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https://www.readbyqxmd.com/read/28531986/biomimicking-synthesis-of-photoluminescent-molecular-lantern-catalyzed-by-in-situ-formation-of-nanogold-catalysts
#1
Yong Yu, Xin Ting Zheng, Boon Wei Yee, Yen Nee Tan
Bioluminescence has been widely recognized as a powerful imaging tool for biological investigations. Synthesis of molecular lanterns that mimic bioluminescence in nature is of great interest. Herein we report a synthesis of molecular lantern by utilizing the catalytic properties of ultrasmall (<2nm) gold nanoclusters (AuNC), which is inspired by the enzymatic light-up of luciferin in the biological system. Small molecules such as hydroquinone and Cys-Gly peptides are used to direct the synthesis of AuNC via a biotemplating approach, while the in-situ formation of AuNC simultaneously catalyze the formation of luciferin-like, brightly fluorescent dye (λem=520nm, QY=0...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531795/coherence-and-polarization-properties-of-laser-propagating-through-biological-tissues
#2
Duan Meiling, Zhang Chao, Li Jinhong
Based on the extended Huygens-Fresnel principle, the analytical expressions of the cross-spectral density matrix elements for random electromagnetic Gaussian Schell-model (GSM) beam propagating in biological tissues are derived, and used to study the changes in spectral degree of coherence μ and spectral degree of polarization P of random electromagnetic GSM beams with the propagation distance z propagating through the different biological tissues. It is shown that the changes closely depend on the species of the biological tissues, beam wave length, the interval between two field points and propagation distance...
May 9, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28531090/fast-multicolor-photodetection-with-graphene-contacted-p-gase-n-inse-van-der-waals-heterostructures
#3
Faguang Yan, Lixia Zhao, Amalia Patane, Ping'an Hu, Xia Wei, Wengang Luo, Dong Zhang, Quanshan Lv, Qi Feng, Chao Shen, Kai Chang, Laurence Eaves, Kaiyou Wang
The integration of different two-dimensional materials within a multilayer van der Waals (vdW) heterostructure offers a promising technology for high performance opto-electronic devices such as photodetectors and light sources. Here we report on the fabrication and electronic properties of vdW heterojunction diodes composed of the direct band gap layered semiconductors InSe and GaSe and transparent monolayer graphene electrodes. We show that the type II band alignment between the two layered materials and their distinctive spectral response, combined with the short channel length and low electrical resistance of graphene electrodes, enable efficient generation and extraction of photoexcited carriers from the heterostructure even when no external voltage is applied...
May 22, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28530816/quantitative-temperature-dependence-of-the-microscopic-hydration-structures-investigated-by-ultraviolet-photodissociation-spectroscopy-of-hydrated-phenol-cations
#4
Haruki Ishikawa, Itaru Kurusu, Reona Yagi, Ryota Kato, Yasutoshi Kasahara
To discuss the temperature effect on microscopic hydration structures in clusters, relative populations of the isomers having different hydration structures at well-defined temperatures are quite important. In the present study, we measured ultraviolet photodissociation spectra of the temperature-controlled hydrated phenol cation, [PhOH(H2O)5](+), trapped in the 22-pole ion trap. Two isomers having a distinct hydration motif with each other are identified in the spectra and a clear change in the relative populations is observed in temperature range from 30 K to 150 K...
