全文获取类型
收费全文 | 115篇 |
免费 | 4篇 |
出版年
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 23篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 7篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1965年 | 1篇 |
排序方式: 共有119条查询结果,搜索用时 281 毫秒
61.
62.
63.
Marleen TJ van Ampting Arjan J Schonewille Carolien Vink Robert Jan M Brummer van der Roelof Meer Ingeborg MJ Bovee-Oudenhoven 《BMC physiology》2009,9(1):6-9
Background
Glutathione, the main antioxidant of intestinal epithelial cells, is suggested to play an important role in gut barrier function and prevention of inflammation-related oxidative damage as induced by acute bacterial infection. Most studies on intestinal glutathione focus on oxidative stress reduction without considering functional disease outcome. Our aim was to determine whether depletion or maintenance of intestinal glutathione changes susceptibility of rats to Salmonella infection and associated inflammation. 相似文献64.
Fukushima H Hirata S Ueno A Matsuda G Fuwa K Sugama K Kusunoki K Hirai M Hiraki K Tomonaga M Hasegawa T 《PloS one》2010,5(10):e13366
Background
The neural system of our closest living relative, the chimpanzee, is a topic of increasing research interest. However, electrophysiological examinations of neural activity during visual processing in awake chimpanzees are currently lacking.Methodology/Principal Findings
In the present report, skin-surface event-related brain potentials (ERPs) were measured while a fully awake chimpanzee observed photographs of faces and objects in two experiments. In Experiment 1, human faces and stimuli composed of scrambled face images were displayed. In Experiment 2, three types of pictures (faces, flowers, and cars) were presented. The waveforms evoked by face stimuli were distinguished from other stimulus types, as reflected by an enhanced early positivity appearing before 200 ms post stimulus, and an enhanced late negativity after 200 ms, around posterior and occipito-temporal sites. Face-sensitive activity was clearly observed in both experiments. However, in contrast to the robustly observed face-evoked N170 component in humans, we found that faces did not elicit a peak in the latency range of 150–200 ms in either experiment.Conclusions/Significance
Although this pilot study examined a single subject and requires further examination, the observed scalp voltage patterns suggest that selective processing of faces in the chimpanzee brain can be detected by recording surface ERPs. In addition, this non-invasive method for examining an awake chimpanzee can be used to extend our knowledge of the characteristics of visual cognition in other primate species. 相似文献65.
Ari Ueno Satoshi Hirata Kohki Fuwa Keiko Sugama Kiyo Kusunoki Goh Matsuda Hirokata Fukushima Kazuo Hiraki Masaki Tomonaga Toshikazu Hasegawa 《Biology letters》2010,6(3):311-313
The brain activity of a fully awake chimpanzee being presented with her name was investigated. Event-related potentials (ERPs) were measured for each of the following auditory stimuli: the vocal sound of the subject''s own name (SON), the vocal sound of a familiar name of another group member, the vocal sound of an unfamiliar name and a non-vocal sound. Some differences in ERP waveforms were detected between kinds of stimuli at latencies at which P3 and Nc components are typically observed in humans. Following stimulus onset, an Nc-like negative shift at approximately 500 ms latency was observed, particularly in response to SON. Such specific ERP patterns suggest that the chimpanzee processes her name differently from other sounds. 相似文献
66.
When rats were fed a low protein diet containing 3% or more of phenylalanine, their growth rate and food intake were depressed, and eye and paw lesions which were similar to those in tyrosine toxicity developed in all rats. Their liver phenylalanine hydroxylase activity was depressed in proportion to the dietary phenylalanine content, and dihydropteridine reductase activity was in a great excess over hydroxylation activity, so phenylalanine hydroxylase activity seemed to be limited firstly in the degradation of phenylalanine. Excessive phenylalanine was accumulated, and the tyrosine concentration was higher than that of phenylalanine in the plasma and tissues of rats fed a diet containing 2% or more of phenylalanine. When p-Cl-phenylalanine (p-Cl-Phe) was injected to the rats fed excess phenylalanine, the phenylalanine hydroxylase was depressed, the concentration of tyrosine in the body was lowered, and the development of eye and paw lesions was prevented completely. The development of eye and paw lesions seemed to be associated with the extremely elevated tyrosine concentration in the body. 相似文献
67.
Dimerumic acid (DMA) is contained in Monascus anka and Monascus pilosus fermented products. The purpose of this study was to evaluate the effect of DMA against salicylic acid (SA)- and tert-butylhydroperoxide (t-BHP)-induced oxidative stress and cytotoxicity in the liver, using rat liver microsomes and isolated rat hepatocytes. DMA was extracted from monascus-garlic-fermented extract using M. pilosus. In rat liver microsomes, 1 microM DMA decreased SA-induced lipid peroxidation but did not affect the production of the oxidative metabolite of SA via CYP. In isolated rat hepatocytes, 1 microM DMA decreased SA-induced lipid peroxidation and chemiluminescence (CL) generation and the intracellular glutathione-reduced form/oxidized form (GSH/GSSG) ratio in the presence of 1 microM DMA was higher than that without DMA; however, 100 microM DMA suppressed the leakage of lactate dehydrogenase (LDH). On the other hand, t-BHP-induced lipid peroxidation, CL generation, and LDH leakage were prevented by 100 microM DMA. Thus, DMA showed an antioxidative effect in hepatocytes and protected against hepatotoxicity by suppressing oxidative stress without affecting CYP enzymes. 相似文献
68.
