In Vivo Nitric Oxide Synthase Inhibitors Can Be Deprived of This Activity: Unexpected Influence of the Tetrachloroplatinate(II) Counteranion. Crystal Structures of Bis(S-Methyl-Isothiouronium)-N,N'-Bis(3-Guanidinopropyl)Piperazinium and Hexamidinium Tetrachloroplatinates(II) Salts

The synthesis and crystal structures of bis(S-methylisothiouronium) (MSTUH)(+), N,N'-bis((3- guanidinopropyl)piperazinium (PipeC3GuaH4)(4+) and hexamidinium (HexaH2)(2+) tetrachloro platinate(ll) salts ( called hereafter PtMSTU, PtPipeC3Gua and PtHexa respectively ) were investigated. These compounds contain the "amidine" function ( - C(=NH)NH(2) ) in which the H atoms supplied by the acid have become attached to the imino group of each terminal amidino function. Moreover, in PtPipeC3Gua, the nitrogen atoms of the chair-piperazine moiety are also protonated. The influence of tetrachloroplatinate(ll) counteranion ( versus sulfate, nitrate and diisethionate ) in the in vivo nitrite inhibition by the (MSTUH)(+), (PipeC3GuaH4)(4+) and (HexaH2)(2+) cations was investigated. The three tetrachloroplatinate(ll) salts, unexpectedly, do not inhibit significantly the in vivo nitrite production in comparison with the other salts (sulfate, nitrate and diisethionate and their corresponding previous countercations) which exhibit NO synthase inhibition, especially bis(S-methylisothiouronium) sulfate, a selective and potent inducible NO synthase (iNOS) inhibitor commonly used as standard.     

Streaming‐Enabled Parallel Dataflow Architecture for Multicore Systems

We propose a new framework design for exploiting multi‐core architectures in the context of visualization dataflow systems. Recent hardware advancements have greatly increased the levels of parallelism available with all indications showing this trend will continue in the future. Existing visualization dataflow systems have attempted to take advantage of these new resources, though they still have a number of limitations when deployed on shared memory multi‐core architectures. Ideally, visualization systems should be built on top of a parallel dataflow scheme that can optimally utilize CPUs and assign resources adaptively to pipeline elements. We propose the design of a flexible dataflow architecture aimed at addressing many of the shortcomings of existing systems including a unified execution model for both demand‐driven and event‐driven models; a resource scheduler that can automatically make decisions on how to allocate computing resources; and support for more general streaming data structures which include unstructured elements. We have implemented our system on top of VTK with backward compatibility. In this paper, we provide evidence of performance improvements on a number of applications.     

Extension of the Nicholls-Lee-Nichols algorithm to three dimensions

A new algorithm for clipping a line segment against a pyramid in E ³ is presented. This algorithm avoids computation of intersection points that are not end points of the output line segment. It also solves all cases more effectively. The performance of this algorithm is shown to be consistently better than that of existing algorithms, including the Cohen–Sutherland, Liang–Barsky, and Cyrus–Beck algorithms.     

Quick and easy game bot detection based on action time interval estimation

Game bots are illegal programs that facilitate account growth and goods acquisition through continuous and automatic play. Early detection is required to minimize the damage caused by evolving game bots. In this study, we propose a game bot detection method based on action time intervals (ATIs). We observe the actions of the bots in a game and identify the most frequently occurring actions. We extract the frequency, ATI average, and ATI standard deviation for each identified action, which is to used as machine learning features. Furthermore, we measure the performance using actual logs of the Aion game to verify the validity of the proposed method. The accuracy and precision of the proposed method are 97% and 100%, respectively. Results show that the game bots can be detected early because the proposed method performs well using only data from a single day, which shows similar performance with those proposed in a previous study using the same dataset. The detection performance of the model is maintained even after 2 months of training without any revision process.     

Do Psychosocial and Study Skill Factors Predict College Outcomes? A Meta-Analysis.

This study examines the relationship between psychosocial and study skill factors (PSFs) and college outcomes by meta-analyzing 109 studies. On the basis of educational persistence and motivational theory models, the PSFs were categorized into 9 broad constructs: achievement motivation, academic goals, institutional commitment, perceived social support, social involvement, academic self-efficacy, general self-concept, academic-related skills, and contextual influences. Two college outcomes were targeted: performance (cumulative grade point average; GPA) and persistence (retention). Meta-analyses indicate moderate relationships between retention and academic goals, academic self-efficacy, and academic-related skills (ps = .340, .359, and .366, respectively). The best predictors for GPA were academic self-efficacy and achievement motivation (ps = .496 and .303, respectively). Supplementary regression analyses confirmed the incremental contributions of the PSF over and above those of socioeconomic status, standardized achievement, and high school GPA in predicting college outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Function of Lipid Storage Droplet 1 (Lsd1) in Wing Development of Drosophila melanogaster

Perilipins are evolutionarily conserved from Drosophila to humans, the lipid storage droplet 1 (Lsd1) is a Drosophila homolog of human perilipin 1. The function of Lsd1 as a regulator of lipolysis in Drosophila has been demonstrated, as the Lsd1 mutant causes an increase of lipid droplet size. However, the functions of this gene during development are still under investigation. In order to determine the function of Lsd1 during development, Lsd1 was knocked down in Drosophila using the GAL4-UAS system. Selective knockdown of Lsd1 in the dorsal wing disc caused an atrophied wing phenotype. The generation of reactive oxygen species in the wing pouch compartment of the Lsd1-knockdown flies was significantly higher than in the control. Immunostaining with caspase-3 antibody revealed a greater number of apoptotic cells in Lsd1-knockdown wing discs than in the control. Cell death by autophagy was also induced in the knockdown flies. Moreover, cells deprived of Lsd1 showed mitochondrial expansion and decreased ATP levels. These results strongly suggest that knockdown of Lsd1 induces mitochondrial stress and the production of reactive oxygen species that result in cell death, via apoptosis and the autophagy pathway. These results highlight the roles of Drosophila Lsd1 during wing development.     

