cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2009.1670
title: Skin delivery of Propylthiouracil from vesicular systems

description: Vesicular systems are known to improve skin delivery of many drugs with diversity in solubility. The mechanism of skin delivery of these systems is inconclusive and likely to depend on the drug delivered. The aim of this present study was to investigate the skin delivery of a model lyophobic drug from vesicular systems. The study focused on skin delivery mechanism and the factors affecting skin permeation from vesicular systems. In this study, propylthiouracil (PTU) was used as a model lyophobic drug. Three vesicular systems containing PTU, i.e. liposomes, niosomes, and ethosomes, were prepared and characterized with regard to size and size distribution, drug entrapment efficiency, phase transition temperature, and drug release. The skin delivery of PTU from vesicular systems was studied using modified Franz diffusion cells. The newborn pig skin was used as a membrane. The results demonstrated that the vesicle size and the drug entrapment efficiency of PTU vesicular systems depended on the composition of the system. All PTU vesicular systems were in liquid crystalline-state at the temperature used in the study. Drug release studies revealed that all vesicular systems could sustain the release of PTU and the release was consistent with the first order kinetics. The 24-hour cumulative percent release of PTU up to 90% was achieved. In skin permeation study under the non-occlusive condition, the liposomal systems did not enhance PTU permeation through the skin, while the niosomal system and the ethosomal systems were likely to improve PTU skin delivery. The application condition had a considerable impact on skin permeation of PTU from the ethosomal systems. The ethosomal systems were thus selected for further investigation under the occlusive condition. The effect of existence of vesicular structure on PTU permeation from ethosomes was less remarkable than the synergistic enhancing effect of the ethosomal components and the solvent used in the study. Analysis of the data from characterization and skin permeation studies under the occlusive condition indicated that the diffusion of free drug, the mixing of the vesicles with the skin lipids, and the penetration enhancement were all possible to occur in skin permeation of PTU from the ethosomal systems. Therefore, skin delivery of PTU from the ethosomal systems appeared to involved several mechanisms that operated simultaneously.
DOI: 10.14457/cu.the.2009.1671
title: Surface modification of starch grains by adsorption of stearic acid using supercritical fluid technology

description: The rapid expansion of supercritical solution with a nonsolvent (RESS-N) was applied to modify the surface of corn starch grains by coating with stearic acid. The effects of temperature and pressure of scCO2, and ratio of starch and stearic acid on the surface modification of starch grains were investigated. Coated starches were characterized using scanning electron microscopy (SEM), laser light scattering particle size analysis, moisture absorption, powder flowability and density measurement, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and Fourier transform infrared (FT-IR) spectroscopy and was applied as lubricant in tabletting process in comparison with stearic acid and magnesium stearate. The pressure of scCO2 did not affect but temperature of scCO2 and ratio of corn starch and stearic acid were found to be the influential factors on surface modification of starch grains. SEM images showed that stearic acid deposited onto the surface of starch grains forming a thin, uniform and smooth film when reducing the content of stearic acid using pressure of 3000 psi and temperature of 60 °C. This result was supported by an increase in particle size of coated starch which corresponding with the amount of stearic acid used in the mixture. The gravimetric vapour sorption analysis of coated starches showed the percentage of mass change lower than uncoated corn starch, this result corresponding with the result obtained from the determination of moisture absorption property using Karl Fischer method. It indicated that coated starches were coated with stearic acid, a hydrophobic material, almost did not absorb moisture. The bulk and tapped density, compressibility index and apparent density showed different between uncoated corn starch and coated starch. Physicochemical characterizations of coated starches indicated that no change and/or evidence of interaction between starch and stearic acid. The stearic acid coated starches could be applied as a lubricant in tablet formulations.
DOI: 10.14457/cu.the.2009.1672
title: Synthesis of oxazolidinones via acid- and halo-induced intramolecular cyclization

