全文获取类型
收费全文 | 178篇 |
免费 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 13篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 10篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有201条查询结果,搜索用时 15 毫秒
1.
CJ von Ruhland 《Biotechnic & histochemistry》2013,88(7):478-484
Amplification of immunohistochemical markers received considerable attention during the 1980s and 1990s. The amplification approach was largely abandoned following the development of antigen retrieval and reporter amplification techniques, because the latter were incorporated more easily into high throughput automated procedures in industrial and diagnostic laboratories. There remain, however, a number of instances where marker amplification still has much to offer. Consequently, we examined experimentally the utility of an optimized marker amplification technique in diagnostically relevant tissue where either the original signal strength was low or positive sites were visible, but sparsely distributed. Marker amplification in the former case not only improved the visibility of existing positive sites, but also revealed additional sites that previously were undetectable. In the latter case, positive sites were rendered more intense and therefore more easily seen during low magnification examination of large areas of tissue. 相似文献
2.
The experiment was organized in a 3×2 factorial arrangement with three dietary fat blends and a basal (20 mg kg?1 diet) or supplemented (220 mg kg?1) level of α-tocopheryl acetate. Dietary vitamin E and monounsaturated to polyunsaturated fatty acid ratio (dietary MUFA/PUFA) affected muscle α-tocopherol concentration (α-tocopherol [log μg g?1]=0.18 (±0.105)+0.0034 (±0.0003)·dietary α-tocopherol [mg kg?1 diet] (P<0.0001)+0.39 (±0.122)·dietary MUFA/PUFA (P<0.0036)). An interaction between dietary α-tocopherol and dietary MUFA/PUFA exists for microsome α-tocopherol concentration (α-tocopherol [log μg g?1]=1.14 (±0.169) (P<0.0001)+0.0056 (±0.00099)·dietary α-tocopherol [mg kg?1 diet] (P<0.0001)+0.54 (±0.206)·dietary MUFA/PUFA (P<0.0131)?0.0033 (±0.0011)·dietary α-tocopherol [mg kg?1)]×dietary MUFA/PUFA (P<0.0067)), and hexanal concentration in meat (hexanal [ng·g?1]=14807.9 (±1489.8)?28.8 (±10.6) dietary α-tocopherol [mg·kg?1] (P<0.01)?8436.6 (±1701.6)·dietary MUFA/PUFA (P<0.001)+24.0 (±11.22)·dietary α-tocopherol·dietary MUFA/PUFA (P<0.0416)). It is concluded that partial substitution of dietary PUFA with MUFA lead to an increase in the concentration of α-tocopherol in muscle and microsome extracts. An interaction between dietary α-tocopherol and fatty acids exists, in which at low level of dietary vitamin E inclusion, a low MUFA/PUFA ratio leads to a reduction in the concentration of α-tocopherol in microsome extracts and a concentration of hexanal in meat above the expected values. 相似文献
3.
CJ Cooksey 《Biotechnic & histochemistry》2016,91(1):71-76
Rhodamines were first produced in the late 19th century, when they constituted a new class of synthetic dyes. These compounds since have been used to color many things including cosmetics, inks, textiles, and in some countries, food products. Certain rhodamine dyes also have been used to stain biological specimens and currently are widely used as fluorescent probes for mitochondria in living cells. The early history and current biological applications are sketched briefly and an account of the ambiguities, complications and confusions concerning dye identification and nomenclature are discussed. 相似文献
4.
CJ Cooksey 《Biotechnic & histochemistry》2016,91(6):438-444
Malachite green was discovered independently by two researchers in Germany in the 19th century and found immediate employment as a dye and a pigment. Subsequently, other uses, such as staining biological specimens, emerged. A much later application was the control of fungal and protozoan infections in fish, for which the dye remains popular, although illegal in many countries owing to a variety of toxicity problems. In solution, malachite green can exist as five different species depending on the pH. The location of the positive charge of the colored cation on a carbon atom or a nitrogen atom is still debated. The original names of this dye, and their origins, are briefly surveyed. 相似文献
5.
Using the patch-clamp technique, we observed profound oscillations of the whole-vacuole outward current across the tonoplast
of Mesembryanthemum crystallinum L. (common ice plant). These current oscillations showed a clear voltage dependence and appeared at membrane potentials more
positive than 90–100 mV. This paper describes the oscillations in terms of two separate mechanisms. First, the Mesembryanthemum vacuolar membrane shows a negative slope conductance at membrane potentials more positive than 100–120 mV. The fact that
the oscillations and the negative slope conductance show a similar threshold potential suggests that (part of) the same mechanism
is involved in both phenomena. The second mechanism involved is the voltage drop across the series resistance. As a result,
the potential actually experienced by the vacuolar membrane deviates from the command potential defined by the patch-clamp
amplifier. This deviation depends in an Ohmic manner on the current magnitude. We suggest that the interplay of the negative
slope conductance and the voltage drop across the series resistance can cause a positive feedback which is responsible for
the current oscillations.
Received: 30 April 1999/Revised: 9 September 相似文献
6.
