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https://www.readbyqxmd.com/read/28241026/acute-hypoxia-diminishes-the-relationship-between-blood-pressure-and-subarachnoid-space-width-oscillations-at-the-human-cardiac-frequency
#1
Magdalena Wszedybyl-Winklewska, Jacek Wolf, Ewa Swierblewska, Katarzyna Kunicka, Agnieszka Gruszecka, Marcin Gruszecki, Wieslawa Kucharska, Pawel J Winklewski, Joanna Zabulewicz, Wojciech Guminski, Michal Pietrewicz, Andrzej F Frydrychowski, Leszek Bieniaszewski, Krzysztof Narkiewicz
BACKGROUND: Acute hypoxia exerts strong effects on the cardiovascular system. Heart-generated pulsatile cerebrospinal fluid motion is recognised as a key factor ensuring brain homeostasis. We aimed to assess changes in heart-generated coupling between blood pressure (BP) and subarachnoid space width (SAS) oscillations during hypoxic exposure. METHODS: Twenty participants were subjected to a controlled decrease in oxygen saturation (SaO2 = 80%) for five minutes. BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography, oxyhaemoglobin saturation with an ear-clip sensor, end-tidal CO2 with a gas analyser, and cerebral blood flow velocity (CBFV), pulsatility and resistive indices with Doppler ultrasound...
2017: PloS One
https://www.readbyqxmd.com/read/28240953/cardiorespiratory-function-in-thoroughbreds-during-locomotion-on-a-treadmill-at-an-incline-or-decline
#2
Hajime Ohmura, Kazutaka Mukai, Toshiyuki Takahashi, Hiroko Aida, James H Jones
OBJECTIVE To determine cardiorespiratory responses of Thoroughbreds to uphill and downhill locomotion on a treadmill at identical gradients. ANIMALS 5 highly trained Thoroughbred geldings. PROCEDURES Thoroughbreds were exercised for 2-minute intervals on a treadmill at 1.7, 3.5, 6.0, 8.0, and 10.0 m/s at a 4% incline, 0% incline (horizontal plane), and 4% decline in random order on different days. Stride frequency, stride length, and cardiopulmonary and O2-transport variables were measured and analyzed by means of repeated-measures ANOVA and Holm-Šidák pairwise comparisons...
March 2017: American Journal of Veterinary Research
https://www.readbyqxmd.com/read/28240874/accurate-evaluation-of-the-dispersion-energy-in-the-simulation-of-gas-adsorption-into-porous-zeolites
#3
Alberto Fraccarollo, Lorenzo Canti, Leonardo Marchese, Maurizio Cossi
The force fields used to simulate the gas adsorption in porous materials are strongly dominated by the van der Waals terms: here we discuss the delicate problem to estimate these terms accurately, analyzing the effect of different models. To this end, we simulated the physisorption of several gases (CH4, CO2, Ar and hexane) into various Al-free microporous zeolites (ITQ-29, SSZ-13, silicalite-1 and Y), comparing the theoretical results with accurate experimental isotherms. The van der Waals (vdW) terms in the force fields were parameterized against the free gas densities and high level quantum mechanical (QM) calculations, comparing different methods to evaluate the dispersion energies...
February 27, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28240707/comparison-of-different-methods-for-the-swimming-aerobic-capacity-evaluation
#4
Jailton Gregório Pelarigo, Ricardo Jorge Fernandes, João Ribeiro, Benedito Sérgio Denadai, Camila Coelho Greco, João Paulo Vilas-Boas
This study compared velocity (v) and bioenergetical factors using different methods applied for the swimming aerobic capacity evaluation. Ten elite female swimmers (17.6 ± 1.9 yrs., 1.70 ± 0.05 m and 61.3 ± 5.8 kg) performed an intermittent incremental velocity protocol until voluntary exhaustion to determine the v associated to the individual anaerobic threshold (IAnT), ventilatory threshold (VT), heart rate threshold (HRT), lactate threshold fixed in 3.5 mmol.L (LT3.5) and maximal oxygen uptake (V[Combining Dot Above]O2max)...
February 23, 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28240413/formation-of-gas-phase-formate-in-thermal-reactions-of-carbon-dioxide-with-diatomic-iron-hydride-anions
#5
Li-Xue Jiang, Chongyang Zhao, Xiao-Na Li, Hui Chen, Sheng-Gui He
The hydrogenation of carbon dioxide involves the activation of the thermodynamically very stable molecule CO2 and formation of a C-H bond. Herein, we report that HCO2(-) and CO can be formed in the thermal reaction of CO2 with a diatomic metal hydride species, FeH(-) . The FeH(-) anions were produced by laser ablation, and the reaction with CO2 was analyzed by mass spectrometry and quantum-chemical calculations. Gas-phase HCO2(-) was observed directly as a product, and its formation was predicted to proceed by facile hydride transfer...
