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Surface Modification of Poly Vinyl Chloride (PVC) Using Low Pressure Argon and Oxygen Plasma

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Plasma Science and Technology 2010年第2期12卷 204-207页

作者： Mahmood GHORANNEVISS sheila SHAHIDI Jakub WIENER Plasma Physics Research Center Science and Research Branch Islamic Azad University Department of Textile Chemistry Faculty of Textile Technical University of Liberec

In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.

关键词： plasma surface modification poly vinyl chloride

Transplacental induction of fatty acid oxidation in term fetal pigs by the peroxisome proliferator-activated receptor alpha agonist clofibrate

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Journal of Animal Science and Biotechnology 2016年第3期7卷 341-352页

作者： Xi Lin sheila Jacobi Jack Odle Laboratory of Developmental Nutrition Department of Animal SciencesNorth Carolina State University

Background： To induce peroxisomal proliferator-activated receptor α（PPARα） expression and increase milk fat utilization in pigs at birth, the effect of maternal feeding of the PPARα agonist, clofibrate（2-（4-chlorophenoxy）-2-methyl-propanoic acid, ethyl ester）, on fatty acid oxidation was examined at ful-term delivery（0 h） and 24 h after delivery in this *** group of pigs（n = 10） was delivered from pregnant sows fed a commercial diet with or without 0.8% clofibrate for the last 7 d of gestation. Blood samples were col ected from the utero-ovarian artery of the sows and the umbilical cords of the pigs as they were removed from the sows by C-section on day 113 of ***： HPLC analysis identified that clofibric acid was present in the plasma of the clofibrate-fed sow（~4.2 μg/m L）and its offspring（~1.5 μg/m L）. Furthermore, the maternal-fed clofibrate had no impact on the liver weight of the pigs at 0 h and 24 h, but hepatic fatty acid oxidation examined in fresh homogenates showed that clofibrate increased（P 〈 0.01）^14C-accumulation in CO2 and acid soluble products 2.9-fold from [1-^14C]-oleic acid and 1.6-fold from[1-^14C]-lignoceric acid respectively. Correspondingly, clofibrate increased fetal hepatic carnitine palmitoyltransferase（CPT）and acyl-Co A oxidase（ACO） activities by 36% and 42% over controls（P 〈 0.036）. The m RNA abundance of CPT I was 20-fold higher in pigs exposed to clofibrate（P 〈 0.0001） but no differences were detected for ACO and PPARα m RNA between the two ***： These data demonstrate that dietary clofibrate is absorbed by the sow, crosses the placental membrane, and enters fetal circulation to induce hepatic fatty acid oxidation by increasing the CPT and ACO activities of the newborn.

关键词： Clofibrate Fatty acid oxidation Pigs Placenta transfer

Effect of Electron Irradiation on Polypropylene Films

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Plasma Science and Technology 2011年第2期13卷 194-196页

作者： sheila SHAHIDI Jakub WIENER Mahmood GHORANNEVISS Abbas ANVARI Department of Textile Chemistry Faculty of Textile Technical University of Liberec Plasma Physics Research Center Science and Research Branch Islamic Azad University Departments of Physics Sharif University of Technology

Effects of both electron beam irradiation on the properties of polypropylene （PP） films and the irradiation on the different layers of a multilayer PP film are studied. A Fourier transform infrared spectroscope was used to investigate the chemical structure of the films. The results showed that the chemical properties of the first layer were improved, that is, more functional groups responsible for dye ability and hydrophilicity of the film were produced on its surface, while noticeable improvement was not detected on the surface of other layers. This was also confirmed by testing the dye ability of the layers. However, the results obtained by atomic force microscopy showed that the electron irradiation caused some topographical changes, not only on the surface of the first layer but also on the others.

关键词： polypropylene electron beam dye ability film

Conditional disruption of the osterix gene in chondrocytes during early postnatal growth impairs secondary ossification in the mouse tibial epiphysis

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Bone Research 2019年第3期7卷 310-317页

作者： Weirong Xing Catrina Godwin sheila Pourteymoor Subburaman Mohan 1Musculoskeletal Disease Center VA Loma Linda Healthcare System Loma Linda CA 92357 USA Department of Medicine Loma Linda University Loma Linda CA 92357 USA Department of Orthopedics Loma Linda University Loma Linda CA 92357 USA Department of Biochemistry Loma Linda University Loma Linda CA 92357 USA

