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1.
2.
The biology ofTetranychus evansi Baker and Pritchard was studied at five different temperatures on excised leaves ofSolanum douglasii Dunal. The theoretical lower threshold temperature of development was ca. 13°C. The combined immature stages required ca. 148 day-degrees for completion. Progressively later initiation of mating resulted in higher peak proportions of females produced, up to an 8-day period between emergence and mating at 30°C. The proportion of male offspring always increased towards the end of the oviposition period, apparently because of sperm depletion. The calculated intrinsic rate of increase was highest (0.432) at 35°C, the highest temperature tested. At that same temperature, daily oviposition rate and net reproductive rate were maximum (9.5 and 111.77, respectively), and mean generation time and doubling time were minimum (10.92 and 1.6 days, respectively). 相似文献
3.
L D Horwitz K M VanBenthuysen F M Sheridan E J Lesnefsky I M Dauber I F McMurtry 《Free radical biology & medicine》1990,8(4):381-386
Using anesthetized mongrel dogs exposed to 60 min of ligation of the left anterior descending coronary artery followed by 60 min of reperfusion, we examined the effect of superoxide dismutase (SOD) and dimethylthiourea (DMTU) on evidence of endothelial injury in coronary rings studied in vitro. In 13 dogs treated with saline rings from the normal left circumflex coronary artery (LCF) relaxed by 98 +/- 4% when exposed to 10(-5) M acetylcholine whereas rings from the left anterior descending coronary artery (LAD) relaxed by 79 +/- 7% (p less than 0.05). In the same rings maximum relaxation with the ionophore A23187 was 107 +/- 5% versus 87 +/- 8% (p less than 0.05) for the LCF and the LAD, respectively. Comparisons of concentration-response curves through a range of doses of both acetylcholine and A23187 revealed significant differences for both vasodilators between the LCF and the LAD (p less than 0.01 for each). Nine dogs were treated with bovine SOD infused in the left atrium the last 20 min of ligation and throughout reperfusion (140 units/kg/min) and six other dogs were treated with DMTU 500 mg/kg i.v. given the last 30 min of the ligation period. Neither SOD nor DMTU prevented endothelial injury in the LAD. Despite pretreatment with these agents, there were significant reductions in maximum relaxation and in total concentration-response curves in the LAD as compared with the results in rings from the LCF with both acetylcholine and A23187. There were normal responses to nitroprusside in both the LCF and LAD in all three experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Robert Y. McMurtry 《CMAJ》1988,138(10):930-931
5.
Differences in responsiveness to potential prey and pollen were tested in the facultative predator,Euseius tularensis Congdon. Following isolation without food for 16 h, adult female mites were observed with one of the following potential foods: pollen ofMalephora crocea (Jacquin) Schwantes,Scirtothrips citri (Moulton) 2nd instar larvae,Tetranychus pacificus McGregor nymphs and ♂,Panonychus citri (McGregor) nymphs and ♂,E. hibisci (Chant) larvae, andE. tularensis larvae. Responses were compared using the proportion of encounters that resulted in consumption. This proportion was highest when pollen was encountered, followed byS. citri andT. pacificus. Consumption was much lower in response toP. citri and congeneric larvae. WhenS. citri larvae were encountered a 2nd time, 1 to 2 h after the initial capture and consumption, responsiveness increased to a level equal to the response observed with pollen. These results suggest thatE. tularensis is a more effective biological control agent of citrus thrips (S. citri) than of citrus red mite (P. citri). 相似文献
6.
