bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quercetin’s effect on cycling efficiency and substrate utilization
Authors: Dumke Charles L. , Nieman David C. , Utter Alan C. , Rigby Michael D. , Quindry John C. , Triplett N. Travis , McAnulty Steven R. , McAnulty Lisa S. 
Published: December 2009

Previous evidence suggests that quercetin supplementation increases performance in humans. We examined the effects of 3 weeks of quercetin supplementation on fuel utilization, gross efficiency (GE), and perceived effort during 3 h of cycling over 3 successive days. Forty cyclists were randomized into quercetin and placebo groups and tested for maximal oxygen consumption (53.2 ± 1.2 and 54.7 ± 1.1 mL·kg–1·min–1). For 3 weeks following maximal oxygen consumption testing, subjects supplemented either 1000 mg·day–1quercetin or placebo during normal training. Following supplementation, subjects cycled at 57% maximum power for 3 h, on 3 successive days, using their own bicycles fitted to CompuTrainer Pro Model trainers (RacerMate, Seattle, Wash.). Metabolic measurements were taken every 30 min for each 3-h ride. Muscle biopsies obtained from the vastus lateralis immediately pre-exercise and postexercise on days 1 and 3 were analyzed for muscle glycogen content. Power output remained constant for all 3 exercise trials, but significant decreases over time were measured for GE, cadence, respiratory exchange ratio, blood glucose, and muscle glycogen. Significant increases were measured for heart rate and volume of oxygen consumption over time. No quercetin treatment effect was observed for any of the outcome measures in this study. These data indicate that GE is reduced during an exhausting 3-h bout of exercise. However, quercetin did not significantly affect any outcomes in these already well-trained subjects.
Serum uric acid is associated with metabolic risk factors for cardiovascular disease in the Uygur population
Authors: Li Nan F. , Wang Hong M. , Yang Jin , Zhou Ling , Yao Xiao G. , Hong Jing 
Published: December 2009

The prevalence of hyperuricemia is low in Uygurs, who have a high prevalence of cardiovascular risk factors such as hypertension, overweight–obesity, dyslipidemia, hyperglycemia, and insulin resistance (IR). This study sought to investigate the relationships between serum uric acid (UA) and these risk factors in this population. A cross-sectional study was conducted in Uygurs (859 males, 1268 females) aged 20 to 70 years. Demographic data, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and fasting and postprandial blood were obtained, and biological measurements were determined. The mean of BMI, SBP, DBP, total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides, fasting blood glucose, fasting insulin, and homeostasis model assessment insulin resistance index (HOMA-IR), and the prevalence of hypertension, IR, hyperglycemia, overweight–obesity, hypercholesteremia, hyper-LDL-c, and hypertriglyceridemia increased with UA but the prevalence of hypo-HDL-c decreased (p < 0.05). Logistic regression analysis showed that the odds ratios for IR, overweight–obesity, hypercholesteremia, hyper-LDL-c, and hypertriglyceridemia against the lowest UA group increased but decreased for hypo-HDL-c (p < 0.05). The UA in the hypo-HDL-c group was lower than that of the controls; the prevalence of hypo-HDL-c in hyperuricemia subjects was lower than in those with normal UA (p < 0.05). But the opposite results were observed between overweight–obesity, hyperglycemia, IR, hypercholesteremia, hypertriglyceridemia, and hyper-LDL-c and correspondence controls, respectively (p < 0.05). In Uygur, elevated UA is associated with overweight–obesity, hypercholesteremia, hyper-LDL-c, hypertriglyceridemia, hyperglycemia, and IR. The HDL-c level significantly increases with UA, whereas the prevalence of hypo-HDL-c decreases. Further studies are needed to clarify why UA is positively correlated to HDL-c.
The effect of prior heavy exercise on the parameters of the power-duration curve for cycle ergometry
Authors: Miura Akira , Shiragiku Chiaki , Hirotoshi Yuiko , Kitano Asami , Endo Masako Yamaoka , Barstow Thomas J. , Morton R. Hugh , Fukuba Yoshiyuki 
Published: December 2009

