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91.
92.
Yutaka Tochihara Teruyuki KumamotoJoo-Young Lee Nobuko Hashiguchi 《Journal of thermal biology》2011,36(2):105-111
The purpose of this study was to investigate age-related differences in cutaneous temperature thresholds for warm thermal sensitivity in a thermoneutral (28 °C) and in a cool environment (22 °C). Peripheral warm thresholds were measured on nine body regions (cheek, chest, abdomen, upper arm, forearm, hand, thigh, shin, and foot) using a thermal stimulator in 12 young (22±1 years) and 13 elderly male subjects (67±3 years). The results showed that: (1) mean skin temperature did not differ by age in both environments; (2) the cutaneous warm thresholds for the hand, shin, and foot were significantly higher for the elderly than for the young in both environments (p<0.01), whereas the remaining body parts showed no age difference; (3) the most insensitive region for elderly males was the shin for both environments (p<0.01), while for young there was no statistical significant difference with Ta 28 °C; (4) the shin of the elderly was seven and nine times less sensitive to warmth when compared to those of the cheek at Ta 28 and 22 °C, respectively; and (5) warm thresholds were 3-4 °C greater at Ta 22 °C than at 28 °C, only for the elderly males' shin and foot (p<0.05), while for young the difference between Ta 22 and 28 °C was not statistically significant. The results indicate that age-related differences in cutaneous warm perception appear to be non-uniform over the body and significant on extremities; there is a greater bluntness of warm sensitivity in the cool environment for elderly males. 相似文献
93.
Imamura M Kato N Yoshioka M Okada H Iwamaru Y Shimizu Y Mohri S Yokoyama T Murayama Y 《Journal of virology》2011,85(6):2582-2588
The pathogenic isoform (PrP(Sc)) of the host-encoded cellular prion protein (PrP(C)) is considered to be an infectious agent of transmissible spongiform encephalopathy (TSE). The detailed mechanism by which the PrP(Sc) seed catalyzes the structural conversion of endogenous PrP(C) into nascent PrP(Sc) in vivo still remains unclear. Recent studies reveal that bacterially derived recombinant PrP (recPrP) can be used as a substrate for the in vitro generation of protease-resistant recPrP (recPrP(res)) by protein-misfolding cyclic amplification (PMCA). These findings imply that PrP modifications with a glycosylphosphatidylinositol (GPI) anchor and asparagine (N)-linked glycosylation are not necessary for the amplification and generation of recPrP(Sc) by PMCA. However, the biological properties of PrP(Sc) obtained by in vivo transmission of recPrP(res) are unique or different from those of PrP(Sc) used as the seed, indicating that the mechanisms mediated by these posttranslational modifications possibly participate in reproductive propagation of PrP(Sc). In the present study, using baculovirus-derived recombinant PrP (Bac-PrP), we demonstrated that Bac-PrP is useful as a PrP(C) substrate for amplification of the mouse scrapie prion strain Chandler, and PrP(Sc) that accumulated in mice inoculated with Bac-PrP(res) had biochemical and pathological properties very similar to those of the PrP(Sc) seed. Since Bac-PrP modified with a GPI anchor and brain homogenate of Prnp knockout mice were both required to generate Bac-PrP(res), the interaction of GPI-anchored PrP with factors in brain homogenates is essential for reproductive propagation of PrP(Sc). Therefore, the Bac-PMCA technique appears to be extremely beneficial for the comprehensive understanding of the GPI anchor-mediated stimulation pathway. 相似文献
94.
95.
Hitoshi Wakabayashi Titis Wijayanto Joo-Young Lee Nobuko Hashiguchi Mohamed Saat Yutaka Tochihara 《Journal of physiological anthropology》2014,33(1):5
Background
This study investigated the effect of hydration differences on body fluid and temperature regulation between tropical and temperate indigenes exercising in the heat.Methods
Ten Japanese and ten Malaysian males with matched physical characteristics (height, body weight, and peak oxygen consumption) participated in this study. Participants performed exercise for 60 min at 55% peak oxygen uptake followed by a 30-min recovery at 32°C and 70% relative air humidity with hydration (4 times each, 3 mL per kg body weight, 37°C) or without hydration. Rectal temperature, skin temperature, heart rate, skin blood flow, and blood pressure were measured continuously. The percentage of body weight loss and total sweat loss were calculated from body weight measurements. The percentage change in plasma volume was estimated from hemoglobin concentration and hematocrit.Results
Malaysian participants had a significantly lower rectal temperature, a smaller reduction in plasma volume, and a lower heart rate in the hydrated condition than in the non-hydrated condition at the end of exercise (P <0.05), whereas Japanese participants showed no difference between the two hydration conditions. Hydration induced a greater total sweat loss in both groups (P <0.05), and the percentage of body weight loss in hydrated Malaysians was significantly less than in hydrated Japanese (P <0.05). A significant interaction between groups and hydration conditions was observed for the percentage of mean cutaneous vascular conductance during exercise relative to baseline (P <0.05).Conclusions
The smaller reduction in plasma volume and percentage body weight loss in hydrated Malaysians indicated an advantage in body fluid regulation. This may enable Malaysians to reserve more blood for circulation and heat dissipation and thereby maintain lower rectal temperatures in a hydrated condition. 相似文献96.
