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排序方式: 共有214条查询结果,搜索用时 31 毫秒
81.
Knowledge about relative poses within a tractor/trailer combination is a vital prerequisite for kinematic modelling and trajectory estimation. In case of autonomous vehicles or driver assistance systems, for example, the monitoring of an attached passive trailer is crucial for operational safety. We propose a camerabased 3D pose estimation system based on a Kalman-filter. It is evaluated against previously published methods for the same problem. 相似文献
82.
Acetylcholinesterase (AchE), an essentially specific and early marker of rodent thrombocytic series, in several tissues acts both as a constituent of the cellular membrane and as a secretory enzyme. This study presents the ultrastructural transport and fate of this substance in the megakaryocytes of mouse bone marrow, using Tranum-Jensen and Behnke's adaptation of the indirect thiocholine method. It is shown that megakaryoblasts and megakaryocytes undergo a typical secretory cycle consisting of (1) enzyme synthesis and segregation on the endoplasmic reticulum and nuclear envelope, (2) enzyme concentration in AchE-vesicles and AchE-granules formed from the cisternae of the Golgi apparatus, and (3) discharge in the demarcation membrane system and extracellular space. The AchE-vesicles and granules appear to be hitherto unrecognized megakaryocytic organelles as they do not resemble alpha nor the dense granules, and their mode of formation and fate differ from those of primary lysosomes and peroxidase granules. Released platelets reveal AchE activity in the open canalicular system. The data are compatible with the hypothesis that by controlling acetylcholine concentration in hematopoietic tissues, the secretion of AchE by megakaryocytes can modulate the proliferative activity of megakaryocytes progenitors. 相似文献
83.
Reports results of a study designed to assess the mood correlates of learned helplessness in human Ss. Results provide support for M. E. Seligman's (1975) proposition that the learned helplessness concept may serve as a model for reactive depression in man. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
84.
CW Hedberg SJ Savarino JM Besser CJ Paulus VM Thelen LJ Myers DN Cameron TJ Barrett JB Kaper MT Osterholm 《Canadian Metallurgical Quarterly》1997,176(6):1625-1628
An outbreak of gastrointestinal illness with clinical and epidemiologic features of enterotoxigenic Escherichia coli (ETEC) occurred among patrons of a restaurant during April 1991. Illnesses among several groups of patrons were characterized by diarrhea (100%) and cramps (79%-88%) lasting a median of 3-5 days. Median incubation periods ranged from 50 to 56 h. A nonmotile strain of E. coli (E. coli O39), which was negative for heat-labile (LT) and heat-stable (STa, STb) ETEC toxins, was isolated only from ill patrons. This organism produced enteroaggregative E. coli heat-stable enterotoxin 1 and contained the enteropathogenic E. coli gene locus for enterocyte effacement; it did not display mannose-resistant adherence, but produced attaching and effacing lesions in the absence of mannose on cultured HEp-2 cells. E. coli that are not part of highly characterized but narrowly defined groups may be important causes of foodborne illness. 相似文献
85.
B. Jarvis K. Paulus 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1982,32(1):233-250
The processing of foods to ensure the availability for the consumer of a wide variety of safe stable products provides a good example of the application of ‘negative biotechnology’. The objectives are to optimise the use of food resources by reduction or elimination of spoilage and waste, control food-borne health problems and develop ‘new’ food products. Our work describes the way in which technology is applied to control of biological, chemical and physical changes in foods. Examples are given to illustrate the implications for product shelf-life of the various process operations including inter alia, thermal and irradiation treatments, restriction of available water, use of chemical preservatives and the choice of packaging systems. Special emphasis is placed on the need to optimise quality and safety by the proper application of kinetic data for the various process operations. The concepts of quality assurance, ‘in-line’ process control and the use of microprocessor technology in the control of critical processes is considered. The work concludes with a look at the future requirements of the food processing industry in relation to developments in ‘negative’ biotechnology. 相似文献
86.
The interrelationship of mesial temporal lobe epilepsy (MTLE), hippocampal sclerosis, and febrile convulsions still remains an enigma. Additional microscopical cortical dysplasia or microdysgenesis has been suggested as pre-existent susceptibility factor rendering the affected brain vulnerable to the development of MTLE after initial precipitating injuries such as febrile convulsions. Twenty-four MTLE cases with histopathologically definite hippocampal sclerosis were examined for clearly defined features of microdysgenesis and further signs of neocortical dysplasia. Although unequivocal signs of dysplasia were absent, 29.2% of cases showed cortical neuronal clustering, 25.0% showed perivascular clustering, and 20.8% showed increased white matter neurons. The features of microdysgenesis studied here were not linked with each other and were not related to initial precipitating injuries, positive family history, or any other clinical parameter. Their suggested fundamental role as dysplastic factor within development of hippocampal sclerosis and MTLE is not confirmed. 相似文献
87.
88.
Stagni C. Guiducci C. Benini L. Ricco B. Carrara S. Paulus C. Schienle M. Thewes R. 《IEEE sensors journal》2007,7(4):577-585
This paper presents a microfabricated DNA chip for fully electronic, label-free DNA recognition based on capacitance measurements. The chip has been fabricated in 0.5-mum CMOS technology and it features an array of individually addressable sensing sites consisting of pairs of gold electrodes and addressing logic. Read-out circuitry is built externally using standard components to provide increased experimental flexibility. The chip has been electrically characterized and tested with various solutions containing DNA samples. Significant capacitance variations due to DNA hybridization have been measured, thus showing that the approach represents a viable solution for a single chip DNA sensor array 相似文献
89.
Guang Chen Jahin Patwary Harnoor Singh Sachar Siddhartha Das 《Microfluidics and nanofluidics》2018,22(10):112
In this paper, we compute the electrokinetic transport in soft nanochannels grafted with poly-zwitterionic (PZI) brushes. The transport is induced by an external pressure gradient, which drives the ionic cloud (in the form of an electric double layer or EDL) at the brush surfaces to induce an electric field that drives an induced electroosmotic transport. We characterize the overall transport by quantifying this electric field, overall flow velocity, and the energy conversion associated with the development of the electric field and a streaming current. We specially focus on how the ability of the PZI to ionize and demonstrate a significant charge at both large and small pH can be efficiently maneuvered to develop a liquid transport, an electric field, and an electrokinetically induced power across a wide range of pH values. 相似文献
90.
D.?LangEmail author S.?Friedmann D.?Paulus 《Pattern Recognition and Image Analysis》2016,26(2):309-315
In this paper we present how adaptable learned models of graphical models are and how they can be used for classification tasks of 3D laser point clouds with different distributions and density. In order to model the contextual information we use a pair-wise conditional random field and an adaptive graph down-sampling method based on voxel grids. As feature we apply the rotation invariant histogram-of-oriented-residuals operator to describe the local point cloud distribution. We validate the approach with data collected from different laser range finders with varying point cloud distribution and density. Our experiments imply, that conditional random field models learned from one dataset can be applied to another dataset without a significant loss of precision. 相似文献