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991.
Effects of human amniotic membrane grafts combined with marrow mesenchymal stem cells on healing of full-thickness skin defects in rabbits 总被引:1,自引:0,他引:1
Sung Soo Kim Chang Keun Song Sung Keun Shon Kyu Yeol Lee Chul Hong Kim Myung Jin Lee Lih Wang 《Cell and tissue research》2009,336(1):59-66
We have investigated the wound-healing effects of mesenchymal stem cells (MSCs) in combination with human amniotic membrane
(HAM) when grafted into full-thickness skin defects of rabbits. Five defects in each of four groups were respectively treated
with HAM loaded with autologous MSCs (group A), HAM loaded with allologous MSCs (group B), HAM with injected autologous MSCs
(group C), and HAM with injected allologous MSCs (group D). The size of the wounds was calculated for each group at 7, 12,
and 15 days after grafting. The wounds were subsequently harvested at 25 days after grafting. Sections stained with hematoxylin
and eosin were used to determine the quality of wound healing, as based on the characteristics and amount of granulated tissue
in the epidermal and dermal layers. Groups A and B showed the most pronounced effect on wound closure, with statistically
significant improvement in wound healing being seen on post-operative days 7, 12, and 15. Although a slight trend toward improved
wound healing was seen in group A compared with group B, no statistically significant difference was found at any time point
between the two groups. Histological examination of healed wounds from groups A and B showed a thin epidermis with mature
differentiation and collagen bundle deposition plus recovered skin appendages in the dermal layer. In contrast, groups C and
D showed thickened epidermis with immature epithelial cells and increased fibroblast proliferation with only partially recovered
skin appendages in the dermal layer. Thus, the graft of HAM loaded with MSCs played an effective role during the healing of
skin defects in rabbits, with no significant difference being observed in wound healing between autologous and allologous
MSC transplantation.
This study was supported by research funds from Dong-A University. 相似文献
992.
Sierra Colavito Margaret Macris-Kiss Changhyun Seong Olive Gleeson Eric C. Greene Hannah L. Klein Lumir Krejci Patrick Sung 《Nucleic acids research》2009,37(20):6754-6764
The SRS2 (Suppressor of RAD Six screen mutant 2) gene encodes an ATP-dependent DNA helicase that regulates homologous recombination in Saccharomyces cerevisiae. Mutations in SRS2 result in a hyper-recombination phenotype, sensitivity to DNA damaging agents and synthetic lethality with mutations that affect DNA metabolism. Several of these phenotypes can be suppressed by inactivating genes of the RAD52 epistasis group that promote homologous recombination, implicating inappropriate recombination as the underlying cause of the mutant phenotype. Consistent with the genetic data, purified Srs2 strongly inhibits Rad51-mediated recombination reactions by disrupting the Rad51-ssDNA presynaptic filament. Srs2 interacts with Rad51 in the yeast two-hybrid assay and also in vitro. To investigate the functional relevance of the Srs2-Rad51 complex, we have generated srs2 truncation mutants that retain full ATPase and helicase activities, but differ in their ability to interact with Rad51. Importantly, the srs2 mutant proteins attenuated for Rad51 interaction are much less capable of Rad51 presynaptic filament disruption. An internal deletion in Srs2 likewise diminishes Rad51 interaction and anti-recombinase activity. We also present evidence that deleting the Srs2 C-terminus engenders a hyper-recombination phenotype. These results highlight the importance of Rad51 interaction in the anti-recombinase function of Srs2, and provide evidence that this Srs2 function can be uncoupled from its helicase activity. 相似文献
993.
994.
995.
Calcium spikes in a leech nonspiking neuron 总被引:1,自引:1,他引:0
Lorena Rela Sung Min Yang Lidia Szczupak 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(2):139-150
The NS neurons are nonspiking cells, present as pairs in each midbody ganglion of the leech nervous system, which display
a very extensive arborization. They were shown to regulate the coactivation of motoneurons. Here we have investigated the
electrophysiological properties of these neurons under the hypothesis that transmission along the extensive neurites requires
the aid of voltage-dependent conductances. The results indicate that NS neurons respond to electrical stimulation with a spike-like
event, which was not an all-or-none but rather a graded phenomenon that depended on the intensity and duration of the electrical
stimulus. The spike-like response was activated at a membrane potential of approximately −50 mV; its amplitude was a logarithmic
function of the extracellular Ca2+ concentration and was unaffected by a broad range of changes in the extracellular Na+ concentration; intracellular application of tetraethylammonium (TEA) caused a large increase in its amplitude and duration.
