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91.
Tissue collagenase: a simplified, semiquantitative enzyme assay 总被引:2,自引:0,他引:2
Tissue collagenase activity from the ulcerating rabbit cornea has been quantitated in a sensitive capillary tube assay system with an unlabeled, native collagen substrate. In this assay system, initial rates of gel lysis are proportional to enzyme concentration over a defined range of enzyme concentrations. Increased sensitivity to enzyme with an unlabeled substrate has been achieved by restricting diffusion of enzyme to one dimension, in a capillary gel. Corneal collagenase activity has been measured at concentrations down to 0.1 μg/μl. In addition to its high sensitivity to enzyme, the precision and simplicity of the assay and minimal equipment requirements all recommend its use for routine screening of biological fluids for collagenase activity and in the investigation of the effects of inhibitors and stimulators of collagenase activity. 相似文献
92.
93.
Y Kimura N Manabe S Nishihara H Matsushita C Tajima S Wada H Miyamoto 《Biology of reproduction》1999,60(6):1475-1482
94.
Yoshiyuki Manabe Satomi Kasahara Yohei Takakura Xiaoxiao Yang Shinji Takamatsu Yoshihiro Kamada Eiji Miyoshi Daisuke Yoshidome Koichi Fukase 《Bioorganic & medicinal chemistry》2017,25(11):2844-2850
We developed α1,6-fucosyltransferase (FUT8) inhibitors through a diversity-oriented synthesis. The coupling reaction between the fucose unit containing alkyne and the guanine unit containing sulfonyl azide under various conditions afforded a series of Guanosine 5′-diphospho-β-l-fucose (GDP-fucose) analogs. The synthesized compounds displayed FUT8 inhibition activity. A docking study revealed that the binding mode of the inhibitor synthesized with FUT8 was similar to that of GDP-fucose. 相似文献
95.
Morishige M Hashimoto S Ogawa E Toda Y Kotani H Hirose M Wei S Hashimoto A Yamada A Yano H Mazaki Y Kodama H Nio Y Manabe T Wada H Kobayashi H Sabe H 《Nature cell biology》2008,10(1):85-92
Epidermal growth factor (EGF) receptor (EGFR) signalling is implicated in tumour invasion and metastasis. However, whether there are EGFR signalling pathways specifically used for tumour invasion still remains elusive. Overexpression of Arf6 and its effector, AMAP1, correlates with and is crucial for the invasive phenotypes of different breast cancer cells. Here we identify the mechanism by which Arf6 is activated to induce tumour invasion. We found that GEP100/BRAG2, a guanine nucleotide exchanging factor (GEF) for Arf6, is responsible for the invasive activity of MDA-MB-231 breast cancer cells, whereas the other ArfGEFs are not. GEP100, through its pleckstrin homology domain, bound directly to Tyr1068/1086-phosphorylated EGFR to activate Arf6. Overexpression of GEP100, together with Arf6, caused non-invasive MCF7 cells to become invasive, which was dependent on EGF stimulation. Moreover, GEP100 knockdown blocked tumour metastasis. GEP100 was expressed in 70% of primary breast ductal carcinomas, and was preferentially co-expressed with EGFR in the malignant cases. Our results indicate that GEP100 links EGFR signalling to Arf6 activation to induce invasive activities of some breast cancer cells, and hence may contribute to their metastasis and malignancy. 相似文献
96.
97.
When we calculate mortality along a gradient such as size, dividing into size classes and calculating rates for every class
often involves a trade-off: fine class intervals produce fluctuating rates along the gradient, whereas broad ones may miss
some trends within an interval. The same trade-off occurs when we want to illustrate size distribution by a histogram. This
paper introduces nonparametric methods, published in a statistical journal, into forest ecology, in which the fine-class strategy
is used in an extreme way: (1) a smoothly changing pattern is approximated by a fine step function, (2) the goodness-of-fit
to the data and the smoothness along the gradient are formulated as a weighting sum within a Bayesian framework, (3) the Akaike
Bayesian Information Criterion (ABIC) selects the weighting system that most appropriately balances the two demands, and (4)
the values of the step function are optimized by the maximum likelihood method. The nonparametric estimates enable us to represent
various patterns visually and, unlike parametric modeling, calculations do not demand the determination of a functional form.
Mortality and size distribution analyses were conducted on 12-year forest tree monitoring data from a 4 ha permanent plot
in an old-growth warm–temperate evergreen broad-leaved forest in Japan. From trees of 11 evergreen species with a diameter
at breast height (DBH) greater than 5 cm, we found three types of trend with increasing DBH: decreasing, ladle-shaped and
constant mortality. These patterns reflect variations in life history particular to each species. 相似文献
98.
The patch mosaic of an old-growth warm-temperate forest: patch-level descriptions of 40-year gap-forming processes and community structures 总被引:1,自引:0,他引:1
Tohru Manabe Kenichiro Shimatani Satoko Kawarasaki Shin-Ichi Aikawa Shin-Ichi Yamamoto 《Ecological Research》2009,24(3):575-586
Old-growth forests consist of various types of small patches that reflect their own gap-forming process, which includes changes
in environmental conditions occurring over several decades. We reconstructed the gap-forming processes that had occurred during
a 40-year period for eight representative patches of an old-growth evergreen broad-leaved forest in Japan, and examined the
current community structure. The selected patches were based on (1) changes in canopy heights estimated from aerial photographs
taken in four different years, (2) long-term ecological research (LTER) monitoring records, and (3) a recent field survey,
so that they sufficiently covered characteristic gap-forming processes such as a new gap, an old gap and consistently closed
canopy. Height and diameter at breast height (DBH) were measured on all living trees taller than 1.3 m. In their height distributions,
currently almost closed patches that were open in 1966 show a rotated sigmoid, whereas their DBH distributions are an inverse
J-shape. In contrast, patches that have been consistently under a closed canopy exhibit gentle inverse J-shapes for both distributions.
For species composition, there are no clear contrasts associated with the past gap-forming processes except for the existence
of fast-growing deciduous species in large currently open patches. Our results suggested that the variation in several decades
of gap-forming processes played a central role in the high patch diversity and the complex patch mosaic of the forest. Diverse
gap-forming processes created micro-environmental heterogeneity both vertically and horizontally, and contributed to the maintenance
of the species-rich, warm-temperate old-growth forest. 相似文献
99.
Makoto Sakurai Susumu Nakakoji Hisaya Manabe Shin-ichi Dewa Akihiko Shinomiya Tomoki Sunobe 《Ichthyological Research》2009,56(1):82-86
Bi-directional sex change in the deep-water gobiid fish Trimma yanagitai was examined. The gonads of all individuals consisted of ovarian and testicular elements, and an accessory gonadal structure.
In no gonads were both testicular and ovarian parts simultaneously active. Bi-directional sex changes occurred during the
rearing experiments in aquaria under conditions of which there was co-existence of two males or plural females. The sex of
individuals could be determined by their relative body size or social dominance: the largest individuals acting as male and
the remainder as female. 相似文献
100.