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https://www.readbyqxmd.com/read/29457861/promoted-fixation-of-molecular-nitrogen-with-surface-oxygen-vacancies-on-plasmon-enhanced-tio2-photoelectrodes
#1
Chengcheng Li, Tuo Wang, Zhi-Jian Zhao, Weimin Yang, Jianfeng Li, Ang Li, Zhilin Yang, Geoffrey A Ozin, Jinlong Gong
A hundred years on energy-intensive Haber-Bosch process continuously turn the nitrogen in air into fertilizer, nourishing billions of people while causing pollution and greenhouse gas emissions. The urgency of mitigating climate change motivates people to progress towards a more sustainable way in fixing nitrogen based on clean energy. Surface oxygen vacancies (surface Ovac) hold great potential for N2 adsorption and activation, but introducing Ovac on the very surface without affecting bulk properties remains a great challenge...
February 19, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29457833/a-green-method-to-determine-vuv-185-nm-fluence-rate-based-on-hydrogen-peroxide-production-in-aqueous-solution
#2
Laxiang Yang, Mengkai Li, Wentao Li, James R Bolton, Zhimin Qiang
A mini-fluidic vacuum ultraviolet/ultraviolet (VUV/UV) photoreaction system (MVPS) was developed in our previous study. Based on the MVPS, a green method to determine VUV fluence rate has been developed using the production rate of H2 O2 when water is exposed to 185 nm VUV. The H2 O2 production followed pseudo-zero-order reaction kinetics well over the first 10 min of VUV/UV exposure. This new method was well calibrated with a standard cis-cyclooctene cis-trans photoisomerization actinometer as recommended by the International Union of Pure and Applied Chemistry...
February 19, 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/29457715/embedding-a-diketopyrrolopyrrole-based-crosslinking-interfacial-layer-enhances-the-performance-of-organic-photovoltaics
#3
Hsiang-Lin Hsu, Ying-Chieh Chao, Yu-Hua Liao, Chung-Lin Chung, Ya-Juan Peng, ChihPing Chen, Ru-Jong Jeng
In this study, we prepared DPPBTDA, a diketopyrrolopyrrole (DPP)-based small molecule presenting a terminal crosslinkable azido group, as a cathode modified layer for organic photovoltaics (OPVs) having the inverted device structure glass/indium tin oxide (ITO)/zinc oxide (ZnO) with or without interfacial layer (IFL)/active layer/MoO3/Ag. The active layer comprised a blend of poly[4,8-bis(5-(2-ethylhexyl)thien-2-yl)benzo[1,2-b;4,5-b´]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene)-2-carboxylate-2,6-diyl] (PTB7-Th) as the electron donating moiety and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the electron acceptor...
February 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29457608/redox-responsive-ucnps-dpa-conjugated-ngo-peg-bpei-dox-for-imaging-guided-ptt-and-chemotherapy-for-cancer-treatment
#4
Arif Gulzar, Jiating Xu, Liangge Xu, Piaoping Yang, Fei He, Dan Yang, Guanghui An, Mohd Bismillah Ansari
The disulfide bond (-S-S-) is an enormously valuable functional group in a variety of chemical and biological agents that display effective reactivity or biological activities (e.g., antitumor activities). The disulfide bonds prevalent in proteins are somewhat oxidizing in the extracellular space; however, such disulfide bonds can rarely be found inside cells because of disulfide cleavage reactions facilitated by abundant free cellular thiols, including glutathione (GSH), which is the most important common thiol-containing small molecule...
February 19, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29457193/genome-shuffling-and-ribosome-engineering-of-streptomyces-virginiae-for-improved-virginiamycin-production
#5
Qian-Qian Tong, Yue-Hui Zhou, Xiang-Song Chen, Jin-Yong Wu, Ping Wei, Li-Xia Yuan, Jian-Ming Yao
The production of virginiamycin (VGM) from Streptomyces virginiae was improved by genome shuffling and ribosome engineering companied with a high-throughput screening method integrating deep-well cultivation and the cylinder-plate detecting. First, a novel high-throughput method was developed to rapidly screen large numbers of VGM-producing mutants. Then, the starting population of genome shuffling was obtained through ultraviolet (UV) and microwave mutagenesis, and four mutants with higher productivity of VGM were selected for genome shuffling...
