全文获取类型
收费全文 | 69篇 |
免费 | 14篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 2篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1922年 | 1篇 |
排序方式: 共有83条查询结果,搜索用时 15 毫秒
51.
In Italian nurseries and young groves of evergreen cypress(Cupressus sempervirens L.), the eriophyoid miteTrisetacus juniperinus (Nal.) is considered a very serious pest. A rating system of damage symptoms was developed to investigate the susceptibility
of different cypress seedling families to the mite. Based on this system, the seedlings were evaluated for three years in
the nursery and in two field locations after transplanting. Data obtained in the nursery allowed the cypress families to be
allocated to at least two different levels of susceptibility. These levels of susceptibility were generally also maintained
in the field. However, the environmental conditions of the two transplanting localities significantly affected the susceptibility
of each family. In all families, scores for each of the damage categories were strongly correlated positively to each other
and negatively with the average increment in the height of plant over the duration of the field experiment. Assessment of
the intensity of the symptoms peculiar to damage category A (buds enlarged, deformed, russet and/or branch apex folded) was
sufficient to give the same susceptibility evaluation as if data for all damage categories were used. The evaluation of susceptibility
on the basis of injury pattern may return very useful information for selection and certification of families of known susceptibility
to eriophyoid mites.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
52.
53.
Despite the interest in the diverse roles of dietary carotenoids in human health, little is known about the transfer of these plant pigments from foods to micelles during digestion and their subsequent transfer across the intestinal epithelium. We conducted this study to characterize the intestinal uptake of micellarized carotenoids using monolayers of differentiated Caco-2 human intestinal cells. Crystalline beta-carotene (BC) and lutein (LUT), solubilized in mixed micelles for delivery to cells, were stable in a tissue culture environment for 20 hours. Cellular accumulation of micellar BC and LUT was proportional to the media content of carotenoids at =2 micromol/L and the length of exposure. Cellular accumulation of BC routinely exceeded LUT and was due in part to the enhanced efflux or possible metabolism of LUT. Cellular BC content increased in a curvilinear manner when cultures were incubated in micellar medium containing 2 to 27 micromol/L BC prepared from water miscible beadlets; cellular BC content was maximum when medium BC was >/=18 micromol/L. There was no indication that high levels of BC in medium or within cells adversely affected micellar LUT accumulation. These data support the use of the Caco-2 human cell line as a model for studying the intestinal uptake, absorption, and possible interactions of dietary carotenoids. 相似文献
54.
Metallothionein metabolism in the liver and kidney of the streptozotocin-diabetic rat 总被引:1,自引:0,他引:1
M L Chen M L Failla 《Comparative biochemistry and physiology. B, Comparative biochemistry》1988,90(2):439-445
1. Elevated levels of metallothionein (MT)-I and -II were identified in the liver and kidney of insulin-deficient diabetic rats. 2. The relative rate of MT synthesis and the turnover of cytoplasmic MT were both accelerated in the liver of diabetic rats. 3. The rate of synthesis of MT, but not its cytoplasmic turnover, was increased in diabetic kidney. 4. Maximal relative rates of MT synthesis in liver and kidney were first observed at 4 and 10 days, respectively, after inducing the diabetic condition. 5. The altered metabolism of hepatic MT in diabetic rats was attributed primarily to disturbances in endocrine status, while the altered metabolism of renal MT was largely due to accumulation of excessive dietary copper in the kidney. 相似文献
55.
Influence of spontaneous diabetes on tissue status of zinc, copper, and manganese in the BB Wistar rat 总被引:1,自引:0,他引:1
M L Failla C Y Gardell 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1985,180(2):317-322
The concentrations of zinc, copper, and manganese in liver, kidney, duodenum, pancreas, testes, bone, and serum from control and untreated, spontaneously diabetic BB Wistar rats were compared. Chronic insulin deficiency resulted in significant alterations in the concentrations of one or more of these essential micronutrients in several tissues. The amounts of zinc and copper bound to metallothionein in the liver and kidney of untreated spontaneously diabetic rats were also markedly increased. The tissue trace metal status in diabetic rats was altered similarly in both male and female rats. Daily injections of insulin blocked many of the changes in the tissue concentrations of the metals. The effects of spontaneous diabetes on tissue trace metal status are quite similar to those reported for chemically induced diabetes. Thus, these results demonstrate that chronic endocrine imbalance is responsible for a series of tissue specific changes in the transport and metabolism of zinc, copper, and manganese. 相似文献
56.
Identification of metallothionein in parenchymal and non-parenchymal liver cells of the adult rat.
