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1.
Exploratory data analysis methods are essential for getting insight into data. Identifying the most important variables and detecting quasi-homogenous groups of data are problems of interest in this context. Solving such problems is a difficult task, mainly due to the unsupervised nature of the underlying learning process. Unsupervised feature selection and unsupervised clustering can be successfully approached as optimization problems by means of global optimization heuristics if an appropriate objective function is considered. This paper introduces an objective function capable of efficiently guiding the search for significant features and simultaneously for the respective optimal partitions. Experiments conducted on complex synthetic data suggest that the function we propose is unbiased with respect to both the number of clusters and the number of features.  相似文献   
2.
We predict that reversed and anomalous non-relativistic Doppler shifts can be observed under some circumstances when light reflects from a shock wave front propagating through a photonic crystal, or material with a periodic modulation of the dielectric. This theoretical prediction is generalizable and applies to wave-like excitations in a variety of periodic media. An experimental observation of this effect has recently been made (Seddon, N. and Bearpark, T. Science, 302 (2003) 1537) and we provide a brief discussion of this experiment.  相似文献   
3.
Ectopic endometrial epithelium associates a wide spectrum of symptomatology. Their evolution can be influenced by inflammatory and vascular changes, that affect not only the structure and cell proliferation rate, but also symptoms. This prospective study involved tissue samples from surgically treated patients, stained using classical histotechniques and immunohistochemistry. We assessed ectopic endometrial glands (CK7+, CK20−), adjacent blood vessels (CD34+), estrogen/progesterone hormone receptors (ER+, PR+), inflammatory cells (CD3+, CD20+, CD68+, Tryptase+), rate of inflammatory cells (Ki67+) and oncoproteins (BCL2+, PTEN+, p53+) involved in the development of endometriosis/adenomyosis. A CK7+/CK20− expression profile was present in the ectopic epithelium and differentiated it from digestive metastases. ER+/PR+ were present in all cases analyzed. We found an increased vascularity (CD34+) in the areas with abdominal endometriosis and CD3+−:T-lymphocytes, CD20+−:B-lymphocytes, CD68+:macrophages, and Tryptase+: mastocytes were abundant, especially in cases with adenomyosis as a marker of proinflammatory microenvironment. In addition, we found a significantly higher division index-(Ki67+) in the areas with adenomyosis, and inactivation of tumor suppressor genes-p53+ in areas with neoplastic changes. The inflammatory/vascular/hormonal mechanisms trigger endometriosis progression and neoplastic changes increasing local pain. Furthermore, they may represent future therapeutic targets. Simultaneous-multiple immunohistochemical labelling represents a valuable technique for rapidly detecting cellular features that facilitate comparative analysis of the studied predictors.  相似文献   
4.
Microfluidics is defined as emerging science and technology based on precisely manipulating fluids through miniaturized devices with micro-scale channels and chambers. Such microfluidic systems can be used for numerous applications, including reactions, separations, or detection of various compounds. Therefore, due to their potential as microreactors, a particular research focus was noted in exploring various microchannel configurations for on-chip chemical syntheses of materials with tailored properties. Given the significant number of studies in the field, this paper aims to review the recently developed microfluidic devices based on their geometry particularities, starting from a brief presentation of nanoparticle synthesis and mixing within microchannels, further moving to a more detailed discussion of different chip configurations with potential use in nanomaterial fabrication.  相似文献   
5.
The extracellular matrix (ECM) is an important regulator of excitability and synaptic plasticity, especially in its highly condensed form, the perineuronal nets (PNN). In patients with drug-resistant mesial temporal lobe epilepsy (MTLE), hippocampal sclerosis type 1 (HS1) is the most common histopathological finding. This study aimed to evaluate the ECM profile of HS1 in surgically treated drug-resistant patients with MTLE in correlation to clinical findings. Hippocampal sections were immunohistochemically stained for aggrecan, neurocan, versican, chondroitin-sulfate (CS56), fibronectin, Wisteria floribunda agglutinin (WFA), a nuclear neuronal marker (NeuN), parvalbumin (PV), and glial-fibrillary-acidic-protein (GFAP). In HS1, besides the reduced number of neurons and astrogliosis, we found a significantly changed expression pattern of versican, neurocan, aggrecan, WFA-specific glycosylation, and a reduced number of PNNs. Patients with a lower number of epileptic episodes had a less intense diffuse WFA staining in Cornu Ammonis (CA) fields. Our findings suggest that PNN reduction, changed ECM protein, and glycosylation expression pattern in HS1 might be involved in the pathogenesis and persistence of drug-resistant MTLE by contributing to the increase of CA pyramidal neurons’ excitability. This research corroborates the validity of ECM molecules and their modulators as a potential target for the development of new therapeutic approaches to drug-resistant epilepsy.  相似文献   
6.
