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排序方式: 共有312条查询结果,搜索用时 281 毫秒
301.
Elzbieta Winnicka Matgorzata Pajak Katarzyna Patka Katarzyna Czerwiflska Marianna Kafiska 《化学与化工:英文版》2014,(1):54-60
The isotopomers of halogenated amino acids (2'-F-L-phenylalanine, 3'-F- and 3'-Cl-L-tyrosine, as well as 5'-F-, 5'-Br-and 6'-F-L-tryptophan) specifically labeled with deuterium at α- and 13-carbon atom of the side chain were synthesized by enzymatic catalyzed H/D exchange in fully deuteriated incubation medium. The extent and site of deuterium incorporation were confirmed by ^1H NMR (proton nuclear magnetic resonance) spectra. 相似文献
302.
Guizzunti G Batova A Chantarasriwong O Dakanali M Theodorakis EA 《Chembiochem : a European journal of chemical biology》2012,13(8):1191-1198
The natural product gambogic acid (GA) has shown significant potential as an anticancer agent as it is able to induce apoptosis in multiple tumor cell lines, including multidrug-resistant cell lines, as well as displaying antitumor activity in animal models. Despite the fact that GA has entered phase I clinical trials, the primary cellular target and mode of action of this compound remain unclear, although many proteins have been shown to be affected by it. By thorough analysis of several cellular organelles, at both the morphological and functional levels, we demonstrate that the primary effect of GA is at the mitochondria. We found that GA induces mitochondrial damage within minutes of incubation at low-micromolar concentrations. Moreover, a fluorescent derivative of GA was able to localize specifically to the mitochondria and was displaced from these organelles after competition with unlabeled GA. These findings indicate that GA directly targets the mitochondria to induce the intrinsic pathway of apoptosis, and thus represents a new member of the mitocans. 相似文献
303.
304.
Shilpa C. Mhadgut Marianna Török Sujaya Dasgupta Béla Török 《Catalysis Letters》2008,123(1-2):156-163
The mode of enantioselection in the proline modified asymmetric hydrogenation of isophorone (3,5,5-trimethyl-2-cyclohexenone) on supported Pd catalysts has been studied. It is shown that several experimental factors, such as modifier structure and chemical nature of the catalyst support, strongly affect the outcome of the hydrogenations. Secondary kinetic resolution was found to be the major reason for obtaining high enantioselectivities on most catalysts. Extensive studies have been carried out to clarify the importance of the interaction of the proline–dihydroisophorone complex with the catalyst. The secondary kinetic resolution of dihydroisophorone was investigated under different conditions. First, racemic-dihydroisophorone was studied using several (S)-proline modified supported Pd catalysts, then the individual enantiomers were subjected to a similar reaction on Pd/BaCO3 catalyst in the presence of (S)-proline. Our results provide convincing support for the heterogeneous enantioselection model under the current experimental conditions. 相似文献
305.
Fabio Montagnaro Marianna Nobili Piero Salatino Antonio Telesca Gian Lorenzo Valenti 《Fuel Processing Technology》2008
Fluidized bed combustion (FBC) enables the in situ capture of SO2, but generates large amounts of wastes whose composition and physico-chemical properties make both landfilling and reuse in traditional fields of application (e.g., cement and concrete industries) problematic. Reactivation by water hydration of the desulphurizing ability of these residues is considered a viable mean for their recycling: besides Ca(OH)2, this process can generate other hydration products, such as ettringite. This paper is devoted to a comparison between the behaviour of Ca(OH)2 and ettringite as SO2 sorbents. To this end, synthetic preparations (in the particle size range 0.4–0.6 mm) of the two materials were dehydrated and then sulphated in a lab-scale fluidized bed reactor. Sulphation tests were carried out at 850 °C by fluidizing the bed with an SO2–N2–O2 mixture (1800 ppm SO2) at 0.8 m/s. Calcium conversion degree and fines elutriation rate were evaluated as a function of sulphation time. The propensity of the sorbents to undergo fragmentation was also estimated by particle sizing of in-bed exhausted sorbent particles, with the aid of laser granulometry. Mercury intrusion porosimetry of samples was directed to the assessment of the influence of sorbent dehydration and subsequent sulphation on pore size distribution and porosimetric texture. X-ray diffraction and differential thermal analysis on the synthetic sorbents complemented the characterization. Results showed that dehydration/thermal decomposition brought about a significant increase of the overall porosity for both sorbents, more extensive than it is commonly observed with calcined commercial limestones. Upon sulphation, the two sorbents showed satisfactory degrees of calcium conversion, larger than those usually observed with limestones. Sulphation resulted into a decrease of particle voidage (that of the Ca(OH)2-based sorbent was negligible after the process). Ettringite was more prone to attrition/fragmentation than calcium hydroxide. Results are discussed with a focus on differences between calcium hydroxide and ettringite and on key-parameters affecting the performance of the two materials as sorbents. 相似文献
306.