下载免费PDF全文
![点击此处可从《The Biochemical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Parenchymal and non-parenchymal cells were isolated from the livers of control, starved, Zn2+-injected and Cd2+-injected rats. Parenchymal cells were prepared by differential centrifugation after perfusion of the liver with collagenase. Non-parenchymal cells were separated from parenchymal cells by unit-gravity sedimentation and differential centrifugation. Yields of 2 x 10(8) non-parenchymal cells with greater than 95% viability and less than 0.2% contamination with parenchymal cells were obtained without exposing cells to Pronase. Metallothioneins-I and -II were identified in parenchymal cells and non-parenchymal cells from Zn2+-treated rats. The metallothionein contents of parenchymal cells, non-parenchymal cells and intact liver were quantified by a competitive 203Hg-binding assay. Administration of heavy-metal salts significantly increased the metallothionein content of both cell populations, although the concentration of the protein was approx. 2.5-fold greater in parenchymal cells than in non-parenchymal cells. Overnight starvation increased the metallothionein content of parenchymal cells without altering that of non-parenchymal cells. The potential significance of this differential response by different liver cell types with regard to the influence of Zn2+ on stress-mediated alterations in hepatic metabolism is discussed. 相似文献
57.
Primary cultures of adult rat liver parenchymal cells, isolated by the collagenase perfusion technique and maintained as a monolayer, were used to investigate the characteristics of hepatic cadmium accumulation and metabolism. Cadmium accumulation was found to be a temperature- and concentration-dependent process that required sulfhydryl groups and was significantly stimulated by the addition of dexamethasone to the medium. Once taken up, cadmium was less available for exit-exchange processes than its biologically required congener, zinc. Moreover, cadmium influx enhanced zinc efflux. While most of the intracellular cadmium was located in the cytosol, its distribution within this fraction was altered with time. Initially the metal was bound to both high molecular weight species (less than 50 000) and metallothionein. As the incubation period increased, the cytosol concentration of cadmium and the percentage of this metal associated with metallothionein was likewise increased. [3H]Amino acid incorporation studies indicated that the accumulation of cadmium resulted in de novo synthesis of the 1 and 2 forms of metallothionein. 相似文献
58.
Anna Both Jiabin Huang Minyue Qi Christian Lausmann Samira Weißelberg Henning Büttner Susanne Lezius Antonio Virgilio Failla Martin Christner Marc Stegger Thorsten Gehrke Sharmin Baig Mustafa Citak Malik Alawi Martin Aepfelbacher Holger Rohde 《PLoS pathogens》2021,17(2)
S. epidermidis is a substantial component of the human skin microbiota, but also one of the major causes of nosocomial infection in the context of implanted medical devices. We here aimed to advance the understanding of S. epidermidis genotypes and phenotypes conducive to infection establishment. Furthermore, we investigate the adaptation of individual clonal lines to the infection lifestyle based on the detailed analysis of individual S. epidermidis populations of 23 patients suffering from prosthetic joint infection. Analysis of invasive and colonizing S. epidermidis provided evidence that invasive S. epidermidis are characterized by infection-supporting phenotypes (e.g. increased biofilm formation, growth in nutrient poor media and antibiotic resistance), as well as specific genetic traits. The discriminating gene loci were almost exclusively assigned to the mobilome. Here, in addition to IS256 and SCCmec, chromosomally integrated phages was identified for the first time. These phenotypic and genotypic features were more likely present in isolates belonging to sequence type (ST) 2. By comparing seven patient-matched nasal and invasive S. epidermidis isolates belonging to identical genetic lineages, infection-associated phenotypic and genotypic changes were documented. Besides increased biofilm production, the invasive isolates were characterized by better growth in nutrient-poor media and reduced hemolysis. By examining several colonies grown in parallel from each infection, evidence for genetic within-host population heterogeneity was obtained. Importantly, subpopulations carrying IS insertions in agrC, mutations in the acetate kinase (AckA) and deletions in the SCCmec element emerged in several infections. In summary, these results shed light on the multifactorial processes of infection adaptation and demonstrate how S. epidermidis is able to flexibly repurpose and edit factors important for colonization to facilitate survival in hostile infection environments. 相似文献
59.
Summary Site directed mutagenesis was employed to modify a vector previously constructed for the convenient, copper-inducible production of fusion proteins in the yeastSaccharomyces cerevisiae. The resulting vector, pYEULCBX, remains versatile and now permits nonfused proteins to be produced. Thevpu gene from HIV-1 was expressed as an example. 相似文献
60.
Can Liu Andrew J. Martins William W. Lau Nicholas Rachmaninoff Jinguo Chen Luisa Imberti Darius Mostaghimi Danielle L. Fink Peter D. Burbelo Kerry Dobbs Ottavia M. Delmonte Neha Bansal Laura Failla Alessandra Sottini Eugenia Quiros-Roldan Kyu Lee Han Brian A. Sellers Foo Cheung John S. Tsang 《Cell》2021,184(7):1836-1857.e22
- Download : Download high-res image (201KB)
- Download : Download full-size image