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https://www.readbyqxmd.com/read/28346917/endocrine-long-term-follow-up-of-children-with-neurofibromatosis-type-1-and-optic-pathway-glioma%C3%A2
#1
Ilaria Sani, Assunta Albanese
BACKGROUND/AIMS: Children with optic pathway glioma (OPG) face sequelae related to tumour location and treatment modalities. We aimed to assess the prevalence of hypothalamic-pituitary dysfunctions in children with neurofibromatosis type 1 (NF1) and OPG who did not receive radiotherapy or surgical resection. The causative role of tumour location on endocrinopathy development is investigated. METHODS: A retrospective follow-up study of 40 children with NF1 and OPG evaluated between August 1996 and May 2015 was undertaken...
March 27, 2017: Hormone Research in Pædiatrics
https://www.readbyqxmd.com/read/28346903/the-oceanus-statue-of-the-fontana-di-trevi-rome-the-analysis-of-black-crust-as-a-tool-to-investigate-the-urban-air-pollution-and-its-impact-on-the-stone-degradation
#2
Mauro F La Russa, Paola Fermo, Valeria Comite, Cristina M Belfiore, Donatella Barca, Annamaria Cerioni, Marina De Santis, Lorena Francesca Barbagallo, Michela Ricca, Silvestro A Ruffolo
This paper deals with the analysis of black crust coming from the statue of Oceanus belonging to the Fontana di Trevi (Rome). This monument is undoubtedly one of the main touristic attractions of Rome. During the restoration held between 2014 and 2015, some diagnostic analyses had been carried out. It has been highlighted that the sheltered surfaces suffer the formation of black crust, especially on the marble statues. The possibility to sample those degradation products, together with the unaltered substrate, represented an excellent opportunity to characterize the marble itself, to assess the impact of the urban air pollution on the stone material, and to detect the pollutant on a precise timescale...
March 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346826/imaging-successive-intermediate-states-of-the-on-surface-ullmann-reaction-on-cu-111-role-of-the-metal-coordination
#3
Sören Zint, Daniel Ebeling, Tobias Schlöder, Sebastian Ahles, Doreen Mollenhauer, Hermann A Wegner, Andre Schirmeisen
The in-depth knowledge about on-surface reaction mechanisms is crucial for the tailor-made design of covalently bonded organic frameworks, for applications such as nanoelectronic or -optical devices. Latest developments in atomic force microscopy, which rely on functionalizing the tip with single CO molecules at low temperatures allow to image molecular systems with submolecular resolution. Here, we are using this technique to study the complete reaction pathway of the on-surface Ullmann-type coupling between bromotriphenylene molecules on a Cu(111) surface...
March 27, 2017: ACS Nano
https://www.readbyqxmd.com/read/28346776/proton-exchange-in-a-paramagnetic-chemical-exchange-saturation-transfer-agent-from-experimental-studies-and-ab-initio-metadynamics-simulation
#4
Rodolphe Pollet, Célia S Bonnet, Pascal Retailleau, Philippe Durand, Éva Tóth
The proton-exchange process between water and a carbamate has been studied experimentally and theoretically in a lanthanide-based paramagnetic chemical exchange saturation transfer agent endowed with potential multimodality detection capabilities (optical imaging, or T1 MRI for the Gd(III) analogue). In addition to an in-depth structural analysis by a combined approach (using X-ray crystallography, NMR, and molecular dynamics), our ab initio simulation in aqueous solution sheds light on the reaction mechanism for this proton exchange, which involves structural Grotthuss diffusion...
March 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28346613/protective-effect-of-met12-a-small-peptide-inhibitor-of-fas-on-the-retinal-pigment-epithelium-and-photoreceptor-after-sodium-iodate-injury
#5
Jianhui Xiao, Jingyu Yao, Lin Jia, Chengmao Lin, David N Zacks
Purpose: A major problem in macular degeneration is the inability to reduce RPE and photoreceptor death. These cells die by necroptosis and apoptosis, respectively, but the upstream activator(s) of these death pathways is unknown. In this study, we use the sodium iodate (NaIO3) model of oxidative stress to test the hypothesis that activation of the Fas receptor contributes to the death of the RPE and photoreceptors. Methods: Sodium iodate was injected in Brown-Norway rats via femoral vein injection...
