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891.
892.
Effective donor cell fusion conditions for production of cloned dogs by somatic cell nuclear transfer 总被引:1,自引:0,他引:1
JungEun ParkHyunJu Oh SoGun HongMinJung Kim GeonA KimOkJae Koo SungKeun KangGoo Jang ByeongChun Lee 《Theriogenology》2011,75(4):777-782
As shown by the birth of the first cloned dog ‘Snuppy', a protocol to produce viable cloned dogs has been reported. In order to evaluate optimum fusion conditions for improving dog cloning efficiency, in vivo matured oocytes were reconstructed with adult somatic cells from a female Pekingese using different fusion conditions. Fusion with needle vs chamber methods, and with low vs high pulse strength was compared by evaluating fusion rate and in vivo development of canine cloned embryos. The fusion rates in the high voltage groups were significantly higher than in the low voltage groups regardless of fusion method (83.5 vs 66.1% for the needle fusion method, 67.4 vs 37.9% for the fusion chamber method). After embryo transfer, one each pregnancy was detected after using the needle fusion method with high and low voltage and in the chamber fusion method with high voltage, whereas no pregnancy was detected using the chamber method with low voltage. However, only the pregnancy from the needle fusion method with high voltage was maintained to term and one healthy puppy was delivered. The results of the present study demonstrated that two DC pulses of 3.8 to 4.0 kV/cm for 15 μsec using the needle fusion method were the most effective method for the production of cloned dogs under the conditions of this experiment. 相似文献
893.
Yoo DY Yoo KY Choi JW Kim W Lee CH Choi JH Park JH Won MH Hwang IK 《Cellular and molecular neurobiology》2011,31(5):729-736
In this study, we observed neuroblast differentiation in the somatosensory cortex (SSC) and hippocampal CA1 region (CA1),
which is vulnerable to oxidative stress, of the mouse at various early postnatal days (P) 1, 7, 14, and 21 using doublecortin
(DCX, a marker for neuroblasts). Cresyl violet and NeuN (Neuronal Nuclei) staining showed development of layers as well as
neurons in the SSC and CA1. At P1, DCX-positive neuroblasts expressed strong DCX immunoreactivity in both the SSC and CA1.
Thereafter, DCX immunoreactivity was decreased with time. At P7, many DCX-immunoreactive neuroblasts were well detected in
the SSC and CA1. At P14, some DCX-positive neuroblasts were found in the SSC and CA1: The immunoreactivity was weak. At P21,
DCX immunoreactivity was hardly found in cells in the SSC and CA1. These results suggest that DCX-positive neuroblasts were
significantly decreased in the mouse SSC and CA1 from P14. 相似文献
894.
Lee CH Yoo KY Ryu PD Park JH Choi JH Kim S Hwang IK Kim YM Won MH 《Cellular and molecular neurobiology》2011,31(3):345-350
In this study, we investigated age-related changes in glucagon-like peptide-1 receptor (GLP-1R) immunoreactivity and its protein
levels in the gerbil hippocampus during normal aging. In the postnatal month 3 (PM 3) group, GLP-1R immunoreaction was well
observed in neurons, especially pyramidal and non-pyramidal cells in the hippocampus proper, and granule and polymorphic cells
in the dentate gyrus. In the hippocampus proper, GLP-1R immunoreactivity in neurons was maintained until PM 24. In the dentate
gyrus, however, GLP-1R immunoreactivity in granule cells, not polymorphic cells, was hardly detected from PM 6. Western blot
analysis also showed that age-dependent change patterns in GLP-1R protein levels in the gerbil hippocampus were similar to
the immunohistochemical changes. These results indicate that GLP-1R immunoreactivity was markedly decreased in dentate granule
cells from PM 6, showing that GLP-1R immunoreactivity and its protein levels were decreased in the adult and aged gerbil hippocampus. 相似文献
895.
