Germicidal UV Sources and Systems†.

The COVID-19 pandemic has generated great interest in reviving an old intervention technology, particularly for air disinfection-ultraviolet germicidal irradiation (UVGI). Since UVGI was developed and refined more than 80-90 years ago, the ultraviolet source of choice has been almost exclusively the low-pressure mercury vapor discharge lamp. Today, with new lamp technologies, there has been significant interest in the application of ultraviolet light-emitting diodes and excimer lamps that emit in the UV-C (180-280 nm) spectral band. This paper reviews these competing technologies with the aim of giving a sound basis for decisions on how to choose and install UV systems for disinfection of air and surfaces given the COVID-19 pandemic.

Prediction of the true IOL position.

PURPOSE: To develop algorithms for preoperative estimation of the true postoperative intraocular lens (IOL) position to be used for IOL power calculation. SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, UK. METHODS: Fifty patients were implanted randomly with a 3-piece IOL model in one eye and a 1-piece model in the other eye. Preoperatively, the IOLMaster was used to determine axial length, anterior chamber depth and mean corneal radius. Lens thickness and corneal width were measured with the ACMaster. Postoperative IOL position was measured with the ACMaster. Partial least squares (PLS) regression analysis of IOL position in terms of preoperative parameters was performed with a commercially available software package. RESULTS: The PLS regression analysis showed that age, refraction, corneal width, lens thickness and corneal radius are not significant predictors of postoperative position of the anterior IOL surface, while axial length and in particular anterior chamber depth are. Regression relationships in terms of the above-mentioned predictors were determined for the two models implanted. Surprisingly, it turned out that the position of the posterior IOL surface could be described by a single regression relationship valid for both models. The residual SD for prediction of IOL position was about 0.17 mm for all relationships. CONCLUSIONS: Accurate relationships to determine the true postoperative IOL position were obtained. In addition to axial length and corneal radius, which are required for the IOL power calculation as such, they require measurement of preoperative anterior chamber depth only.

Interlaboratory Evaluation of Ultraviolet Radiation Emissions from Compact Fluorescent Lamps.

There have been many recent reports regarding the potential risks of UV emissions from compact fluorescent lamps (CFLs). In some of these reports, the robustness of the measurements was difficult to discern. We conducted round-robin measurements, involving three lamp manufacturers and two government research laboratories to gather reliable data on the UV emissions from commercially available CFLs. The initial sample of lamps consisted of 71 spiral-shaped CFLs purchased from local retailers. From the initial sample, 14 "high UV emitting" CFLs were chosen for further evaluation. We compared the UV emissions at a distance of 20 cm with the UV exposure limits (ELs) published by the International Commission on Non-ionizing Radiation Protection (ICNIRP). We found that the allowable exposure time for measured lamps ranged from 21 to 415 h. This indicates that the emissions would not exceed the short-term ELs that have been established by the ICNIRP for healthy individuals. We also evaluated the potential long-term risk and found it to be insignificant. There was a large variation in the UV emissions found, even for lamps from a single package, indicating that it is impossible to predict the UV output of a CFL based on its physical appearance and model designation.

Discovery of (3-(4-(2-Oxa-6-azaspiro[3.3]heptan-6-ylmethyl)phenoxy)azetidin-1-yl)(5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-yl)methanone (AZD1979), a Melanin Concentrating Hormone Receptor 1 (MCHr1) Antagonist with Favorable Physicochemical Properties.

A novel series of melanin concentrating hormone receptor 1 (MCHr1) antagonists were the starting point for a drug discovery program that culminated in the discovery of 103 (AZD1979). The lead optimization program was conducted with a focus on reducing lipophilicity and understanding the physicochemical properties governing CNS exposure and undesired off-target pharmacology such as hERG interactions. An integrated approach was taken where the key assay was ex vivo receptor occupancy in mice. The candidate compound 103 displayed appropriate lipophilicity for a CNS indication and showed excellent permeability with no efflux. Preclinical GLP toxicology and safety pharmacology studies were without major findings and 103 was taken into clinical trials.

Differences in micronucleus frequency and acrylamide adduct levels with hemoglobin between vegetarians and non-vegetarians.

PURPOSE: Nutrients and food constituents can prevent or contribute to genotoxicity. In this study, the possible influence of a vegetarian/non-vegetarian diet on genotoxic effects was investigated in 58 non-smoking healthy vegetarians (V) and non-vegetarians (NV), age 21-37 years from the Stockholm area in Sweden. METHODS: Physical activity and dietary habits were similar in both groups, with the exception of the intake of meat and fish. Using flow cytometry, we determined the formation of micronuclei (MN) in transferrin-positive immature peripheral blood reticulocytes (Trf-Ret) (Total: n = 53; V: n = 27; NV: n = 26). Dietary exposure to acrylamide was measured through hemoglobin (Hb) adducts in peripheral erythrocytes (Total: n = 53; V: n = 29; NV: n = 24). Hb adducts of both acrylamide and its genotoxic metabolite glycidamide were monitored as a measure of the corresponding in vivo doses. RESULTS: Our data demonstrated that compared with the non-vegetarians, the vegetarians exhibited lower frequencies of MN (fMN) in the Trf-Ret (p < 0.01, Student's t test). A multivariate analysis demonstrated that there was no association between the fMN and factors such as age, sex, intake of vitamins/minerals, serum folic acid and vitamin B12 levels, physical activity, and body mass index. The mean Hb adduct levels of acrylamide and glycidamide showed no significant differences between vegetarians and non-vegetarians. Furthermore, there were no significant relationships between the adduct levels and fMN in the individuals. The ratio of the Hb adduct levels from glycidamide and acrylamide, however, showed a significant difference (p < 0.04) between the two groups. CONCLUSIONS: These data suggest that the vegetarian diet might be beneficial in lowering genomic instability in healthy individuals. The measured Hb adduct levels indicate that the total intake of acrylamide does not differ between the two studied groups and does not contribute to the observed difference in fMN, although an influence of the diet on the metabolic rates of acrylamide was indicated. In addition, the observed significant difference in the background fMN in the two groups demonstrated that the MN analysis method has a sensitivity applicable to the biomonitoring of human lifestyle factors.

Determination of the distribution of molecular masses of sodium hyaluronate by high-performance anion-exchange chromatography.

Sodium hyaluronate, or hyaluronic acid (HA), is a glucosaminoglucan used in pharmaceuticals in ophthalmic surgery and for treatment of rheumatoid arthritis. The average molecular mass of the HA polymer used in these products is often in the range 1 x 10(6)-5 x 10(6). Size-exclusion chromatography has been used for analysis of molecular masses, including the distribution, up to about 3 x 10(6). In this work, an anionic exchange chromatography method is presented by which the peak molecular mass and an estimation of the distribution of the molecular masses of HA is possible in the range 0.1 x 10(6)-5 x 10(6).