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1.
JOSEPH WESTERMEYER 《American anthropologist》1973,75(1):123-131
Ten cases of political homicide in Laos were intensively studied, with particular attention to the assassin, the victim, the homicidal event, the provocation, and the social context. Each assassination provided a resolution for a social dilemma which had proven refractory to other means of social problem solving. Certain demographic characteristics and psycho-social correlates of political homicide in Laos resemble those of other cultures. 相似文献
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ELISA absorbance cut-off method affects malaria sporozoite rate determination in wild Afrotropical Anopheles 总被引:1,自引:0,他引:1
JOHN C. BEIER CHARLES M. ASIAGO FRED K. ONYANGO JOSEPH K. KOROS 《Medical and veterinary entomology》1988,2(3):259-264
ABSTRACT. Malaria sporozoite infection rates in a mixed species group of 244 Anopheles gambiae Giles sensu lato and 115 An. funestus Giles wild female mosquitoes were compared using three methods to determine cutoff absorbance values for positivity of a Plasmodium falciparum Welch enzyme-linked immunosorbent assay (ELISA). Positive controls were based on P. falciparum circumsporozoite protein. As negative controls, four wild male Anopheles were included on each microtitre plate; tests were repeated on four consecutive days for each plate.
Infection rates were estimated at 13.1–22.8% using the mean absorbance value of negative controls plus three standard deviations, 11.7–12.8% using double the mean and 12.5–13.6% using the fixed cut-off value of 0.20 (allowing for 20% variation in negative control absorbance values).
Observed agreement for positivity or negativity among samples tested four times was 98.6% for the 2× mean method, 97.2% for the fixed cut-off 0.20 value, but only 82.7% for the mean +3 SD method. It was concluded that the 2× mean cut-off method is most reliable for field studies. P. falciparum sporozoite rates of 12.2% in An. funestus and 11.9% in An. gambiae s. l . were thus determined on the basis of the 2× mean cut-off method.
This comparative evaluation demonstrates that vector infectivity rates can be seriously over-estimated from sporozoite ELISA tests, by as much as 87% in one case considered here, depending on the absorbance cut-off method applied for negative controls. 相似文献
Infection rates were estimated at 13.1–22.8% using the mean absorbance value of negative controls plus three standard deviations, 11.7–12.8% using double the mean and 12.5–13.6% using the fixed cut-off value of 0.20 (allowing for 20% variation in negative control absorbance values).
Observed agreement for positivity or negativity among samples tested four times was 98.6% for the 2× mean method, 97.2% for the fixed cut-off 0.20 value, but only 82.7% for the mean +3 SD method. It was concluded that the 2× mean cut-off method is most reliable for field studies. P. falciparum sporozoite rates of 12.2% in An. funestus and 11.9% in An. gambiae s. l . were thus determined on the basis of the 2× mean cut-off method.
This comparative evaluation demonstrates that vector infectivity rates can be seriously over-estimated from sporozoite ELISA tests, by as much as 87% in one case considered here, depending on the absorbance cut-off method applied for negative controls. 相似文献
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JEFFREY M. BLACK 《Ibis》1995,137(S1):S153-S160
Since 1960, about 2150 Hawaiian Geese or Nene Branta sandvicensis were reintroduced in Hawaii to supplement the remaining wild population of about 30 birds. These geese were released mostly in high mountain sanctuaries. These sites became unsuitable during prolonged drought and the few surviving birds were those which had moved away from the release sites. The geese that survived had moved to, or were released near, agricultural pasture land. About 600 Nene are currently living in the wild; numbers are declining on the island of Hawaii, stable on Maui and increasing on Kauai. Management priorities include enhancement of grasslands, predator control and maximizing genetic diversity. To enable the species to recover, management will probably have to be large scale, intensive and prolonged. Further released captive-bred or translocated Nene should have access to enhanced habitats after predators have been controlled. 相似文献
6.
