One-Pot Reducing Agent-Free Synthesis of Silver Nanoparticles/Nitrocellulose Composite Surface Coating with Antimicrobial and Antibiofilm Activities.

Nitrocellulose with silver nanoparticle (AgNP/NC) composite was prepared in situ using Ag(CH3CO2) and nitrocellulose without any reducing agent. The composite materials synthesized were spray coated onto glass substrates to obtain thin films. The AgNPs/NC composites were characterized by ultraviolet-visible, Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The antimicrobial activity of AgNPs/NC composite was investigated by tube method and time-kill kinetic studies against three microbial species, including Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), and Candida albicans (ATCC 10231). The antibiofilm activities were qualitatively determined against all three organisms. Prepared AgNPs/NC films exhibited good antimicrobial activity and significant inhibition of biofilm development against all three microbial species. The effective dispersion of AgNPs/NC in biofilm was responsible for the significant antibiofilm activity of the prepared material. The reported AgNPs/NC composite can be used as coating additive in bacteriocidal paint which can be applied onto surfaces such as in healthcare environments.

Physico-chemical and sensory quality of fresh cut papaya (Carica papaya) packaged in micro-perforated polyvinyl chloride containers.

Papaya cubes at maturity stages, 5-45 % yellow (more green than yellow) and 55-80 % yellow (more yellow than green) were washed with 5 % H2O2, drained and packaged in PVC trays having five, seven and ten micro-perforations and stored for 19 days. PVC trays with 3 mm diameter punch holes were used as the control. Based on physico-chemical properties, optimum maturity for papaya and micro-perforation level of PVC trays were determined. Effectiveness of citric acid in prevention of browning was also tested. Firmness and TSS changed significantly, on day 19. O2, CO2 and C2H4 concentration changed 2.4 to 4.2 %, 23.4 to 5.9 %, and 0 to 0.13 % respectively, from day 3 to 19. pH and titratable acidity did not change significantly throughout the storage. Pretreated papaya cubes, packaged in PVC trays with ten micro-perforations, kept under 4 °C had storage lives of 19 days.

Prevention of HIV infection in street-recruited injection drug users. The Collaborative Injection Drug User Study (CIDUS).

BACKGROUND: Injection drug users (IDUs) and their sex partners account for an increasing proportion of new AIDS and HIV cases in the United States, but public debate and policy regarding the effectiveness of various HIV prevention programs for them must cite data from other countries, from non-street-recruited IDUs already in treatment, or other programs, and from infection rates for pathogens other than HIV. METHODS: Participants were recruited from the street at six sites (Baltimore [Maryland], New York [two sites], Chicago [Illinois], San Jose [California], Los Angeles [California], and at a state women's correctional facility [Connecticut]), interviewed with a standard questionnaire, and located and reinterviewed at one or more follow-up visits (mean, 7.8 months later). HIV serostatus and participation in various programs and behaviors that could reduce HIV infection risk were determined at each visit. RESULTS: In all, 3773 participants were recruited from the street, and 2306 (61%) were located and interviewed subsequently. Of 3562 initial serum specimens, 520 (14.6%) were HIV-seropositive; at subsequent assessment, 19 people, all from the East Coast and Chicago, had acquired HIV. Not using previously used needles was substantially protective against HIV acquisition (relative risk [RR], 0.29; 95% confidence interval [CI], 0.11-0.80 ) and, in a multivariate model, was significantly associated with use of needle and syringe exchange programs (adjusted odds ratio [ORadj], 2.08; 95% CI, 1.15-3.85). Similarly, reduction of injection frequency was very protective against seroconversion (RR, 0.33; 95% CI, 0.14-0.80), and this behavior was strongly associated with participation in drug treatment programs (ORadj, 3.54; 95% CI, 2.50-5.00). In a separate analysis, only 37.5% of study-participants had sufficient new needles to meet their monthly demand. CONCLUSIONS: In this large multicity study of IDUs in the United States, several HIV prevention strategies appeared to be individually and partially effective; these results indicate the continued need for, and substantial gaps in, effective approaches to preventing HIV infection in drug users.