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1.
Many gamblers claim that gambling is intrinsically exciting, with money playing only a secondary role. To examine the effects of the expectancy of winning money, the authors randomly assigned 243 male college student gamblers to 1 of 6 experimental or 1 of 3 control conditions. Control participants either simply watched a videotaped horse race or they picked a horse, but without wagering; that horse later turned out to be either the winner of the race or the runner-up. Experimental participants wagered $1 on a horse for a chance of winning either $2, $7, or $15, with half winning and half losing their wagers. Wagering led to increased heart rates and subjective excitement as a function of the expected payoff and of winning as opposed to losing the wager. The study was replicated with 200 female college student gamblers with similar results. These findings support the notion that the excitement of gambling is tied to the expectancy of winning money. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
N-Nitrosomethylbenzylamine (NMBA) is a potent esophagus-specific carcinogen that has been utilized extensively in the study of esophageal carcinogenesis in rats. While many studies have focused on the pathogenesis of NMBA-induced esophageal tumors, the tumorigenicity of NMBA itself has not been thoroughly investigated in any single, systematic dose-response study. Therefore, in this study we evaluated NMBA tumorigenicity in rats following various short-term s.c. treatment regimens with the aim of developing an abbreviated treatment protocol which could be used in future studies. To assess the possible correlation of basal cell proliferation with NMBA tumorigenicity, we evaluated the expression of proliferating cell nuclear antigen (PCNA) in both control and NMBA-treated rats. In rats which received a cumulative NMBA dosage of 7.5 mg/kg over the course of 5 weeks, tumor incidence and multiplicity were as follows: 40% with 0.4 +/- 0.3 tumors/rat at week 10; 100% with 2.2 +/- 1.0 tumors/rat at week 20; and 100% with 2.3 +/- 1.0 tumors/rat at week 30. These rats exhibited marked increases in basal cell labeling, with indices that were 1.5- to 1.8-fold higher than controls. NMBA treatment regimens of shorter duration with equivalent or higher cumulative dosages were generally ineffective in producing esophageal tumors, even though significantly elevated levels of basal cell proliferation occurred. Together, these findings indicate that the duration of NMBA treatment is of critical importance in the tumorigenic potential of the carcinogen.  相似文献   
3.
Short-term cultures of androgen-responsive Shionogi 115 (S115) cells exhibited density-dependent regulation of proliferation rate in the presence or absence of testosterone. The average surface area per cell exposed to the growth medium was inversely proportional to population density. By contrast, long-term cultures (serially passaged in testosterone-containing medium for several months) did not exhibit density-dependent regulation of proliferation rate when grown in testosterone-containing medium. In this medium, cells became elongated and no longer exhibited any obvious decrease in exposed surface area with increasing density. Nevertheless, when subcultured into testosterone-free medium, these cells reverted to an epithelial morphology and exhibited density-dependent regulation of proliferation rate. These relationships suggested that the proliferation rate of cells decreased with density in proportion to the decrease in exposed surface area...  相似文献   
4.
We have identified the human papillomavirus (HPV) DNA replication initiation protein E1 as a tight-binding substrate of cyclin E/cyclin-dependent kinase (Cdk) complexes by using expression cloning. E1, a DNA helicase, collaborates with the HPV E2 protein in ori-dependent replication. E1 formed complexes with cyclin E in insect and mammalian cells, independent of Cdks and E2. Additional cyclins, including A-, B-, and F-type (but not D-type), interacted with the E1/E2 complex, and A- and E-type cyclin kinases were capable of phosphorylating E1 and E2 in vitro. Association with cyclins and efficient phosphorylation of E1 required the presence of a cyclin interaction motif (the RXL motif). E1 lacking the RXL motif displayed defects in E2-dependent HPV ori replication in vivo. Consistent with a role for Cdk-mediated phosphorylation in E1 function, an E1 protein lacking all four candidate Cdk phosphorylation sites still associated with E2 and cyclin E but was impaired in HPV replication in vitro and in vivo. Our data reveal a link between cyclin/Cdk function and activation of HPV DNA replication through targeting of Cdk complexes to the E1 replication-initiation protein and suggest a functional role for E1 phosphorylation by Cdks. The use of cyclin-binding RXL motifs is now emerging as a major mechanism by which cyclins are targeted to key substrates.  相似文献   
5.
