ß-alanine supplementation improves YoYo intermittent recovery test performance

ABSTRACT: BACKGROUND: beta-alanine supplementation has been shown to improve high-intensity exercise performance and capacity. However, the effects on intermittent exercise are less clear, with no effect shown on repeated sprint activity. The aim of this study was to investigate the effects of beta-alanine supplementation on YoYo Intermittent Recovery Test Level 2 (YoYo IR2) performance. METHODS: Seventeen amateur footballers were allocated to either a placebo (PLA; N = 8) or beta-alanine (BA; N = 9) supplementation group, and performed the YoYo IR2 on two separate occasions, pre and post 12 weeks of supplementation during a competitive season. Specifically, players were supplemented from early to mid-season (PLA: N = 5; BA: N = 6) or mid- to the end of the season (PLA: N = 3; BA: N = 3). Data were analysed using a two factor ANOVA with Tukey post-hoc analyses. RESULTS: Pre supplementation scores were 1185 [PLUS-MINUS SIGN] 216 and 1093 [PLUS-MINUS SIGN] 148 m for PLA and BA, with no differences between groups (P = 0.41). YoYo performance was significantly improved for BA (+34.3%, P [LESS-THAN OR EQUAL TO] 0.001) but not PLA ([MINUS SIGN]7.3%, P = 0.24) following supplementation. 2 of 8 (Early -- Mid: 2 of 5; Mid -- End: 0 of 3) players improved their YoYo scores in PLA (Range: -37.5 to + 14.7%) and 8 of 9 (Early -- Mid: 6 of 6; Mid -- End: 2 of 3) improved for BA (Range: +0.0 to +72.7%). CONCLUSIONS: 12 weeks of beta-alanine supplementation improved YoYo IR2 performance, likely due to an increased muscle buffering capacity resulting in an attenuation of the reduction in intracellular pH during high-intensity intermittent exercise.     

Preparation and phosphorus recovery performance of porous calcium–silicate–hydrate

Porous calcium–silicate–hydrate was synthesized and used to recover phosphorus from wastewater. The principal objective of this study was to explore the phosphorus recovery performance of porous calcium–silicate–hydrate prepared by different Ca/Si molar ratios. Phosphorus recovery mechanism was also investigated via Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectrum (EDS), Brunauer–Emmett–Teller (BET) and X-ray Diffraction (XRD). The law of Ca²⁺ release was the key of phosphorus recovery performance. Different Ca/Si molar ratios resulted in the changes of pore structures. The increase of specific surface area and the increase in concentration of Ca²⁺ release were well agreement together. The Ca/Si molar ratio of 1.6 for porous calcium–silicate–hydrate is more proper to recover phosphorus. The pore structure of porous calcium–silicate–hydrate provided a local condition to maintain a high concentration of Ca²⁺ release. Porous calcium–silicate–hydrate could release a proper concentration of Ca²⁺ and OH^? to maintain the pH values at 8.5–9.5. This condition was beneficial to the formation of hydroxyapatite. Phosphorus content of porous calcium–silicate–hydrate reached 18.64% after phosphorus recovery.     

The effect of two β-alanine dosing strategies on 30-minute rowing performance: a randomized,controlled trial

Background

β-alanine (βA) supplementation has been shown to increase intramuscular carnosine content and subsequent high-intensity performance in events lasting <?4?minutes (min), which may be dependent on total, as opposed to daily, dose. The ergogenic effect of βA has also been demonstrated for 2000-m rowing performance prompting interest in whether βA may be beneficial for sustained aerobic exercise. This study therefore investigated the effect of two βA dosing strategies on 30-min rowing and subsequent sprint performance.

Methods

Following University Ethics approval, twenty-seven healthy, male rowers (age: 24?±?2?years; body-height: 1.81?±?0.02?m; body-mass: 82.3?±?2.5?kg; body-fat: 14.2?±?1.0%) were randomised in a double-blind manner to 4?weeks of: i) βA (2.4?g·d^??1, βA1); ii) matched total βA (4.8?g on alternate days, βA2); or iii) cornflour placebo (2.4?g·d^??1, PL). Participants completed a laboratory 30-min rowing time-trial, followed by 3x30-seconds (s) maximal sprint efforts at days 0, 14 and 28 (T1-T3). Total distance (m), average power (W), relative average power (W·kg^??1), cardio-respiratory measures and perceived exertion were assessed for each 10-min split. Blood lactate ([La-]_b mmol·L^??1) was monitored pre-post time-trial and following maximal sprint efforts. A 3-way repeated measures ANOVA was employed for main analyses, with Bonferonni post-hoc assessment (P?≤?0.05).

