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https://www.readbyqxmd.com/read/28332018/seasonal-loss-and-resumption-of-circadian-rhythms-in-hibernating-arctic-ground-squirrels
#1
Cory T Williams, Maya Radonich, Brian M Barnes, C Loren Buck
Circadian clocks are near universal among organisms and play a key role in coordinating physiological and metabolic functions to anticipate or coincide with predictable daily changes in the physical and social environment. However, whether circadian rhythms persist and are functionally important during hibernation in all mammals is currently unclear. We examined whether circadian rhythms of body temperature (T b) persist during multi-day, steady-state torpor and investigated the association between timing of animal emergence, exposure to light, and resumption of activity and T b rhythms in free-living and captive male arctic ground squirrels...
March 22, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28330987/architecture-and-mechanism-of-the-central-gear-in-an-ancient-molecular-timer
#2
REVIEW
Martin Egli
Molecular clocks are the product of natural selection in organisms from bacteria to human and their appearance early in evolution such as in the prokaryotic cyanobacterium Synechococcus elongatus suggests that these timers served a crucial role in genetic fitness. Thus, a clock allows cyanobacteria relying on photosynthesis and nitrogen fixation to temporally space the two processes and avoid exposure of nitrogenase carrying out fixation to high levels of oxygen produced during photosynthesis. Fascinating properties of molecular clocks are the long time constant, their precision and temperature compensation...
March 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28327136/perceptions-of-interprofessional-collaboration-of-general-practitioners-and-community-pharmacists-a-qualitative-study
#3
Christin Löffler, Carolin Koudmani, Femke Böhmer, Susanne D Paschka, Jennifer Höck, Eva Drewelow, Martin Stremme, Bernd Stahlhacke, Attila Altiner
BACKGROUND: Despite numerous evidences for the positive effect of community pharmacists on health care, interprofessional collaboration of pharmacists and general practitioners is very often limited. Though highly trained, pharmacists remain an underutilised resource in primary health care in most western countries. This qualitative study aims at investigating pharmacists' and general practitioners' views on barriers to interprofessional collaboration in the German health care system...
March 21, 2017: BMC Health Services Research
https://www.readbyqxmd.com/read/28326779/illuminating-photochemistry-of-an-excitation-ratiometric-fluorescent-protein-calcium-biosensor
#4
Longteng Tang, Yanli Wang, Weimin Liu, Yongxin Zhao, Robert E Campbell, Chong Fang
Fluorescent protein (FP) based biosensors have become an important and promising tool to track metal ion movement inside living systems. Their working principles after light irradiation, however, remain elusive. To facilitate the rational design of biosensors, we dissect the fluorescence modulation mechanism of a newly developed excitation ratiometric green FP-based Ca(2+) biosensor, GEX-GECO1, using femtosecond stimulated Raman spectroscopy (FSRS) in the electronic excited state. Upon 400 nm photoexcitation, characteristic vibrational marker bands at ~1180 and 1300 cm(-1) show concomitant decay and rise dynamics, probing the progression of an ultrafast excited state proton transfer (ESPT) reaction...
March 22, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28325907/photosensitization-of-tio2-nanofibers-by-ag2s-with-the-synergistic-effect-of-excess-surface-ti-3-states-for-enhanced-photocatalytic-activity-under-simulated-sunlight
#5
Samina Ghafoor, Sadia Ata, Nasir Mahmood, Salman Noshear Arshad
TiO2 nanofibers, with mean diameter ~200 nm, were fabricated by electrospinning and successfully photosensitized with low bandgap Ag2S nanoparticles of 11, 17, 23 and 40 nm mean sizes, with corresponding loading of 4, 10, 18 and 29 wt.% Ag2S, respectively. 17 nm Ag2S@TiO2 nanofibers exhibited optimal activity in the photodegradation of methylene blue under simulated sunlight with pseudo-first order rate constant of 0.019 min(-1) compared to 0.009 min(-1) for pure TiO2 nanofibers. In spite of greater visible-light absorption and reduced bandgap, larger than 17 nm Ag2S nanoparticles exhibited sluggish photodegradation kinetics probably due to less photo-induced carriers generation in TiO2 and reduced electron injection rates from the larger sized Ag2S into TiO2...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28322540/a-rapid-recovery-double-crosslinking-hydrogel-with-stable-mechanical-properties-and-high-resilience-triggered-by-visible-light
#6
Longxiang Zhu, Jianhui Qiu, Eiichi Sakai, Kazushi Ito
The designed tough hydrogels, depending on energy dissipation mechanism, possess excellent biocompatibility, stimuli-responsiveness and outstanding mechanical properties. However, the application of hydrogels are greatly limited in actuators and sensors for the lack of instantaneous recovery and resilience. In this work, we synthesized a double crosslinking polyacrylic acid hydrogel via a simple, one-pot, visible-light-trigger polymerization, where carboxymethyl cellulose as initiator and the first cross-linker, N,N'-methylene bisacrylamide (MBA) as the second cross-linker...
