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991.
目的研究青蒿水提液对肺癌A549细胞株增殖的影响和诱导凋亡的情况。方法不同浓度青蒿水提液作用于细胞不同时间,四甲基氮噻唑蓝(MTT)法检测吸光度值(A490nm)并计算增殖抑制率;AnnexinV-FITC/PI荧光染色后流式细胞仪检测细胞凋亡率;并以荧光显微镜观察细胞形态改变情况;蛋白质印迹法分析细胞凋亡相关蛋白Bax、Bcl-2的表这。结果青蒿水提液呈时间和剂量依赖性抑制A549细胞增殖;荧光显微镜下A549细胞出现不同时期凋亡特征性改变;流式细胞仪检测细胞凋亡率随着药物浓度增加而升高;A549细胞株的Bax蛋白表达量增多、Bcl-2蛋白表达量下降。结论青蒿水提液促进体外培养的A549细胞株增殖抑制并诱导凋亡,其机制可能与A549细胞Bax表达上调和Bcl-2表达下调有关。 相似文献
992.
Colorectal carcinoma: from tumorigenesis to treatment 总被引:10,自引:0,他引:10
Colorectal carcinoma (CRC) is a complicated and often fatal genetic disease. Fortunately, owing to rapid expansion of knowledge
and technology development in oncology, much progress has been made regarding the diagnosis, understanding of the molecular
genetics and malignant progression, as well as the novel regimens of CRC. In this review, we summarize the staging system,
the most critical genetic and epigenetic alterations, the pleiotropic effects of MMP-7, the controversial roles of Hedgehog
signaling, the intriguing involvement of thymosin β-4, and the possible contribution of the putative colon (cancer) stem cells
in CRC tumorigenesis. Current treatments as well as several potentially applicable therapeutic strategies for CRC are also
discussed.
Received 15 September 2005; received after revision 3 November 2005; accepted 25 November 2005 相似文献
993.
简述了染料敏化太阳能电池中电子的传递和复合的机制,以及抑制电子复合的二种方法:包覆改性和共吸附剂小分子改性,分别对包覆改性和共吸附剂小分子改性的基本作用原理和研究现状进行了介绍. 相似文献
994.
K. Mutyambizi C. L. Berger R. L. Edelson 《Cellular and molecular life sciences : CMLS》2009,66(5):831-840
Langerhans cells are immature skin-homing dendritic cells that furnish the epidermis with an immune surveillance system, and
translate information between the internal and external milieu. Dendritic cells, in particular Langerhans cells, are gaining
prominence as one of the potential principal players orchestrating the decision between immunity and tolerance. Langerhans
cells capture aberrant self-antigen and pathogen-derived antigen for display to the efferent immune response. Recent evidence
suggests redundancy in the antigen-presenting function of Langerhans cells, with dermal dendritic subsets capable of fulfilling
an analogous role. There is mounting evidence that Langerhans cells can cross-prime T cells to recognize antigens. Langerhans
cells are proposed to stimulate T regulatory cells, and are implicated in the pathogenesis of cutaneous T cell lymphoma.The
phenotype of Langerhans cells, which may be tolerogenic or immunogenic, appears to depend on their state of maturity, inciting
immunogen and cytokine environment, offering the potential for manipulation in immunotherapy.
Received 6 August 2008; received after revision 18 September 2008; accepted 13 October 2008 相似文献
995.
T. Mueller J. Luetzkendorf K. Nerger H.-J. Schmoll L. P. Mueller 《Cellular and molecular life sciences : CMLS》2009,66(3):495-503
OCT4 is considered a main regulator of embryonic stem cell pluripotency and self renewal capacity. It was shown that relevant
OCT4 expression only occurs in cells of embryonic pluripotent nature. However, several recent publications claimed to have
demonstrated OCT4 expression in human somatic tumor cells, human adult stem or progenitor cells and differentiated cells.We
analysed 42 human tumor cell lines from 13 entities and human bone marrowderived mesenchymal stem cells (MSC). To validate
OCT4 expression we used germ cell tumor (GCT) cell lines, derived xenografts and GCT samples. Analysis by RT-PCR, western
blotting, immunocytochemistry and immunohistochemistry was performed. With exception of typical embryonal carcinoma cells,
we did not observe reliable OCT4 expression in somatic tumor cell lines and MSC. We suggest that a high level of expression
of the OCT4 protein together with its nuclear localization still remains a reliable and definitive feature of cells with embryonic
pluripotent nature.
Received 30 September 2008; received after revision 05 November 2008; accepted 10 November 2008 相似文献
996.
