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1.
K. Korcsak-Gorzo G. Grzelak K. Oliver M. Dawson R. Devenish J. Ferrando T. Matsushita P. Shield R. Walczak 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2007,580(3):1227-1242
The laser alignment system of the ZEUS microvertex detector is described. The detector was installed in 2001 as part of an upgrade programme in preparation for the second phase of electron–proton physics at the HERA collider. The alignment system monitors the position of the vertex detector support structure with respect to the central tracking detector using semi-transparent amorphous-silicon sensors and diode lasers. The system is fully integrated into the general environmental monitoring of the ZEUS detector and data has been collected over a period of 5 years. The primary aim of defining periods of stability for track-based alignment has been achieved and the system is able to measure movements of the support structure to a precision around . 相似文献
2.
The consumers should have access to food that is safe and free of contaminants. Unfortunately, the wide use of antibiotics in livestock, not only for medicinal purposes but also as illegal feed additives, may be the reason for emergence of the antibiotic residues in foodstuffs of animal origin. Milk is one of the most essential nutrients for humans during their lifetimes. Failure of the withdrawal periods, or what is highly prohibited but in spite of this increasingly practiced, addition of the antibiotics to milk in order to prolong its freshness, may lead to occurrence of their residues. Cefacetrile is a first generation cephalosporin that is commonly use for the treatment of bovine mastitis. The aim of this work was to determine the stability of cefacetrile in milk samples of different fat content, that is, 0 , 2 , 3.2 % UHT, 2 % pasteurized and ~3.9 % raw cattle milk, for 5 days. Two chromatographic methods were applied and compared for this purpose, that is, thin-layer chromatography and high-performance liquid chromatography. According to the results coming from HPLC-UV analysis, the stability of cefacetrile increase with the increase in the fat mass content in UHT milk. The cefacetrile level in pasteurized and raw cattle milk is similar to that in 3.2 % UHT milk. For the TLC method, this relation can be observed only in the second day of the analysis. The spiked milk samples analyzed by HPLC were deproteinized with MeCN and stored for 5 days of the experiment. Whereas, in the TLC-UV method, the spiked milk samples prepared in the first day of experiment were analyzed directly, without deproteinization. The lower stability of cefacetrile in milk samples observed from the TLC analysis can be related to its partial enzymatic decomposition. 相似文献
3.
In the paper the spectral analysis of several fatigue criteria under simple and complex states of stress has been done and limitations appearing while formulating new criteria for multiaxial random loadings have been shown. The presented analysis includes determination, with digital simulation, of probability density function and power spectral density function of the equivalent stress according to three special linear criteria of multiaxial random fatigue and six nonlinear criteria. Calculations were carried out for four kinds of random stress state. It has been shown that mathematical models for the criteria of multiaxial random fatigue formulated as nonlinear combinations of stress state components have unfavourable statistical properties, which make their application for fatigue life determination difficult. 相似文献
4.
Résumé Les auteurs proposent, sur la base de l'examen de la cassure d'éprouvettes de béton, un critère de détermination de la résistance
limite du mortier et du granulat en fonction de la résistance donnée du béton. Ils définissent les charges de compression
permettant de déterminer les grains faibles, peu résistants et désagrégés d'un granulat et mettent en évidence l'influence
de l'emploi de granulats de résistance inadéquate sur la résistance mécanique des bétons.
Les essais effectués par les auteurs confirment les hypothèses avancées.
Summary On the basis of an examination of the fracture of concrete test pieces the authors propose a criterion for determining the limit strength of the mortar and the granulate in terms of the expected strength of the concrete. They define the compressive loads by which the feeble, low-strength and disaggregated grains of a granulate can be determined and show the influence of the use of granulates of inadequate strength on the mechanical strength of the concretes. The tests carried out by the authors confirm the hypotheses advanced.相似文献
5.
Joanna Milala Katarzyna Grzelak‐Błaszczyk Michał Sójka Monika Kosmala Agnieszka Dobrzyńska‐Inger Edward Rój 《Journal of Food Processing and Preservation》2018,42(1)
The objective of the work was to elucidate the chemical composition of fractions of oil extracts obtained during the supercritical extraction on a semi‐industrial scale from strawberry (Fragaria x ananassa Duch.), chokeberry [Aronia melanocarpa (Michx.)], and raspberry (Rubus idaeus L.) seeds from industrial press cake. The oil extracts differed in terms of their content of bioactive components: carotenoids, tocopherols, chlorophylls, and fatty acids. Raspberry seed oil was the richest source of tocopherols (620.1–2166.7 mg kg?1) and α‐linolenic acid (above 37%). Chokeberry seed oil had the highest content of linoleic acid (above 70%), and α‐tocopherol (166.0–1104.8 mg kg?1). Strawberry oil was characterized by the highest content of chlorophylls and α‐linolenic acid (above 30%). It was showed that the oil fraction collected at the beginning of extraction is characterized by a high acid value, which requires purification steps to be used for food purposes.
