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https://www.readbyqxmd.com/read/28548847/simulating-the-electronic-circular-dichroism-spectra-of-photo-reversible-peptide-conformations
#1
Hugo Gattuso, Cristina García-Iriepa, Diego Sampedro, Antonio Monari, Marco Marazzi
Electronic circular dichroism (CD) spectroscopy of peptides is one of the most important experimental char-acterization tools to get insights regarding their structure. Nevertheless, even though highly useful, the reliable simulations of CD spectra result in a complex task. Here, we propose a combination of quantum mechanics/molecular mechanics (QM/MM) methods with a semi-empirical Hamiltonian based on the Frankel excitons theory to efficiently describe the behavior of a 27-amino acid α-helical peptide in water...
May 26, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28547826/cspbbr3-qd-alox-inorganic-nanocomposites-with-exceptional-stability-in-water-light-and-heat
#2
Anna Loiudice, Seryio Saris, Emad Oveisi, Duncan T L Alexander, Raffaella Buonsanti
Herein, the assembly of CsPbBr3 QD/AlOx inorganic nanocomposite, using atomic layer deposition (ALD) for the growth of the amorphous alumina matrix (AlOx), is proven as a novel protection scheme for this new class of QDs. The nucleation and growth process of AlOx on the QD surface was thoroughly investigated by a miscellanea of techniques which highlighed the importance of the interaction between the ALD precursor and the QD surface to uniformely coat the QDs while preserving the optoelectronic properties. These nanocomposites show an exceptional stability against exposure to air (for at least 45 days), irradiation under simulated solar spectrum (for at least 8h), to thermal treatment (at least up to 200ºC in air), and finally against immersion in water...
May 26, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28545361/applying-melanopic-lux-to-measure-biological-light-effects-on-melatonin-suppression-and-subjective-sleepiness
#3
Claudia Nowozin, Amely Wahnschaffe, Andrea Rodenbeck, Jan de Zeeuw, Sven Hädel, Ruslan Kozakov, Heinz Schöpp, Mirjam Münch, Dieter Kunz
In the beginning of this century a novel photopigment, melanopsin, was discovered in a sub-class of retinal ganglion cells and its action spectrum was described. Shortly after, it became clear that melanopsin is one major contributor to non-visual eye-mediated effects of light on e.g. the circadian, neuroendocrine and neurobehavioral systems. First applied studies pointed out that these non-visual effects of light are relevant for wellbeing, performance and general health. A standardized measurement quantity for these non-visual effects does not exist, but would ease application...
May 22, 2017: Current Alzheimer Research
https://www.readbyqxmd.com/read/28542006/an-efficient-affordable-optically-stimulated-luminescent-osl-annealer
#4
Sara A Abraham, Samuel J Frank, Kimberlee J Kearfott
Optically stimulated luminescent (OSL) dosimeters are devices used for measuring doses of ionizing radiation. Signal is stored within an OSL material so that when stimulated with light, light of a specific wavelength is emitted in proportion to the integrated ionizing radiation dose. Each interrogation of the material results in the loss of a small fraction of signal, thus allowing multiple interrogations leading to more accurate measurements of dose. In order to reuse a dosimeter, the residual signals from prior doses must be taken into account and subtracted from current readings, adding uncertainty to any future measurements...
July 2017: Health Physics
https://www.readbyqxmd.com/read/28540380/online-measurement-of-photoisomerisation-efficiency-in-solution-using-ion-mobility-mass-spectrometry
#5
James N Bull, Eduardo Carrascosa, Michael S Scholz, Neville J A Coughlan, Evan J Bieske
The photoisomerisation of charged molecules in solution is probed directly using ion mobility mass spectrometry with electrospray ionisation. The technique is demonstrated using a prototype azoheteroarene cation in methanol. By scanning the wavelength of the excitation light while monitoring the photoisomer intensity a photoisomerisation action spectrum is generated, which, when compared with a conventional absorption spectrum, allows the relative photoisomerisation quantum yield to be determined across a range of wavelengths...