March 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28346548/kinetics-of-light-induced-ordering-and-deformation-in-lc-azobenzene-containing-materials
#6
Vladimir Toshchevikov, Tatiana Petrova, Marina Saphiannikova
Azobenzene-containing smart materials are able to transform the energy of light into directional mechanical stress. We develop a theory of time-dependent light-induced ordering and deformation in azobenzene materials starting from the kinetic equations of photoisomerization. The liquid crystalline (LC) interactions between rod-like trans-isomers are taken into account. Angular selectivity of the photoisomerization known as an "angular hole burning" or the Weigert effect leads to the light-induced ordering and deformation of the azobenzene materials...
March 27, 2017: Soft Matter
https://www.readbyqxmd.com/read/28346545/aqueous-cytokine-levels-are-associated-with-reduced-macular-thickness-after-intravitreal-ranibizumab-for-diabetic-macular-edema
#7
Tomoyasu Shiraya, Satoshi Kato, Fumiyuki Araki, Takashi Ueta, Tempei Miyaji, Takuhiro Yamaguchi
PURPOSE: It is controversial whether the administration of anti-vascular endothelial growth factor drugs for diabetic macular edema (DME) affects intraocular inflammatory cytokines. In this study, we measured cytokine concentration in aqueous humor before and after intravitreal injection of ranibizumab (IVR). The aim was to determine changes in cytokine concentration and their effects on DME reduction. METHODS: Twelve patients (13 eyes) with DME received two IVR (0...
2017: PloS One
https://www.readbyqxmd.com/read/28346494/the-effects-of-surface-structure-mutations-in-arabidopsis-thaliana-on-the-polarization-of-reflections-from-virus-infected-leaves
#8
D J Maxwell, J C Partridge, N W Roberts, N Boonham, G D Foster
The way in which light is polarized when reflected from leaves can be affected by infection with plant viruses. This has the potential to influence viral transmission by insect vectors due to altered visual attractiveness of infected plants. The optical and topological properties of cuticular waxes and trichomes are important determinants of how light is polarized upon reflection. Changes in expression of genes involved in the formation of surface structures have also been reported following viral infection...
2017: PloS One
https://www.readbyqxmd.com/read/28346278/effects-of-myopic-orthokeratology-on-visual-performance-and-optical-quality
#9
Guihua Liu, Zhi Chen, Feng Xue, Jing Li, Mi Tian, Xingtao Zhou, Ruihua Wei
OBJECTIVES: To analyze the changes in visual performance and optical quality after orthokeratology (ortho-k) treatment and its correlation with the magnitude of lens decentration and the diameter of treatment zone (TxZ). METHODS: A prospective study was conducted in 27 eyes of 27 patients wearing ortho-k contact lens. Area under log contrast sensitivity function (AULCSF), modulation transfer function cutoff values (MTFcutoff), Strehl ratio (SR), and objective scattering index (OSI) were measured and compared before and 1 month after ortho-k lens treatment...
March 24, 2017: Eye & Contact Lens
https://www.readbyqxmd.com/read/28346259/igg4-related-ophthalmic-disease-presenting-as-choroidal-and-orbital-lesions
#10
William S Gange, Stephen M Holland, Felipe De Alba
PURPOSE: To report a case of IgG4-related ophthalmic disease (IgG4-ROD) which presented as choroidal and orbital lesions. METHODS: Case report. RESULTS: A 64-year-old man presented with left eye photopsias and a history of IgG4-related perirenal fibrosis. Fundoscopic examination showed multiple bilateral yellow choroidal lesions, and optical coherence tomography showed multiple choroidal lesions. Magnetic resonance imaging of the orbits showed an enhancing lesion present circumferential to the optic nerve, but greater medially, abutting the posterior surface of the left globe...
March 24, 2017: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/28346218/wafer-scale-production-of-highly-uniform-two-dimensional-mos2-by-metal-organic-chemical-vapor-deposition
#11
TaeWan Kim, Jihun Mun, Hyeji Park, DaeHwa Joung, Mangesh Diware, Won Chegal, Jonghoo Park, Soo-Hwan Jeong, Sang-Woo Kang
Semiconducting two-dimensional (2D) materials, particularly, extremely thin molybdenum disulfide (MoS2) films are attracting considerable attention from the academia and industry owing to their distinctive optical and electrical properties. Here, we present the direct growth of a MoS2 monolayer with unprecedented spatial and structural uniformity across an entire 8-inch SiO2/Si wafer. The influences of growth pressure, ambient gases (Ar, H2), and S/Mo molar flow ratio on the MoS2 layered growth were explored by considering the domain size, nucleation sites, morphology, and impurity incorporation...