The tolerable duration (t) of high-intensity cycle ergometry is well characterized by a hyperbolic function of power output (P) with an asymptote (termed the critical power (CP)) and a curvature constant (denoted W′). The purpose of this study was to investigate the effect of prior heavy exercise (W-up) that specifically engenders an acidosis on CP and W′. Eight healthy subjects performed 2 sets of 4 high-intensity square-wave exercise bouts on a bicycle ergometer to estimate CP and W′, with (W-up) and without (control) prior exercise, respectively. Exercise intensities of the 4 main bouts were selected in the range of 90% to 135% peak oxygen uptake so as to reach the limit of tolerance between approximately 1.5 and 10 min. The W-up bout was preceded by 6 min cycling at a work rate halfway between the lactate threshold and peak oxygen uptake (mean ± SD of 153.8 ± 29.8 W) starting 12 min before the main bout. Blood lactate levels ([La]b) just before the main exercise bouts in W-up conditions were significantly higher than those of the control (4.7 ± 1.1 and 1.4 ± 0.4 mEq·L–1, respectively; p < 0.05). However, there were no significant differences in end-exercise [La]b. W-up increased significantly the tolerable duration at every work rate compared with the control, which was attributable exclusively to increased CP (176.5 ± 34.3 and 168.7 ± 31.3 W, respectively; p < 0.05), without any significant change in W′ (11.0 ± 3.2 and 11.0 ± 3.1 kJ, respectively). It is concluded that the prior heavy exercise improved performance mainly because of an enhanced aerobic component of exercise energetics, as indicated by a higher CP and lower increment in the [La]b.
Acute effects of chocolate milk and a commercial recovery beverage on postexercise recovery indices and endurance cycling performance
Authors: Pritchett Kelly , Bishop Philip , Pritchett Robert , Green Matt , Katica Charlie 
Published: December 2009

To maximize training quality, athletes have sought nutritional supplements that optimize recovery. This study compared chocolate milk (CHOC) with a carbohydrate replacement beverage (CRB) as a recovery aid after intense exercise, regarding performance and muscle damage markers in trained cyclists. Ten regional-level cyclists and triathletes (maximal oxygen uptake 55.2 ± 7.2 mL·kg–1·min–1) completed a high-intensity intermittent exercise protocol, then 15–18 h later performed a performance trial at 85% of maximal oxygen uptake to exhaustion. Participants consumed 1.0 g carbohydrate·kg–1·h–1 of a randomly assigned isocaloric beverage (CHOC or CRB) after the first high-intensity intermittent exercise session. The same protocol was repeated 1 week later with the other beverage. A 1-way repeated measures analysis of variance revealed no significant difference (p = 0.91) between trials for time to exhaustion at 85% of maximal oxygen uptake (CHOC 13 ± 10.2 min, CRB 13.5 ± 8.9 min). The change in creatine kinase (CK) was significantly (p < 0.05) greater in the CRB trial than in the CHOC trial (increase CHOC 27.9 ± 134.8 U·L–1, CRB 211.9 ± 192.5 U·L–1), with differences not significant for CK levels before the second exercise session (CHOC 394.8 ± 166.1 U·L–1, CRB 489.1 ± 264.4 U·L–1) between the 2 trials. These findings indicate no difference between CHOC and this commercial beverage as potential recovery aids for cyclists between intense workouts.
Effects of magnesium on exercise performance and plasma glucose and lactate concentrations in rats using a novel blood-sampling technique
Authors: Chen Ying-Ju , Chen Hsuan-Ying , Wang Ming-Fu , Hsu Mei-Hsiang , Liang Woei-Ming , Cheng Fu-Chou 
Published: December 2009

Repeated blood sampling in rodents is often necessary and difficult. Magnesium has been touted as an agent for enhancing physical activity. An auto-blood-sampling device coupled with a microdialysis analyzer was developed to determine blood glucose and lactate concentrations in rats subjected to treadmill exercise. The effects of magnesium on exercise performance and blood energy metabolism were also evaluated. Sprague–Dawley rats fed a magnesium-adequate diet were randomly assigned to 2 experimental groups. Exercise performance was evaluated at 3 treadmill speeds (10, 15, and 20 m·min–1) with or without magnesium administration (90 mg·kg–1, intraperitoneal) in the first experiment. In the other experiment, each rat was fitted with a catheter in the jugular vein for collection of blood samples during the treadmill exercise at a speed of 20 m·min–1. Exercise performance was significantly higher at the lower speed of 10 m·min–1 in the control group. In addition, exercise performance was significantly enhanced only at 20 m·min–1 in the magnesium-sulfate-treated group when compared with the control group. Blood samples were collected every 15 min. Glucose concentrations increased significantly and then declined immediately after completion of the exercise task at 20 m·min–1 in both groups. However, glucose concentrations increased immediately after administration of magnesium and increased further during exercise when compared with those of the control group. Findings from a repeated blood-sampling assay suggest that increased blood glucose contributes to enhanced exercise performance by rats injected intraperitoneally with magnesium.
Effect of extracellular osmolality on metabolism in contracting mammalian skeletal muscle in vitro
Authors: Cermak Naomi M. , LeBlanc Paul J. , Peters Sandra J. , Vandenboom Rene , Roy Brian D. 
Published: December 2009

