Effect of betaine supplementation on cycling sprint performance

Purpose

To examine the effect of betaine supplementation on cycling sprint performance.

Methods

Sixteen recreationally active subjects (7 females and 9 males) completed three sprint tests, each consisting of four 12 sec efforts against a resistance equal to 5.5% of body weight; efforts were separated by 2.5 min of cycling at zero resistance. Test one established baseline; test two and three were preceded by seven days of daily consumption of 591 ml of a carbohydrate-electrolyte beverage as a placebo or a carbohydrate-electrolyte beverage containing 0.42% betaine (approximately 2.5 grams of betaine a day); half the beverage was consumed in the morning and the other half in the afternoon. We used a double blind random order cross-over design; there was a 3 wk washout between trials two and three. Average and maximum peak and mean power were analyzed with one-way repeated measures ANOVA and, where indicated, a Student Newman-Keuls.

Results

Compared to baseline, betaine ingestion increased average peak power (6.4%; p < 0.001), maximum peak power (5.7%; p < 0.001), average mean power (5.4%; p = 0.004), and maximum mean power (4.4%; p = 0.004) for all subjects combined. Compared to placebo, betaine ingestion significantly increased average peak power (3.4%; p = 0.026), maximum peak power max (3.8%; p = 0.007), average mean power (3.3%; p = 0.034), and maximum mean power (3.5%; p = 0.011) for all subjects combined. There were no differences between the placebo and baseline trials.

Conclusions

One week of betaine ingestion improved cycling sprint power in recreationally active males and females.     

Application of plasma spraying in the preparation of metal-supported catalysts

Catalysts supported on metals are widely used today, but room still remains for further improvement of catalyst characteristics. The subject of this paper is the application of a plasma spray for the deposition of alumina coatings on metal substrates of different geometry (plates, foams) for subsequent synthesis of catalysts. The alumina layer sprayed successfully solves two different problems: (i) it serves as a washcoat on which a catalyst is synthesized, and (ii) it protects the metal surface from oxidation at high temperatures.     

Structural changes in a nickel-copper catalyst during growth of nitrogen-containing carbon nanofibers by ethylene/ammonia decomposition

Structural changes in a 65Ni-25Cu-Al₂O₃ catalyst during the decomposition of a C₂H₄/NH₃ mixture at different stages of nitrogen-containing carbon nanofiber (N-CNF) synthesis were studied by X-ray diffraction (XRD) analysis, X-ray diffraction using anomalous scattering effect and extended X-ray absorption fine structure (EXAFS) spectroscopy. The N-CNF growth over a catalyst particle was supposed to proceed via the formation of an oversaturated solid solution of carbon and nitrogen in a nickel-enriched alloy “NiCu_xC_yN_z”. The latter resulted in an increase of the alloy lattice parameter to abnormally large values а = 3.616-3.706 Å without destruction of its cubic structure. The formation of the “NiCu_xC_yN_z” phase and its presence in the system coincide with the optimum time for the synthesis of N-CNFs with the highest nitrogen concentration and maximum values of specific surface area and total pore volume.     

Nutritional pattern of the "Komsomolskaya Pravda" Arctic expedition]

Data on the chemical composition, nutritional value and caloricity of food ration used by the "Komsomolskaya Pravda" expedition during ski marches in the Arctics are reported. The rations consisted chiefly of dehydrated products and weighed 800-1000 g. The daily caloricity of the rations amounted to 3400 and 4400 great calories.     

On the construction of resolving controls in control problems with phase constraints

Problems associated with the construction of resolving controls in problems of dynamics of control systems with phase constraints are considered. Here, it is topical to construct and estimate the reachability sets of control systems and differential inclusions. Moreover, the problem of steering the phase vector of the controlled system into a given point of the reachability set is very important. This problem is naturally connected with various problems of optimal control, in particular, with the time optimal control problem. In the general case, this problem cannot be solved explicitly. In this paper, a method for constructing a control that steers the phase vector into a specified neighborhood of a point in the reachability set is proposed. The method is based on the so-called guide constructions.     

Dynamic range of quadrature radio-frequency time-integrating acousto-optic correlator

A new time-integrating acousto-optic correlator (TIAOC) was developed. It combines relatively low complexity with an exceedingly wideband of signals analyzed. The main feature of the architecture is the use of the light beams interference to provide the quadrature processing channel. The dynamic range (DR) of the new TIAOC is calculated for the active and passive operating modes. Parameter optimization to achieve the maximum DR is performed. The photodetector charge handling capacity is shown to be the main DR limiter.     

