Characteristics and Assessing Biological Risks of Airborne Bacteria in Waste Sorting Plant

Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m−3) were: Staphylococcus sp. (72.4) \u3e Micrococcus sp. (52.2) \u3e Bacillus sp. (30.3) \u3e Enterococcus sp. (24.0) \u3e Serratia marcescens (20.1) \u3e E. coli (19.1) \u3e Pseudomonas sp. (16.0) \u3e Nocardia sp. (1.9). The lifetime average daily dose (LADD) for the inhalation and dermal routes for the intake of airborne bacteria ranged from 3.7 × 10−3 ≤ LADDInhalation ≤ 2.07 × 101 CFU (kg d)−1 and 4.75 × 10−6 ≤ LADDDermal ≤ 1.64 × 10−5 CFU (kg d)−1, respectively. Based on a sensitivity analysis (SA), the concentration of airborne bacteria (C) and the exposure duration (ED) had the most effect on the LADDInhalation and LADDDermal for all sampling locations. Although the Hazard Quotient of airborne bacteria was HQ \u3c 1, an acceptable level, the indoor/outdoor ratio (1.5 ≤ I/O ≤ 6.6) of airborne bacteria typically exceeded the threshold value (I/O \u3e 2), indicating worker’s exposure to an infected environment. Therefore, in the absence of sufficient natural ventilation the indoor ambient conditions of the WPCSP studied should be controlled by supplying mechanical ventilation

Chromium removal from aqueous solution by a PEI-silica nanocomposite

It is essential and important to determine the adsorption mechanism as well as removal efficiency when using an adsorption technique to remove toxic heavy metals from wastewater. In this research, the removal efficiency and mechanism of chromium removal by a silica-based nanoparticle were investigated. A PEI-silica nanoparticle was synthesized by a one-pot technique and exhibited uniformly well-dispersed PEI polymers in silica particles. The adsorption capacity of chromium ions was determined by a batch adsorption test, with the PEI-silica nanoparticle having a value of 183.7 mg/g and monolayer sorption. Adsorption of chromium ions was affected by the solution pH and altered the nanoparticle surface chemically. First principles calculations of the adsorption energies for the relevant adsorption configurations and XPS peaks of Cr and N showed that Cr(VI), [HCrO4](-) is reduced to two species, Cr(III), CrOH2+ and Cr3+, by an amine group and that Cr(III) and Cr(VI) ions are adsorbed on different functional groups, oxidized N and NH3+

Beeinflussung von Netzhautdickenwerten durch antiangiogenetische Therapie bei altersbedingter Makuladegeneration

BACKGROUND: This study evaluated the impact of antiangiogenetic therapy on differences in central retinal thickness (CRT) as measured with two optical coherence tomography (OCT) systems from the same manufacturer. MATERIAL AND METHODS: Data were obtained from a group of 20 patients with neovascular age-related macular degeneration before and after intravitreal treatment with ranibizumab. Imaging was performed using the Stratus and the high-definition (HD) Cirrus OCT systems. RESULTS: The mean CRT was revealed to be significantly lower as measured by OCT compared with HD-OCT before and after treatment (p>0.002). CRT differences varied more strongly before treatment than after treatment. A higher standard deviation was noted before treatment. The difference in the mean deviation of CRT measurements before and following antiangiogenetic therapy was highly significant. CONCLUSION: This study showed that differences in CRT measurements between different OCT systems were subject not only to technical differences but also to treatment effects of current antiangiogenetic strategies. These effects should be recognized because clinical studies increasingly define OCT parameters as primary or secondary outcome measures

Time course of morphologic effects on different retinal compartments after ranibizumab therapy in age-related macular degeneration

PURPOSE: To analyze the effect of ranibizumab therapy on retinal and subretinal compartments in age-related macular degeneration and to compare the time course of compartment specific effects to visual function. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Fourteen patients with changes in 3 major compartments owing to neovascular age-related macular degeneration. METHODS: Standard treatment with 3 monthly doses of intravitreal ranibizumab was performed. Eyes were examined at baseline and weeks 1, 4, and 12 using a standardized protocol. Manual segmentation was applied to all 128 B-scans contained in a macular raster scan (MRS). MAIN OUTCOME MEASURES: Morphology and time course of different retinal and subretinal compartments. RESULTS: High-definition optical coherence tomography and manual segmentation allowed for precise identification of volumes within individual compartments. All morphologic parameters responded positively to therapy, but demonstrated a specific time course. Subretinal fluid was identified as the most relevant factor for visual function, whereas changes in retinal and subpigment epithelial volumes did not correlate with the time course of functional rehabilitation. CONCLUSION: Analysis of MRS identified a characteristic impact of therapy on retinal and subretinal morphology

[The role of Stratus OCT in anti-VEGF therapy. Qualitative and quantitative assessment of neovascular AMD]

BACKGROUND: The evaluation of OCT3 during anti-VEGF therapy. METHODS: A total of 29 patients with choroidal neovascularization secondary to AMD received 3 intravitreal injections of ranibizumab. OCT examination and visual acuity testing (ETDRS) were performed before therapy onset, after 1 week and after 1, 2 and 3 months. RESULTS: The central retinal thickness (CRT) was assessed correctly by OCT in 128 out of 145 measurements. There was a distinct (84%) but not significant correlation between decrease in central retinal thickness and increase in visual acuity. Incorrect retinal layer segmentation and inadequate CRT measurements were a significant technical limitation. CONCLUSION: During anti-VEGF therapy, OCT allows documentation and quantification of morphologic retinal changes and in most cases also for an estimation of functional improvement