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Ultraviolet radiation

Dimitar Popmintchev, Benjamin R Galloway, Ming-Chang Chen, Franklin Dollar, Christopher A Mancuso, Amelia Hankla, Luis Miaja-Avila, Galen O'Neil, Justin M Shaw, Guangyu Fan, Skirmantas Ališauskas, Giedrius Andriukaitis, Tadas Balčiunas, Oliver D Mücke, Audrius Pugzlys, Andrius Baltuška, Henry C Kapteyn, Tenio Popmintchev, Margaret M Murnane
Recent advances in high-order harmonic generation have made it possible to use a tabletop-scale setup to produce spatially and temporally coherent beams of light with bandwidth spanning 12 octaves, from the ultraviolet up to x-ray photon energies >1.6  keV. Here we demonstrate the use of this light for x-ray-absorption spectroscopy at the K- and L-absorption edges of solids at photon energies near 1 keV. We also report x-ray-absorption spectroscopy in the water window spectral region (284-543 eV) using a high flux high-order harmonic generation x-ray supercontinuum with 10^{9}  photons/s in 1% bandwidth, 3 orders of magnitude larger than has previously been possible using tabletop sources...
March 2, 2018: Physical Review Letters
Ramón Mazzucchelli, Natalia Crespí-Villarías, Elia Pérez-Fernández, María Luz Durbán Reguera, Olalla Guzón Illescas, Javier Quirós, Alberto García-Vadillo, Loreto Carmona, Gil Rodriguez-Caravaca, Angel Gil de Miguel
Our aim was to analyze the seasonality and the effect of weather conditions on the incidence of osteoporotic hip fracture in a Southern European region. INTRODUCTION: The objective of this work is to evaluate seasonality and the effect of weather conditions on the incidence of osteoporotic hip fracture in a Southern European region. METHODS: This retrospective cohort study included all patients admitted to Alcorcón Foundation University Hospital with a diagnosis of osteoporotic hip fracture between the years 1999 and 2015...
March 15, 2018: Archives of Osteoporosis
Andrzej T Slominski, Michal A Zmijewski, Przemyslaw M Plonka, Jerzy P Szaflarski, Ralf Paus
The skin, a self-regulating protective barrier organ, is empowered with sensory and computing capabilities to counteract the environmental stressors to maintain/restore disrupted cutaneous homeostasis. These complex functions are coordinated by a cutaneous neuro-endocrine system that also communicates in a bidirectional fashion with the central nervous, endocrine and immune systems, all acting in concert to control body homeostasis. While ultraviolet energy (UV) has played an important role in the origin and evolution of life, UV absorption by the skin not only triggers mechanisms that defend skin integrity and regulate global homeostasis, but also induces skin pathology (e...
March 12, 2018: Endocrinology
Luyan Tang, Wenyu Wu, Wenwen Fu, Yao Hu
Phototherapy is widely used in the treatment of vitiligo. Previous studies have focused on the effects of ultraviolet (UV) radiation on melanocytes; however, the biological effects of phototherapy and melanocytes on keratinocytes remain to be elucidated. To investigate and assess the effects of clinically doses of broad band (BB)-UVA, narrow band (NB)-UVB and melanocytes on human keratinocytes in vitro , clinical doses of BB-UVA or NB-UVB radiation and human melanoma cell A375 co-culture were performed as stress divisors to HaCaT cells...
April 2018: Experimental and Therapeutic Medicine
Haiyan Qin, Guang Zhang, Lianbo Zhang
Polycomb group genes (PcG) encode chromatin modification proteins that are involved in the epigenetic regulation of cell differentiation, proliferation and the aging processes. The key subunit of the PcG complex, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), has a central role in a variety of mechanisms, such as the formation of chromatin structure, gene expression regulation and DNA damage. In the present study, ultraviolet A (UVA) was used to radiate human dermal fibroblasts in order to construct a photo-aged cell model...
April 2018: Experimental and Therapeutic Medicine
Magdalena Izdebska, Marta Hałas-Wiśniewska, Iwona Adamczyk, Ismena Lewandowska, Iga Kwiatkowska, Maciej Gagat, Alina Grzanka
BACKGROUND: Niacinamide is a stable and water-soluble form of vitamin B3, a valuable and versatile cosmetic ingredient, which is well absorbed and tolerated by the skin. A large body of literature has reported on the antioxidant and cell repair properties of niacinamide. Therefore, it has been shown to be useful in the protection of the skin against ultraviolet B (UVB) radiation and free radicals. Despite numerous hypotheses on the mechanism of vitamin B3, its protective effects have not yet been fully elucidated...
