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https://www.readbyqxmd.com/read/29036103/modeling-the-response-of-mesospheric-sodium-to-pulsed-laser-excitation
#1
Joschua A Hellemeier, Paul Hickson, Lucas Labadie
A simulation modeling excitation of the sodium D2 line by nanosecond time scale pulsed lasers is described. By numerically integrating transition rates in the sodium hyperfine structure, the return flux per sodium atom is predicted as a function of laser power. The simulation should be useful for studies of mesospheric sodium and adaptive optics. Applications include the estimation of sodium column density from lidar return flux, and of laser guide star brightness for different pulsed laser formats. The simulation assumes that the pulse repetition frequency is sufficiently low (smaller than a few kilohertz) that atomic collisions restore local thermodynamic equilibrium between pulses...
August 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/29036059/modeling-astronomical-adaptive-optics-performance-with-temporally-filtered-wiener-reconstruction-of-slope-data
#2
Carlos M Correia, Charlotte Z Bond, Jean-François Sauvage, Thierry Fusco, Rodolphe Conan, Peter L Wizinowich
We build on a long-standing tradition in astronomical adaptive optics (AO) of specifying performance metrics and error budgets using linear systems modeling in the spatial-frequency domain. Our goal is to provide a comprehensive tool for the calculation of error budgets in terms of residual temporally filtered phase power spectral densities and variances. In addition, the fast simulation of AO-corrected point spread functions (PSFs) provided by this method can be used as inputs for simulations of science observations with next-generation instruments and telescopes, in particular to predict post-coronagraphic contrast improvements for planet finder systems...
October 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/29035554/star-polymers-reduce-iapp-toxicity-via-accelerated-amyloid-aggregation
#3
Emily H Pilkington, May Lai, Xinwei Ge, William J Stanley, Bo Wang, Miaoyi Wang, Aleksandr Kakinen, Marc-Antoine Sani, Michael R Whittaker, Esteban N Gurzov, Feng Ding, John F Quinn, Thomas P Davis, Pu Chun Ke
Protein aggregation into amyloid fibrils is a ubiquitous phenomenon across the spectrum of neurodegenerative disorders and type 2 diabetes. A common strategy against amyloidogenesis is to minimize the populations of toxic oligomers and protofibrils by inhibiting protein aggregation with small molecules or nanoparticles. However, melanin synthesis in nature is realized by accelerated protein fibrillation to circumvent accumulation of toxic intermediates. Accordingly, we designed and demonstrated the use of star-shaped poly(2-hydroxyethyl acrylate) (PHEA) nanostructures for promoting the aggregation while ameliorating the toxicity of human islet amyloid polypeptide (IAPP), the peptide involved in glycemic control and the pathology of type 2 diabetes...
October 16, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/29034594/toward-molecular-re-i-cages-structural-and-luminescent-properties
#4
Biing-Chiau Tzeng, An Chao, Mei-Chun Lin, Gene-Hsiang Lee, Ting-Shen Kuo
As a new synthetic approach, a versatile building block of [(Re(CO)4)3(N3S3)] (1a) can be used to react with linear dipyridyl ligands (i.e., pyrazine (pz), 4,4'-bipyridine (bpy), 1,2-di(4-pyridyl)ethylene (dpe), bis(4-pyridyl)acetylene (bpa), and 1,4-bis(pyridyl-4-ylethynyl)benzene (bpb)) and a tripyridyl one (1,3,5-tris(4-pyridylethynyl)benzene (tpb)) to afford a series of molecular cages, [(Re(CO)3)6(L)3(N3S3)2] (L = pz 2; bpy 3; bpe 4; bpa 5; bpb 6) and [(Re(CO)3)9(tpb)3(N3S3)3] (7) by solvothermal methods...
October 15, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29034469/effect-of-mono-2-ethylhexyl-phthalate-mehp-on-proliferation-of-and-steroid-hormone-synthesis-in-rat-ovarian-granulosa-cells-in-vitro
#5
Na Li, Te Liu, Kun Guo, Jian Zhu, Guangyan Yu, Shuyue Wang, Lin Ye
This study aimed to examine the proliferation of and secretion by rat ovarian granulosa cells (GCs) treated with mono-(2-ethylhexyl) phthalate (MEHP). Ovarian GCs were incubated with MEHP at concentration of 0, 25, 50, 100, and 200µM for 24 hours. Cell viability was determined using the MTT Cell Proliferation Assay. Progesterone and estradiol production was evaluated by radioimmunoassay (RIA) and the expression of FSHR, PR, and ER was measured by immunocytochemistry. StAR, P450scc, 3β-HSD, 17β-HSD, and P450 arom mRNA levels were determined by RT-PCR...