Ben C Collins Ludovic CJ Gillet Lorenz C Blum Lin‐Yang Cheng Olga Vitek Jeppe Mouritsen Genevieve Lachance Tim D Spector Emmanouil T Dermitzakis Ruedi Aebersold 《Molecular systems biology》2015,11(2)
The degree and the origins of quantitative variability of most human plasma proteins are largely unknown. Because the twin study design provides a natural opportunity to estimate the relative contribution of heritability and environment to different traits in human population, we applied here the highly accurate and reproducible SWATH mass spectrometry technique to quantify 1,904 peptides defining 342 unique plasma proteins in 232 plasma samples collected longitudinally from pairs of monozygotic and dizygotic twins at intervals of 2–7 years, and proportioned the observed total quantitative variability to its root causes, genes, and environmental and longitudinal factors. The data indicate that different proteins show vastly different patterns of abundance variability among humans and that genetic control and longitudinal variation affect protein levels and biological processes to different degrees. The data further strongly suggest that the plasma concentrations of clinical biomarkers need to be calibrated against genetic and temporal factors. Moreover, we identified 13 cis‐SNPs significantly influencing the level of specific plasma proteins. These results therefore have immediate implications for the effective design of blood‐based biomarker studies. 相似文献
7.
Background
Although simulation studies show that combining multiple breeds in one reference population increases accuracy of genomic prediction, this is not always confirmed in empirical studies. This discrepancy might be due to the assumptions on quantitative trait loci (QTL) properties applied in simulation studies, including number of QTL, spectrum of QTL allele frequencies across breeds, and distribution of allele substitution effects. We investigated the effects of QTL properties and of including a random across- and within-breed animal effect in a genomic best linear unbiased prediction (GBLUP) model on accuracy of multi-breed genomic prediction using genotypes of Holstein-Friesian and Jersey cows.Methods
Genotypes of three classes of variants obtained from whole-genome sequence data, with moderately low, very low or extremely low average minor allele frequencies (MAF), were imputed in 3000 Holstein-Friesian and 3000 Jersey cows that had real high-density genotypes. Phenotypes of traits controlled by QTL with different properties were simulated by sampling 100 or 1000 QTL from one class of variants and their allele substitution effects either randomly from a gamma distribution, or computed such that each QTL explained the same variance, i.e. rare alleles had a large effect. Genomic breeding values for 1000 selection candidates per breed were estimated using GBLUP modelsincluding a random across- and a within-breed animal effect.Results
For all three classes of QTL allele frequency spectra, accuracies of genomic prediction were not affected by the addition of 2000 individuals of the other breed to a reference population of the same breed as the selection candidates. Accuracies of both single- and multi-breed genomic prediction decreased as MAF of QTL decreased, especially when rare alleles had a large effect. Accuracies of genomic prediction were similar for the models with and without a random within-breed animal effect, probably because of insufficient power to separate across- and within-breed animal effects.Conclusions
Accuracy of both single- and multi-breed genomic prediction depends on the properties of the QTL that underlie the trait. As QTL MAF decreased, accuracy decreased, especially when rare alleles had a large effect. This demonstrates that QTL properties are key parameters that determine the accuracy of genomic prediction.Electronic supplementary material
The online version of this article (doi:10.1186/s12711-015-0124-6) contains supplementary material, which is available to authorized users. 相似文献8.
9.
Taura syndrome virus (TSV) is a member of the family Dicistroviridae that infects Pacific white shrimp Litopenaeus vannamei (also called Penaeus vannamei), and its replication strategy is largely unknown. To identify the viral replication site within infected shrimp cells, the viral RNA was located in correlation with virus-induced membrane rearrangement. Ultrastructural changes in the infected cells, analyzed by transmission electron microscopy (TEM), included the induction and proliferation of intracellular vesicle-like membranes, while the intracytoplasmic inclusion bodies and pyknotic nuclei indicative of TSV infection were frequently seen. TSV plus-strand RNA, localized by electron microscopic in situ hybridization (EM-ISH) using TSV-specific cDNA probes, was found to be associated with the membranous structures. Moreover, TSV particles were observed in infected cells by TEM, and following EM-ISH, they were also seen in close association with the proliferating membranes. Taken together, our results suggest that the membranous vesicle-like structures carry the TSV RNA replication complex and that they are the site of nascent viral RNA synthesis. Further investigations on cellular origins and biochemical compositions of these membranous structures will elucidate the morphogenesis and propagation strategy of TSV. 相似文献
10.
Elena Pantoja Steven van Zutphen Anthony L. Spek Jan Reedijk 《Inorganica chimica acta》2006,359(13):4335-4342
Asymmetric cis-platinum(II) complexes with isopropylamine and two different azole ligands were synthesized and characterized with different techniques. In addition, for one of the complexes the X-ray structure was determined. Cytotoxicity tests using several human tumor cell lines, including the cisplatin-sensitive cell line A2780 and its cisplatin-resistant analogue. These results were compared with the results obtained for the trans isomers of the presented complexes and a relation between the structure and the activity was established. It was found that complexes with cis geometry are less active than their trans analogues, in particular in the resistant cell line A2780R. However, complex 1 can overcome cisplatin resistance to a certain extent. In the interaction with GMP, the asymmetric cis-Pt(II) complexes react with similar rates as their trans analogues and they behave as bifunctional species. 相似文献