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121.
ABSTRACT

The vegetation of sandy coasts of California between Point Arena and Morro Bay, was investigated. Near the tide line, was annual vegetation of the Cakile maritima community. Dunal vegetation included the new Abronio latifoliae-Ambrosietea chamissonis class with the new Ambrosietalia chamissonis order and the new Ambrosion chamissonis alliance (proposed). Foredune vegetation included the two new Abronio latifoliae-Elymetum mollis and Atriplici leucophyllae-Abronietum maritimae associations, with the new Polygono paronychiae-Artemisietum pycnocephalae and Erigero glauci-Abronietum latifoliae associations on more stabilised surfaces. In some localities, Ammophila arenaria var. australis occurs within a Lupino variicoloris-Ammophiletum australis association, which colonises the whole dune ecosystem. In the flat areas characterised by grit and affected by frequent sea ingression is an association characterised by Juncus lesueurii and Distichlis spicata (Junco lesueurii-Distichletum spicatae). In the hollows among inland dunes, affected by stagnation, thick meadows develop which contain two new associations: Stachydo rigidae-Iridetum douglasianae developing on flat areas with a stronger stagnation and Achilleo millefoliae-Elymetum pacifici.  相似文献   
122.
Structural and functional characteristics of the photosynthetic apparatus in 15-day old Brassica rapa plants grown aboard the space shuttle Columbia (STS-87) have been studied. Maintaining of the same growth conditions for control plants was realized using the Orbiter Environmental Simulator in Kennedy Space Center. The main differences in spaceflight plants in comparison with control ones have been shown to be the following. An average volume of one mesophyll palisade cell increased approximately twice and the chloroplast number per cell by 69.8%. Partial volumes of stromal thylakoids, starch grains and plastoglobuli also increased by 19.4%, 20.6% and 2 times accordingly. At the same time, the grana number per chloroplast decreased. Greater diversity of the thylakoid length in grana and a decrease in thylakoid membrane stacking were revealed. A decrease of PSII and PSI light-harvesting antennae has been detected, for PSII by an increase of Chl a/b ratio and kinetics delay in chlorophyll fluorescence induction, and for PSI by a decrease of integral intensity in the excitation spectrum of fluorescence at 735?nm, which indicated a decline of PSI absorption cross-section. Some distortion of PSI complexes have been displayed by fluorescence spectra. A slight decrease in PSII photochemistry yield was detected for the spaceflight material. PSI is concluded to be more susceptible to the microgravity conditions.  相似文献   
123.
Riassunto

L'A. mette in rilievo le differenze esistenti fra l'apice dei fusti sotterranei e quello dei fusti aerei di Equisetum ramosissimum Desf. Tali differenze sono : secrezione di abbondante mucillaggine da parte delle cellule dell'epidermide esterna delle guaine pi[ugrave] periferiche che incappucciano l'apice dei rizomi, mentre le cellule epidermiche esterne delle guaine dei fusti aerei si differenziano nello stesso senso delle cellule epidermiche degli internodi; presenza di tricomi nella parte interna delle guaine che incappucciano l'apice del rizoma, tricomi che mancano nelle guaine dei fusti aerei; localizzazione dell'acerescimento in lunghezza al primo internodio del rizoma (quello pi[ugrave] vicino alla gemma apicale), mentre nei fusti aerei l'acerescimento è scaglionato su diversi internodi.

La mucillaggine che viene secreta dalle cellule epidermiche delle guaine del rizoma prende origine direttamente dai granuli d'amido, che sono abbondantissimi e particolarmente grossi in talli cellule all'inizio del processo di formazione della mucillaggine.  相似文献   
124.
Abstract

Temperatures recorded in a olive-tree stem in 1961–1962. — In the Botanical Garden of Bari a temperature recorder has been placed, bearing 6 electrothermometers with platinum resistences having a sensitivity of 2,4 mm/C[ddot], with a recording approximation of 0,1 C[ddot].

The olive tree under examination is a grown-up tree, which has been pruned according to the local methode, and it belongs to a local breed named « Ogliarola leccese ».

Five thermometers have been employed as follows: 1rst in the air, hanging from the stem, m. 1,30, high; 2nd into the outer bark, cm, 0,5 deep; 3rd into the cambium, cm. 1,5 deep; 4th into the sap-wood, cm. 6 deep; 5th into the hearth-wood, cm. 22 deep.

The thermometers were all placed on the east side of the stem.

