全文获取类型
收费全文 | 387篇 |
免费 | 38篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 19篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 16篇 |
2011年 | 14篇 |
2010年 | 17篇 |
2009年 | 16篇 |
2008年 | 21篇 |
2007年 | 16篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 12篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 7篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1952年 | 1篇 |
排序方式: 共有425条查询结果,搜索用时 15 毫秒
91.
Olga Shakhova Phil Cheng Pravin J. Mishra Daniel Zingg Simon M. Schaefer Julien Debbache Jessica H?usel Claudia Matter Theresa Guo Sean Davis Paul Meltzer Daniela Mihic-Probst Holger Moch Michael Wegner Glenn Merlino Mitchell P. Levesque Reinhard Dummer Raffaella Santoro Paolo Cinelli Lukas Sommer 《PLoS genetics》2015,11(1)
92.
93.
Automated detection of elementary calcium release events using the á trous wavelet transform
下载免费PDF全文
![点击此处可从《Biophysical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We developed an algorithm for the automated detection and analysis of elementary Ca2+ release events (ECRE) based on the two-dimensional nondecimated wavelet transform. The transform is computed with the "à trous" algorithm using the cubic B-spline as the basis function and yields a multiresolution analysis of the image. This transform allows for highly efficient noise reduction while preserving signal amplitudes. ECRE detection is performed at the wavelet levels, thus using the whole spectral information contained in the image. The algorithm was tested on synthetic data at different noise levels as well as on experimental data of ECRE. The noise dependence of the statistical properties of the algorithm (detection sensitivity and reliability) was determined from synthetic data and detection parameters were selected to optimize the detection of experimental ECRE. The wavelet-based method shows considerably higher detection sensitivity and less false-positive counts than previously employed methods. It allows a more efficient detection of elementary Ca2+ release events than conventional methods, in particular in the presence of elevated background noise levels. The subsequent analysis of the morphological parameters of ECRE is reliably reproduced by the analysis procedure that is applied to the median filtered raw data. Testing the algorithm more rigorously showed that event parameter histograms (amplitude, rise time, full duration at half-maximum, and full width at half-maximum) were faithfully extracted from synthetic, "in-focus" and "out-of-focus" line scan sparks. Most importantly, ECRE obtained with laser scanning confocal microscopy of chemically skinned mammalian skeletal muscle fibers could be analyzed automatically to reproducibly establish event parameter histograms. In summary, our method provides a new valuable tool for highly reliable automated detection of ECRE in muscle but can also be adapted to other preparations. 相似文献
94.
Kurtz J Wegner KM Kalbe M Reusch TB Schaschl H Hasselquist D Milinski M 《Proceedings. Biological sciences / The Royal Society》2006,273(1592):1407-1414
Individual variation in the susceptibility to infection may result from the varying ability of hosts to specifically recognize different parasite strains. Alternatively, there could be individual host differences in fitness costs of immune defence. Although, these two explanations are not mutually exclusive, they have so far been treated in separate experimental approaches. To analyse potential relationships, we studied body condition and oxidative stress, which may reflect costs of immunity, in three-spined sticklebacks that had been experimentally exposed to three species of naturally occurring parasite. These sticklebacks differed in a trait, which is crucial to specific parasite defence, i.e. individual genetic diversity at major histocompatibility complex (MHC) class IIB loci. Oxidative stress was quantified as tissue acrolein, a technique that has been applied to questions of immuno-ecology for the first time. We measured gene expression at the MHC and other estimates of immune activation. We found that fish with high levels of MHC expression had poor condition and elevated oxidative stress. These results indicate that MHC-based specific immunity is connected with oxidative stress. They could, thus, also be relevant in the broader context of the evolution of sexually selected signals that are based on carotenoids and are, thus supposed to reflect oxidative stress resistance. 相似文献
95.
M. Westhoff D. Zimmermann G. Zimmermann P. Gessner L. H. Wegner F.-W. Bentrup U. Zimmermann 《Protoplasma》2009,235(1-4):101-105
Investigation of 67 gymnosperm and angiosperm species belonging to 25 orders shows that epistomatal mucilage plugs are a widespread phenomenon. Measurements of the leaf water status by using the leaf patch clamp pressure technique suggest that the mucilage plugs are involved in moisture uptake and buffering leaf cells against complete turgor pressure loss at low humidity. 相似文献
96.
Thomas Berghöfer Bianca Flickinger Lars H. Wegner Wolfgang Frey 《Biochemical and biophysical research communications》2009,387(3):590-3593
We have analyzed the cellular effects of nanosecond pulsed electrical fields on plant cells using fluorescently tagged marker lines in the tobacco cell line BY-2 and confocal laser scanning microscopy. We observe a disintegration of the cytoskeleton in the cell cortex, followed by contraction of actin filaments towards the nucleus, and disintegration of the nuclear envelope. These responses are accompanied by irreversible permeabilization of the plasma membrane manifest as uptake of Trypan Blue. By pretreatment with the actin-stabilizing drug phalloidin, the detachment of transvacuolar actin from the cell periphery can be suppressed, and this treatment can also suppress the irreversible perforation of the plasma membrane. We discuss these findings in terms of a model, where nanosecond pulsed electric fields trigger actin responses that are key events in the plant-specific form of programmed cell death. 相似文献
97.