February 27, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28240403/an-intramolecular-silylene-borane-capable-of-facile-activation-of-small-molecules-including-metal-free-dehydrogenation-of-water
#6
Zhenbo Mo, Tibor Szilvási, Yu-Peng Zhou, Shenglai Yao, Matthias Driess
The first single-component N-heterocyclic silylene borane 1 (LSi-R-BMes2 ; L=PhC(N(t) Bu)2 ; R=1,12-xanthendiyl spacer; Mes=2,4,6-Me3 C6 H2 ), acting as a frustrated Lewis pair (FLP) in small-molecule activation, can be synthesized in 65 % yields. Its HOMO is largely localized at the silicon(II) atom and the LUMO has mainly boron 2p character. In small-molecule activation 1 allows access to the intramolecular silanone-borane 3 featuring a Si=O→B interaction through reaction with O2 , N2 O, or CO2 , and formation of silanethione borane 4 from reaction with S8 ...
February 27, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28240391/au-sub-nanoclusters-on-tio2-toward-highly-efficient-and-selective-electrocatalyst-for-n2-conversion-to-nh3-at-ambient-conditions
#7
Miao-Miao Shi, Di Bao, Ba-Ri Wulan, Yong-He Li, Yue-Fei Zhang, Jun-Min Yan, Qing Jiang
As the NN bond in N2 is one of the strongest bonds in chemistry, the fixation of N2 to ammonia is a kinetically complex and energetically challenging reaction and, up to now, its synthesis is still heavily relying on energy and capital intensive Haber-Bosch process (150-350 atm, 350-550 °C), wherein the input of H2 and energy are largely derived from fossil fuels and thus result in large amount of CO2 emission. In this paper, it is demonstrated that by using Au sub-nanoclusters (≈0.5 nm ) embedded on TiO2 (Au loading is 1...
February 27, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28240369/growth-reduction-after-defoliation-is-independent-of-co2-supply-in-deciduous-and-evergreen-young-oaks
#8
Sandra Schmid, Sara Palacio, Günter Hoch
Reduced productivity of trees after defoliation might be caused by limited carbon (C) availability. We investigated the combined effect of different atmospheric CO2 concentrations (160, 280 and 560 ppm) and early season defoliation on the growth and C reserves (nonstructural carbohydrates (NSC)) of saplings of two oak species with different leaf habits (deciduous Quercus petraea and evergreen Quercus ilex). In both species, higher CO2 supply significantly enhanced growth. Defoliation had a strong negative impact on growth (stronger for Q...
February 27, 2017: New Phytologist
https://www.readbyqxmd.com/read/28240022/the-role-of-the-freight-sector-in-future-climate-change-mitigation-scenarios
#9
Matteo Muratori, Steven J Smith, G Page Kyle, Robert Link, Bryan K Mignone, Haroon S Kheshgi
The freight sector's role is examined using the Global Change Assessment Model (GCAM) for a range of climate change mitigation scenarios and future freight demand assumptions. Energy usage and CO2 emissions from freight have historically grown with a correlation to GDP, and there is limited evidence of near-term global decoupling of freight demand from GDP. Over the 21st century, greenhouse gas (GHG) emissions from freight are projected to grow faster than passenger transportation or other major end-use sectors, with the magnitude of growth dependent on the assumed extent of long-term decoupling...
February 27, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28240011/enhancing-effects-of-curcumin-on-cytotoxicity-of-paclitaxel-methotrexate-and-vincristine-in-gastric-cancer-cells
#10
Meysam Ebrahimifar, Majid Hasanzadegan Roudsari, S Maryam Kazemi, Hasan Ebrahimi Shahmabadi, Leila Kanaani, S A Alavi, Mehdi Izadi Vasfi
Curcumin (Diferuloylmethane), a polyphenolic compound with antioxidant, anti-inflammatory and anticancer properties, has been found to increase chemotherapeutic agents-induced cytotoxicity in some resistant cancer cell lines. This investigation aimed to study the effects of curcumin on efficacy of some common anticancer agents in gastric cancer cells. AGS cells were cultured in RPMI-1640 medium under standard culture conditions (5% CO2 and 95% humidified air at 37°C). Curcumin was used at concentrations of 5, 15, 30 and 50 μM...