In our previous studies, we have found that the prepubertal increase in thyroid hormone levels induces osterix(Osx) signaling in hypertrophic chondrocytes to transdifferentiate them into osteoblasts. To test if Osx expressed in chondrocytes directly contributes to transdifferentiation and secondary ossification, we generated Osx^flox/flox;Col2-Cre-ERT2 mice and knocked out Osx with a single injection of tamoxifen at postnatal day(P) 3 prior to evaluation of the epiphyseal bone phenotype by μCT, histology, and immunohistochemistry(IHC) at P21. Vehicle(oil)-treated Osx^flox/flox;Col2-Cre-ERT2 and tamoxifen-treated, Cre-negative Osx^flox/flox mice were used as controls.μCT analysis of tibial epiphyses revealed that trabecular bone mass was reduced by 23% in the Osx conditional knockout(c KO) compared with control mice. Trabecular number and thickness were reduced by 28% and 8%,respectively, while trabecular separation was increased by 24% in the c KO mice. Trichrome staining of longitudinal sections of tibial epiphyses showed that bone area and bone area adjusted for total area were decreased by 22% and 18%, respectively. IHC studies revealed the presence of abundant Osx-expressing prehypertrophic chondrocytes in the epiphyses of control mice at P10, but not in the cKO mice. Furthermore, expression levels of MMP13, COL10, ALP, and BSP were considerably reduced in the epiphyses of cKO mice. We also found that Osx overexpression in ATDC5 chondrocytes increased expression of Col10, Mmp13, Alp, and Bsp. Our data indicate that Osx expressed in chondrocytes plays a significant role in secondary ossification by regulating expression of genes involved in chondrocyte hypertrophy and osteoblast transdifferentiation.

关键词： ossification thyroid hormone Large chondrocyte

Simultaneous Raman and reflection UV/Vis absorption spectroelectrochemistry

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Nano Research 2022年第6期15卷 5340-5346页

作者： sheila Hernandez Juan V.Perales-Rondon Aranzazu Heras Alvaro Colina Department of Chemistry Universidad de BurgosPza.Misael Banuelos s/ñBurgos E-09001Spain Department of Analytical Chemistry Physical Chemistry and Chemical EngineeringUniversity of Alcala.Ctra.Madrid-BarcelonaKm.33.600MadridAlcaláde Henares E-28871Spain

In the present work,a new combination of Raman and ultraviolet and visible(UV/Vis)absorption spectroelectrochemistry in reflection mode is *** new experimental setup allows obtaining the two kinds of spectroscopic data without interferences concomitantly with the electrochemical *** the best of our knowledge,it is the first time to report the simultaneous obtention of electrochemical,electronic,and vibrational information in the same *** new combination provides time-resolved information about the processes that are taking place on the electrode/solution interface which has significant implications in different fields of chemistry,such as modification of electrodes,studies of electrocatalytic reaction mechanisms,development of sensors,among *** different systems were used to demonstrate the advantages and capabilities of the brand-new technique,namely,the oxidation of potassium ferrocyanide,an out-sphere system that is usually employed in the validation of SEC techniques,and the electrochemical-surface enhanced Raman spectroscopy(EC-SERS)detection of crystal violet by in-situ formation of the silver SERS substrate,where the UV/Vis spectra were used to follow the formation of the SERS substrate,whereas the Raman response of a probe molecule was used to confirm either the formation of a nanostructured surface and to obtain the fingerprint of the molecule with a high time *** brand-new experimental setup has shown to be useful,versatile,robust,compact,and easy to use for future applications.

关键词： spectroelectrochemistry surface enhanced Raman spectroscopy(SERS) Raman ultraviolet and visible(UV/Vis)absorption nanoparticles

Steam Pretreatment of Rice Hulls to Release Fermentable Saccharides:An Approach to Improve Recovery of(Hemi)Cellulosic Sugars Through Multivariate Design

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Rice science 2021年第5期28卷 501-510,I0037-I0039页

作者： sheila MONTIPO Christian Roslander Marli Camassola Mats Galbe Ola Wallberg Department of Chemical Engineering Lund UniversityP.O.Box 124Lund SE-22100Sweden Biotechnology Institute University of Caxias do SulCaxias do Sul 95070-560Brazil

The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface method to achieve optimum contents of C6-sugars in water-insoluble solids(WIS)and C5-sugars in the *** carried out at 218℃ for 2.3 min released liquor containing 55.4 g/L of sugars(29.1 g/L of xylose).In parallel,the WIS was subjected to enzymatic saccharification using different solid and enzyme loads via an experimental design:assays using 22.0% WIS and 20.0 filter paper units(FPU)/g led to 90.6 g/L of glucose,corresponding to a yield of 86.4% and an overall yield of 72.4%.The data reported are the highest ever found for such raw material,making it attractive to compete with conventi on al lig no cellulosic biomass.

关键词： ligno cellulosic feedstock sulfur dioxide high solid loading hydrolysis central composite rotatable design