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771.
Kazumasa Uematsu 《Ichthyological Research》1986,33(3):293-303
The autonomic innervation of the ovary of the dab was studied histologically and physiologically. The ovary receives a branch of nerve bundles that emerge into the abdominal cavity at the postero-ventral end of the kidney and can be traced back to the sympathetic chain in the vicinity of the 5th vertebra. Almost all the nerve fibers are AChE-positive, and some of them also emit adrenergic fluorescence. Electrical stimulation of the ovarian nerves caused ovarian contractions, and administration of ACh elicited contractions of the ovary preparations, supporting the hypothesis that the ovary is innervated by excitatory cholinergic fibers. In the ovarian nerve bundles, many AChE-positive and non-fluorescent ganglion cells are scattered. Ultrastructural studies suggest that nerve endings situated on the ovarian smooth muscle and on ganglion cells are cholinergic. These results also suggest that the cells are the post-ganglionic neurons of the cholinergic innervation and the axons of the cells reach to the muscle cells. On the other hand, the adrenergic fluoresecent fibers possibly participate in the inhibitory innervation, since the presence of inhibitory beta-adrenoceptors were demonstrated by pharmacological studies. 相似文献
772.
The current-voltage relationship of ion leak (i.e., ion transport involving neither special channels nor carriers) across the lipid-bilayer membrane has been observed to be log-linear above the ohmic regime. The coefficient of the linear term has been found to be universal for membranes and penetrants examined. This universality has been explained in terms of diffusion in an external field, where the ion position is described as a Markovian process. Such a diffusion picture can be questioned, however. It is also probable that a leaking ion gets over the potential barrier before experiencing sufficient random collision in the membrane, considering that each ion is surrounded with long lipid molecules aligned almost unidirectionally. As an alternative, we discuss this ion leak in terms of velocity distribution of the ions entering the membrane and density fluctuation of the lipids. We conclude that we can explain the universality without resorting to the diffusion picture. 相似文献
773.
Valentijn van den Brink Isabelle Henry Kazumasa Wakamatsu Alexandre Roulin 《Ethology : formerly Zeitschrift fur Tierpsychologie》2012,118(7):673-682
Recent studies have shown that melanin‐based coloration is associated with the ability to cope with stressful environments, potentially explaining why coloration covaries with anti‐predator behaviours, boldness and docility. To investigate whether these relationships are consistent across species, we performed a study in the European kestrel ( Falco tinnunculus). Similar to our results found previously in the barn owl ( Tyto alba), nestling kestrels displaying a larger sub‐terminal black tail band stayed on their back longer (tonic immobility test) and breathed at a lower rate than individuals with a smaller black band when handled. However, in contrast to barn owls, nestling kestrels with a larger black tail band were more aggressive and more agitated. Our results strengthen the hypothesis that melanin coloration is related to stress response and in turn to the reaction to predators, a very important personality trait (i.e. boldness). 相似文献
774.
Hideyuki Matsuura Yosuke Yamamoto Misa Muraoka Kenji Akaishi Yasuhisa Hori Kanoko Uemura Naoki Tsuji Kazuo Harada Kazumasa Hirata Takeshi Bamba Hitoshi Miyasaka Kouichi Kuroda Mitsuyoshi Ueda 《Biotechnology progress》2013,29(5):1197-1202
The development of simple, portable, inexpensive, and rapid analytical methods for detecting and monitoring toxic heavy metals are important for the safety and security of humans and their environment. Herein, we describe the application of phytochelatin (PC) synthase, which plays a critical role in heavy metal responses in higher plants and green algae, in a novel fluorescent sensing platform for cadmium (Cd). We first created surface‐engineered yeast cells on which the PC synthase from Arabidopsis (AtPCS1) was displayed with retention of enzymatic activity. The general concept for the sensor is based on the Cd level‐dependent synthesis of PC2 from glutathiones by AtPCS1‐displaying yeast cells, followed by simple discriminative detection of PC2 via sensing of excimer fluorescence of thiol‐labeling pyrene probes. The intensity of excimer fluorescence increased in the presence of Cd up to 1.0 μM in an approximately dose‐dependent manner. This novel biosensor achieved a detection limit of as low as 0.2 μM (22.5 μg/L) for Cd. Although its use may be limited by the fact that Cu and Pb can induce cross‐reaction, the proposed simple biosensor holds promise as a method useful for cost‐effective screening of Cd contamination in environmental and food samples. The AtPCS1‐displaying yeast cells also might be attractive tools for dissection of the catalytic mechanisms of PCS. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1197–1202, 2013 相似文献
775.
