全文获取类型
收费全文 | 279篇 |
免费 | 21篇 |
专业分类
300篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 22篇 |
2013年 | 28篇 |
2012年 | 22篇 |
2011年 | 28篇 |
2010年 | 13篇 |
2009年 | 5篇 |
2008年 | 16篇 |
2007年 | 17篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1978年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有300条查询结果,搜索用时 15 毫秒
61.
Preparation of isolated liver endothelial cells and Kupffer cells in high yield by means of an enterotoxin 总被引:6,自引:0,他引:6
Rune Blomhoff Bård Smedsrød Winnie Eskild Per Einar Granum Trond Berg 《Experimental cell research》1984,150(1):194-204
A new method for preparing non-parenchymal rat liver cells (NPC) is described. The liver cell suspension, prepared by perfusing the liver with collagenase, was treated with enterotoxin from Clostridium perfringens for 15 min. The enterotoxin made the parenchymal cells leaky, and these cells could be separated from the NPC by centrifugation in a solution containing Nycodenz (20%, w/v). During the centrifugation, the NPC floated, while the parenchymal cells sedimented. The yield of NPC per liver (200 g rat) was about 250 X 10(6) cells. The NPC were further separated into endothelial cells, Kupffer cells and stellate cells by centrifugal elutriation. This method was particularly useful for preparing endothelial cells in high yield (100 X 10(6) cells per liver). Intravenously injected formaldehyde-treated albumin was selectively taken up by the endothelial cells. Isolated endothelial cells in suspension as well as in surface culture maintained their ability to endocytose this ligand. 相似文献
62.
63.
From seedlings of two violet flowering, inbred lines of Portulaca grandiflora hypocotyls were isolated and then halved by cross sections. On a modified Murashige-Skoog medium the pairs of segments frequently yielded quartetts of primary calli from the four cut surfaces. After some subcultivations of these groups, the betacyanin concentrations of cell cultures were measured and subjected to several statistical methods.In 5.0 per cent of all cell cultures belonging to line L and in 2.1 per cent of those derived from line H extremely high and low concentrations were caused by the in vitro conditions. Some other ones are obviously due to the character of seedlings used for experiment L 2.Furthermore it is statistically detectable that the cell culture coming from the basipetal cut of a hypocotyl segment is superior to the cell culture of acropetal origin with regard to betacyanin concentration. These differences indicate the polarization of physiological conditions in the hypocotyl segments.Abbreviations DW
dry weight
- FW
fresh weight 相似文献
64.
Role of the Jak/STAT pathway in the regulation of interleukin-8 transcription by oxidized phospholipids in vitro and in atherosclerosis in vivo 总被引:1,自引:0,他引:1
Gharavi NM Alva JA Mouillesseaux KP Lai C Yeh M Yeung W Johnson J Szeto WL Hong L Fishbein M Wei L Pfeffer LM Berliner JA 《The Journal of biological chemistry》2007,282(43):31460-31468
65.
Winnie S. Liang Jessica Aldrich Waibhav Tembe Ahmet Kurdoglu Irene Cherni Lori Phillips Rebecca Reiman Angela Baker Glen J. Weiss John D. Carpten David W. Craig 《Nucleic acids research》2014,42(2):e8
As next-generation sequencing continues to have an expanding presence in the clinic, the identification of the most cost-effective and robust strategy for identifying copy number changes and translocations in tumor genomes is needed. We hypothesized that performing shallow whole genome sequencing (WGS) of 900–1000-bp inserts (long insert WGS, LI-WGS) improves our ability to detect these events, compared with shallow WGS of 300–400-bp inserts. A priori analyses show that LI-WGS requires less sequencing compared with short insert WGS to achieve a target physical coverage, and that LI-WGS requires less sequence coverage to detect a heterozygous event with a power of 0.99. We thus developed an LI-WGS library preparation protocol based off of Illumina’s WGS library preparation protocol and illustrate the feasibility of performing LI-WGS. We additionally applied LI-WGS to three separate tumor/normal DNA pairs collected from patients diagnosed with different cancers to demonstrate our application of LI-WGS on actual patient samples for identification of somatic copy number alterations and translocations. With the evolution of sequencing technologies and bioinformatics analyses, we show that modifications to current approaches may improve our ability to interrogate cancer genomes. 相似文献
66.