To ensure a continued place in hospital care, clinical nurse specialists (CNSs) must adapt their role to positively impact the bottom line for hospitals and patients. This article reviews the literature on CNSs' cost-effectiveness in acute care settings.  相似文献   
6.
Two-dimensional nutation pure NQR experiments on 35Cl have been carried out on a single crystal of NaClO3. The 2D nutation experiment separates out different orientations of each chemically equivalent site in a unit cell as a separate frequency in the omega1 domain. The squares of the observed frequencies lie on a straight line with respect to the squares of the offsets, confirming the expected offset dependence quantitatively. The intercepts at zero offset yield the relative orientations of the efg tensors with respect to the axis of the radiofrequency coil.  相似文献   
7.
Susceptibility to audiogenic seizures can be induced in some strains of resistant mice by exposure to an initial auditory stimulus (acoustic priming). Aminooxyacetic acid, hydrazine, glutamic acid, gamma-aminobutyric acid (GABA), cycloheximide, and metyrapone antagonize the acoustic priming of audiogenic seizure susceptibility in C57BL/6Bg mice, whereas only metyrapone attenuates that of DBA/1Bg-asr mice. The strain difference in the effect of AOAA and cycloheximide is correlated with a small, transient fall in level of brain GABA in C57BL/6Bg but not DBA41Bg-asr mice. These findings support our hypothesis that there are at least two neural mechanisms of acoustic priming, each with its own genetic basis and that corticosteroids are required by both mechanisms for the development of primed seizures.  相似文献   
8.
To examine whether gambling cue reactivity is cue-specific, 47 scratch-off lottery players and 47 horse race gamblers were presented with video clips of their preferred and nonpreferred modes of gambling, and two control stimuli including an exciting car race and a mental stressor task while heart rates, excitement, and urge to gamble were being measured. Heart rates for both groups of gamblers were highest to the mental stressor and did not differ in response to the other three cues. Excitement for both groups was highest in response to the action cues (horse race and car chase). Urge to gamble was significantly higher for each group to their preferred mode of gambling. A post hoc exploratory analysis comparing social gamblers (n = 54) and probable pathological gamblers (n = 40) revealed a similar pattern of responses. However, pathological gamblers reported overall significantly higher urges to gamble than social gamblers. As urges have been shown to play a pivotal role in addictive behaviors and relapse, the current findings may have implications for the development of gambling problems and relapse after successful treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
We report on the generation of tunable infrared picosecond pulses by a short-cavity dye laser system consisting of a short cavity, a three-stage amplifier, and a wavelength control unit. The laser emission is temporally, spectrally, and spatially resolved. The conditions for optimum performance are ascertained, and the output characteristics important to experimental applications are determined.  相似文献   
10.
Despite the tremendous potential of bioprinting techniques toward the fabrication of highly complex biological structures and the flourishing progress in 3D bioprinting, the most critical challenge of the current approaches is the printing of hollow tubular structures. In this work, an advanced 4D biofabrication approach, based on printing of shape‐morphing biopolymer hydrogels, is developed for the fabrication of hollow self‐folding tubes with unprecedented control over their diameters and architectures at high resolution. The versatility of the approach is demonstrated by employing two different biopolymers (alginate and hyaluronic acid) and mouse bone marrow stromal cells. Harnessing the printing and postprinting parameters allows attaining average internal tube diameters as low as 20 µm, which is not yet achievable by other existing bioprinting/biofabrication approaches and is comparable to the diameters of the smallest blood vessels. The proposed 4D biofabrication process does not pose any negative effect on the viability of the printed cells, and the self‐folded hydrogel‐based tubes support cell survival for at least 7 d without any decrease in cell viability. Consequently, the presented 4D biofabrication strategy allows the production of dynamically reconfigurable architectures with tunable functionality and responsiveness, governed by the selection of suitable materials and cells.  相似文献   
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