In order to harness the potential of block copolymers to produce nanoscale structures that can be integrated with existing silicon-based technologies, there is a need for compatible chemistries. Block copolymer nanostructures can form a wide variety of two-dimensional patterns, and can be controlled to present long-range order. Here we use the acid-responsive nature of self-assembled monolayers of aligned, horizontal block copolymer cylinders for metal loading with simple aqueous solutions of anionic metal complexes, followed by brief plasma treatment to simultaneously remove the block copolymer and produce metallic nanostructures. Aligned lines of metal with widths on the order of 10 nm and less are efficiently produced by means of this approach on Si(100) interfaces. The method is highly versatile because the chemistry to manipulate nanowire composition, structure and choice of semiconductor is under the control of the user.

BackgroundVitamin D deficiency is prevalent worldwide, but some groups are at greater risk. We aim to evaluate vitamin D levels in different occupations and identify groups vulnerable to vitamin D deficiency.MethodsAn electronic search conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and CINAHL Plus with Full Text generated 2505 hits; 71 peer-reviewed articles fulfilled the inclusion criteria. Occupations investigated included outdoor and indoor workers, shiftworkers, lead/smelter workers, coalminers, and healthcare professionals. We calculated the pooled average metabolite level as mean ± SD; deficiency/insufficiency status was described as % of the total number of subjects in a given category.ResultsCompared to outdoor workers, indoor workers had lower 25-hydroxyvitamin D (25-(OH)D) levels (40.6 ± 13.3 vs. 66.7 ± 16.7 nmol/L; p < 0.0001). Mean 25-(OH)D levels (in nmol/L) in shiftworkers, lead/smelter workers and coalminers were 33.8 ± 10.0, 77.8 ± 5.4 and 56.6 ± 28.4, respectively. Vitamin D deficiency (25-(OH)D < 50 nmol/L), was high in shiftworkers (80%) and indoor workers (78%) compared to outdoor workers (48%). Among healthcare professionals, medical residents and healthcare students had the lowest levels of mean 25-(OH)D, 44.0 ± 8.3 nmol/L and 45.2 ± 5.5 nmol/L, respectively. The mean 25-(OH)D level of practising physicians, 55.0 ± 5.8 nmol/L, was significantly different from both medical residents (p < 0.0001) and healthcare students (p < 0.0001). Nurses and other healthcare employees had 25-(OH)D levels of 63.4 ± 4.2 nmol/L and 63.0 ± 11.0 nmol/L, respectively, which differed significantly compared to practising physicians (p = 0.01), medical residents (p < 0.0001) and healthcare students (p < 0.0001).Rates of vitamin D deficiency among healthcare professionals were: healthcare students 72%, medical residents 65%, practising physicians 46%, other healthcare employees 44%, and nurses 43%. Combined rates of vitamin D deficiency or insufficiency (25-(OH)D < 75 nmol/L) were very high in all investigated groups.Potential confounders such as gender and body composition were not consistently reported in the primary studies and were therefore not analyzed. Furthermore, the descriptions of occupational characteristics may be incomplete. These are limitations of our systematic review.ConclusionsOur review demonstrates that shiftworkers, healthcare workers and indoor workers are at high risk to develop vitamin D deficiency, which may reflect key lifestyle differences (e.g. sunlight exposure). This may help target health promotion and preventive efforts.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-017-4436-z) contains supplementary material, which is available to authorized users.

Data linkage of administrative records can demonstrate under-reporting of occupational asthma and indicate areas for prevention.

We studied the relationships between physician-assessed damage, severity and activity in a large, multicentre systemic sclerosis (SSc, scleroderma) cohort. We hypothesized that there is a relationship between disease activity and severity and damage, but that severity would be more strongly related to damage. A total of 520 SSc patients (87% women, mean age 56 years, mean 8.6 years disease duration, 39% diffuse SSc) were studied. The correlations between physician's global assessments of damage, activity and severity were determined overall and in a subset of early, diffuse SSc (n = 74). The mean (SD) patient global health score was 3.6 (2.4) on a 0-10 scale. Physician-rated severity, activity and damage were 2.8 (2.2), 2.3 (2.0), and 3.4 (2.4) respectively. Damage was more strongly related to severity (r = 0.744, P < 0.001) than activity (r = 0.596, P < 0.001). Damage was not related to disease duration (r = 0.046, P = 0.3). In early diffuse SSc, the correlations were: damage and severity 0.771 (P < 0.001), damage and activity 0.596 (P < 0.001), severity and activity 0.809 (P < 0.001). The relationships vary in the overall cohort versus the early diffuse SSc subset where activity, severity and damage appear more strongly related. Thus, the exact nature of the relationship between damage, activity and severity will depend upon the characteristics of the population studied.