1, 2017: Asian Pacific Journal of Cancer Prevention: APJCP
https://www.readbyqxmd.com/read/28239971/characterization-of-n-methylated-amino-acids-by-gc-ms-after-ethyl-chloroformate-derivatization
#11
B Sudarshana Reddy, V Naresh Chary, P Pavankumar, S Prabhakar
Methylation is an essential metabolic process in the biological systems, and it is significant for several biological reactions in living organisms. Methylated compounds are known to be involved in most of the bodily functions, and some of them serve as biomarkers. Theoretically, all α-amino acids can be methylated, and it is possible to encounter them in most animal/plant samples. But the analytical data, especially the mass spectral data, are available only for a few of the methylated amino acids. Thus, it is essential to generate mass spectral data and to develop mass spectrometry methods for the identification of all possible methylated amino acids for future metabolomic studies...
August 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28239970/atmospheric-pressure-chemical-ionization-of-explosives-induced-by-soft-x-radiation-in-ion-mobility-spectrometry-mass-spectrometric-investigation-of-the-ionization-reactions-of-drift-gasses-dopants-and-alkyl-nitrates
#12
Daniel Riebe, Alexander Erler, Thomas Ritschel, Toralf Beitz, Hans-Gerd Löhmannsröben, Andreas Beil, Michael Blaschke, Thomas Ludwig
A promising replacement for the radioactive sources commonly encountered in ion mobility spectrometers is a miniaturized, energy-efficient photoionization source that produce the reactant ions via soft X-radiation (2.8 keV). In order to successfully apply the photoionization source, it is imperative to know the spectrum of reactant ions and the subsequent ionization reactions leading to the detection of analytes. To that end, an ionization chamber based on the photoionization source that reproduces the ionization processes in the ion mobility spectrometer and facilitates efficient transfer of the product ions into a mass spectrometer was developed...
August 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28239750/light-and-laser-treatment-modalities-for-disseminated-superficial-actinic-porokeratosis-a-systematic-review
#13
Gregory A Aird, Jenna L Sitenga, Austin Huy Nguyen, Adam Vaudreuil, Christopher J Huerter
Treatment of disseminated superficial actinic porokeratosis (DSAP) is poorly standardized. The present review seeks to comprehensively discuss the potential for laser and light modalities in the treatment of DSAP. A systematic review of light and laser treatment modalities was conducted to include 26 cases of patients with DSAP. Systematic review resulted in 14 articles to be included. Photodynamic therapy (PDT) overall was the least successful treatment modality, with clinical improvement seen in a minority of patients (MAL-PDT: N = 9 patients, 33...
February 27, 2017: Lasers in Medical Science
https://www.readbyqxmd.com/read/28239732/catalytic-decomposition-and-mechanism-of-formaldehyde-over-pt-al2o3-molecular-sieves-at-room-temperature
#14
Xiaofeng Zhu, Jiaguo Yu, Chuanjia Jiang, Bei Cheng
To overcome the drawbacks of powder-like catalysts in practical application, an Al2O3 molecular sieve supported Pt (Pt-Al2O3) catalyst was prepared by the impregnation method combined with dilute hydrochloric acid solution pretreatment. The role of the pretreatment solution in catalyst preparation and formaldehyde (HCHO) decomposition over Pt-Al2O3 catalysts was investigated. The acid solution with pH = 1 was optimal for Pt dispersion on the Al2O3 surface. The Pt-Al2O3 catalyst was capable of achieving complete and stable HCHO oxidation at ambient temperature...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239405/long-term-intake-of-saccharin-decreases-post-absortive-energy-expenditure-at-rest-and-is-associated-to-greater-weight-gain-relative-to-sucrose-in-wistar-rats
#15
Denise Entrudo Pinto, Kelly Carraro Foletto, Ramiro Barcos Nunes, Pedro Dal Lago, Marcello Casaccia Bertoluci
BACKGROUND: Non-nutritive sweeteners (NNS) have been associated with increased prevalence of obesity. In previous studies, we demonstrated that saccharin could induce an increase in weight gain either when compared to sucrose or to a non-sweetened control at a similar total caloric intake. These data raised the hypothesis that reduced energy expenditure (EE) could be a potential mechanism explaining greater weight gain with saccharin use in rats. The aim of the present study was to compare long-term energy expenditure at rest between rats using saccharin or sucrose and correlate it with weight gain...
