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21.
We report on the synthesis of SnO2 and CuO nanowires and their application as gas sensing components. The fabrication of SnO2 and CuO single nanowire devices by optical and electron beam lithography is described, and sensing performance to the toxic gas carbon monoxide is demonstrated. We briefly present the development of CMOS fabricated micro-hotplates as platforms for gas sensors and show our approach for nanowire implementation. Finally, we demonstrate a fully CMOS integrated CuO multi nanowire device and present our roadmap for a fully integrated multi-parameter smart sensor device which could be implemented as safety feature in smart phones.  相似文献   
22.
Scientometrics - In this paper, we analyze the structure of the article citation network of a particular subject obtained from the Web of Science (WoS) database. In specific, we modify a model...  相似文献   
23.
Despite suggestibility researchers' focus on adult behaviors that distort children's reports, whether behaviors examined in experimental work are used in the field is unknown. The current study presents a mutually exclusive and exhaustive hierarchical coding system that reflects interview questioning behaviors of concern in experimental work. The study examined 80 unstructured interviews conducted by 41 field interviewers with 40 children ages 3 to 7 about known events. Data on the use of leading and neutral questions are presented and include distinctions between accurate and inaccurate suggested information. In addition, analyses show that interviewers are consistent in their style of questioning and that a preinterview measure of interviewers' preference for a qualitative versus a quantitative interviewing style predicted the introduction of novel information into the interview. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
24.
Epidemiological and intervention studies correlate anthocyanin-rich beverages and a low incidence of coronary heart diseases. Since endothelin-1 (ET-1) and nitric oxide (NO) produced by endothelial NO synthase (eNOS) are vascular tension regulators secreted by endothelial cells, we studied the influence of two anthocyanidins, namely cyanidin (CY) and delphinidin (DP), on the regulation of ET-1 and eNOS in cultured human umbilical vein endothelial cells (HUVECs). Aglycon anthocyanidin forms, such as CY and DP, may be present in vivo after the first deglycosylation step occurring in the jejunum and in the liver. DP showed a major action compared to CY inducing a significant dose-dependent inhibitory effect on both protein and mRNA levels of ET-1. CY and DP both increased the protein level of eNOS, but DP showed the major effect raising eNOS protein in a dose-dependent manner. To correlate the vasoprotective effect of CY and DP with their antioxidant activity, we analysed also the antioxidant effect of anthocyanidins both in vitro and in HUVECs. In particular, we examined the effect of anthocyanidins on endothelial heme oxygenase-1 (HO-1), an inducible stress protein. In all tests, DP showed a higher antioxidant activity than CY. Finally, the antiproliferative effect induced by DP was detected in HUVECs. DP and CY differ in the number and position of hydroxyl groups in their structure; therefore, the greater biological activity by DP, compared with CY, seems to be due to the presence of the three hydroxyl groups on the B ring in the molecular structure of DP.  相似文献   
25.
Metabolomic analysis by liquid chromatography-high-resolution mass spectrometry results in data sets with thousands of features arising from metabolites, fragments, isotopes, and adducts. Here we describe a software package, Metabolomic Analysis and Visualization ENgine (MAVEN), designed for efficient interactive analysis of LC-MS data, including in the presence of isotope labeling. The software contains tools for all aspects of the data analysis process, from feature extraction to pathway-based graphical data display. To facilitate data validation, a machine learning algorithm automatically assesses peak quality. Users interact with raw data primarily in the form of extracted ion chromatograms, which are displayed with overlaid circles indicating peak quality, and bar graphs of peak intensities for both unlabeled and isotope-labeled metabolite forms. Click-based navigation leads to additional information, such as raw data for specific isotopic forms or for metabolites changing significantly between conditions. Fast data processing algorithms result in nearly delay-free browsing. Drop-down menus provide tools for the overlay of data onto pathway maps. These tools enable animating series of pathway graphs, e.g., to show propagation of labeled forms through a metabolic network. MAVEN is released under an open source license at http://maven.princeton.edu.  相似文献   
26.
Microwave-assisted extraction of free amino acids from foods   总被引:11,自引:0,他引:11  
 A microwave-assisted solvent extraction technique was developed for the extraction of free amino acids from foods. Four different samples were subjected to microwave extraction with varying amounts of extractant at several temperature values, for varying times to determine optimum extraction conditions. The extractions were performed with or without shaking the vessels in order to investigate the effects of mixing on the extraction efficiency and reproducibility. A comparison was made between this method and the traditional 1 h shaking extraction. The experiments indicated that the microwave-assisted extraction is an effective technique for the extraction of free amino acids from samples of plant or animal origin. The extraction yields obtained by the microwave method were about 10% better than by the conventional shaking technique. The times needed for the complete sample preparations were reduced by 66% with the application of microwaves. Received: 10 October 1997 / Revised version: 23 January 1998  相似文献   
27.
