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排序方式: 共有419条查询结果,搜索用时 468 毫秒
31.
Examined the effectiveness of child-centered play therapy sessions every day for 2 wks as an intervention for child witnesses of domestic violence. 22 children (aged 4–10 yrs) participated. The analyses of covariance indicated that children in the experimental group experience a significant increase in self-concept, a significant decrease in external and total behavior problems, a significant increase in the play behavior of physical proximity to the therapist, and a significant increase in the play behavior of nurturing and creative play themes. The results support utilizing intensive play therapy to treat child witnesses of domestic violence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
32.
AR Collins B Olmedilla S Southon F Granado SJ Duthie 《Canadian Metallurgical Quarterly》1998,19(12):2159-2162
Carotenoids are thought to act as antioxidants in vivo, decreasing oxidative damage to biomolecules and thus protecting against coronary heart disease and cancer. However, human intervention studies with beta-carotene have given equivocal results in terms of cancer incidence. In an alternative molecular epidemiological approach, we have employed the 'comet assay' (single cell alkaline gel electrophoresis) to measure strand breaks, oxidized pyrimidines and altered purines in the DNA of lymphocytes from volunteers supplemented with alpha/beta-carotene, lutein, lycopene or placebo. In addition, we measured concentrations of the main serum carotenoids, and vitamins E and C, by HPLC. We report a significant negative correlation between basal concentrations of total serum carotenoids and oxidized pyrimidines. A similar correlation was seen between individual carotenoids (notably lutein and beta-carotene) and oxidized pyrimidines. However, carotenoid supplementation did not have a significant effect on endogenous oxidative damage. This suggests that there are some factors in the basal diet, probably found in fruit and vegetables, that decrease oxidative damage to DNA. In this case, basal serum carotenoids may simply be markers of consumption of fruit and vegetables, they themselves having little or no protective value. 相似文献
33.
Fundamental data, including density and rheological behavior, of nitrile butadiene rubber in solutions of monochlorobenzene and o‐dichlorobenzene were investigated, under a wide range of experimental conditions, including operation temperatures and polymer concentrations up to 165°C and 20% (wt), respectively. Shear rates of up to 1300/s were used for the measurement of rheological behavior. Within the range of the operational conditions employed, the solutions of nitrile butadiene rubber show Newtonian fluid behavior. A characteristic viscosity is proposed as a model parameter to correlate the viscosity of the NBR solutions. As a result, empirical correlation equations for density and viscosity are formed. The purpose of this work is to provide fundamental data for process development of the solution hydrogenation of nitrile butadiene rubber. 相似文献
34.
Logi Vidarsson Charles Cunningham Garry E Gold John M Pauly 《IEEE transactions on medical imaging》2007,26(7):981-989
The purpose of this work was to present and evaluate a new method for directly designing T2-selective preparation pulses. Using a modified Shinnar-Le-Roux (SLR) transform, the design of T2-selective pulses becomes equivalent to designing a pair of polynomials one of which represents the longitudinal magnetization and the other the transverse magnetization. The polynomials enable one to directly analyze the various tradeoffs involved in the design. To evaluate the new method, a short-T2-selective magnetization preparation pulse was designed. Following the preparation pulse, a 2D Fourier transform (2DFT) multislice gradient echo sequence was used for imaging. For verification Bloch equation simulations were performed along with both in vivo and phantom scans. Phantom scans showed good signal suppression of long-T2 species. This is supported by good long-T2 signal suppression seen on the in vivo images. Simulations indicate that the pulse is robust to +/-150 Hz B0 inhomogeneities and +/-10% B1 inhomogeneities. 相似文献
35.
IE Ehrmann PS Ellis S Mazeyrat S Duthie N Brockdorff MG Mattei MA Gavin NA Affara GM Brown E Simpson MJ Mitchell DM Scott 《Canadian Metallurgical Quarterly》1998,7(11):1725-1737
The Delta Sxrb interval of the mouse Y chromosome is critical for spermatogenesis and expression of the male-specific minor transplantation antigen H-Y. Several genes have been mapped to this interval and each has a homologue on the X chromosome. Four, Zfy1 , Zfy2 , Ube1y and Dffry , are expressed specifically in the testis and their X homologues are not transcribed from the inactive X chromosome. A further two, Smcy and Uty , are ubiquitously expressed and their X homologues escape X-inactivation. Here we report the identification of another gene from this region of the mouse Y chromosome. It encodes the highly conserved eukaryotic translation initiation factor eIF-2gamma. In the mouse this gene is ubiquitously expressed, has an X chromosome homologue which maps close to Dmd and escapes X-inactivation. The coding regions of the X and Y genes show 86% nucleotide identity and encode putative products with 98% amino acid identity. In humans, the eIF-2gamma structural gene is located on the X chromosome at Xp21 and this also escapes X-inactivation. However, there is no evidence of a Y copy of this gene in humans. We have identified autosomal retroposons of eIF-2gamma in both humans and mice and an additional retroposon on the X chromosome in some mouse strains. Ark blot analysis of eutherian and metatherian genomic DNA indicates that X-Y homologues are present in all species tested except simian primates and kangaroo and that retroposons are common to a wide range of mammals. These results shed light on the evolution of X-Y homologous genes. 相似文献
36.