Masayuki Kondo Kazuhito Ichii Masahito Ueyama Yasuko Mizoguchi Ryuichi Hirata Nobuko Saigusa 《Ecological Research》2013,28(5):893-905
The process of confining unnecessary freedom is a step toward advanced ecosystem modeling. This study demonstrates the importance of carbon flux and biometric observation in constraining a terrestrial ecosystem model with a simple optimization scheme. At the selected sites from AsiaFlux network, a simultaneous optimization scheme for both carbon flux and biomass was compared with carbon flux-oriented and biomass-oriented optimization schemes using the Biome-BGC model. The optimization scheme oriented to either carbon flux or biomass provided simulation results that were consistent with observations, but with reduced performance in unconstrained variables. The simultaneous optimization scheme yielded results that were consistent with observations for both carbon flux and biomass. By comparing long-term projections simulated by three schemes, it was found that the optimization oriented only to carbon flux has limited performance because misrepresented biomass significantly affected a projection of carbon exchange through heterotrophic respiration. From these experiments, we found that (1) a process model like Biome-BGC is capable of reproducing both carbon flux and biomass within acceptable proximity, (2) constraining biomass is importance not just because it is one of carbon cycle components, but also it significantly affects simulations of carbon flux. Thus, it is important to invest more effort to improve simulation of biomass as well as carbon flux. 相似文献
97.
Go , a GTP-Binding Protein: Immunochemical and Immunohistochemical Localization in the Rat 总被引:12,自引:6,他引:6
Tomiko Asano Reiji Semba Nobuko Kamiya Nobuaki Ogasawara Kanefusa Kato 《Journal of neurochemistry》1988,50(4):1164-1169
The tissue and cellular distribution of a GTP-binding protein, Go, was investigated in the rat by immunochemical and immunohistochemical methods. Because the specific antibody for the alpha subunit of bovine Go (Go alpha) cross-reacted with rat Go alpha, an enzyme immunoassay method developed for bovine Go alpha was applied for measuring the tissue concentration of Go alpha in the rat. Go alpha was detected in all tissues examined except blood cells. The concentration of Go alpha was highest in the CNS (approximately 7.7 and 4.4 nmol/g in the cerebrum and cerebellum, respectively), followed by the pituitary gland and sciatic nerve. Among the other peripheral tissues, relatively high concentrations of Go alpha were observed in the urinary bladder, stomach, and intestines; however, these values were less than 2% of the concentration in the cerebrum. Go alpha in the intestine was located mostly in the muscle layer. Immunohistochemical study showed that Go alpha was associated mostly with the neural elements but not with cells particular to each peripheral organ. Go alpha was also present in the membranes of neuroendocrine cells, including glandular cells in the anterior lobe of the pituitary gland, chromaffin cells in the medulla of the adrenal gland, islets cells in the pancreas, and parafollicular cells in the thyroid. These results indicate that Go is localized exclusively in the nervous tissues and neuroendocrine cells. 相似文献
98.
Ontogeny of the GTP-Binding Protein Go in Rat Brain and Heart 总被引:6,自引:6,他引:0
Tomiko Asano Nobuko Kamiya Reiji Semba Kanefusa Kato 《Journal of neurochemistry》1988,51(6):1711-1716
We determined the ontogeny of the GTP-binding protein Go in rat brain and heart by employing highly sensitive enzyme immunoassay methods. In the brain, the alpha subunit of Go (Go alpha) gradually increased and reached adult levels approximately 20 and 30 days after birth in cerebral cortex and cerebellum, respectively. Concentrations of beta subunits, which were also quantified by the immunoassay, were almost equal to those of Go alpha in the brain of rats younger than 10 days, but were higher than those of Go alpha after 10 days. These results suggest that late development of GTP-binding proteins other than Go. Go alpha was immunohistochemically positive in neuropils and negative in cell bodies at any age tested. In the heart, the concentrations of Go alpha increased up to several times of the adult level just after birth, and then gradually decreased after the 20th postnatal day. The level of Go alpha in the liver, however, was very low and constant throughout ontogenic development. An immunohistochemical study indicated that Go alpha was positive in the cardiac muscle of young rat, but negative in that of adult rat. These results indicate that Go alpha exists in cells other than those of nervous tissues and neuroendocrine cells in some periods of ontogenic development. 相似文献
99.
Nobuko Mutoh Makoto Kimura Yasuyuki Oshima Hideo Iwaki 《Journal of plant research》1985,98(2):159-170
In an old field grassland dominated byMiscanthus sinensis Anderss. the community structures, phytomass, dominance ofM. sinensis and species diversity were measured. Species and life form composition of the stand were characterized by higher percentages
of therophytes, woody and shrubby species, liana and alien species.
From May so September in 1982, all the aboveground parts were harvested from each of the four quadrats (2 m×2 m) once a month.
Seasonal peak of aboveground phytomass, in September, was 1027 g d.w.m−2 to whichM. sinensis contributed as much as 96.5%. With the progress of the growing season,M. sinensis became increasingly important both in stand phytomass and in dominance, whereas species diversity based on the dry weight
contributions of constituent species decreased. Our analysis of these seasonal trends showed that the diversity was largely
a function of dominance of the most important species, rather than that of stand phytomass or productivity. The simultaneous
measurements of 20 quadrats in late August 1983, also supported the above conclusion. 相似文献