Synthesis of silica nanoparticles from Vietnamese rice husk by sol–gel method

Silica powder at nanoscale was obtained by heat treatment of Vietnamese rice husk following the sol–gel method. The rice husk ash (RHA) is synthesized using rice husk which was thermally treated at optimal condition at 600°C for 4 h. The silica from RHA was extracted using sodium hydroxide solution to produce a sodium silicate solution and then precipitated by adding H₂SO₄ at pH = 4 in the mixture of water/butanol with cationic presence. In order to identify the optimal condition for producing the homogenous silica nanoparticles, the effects of surfactant surface coverage, aging temperature, and aging time were investigated. By analysis of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, the silica product obtained was amorphous and the uniformity of the nanosized sample was observed at an average size of 3 nm, and the BET result showed that the highest specific surface of the sample was about 340 m²/g. The results obtained in the mentioned method prove that the rice husk from agricultural wastes can be used for the production of silica nanoparticles.     

Hydrogen production from CH4 dry reforming over bimetallic Ni–Co/Al2O3 catalyst

Bimetallic 5%Ni–10%Co/Al₂O₃ catalyst was synthesized using impregnation method and evaluated for methane dry reforming reaction at different reaction temperatures. NiO, Co₃O₄ and spinal metal aluminates, namely, CoAl₂O₄ and NiAl₂O₄ phases were formed on γ-Al₂O₃ support surface during calcination process. 5%Ni–10%Co/Al₂O₃ catalyst exhibited reasonable surface area of 86.93 m² g^?1 with small crystallite dimension of less than 10 nm suggesting that both Co₃O₄ and NiO phases were finely dispersed on the surface of support in agreement with results from scanning electron microscopy (SEM) measurement. Temperature-programmed calcination measurement indicates the complete thermal decomposition and oxidation of metal precursors, viz. Ni(NO₃)₂ and Co(NO₃)₂ to metal oxides and metal aluminates at below 700 K. Both CH₄ and CO₂ conversions were stable over a period of 4 h on-stream and attained an optimum at about 67% and 71%, respectively at 973 K whilst H₂ selectivity and yield were higher than 49%. The ratio of H₂/CO was always less than unity for all runs indicating the presence of reverse water–gas shift reaction. The activation energy for CH₄ and CO₂ consumption was computed as 55.60 and 40.25 kJ mol^?1, correspondingly. SEM micrograph of spent catalyst detected the formation of whisker-like carbon on catalyst surface whilst D and G bands characteristic for the appearance of amorphous and graphitic carbons in this order were observed on surface of used catalyst by Raman spectroscopy analysis. Additionally, the percentage of filamentous carbon was greater than that of graphitic carbon.     

Carbon nanofibre/hydrous RuO2 nanocomposite electrodes for supercapacitors

Amorphous RuO₂·xH₂O and a VGCF/RuO₂·xH₂O nanocomposite (VGCF = vapour-grown carbon fibre) are prepared by thermal decomposition. The morphology of the materials is investigated by means of scanning electron microscopy. The electrochemical characteristics of the materials, such as specific capacitance and rate capability, are investigated by cyclic voltammetry over a voltage range of 0–1.0 V at various scan rates and with an electrolyte solution of 1.0 M H₂SO₄. The specific capacitance of RuO₂·xH₂O and VGCF/RuO₂·xH₂O nanocomposite electrodes at a scan rate of 10 mV s⁻¹ is 410 and 1017 F g⁻¹, respectively, and at 1000 mV s⁻¹ are 258 and 824 F g⁻¹, respectively. Measurements of ac impedance spectra are made on both the electrodes at various bias potentials to obtain a more detailed understanding of their electrochemical behaviour. Long-term cycle-life tests for 10⁴ cycles shows that the RuO₂·xH₂O and VGCF/RuO₂·xH₂O electrodes retain 90 and 97% capacity, respectively. These encouraging results warrant further development of these electrode materials towards practical application.     

Simultaneous effects of silanized coal fly ash and nano/micro glass fiber on fracture toughness and mechanical properties of carbon fiber‐reinforced vinyl ester resin composites

In this study, the simultaneous effects of both silanized coal fly ash (S‐CFA) and nano/micro glass fiber (nGF) on fracture toughness and mechanical properties of vinyl ester (VE) resin filled with carbon fiber‐based composite materials were investigated. The CFA was treated with (3‐trimethoxysilyl) propyl methacrylate to introduce the methacryloxy groups into the surface of CFA, and was confirmed by using FTIR technique. The nGF and S‐CFA with different weight ratios were well mixed with VE resin by using of high‐speed mechanical stirrer, and ultrasonic technique before using as matrices for fabrication of carbon fiber‐based composite materials via sheet molding compound (SMC) method and hot curing processing. Many characteristics of both cured VE resin composites and carbon fiber‐based composite were examined such as mechanical properties, fracture toughness, and morphology. The results showed that by adding of both 0.1 wt% nGF and 1 wt% S‐CFA into VE resin the tensile strength, tensile modulus, flexural strength, K_IC, impact strength as well as the Mode I interlaminar fracture toughness (G_IC) of VE composites and carbon fiber based composites get optimum values and increased about 61.39%; 39.83%; 36.21%; 103.1%; 81.79%; 48.61%, respectively when compared with pristine materials. POLYM. ENG. SCI., 59:584–591, 2019. © 2018 Society of Plastics Engineers