October 15, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/29032674/doxorubicin-loaded-unimolecular-micelles-stabilized-gold-nanoparticles-as-a-theranostic-nanoplatform-for-tumor-targeted-chemotherapy-and-ct-imaging
#6
Wenjing Lin, Xiaofang Zhang, Long Qian, Na Yao, Ya Pan, Lijuan Zhang
Current researches are mainly trend to address the development of multi-functional nanocarriers which could precisely reach the disease sites, release drugs in a controlled-manner and act as an imaging agent for both diagnosis and targeted therapy. In this study, a pH-sensitive theranostic nanoplatform as a promising dual-functional nanovector for tumor therapy and CT imaging was developed. 21-arm star like triblock polymerof β-cyclodextrin-{poly(-caprolactone)-poly(2-aminoethyl methacrylate)-poly[poly(ethylene glycol) methyl ether methacrylate]}21 [β-CD-(PCL-PAEMA-PPEGMA)21] with stable unimolecular micelles formed in aqueous solution was firstly synthesized by combined ROP with ARGET ATRP techniques, and then were used as template for fabrication of gold nanoparticles (AuNPs) with uniform sizes and excellent colloidal stability in situ, followed by the encapsulation of doxorubicin (DOX) with maximum entrapment efficiency up to 60% to generate the final product β-CD-(PCL-PAEMA-PPEGMA)21/AuNPs/DOX...
October 15, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/29030260/cyanidin-3-o-glucoside-promotes-the-biosynthesis-of-progesterone-through-the-protection-of-mitochondrial-function-in-pb-exposed-rat-leydig-cells
#7
Luona Wen, Xinwei Jiang, Jianxia Sun, Xia Li, Xusheng Li, Lingmin Tian, Ye Li, Weibin Bai
Cyanidin-3-O-glucoside (C3G) is an anthocyanin that has been reported to reduce the toxicity of heavy metals. In the present study, the protection effects of C3G on the biosynthesis of progesterone, the precursor of testosterone, against lead (Pb) in R2C rat Leydig cells were examined. Treatment of R2C cells with 100 μM Pb resulted in a significant decrease in progesterone production. After being cultured in a medium containing C3G and Pb, R2C cells exhibited an increase in progesterone concentration compared with the Pb treatment, as a result of up-regulation of the expression of the steroidogenic enzymes steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD) and cytochrome P450 enzyme cholesterol side chain cleavage enzyme (CYP11A1)...
October 10, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/29029827/dancing-with-the-stars-an-asterid-nlr-family
#8
John P Rathjen, Peter N Dodds
Wu and co-workers show how a network of sensor and helper NOD-like receptor proteins (NLRs) act together to confer robust resistance to diverse plant pathogens.
October 10, 2017: Trends in Plant Science
https://www.readbyqxmd.com/read/29029346/botanical-compound-p-anisaldehyde-repels-larval-lone-star-tick-acari-ixodidae-and-halts-reproduction-by-gravid-adults
#9
Allan T Showler, Jessica L Harlien
The lone star tick, Amblyomma americanum (L.), widely distributed across eastern, southeastern, and midwestern regions of the United States and south into Mexico, is an obligate blood feeder that attaches to three hosts during the larval, nymphal, and adult stages. White-tailed deer and wild turkey are common hosts, as well as a wide variety of other avian and mammalian hosts. Amblyomma americanum is the most frequently reported species of tick to bite humans in the southeastern and southcentral United States, and it can transmit diseases that include erhlichiosis, rickettsiosis, tularemia, and protozoan infections...
October 4, 2017: Journal of Medical Entomology
https://www.readbyqxmd.com/read/29029336/differential-effects-of-exposure-to-single-versus-a-mixture-of-endocrine-disrupting-chemicals-on-steroidogenesis-pathway-in-mouse-testes
#10
Julio Buñay, Eduardo Larriba, Daniel Patiño-Garcia, Leonor Cruz-Fernandes, Sergio Castañeda-Zegarra, María Rodriguez-Fernandez, Jesús Del Mazo, Ricardo D Moreno
Endocrine-disrupting chemicals (EDCs) generate reproductive dysfunctions affecting the biosynthesis of steroid hormones and genes of the steroidogenic pathway. EDCs effects are mainly reported as a result of exposure to single compounds. However, humans are environmentally exposed to a mixture of EDCs. Herein, we assess chronic exposure to single alkylphenols and phthalates versus a mixture in mouse testes histology and steroidogenesis. Pregnant mice were exposed through drinking water to: 0.3 mg/Kg-body weight (BW)/day of each phthalate (DEHP, DBP, BBP), 0...
