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991.
The long lasting scientific collaboration of Adelchi Negri with Camillo Golgi in the Laboratory of General Pathology and Histology of Pavia began in 1898–99, when he was still a medical student, and at about the time basic knowledge about human malaria transmission cycle (to which Golgi himself had given important contributions) was completed. On the occasion of the 100th anniversary of the discovery of Negri bodies, this article provides a short overview of the scientific and cultural context in whichNeurocytes hydrophobiae hypothesis matured. To the same intent and purposes, this article also delineates some of the important scientific achievements in the field of General Pathology by Negri’s contemporaries, reflecting both the influence of the two great pioneers in the field (Bizzozero and Golgi), and the close contact with European science in the 1890’s to the end of the first World War, when biological science in Italy entered a new crisis.
Adelchi Negri e le Scuole di Patologia generale nel passaggio dall’Ottocento al Novecento
Riassunto  La lunga collaborazione scientifica di Adelchi Negri con Camillo Golgi, nel Laboratorio di Patologia generale ed Istologia di Pavia, ebbe inizio nel 1898–99, quando questi era ancora studente di Medicina, e la conoscenza di base sul ciclo di trasmissione della malaria nell’uomo (alla quale lo stesso Golgi aveva dato importanti contributi in studi pionieristici) era completata. In occasione del Centenario della scoperta dei Corpi del Negri, questo articolo offre una rassegna sintetica del contesto scientifico-culturale in cui maturò l’ipotesi delNeurocytes hydrophobiae come agente causale della rabbia. Con questo intento e per lo stesso scopo, questo articolo traccia anche alcuni degli importanti raggiungimenti scientifici nel campo della Patologia generale da parte dei contemporanei di Negri, nei quali è rinvenibile, sia l’influenza dei grandi pionieri della disciplina (Bizzozero e Golgi), sia lo stretto contatto con la scienza europea, tra il 1890 circa e la fine della prima guerra mondiale, allorché la scienza biologica italiana entrò in una nuova crisi.
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992.
Lysine acylation of proteins is a crucial chemical reaction, both as a post-translational modification and as a method for bioconjugation. We previously developed a chemical catalyst, DSH, which activates a chemically stable thioester including acyl-CoA, allowing the site-selective lysine acylation of histones under physiological conditions. However, a more active catalyst is required for efficient lysine acylation in more complex biological milieu, such as in living cells, but there are no rational guidelines for developing efficient lysine acylation catalysts for use under physiological conditions as opposed to in organic solvents. We, herein, conducted a kinetic analysis of the ability of DSH and several derivatives to mediate lysine acetylation to better understand the structural elements essential for high acetylation activity under physiological conditions. Interestingly, the obtained trend in reactivity was different from that observed in organic solvents, suggesting that a different principle is necessary for designing chemical catalysts specifically for use under physiological conditions compared to catalysts for use in organic solvents. Based on the obtained information, we identified a new catalyst scaffold with high activity and structural flexibility for further modification to improve this catalyst system.  相似文献   
993.
The elongate loach (Leptobotia elongata) is a typical migratory fish that was formerly found in abundance throughout the upper and middle reaches of the Yangtze River but is now classified as a highly threatened fish on the China Species Red List. Here, a comparative study of microsatellite loci was performed to evaluate the genetic diversity and analyze the population structure in seven locations in the upper reaches of the Yangtze River, China. The results showed that genetic diversity of L. elongata is generally still at a high level. Populations from Xinshi, Panzhihua, Hechuan and Chishui, were found to have lower levels of genetic diversity than those that lived in Leshan, Yibin and Jiangjin. The IAM model indicated that populations from Panzhihua, Xinshi and Hechuan have undergone recent bottlenecks. AMOVA analysis revealed a small amount of differentiation among populations (3.6%), but most of the total variation occurred within populations (96.4%). Pairwise comparisons of populations confirmed a low population differentiation. STRUCTURE analysis showed no obvious genetic structure among populations, indicating that L. elongata living in the main stem of the river and its tributaries should be considered a single management unit.  相似文献   
994.
This article seeks to contribute some new insights to the discussion about the colonisation of the North-Netherlands coastal area in the Iron Age. The aim of the study presented here was to investigate whether archaeobotanical research can demonstrate the absence or presence of grazing and the changes in vegetation that follow the development of the salt marsh and that may be related to activities connected with human occupation. The material studied was sampled in the terp of Peins in the Dutch province of Friesland during the 1999 excavation. The beginnings of this terp can be dated in the first century A.D., although a small dike and two parallel ditches preceded it. The macroremains from these ditches proved useful in describing the changes in the salt marsh vegetation. It was shown that the salt marsh was not used for grazing cattle prior to habitation. Grazing only started at the time the first terp podium was raised.  相似文献   
995.
