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排序方式: 共有1059条查询结果,搜索用时 15 毫秒
991.
JF Dymling O Ljungberg CJ Hillyard PB Greenberg IM Evans I MacIntyre 《Canadian Metallurgical Quarterly》1976,82(3):500-509
Oral whisky is a potent stimulus of calcitonin secretion. Peak increments of immunoreactive calcitonin are observed within 15 min after the ingestion of 50 ml of whisky; the magnitude of the response is similar to that observed during a four-hour calcium infusion. This procedure has several advantages over standard methods of stimulating calcitonin release in patients at risk of developing medullary carcinoma of the thyroid, and this is shown by a study in a large family with familial chromaffinomatosis. 相似文献
992.
Nadia Bouaziz Fatma Aouaini Yosra Ben Torkia Abeer S. Altowyan Abdelmottaleb Ben Lamine 《International Journal of Hydrogen Energy》2021,46(17):10389-10395
To obtain good economic and environmental benefits, LaMgNi3.6M0.4 (M = Al, Mn, Ni, Co, Cu) alloys are investigated for the hydrogen storage. The absorption data of hydrogen in the tested alloys are measured experimentally at 373 K. The hydrogen absorption isotherms are analyzed using three models derived from statistical physics formalism. The adequate model permits to discover significant details about the absorption phenomenon via determining the density of the interstitial sites (Dm), the number of hydrogen atoms per site (n) and the energetic parameter ΔE. The results indicate that multi-atomic (n > 1) and multi-linking (n < 1) phenomena are feasible for hydrogen absorption in LaMgNi3.6M0.4 (M = Al, Mn, Ni, Cu, Co) metals. The effects of the substitutions of Ni with Mn, Co, Cu and Al on the hydrogen absorption capacity are investigated. The interaction hydrogen/metal is analyzed by the calculation of the absorption energies. The chemical interaction is the responsible for the hydrogen absorption phenomenon. The contribution of this work is to provide advanced investigations of the hydrogen absorption mechanism in LaMgNi3.6M0.4 (M = Al, Mn, Ni, Co, Cu) metals, which are promising alloys for the hydrogen storage. 相似文献
993.
Nadia Magnenat-Thalmann 《Computer Languages, Systems and Structures》1982,7(3-4):161-170
The purpose of this paper is to analyze the major characteristics of the implementation language for very large portable software packages and to identify the most suitable programming languages for Automatic Translation. Criteria such as Portability, Modularity, Reliability, Human Factors, Technical Richness, Performance and Adaptability are analyzed.
Four programming languages (PASCAL, C, FORTRAN 77 and ADA) are selected. The advantages and disadvantages of each of the four programming languages are studied according to the criteria presented above. 相似文献
994.
Holy Nadia Rabetafika Brahim Bchir Mario Aguedo Michel Paquot Christophe Blecker 《Food and Bioprocess Technology》2014,7(3):749-760
This study examined the influence of applied technologies namely desugaring, grinding, and bleaching on the compositions (cellulose, hemicelluloses, lignins, and pectins), physicochemical properties (water-holding capacity (WHC), swelling capacity (SWC), oil-holding capacity (OHC)) and the colour of dietary fibre (DF) during the production of fibre concentrates from unusual cooked apple and pear pomaces. Thermogravimetric analysis (TGA) and optical microscopy were also performed to monitor process-induced modification. All the processing conditions affected the compositions and physicochemical properties of DF. The bleaching treatment induced the greatest changes on DF producing yellow cellulose-rich fibre concentrates with improved WHC from 3.2 to 10.0 g/g and improved SWC from 4.0 to 8.8 ml/g. Otherwise, reduction of the particle size influenced hydration properties and colours of DF. WHC and SWC tended to increase with the particle size whereas smaller granulometric size increased the lightness of fibres. Desugaring increased the DF content in both pomaces by 1.2-fold with slight modification of apple insoluble dietary fibre ratio. Fibre concentrates had improved WHC and SWC up to 1.4-fold. All processes had no significant effect (p?<?0.05) on OHC of DF except with ultrafine apple fibre concentrates. Results showed that processing had overall positive effects on DF contents and hydration properties of pomaces from cooked fruits. Bleached fibre concentrates from apple pomace had the highest WHC (10.0 g/g) whereas that of pear had the highest fibre content (89.9 %). Fibres from cooked fruit pomaces may therefore be used as textural ingredients or functional foods. 相似文献
995.
Mutamed M. Ayyash Abdelmoneim K. Abdalla Nadia S. AlKalbani Mohd Affan Baig Mark S. Turner Shao-Quan Liu Nagendra P. Shah 《Journal of dairy science》2021,104(8):8363-8379
The selection of potential probiotic strains that possess the physiological capacity of performing successfully in the gastrointestinal tract (GIT) is a critical challenge. Probiotic microorganisms must tolerate the deleterious effects of various stresses to survive passage and function in the human GIT. Adhesion to the intestinal mucosa is also an important aspect. Recently, numerous studies have been performed concerning the selection and evaluation of novel probiotic microorganisms, mainly probiotic bacteria isolated from dairy and nondairy products. Therefore, it would be crucial to critically review the assessment methods employed to select the potential probiotics. This article aims to review and discuss the recent approaches, methods used for the selection, and outcomes of the evaluation of novel probiotic strains with the main purpose of supporting future probiotic microbial assessment studies. The findings and approaches used for assessing acid tolerance, bile metabolism and tolerance, and adhesion capability are the focus of this review. In addition, probiotic bile deconjugation and bile salt hydrolysis are explored. The selection of a new probiotic strain has mainly been based on the in vitro tolerance of physiologically related stresses including low pH and bile, to ensure that the potential probiotic microorganism can survive the harsh conditions of the GIT. However, the varied experimental conditions used in these studies (different types of media, bile, pH, and incubation time) hamper the comparison of the results of these investigations. Therefore, standardization of experimental conditions for characterizing and selecting probiotics is warranted. 相似文献
996.