description: Two novel synthetic pathways toward 2-oxazolidinone derivatives were developed. The first pathway is the acid-induced intramolecular cyclization of β-(N-arylcarbamyl) epoxides. Simple treatment of a β-(N-arylcarbamyl)epoxide with trifluoroacetic acid exclusively gave the corresponding N-aryl-2-oxazolidinone in excellent yield. Mechanistically, the Boc carbonyl oxygen intramolecularly attacks the acid-activated epoxide ring in 5-exo-tet fashion to form the desired oxazolidin-2-ones. Toloxatone, a well known antidepressant, and Linezolid (Zyvox®) antibacterial medicine were successfully synthesized from this cyclization method. The second synthetic pathway involves halo-induced cyclization of tert-butyl allyl(phenyl)carbamate. Various halogenated reagents were evaluated for reaction optimization. The synthesis of oxazolidinone derivatives containing one or two halogen atoms were successfully established for all chloro, bromo and iodo compounds. Either unsubstituted-aryl oxazolidinone or p-halo-substituted-aryl oxazolidinone were selectively produced with appropriate choice of halogenated reagents.
DOI: 10.14457/cu.the.2009.1674
title: Inhibitory effect of asiaticoside and madecassoside on human cytochrome P450

description: Asiaticoside and madecassoside, the triterpenoid compounds found in Centella asiatica (Linn.) Urban, are the major constituents in the standardized extract of C. asiatica (ECa233). Both compounds possess several interesting pharmacological effects. To obtain the preliminary drug interaction data, the aim of this study was to investigate inhibitory effects and types of inhibition of asiaticoside and madecassoside on human CYPs by using recombinant human CYPs in an in vitro study. This study included 3 parts: IC50 determination of asiaticoside and madecassoside on human CYP, assessment of mechanism-based inhibition and determination of the type of inhibition using enzyme kinetic study. For IC50 determination, asiaticoside inhibited CYP2C19 (IC50 = 412.68 µM) and CYP3A4 (IC50 = 343.35 µM). Madecassoside inhibited CYP2C19 (IC50 = 539.04 µM) and CYP3A4 (IC50 = 453.32 µM). Both asiaticoside and madecassoside did not affect CYP1A2, CYP2C9 and CYP2D6 (IC50&gt;1,000 µM). Inhibition of asiaticoside on CYP2E1 was not observed at the concentration up to 200 µM while madecassoside did not affect CYP2E1 (IC50&gt;1,000 µM). As asiaticoside and madecassoside demonstrated inhibitory effects on CYP2C19 and CYP3A4, types of inhibition of both CYPs were performed. In the mechanism-based inhibition study, madecassoside was shown to probably be a mechanism-based inhibitor of CYP2C19 and CYP3A4. Asiaticoside which was limited by its solubility, assessment of its mechanism-based inhibition potential could not be achieved. To determine the type of reversible inhibition, asiaticoside exhibited a pattern of noncompetitive inhibition of CYP2C19 (Ki = 588 µM) and CYP3A4 (Ki = 769 µM). Madecassoside also exhibited a pattern of noncompetitive inhibition of CYP2C19 (Ki = 140 µM) and CYP3A4 (Ki = 692.86 µM). Results from this study provided the potential information that both asiaticoside and madecassoside are probable to cause drug–drug interactions with medicines that are metabolized by CYP2C19 and CYP3A4. Further investigation is needed to evaluate whether these inhibitory effects of both compounds on both CYP isoforms are clinically significant.
DOI: 10.14457/cu.the.2009.1675
title: Gene expression related to free fatty acid synthesis in physic nut Jatropha curcas L. kernel by proteomics technique analysis

description: Jatropha curcas L. is one of economic important crops used for its seed oil which can substitute for diesel. Free fatty acid profiles and proteins profiles of J. curcas kernel during development were studied. Developmental seeds were divided into 8 stages based on morphology. Free fatty acid was analyzed using gas chromatography. The results suggested that free fatty acid levels were changed at all stages of development from stage I to stage VIII. The major free fatty acid was oleic acid and the minor free fatty acids included linoleic acid, palmitic acid, and stearic acid. Furthermore, the protein profiles determined by proteomics technique indicated that 245 proteins were differentially expressed during the seed development such as proteins related to seed development (AP2 domain-containing protein and late embryogenesis abundant protein), proteins related to free fatty acid synthesis (acetyl CoA carboxylase and phosphoenolpyruvate carboxylase), and proteins related to fruit ripening (ACC oxidase and ACC deaminase). Moreover, a protein related to toxicity (curcin), that was only found in J. curcas was discovered. Real-time RT PCR was employed in a study of proteins involved in the biosynthesis of free fatty acids. These proteins included acetyl CoA carboxylase (ACCase), phosphoenolpyruvate carboxylase (PEPC), mercaptopyruvate sulfurtransferase (MST) and 4-coumarate: coenzyme A ligase (CMCoA). The results revealed that the relative mRNA expression level of each gene was altered in a similar pattern with regard to the amount of most free fatty acids. The decreased level of free fatty acids from stage IV to stage VI may caused by β-oxidation metabolism to generate energy for other metabolism. Additionally, intermediate substances from β-oxidation process may be used in flavonoid biosynthesis.
DOI: 10.14457/cu.the.2009.1676
title: Using RNAi technique to investigate the roles of Notch1 gene in macrophages

