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A high-quality distance preserving output representation is provided to the neural gas (NG) network. The nonlinear mapping is determined concurrently along with the codebook vectors. The adaptation rule for codebook positions in the projection space minimizes a cost function that favors the trustworthy preservation of the local topology. The proposed visualization method, called OVI-NG, is an enhancement over curvilinear component analysis (CCA). The results show that the mapping quality obtained with OVI-NG outperforms the original CCA, in terms of the trustworthiness, continuity, topographic function and topology preservation measures. 相似文献
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C. González Solveyra A. G. Estérez D. P. Cardinali 《Journal of neural transmission (Vienna, Austria : 1996)》1989,78(1):17-28
Summary By using a radioreceptor assay GABA was detectable in rat interscapular brown adipose tissue (IBAT), the levels being 1% those of CNS and 10-fold those of peripheral plasma. Injection of the glutamic acid decarboxylase (GAD) inhibitor 3-mercaptopropionic acid lowered IBAT GABA levels by about half while injection of the GABA transaminase inhibitor -acetylenic GABA increased them by 230%. Rats kept at 4C for 14 days exhibited IBAT GABA levels that were about half those found at 22C. Accumulation of IBAT GABA after -acetylenic GABA increased by 2-fold in cold-exposed rats. Sympathetic denervation of IBAT prevented the effect of the cold environment on GABA content and impaired that on GABA accumulation. GAD activity was detectable in IBAT homogenates and isolated brown adipocytes. Exposure of rats to cold increased Vmax of GAD without modifying its Km, regardless of intactness of innervation. In binding studies with3H-GABA as a ligand, two types of sites were uncovered of KD=14 and 146 nM, respectively. In the presence of 2.5 mM Ca2+ bicuculline and baclofen were 57 and 46% as effective as GABA to displace3H-GABA from IBAT binding sites. The results indicate existence, possible synthesis and type A and B receptors of GABA in rat IBAT. 相似文献
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Monsalve-De Castillo F Romero TA Estévez J Costa LL Atencio R Porto L Callejas D 《Clinical and diagnostic laboratory immunology》2002,9(6):1372-1375
The immunoregulatory roles of interleukin-2 (IL-2), IL-4, IL-10, gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), the soluble form of the IL-2 receptor (sIL-2R), and the soluble form of CD30 (sCD30) were evaluated in patients with hepatitis B virus (HBV) infection. Two groups of subjects were studied: 15 healthy individuals without hepatitis antecedents and 15 patients with HBV infection. Blood samples were taken during the acute and convalescent phases. The analysis of the samples was done by the enzyme-linked immunosorbent assay technique. IFN-gamma and TNF-alpha levels decreased in the convalescent phase. IL-10, IL-2, and sIL-2R levels increased in the acute and convalescent phases, while sCD30 levels increased during the acute phase. The IL-4 concentrations decreased in both phases. During the acute phase, IFN-gamma and TNF-alpha induced increases in IL-2, sIL-2R, IL-10, and sCD30 levels in serum, which allowed the development of immunity characterized by the nonreactivity of the HBV surface antigen, the onset of antibodies to the HBV surface antigen (anti-HBs), and normal alanine aminotransferase levels during the convalescent phase. Increased IL-2 levels during the acute phase would stimulate the activities of NK cells and CD8(+) lymphocytes, which are responsible for viral clearing. The raised sIL-2R levels reveal activation of T lymphocytes and control of the IL-2-dependent immune response. The sCD30 increment during the acute phase reflects the greater activation of the Th2 cellular phenotype. Its decrease in the convalescent phase points out the decrease in the level of HBV replication. The increase in IL-10 levels could result in a decrease in IL-4 levels and modulate IFN-gamma and TNF-alpha levels during both phases of disease, allowing the maintenance of anti-HBs concentrations. 相似文献
5.
