keyword
MENU ▼
Read by QxMD icon Read
search

Energetics

keyword
https://www.readbyqxmd.com/read/28433833/in-vitro-antitumor-activity-metal-uptake-and-reactivity-with-ascorbic-acid-and-bsa-of-some-gold-iii-complexes-with-n-n-ethylenediamine-bidentate-ester-ligands
#1
Nebojša Pantelić, Bojana B Zmejkovski, Branka Kolundžija, Marija Đorđić Crnogorac, Jelena M Vujić, Biljana Dojčinović, Srećko R Trifunović, Tatjana P Stanojković, Tibor J Sabo, Goran N Kaluđerović
Four novel gold(III) complexes of general formulae [AuCl2{(S,S)-R2eddl}]PF6 (R2eddl=O,O'-dialkyl-(S,S)-ethylenediamine-N,N'-di-2-(4-methyl)pentanoate, R=n-Pr, n-Bu, n-Pe, i-Bu; 1-4, respectively), were synthesized and characterized by elemental analysis, UV/Vis, IR, and NMR spectroscopy, as well as high resolution mass spectrometry. Density functional theory calculations pointed out that (R,R)-N,N'-configuration diastereoisomers were energetically the most favorable. Duo to high cytotoxic activity complex 3 was chosen for stability study in DMSO, no decomposition occurs within 24h, and for the reaction with ascorbic acid in which was reduced immediately...
April 4, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28433468/environmental-structure-and-energetic-consequences-in-groups-of-young-mice
#2
Delia S Shelton, Paul M Meyer, Karen M Ocasio
Microenvironments can have considerable physiological consequences for the inhabitants by influencing the movements of individual members. The microenvironment can permit more diverse aggregation patterns or restrict movements to certain dimensions. Here, we tested whether aspects of the microenvironment that influenced aggregation patterns also influenced the energetics of groups of young animals. We tested the effects of enclosure configuration on the group temperature and respiration of infant mice (Mus musculus)...
April 19, 2017: Physiology & Behavior
https://www.readbyqxmd.com/read/28433027/potential-of-mean-force-for-insertion-of-antimicrobial-peptide-melittin-into-a-pore-in-mixed-dopc-dopg-lipid-bilayer-by-molecular-dynamics-simulation
#3
Yuan Lyu, Ning Xiang, Xiao Zhu, Ganesan Narsimhan
Antimicrobial peptides (AMPs) inactivate microorganisms by forming transmembrane pores in a cell membrane through adsorption and aggregation. Energetics of addition of an AMP to a transmembrane pore is important for evaluation of its formation and growth. Such information is essential for the characterization of pore forming ability of peptides in cell membranes. This study quantifies the potential of mean force through molecular dynamics (MD) simulation for the addition of melittin, a naturally occurring AMP, into a DOPC/DOPG mixed bilayer, a mimic of bacterial membrane, for different extents of insertion into either a bilayer or a pore consisting of three to six transmembrane peptides...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28433025/a-combined-theoretical-and-experimental-study-of-phenol-acetylene-n-n-%C3%A2-7-clusters
#4
Gurmeet Singh, Apurba Nandi, Shridhar R Gadre, Takashi Chiba, Asuka Fujii
Structures and vibrational spectra of phenol-(acetylene)n (Ph(Ac)n) clusters are studied by a combination of theoretical calculations and infrared (IR) spectroscopy. The molecular electrostatic potential features are utilized for generating trial geometries of the medium-sized Ph(Ac)n (n = 1, 2, 4, 6, and 7) clusters. These initial geometries are subjected to geometry optimization within the second-order Møller-Plesset (MP2) theory, employing correlation consistent aug-cc-pVDZ (aVDZ) basis set. Minimal nature of the reported structures is confirmed by doing vibrational frequency run at MP2/aVDZ level of theory using full calculations for n = 1 and 2 and employing grafting based molecular tailoring approach for the n = 4, 6, and 7...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28433021/to-kink-or-not-a-search-for-long-chain-cumulenones-using-microwave-spectral-taxonomy
#5
Michael C McCarthy, Luyao Zou, Marie-Aline Martin-Drumel
A systematic search for carbon-chain cumulenones beyond H2C4O has been undertaken using microwave spectral taxonomy in combination with a pulsed jet discharge source. No evidence was found for the C2υ isomer of H2C5O or its longer derivatives, but HC(O)C4H, the longer variant of propynal, HC(O)CCH, was identified instead. Its rotational and leading centrifugal distortion constants have been derived to high accuracy from detection of both a- and b-type lines; those below 40 GHz were measured using a Fabry-Perot cavity, while lines between 40 and 72 GHz were recorded by double resonance techniques...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28433010/about-the-nature-of-halogen-bond-interaction-under-the-spatial-confinement