May 22, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28530270/two-photon-photoelectron-emission-microscopy-for-surface-plasmon-polaritons-at-the-au-111-surface-decorated-with-alkanethiolate-self-assembled-monolayers
#5
Kana Yamagiwa, Masahiro Shibuta, Atsushi Nakajima
In this study, we have employed dual-color photoelectron emission microscopy (2P-PEEM) to visualize surface plasmon polaritons (SPPs) propagating along a chemically modified organic/metal interface of alkanethiolate self-assembled monolayers (Cn-SAMs; n is the number of alkyl carbon atoms) formed on Au(111). In dual-color 2P-PEEM, near-infrared photons around 900 nm generate SPPs at the Cn-SAMs/Au(111) interface, which interfere with the remaining light field. The resulting surface polarization beats are imaged as local distributions of 2P-photoelectrons probed by ultraviolet photons...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530200/antioxidant-antibacterial-and-anticancer-properties-of-phyto-synthesised-artemisia-quttensis-podlech-extract-mediated-agnps
#6
Farinaz Ghanbar, Amir Mirzaie, Fatemeh Ashrafi, Hassan Noorbazargan, Mojgan Dalirsaber Jalali, Soheil Salehi, Seyed Ataollah Sadat Shandiz
The focus of this study is on a rapid and cost-effective approach for the synthesis of silver nanoparticles (AgNPs) using Artemisia quttensis Podlech aerial parts extract and assessment of their antioxidant, antibacterial and anticancer activities. The prepared AgNPs were determined by ultraviolet-visible spectroscopy, X-ray diffraction, Fourier transform infra-red spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, and dynamic light scattering and zeta-potential analysis...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28530190/green-synthesis-of-ce2o3-nps-and-determination-of-its-antioxidant-activity
#7
Hayrunnisa Nadaroglu, Hicran Onem, Azize Alayli Gungor
In this study, the authors presented synthesis of ceria nanoparticles (NPs) by the bio-reduction method and their antioxidative activity. Aqueous extract of Euphorbia (Euphorbia amygdaloides) was used as reducing and stabilising agents. They used aqueous extract of Euphorbia (E. amygdaloides) as reducing and stabilising agent. Ultraviolet-visible (UV-vis) absorption spectroscopy was used to monitor the quantitative formation of ceria NPs. They also addressed the characteristics of the obtained ceria NPs using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmitting electron microscope (TEM)...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28530182/green-synthesis-of-highly-stable-carbon-nanodots-and-their-photocatalytic-performance
#8
Rashmi Mahajan, Akhshay Singh Bhadwal, Nishant Kumar, Mukil Madhusudanan, Ramesh Namdeo Pudake, Ravi Mani Tripathi
The present study reports a novel, facile, biosynthesis route for the synthesis of carbon nanodots (CDs) with an approximate quantum yield of 38.5%, using Musk melon extract as a naturally derived-precursor material. The synthesis of CDs was established by using ultraviolet-visible (UV-vis) spectroscopy, Dynamic light scattering, photoluminescence spectroscopy, X-ray diffraction, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The as-prepared CDs possess an eminent fluorescence under UV-light (λex = 365 nm)...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28528929/female-brazilian-whiptail-lizards-cnemidophorus-ocellifer-prefer-males-with-high-ultraviolet-ornament-reflectance
#9
Carolina M C A Lisboa, Katalin Bajer, Daniel M A Pessoa, Marc Huber, Gabriel C Costa
Conspicuous colouration is an important way of social communication in many taxa. The role of ultraviolet (UV) signals in intraspecific communication has only recently been studied in lizards, and there is not a general understanding of the adaptive role of UV colouration. Colour ornaments can signal male quality in mate choice and are therefore suitable for reliably predicting the outcome of female preference. Here, we tested the potential role of UV colouration in female spatial preference in a non-territorial teiid lizard, Cnemidophorus ocellifer...
May 18, 2017: Behavioural Processes
https://www.readbyqxmd.com/read/28527979/degradation-of-chloramphenicol-by-uv-chlorine-treatment-kinetics-mechanism-and-enhanced-formation-of-halonitromethanes
#10
Huiyu Dong, Zhimin Qiang, Jun Hu, Jiuhui Qu
Ultraviolet (UV)/chlorine process is considered as an emerging advanced oxidation process for the degradation of micropollutants. This study investigated the degradation of chloramphenicol (CAP) and formation of disinfection by-products (DBPs) during the UV/chlorine treatment. It was found that CAP degradation was enhanced by combined UV/chlorine treatment compared to that of UV and chlorination treatment alone. The pseudo-first-order rate constant of the UV/chlorine process at pH 7.0 reached 0.016 s(-1), which was 10...
