全文获取类型
收费全文 | 133篇 |
免费 | 13篇 |
国内免费 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 17篇 |
2014年 | 8篇 |
2013年 | 12篇 |
2012年 | 12篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1988年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有147条查询结果,搜索用时 15 毫秒
121.
The effects of 0, 2.5, 5.0, and 10.0 mg(Cd2+) m-3 [Cd(NO3)2×4 H2O] and 0 and 10.0 mg m-3 gibberellin on certain parameters of photosynthesis and growth in soybean (Glycine max L. cv. Pershing) plants were studied. With increasing Cd2+ concentration in the Hoagland nutrient solution, the contents of chlorophyll and CO2 compensation concentration decreased. The addition of 10 mg m-3 gibberellin reduced the negative effects of Cd2+ in shoot and root growth. With increasing of Cd2+ concentration in the culture medium, the dry matter production in both the roots and shoots decreased as shown by the decline in growth rate (PGR), net assimilation rate (NAR), and leaf area ratio. The addition of gibberellin caused a partial elimination of the Cd effects on the roots and shoots and the PGR and NAR and it increased leaf area and length of stem. 相似文献
122.
Steven A. Goldman Andrey Zukhar Kaveh Barami Takashi Mikawa Donna Niedzwiecki 《Developmental neurobiology》1996,30(4):505-520
The songbird forebrain continues to generate neurons in adulthood, from precursor cells located in the ependymal/subependymal zone (SZ) over the mediocaudal neostriatum. Precursor mitosis is followed by migration of neuronal daughter cells into the underlying forebrain, along radial fibers derived from the SZ. To define the ontogeny of both the new neurons and their radial guide cells, we employed retroviral insertion of the lacZ gene into neostriatal SZ precursor cells derived from postnatal and adult songbirds. We found that single SZ cells generate both neurons and substrate glia in vitro, and in an analogous fashion, both neurons and radial cells in vivo. This suggests that newly generated neurons and radial cells of the adult avian brain derive from a common pluripotential progenitor. © 1996 John Wiley & Sons, Inc. 相似文献
123.
124.
Light-induced Changes in the Pattern of Protein Synthesis during the Early Stages of Greening of Etiolated Maize Leaves 总被引:4,自引:3,他引:1
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The effect of light on protein synthesis during the early stages of greening of etiolated maize (Zea mays) leaves was studied using double labeling with leucine and fractionation of proteins by gel filtration and acrylamide gel electrophoresis. The incorporation of labeled leucine into a relatively small number of plastid proteins is effected within the first 30 to 60 minutes of illumination. These proteins do not accumulate with time. When illumination is prolonged, additional proteins are effected. 相似文献
125.
126.
Systematic in vitro and in vivo characterization of Leukemia‐inhibiting factor‐ and Fibroblast growth factor‐derived porcine induced pluripotent stem cells
下载免费PDF全文
![点击此处可从《Molecular reproduction and development》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jan O. Secher Ahmet Ceylan Gianluca Mazzoni Kaveh Mashayekhi Tong Li Suchitra Muenthaisong Troels T. Nielsen Dong Li Shengting Li Stoyan Petkov Susanna Cirera Yonglun Luo Lori Thombs Haja N. Kadarmideen Andras Dinnyes Lars Bolund Bernard A.J. Roelen Mette Schmidt Henrik Callesen Poul Hyttel Kristine K. Freude 《Molecular reproduction and development》2017,84(3):229-245
127.