May 25, 2017: Analyst
https://www.readbyqxmd.com/read/28540321/novel-scn1a-and-gabra1-gene-mutations-with-diverse-phenotypic-features-and-the-question-on-the-existence-of-a-broader-spectrum-of-dravet-syndrome
#6
Maria P Gontika, Christopher Konialis, Constantine Pangalos, Antigone Papavasiliou
In the light of modern molecular technologies, the understanding of the complexity of the numerous genotype-phenotype correlations regarding Dravet syndrome is mandatory. Motivated by 2 patients, whose whole-exome sequencing revealed novel mutations that exemplify the phenotypic and genetic heterogeneities associated with typical and atypical Dravet syndrome presentations, the authors discuss the existence of a broader spectrum of Dravet syndrome. The first patient is a 4-year-old boy with fairly typical Dravet syndrome and a novel sodium channel α1 subunit gene mutation of high-predicted combined pathogenicity likelihood...
January 2017: Child Neurol Open
https://www.readbyqxmd.com/read/28539850/spectral-response-of-metallic-optical-antennas-driven-by-temperature
#7
Alexander Cuadrado, José Manuel López-Alonso, Francisco Javier González, Javier Alda
When optical antennas are used as light detectors, temperature changes their spectral response. Using this relation, we determine the spectrum of a light beam from an optical antenna's signal. A numerical evaluation of the temperature-spectral response has been completed with a model for the noise of the device. Using both the response and the noise model, we have established the capabilities of the device by quantifying the error in the spectrum determination both for broadband spectrum and monochromatic radiation...
2017: Plasmonics
https://www.readbyqxmd.com/read/28535413/controllable-synthesis-and-luminescent-properties-of-rare-earth-doped-gd2-moo4-3-nanoplates
#8
Lei Zhang, Bohua Dong, Guohua Wang, Rongjie Gao, Ge Su, Wei Wang, Lixin Cao
For the first time, we have successfully synthesized rare-earth doped Gd2(MoO4)3: RE(3+) (RE=Eu, Tb) nanoplates by solvothermal method. The morphology of Gd2(MoO4)3 can be manipulated by changing the reaction times and reaction temperatures. The composition and surface morphology have been investigated by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM), respectively. Under the excitation of UV, Photoluminescence (PL) has been used to explore the excellent luminescence properties of the synthesized nanophosphors...
April 21, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28535346/on-the-optimization-of-current-injection-in-algainp-core-shell-nanowire-light-emitting-diodes
#9
Pyry Kivisaari, Alexander Berg, Mohammad Karimi, Kristian Storm, Steven Limpert, Jani Oksanen, Lars Samuelson, Håkan Jan Pettersson, Magnus T Borgström
Core-shell nanowires offer great potential to enhance the efficiency of light-emitting diodes (LEDs) and expand the attainable wavelength range of LEDs over the whole visible spectrum. Additionally, nanowire LEDs can offer both improved light extraction and emission enhancement if the diameter of the wires is not larger than half the emission wavelength (λ/2). However, AlGaInP nanowire LEDs have so far failed to match the high efficiencies of traditional planar technologies, and the parameters limiting the efficiency remain unidentified...
May 23, 2017: Nano Letters
https://www.readbyqxmd.com/read/28535147/mechanics-of-post-fusion-exocytotic-vesicle
#10
Thomas Stephens, Zhanghan Wu, Jian Liu
Exocytosis is an important cellular process controlled by metabolic signaling. It involves vesicle fusion to the plasma membrane, followed by the opening of a fusion pore, and the subsequent release of the vesicular lumen content into the extracellular space. While most modeling efforts focus on the events leading to membrane fusion, how the vesicular membrane remodels after fusing to plasma membrane remains unclear. This latter event dictates the nature and the efficiency of exocytotic vesicular secretions, and is thus critical for exocytotic function...
