The aim of this study was to evaluate the concentration and size distribution of airborne culturable Staphylococcus aureus ( S. aureus ) (including MRSA) in Chinese public buildings. Air samples were collected, using six-stage Andersen sampler from five different public buildings in one large Chinese community. The mean indoor concentrations of the total and respirable airborne S. aureus were 72 and 50 CFU/m 3 in the general hospital, 72 and 49 CFU/m 3 in the kindergarten, 76 and 52 CFU/m 3 in the hotel, 84 and 57 CFU/m 3 in the movie theater, and 55 and 40 CFU/m 3 in the university classroom. Respirable S. aureus amounted to approximately 57–73 % of the total S. aureus concentrations. Mean total and respirable concentrations of airborne MRSA were 32 and 20 CFU/m 3 in the general hospital, 20 and 13 CFU/m 3 in the kindergarten, 23 and 16 CFU/m 3 in the hotel, 33 and 20 CFU/m 3 in the movie theater, and 24 and 17 CFU/m 3 in the university classroom. Respirable MRSA amounted to approximately 61–72 % of the total MRSA concentrations. The ratios of indoor and outdoor concentration for airborne S. aureus and MRSA were more than 1.0 in all the investigated public buildings. The size distribution results showed relatively high collection rates on stage 4 (2.1–3.3 μm) for both airborne culturable S. aureus and MRSA regardless of the type of public buildings.

An understanding of the global migration dynamics of highly pathogenic avian influenza A(H5N1) virus is helpful for surveillance and disease prevention. To characterize the migration network of this virus, we used genetic analysis, which supported a global persistence model in which each of 9 regions acts to some extent as a source. Siberia is the major hub for the dispersal of the virus. Southeast Asia and Africa are major sources of genetically and antigenically novel strains. We found evidence of local persistence of the virus in Southeast Asia and Africa, which is rare for human influenza A viruses. The differences in migration dynamics between avian and human influenza viruses might help with the design of region-specific surveillance efforts and the selection of vaccine candidates.

Hepatitis B virus (HBV) has evolved into phylogenetically separable genotypes and subgenotypes. Accurately assigning the subgenotype for an HBV strain is of clinical and epidemiological significance. In this paper, we review the recommendations currently employed for HBV subgenotyping, the history of HBV subgenotyping, the effects of recombination on HBV subgenotyping, misclassifications in HBV subgenotyping, and suggestions are made to correct the misclassifications. Finally, proposals are made to guide future HBV subgenotyping.

目的:评价PBL+ LBL双轨教学法在留学生医学微生物学教学中应用效果.方法:采用期末考试成绩和问卷调查综合评价PBL+ LBL双轨教学法的教学效果.结果:期末考试实验班学生成绩显著高于对照班学生成绩(P＜0.05).90％以上的学生认为PBL+ LBL双轨教学模式可激发学习兴趣,提高自身多重能力.结论:PBL+ LBL双轨教学法在留学生的教学效果明显优于传统LBL教学.

IFN-γ plays an indirect anti-cancer role through the immune system but may have direct negative effects on cancer cells. It regulates the viability of gastric cancer cells, so we examined whether it affects their proliferation and how that might be brought about. We exposed AGS, HGC-27 and GES-1 gastric cancer cell lines to IFN-γ and found significantly reduced colony formation ability. Flow cytometry revealed no effect of IFN-γ on apoptosis of cell lines and no effect on cell aging as assessed by β-gal staining. Microarray assay revealed that IFN-γ changed the mRNA expression of genes related to the cell cycle and cell proliferation and migration, as well as chemokines and chemokine receptors, and immunity-related genes. Finally, flow cytometry revealed that IFN-γ arrested the cells in the G1/S phase. IFN-γ may slow proliferation of some gastric cancer cells by affecting the cell cycle to play a negative role in the development of gastric cancer.

Background: Nine subgenotypes from genotype B have been identified for hepatitis B virus (HBV). However, these subgenotypes were less conclusive as they were often designated based on a few representative strains. In addition, subgenotype B6 was designated twice for viruses of different origin.Methods: All complete genome sequences of genotype B HBV were phylogenetically analyzed. Sequence divergences between different potential subgenotypes were also assessed.Results: Both phylogenetic and sequence divergence analyses supported the designation of subgenotypes B1, B2, B4, and B6 (from Arctic). However, sequence divergences between previously designated B3, B5, B7, B8, B9 and another B6 (from China) were mostly less than 4%. In addition, subgenotype B3 did not form a monophyly.Conclusion: Current evidence failed to classify original B5, B7, B8, B9, and B6 (from China) as subgenotypes. Instead, they could be considered as a quasi-subgenotype B3 of Southeast Asian and Chinese origin. In addition, previously designated B6 (from Arctic) should be renamed as B5 for continuous numbering. This novel classification is well supported by both the phylogeny and sequence divergence of > 4%.