Determined the effectiveness of a 10-wk filial therapy training model as an intervention method for Chinese parents living in the US. Results of the analyses of covariance reveal that the Chinese parents in the experimental group had a significant increase in their level of empathic interactions with their children; a significant increase in their attitude of acceptance toward their children; and a significant reduction in their level of stress related to parenting. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
37.
RJ O'Hara J Greenman AW MacDonald KM Gaskell KP Topping GS Duthie MJ Kerin PW Lee JR Monson 《Canadian Metallurgical Quarterly》1998,4(8):1943-1948
Interleukin 12 (IL-12) is a heterodimeric cytokine that has been demonstrated to have a major role in stimulating a cell-mediated antitumor response. IL-10, a product of T helper 2 lymphocytes, is its most potent inhibitor. The aim of this study was to investigate whether patients with colorectal cancer had an imbalance in production of IL-12 and IL-10 preoperatively, and whether this was associated with advanced disease at surgery. Blood was obtained before surgery from 60 patients with colorectal cancer and from 30 controls. Peripheral blood mononuclear cells were incubated with Staphylococcus aureus Cowan's strain 1 in vitro for 24 h to assess IL-12 expression after stimulation, and serum was used for IL-10 measurement. IL-12 and IL-10 levels were assessed by ELISA. A single pathologist staged the tumors according to the tumor-node-metastasis (TNM) and Dukes' classifications. Patients with colorectal cancer had significantly lower levels of IL-12 (P <0.001) and higher levels of IL-10(P = 0.004) compared to controls. In addition, lower levels of IL-12 were detected in those patients who were node positive (P<0.05), had Dukes' C lesions (P < or = 0.001), and T3 or T4 lesions (P<0.033) when compared to controls. Patients with Dukes' B and C lesions (P<0.01) and T3 and T4 lesions (P<0.05) also had higher levels of IL-10 compared to controls. This study is the first to demonstrate that patients with colorectal cancer have decreased IL-12 production and increased serum IL-10. This suggests an impaired T helper 1 cell-mediated antitumor response and provides some justification for exogenous IL-12 therapy or anti-IL-10 therapy in these patients. 相似文献
38.
Garry W. Timco 《Cold Regions Science and Technology》1981,4(2):81-92
A series of experiments have been performed to measure the ultimate (flexural) strength of ice grown from impure melts containing one of a number of chemical dopants (chloride and sulfate salts, salts of the carboxylic acids, alcohols, amides and sugars). The results of these experiments indicate: (1) within a homologous series, the greatest strength reduction in the ice usually occurs for the lowest member of the series; (2) the overall reduction in strength of the ice to a limiting value is greater for the lower molecular weight dopants; and (3) of the chemical families tested, the most effective ice-strength reducing ones were the R-OH alcohols, the salts of the carboxylic acids and the amides. These results are discussed in terms of the structural features of the ice. An empirical relationship is presented for electrolytic dopants which predicts the optimum concentration of dopant necessary for reducing the strength of ice. 相似文献
39.
The design and construction of a lithium niobate 8×8 optical switch with a rearrangeably nonblocking architecture is described. The design is compared with the more familiar strictly nonblocking architecture. The switch has 28 elements, a switching voltage of 26 V and a loss of 5.5 dB at 1.3 μm wavelength 相似文献
40.
During pregnancy, zinc (Zn) levels in the rat fetal liver increase markedly. Why they do so or how the increase is regulated is unknown. We firstly investigated whether the increase occurs as a result of increased Zn transfer across the placenta and then tested whether the regulation occurred at the level of the microvillar membrane of the placenta or the fetal liver plasma membrane. Rats at different stages of gestation were injected with 7.5 microCi 65Zn in 100 microliters rat serum and killed after 1 h. 65Zn levels in the fetus remained constant at equivalent to the amount in 50 microliters maternal plasma per fetus until Day 18; at this time they increased to equivalent to 1.33 ml and then continued to increase until term. We isolated placental microvillar vesicles from placentas at each stage of gestation, characterized them, and measured Zn uptake. Zn uptake rates did not change during pregnancy. Similarly, we isolated vesicles from fetal liver plasma membrane and measured Zn uptake. Again, the uptake properties did not change during pregnancy. The data suggest that some other step in the transport process is rate limiting and that the increase in Zn levels in the fetal liver that occurs during pregnancy is possibly a result, rather than a cause, of metallothionein induction. 相似文献