The reproduction biology and some biochemicalbiomarkers of viviparous blenny (Zoarcesviviparus L.) were studied in a Swedish fjord on theNorth Sea coast which receives chemical industrywaste-water. Data for comparison purposes wereobtained from a reference area used in the nationalmonitoring programme. The viviparous blenny has agestation period of 4–5 months. By analysing larvalsurvival and growth, reproductive performance wasshown to be significantly reduced in female blennyexposed to petrochemical effluents. Larval growth wassignificantly lowered, and the proportion of femalescarrying dead juveniles was higher than at thereference site. Also, the mean number of deadjuveniles per female was significantly higher in theeffluent area. Among sampling sites, responses were negatively correlated with the distance from theeffluent outlets. The narrow age distribution ofadults in exposed areas, and the difference in catchper unit effort, indicated increased adult mortality.No significant improvements in reproductiveperformance were seen when results were compared withprevious studies from 1988–1989. Significantdifferences in a set of enzymes associated with thedetoxification of xenobiotics, or the antioxidantdefence against organo- and oxyradicals, confirmed theexposure of the studied population to organic pollutants.  相似文献   
996.
Tolerance to the anorexic effect of d-amphetamine was studied in rats with selective dopamine lesions in the forebrain by means of 6-hydroxy dopamine, and measuring the food intake during two consecutive 2 h periods. Lesions placed in the perifornical hypothalamus (PFH) strongly antagonised the anorexic effect, whereas, lesions produced via intraventricular injections affected the anorexia only marginally. Amphetamine anorexia observed in the first 2 h in control and lesioned groups remained persistently, without any evidence of tolerance, up to 2 weeks of treatment. The second 2 h food intake exhibited a progressive increase which contributed to the apparent tolerance seen in total 4 h food intake in the control and lesioned animals. The onset and completion of this apparent tolerance was markedly delayed in the dopamine depleted group; lesions placed in the relatively medial areas delayed the tolerance development more effectively than that of PFH lesions. The stimulant effect of amphetamine on locomotion was abolished in lesioned animals. The results indicate that an apparent tolerance to amphetamine anorexia still developed in animals with forebrain dopamine loss. Although both the beta adrenergic and dopaminergic systems act together in mediating AMPH anorexia, the onset and the rate of completion of tolerance appear to be under the influence of hypothalamic dopaminergic system.  相似文献   
997.
A system of delay equations describing a simple model of the respiratory control mechanism in humans is considered and conditions guaranteeing stability, instability of steady-state equilibrium solutions of that system are presented.This research was supported in part by an NSF research grant (K. C.), and by the Institute of Mathematics and Its Applications with funds provided by the NSF (K. C. and J. T.)  相似文献   
998.
ABSTRACT Student Chapters of The Wildlife Society serve the parent organization as a source of new members while promoting professional development among aspiring wildlife biologists. However, little is known about the operation of the Student Chapters across North America. I conducted an online survey between March and May 2006 to learn about variation among chapters and to define successful chapters with a quantifiable, objective parameter (e.g., the active members or budgets). I sent chapter advisors and student officers the online survey via e-mail. Of 92 Student Chapters known to the parent Society in 2005, 66 active and one inactive chapters responded. Activities, sizes, and budgets varied greatly among chapters. Additionally, perceived values of membership by survey participants matched the parent Society's goals. No clear definition of a successful chapter (e.g., those with the most money or members) emerged, but chapters faced some evident problems including apathy from students and advisors as well as a lack of support from the parent Society. Based upon the survey, I recommend Student Chapters have strong projects and activities as well as consider collaborating with other professional organizations. I recommend the parent Society continue to expand student programs and incorporate students into the Society.  相似文献   
999.
The SeaGen tidal energy turbine is located in the Strangford Narrows, Northern Ireland. The Narrows are designated as a Natura 2000 site, host unique biological assemblages and exhibit very high tidal velocities.This study describes an asymmetrical BACI design monitoring program that was aimed at assessing the potential impact the SeaGen may have on epifaunal boulder reef communities. This study presents a novel methodology for monitoring epifaunal communities within highly variable and poorly understood tidal rapid environments.We identify bare rock as a key measure of disturbance within tidal energy extraction sites and propose a new successional model for epifaunal reef communities on subtidal stable substrates. We also present an Ecological Quality Ratio (EQR); the High Energy Hard Substrate (HEHS) index for use in monitoring programs within tidal energy extraction sites.Seasonality significantly affected epifaunal community structure, bare rock distributions and EQR values at all stations equally over time. SeaGen is not significantly affecting epifaunal community structure, bare rock distributions or EQR values at the impact site. The HEHS index has the potential to standardise benthic monitoring in tidal energy extraction sites.  相似文献   
1000.
The secular trend of perinatal mortality in Utrecht between 1880 and 1940 and its causes are examined in this study, based on patient records of two maternity clinics, those of the city's academic hospital, and of its outpatient clinic. The sample includes 17,111 deliveries. Over the period the proportion of births in the city occurring in the two institutions rose from 3 to 90%. The perinatal mortality rate in the hospital declined and then rose slightly at the end of the 19th century, but remained constant, even if cyclical, thereafter in both the hospital and the outpatient clinic. Rates differed substantially between the two maternity services. Logistic regression analysis reveals a cluster of factors related to perinatal death. Low birth weight had a powerful association with perinatal mortality in both samples. Most of the other factors associated with perinatal mortality were related to the health of the patients, to obstetric problems related to deliveries, and to infant sex and maternal age. Relationships between perinatal mortality and other measures of human welfare in The Netherlands are explored.  相似文献   
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