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排序方式: 共有104条查询结果,搜索用时 15 毫秒
1.
Franco Chialva Carlotta Frattini Aldo Martelli 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1985,181(1):32-34
Summary The essential oil obtained by steam distillation of cinchona bark (Cinchona spp.,Rubiaceae family) — a plant well known for its pharmacological properties, also employed in the food industry, especially in making liqueurs - was investigated. The oil, of completely unknown chemical composition, was analyzed by GLC and GLC/MS after separation on a silica gel column, and one hundred components were identified. The presence of 2-hexyl-3-methylmaleic anhydride is rather unusual.
Ungewöhnliche ätherische Öle mit aromatischen Eigenschaften. Die flüchtigen Aromastoffe der China-Rinde
Zusammenfassung Es wurde ätherisches Öl analysiert, das durch Wasserdampfdestillation von Chinarinde (Cinchona spp. derRubiaceae-Familie) gewonnen wurde. Diese Pflanze ist aufgrund ihrer pharmakologischen Eigenschaften bekannt und wird auch in der Lebensmittelindustrie verwendet, ganz besonders für die Likör- und Magenbitterherstellung. Die chemische Zusammensetzung dieses Öls war unbekannt. Nach Abtrennung auf einer Kieselgelsäule wurden im Öl mit GLC und GLC/MS etwa 100 Verbindungen identifiziert. Das Vorhandensein von 2-Hexyl-3-methyl-maleinsäureanhydrid ist ziemlich ungewöhnlich.相似文献
2.
Manifold learning methods for unsupervised nonlinear dimensionality reduction have proven effective in the visualization of high dimensional data sets. When dealing with classification tasks, supervised extensions of manifold learning techniques, in which class labels are used to improve the embedding of the training points, require an appropriate method for out-of-sample mapping.In this paper we propose multi-output kernel ridge regression (KRR) for out-of-sample mapping in supervised manifold learning, in place of general regression neural networks (GRNN) that have been adopted by previous studies on the subject. Specifically, we consider a supervised agglomerative variant of Isomap and compare the performance of classification methods when the out-of-sample embedding is based on KRR and GRNN, respectively. Extensive computational experiments, using support vector machines and k-nearest neighbors as base classifiers, provide statistical evidence that out-of-sample mapping based on KRR consistently dominates its GRNN counterpart, and that supervised agglomerative Isomap with KRR achieves a higher accuracy than direct classification methods on most data sets. 相似文献
3.
Ilaria Paterni Carlotta Granchi 《Critical reviews in food science and nutrition》2017,57(16):3384-3404
Xenoestrogens are widely diffused in the environment and in food, thus a large portion of human population worldwide is exposed to them. Among alimentary xenoestrogens, phytoestrogens (PhyEs) are increasingly being consumed because of their potential health benefits, although there are also important risks associated to their ingestion. Furthermore, other xenoestrogens that may be present in food are represented by other chemicals possessing estrogenic activities, that are commonly defined as endocrine disrupting chemicals (EDCs). EDCs pose a serious health concern since they may cause a wide range of health problems, starting from pre-birth till adult lifelong exposure. We herein provide an overview of the main classes of xenoestrogens, which are classified on the basis of their origin, their structures and their occurrence in the food chain. Furthermore, their either beneficial or toxic effects on human health are discussed in this review. 相似文献
4.
Carlotta Lassandro Giuseppe Banderali Giovanni Radaelli Elisa Borghi Francesca Moretti Elvira Verduci 《International journal of molecular sciences》2015,16(8):19989-20000
Prevalence of metabolic syndrome is increasing in the pediatric population. Considering the different existing criteria to define metabolic syndrome, the use of the International Diabetes Federation (IDF) criteria has been suggested in children. Docosahexaenoic acid (DHA) has been associated with beneficial effects on health. The evidence about the relationship of DHA status in blood and components of the metabolic syndrome is unclear. This review discusses the possible association between DHA content in plasma and erythrocytes and components of the metabolic syndrome included in the IDF criteria (obesity, alteration of glucose metabolism, blood lipid profile, and blood pressure) and non-alcoholic fatty liver disease in obese children. The current evidence is inconsistent and no definitive conclusion can be drawn in the pediatric population. Well-designed longitudinal and powered trials need to clarify the possible association between blood DHA status and metabolic syndrome. 相似文献
5.
