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121.
Blackfordia virginica, a hydromedusa native to the Black Sea, has become established in a number of estuarine areas worldwide. In estuaries of northeastern Brazil, only a single published report, from the early 1960s, exists of the species and its establishment here has remained doubtful. On discovering specimens collected in the region at various times between 1987 and 2000, however, we hypothesized that this hydromedusa has long inhabited estuaries in the area while going unnoticed. The objective of this study was to investigate its occurrence in brackish waters of tropical northeastern Brazil over the past 50 years. In a search for specimens we found 1,759 individuals from estuaries of the Santa Cruz Channel (Itamaracá) and Capibaribe and Jiquiá rivers that had been collected between 1987 and 2000. In addition, an analysis of grey literature (Ph.D. theses) suggests that the species has been present in the Santa Cruz Channel for at least five decades. Results thus support the hypothesis that this non-indigenous species has been established in the region for several decades at least, and that it constitutes an exotic component of the community.  相似文献   
122.

Background

N-acetylcysteine (NAC) or sodium bicarbonate (NaHCO3), singly or combined, inconsistently prevent patients exposed to radiographic contrast media from developing contrast-induced acute kidney injury (CI-AKI).

Objective

We asked whether intravenous isotonic saline and either NaHCO3 in 5% dextrose or else a high dose of NAC in 5% dextrose prevent CI-AKI in outpatients exposed to high-osmolal iodinated contrast medium more than does saline alone.

Methods

This completed prospective, parallel, superiority, open-label, controlled, computer-randomized, single-center, Brazilian trial (NCT01612013) hydrated 500 adult outpatients (214 at high risk of developing CI-AKI) exposed to ioxitalamate during elective coronary angiography and ventriculography. From 1 hour before through 6 hours after exposure, 126 patients (group 1) received a high dose of NAC and saline, 125 (group 2) received NaHCO3 and saline, 124 (group 3) received both treatments, and 125 (group 4) received only saline.

Results

Groups were similar with respect to age, gender, weight, pre-existing renal dysfunction, hypertension, medication, and baseline serum creatinine and serum cystatin C, but diabetes mellitus was significantly less prevalent in group 1. CI-AKI incidence 72 hours after exposure to contrast medium was 51.4% (257/500), measured as serum creatinine > (baseline+0.3 mg/dL) and/or serum cystatin C > (1.1· baseline), and 7.6% (38/500), measured as both serum creatinine and serum cystatin C > (baseline+0.3 mg/dL) or > (1.25 · baseline). CI-AKI incidence measured less sensitively was similar among groups. Measured more sensitively, incidence in group 1 was significantly (p<0.05) lower than in groups 2 and 3 but not group 4; adjustment for confounding by infused volume equalized incidence in groups 1 and 3.

Conclusion:

We found no evidence that intravenous isotonic saline and either NaHCO3 or else a high dose of NAC prevent CI-AKI in outpatients exposed to high osmolal iodinated contrast medium more than does saline alone.