May 17, 2017: Water Research
https://www.readbyqxmd.com/read/28527425/effects-of-the-summer-holiday-season-on-uv-filter-and-illicit-drug-concentrations-in-the-korean-wastewater-system-and-aquatic-environment
#11
Ki Yong Kim, Kalu Ibe Ekpeghere, Hee-Jin Jeong, Jeong-Eun Oh
Seasonal variations in the concentrations of eight ultraviolet (UV) filters and 22 illicit drugs including their metabolites in the Korean aquatic environment were investigated. Seawater samples from three beaches, water samples from two rivers, and influents and effluents from three wastewater treatment plants were analyzed. The UV filter concentrations in the seawater, river water, and effluent samples were 39.4-296, 35.4-117, and 6.84-51.1 ng L(-1), respectively. The total UV filter concentrations in the seawater samples were 1...
May 17, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28526633/facial-skin-rejuvenation-by-autologous-dermal-microfat-transfer-in-photoaged-patients-clinical-evaluation-and-skin-surface-digital-profilometry-analysis
#12
Angelo Trivisonno, Alfredo Rossi, Massimo Monti, Donato Di Nunno, Christophe Desouches, Claudio Cannistra, Gabriele Toietta
Cumulative long-term exposure to solar ultraviolet radiation promotes premature skin aging characterized by wrinkle formation and reduced skin elasticity. In this study, we assessed whether microfat transfer could improve dermal and subcutaneous tissue thickness loss associated with photoaging. Twenty-one patients affected by facial photoaging (photodamage grade II-IV; age range 35-62 years; 19 females, 2 males; all of Caucasian origin) were treated using minimally invasive autologous dermal white fat transfer harvested with a recently designed microcannula...
April 22, 2017: Journal of Plastic, Reconstructive & Aesthetic Surgery: JPRAS
https://www.readbyqxmd.com/read/28526347/preparation-of-chitosan-ferulic-acid-conjugate-structure-characterization-and-in-the-application-of-pharmaceuticals
#13
Chen Li, Jian-Bin Li
A novel drug delivery system based on chitosan derivatives was prepared by introducting ferulic acid to chitosan adopting a free radical-induced grafting procedure. This paper used an ascorbic acid/hydrogen peroxide redox pair as radical initiator. The chitosan derivative was characterized by Fourier transformed infrared (FTIR), Ultraviolet-visible spectrum (UV), Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Electron microscopic scanning (SEM). What is more, preparing microcapsules with the chitosan conjugate as wall material, the drug release propertie of chitosan conjugates were compared with that of a blank chitosan, which treated in the same conditions but in the absence of ferulic acid...
May 16, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28526240/endocrine-actions-of-vitamin-d-in-skin-relevance-for-photocarcinogenesis-of-non-melanoma-skin-cancer-and-beyond
#14
REVIEW
Jörg Reichrath, Roman Saternus, Thomas Vogt
The skin represents a pivotal organ for the human body's vitamin D endocrine system, being both the site of ultraviolet (UV)-B-induced vitamin D synthesis and a target tissue for the pluripotent effects of 1,25(OH)2D3 and other biologically active vitamin D metabolites. As many other steroid hormones, 1,25(OH)2D3 exerts its effects via two independent signal transduction pathways: the classical genomic and the non-genomic pathway. While non-genomic effects of 1,25(OH)2D3 are in part exerted via effects on intracellular calcium, genomic effects are mediated by the vitamin D receptor (VDR)...
May 16, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/28525866/theoretical-spectroscopic-insights-of-tautomers-and-enantiomers-of-penicillamine
#15
J Mendes, K J de Almeida, J L Neto, T C Ramalho, H A Duarte
B3LYP and MP2 calculations have been carried out to investigate tautomers and enantiomers of penicillamine (Pen). Their infrared (IR), ultraviolet (UV), circular dichroism (CD) and nuclear magnetic resonance (NMR) spectra were obtained at linear-response, time-dependent DFT (TD-DFT). IR, UV and NMR spectra cannot be used to identify Pen enantiomers, showing nearly equal spectral profiles. CD spectra, however, give rise to completely symmetric signals, forming a perfect specular image to each other. Distinct CD profiles were also obtained for Pen tautomers...