These data indicate that NS neurons bear voltage-dependent low-threshold Ca2+ and TEA-sensitive K+ conductances that could contribute to shaping synaptic signals, or transmission along the extensive neuritic tree. 相似文献
996.
Yi SS Hwang IK Yoo KY Park OK Yu J Yan B Kim IY Kim YN Pai T Song W Lee IS Won MH Seong JK Yoon YS 《Neurochemical research》2009,34(6):1039-1046
In the present study, we investigated the effects of a treadmill exercise on serum glucose levels and Ki67 and doublecortin
(DCX) immunoreactivity, which is a marker of cell proliferation expressed during cell cycles except G0 and early G1 and a
marker of progenitors differentiating into neurons, respectively, in the subgranular zone of the dentate gyrus (SZDG) using
a type II diabetic model. At 6 weeks of age, Zucker lean control (ZLC) and Zucker diabetic fatty (ZDF) rats were put on a
treadmill with or without running for 1 h/day/5 consecutive days at 22 m/min for 5 weeks. Body weight was significantly increased
in the control (without running)-ZDF rats compared to that in the other groups. In the control groups blood glucose levels
were increased by 392.7 mg/dl in the control-ZDF rats and by 143.3 mg/dl in the control-ZLC rats. However, in the exercise
groups, blood glucose levels were similar between the exercise-ZLC and ZDF rats: The blood glucose levels were 110.0 and 118.2 mg/dl,
respectively. Ki67 positive nuclei were detected in the SZDG in control and exercise groups. The number of Ki67 positive nuclei
was significantly high in exercise groups compared to that in the control groups. In addition, Ki67 positive cells were abundant
in ZLC groups compared to those in ZDF groups. DCX-immunoreactive structures in the control-ZDF rats were lower than that
in the control-ZLC rats. In the exercise groups, DCX-immunoreactive structures (somata and processes with tertiary dendrites)
and DCX protein levels were markedly increased in both the exercise-ZLC and ZDF rats compared to that in the control groups.
These results suggest that a treadmill exercise reduces blood glucose levels in ZDF rats and increases cell proliferation
and differentiation in the SZDG in ZLC and ZDF rats compared to those in control groups. 相似文献
997.
Hwang IK Kim IY Kim YN Yi SS Park IS Min BH Doo HK Ahn SY Kim YS Lee IS Yoon YS Seong JK 《Neurochemical research》2009,34(5):964-972
In the present study, we investigated the influences of a high fat diet (HD) fed for 12 weeks, on lipid peroxidation and antioxidant
enzyme using 4-hydroxy-2E-nonenal (HNE)-modified proteins (HNE-mp) and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region (CA1) in C57BL/6N
and C3H/HeN mice. Body weights and body weight gains were significantly higher in HD fed C57BL/6N mice than in low fat diet
(LD) fed C57BL/6N and LD or HD fed C3H/HeN mice. In the HD fed C57BL/6N and C3H/HeN mice, HNE-mp immunoreactivity and protein
levels were much higher than in the LD fed C57BL/6N or C3H/HeN mice. In particular, HNE-mp immunoreactivity and protein levels
in HD fed C57BL/6N mice was higher than that in the HD fed C3H/HeN mice. SOD1 immunoreaction was detected in the non-pyramidal
cells of C57BL/6N mice, while in the C3H/HeN mice SOD1 immunoreaction was observed in CA1 pyramidal cells. The SOD1 immunoreactivity
in the LD fed C57BL/6N and C3H/HeN mice was slightly, but not significantly decreased compared to that in the HD fed C57BL/6N
and C3H/HeN mice, respectively. In addition, ionized calcium-binding adapter molecule 1 (Iba-1) immunoreactive microglia in
the HD fed C57BL/6N showed hypertrophy of cytoplasm, which is the characteristics of activated microglia. These results suggest
that HD fed C57BL/6N mice are more susceptible to lipid peroxidation in the CA1 than in LD fed C57BL/6N and LD or HD fed C3H/HeN
mice without any differences of SOD1 expression.