Practical applications
Strawberry, raspberry, and chokeberry by‐products left over from the production of concentrated juice are a valuable source of oils rich in n‐3 and n‐6 polyunsaturated fatty acids, tocopherols, and carotenoids. The research showed that the fractionation of extracts in the course of supercritical extraction leads to oils with varying amounts of different bioactive compounds, and thus to products with potentially wide applications. Seeds oils have high potential utility as a source of unconventional oil for cosmetic and pharmaceutical sectors and biodiesel. Their targeted utilization may be exploited for economic, environmental and health benefits. 相似文献6.
Katarzyna Grzelak Joanna Milala Bogusław Król Franciszek Adamicki Ewa Badełek 《European Food Research and Technology》2009,228(6):1001-1007
In the paper, the authors present the qualitative and quantitative composition of quercetin glycosides and fructooligosaccharides
(FOS) in onions commonly grown in Poland of the varieties: Napoleon, Sprinter and Grabowska from the 2006 and 2007 crops,
stored in a cold room under standard conditions from October until February. Quercetin glycosides and FOS have been determined
using the HPLC method. It has been demonstrated that the mean content of quercetin glycosides in the three varieties of onions
from the 2006 and 2007 seasons is 1,381.6 ± 123.1 and 1,479.4 ± 125.5 mg/100 g d.m., respectively, in the edible part, whereby
the proportion of quercetin 3-glucoside and quercetin 4′-glucoside amounts to about 60%. In 2006 in the three onion varieties
the FOS content was on average 7.0 ± 1.2 g/100 g d.m., while in 2007 it was 6.2 ± 0.9 g/100 g d.m., of the edible part. The
content of quercetin glycosides in outer and middle scales of the onions was 3,386.3 ± 190 and 1,017.4 ± 188 mg/100 g d.m.,
respectively. In the outer scales the FOS content was lower and amounted to 3.1 ± 0.2 g in 100 g d.m., while in the middle
scales it was significantly higher 6.8 ± 0.7 g/100 g d.m. The content of quercetin glycosides in onions is high and remains
at a constant level during storage; however, since they are found mainly in outer scales, their total removal with a view
to obtaining white and milder culinary products results in a loss of approximately half of polyphenols. 相似文献
7.
Jozef Kula Krzysztof Smigielski Thuat B. Quang Iwona Grzelak Magdalena Sikora 《Journal of the American Oil Chemists' Society》1999,76(7):811-817
Methyl ricinoleate was ozonized in methanol or in acetic acid and the intermediate hydroperoxides were reduced electrochemically
on Pb-cathode to give 9-hydroxynonanoic acid 1 in high yields. The acid 1 was also prepared by direct castor oil ozonolysis in methanol followed by sodium borohydride reduction of the intermediate
hydroperoxides. The cost of the electricity for the electroreduction was at least 30 times lower as compared with sodium borohydride
consumption. 9-Hydroxynonanoic acid was then transformed to alkyl 9-acetoxynonanoates 3a–3d, for which 1H nuclear magnetic reasonance, mass, and infrared spectra are given. Esterification of the hydroxy acid 1 with boric acid and pyrolysis of the resultant orthoborates produced 8-nonenoic acid 4 in a 45% yield. Reaction of 4 with lower aliphatic alcohols in presence of Amberlyst 15 produced alkyl 8-noneates 5a–5d along with some amounts of a cis/trans mixture of alkyl 7-noneates. 相似文献
8.
Micha Rakowski Szymon Porbski Agnieszka Grzelak 《International journal of molecular sciences》2022,23(7)
Dietary supplements and nutraceuticals have entered the mainstream. Especially in the media, they are strongly advertised as safe and even recommended for certain diseases. Although they may support conventional therapy, sometimes these substances can have unexpected side effects. This review is particularly focused on the modulation of autophagy by selected vitamins and nutraceuticals, and their relevance in the treatment of neurodegenerative diseases, especially Parkinson’s disease (PD). Autophagy is crucial in PD; thus, the induction of autophagy may alleviate the course of the disease by reducing the so-called Lewy bodies. Hence, we believe that those substances could be used in prevention and support of conventional therapy of neurodegenerative diseases. This review will shed some light on their ability to modulate the autophagy. 相似文献
9.
Short-chain fructooligosaccharides (FOS) of DP 3–5 in various bread were determined by means of HPLC method with the use of water–alcohol extracts. Crisp bread produced without yeast contains kestose, nystose and fructosyl-nystose in the total amount varying from 0.3 to 0.81 g FOS/100 g. Contents of short-chain fructooligosaccharides (FOS) of DP 3–5 in another kinds of bread examined–wheat, rye and wholemeal bread produced with the use of yeast–did not exceed 0.03 g/100 g DM. 相似文献
10.
Hetaryl-substituted thiochalcones react with acetylenic mono- and diesters in the THF solution in the presence of LiClO4 at 65°C to give, after 24?h, 4H-thiopyran carboxylates and dicarboxylates, respectively, in moderate to good yields. The same reactions were performed also in the THF solution without a catalyst under microwave irradiation. In that case, the reaction time was reduced to three minutes and, in most cases, an improvement in the yield of the [4+2]-cycloadduct was observed. The reactions with methyl propiolate occurred regioselectively and the 3-carboxylates were formed exclusively. 相似文献