ; Radiography ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; X-Rays