More than ten subgenotypes of genotype C Hepatitis B virus (HBV) have been reported, including C1 to C16 and two C/D recombinant subgenotypes (CD1 and CD2), however, inconsistent designations of these subgenotypes still exist.We performed a phylogenetic analysis of all full-length genotype C HBV genome sequences to correct the misclassifications of HBV subgenotypes and to study the influence of recombination on HBV subgenotyping. Our results showed that although inclusion of the recombinant sequences changed the topology of the phylogenetic tree, it did not affect the subgenotyping of the non-recombinant sequences, except subgenotype C2. In addition, most of the subgenotypes have been properly designated. However, several misclassifications of HBV subgenotypes have been identified and corrected. For example, C11 proposed by Utsumi and colleagues in 2011 was found to be grouped with C12 proposed by Mulyanto and colleagues. Two sequences, GQ358157 and GU721029, previously designated as C6 have been re-designated as C12 and C7, respectively. Moreover, a quasi-subgenotype C2 was proposed, which included the old C2, several previously unclassified sequences and previously designated C14. In particular, we identified a novel subgenotype, tentative C14, which was well supported by phylogenetic analysis and sequence divergence of >4%.A number of misclassifications in the subgenotyping of genotype C HBV have been identified in this study. After correcting the misclassifications, we proposed a better classification for the subgenotyping of genotype C HBV, in which a novel quasi-subgenotype C2 and a novel subgenotype, tentative C14, were described. Based on this large-scale analysis, we propose that a novel subgenotype should only be reported after a complete comparison of all relevant sequences rather than a few representative sequences only.

Background: More than ten subgenotypes of genotype C Hepatitis B virus (HBV) have been reported, including C1 to C16 and two C/D recombinant subgenotypes (CD1 and CD2), however, inconsistent designations of these subgenotypes still exist.Methodology/Principal Findings: We performed a phylogenetic analysis of all full-length genotype C HBV genome sequences to correct the misclassifications of HBV subgenotypes and to study the influence of recombination on HBV subgenotyping. Our results showed that although inclusion of the recombinant sequences changed the topology of the phylogenetic tree, it did not affect the subgenotyping of the non-recombinant sequences, except subgenotype C2. In addition, most of the subgenotypes have been properly designated. However, several misclassifications of HBV subgenotypes have been identified and corrected. For example, C11 proposed by Utsumi and colleagues in 2011 was found to be grouped with C12 proposed by Mulyanto and colleagues. Two sequences, GQ358157 and GU721029, previously designated as C6 have been re-designated as C12 and C7, respectively. Moreover, a quasi-subgenotype C2 was proposed, which included the old C2, several previously unclassified sequences and previously designated C14. In particular, we identified a novel subgenotype, tentative C14, which was well supported by phylogenetic analysis and sequence divergence of >4%.Conclusions/Significance: A number of misclassifications in the subgenotyping of genotype C HBV have been identified in this study. After correcting the misclassifications, we proposed a better classification for the subgenotyping of genotype C HBV, in which a novel quasi-subgenotype C2 and a novel subgenotype, tentative C14, were described. Based on this large-scale analysis, we propose that a novel subgenotype should only be reported after a complete comparison of all relevant sequences rather than a few representative sequences only.

重点学科建设是高校科研管理的一项重要内容,本文以泰山医学院为例,通过分析以重点学科建设为龙头,带动学校整体发展的管理模式,总结推动学校科研发展的做法和经验,找出差距和不足,从而推动学校整体教学水平和科研水平的不断提高.

结合硕士研究生培养的具体要求,提出了研究生导师应该具备高尚的师德,在政治思想、道德品质、学识学风方面,做到为人师表、以身作则和言传身教;树立以学生为本的现代教育理念,在教育过程中的角色定位上,从单一知识的传授者转变为教育过程的指导者、组织者和参与者,注重学生的个性发展;导师带动研究生增强创新意识、提高创新能力和创新素质;导师必须有渊博的知识修养和丰富的教学经验,把握学科发展的动态,并具有稳定的研究方向。

To trace the endemic situation of highly pathogenic influenza H5N1 virus in wildlife in the Lake Qinghai area of northwest China, a continuous surveillance program was implemented from September 2005 to September 2007. A total of 2699 field samples were collected, and 95 of the samples were positive by a reverse transcription-polymerase chain reaction (RT-PCR) test of subtype H5 influenza virus. To some extent, the detection rate correlated with the species, the location, and the seasons of collection. In 2007, two H5N1 isolates were identified from two species of migratory birds. The two 2007 isolates showed high similarities of the hemagglutinin and neuraminidase genes with those of the 2005 and 2006 Qinghai isolates (98.6-99.8% for HA and 98.7-98.9% for NA at the nucleotide level). Both isolates fell into clade 2.2.2 and were experimentally highly pathogenic to chickens and mice. According to our surveillance results, HPAI H5N1 viruses still exist in this region.

Human enterovirus 71 viruses have been long circulating throughout the world. In this study, we performed a positive selection analysis of the VP1 genes of capsid proteins from Enterovirus 71 viruses. Our results showed that although most sites were under negative or neutral evolution, four positions of the VP1 genes were under positive selection pressure. This might account for the spread and frequent outbreaks of the viruses and the enhanced neurovirulence. In particular, position 98 might be involved in neutralizing antibodies, modulating the virus-receptor interaction and enhancing the virulence of the viruses. Moreover, both positions 145 and 241 might correlate to determine the receptor specificity. However, these positions did not display much difference in amino acid polymorphism. In addition, no position in the VP1 genes of viruses isolated from China was under positive selection.