Anthocyanidins, the aglycons of anthocyanins, are known, beyond their function in plants, also as compounds with a wide range of biological and pharmacological activities, including cytostatic effect against various cancer cells. The nature and position of the substituents in the flavylium cation is essential for such biological properties, as well as the equilibrium between the multistate of the different chemical species that are generated by the flavylium cation, including quinoidal base, hemiketal, and cis- and trans-chalcones. In this work, eight new flavylium derivatives were synthesized, characterized for confirmation of the structure by FT-IR and 2D-NMR, and investigated in vitro as possible cytostatic compounds against HCT116 and HepG2 cancer cells. The most active two compounds were explored for their halochromic properties that can influence the biological activity and subjected to molecular encapsulation in β-cyclodextrin derivatives in order to increase their solubility in water and bioavailability. The anticancer effect was influenced by the position (6-, 7-, or 8-) of the methoxy group in the β-ring of the methoxy-4′-hydroxy-3′-methoxyflavylium cation, while the study of the halochromic properties revealed the important role played by the chalcone species of the pH-dependent multistate in both the uncomplexed and inclusion complex forms of these anthocyanidins.  相似文献   
7.
Water resources management may be improved through the activities of organizations devoted to practice-oriented research, continuing education, and technical assistance. The experience carried out in southern Italy by CSEI Catania during 13 years of activity is presented. Two main activities are discussed: the research and training program on regional pollution control plans and the development of a water data bank.  相似文献   
8.
Being one of the leading causes of death and disability worldwide, cancer represents an ongoing interdisciplinary challenge for the scientific community. As currently used treatments may face limitations in terms of both efficiency and adverse effects, continuous research has been directed towards overcoming existing challenges and finding safer specific alternatives. In particular, increasing interest has been gathered around integrating nanotechnology in cancer management and subsequentially developing various tumor-targeting nanoparticles for cancer applications. In this respect, the present paper briefly describes the most used cancer treatments in clinical practice to set a reference framework for recent research findings, further focusing on the novel developments in the field. More specifically, this review elaborates on the top recent studies concerning various nanomaterials (i.e., carbon-based, metal-based, liposomes, cubosomes, lipid-based, polymer-based, micelles, virus-based, exosomes, and cell membrane-coated nanomaterials) that show promising potential in different cancer applications.  相似文献   
9.
The systemic inflammatory syndrome concept is one of the foundations that stand at the basis of revolutionary modern and future therapies, based on the in-depth understanding of the delicate mechanisms that govern the collaboration between the systems and organs of the human body and, at the same time, the fine balance that ensures a reproach-free operation. An interesting concept that we propose is that of the environment-inadequacy status, a concept that non-specifically incorporates all the situations of the organism’s response disorders in the face of imprecisely defined situations of the environment. The correlation between these two concepts will define the future of modern medicine, along with the gene-adjustment mechanisms. Psoriasis is a clear example of an inadequate body response as a result of exposure to as of yet undefined triggers with an excessive systemic inflammatory reaction and hitherto insufficiently controllable. Modern biological therapies, such as TNF-α, IL-12 family, and IL-17 inhibitors, are intended to profoundly reshape the cytokine configuration of patients with inflammatory diseases such as psoriasis, with tremendous success in disease control. Yet, because of the important roles of cytokines in cancer promotion and control, concern was raised about the fact that the use of biologicals may alter immune surveillance and promote cancer progression. Both theoretical and practical data nevertheless showed that the treatment-induced control of cytokines may be beneficial for reducing the inflammatory milieu that promotes cancer and such have a beneficial role in maintaining health. We briefly present the intricate roles of those cytokine families on cancer control, with some debates on if their inhibition might or might not promote additional tumoral development.  相似文献   
10.