Results

Total 30-min time-trial distance significantly increased from T1-T3 within βA1 only (7397?±?195?m to 7580?±?171?m, P?=?0.002, ?p²?=?0.196), including absolute average power (194.8?±?18.3?W to 204.2?±?15.5?W, P?=?0.04, ?p²?=?0.115) and relative average power output (2.28?±?0.15?W·kg^??1 to 2.41?±?0.12?W·kg^??1, P?=?0.031, ?p²?=?0.122). These findings were potentially explained by within-group significance for the same variables for the first 10?min split (P?≤?0.01), and for distance covered (P?=?0.01) in the second 10-min split. However, no condition x time interactions were observed. No significant effects were found for sprint variables (P?>?0.05) with comparable values at T3 for mean distance (βA1: 163.9?±?3.8?m; βA2: 161.2?±?3.5?m; PL: 162.7?±?3.6?m), average power (βA1: 352.7?±?14.5?W; βA2: 342.2?±?13.5?W; PL: 348.2?±?13.9?W) and lactate (βA1: 10.0?±?0.9?mmol·L^??1; βA2: 9.2?±?1.1?mmol·L^??1; PL: 8.7?±?0.9?mmol·L^??1).

Conclusions

Whilst daily βA may confer individual benefits, these results demonstrate limited impact of βA (irrespective of dosing strategy) on 30-min rowing or subsequent sprint performance. Further investigation of βA dosage >?2.4?g·d^??1 and/or chronic intervention periods (>?4–8?weeks) may be warranted based on within-group observations.

     

An imidazolium iodide–containing hyperbranched polymer ionic liquid that improves the performance of dye-sensitized solar cells

In this study, we synthesized an imidazolium iodide–containing hyperbranched polymer ionic liquid (HPIL) for use as the gel electrolyte of dye-sensitized solar cells (DSSCs). We incorporated HPIL at various contents (4, 8, and 15 wt%) in a solvent-free ionic liquid (1-propyl-2,3-dimethylimidazolium iodide and 1-ethyl-3-methylimidazolium tetrafluoroborate)–based quasi-solid gel electrolyte (IL-A) and a solvent (3-methoxypropionitrile)-based fluid gel electrolyte (IL-B). After fabricating N719 dye–based DSSCs incorporating the HPIL/IL-A and HPIL/IL-B gel electrolytes, we recorded the electrochemical impedance spectra and measured the photovoltaic (PV) performance of these devices. In the dark, the DSSCs incorporating HPIL exhibited higher charge recombination resistances at the interface between TiO₂/dye and the electrolyte. This high recombination resistance suppressed the dark current and improved the PV performance of the devices incorporating HPIL. The DSSCs fabricated from the HPIL/IL-B gel electrolyte displayed higher photo-conversion efficiency, while those fabricated from the HPIL/IL-A gel electrolyte provided superior operational stability. Under AM 1.5 illumination (100 mW cm^?2), we measured a photo-conversion efficiency of 7.18 %, a short-circuit current density of 16.09 mA cm^?2, an open-circuit voltage of 0.69 V, and a fill factor of 0.65 for the DSSC incorporating the gel electrolyte HPIL/IL-B (4:96, w/w). The DSSC incorporating the gel electrolyte HPIL/IL-A (15:85, w/w) exhibited good operational stability, retaining approximately 93 % of its original efficiency after 500 h.

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Graphical abstract An imidazolium iodide-containing hyperbranched polymer ionic liquid HPIL was synthesized for use as the gel electrolyte of dye-sensitized solar cells.

     

β-Cyclodextrin-functionalized copolymers based on multiple intermolecular forces for enhanced oil recovery