15‐Methylene‐Eburnamonine Kills Leukemic Stem Cells and Reduces Engraftment in a Humanized Bone Marrow Xenograft Mouse Model of Leukemia 下载免费PDF全文
Dr. Dilini C. Gunasekara Dr. Mary M. Zheng Tara Mojtahed Dr. James R. Woods Prof. Tamer E. Fandy Dr. Mark V. Riofski Prof. Carlotta A. Glackin Prof. Hazem E. Hassan Dr. Julia Kirshner Prof. David A. Colby 《ChemMedChem》2016,11(21):2392-2397
Recent studies suggest that leukemia stem cells (LSCs) play a critical role in the initiation, propagation, and relapse of leukemia. Herein we show that (?)‐15‐methylene‐eburnamonine, a derivative of the alkaloid (?)‐eburnamonine, is cytotoxic against acute and chronic lymphocytic leukemias (ALL and CLL) and acute myelogenous leukemia (AML). The agent also decreases primary LSC frequency in vitro. The cytotoxic effects appear to be mediated via the oxidative stress pathways. Furthermore, we show that the compound kills AML, ALL, and CLL stem cells. By the use of a novel humanized bone marrow murine model of leukemia (huBM/NSG), it was found to decrease progenitor cell engraftment. 相似文献
6.
L Romano F Lassandro M Scaglione S Giovine A Di Blasi 《Canadian Metallurgical Quarterly》1997,93(3):294-295
Diagnosis of vertically acquired human immunodeficiency virus (HIV) infection is often difficult because of transplacentally acquired maternal antibodies. The polymerase chain reaction (PCR) test is commercially available and has high sensitivity and specificity. To evaluate the usefulness of PCR testing in the early diagnosis of perinatally acquired HIV infection, we reviewed records of 122 children having follow-up in the Northeast Florida Pediatric AIDS Program. Seventy-two children were excluded for various reasons. Of the remaining 50 children, 37 had PCR testing. In 5 children, the initial PCR test was done at > 18 months of age. Results of PCR testing were positive in 8 of 13 (62%) at birth, 12 of 18 (67%) by 1 month of age, 18 of 23 (78%) by 2 months of age, and 20 of 24 (83%) by 3 months of age. In 24 of 27 (85%), results were positive by the time the children reached 4 months of age. Our data suggest that the PCR test is a useful tool for early diagnosis of vertically transmitted HIV infection. 相似文献
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9.
Grocery shopping represents a challenging task for visually impaired (VI), but the neuroscientific literature on the consumption patterns of this group is still scarce. The aim of the study was to analyse the relationship between explicit consumer experience and neuropsychological measures. A group of VI and sighted explored and manipulated three different product categories inside the supermarket, while EEG, behavioral and self-report data were collected. Electroencephalogram (EEG) findings showed a generalized delta band activity in pasta compared to frozen food and it was interpreted as higher emotional activation probably required by selecting the correct stimuli in a multisensory environment. A delta band activation was also found in frontal area in VI compared to control and it was supposed to be an index of greater cognitive control. Finally, higher delta band activity in parieto-occipital and temporal areas were related to greater sense of disorientation. In conclusion, it was found that VI experience grocery shopping more stressfully and with greater cognitive effort (parieto-occipital area) than people without visual disability. In general, VI use the sense of touch (temporal area) more and have more difficulties in orienting themselves internally in the store. The results could encourage the use of tactile touchpoints, braille maps, or an initial guided exploration of the supermarket, to allow the VI to memorize the internal layout of the different product categories and allow them to shop independently. Another suggestion would be to make products within the same product category more distinctive, perhaps by adding additional tactile information. 相似文献
10.
Giorgia Foca Carlotta Ferrari Alessandro Ulrici Maria Cristina Ielo Giovanna Minelli Domenico Pietro Lo Fiego 《Food Analytical Methods》2016,9(10):2791-2806
In this work, FT-NIR spectroscopy was employed to determine iodine value (IV) and fatty acids (FA) content of pig fat samples, through the combined use of signal preprocessing, multivariate calibration, and variable selection methods. In particular, the main focus was on the use of variable selection methods, both in order to improve the predictive performance of the calibration models, and to identify relevant wavelengths that could be subsequently used for the development of simple, fast, and cheap hand-held devices, able to measure IV and FA content directly on the fat without the need of any sample pretreatment. Firstly, for each property of interest, partial least squares (PLS) multivariate calibration models were calculated considering the whole spectral range and testing different signal preprocessing methods. Then, once chosen the optimal signal preprocessing method, a two-step variable selection procedure was applied. In the first step, the interval-PLS variable selection algorithm was used to calculate a set of calibration models, whose outcomes were considered altogether in the second step, in order to select the optimal calibration model. The variable selection procedure allowed to lower the number of spectral variables retained by the model, and often led to an increase of the performance in prediction of the external test set samples. 相似文献