首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   0篇
工业技术   13篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2015年   2篇
  2014年   1篇
  2013年   1篇
  2012年   2篇
  2008年   1篇
  1997年   1篇
排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
Neural Computing and Applications - Colonoscopy is the “gold” standard for evaluating disease activity in ulcerative colitis (UC). An important area of research is finding a...  相似文献   
2.
This paper presents a real-time architecture for visual servoing of robot manipulators using nonlinear based predictive control. In order to increase the robustness of the control algorithm, image moments were chosen to be the visual features which describe the objects from the image. A visual predictive architecture is designed to solve tasks addressed to robot manipulators with an eye-in-hand configuration. An implementation of the proposed architecture is done so that the capabilities of a 6 d.o.f robot manipulator are extended. The results of different experiments conducted with two types of image moments based controllers (proportional and predictive with reference trajectory) are presented and discussed.  相似文献   
3.
The present work aims to show how the main properties of poly(methacrylic acid) (PMAA) hydrogels can be engineered by means of several silicon-based fillers (Laponite XLS/XLG, montmorillonite (Mt), pyrogenic silica (PS)) employed at 10 wt% concentration based on MAA. Various techniques (FT-IR, XRD, TGA, SEM, TEM, DLS, rheological measurements, UV-VIS) were used to comparatively study the effect of these fillers, in correlation with their characteristics, upon the structure and swelling, viscoelastic, and water decontamination properties of (nano)composite hydrogels. The experiments demonstrated that the nanocomposite hydrogel morphology was dictated by the way the filler particles dispersed in water. The equilibrium swelling degree (SDe) depended on both the pH of the environment and the filler nature. At pH 1.2, a slight crosslinking effect of the fillers was evidenced, increasing in the order Mt < Laponite < PS. At pH > pKaMAA (pH 5.4; 7.4; 9.5), the Laponite/Mt-containing hydrogels displayed a higher SDe as compared to the neat one, while at pH 7.4/9.5 the PS-filled hydrogels surprisingly displayed the highest SDe. Rheological measurements on as-prepared hydrogels showed that the filler addition improved the mechanical properties. After equilibrium swelling at pH 5.4, G’ and G” depended on the filler, the Laponite-reinforced hydrogels proving to be the strongest. The (nano)composite hydrogels synthesized displayed filler-dependent absorption properties of two cationic dyes used as model water pollutants, Laponite XLS-reinforced hydrogel demonstrating both the highest absorption rate and absorption capacity. Besides wastewater purification, the (nano)composite hydrogels described here may also find applications in the pharmaceutical field as devices for the controlled release of drugs.  相似文献   
4.
In this paper, a control strategy based on fractional calculus for visual servoing systems is proposed. The image-based control strategy is designed using a point features based fractional-order PI controller. A real-time visual servoing system, composed of a manipulator robot with 6 degrees of freedom (d.o.f.) with an eye-in-hand camera, is used for performance evaluation of the proposed control strategy. The image acquisition and processing, together with the computing of the image-based control law are implemented in MATLAB. Using planar static objects, real-time experiments are conducted and the results reveal that the image-based fractional-order PI controller outperforms the conventional image-based integer-order PI controller.  相似文献   
5.
Silicon-based quantum dots were intraperitoneally injected in Carassius auratus gibelio specimens and, over one week, the effects on renal tissue were investigated by following their distribution and histological effects, as well as antioxidative system modifications. After three and seven days, detached epithelial cells from the basal lamina, dilated tubules and debris in the lumen of tubules were observed. At day 7, nephrogenesis was noticed. The reduced glutathione (GSH) concentration decreased in the first three days and started to rise later on. The superoxide dismutase (SOD) activity increased only after one week, whereas catalase (CAT) was up-regulated in a time-dependent manner. The activities of glutathione reductase (GR) and glutathione peroxidise (GPX) decreased dramatically by approximately 50% compared to control, whereas the glutathione-S-transferase (GST) and glucose-6-phosphate dehydrogenase (G6PDH) increased significantly after 3 and 7 days of treatment. Oxidative modifications of proteins and the time-dependent increase of Hsp70 expression were also registered. Our data suggest that silicon-based quantum dots induced oxidative stress followed by structural damages. However, renal tissue is capable of restoring its integrity by nephron development.  相似文献   
6.
