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Wanle Sheng, Yayang Wu, Changjiang Yu, Petia Bobadova-Parvanova, Erhong Hao, Lijuan Jiao
Annularly fused azaBODIPY-based organic fluorophores (HBPs 2) containing up to 13 aromatic ring fusions were synthesized by a Suzuki coupling reaction with bromoazadipyrromethenes and a subsequent regioselective oxidative ring-fusion reaction. X-ray analysis indicates almost planar dipyrrin cores for all crystals but overall curved or "wave" conformations for those HBP dyes. These molecules exhibit unique structural and physical properties including excellent spectral selectivity (negligible absorption between 300 and 700 nm), sharp near-infrared (NIR) absorption (up to 878 nm) and emission (up to 907 nm), large extinction coefficient (up to 4...
April 18, 2018: Organic Letters
Victoria L Wright, Polymnia Georgiou, Alexis Bailey, David J Heal, Christopher P Bailey, Susan Wonnacott
Recurrent relapse is a major problem in treating opiate addiction. Pavlovian conditioning plays a role in recurrent relapse whereby exposure to cues learned during drug intake can precipitate relapse to drug taking. α7 nicotinic acetylcholine receptors (nAChRs) have been implicated in attentional aspects of cognition and mechanisms of learning and memory. In this study we have investigated the role of α7 nAChRs in morphine-conditioned place preference (morphine-CPP). CPP provides a model of associative learning that is pertinent to associative aspects of drug dependence...
April 17, 2018: Addiction Biology
Andreas Hoffmann, Kerstin Grassl, Janine Gommert, Christian Schlesak, Alexander Bepperling
The accurate determination of protein concentration is an important though non-trivial task during the development of a biopharmaceutical. The fundamental prerequisite for this is the availability of an accurate extinction coefficient. Common approaches for the determination of an extinction coefficient for a given protein are either based on the theoretical prediction utilizing the amino acid sequence or the photometric determination combined with a measurement of absolute protein concentration. Here, we report on an improved SV-AUC based method utilizing an analytical ultracentrifuge equipped with absorbance and Rayleigh interference optics...
April 17, 2018: European Biophysics Journal: EBJ
Rachael C Bible, A Townsend Peterson
OBJECTIVES: To assess ecological niche similarity for biological and archaeological samples representing late-surviving Neandertals in Europe to evaluate the validity of combining these two types of data in ecological niche modeling analyses. MATERIALS AND METHODS: Tests of niche conservatism were used to assess niche similarity and niche identity of samples of morphologically diagnostic Neandertal remains and Middle Paleolithic (MP) archaeological sites dating to the time period leading up to Neandertal extinction...
April 17, 2018: American Journal of Physical Anthropology
David J Castro, Isabel Cerezo, Inmaculada Sampedro, Fernando Martínez-Checa
Strain D15T was isolated from a soil sample taken from Rambla Salada (Murcia), south-eastern Spain, by using the dilution-to-extinction method. The strain, a Gram-stain-negative aerobic bacteria, is non-motile, ovoid- or rod-shaped, catalase- and oxidase-positive, and grows at NaCl concentrations within the range 0.5-10 % (w/v) [optimum 3 % (w/v)], at 5-30 °C (optimum 28 °C) and at pH 6-9 (optimum pH 7.0). The 16S rRNA gene sequence indicates that it belongs to the genus Roseovarius in the class Alphaproteobacteria...
April 17, 2018: International Journal of Systematic and Evolutionary Microbiology
Lindsay P Cameron, Charlie J Benson, Lee E Dunlap, David E Olson
Depression and anxiety disorders are debilitating diseases resulting in substantial economic costs to society. Traditional antidepressants often take weeks to months to positively affect mood and are ineffective for about 30% of the population. Alternatives, such as ketamine, a dissociative anesthetic capable of producing hallucinations, and the psychoactive tisane ayahuasca have shown great promise due to their fast-acting nature and effectiveness in treatment-resistant populations. Here, we investigate the effects of N,N-dimethyltryptamine (DMT), the principle hallucinogenic component of ayahuasca, in rodent behavioral assays relevant to anxiety and depression using adult, male, Sprague-Dawley rats...