March 13, 2018: Advances in Clinical and Experimental Medicine: Official Organ Wroclaw Medical University
A Haylett, D Koumaki, L E Rhodes
BACKGROUND: Solar urticaria (SU) is a rare chronic inducible urticaria triggered via uncharacterised chromophores. We detail responses of a large patient series to monochromator phototesting and broadband ultraviolet radiation (UVR); relationship to life quality is explored. METHODS: Retrospective review of all SU patients undergoing standardised diagnostic photoinvestigation at a specialist centre during 2000-2016. From 2011, patients completed dermatology life quality index (DLQI) questionnaires for the past week and year...
March 13, 2018: Photodermatology, Photoimmunology & Photomedicine
B Raone, A Patrizi, C Gurioli, A Gazzola, G M Ravaioli
BACKGROUND: Narrowband-ultraviolet B (NB-UVB) is widely used for the treatment of several dermatological diseases. A cutaneous carcinogenic effect has been hypothesized, but not proved. METHODS: We retrospectively reviewed the data of patients treated with NB-UVB between January 1998 and December 2013 at the Dermatology Unit of our University Hospital, to evaluate the cutaneous carcinogenic risk of NB-UVB. RESULTS: 375 patients were included, each receiving a mean follow-up of 6...
March 13, 2018: Photodermatology, Photoimmunology & Photomedicine
M Say, A Beauchet, I Vouldoukis, P Beauchet, D Boudet, E Tella, E Mahé
BACKGROUND: The major risk factor is exposure to solar and artificial ultraviolet radiation, in particular during childhood and adolescence. In France a law was restricted tanning-bed access to adults (≥18 years) since 1997. OBJECTIVE: To evaluate teenagers' artificial tanning behaviour in 2016 and to compare results with those obtained in a similar survey performed in 2011. METHODS: The SOLADO 2011 and 2016 surveys were conducted in a general school in Antony and a technical school in Fontenay-aux-Roses (Paris suburb)...
March 13, 2018: Photodermatology, Photoimmunology & Photomedicine
Bingxin Zhang, Zishen Zhao, Xiaoyin Meng, Hongguang Chen, Guojun Fu, Keliang Xie
Chronic ultraviolet (UV) exposure-induced oxidative stress is associated with the pathogenesis of skin damage. However, the nuclear factor erythroid‑2‑related factor 2 (Nrf2) pathway is a critical factor in protecting cells against UVB‑induced injury through inhibiting oxidative stress. Furthermore, Nrf2 activation requires the involvement of the phosphoinositide-3 kinase (PI3K)/protein kinase B (AKT) pathway, which has a major role in survival of various cell types. Molecular hydrogen exerts protective effects on UV‑induced injury, but the underlying mechanisms have remained elusive...
March 7, 2018: International Journal of Molecular Medicine
Abidullah Khan, Bai Hongliang, Enqi Liu, Chen Mingxia, Yu Chunshui, Rai Wang, Khan Amin, Bai Zhuanli
Studies have shown that skin exposure to ultraviolet radiation (UVR) results in the formation of reactive oxygen species (ROS), thus altering the cellular function. The human epidermal skin layer is mainly composed of keratinocytes, which is damaged by UV-B radiation induced intracellular oxidative stress. Neferine is an alkaloid extract from lotus seed embryos, and its photoprotective action against UV-B produced oxidative damage in human epidermal keratinocytes (HEKs) has never been proposed. Neferine inhibited UV-B mediated increase in ROS and malondialdehyde (MDA) levels in pretreated keratinocytes...
March 13, 2018: Journal of Dermatological Treatment
F Vizzarri, M Palazzo, S Bartollino, D Casamassima, B Parolini, P Troiano, C Caruso, C Costagliola
Ultraviolet-radiation exerts a well-known role in the development of various ocular diseases and may contribute to the progress of age-related macular degeneration. Therefore, the use of compounds able to protect the eyes from UV-induced cellular damage is challenging. The aim of this study has been to test the protective effects of an antioxidant topical formulation against UV-induced damage in rabbit eyes. Twelve male rabbits were used. Animals were divided into 4 groups of 3 animals each. Control group (CG) did not receive any irradiation and/or eye drop...
March 12, 2018: Physiological Research
Suh-Yeon Choi, Bum-Ho Bin, Wanil Kim, Eunkyung Lee, Tae Ryong Lee, Eun-Gyung Cho
BACKGROUND: Ultraviolet radiation (UVR) is a well-known factor in skin aging and pigmentation, and daily exposure to subcytotoxic doses of UVR might accelerate senescence and senescence-associated phenomena in human melanocytes. OBJECTIVE: To establish an in vitro melanocyte model to mimic the conditions of repeated exposure to subcytotoxic doses of UVB irradiation and to investigate key factor(s) for melanocyte senescence and senescence-associated phenomena. METHODS: Human epidermal melanocytes were exposed twice with 20 mJ/cm2 UVB over a 24-h interval and subsequently cultivated for 2 weeks...