description: Notch gene encodes a protein family of conserved transmembrane receptors expressed on a cell surface. There are four Notch genes, i.e. Notch1, 2, 3 and 4 in veterbrates. Five ligands have been identified, i.e. Jagged-1 and-2 and Dll-1, 3 and 4. Notch signaling is initiated with the interaction of receptor and ligand. Notch signaling is involved in maintenance of stem cells, binary cell-fate decisions, induction of terminal differentiation and also in tumorigenesis. Macrophages are white blood cells performing important roles in both innate and acquired immunity. Previously, it was reported that Notch receptors are expressed in lipopolysaccharide (LPS)/interferon gamma (IFNγ) - activated macrophages. To investigate the role of Notch1 in macrophages in this study, RNAi technique was applied to specifically silence Notch1 expression in RAW264.7 macrophage-like cell line. Silencing of Notch1 resulted in cellular morphological alteration, and increased pro-inflammatory molecule production such as the nitric oxide and MHC class II and cytokines expression including IL-10, IL-12p40 and TNF. We unexpectedly found that one of the target genes of Notch signaling Deltex1 was significantly up-regulated in the absence of LPS / IFNγ stimulation. Knock down Notch1 in macrophages increased efficacy in bactericidal activities against both gram negative and positive bacteria. Therefore, Notch1 is involved in effector functions of macrophages during both innate and acquired immune responses. Hence, Notch1 might be the therapeutic target for manipulating macrophage functions.
DOI: 10.14457/cu.the.2009.1677
title: Preparation and electrical conductivity of nutural rubber/polypyrole/montmorillonite nanocomposites

description: The natural rubber (NR) /polypyrrole (PPy) composites were prepared by the chemical oxidative polymerization of pyrrole in aqueous solution of natural rubber latex. The reactions were carried out at 0 ºC for 1 hour using FeCl3 solution as an oxidant with constant FeCl3:pyrrole mole ratio of 2.5. The amount of PPy in the composite was weight determined from 60 ºC oven-dried material. The electrical conductivities of the composites were measured with a home-made four-point probe set up. Parameters affecting the electrical conductivity of the composites were studied, i.e. the amount of pyrrole monomer, types of solvent, the addition of surfactant, the amount of montmorillonite (MMT), and types of organically modified montmorillonite (oMMT). It was found that loading of pyrrole gave the composites with increasing electrical conductivities, with the highest value of which was 4.44 Scm-1 for 15 wt% of PPy. Higher electrical conductivity (7.16 Scm-1) was obtained with addition of sodium dodecylbenzene sulfonate(SDBS). In the presence of MMT, the nanocomposites exhibited higher electrical conductivity with increasing MMT content. The electrical conductivity of the nanocomposites prepared with sodium dodecylbenze sulfonate montmorillonite modifier gave the highest value of 7.38 Scm-1. An XRD pattern showed an increase in d-spacing of MMT from 1.26 nm to 1.84 nm of NR/PPy/MMT nanocomposite, confirming the intercalation of conducting PPy into MMT layers. The use of organic modifier increased the d-spacing of MMT to 2.80 nm. The thermal stabilities of NR/PPy, NR/PPy/MMT, and NR/PPy/oMMT composites were found to be higher than pristine PPy.
DOI: 10.14457/cu.the.2009.1678
title: Preparation Cr₂O₃ and CrN diffusion barriers for stainless steel supported palladium membrane

