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排序方式: 共有394条查询结果,搜索用时 31 毫秒
131.
Felipe MS Andrade RV Arraes FB Nicola AM Maranhão AQ Torres FA Silva-Pereira I Poças-Fonseca MJ Campos EG Moraes LM Andrade PA Tavares AH Silva SS Kyaw CM Souza DP Pereira M Jesuíno RS Andrade EV Parente JA Oliveira GS Barbosa MS Martins NF Fachin AL Cardoso RS Passos GA Almeida NF Walter ME Soares CM Carvalho MJ Brígido MM;PbGenome Network 《The Journal of biological chemistry》2005,280(26):24706-24714
132.
Kinin B1 receptor up-regulation after lipopolysaccharide administration: role of proinflammatory cytokines and neutrophil influx 总被引:5,自引:0,他引:5
133.
This study examines the dispersal system of Guapira opposita in a tropical sandy rainforest in southeast Brazil. Guapira trees produce small fruits with a high protein content (28.4%) and low lipid content (0.3%), and the plant is primarily dispersed by birds. Mature fruits of G. opposita can fall spontaneously with the pulp intact, or be dropped by birds with bits of pulp attached. In either case, ground-dwelling ants rapidly remove the fruits to their nest (93% after 12 h). The ponerine ants Odontomachus chelifer and Pachycondyla striata are the main seed vectors among the ants, and together account for 56% (20 of 36) of the ant-fruit interactions recorded on the forest floor. Individual workers of O. chelifer and P. striata transport single fruits to their nests. Bits of pulp are fed to larvae and worker nestmates, and intact seeds are discarded outside the nest. Germination success in Guapira is higher for cleaned seeds (pulp removed) than for seeds coated by pulp. Guapira seedlings and juveniles are more frequent close to Odontomachus nests than at sites without such nests. Soil samples from Odontomachus nests had greater penetrability, and higher concentrations of P, K, and Ca than random soil samples. Field experiments suggest that the association between G. opposita seedlings and O. chelifer nests can potentially render the plant some protection against herbivores. Results indicate that fruit displacement by ponerine ants play an important role in the biology of G. opposita seeds and seedlings in the sandy forest, and illustrate the complex nature of the dispersal ecology of tropical tree species. 相似文献
134.
Tarcisio Passos Ribeiro de Campos Bruno M. Mendes Bruno Trindade Wagner L. Araujo 《Reports of Practical Oncology and Radiotherapy》2018,23(5):384-391
Aim
The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6?MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16?MeV applied in the left breast, considering the adoption of a combined photon (16?Gy) and electron (30?Gy) protocols.Materials and methods
The modified ICRP-reference female model of 60?kg, 163?cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered.Results
CR associated with the 6?MV, 4?MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16?MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3–5.0?Gy.Conclusions
To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16?Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8?MeV portal while 12–16?MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8–12?MeV may bring benefits, reducing CR. The lowest risk was found to 46?Gy electron portals exclusively. 相似文献135.
Mariana G. Tarragó Claudia C.S. Chini Karina S. Kanamori Gina M. Warner Ariel Caride Guilherme C. de Oliveira Micaela Rud Adrienne Samani Kyaw Z. Hein Runqing Huang Diana Jurk Dong Seong Cho James J. Boslett Jordan D. Miller Jay L. Zweier João F. Passos Jason D. Doles David J. Becherer Eduardo N. Chini 《Cell metabolism》2018,27(5):1081-1095.e10
136.
Thaís B. Guedes Ricardo J. Sawaya Alexander Zizka Shawn Laffan Søren Faurby R. Alexander Pyron Renato S. Bérnils Martin Jansen Paulo Passos Ana L. C. Prudente Diego F. Cisneros‐Heredia Henrique B. Braz Cristiano de C. Nogueira Alexandre Antonelli 《Global Ecology and Biogeography》2018,27(1):14-21
Motivation
We generated a novel database of Neotropical snakes (one of the world's richest herpetofauna) combining the most comprehensive, manually compiled distribution dataset with publicly available data. We assess, for the first time, the diversity patterns for all Neotropical snakes as well as sampling density and sampling biases.Main types of variables contained
We compiled three databases of species occurrences: a dataset downloaded from the Global Biodiversity Information Facility (GBIF), a verified dataset built through taxonomic work and specialized literature, and a combined dataset comprising a cleaned version of the GBIF dataset merged with the verified dataset.Spatial location and grain
Neotropics, Behrmann projection equivalent to 1° × 1°.Time period
Specimens housed in museums during the last 150 years.Major taxa studied
Squamata: Serpentes.Software format
Geographical information system (GIS).Results
The combined dataset provides the most comprehensive distribution database for Neotropical snakes to date. It contains 147,515 records for 886 species across 12 families, representing 74% of all species of snakes, spanning 27 countries in the Americas. Species richness and phylogenetic diversity show overall similar patterns. Amazonia is the least sampled Neotropical region, whereas most well‐sampled sites are located near large universities and scientific collections. We provide a list and updated maps of geographical distribution of all snake species surveyed.Main conclusions
The biodiversity metrics of Neotropical snakes reflect patterns previously documented for other vertebrates, suggesting that similar factors may determine the diversity of both ectothermic and endothermic animals. We suggest conservation strategies for high‐diversity areas and sampling efforts be directed towards Amazonia and poorly known species. 相似文献137.
