全文获取类型
收费全文 | 151篇 |
免费 | 3篇 |
专业分类
林业 | 2篇 |
农学 | 1篇 |
基础科学 | 1篇 |
16篇 | |
综合类 | 85篇 |
农作物 | 1篇 |
水产渔业 | 9篇 |
畜牧兽医 | 34篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2022年 | 2篇 |
2020年 | 2篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1991年 | 5篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 2篇 |
1969年 | 5篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1963年 | 4篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1948年 | 1篇 |
1943年 | 1篇 |
1941年 | 3篇 |
1938年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 10 毫秒
1.
Goldberg ME 《Science (New York, N.Y.)》1989,246(4930):681-682
2.
W Ingwersen D G Allen D H Dyson W D Black M T Goldberg A E Valliant 《Canadian journal of veterinary research》1988,52(4):428-433
The cardiopulmonary effects of a halothane/oxygen combination were studied in eight cats subjected to a 25% whole blood volume loss. Test parameters included cardiac output measured via thermodilution, heart rate, respiratory rate, arterial blood pressure (systolic, diastolic and mean) and blood gas analysis. Values for cardiac index, stroke volume and systemic vascular resistance were calculated from these data. Posthemorrhage cardiac output, cardiac index, stroke volume and measurements of arterial blood pressure were significantly decreased (p less than 0.05). Heart rate remained unchanged. Following induction of halothane anesthesia the above parameters experienced a further significant decline (p less than 0.05) from their immediate preanesthetic (i.e. posthemorrhage) values. Heart rate also significantly decreased (p less than 0.05). Thirty minutes following the cessation of halothane anesthesia these values returned to near-hemorrhage levels, being above their respective preanesthetic values. Systemic vascular resistance initially rose, peaking ten minutes into halothane anesthesia, before gradually falling to prehemorrhage values at the end of halothane anesthesia. Following hemorrhage, respiratory rate demonstrated a transient increase, associated with an arterial CO2 tension fall, before returning to initial values at the preanesthetic time. During halothane anesthesia respiratory rate remained unchanged whereas arterial CO2 tension rose significantly (p less than 0.05) and pH declined slightly from preanesthetic readings. These returned to prehemorrhage values 30 minutes following the cessation of halothane anesthesia. 相似文献
3.
Karas AZ Goldberg AM 《Journal of the American Veterinary Medical Association》2003,223(3):298-9; author reply 299
4.
R. Smith W. McIlwraith R. Schweitzer K. Kadler J. Cook B. Caterson S. Dakin D. Heinegård H. Screen S. Stover N. Crevier‐Denoix P. Clegg M. Collins C. Little D. Frisbie M. Kjaer R. van Weeren N. Werpy J.‐M. Denoix A. Carr A. Goldberg L. Bramlage M. Smith A. Nixon 《Equine veterinary journal》2014,46(1):4-9
5.
To routinely assay the concentrations of ochratoxin A (OTA) in wines and beers, two new methods were developed and evaluated. The first utilized solid-phase extraction on a C(18) cartridge to achieve a 100-fold sample concentration followed by high-performance liquid chromatography on a C(18) column with gradient elution and quantitation at 333 nm by means of a photodiode array detector. Positive confirmation can be carried out by purity and match-factor analysis as well as peak shift following esterification with BF(3). Total run time is 28 min. The limits of detection (LOD) and quantitation (LOQ) are 0.05 and 0.10 microg/L, respectively. Recovery and imprecision ranged from 83 to 94% and from 4.0 to 8.9%, respectively. With a throughput of 35 assays per working day, this method is ideal for routine OTA analysis. It was used to survey the concentrations of OTA in 942 wines (2 of which gave values between 0.1 and 0.2 microg/L) and 107 beers (2 of which gave values between 0.05 and 0.1 microg/L). OTA was detected more frequently in red than white wines, with the highest incidence in red wines from Spain and Argentina. There was no association between OTA and country of origin or beverage type among the beers analyzed. The second method utilized gas chromatography with mass selective detection monitoring eight specific ions, preceded by extraction in dichloromethane and derivatization with bis[trimethylsilyl]trifluoroacetamide. LOD and LOQ were 0.1 and 2 microg/L, respectively; recovery and imprecision were 69-75 and 9.0-11.1%, respectively. The method is not suitable for routine quantitation but is potentially useful as a confirmatory tool for samples with OTA > or =0.1 microg/L. 相似文献
6.
Growth of L1210 leukemia cells which had been previously incubated with thymus DNA was inhibited. Leukemia-cell DNA did not affect tumor growth under similar conditions. Pretreatment of the thymus DNA with deoxyribonuclease suppressed the DNA induced inhibition. Both ribonucleasetreated DNA and untreated DNA inhibited tumor growth. 相似文献
7.
Selectivity of intracellular proteolysis: protein substrates activate the ATP-dependent protease (La) 总被引:19,自引:0,他引:19
A critical enzyme in protein breakdown in Escherichia coli is protease La (the lon gene product), which hydrolyzes proteins and adenosine triphosphate (ATP) in a coupled process. The mechanism of this process was studied with fluorogenic tripeptides. Although proteins and peptides are degraded at the same active site, protein substrates enhance the ability of the enzyme to degrade these peptides two- to tenfold. Proteins that are not substrates had little or no effect. Thus, protein substrates must bind to protease La at two sites, the active site and an allosteric site whose occupancy enhances proteolytic activity. This effect did not require that the proteins themselves be degraded. Proteins could induce peptide breakdown even in the absence of ATP, and proteins and ATP had additive effects in stimulating peptidase activity. A multistep cyclical mechanism is proposed in which the binding of the substrate and ATP activates the protease. The enzyme can then cleave a peptide bond, but is inactivated through ATP hydrolysis. Such a mechanism may help account for the selectivity of protein breakdown and prevent inappropriate or excessive proteolysis in vivo. 相似文献
8.
9.
Wadley L Sievers C Bamford M Goldberg P Berna F Miller C 《Science (New York, N.Y.)》2011,334(6061):1388-1391
The Middle Stone Age (MSA) is associated with early behavioral innovations, expansions of modern humans within and out of Africa, and occasional population bottlenecks. Several innovations in the MSA are seen in an archaeological sequence in the rock shelter Sibudu (South Africa). At ~77,000 years ago, people constructed plant bedding from sedges and other monocotyledons topped with aromatic leaves containing insecticidal and larvicidal chemicals. Beginning at ~73,000 years ago, bedding was burned, presumably for site maintenance. By ~58,000 years ago, bedding construction, burning, and other forms of site use and maintenance intensified, suggesting that settlement strategies changed. Behavioral differences between ~77,000 and 58,000 years ago may coincide with population fluctuations in Africa. 相似文献
10.