Jürgen Schnekenburger Ina-Alexandra Weber Daniela Hahn Igor Buchwalow Burkhard Krüger Elke Albrecht Wolfram Domschke Markus M. Lerch 《Cellular and molecular life sciences : CMLS》2009,66(15):2525-2537
The regulated secretion of pancreatic zymogens depends on a functional cytoskeleton and intracellular vesicle transport. To
study the dynamics of tubulin and its motor proteins dynein and kinesin during secretion in pancreatic acinar cells, we infused
rats with 0.1 μg/kg/h caerulein. Electron and fluorescence microscopy detected neither dynein nor kinesin at the apical secretory
pole, nor on the surface of mature zymogen granules. After 30 min of secretagogue stimulation, kinesin and the Golgi marker
protein 58 K were reallocated towards the apical plasma membrane and association of kinesin with tubulin was enhanced. Disruption
of acinar cell microtubules had no effect on initial caerulein-induced amylase release but completely blocked secretion during
a second stimulus. Our results suggest that mature zymogen granule exocytosis is independent of intact microtubules, kinesin
and dynein. However, microtubule-dependent mechanisms seem to be important for the replenishment of secretory vesicles by
redistribution of Golgi elements towards the apical cell pole.
J. Schnekenburger and I.-A. Weber have contributed equally to this work. 相似文献
997.
目的探讨人结直肠肿瘤干细胞在体外分化过程中细胞形态和干细胞相关标志物CD133的表达变化,为进一步研究结直肠肿瘤干细胞分化走向提供实验依据。方法取来源于人结直肠癌的细胞系HCT116,无血清培养分离出CD133+细胞,加血清诱导分化,相差显微镜下观察其形态变化;在未分化状态下无血清培养第7天和14天与血清诱导分化后收集细胞,利用流式细胞仪检测干细胞标志物CD133的表达量,采用激光共聚焦检测CD133表面标记分子的表达。结果 1)细胞形态:无血清培养分离的CD133+细胞,在生长过程中聚集成规则的细胞球,血清诱导后即贴壁生长,贴壁形态与同来源细胞形态一致,且再次无血清悬浮培养后聚集成球稳定生长。2)标志物变化:结直肠肿瘤干细胞未分化时CD133表面标记分子高表达,流式细胞仪检测未分化细胞CD133第7天表达率为(20.4±0.52)%,第14天表达率为(78.5±2.80)%,分化后表达率为(0.50±0.17)%。结论细胞形态和标志物表达改变均表明高表达CD133+的HCT116结直肠癌肿瘤干细胞可定向分化为同源的结直肠癌细胞,CD133+细胞经血清诱导后表达下调而使细胞失去干细胞特性。 相似文献
998.
Serglycin is a proteoglycan found in hematopoietic cells and endothelial cells. It has important functions related to formation
of several types of storage granules. In connective tissue mast cells the covalently attached glycosaminoglycan is heparin,
whereas mucosal mast cells and activated macrophages contain oversulfated chondroitin sulfate (type E). In mast cells, serglycin
interact with histamine, chymase, tryptase and carboxypeptidase, in neutrophils with elastase, in cytotoxic T cells with granzyme
B, in endothelial cells with tissue-type plasminogen activator and in macrophages with tumor necrosis factor-α. Serglycin
is important for the retention of key inflammatory mediators inside storage granules and secretory vesicles. Serglycin can
further modulate the activities of partner molecules in different ways after secretion from activated immune cells, through
protection, transport, activation and interactions with substrates or target cells. Serglycin is a proteoglycan with important
roles in inflammatory reactions.
Received 2 October 2007; received after revision 7 November 2007; accepted 12 November 2007 相似文献
999.
1000.
Ghaskadbi S Patwardhan V Chakraborthy M Agrawal S Verma MK Chatterjee A Lenka N Parab PB 《Cellular and molecular life sciences : CMLS》2008,65(20):3312-3324
Cardiac myocytes are the first cells to differentiate during the development of a vertebrate embryo. A wide variety of molecules take part in various steps in this process. While exploring biologically active molecules from marine sources, we found that a constituent of perivitelline fluid from embryos of the Indian horseshoe crab can enhance growth and differentiation of chick embryonic heart. We have purified the factor and identified the cardiac promoting molecule to be a novel lectin. We show that this molecule influences cardiac development by increasing the number of cells constituting the heart and by modulating the expression of several cardiac development regulatory genes in chick embryos. Using mouse embryonic stem cells we show that the cardiac myocyte-enhancing capacity of this molecule extends to mammals and its effects can be blocked using methylated sugars. This molecule may prove to be an important tool in the study of cardiomyocyte differentiation. 相似文献