JOSEPH J. NAPOLITANO MARY E. WALL CAROL S. GANZ 《The Journal of eukaryotic microbiology》1970,17(2):158-161
SYNOPSIS. An amoeboflagellate isolated from common soil is described. The amoeboid stage is typically limax and contains a well differentiated uroid region. The flagellate has 2 flagella, which emerge anteriorly and are equal in length. It has a ventral cytostome near the anterior border. The cyst is helmet-shaped and without opercula. Polar masses are present during nuclear division. 相似文献
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JOHN C. BEIER FRED K. ONYANGO JOSEPH K. KOROS MUTALIB RAMADHAN ROSE OGWANG ROBERT A. WIRTZ DAVY K. KOECH CLIFFORD R. ROBERTS 《Medical and veterinary entomology》1991,5(1):71-79
Abstract. The malaria transmission potential of wild, infective Anopheles from western Kenya was evaluated by determining the number of sporozoites transmitted in vitro by salivation when their mouthparts were inserted into capillary tubes containing either sucrose or blood. With sucrose, 86.6% of 102 infective Anopheles transmitted a geometric mean (GM) of 3.84 sporozoites (range 1–34). With blood, 23.1% of 104 infective Anopheles , tested on the day of collection, transmitted a GM of 2.30 sporozoites (range 1–117). For Anopheles held 5 days postcapture before testing with blood, 53.6% of 56 transmitted a GM of 6.04 sporozoites (range 1–420). Transmitting Anopheles contained significantly more salivary gland sporozoites than non-transmitters. No significant differences were detected between Anopheles gambiae Giles sensu lato and Anopheles funestus Giles in sporozoite transmission by individuals with sporozoites in their salivary glands.
Sporozoites were detected microscopically in the salivary duct from heads in 80.3% of 117 infective Anopheles (GM=11.2, range 1–71). Sporozoite detection in mosquito heads by ELISA was 25% less efficient than microscopic detection.
Over 98% of the infective Anopheles transmitted less than twenty-five sporozoites. Transmitted sporozoites represented only about 3% of the total sporozoites in the salivary glands suggesting that sporozoite transmission may be restricted to sporozoites in the salivary duct at the time of feeding. Results are discussed in relation to anti-sporozoite vaccine development. 相似文献
Sporozoites were detected microscopically in the salivary duct from heads in 80.3% of 117 infective Anopheles (GM=11.2, range 1–71). Sporozoite detection in mosquito heads by ELISA was 25% less efficient than microscopic detection.
Over 98% of the infective Anopheles transmitted less than twenty-five sporozoites. Transmitted sporozoites represented only about 3% of the total sporozoites in the salivary glands suggesting that sporozoite transmission may be restricted to sporozoites in the salivary duct at the time of feeding. Results are discussed in relation to anti-sporozoite vaccine development. 相似文献
9.
KIRSCHVINK JOSEPH L.; KIRSCHVINK ATSUKO KOBAYASHI 《Integrative and comparative biology》1991,31(1):169-186
Although the presence of geomagnetic sensitivity has been suspectedfor a long time in a variety of marine and terrestrial animals,many responses reported in the literature have been based onextensive statistical analysis of orientation results or relyon obscure behavioral activities (like cetacean strandings orhoney bee waggle dances.) None of these reports have yet approachedthe level of clarity and simplicity displayed in experimentswith the magnetotactic bacteria, which is the best example ofgeomagnetic sensitivity in any living organism. Furthermore,claims of magnetic effects on living organisms pervade the literatureof biomagnetism, but many have failed subsequent attempts atreplication. We need to develop simple and easily replicatedexperiments for marine and terrestrial animals which can bemodified to answer basic questions concerning the psychophysicsof any geomagnetic sensory system which might be present. Inthis paper, we report the first replication of the Walker-Bittermanmagnetic anomaly conditioning experiment in honey bees, as wellas one of our attempts to slightly alter their basic protocol.We also report our attempts to condition honey bees to magneticdirection in simple maze experiments, and the initial resultsof a pulse-remagnetization experiment designed to test the ferromagnetictransduction hypothesis. We conclude honey bees are sensitiveto the geomagnetic field, that the signal processing for itis more complex than previously thought, and that a ferromagnetictransducer is compatible with all known behavioral data. 相似文献
10.
MICHAEL D. BAKER CHARLES R. VOSSBRINCK JAMES J. BECNEL JOSEPH V. MADDOX 《The Journal of eukaryotic microbiology》1997,44(3):220-225
ABSTRACT. Sequences of the small subunit rRNA genes of Amblyospora californica and an Amblyospora sp. from Culex salinarius were determined. These sequences were compared phylogenetically with 16 other microsporidia. The results suggest Amblyospora forms a sister taxon to the rest of the microsporidia examined. The basal position of Amblyospora is discussed with respect to the evolution of microsporidian life cycles. These sequences represent the longest microsporidian small subunit rRNA genes sequenced to date, 1,359 and 1,358 bp, respectively. Structural features and GC content (49% for both) are comparable to those of other microsporidia which have been sequenced. 相似文献