September 22, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
https://www.readbyqxmd.com/read/29028037/hopping-induced-inversions-and-pancharatnam-excursions-of-c-points
#11
Ruchi, B S Bhargava Ram, P Senthilkumaran
In this Letter, we show the acquisition of the Pancharatnam phase by a C-point singularity when it is subjected to discrete cyclic polarization transformations. The changes in state of polarizations (SOPs) are mapped onto a Poincaré sphere as geodesical closed trajectories. The Pancharatnam phase acquired by a C-point is equal to the solid angle subtended by the closed trajectories at the center of the Poincaré sphere. We show this by considering index hopping induced inversions of C-points. For example, a lemon from the North Pole of a Poincaré sphere is first converted into a star whose location can be traced to the South Pole of the Poincaré sphere and retrieved back as a lemon at the North Pole to complete a closed geodesical trajectory on the Poincaré sphere...
October 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29027145/novel-biocompatible-au-nanostars-peg-nanoparticles-for-in-vivo-ct-imaging-and-renal-clearance-properties
#12
Daiyuan Tang, Wei Gao, Yajiang Yuan, Lingling Guo, Xifan Mei
Nanoprobes are rapidly becoming potentially transformative tools on disease diagnostics for a wide range of in vivo computed tomography (CT) imaging. Compared with conventional molecular-scale contrast agents, nanoparticles (NPs) promise improved abilities for in vivo detection. In this study, novel polyethylene glycol (PEG)-functionalized Au nanoparticles with star shape (AuNS@PEG) with strong X-ray mass absorption coefficient were synthesized as CT imaging contrast agents. Experimental results revealed that AuNS@PEG nanoparticles are well constructed with ultrasmall sizes, effective metabolisability, high computed tomography value, and outstanding biocompatibility...
October 12, 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/29026043/mapping-spiral-structure-on-the-far-side-of-the-milky-way
#13
Alberto Sanna, Mark J Reid, Thomas M Dame, Karl M Menten, Andreas Brunthaler
Little is known about the portion of the Milky Way lying beyond the Galactic center at distances of more than 9 kiloparsec from the Sun. These regions are opaque at optical wavelengths because of absorption by interstellar dust, and distances are very large and hard to measure. We report a direct trigonometric parallax distance of [Formula: see text] kiloparsec obtained with the Very Long Baseline Array to a water maser source in a region of active star formation. These measurements allow us to shed light on Galactic spiral structure by locating the Scutum-Centaurus spiral arm as it passes through the far side of the Milky Way and to validate a kinematic method for determining distances in this region on the basis of transverse motions...
October 13, 2017: Science
https://www.readbyqxmd.com/read/29022593/the-size-shape-density-and-ring-of-the-dwarf-planet-haumea-from-a-stellar-occultation
#14
J L Ortiz, P Santos-Sanz, B Sicardy, G Benedetti-Rossi, D Bérard, N Morales, R Duffard, F Braga-Ribas, U Hopp, C Ries, V Nascimbeni, F Marzari, V Granata, A Pál, C Kiss, T Pribulla, R Komžík, K Hornoch, P Pravec, P Bacci, M Maestripieri, L Nerli, L Mazzei, M Bachini, F Martinelli, G Succi, F Ciabattari, H Mikuz, A Carbognani, B Gaehrken, S Mottola, S Hellmich, F L Rommel, E Fernández-Valenzuela, A Campo Bagatin, S Cikota, A Cikota, J Lecacheux, R Vieira-Martins, J I B Camargo, M Assafin, F Colas, R Behrend, J Desmars, E Meza, A Alvarez-Candal, W Beisker, A R Gomes-Junior, B E Morgado, F Roques, F Vachier, J Berthier, T G Mueller, J M Madiedo, O Unsalan, E Sonbas, N Karaman, O Erece, D T Koseoglu, T Ozisik, S Kalkan, Y Guney, M S Niaei, O Satir, C Yesilyaprak, C Puskullu, A Kabas, O Demircan, J Alikakos, V Charmandaris, G Leto, J Ohlert, J M Christille, R Szakáts, A Takácsné Farkas, E Varga-Verebélyi, G Marton, A Marciniak, P Bartczak, T Santana-Ros, M Butkiewicz-Bąk, G Dudziński, V Alí-Lagoa, K Gazeas, L Tzouganatos, N Paschalis, V Tsamis, A Sánchez-Lavega, S Pérez-Hoyos, R Hueso, J C Guirado, V Peris, R Iglesias-Marzoa
Haumea-one of the four known trans-Neptunian dwarf planets-is a very elongated and rapidly rotating body. In contrast to other dwarf planets, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system, and the Centaur Chiron was later found to possess something similar to Chariklo's rings. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation)...