March 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28322428/xenotransplantation-where-do-we-stand-in-2016
#7
Gisella L Puga Yung, Robert Rieben, Leo Bühler, Henk-Jan Schuurman, Jörg Seebach
Worldwide, there is a constant rise in the number of patients with end-stage organ failure in critical need for transplants, but the number of organs/cells available from deceased or living human donors is limited. Xenotransplantation using pig organs/tissues repre-sents a potential solution for this shortage; however, it has been hampered by a number of mainly immuno-logical hurdles. Remarkable progress was presented at the latest biennial (13th) international congress of the International Xenotransplantation Association, November 2015 in Melbourne, Australia, and the American Transplant Congress, May 2016 in Boston, USA...
March 21, 2017: Swiss Medical Weekly
https://www.readbyqxmd.com/read/28322307/bio-inspired-colorimetric-film-based-on-hygroscopic-coloration-of-longhorn-beetles-tmesisternus-isabellae
#8
Han-Bok Seo, Seung-Yop Lee
Structure-dependent colour is caused by the interaction of light with photonic crystal structures rather than pigments. The elytra of longhorn beetles Tmesisternus isabellae appear to be iridescent green in a dry state and turn to red when exposed to humidity. Based on the hygroscopic colouration of the longhorn beetle, we have developed centimeter-scale colorimetric opal films using a novel self-assembly method. The micro-channel assisted assembly technique adopts both natural evaporation and rotational forced drying, enhancing the surface binding of silica particles and the packing density by reducing the lattice constant and structural defects...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28320839/sleep-deprivation-and-caffeine-treatment-potentiate-photic-resetting-of-the-master-circadian-clock-in-a-diurnal-rodent
#9
Pawan Kumar Jha, Hanan Bouâouda, Sylviane Gourmelen, Stephanie Dumont, Fanny Fuchs, Yannick Goumon, Patrice Bourgin, Andries Kalsbeek, Etienne Challet
Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light-dark cycle. However, non-photic factors, such as behavioural arousal and metabolic cues, can also phase-shift the master clock in the suprachiasmatic nuclei (SCN) and/or reduce the synchronizing effects of light in nocturnal rodents. In diurnal rodents, the role of arousal or insufficient sleep in these functions is still poorly understood. In the present study, diurnal Sudanian grass rats, Arvicanthis ansorgei, were aroused at night by sleep deprivation (gentle handling) or caffeine treatment that both prevented sleep...
March 20, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28319615/dual-light-control-of-nanomachines-that-integrate-motor-and-modulator-subunits
#10
Justin T Foy, Quan Li, Antoine Goujon, Jean-Rémy Colard-Itté, Gad Fuks, Emilie Moulin, Olivier Schiffmann, Damien Dattler, Daniel P Funeriu, Nicolas Giuseppone
A current challenge in the field of artificial molecular machines is the synthesis and implementation of systems that can produce useful work when fuelled with a constant source of external energy. The first experimental achievements of this kind consisted of machines with continuous unidirectional rotations and translations that make use of 'Brownian ratchets' to bias random motions. An intrinsic limitation of such designs is that an inversion of directionality requires heavy chemical modifications in the structure of the actuating motor part...