April 17, 2018: ACS Chemical Neuroscience
Hai-Fei Yan, Cai-Yun Zhang, Arne A Anderberg, Gang Hao, Xue-Jun Ge, John J Wiens
What causes the disparity in biodiversity among regions is a fundamental question in biogeography, ecology, and evolutionary biology. Evolutionary and biogeographic processes (speciation, extinction, dispersal) directly determine species richness patterns, and can be studied using integrative phylogenetic approaches. However, the strikingly high richness of East Asia relative to other Northern Hemisphere regions remains poorly understood from this perspective. Here, for the first time, we test two general hypotheses (older colonization time, faster diversification rate) to explain this pattern, using the plant tribe Lysimachieae (Primulaceae) as a model system...
April 17, 2018: New Phytologist
Christoph Ratzke, Jonas Denk, Jeff Gore
The growth and survival of organisms often depend on interactions between them. In many cases, these interactions are positive and caused by a cooperative modification of the environment. Examples are the cooperative breakdown of complex nutrients in microbes or the construction of elaborate architectures in social insects, in which the individual profits from the collective actions of her peers. However, organisms can similarly display negative interactions by changing the environment in ways that are detrimental for them, for example by resource depletion or the production of toxic byproducts...
April 16, 2018: Nature Ecology & Evolution
Hanna Kokko
No abstract text is available yet for this article.
April 2018: Nature
Félix Forest, Justin Moat, Elisabeth Baloch, Neil A Brummitt, Steve P Bachman, Steffi Ickert-Bond, Peter M Hollingsworth, Aaron Liston, Damon P Little, Sarah Mathews, Hardeep Rai, Catarina Rydin, Dennis W Stevenson, Philip Thomas, Sven Buerki
Driven by limited resources and a sense of urgency, the prioritization of species for conservation has been a persistent concern in conservation science. Gymnosperms (comprising ginkgo, conifers, cycads, and gnetophytes) are one of the most threatened groups of living organisms, with 40% of the species at high risk of extinction, about twice as many as the most recent estimates for all plants (i.e. 21.4%). This high proportion of species facing extinction highlights the urgent action required to secure their future through an objective prioritization approach...
April 16, 2018: Scientific Reports
Massimo Bernardi, Piero Gianolla, Fabio Massimo Petti, Paolo Mietto, Michael J Benton
Dinosaurs diversified in two steps during the Triassic. They originated about 245 Ma, during the recovery from the Permian-Triassic mass extinction, and then remained insignificant until they exploded in diversity and ecological importance during the Late Triassic. Hitherto, this Late Triassic explosion was poorly constrained and poorly dated. Here we provide evidence that it followed the Carnian Pluvial Episode (CPE), dated to 234-232 Ma, a time when climates switched from arid to humid and back to arid again...
April 16, 2018: Nature Communications
Ronny N Gentry, Matthew R Roesch
Ventromedial prefrontal cortex (vmPFC) is thought to provide regulatory control over Pavlovian fear responses and has recently been implicated in appetitive approach behavior, but much less is known about its role in contexts where appetitive and aversive outcomes can be obtained and avoided, respectively. To address this issue, we recorded from single neurons in vmPFC while male rats performed our combined approach and avoidance task under reinforced and non-reinforced (extinction) conditions. Surprisingly, we found that cues predicting reward modulated cell firing in vmPFC more often and more robustly than cues preceding avoidable shock; additionally, firing of vmPFC neurons was both response (press or no-press) and outcome (reinforced or extinction) selective...
April 16, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Xuwu Chen, Xiaodong Li, Xingzhong Yuan, Guangming Zeng, Jie Liang, Xin Li, Wanjun Xu, Yuan Luo, Gaojie Chen
Both climate change and intensive human activities are thought to have contributed to the impairment of atmospheric visibility in Beijing. But the detailed processes involved and relative roles of human activities and climate change have not been quantified. Optical extinction of aerosols, the inverse of meteorological visibility is especially sensitive to fine particles <1.0 μm. These submicron particles are considered more hazardous than larger ones in terms of cardiovascular and respiratory diseases...