description: In this research, chromium oxide (Cr₂O₃ ) and chromium nitride (CrN) thin films were fabricated as the intermetallic diffusion barriers between the palladium (Pd) membrane and stainless steel (SS) support. Three different methods for preparation of Cr₂O₃ were investigated, i.e., thermal oxidation, oxidized Cr-electroplating, and oxidized Cr-sputtering. The thickness of chromium thin films was controlled by chromium deposition time and measured by gravimetric method and SEM. They were found to be 2 to 6 µm as determined by SEM. The optimum condition for the oxidation of chromium to Cr₂O₃ was at 600°C for 6 hours. The CrN thin film was formed by Cr-sputtering in nitrogen atmosphere. The composition and phase structures of Cr-based thin films were studied by EDS and XRD. The Pd membranes were then developed on top of Cr-based thin films by electroless plating. The efficacies in preventing intermetallic diffusion were assessed employing SEM-EDS to analyze the elemental content of the palladium layer after hydrogen exposure for 24 hours at 400, 500 or 600°C. After the hydrogen exposure, all Cr-based thin films acted as the good intermetallic diffusion barriers, with no detectable presence of elementals from the SS disk on Pd layer. Among the four types of thin films, Cr₂O₃ created by sputtering and oxidation showed the highest permeation flux which was measured at 350-500°C in pressure differences of 1-3 atm.
DOI: 10.14457/cu.the.2009.1679
title: Preparation of bromosilane from hydrosilane using brominating agents

description: Two methodologies for the preparation of bromosilane from hydrosilane have been developed. The first system comprising of ethyl tribromoacetate (Br₃ CCOOEt) with a catalytic amount of PdCl₂ at reflux THF, could convert hydrosilane to bromosilane in high yield within 15 min. The mechanism of this system was proposed to occur via the interaction of brominating agent with Pd(0) by oxidative addition, followed by reductive elimination. For the second system, high yield of bromosilane could be achieved by using hexabromoacetone (Br₃ CCOCBr₃ ) in the presence of UV irradiation (254 nm, 6W) within 45 min. The mechanism was believed to occur via a radical pathway supporting by the evidence of trapping experiment. In addition, the relative reactivity of brominating agent towards the synthesis of bromosilane was studied. Br₃ CCOOEt revealed the highest reactivity. These developed methodologies could further be applied for the synthesis of silyl ethers and silyl esters in high yield by one-pot reaction.
DOI: 10.14457/cu.the.2009.1680
title: The effect of inclination of the maxillary central incisor and the M/F ratio on the tooth movement, periodontal stress and strain : finite element method

description: The purpose of this study was to determine the effect of inclination of a maxillary central incisor and the moment to force ratio on anteroposterior and vertical movement and periodontal stress and strain by using the finite element method (FEM). Five 3D models of a right maxillary central incisor were constructed based on average anatomical dimensions with 0, 10, 20, 30, and 40 -degree inclination. A constant lingual force of 1 N at 4.5 mm apical to the incisal edge and the moment varied from 8 to 9, 10, 11, and 12 N-mm were applied to each model. Anteroposterior movement of the incisal edge and apex and vertical movement of incisal edge were measured. Periodontal stress and strain were expressed as the areas and magnitude of the highest maximum principal stress and strain and also the lowest minimum principal stress and strain. The results showed that with increasing inclination and the moment to force ratio, the incisal edge tended to move labioapically and the apex tended to move lingually. Moreover, with increased inclination, the moment to force ratio which produced bodily movement decreased but the location of the center of resistance of a maxillary central incisor was relatively constant in terms of the proportion of vertical distance to the root length from the apex, which was approximately 0.67. In bodily movement, the area of maximum compressive stress and strain changed from mid root area in 0° inclination to apical area in 40° inclination; while the area of maximum tensile stress changed from mid root area to cervical area but the area of maximum tensile strain was still in the mid root area. With increased inclination, magnitude of maximum compressive stress and strain and tensile strain increased but maximum tensile stress decreased.
DOI: 10.14457/cu.the.2009.1681
title: Zr-based intermetallic diffusion barrier for stainless steel supported palladium membrane

description: Electroless-plated palladium membranes were prepared on 316L stainless steel supports with Zr-based intermetallic diffusion barriers, i.e., Zr, ZrO₂ and ZrN. A dc magnetron sputtering method was used to deposit Zr films. The ZrO₂ thin films were obtained from oxidation of Zr thin films in air at 500°C for 1 hour. The ZrN thin films were grown by dc reactive magnetron sputtering at nitrogen flow rate of 2 sccm to obtain stoichiometriccomposition. The prepared films were characterized by XRD, EDS and SEM for phase structure, elemental composition, and surface morphology, respectively. SEM-EDS line scan was used to investigate palladium membranes with and without the diffusion barriers under hydrogen atmosphere at 400-600°C for 24 hours. It was found that ZrO₂ intermetallic diffusion barrier was more effective than ZrN and Zr. The hydrogen permeation flux obtained from palladium membranes with the diffusion barriers was higher than that without, with increasing order, Zr 0.5 µm &lt; ZrN 0.5 µm &lt; ZrO₂ 0.17 µm &lt; ZrO₂ 0.5 µm. Thus, ZrO₂ thin film is the most suitable intermetallic diffusion barrier due not only to prevent the metal migration into palladium membranes but also giving high hydrogen permeance.
DOI: 10.14457/cu.the.2009.1682
title: Synthesis and protein immobilization of poly(acrylic acid) brushes for stem cell culture