October 11, 2017: Nature
https://www.readbyqxmd.com/read/29021117/there-is-an-app-for-that-or-is-there-a-content-analysis-of-publicly-available-smartphone-apps-for-managing-alcohol-use
#15
Bettina B Hoeppner, Melissa R Schick, Lourah M Kelly, Susanne S Hoeppner, Brandon Bergman, John F Kelly
INTRODUCTION: Smartphone apps are emerging as a promising tool to support recovery from and prevention of problematic alcohol use, yet it is unclear what type of apps are currently available in the public domain, and to what degree these apps use interactive tailoring or other dynamic features to meet users' specific needs. METHODS: We conducted a content analysis of Android apps for managing drinking available on Google Play (n=266), downloaded between November 21, 2014 and June 25, 2015...
November 2017: Journal of Substance Abuse Treatment
https://www.readbyqxmd.com/read/29020510/secretory-expression-and-enzymatic-characterization-of-recombinant-agarivorans-albus-%C3%AE-agarase-in-escherichia-coli
#16
Sug-Young Yoon, Hyung-Min Lee, Ji-Na Kong, Kwang-Hoon Kong
Agarase catalyzes the hydrolysis of agar, which is primarily used as a medium for microbiology, various food additives, and new biomass materials. In this study, we described the expression of the synthetic gene encoding β-agarase from Agarivorans albus in Escherichia coli. The synthetic β-agarase gene was designed based on the biased codons of E. coli in order to optimize its expression and extracellular secretion in an active, soluble form. The synthesized agarase gene, including its signal sequence, was cloned into the pET-26 expression vector, and the pET-Aaβ-agarase plasmid was introduced into E...
October 11, 2017: Preparative Biochemistry & Biotechnology
https://www.readbyqxmd.com/read/29020447/efficiently-synergistic-hydrogen-evolution-realized-by-trace-amount-of-pt-decorated-defect-rich-sns2-nanosheets
#17
Guangbo Liu, Yunfeng Qiu, Zhiguo Wang, Jia Zhang, Xiaoshuang Chen, Mingjin Dai, Dechang Jia, Yu Zhou, Zhonghua Li, PingAn Hu
The electrocatalytic hydrogen evolution reactions (HER) has attracted increasing attention in the field of hydrogen-based economy, whereat developing cheap and efficient catalysts to reduce the use of Pt-based catalysts is highly required. Tin disulfide (SnS2) as a new rising star has exhibited intriguing properties in energy storage and conversion applications, while showing slow progress in HER due to the inherent poor activity. Herein, we demonstrate the successfully structural engineering and simultaneous integration of trace amount Pt in SnS2 nanosheets via a facile and effective in situ cycling voltammetry (CV) activation process, leading to the efficiently synergistic HER...
October 11, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29018514/a-future-perspective-on-the-europace-journal-its-star-is-rising
#18
EDITORIAL
Gerhard Hindricks
No abstract text is available yet for this article.
August 2017: Arrhythmia & Electrophysiology Review
https://www.readbyqxmd.com/read/29017984/superficial-siderosis-associated-with-a-pineal-cavernous-malformation
#19
Takafumi Ogura, Atsushi Kambe, Makoto Sakamoto, Yuki Shinohara, Toshihide Ogawa, Masamichi Kurosaki
BACKGROUND: Cavernous malformations in the pineal region are very rare and are difficult to anticipate from preoperative evaluation in patients with pineal apoplexy. We herein report the first case of a pineal cavernous malformation with superficial siderosis. Radiological findings were helpful in identifying the presence of the cavernous malformation. CASE DESCRIPTION: A 47-year-old female presented with a 4-month history of progressive headache, nausea, and dizziness...
October 7, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28994849/unexpected-formation-of-gold-nanoflowers-by-a-green-synthesis-method-as-agents-for-a-safe-and-effective-photothermal-therapy
#20
Da-Peng Yang, Xuan Liu, Choon Peng Teng, Cally Owh, Khin Yin Win, Ming Lin, Xian Jun Loh, Yun-Long Wu, Zibiao Li, Enyi Ye
Star fruit (Averrhoa carambola) juice rich in vitamin C and polyphenolic antioxidants was used to synthesize branched gold nanoflowers. These biocompatible and stable gold nanoflowers show strong near-infrared absorption. They are successfully demonstrated to be highly efficient for both in vitro and in vivo photothermal therapy by using an 808 nm laser.
October 10, 2017: Nanoscale
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