Vegetable Surface Sterilization System Using UVA Light Emitting Diodes

Surface sterilization of fresh produce has been needed in the food manufacturing/ processing industry. Here we report a UVA-LED (Ultra Violet A-Light Emitting Diode) system for surface sterilization that is safe, efficacious, low cost, and apparently harmless to fresh produce. To test the system, Escherichia coli strain DH5α was spot-inoculated onto vegetable tissues, and treated under UVA-LED. Tissues were homogenized and bacteria quantified by colony-forming assay. Possible effects of UVA-LED on vegetable quality were evaluated by HPLC. Tissue weight changes were checked after treatment at 4℃, 15℃, and 30℃. Bacterial inactivation by UVA-LED radiation was observed after a 10 min treatment and increased with increasing time of irradiation. The log survival ratio reached -3.23 after a 90 min treatment. Bacterial cells surviving treatment grew slowly compared to non-irradiated control cells. Cabbage tissue lost weight over time after treatment, and weight loss increased with increasing incubation temperature, but there was no difference between losses by UVA-LED treated and control tissues at any temperature tested. In addition, no differences of Vitamin C content in cabbage tissue were detected by HPLC after UVA-LED treatment. These results suggest that UVA-LED treatment has great potential for vegetable surface sterilization in the food manufacturing/processing industry

Genetic polymorphisms related to muscular strength and flexibility are associated with artistic gymnastic performance in the Japanese population

departmental bulletin pape

Combined treatment of UVA and antibiotics

The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and UVA irradiation was more bactericidal than UVA irradiation or antibacterial drugs alone. The bactericidal synergy was observed at low concentrations of each drug that are normally unable to kill the bacteria. This combination has the potential to become a sterilization technology

Suitability of ultraviolet (A)-light emitting diode for air stream disinfection

We previously developed a high powered light-emitting diode device capable of discharging germicidal ultraviolet irradiation (UVA-LED) at an approximate wavelength of 365 nm. This study examined the bactericidal activity of UVA-LED in moving air streams. Aerosols of Escherichia coli DH5α were exposed to UVA-LED irradiation using a stable current (0.5 A and 1.2 mW/cm2) or pulse current (1.0 A and 0.2 mW/cm2). Settle plate analysis was used for bioaerosol sampling, where results were expressed as Colony Forming Units. A-3 Log inactivation of the E. coli population occurred after 75 minutes of constant exposure to stable current. The pulse current produced inactivation within a similar timeframe. Our results might be significant as a basic study for further investigations about the effect of UVA-LED on airborne bacteria and its suitability for air disinfection applications

Infection risk in hemodialysis patient

Chronic care patients undergoing hemodialysis for treatment of end-stage renal failure experience higher rates of bloodstream-associated infection due to the patients' compromised immune system and management of the bloodstream through catheters. Staphylococcus species are a common cause of hemodialysis catheter-related bloodstream infections. We investigated environmental bacterial contamination of dialysis wards and contamination of hemodialysis devices to determine the source of bacteria for these infections. All bacterial samples were collected by the swab method and the agarose stamp method. And which bacterium were identified by BBL CRYSTAL Kit or 16s rRNA sequences. In our data, bacterial cell number of hemodialysis device was lower than environment of patient surrounds. But Staphylococcus spp. were found predominantly on the hemodialysis device (46.8%), especially on areas frequently touched by healthcare-workers (such as Touch screen). Among Staphylococcus spp., Staphylococcus epidermidis was most frequently observed (42.1% of Staphylococcus spp.), and more surprising, 48.2% of the Staphylococcus spp. indicated high resistance for methicillin. Our finding suggests that hemodialysis device highly contaminated with bloodstream infection associated bacteria. This study can be used as a source to assess the risk of contamination-related infection and to develop the cleaning system for the better prevention for bloodstream infections in patients with hemodialysis

Glutamine protects small intestinal mucosa

Supportive therapy during chemotherapy has become essential, but effective preventive therapies to gastrointestinal mucosal injury are few. We investigated the efficacy of glutamine in rat anticancer drug-induced enteritis model. In this study, we used twenty male SD rats. They were divided into control, 5-fluorouracil (5-FU) (orally administered at 20mg/kg day), 5-FU+glutamine (1000 mg/kg/day) and 5-FU+glutamine+fiber and oligosaccharide (GFO[○R]) (1000 mg/kg/day) groups. All groups were sacrificed on day 6 and upper jejunums were excised. The jejunal villous height was measured in specimens. IgA level in jejunal washing solution, and serum diamine oxidase activity were also measured. The jejunal villous height was recognized as shorter in the specimen from 5-FU treated rats compared with 5-FU+glutamine treated rats (p<0.001). Serum diamine oxidase activity in 5-FU+glutamine group were significantly superior to that in 5-FU group (p=0.028). IgA level in jejunal washing solution tended to be higher in 5-FU+glutamine group than that in 5-FU group (p=0.076). On the other hand, serum diamine oxidase activity and IgA level in jejunal washing solution showed no significant difference between 5-FU+GFO and 5-FU treatment group. Our results suggest that glutamine showed protective effects on mucosal injury of small intestine in rat anticancer drug-induced enteritis model

POTENTIAL ENERGEY SURFACE OF THE ARHCN CLUSTER DETERMINED WITH THE VAN DER WAALS BANDS OBSERVED BY MILLIMETER-WAVE SPECTROSCOPY

Author Institution: Kyushu University; Department of Chemistry, Kyushu University; Department of Chemistry, Institute for Molecular ScienceMillimeter-wave absorption spectroscopy combined with a pulsed-jet expansion technique was applied to the measurement of the rovibrational transitions of the van der Waals (vdW) bending bands of the ArHCN and ArDCN clusters in the frequency region up to 300 GHz. Foundamental band $(j = 1-0)$ together with the hot band $(j = 2-1)$ of the vdW bending bands were observed to obtain a precise set of molecular constants, including band origins, rotational and centrifugal distortion constants, Coriolis interaction constants and hyperfine interaction constants. From these spectroscopic data, accurate term values for the $j = 0 (\Sigma_{0})$, $j = 1 (\Sigma_{1}$ and $\Pi_{1})$, and $j = 2 (\Sigma_{2}$, $\Pi_{2}$, and $\Delta_{2}$) vdW bending substates were derived for total J up to about 15 levels for both ArHCN and ArDCN. The determined molecular constants were compared with those derived with the potential energy surface (PES) calculated at CCSD(T) level. The CCSD(T) PES explains fairly well the observed spectroscopic constants such as the rotational and centrifugal distortion constants, and Coriolis interaction constants, but not the vdW beding band frequencies. Experimental PES, for both ArHCN and ArDCN, was determined fitting to the observed term values. The determined PES explains rovibrational energy levels within 100 kHz for the $j = 0, 1$ and 2 vdW bending vibrational levels, J up to 5. Wavefuctions calculated with this PES explains also well the observed hyperfine constants