Hwang IK Yi SS Yoo KY Park OK Yan B Song W Won MH Yoon YS Seong JK 《Neurochemical research》2011,36(2):281-287
Abnormal excess of glucocorticoid is one of feature characteristics in type 2 diabetes. In the present study, we investigated
the effect of treadmill exercise at chronic diabetic stages on glucocorticoid receptor (GR) immunoreactivity in the hippocampal
CA1 region and dentate gyrus, which are very vulnerable to diabetes. For this study, we used Zucker diabetic fatty (ZDF) rats
and Zucker lean control (ZLC) rats. Twenty-three-week-old ZLC and ZDF rats were put on the treadmill with or without running
for 7 weeks and sacrificed at 30 weeks of age. Treadmill exercise significantly decreased diabetes-induced blood glucose and
serum corticosteroid levels although they did not drop to control levels. In sedentary ZLC rats, GR immunoreactivity was detected
in pyramidal cells of the CA1 region as well as in granule cells of the dentate gyrus. In the sedentary ZDF rats, GR immunoreactivity
was significantly increased in these regions. However, treadmill exercise significantly decreased GR immunoreactivity in these
regions. These results indicate that treadmill exercise in chronic diabetic rats significantly decreased GR immunoreactivity
in the hippocampal CA1 region and dentate gyrus, although blood glucose and serum corticosteroid levels did not fully recover
to normal state. 相似文献
896.
Kim HN Kim H Kong JM Bae S Kim YS Lee N Cho BJ Lee SK Kim HR Hwang YI Kang JS Lee WJ 《Journal of cellular biochemistry》2011,112(3):894-901
It is known that vitamin C induces apoptosis in several kinds of tumor cells, but its effect on the regulation of the angiogenic process of tumors is not completely studied. Vascular endothelial growth factor (VEGF) is the most well-known angiogenic factor, and it has a potent function as a stimulator of endothelial survival, migration, as well as vascular permeability. Therefore, we have investigated whether vitamin C can regulate the angiogenic process through the modulation of VEGF production from B16F10 melanoma cells. VEGF mRNA expression and VEGF production at protein levels were suppressed by vitamin C. In addition, we found that vitamin C suppressed the expression of cyclooxygenase (COX)-2 and that decreased VEGF production by vitamin C was also restored by the administration of prostaglandin E2 which is a product of COX-2. These results suggest that vitamin C suppresses VEGF expression via the regulation of COX-2 expression. Mitogen-activated protein kinases are generally known as key mediators in the signaling pathway for VEGF production. In the presence of vitamin C, the activation of p42/44 MAPK was completely inhibited. Taken together, our data suggest that vitamin C can down-regulate VEGF production via the modulation of COX-2 expression and that p42/44 MAPK acts as an important signaling mediator in this process. 相似文献
897.
898.
Most current Alzheimer's disease (AD) therapies in advanced phases of development target amyloid β-peptide (Aβ) production, aggregation, or accumulation. Translational models suggest that anti-Aβ therapies may be highly effective if tested as agents to prevent or delay development of the disease or as therapies for asymptomatic patients with very early signs of AD pathology. However, anti-Aβ therapeutics are currently being tested in symptomatic patients where they are likely to be much less effective or ineffective. The lack of alignment between human clinical studies and preclinical studies, together with predictions about optimal trial design based on our understanding of the initiating role of Aβ aggregates in AD, has created a treatment versus prevention dilemma. In this perspective, we discuss why it is imperative to resolve this dilemma and suggest ways for moving forward in the hopes of enhancing the development of truly effective AD therapeutics. 相似文献
899.
Mi‐Young Son Min‐Jeong Kim Kweon Yu Deog‐Bon Koo Yee Sook Cho 《Journal of cellular and molecular medicine》2011,15(1):152-165
Neuropeptide Y (NPY) and NPY receptors are widely expressed in various organs and cell types and have been shown to have pleiotropic functions. However, their presence or role in human embryonic stem cells (hESCs) remains unknown. We now show that undifferentiated hESCs primarily express NPY and its Y1 and Y5 receptors. Inhibition of NPY signalling using either the selective NPY Y1 or Y5 receptor antagonist reduces the maintenance of self‐renewal and proliferation of undifferentiated hESCs. We also provide compelling evidence that exogenous NPY supports the long‐term growth of undifferentiated hESCs in the absence of feeder cell factors using only knockout serum replacement media. Further, NPY facilitates the use of chemically defined medium made up of N2/B27 supplement and basic fibroblast growth factor (bFGF) for hESC feeder‐free culture. Our results indicate that both Y1 and Y5 receptors appear to be involved in the NPY‐mediated activation of AKT/protein kinase B and extracellular signal‐regulated kinase 1/2 (ERK1/2) in hESCs. Notably, only Y1 receptor, but not Y5 receptor, is responsible for the NPY‐induced activation of cAMP‐response element binding (CREB) in hESCs. These results provide the first evidence that NPY and its Y1 and Y5 receptors have potential role in maintaining hESC self‐renewal and pluripotency. We demonstrate the underlying importance of NPY signalling and its usefulness in the development of a defined and xeno‐free culture condition for the large‐scale propagation of undifferentiated hESCs. 相似文献
900.