description: Surface-tethered poly(acrylic acid) (PAA) brushes were prepared by surface initiated polymerization of tert-butyl acrylate from glass substrates via activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) followed by hydrolysis using methanesulfonic acid. Upon using an optimized condition, poly(tert-butyl acrylate) brushes having a graft density of approximately 0.33 chains/nm² were obtained. Carboxyl groupdensityof the PAA brushes can be varied as a function of the chain length or molecular weight ranging from 0.7 x10⁻⁹ to 1.6 x10⁻⁹ mol/cm². It has been demonstrated that the carboxyl groups of PAA brushes are readily available for attachment of BSA and N-cadherin mimic cyclic peptide. The successive surface modification via polymer brushes formation and protein/peptide immobilization were also verified by ATR-FTIR analysis and water contact angle measurements. According to cytotoxicity test against mouse neural progenitor cell, it was found that the immobilized N-cadherin mimic cyclic peptide on PAA brushes was non toxic and provided a level of cell compatibility equivalent to that of the surface coated with laminin, a commonly used adhesive protein for stem cell culture suggesting its potential in stem cell culture applications.
DOI: 10.7910/dvn/eple6o/9km4ga
title: 02 Questionnaire (English).pdf

description: :unav
DOI: 10.7910/dvn/eple6o/egx9oy
title: 03 Data.do

description: :unav
DOI: 10.7910/dvn/eple6o/qpvvlx
title: 04 Codebook.tab

description: :unav
DOI: 10.7910/dvn/eple6o/qvndm2
title: 01 Questionnaire (Pashtu).pdf

description: :unav
DOI: 10.7910/dvn/eple6o/p7tcxo
title: 00 Description.pdf

description: :unav
DOI: 10.7910/dvn/eple6o/xlpezw
title: 03 Data.tab

description: :unav
DOI: 10.7910/dvn/zmdavl/gov1eh
title: make_tables_figures.do

description: :unav
DOI: 10.7910/dvn/zmdavl/l4fxke
title: README.txt

description: :unav
DOI: 10.7910/dvn/zmdavl/6ff4mm
title: nonrespondent_major_groups.tab

description: :unav
DOI: 10.7910/dvn/zmdavl/fid6hb
title: final_data.tab

description: :unav
DOI: 10.17632/6ktcs4c5j6.1
title: Data for: Social norm nudging and preferences for household recycling

description: Data, code and full results for the models presented in this study.
DOI: 10.14457/cu.the.2009.1621
title: Thermochromic polydiacetylene from nano aggregate of diacetylene lipids with varying alkyl chain lengths

description: Four series of diynoic acid, monoamide, diamide and unsymmetrical diamide lipids containing various lengths of methylene spacer (m = 2, 3 and 4) between the diyne and the head groups and number of methylene units (n = 6 and 9) in their hydrophobic tails are synthesized. After sonication in water, the diynoic acid and monoamide lipids with m = 4 can be dispersed in water while all diamide and unsymmetrical diamide lipids can be dispersed in water very well. All successfully dispersed diacetylene sols were photopolymerized by UV irradiation at 254 nm to give the corresponding polydiacetylene (PDA) sols. The color transitions from blue to red upon heating of the PDA sols from 20-90 °C are photographically recorded and monitored by UV-vis absorption spectroscopy. The diynoic acid and monoamide exhibited irreversible thermochromism while the diamide and unsymmetrical diamide exhibited reversible thermochromism. The color transition temperatures of diamide PDA sols can be tuned between 10-70 °C by the variation of m and n values. The increase of n value enhances the thermal stability resulting in higher color transition temperature. For m value, both the length and odd/even number affect the thermal stability of the PDAs. The lower or the even m values tend to reduce the thermal sensibility and thus increase the color transition temperature while the higher or the odd m values pose the opposite effects. The degree of reversibility, stability and morphology of these PDAs are also investigated.