Extensive research has been conducted on hepatocyte metabolism perturbed under the influence of anisosmotic stress. However, much less is known about the behaviour of skeletal muscle metabolism under similar conditions. After establishing a working model to study anisosmotic stress in resting mammalian skeletal muscle, the current study tested the hypothesis that hyperosmotic (HYPER) stress would lead to increased creatine, lactate, and measured enzyme activity, whereas hypo-osmotic (HYPO) stress would lead to decreased metabolites and enzyme activity vs. iso-osmotic (ISO) stress post contraction. Rat soleus (SOL) and extensor digitorum longus (EDL) were isolated and incubated in an organ bath (95% O2, 5% CO2, pH 7.4, 25 °C) altered to targeted osmotic conditions (ISO, 290 osmol·L–1; HYPO, 180 osmol·L–1; HYPER, 400 osmol·L–1). Muscle samples were flash frozen after 10 min of contraction. Post contraction, muscle water content in the SOL HYPO condition was 18% greater than ISO, and HYPER had approximately 14% less water content than ISO (p < 0.05). In the HYPO condition, EDL had 21% greater water content than ISO, and HYPER had 17% less water content than ISO (p < 0.05). SOL HYPO resulted in higher phosphocreatine and lower lactate and creatine vs. HYPER (p < 0.05) but there were no differences in EDL between HYPO and HYPER. Pyruvate dehydrogenase activity increased in SOL HYPER vs. HYPO, whereas glycogen phosphorylase a increased in EDL HYPER vs. HYPO. In conclusion, fibre-type-specific responses exist after contraction such that when SOL muscle is perturbed in HYPER, as compared with HYPO, media, metabolic activity increases. Future work should focus on glucose uptake–regulation during anisosmotic conditions.
The C allele of the AGT Met235Thr polymorphism is associated with power sports performance
Authors: Gomez-Gallego Felix , Santiago Catalina , González-Freire Marta , Yvert Thomas , Muniesa Carlos A. , Serratosa Luis , Altmäe Signe , Ruiz Jonatan R. , Lucia Alejandro 
Published: December 2009

Whether the Met235Thr (rs699) variation in the angiotensinogen (AGT) gene, encoding a threonine instead of a methionine in codon 235 of the mature protein, is associated with athletic performance remains to be elucidated. We compared the genotype and allele frequencies for the AGT Met235Thr variation (rs699) in 119 nonathletic controls, 100 world-class endurance athletes (professional cyclists, Olympic-class runners), and 63 power athletes (top-level jumpers, throwers, sprinters). Participants were all males and from the same descent (Caucasian) for ≥3 generations. The proportion of the CC genotype was significantly higher in the power group (34.9%) than in either the control (16%) or the endurance group (16%) (p = 0.008 and p = 0.005, respectively). The odds ratio (95% CI) of being a power athlete if the subject has a CC genotype was 1.681 (1.176–2.401), compared with the control group. In summary, the C allele of the AGT Met235Thr polymorphism might favour power sports performance. Although more research is needed, this could be attributed to the higher activity of angiotensin II, a skeletal muscle growth factor.
Effects of ingesting a commercial thermogenic product on hemodynamic function and energy expenditure at rest in males and females
Authors: Wilborn Colin , Taylor Lem , Poole Chris , Bushey Brandon , Williams Laura , Foster Cliffa , Campbell Bill 
Published: December 2009

