Pedestrian traffic safety behaviors among primary and secondary school students in Xiacheng District / 预防医学

Objective@#To investigate the pedestrian traffic safety behaviors of primary and secondary school students in Xiacheng District of Hangzhou,and to provide reference for formulating traffic safety strategy. @*Methods@# In October 2015,nine campuses of six schools in Xiacheng District were selected to observe the pedestrian traffic safety behaviors of the primary and secondary school students walking to and from school,such as taking the zebra crossing,observing the traffic condition,running and playing with cellphones when walking across the road.@*Results@#Totally 2 585 students were investigated,and 2 580 students were valid（99.81%）. When walking across the road,1 887 people took the zebra crossing,accounting for 73.14%;71.89% of boys and 74.51% of girls took the zebra crossing,and there was no significant difference（P>0.05）;64.76% and 81.32% of the students took the zebra crossing on the way to school and home,with a significant difference（P<0.05）. When walking across the road,1 683 students people observed the traffic conditions,accounting for 65.23%;63.61% of boys and 67.02% of girls observed the traffic conditions,and there was no significant difference（P>0.05）;64.05% and 66.39% of the students observed the traffic conditions on the way to school and home,with a significant difference（P<0.05）.There were 362 students running across the road, accounting for 14.03%;15.31% of boys and 12.62% of girls ran across the road,and there was no significant difference（P>0.05）;9.26% and 18.68% of the students ran across the road on the way to school and home,with a significant difference（P<0.05）. There were 53 students playing with cellphones when crossing the road,accounting for 2.05%;2.29% of boys and 1.79% of girls played with cellphones,and there was no significant difference（P>0.05）;1.41% and 2.68% of the students played with cellphones on the way to school and home,with a significant difference（P<0.05）. @*Conclusions @#Primary and secondary school students have dangerous behaviors when walking across the road. We should focus on the intervention of not taking the zebra crossing and not observing traffic conditions when crossing the road on the way to school,and playing with cellphones on the way home.

Cysteine protease inhibitor of Schistosoma japonicum - A parasite-derived negative immunoregulatory factor.

Studies have shown that cysteine protease inhibitors from some parasites have immunosuppressive effects on the host. We previously have cloned a novel cysteine protease inhibitor from Schistosoma japonicum and purified its recombinant version (protein named rSj-C). Its possible inhibitory effect on the host immune response has not been described.This study shows that rSj-C inhibits lysosomal cysteine protease of murine dendritic cells (DCs). After DCs were incubated with rSj-C and then with soluble adult worm antigen (AWA) of S. japonicum, the mean fluorescence intensity of MHC class II antigens on the surface of DCs decreased significantly by flow cytometry. These results indirectly proved that rSj-C can suppress exogenous-antigen presentation by DCs. The flow cytometric assay revealed that in comparison with control groups, the proportion of CD4+CD25+Foxp3+ T cells among CD4+CD25+ T cells of Schistosom-infected mice increased significantly 8 weeks after the infected mice were injected with rSj-C (p Ë‚ 0.05). Additionally, the expression levels of cytokines IL-4 and TGF-ß produced by T cells increased significantly as compared with these levels in the normal group (p Ë‚ 0.05). These results clearly show that the cysteine protease inhibitor from S. japonicum is a new parasite-derived immunosuppressive factor.

Inhibitory effect of bone morphogenetic protein-2 on the proliferation of giant cell tumor of bone stromal cells in vitro.

The inhibitory effect of bone morphogenetic protein-2 (BMP-2) on the proliferation of giant cell tumor of bone stromal cells (GCTSCs) has not been fully elucidated. Therefore, the aim of this study was to evaluate the role of recombinant human BMP-2 (rhBMP-2) in the growth of GCTSCs. The effects of exposure to different concentrations of rhBMP-2 (0, 10, 100 and 300 ng/ml) for 1, 3, 5 and 7 days on GCTSC proliferation were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, the effect of treatment with rhBMP-2 (0 or 10 ng/ml) for 48 h on the cell cycle pattern of GCTSCs was examined by flow cytometry. The apoptosis-inducing effect of rhBMP-2 (0 or 10 ng/ml) in GCTSCs was also determined by flow cytometry after 48 and 72 h. In addition, western blot assays were conducted to determine whether rhBMP-2 acts on non-Smad mitogen-activated protein kinase (MAPK) signaling pathways, namely extracellular signal-regulated kinase (ERK1/2), p38 and c-jun-N-terminal kinase (JNK) pathways. The proliferation of GCTSCs treated with rhBMP-2 (10, 100 or 300 ng/ml) for 5 or 7 days was significantly inhibited in a non dose-dependent and non-time-dependent manner (P<0.05). The treatment of GCTSCs with rhBMP-2 (10 ng/ml) for 48 h had no effect on cell cycle distribution. The apoptosis of GCTSCs induced by exposure to rhBMP-2 (10 ng/ml) for 48 or 72 h was significant (P<0.05). Expression levels of phospho-ERK1/2, phospho-p38 and phospho-JNK increased significantly when GCTSCs were treated with rhBMP-2 (10 ng/ml) for 72 h (P<0.05). The results indicate that rhBMP-2 has no stimulatory effect on GCTSC growth. However, it may lead to the apoptosis of GCTSCs by non-Smad MAPK signaling pathways.

Addition of Zn to the ternary Mg-Ca-Sr alloys significantly improves their antibacterial property.