Trial Registration

ClinicalTrials.gov NCT01612013.  相似文献   
123.
Although accurate and continuous assessment of cerebral vasculature status is highly desirable for managing cerebral vascular diseases, no such method exists for current clinical practice. The present work introduces a novel method for real-time detection of cerebral vasodilatation and vasoconstriction using pulse morphological template matching. Templates consisting of morphological metrics of cerebral blood flow velocity (CBFV) pulse, measured at middle cerebral artery using Transcranial Doppler, are obtained by applying a morphological clustering and analysis of intracranial pulse algorithm to the data collected during induced vasodilatation and vasoconstriction in a controlled setting. These templates were then employed to define a vasodilatation index (VDI) and a vasoconstriction index (VCI) for any inquiry data segment as the percentage of the metrics demonstrating a trend consistent with those obtained from the training dataset. The validation of the proposed method on a dataset of CBFV signals of 27 healthy subjects, collected with a similar protocol as that of training dataset, during hyperventilation (and CO2 rebreathing tests) shows a sensitivity of 92% (and 82%) for detection of vasodilatation (and vasoconstriction) and the specificity of 90% (and 92%), respectively. Moreover, the proposed method of detection of vasodilatation (vasoconstriction) is capable of rejecting all the cases associated with vasoconstriction (vasodilatation) and outperforms other two conventional techniques by at least 7% for vasodilatation and 19% for vasoconstriction.  相似文献   
124.
Sirenian vertebrae and ribs have been recently discovered from two Middle Eocene localities of the Pamplona Basin, Navarre (western Pyrenees). These outcrops correspond to different lower Bartonian lithostratigraphic units: the lower part of the Pamplona Marl Formation (Uztarrotz site) and the upper part of the Ardanatz Sandstone (Ardanatz site). The former represents a deep and low-energy sea floor far away from a deltaic slope; the Ardanatz environment probably corresponds to a semi-closed deltaic bay periodically affected by catastrophic floods (i.e., fluvial hyperpycnal flows). The presence of epibiontic activity suggests that the bones were exposed for a while prior to the burial. The histological structures are well preserved except in the peripheral region, where tubular-like microstructures filled by pyrite and iron oxides probably correspond to microbial bioerosion. The major mineral component of the fossil bones is francolite (carbonate fluorapatite). In the Ardanatz samples there is evidence of secondary francolite due to the late replacement of original carbonate fluorapatite through internal fractures. The Ardanatz and Uztarrotz sirenian fossils do not show any evidence of reelaboration. They have similar sum of rare earth elements (REE) concentrations relative to the host rock, but comparatively lower than in other vertebrate fossil bones. This feature may be due to the dense compact structure of pachyosteosclerotic sirenian bones.  相似文献   
125.
Targeted cancer therapies rely on bifunctional molecules, typically a protein that specifically recognizes tumor cells and a toxic component which is linked to the protein. Therefore, development of such therapies includes detailed characterizations of protein-cell interactions in order to find a good targeting agent. Knowledge of factors such as antibody-antigen specificity, as well as cellular uptake, retention and affinity of the antibody are necessary in order to be successful.In this paper, we have used a novel instrument, LigandTracer Yellow, to characterize the interactions of (111)In and (177)Lu-labeled monoclonal antibodies (MAbs) with CD44v6. Uptake studies with varying specific radioactivity of the chimeric MAb U36 and with an irrelevant antibody for the CD44v6 receptor verified the reliability of the method, as well as the specificity of the antibody-receptor binding. Uptake, retention, and affinity were very similar for the (111)In and (177)Lu-labeled conjugate, and were in line with earlier studies using manual methods. The fact that no adverse effects from labeling were seen, together with the high retention, could make these conjugates promising candidates for imaging and therapy of certain cancer types in the future. The novel LigandTracer technology reduced the workload and reagent spending while providing data with superior time resolution. The obtained results were in agreement with previously reported findings. In addition the real-time detection and higher time resolution made more detailed studies of the interactions possible.  相似文献   
126.
High glucose (HG) increases angiotensin II (AngII) generation in mesangial cells (MC). Chymase, an alternative AngII-generating enzyme, is upregulated in the glomeruli of diabetic kidneys. In this study, we examined AngII synthesis by human MC via angiotensin-converting enzyme (ACE)-dependent and chymase-dependent pathways under normal glucose (NG, 5 mM) and HG (30 mM) conditions. NG cells expressed ACE and chymase mRNA. Under NG conditions the chymase inhibitor chymostatin reduced AngII levels in cell lysates and in the culture medium, and the ACE inhibitor captopril had no effect. HG induced a 3-fold increase in chymase mRNA and protein but not in ACE mRNA; however, HG induced a 10-fold increase in intracellular ACE activity. The increase in AngII generation induced by HG was found in the cell lysate but not in the culture medium. The rise in intracellular AngII was not prevented by captopril or by chymostatin. Moreover, captopril inhibited extracellular ACE activity but failed to block intracellular ACE activity; these results suggested that captopril was unable to reach intra-cellular ACE. Losartan did not change the intracellular AngII content in either NG or HG conditions, and this lack of change suggested that the increase in AngII was due to intracellular generation. Together these results suggest that chymase may be active in human MC and that both ACE and chymase are involved in increased AngII generation during the HG stimulus by different mechanisms, including an upregulation of chymase mRNA and a rise in intracellular ACE activity, favoring the generation and accumulation of intracellular AngII.  相似文献   
127.
Discovery of potent renin inhibitors which contain a simplified alkylamino Asp-binding group and exhibit improved selectivity for renin over Cyp3A4 is described. Structure-function results in this series are rationalized based on analysis of selected compounds bound to renin, and the contribution of each molecular feature leading to the reduced P450 inhibition is quantified.  相似文献   
128.
Upper Maastrichtian to lower Paleocene, coarse‐grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynological and organic geochemical analyses were performed on the K–Pg boundary interval of the Lefipán Formation at the San Ramón section. The palynological and organic geochemical records from the San Ramón K–Pg boundary section are characteristic of a highly dynamic, nearshore setting. High abundances of terrestrial palynomorphs, high BIT‐index values and the occasional presence of plant fossils are indicative of a large input of terrestrial organic material. The organic‐walled dinoflagellate cyst (dinocyst) assemblage is generally dominated by Senegalinium and other peridinioid dinocyst taxa, indicative of high‐nutrient conditions and decreased salinities, probably associated with a large fluvial input. The reconstructed sea surface temperatures range from 25°C to 27°C, in accordance with the tropical climate inferred by palynological and megafloral studies. As in the Bajada del Jagüel section, ~500 km north‐north‐east of San Ramón, peaks of Senegalinium spp. were recorded below and above the K–Pg boundary, possibly related to enhanced runoff resulting from more humid climatic conditions. The lithological, palynological and organic geochemical records suggest the occurrence of a sea‐level regression across the K–Pg boundary, resulting in a hiatus directly at the boundary in both sections, followed by a transgression in the Danian.  相似文献   
129.
Summary The liver chromatin fromMus musculus andAkodon molinae was separated in 8 fractions by differential centrifugation. Like fractions from both species showed approximately similar contents of DNA, equivalent ratios of histone to non-histone proteins, corresponding template activities and equal amounts of positive C-banded material. On the other hand, heavy chromatin fractions ofMus were highly enriched in satellite DNA whereas no satellite DNA was found inAkodon chromatin. Heavy chromatin fractions isolated by differential sedimentation have been usually homologued with the constitutive heterochromatin. The properties of the constitutive chromatin are discussed and the validity of the foregoing concept is challenged. It is proposed to define the constitutive heterochromatin as those chromatin regions comprising highly repeated DNA sequences clustered in restricted areas of chromosomes and not transcribed (satellite DNA).  相似文献   
130.
The medial orbitofrontal cortex (mOFC) and rostral anterior cingulate cortex (rACC) are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA), which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%–34% of the variance in IQ, in comparison to 11%–16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC, two gray matter regions of interests that are very close in physical proximity, and underscores the important independent contributions of variations in rACC gray matter volume and mOFC-rACC white matter connectivity to individual differences in general intelligence.  相似文献   
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