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171.
Siah-1 mediates a novel beta-catenin degradation pathway linking p53 to the adenomatous polyposis coli protein 总被引:7,自引:0,他引:7
Liu J Stevens J Rote CA Yost HJ Hu Y Neufeld KL White RL Matsunami N 《Molecular cell》2001,7(5):927-936
The adenomatous polyposis coli (APC) tumor-suppressor protein, together with Axin and GSK3beta, forms a Wnt-regulated signaling complex that mediates phosphorylation-dependent degradation of beta-catenin by the proteasome. Siah-1, the human homolog of Drosophila seven in absentia, is a p53-inducible mediator of cell cycle arrest, tumor suppression, and apoptosis. We have now found that Siah-1 interacts with the carboxyl terminus of APC and promotes degradation of beta-catenin in mammalian cells. The ability of Siah-1 to downregulate beta-catenin signaling was also demonstrated by hypodorsalization of Xenopus embryos. Unexpectedly, degradation of beta-catenin by Siah-1 was independent of GSK3beta-mediated phosphorylation and did not require the F box protein beta-TrCP. These results indicate that APC and Siah-1 mediate a novel beta-catenin degradation pathway linking p53 activation to cell cycle control. 相似文献
172.
173.
Michael B Coulthart Gerard H Jansen Elina Olsen Deborah L Godal Tim Connolly Bernard CK Choi Zheng Wang Neil R Cashman 《BMC neurology》2011,11(1):133
Background
To better characterize the value of cerebrospinal fluid (CSF) proteins as diagnostic markers in a clinical population of subacute encephalopathy patients with relatively low prevalence of sporadic Creutzfeldt-Jakob disease (sCJD), we studied the diagnostic accuracies of several such markers (14-3-3, tau and S100B) in 1000 prospectively and sequentially recruited Canadian patients with clinically suspected sCJD. 相似文献174.
Plasmid DNA minipreps are fundamental techniques in molecular biology. Current plasmid DNA minipreps use alkali and the anionic detergent SDS in a three-solution format. In addition, alkali minipreps usually require additional column-based purification steps and cannot isolate other extra-chromosomal elements, such as bacteriophages. Non-ionic detergents (NIDs) have been used occasionally as components of multiple-solution plasmid DNA minipreps, but a one-step approach has not been developed. Here, we have established a one-tube, one-solution NID plasmid DNA miniprep, and we show that this approach also isolates bacteriophage lambda particles. NID minipreps are more time-efficient than alkali minipreps, and NID plasmid DNA performs better than alkali DNA in many downstream applications. In fact, NID crude lysate DNA is sufficiently pure to be used in digestion and sequencing reactions. Microscopic analysis showed that the NID procedure fragments E. coli cells into small protoplast-like components, which may, at least in part, explain the effectiveness of this approach. This work demonstrates that one-step NID minipreps are a robust method to generate high quality plasmid DNA, and NID approaches can also isolate bacteriophage lambda particles, outperforming current standard alkali-based minipreps. 相似文献
175.
Characterization of a mobile and multiple resistance plasmid isolated from swine manure and its detection in soil after manure application 总被引:1,自引:0,他引:1
Aims: To isolate and characterize multiple antibiotic resistance plasmids found in swine manure and test for plasmid‐associated genetic markers in soil following manure application to an agricultural field. Methods and Results: Plasmids were isolated from an erythromycin enrichment culture that used liquid swine manure as an inoculant. Plasmids were transformed into Escherichia coli DH10β for subsequent characterization. We isolated and DNA sequenced a 22 102‐bp plasmid (pMC2) that confers macrolide, and tetracycline resistances, and carries genes predicted to code for mercury and chromium resistance. Conjugation experiments using an pRP4 derivative as a helper plasmid confirm that pMC2 has a functional mobilization unit. PCR was used to detect genetic elements found on pMC2 in DNA extracted from manure amended soil. Conclusions: The pMC2 plasmid has a tetracycline‐resistant core and has acquired additional resistance genes by insertion of an accessory region (12 762 bp) containing macrolide, mercury and chromium resistance genes, which was inserted between the truncated DDE motifs within the Tn903/IS102 mobile element. Significance and Impact of the Study: Liquid swine manure used for manure spreading contains multiple antibiotic resistance plasmids that can be detected in soil following manure application. 相似文献
176.
