383 research outputs found

    Synthesis of polymer encapsulated nano-clay hybrid via miniemulsion

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    Issued as final reportNational Science Foundation (U.S.

    Contact Angle Measurement of Wood Fibers in Surfactant and Polymer Solutions

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    The Wilhelmy principle was used to investigate the wettability of wood fibers in various aqueous solutions. The sensitivity and reproducibility of the measurement were significantly improved by using a group of separated fibers as compared to a single-fiber method that was reported previously. This accurate and reproducible method allowed us to investigate contact angle and wettability of wood fibers in aqueous solutions using a common dynamic contact angle analyzer without the interference of capillary and roughness from the paper sheet surface.The wettability of different solutions on various wood fibers, including bleached and unbleached, and AKD (alkyl ketene dimer) sized and unsized fibers, was studied. The results indicated that the receding contact angle of aqueous solution against wood fibers is zero or close to zero regardless of the nature of the wood fiber surface. However, the advancing contact angle of aqueous solution against wood fibers strongly depends on the fiber surface properties.A decrease in advancing contact angle with an increase of the surfactant concentration was observed for all types of surfactants and fibers used in this study. The water-soluble cationic polyDADMAC [poly(diallydimethylammonium chloride)] and nonionic PEO (polyethylene oxide) have no significant effect on the wettability of wood fibers in aqueous solutions

    Attenuation of Biochemical Parameters in Streptozotocin-induced Diabetic Rats by Oral Administration of Extracts and Fractions of Cephalotaxus sinensis

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    Cephalotaxus sinensis (C. sinensis) large size, evergreen tree common in China and utilized for numerous effective pharmacological applications in Chinese traditional medicine. The hepato-renal effects of C. sinensis were evaluated in vivo using Streptozotocin (STZ)-induced diabetic rats as an tentative model. Animals were orally treated with 80% EtOH extract (aq.EE), H2O extract (WtE) and ethylacetate (EaF)/butanol fractions (BtF) of C. sinensis (200 mg/kg, b.w.) for 28 days whereas control received vehicle merely. The degree of fortification was measured by using biochemical parameters like serum transaminases (ALT and AST), alkaline phosphatase (ALP), creatinine, urea and urine sugar. Meanwhile, the histopathological studies were conducted out to support the above parameters. Administration of C. sinensis aq.EE/BtF (p<0.05) and EaF (p<0.01) patently prevented STZ-induced elevation levels of serum ALT, AST, ALP, creatinine, urea, urine sugar and increase body weight respectively, which were comparable with the standard drug tolbutamide, while WtE did not show any significant effect (p>0.05). Phytochemical studies revealed the presence of saponins, terpenes, sterols and flavonoids in C. sinensis which could be responsible for the possible hepato-renal protective action. The results sustain the fact that the extract/fractions of C. sinensis have an immense potential to be developed further into a phytomedicine

    Cebranopadol, a Mixed Opioid Agonist, Reduces Cocaine Self-administration through Nociceptin Opioid and Mu Opioid Receptors

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    Cocaine addiction is a widespread psychiatric condition still waiting for approved efficacious medications. Previous studies suggested that simultaneous activation of nociceptin opioid (NOP) and mu opioid (MOP) receptors could be a successful strategy to treat cocaine addiction, but the paucity of molecules co-activating both receptors with comparable potency has hampered this line of research. Cebranopadol is a non-selective opioid agonist that at nanomolar concentration activates both NOP and MOP receptors and that recently reached phase-III clinical trials for cancer pain treatment. Here, we tested the effect of cebranopadol on cocaine self-administration (SA) in the rat. We found that under a fixed-ratio-5 schedule of reinforcement, cebranopadol (25 and 50 µg/kg) decreased cocaine but not saccharin SA, indicating a specific inhibition of psychostimulant consumption. In addition, cebranopadol (50 µg/kg) decreased the motivation for cocaine as detected by reduction of the break point measured in a progressive-ratio paradigm. Next, we found that cebranopadol retains its effect on cocaine consumption throughout a 7-day chronic treatment, suggesting a lack of tolerance development toward its effect. Finally, we found that only simultaneous blockade of NOP and MOP receptors by concomitant administration of the NOP antagonist SB-612111 (30 mg/kg) and naltrexone (2.5 mg/kg) reversed cebranopadol-induced decrease of cocaine SA, demonstrating that cebranopadol activates both NOP and classical opioid receptors to exert its effect. Our data, together with the fairly advanced clinical development of cebranopadol and its good tolerability profile in humans, indicate that cebranopadol is an appealing candidate for cocaine addiction treatment

