Contact Mechanism of the Ag-doped Trimolybdate Nanowire as An Antimicrobial Agent

Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(NH_4)xMo_3O_(10) ·3H_2O nanowires(NWs). Carrying Ag atoms in the lattice and Ag-rich nanoparticles on the surface, the Ag-doped NWs show strong antibacterial effects for a variety of bacteria including E.coli, Staphylococcus aureus, Candida albicans and Aspergil lus niger. By performing systematic comparison experiments, we have proven that the main antibacterial effects are neither resulted from the tiny amount of Ag+ions released from the Ag-doped NWs in aqueous solutions, nor resulted from Ag-rich nanoparticles of fragments of the NWs when they are slowly dissolved in the Martin broth. Instead, the effects are mainly resulted from a contact mechanism, under which, the Ag-doped NWs need to be physically in contact with the bacteria to be eliminated. This is a novel phenomenon observed in the interactions between nanomaterials and live cells, which is worthy of further investigation at the molecular scale. As the Ag-doped NWs are not dissolved in pure water or weak acids, one may find practical antibacterial applications in textile industry and food storage industry for these unique nanomaterials.

Severe Acute Respiratory Syndrome-Retrospect and Lessons of 2004 Outbreak in China

Objective To summarize lessons learned from an outbreak of severe acute respiratory syndrome （SARS） in China during the spring of 2004. Methods Data of SARS cases were officially reported by Beijing Municipal Center for Disease Control and Prevention （BCDC） and Anhui Provincial Center for Disease Control and Prevention （APCDC） and results of epidemiological investigations were collected and analyzed. Results Three generations of 11 cases of SARS were identified during the outbreak, Initial two cases were most likely to be infected in Diarrhea Virus Laboratory of National Institute of Virology, China Centers for Disease Control and Prevention and main mode of transmission was direct contact with SARS patients, Delay in detecting initial case resulted in spread of the illness at hospitals and communities with two generations of secondary cases, Conclusions SARS outbreak in 2004 has yielded following lessons for public health globally. （1） Lab bio-safety programs should be made and should be strictly abided by, Studies in highly pathogenic viruses such as SARS coronavirus should be utmost cautious, （2） Management systems of occupational exposure to virus and disease surveillance need to be strengthened to take all risk factors into account so as to detect potential patients with infectious disease as early as possible.

Biological Safety Issues in Animal Laboratory of Colleges and Universities

As a crucial link in fostering talented students, laboratories in universities have been attached great significance since they help developing practical op- erational ability of students. The unknown factors in laboratories are likely to pose threat to operators. Therefore, it is especially important to guarantee the safety of laboratories. The paper expounded the measures supposed to be taken in university lab-teaching based on bias-safety management problems and hoping to serve the research work and teaching by adopting proper and reasonable methods which are in accordance with scientific purposes.