April 13, 2018: Environment International
Peter Vdacný
Trichostome ciliates are among the most conspicuous protists in the gastrointestinal tract of a large variety of vertebrates. However, little is still known about phylogeny of the trichostome/vertebrate symbiotic systems, evolutionary correlations between trichostome extrinsic traits, and character-dependent diversification of trichostomes. These issues were investigated here, using the relaxed molecular clock technique along with stochastic mapping of character evolution, and binary-state speciation and extinction models...
April 11, 2018: Molecular Biology and Evolution
Oleg V Ivanov, Elena V Maslova, Michael S Ignatov
Background and Aims: Protosphagnalean mosses constitute the largest group of extinct mosses of still uncertain affinity. Having the general morphology of the Bryopsida, some have leaves with an areolation pattern characteristic of modern Sphagna. This study describes the structure and variation of these patterns in protosphagnalean mosses and provides a comparison with those of modern Sphagna. Methods: Preparations of fossil mosses showing preserved leaf cell structure were obtained by dissolving rock, photographed, and the resulting images were transformed to graphical format and analysed with Areoana computer software...
April 11, 2018: Annals of Botany
Tiffany A Yap, Michelle S Koo, Richard F Ambrose, Vance T Vredenburg
Batrachochytrium dendrobatidis (Bd), a causal agent of the amphibian fungal skin disease chytridiomycosis, has been implicated in the decline and extinction of over 200 species worldwide since the 1970s. Despite almost two decades of research, the history of Bd and its global spread is not well understood. However, the spread of the Global Panzootic Lineage of Bd (Bd-GPL), the lineage associated with amphibian die-offs, has been linked with the American bullfrog (Rana [Aqurana] catesbeiana) and global trade...
2018: PloS One
Christopher Wolf, William J Ripple
Earth's terrestrial large carnivores form a highly endangered group of species with unique conservation challenges. The majority of these species have experienced major geographical range contractions, which puts many of them at high risk of extinction or of becoming ecologically ineffective. As a result of these range contractions and the associated loss of intact predator guilds, the ecological effects of these species are now far less widespread and common, with inevitable consequences for ecosystem function...
March 2018: Royal Society Open Science
V Fischer, R B J Benson, P S Druckenmiller, H F Ketchum, N Bardet
Polycotylidae is a clade of plesiosaurians that appeared during the Early Cretaceous and became speciose and abundant early in the Late Cretaceous. However, this radiation is poorly understood. Thililua longicollis from the Middle Turonian of Morocco is an enigmatic taxon possessing an atypically long neck and, as originally reported, a series of unusual cranial features that cause unstable phylogenetic relationships for polycotylids. We reinterpret the holotype specimen of Thililua longicollis and clarify its cranial anatomy...
March 2018: Royal Society Open Science
Alessandro Palci, Mark N Hutchinson, Michael W Caldwell, John D Scanlon, Michael S Y Lee
Madtsoiids are among the most basal snakes, with a fossil record dating back to the Upper Cretaceous (Cenomanian). Most representatives went extinct by the end of the Eocene, but some survived in Australia until the Late Cenozoic. Yurlunggur and Wonambi are two of these late forms, and also the best-known madtsoiids to date. A better understanding of the anatomy and palaeoecology of these taxa may shed light on the evolution and extinction of this poorly known group of snakes and on early snake evolution in general...
March 2018: Royal Society Open Science
Gabriel S Ferreira, Mario Bronzati, Max C Langer, Juliana Sterli
Pleurodires or side-necked turtles are today restricted to freshwater environments of South America, Africa-Madagascar and Australia, but in the past they were distributed much more broadly, being found also on Eurasia, India and North America, and marine environments. Two hypotheses were proposed to explain this distribution; in the first, vicariance would have shaped the current geographical distribution and, in the second, extinctions constrained a previously widespread distribution. Here, we aim to reconstruct pleurodiran biogeographic history and diversification patterns based on a new phylogenetic hypothesis recovered from the analysis of the largest morphological dataset yet compiled for the lineage, testing which biogeographical process prevailed during its evolutionary history...
March 2018: Royal Society Open Science
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