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991.
992.
《Biomarkers》2013,18(4):340-344
Background: The leptin:adiponectin ratio (L:A ratio) is an independent predictor of carotid intima-media thickness (CIMT).

Objective: To evaluate whether the leptin:high-molecular-weight adiponectin ratio (L:HA ratio) is associated with CIMT in the general population.

Methods: We investigated the relationship between the L:HA ratio and CIMT in 233 Japanese study participants (106 men and 127 women).

Results: After adjustment for confounding factors, CIMT was significantly correlated with the log L:HA ratio (β?=?0.11, p?=?0.014) in men, whereas no correlation was observed in women (β?=?0.01, p?=?0.50).

Conclusion: The L:HA ratio is closely correlated with CIMT in men, but not in women.  相似文献   
993.
The cricket Modicogryllus siamensis Chopard shows photoperiod‐dependent changes in the duration of nymphal development: nymphs become adult within 60 days after hatching, undergoing seven moults under long‐day conditions, whereas, under short‐day conditions, nymphal development takes much longer (approximately 180 days) with an increased number of moults. Because removal of the compound eyes alters this photoperiodic response, the eyes may be involved in light detection during the photoperiodic response. The role of opsins, expressed in the compound eye, is examined in the present study with reference to the photoperiodic response. Molecular cloning identifies cDNAs of three opsins, opsin‐Ultra Violet (Ms'op‐UV), opsin‐Blue (Ms'op‐B) and opsin‐Long Wave (Ms'op‐LW), and in situ hybridization reveals that the opsin genes are expressed in specific regions of the compound eye in a gene‐specific manner. RNA interference (RNAi) technology using the opsin genes results in a partial disruption in the long‐day responses; most of the treated crickets showed eight or more moults and up to 23.5% show a prolonged nymphal period that is typical of short‐day responses. Under short‐day conditions, op‐UV RNAi crickets show earlier adult development, whereas no distinct alterations are observed in op‐B and op‐LW RNAi insects. The results suggest that the opsin genes may play differential roles in the photoperiodic response in the cricket and that the results can be at least partially explained in terms of the external coincidence model of photoperiodic time measurement.  相似文献   
994.
A rupture-prone carotid plaque can potentially be identified by calculating the peak cap stress (PCS). For these calculations, plaque geometry from MRI is often used. Unfortunately, MRI is hampered by a low resolution, leading to an overestimation of cap thickness and an underestimation of PCS. We developed a model to reconstruct the cap based on plaque geometry to better predict cap thickness and PCS.We used histological stained plaques from 34 patients. These plaques were segmented and served as the ground truth. Sections of these plaques contained 93 necrotic cores with a cap thickness <0.62 mm which were used to generate a geometry-based model. The histological data was used to simulate in vivo MRI images, which were manually delineated by three experienced MRI readers. Caps below the MRI resolution (n = 31) were (digitally removed and) reconstructed according to the geometry-based model. Cap thickness and PCS were determined for the ground truth, readers, and reconstructed geometries.Cap thickness was 0.07 mm for the ground truth, 0.23 mm for the readers, and 0.12 mm for the reconstructed geometries. The model predicts cap thickness significantly better than the readers. PCS was 464 kPa for the ground truth, 262 kPa for the readers and 384 kPa for the reconstructed geometries. The model did not predict the PCS significantly better than the readers.The geometry-based model provided a significant improvement for cap thickness estimation and can potentially help in rupture-risk prediction, solely based on cap thickness. Estimation of PCS estimation did not improve, probably due to the complex shape of the plaques.  相似文献   
995.
No study has examined the differential value of arterial intima thickness in the subtypes of acute ischaemic stroke. This study aimed to assess whether intima thickness of carotid artery (CIT), radial artery (RIT) and dorsalis pedis artery (PIT) have an independent and additive value in differentiating ischaemic stroke subtypes due to large-artery atherosclerosis (LAA) or small-vessel occlusion (SVO). One hundred and sixty-one patients with LAA and 79 patients with SVO were recruited. CIT, RIT and PIT were measured with a 24-MHz ultrasound transducer. Binary logistic regression analysis was used to evaluate the differential values of the different parameters in the two subtypes. ROC curve analyses were plotted to compare the differential performance of different parameters and the combination model. Both RIT and PIT were substantially thicker in LAA than in SVO stroke patients. RIT and carotid intima-media thickness had similar performances in differentiating stroke subtypes. Introduction of RIT to traditional atherosclerotic associated risk factors had a marginal satisfactory differential performance for LAA and SVO stroke patients (AUC 0.775). RIT is a promising parameter for LAA and SVO subgroup classification. The combination of RIT and traditional risk factors might be a promising tool for differentiating ischaemic stroke subgroups.  相似文献   
996.