March 20, 2017: Nature Nanotechnology
https://www.readbyqxmd.com/read/28314964/increased-intake-of-energy-dense-diet-and-negative-energy-balance-in-a-mouse-model-of-chronic-psychosocial-defeat
#11
Roberto Coccurello, Adele Romano, Giacomo Giacovazzo, Bianca Tempesta, Marco Fiore, Anna Maria Giudetti, Ilaria Marrocco, Fabio Altieri, Anna Moles, Silvana Gaetani
PURPOSE: Chronic exposure to stress may represent a risk factor for developing metabolic and eating disorders, mostly driven by the overconsumption of easily accessible energy-dense palatable food, although the mechanisms involved remain still unclear. In this study, we used an ethologically oriented murine model of chronic stress caused by chronic psychosocial defeat (CPD) to investigate the effects of unrestricted access to a palatable high fat diet (HFD) on food intake, body weight, energy homeostasis, and expression of different brain neuropeptides...
March 17, 2017: European Journal of Nutrition
https://www.readbyqxmd.com/read/28303390/the-hydroperoxide-lyase-branch-of-the-oxylipin-pathway-protects-against-photoinhibition-of-photosynthesis
#12
Tatyana Savchenko, Denis Yanykin, Andrew Khorobrykh, Vasily Terentyev, Vyacheslav Klimov, Katayoon Dehesh
This study describes a new role for hydroperoxide lyase branch of oxylipin biosynthesis pathway in protecting photosynthetic apparatus under high light conditions. Lipid-derived signaling molecules, oxylipins, produced by a multi-branch pathway are central in regulation of a wide range of functions. The two most known branches, allene oxide synthase (AOS) and 13-hydroperoxide lyase (HPL) pathways, are best recognized as producers of defense compounds against biotic challenges. In the present work, we examine the role of these two oxylipin branches in plant tolerance to the abiotic stress, namely excessive light...
March 16, 2017: Planta
https://www.readbyqxmd.com/read/28302870/relative-colour-cues-improve-colour-constancy-in-birds
#13
Peter Olsson, Almut Kelber
A ripe strawberry looks red to our eyes in sunlight and in the green light of a forest, although the spectrum of light reflected from its surface differs dramatically. This is caused by two effects, colour constancy, and our ability to learn relative colour cues: the ripe strawberry remains relatively "redder" than an unripe green strawberry. While colour constancy - the ability to recognize colours in shifted illumination - has been studied in many animals, the use of relative colour cues is investigated more rarely...
March 16, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28300754/effects-of-light-emitting-diode-irradiation-on-growth-characteristics-and-regulation-of-porphyrin-biosynthesis-in-rice-seedlings
#14
Lien Hong Tran, Sunyo Jung
We examined the effects of light quality on growth characteristics and porphyrin biosynthesis of rice seedlings grown under different wavelengths from light emitting diodes (LEDs). After 10 days of exposure to various wavelengths of LEDs, leaf area and shoot biomass were greater in seedlings grown under white and blue LEDs than those of green and red LEDs. Both green and red LED treatments drastically decreased levels of protoporphyrin IX (Proto IX) and Mg-porphyrins compared to those of white LED, while levels of Mg-Proto IX monomethyl ester and protochlorophyllide under blue LED were decreased by 21% and 49%, respectively...
March 16, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28298105/photoswitching-of-azobenzene-containing-self-assembled-monolayers-as-a-tool-for-control-over-silicon-surface-electronic-properties
#15
Ivan V Malyar, Evgenii Titov, Nino Lomadze, Peter Saalfrank, Svetlana Santer
We report on photoinduced remote control of work function and surface potential of a silicon surface modified with a photosensitive self-assembled monolayer consisting of chemisorbed azobenzene molecules (4-nitroazobenzene). It was found that the attachment of the organic monolayer increases the work function by hundreds of meV due to the increase in the electron affinity of silicon substrates. The change in the work function on UV light illumination is more pronounced for the azobenzene jacketed silicon substrate (ca...