T. Yamaguchi R.F. O'Brien W.L. Hanson W.W. Wagner Jr. I.F. McMurtry 《Prostaglandins & other lipid mediators》1989,38(1)
The mechanism by which extracellular alkalosis inhibits hypoxic pulmonary vasoconstriction is unknown. We investigated whether the inhibition was due to intrapulmonary production of a vasodilator prostaglandin such as prostacyclin (PGI2). Hypoxic vasoconstriction in isolated salt-solution-perfused rat lungs was blunted by both hypocapnic and NaHCO3_induced alkalosis (perfusate pH increased from 7.3 to 7.7). The NaHCO3-induced alkalosis was accompanied by a significant increase in the perfusate level of 6-keto-prostaglandin F1α (6-keto-PGF1α), an hydrolysis product of PGI1. Meclofenamate, an inhibitor of cyclooxygenase, counteracted both the blunting of hypoxic vasoconstriction and the increased level of 6-keto-PGF1α. In intact anesthetized dogs, hypocapnic alkalosis (blood pH increased from 7.4 to 7.5) blunted hypoxic pulmonary vasoconstriction before but not after administration of meclofenamate. In separate cultures of bovine pulmonary artery endothelial and smooth muscle cells stimulated by bradykinin, the incubation medium levels of 6-keto-PGF1α were increased by both hypocapnia and NaHCO3-induced alkalosis (medium pH increased from 7.4 to 7.7). These results suggest that inhibition of hypoxic pulmonary vasoconstriction by alkalosis is mediated at least partly by PGI2. 相似文献
7.
Sunnybrook Medical Centre is a tertiary care teaching hospital situated in metropolitan Toronto. Its trauma unit, opened in June 1976, serves the inhabitants of metropolitan Toronto and the surrounding area (approximately 5 million). More than 3200 patients were admitted to the unit between 1976 and 1987. The criteria for admission were age at least 14 years and an Injury Severity Score (ISS) of 16 or greater, two or more significant injuries at anatomically discrete sites when the score on the Abbreviated Injury Scale was 3 or greater, or grade IV shock (systolic blood pressure of 80 mm Hg or less). The number of patients admitted annually to the unit increased over the study period. The survival rate also increased, from 76% in 1976 to 88% in 1987, although the average age and ISS of the patients remained unchanged. Less than 2% of the patients required long-term rehabilitative or chronic care. The patient profile is similar to that seen in other trauma centres in North America. The success of this program is largely the result of expeditious stabilization and transfer from referring hospitals coupled with early definitive surgical intervention. 相似文献
8.
Capillary recruitment and transit time in the rat lung 总被引:1,自引:0,他引:1
Presson Robert G. Jr.; Todoran Thomas M.; De Witt Bracken J.; McMurtry Ivan F.; Wagner Wiltz W. Jr. 《Journal of applied physiology》1997,83(2):543-549
Presson, Robert G., Jr., Thomas M. Todoran, Bracken J. DeWitt, Ivan F. McMurtry, and Wiltz W. Wagner, Jr.Capillary recruitment and transit time in the rat lung.J. Appl. Physiol. 83(2): 543-549, 1997.Increasing pulmonary blood flow and the associated rise incapillary perfusion pressure cause capillary recruitment. The resultingincrease in capillary volume limits the decrease in capillary transittime. We hypothesize that small species with relatively high restingmetabolic rates are more likely to utilize a larger fraction ofgas-exchange reserve at rest. Without reserve, we anticipate thatcapillary transit time will decrease rapidly as pulmonary blood flowrises. To test this hypothesis, we measured capillary recruitment andtransit time in isolated rat lungs. As flow increased, transit timedecreased, and capillaries were recruited. The decrease in transit timewas limited by an increase in the homogeneity of the transit time distribution and an increased capillary volume due, in part, to recruitment. The recruitable capillaries, however, were nearly completely perfused at flow rates and pressures that were less thanbasal for the intact animal. This suggests that a limited reserve ofrecruitable capillaries in the lungs of species with high restingmetabolic rates may contribute to their inability to raiseO2 consumption manyfold abovebasal values. 相似文献
9.