Zalán Z Hudáček J Tóth-Markus M Husová E Solichová K Hegyi F Plocková M Chumchalová J Halász A 《Journal of the science of food and agriculture》2011,91(4):672-679
BACKGROUND: In the tubers of Jerusalem artichoke (Helianthus tuberosus L.) the main carbohydrate is the well‐known prebiotic inulin, which is a good growth substrate for gut microorganisms. Jerusalem artichoke tuber is traditionally consumed boiled or pickled rather than in fermented form. Lactic acid bacteria are traditionally used in the production of fermented foods; nevertheless their behavior and metabolite production are considerably influenced by the substrate. The purpose of this study was to investigate the growth and production of the most important sensorically and antimicrobially active metabolites of different Lactobacillus strains on Jerusalem artichoke juice. RESULTS: All investigated strains grew well (in the range 109 cfu mL?1) in the media. The organic acids (lactic acid, 110–337 mmol L?1; acetic acid, 0–180 mmol L?1; and succinic acid, 0–79 mmol L?1), hydrogen peroxide (0.25–1.77 mg L?1), mannitol (0.06–3.24 g L?1), acetoin and diacetyl production of strains varies not only according to the species but also from strain to strain, which will be demonstrated and discussed in the paper. CONCLUSION: Our results showed that lactobacilli can be used for the fermentation of Jerusalem artichoke, which in this form could be used, alone or mixed with other raw food material, as a new synbiotic functional food. Copyright © 2011 Society of Chemical Industry 相似文献
307.
Oxidative and Microbiological Profiles of Chicken Drumsticks Treated with Ultraviolet‐C Radiation 下载免费PDF全文
308.
Marianna Mastromatteo Amalia Conte Michele Faccia Matteo Alessandro Del Nobile Angelo Vittorio Zambrini 《Journal of dairy science》2014
In this work, the effect of active coating on the shelf life of low-moisture Mozzarella cheese packaged in air and modified atmosphere (MAP) was studied. The active coating was based on sodium alginate (2%, wt/vol) and potassium sorbate (1%, wt/vol). The MAP was made up of 75% CO2 and 25% N2 (MAP1), 25% CO2 and 75% N2 (MAP2), or 50% CO2 and 50% N2 (MAP3). The product quality decay was assessed by monitoring microbiological and sensory changes during storage at 4, 8, and 14°C. Results showed that the combination of active coating and MAP was able to improve the preservation of low-moisture Mozzarella cheese. Specifically, the shelf life increased up to 160 d for samples stored at 4°C, and 40 and 11 d for those at 8 and 14°C, respectively. A faster quality decay for untreated samples packaged in air was observed. In particular, the Pseudomonas spp. growth and the appearance of molds were responsible for product unacceptability. The combination of active coating and MAP represents a strategic solution to prolong the shelf life of low-moisture Mozzarella cheese and to ensure the safety of the product under thermal abuse conditions. 相似文献
309.
Elena Messina Chiara Giuliani Marianna Pascucci Cristina Riccucci Maria Paola Staccioli Monica Albini Gabriella Di Carlo 《International journal of molecular sciences》2021,22(19)
The protection of metals from atmospheric corrosion is a task of primary importance for many applications and many different products have been used, sometimes being toxic and harmful for health and the environment. In order to overcome drawbacks due to toxicity of the corrosion inhibitors and harmful organic solvents and to ensure long-lasting protection, new organic compounds have been proposed and their corrosion inhibition properties have been investigated. In this work, we describe the use of a new environment-friendly anticorrosive coating that takes advantage of the synergism between an eco-friendly bio-polymer matrix and an amino acid. The corrosion inhibition of a largely used Copper-based (Cu-based) alloy against the chloride-induced indoor atmospheric attack was studied using chitosan (CH) as a biopolymer and l-Cysteine (Cy) as an amino acid. To evaluate the protective efficacy of the coatings, tailored accelerated corrosion tests were carried out on bare and coated Cu-based alloys, further, the nature of the protective film formed on the Cu-based alloy surface was analyzed by Fourier-transformed infrared spectroscopy (FTIR) while the surface modifications due to the corrosion treatments were investigated by optical microscopy (OM). The evaluation tests reveal that the Chitosan/l-Cysteine (CH/Cy) coatings exhibit good anti-corrosion properties against chloride attack whose efficiency increases with a minimum amount of Cy of 0.25 mg/mL. 相似文献
310.
Beata Smolarz Marianna Makowska Hanna Romanowicz 《International journal of molecular sciences》2021,22(21)
Pharmacogenomic studies in epilepsy are justified by the high prevalence rate of this disease and the high cost of its treatment, frequent drug resistance, different response to the drug, the possibility of using reliable methods to assess the control of seizures and side effects of antiepileptic drugs. Candidate genes encode proteins involved in pharmacokinetic processes (drug transporters, metabolizing enzymes), pharmacodynamic processes (receptors, ion channels, enzymes, regulatory proteins, secondary messengers) and drug hypersensitivity (immune factors). This article provides an overview of the literature on the influence of genetic factors on treatment in epilepsy. 相似文献