The membrane-bound alpha-glucuronidase from Pseudomonas cellulosa hydrolyzes 4-O-methyl-D-glucuronoxylooligosaccharides but not 4-O-methyl-D-glucuronoxylan
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nagy T Emami K Fontes CM Ferreira LM Humphry DR Gilbert HJ 《Journal of bacteriology》2002,184(17):4925-4929
The microbial degradation of xylan is a key biological process. Hardwood 4-O-methyl-D-glucuronoxylans are extensively decorated with 4-O-methyl-D-glucuronic acid, which is cleaved from the polysaccharides by alpha-glucuronidases. In this report we describe the primary structures of the alpha-glucuronidase from Cellvibrio mixtus (C. mixtus GlcA67A) and the alpha-glucuronidase from Pseudomonas cellulosa (P. cellulosa GlcA67A) and characterize P. cellulosa GlcA67A. The primary structures of C. mixtus GlcA67A and P. cellulosa GlcA67A, which are 76% identical, exhibit similarities with alpha-glucuronidases in glycoside hydrolase family 67. The membrane-associated pseudomonad alpha-glucuronidase released 4-O-methyl-D-glucuronic acid from 4-O-methyl-D-glucuronoxylooligosaccharides but not from 4-O-methyl-D-glucuronoxylan. We propose that the role of the glucuronidase, in combination with cell-associated xylanases, is to hydrolyze decorated xylooligosaccharides, generated by extracellular hemicellulases, to xylose and 4-O-methyl-D-glucuronic acid, enabling the pseudomonad to preferentially utilize the sugars derived from these polymers. 相似文献
128.
Sukalovic V Ignjatovic D Tovilovic G Andric D Shakib K Kostic-Rajacic S Soskic V 《Bioorganic & medicinal chemistry letters》2012,22(12):3967-3972
It is suggested that the ratio of dopamine D(2) to 5-hydroxytryptamine 5-HT(1A) activity is an important parameter that determines the efficiency of antipsychotic drugs. Here we present the synthesis of N-{[2-(4-phenyl-piperazin-1-yl)-ethyl]-phenyl}-2-aryl-2-yl-acetamides and 1-{[2-(4-phenyl-piperazin-1-yl)-ethyl]-phenyl}-3-aryl-2-yl-ureas and their structure-activity relationship studies on dopamine D(2) and 5-hydrohytryptamine 5-HT(1A) receptors. It was shown that ligand selectivity and affinity strongly depends on their topology and the presence of a pyridyl group in the head of molecules. Molecular modeling studies using homology modeling and docking simulation revealed a rational explanation for the ligand behavior. The observed binding modes and receptor-ligand interactions provided us with a clue for optimizing the optimal selectivity towards 5-HT(1A) receptors. 相似文献
129.
130.
Katherine A. Cunningham Aude D. Bouagnon Alexandre G. Barros Lin Lin Leandro Malard Marco Aurélio Romano-Silva Kaveh Ashrafi 《PLoS genetics》2014,10(6)
AMP-activated protein kinase (AMPK) is an evolutionarily conserved master regulator of metabolism and a therapeutic target in type 2 diabetes. As an energy sensor, AMPK activity is responsive to both metabolic inputs, for instance the ratio of AMP to ATP, and numerous hormonal cues. As in mammals, each of two genes, aak-1 and aak-2, encode for the catalytic subunit of AMPK in C. elegans. Here we show that in C. elegans loss of aak-2 mimics the effects of elevated serotonin signaling on fat reduction, slowed movement, and promoting exit from dauer arrest. Reconstitution of aak-2 in only the nervous system restored wild type fat levels and movement rate to aak-2 mutants and reconstitution in only the ASI neurons was sufficient to significantly restore dauer maintenance to the mutant animals. As in elevated serotonin signaling, inactivation of AAK-2 in the ASI neurons caused enhanced secretion of dense core vesicles from these neurons. The ASI neurons are the site of production of the DAF-7 TGF-β ligand and the DAF-28 insulin, both of which are secreted by dense core vesicles and play critical roles in whether animals stay in dauer or undergo reproductive development. These findings show that elevated levels of serotonin promote enhanced secretions of systemic regulators of pro-growth and differentiation pathways through inactivation of AAK-2. As such, AMPK is not only a recipient of hormonal signals but can also be an upstream regulator. Our data suggest that some of the physiological phenotypes previously attributed to peripheral AAK-2 activity on metabolic targets may instead be due to the role of this kinase in neural serotonin signaling. 相似文献