Phytoseius hawaiiensis (Acari: Phytoseiidae) had relatively long periods of preoviposition, oviposition and postoviposition (4.6, 46.9 and 52.0 days, respectively, at 24 °C), and a relatively low fecundity (31.4 eggs per female), compared to other phytoseiid species. The most favorable food tested was all stages of Oligonychus punicae (Hirst), but various other species of mite prey as well as pollen also promoted oviposition. Extreme variation was observed in hatching time of the eggs, from 10 min (rare) to over 4 days (common). Occasionally, females apparently retain their eggs until just before larvae hatch, as eggs containing developed larvae were observed inside some females. Results of experiments suggested that unsuitable substrate (e.g. for oviposition) is a factor which induces longer egg retention prior to oviposition.
Résumé Chez Phytoseius hawaiiensis, les durées des périodes précédant la ponte, correspondant à la ponte et succédant à la ponte, sont relativement longues; respectivement 4, 6; 31, 4 et 52 jours à 24 °C; dans ces conditions, la fécondité est relativement basse: 31, 4 oeufs par femelle. Oligonychus punicae (aux différents stades) a constitué le meilleur aliment essayé, mais diverses autres espèces d'acariens ainsi que le pollen induisent la ponte. La date d'éclosion des oeufs a présenté une très grande variabilité, de 10 min (rare) à plus de 4 jours (fréquent). Souvent, les femelles semblent retenir leurs oeufs jusqu'au moment précédant l'éclosion des larves, car des oeufs contenant des larves développées on été observés dans quelques femelles. Les résultats des expériences ont suggére qu'un substrat défavorable (pour la ponte) induit une plus longue rétention de la ponte.相似文献
10.
J. A. McMurtry 《BioControl》1977,22(1):19-30
Seven species of phytoseiid mites were collected from citrus trees in the Mediterranean region during a survey in 1971.Amblyseius stipulatus
Athias-Henriot was the most abundant and widespread species in all countries surveyed (Turkey, Greece, Italy, Spain).A. californicus (McGregor) was collected only in Spain;A. potentillae (Garman) andPhytoseiulus persimilis. A.-H. only in Italy.Typhlodromus talbii A.-H. was collected in Greece and Spain,T. athiasae
Porath & Swirski in Greece and Turkey, andIphiseius degenerans (Berl.) in Greece and Italy. Living material of all species exceptT. talbii was successfully shipped to California and insectary cultures established. Biologies were studied in the laboratory under
2 food regimes:Tetranychus pacificus
McGregor eggs and larvae, and pollen ofMalephora crocea (Jacq.). Pollen was not a satisfactory food forp. persimilis, A. californicus andT. athiasae. Pollen was slightly less satisfactory than tetranychid mites fora. potentillae, but was equally or more favorable than mites forA. stipulatus andI. degenerans. A. stipulatus has become established in southern California.
Résumé Sept espèces d'acariens de la famille desPhytoseiidae ont été récoltées sur des plants d'agrumes dans la région méditerranéenne au cours d'une étude effectuée en 1971.Amblyseius stipulatus Athias-Henriot est l'espèce la plus abondante et la plus répandue dans tous les pays visités (Turquie, Grèce, Italie, Espagne).A. californicus (McGregor) n'a été trouvé qu'en Espagne.A. potentillae (Garman) etPhytoseiulus persimilis A.-H. n'ont été trouvés qu'en Italie.Typhlodromus talbii. A.-H. a été récolté en Grèce et en Espagne,T. athiasae Porath & Swirski en Grèce et en Turquie, etIphiseius degenerans (Berl.) en Grèce et en Italie. Des spécimens vivants de toutes ces espèces, saufT. talbii, ont été réalisés avec succès en Californie où des élevages en laboratoire ont été réalisés. Ces élevages ont été réalisés avec deux régimes: œufs et larves deTetranychus pacificus, d'une part, pollen deMalephora crocea, d'autre part; ils ont permis de faire les observations biologiques suivantes. Le pollen n'est pas une nourriture satisfaisante pourP. persimilis, A. californicus etT. athiasae. Le pollen convient un peu moins que les tétranyques àA. potentillae; il est aussi favorable ou plus favorable que les tétranyques àA. stipulatus etI. degenerans. A la suite de son introduction dans le sud de la Californie,A. stipulatus semble s'y maintenir.相似文献