BIOMECHANICAL ANALYSIS OF FOUR SHOOTING TECHNIQUES IN ICE HOCKEY

The purpose of this study was to analyze four shooting techniques used in ice hockey. Under the experimental conditions, the shooting techniques, performed by high performance male Chinese ice hockey players were filmed and analyzed from the viewpoint of Sports Biomechanics. These included the pulling shot, reflection shot, flick shot and the hitting shot. The results showed that each kind of shooting technique had a distinctive motion structure and technical feature. In competition, correct choice of shooting methods is one of the important factors for improving shooting average

Shotgun lipidomics identifies a paired rule for the presence of isomeric ether phospholipid molecular species

BACKGROUND: Ether phospholipids are abundant membrane constituents present in electrically active tissues (e.g., heart and the brain) that play important roles in cellular function. Alterations of ether phospholipid molecular species contents are associated with a number of genetic disorders and human diseases. METHODOLOGY/PRINCIPAL FINDINGS: Herein, the power of shotgun lipidomics, in combination with high mass accuracy/high resolution mass spectrometry, was explored to identify a paired rule for the presence of isomeric ether phospholipid molecular species in cellular lipidomes. The rule predicts that if an ether phospholipid A′-B is present in a lipidome, its isomeric counterpart B′-A is also present (where the ′ represents an ether linkage). The biochemical basis of this rule results from the fact that the enzymes which participate in either the sequential oxidation of aliphatic alcohols to fatty acids, or the reduction of long chain fatty acids to aliphatic alcohols (metabolic precursors of ether lipid synthesis), are not entirely selective with respect to acyl chain length or degree of unsaturation. Moreover, the enzymatic selectivity for the incorporation of different aliphatic chains into the obligatory precursor of ether lipids (i.e., 1-O-alkyl-glycero-3-phosphate) is also limited. CONCLUSIONS/SIGNIFICANCE: This intrinsic amplification of the number of lipid molecular species present in biological membranes predicted by this rule and demonstrated in this study greatly expands the number of ether lipid molecular species present in cellular lipidomes. Application of this rule to mass spectrometric analyses provides predictive clues to the presence of specific molecular species and greatly expands the number of identifiable and quantifiable ether lipid species present in biological samples. Through appropriate alterations in the database, use of the paired rule increases the number of identifiable metabolites in metabolic networks, thereby facilitating identification of biomarkers presaging disease states

Electrochemical Investigations of Sulfur‐Decorated Organic Materials as Cathodes for Alkali Batteries

Alkali metal–sulfur batteries (particularly, lithium/sodium- sulfur (Li/Na–S)) have attracted much attention because of their high energy density, the natural abundance of sulfur, and environmental friendliness. However, Li/Na–S batteries still face big challenges, such as limited cycle life, poor conductivity, large volume changes, and the “shuttle effect” caused by the high solubility of Li/Na–polysulfides. Herein, novel organosulfur-containing materials, i.e., bis(4-hydroxy-2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS-OH) and 2,4-thiophene/arene copolymer (TAC) are proposed as cathode materials for Li and Na batteries. BiTEMPS-OH shows an initial discharge/charge capacity of 353/192 mAh g−1 and a capacity of 62 mAh g−1 after 200 cycles at 100 mA g−1 in ether-based Li-ion electrolyte. Meanwhile, TAC has an initial discharge/charge capacity of 270/248 mAh g−1 and better cycling performance (106 mAh g−1 after 200 cycles) than BiTEMPS-OH in the same electrolyte. However, the rate capability of TAC is limited by the slow diffusion of Li-ions. Both materials show inferior electrochemical performances in Na battery cells compared to the Li analogs. X-ray powder diffraction reveals that BiTEMPS-OH loses its crystalline structure permanently upon cycling in Li battery cells. X-ray photoelectron spectroscopy demonstrates the cleavage and partially reversible formation of S−S bonds in BiTEMPS-OH and the formation/decomposition of thick solid electrolyte interphase on the electrode surface of TAC

Study of the Lithium Storage Mechanism of N-Doped Carbon-Modified Cu₂S Electrodes for Lithium-Ion Batteries

Owing to their high specific capacity and abundant reserve, Cu$_{x}$S compounds are promising electrode materials for lithium-ion batteries (LIBs). Carbon compositing could stabilize the Cu$_{x}$S structure and repress capacity fading during the electrochemical cycling, but the corresponding Li$^{+}$ storage mechanism and stabilization effect should be further clarified. In this study, nanoscale Cu$_{2}$S was synthesized by CuS co-precipitation and thermal reduction with polyelectrolytes. High-temperature synchrotron radiation diffraction was used to monitor the thermal reduction process. During the first cycle, the conversion mechanism upon lithium storage in the Cu$_{2}$S/carbon was elucidated by operando synchrotron radiation diffraction and in situ X-ray absorption spectroscopy. The N-doped carbon-composited Cu$_{2}$S (Cu$_{2}$S/C) exhibits an initial discharge capacity of 425 mAh g$^{-1}$ at 0.1 A g$^{-1}$, with a higher, long-term capacity of 523 mAh g$^{-1}$ at 0.1 A g$^{-1}$ after 200 cycles; in contrast, the bare CuS electrode exhibits 123 mAh g$^{-1}$ after 200 cycles. Multiple-scan cyclic voltammetry proves that extra Li+ storage can mainly be ascribed to the contribution of the capacitive storage

Standardized immunoprecipitation protocol for efficient isolation of native apolipoprotein E particles utilizing HJ15.4 monoclonal antibody

The apolipoprotein E protein (apoE) confers differential risk for Alzheimer\u27s disease depending on which isoforms are expressed. Here, we present a 2-day immunoprecipitation protocol using the HJ15.4 monoclonal apoE antibody for the pull-down of native apoE particles. We describe major steps for apoE production via immortalized astrocyte culture and HJ15.4 antibody bead coupling for apoE particle pull-down, elution, and characterization. This protocol could be used to isolate native apoE particles from multiple model systems or human biospecimens

The functional characterization of long noncoding RNA SPRY4-IT1 in human melanoma cells

Expression of the long noncoding RNA (lncRNA) SPRY4-IT1 is low in normal human melanocytes but high in melanoma cells. siRNA knockdown of SPRY4-IT1 blocks melanoma cell invasion and proliferation, and increases apoptosis. To investigate its function further, we affinity purified SPRY4-IT1 from melanoma cells and used mass spectrometry to identify the protein lipin 2, an enzyme that converts phosphatidate to diacylglycerol (DAG), as a major binding partner. SPRY4-IT1 knockdown increases the accumulation of lipin2 protein and upregulate the expression of diacylglycerol O-acyltransferase 2 (DGAT2) an enzyme involved in the conversion of DAG to triacylglycerol (TAG). When SPRY4-IT1 knockdown and control melanoma cells were subjected to shotgun lipidomics, an MS-based assay that permits the quantification of changes in the cellular lipid profile, we found that SPRY4-IT1 knockdown induced significant changes in a number of lipid species, including increased acyl carnitine, fatty acyl chains, and triacylglycerol (TAG). Together, these results suggest the possibility that SPRY4-IT1 knockdown may induce apoptosis via lipin 2-mediated alterations in lipid metabolism leading to cellular lipotoxicity