The reduction in zinc concentration of wheat grain upon increased phosphorus-fertilization and its mitigation by foliar zinc application 总被引:4,自引:0,他引:4
Yue-Qiang Zhang Yan Deng Ri-Yuan Chen Zhen-Ling Cui Xin-Ping Chen Russell Yost Fu-Suo Zhang Chun-Qin Zou 《Plant and Soil》2012,361(1-2):143-152
Background and aims
Malnutrition resulting from zinc (Zn) and iron (Fe) deficiency has become a global issue. Excessive phosphorus (P) application may aggravate this issue due to the interactions of P and micronutrients in soil crop. Crop grain micronutrients associated with P applications and the increase of grain Zn by Zn fertilization were field-evaluated.Methods
A field experiment with wheat was conducted to quantify the effect of P applications on grain micronutrient quality during two cropping seasons. The effect of foliar Zn applications on grain Zn quality with varied P applications was tested in 2011.Results
Phosphorus applications decreased grain Zn concentration by 17–56%, while grain levels of Fe, manganese (Mn) and copper (Cu) either remained the same or increased. Although P applications increased grain yield, they restricted the accumulation of shoot Zn, but enhanced the accumulation of shoot Fe, Cu and especially Mn. In 2011, foliar Zn application restored the grain Zn to levels occurring without P and Zn application, and consequently reduced the grain P/Zn molar ratio by 19–53% than that without Zn application.Conclusions
Foliar Zn application may be needed to achieve both favorable yield and grain Zn quality of wheat in production areas where soil P is building up. 相似文献177.
178.
179.
Li Tang Yu Zhang Hong Pan Qiong Luo Xiao-Ming Zhu Min-Yue Dong Peter CK Leung Jian-Zhong Sheng He-Feng Huang 《Reproductive biology and endocrinology : RB&E》2009,7(1):144-8
Background
Progesterone plays an important role in the proliferation and differentiation of human endometrial cells (hECs). Large-dose treatment with progesterone has been used for treatment of endometrial proliferative disorders. However, the mechanisms behind remain unknown. 相似文献180.
Dong Wook Park Kyung-Chul Choi Colin D MacCalman Peter CK Leung 《Reproductive biology and endocrinology : RB&E》2009,7(1):81
Endometrial carcinoma is the most common neoplasm of the female genital tract, accounting for nearly one half of all gynecologic
cancers in the Western world. Although intensive research on pathological phenomena of endometrial cancer is currently going
on, but exact cause and biological aspects of this disease are not well described yet. In addition to well-documented roles
of gonadotropin-releasing hormone (GnRH) in hypopituitary ovarian (HPO) axis, the agonistic or antagonistic analogs (or both)
of GnRH have been shown to inhibit the proliferation of a variety of human gynecologic cancers. Thus, in the present study,
we further examined the possibility that GnRH induces integrin beta3 and activation of focal adhesion kinase (FAK) through
mitogen-activated protein kinases (MAPKs), ERK1/2 and p38, to inhibit the growth of HEC1A endometrial cancer cell line. As
a result, both GnRH-I and GnRH-II resulted in a significant increase in integrin beta3 expression and evoked the activation
of FAK in a time-dependent manner in these cells. In addition, these analogs induced an activation of ERK1/2 and p38 MAPK
in a time-dependent manner as downstream pathways of FAK. It appears that GnRH-II has much greater effect on the activation
of FAK, ERK1/2 and p38 compared to GnRH-I in these cells. Further, we demonstrated that the growth inhibition of HEC1A cells
by GnRH-I or GnRH-II is involved in the activation of integrin-FAK and ERK1/2 and p38 MAPK pathways. Taken together, these
results suggest that GnRH may be involved in the inhibition of endometrial cancer cell growth via activation of integrin beta3
and FAK as a direct effect. This knowledge could contribute to a better understanding of the mechanisms implicated in the
therapeutic action of GnRH and its biomedical application for the treatment against endometrial cancer. 相似文献