Characteristics of Postural Muscle Activity in Response to A Motor-Motor Task in Elderly

The purpose of the current study was to evaluate postural muscle performance of older adults in response to a combination of two motor tasks perturbations. Fifteen older participants were instructed to perform a pushing task as an upper limb perturbation while standing on a fixed or sliding board as a lower limb perturbation. Postural responses were characterized by onsets and magnitudes of muscle activities as well as onsets of segment movements. (Please see full abstract article

Reflection on the Experiences of US and European Automobile Industry to Hubei’s Future Development

Surpassing the US in car sales in 2009. China has, since the world financial crisis, been showing big potential while US automobiles industry under complete depression. Green car, which has long been popular in European countries such as Belgium, has therefore become a key for the revival of the world car industry. As one of the three major automobile bases in China, how can Hubei benefit from the current challenge and development opportunity in the pro-crisis era?Key words: Saving and new energy vehicles; US automobile; decay; European “green” plastics; Hubei; developmen

Predictability of the corneal flap creation with the VisuMax femtosecond laser in LASIK

AIM: To observe the predictability of corneal flap creation with the VisuMax femtosecond laser and preliminarily analyze the factors correlated to the thickness and diameter of the flap. <p>METHODS: This retrospective case series study included 300 eyes of 150 consecutive patients. The eyes were assigned to two groups according to intended flap thickness, 100μm(204 eyes)and 110μm(96 eyes), which created with the VisuMax femtosecond laser. Intended flap diameters were 7.9mm and 8.3mm. Difference analysis of flap diameter and intended diameter as well as flap thickness and intended thickness were made. The data were analyzed with SPSS to sum up a multiple stepwise regression formula that could express their quantitative relationship. <p>RESULTS: The 100μm flap group had an average flap thickness of 103.11±4.07μm, while for the 110μm group the average flap thickness was 113.35±5.71μm. The difference between right and left eyes was not statistically significant(<i>t</i>_100μm =-0.901, <i>t</i> _110μm=-0.490; <i>P</i>>0.05). Corneal flap thickness was not related to flap diameter(<i>r</i>=0.003, 0.018; <i>P</i>>0.05), preoperative patient age(<i>r</i>=0.022, 0.050; <i>P</i>>0.05), corneal thickness(<i>r</i>=0.051, 0.101; <i>P</i>>0.05), keratometric value K(<i>r</i>=-0.048, -0.136; <i>P</i>>0.05)or intraocular pressure(<i>r</i>=-0.113, 0.047; <i>P</i>>0.05). Preoperative corneal keratometric value K was positively correlated with corneal flap diameter(<i>r</i>=0.359, 0.532; <i>P</i>=0.01, 0.007<0.05). <p>CONCLUSION:The LASIK flap creation with the VisuMax femtosecond laser has relatively good predictability. There is no influencing factor for flap thickness

3-[(E)-2-Chloro-3,3,3-trifluoro­prop-1-en-1-yl]-N-(2-fluoro­phen­yl)-2,2-dimethyl­cyclo­propane-1-carboxamide

The phenyl ring in the title compound, C15H14ClF4NO, makes a dihedral angle of 80.3 (3)° with the cyclo­propane ring. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into chains running along the a axis

Ukupna kinetika redukcije niskokvalitetnog piroluzita smjesom hemiceluloze i lignina kao redukcijskog sredstva