May 23, 2017: Physical Biology
https://www.readbyqxmd.com/read/28533987/exoskeleton-may-influence-the-internal-body-temperatures-of-neotropical-dung-beetles-col-scarabaeinae
#11
Valentina Amore, Malva I M Hernández, Luis M Carrascal, Jorge M Lobo
The insect exoskeleton is a multifunctional coat with a continuum of mechanical and structural properties constituting the barrier between electromagnetic waves and the internal body parts. This paper examines the ability of beetle exoskeleton to regulate internal body temperature considering its thermal permeability or isolation to simulated solar irradiance and infrared radiation. Seven Neotropical species of dung beetles (Coleoptera, Scarabaeinae) differing in colour, surface sculptures, size, sexual dimorphism, period of activity, guild category and altitudinal distribution were studied...
2017: PeerJ
https://www.readbyqxmd.com/read/28533509/vector-beam-polarization-state-spectrum-analyzer
#12
Ignacio Moreno, Jeffrey A Davis, Katherine Badham, María M Sánchez-López, Joseph E Holland, Don M Cottrell
We present a proof of concept for a vector beam polarization state spectrum analyzer based on the combination of a polarization diffraction grating (PDG) and an encoded harmonic q-plate grating (QPG). As a result, a two-dimensional polarization diffraction grating is formed that generates six different q-plate channels with topological charges from -3 to +3 in the horizontal direction, and each is split in the vertical direction into the six polarization channels at the cardinal points of the corresponding higher-order Poincaré sphere...
May 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28532114/hypocrellin-b-and-nano-silver-loaded-polymeric-nanoparticles-enhanced-generation-of-singlet-oxygen-for-improved-photodynamic-therapy
#13
Subramanian Natesan, Venkateshwaran Krishnaswami, Chandrasekar Ponnusamy, Madi Madiyalakan, Thomas Woo, Rajaguru Palanisamy
A nanoparticulate photodynamic approach was employed with an objective to achieve enhanced production of singlet oxygen ((1)O2), for the management of posterior segment eye diseases like age related macular degeneration. The hypocrellin B (HB) loaded poly lactide-co-glycolide nanoparticle formulations were incorporated with nano silver (HBS-NPs). The optimized HBS-NPs contained 2.60±0.06mg/mL of HB and showed (i) 135.6 to 828.2nm size range, and (ii) negative zeta potential with a narrow polydispersity index...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28530249/large-scale-quantum-emitter-arrays-in-atomically-thin-semiconductors
#14
Carmen Palacios-Berraquero, Dhiren M Kara, Alejandro R-P Montblanch, Matteo Barbone, Pawel Latawiec, Duhee Yoon, Anna K Ott, Marko Loncar, Andrea C Ferrari, Mete Atatüre
Quantum light emitters have been observed in atomically thin layers of transition metal dichalcogenides. However, they are found at random locations within the host material and usually in low densities, hindering experiments aiming to investigate this new class of emitters. Here, we create deterministic arrays of hundreds of quantum emitters in tungsten diselenide and tungsten disulphide monolayers, emitting across a range of wavelengths in the visible spectrum (610-680 nm and 740-820 nm), with a greater spectral stability than their randomly occurring counterparts...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28529896/advances-in-radiotherapy-techniques-and-delivery-for-non-small-cell-lung-cancer-benefits-of-intensity-modulated-radiation-therapy-proton-therapy-and-stereotactic-body-radiation-therapy
#15
REVIEW
Tejan P Diwanji, Pranshu Mohindra, Melissa Vyfhuis, James W Snider, Chaitanya Kalavagunta, Sina Mossahebi, Jen Yu, Steven Feigenberg, Shahed N Badiyan
The 21st century has seen several paradigm shifts in the treatment of non-small cell lung cancer (NSCLC) in early-stage inoperable disease, definitive locally advanced disease, and the postoperative setting. A key driver in improvement of local disease control has been the significant evolution of radiation therapy techniques in the last three decades, allowing for delivery of definitive radiation doses while limiting exposure of normal tissues. For patients with locally-advanced NSCLC, the advent of volumetric imaging techniques has allowed a shift from 2-dimensional approaches to 3-dimensional conformal radiation therapy (3DCRT)...
