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The wall shear-stress sensor [MPS.sup.3] based on flexible micropillars has been used to experimentally assess the two- dimensional wall shear-stress distribution in turbulent duct flow at moderate Reynolds number. The sensor covers an area of 90 x 125 viscous length scales along the streamwise and spanwise directions, respectively. Applying Taylor's hypothesis allows a further increase in the streamwise extension. Preliminary results evidence the coexistence of low- and high-shear regions representing footprints of near-wall coherent structures. The low-shear regions resemble long meandering bands interrupted by local high-shear-stress regions. A qualitative comparison evidences the structures detected in the present study to be similar to wall shear-stress distributions reported in the literature and to structures found in higher regions of the boundary layer. These preliminary findings indicate the potential of the micropillar sensor concept to be capable of detecting the multidirectional planar wall shear-stress distribution in turbulent flows. A detailed discussion of the wall shear-stress characteristics and of the geometric properties of the streaklike structures is beyond the scope of this paper, and a more intrusive discussion needs to be done in the future.

Background: A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates., Objectives: To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure., Methods: Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age 2 , sex, phototype and non-occupational UV exposure were calculated., Results: Participants with high versus no (OR 2.08; 95% CI 1.24-3.50; p  = 0.006) or versus moderate (OR 2.05; 95% CI 1.15-3.65; p  = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses., Conclusion: The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype., Competing Interests: Competing interestsFunds. SJ received funding for educational lectures from the German Social Accident Insurance (DGUV). Outside the scope of this paper, he received institutional funding for investigator-initiated research from Pfizer, Novartis, ALK, and Sanofi. BA received funding for educational lectures, workshops and expert opinions from the German Social Accident Insurance (DGUV). Outside the scope of this paper, she received grants for research paid to the institution, fees for lectures and advisory boards from Novartis, Leo, Sanofi, Biofrontera, Lofarma, Circassia, ALK, Incyte Corporation, Genentech, Shire, and Atopixs Therapeutics Ltd. EP, FM, BT, BR, LB, DGS, SHJ received payments for expert witness for one of the collaborating as well as for other funds. BI, AP, KP, DH, LS, JSM, HL, HE do not declare any COI. Employer. FM and BT declare no conflicts of interest. As staff of the Institute for Prevention and Occupational Medicine (IPA), they are employed at the ‘Berufsgenossenschaft Rohstoffe und chemische Industrie’ (BG RCI), a public body which is a member of the study’s main sponsor, the German Social Accident Insurance. IPA is an independent research institute of the Ruhr-University Bochum. The authors are independent of the German Social Accident Insurance regarding study design, access to the collected data, responsibility for data analysis and interpretation, and the right to publish. The views expressed in this paper are those of the authors and not necessarily those of the sponsor. The other authors declare no potential conflicts of interest., (© The Author(s) 2020.)