全文获取类型
收费全文 | 856篇 |
免费 | 53篇 |
专业分类
909篇 |
出版年
2022年 | 23篇 |
2021年 | 30篇 |
2020年 | 10篇 |
2019年 | 17篇 |
2018年 | 15篇 |
2017年 | 17篇 |
2016年 | 26篇 |
2015年 | 41篇 |
2014年 | 47篇 |
2013年 | 53篇 |
2012年 | 64篇 |
2011年 | 54篇 |
2010年 | 34篇 |
2009年 | 39篇 |
2008年 | 53篇 |
2007年 | 38篇 |
2006年 | 31篇 |
2005年 | 27篇 |
2004年 | 24篇 |
2003年 | 26篇 |
2002年 | 18篇 |
2001年 | 22篇 |
2000年 | 23篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 8篇 |
1975年 | 3篇 |
1971年 | 4篇 |
1965年 | 2篇 |
排序方式: 共有909条查询结果,搜索用时 0 毫秒
871.
Bieby Voijant Tangahu Siti Rozaimah Sheikh Abdullah Hassan Basri Mushrifah Idris Nurina Anuar Muhammad Mukhlisin 《International journal of phytoremediation》2013,15(7):663-676
Phytoremediation is a technology to clean the environment from heavy metals contamination. The objectives of this study are to threat Pb contaminated wastewater by using phytoremediation technology and to determine if the plant can be mention as hyperaccumulator. Fifty plants of Scirpus grossus were grown in sand medium and 600 L spiked water in various Pb concentration (10, 30 and 50 mg/L) was exposed. The experiment was conducted with single exposure method, sampling time on day-1, day-14, day-28, day-42, day-70, and day-98. The analysis of Pb concentration in water, sand medium and inside the plant tissue was conducted by ICP-OES. Water samples were filtered and Pb concentration were directly analyzed, Pb in sand samples were extracted by EDTA method before analyzed, and Pb in plant tissues were extracted by wet digestion method and analyzed. The results showed that on day-28, Pb concentration in water decreased 100%, 99.9%, 99.7%, and the highest Pb uptake by plant were 1343, 4909, 3236 mg/kg for the treatment of 10, 30, and 50 mg/L respectively. The highest BC and TF were 485,261 on day-42 and 2.5295 on day-70 of treatment 30 mg/L, it can be mentioned that Scirpus grossus is a hyperaccumulator. 相似文献
872.
873.
874.
875.
876.
Germinated maize is generally discarded as a waste material. In the present investigation starch obtained from germinated maize has been compared with the starch from non-germinated maize, as a thickener in textile printing. Extraction of starch was done by alkali steeping method. Analysis of both the starches was done by measuring swelling power, paste clarity, particle size, crystallinity and iodine binding. Printing of vat dyes on 100% cotton fabric was carried out using both the starches. The prints were analysed by measuring colour value (K/S and L*, a*, b* value), bending length and fastness to washing and crocking. Results suggest that germinated maize starch can substitute the non-germinated maize starch partially if not fully, as a thickener in printing. 相似文献
877.
Khalid M.A. Sheikh Michael L.J. Apuzzo Kim R. Kochsiek Martin H. Weiss 《The Yale journal of biology and medicine》1977,50(4):397-403
There is increasing evidence that human tumors possess tumor-associated neo-antigens. The host mounts an immunological response to these antigens, as evidenced by the detection of circulating humoral antibodies in a variety of human neoplasia.An indirect immunofluorescent antibody technique was employed to detect antibodies to tumor-associated antigens in the sera of patients with malignant gliomas. Viable single cell suspensions were used to demonstrate antibodies to surface contents of tumor cells and cell preparations were snap-frozen at −160° C to demonstrate antibodies to cytoplasmic components of tumor cells. After incubation with serum, the preparations were treated with polyvalent sheep antihuman globulin conjugated to isomer-1-fluorescein isothiocyanate, washed, and examined with a Leitz incident fluorescent microscope.Of the 17 sera from histologically proven malignant glial neoplasm patients, 2 (11%) were positive for an autologous surface antibody reaction. Five (23%) of 21 were positive for an autologus cytoplasmic antibody, however, 10 (47%) of 21 of the sera gave a positive reaction for cross-reacting cytoplasmic antibodies when tested with a battery of tumor cells obtained from different patients with malignant glial tumors.No reaction was observed with normal brain tissue. Absorption studies indicated the presence of a tumor-associated antigen.This study demonstrated that certain patients with malignant gliomas possess circulating antibodies to cytoplasmic components of their own tumor cells. The fact that a number of sera cross-reacted with tumor cells obtained from different patients suggests that antigenic cross-reactivity exists between malignant glioma cells from different patients. It is suggested that with further refinement, immunofluorescent detection of antibodies could evolve as a useful diagnostic adjunct in malignant glioma. 相似文献
878.
879.
Ursodeoxycholic acid protects cardiomyocytes against cobalt chloride induced hypoxia by regulating transcriptional mediator of cells stress hypoxia inducible factor 1α and p53 protein
下载免费PDF全文
![点击此处可从《Cell biochemistry and function》网站下载免费的PDF全文](/ch/ext_images/free.gif)
880.
M I Sheikh C Jacobsen M Stahl 《Archives internationales de physiologie et de biochimie》1978,86(5):1043-1054
The uptake of cyclic analogues of probenecid by kidney cortical slices has been studied in detail, in order to obtain more information on the secretory system for these compounds. Both p-piperidyl sulfamyl benzoic acid and p-benzyl sulfamyl benzoic acid were accumulated against concentration gradient, by renal tissue under aerobic as well as anerobic conditions. PAH, phenol red and probenecid competitively inhibited the active accumulation of these compounds by kidney tissue. Aerobic uptake of probenecid analogues was stimulated by succinate and octanoate at low medium concentrations while inhibition of renal accumulation of these compounds occurred at higher concentrations. Both p-piperidyl and p-benzyl sulfamyl benzoic acids like probenecid strongly interact with kidney cortex homogenates. Binding of these cyclic analogues to various cellular constituents of homogenate was efficiently inhibited by probenecid. The binding affinity of probenecid and analogues for kidney tissue, phospholipid vesicles (liposomes) and human serum albumin increased in the order : p-piperidyl sulfamyl benzoic acid less than p-benzyl sulfamyl benzoic acid less than di-n-propyl sulfamyl benzoic acid (probenecid). By contrast to the view put forward by Beyer (1950 & 1954), the results presented in this paper established that probenecid analogues are the true substrates of renal organic anion transport system. 相似文献