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991.
During normal metaphase in Saccharomyces cerevisiae, chromosomes are captured at the kinetochores by microtubules emanating from the spindle pole bodies at opposite poles of the dividing cell. The balance of forces between the cohesins holding the replicated chromosomes together and the pulling force from the microtubules at the kinetochores result in the biorientation of the sister chromatids before chromosome segregation. The absence of kinetochore–microtubule interactions or loss of cohesion between the sister chromatids triggers the spindle checkpoint which arrests cells in metaphase. We report here that an MEN mutant, cdc15-2, though competent in activating the spindle assembly checkpoint when exposed to Noc, mis-segregated chromosomes during recovery from spindle checkpoint activation. cdc15-2 cells arrested in Noc, although their Pds1p levels did not accumulate as well as in wild-type cells. Genetic analysis indicated that Pds1p levels are lower in a mad2Δ cdc15-2 and bub2Δ cdc15-2 double mutants compared with the single mutants. Chromosome mis-segregation in the mutant was due to premature spindle elongation in the presence of unattached chromosomes, likely through loss of proper control on spindle midzone protein Slk19p and kinesin protein, Cin8p. Our data indicate that a slower rate of transition through the cell division cycle can result in an inadequate level of Pds1p accumulation that can compromise recovery from spindle assembly checkpoint activation. 相似文献
992.
Nack-Shick Choi Dong-Min Chung Chan-Sun Park Keug-Hyun Ahn Joong Su Kim Jae Jun Song Seung-Ho Kim Byung-Dae Yoon Min-Soo Kim 《Biotechnology and Bioprocess Engineering》2010,15(3):446-452
Previously, three extracellular proteases, Vpr, PepT, and subtilisin were identified from Bacillus subtilis KCTC 3014. To confirm the activity of Vpr, two recombinant Vpr proteins, full Vpr with TTG (pGST-fTTG-Vpr) and full Vpr with
ATG (pGST-fATG-Vpr) as an initiation codon were expressed using a pGEX-2T vector encoding glutathione S-transferase (GST)
in Escherichia coli. Vpr was produced in two forms, occurring as four spots on a 2-DE gel, 68 and 75 kDa proteins with similar pI values (4.0
∼ 4.5). Activity was detected in a fibrin zymography at the expected molecular size of 68 kDa (mature form) processed from
full Vpr. However, the recombinant 75 kDa of GST-fVpr did not exhibit activity. Replacement of the TTG codon with ATG led
to 1.9-fold increased enzyme activity in 68 kDa. Interestingly, the expression of GSTVpr resulted in the proteolytic degradation
of the protein and no GST fusion Vpr protein was detected. 相似文献
993.
Hye Jin Chung Dong Woon Lee Hee Suk Yoon Sang Myeong Lee Chung Gyoo Park Ho Yul Choo 《Journal of Asia》2010,13(4):277-282
Out of some isolated Heterorhabditis bacteriophora from Korea, ecological study on two isolates which had different geographical features was investigated. That is, effects of temperature and dose on the pathogenicity and reproduction of two Korean isolates of H. bacteriophora were investigated using Galleria mellonella larvae in the laboratory. The median lethal dose (LD50) decreased with increasing temperature, but increased at 35 °C. The optimal temperatures for infection were 30 °C for H. bacteriophora Jeju strain and 24 °C for H. bacteriophora Hamyang strain. The median lethal time, LT50 of H. bacteriophora Hamyang strain was recorded at 13 °C to 35 °C and that of H. bacteriophora Jeju strain was recorded at 18 °C to 30 °C. The number of established nematodes in G. mellonella larvae was significantly different depending on temperature and dose. When G. mellonella larvae were exposed to 300 infective juveniles (IJs), mortality of G. mellonella gradually increased with exposure time with H. bacteriophora Jeju strain but not with H. bacteriophora Hamyang strain. 87.5% mortality of G. mellonella was recorded by H. bacteriophora Hamyang strain after 1440 min whereas 100% mortality was recorded by H. bacteriophora Jeju strain after 4320 min. The time from infection to the first emergence of nematodes decreased with increasing temperature. Duration of emergence of the two strains in the White traps also decreased with increasing temperature. The highest progeny numbers of H. bacteriophora Jeju strain were 264,602 while those of H. bacteriophora Hamyang strain were 275,744 at the rate of 160 IJs at 24 °C. 相似文献
994.
The brown-winged green stink bug, Plautia stali Scott (Hemiptera: Pentatomidae), is an important fruit-piercing bug. A monitoring study on the seasonal density change of P. stali using traps baited with methyl (E,E,Z)-2,4,6-decatrienoate, the aggregation pheromone of the P. stali, resulted in the first capture of adult tachinid flies, Gymnosoma rotundatum (Diptera: Tachinidae), in Korea. The parasitoid fly may worth studying as a biological control agent in the management of P. stali. 相似文献
995.
