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排序方式: 共有232条查询结果,搜索用时 15 毫秒
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Josa. Trujillo-Quijano Delia B. Rodriguez-Amaya W. Esteves Gerhard F. Plonis 《European Journal of Lipid Science and Technology》1990,92(6):222-226
In oils extracted from fresh and sterilized palm fruits (Elaeis guineensis, Jacq. tenera, dura dumpy and psifera and E. oleifera), cis-phytofluene, 13-cis-α-carotene, α-carotene, 13-cis-β-carotene, β-carotene, 9-cis-β-carotene, σ-carotene, zeaxanthin, --cryptoxanthin, poly-cis-lycopene, mono-lycopene and lycopene, were identified and quantified by normal phase open column chromatography (stepwise-elution), TLC, UV/Vis spectroscopy and specific chemical reactions. The sum of α- and β-carotene in all samples analysed was higher than 80% of the total carotenoid content, while the α/β-carotene ratios were W.9, 1/11.1, 1/22 and V2.6 for oils extracted from fresh fruits of dura dumpy, psifera, tenera and E. oleifera, respectively. Total carotenoid contents (pg/g) and vitamin A values (R. E./100 g) of these samples were 1 120.7 and 12 404 for dura dumpy, 283.2 and 3612 for psifera, 660.5 and 7630 for tenera and 1576.8 and 21691 for E. oleifera. The sterilization of fruits (127°C × 35 min.) resulted in isomerization of pigments and reduction of vitamin A values of approximately 45% and 25%, respectively. 相似文献
3.
The incorporation of [1-14C] acetate into fatty acids by cultured epimastigotes ofTrypanosoma cruzi was studied. After 8, 24, and 48 hr incubation with labeled precursor, up to 2.8% of the initial radioactivity added to the
medium was found in theT. cruzi long chain fatty acids. Saturated (16∶0 and 18∶0), monounsaturated (18∶1ω9), and diunsaturated (18∶2ω6) fatty acids were
synthesized. Both the pattern of incorporation of labeled acetate into the fatty acids and the decarboxylation ratios found
suggest that de novo synthesis of fatty acids has taken place. 相似文献
4.
Inspired by the Multiplicative Exponential fragment of Linear Logic, we define a framework called the prismoid of resources where each vertex is a language which refines the λ-calculus by using a different choice to make explicit or implicit (meta-level) the definition of the contraction, weakening, and substitution operations. For all the calculi in the prismoid we show simulation of β-reduction, confluence, preservation of β-strong normalisation and strong normalisation for typed terms. Full composition also holds for all the calculi of the prismoid handling explicit substitutions. The whole development of the prismoid is done by making the set of resources a parameter of the formalism, so that all the properties for each vertex are obtained as a particular case of the general abstract proofs. 相似文献
5.
Delia Neuman 《Computers and the Humanities》1991,25(4):239-246
Delia Neuman is an assistant professor in the College of Library and Information Services at the University of Maryland, College Park. She has written several articles on the use of naturalistic inquiry to study electronic environments, including two published in Educational Technology Research and Development: Naturalistic Inquiry and Computer-Based Instruction: Rationale, Procedures and Potential (Spring 1989) and Learning Disabled Students' Interactions with Commercial Courseware: A Naturalistic Study (Spring 1991). She is currently involved in a study funded by the American Library Association to use naturalistic methods to investigate high school students' use of CD-ROM and online databases. 相似文献
6.
Elena Piacenza Simona Campora Francesco Carfì Pavia Delia Francesca Chillura Martino Vito Armando Laudicina Rosa Alduina Raymond Joseph Turner Davide Zannoni Alessandro Presentato 《International journal of molecular sciences》2022,23(20)
The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO32−) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO32− biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in environmental biotechnology. However, their exploration in TeO32− biotransformation is scarce due to limited knowledge regarding oxyanion microbial processing. Here, this gap was filled by investigating the cell tolerance, adaptation, and response to TeO32− of a Micromonospora strain isolated from a metal(loid)-rich environment. To this aim, an integrated biological, physical-chemical, and statistical approach combining physiological and biochemical assays with confocal or scanning electron (SEM) microscopy and Fourier-transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) was designed. Micromonospora cells exposed to TeO32− under different physiological states revealed a series of striking cell responses, such as cell morphology changes, extracellular polymeric substance production, cell membrane damages and modifications, oxidative stress burst, protein aggregation and phosphorylation, and superoxide dismutase induction. These results highlight this Micromonospora strain as an asset for biotechnological purposes. 相似文献
7.