This paper presents a TriMedia processor extended with an IDCT reconfigurable design, and assesses the performance gain such an extension has when performing MPEG-2 decoding. We first propose the skeleton of an extension of the TriMedia architecture, which consists of a Field-Programmable Gate Array (FPGA)-based Reconfigurable Functional Unit (RFU), a Configuration Unit managing the reconfiguration of the RFU, and their associated instructions. Then, we address the computation of the 8 × 8 (2-D) IDCT on such extended TriMedia and propose a scheme to implement the 1-D IDCT operation on the RFU. When mapped on an ACEX EP1K100 FPGA from Altera, the proposed 1-D IDCT exhibits a latency of 16 and a recovery of 2 TriMedia@200 MHz cycles, and occupies 45% of the logic cells of the device. By configuring the 1-D IDCT on the RFU at application launch-time, the IEEE-compliant 2-D IDCT can be computed with the throughput of 1/32 IDCT/cycle. This figure translates to an improvement over the standard TriMedia of more than 40% in terms of computing time when 2-D IDCT is carried out in the framework of MPEG-2 decoding. Finally, the proposed reconfigurable IDCT is compared to a number of existing designs.Mihai Sima was born in Bucharest, Romania. He received the MS degree in Electrical Engineering from Politehnica University of Bucharest, and the Ph.D. degree in Electrical Engineering from Delft University of Technology, The Netherlands. He had been with the Microelectronics Company in Bucharest for 3 years, where he was involved in instrumentation electronics for integrated circuit testing. Subsequently, he joined the Telecommunications Department of Politehnica University of Bucharest, where he had been involved in digital signal processing and speech recognition for 6 years. More recently, he had been with the Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, where he worked on reconfigurable architectures for mediaprocessing domain. He is currently an assistant professor with the Department of Electrical and Computer Engineering, University of Victoria, B.C., Canada. His research interests include computer architecture, reconfigurable computing, embedded systems, digital signal processing, and speech recognition.Sorin D. Coofan was born in Mizil, Romania. He received the MS degree in Computer Science from the Politehnica University of Bucharest, Romania, and the Ph.D. degree in Electrical Engineering from Delft University of Technology, The Netherlands. He had worked with the Research & Development Institute for Electronic Components (ICCE) in Bucharest for a decade, being involved in structured design of digital systems, design rule checking of ICs layout, logic and mixed-mode simulation of electronic circuits, testability analysis, and image processing. He is currently an associate professor with the Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, The Netherlands. His research interests include computer arithmetic, parallel architectures, embedded systems, reconfigurable computing, nano-electronics, neural networks, computational geometry, and computer aided design.Jos T.J. van Eijndhoven was born in Roosendaal, The Netherlands. He studied Electrical Engineering at the Eindhoven University of Technology, The Netherlands, obtaining the M.Sc. and Ph.D. degrees in 1981 and 1984, respectively, for a work on piecewise linear circuit simulation. Then, he became a senior research member in the design automation group of the Eindhoven University of Technology. In 1986 he spent a sabbatical period at the IBM Thomas J. Watson Research Laboratory, Yorktown Heights, New York, for research on high level synthesis. In 1998 he joined Philips Research Laboratories in Eindhoven, The Netherlands, to work on the architectural design of programmable multimedia hardware and the associated mapping of media processing applications.Stamatis Vassiliadis was born in Manolates, Samos, Greece. He is a professor with the Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, The Netherlands. He has also served in the faculties of Cornell University, Ithaca, NY, and the State University of New York (S.U.N.Y.), Binghamton, NY.He hadworked for a decade with IBM in the AdvancedWorkstations and Systems laboratory in Austin TX, the Mid-Hudson Valley Laboratory in Poughkeepsie, NY, and the Glendale Laboratory in Endicott, NY. In IBM he was involved in a number of projects regarding computer design, organizations, and architectures and the leadership to advanced research projects. A number of his design and implementation proposals have been implemented in commerciallyavailable systems and processors including the IBM 9370 model 60 computer system, the IBM POWER II, the IBM AS/400 Models 400, 500, and 510, Server Models 40S and 50S, the IBM AS/400 Advanced 36, and the IBM S/390 G4 and G5 computer systems. For his work, he received numerous awards including 23 levels of Publication Achievement Awards, 15 levels of Invention Achievement Awards and an Outstanding Innovation Award for Engineering/Scientific Hardware Design in 1989. In 1990 he has been awarded the highest number of USA patents in IBM, six of his 70 USA patents being rated with the highest patent ranking in IBM.Kees A. Vissers graduated the Delft University of Technology, receiving his M.Sc. in 1980. He started directly with Philips Research Laboratories in Eindhoven where he was involved in highlevel simulation and high-level synthesis. He had been heading the research on hardware/software co-design and system level design for many years, and had a significant contribution to the TriMedia VLIW processor. From 1987 till 1988 he was a visiting researcher at Carnegie Mellon University, Pittsburgh, Pennsylvania, with the group of Don Thomas. He is currently a Research Fellow with University of California at Berkeley, Department of Electrical Engineering and Computer Sciences. His research interests include video processing, embedded media processing systems, and reconfigurable computing.  相似文献   
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