Forensic psychiatric expertise in brain tumors]

Dynamics of transplants of human embryonic spinal cord fragments development in adult rat spinal cord was studied in immunosuppression. Transplants were shown to take roots and their cellular elements proliferated and differentiated. The peculiarity of such transplants is the lack of rough glio-connective tissue scar. Graft development in the spinal cord depends on histoblastic potential of the tissue transplanted and recipient spinal cord reaction to the transplantation.     

NMR studies of caldesmon-calmodulin interactions

The binding of the calcium-regulatory protein calmodulin (CaM) to caldesmon (CaD) contributes to the regulation of smooth muscle contraction. Two regions of caldesmon have been identified as putative calmodulin-binding domains. We have earlier reported on the binding of one of these domains to calmodulin (Zhang & Vogel (1994) Biochemistry 33, 1163-1171). Here we have studied the binding of CaM to synthetic peptides of CaD which contain: (1) both the first and second CaM-binding domains; (2) the second CaM-binding domain; and (3) the sequence between the first and second CaM-binding domains. Two-dimensional transferred nuclear Overhauser enhancement proton NMR measurements as well as circular dichroism studies of a 22-residue peptide NKETAGLKVGVSSRINEWLTK, which contains the second CaM-binding domain, show that only the C-terminal half of the peptide becomes alpha-helical upon binding to CaM. Somewhat surprisingly, the shorter 9-residue peptide SRINEWLTK was sufficient to form a 1:1 complex with CaM; this peptide appears to bind as a 3(10)-helix. Proton-carbon-13 correlation NMR titration studies with specifically labeled [methyl-13C]methionine CaM were used to study the participation of the hydrophobic regions in both domains of the dumbbell shaped CaM in peptide binding. Binding of a 54-residue CaD peptide containing both CaM-binding domains affects all the 8 Met residues in the two hydrophobic domains of CaM (only Met 76 in the linker region of CaM is not involved), while binding of the second CaM-binding domain of CaD influences principally Met 51, 71, and Met 124, 144. Simultaneous binding to CaM of two peptides comprising the first and the second CaM-binding domains also caused changes to all Met residues except Met 76. Taken together, these data demonstrate that both CaM-binding domains of CaD can bind simultaneously to the two hydrophobic regions of CaM.     

Views of hospital staff on the management of hypertension

A questionnaire concerning the detection and management of hypertension was presented to 265 hospital doctors, 114 medical students and 59 student nurses. Of these 75% were completed. Although only 76% thought that routine measurement was necessary in outpatients, 92% of respondents thought that blood pressure (BP) should be measured routinely in all in-patients. A total of 17% of all doctors and 11% of physicians indicated that they would not use drug treatment until the diastolic BP exceeded 105 mmHg. Thirty-four per cent of respondents still use diastolic phase IV and 84% felt that BP should be measured 2-4 times before deciding on treatment but the posture of the patient (lying, sitting or standing) during recording was inconsistent. Seventy-seven per cent of respondents indicated that they recorded BP to the nearest 5 mmHg and 4% to the nearest 10 mmHg. Despite the literature on the subject, there are still widely differing opinions amongst medical staff on how to record BP and at what level it should be treated.     

The development and cross-validation of methods based on radioimmunoassay and LC/MS-MS for the quantification of the class III antiarrhythmic agent, MK-0499, in human plasma and urine

An analytical method based on radioimmunoassay (RIA) has been developed for the determination of the antiarrhythmic agent, MK-0499, in plasma and urine. Owing to the potency of the drug, the specificity of this assay in human plasma could not be adequately determined using conventional RIA procedures. A highly specific procedure, based on LC/MS-MS, was developed to cross-validate the RIA. The lower quantifiable limits of the RIA and LC/MS-MS-based methods were 0.05 and 0.013 ng ml-1, respectively. Cross-validation data, compared using paired student's t-test regression analysis, showed excellent correlation between methods. The mass spectrometric assay was also used to simultaneously measure plasma concentrations of unlabeled and 14C-labeled MK-0499 following administration of the drug at high specific activity to volunteers.