全文获取类型
收费全文 | 144篇 |
免费 | 8篇 |
出版年
2021年 | 4篇 |
2019年 | 1篇 |
2016年 | 3篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 18篇 |
2011年 | 7篇 |
2010年 | 14篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1952年 | 3篇 |
1951年 | 1篇 |
1950年 | 1篇 |
排序方式: 共有152条查询结果,搜索用时 15 毫秒
41.
Jan Willem Bek Adelbert De Clercq Hanna De Saffel Mieke Soenens Ann Huysseune P. Eckhard Witten Paul J. Coucke Andy Willaert 《Journal of fish biology》2021,98(4):1007-1017
One of the most frequently applied techniques in zebrafish (Danio rerio) research is the visualisation or manipulation of specific cell populations using transgenic reporter lines. The generation of these transgenic zebrafish, displaying cell- or tissue-specific expression of frequently used fluorophores such as Green Fluorescent Protein (GFP) or mCherry, is relatively easy using modern techniques. Fluorophores with different emission wavelengths and driven by different promoters can be monitored simultaneously in the same animal. Photoconvertible fluorescent proteins (pcFPs) are different from these standard fluorophores because their emission spectrum is changed when exposed to UV light, a process called photoconversion. Here, the benefits and versatility of using pcFPs for both single and dual fluorochrome imaging in zebrafish skeletal research in a previously generated osx:Kaede transgenic line are illustrated. In this line, Kaede, which is expressed under control of the osterix, otherwise known as sp7, promoter thereby labelling immature osteoblasts, can switch from green to red fluorescence upon irradiation with UV light. First, this study demonstrates that osx:Kaede exhibits an expression pattern similar to a previously described osx:nuGFP transgenic line in both larval and adult stages, hereby validating the use of this line for the imaging of immature osteoblasts. More in-depth experiments highlight different applications for osx:Kaede, such as lineage tracing and its combined use with in vivo skeletal staining and other transgenic backgrounds. Mineral staining in combination with osx:Kaede confirms osteoblast-independent mineralisation of the notochord. Osteoblast lineage tracing reveals migration and dedifferentiation of scleroblasts during fin regeneration. Finally, this study shows that combining two transgenics, osx:Kaede and osc:GFP, with similar emission wavelengths is possible when using a pcFP such as Kaede. 相似文献
42.
In this paper, we develop a theoretical contribution towards the understanding of the complex behavior of conjoint tumor-normal cell growth under the influence of immuno-chemotherapeutic agents under simple immune system response. In particular, we consider a core model for the interaction of tumor cells with the surrounding normal cells. We then add the effects of a simple immune system, and both immune-suppression factors and immuno-chemotherapeutic agents as well. Through a series of numerical simulations, we illustrate that the interdependency of tumor-normal cells, together with choice of drug and the nature of the immunodeficiency, leads to a variety of interesting patterns in the evolution of both the tumor and the normal cell populations. 相似文献
43.
Andrew MF Liu Rico KH Lo Emily X Guo Maurice KC Ho Richard D Ye Yung H Wong 《BMC structural biology》2011,11(1):17
Background
G protein-coupled receptors constitute the largest family of cell surface receptors in the mammalian genome. As the core of the G protein signal transduction machinery, the Gα subunits are required to interact with multiple partners. The GTP-bound active state of many Gα subunits can bind a multitude of effectors and regulatory proteins. Yet it remains unclear if the different proteins utilize distinct or common structural motifs on the Gα subunit for binding. Using Gα16 as a model, we asked if its recently discovered adaptor protein tetratricopeptide repeat 1 (TPR1) binds to the same region as its canonical effector, phospholipase Cβ (PLCβ). 相似文献44.
45.
