4,285 research outputs found
Mechanochemical Synthesis of Active Magnetite Nanoparticles Supported on Charcoal for Facile Synthesis of Alkynyl Selenides by C−H Activation
Magnetite (Fe3O4) nanoparticles supported on charcoal, graphene, or SBA‐15 were prepared by a simple solid‐state grinding technique and subsequent thermal treatment. The Fe3O4 nanoparticles supported on activated charcoal exhibited high catalytic activity and furnished good yields of the alkynyl selenide product in the cross‐coupling reaction of diphenyl diselenide and alkynes through activation of C−H and Se−Se bonds under ecofriendly conditions, surpassing traditional copper‐based catalysts to effect the same organic transformation.Alkynes of fun: Fe3O4 nanoparticles separately supported on charcoal, graphene, and SBA‐15 are prepared by solid‐state grinding and subsequent thermal treatment. The Fe3O4 nanoparticles supported on activated charcoal exhibit high catalytic activity and furnish good yields of alkynyl selenide products in the cross‐coupling reactions of diphenyl diselenide with alkynes through C−H and Se−Se bond activation under ecofriendly conditions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137502/1/cctc201600280-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137502/2/cctc201600280_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137502/3/cctc201600280.pd
511 keV -ray emission from the galactic bulge by MeV millicharged dark matter
We propose a possible explanation for the recently observed anomalous 511 keV
line with a new "millicharged" fermion. This new fermion is light []. Nevertheless, it has never been observed by any collider
experiments by virtue of its tiny electromagnetic charge . In
particular, we constrain parameters of this millicharged particle if the 511
keV cosmic -ray emission from the galactic bulge is due to positron
production from this new particle.Comment: 3 pages, 1 figure, A talk given by J.C.Park at the 16th International
Conference on Supersymmetry and the Unification of Fundamental Interactions
(SUSY08), Seoul, Korea, June 16-21, 200
Design and Implementation of Reader Baseband Receiver Structure in a Passive RFID Environment
Protective Effect of Proanthocyanidin against Diabetic Oxidative Stress
We investigated the antidiabetic potential of proanthocyanidin and its oligomeric form in STZ-induced diabetic model rats and db/db type 2 diabetic mice. Proanthocyanidin ameliorated the diabetic condition by significant decreases of serum glucose, glycosylated protein, and serum urea nitrogen as well as decreases of urinary protein and renal-AGE in STZ-induced diabetic rats and decrease of serum glucose as well as significant decrease of glycosylated protein in db/db type 2 diabetic mice. The suppression of ROS generation and elevation of the GSH/GSSG ratio were also observed in the groups administered proanthocyanidin. Moreover, proanthocyanidin, especially its oligomeric form, affected the inflammatory process with the regulation of related protein expression, iNOS, COX-2 and upstream regulators, NF-κB, and the IκB-α. In addition, it had a marked effect on hyperlipidemia through lowering significant levels of triglycerides, total cholesterol, and NEFA. Moreover, expressions in the liver of SREBP-1 and SREBP-2 were downregulated by the administration of proanthocyanidins. The protective effect against hyperglycemia and hyperlipidemia in type 1 and 2 diabetic models was significantly strong in the groups administered the oligomeric rather than polymeric form. This suggests that oligomers act as a regulator in inflammatory reactions caused by oxidative stress in diabetes
Bonding Characteristics of Macrosynthetic Fiber in Latex-Modified Fiber-Reinforced Cement Composites as a Function of Carbon Nanotube Content
The effect of carbon nanotube content (0, 0.5, 1.0, 1.5, and 2.0% of the cement weight) on the bonding properties of macrosynthetic fiber in latex-modified hybrid fiber cement-based composites (LMHFRCCs) was evaluated. The slump value, compressive strength, and bonding strength were measured for each LMHFRCC. As the carbon nanotube content increased to 1.5%, the bonding properties of the macrosynthetic fiber improved. However, the bonding performance deteriorated at a carbon nanotube content of 2.0%. A decrease in the fluidity of the mix negatively affected the dispersion of the nanotubes in the LMHFRCCs. The addition of carbon nanotubes also affected the relative bonding strength independently of the improvement in compressive strength. Microscopic analysis of the macrosynthetic fiber surfaces was used to understand changes in the bonding behavior