In Koo Hwang and Il Yong Kim have contributed equally to this article. 相似文献
998.
Hye Kyung Ju Su-Jeong Hwang Choon-Ju Jeon Gyun Min Lee Sung Kwan Yoon 《Journal of biotechnology》2009,143(2):145-150
To investigate the effect of hyperosmotic medium on production and aggregation of the variant of Angiopoietin-1 (Ang1), cartilage oligomeric matrix protein (COMP)–Ang1, in recombinant Chinese hamster ovary (CHO) cells, CHO cells were cultivated in shaking flasks. NaCl and/or sorbitol were used to raise medium osmolality in the range of 300–450 mOsm/kg. The specific productivity of COMP–Ang1, qCOMP–Ang1, increased as medium osmolality increased. At NaCl-450 mOsm/kg, the qCOMP–Ang1 was 7.7-fold higher than that at NaCl-300 mOsm/kg, while, at sorbitol-450 mOsm/kg, it was 2.9-fold higher than that at sorbitol-300 mOsm/kg. This can be attributed to the increased relative mRNA level of COMP–Ang1 at NaCl-450 mOsm/kg which was approximately 2.4-fold higher than that at sorbitol-450 mOsm/kg. Western blot analysis showed that COMP–Ang1 aggregates started to occur in the late-exponential phase of cell growth. When sorbitol was used to raise the medium osmolality, a severe aggregation of COMP–Ang1 was observed. On the other hand, when NaCl was used, the aggregation of COMP–Ang1 was drastically reduced at NaCl-400 mOsm/kg. At NaCl-450 mOsm/kg, the aggregation of COMP–Ang1 was hardly observed. This suggests that environmental conditions are critical for the aggregation of COMP–Ang1. Taken together, the use of NaCl-induced hyperosmotic medium to cell culture process turns out to be an efficient strategy for enhancing COMP–Ang1 production and reducing COMP–Ang1 aggregation. 相似文献
999.
Hee Sun Rho Jae Bok Heo Woo Young Bang Sung Min Hwang Min Yeop Nahm Hyun Jin Kwon Sam Woong Kim Byung Hyun Lee Jeong Dong Bahk 《Plant science》2009,177(5):411-417
PRA1 has been reported as a prenylated Rab acceptor containing GDF activity in human, rat and yeast. Its existence was also proved in plants by sequence analysis, anticipating its important role as a Rab effector, but defined roles of the plant PRA1 homologs remain to be obscure. Here, to get an insight for their role, we performed yeast two-hybrid screen using the OsRab7 as bait and first isolated the OsPRA1, a putative prenylated Rab acceptor, interacting with this protein. Detailed interaction analysis showed that OsPRA1 interacted not only with GDP-bound OsRab7, but also with several other Rab GTPases involved in vacuolar trafficking, in a prenylation-dependent manner. In addition, GFP-fusion analysis demonstrated that OsPRA1 localized to the prevacuolar compartment, and RNA gel blot analysis revealed its significant expression in rice green-aerial tissues such as shoots and mature stems. These results suggest that OsPRA1 may function as a Rab effector for vacuolar trafficking in the plant system. 相似文献
1000.
Lim Jeong In-Sung Yeo Ha Na Kim Young Il Yoon Da Hyun Jang Sung Youn Jung Byung-Moo Min Won Ho Park 《International journal of biological macromolecules》2009,44(3):222-228
Silk fibroin (SF) nanofibers were prepared by electrospinning and treated with plasma in the presence of oxygen or methane gas to modify their surface characteristics. The surface characteristics of the SF nanofibers after plasma treatment were examined using contact angle measurements and XPS analysis. The hydrophilicity of the electrospun SF nanofibers decreased slightly by the CH4 plasma treatment. On the other hand, the hydrophilicity of the SF nanofibers increased greatly by an O2 plasma treatment. The O2-treated SF nanofibers showed higher cellular activities for both normal human epidermal keratinocytes (NHEK) and fibroblasts (NHEF) than the untreated ones. 相似文献