As one of mature enhanced oil recovery (EOR) technologies, polymer flooding has been extensively applied in oilfield. In this study, new hydrophobically associative copolymers were synthesized by free-radical polymerization of acrylamide (AM), acrylic acid (AA), vinyl-modified β-cyclodextrins, and a water-soluble hydrophobic macromonomer (AA-APE-20). Fourier transform infrared, proton-nuclear magnetic resonance, and scanning electron microscopy verified the structure of hydrophobically associative polymers (HDAPAMs). Compared with partially hydrolyzed polyacrylamide (HPAM), multiple intermolecular forces including chelation between ethoxyl (EO) group and Ca²⁺/Mg²⁺, electrostatic bridges between EO groups and carboxyl groups ( COO⁻), hydrogen bonding between EO groups and AM groups ( CONH₂), hydrophobic association among nonyl phenol groups, and host-guest inclusion interaction endowed HDAPAMs favorable temperature-resistance, salt-resistance, and displacement efficiency. It was found that HDAPAMs showed evident temperature-response, salt thickening effect, favorable thixotropy, and viscoelasticity. Compared with HPAM, the core flooding experiments demonstrated that HDAPAMs could further enhance 6.97% to 8.43% oil recovery, even after HPAM flooding used. All the results revealed the EOR potential in HDAPAMs flooding.     

Stretchable poly(glycerol-sebacate)/β-tricalcium phosphate composites with shape recovery feature by extrusion

There has been a great interest in research towards elastomers and their composites with an attempt to obtain the desired biological and mechanical response to scaffold materials in bone tissue engineering. Composites made of ceramic-thermoplastic mixtures have been shown success to deliver the inorganic component while fail to provide replacement of an elastic protein, that is, collagen, of the target bone tissue. Thus, in order to match up with the inherent elasticity of the native tissue, it is proposed an alternative to well-known thermoplastic-containing matrices by using a poly(glycerol-sebacate) (PGS)–beta-tricalcium phosphate elastomeric composite to offer flexibility and mechanical integrity. This study reports for the first time a successful extrusion of PGS containing biodegradable composites with shape-memory feature. The resulting structures are physically and chemically characterized. In vitro cell culture performance of the obtained materials is investigated by using an MC3T3-E1 mouse preosteoblast cell line. The materials obtained in this study can be shaped into the desired size and various forms via temperature stimuli. Resulting materials have been proposed for craniofacial tissue engineering as a bone filler in which surgeons need to shape biomaterials during the surgical procedure due to the complex geometry of the bones. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48689.     

Enhancement of scaffolding properties for poly(3-hydroxybutyrate): blending with poly-β-alanine and wet electrospinning

Poly-β-alanine (PBA), and its derivatives poly(α-methyl-β-alanine) and poly[N-(3-methoxypropyl-β-alanine) were synthesized by hydrogen transfer polymerization (HTP). Porous 3?D matrices of poly(3-hydroxybutyrate) (P3HB) reinforced with PBA/its derivatives were obtained via lyophilization and wet electrospinning. However, mechanical properties of the porous matrices prepared by wet electrospinning were found to present superior performance for tissue engineering applications. Cell culture study was performed by using wet electrospun P3HB matrices doped with 10% (w/w) PBA which show better manipulation ability, chemical and mechanical properties. Scaffolds of P3HB-PBA (10% w/w) blend was determined to demonstrate better cell attachment and proliferation compared to the scaffolds of pure P3HB.     

Desulphation pretreatment for 138°C (280 °F) operation : performance test of a 1 MGD plant at Doha East (Kuwait) power station

During the period of June–July 1985, the start-up and the performance test of a desulphation unit annexed to a 1 MGD sea water MSF desalination plant at Doha East (Kuwait'power station) was carried out.The plant is the first based on the DESULF acid pretreatment built in Kuwait.The performance test data show the high reliability of the DESULF pretreatment that allowed to operate at 138 °C top brine temperature for several days without calcium sulfate scaling problems.The paper reports project and operation data collected during the performance test as well as the results of the internal inspection of the evaporator.     

Efficient recovery of aromatic compounds from the wastewater of styrene monomer and propylene oxide co-production plant via hypercrosslinked aryl-rich starch-β-cyclodextrin polymeric sorbent

Adsorptive recovery of valuable components from industrial wastewater is highly desirable for avoiding resource wastage but remains a challenge. Herein, we develop an efficient continuous adsorption process for recovering aromatic compounds in wastewater from styrene monomer and propylene oxide coproduction(SMPO) plant. Based on our insight into the potential of bio-based porous materials for adsorption application, starch-graft-polystyrene(SPS) and aryl-modified β-cyclodextrin(ACD) were prepare...     