May 11, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28525650/detection-of-damage-on-single-or-double-stranded-dna-in-a-population-exposed-to-arsenic-in-drinking-water
#16
J Jiménez-Villarreal, D I Rivas-Armendariz, C P Pineda-Belmontes, N D Betancourt-Martínez, M A Macías-Corral, A J Guerra-Alanis, M S Niño-Castañeda, J Morán-Martínez
Different studies have suggested an association between arsenic (As) exposure and damage to single-stranded DNA by reactive oxygen species derived from the biotransformation of arsenic. The single strand damages are converted to double strand damage upon interaction with ultraviolet radiation. Analysis of genomic integrity is important for assessing the genotoxicity caused by environmental pollutants. In this study, we compared the concentration of As in drinking water, nutritional status, lifestyle variables, and the level of genotoxicity in an exposed population and a control group...
May 18, 2017: Genetics and Molecular Research: GMR
https://www.readbyqxmd.com/read/28525298/experimental-and-computational-evidence-on-the-interaction-of-cycloalkyl-%C3%AE-aminobisphosphonates-with-calf-thymus-dna
#17
Mohammad Bagher Gholivand, Hossein Peyman, Khodayar Gholivand, Hamideh Roshanfekr, Avat Arman Taherpour, Rouhollah Yaghoubi
Fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, circular dichroism spectroscopy, viscometry, cyclic voltammetry, and differential pulse voltammetry were applied to investigate the competitive interaction of DNA with the three new cycloalkyl α-aminobisphosphonates (D1-D3) and spectroscopic probe, neutral red dye, and Hoechst (HO), in a Tris-hydrogen chloride buffer (pH 7.4). The spectroscopic and voltammetric studies showed that the groove binding mode of interaction is predominant in the solution containing DNA and α-aminobisphosphonates...
May 19, 2017: DNA and Cell Biology
https://www.readbyqxmd.com/read/28524926/a-980-nm-laser-activated-upconverted-persistent-probe-for-nir-to-nir-rechargeable-in-vivo-bioimaging
#18
Zhenluan Xue, Xiaolong Li, Youbin Li, Mingyang Jiang, Guozhong Ren, Hongrong Liu, Songjun Zeng, Jianhua Hao
Long-lasting persistent luminescent nanoparticles (PLNPs) with efficient near-infrared (NIR) emission have emerged as a new generation of probes for in vivo optical bioimaging owing to their advantages of zero-autofluorescence benefited from the self-sustained emission after excitation, deep penetration depth, and a high signal-to-noise ratio. However, most of the PLNPs are charged by ultraviolet (UV) or visible light, remarkably limiting their applications for in vivo long-term bioimaging. Here we demonstrate 980 nm laser activated upconversion-PLNPs (UC-PLNPs) with efficient NIR emission...
May 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28523297/the-ultraviolet-influence-upon-soft-eye-tissues
#19
Sanda Jurja, Mălina Coman, Mihaela Cezarina Hîncu
The climate changes, which occurred during the last decades, put all living species in front of new challenges. Human biology is no exception to it, all tissues have to face new effects, with unpredictable consequences. Many cancers, mainly affecting the skin, but also many of the eye various structures diseases, have ultraviolet radiation as recognized causative agent. The aim of our work is to highlight the changes that can occur after exposure to ultraviolet radiations of soft tissues, including eye structures, by reviewing data from the scientific literature regarding the matter...
2017: Romanian Journal of Morphology and Embryology, Revue Roumaine de Morphologie et Embryologie
https://www.readbyqxmd.com/read/28522878/the-photodissociation-of-hcn-and-hnc-effects-on-the-hnc-hcn-abundance-ratio-in-the-interstellar-medium
#20
Alfredo Aguado, Octavio Roncero, Alexandre Zanchet, Marcelino Agúndez, José Cernicharo
The impact of the photodissociation of HCN and HNC isomers is analyzed in different astrophysical environments. For this purpose, the individual photodissociation cross section of HCN and HNC isomers have been calculated in the 7-13.6 eV photon energy range for a temperature of 10 K. These calculations are based on the ab initio calculation of three-dimensional adiabatic potential energy surfaces of the 21 lower electronic states. The cross sections are then obtained using a quantum wave packet calculation of the rotational transitions needed to simulate a rotational temperature of 10 K...
March 20, 2017: Astrophysical Journal
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