R Matsuo A Asada K Fujitani K Inokuchi 《Biochemical and biophysical research communications》2001,289(2):479-484
We describe here an LTP-induced gene, LIRF, which encodes a novel protein with RING finger and B30.2 domains in its N- and C-terminal portions, respectively. Each domain is encoded by one exon, suggesting that the organization of the gene was generated by exon shuffling. The amino acid sequences of the mouse, rat, and human LIRF proteins are highly conserved and contain a putative PEST sequence. LIRF is an immediate-early gene in hippocampal granule cells, and its expression is upregulated immediately after the induction of long-lasting long-term potentiation at perforant pathway-dentate gyrus synapses and returns to the basal level within 150 min. A heterologously expressed LIRF protein fused to EGFP localizes specifically to the cytoplasm in COS-7 cells. These findings suggest a possible involvement of LIRF in a limited, early phase of synaptic plasticity. 相似文献
776.
Growth of fetal rat gastro-intestinal epithelial cells is region-specifically controlled by growth factors and substrata in primary culture 总被引:2,自引:2,他引:0
Hiroshi Fukamachi Masao Ichinose Shinko Tsukada Kiyoshi Kurokawa Koichiro Shiokawa Kazumasa Miki Shigeo Takeuchi 《Development, growth & differentiation》1995,37(1):11-19
The mammalian gastro-intestinal tract can be divided into three parts: esophagus and forestomach, glandular stomach, and intestine. We have previously reported primary culture systems for duodenal and glandular stomach epithelial cells in which the cells express tissue-specific marker proteins. However, the effects of growth factors and substrata on cell growth have not been fully investigated. In this study a primary culture system was established for forestomach epithelial cells and the mechanism by which the growth of gastro-intestinal epithelial cells is controlled in primary culture was examined. Forestomach, glandular stomach and duodenal epithelial cells proliferated rapidly in culture, increasing their numbers about 30-, 20-and 10-fold, respectively, in the first 5 days. Scanning electron microscopy showed that these three types of epithelial cells exhibited region-specific morphologies in culture. Results on the effects of growth factors and substrata on the proliferation of the epithelial cells revealed that the culture conditions required to induce maximal epithelial growth differed. Forestomach and glandular stomach epithelial cells required similar combinations of growth factors to proliferate, and these were quite different from those required for duodenal epithelial cells. Glandular stomach and duodenal epithelial cells could proliferate in a serum-free condition while forestomach epithelial cells could not. Thus, glandular stomach epithelial cells exhibited intermediate characteristics between forestomach and duodenal epithelial cells regarding their growth factor requirement. Glandular stomach and duodenal epithelial cells could not proliferate on plastic without collagen substrata while forestomach epithelial cells could. Duodenal epithelial cells proliferated faster on collagen gels than on collagen films, and forestomach epithelial cells faster on collagen films than on collagen gels. Glandular stomach epithelial cells proliferated similarly on both substrata. Thus again, glandular stomach epithelial cells exhibited intermediate characteristics between forestomach and duodenal epithelial cells regarding their substratum dependency. We conclude that the growth of gastro-intestinal epithelial cells is affected by both growth factors and substrata, and that glandular stomach epithelial cells exhibit intermediate characteristics between forestomach and duodenal epithelial cells in responding to these factors. These results suggest that a head-to-tail gradient exists in the gastro-intestinal tract which controls the epithelial response to growth factors and substrata. 相似文献
777.
K Nishimura K Utsumi M Yuhara Y Fujitani A Iritani 《The Journal of experimental zoology》1989,251(3):300-305
Gas chromatography-mass spectrometry was employed to identify the two volatile amines in male mouse urine. These amines were much less concentrated in urine of castrated males. The identified amines, isobutylamine and isoamylamine, were assayed for the potential of puberty acceleration in postweaning female mice. A total of 105 young female mice were exposed to one of the following five odors: distilled water (control), 0.1 M isobutylamine, 0.1 M isoamylamine, a mixture of 0.05 M isobutylamine and 0.05 M isoamylamine, or fresh male mouse urine. The mixture of these amines accelerated the vaginal opening of young females. Except for the control, all experimental odors accelerated the first vaginal estrus in ICR strain mice. 相似文献