#6
Agnieszka Roztoczyńska, Paweł Lipkowski, Justyna Kozłowska, Wojciech Bartkowiak
Nowadays, much attention is put toward the description of noncovalent complexes exposed to the high pressure or embedded in confining environments. Such conditions may strongly modify the physical and chemical properties of molecular systems. This study focuses on the theoretical description of the confinement induced changes in geometry and energetic parameters of the halogen bonded FCl⋯CNF complex. A model analytical potential is applied to render the effect of orbital compression. In order to analyze the nature of halogen bond interaction, in the presence of spatial confinement, the supermolecular approach together with the symmetry-adapted perturbation theory is used...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28432960/molecular-dynamic-simulations-on-tkx-50-rdx-cocrystal
#7
Shuling Xiong, Shusen Chen, Shaohua Jin
Dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) is a newly synthesized energetic material with excellent comprehensive properties. Cyclotrimethylenetrinitramine (RDX) is currently one of the most widely used energetic materials in the world. TKX-50 and RDX supercell models and TKX-50/RDX cocrystal model were constructed based on their crystal cell parameters and the formation mechanism of cocrystal, respectively, then they were simulated by molecular dynamics (MD) simulations. The maximum trigger bond (NNO2) length(Lmax), binding energy (Ebind), radial distribution function (RDF), cohesive energy density(CED) and mechanical properties were simulated at different temperatures based on the simulated equilibrium structures of the models...
March 19, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28432814/do-males-choose-their-mates-in-the-lekking-moth-achroia-grisella-influence-of-female-body-mass-and-male-reproductive-status-on-male-mate-choice
#8
Marlène Goubault, Rebecca Burlaud
Lekking males aggregate to attract females and contribute solely to egg fertilization, without any further parental care. Evolutionary theory therefore predicts them to be non-choosy towards their mates, because any lost mating opportunities would outweigh the benefits associated with such preferences. Nevertheless, due to time costs, the production of energetically costly sexual displays, and potential sperm limitation, the mating effort of lekking males is often considerable. These factors, combined with the fact that many females of varying quality are likely to visit leks, could favor the evolution of male mate preferences...
April 22, 2017: Insect Science
https://www.readbyqxmd.com/read/28432486/cholesterol-as-a-modifying-agent-of-the-neurovascular-unit-structure-and-function-under-physiological-and-pathological-conditions
#9
REVIEW
Ewelina Czuba, Aleksandra Steliga, Grażyna Lietzau, Przemysław Kowiański
The brain, demanding constant level of cholesterol, precisely controls its synthesis and homeostasis. The brain cholesterol pool is almost completely separated from the rest of the body by the functional blood-brain barrier (BBB). Only a part of cholesterol pool can be exchanged with the blood circulation in the form of the oxysterol metabolites such, as 27-hydroxycholesterol (27-OHC) and 24S-hydroxycholesterol (24S-OHC). Not only neurons but also blood vessels and neuroglia, constituting neurovascular unit (NVU), are crucial for the brain cholesterol metabolism and undergo precise regulation by numerous modulators, metabolites and signal molecules...
April 21, 2017: Metabolic Brain Disease
https://www.readbyqxmd.com/read/28432465/ppar%C3%AE-activation-regulates-lipid-droplet-formation-and-lactate-production-in-rat-sertoli-cells
#10
A Gorga, G M Rindone, M Regueira, E H Pellizzari, M C Camberos, S B Cigorraga, M F Riera, M N Galardo, S B Meroni
Sertoli cells provide the structural and nutritional support for germ cell development; they actively metabolize glucose and convert it to lactate, which is an important source of energy for germ cells. Furthermore, Sertoli cells can oxidize fatty acids, a metabolic process that is assumed to fulfill their own energy requirements. Fatty acids are stored as triacylglycerides within lipid droplets. The regulation of fatty acid storage in conjunction with the regulation of lactate production may thus be relevant to seminiferous tubule physiology...