March 27, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28345918/direct-s0%C3%A2-t-excitation-of-a-conjugated-polymer-repeat-unit-unusual-spin-forbidden-transitions-probed-by-time-resolved-electron-paramagnetic-resonance-spectroscopy
#12
Deborah L Meyer, Florian Lombeck, Sven Huettner, Michael Sommer, Till Biskup
A detailed understanding of the electronic structure of semiconducting polymers and their building blocks is essential to develop efficient materials for organic electronics. (Time-resolved) electron paramagnetic resonance (EPR) is particularly suited to address these questions, allowing to directly detect paramagnetic states and to reveal their spin-multiplicity, besides its clearly superior resolution compared to optical meth- ods. We present here evidence for a direct S0→T optical excitation of distinct triplet states in the repeat unit of a conjugated polymer used in organic photovoltaics...
March 27, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28345878/multispectral-optical-tweezers-for-biochemical-fingerprinting-of-cd9-positive-exosome-subpopulations
#13
Randy P Carney, Sidhartha Hazari, Macalistair Colquhoun, Di Tran, Billanna Hwang, Michael S Mulligan, James D Bryers, Eugenia Girda, Gary S Leiserowitz, Zachary James Smith, Kit S Lam
Extracellular vesicles (EVs), including exosomes, are circulating nanoscale particles heavily implicated in cell signaling, and can be isolated in vast numbers from human biofluids. Study of their molecular profiling and materials properties is currently underway for purposes of describing a variety of biological functions and diseases. However, the large, and as yet unquantified, variety of EV subpopulations differing in composition, size, and likely function, necessitates characterization schemes capable of measuring single vesicles...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28345876/engineering-cellular-microenvironments-with-photo-and-enzymatically-responsive-hydrogels-toward-biomimetic-3d-cell-culture-models
#14
Roger Y Tam, Laura J Smith, Molly S Shoichet
Conventional cell culture techniques using 2D polystyrene or glass have provided great insight into key biochemical mechanisms responsible for cellular events such as cell proliferation, differentiation, and cell-cell interactions. However, the physical and chemical properties of 2D culture in vitro are dramatically different than those found in the native cellular microenvironment in vivo. Cells grown on 2D substrates differ significantly from those grown in vivo, and this explains, in part, why many promising drug candidates discovered through in vitro drug screening assays fail when they are translated to in vivo animal or human models...
March 27, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28345862/quantification-of-lipid-metabolism-in-living-cells-through-the-dynamics-of-lipid-droplets-measured-by-stimulated-raman-scattering-imaging
#15
Chi Zhang, Junjie Li, Lu Lan, Ji-Xin Cheng
Dysregulation of lipid metabolism is associated with many diseases including cancer. Lipid droplet (LD), a ubiquitous organelle in mammalian cells, serves as a hub for lipid metabolism. Conventional assays on the measurement of lipid metabolism rely on the quantification of the lipid composition or amount. Such methods cannot distinguish LDs having different bio-functionalities in living cells, and thus could be inaccurate in measuring the instantaneous lipogenesis of the living cells. We applied label-free stimulated Raman scattering microscopy to quantify the LDs' spatial-temporal dynamics, which showed direct links to cellular lipid metabolisms and can separate LDs involving in different metabolic events...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28345727/intrinsic-defects-and-their-effects-on-the-optical-properties-in-the-nonlinear-optical-crystal-cdsip2-a-first-principles-study
#16
Ci Wang, Jie Sun, Huiyang Gou, Shanpeng Wang, Jian Zhang, Xutang Tao
