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排序方式: 共有263条查询结果,搜索用时 15 毫秒
1.
Simonetta Pazzaglia Barbara Tanno Francesca Antonelli Paola Giardullo Gabriele Babini Prabal Subedi Omid Azimzadeh Zohaib N. Khan Kateryna Oleksenko Fabian Metzger Christine von Toerne Damien Traynor Dinesh Medipally Aidan D. Meade Munira Kadhim Fiona M. Lyng Soile Tapio Anna Saran Mariateresa Mancuso 《International journal of molecular sciences》2021,22(8)
The brain undergoes ionizing radiation exposure in many clinical situations, particularly during radiotherapy for brain tumors. The critical role of the hippocampus in the pathogenesis of radiation-induced neurocognitive dysfunction is well recognized. The goal of this study is to test the potential contribution of non-targeted effects in the detrimental response of the hippocampus to irradiation and to elucidate the mechanisms involved. C57Bl/6 mice were whole body (WBI) or partial body (PBI) irradiated with 0.1 or 2.0 Gy of X-rays or sham irradiated. PBI consisted of the exposure of the lower third of the mouse body, whilst the upper two thirds were shielded. Hippocampi were collected 15 days or 6 months post-irradiation and a multi-omics approach was adopted to assess the molecular changes in non-coding RNAs, proteins and metabolic levels, as well as histological changes in the rate of hippocampal neurogenesis. Notably, at 2.0 Gy the pattern of early molecular and histopathological changes induced in the hippocampus at 15 days following PBI were similar in quality and quantity to the effects induced by WBI, thus providing a proof of principle of the existence of out-of-target radiation response in the hippocampus of conventional mice. We detected major alterations in DAG/IP3 and TGF-β signaling pathways as well as in the expression of proteins involved in the regulation of long-term neuronal synaptic plasticity and synapse organization, coupled with defects in neural stem cells self-renewal in the hippocampal dentate gyrus. However, compared to the persistence of the WBI effects, most of the PBI effects were only transient and tended to decrease at 6 months post-irradiation, indicating important mechanistic difference. On the contrary, at low dose we identified a progressive accumulation of molecular defects that tended to manifest at later post-irradiation times. These data, indicating that both targeted and non-targeted radiation effects might contribute to the pathogenesis of hippocampal radiation-damage, have general implications for human health. 相似文献
2.
Jeannette Aumo Johanna Lilja Päivi Mäki-Arvela Tapio Salmi Mats Sundell Hanna Vainio Dmitry Yu. Murzin 《Catalysis Letters》2002,84(3-4):219-224
A polymer-supported Pd catalyst was investigated in hydrogenation of citral (3,7-dimethyl-2,6-octadienal), which is a stereoisomer with an isolated and a conjugated double bond as well as a carbonyl group. The catalyst was a fibrous polymer-supported catalyst modified with functional groups and immobilized metals. A comparison of the polymer-supported catalyst with conventional catalysts was made. 相似文献
3.
Ye Liang Yan Susu Zhen Jialing Han Tian Ferdinando Hany Seppänen Tapio Alasaarela Esko 《Mobile Networks and Applications》2022,27(4):1688-1699
Mobile Networks and Applications - In recent years, physical violence detection has become a research hotspot in the area of human activity recognition. With the improvement and full coverage of... 相似文献
4.
Actions performed by a virtual character can be controlled with verbal commands such as ‘walk five steps forward’. Similar control of the motion style, meaning how the actions are performed, is complicated by the ambiguity of describing individual motions with phrases such as ‘aggressive walking’. In this paper, we present a method for controlling motion style with relative commands such as ‘do the same, but more sadly’. Based on acted example motions, comparative annotations, and a set of calculated motion features, relative styles can be defined as vectors in the feature space. We present a new method for creating these style vectors by finding out which features are essential for a style to be perceived and eliminating those that show only incidental correlations with the style. We show with a user study that our feature selection procedure is more accurate than earlier methods for creating style vectors, and that the style definitions generalize across different actors and annotators. We also present a tool enabling interactive control of parametric motion synthesis by verbal commands. As the control method is independent from the generation of motion, it can be applied to virtually any parametric synthesis method. 相似文献
5.