April 21, 2017: Cell and Tissue Research
https://www.readbyqxmd.com/read/28432324/optimization-of-amino-acid-replacement-costs-by-mutational-pressure-in-bacterial-genomes
#11
Paweł Błażej, Dorota Mackiewicz, Małgorzata Grabińska, Małgorzata Wnętrzak, Paweł Mackiewicz
Mutations are considered a spontaneous and random process, which is important component of evolution because it generates genetic variation. On the other hand, mutations are deleterious leading to non-functional genes and energetically costly repairs. Therefore, one can expect that the mutational pressure is optimized to simultaneously generate genetic diversity and preserve genetic information. To check if empirical mutational pressures are optimized in these ways, we compared matrices of nucleotide mutation rates derived from bacterial genomes with their best possible alternatives that minimized or maximized costs of amino acid replacements associated with differences in their physicochemical properties (e...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28432304/decreasing-temperature-enhances-the-formation-of-sixfold-hydrogen-bonded-rings-in-water-rich-water-methanol-mixtures
#12
Imre Bakó, László Pusztai, László Temleitner
The evolution of the structure of liquid water-methanol mixtures as a function of temperature has been studied by molecular dynamics simulations, with a focus on hydrogen bonding. The combination of the OPLS-AA (all atom) potential model of methanol and the widely used SPC/E water model has provided excellent agreement with measured X-ray diffraction data over the temperature range between 298 and 213 K, for mixtures with methanol molar fractions of 0.2, 0.3 and 0.4. Hydrogen bonds (HB-s) have been identified via a combined geometric/energetic, as well as via a purely geometric definition...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28432117/control-of-muscle-metabolism-by-the-mediator-complex
#13
Leonela Amoasii, Eric N Olson, Rhonda Bassel-Duby
Exercise represents an energetic challenge to whole-body homeostasis. In skeletal muscle, exercise activates a variety of signaling pathways that culminate in the nucleus to regulate genes involved in metabolism and contractility; however, much remains to be learned about the transcriptional effectors of exercise. Mediator is a multiprotein complex that links signal-dependent transcription factors and other transcriptional regulators with the basal transcriptional machinery, thereby serving as a transcriptional "hub...
April 21, 2017: Cold Spring Harbor Perspectives in Medicine
https://www.readbyqxmd.com/read/28432097/diazotrophy-overcomes-the-deleterious-growth-phenotype-of-glne-deletion-in-azotobacter-vinelandii
#14
Florence Mus, Alex Tseng, Ray Dixon, John W Peters
Overcoming the inhibitory effects of excess environmental ammonium on nitrogenase synthesis or activity, or preventing ammonium assimilation, have both been considered as strategies to increase the amount of fixed nitrogen transferred from bacterial to plant partners in associative or symbiotic plant-diazotroph relationships. The GlnE adenylyltransferase/adenylyl-removing enzyme catalyzes reversible adenylylation of glutamine synthetase (GS), thereby affecting the post translational regulation of ammonium assimilation critical for appropriate coordination of carbon and nitrogen assimilation...
April 21, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28431764/seasonal-monitoring-of-blue-mussel-mytilus-spp-populations-in-a-harbor-area-a-focus-on-responses-to-environmental-factors-and-chronic-contamination
#15
C Lacroix, E Duvieilbourg, N Guillou, J Guyomarch, C Bassoulet, D Moraga, G Chapalain, M Auffret
Coastal waters corresponding to macrotidal systems are among the most variable marine biotopes. Sessile animals as bivalve mollusks may however be found forming intertidal beds at high densities, as allowed by full adaptation to local conditions. A better knowledge of adaptive responses to environmental factors is required to foresee possible adverse effects of global change. At the sub-cellular level, transcriptional responses are among the earliest signals of environmental disturbances and they can reveal subtle and meaningful changes in organism exposed to stress...