The purpose of this study was to examine the effects of a commercially available thermogenic product (TP) on resting energy expenditure (REE) and hemodynamic variables in a randomized, double-blind, placebo (PL)-controlled study. Eight male (age: 23.0 ± 3.70 years, weight: 95.77 ± 16.44 kg, height: 182.4 ± 7.87 cm) and 10 female (age: 23.6 ± 4.81 years, weight: 67.25 ± 5.74 kg, height: 172.42 ± 10.31 cm) physically active individuals participated in this study. Participants reported to the laboratory on a 10-h fast and performed baseline testing on REE, heart rate, and blood pressure. Participants were then randomly assigned to ingest 3 capsules of either an experimental TP or a vitamin E PL. Criterion variables were then measured at 1-, 2-, and 3-h post ingestion. Data were analyzed by 2-factor analysis of variance (ANOVA) using SPSS, version 16.0 (SPSS Inc., Chicago, Ill.). Supplementation of the TP resulted in a significant main effect for time (p = 0.040) and for interaction (p < 0.01) in REE when compared with PL. Post hoc analysis revealed that there was no significant difference (p > 0.05) between groups at baseline, but the TP group was significantly higher (p < 0.01) than the PL group at 1-, 2-, and 3-h post, with peak values being achieved at 2-h post time point. The TP group also experienced an overall increase in REE by 17.3%, 19.6%, and 15.3% at the 1-, 2-, and 3-h time points, respectively, over baseline values. Conversely, the PL group experienced a reduction in REE by 2.5%, 1.8%, and 0.3% at the same time points compared with baseline values. There was no significant change in heart rate, systolic blood pressure, or diastolic blood pressure in either group. Taken on a daily basis, a TP may increase overall energy expenditure. Caloric expenditure significantly increased at all 3 time points in the TP group, whereas the PL group experienced no change in energy expenditure.
Effects of ovariectomy and resistance training on lipid content in skeletal muscle, liver, and heart; fat depots; and lipid profile
Authors: Leite Richard Diego , Prestes Jonato , Bernardes Celene Fernandes , Shiguemoto Gilberto Eiji , Pereira Guilherme Borges , Duarte Josiane Oliveira , Domingos Mateus Moraes , Baldissera Vilmar , de Andrade Perez Sérgio Eduardo 
Published: December 2009

The aim of the present study was to investigate the effects of resistance training on skeletal muscle lipid content, liver lipid content, heart lipid content, fat depots, and lipid profile in ovariectomized rats. Wistar adult female rats were divided into 4 groups (n = 10 per group): sedentary (Sed-Intact), sedentary ovariectomized (Sed-Ovx), strength trained (ChronicEx-intact), and strength trained ovariectomized (ChronicEx-Ovx). A 12-week strength-training period was used, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with 4–9 climbs and 8–12 dynamic movements per climb. Ovariectomy increased liver lipid content and fat depots, and heart and muscle lipid content. There was an increase in the atherogenic index and a negative change in lipid profile because of the ovariectomy. Resistance training decreased lipid content in the liver, soleus, and tibialis anterior, decreased fat depots (mesenteric and retroperitoneal), and changed the lipid profile, independently of ovarian hormone status. These results indicate the potential benefits of resistance training as an alternative strategy to control the effects of ovariectomy on fat depot, lipid profile, and tissue lipid content.
Synthesis and electrochemical behavior of triazole-containing nicotinamide adenine dinucleotide analogs
Authors: Liu Wujun , Hou Shuhua , Zhao Zongbao Kent 
Published: December 2009

The coupling of 2′,3′-di-O-acetyl nicotinamide mononucleotide with 3-butyn-1-ol in the presence of 2,4,6-triisopropylbenzenesulfonyl chloride quantitatively afforded a terminal alkyne-containing intermediate. Furthermore, copper(I)-mediated Huisgen [3 + 2] cycloaddition with a series of azido compounds in a two-phase solvent system gave eight triazole-containing nicotinamide adenine dinucleotide analogs with yields over 88%. The cyclic voltammetric behaviors of these novel analogs were investigated with a glassy carbon electrode, and structural features of these analogs on their electrochemical properties were briefly discussed.
Timing of dextral strike-slip processes and basement exhumation in the Elbe Zone (Saxo-Thuringian Zone): the final pulse of the Variscan Orogeny in the Bohemian Massif constrained by LA-SF-ICP-MS U-Pb zircon data
Authors: Hofmann M. , Linnemann U. , Gerdes A. , Ullrich B. , Schauer M. 
Published: December 2009