Alejandro Aparicio-Saguilán Andrés Aguirre-Cruz Guadalupe Méndez-Montealvo Sandra L. Rodriguez-Ambriz Francisco J. Garcia-Suarez Delia E. Páramo-Calderón Luis A. Bello-Pérez 《LWT》2014
Two banana starches were studied to analyze the effect of the acid hydrolysis on their molecular structure, and the impact in their physicochemical features. The native banana starches exhibit differences in the amylose content, molar mass, gelatinization parameters, X-ray diffraction pattern, and pasting profile. These results suggested that different acid hydrolysis mechanisms may be operative in these two starches. The kinetic hydrolysis is different in both banana starches that are related to the crystalline packing of the starch molecules. This was confirmed by the amylose content, the X-ray diffraction pattern, and the thermal study in the acid hydrolyzed starches at different times. The acid-treated Roatan starch showed higher retrogradation than Macho starch, a phenomenon that increases in the sample hydrolyzed for the longer time. This pattern is related to the amylose/amylopectin ratio, the reduction in the molar mass and the gyration radius. The acid hydrolysis of banana starches, although they have some similarities, they are different. 相似文献
8.
Norberto Labrador Delia Gutiérre-Campos Olivier Rapaud Hélène Ageorges Alexandre Maitre 《Ceramics International》2019,45(9):11677-11685
High-purity nanocrystalline aluminum nitride powders were synthesized by using a 12?kW non-transferred arc plasma. The synthesis was conducted in a versatile, new designed, one-chamber thermal plasma reactor (TPR). The novel experimental assembly incorporated better working conditions like: high temperature gradient between the crucible and reactor's wall, and high super-saturation of the system by nitrogen and carbon. Thermodynamic modelling of the synthesis was conducted in order to achieve the best conditions for AlN formation. In this study, aluminum discs of Al 1100 were used as precursor material and pure nitrogen was the only gas used as reagent and plasmogenic gas.Nanopowders collected from reactor's wall were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-Ray diffraction (XRD). Synthesized h-AlN nano-powders were found to be free of oxides and aluminum metal. A thin carbon-layer around the particles was detected. TEM results indicated that the carbon-layer was around 5 and 10?nm. This outcome could make a significant difference with other synthesis reported in the literature since the occurrence of the carbon-layer, could delay AlN oxidation, prevent hydration, and could avoid the agglomeration of the particles. 相似文献
9.
10.
N‐Benzyl‐4‐((heteroaryl)methyl)benzamides: A New Class of Direct NADH‐Dependent 2‐trans Enoyl–Acyl Carrier Protein Reductase (InhA) Inhibitors with Antitubercular Activity
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Ana Guardia Dr. Gulcin Gulten Dr. Raquel Fernandez Jesus Gómez Dr. Feng Wang Dr. Maire Convery Delia Blanco María Martínez Dr. Esther Pérez‐Herrán Marta Alonso Dr. Fátima Ortega Dr. Joaquín Rullás Dr. David Calvo Lydia Mata Dr. Robert Young Prof. James C. Sacchettini Dr. Alfonso Mendoza‐Losana Dr. Modesto Remuiñán Dr. Lluís Ballell Pages Dr. Julia Castro‐Pichel 《ChemMedChem》2016,11(7):687-701
Isoniazid (INH) remains one of the cornerstones of antitubercular chemotherapy for drug‐sensitive strains of M. tuberculosis bacteria. However, the increasing prevalence of multidrug‐resistant (MDR) and extensively drug‐resistant (XDR) strains containing mutations in the KatG enzyme, which is responsible for the activation of INH into its antitubercular form, have rendered this drug of little or no use in many cases of drug‐resistant tuberculosis. Presented herein is a novel family of antitubercular direct NADH‐dependent 2‐trans enoyl–acyl carrier protein reductase (InhA) inhibitors based on an N‐benzyl‐4‐((heteroaryl)methyl)benzamide template; unlike INH, these do not require prior activation by KatG. Given their direct InhA target engagement, these compounds should be able to circumvent KatG‐related resistance in the clinic. The lead molecules were shown to be potent inhibitors of InhA and showed activity against M. tuberculosis bacteria. This new family of inhibitors was found to be chemically tractable, as exemplified by the facile synthesis of analogues and the establishment of structure–activity relationships. Furthermore, a co‐crystal structure of the initial hit with the enzyme is disclosed, providing valuable information toward the design of new InhA inhibitors for the treatment of MDR/XDR tuberculosis. 相似文献