March 2, 2018: Journal of Dermatological Science
Stefan A Rensing
500Ma ago the terrestrial habitat was a barren, unwelcoming place for species other than, for example, bacteria or fungi. Most probably, filamentous freshwater algae adapted to aerial conditions and eventually conquered land. Adaptation to a severely different habitat apparently included sturdy cell walls enabling an erect body plan as well as protection against abiotic stresses such as ultraviolet radiation, drought and varying temperature. To thrive on land, plants probably required more elaborate signaling pathways to react to diverse environmental conditions, and phytohormones to control developmental programs...
March 8, 2018: Current Opinion in Plant Biology
Marina E Borisova, Andrea Voigt, Maxim A X Tollenaere, Sanjeeb Kumar Sahu, Thomas Juretschke, Nastasja Kreim, Niels Mailand, Chunaram Choudhary, Simon Bekker-Jensen, Masato Akutsu, Sebastian A Wagner, Petra Beli
Ultraviolet (UV) light radiation induces the formation of bulky photoproducts in the DNA that globally affect transcription and splicing. However, the signaling pathways and mechanisms that link UV-light-induced DNA damage to changes in RNA metabolism remain poorly understood. Here we employ quantitative phosphoproteomics and protein kinase inhibition to provide a systems view on protein phosphorylation patterns induced by UV light and uncover the dependencies of phosphorylation events on the canonical DNA damage signaling by ATM/ATR and the p38 MAP kinase pathway...
March 9, 2018: Nature Communications
Titus Josef Brinker, Marlene Heckl, Martina Gatzka, Markus V Heppt, Henrique Resende Rodrigues, Sven Schneider, Wiebke Sondermann, Carolina de Almeida E Silva, Michael C Kirchberger, Joachim Klode, Alexander H Enk, Sarah Knispel, Christof von Kalle, Ingo Stoffels, Dirk Schadendorf, Yasuhiro Nakamura, Stefan Esser, Aisllan Assis, Breno Bernardes-Souza
BACKGROUND: The incidence of melanoma is increasing faster than any other major cancer both in Brazil and worldwide. Southeast Brazil has especially high incidences of melanoma, and early detection is low. Exposure to ultraviolet (UV) radiation is a primary risk factor for developing melanoma. Increasing attractiveness is a major motivation among adolescents for tanning. A medical student-delivered intervention that takes advantage of the broad availability of mobile phones and adolescents' interest in their appearance indicated effectiveness in a recent study from Germany...
March 9, 2018: JMIR MHealth and UHealth
Nidhi Sharma, Srinivas Chakravarthy, Matthew J Longley, William C Copeland, Aishwarya Prakash
The 16.5 kb mitochondrial genome is subjected to damage from reactive oxygen species (ROS) generated in the cell during normal cellular metabolism and external sources such as ionizing radiation and ultraviolet light. ROS cause harmful damage to DNA bases that could result in mutagenesis and various diseases, if not properly repaired. The base excision repair (BER) pathway is the primary pathway involved in maintaining the integrity of mtDNA. Several enzymes that partake in BER within the nucleus have also been identified in the mitochondria...
March 6, 2018: DNA Repair
Megha K Trivedi, Alexandra R Vaughn, Jenny E Murase
Pustular psoriasis of pregnancy (PPP) is a life-threatening condition for both the pregnant mother and fetus, and must be efficiently and accurately diagnosed and treated. This condition has historically been classified as a unique, separate dermatosis of pregnancy. However, current opinion and data suggest that it may be a variant of generalized pustular psoriasis. PPP typically occurs in the third trimester and is characterized by widespread coalescent pustules, desquamation, and systemic symptoms. Clinical features and histopathologic evaluation aid in diagnosis...
2018: International Journal of Women's Health
Shakirat A Adetunji, Rosina C Krecek, Nicolize O'Dell, Leon Prozesky, Johan Steyl, Angela M Arenas-Gamboa
Pigmentation of the skin is a crucial component in the pathogenesis of melanocytic neoplasms and other skin-related tumors, as melanin is known to function in both the absorbance of ultraviolet radiation and as an antioxidant. Very limited information exists regarding the incidence and metastatic potential of neoplastic conditions of the skin in game animals, especially wildebeests, relative to domestic animals. Four cases of cutaneous melanoma in color-variant golden and king wildebeests ( Connochaetes taurinus) (from 2014 to 2015) in South Africa were investigated...
March 2018: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
J Llanos, I Brito, D Espinoza, Ramkumar Sekar, P Manidurai
Y1.86 Eu0.14 WO6 phosphors were prepared using a solid-state reaction method. Their optical properties were analysed, and they was mixed with TiO2 , sintered, and used as a photoelectrode (PE) in dye-sensitized solar cells (DSSCs). The as-prepared photoelectrode was characterized by photoluminescence spectroscopy, diffuse reflectance, electrochemical impedance spectroscopy (EIS) and X-ray diffraction. The photoelectric conversion efficiency of the DSSC with TiO2 :Y1.86 Eu0.14 WO6 (100:2.5) was 25.8% higher than that of a DSCC using pure TiO2 as PE...
February 2018: Royal Society Open Science
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