Manganese is widely used in many fields. Many efforts have been made to recover manganese from low-grade pyrolusite due to the depletion of high-grade manganese ore. Thus, it is of practical significance to develop a clean, energy-saving and environmentally friendly technical route to reduce the low-grade pyrolusite. The reported results show that biomass wastes from crops, crop waste, wood and wood waste are environmentally friendly, energy-saving, and low-cost reducing agents for roasting reduction of low-grade pyrolusite. Kinetics of the reduction reactions is necessary for an efficient design of biomass reduction of pyrolusite. Therefore, it is important to look for a general kinetics equation to describe the reduction of pyrolusite by different kinds of biomass, because there is a wide variety of biomass wastes, meaning that it is impossible to investigate the kinetics for each biomass waste. In this paper, thermal gravimetric analysis and differential thermal analysis were applied to study the overall reduction kinetics of pyrolusite using a mixture of hemicellulose and lignin, two major components of biomass. Overall reduction process is the overlap of the respective reduction processes. A new empirical equation based on the Johnson–Mehl–Avrami equation can be used to describe the respective reduction kinetics using hemicellulose and lignin as reductants, and the corresponding apparent activation energy is 30.14 kJ mol−1 and 38.91 kJ mol−1, respectively. The overall kinetic model for the reduction of pyrolusite by the mixture of hemicellulose and lignin can be simulated by the summation of the respective kinetics by considering their mass-loss fractions, while a unit step function was used to avoid the invalid conversion data. The obtained results in this work are necessary to understand the biomass reduction of pyrolusite and provide valuable assistance in the development of a general kinetics equation.Ukupna kinetika redukcije piroluzita istraživana je termogravimetrijom i diferencijalnom termogravimetrijom. Kao redukcijsko sredstvo upotrijebljeni su hemiceluloza i lignin, glavni sastojci poljoprivrednog biljnog biootpada, drva i drvnog otpada. Ukupnu redukciju čine isprepleteni pojedinačni redukcijski procesi. Kinetika redukcije piroluzita smjesom hemiceluloze i lignina može se opisati novom empirijskom jednadžbom temeljenoj na jednadžbi Johnson–Mehl–Avrami, a odgovarajuća prividna energija aktivacije iznosi 30.14 kJ mol−1, odnosno 38.91 kJ mol−1. Sveobuhvatna kinetika može se modelirati kao zbroj pojedinačnih udjela uzimajući u obzir masene udjele sastojaka smjese te uz primjenu jedinične odskočne funkcije kako bi se izbjegli nevaljani podaci

Jets in a Gamma-Ray Burst During its Prompt Emission: Evolution of Lorentz Factor

Knowledge about the Lorentz factor and its evolution of relativistic jets in gamma-ray bursts (GRBs) is crucial to understand their physics. An exact value of bulk Lorentz factor can be estimated based on a high-energy spectral cutoff, which may appear in GRBs' prompt emission owing to the absorption of photon-photon pair production. In this work, we focus on the investigation of the bulk Lorentz factor evolution of jets in an individual burst. Based on \textsl{Fermi} observations, we search for the bursts with multiple $\gamma$-ray pulses characterized by a high-energy spectral cutoff, and nine GRBs are obtained. Together with the estimation of the pulse duration and radiation spectrum, the Lorentz factor of jets corresponding to different pulses in an individual GRB are estimated. It is shown that the Lorentz factor of jets in an individual GRB fluctuates within a certain range and without a general trend in these nine GRBs. In addition, the Lorentz factors of the jets in GRBs~130821A, 160509A and 160625B seem to increase with time. We also study the relations among $L_{\rm iso }$, $E_{\rm p,z}$, and $\Gamma$ for the pulses in our sample, which is found to be consistent with that found in previous works.Comment: Accepted for publication in Ap

6-Nitro­benzimidazolium dihydrogen phosphate 6-nitro­benzimidazole solvate dihydrate

In the crystal structure of the title compound, C7H6N3O2 +·H2PO4 −·C7H5N3O2·2H2O, the components are connected through O—H⋯O, N—H⋯O and O—H⋯N hydrogen-bonding inter­actions, forming a sheet-like structure parallel to (101). Adjacent sheets are further linked together by strong O—H⋯O hydrogen-bonds involving the dihydrogenphosphate groups. π–π stacking inter­actions between neighbouring aromatic constituents [centroid–centroid distance 3.653 (3) Å] help to consolidate the crystal packing