The present study is an attempt to reveal the protective role of Punica granatum peel and seed oil extracts against diethylnitrosamine (DEN) and phenobarbital (PB) induced hepatic injury in rats. DEN administration increased the levels of malondialdehyde (MDA), DNA fragmentation, caspase-3 and glutathione reductase (GSR) activities, while the level of reduced glutathione (GSH) and the activities of superoxide dismutase (SOD), glutathione S-transferase (GST) and total glutathione peroxidase (t-GPx) were decreased compared with the control. Treatment with peel and seed oil extracts pre, during and post DEN administration improved liver functions, decreased the levels of MDA, DNA fragmentation, caspase-3 and GSR activities with an elevation in levels of GSH, SOD, GST and t-GPx activities. This indicates that these extracts reduced the oxidative stress and apoptosis induced by DEN. Also the effect of administration of PE and SOE separately for a long time (23 weeks) on healthy rats was studied. 相似文献
997.
Chitin is a polysaccharide composed from N-acetyl-D-glucosamine units. It is the second most abundant biopolymer on Earth and found mainly in invertebrates, insects, marine diatoms, algae, fungi, and yeasts. Recent investigations confirm the suitability of chitin and its derivatives in chemistry, biotechnology, medicine, veterinary, dentistry, agriculture, food processing, environmental protection, and textile production. The development of technologies based on the utilization of chitin derivatives is caused by their polyelectrolite properties, the presence of reactive functional groups, gel-forming ability, high adsorption capacity, biodegradability and bacteriostatic, and fungistatic and antitumour influence. Resources of chitin for industrial processing are crustacean shells and fungal mycelia. Fungi contain also chitosan, the product of N-deacetylation of chitin. Traditionally, chitin is isolated from crustacean shells by demineralization with diluted acid and deproteinization in a hot base solution. Furthermore, chitin is converted to chitosan by deacetylation in concentrated NaOH solution. It causes changes in molecular weight and a degree of deacetylation of the product and degradation of nutritionally valuable proteins. Thus, enzymatic procedures for deproteinization of the shells or mold mycelia and for chitin deacetylation were investigated. These studies show that chitin is resistant to enzymatic deacetylation. However, chitin deacetylated partially by chemical treatment can be processed further by deacetylase. Efficiency of enzymatic deproteinization depends on the source of crustacean offal and the process conditions. Mild enzymatic treatment removes about 90% of the protein and carotenoids from shrimp-processing waste, and the carotenoprotein produced is useful for feed supplementation. In contrast, deproteinization of shrimp shells by Alcalase led to the isolation of chitin containing about 4.5% of protein impurities and recovery of protein hydrolysate. 相似文献
998.
Physicochemical Properties,Minerals, Trace Elements,and Heavy Metals in Honey of Different Origins: A Comprehensive Review 下载免费PDF全文
Md. Solayman Md. Asiful Islam Sudip Paul Yousuf Ali Md. Ibrahim Khalil Nadia Alam Siew Hua Gan 《Comprehensive Reviews in Food Science and Food Safety》2016,15(1):219-233
Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution. 相似文献
999.
Characterization of monomeric and gemini cationic amphiphilic molecules by fluorescence intensity and anisotropy. Part 2 总被引:2,自引:1,他引:1
Nadia Barbero Pierluigi Quagliotto Claudia Barolo Emma Artuso Roberto Buscaino Guido Viscardi 《Dyes and Pigments》2009,83(3):396-402
Four fluorophores of different nature, structure and properties were employed as probes for the characterization of a series of alkanediyl-α,ω-bis(alkyldimethyl ammonium bromide) surfactants. Pyrene and 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (coumarin 6) fluorescence intensity as well as coumarin 6 and fluorescein sodium salt fluorescence anisotropy were used to determine cmc whilst coumarin 6, fluorescein sodium salt and perylene fluorescence anisotropy was exploited to provide information on micellar structure; cmc values were confirmed using conductivity measurements. Conductivity data were analysed by means of a method which reveals the formation of ion pairs or premicellar aggregates; this approach was useful to justify and confirm results obtained using fluorescence. 相似文献
1000.
The purposes of this study were to extend the literature on lateralization of perception of emotional verbal stimuli in normal individuals, including a test of both the right hemisphere and valence models, and to investigate predictions from these models regarding lateralization of memory for emotional verbal stimuli in normal individuals, an area that, to our knowledge, has not been investigated. Seventy-nine undergraduates were presented lateralized positive, negative, and neutral English words and nonwords. Participants were then asked to freely recall the presented words and, after a 20-min delay, to recognize the words. Recognition memory data provided strong support for the valence model. In addition, free-recall and perception data provided partial support for this model. The literature on the lateralization of processing emotional verbal and nonverbal material is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献