Multivesicular Endosome Biogenesis in the Absence of ESCRTs 总被引:1,自引:0,他引:1
Susanne Stuffers Catherine Sem Wegner Harald Stenmark Andreas Brech 《Traffic (Copenhagen, Denmark)》2009,10(7):925-937
The endosomal sorting complex required for transport (ESCRT) protein machinery comprises four complexes, ESCRT-0, ESCRT-I, ESCRT-II and ESCRT-III, that facilitate receptor sorting into the lumen of multivesicular endosomes (MVEs) in order to terminate signalling receptors for final degradation within the lysosomes. Even though ESCRT proteins appear to be essential for the biogenesis of MVEs in Saccharomyces cerevisae , it is not clear whether ESCRT-independent pathways for MVE biogenesis exist in higher organisms. In this study we maximized inhibition of ESCRT-dependent pathway by depleting cells of key subunits of all four ESCRTs and followed MVE formation and epidermal growth factor (EGF) receptor (EGFR) traffic using electron and confocal microscopy. There was a dramatic alteration in the morphology of components of the endocytic pathway in ESCRT-depleted cells, but early and late endosomes stayed clearly differentiated. Importantly, although EGF-induced formation of MVEs was highly sensitive to ESCRT depletion, EGF-independent formation of MVEs could still occur. The MVEs remaining in ESCRT-depleted cells contained enlarged intralumenal vesicles into which EGFRs were not sorted. Our observations suggest that both ESCRT-dependent and ESCRT-independent mechanisms of MVE biogenesis exist in mammalian cells. 相似文献
98.
Pamela Mangat Natalia Wegner Patrick J Venables Jan Potempa 《Arthritis research & therapy》2010,12(3):209
Peptidylarginine deiminases (PADs) convert arginine within a peptide (peptidylarginine) into peptidylcitrulline. Citrullination
by human PADs is important in normal physiology and inflammation. Porphyromonas gingivalis, a major pathogen in periodontitis, is the only prokaryote described to possess PAD. P. gingivalis infection may generate citrullinated peptides, which trigger anti-citrullinated peptide antibodies. In susceptible individuals,
host protein citrullination by human PADs in the joint probably perpetuates antibody formation, paving the way for the development
of chronic arthritis. Blockades of bacterial and human PADs may act as powerful novel therapies by inhibiting the generation
of the antigens that trigger and sustain autoimmunity in rheumatoid arthritis. 相似文献
99.
Jakub Pazdrowski Pieńkowski Piotr Magdalena Kordylewska Anna Wegner Paweł Golusiński Wojciech Golusiński 《Reports of Practical Oncology and Radiotherapy》2010,15(3):60-63
Background
The exact assessment of a tonsil carcinoma''s size is often difficult because of the tumour''s submucosal extension and deep infiltration.Aim
The aim of the study is to assess the usefulness of intraoperative ultrasonography in tonsil cancer.Material
Twenty patients with carcinoma of the tonsil were included in the study (squamous cell carcinoma keratosis – 12, squamous cell carcinoma akeratosis – 6, diffuse large B cell lymphoma – 1, neoplasma malignum microcellulare – 1).Method
Transcutaneous, endoscopic, and intraoperative ultrasonography were performed using a linear 7.5 MHz probe.Results
The difference in the results was statistically significant between palpation examination and intraoperative ultrasonographic examination, between transcutaneous ultrasonographic examination and intraoperative ultrasonographic examination, and between endoscopic ultrasonographic examination and intraoperative ultrasonographic examination in tonsil tumours. Generally, tumour size assessed by intraoperative ultrasonography was more advanced than those assessed by other methods.Conclusions
Intraoperative ultrasonography is a safe, non-invasive method, which can be repeated at every stage of surgery. There were no contraindications or side effects. In all cases histological margins corresponded to sonographic margins. Intraoperative ultrasonography provides a quick and reliable orientation during resection of tonsil carcinoma. 相似文献100.
Early, rapid and reliable diagnosis is of first priority in prenatal medicine. The combination of specific sonographic markers (e.g. nuchal translucency) and biochemical parameters in maternal serum (e.g. free beta-human chorionic gonadotropin, pregnancy-associated plasma protein A), has already dramatically improved the sensitivity of non-invasive first trimester risk screening in pregnancy. In invasive prenatal diagnosis, in addition to well-established chorionic villi short-term culture, interphase multi-colour-fluorescence in situ hybridisation (M-FISH) on uncultured amnion cells has become a reliable tool for the rapid detection of fetal aneuploidies. Interphase M-FISH applications have enabled the diagnosis of selected chromosomal abnormalities in single cells and, therefore, have also become an important diagnostic tool for preimplantation diagnosis (PGD). The development of commercially available probe sets, in particular, has led to a broad use of interphase M-FISH in prenatal and PGD diagnosis. 相似文献