Silver Cluster-Porphyrin-Assembled Materials as Advanced Bioprotective Materials for Combating Superbacteria.

Superbugs are bacteria that have grown resistant to most antibiotics, seriously threating the health of people. Silver (Ag) nanoparticles are known to exert a wide-spectrum antimicrobial property, yet remains challenging against superbugs. Here, Ag clusters are assembled using porphyrin-based linkers and a novel framework structure (Ag9 -AgTPyP) is produced, in which nine-nuclearity Ag9 clusters are uniformly separated by Ag-centered porphyrin units (AgTPyP) in two dimensions, demonstrating open permeant porosity. Ag9 -AgTPyP eliminates over 99.99999% and 99.999% methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) within 2 h upon visible-light irradiation, which are superior to a majority of bacteria inactivation photocatalysts. The novel-established long-term charge-transfer states from AgTPyP to adjacent Ag9 cluster that has preferential affinity to O2 greatly promote reactive oxygen species (ROS) production efficiency; and its unique framework accelerates the ROS transportation. Personal protective equipment (masks and protective suits) incorporating Ag9 -AgTPyP film also shows excellent performances against superbugs. This superbugs-killing efficiency is unprecedented among silver complexes and porphyrin derivatives. Utilizing efficient photogenerated electrons and holes between metal cluster and linkers can open up new interests of research in photocatalytic areas.

[Analysis of disease types of outpatients with intestinal diseases from two grade-three general hospitals in Beijing].

OBJECTIVE: To understand the spectrum of diseases and epidemiological characteristics of outpatients at Entric Disease Clinic, with a focus on analysis of the distribution of infectious diarrheal diseases in different populations and to explore disease control strategies on Enteric Infectious Diseases for focal groups. METHODS: A census on outpatients at Entric Disease Clinics was conducted in two class Three comprehensive hospitals in Beijing from April 1 to October 31, 2009 based on a descriptive study using diarrhea-syndrome surveillance system set in the two clinics, thus to depict the spectrum of diseases and epidemiological characteristics of outpatients, and analyze the proportion of infectious diarrhea in diarrheal diseases specifically and the rate changes of infectious diarrhea in different months, age groups and occupational groups. RESULTS: Diseases are varied at the two enteric diseases clinics among the patients and there are mainly 10 kinds of diseases, "non-infectious diarrhea" accounted for the highest percentage (77.4%), followed by "unspecified diarrhea" (11.7%), and infectious diarrhea accounted for the least proportion(8.7%)."Gastroenteritis and enteritis" are the most frequently diagnosed cases among all the diseases, was a total of 7 565 cases, accounting for 70.2%. The volume of visits reached its top during summer and autumn(July to September), and the mean volume of visits in this period is (60.78+/-16.85) cases/day. The volume of visits has an obvious seasonal trend, and visits during July and August are the most frequent (41.82% altogether). Patients with "infectious diarrhea" had a highest ratio(5.3%) in May and lowest (1.1%) in October while patients with "bacillary dysentery" accounted for a highest ratio(8.2%) in September and lowest(3.8%) in April. Outpatients are mainly from Beijing city(61.9%), in which young and middle-aged people accounted for 73.9% in total, and student is the main occupation (28.8%). The distributions of diarrheal diseases are the same in different age groups but differ from different occupational groups. Infectious diarrhea accounted for a highest proportion(9.2%) in 18-to-44-year-old age group when using age grouping, and a highest proportion(15.2%) in restaurant service personnel when using occupation grouping. CONCLUSION: The volume of outpatients attended at general hospitals is overwhelming especially in July and August, and the major type is "non-infectious diseases", which indicates an arduous task on prevention and control of Enteric Infectious Diseases. Infectious diarrhea took up a certain amount, but the rate is not that high, which indicates possible missing diagnosis of patients with infectious diseases.Our focal groups would be young and middle-aged people and students in the city. Therefore, the need to extend the consultation hours is urgent. Meanwhile, for the main goal of surveillance and early warning on Enteric Infectious Diseases, all aspects of construction of Enteric Disease Clinic should be strengthened, such as enhance laboratory tests on pathogens, improve diagnosis level of physicians and etc.