Preservation of plant germplasm is important to safeguard biodiversity and to store elite plants. Cryopreservation is one of the possible preservation techniques. Research for a cryopreservation protocol is often inefficient because of slow or poor regrowth of plant material. Therefore, at least one technique, that allows a quick and accurate prognosis of viability after cryopreservation, is required. We evaluated five techniques: electrolyte leakage, triphe-nyltetrazoliumchloride (TTC) staining (visual and spectrophotometrical analysis), malondialdehyde concentrations in plant tissue and a mathematical model that relates ‘water content’ to the weight of encapsulated plant material. Electrolyte leakage and TTC-staining (if visually analysed) are efficient to predict viability. Our mathematical model allows us to save time and plant material in order to develop an efficient encapsulation—dehydration protocol. All other techniques were rejected because of the high variability of the results. This is due to the variability of biochemical activity in plant tissue and the small amount of tissue used in the experiments.  相似文献   
997.
It has recently been shown that shear wave speed in tendons is directly dependent on axial stress. Hence, wave speed could be used to infer tendon load provided that the wave speed-stress relationship can be calibrated and remains robust across loading conditions. The purpose of this study was to investigate the effects of loading rate and fluid immersion on the wave speed-stress relationship in ex vivo tendons, and to assess potential calibration techniques. Tendon wave speed and axial stress were measured in 20 porcine digital flexor tendons during cyclic (0.5, 1.0 and 2.0 Hz) or static axial loading. Squared wave speed was highly correlated to stress (r2avg = 0.98) and was insensitive to loading rate (p = 0.57). The constant of proportionality is the effective density, which reflects the density of the tendon tissue and additional effective mass added by the adjacent fluid. Effective densities of tendons vibrating in a saline bath averaged 1680 kg/m3 and added mass effects caused wave speeds to be 22% lower on average in a saline bath than in air. The root-mean-square error between predicted and measured stress was 0.67 MPa (6.7% of maximum stress) when using tendon-specific calibration parameters. These errors increased to 1.31 MPa (13.1% of maximum stress) when calibrating based on group-compiled data from ten tendons. These results support the feasibility of calculating absolute tendon stresses from wave speed squared based on linear calibration relationships.  相似文献   
998.
Gap filling strategies and error in estimating annual soil respiration   总被引:3,自引:0,他引:3  
Soil respiration (Rsoil) is one of the largest CO2 fluxes in the global carbon (C) cycle. Estimation of annual Rsoil requires extrapolation of survey measurements or gap filling of automated records to produce a complete time series. Although many gap filling methodologies have been employed, there is no standardized procedure for producing defensible estimates of annual Rsoil. Here, we test the reliability of nine different gap filling techniques by inserting artificial gaps into 20 automated Rsoil records and comparing gap filling Rsoil estimates of each technique to measured values. We show that although the most commonly used techniques do not, on average, produce large systematic biases, gap filling accuracy may be significantly improved through application of the most reliable methods. All methods performed best at lower gap fractions and had relatively high, systematic errors for simulated survey measurements. Overall, the most accurate technique estimated Rsoil based on the soil temperature dependence of Rsoil by assuming constant temperature sensitivity and linearly interpolating reference respiration (Rsoil at 10 °C) across gaps. The linear interpolation method was the second best‐performing method. In contrast, estimating Rsoil based on a single annual Rsoil – Tsoil relationship, which is currently the most commonly used technique, was among the most poorly‐performing methods. Thus, our analysis demonstrates that gap filling accuracy may be improved substantially without sacrificing computational simplicity. Improved and standardized techniques for estimation of annual Rsoil will be valuable for understanding the role of Rsoil in the global C cycle.  相似文献   
999.
1000.
Moisture dynamics and fungal susceptibility of plywood   总被引:1,自引:0,他引:1  
Engineered wood products are widely used in construction and transportation. Plywood has one of the best physical and mechanical properties for application under moist conditions in use class 3, i.e. exterior exposure without ground contact. Yet a profound knowledge of their moisture dynamics and fungal susceptibility is a prerequisite for proper use. In this paper the results of more than two years of continuous recording of the moisture content of different plywood types in exterior exposure is presented. Clear differences concerning moisture dynamics are apparent regarding wood species, glue type, and veneer thickness. X-ray tomography scans literally offer insight into the weathering state of the veneer layers and glue lines. Fungal susceptibility of the samples relates primarily to wood species and glue type. Furthermore, edge-sealing for fungal testing is necessary to represent in-service situations and yields distinct differences compared to non-sealed test results. There seems to be a relationship between the accumulated moisture content and layered structure of the plywood, but an unequivocal link with fungal decay is not straightforward.  相似文献   
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