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排序方式: 共有8220条查询结果,搜索用时 15 毫秒
941.
F Mokhtarian D Shirazian L Morgante A Miller D Grob E Lichstein 《Canadian Metallurgical Quarterly》1997,3(4):243-247
Our previous data showed that at least five PKC isoforms (alpha, delta, zeta, lambda and tau) were present in the decidualization. In this study, we then localized the PKC alpha and zeta by immunohistochemistry in the decidualized uterine tissues. The decidualized uterine tissues were induced by trauma-stimulation and fixed in formalin. The immunofluorescence were photographed by confocal microscope. The data revealed that the fluorescence of PKC alpha was present in the deciduomata and myometrium. In the deciduomata, PKC alpha was mainly located in the surrounding nuclear. This phenomenon of localization was especially performed on day 2 and 3 of the decidualization, just on the time of higher frequence of cell mitosis. Since the myometrium with hypertrophy did not display the phenomenon of perinuclear localization, these suggested that the expression and localization of PKC alpha may be associated with the cell proliferation. On the other hand, the PKC zeta was also present and distributed broadly in the deciduomata and myometrium. This expression was increased and similar to the previous Western blot studies. Thus, the data confirmed that the various expression and localization of PKC isoforms may be correlated with the development of deciduomata. 相似文献
942.
Kazi Z. A. Hassan Kevin C. Bower Christopher M. Miller 《Canadian Metallurgical Quarterly》2006,132(12):1609-1616
This study investigates the interaction of natural organic matter with iron oxide (goethite) on chlorine decay, disinfection by-product (DBP) formation, and DBP compound speciation [total trihalomethanes (TTHM4) and haloacetic acids (HAA5)]. Batch experiments were conducted with goethite, multiple finished drinking waters, variable chlorine dose, and fixed pH 8. The overall objective was to assess natural organic matter (NOM) adsorption onto goethite and its effect on chlorine decay and DBP formation. Chlorine consumption always increased in the presence of goethite and is attributed to an increase in the reactivity and/or modification of adsorbed NOM. Adsorbed NOM also led to an overall increase in TTHM4, however, HAA5 formation was suppressed during the first 2?h. Chloroform was identified as the increasing species and dichloracetic acid was identified as the suppressed species. This study clearly shows that goethite, which is the predominant iron oxide of pipe deposits, alters both chlorine decay and DBP formation and should be considered when assessing water treatment plant operations and DBP monitoring site selection. 相似文献
943.
S Sharma PW Miller M Stolina L Zhu M Huang RW Paul SM Dubinett 《Canadian Metallurgical Quarterly》1997,4(12):1361-1370
Multiple antitumor modalities may be necessary to overcome lung tumor-mediated immunosuppression and effectively treat non-small cell lung cancer (NSCLC). To evaluate a multimodality gene therapy approach for control of local tumor growth, a weakly immunogenic murine alveolar cell carcinoma, L1C2, was transduced with either the interleukin-7/hygromycin-herpes simplex thymidine kinase (IL-7/HyHSVtk) internal ribosome entry site (IRES) retroviral vector or a vector containing the HyHSVtk, but not the IL-7 gene. Of the many cytokines available for gene transfer, IL-7 was chosen for these studies because it both stimulates CTL responses and down-regulates tumor production of the immunosuppressive peptide TGF-beta. Following selection in hygromycin, IL-7 transduction was confirmed by ELISA. Clones produced 1.25 to 10 ng of IL-7/ml/10(6) cells per 24 h. In vitro, genetically modified tumor cells were significantly more sensitive to ganciclovir (GCV) than unmodified parental tumor cells. The in vivo growth of ex vivo modified L1C2 cells was evaluated. There was a dose-response relationship between the amount of IL-7 secreted in vitro and the growth of genetically modified murine tumor in vivo. Transduced tumor cells regressed in mice following GCV therapy. Although ex vivo gene modification of tumor cells led to complete resolution of the tumor following implantation in vivo, IL-7 and HSVtk gene modified tumor cells were not effective in treating established parental tumors. However when 5 x 10(5) bone marrow-derived, in vitro activated dendritic cells (DC) were administered in combination with transduced tumor and GCV, 5 day old established tumors were eradicated in 80% of mice. These studies suggest that multicomponent vaccines may facilitate improved host responses by replacing host immune deficits and thus could have a role in adjuvant therapy and local control of NSCLC. 相似文献
944.
945.
Observations of single neurons in the primary motor cortex of 1 monkey provided evidence that preliminary perceptual information reaches the motor system before perceptual analysis is complete. Neurons were recorded during a task in which 1 stimulus was assigned to a wrist flexion response and another was assigned to wrist extension. Two stimuli were assigned to a no-go response; each was visually similar to either the flexion or the extension stimulus. When a no-go stimulus was presented, neurons responded with weaker versions of the discharge patterns exhibited to the visually similar stimulus requiring a movement, suggesting that neurons receive partial perceptual information favoring that movement. Functionally separate neuronal populations were identified, and differences in the activations of these provide evidence about the functional effects of preliminary perceptual output on movement control processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
946.
For implementations of iterative reconstruction algorithms that rotate the image matrix, the characteristics of the rotator may affect the reconstruction quality. Desirable qualities for the rotator include: (1) preservation of global and local image counts; (2) accurate count positioning; (3) a uniform and predictable amount of blurring due to the rotation. A new rotation method for iterative reconstruction is proposed which employs Gaussian interpolation. This method was compared to standard rotation techniques and is shown to be superior to standard techniques when measured by these qualities. The computational cost was demonstrated to be only slightly more than bilinear interpolation 相似文献
947.