Abstract

The final pulse of the Variscan Orogeny in the northern Bohemian Massif (Saxo-Thuringian Zone) is related to the closure of the Rheic Ocean, which resulted in subduction-related D
1
-deformation followed by dextral strike-slip activity (D
2
-deformation, the Elbe Zone). Taken together, these deformation events reflect the amalgamation of Pangaea in central Europe. Lateral extrusion of high-grade metamorphosed rocks from an allochthonous domain (Saxonian Granulitgebirge) and the top–NW-directed transport of these domains (Erzgebirge nappe complex, Saxonian Granulitgebirge) are responsible for these dextral strike-slip movements. Geochronological data presented herein, together with published data, allow the timing of the final pulse of the Variscan Orogeny and related plutonic, volcano-sedimentary and tectonic processes. Marine sedimentation lasted at least until the Tournaisian (357 Ma). Onset of Variscan strike-slip along the Elbe Zone is assumed to be coeval with the beginning of the top–NW-directed lateral extrusion of the Saxonian Granulitgebirge at 342 Ma (D
2
-deformation). The sigmoidal shape of the Meissen Massif indicates that strike-slip activity was coexistent with intrusion of the pluton at
c
. 334 Ma into the schist belt of the Elbe Zone. In contrast, the intrusion of the Markersbach Granite provides a minimum age of
c
. 327 Ma for the termination of D
2
strike-slip activity, because this undeformed pluton cross-cuts all strike-slip related tectonic structures. Geochronological data of an ash bed from the Permo-Carboniferous Döhlen Basin show clearly that post-orogenic sedimentation of Variscan molasse in that area was already active at 305 Ma. This pull-apart basin is a local example of regional Permo-Carboniferous extension within Pangaea. The uplift and denudation of the Variscan basement in the Saxo-Thuringian Zone occurred between
c
. 327–305 Ma.
Extrusion of high-pressure Cache Creek rocks into the Triassic Stikinia–Quesnellia arc of the Canadian Cordillera: implications for terrane analysis of ancient orogens and palaeogeography
Authors: Dostal Jaroslav , Keppie J. Duncan , Ferri Filippo 
Published: December 2009

Abstract

The volcanic Triassic Takla Group constitutes a significant part of Stikinia and Quesnellia, two major terranes of the Canadian Cordillera that are separated by high-pressure rocks of the Cache Creek terrane containing Asian fauna. The geochemical and isotopic characteristics of the Takla Group in Quesnellia and Stikinia are similar, that is, tholeiitic basalts characterized by low abundances of strongly incompatible trace elements, negative Nb anomalies, +6 to +8 ε
Nd
values, the low initial Sr isotopic ratios, and relatively horizontal chondrite-normalized heavy REE patterns, all features typical of relatively primitive arcs with little or no continental crust involvement. These similarities have led to several geometric models: post-Middle Jurassic duplication by strike-slip faulting, and oroclinal or synformal folding. However, they are all inconsistent with either palaeomagnetic or faunal data, and the presence of a Triassic overstep sequence, which indicates amalgamation
c
. 50 ma before emplacement of the youngest oceanic rocks of the Cache Creek terrane. An alternative model is proposed: oblique eastward subduction of the Cache Creek accretionary prism and fore-arc producing high-pressure metamorphism, followed by extrusion into the arc and exhumation by the Middle Jurassic. This model implies that these high-pressure rocks, rather than marking an oceanic suture between disparate arc terranes, support a para-autochthonous origin.
The evolution of the Uralian orogen
Authors: Puchkov Victor N. 
Published: December 2009

Abstract
The Uralian orogen is located along the western flank of a huge (>4000 km long) intracontinental Uralo-Mongolian mobile belt. The orogen developed mainly between the Late Devonian and the Late Permian, with a brief resumption of orogenic activity in the Lower Jurassic and Pliocene–Quaternary time. Although its evolution is commonly related to the Variscides of Western Europe, its very distinctive features argue against a simple geodynamic connection. To a first order, the evolution of Uralian orogen shows similarities with the ‘Wilson cycle’, beginning with epi-continental rifting (Late Cambrian–Lower Ordovician) followed by passive margin (since Middle Ordovician) development, onset of subduction and arc-related magmatism (Late Ordovician) followed by arc–continent collision (Late Devonian in the south and Early Carboniferous in the north) and continent–continent collision (beginning in the mid-Carboniferous). In detail, however, the Uralides preserve a number of rare features. Oceanic (Ordovician to Lower Devonian) and island–arc (Ordovician to Lower Carboniferous) complexes are particularly well preserved as is the foreland belt in the Southern Urals, which exhibits very limited shortening of deformed Mesoproterozoic to Permian sediments. Geophysical studies indicate the presence of ‘cold’, isostatically equilibrated root. Other characteristic features include a Silurian platinum-rich belt of subduction-related layered plutons, a simultaneous development of orogenic and rift-related magmatism, a succession of collisions that are both diachronous and oblique, and a single dominant stage of transpressive deformation after the Early Carboniferous. The end result is a pronounced bi-vergent structure. The Uralides are also characterized by Meso-Cenozoic post-orogenic stage and plume-related tectonics in Ordovician, Devonian and especially Triassic time. The evolution of the Uralides is consistent with the development and destruction of a Palaeouralian ocean to form part of a giant Uralo-Mongolian orogen, which involved an interaction of cratonic Baltica and Siberia with a young and rheologically weak Kazakhstanian continent. The Uralides are characterized by protracted and recurrent orogenesis, interrupted in the Triassic by tectonothermal activity associated with the Uralo-Siberian superplume.