March 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28298004/driven-optical-matter-dynamics-of-electrodynamically-coupled-nanoparticles-in-an-optical-ring-vortex
#16
Patrick Figliozzi, Nishant Sule, Zijie Yan, Ying Bao, Stanislav Burov, Stephen K Gray, Stuart A Rice, Suriyanarayanan Vaikuntanathan, Norbert F Scherer
To date investigations of the dynamics of driven colloidal systems have focused on hydrodynamic interactions and often employ optical (laser) tweezers for manipulation. However, the optical fields that provide confinement and drive also result in electrodynamic interactions that are generally neglected. We address this issue with a detailed study of interparticle dynamics in an optical ring vortex trap using 150-nm diameter Ag nanoparticles. We term the resultant electrodynamically interacting nanoparticles a driven optical matter system...
February 2017: Physical Review. E
https://www.readbyqxmd.com/read/28297026/biomechanical-changes-after-in-vivo-collagen-cross-linking-with-rose-bengal-green-light-and-riboflavin-uva
#17
Nandor Bekesi, Patricia Gallego-Muñoz, Lucía Ibarés-Frías, Pablo Perez-Merino, M Carmen Martinez-Garcia, Irene E Kochevar, Susana Marcos
Purpose: To compare corneal biomechanical properties after in vivo and ex vivo cross-linking (CXL) using rose bengal-green light (RGX) or riboflavin-UVA (UVX). Methods: Corneas of 30 rabbits were treated in vivo by the two CXL modalities monolaterally (Group 1) or bilaterally (Group 2). Rabbits in Group 1 were euthanized 1 month after treatments and in Group 2 two months after treatment. Ex vivo CXL was also performed. Eyes were measured by Scheimpflug air puff corneal deformation imaging (Corvis ST) under constant IOP...
March 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28295815/elucidating-the-interaction-of-clofazimine-with-bovine-liver-catalase-a-comprehensive-spectroscopic-and-molecular-docking-approach
#18
Masihuz Zaman, Saima Nusrat, Syed Mohammad Zakariya, Mohsin Vahid Khan, Mohammad Rehan Ajmal, Rizwan Hasan Khan
Nowadays, understanding of interface between protein and drugs has become an active research area of interest. These types of interactions provide structural guidelines in drug design with greater clinical efficacy. Thus, structural changes in catalase induced by clofazimine were monitored by various biophysical techniques including UV-visible spectrometer, fluorescence spectroscopy, circular dichroism, and dynamic light scattering techniques. Increase in absorption spectra (UV-visible spectrum) confers the complex formation between drug and protein...
March 14, 2017: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/28293952/higher-pedot-molecular-weight-giving-rise-to-higher-thermoelectric-property-of-pedot-pss-a-comparative-study-of-cleviostm-p-and-cleviostm-ph1000
#19
Zeng Fan, Donghe Du, Hongyan Yao, Jianyong Ouyang
Poly(3,4-ethylenedioxuthiphene):poly(styrenesulfonate) (PEDOT:PSS) is a promising candidate as the next-generation thermoelectric (TE) material. Its TE properties are strongly dependent on its chemical and electronic structures. In this paper, we investigated the effect of PEDOT molecular weight on the TE properties of PEDOT:PSS films by a comparative study on two commercial grades of PEDOT:PSS, CleviosTM P and CleviosTM PH1000. Dynamic light scattering (DLS) and Raman spectra imply that the PEDOT of CleviosTM PH1000 possesses longer conjugated chains than that of CleviosTM P...
March 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28290089/sonophotocatalytic-degradation-of-bisphenol-a-and-its-intermediates-with-graphitic-carbon-nitride
#20
Sharmini Sunasee, Kah Hon Leong, Kien Tiek Wong, Gooyong Lee, Saravanan Pichiah, InWook Nah, Byong-Hun Jeon, Yeomin Yoon, Min Jang
Since bisphenol A (BPA) exhibits endocrine disrupting action and high toxicity in aqueous system, there are high demands to remove it completely. In this study, the BPA removal by sonophotocatalysis coupled with nano-structured graphitic carbon nitride (g-C3N4, GCN) was conducted with various batch tests using energy-based advanced oxidation process (AOP) based on ultrasound (US) and visible light (Vis-L). Results of batch tests indicated that GCN-based sonophotocatalysis (Vis-L/US) had higher rate constants than other AOPs and especially two times higher degradation rate than TiO2-based Vis-L/US...
March 13, 2017: Environmental Science and Pollution Research International
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