The figures and the graphs of the paper show that:

a) The whole stem of the specimen under examination has a mean temperature which is higher than that of the surrounding air.

b) The outer bark gets warmer than the air, during the day-time; during the night it gives up heat outside and inside, namely towards the stem tissues, particularly to the bark-cambium-sapwood zone, and also as far as the hearth wood zone.

c) The whole living zone of the stem (bark-cambium-sapwood) generally keeps temperature values intermediate between those of the outer bark and those of the air. The temperature values vary along the year.

d) In spring the cambium is warmer than the outer bark.

e) In winter cambium and sapwood generally have the same temperature. The temperature values recorded in this season are much lower than those of the outer bark and almost the same of those of the air.

f) The behaviour of temperature in cambium and sapwood is probably ruled by biological factors.

g) The hearth-wood keeps generally warmer than the air and cooler than other outer tissues. Its thermic rhytm is almost reversed in comparison with that of the outer tissues.

Il seems that hearth wood acts as an useful heat collector and distributor towards the living outer tissues during the diurnal and seasonal temperature remissions, at least in mild climates as that of Bari.  相似文献   
125.
Background aimsBone marrow (BM)-derived cells appear to be a promising therapeutic source for the treatment of acute myocardial infarction (AMI). However, the quantity and quality of the cells to be used, along with the appropriate time of administration, still need to be defined. We thus investigated the use of BM CD34+-derived cells as cells suitable for a cell therapy protocol (CTP) in the treatment of experimental AMI.MethodsThe need for a large number of cells was satisfied by the use of a previously established protocol allowing the expansion of human CD34+ cells isolated from neonatal and adult hematopoietic tissues. We evaluated gene expression, endothelial differentiation potential and cytokine release by BM-derived cells during in vitro culture. Basal and expanded CD34+ cells were used as a delivery product in a murine AMI model consisting of a coronary artery ligation (CAL). Cardiac function recovery was evaluated after injecting basal or expanded cells.ResultsGene expression analysis of in vitro-expanded cells revealed that endothelial markers were up-regulated during culture. Moreover, expanded cells generated a CD14+ subpopulation able to differentiate efficiently into VE-cadherin-expressing cells. In vivo, we observed a cardiac function recovery in mice sequentially treated with basal and expanded cells injected 4 h and 7 days after CAL, respectively.ConclusionsOur data suggest that combining basal and expanded BM-derived CD34+ cells in a specific temporal pattern of administration might represent a promising strategy for a successful cell-based therapy.  相似文献   
126.

Introduction

Media sensationalism on the H1N1 outbreak may have influenced decisional processes and clinical diagnosis.

Case Presentation

We report two cases of patients who presented in 2009 with coexisting H1N1 virus and Legionella infections: a 69-year-old Caucasian man and a 71-year-old Caucasian woman. In our cases all the signs and symptoms, including vomiting, progressive respiratory disease leading to respiratory failure, refractory hypoxemia, leukopenia, lymphopenia, thrombocytopenia, and elevated levels of creatine kinase and hepatic aminotransferases, were consistent with critical illness due to 2009 H1N1 virus infection. Other infectious disorders may mimic H1N1 viral infection especially Legionnaires' disease. Because the swine flu H1N1 pandemic occurred in Autumn in Italy, Legionnaires disease was to be highly suspected since the peak incidence usually occurs in early fall. We do think that our immediate suspicion of Legionella infection based on clinical history and X-ray abnormalities was fundamental for a successful resolution.