The biochemical and histopathological changes induced by the exposure to iron oxide nanoparticles coated with phospholipid-based polymeric micelles (IONPs-PM) in CD-1 mice lungs were analyzed. After 2, 3, 7 and 14 days following the intravenous injection of IONPs-PM (5 and 15 mg Fe/kg bw), lactate dehydrogenase (LDH) activity, oxidative stress parameters and the expression of Bax, Bcl-2, caspase-3 and TNF-α were evaluated in lung tissue. An increase of catalase (CAT) and glutathione reductase (GR) activities on the second day followed by a decrease on the seventh day, as well as a decline of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity on the third and seventh day were observed in treated groups vs. controls. However, all these enzymatic activities almost fully recovered on the 14th day. The reduced glutathione (GSH) and protein thiols levels decreased significantly in nanoparticles-treated groups and remained diminished during the entire experimental period; by contrast malondialdehyde (MDA) and protein carbonyls increased between the 3rd and 14th day of treatment vs. control. Relevant histopathological modifications were highlighted using Hematoxylin and Eosin (H&E) staining. In addition, major changes in the expression of apoptosis markers were observed in the first week, more pronounced for the higher dose. The injected IONPs-PM generated a dose-dependent decrease of the mouse lung capacity, which counteracted oxidative stress, thus creating circumstances for morphopathological lesions and oxidation processes.  相似文献   
7.
Stroke accounts for the second leading cause of death and a major cause of disability, with limited therapeutic strategy in both the acute and chronic phases. Blood-based biomarkers are intensively researched and widely recognized as useful tools to predict the prognoses of patients confronted with therapeutically limited diseases. We performed a systematic review of the circulating biomarkers in IS patients with prognostic value, with a focus on microRNAs and exosomes as predictive biomarkers of motor and cognitive recovery. We identified 63 studies, totalizing 72 circulating biomarkers with prognostic value in stroke recovery, as follows: 68 miRNAs and exosomal-miRNAs being identified as predictive for motor recovery after stroke, and seven biomarkers being predictive for cognitive recovery. Twelve meta-analyses were performed using effect sizes (random-effects and fixed-effects model). The most significant correlation findings obtained after pooling were with miR-21, miR-29b, miR-125b-5p, miR-126, and miR-335. We identified several miRNAs that were correlated with clinical outcomes of stroke severity and recovery after ischemic stroke, providing predictive information on motor and cognitive recovery. Based on the current state of research, we identified serum miR-9 and neutrophil miR-29b as the most promising biomarkers for in-depth follow-up studies, followed by serum miR-124 and plasma miR-125b.  相似文献   
8.
Mechanoelectrical transduction by a hair cell displays adaptation, which is thought to occur as myosin-based molecular motors within the mechanically sensitive hair bundle adjust the tension transmitted to transduction channels. To assess the enzymatic capabilities of the myosin isozymes in hair bundles, we examined the actin-dependent ATPase activity of bundles isolated from the bullfrog's sacculus. Separation of 32P-labeled inorganic phosphate from unreacted [gamma-32P]ATP by thin-layer chromatography enabled us to measure the liberation of as little as 0.1 fmol phosphate. To distinguish the Mg(2+)-ATPase activity of myosin isozymes from that of other hair-bundle enzymes, we inhibited the interaction of hair-bundle myosin with actin and determined the reduction in ATPase activity. N-ethylmaleimide (NEM) decreased neither physiologically measured adaptation nor the nucleotide-hydrolytic activity of a 120-kDa protein thought to be myosin 1 beta. The NEM-insensitive, actin-activated ATPase activity of myosin increased from 1.0 fmol x s-1 in 1 mM EGTA to 2.3 fmol x s-1 in 10 microM Ca2+. This activity was largely inhibited by calmidazolium, but was unaffected by the addition of exogenous calmodulin. These results, which indicate that hair bundles contain enzymatically active, Ca(2+)-sensitive myosin molecules, are consistent with the role of Ca2+ in adaptation and with the hypothesis that myosin forms the hair cell's adaptation motor.  相似文献   
9.
10.
It is shown that ZnO nanorods and nanodots grown by MOCVD exhibit enhanced radiation hardness against high energy heavy ion irradiation as compared to bulk layers. The decrease of the luminescence intensity induced by 130?MeV Xe(23+) irradiation at a dose of 1.5 × 10(14)?cm(-2) in ZnO nanorods is nearly identical to that induced by a dose of 6 × 10(12)?cm(-2) in bulk layers. The damage introduced by irradiation is shown to change the nature of electronic transitions responsible for luminescence. The change of excitonic luminescence to the luminescence related to the tailing of the density of states caused by potential fluctuations occurs at an irradiation dose around 1 × 10(14)?cm(-2) and 5 × 10(12)?cm(-2) in nanorods and bulk layers, respectively. More than one order of magnitude enhancement of radiation hardness of ZnO nanorods grown by MOCVD as compared to bulk layers is also confirmed by the analysis of the near-bandgap photoluminescence band broadening and the behavior of resonant Raman scattering lines. The resonant Raman scattering analysis demonstrates that ZnO nanostructures are more radiation-hard as compared to nanostructured GaN layers. High energy heavy ion irradiation followed by thermal annealing is shown to be a way for the improvement of the quality of ZnO nanorods grown by electrodeposition and chemical bath deposition.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号