February 19, 2018: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/29456258/modifying-the-standard-disk-model-for-the-ultraviolet-spectral-analysis-of-disk-dominated-cataclysmic-variables-i-the-novalikes-mv-lyrae-bz-camelopardalis-and-v592-cassiopeiae
#6
Patrick Godon, Edward M Sion, Şölen Balman, William P Blair
The standard disk is often inadequate to model disk-dominated cataclysmic variables (CVs) and generates a spectrum that is bluer than the observed UV spectra. X-ray observations of these systems reveal an optically thin boundary layer (BL) expected to appear as an inner hole in the disk. Consequently, we truncate the inner disk. However, instead of removing the inner disk, we impose the no-shear boundary condition at the truncation radius, thereby lowering the disk temperature and generating a spectrum that better fits the UV data...
September 1, 2017: Astrophysical Journal
https://www.readbyqxmd.com/read/29456255/fuse-spectroscopy-of-the-accreting-hot-components-in-symbiotic-variables
#7
Edward M Sion, Patrick Godon, Joanna Mikolajewska, Bassem Sabra, Craig Kolobow
We have conducted a spectroscopic analysis of the far ultraviolet archival spectra of four symbiotic variables, EG And, AE Ara, CQ Dra and RW Hya. RW Hya and EG And have never had a recorded outburst while CQ Dra and AE Ara have outburst histories. We analyze these systems while they are in quiescence in order to help reveal the physical properties of their hot components via comparisons of the observations with optically thick accretion disk models and NLTE model white dwarf photospheres. We have extended the wavelength coverage down to the Lyman Limit with FUSE spectra...
April 2017: Astronomical Journal
https://www.readbyqxmd.com/read/29456254/far-ultraviolet-spectroscopy-of-old-novae-ii-rr-pic-v533-her-and-di-lac
#8
Edward M Sion, Patrick Godon, Liam Jones
The old novae V533 Her (Nova Her 1963), DI Lac (Nova Lac 1910), and RR Pic (Nova Pic 1891) are in (or near) their quiescent stage, following their nova explosions, and continue to accrete at a high rate in the aftermath of their explosions. They exhibit continua that are steeply rising into the FUV, as well as absorption lines and emission lines of uncertain origin. All three have Far Ultraviolet Spectroscopic Explorer ( FUSE ) spectra that offer not only higher spectral resolution but also wavelength coverage extending down to the Lyman Limit...
March 2017: Astronomical Journal
https://www.readbyqxmd.com/read/29455976/near-infrared-emissive-lanthanide-hybridized-nanofibrillated-cellulose-nanopaper-as-ultraviolet-filter
#9
Bailiang Xue, Zhao Zhang, Yongchang Sun, Junjie Wang, Huie Jiang, Min Du, Congcong Chi, Xinping Li
The lanthanide complexes [Yb(fac)3 (H2 O)2 , Yb(tta)3 (H2 O)2 , Nd(tta)3 (H2 O)2 ] functionalized nanofibrillated cellulose (Ln-NFC) nanopapers with near-infrared (NIR) luminescence and high transparency are rapidly fabricated after solvent exchange using a simple suction filtration film-making method. The effects of NFC and lanthanide complexes content on their photophysical properties of Ln-NFC nanopapers and their mechanism of UV filters are fully investigated. With increasing lanthanide complexes content in the Ln-NFC nanopaper, their transmittances are gradually decreased while their NIR luminescences are obviously increased...
April 15, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29455071/the-use-of-satellite-data-to-measure-ultraviolet-b-penetrance-and-its-potential-association-with-age-of-multiple-sclerosis-onset
#10
Ofer Amram, Nadine Schuurman, Ellen Randall, Feng Zhu, Jameelah Saeedi, Peter Rieckmann, Irene Yee, Helen Tremlett
BACKGROUND: Studies have indicated an association between low Ultraviolet B (UVB) exposure and an increased risk of developing multiple sclerosis (MS). Few studies, however, have explored whether UVB exposure is associated with the age at MS symptom onset. OBJECTIVE: We investigated the potential association between cumulative early life ambient UVB exposure and age at MS onset, using satellite data to measure ambient UVB exposure. METHODS: Adult onset MS patients were selected from the University of British Columbia's MS genetic database (1980-2005)...