    4-(4-Bromo­phen­yl)-5-oxo-1,2,3,4,5,6,7,8-octa­hydro­quinazoline-2-thione

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    The title compound, C14H13BrN2OS, was synthesized from the multicomponent reaction between thio­urea, 4-bromo­benzaldehyde and cyclo­hexane-1,3-dione. The crystal packing is stabilized by inter­molecular N—H⋯O, N—H⋯S, C—H⋯O and C—H⋯S hydrogen bonds. Br⋯O inter­actions [3.183 (3) Å] are also observed in the crystal structure

    The effect of pressure-sensitive adhesive properties on screenability

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    "July 2002."Submitted to 2nd International Symposium on Emerging Technologies of Pulping and Papermaking of Fast Growing Wood, October 9-11, 2002, Guangzhou, China

    Dry Kraft Pulping at Ambient Pressure for Cost Effective Energy Saving and Pollution Deduction

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    Sponsored by the DOE Industrial Energy Efficiency Grand Challenge program, our research team at the Georgia Institute of Technology conducted laboratory studies and confirmed the concept of making wood pulp using a dry pulping technology. This technology is a new process different from any prior pulping technology used in Kraft and CTMP pulping. Three different kinds of dry pulping methods were investigated. (a) Dry Pulping at Atmospheric Pressure: The first one is to dry and bake the pretreated woodchips in a conventional oven at atmospheric pressure without the use of a catalyst. (b) Dry Pulping at Reduced Pressure: The second method is to dry the pretreated woodchips first in a vacuum oven in the presence of anthraquinone (AQ) as a pulping catalyst, followed by baking at elevated temperature. (c) Liquid Free Chemical Pulping, LFCP. The third method is to first remove the free water of pretreated woodchips, followed by dry pulping using a conventional Kraft pulping digester with AQ and triton as additives. Method one: Experimental results indicated that Dry Pulping at Atmospheric Pressure could produce pulp with higher brightness and lower bulk than conventional Kraft pulp. However, tensile strength of the acquired pulp is much lower than traditional Kraft pulp, and their Kappa number and energy consumption are higher than conventional Kraft pulp. By fully analyzing the results, we concluded that wood fibers might be damaged during the drying process at elevated temperature. The main reason for wood fiber damage is that a long drying time was used during evaporation of water from the woodchips. This resulted in an un-uniform reaction condition on the woodchips: the outside layer of the woodchips was over reacted while inside the woodchips did not reacted at all. To solve this problem, dry pulping at reduced pressure was investigated. Method two: To achieve uniform reaction throughout the entire reaction system, the water inside the pretreated woodchips was evaporated first under vacuum condition at low temperature. Then, the dry woodchips were baked at high temperature (120-130 C) at atmospheric pressure. The qualities of the pulp made with this method were improved compared to that made with method one. The pulp shows higher brightness and lower bulk than Kraft pulping. The tensile strength is significantly higher than the pulp made from the first method. Although the pulp is stronger than that of TMP pulp, it is still lower than conventional Kraft fiber. Method Three: The third dry method was done in a Kraft pulping digester at elevated pressure but without free liquid in the digester. With this method, pulp that has almost the same qualities as conventional Kraft pulp could be produced. The screen yield, Kappa number, fiber brightness, pulp strength and pulp bulk are almost identical to the conventional Kraft pulp. The key advantages of this dry pulping method include ca. 55 % of cooking energy saved during the pulping process, as high as 50 wt% of NaOH saving as well as 3 wt% of Na2S saving comparing to Kraft one. By analyzing fiber properties, yields, chemical and energy consumptions, we concluded that the dry pulping method based on Liquid Free Chemical Pulping, LFCP, could be very attractive for the pulp and paper industry. More fundamental studies and scale up trials are needed to fully commercialize the technology. We expect to conduct pilot trials between 12 to 24 months of period if the DOE or industry can provide continual research funding. Based on the technology we demonstrated in this report, several pilot trial facilities in the United States will be available after small modifications. For example, the Herty Foundation in Savannah, Georgia is one of these potential locations. DOE funding for continuous study and final lead to commercialization of the technique is important
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