I T Bonomo P C Lisboa M C F Passos C C Pazos-Moura A M Reis E G Moura 《Hormones et métabolisme》2005,37(4):220-225
Malnutrition during lactation reduces milk production and changes pup's leptin serum levels. To test prolactin role in this nutritional state, we evaluated whether prolactin suppression during lactation changes serum leptin in dams, its transfer through the milk, and pup's serum leptin. Lactating rats were treated with bromocryptine (1 mg/twice a day, s.c.) or saline three days before sacrifice (days 2-4 or days 19-21). Food intake and body weight were measured until sacrifice (4th and 21st day). Serum prolactin and leptin were determined by radioimmunoassay. Bromocryptine injected dams had lower serum prolactin and milk production as expected. The mothers presented lower food ingestion (day 21: -25%), lower body weight (day 4: -12%; day 21: -10%), higher serum leptin (day 4: +68%), lower milk leptin on the 4th day (11 times) and higher (8 times) on the 21st day. The offspring of bromocryptine-treated mothers presented lower body weight in both periods of lactation and lower serum leptin on the 4th day (-40%) and higher on the 21st day (+37%) of lactation. We suggest that prolactin, through its effect on leptin secretion into the milk, may play an important role in signalizing maternal nutritional status to the pups. 相似文献
138.
Kinetics and Modeling of Lactic Acid Production by Lactobacillus plantarum 总被引:1,自引:0,他引:1
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Frederico V. Passos Henry P. Fleming David F. Ollis Richard M. Felder R. F. McFeeters 《Applied microbiology》1994,60(7):2627-2636
An unstructured model was developed to describe bacterial growth, substrate utilization, and lactic acid production by Lactobacillus plantarum in cucumber juice. Significant lactic acid production occurred during growth, as well as stationary phases. The percentage of acid produced after growth ceased was a function of the medium composition. Up to 51% of the lactic acid was produced after growth ceased when NaCl was not present in the medium, whereas not more than 18% of the total lactic acid was produced after the growth ceased in presence of NaCl, probably because of an increase in the cell death rate. An equation relating the specific death rate and NaCl concentration was developed. With the kinetic model proposed by R. Luedeking and E. L. Piret (J. Biochem. Microbiol. Technol. Eng. 1:393-412, 1958) for lactic acid production rate, the growth-associated and non-growth-associated coefficients were determined as 51.9 (±4.2) mmol/g of cells and 7.2 (±0.9) mmol/g of cells h-1 respectively. The model was demonstrated for batch growth of L. plantarum in cucumber juice. Mathematical simulations were used to predict the influence of variations in death rate, proton concentration when growth ceased, and buffer capacity of the juice on the overall fermentation process. 相似文献
139.
Orlando J. Luis Ana M. Passos 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》1995,111(4):579-586
The lipid content and composition of Nereis (Hediste) diversicolor O. F. Müller (Annelida, Polychaeta, Nereidae) a mud-dwelling, intertidal errant polychaete in the Tagus estuary (Portugal), were examined on the monthly basis by lipid extraction, TLC and capillary GC. In this estuary, N. diversicolor is by far the dominant species among polychaeta and the main food item in the natural diet of several flatfishes. The biochemical elucidation of its lipid structure and distribution throughout the year, described in this study, provides information not only about the physiological role of lipids in the animal under consideration but also about dietary fatty acid requirements of some flatfishes in the wild and under laboratory conditions.The total lipid content varied between a maximum of 19.3% lyophilized dry weight in February (4.4% fresh weight) and a minimum of 6.6% in August (1.9% fresh weight). The major lipid classes were triacylglycerol, phospholipid, free sterol, free fatty acid, sterol ester/wax ester and alkyldiacylglycerol.The fatty acid composition was rather unsaturated with a 1:2 mean ratio of n-3: n-6. The major fatty acids were C160:0, C18:1n-9, C18:2n-6, and C20:5n-3; there were smaller amounts of C180:0, C18:1n-11, C18:1n-7, C18:3n-3, C20:1, C20:2n-6, C20:4n-6, C22:2, C22:5n-3, and many other fatty acids were detected at trace levels. The unsaturation ranged from 36.9 mg/g dry weight in summer to 107.4 mg/g in winter. An accumulation of fatty acids from plant origin was evident, in particular linoleic acid (C18:2n-6), which was quantitatively one of the major fatty acids throughout the year. 相似文献
140.
The reproductive biology of Manettia luteo-rubra was studied in the coastal montane Atlantic rain forest of southeastern Brazil. This Rubiaceae is a perennial vine that flowers all the year round, but has a flowering peak during the dry season. It presents reciprocal herkogamy, thus the plants are morphologically distylous. The morphs occur in a 1:1 ratio, and pollen diameter and corolla length vary between short and long-styled flowers. Manettia luteo-rubra displays typical heterostylous self-incompatibility and sets almost no fruits from self- or intramorph pollinations. The flowers are tubular, red with yellow lobes, and odourless. Anthesis is asynchronous, and the flowers last about four days. Concentration of sugars in nectar is similar in both morphs, ca. 24%, this concentration being typical for hummingbird flowers. Three species of hummingbirds are the major pollinators of the flowers of M. luteo-rubra at the study site: the hermits Phaethornis eurynome and P. squalidus, and the trochiline Thalurania glaucopis. Three species of Heliconius butterflies act as minor pollinators. Both morphs of M. luteo-rubra exhibit natural fruit-set of about 80%, this reproductive output being maintained throughout the year by the pollinators' constancy to the flowers. 相似文献