Luque-Reca Octavio Soriano-Maldonado Alberto Gavilán-Carrera Blanca Acosta-Manzano Pedro Ariza-Vega Patrocinio del Paso Gustavo A. Reyes Álvarez-Gallardo Inmaculada C. Estévez-López Fernando 《Quality of life research》2022,31(7):2059-2059
Quality of Life Research - 相似文献
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L. Moreno J. L. Sánchez S. Mañas J. D. Piñeiro J. J. Merino J. Sigut R. M. Aguilar J. I. Estévez R. Marichal 《Journal of medical systems》2001,25(3):177-194
The objective of our research is to develop computer-based tools to automate the clinical evaluation of the electroencephalogram (EEG) and visual evoked potentials (VEP). This paper describes a set of solutions to support all the aspects regarding the standard procedures of the diagnosis in neurophysiology, including: (1) acquisition and real-time processing and compression of EEG and VEP signals, (2) real-time brain mapping of spectral powers, (3) classifier design, (4) automatic detection of morphologies through supervised neural networks. (5) signal analysis through fuzzy modelling, and (6) a knowledge based approach to classifier design. 相似文献
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Nutrition and laryngeal cancer 总被引:3,自引:0,他引:3
The main etiologic factors of cancers of the larynx and hypopharynx are alcohol and tobaeco, and their prevalence in different populations explains, to a large extent, the wide variations in incidence observed around the world. Besides these two main risk factors, however, diet also seems to play a role in determining the risk of these cancers. There is consistent evidence that low consumption of fruit and vegetables is associated with higher risk, after statistical adjustment for alcohol and tobacco. Consumption of vegetable oils and fish and a moderately high polyunsaturated/saturated fatty acid ratio (P/S ratio) were reported to be associated with reduced risk. Low intake of vitamin C, -carotene and vitamin E were reported consistently to be associated with higher laryngeal cancer risk, but there was no clear evidence that these micronutrients are better predictors of cancer risk than the principal food groups from which their intake levels were estimated, i.e., fruits, vegetables, vegetable oils, and fish. Given the overwhelming role of tobacco and alcohol in the etiology of these cancers and the extremely low incidence among nonsmokers/nondrinkers, the available studies provide no estimate of the role of diet in subjects not exposed to these factors. The evidence indicates, however, that, in the presence of tobacco and/or alcohol, low intake of fruit and vegetables may account for 25 to 50 percent of the cases among men. 相似文献
9.
Neoadjuvant chemotherapy (NC) is standard therapy for patients with locally advanced breast cancer and is increasingly used for early-stage operable disease. The aim of NC is a pathological complete response (pCR) in the breast and axillary lymph nodes, which is the best predictor of improved outcome and prolonged survival. The taxanes docetaxel and paclitaxel are potent agents in breast cancer management, with promising single-agent activity and acceptable tolerability in the neoadjuvant setting. In this review of the taxanes as NC for operable and inoperable breast cancer, we include all fully published Phase II-III studies enrolling > or =30 patients. Current evidence suggests that the sequential administration of taxane- and anthracycline-based therapy may be superior to concomitant administration. Indeed, until the recent Phase III Aberdeen study (n = 162), it was uncertain whether NC could prolong survival. In this study, sequential docetaxel after anthracycline-based NC significantly enhanced the clinical response rate and pathological complete response, and yielded a significant 3-year survival advantage, versus anthracycline-based NC alone. Recently, the Phase III National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B27 trial (n = 2411) showed that sequential docetaxel after doxorubicin-cyclophosphamide significantly increased both clinical and pathological response rates for operable breast cancer, with the benefit evident in both estrogen receptor-positive and estrogen receptor-negative patients. This apparent superiority of a sequential anthracycline-taxane regimen is limited to docetaxel, with no similar Phase III trials of paclitaxel versus a non-taxane-based comparator having been conducted to date. In conclusion, current evidence supports the inclusion of a taxane in NC schedules for patients with large and locally advanced breast cancer. 相似文献
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