全文获取类型
收费全文 | 705篇 |
免费 | 36篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 30篇 |
2014年 | 27篇 |
2013年 | 69篇 |
2012年 | 41篇 |
2011年 | 39篇 |
2010年 | 26篇 |
2009年 | 23篇 |
2008年 | 39篇 |
2007年 | 43篇 |
2006年 | 45篇 |
2005年 | 33篇 |
2004年 | 37篇 |
2003年 | 41篇 |
2002年 | 36篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 14篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1975年 | 3篇 |
1974年 | 6篇 |
1972年 | 2篇 |
1969年 | 3篇 |
1967年 | 4篇 |
排序方式: 共有741条查询结果,搜索用时 31 毫秒
1.
Priya Gogoi Saedeh Sepehri Yi Zhou Michael A. Gorin Carmela Paolillo Ettore Capoluongo Kyle Gleason Austin Payne Brian Boniface Massimo Cristofanilli Todd M. Morgan Paolo Fortina Kenneth J. Pienta Kalyan Handique Yixin Wang 《PloS one》2016,11(1)
Current analysis of circulating tumor cells (CTCs) is hindered by sub-optimal sensitivity and specificity of devices or assays as well as lack of capability of characterization of CTCs with clinical biomarkers. Here, we validate a novel technology to enrich and characterize CTCs from blood samples of patients with metastatic breast, prostate and colorectal cancers using a microfluidic chip which is processed by using an automated staining and scanning system from sample preparation to image processing. The Celsee system allowed for the detection of CTCs with apparent high sensitivity and specificity (94% sensitivity and 100% specificity). Moreover, the system facilitated rapid capture of CTCs from blood samples and also allowed for downstream characterization of the captured cells by immunohistochemistry, DNA and mRNA fluorescence in-situ hybridization (FISH). In a subset of patients with prostate cancer we compared the technology with a FDA-approved CTC device, CellSearch and found a higher degree of sensitivity with the Celsee instrument. In conclusion, the integrated Celsee system represents a promising CTC technology for enumeration and molecular characterization. 相似文献
2.
3.
4.
Vanna Fierabracci Pellegrino Masiello Michela Novelli Ettore Bergamini 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1991,570(2):285-291
An amino acid analysis by reversed-phase high-performance liquid chromatography after precolumn derivatization with phenyl isothiocyanate was adapted to the determination of free amino acids in plasma or other biological fluids and in tissue homogenates. Preparation of samples included deproteinization by 3% sulphosalicylic acid, and careful removal under high vacuum of residual phenyl isothiocyanate after derivatization. A Waters Pico-Tag column (15 cm long) was used, immersed in a water-bath at 38°C. In rat or human plasma, separation of 23 individual amino acids, plus the unresolved pair tryptophan and ornithine, was obtained within 13 min. Including the time for column washing and re-equilibration, samples could be chromatographed at 23-min intervals. Variability was tested for each amino acid by calculating the coefficients of variation of retention times (less than 1% in the average) and peak areas (less than 4% for both intra-day and inter-day determinations). The linearity for each standard amino acid was remarkable over the concentration range 3–50 nmol/ml. The mean recovery of amino acid standards added to plasma prior to derivatization was 97 ± 0.8%, except for aspartate (82%) and glutamate (81%). This method is rapid (almost three samples per hour can be analysed, more than in any other reported technique), with satisfactory precision, sensitivity and reproducibility. Therefore, it is well suited for routine analysis of free amino acids in both clinical and research work. 相似文献
5.
6.
7.
8.
Luca Luiselli Thomas Madsen Dario Capizzi Lorenzo Rugiero Nic Pacini Massimo Capula 《Ecological Research》2011,26(4):745-753
A review of several long-term studies has recently suggested that snakes might be declining in large parts of the world. Additional
data from other long-term studies are therefore urgently needed in order to assess the generalities of such suggested declines.
Based on a 20-year study, we analyzed demographic data on adult dice snakes (Natrix tessellata) studied in central Italy between 1985 and 2004. Both male and female dice snakes were relatively long-lived, with no significant
differences in longevity between the sexes. Individual males and females were observed over a maximum of 10 and 14 years,
respectively. However, the among-year recapture rates between the year the snakes were initially captured and the subsequent
year (i.e., year 1 to year 2) was significantly lower (45%) than the among-year recapture rates during subsequent years (74%;
i.e., year 2 to year 3), suggesting that a large proportion of the snakes at first capture were in fact not resident within
our study area, and hence many snakes were migrating in and out of our 2-km stream study site, with no inter-sexual difference
in dispersal rates. Sex ratio was virtually equal if we consider the study period as a whole. Significant annual fluctuations
were, however, observed through the study. In 1985–1990, 1993–1995, 1998 and 1999 the sex ratio was male-biased, whereas in
2000–2004 female-biased. In terms of both survival and recapture probabilities, model selection showed that Akaike’s information
criterion favored the model incorporating body size, with the model incorporating year having an intermediate likelihood,
and the model with sex included being the most disfavored. Total population number estimates suggest an average 86 adult individuals
along the 2 km of stream with only minor annual variations. However, a significant decrease in the number of males occurred
during the last 6 years of our study. Thus, further monitoring of this population is warranted in light of the decline of
snake populations reported recently. 相似文献
9.
Simon Gonzalez Florian Gallier Sabrina Kellouche Franck Carreiras Ettore Novellino Alfonso Carotenuto Gérard Chassaing Paolo Rovero Jacques Uziel Nadège Lubin-Germain 《生物化学与生物物理学报:生物膜》2019,1861(1):50-61
Over the past decades, membranotropic peptides such as positively charged cell-penetrating peptides (CPPs) or amphipathic antimicrobial peptides (AMPs) have received increasing interest in order to improve therapeutic agent cellular uptake.As far as we are concerned, we were interested in studying HCV fusion peptides as putative anchors. Two peptides, HCV6 and HCV7, were identified and conjugated to a fluorescent tag NBD and tested for their interaction with liposomes as model membranes. DSC and spectrofluorescence analyses demonstrate HCV7 propensity to insert or internalize in vesicles containing anionic lipids DMPG whereas no activity was observed with zwitterionic DMPC. This behavior could be explained by the peptide sequence containing a cationic arginine residue. On the contrary, HCV6 did not exhibit any membranotropic activity but was the only sequence able to induce liposomes' fusion or aggregation monitored by spectrofluorescence and DLS. This two peptides mild activity was related to their inefficient structuration in contact with membrane mimetics, which was demonstrated by CD and NMR experiments.Altogether, our data allowed us to identify two promising membrane-active peptides from E1 and E2 HCV viral proteins, one fusogenic (HCV6) and the other membranotropic (HCV7). The latter was also confirmed by fluorescence microscopy with CHO cells, indicating that HCV7 could cross the plasma membrane via an endocytosis process. Therefore, this study provides new evidences supporting the identification of HCV6 as the HCV fusion peptide as well as insights on a novel membranotropic peptide from the HCV-E2 viral protein. 相似文献
10.
Genomic Resources Development Consortium Mariella Baratti Federica Cattonaro Tiziana Di Lorenzo Diana Maria Paola Galassi Valentina Iannilli Alessio Iannucci Just Jensen Peter Foged Larsen Rasmus O. Nielsen Cino Pertoldi Dragos Postolache Jose Martin Pujolar Ettore Randi Aritz Ruiz‐Gonzalez Janne Pia Thirstrup Giovanni Giuseppe Vendramin Andrzej Zalewski 《Molecular ecology resources》2015,15(2):458-459