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531.
532.
The effects of three ligands for ligandin on the biliary excretion of methylmercury were investigated in male rats injected intravenously with 1.0 mg/kg Hg as Me203 HgCl. Bromosulphophthalein and indocyanine green inhibited the biliary excretion of methylmercury, while bilirubin had no such effect. None of the compounds tested which inhibited the biliary excretion of methylmercury decreased bile flow or changed the hepatic concentration of mercury of non-protein thiols. The possibility of the involvement of ligandin in the biliary excretion of methylmercury is discussed. 相似文献
533.
Summary The patterns of uptake and translocation of magnesium in different regions of the root are very similar to those of calcium. Once the endodermis has become suberized translocation of either ion to the shoot is greatly reduced and it is concluded that magnesium, like calcium, appears to move across the root cortex largely in the free space. 相似文献
534.
J Atzpodien S C Gulati J H Kwon M Wachter J Fried B D Clarkson 《Experimental cell biology》1987,55(5):265-270
Flow cytometric separation was performed on the normal human bone marrow (BM) by using the low-angle (0 degrees) or high-angle (90 degrees) light scatter. Four distinct subpopulations of cells can be enriched from normal human BM and these fractions were subsequently evaluated for their morphological properties as well as their clonogenic capacity in various progenitor cell assays. Our results indicate that human erythroid and granulocyte-macrophage progenitor cells can be separated from BM low-density cells by cell sorting, and these cells show similar 0 degrees and 90 degrees light scatter properties to those observed with murine bone marrow studies. Flow cytometric analysis also suggests that the majority of sorted BFU-E and CFU-GM resides in the blast cell subset of human BM mononuclear cells. 相似文献
535.
A. I. Clarkson M. Bulmer N. J. Titchener-Hooker 《Bioprocess and biosystems engineering》1996,14(2):81-89
The development of a model for simulating the recoveries by pilot-scale disc-stack centrifugation of whole yeast cells, yeast cell debris and protein precipitates prepared by ammonium sulphate salting-out is presented. The model is based on the grade efficiency concept and incorporates the effects of hindered settling at high biomass concentrations and the breakage of shear-sensitive material within the centrifuge feed-zone to give an accurate prediction of solid/liquid separation. The simulations have been proven by comparison with data from pilot-scale verification trials. The trials have highlighted where improvements to the models were required to increase their accuracy. The value of verification trials in proving the validity of models is commented upon. 相似文献
536.
Loss of thymine dimers from mammalian cell DNA. The kinetics for antibody-binding sites are not the same as that for T4 endonuclease V sites 总被引:3,自引:0,他引:3
Antiserum specific for thymine-containing dimers was used to assay DNA isolated from ultraviolet-irradiated cells following different repair periods. A 50% loss in antibody-binding sites was evident 1 h post-irradiation, and within 4 h 80% of the sites were removed. This result contrasts with data obtained with dimer-specific T4 endonuclease V and does not appear to be due to masking of the dimers by repair enzymes. T4 endonuclease V treatment of ultraviolet-irradiated DNA at 0 degree C resulted in conversion of the thymine dimers to apyrimidinic sites. This did not result in loss of antigenicity in either PM2 or CHO cell DNA. Likewise, treatment of ultraviolet-irradiated CHO cell DNA with T4 endonuclease at 37 degrees C did not change its antigenicity. These results suggest that aglycosylation of the dimers is not responsible for their inability to bind dimer-specific antibody 2-4 h post-irradiation. The possibility that T4 endonuclease V and the antiserum have different specificities for different dimers is discussed. 相似文献
537.
Kirrilly R. Thompson Larissa Clarkson Christopher B. Riley Mariette van den Berg 《Journal of applied animal welfare science : JAAWS》2018,21(4):347-361
Little is known about the horse health management practices of Australian horse caregivers (owners). This article presents findings from a convenience sample of 505 horse owners who participated in an online survey. No large-scale welfare issues were identified, but there were some areas of potential concern, including owners who did not regularly deworm their horses (4%), a lack of strategic parasite control (3.1%), and a lack of regular dental care (11%). Several participants did not have their horse’s hooves regularly shod or trimmed (2%), and 14% had an unqualified person maintain their horse’s hooves. One in five owners (19%) did not vaccinate their horses against tetanus. The findings are discussed in relation to current Australian horse health guidelines and traditional sources of horse health information, together with recommendations for providing horse owners with relevant information in relevant forms. 相似文献
538.
L R Krumholz J Li W W Clarkson G G Wilber J M Suflita 《Journal of industrial microbiology & biotechnology》1997,18(2-3):161-169
The transport and fate of pollutants is often governed by both their tendency to sorb as well as their susceptibility to
biodegradation. We have evaluated these parameters for 2,4,6-trinitrotoluene (TNT) and several biodegradation products. Slurries
of aquifer sediment and groundwater depleted TNT at rates of 27, 7.7 and 5.9 μM day−1 under methanogenic, sulfate-reducing and nitrate-reducing conditions, respectively. Abiotic losses of TNT were determined
in autoclaved controls. Abiotic TNT loss and subsequent transformation of the products was also observed. These transformations
were especially important during the first step in the reduction of TNT. Subsequent abiotic reactions could account for all
of the transformations observed in bottles which were initially nitrate-reducing. Other controls removed TNT reduction products
at much slower rates than slurries containing live organisms. 2-Amino-4,6-dinitrotoluene was produced in all slurries but
disappeared in methanogenic and in sulfate-reducing slurries within several weeks. This compound was converted to 2,4-diamino-6-nitrotoluene
in all slurries with subsequent removal of the latter from methanogenic and sulfate-reducing slurries, while it persisted
in autoclaved controls and in the nitrate-reducing slurries. Aquifer slurries incubated with either 2,4- or 2,6-diaminotoluene
showed losses of these compounds relative to autoclaved controls under nitrate-reducing conditions but not under sulfate-reducing
or methanogenic conditions. These latter compounds are important as reduced intermediates in the biodegradation of dinitrotoluenes
and as industrial chemicals. In experiments to examine sorption, exposure to landfill sediment resulted in losses of approximately
15% of diaminotoluene isomers and 25% of aminodinitrotoluene isomers from initial solution concentrations within 24 h. Isotherms
confirmed that the diaminotoluenes were least strongly sorbed and the amino-dinitrotoluenes most strongly sorbed to this
sediment, while TNT sorption capacity was intermediate. In our studies, 2,4,6-triaminotoluene sorption capacity was indeterminate
due to its chemical instability. Coupled with biodegradation information, isotherms help describe the likelihood of contaminant
removal, persistence, and movement at impacted sites.
Received 11 March 1996/ Accepted in revised form 24 July 1996 相似文献
539.