Conclusion

Our two case reports suggest that patients with H1N1 should be screened for Legionella, which is not currently common practice. This is particularly important since the signs and symptoms of both infections are similar.
  相似文献   
127.
There is evidence that inflammatory mechanisms play a role in the pathogenesis of temporal lobe epilepsy (TLE). MicroRNAs (miRNAs), a class of small non-coding endogenous RNAs, which negatively regulate target gene expression, have shown different expression patterns in immune diseases. Recently, several miRNAs have been found to be differentially expressed in animal models of TLE. To understand the role of miRNAs in the molecular mechanisms of TLE, we sought to determine whether genetic variant rs2910164 in the pre-miR-146a gene could influence susceptibility to TLE in an Italian population sample. A cohort of 357 TLE patients and 543 healthy controls were genotyped for detection of this SNP using TaqMan Allelic Discrimination assays, on an Applied Biosystems PCR platform. Analysis of genotype or allelic frequencies between patients and controls showed no statistically significant differences (p = 0.536 and p = 0.361 respectively). Moreover, such variant did not influence the main clinical characteristics of TLE. In conclusion, our data suggest that the rs2910164 variant in the pre-miR-146a gene is unlikely to influence significantly the risk of developing TLE or its severity.  相似文献   
128.
Aim of this work is to provide a detailed comparison of clinical‐pathologic features between well‐differentiated and poorly differentiated tumors according to their BRAF and RASSF1A status. We analyzed RASSF1A methylation by MSP and BRAF mutation by LCRT‐PCR with LightMix® kit BRAF V600E in neoplastic thyroid tissues. Immunohistochemical evaluation of RASSF1A expression was also performed by standard automated LSAB‐HRP technique. An overall higher degree of RASSF1A over‐expression than normal thyroid parenchyma surrounding tumors (P < 0.05) has been found in all malignant well‐differentiated lesions. Moreover, statistically significant higher levels of RASSF1A expression were observed in differentiated cancers associated to an inflammatory autoimmune background (P = 0.01). Amplifiable DNA for LC PCR with LightMix® kit BRAF V600E was obtained in nine PTCs, four FVPTCs, five ATCs, and one control. The V600E mutation was found in 13 of 18 (72%) tumors. BRAF was mutated in 6 of 9 (66%) classical PTC, in 2 of 4 (50%) follicular variant PTC and in all ACs (100%). The overall frequency of RASSF1A promoter methylation observed was 20.5% (9 cases out 44). Hypermethylation of RASSF1A in primary tumors was variable according to histotypes ranging from100% (5/5) in ACs to only 12.5% (4/32) in PTCs. We show a correlation between RASSF1A methylation status and RASSF1A protein expression. Finally, we conclude that BRAF V600E mutation and RASSF1A methylation were pathogenetic event restricted to a subgroup of PTC/FVPTCs in early stage and to clinically aggressive ATCs. J. Cell. Biochem. 114: 1174–1182, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
129.
Anthropogenic nitrogen (N) deposition and resulting differences in ecosystem N and phosphorus (P) ratios are expected to impact photosynthetic capacity, that is, maximum gross primary productivity (GPPmax). However, the interplay between N and P availability with other critical resources on seasonal dynamics of ecosystem productivity remains largely unknown. In a Mediterranean tree–grass ecosystem, we established three landscape‐level (24 ha) nutrient addition treatments: N addition (NT), N and P addition (NPT), and a control site (CT). We analyzed the response of ecosystem to altered nutrient stoichiometry using eddy covariance fluxes measurements, satellite observations, and digital repeat photography. A set of metrics, including phenological transition dates (PTDs; timing of green‐up and dry‐down), slopes during green‐up and dry‐down period, and seasonal amplitude, were extracted from time series of GPPmax and used to represent the seasonality of vegetation activity. The seasonal amplitude of GPPmax was higher for NT and NPT than CT, which was attributed to changes in structure and physiology induced by fertilization. PTDs were mainly driven by rainfall and exhibited no significant differences among treatments during the green‐up period. Yet, both fertilized sites senesced earlier during the dry‐down period (17–19 days), which was more pronounced in the NT due to larger evapotranspiration and water usage. Fertilization also resulted in a faster increase in GPPmax during the green‐up period and a sharper decline in GPPmax during the dry‐down period, with less prominent decline response in NPT. Overall, we demonstrated seasonality of vegetation activity was altered after fertilization and the importance of nutrient–water interaction in such water‐limited ecosystems. With the projected warming‐drying trend, the positive effects of N fertilization induced by N deposition on GPPmax may be counteracted by an earlier and faster dry‐down in particular in areas where the N:P ratio increases, with potential impact on the carbon cycle of water‐limited ecosystems.  相似文献   
130.
Neurons are highly polarized cells that critically depend on long‐range, bidirectional transport between the cell body and synapse for their function. This continual and highly coordinated trafficking process, which takes place via the axon, has fascinated researchers since the early 20th century. Ramon y Cajal first proposed the existence of axonal trafficking of biological material after observing that dissociation of the axon from the cell body led to neuronal degeneration. Since these first indirect observations, the field has come a long way in its understanding of this fundamental process. However, these advances in our knowledge have been aided by breakthroughs in other scientific disciplines, as well as the parallel development of novel tools, techniques and model systems. In this review, we summarize the evolution of tools used to study axonal transport and discuss how their deployment has refined our understanding of this process. We also highlight innovative tools currently being developed and how their addition to the available axonal transport toolkit might help to address key outstanding questions.  相似文献   
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