April 12, 2017: Marine Environmental Research
https://www.readbyqxmd.com/read/28431748/a-benchtop-biorobotic-platform-for-in-vitro-observation-of-muscle-tendon-dynamics-with-parallel-mechanical-assistance-from-an-elastic-exoskeleton
#16
Benjamin D Robertson, Siddarth Vadakkeveedu, Gregory S Sawicki
We present a novel biorobotic framework comprised of a biological muscle-tendon unit (MTU) mechanically coupled to a feedback controlled robotic environment simulation that mimics in vivo inertial/gravitational loading and mechanical assistance from a parallel elastic exoskeleton. Using this system, we applied select combinations of biological muscle activation (modulated with rate-coded direct neural stimulation) and parallel elastic assistance (applied via closed-loop mechanical environment simulation) hypothesized to mimic human behavior based on previously published modeling studies...
March 21, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28430414/dynamic-and-energetic-signatures-of-adenine-tracts-in-a-ra-dt-rna-dna-hybrid-and-in-homologous-rna-dna-rna-rna-and-dna-dna-double-helices
#17
Yuegao Huang, Irina M Russu
Nuclear magnetic resonance spectroscopy and proton exchange are being used to characterize the opening reactions of individual base pairs in the RNA-DNA hybrid 5'-rGCGAUAAAAAGGCC-3'/5'-dGGCCTTTTTATCGC-3'. The hybrid contains a central tract of five rA-dT base pairs. The rates and the equilibrium constant of the opening reaction for each base pair are determined from the dependence of the exchange rates of imino protons on ammonia concentration, at 10°C. The results are compared to those previously obtained by our laboratory for three homologous duplexes of the same base sequence (except for the appropriate T/U substitution), containing tracts of dA-rU, rA-rU or dA-dT base pairs...
April 21, 2017: Biochemistry
https://www.readbyqxmd.com/read/28430263/energetic-materials-identification-by-laser-induced-breakdown-spectroscopy-combined-with-artificial-neural-network
#18
Amir Hossein Farhadian, Masoud Kavosh Tehrani, Mohammad Hossein Keshavarz, Seyyed Mohammad Reza Darbani
In this study, for the first time to the best of our knowledge, a combination of the laser-induced breakdown spectroscopy (LIBS) technique and artificial neural network (ANN) analysis has been implemented for the identification of energetic materials, including TNT, RDX, black powder, and propellant. Also, aluminum, copper, inconel, and graphite have been used for more accurate investigation and comparison. After the LIBS test and spectrum acquisition on all samples in both air and argon ambient, optimized neural networks were designed by LIBS data...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430190/tuning-underwater-adhesion-with-cation-%C3%AF-interactions
#19
Matthew A Gebbie, Wei Wei, Alex M Schrader, Thomas R Cristiani, Howard A Dobbs, Matthew Idso, Bradley F Chmelka, J Herbert Waite, Jacob N Israelachvili
Cation-π interactions drive the self-assembly and cohesion of many biological molecules, including the adhesion proteins of several marine organisms. Although the origin of cation-π bonds in isolated pairs has been extensively studied, the energetics of cation-π-driven self-assembly in molecular films remains uncharted. Here we use nanoscale force measurements in combination with solid-state NMR spectroscopy to show that the cohesive properties of simple aromatic- and lysine-rich peptides rival those of the strong reversible intermolecular cohesion exhibited by adhesion proteins of marine mussel...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28429170/comparison-of-energy-balance-between-two-different-sized-groups-of-japanese-macaques-macaca-fuscata-yakui
#20
Yosuke Kurihara, Goro Hanya
Quantifying the energy balance is essential for testing socio-ecological models. To reveal costs and benefits of group living in Japanese macaques from the perspective of feeding competition, Kurihara and Hanya (Am J Primatol 77:986-1000, 2015) previously compared feeding behavior between two different-sized groups of macaques (larger group 30-35 individuals; smaller group 13-15 individuals) in the coastal forest of Yakushima, Japan. The results suggested that the larger group exhibited greater feeding effort because of intragroup scramble competition and that the smaller group suffered from higher travel costs, possibly owing to intergroup contest competition...
April 20, 2017: Primates; Journal of Primatology
keyword
keyword
7988
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"