Changes in the biogenic amine content relative to microbial activities in mung bean, lentil and radish sprouts were investigated in prepacked and homegrown products. Biogenic amines were determined by ion-exchange chromatography. The major groups of micro-organisms were enumerated by aerobic plate count procedures, using universal and selective media. Putrescine, cadaverine, spermidine, agmatine and spermine were detected in different concentrations, depending on the type of sprouts. In prepacked retail products the total biogenic amine content was higher than in home-grown samples (mung bean 106 g/g compared to 87 g/g; lentil 316 g/g compared to 181 g/g; radish 1486 g/g compared to 252 g/g). It is concluded that sprouting time and storage conditions play a major part in the hygienic quality of legume sprouts.
Gehalt an biogenen Aminen und mikrobiologische Qualität von Keimlingen
Zusammenfassung Der Gehalt an biogenen Aminen in Mungbohnen-, Linsen- und Rettichkeimlingen in Abhängigkeit von der mikrobiellen Belastung wurde an vorverpackten Produkten des Einzelhandels und hausgezogenen Keimlingen untersucht. Die biogenen Amine wurden mit Hilfe der Ionenaustauschchromatographie, die Mikroorganismen auf universellen und selektiven Medien bestimmt. Die Konzentrationen von Putrescin, Cadaverin, Spermidin, Agmatin und Spermin waren je nach Art der Keimlinge unterschiedlich hoch. In vorverpackten Produkten aus dem Einzelhandel war der Gesamtgehalt an biogenen Aminen höher als in hausgezogenen Keimlingen (Mungbohnen: 106 bzw. 87 g/g; Linsen: 316 bzw. 181 g/g; Rettich: 1486 bzw. 252 g/g). Keimdauer und Lagerungsbedingungen beeinflussen die hygienische Qualität von Keimlingen deutlich.
  相似文献   
28.
Traumatic brain injury (TBI) disrupts the blood–brain barrier (BBB). Vascular endothelial growth factor (VEGF) is believed to play a key role in TBI and to be overexpressed in the absence of apolipoprotein E (ApoE). Bevacizumab, a VEGF inhibitor, demonstrated neuroprotective activity in several models of TBI. However, the effects of bevacizumab on Apo-E deficient mice are not well studied. The present study aimed to evaluate VEGF expression and the effects of bevacizumab on BBB and neuroinflammation in ApoE−/− mice undergoing TBI. Furthermore, for the first time, this study evaluates the effects of bevacizumab on the long-term consequences of TBI, such as atherosclerosis. The results showed that motor deficits induced by controlled cortical impact (CCI) were accompanied by increased brain edema and VEGF expression. Treatment with bevacizumab significantly improved motor deficits and significantly decreased VEGF levels, as well as brain edema compared to the control group. Furthermore, the results showed that bevacizumab preserves the integrity of the BBB and reduces the neuroinflammation induced by TBI. Regarding the effects of bevacizumab on atherosclerosis, it was observed for the first time that its ability to modulate VEGF in the acute phase of head injury prevents the acceleration of atherosclerosis. Therefore, the present study demonstrates not only the neuroprotective activity of bevacizumab but also its action on the vascular consequences related to TBI.  相似文献   
29.
Neuroinflammation underlies neurodegenerative diseases. Herein, we test whether acute colon inflammation activates microglia and astrocytes, induces neuroinflammation, disturbs neuron intrinsic electrical properties in the primary motor cortex, and alters motor behaviors. We used a rat model of acute colon inflammation induced by dextran sulfate sodium. Inflammatory mediators and microglial activation were assessed in the primary motor cortex by PCR and immunofluorescence assays. Electrophysiological properties of the motor cortex neurons were determined by whole-cell patch-clamp recordings. Motor behaviors were examined using open-field and rotarod tests. We show that the primary motor cortex of rats with acute colon inflammation exhibited microglial and astrocyte activation and increased mRNA abundance of interleukin-6, tumor necrosis factor-alpha, and both inducible and neuronal nitric oxide synthases. These changes were accompanied by a reduction in resting membrane potential and rheobase and increased input resistance and action potential frequency, indicating motor neuron hyperexcitability. In addition, locomotion and motor coordination were impaired. In conclusion, acute colon inflammation induces motor cortex microglial and astrocyte activation and inflammation, which led to neurons’ hyperexcitability and reduced motor coordination performance. The described disturbances resembled some of the early features found in amyotrophic lateral sclerosis patients and animal models, suggesting that colon inflammation might be a risk factor for developing this disease.  相似文献   
30.
The fine-tuning of the physicochemical properties of gold nanoparticles has facilitated the rapid development of multifunctional gold-based nanomaterials with diagnostic, therapeutic, and therapeutic applications. Work on gold nanoparticles is increasingly focusing on their cancer application. This review provides a summary of the main biological effects exerted by gold nanoparticles on cancer cells and highlights some critical factors involved in the interaction process (protein corona, tumor microenvironment, surface functionalization). The review also contains a brief discussion of the application of gold nanoparticles in target discovery.  相似文献   
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