The effects of different amounts of drug microspheres on the vivo and vitro performance of the PLGA/β-TCP scaffold

OIC-A006 (BMPs osteogenesis compounds), can stimulate bone marrow mesenchymal stem cells ALP, OPN, OC, Cbfal expression. To stimulate new bone formation in the body. We postulate different amounts of drug microspheres on the PLGA/β-CPT scaffold can produce the effects on performance and sustained release characteristics. In this paper, through adding different amount of carrier drug microsphere, three concentrations scaffolds which are 12.5, 18.75 and 25 μmol/L are prepared by adding different amounts of drug-loaded microspheres. Hereafter called OICM/CPT-200, OICM/CPT-300, OICM/CPT-400. We implant them in rat femur diameter 3 mm depth of 3 mm hole for eight weeks. The degradation, microsphere, delivery properties, with X-ray, micro-CT and histology are tested. Results show that the contain carrier drug microsphere scaffolds become radiopaque, and the gaps between the scaffold and radial cut ends are often invisible. This preliminary study reveals that different carrier drug microsphere has a corresponding effect the performance of stent body, OICM/CPT – 200 scaffolds induction effect is best. Illustrates that the low concentration load OIC-A006 microspheres can promote bone healing, and high concentration of OIC-A006 micro ball is played a inhibitory effect on bone healing process.     

Light assisted room-temperature NO2 sensors with enhanced performance based on black SnO1-α@ZnO1-β@SnO2-γ nanocomposite coatings deposited by solution precursor plasma spray

The development of room-temperature gas sensors with high performance for nitrogen dioxide gases is of great importance and appealing. Our previous works show that visible light illumination is an effective method to replace heating. In this paper, solution precursor plasma spray (SPPS) process is used to prepare black SnO_1-α@ZnO_1-β@SnO_2-γ sensitive coatings. Stoichiometric ZnO, SnO₂ and SnO are in white color. The introduced highly concentrated donor defects provided by SPPS process make them turn to black. The light absorption range of the black coatings was extended from ultraviolet area to yellow light region. Raman spectroscopy, photoluminescence spectroscopy and X-ray photoelectron spectroscopy were used to characterize the chemical compositions and oxidation states of SPPS coatings. Donor defects formed deep donor levels between the valence band and conduction band, which can be excited under visible light illumination. FE-SEM and HRTEM images exhibited a highly porous nanostructure, and n-n heterojunctions were formed between SnO_1-α, ZnO_1-β and SnO_2-γ. The SPPS coatings exhibited an obvious response towards 1.0 ppm NO₂ gas under visible light illumination at room temperature. The enhanced sensing performance was mainly attributed to the presence of donor defects and homogenous heterojunctions.     

Synthesis of high-stability acidic Ce3 + (La3 + or Sm3 +)~β/Al-MCM-41 and the catalytic performance for the esterification of oleic acid

Ce^3 + (La^3 + or Sm^3 +)~β/Al-MCM-41 molecular sieves were synthesized by impregnation and used to catalyze the esterification of oleic acid with short chain alcohols, such as methanol, ethanol, isopropanol, and isobutanol, to obtain biodiesel. Ce^3 +(La^3 + or Sm^3 +)~β/Al-MCM-41 was found to exhibit excellent catalytic activity and stability. The effect of rare earth elements on the acidity of catalysts was examined in detail by NH₃-TPD and Py-FTIR. The optimum conditions for the esterification of oleic acid with methanol were determined. Moreover, the kinetics of the esterification showed that the average reaction order (n) was 1.92, with an activation energy of 51.46 kJ/mol.     

Relative performance of neem (<Emphasis Type="Italic">Azadirachta indica</Emphasis>) coated urea vis-à-vis ordinary urea applied to rice on the basis of soil test or following need based nitrogen management using leaf colour chart

Neem coated urea (NCU) applied to rice can result in high N use efficiency as it contains nitrification inhibition properties. Field experiments were conducted for three years (2005–2007) at Ludhiana (sandy loam soil) and Gurdaspur (clay loam soil) for evaluating the relative performance of NCU vis-à-vis ordinary urea as a source of N for transplanted wetland rice. Along with a no-N control, the two N sources were tried at three N levels––40, 80 and 100% of the recommended level of 120 kg N ha⁻¹. Different doses of N were applied in three equal split doses at transplanting, 21 and 42 days after transplanting (DAT). For need based site specific N management for improved N use efficiency, the two sources of N were applied using leaf colour chart (LCC). In this treatment a basal dose of N at the rate of 20 kg N ha⁻¹ was applied after 7 DAT and LCC readings were recorded at weekly intervals starting 14 DAT. Whenever the intensity of green colour of the first fully opened leaf from the top was less than shade 4 of the LCC, N was applied at the rate of 30 kg N ha⁻¹.