We introduce an efficient method for training the linear ranking support vector machine. The method combines cutting plane optimization with red-black tree based approach to subgradient calculations, and has O(ms + mlog (m)) time complexity, where m is the number of training examples, and s the average number of non-zero features per example. Best previously known training algorithms achieve the same efficiency only for restricted special cases, whereas the proposed approach allows any real valued utility scores in the training data. Experiments demonstrate the superior scalability of the proposed approach, when compared to the fastest existing RankSVM implementations. 相似文献
6.
Tapio Frantti 《Expert systems with applications》2012,39(11):10191-10201
This paper considers an embedded fuzzy expert system for non-feedback uplink power control of wireless local area networks (WLANs). The main idea is to minimize the transmission power of the nodes while keeping the transmission errors at an acceptable level. In the developed method, receivers collect signal strength values which are used by the control systems to define an acceptable transmission power level. The functionality of the proposed solution is demonstrated with simulations, which prove that the use of the expert system to open-loop systems can significantly decrease transmission power, increase energy efficiency and decrease interference to adjacent access points and associated nodes. 相似文献
7.
A poorly designed OLAP (on-line analytical processing) cube can have a size much larger than the volume of information, potentially leading to problems with performance and usability. We give a new normal form for OLAP cube design and synthesis and decomposition algorithms to produce normalised OLAP cube schemata. OLAP cube normalisation controls the structural sparsity resulting from inter-dimensional functional dependencies. We assume that functional dependencies are used to describe the constraints of the application universe of discourse. Our methods help the user to identify cube schemata with structural sparsity, and to change the design in order to obtain more economy of space. 相似文献
8.
Induction of decision trees is one of the most successful approaches to supervised machine learning. Branching programs are a generalization of decision trees and, by the boosting analysis, exponentially more efficiently learnable than decision trees. However, this advantage has not been seen to materialize in experiments. Decision trees are easy to simplify using pruning. Reduced error pruning is one of the simplest decision tree pruning algorithms. For branching programs no pruning algorithms are known. In this paper we prove that reduced error pruning of branching programs is infeasible. Finding the optimal pruning of a branching program with respect to a set of pruning examples that is separate from the set of training examples is NP-complete. Because of this intractability result, we have to consider approximating reduced error pruning. Unfortunately, it turns out that even finding an approximate solution of arbitrary accuracy is computationally infeasible. In particular, reduced error pruning of branching programs is APX-hard. Our experiments show that, despite the negative theoretical results, heuristic pruning of branching programs can reduce their size without significantly altering the accuracy. 相似文献
9.
A method for embedding a watermark in print media, posters or other paper printouts and reading the watermark information blindly with a camera phone is proposed. A subtractive-additive embedding method is applied in which the message is coded with a directed periodic pattern. The message is detected and read by searching regularities in the autocorrelation function of a periodic signal. The robustness to disturbance occurring during printing process due to air interface and camera phone properties is ensured using noise reduction, modified JND model, enhanced peak detection with filtering and shaping and two-level coding of the message. The validity of the approach is proven with tests, and an application example of an interactive poster is examined. 相似文献
10.
Combination of Reaction and Separation in Heterogeneous Catalytic Hydrogenation of Ethylformate 下载免费PDF全文
Gerson Martin Carla Pereira Frank Pettersson Henrik Saxén Dmitry Y. Murzin Alírio Rodrigues Tapio Salmi 《化学工程与技术》2015,38(5):804-812
Continuous hydrogenation reaction of ethyl benzoylformate was studied over a (–)‐cinchonidine (CD)‐modified Pt/Al2O3 catalyst. The catalyst showed a good stability, and high enantioselectivity was achieved in the fixed‐bed reactor. Chromatographic separation of (R)‐ and (S)‐ethyl mandelate originating from a post‐continuous hydrogenation reaction of ethyl benzoylformate over the (–)‐CD‐modified Pt/Al2O3 catalyst was investigated in the same reaction mixture. A commercial column filled with a chiral selector resin was chosen as a perspective preparative‐scale adsorbent. Since adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post‐reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug‐flow model with linear driving force approximation. 相似文献