Adaptive two-pass rank order filter to remove impulse noise in highly corrupted images 总被引:5,自引:0,他引:5
Xiaoyin Xu Miller E.L. Dongbin Chen Sarhadi M. 《IEEE transactions on image processing》2004,13(2):238-247
In this paper, we present an adaptive two-pass rank order filter to remove impulse noise in highly corrupted images. When the noise ratio is high, rank order filters, such as the median filter for example, can produce unsatisfactory results. Better results can be obtained by applying the filter twice, which we call two-pass filtering. To further improve the performance, we develop an adaptive two-pass rank order filter. Between the passes of filtering, an adaptive process is used to detect irregularities in the spatial distribution of the estimated impulse noise. The adaptive process then selectively replaces some pixels changed by the first pass of filtering with their original observed pixel values. These pixels are then kept unchanged during the second filtering. In combination, the adaptive process and the second filter eliminate more impulse noise and restore some pixels that are mistakenly altered by the first filtering. As a final result, the reconstructed image maintains a higher degree of fidelity and has a smaller amount of noise. The idea of adaptive two-pass processing can be applied to many rank order filters, such as a center-weighted median filter (CWMF), adaptive CWMF, lower-upper-middle filter, and soft-decision rank-order-mean filter. Results from computer simulations are used to demonstrate the performance of this type of adaptation using a number of basic rank order filters. 相似文献
948.
A multisite, longitudinal study of patients undergoing inpatient alcohol and drug dependence treatment was conducted in private inpatient facilities, consisting of 4339 subjects from 38 independent programs enrolled in a national addiction treatment outcomes registry. Structured interviews were conducted upon admission, including documentation of current alcohol/drug disorder (DSM-III-R) and lifetime diagnosis of major depressive syndrome; structured interviews were conducted prospectively at 6- and 12-month follow-up periods. The prevalence rate of lifetime diagnosis of major depression in the sample was 39%. Comorbidity varied according to gender and substance of choice. Lifetime depressive symptoms did not correlate with differential length-of-stay, treatment completion, or follow-up consent and, at best, were very weakly associated with follow-up contact. Patients diagnosed with lifetime depression showed the same frequency of participation in posttreatment continuing care: they also showed statistically significant reductions in job absenteeism, inpatient hospitalizations, and arrest rates pre- vs. posttreatment comparable to those of patients without lifetime depression diagnosis. Lifetime major depressive syndrome was not a predictor of outcome in response to abstinence-based treatment. Involvement in posttreatment continuing care accounted for far greater outcome variance. Posttreatment vs. pretreatment factors may be more decisive in influencing risk for relapse. 相似文献
949.
JD Peuler JA Miller M Bourghli HY Zammam EE Soltis JR Sowers 《Canadian Metallurgical Quarterly》1997,46(10):1199-1205
Type II diabetic patients and others with insulin resistance are at risk for development of hypertension characterized by elevated peripheral vascular resistance and loss of insulin's normal vasodilating activity. Oral antidiabetic drugs have recently been recognized to have disparate effects on arterial pressure in such patients and in related rodent models. Sulfonylureas (e.g., glyburide), which stimulate insulin secretion, have been reported either to increase or not to affect arterial pressure, whereas nonsulfonylurea agents with insulin-sensitizing properties, the biguanide metformin and various thiazolidinediones (eg, pioglitazone), have been reported to decrease arterial pressure in humans and rodents. To help elucidate these disparate effects, we investigated these agents for direct actions on arterial vascular contractility and its sensitivity to insulin. Preincubation of intact rat tail arterial tissue rings for 2 hours with known therapeutically effective antidiabetic concentrations of metformin and pioglitazone significantly attenuated the force of contractions produced by either potassium (membrane depolarization) or norepinephrine ([NE] adrenergic receptor activation). Glyburide did not influence these contractions. Preincubation with metformin also induced an attenuating (vasodilating-like) action of insulin on arterial tissue rings contracted by potassium. Conversely, glyburide induced an accentuating action of insulin on potassium-mediated contractions. These results are consistent with measures of vascular function obtained in the past after oral administration of the drugs, which suggested but did not prove that they may exert direct effects on arterial vascular contractility. Thus, metformin and thiazolidinediones may decrease arterial pressure partly by direct vasorelaxant mechanisms, with metformin having an additional effect of inducing vasorelaxation by insulin. In contrast, sulfonylureas may directly induce a paradoxical vasoconstrictor response to insulin. 相似文献
950.
Remote sensing in BOREAS: Lessons learned 总被引:1,自引:0,他引:1
J.A. Gamon D.R. Peddle D. Fuentes J.S. Kimball J. Gu J.R. Miller A.F. Rahman E.A. Smith P. Zarco-Tejada R. Fernandes 《Remote sensing of environment》2004,89(2):139-162
The Boreal Ecosystem Atmosphere Study (BOREAS) was a large, multiyear internationally supported study designed to improve our understanding of the boreal forest biome and its interactions with the atmosphere, biosphere, and the carbon cycle in the face of global climate change. In the initial phase of this study (early 1990s), remote sensing played a key role by providing products needed for planning and modeling. During and after the main BOREAS field campaigns (1994 and 1996), innovative remote sensing approaches and analyses expanded our understanding of the boreal forest in four key areas: (1) definition of vegetation structure, (2) land-cover classification, (3) assessment of the carbon balance, and (4) links between surface properties, weather, and climate. In addition to six BOREAS special issues and over 500 journal papers, a principal legacy of BOREAS is its well-documented and publicly available database, which provides a lasting scientific resource and opportunity to further advance our understanding of this critical northern biome. 相似文献