February 6, 2018: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/29454853/the-photoprotective-and-anti-inflammatory-activity-of-red-propolis-extract-in-rats
#11
C M Batista, A V F Alves, L A Queiroz, B S Lima, R N P Filho, A A S Araújo, R L C de Albuquerque Júnior, J C Cardoso
The negative effects triggered by ultraviolet radiation, such as premature aging and carcinogenesis, have motivated several studies on photoprotection. Recent strategies for photoprotection have included the incorporation of natural antioxidant and anti-inflammatory compounds, such as flavonoids, into sunscreens and the oral administration of natural antioxidant extracts. Brazilian Red propolis extract contains isoflavonoids with antioxidant and anti-inflammatory activities. Here, we investigate the photoprotective effects of orally- or topically-administered formulations containing hydroalcoholic extract of red propolis (HERP) in a rodent model...
January 31, 2018: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29454251/uv-absorption-spectrum-of-allene-radical-cations-in-solid-argon
#12
Chih-Hao Chin, Meng-Yeh Lin, Tzu-Ping Huang, Yu-Jong Wu
Electron bombardment during deposition of an Ar matrix containing a small proportion of allene generated allene cations. Further irradiation of the matrix sample at 385 nm destroyed the allene cations and formed propyne cations in solid Ar. Both cations were identified according to previously reported IR absorption bands. Using a similar technique, we recorded the ultraviolet absorption spectrum of allene cations in solid Ar. The vibrationally resolved progression recorded in the range of 266-237 nm with intervals of about 800 cm -1 was assigned to the A 2 E ← X 2 E transition of allene cations, and the broad continuum absorption recorded in the region of 229-214 nm was assigned to their B 2 A 1 ← X 2 E transition...
February 8, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29454238/transformations-of-dissolved-organic-matter-induced-by-uv-photolysis-hydroxyl-radicals-chlorine-radicals-and-sulfate-radicals-in-aqueous-phase-uv-based-advanced-oxidation-processes
#13
Lathika Varanasi, Erica Coscarelli, Maryam Khaksari, Lynn R Mazzoleni, Daisuke Minakata
Considering the increasing identification of trace organic contaminants in natural aquatic environments, the removal of trace organic contaminants from water or wastewater discharge is an urgent task. Ultraviolet (UV) and UV-based advanced oxidation processes (AOPs), such as UV/hydrogen peroxide (UV/H 2 O 2 ), UV/free chlorine and UV/persulfate, are attractive and promising approaches for the removal of these contaminants due to the high reactivity of active radical species produced in these UV-AOPs with a wide variety of organic contaminants...
February 8, 2018: Water Research
https://www.readbyqxmd.com/read/29454167/polydopamine-coated-nanocomposites-of-angelica-gigas-nakai-extract-and-their-therapeutic-potential-for-triple-negative-breast-cancer-cells
#14
Suyeong Nam, Song Yi Lee, Jung-Jin Kim, Wie-Soo Kang, In-Soo Yoon, Hyun-Jong Cho
Polydopamine (PD)-coated nanocomposites (NCs) based on the ethanol extract of Angelica gigas Nakai (AGN EtOH ext) were fabricated and evaluated for breast cancer therapy. AGN NCs were prepared using a modified emulsification-solvent evaporation method and were further incubated in dopamine solution (at pH 8.6) to be covered with the PD layer. PD-AGN NCs with a 213-nm mean diameter, narrow size distribution, and negative zeta potential values were fabricated in this study. Less negative (close to zero) zeta potential value of PD-AGN NCs than that of AGN NCs implied the existence of the PD layer in the outer surface of NCs...
February 11, 2018: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/29453716/occurrence-and-assessment-of-the-risk-of-ultraviolet-filters-and-light-stabilizers-in-victorian-estuaries
#15
Mayumi Allinson, Yutaka Kameda, Kumiko Kimura, Graeme Allinson
This reconnaissance study was undertaken to examine the occurrence of common ultraviolet filters (UVF) and light stabilizers (UVLS), and preservatives in four different estuaries in Port Philip Bay, Victoria, for the first time. In total, 11 UV filters, 10 UV stabilizers, 12 preservatives and a metabolite, and one fragrance were screened in grab samples of water and sediment using a combination of solid phase extraction and gas and liquid chromatography mass spectrometry measurement techniques. In that context, 16 of the UVF and UVLS and 5 of the preservatives screened were observed in water and/or sediment samples...