996.
Liu Y Jiang X Yu MK Dong J Zhang X Tsang LL Chung YW Li T Chan HC 《Cell biology international》2010,34(11):1075-1083
While the ability of stem cells to switch lineages has been suggested, the route(s) through which this may happen is unclear. To date, the best characterized adult stem cell population considered to possess transdifferentiation capacity is BM-MSCs (bone marrow mesenchymal stem cells). We investigated whether BM-MSCs that had terminally differentiated into the neural or epithelial lineage could be induced to transdifferentiate into the other phenotype in vitro. Our results reveal that neuronal phenotypic cells derived from adult rat bone marrow cells can be switched to epithelial phenotypic cells, or vice versa, by culture manipulation allowing the differentiated cells to go through, first, dedifferentiation and then redifferentiation to another phenotype. Direct transdifferentiation from differentiated neuronal or epithelial phenotype to the other differentiated phenotype cannot be observed even when appropriate culture conditions are provided. Thus, dedifferentiation appears to be a prerequisite for changing fate and differentiating into a different lineage from a differentiated cell population. 相似文献
997.
Xiaojuan Sun Hui He Zhihui Xie Weiping Qian Haiyen E. Zhau Leland W. K. Chung Fray F. Marshall Ruoxiang Wang 《In vitro cellular & developmental biology. Animal》2010,46(6):538-546
Prostate stromal cells may play binary roles in the process of prostate cancer development. As the first to be encountered
by infiltrating prostate cancer cells, prostate stromal cells form the first defense line against prostate cancer progression
and metastasis. However, interaction between prostate cancer and stromal cells may facilitate the formation of a tumor microenvironment
favoring cancer cell growth and survival. To establish an experimental system for studying the interaction between cancer
and stromal cells, we isolated three matched pairs of normal and cancer-associated human prostate stromal clones. In this
report, we describe the morphologic and behavioral characteristics of these cells and their effect on LNCaP prostate cancer
cells in co-culture. Unlike LNCaP prostate cancer cells, the isolated prostate stromal clones are large fibroblast-like cells
with a slow proliferation rate. Growth and survival of these clones are not affected by androgens. The stromal cells display
high resistance to serum starvation, while cancer-associated stromal clones have differentiated survival ability. In co-culture
experiments, the stromal cells protected some LNCaP prostate cancer cells from death by serum starvation, and cancer-associated
stromal clones showed more protection. This work thus established a panel of valuable human prostate stromal cell lines, which
could be used in co-culture to study the interaction between prostate cancer and prostate stromal cells. 相似文献
998.
Parkinson's disease (PD) is a common neurodegenerative movement disorder that affects increasing number of elderly in the world population. The disease is caused by a selective degeneration of dopaminergic neurons in the substantia nigra pars compacta with the molecular mechanism underlying this neurodegeneration still not fully understood. However, various studies have shown that mitochondrial dysfunction and abnormal protein aggregation are two of the major contributors for PD. In fact this notion has been supported by recent studies on genes that are linked to familial PD (FPD). For instance, FPD linked gene products such as PINK1 and parkin have been shown to play critical roles in the quality control of mitochondria, whereas α-synuclein has been found to be the major protein aggregates accumulated in PD patients. These findings suggest that further understanding of how dysfunction of these pathways in PD will help develop new approaches for the treatment of this neurodegenerative disorder. 相似文献
999.
Won Il Choi Kwang-Sik Choi Dong-Pyeo Lyu Jung-Su Lee Jongok Lim Seunghwan Lee Sang-Chul Shin Yeong-Jin Chung Young-Seuk Park 《Biodiversity and Conservation》2010,19(8):2291-2305
Fauna assemblages reflect their habitat relating to ecological function in an ecosystem. The functional groups are concerned
with how a resource is processed by different species to provide a specific ecosystem service or function. We elucidated seasonal
changes of coleopteran functional groups in forests, and evaluated their ecological roles related to available food resources.
Coleopteran communities were collected weekly or biweekly using Malaise traps at nine study sites in Japanese red pine forests
in Korea from late June to September 2005. Compositions of the functional groups were compared at the different sites and
at sampling times with respect to taxa richness and abundance. Cluster analysis and non-metric multidimensional scaling were
used to characterize spatial and temporal changes of functional groups. Herbivores and dead/live wood feeders regulating primary
production in the pine forests were the dominant coleopteran groups in July, followed by detritivores and predators that dominated
from July to August, resulting from the accumulation of detritus. Then, fungivores became dominant due to increased fungal
biomass in the forest. Seasonal changes of coleopteran functional groups shifted from regulators of primary production to
regulators of decomposition, reflecting their available food resources. In addition, abundance of detritivores and predators
were dependent on total abundance of coleopterans, suggesting that these two groups reflect their habitat condition. 相似文献
1000.