April 2017: Translational Lung Cancer Research
https://www.readbyqxmd.com/read/28527413/monochromatic-green-light-induces-an-aberrant-accumulation-of-geranylgeranyled-chlorophylls-in-plants
#16
Zuzana Materová, Roman Sobotka, Barbora Zdvihalová, Michal Oravec, Jakub Nezval, Václav Karlický, Daniel Vrábl, Michal Štroch, Vladimír Špunda
Light quality is an important environmental factor affecting the biosynthesis of photosynthetic pigments whose production seems to be affected not only quantitatively but also qualitatively. In this work, we set out to identify unusual pigment detected in leaves of barley (Hordeum vulgare L.) and explain its presence in plants grown under monochromatic green light (GL; 500-590 nm). The chromatographic analysis (HPLC-DAD) revealed that a peak belonging to this unknown pigment is eluted between chlorophyll (Chl) a and b...
May 6, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28526061/photosynthesis-at-the-far-red-region-of-the-spectrum-in-acaryochloris-marina
#17
REVIEW
Syed Lal Badshah, Yahia Mabkhot, Salim S Al-Showiman
Acaryochloris marina is an oxygenic cyanobacterium that utilizes far-red light for photosynthesis. It has an expanded genome, which helps in its adaptability to the environment, where it can survive on low energy photons. Its major light absorbing pigment is chlorophyll d and it has α-carotene as a major carotenoid. Light harvesting antenna includes the external phycobilin binding proteins, which are hexameric rods made of phycocyanin and allophycocyanins, while the small integral membrane bound chlorophyll binding proteins are also present...
May 19, 2017: Biological Research
https://www.readbyqxmd.com/read/28525618/establishing-expanding-and-certifying-a-closed-colony-of-phlebotomus-argentipes-diptera-psychodidae-for-xenodiagnostic-studies-at-the-kala-azar-medical-research-center-muzaffarpur-bihar-india
#18
Puja Tiwary, Shakti Kumar Singh, Anurag Kumar Kushwaha, Edgar Rowton, David Sacks, Om Prakash Singh, Shyam Sundar, Phillip Lawyer
This pilot project was preliminary and essential to a larger effort to define the ability of certain human-subject groups across the infection spectrum to serve as reservoirs of Leishmania donovani infection to sand flies in areas of anthroponotic transmission such as in Bihar state, India. This is possible only via xenodiagnosis of well-defined subject groups using live vector sand flies. The objective was to establish at the Kala Azar Medical Research Center (KAMRC), Muzaffarpur, Bihar, India, a self-sustaining colony of Phlebotomus argentipes (Annandale & Brunneti), closed to infusion with wild-caught material and certified safe for human xenodiagnosis...
May 19, 2017: Journal of Medical Entomology
https://www.readbyqxmd.com/read/28524680/cavity-cooling-of-many-atoms
#19
Mahdi Hosseini, Yiheng Duan, Kristin M Beck, Yu-Ting Chen, Vladan Vuletić
We demonstrate cavity cooling of all motional degrees of freedom of an atomic ensemble using light that is far detuned from the atomic transitions by several gigahertz. The cooling is achieved by cavity-induced frequency-dependent asymmetric enhancement of the atomic emission spectrum, thereby extracting thermal kinetic energy from the atomic system. Within 100 ms, the atomic temperature is reduced from 200 to 10  μK, where the final temperature is mainly limited by the linewidth of the cavity. In principle, the technique can be applied to molecules and atoms with complex internal energy structure...
May 5, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28523301/large-variability-of-the-activity-and-chronicity-indexes-within-and-between-histological-classes-of-lupus-nephritis
#20
Tudor Azoicăi, Ioana Mădălina Belibou, Ludmila Lozneanu, Simona Eliza Giuşcă, Elena Cojocaru, Irina Draga Căruntu
Systemic lupus erythematosus (SLE) is characterized by a multifaceted pathogenesis and a heterogeneous clinical expression. The kidney involvement is almost unavoidable in all forms of SLE with chronic evolution, 75% of patients developing renal lesions defined as lupus nephritis (LN) - a glomerulonephritis with an extremely diverse lesion spectrum. The present study aimed to reevaluate a series of cases diagnosed as LN, focusing on the histological features in correlation with the level of activity and chronicity...
2017: Romanian Journal of Morphology and Embryology, Revue Roumaine de Morphologie et Embryologie
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