In view of their high nonlinear optical coefficients and good phase-matching properties, CdSiP2 (CSP) crystals are considered as one of the most promising materials in the field of nonlinear optical applications. However, the slight absorption losses around 1.34 μm and 1.78 μm under e-polarized light have been affecting its performance. In this study, first-principles calculations were performed to identify the effects of various charge defects on the absorption properties. Different intrinsic defects in the CSP crystal were calculated using the HSE method and compared according to the specific chemical environments in the experiments...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28345709/a-study-of-asymmetrical-mixed-valent-mo2-mo2-complexes-in-the-class-iii-regime
#17
Suman Mallick, Tao Cheng, Lu Chen, Miao Meng, Yu Yu Zhang, Chun Y Liu
Three novel asymmetrical dimolybdenum dimers, [Mo2(DAniF)3]2(μ-OOCCOS) (DAniF = N,N'-di(p-anisyl)formamidinate) ([OO-OS]), [Mo2(DAniF)3]2(μ-S2CCO2) ([SS-OO]), and [Mo2(DAniF)3]2(μ-SSCCOS) ([SS-OS]), have been synthesized and characterized by either single-crystal X-ray crystallography or (1)H NMR spectroscopy. The structural asymmetry for these compounds gives rise to a redox asymmetry, which enlarges the potential separation (ΔE1/2) between the two [Mo2] units. The mixed-valance (MV) species [OO-OS](+), [SS-OO](+) and [SS-OS](+), prepared by one-electron chemical oxidation of the neutral precursors, exhibit an intense and symmetrical intervalence charge transfer (IVCT) absorption band in the near-IR region, along with the high energy metal (δ) to ligand (π*) (ML) and ligand (π) to metal (δ) charge transfer (LMCT) absorptions...
March 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28345696/interfacially-al-doped-zno-nanowires-greatly-enhanced-near-band-edge-emission-through-suppressed-electron-phonon-coupling-and-confined-optical-field
#18
Yiming Wu, Yanmeng Dai, Shenlong Jiang, Chao Ma, Yue Lin, Dongxue Du, Yukun Wu, Huaiyi Ding, Qun Zhang, Nan Pan, Xiaoping Wang
Aluminium (Al)-doped zinc oxide (ZnO) nanowires (NWs) with a unique core-shell structure and a Δ-doping profile at the interface were successfully grown using a combination of chemical vapor deposition re-growth and few-layer AlxOy atomic layer deposition. Unlike the conventional heavy doping which degrades the near-band-edge (NBE) luminescence and increases the electron-phonon coupling (EPC), it was found that there was an over 20-fold enhanced NBE emission and a notably-weakened EPC in this type of interfacially Al-doped ZnO NWs...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28345641/iii-nitride-core-shell-nanorod-array-on-quartz-substrates
#19
Si-Young Bae, Jung-Wook Min, Hyeong-Yong Hwang, Kaddour Lekhal, Ho-Jun Lee, Young-Dahl Jho, Dong-Seon Lee, Yong-Tak Lee, Nobuyuki Ikarashi, Yoshio Honda, Hiroshi Amano
We report the fabrication of near-vertically elongated GaN nanorods on quartz substrates. To control the preferred orientation and length of individual GaN nanorods, we combined molecular beam epitaxy (MBE) with pulsed-mode metal-organic chemical vapor deposition (MOCVD). The MBE-grown buffer layer was composed of GaN nanograins exhibiting an ordered surface and preferred orientation along the surface normal direction. Position-controlled growth of the GaN nanorods was achieved by selective-area growth using MOCVD...
March 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28345640/degree-of-functionalisation-dependence-of-individual-raman-intensities-in-covalent-graphene-derivatives
#20
Philipp Vecera, Siegfried Eigler, Maria Koleśnik-Gray, Vojislav Krstić, Asmus Vierck, Janina Maultzsch, Ricarda A Schäfer, Frank Hauke, Andreas Hirsch
Covalent functionalisation of graphene is a continuously progressing field of research. The optical properties of such derivatives attract particular attention. In virtually all optical responses, however, an enhancement in peak intensity with increase of sp(3) carbon content, and a vanishing of the peak position shift in monolayer compared to few-layer systems, is observed. The understanding of these seemingly connected phenomena is lacking. Here we demonstrate, using Raman spectroscopy and in situ electrostatic doping techniques, that the intensity is directly modulated by an additional contribution from photoluminescent π-conjugated domains surrounded by sp(3) carbon regions in graphene monolayers...
March 27, 2017: Scientific Reports
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