Most of the magnesium (Mg) alloys possess excellent biocompatibility, mechanical property and biodegradability in orthopedic applications. However, these alloys may suffer from bacterial infections due to their insufficient antibacterial capability. In order to reduce the post-surgical infections, a series of biocompatible Mg-1Ca-0.5Sr-xZn (x=0, 2, 4, 6) alloys were fabricated with the addition of antibacterial Zn with variable content and evaluated in terms of their biocompatibility and antibacterial property. The in vitro corrosion study showed that Mg-1Ca-0.5Sr-6Zn alloys exhibited a higher hydrogen evolution volume after 100 h immersion and resulted in a higher pH value of the immersion solution. Our work indicated that Zn-containing Mg alloys exhibited good biocompatibility with high cell viability. The antibacterial studies reveal that the number of bacteria adhered on all of these Mg alloy samples diminished remarkably compared to the Ti-6Al-4V control group. We also found that the proliferation of the bacteria was inhibited by these Mg alloys extracts. Among the prepared alloys, Mg-1Ca-0.5Sr-6Zn alloy not only exhibited a strong antibacterial effect, but also promoted the proliferation of MC3T3-E1 osteoblasts, suggesting that it is a promising alloy with both good antibacterial property and good biocompatibility for use as an orthopedic implant.

CC4821 serogroup W meningococcal disease in China.

Neisseria meningitidis is a major public health concern worldwide, including China. A few cases of serogroup W meningococcal disease have been reported in southeast China in recent years. Thus far, invasive disease due to W isolates has involved sequence type 11. We report two cases of N. meningitidis infection caused by CC4821 serogroup W strains.

Characterization and expression of a novel cystatin gene from Schistosoma japonicum.

Cystatins are a family of cysteine protease inhibitors that play a crucial role in the immune evasion from their host and in the adaptation to host defence. Here, we isolated a full-length cDNA sequence inferred to encode a novel cystatin gene from a blood fluke, Schistosoma japonicum. The cDNA, designated SjCystatin, comprised an open reading frame (ORF) of 306 bp, and encoded 101 amino acids with a predicted molecular weight of 11.3 kDa. This predicted protein shared a significant degree of sequence identity with the type I cystatin (stefin) of Schistosoma mansoni and Homo sapiens. These proteins exhibited a typical cystatin topology, including the absence of disulfide bonds and three conserved catalytic motifs, Gly at the N-terminus (Gly(6)), Gln-X-Val-X-Gly motif (Q(49)VVAG(53)) and an LP pair at the C-terminus (L(76)P(77)). The SjCystatin gene spanned 376 bp and contained three exons. The positions of two introns were conserved between the cystatin genes of trematodes and their vertebrate hosts. Reverse transcription polymerase chain reaction confirmed the transcription of SjCystatin in the egg, schistosomula and adult stages of S. japonicum. The encoding ORF region was cloned into pET-28a (+) prokaryotic expression vector. After purification, the recombinant protein SjCystatin (recSjCystatin), expressed in Escherichia coli, was used to immunize animals and produce its specific polyclonal antibody. Western blot analysis revealed that the native SjCystatin was expressed in the egg and adult stages. The enzyme activity assay of the recSjCystatin showed that it inhibited the proteolytic activity of papain. SjCystatin protein was mainly localized on the miracidium within eggs. Immunohistochemistry revealed that SjCystatin mainly localized in the epithelial cells lining the gut as well as the tegument on the surface of adult worms. The conserved genomic DNA structure among cystatin homologues of trematode and their vertebrate host emphasized the characteristics of compatibility between parasites and their hosts. This study provides the first insight into the gene and protein of S. japonicum cystatin and a basis for a further understanding the functions of this gene.

[Retrieval and validation of the surface reflectance using HJ-1-CCD data].

The potentiality of the retrieval of surface reflectance using CCD camera aboard HJ-1A/B satellite was studied. It is very difficult to use dark targets in atmospheric correction due to the lack of near infrared band. The alternative normalized difference vegetation index (NDVI) and the red/blue reflectance ratio are detected from the spectral experiment in Beijing and the Pearl River Delta. Ground-based spectral data including grass, dense vegetation, water body, soil, residential roof and bright building etc. were used to validate the surface reflectance in Beijing, and the relative error in red, blue band is under 38.7% and 37.2% respectively. Uncertainties of the surface reflectance retrievals were analyzed. The comparison of MODIS surface reflectance product showed that there is a good agreement in the dense targets, and the correlation coefficient (R2) in red, blue band is as high as 0.809 4 and 0.723 9 respectively. HJ-1-CCD data can effectively reduce pixel-mixed impact on the cement roof and bright buildings, and the inversion accuracy is higher than MODIS products.

[Fronto-temporal anatomy and its application for augmentation plasty].

OBJECTIVE: To decide the safe dissection plane and evaluate the multiple materials used for the fronto-temporal augmentation. METHODS: Clinical anatomical observation were made during the fronto-temporal operations. Forty-one patients were treated for the fronto-temporal augmentation with various granular or patched materials in different anatomical plane. RESULTS: Four relatively safe dissection planes were found in the fronto-temporal area: (1) subcutaneous or above superficial temporal fascia, (2) subgalea plane 1.5 cm above the zygomatic arch, (3) between the deep temporal fascia and the temporal muscle, and (4) beneath the temporal periosteum. With the follow-ups from 6 months to 1 year, the appearance after the fronto-temporal augmentation in each patient was satisfactory or improved, except for the fat granule group with partial absorption and the ePTFE or Medpor hypothesis group shown a stepped contouring at the margin in a few patients. CONCLUSION: Four dissection planes could be shown in the fronto-temporal region for the augmentation plasty with different advantages and disadvantages. The combination could be overcome the disadvantages to improve the results. Fat granule could be the best autograft for frontotemporal augmentation.