Anthony Basooma Herbert Nakiyende Mark Olokotum John S. Balirwa Winnie Nkalubo Laban Musinguzi Vianny Natugonza 《Ecology and evolution》2022,12(3)
Funding biodiversity conservation strategies are usually minimal, thus prioritizing habitats at high risk should be conducted. We developed and tested a conservation priority index (CPI) that ranks habitats to aid in prioritizing them for conservation. We tested the index using 1897 fish species from 273 African inland lakes and 34 countries. In the index, lake surface area, rarity, and their International Union for Conservation of Nature (IUCN) Red List status were incorporated. We retrieved data from the Global Biodiversity Information Facility (GBIF) and IUCN data repositories. Lake Nyasa had the highest species richness (424), followed by Tanganyika (391), Nokoué (246), Victoria (216), and Ahémé (216). However, lakes Otjikoto and Giunas had the highest CPI of 137.2 and 52.1, respectively. Lakes were grouped into high priority (CPI > 0.5; n = 56) and low priority (CPI < 0.5; n = 217). The median surface area between priority classes was significantly different (W = 11,768, p < .05, effect size = 0.65). Prediction accuracy of Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) for priority classes were 0.912 and 0.954, respectively. Both models exhibited lake surface area as the variable with the highest importance. CPI generally increased with a decrease in lake surface area. This was attributed to less ecological substitutability and higher exposure levels of anthropogenic stressors such as pollution to a species in smaller lakes. Also, the highest species richness per unit area was recorded for high‐priority lakes. Thus, smaller habitats or lakes may be prioritized for conservation although larger waterbodies or habitats should not be ignored. The index can be customized to local, regional, and international scales as well as marine and terrestrial habitats. 相似文献
67.
Neha Babbar Winnie Dejonghe Monica Gatti Stefano Sforza 《Critical reviews in biotechnology》2016,36(4):594-606
Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc. However, extensive research is needed to establish the role of POS, both as a prebiotic as well as therapeutic agent. This review comprehensively covers different facets of POS, including the nature and chemistry of pectin and POS, potential agricultural residual sources of pectin, pre-treatment methods for facilitating selective extraction of pectin, identification and characterization of POS, health benefits and important applications of POS in food and feed. This review has been compiled to establish a platform for future research in the purification and characterization of POS and for in vivo and in vitro studies of important POS, so that they could be commercially exploited. 相似文献
68.
Hoepping A Diekers M Deuther-Conrad W Scheunemann M Fischer S Hiller A Wegner F Steinbach J Brust P 《Bioorganic & medicinal chemistry》2008,16(3):1184-1194
Neuroimaging of GABA(A) receptors offers the potential for a better diagnosis of diseases related to a dysfunction of the GABAergic neurotransmission. A series of potent fluorinated analogues of the pyrazolopyrimidine Indiplon has been synthesized and evaluated in vitro as potential agents for imaging the GABA(A) receptor by means of positron emission tomography (PET). The most promising compound N-(3-fluoropropyl)-N-[3-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl]-acetamide (5b) showed an IC(50) value of 2.78+/-0.63 nM comparable to the lead compound Indiplon (IC(50) 3.29+/-0.37 nM), thus making it an interesting candidate for further investigations. In addition to the fluorinated reference compounds, suitable precursors for (18)F-radiolabelling studies have been synthesized. 相似文献
69.
The presence of the translocator protein (TSPO), previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3)H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1), 499±106 Bq x mg(-1) in saline-treated controls). In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3)H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1)). Further, our study includes technical feasibility data on [(18)F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18)F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18)F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone. 相似文献
70.
Christina M. Wyatt George J. Schwartz Willis Owino Ong'or Joseph Abuya Alison G. Abraham Charles Mboku Loice B. M'mene Winnie J. Koima Mathew Hotta Paula Maier Paul E. Klotman Kara Wools-Kaloustian 《PloS one》2013,8(8)