2017: Nutrition & Metabolism
https://www.readbyqxmd.com/read/28239149/timing-and-nature-of-amoc-recovery-across-termination-2-and-magnitude-of-deglacial-co2-change
#16
Emily L Deaney, Stephen Barker, Tina van de Flierdt
Large amplitude variations in atmospheric CO2 were associated with glacial terminations of the Late Pleistocene. Here we provide multiple lines of evidence suggesting that the ∼20 p.p.m.v. overshoot in CO2 at the end of Termination 2 (T2) ∼129 ka was associated with an abrupt (≤400 year) deepening of Atlantic Meridional Overturning Circulation (AMOC). In contrast to Termination 1 (T1), which was interrupted by the Bølling-Allerød (B-A), AMOC recovery did not occur until the very end of T2, and was characterized by pronounced formation of deep waters in the NW Atlantic...
February 27, 2017: Nature Communications
https://www.readbyqxmd.com/read/28238511/comparison-of-the-anion-inhibition-profiles-of-the-%C3%AE-and-%C3%AE-carbonic-anhydrases-from-the-pathogenic-bacterium-burkholderia-pseudomallei
#17
Sonia Del Prete, Daniela Vullo, Pietro di Fonzo, Vincenzo Carginale, Claudiu T Supuran, Clemente Capasso
We report the cloning, purification and characterization of BpsβCA, a β-class carbonic anhydrase (CA, EC 4.2.1.1) from the pathogenic bacterium Burkholderia pseudomallei, the etiological agent of melioidosis, and compare its activity and inhibition with those of the γ-CA from the same organism, BpsγCA, recently investigated by our groups. BpsβCA showed a significant catalytic activity for the physiologic, CO2 hydration reaction, with the following kinetic parameters, kcat of 1.6×10(5)s(-1) and kcat/Km of 3...
February 16, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28238477/cardiac-rehabilitation-after-acute-coronary-syndrome-do-all-patients-derive-the-same-benefit
#18
Sílvia Aguiar Rosa, Ana Abreu, Rui Marques Soares, Pedro Rio, Custódia Filipe, Inês Rodrigues, André Monteiro, Cristina Soares, Vítor Ferreira, Sofia Silva, Sandra Alves, Rui Cruz Ferreira
INTRODUCTION: Cardiac rehabilitation (CR) has been demonstrated to improve exercise capacity in acute coronary syndrome (ACS), but not all patients derive the same benefit. Careful patient selection is crucial to maximize resources. OBJECTIVE: To identify in a heterogeneous ACS population which patients would benefit the most with CR, in terms of functional capacity (FC), by using cardiopulmonary exercise testing (CPET). METHODS: A retrospective analysis of consecutive ACS patients who underwent CR and CPET was undertaken...
February 23, 2017: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
https://www.readbyqxmd.com/read/28238376/carbon-budget-of-a-rainfed-spring-maize-cropland-with-straw-returning-on-the-loess-plateau-china
#19
Xiang Gao, Fengxue Gu, Weiping Hao, Xurong Mei, Haoru Li, Daozhi Gong, Lili Mao, Zuguang Zhang
Assessing the carbon budget of rainfed agricultural ecosystems is a vital component in the process of estimating the global carbon balance. We used eddy covariance techniques combined with soil respiration measurements to estimate the carbon budget of a rainfed spring maize field where straw returning was practiced, on the Loess Plateau, China, during 2012-2014. Carbon fluxes and their components (except heterotrophic respiration, Rh) exhibited single-peak seasonal patterns, and linear relationships were found between daily gross primary productivity (GPP) and net ecosystem exchange (NEE), and between daily GPP and ecosystem respiration (Re), with goodness of fit value of 0...
February 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28238122/amelioration-of-drought-induced-negative-responses-by-elevated-co2-in-field-grown-short-rotation-coppice-mulberry-morus-spp-a-potential-bio-energy-tree-crop
#20
Kalva Madhana Sekhar, Kanubothula Sitarami Reddy, Attipalli Ramachandra Reddy
Present study describes the responses of short rotation coppice (SRC) mulberry, a potential bio-energy tree, grown under interactive environment of elevated CO2 (E) and water stress (WS). Growth in E stimulated photosynthetic performance in well-watered (WW) as well as during WS with significant increases in light-saturated photosynthetic rates (A Sat), water use efficiency (WUEi), intercellular [CO2], and photosystem-II efficiency (F V/F M and ∆F/F M') with concomitant reduction in stomatal conductance (g s) and transpiration (E) compared to ambient CO2 (A) grown plants...
February 25, 2017: Photosynthesis Research
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