February 16, 2018: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29453667/dissolved-organic-matter-characteristics-along-sabo-dammed-streams-based-on-ultraviolet-visible-and-fluorescence-spectral-properties
#16
Susan Praise, Hiroaki Ito, Ying An, Kazuya Watanabe, Toru Watanabe
Changes in dissolved organic matter (DOM) characteristics were investigated in two mountainous streams with closed-type sabo dams. Surface water was collected from four stations along the two mountainous streams and analyzed using ultraviolet-visible spectrophotometry and excitation-emission fluorescence matrix (EEM) methods. Optical properties of DOM indicated an increase in molecular weight and aromaticity at stations near the sabo dams. Average spectral ratio values were low before and after the dam (i.e...
February 17, 2018: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/29453184/is-it-photosensitization-or-photodegradation-when-uv-b-irradiation-is-combined-with-bde-47-evidence-from-the-growth-and-reproduction-changes-of-rotifer-brachionus-plicatilis
#17
Chunchen Liu, Xuexi Tang, Bin Zhou, Yongshun Jiang, Mengchen Lv, Yu Zang, You Wang
Ecotoxicological methods were applied in the present study, and the marine rotifer Brachionus plicatilis was used as the toxic endpoint to depict what occurred when 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was combined with solar ultraviolet-B radiation (UV-B). B. plicatilis was exposed to three different combination methods of BDE-47 and UV-B at an equal toxicity ratio, including normal rotifer co-cultured with UV-B-irradiated BDE-47 (known as Method I), UV-B-irradiated rotifer co-cultured with BDE-47 exposure (known as Method II) and normal rotifer co-cultured with the simultaneous addition of BDE-47 and UV-B irradiation (known as Method III)...
February 13, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29451390/vacuum-ultraviolet-treatment-of-acid-and-ester-terminated-self-assembled-monolayers-chemical-conversions-and-friction-reduction
#18
Ahmed Ibrahim Abdelhamid Soliman, Toru Utsunomiya, Takashi Ichii, Hiroyuki Sugimura
We have prepared COOH- and COOCH3-terminated self-assembled monolayers (SAMs) from undec-10-enoic acid (UDA) and methyl undec-10-enoate (MUDO) molecules on hydrogen-terminated silicon (H Si) substrates through ultraviolet (UV) irradiation. The as-prepared UDA- and MUDO-SAMs were exposed to 172-nm vacuum UV (VUV) light in a high vacuum environment (HV, < 10-3 Pa) for different periods. The presence of COO components at the surfaces of these SAMs without prior oxidation would simplify the understanding of the origin of the chemical conversions and the changes of surface properties, as the prior oxidation would change the surface properties and generate different oxygenated groups...
February 16, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29451386/optically-switchable-photocatalysis-in-ultrathin-black-phosphorus-nanosheets
#19
Hui Wang, Shenlong Jiang, Wei Shao, Xiaodong Zhang, Shichuan Chen, Xianshun Sun, Qun Zhang, Yi Luo, Yi Xie
Recently low-dimensional materials hold great potential in the field of photocatalysis, whereas the concomitantly promoted many-body effects have long been ignored. Such Coulomb interaction-mediated effects would lead to some intriguing, nontrivial band structures, thus promising versatile photocatalytic performances and optimized strategies. Here, we demonstrate that ultrathin black phosphorus (BP) nanosheets exhibit an exotic, excitation-energy-dependent, optical switching effect in photocatalytic reactive oxygen species (ROS) generation...
February 16, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29451385/control-of-photomechanical-crystal-twisting-by-illumination-direction
#20
Daichi Kitagawa, Hajime Tsujioka, Fei Tong, Xinning Dong, Christopher J Bardeen, Seiya Kobatake
Photomechanical molecular crystals have been investigated as mesoscopic photoactuators. Here, we report how the photomechanical twisting of 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a) crystals depends on illumination direction. The ribbon-like crystal of 1a could be successfully prepared by a sublimation method. The ribbon crystal exhibited reversible photomechanical crystal twisting upon alternating irradiation with ultraviolet (UV) and visible light. Moreover, changing the UV illumination direction with respect to the crystal resulted in different twisting modes, ranging from helicoid to cylindrical...
February 16, 2018: Journal of the American Chemical Society
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