KINEMATICAL ANALYSIS OF FEMALE VOLLEYBALL SPIKE

The purpose of this study was to analyze female volleyball players’ body centre of mass (CM) displacement and velocity when spiking at front and back row. Six high school players participated in this study. Two JVC9800 digital video cameras (120Hz) were used to collect spiking motion. Kwon 3D motion system was used to analyze the kinematic variables. The results indicated that the back-row spike had greater CM resultant velocity at approach and take-off than front-row spike. The back-row spike had greater jumping height and the CM horizontal displacement than front-row spike. The initial ball velocity and angular velocity of shoulder, elbow, and wrist of the front-row spike were greater than back-row spike. This study provides information for coaches in teaching volleyball spike

All­yl(ferrocenylmeth­yl)dimethyl­ammonium perchlorate

The asymmetric unit of the title complex, [Fe(C5H5)(C11H17N)]ClO4, contains two independent all­yl(ferro­cenyl­meth­yl)dimethyl­ammonium cations and two ClO4 − anions. The anions are disordered each over two sets of sites, with an occupancy ratio of 0.617 (6):0.383 (6). The distances from the Fe atoms to the centroids of the unsubstituted and substituted cyclo­penta­dienyl (Cp) rings are 1.645 (1)/1.657 (1) and 1.644 (1)/1.647 (1) Å. The dihedral angles between the two Cp rings are 2.49 (3) and 1.45 (4)° in the two ferrocenyl groups of the cations

Rapid (<5 min) identification of pathogen in human blood by electrokinetic concentration and surface-enhanced Raman spectroscopy.

This study reports a novel microfluidic platform for rapid and long-ranged concentration of rare-pathogen from human blood for subsequent on-chip surface-enhanced Raman spectroscopy (SERS) identification/discrimination of bacteria based on their detected fingerprints. Using a hybrid electrokinetic mechanism, bacteria can be concentrated at the stagnation area on the SERS-active roughened electrode, while blood cells were excluded away from this region at the center of concentric circular electrodes. This electrokinetic approach performs isolation and concentration of bacteria in about three minutes; the density factor is increased approximately a thousand fold in a local area of ~5000 μm(2) from a low bacteria concentration of 5 × 10(3) CFU/ml. Besides, three genera of bacteria, S. aureus, E. coli, and P. aeruginosa that are found in most of the isolated infections in bacteremia were successfully identified in less than one minute on-chip without the use of any antibody/chemical immobilization and reaction processes

Acute aortic dissection: An update

AbstractThe aorta, which has a complex intrinsic biology and sophisticated mechanical properties for conducting the blood ejected from the left ventricle to the rest of the systemic arterial bed, is the largest and strongest artery in the body. It carries roughly 200 million liters of blood in an average lifetime. Any process that undermines the architecture threatens the structure, stability, and functionality of the aorta. In this regard, acute aortic dissection (AAD) requires special attention because it is the most catastrophic acute illness of the aorta; it has high morbidity and mortality because of potentially fatal complications. AAD has, therefore, become an important topic of recent research, and knowledge about this disease has improved during the past few years. Up-to-date knowledge about the natural history, epidemiology, presentation, physiopathology, evolution, management, follow-up, and long-term outcomes of AAD are summarized in this review

Optical characterization of colloidal CdSe quantum dots in endothelial progenitor cells

We have quantitatively analyzed the confocal spectra of colloidal quantum dots (QDs) in rat endothelial progenitor cells (EPCs) by using Leica TCS SP5 Confocal Microscopy System. Comparison of the confocal spectra of QDs located inside and outside EPCs revealed that the interaction between the QDs and EPCs effectively reduces the radius of the exciton confinement inside the QDs so that the excitonic energy increases and the QD fluorescence peak blueshifts. Furthermore, the EPC environment surrounding the QDs shields the QDs so that the excitation of the QDs inside the cells is relatively weak, whereas the QDs outside the cells can be highly excited. At high excitations, the occupation of the ground excitonic state in the QD outside the cells becomes saturated and high-energy states excited, resulting in a large relaxation energy and a broad fluorescence peak. This permits, in concept, to use QD biomarkers to monitor EPCs by characterizing QD fluorescence spectra

Surface polaritons in two-dimensional left-handed photonic crystals

Using an extended plane-wave-based transfer-matrix method, the photonic band structures and the corresponding transmission spectrum of a two-dimensional left-handed photonic crystal are calculated. Comparisons between the periodic structure with a single left-handed cylindric rod are made, and many interesting similarities are found. It is shown that, due to the localized surface polaritons presented by an isolated left-handed rod, there exist many exciting physical phenomena in high-dimensional left-handed photonic crystals. As direct results of coupling of the localized surface polaritons of neighboring left-handed rod, a lot of almost dispersionless bands, anti-crossing behavior, and a zero $\bar{n}$ gap are exhibited in the left-handed periodic structure. Moreover, in a certain frequency region, except distorted by a lot of anti-crossing behavior, there exists a continual dispersion relation, which can be explained by the long-wavelength approximation. It is also pointed out that high-dimensional left-handed photonic crystals can be used to design narrow-band filter.Comment: sign errors in equation