KINEMATIC ANALYSIS OF DIVING BACK PIKE SOMERSAULT IN PLATFORM ACCORDING TO PLAYERS’ SKILL LEVEL
The purpose of this study was to investigate the kinematic difference in Back Pike somersault in platform diving according to players‘ skill level and to assist them to improve performances. Ten Korean diving athletes participated in this study and they were divided into skilled group (n=5) and less-skilled group (n=5) and t-test was performed to find the difference at the moment of take-off between groups. The results showed that the hip extension angle was greater and the extension velocity of knee and hip joints were faster in skilled group compared to less-skilled group. It is recommended, therefore that the flexibility training of hip joint and muscle strength training to enhance extension velocity of knee and hip joints are needed
DIFFERENCES IN TRUNK ANGLES THROUGH DIFFERENT SHOOTING DIRECTIONS IN WATER POLO PENALTY SHOOTING
The purpose of this study was to investigate three-dimensionally the shooter’s trunk motion through 4 different shooting directions. Ten Korean national level water polo players who are right-handed were participated in this study (age, 21.60±3.20 years; weight, 86.30±8.86 kg; height, 1.83±0.05 m). To analyze the shooter’s trunk motion among different target, a three-dimensional motion analysis with six video cameras was performed.The analysis events were coking when the trunk was externally rotated maximally and release moment. A one-way ANOVA with repeated measure was performed as main statistical tests and Bonferroni correction was used as a post-hoc test. The results showed that there was statistically significant difference in trunk angle between left and right shooting directions. Especially, the posterior leaning and external rotation angles of trunk in cocking moment were bigger in left shooting direction compared to right one (p\u3c.05). These results suggest that goalkeepers predict shooting direction more precisely by identifying the trunk posture at coking moment
Unleashing the full potential of Hsp90 inhibitors as cancer therapeutics through simultaneous inactivation of Hsp90, Grp94, and TRAP1
Cancer therapeutics: Extending a drug's reach A new drug that blocks heat shock proteins (HSPs), helper proteins that are co-opted by cancer cells to promote tumor growth, shows promise for cancer treatment. Several drugs have targeted HSPs, since cancer cells are known to hijack these helper proteins to shield themselves from destruction by the body. However, the drugs have had limited success. Hye-Kyung Park and Byoung Heon Kang at Ulsan National Institutes of Science and Technology in South Korea and coworkers noticed that the drugs were not absorbed into mitochondria, a key cellular compartment, and HSPs in this compartment were therefore not being blocked. They identified a new HSP inhibitor that can reach every cellular compartment and inhibit all HSPs. Testing in mice showed that this inhibitor effectively triggered death of tumor cells, and therefore shows promise for anti-cancer therapy. The Hsp90 family proteins Hsp90, Grp94, and TRAP1 are present in the cell cytoplasm, endoplasmic reticulum, and mitochondria, respectively; all play important roles in tumorigenesis by regulating protein homeostasis in response to stress. Thus, simultaneous inhibition of all Hsp90 paralogs is a reasonable strategy for cancer therapy. However, since the existing pan-Hsp90 inhibitor does not accumulate in mitochondria, the potential anticancer activity of pan-Hsp90 inhibition has not yet been fully examined in vivo. Analysis of The Cancer Genome Atlas database revealed that all Hsp90 paralogs were upregulated in prostate cancer. Inactivation of all Hsp90 paralogs induced mitochondrial dysfunction, increased cytosolic calcium, and activated calcineurin. Active calcineurin blocked prosurvival heat shock responses upon Hsp90 inhibition by preventing nuclear translocation of HSF1. The purine scaffold derivative DN401 inhibited all Hsp90 paralogs simultaneously and showed stronger anticancer activity than other Hsp90 inhibitors. Pan-Hsp90 inhibition increased cytotoxicity and suppressed mechanisms that protect cancer cells, suggesting that it is a feasible strategy for the development of potent anticancer drugs. The mitochondria-permeable drug DN401 is a newly identified in vivo pan-Hsp90 inhibitor with potent anticancer activity
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