David J Sewell Richard Turner Ray Field William Holmes Rahul Pradhan Christopher Spencer Stephen G Oliver Nigel KH Slater Duygu Dikicioglu 《Biotechnology and bioengineering》2019,116(6):1315-1325
Without a scale-down model for perfusion, high resource demand makes cell line screening or process development challenging, therefore, potentially successful cell lines or perfusion processes are unrealized and their ability untapped. We present here the refunctioning of a high-capacity microscale system that is typically used in fed-batch process development to allow perfusion operation utilizing in situ gravity settling and automated sampling. In this low resource setting, which involved routine perturbations in mixing, pH and dissolved oxygen concentrations, the specific productivity and the maximum cell concentration were higher than 3.0 × 106 mg/cell/day and 7 × 10 7 cells/ml, respectively, across replicate microscale perfusion runs conducted at one vessel volume exchange per day. A comparative analysis was conducted at bench scale with vessels operated in perfusion mode utilizing a cell retention device. Neither specific productivity nor product quality indicated by product aggregation (6%) was significantly different across scales 19 days after inoculation, thus demonstrating this setup to be a suitable and reliable platform for evaluating the performance of cell lines and the effect of process parameters, relevant to perfusion mode of culturing. 相似文献
46.
David Haase Jennifer K. Rieger Anika Witten Monika Stoll Erich Bornberg-Bauer Martin Kalbe Thorsten B. H. Reusch 《PloS one》2014,9(9)
Vertebrate innate immunity is the first line of defense against an invading pathogen and has long been assumed to be largely unspecific with respect to parasite/pathogen species. However, recent phenotypic evidence suggests that immunogenetic variation, i.e. allelic variability in genes associated with the immune system, results in host-parasite genotype-by-genotype interactions and thus specific innate immune responses. Immunogenetic variation is common in all vertebrate taxa and this reflects an effective immunological function in complex environments. However, the underlying variability in host gene expression patterns as response of innate immunity to within-species genetic diversity of macroparasites in vertebrates is unknown. We hypothesized that intra-specific variation among parasite genotypes must be reflected in host gene expression patterns. Here we used high-throughput RNA-sequencing to examine the effect of parasite genotypes on gene expression patterns of a vertebrate host, the three-spined stickleback (Gasterosteus aculeatus). By infecting naïve fish with distinct trematode genotypes of the species Diplostomum pseudospathaceum we show that gene activity of innate immunity in three-spined sticklebacks depended on the identity of an infecting macroparasite genotype. In addition to a suite of genes indicative for a general response against the trematode we also find parasite-strain specific gene expression, in particular in the complement system genes, despite similar infection rates of single clone treatments. The observed discrepancy between infection rates and gene expression indicates the presence of alternative pathways which execute similar functions. This suggests that the innate immune system can induce redundant responses specific to parasite genotypes. 相似文献
47.
48.
Hans Goost Johannes Witten Andreas Heck Dariusch R. Hadizadeh Oliver Weber Ingo Gr?ff Christof Burger Mareen Montag Felix Koerfer Koroush Kabir 《PloS one》2012,7(10)
Introduction
Developments in telemedicine have not produced any relevant benefits for orthopedics and trauma surgery to date. For the present project study, several parameters were examined during assessment of x-ray images, which had been photographed and transmitted via cell phone.Materials and Methods
A total of 100 x-ray images of various body regions were photographed with a Nokia cell phone and transmitted via email or MMS. Next, the transmitted photographs were reviewed on a laptop computer by five medical specialists and assessed regarding quality and diagnosis.Results
Due to their poor quality, the transmitted MMS images could not be evaluated and this path of transmission was therefore excluded. Mean size of transmitted x-ray email images was 394 kB (range: 265–590 kB, SD ±59), average transmission time was 3.29 min ±8 (CI 95%: 1.7–4.9). Applying a score from 1–10 (very poor - excellent), mean image quality was 5.8. In 83.2±4% (mean value ± SD) of cases (median 82; 80–89%), there was agreement between final diagnosis and assessment by the five medical experts who had received the images. However, there was a markedly low concurrence ratio in the thoracic area and in pediatric injuries.Discussion
While the rate of accurate diagnosis and indication for surgery was high with a concurrence ratio of 83%, considerable differences existed between the assessed regions, with lowest values for thoracic images. Teleradiology is a cost-effective, rapid method which can be applied wherever wireless cell phone reception is available. In our opinion, this method is in principle suitable for clinical use, enabling the physician on duty to agree on appropriate measures with colleagues located elsewhere via x-ray image transmission on a cell phone. 相似文献49.
50.
J. R. Managbanag Tarynn M. Witten Danail Bonchev Lindsay A. Fox Mitsuhiro Tsuchiya Brian K. Kennedy Matt Kaeberlein 《PloS one》2008,3(11)