To study whether absolute (m/s) or relative (body lengths/s) speed should be used to compare the vulnerability of differently sized animals, we developed a simple computer simulation. Human 'predators' were asked to 'catch' (mouse-click) prey of different sizes, moving at different speeds across a computer screen. Using the simulation, a prey's chances of escaping predation depended on its speed (faster prey were more difficult to catch than slower prey of the same body size), but also on its size (larger prey were easier to catch than smaller prey at the same speed). Catching time, the time needed to catch a prey, also depended on both prey speed and prey size. Relative prey speed (body lengths/s or body surface/s) was a better predictor of catching time than was absolute prey speed (m/s). Our experiment demonstrates that, in contrast to earlier assertions, per unit body length speed of prey may be more 'ecologically relevant' than absolute speed. Copyright 1998 The Association for the Study of Animal Behaviour. 相似文献
69.
The phylogenetic position of the Pedetidae, represented by a single species
Pedetes capensis, is controversial, reflecting in part the retention of
both Hystricomorphous and Sciurognathous characteristics in this rodent. In
an attempt to clarify the species evolutionary relationships, mtDNA gene
sequences from 10 rodent species (representing seven families) were
analyzed using phenetic, parsimony, and maximum-likelihood methods of
phylogenetic inference; the rabbit, Oryctolagus cuniculus (Order
Lagomorpha), and cow, Bos taurus (Order Artiodactyla), were used as
outgroups. Investigation of 714 base pairs of the protein-coding cytochrome
b gene indicate strong base bias at the third codon position with
significant rate heterogeneity evident between the three structural domains
of this gene. Similar analyses conducted on 816 base pairs of the 12S rRNA
gene revealed a transversion bias in the loop sections of all taxa. The
cytochrome b gene sequences proved useful in resolving associations between
closely related species but failed to produce consistent tree topologies at
the family level. In contrast, phylogenetic analysis of the 12S rRNA gene
resulted in strong support for the clustering of
Pedetidae/Heteromyidae/Geomyidae and Muridae in one clade to the exclusion
of the Hystricidae/Thryonomyidae and Sciuridae, a finding which is
concordant with studies of rodent fetal membranes as well as reproductive
and other anatomical features.
相似文献
70.
Esashi Yohji; Fuwa Noritoshi; Kurota Akiko; Oota Hiroshi; Abe Michikazu 《Plant & cell physiology》1987,28(1):141-150
Effects of C2H4 and CO2 on respiration of pre-soaked upper cocklebur(Xanthium pennsylvanicum Wallr.) seeds during a pre-germinationperiod were examined in relation to effects of the two gaseson germination. At 33?C, cocklebur seed germination was greatlystimulated. This high temperature-stimulated germination wasseverely inhibited by C2H4, but not by CO2, although both gasesstimulated germination at 23?C. C2H4 promoted seed respirationat 23?C, but its promotive effect decreases with increasingtemperature and disappeared at about 35?C, while CO2 stimulatedrespiration regardless of temperature. CO2 augmented the operationof the CN-sensitive, cytochrome path (CP) regardless of temperature,resulting in an increase in the ratio of the CP flux to a CN-resistant,alternative path (AP) flux. On the other hand, C2H4 augmentedthe operation of both paths, particularly of the AP, at 23?C,where it promoted germination. However, at 33?C where germinationis suppressed by C2H4, C2H4 preferentially stimulated respirationvia the AP, thus leading to an extremely high ratio of AP toCP. The inhibitory effect of C2H4 on germination at 33?C disappearedcompletely in enriched O2, under which conditions CP is knownto be augmented. At 23?C, CO2 and C2H4 acted independently incontrolling seed respiration, but they were antagonistic at33?C. The independent action appeared when the AP flux was verylow relative to the CP flux, while the antagonism appeared whenthe AP flux had risen. This differential action of the two gasesat different temperatures was also observed in the ATP level,adenylate pool size and energy charge of the axial tissues.These results suggest that the germination-controlling actionsof both CO2 and C2H4 are fundamentally manifested through themodification of respiratory systems. However, the germination-inhibitingeffect of C2H4 at 33 ?C was not removed by inhibitors of AP,and there was little difference in the adenylate compounds betweenthe C2H4-treated and non-treated seeds at 33?C. Therefore, thephysiological action of C2H4 can not be explained only in termsof regulation of the respiratory system. (Received January 24, 1986; Accepted November 17, 1986) 相似文献