This paper focuses on the study influencing students' learning ability using the problem-based learning(PBL)methods.The present work is based on questionnaire surveys and discussions among students,analyzing the effects of the PBL and traditional teaching methods on the students in learning medical microbiology.The results show that the PBL can promote the communication between teachers and students,enhancs the sludents competition and participation and improve their thinking and self-learning skills of students.

BACKGROUND:The highly pathogenic H5N1 avian influenza emerged in the year 1996 in Asia, and has spread to Europe and Africa recently. At present, effective monitoring and data analysis of H5N1 are not sufficient in Chinese mainland.METHODOLOGY/PRINCIPAL FINDINGS:During the period from April of 2004 to August of 2007, we collected 14,472 wild bird samples covering 56 species of 10 orders in 14 provinces of China and monitored the prevalence of flu virus based on RT-PCR specific for H5N1 subtype. The 149 positive samples involved six orders. Anseriformes had the highest prevalence while Passeriformes had the lowest prevalence (2.70% versus 0.36%). Among the 24 positive species, mallard (Anas platyrhynchos) had the highest prevalence (4.37%). A difference of prevalence was found among 14 provinces. Qinghai had a higher prevalence than the other 13 provinces combined (3.88% versus 0.43%). The prevalence in three species in Qinghai province (Pintail (Anas acuta), Mallard (Anas platyrhynchos) and Tufted Duck (Aythya fuligula)) were obviously higher than those in other 13 provinces. The results of sequence analysis indicated that the 17 strains isolated from wild birds were distributed in five clades (2.3.1, 2.2, 2.5, 6, and 7), which suggested that genetic diversity existed among H5N1 viruses isolated from wild birds. The five isolates from Qinghai came from one clade (2.2) and had a short evolutionary distance with the isolates obtained from Qinghai in the year 2005.CONCLUSIONS/SIGNIFICANCE:We have measured the prevalence of H5N1 virus in 56 species of wild birds in 14 provinces of China. Continuous monitoring in the field should be carried out to know whether H5N1 virus can be maintained by wild birds.

Positive selection and differential selective pressure analyses were carried out to study Haemagglutinin (HA) genes of H9N2 influenza viruses from different hosts in this paper. Results showed that, although most positions in HAs were under neutral or purifying evolution, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection and some of them were even positively selected at the population level. In addition, there were always some positions differentially selected for viruses from different hosts. Both selection pressure working on HA codons and positions differentially selected might account for the extension of the host range and adaptations to different hosts of H9N2 influenza viruses.

Objective The parasitic behavior of female Nasonia vitripennis was studied.Methods Dissecting the parasitized fly pupae,the eggs number of female N.vitripennis laid in different parts of the three species of fly pupae was counted.The effect of parasitic times on the fecundity of female N.vitripennis was studied.Results Feeding with 20% honey water,the longevity of female was prolonged significantly.The female N.vitripennis mainly laid eggs in the abdomen of its host flies,especially on the sternites.Mating or not had no significant effect on the parasitic ability of the female parasitoid,but the fecundity of the parasitoid was decreased with the increase of the parasitic times.Conclusion The parasitic ability of female N.vitripennis had correlation with the parasitic times.

Phylogenetic methods have been widely used to detect the evolution of influenza viruses. However, previous phylogenetic studies of influenza viruses do not make full use of the genetic information at the protein level and therefore cannot distinguish the subtle differences among viral genes. Proteotyping is a new approach to study influenza virus evolution. It aimed at mining the potential genetic information of the viral gene at the protein level by visualizing unique amino acid signatures (proteotypes). Neuraminidase gene fragments of some H5N1 avian influenza viruses were used as an example to illustrate how the proteotyping method worked. Bayesian analysis confirmed that the NA gene tree was mainly divided into three lineages. The NA proteotype analysis further suggested there might be multiple proteotypes within these three lineages and even within single genotypes. At the same time, some proteotypes might even involve more than one genotype. In particular, it also discovered some amino acids of viruses of some genotypes might co-reassort. All these results proved this approach could provide additional information in contrast to results from standard phylogenetic tree analysis.

Avian influenza H5N1 viruses pose a significant threat to human health because of their ability to infect humans directly. In the paper, three highly pathogenic H5N1 influenza viruses were isolated from three species of migratory birds in Qinghai Province of China in 2006. The analysis of the genome sequences indicated that the three isolates shared high homology with each other (94% to 99%). Three isolates shared a common ancestor and were closest to strains isolated from Qinghai and Siberia in 2005, but distinct from poultry viruses found in Southeast Asia. In experimental infection, all three viruses were highly pathogenic to chickens and mice. The results suggest that highly pathogenic avian influenza H5N1 viruses still exist in the migratory birds and could spread to other regions with wild bird migration.