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51.
Burn depth assessment by dual-wavelength light emitting diodes-excited photoacoustic imaging in rats
Yasuyuki Tsunoi PhD Naoto Sato BE Izumi Nishidate PhD Fumiyuki Ichihashi PhD Daizoh Saitoh MD PhD Shunichi Sato PhD 《Wound repair and regeneration》2023,31(1):69-76
Accurate burn depth assessment is crucial to determine treatment plans for burn patients. We have previously proposed a method for performing burn depth assessments based on photoacoustic (PA) imaging, and we have demonstrated the validity of this method, which allows the successful detection of PA signals originating from the blood under the bloodless burned tissue, using rat burn models. Based on these findings, we started a clinical study in which we faced two technical issues: (1) When the burn depth was shallow, PA signals due to skin contamination and/or melanin in the epidermis (surface signals) could not be distinguished from PA signals originating from the blood in the dermis; (2) the size of the system was too large. To solve these issues, we propose a burn depth diagnosis based on dual-wavelength light emitting diodes (LEDs)-excited PA imaging. The use of LEDs rendered the system compact compared to the previous one that used a conventional solid-state laser. We replicated human burned skin by applying a titrated synthetic melanin solution onto the wound surface in albino rat burn models and measured their burn depths by PA excitation at 690 and 850 nm, where melanin and haemoglobin show greatly different absorption coefficients. As a result, the surface signals were eliminated by subtracting the PA signals at 690 nm from those at 850 nm. The resultant estimated burn depths were strongly correlated with the histological assessment results. The validity of the proposed method was also examined using a burn model of rats with real melanin. 相似文献
52.
Mohamed Oukka Patrice Andre Pascale Tunnel Nelly Besnard Veronique Angevin Lars Karlsson Phuong L. Trans Dominique Charron Bernard Bihain Kostadinos Kosmatopoulos Vincent Lotteau 《European journal of immunology》1997,27(4):855-859
Major histocompatibility complex (MHC) restriction of the immune response is established during positive selection of T cells in the thymus. This occurs mainly through interactions of T cell receptor of developing thymocytes with MHC/peptide ligands on cortical thymic epithelial cells (TEC). An ongoing controversy concerns the origin and the role of peptides involved in the positive selection of thymocytes. Evidence provided here shows that processing of MHC class II complexes in cortical TEC differs from that of medullary TEC. Removal of the invariant chain associated with MHC class II complexes was rapid and complete in medullary TEC which present peptides from both exogenous and cytosolic origin. In cortical TEC, a large fraction of class II dimers remained associated with a 10–12-kDa fragment of invariant chain (Ii). Incomplete removal of Ii correlated with the inability of cortical TEC to present peptides from exogenous origin. However, presentation of peptides from cytosolic proteins by cortical TEC remained possible. Thus, most peptides from exogenous proteins may be excluded from participating in positive selection of CD4+ T cells by a mechanism limiting Ii breakdown. 相似文献
53.
New dynamic particle image velocimetry (PIV) technology was applied to the study of the flow field associated with prosthetic
heart valves. Four bileaflet prostheses, the St. Jude Medical (SJM) valve, the On-X valve with straight leaflets, the Jyros
(JR) valve, and the Edwards MIRA (MIRA) valve with curved leaflets, were tested in the mitral position under pulsatile flow
conditions to find the effect of the leaflet shape and overall valve design on the flow field, particularly in terms of the
turbulent stress distribution, which may influence hemolysis, platelet activation, and thrombus formation. Comparison of the
time-resolved flow fields associated with the opening, accelerating, peak, and closing phases of the diastolic flow revealed
the effects of the leaflet shape and overall valve design on the flow field. Anatomically and antianatomically oriented bileaflet
valves were also compared in the mitral position to study the effects of the orientation on the downstream flow field. The
experimental program used a dynamic PIV system utilizing a high-speed, high-resolution video camera to map the true time-resolved
velocity field inside the simulated ventricle. Based on the experimental data, the following general conclusions can be made.
High-resolution dynamic PIV can capture true chronological changes in the velocity and turbulence fields. In the vertical
measuring plane that passes the centers of both the aortic and mitral valves (A-A section), bileaflet valves show clear and
simple circulatory flow patterns when the valve is installed in the antianatomical orientation. The SJM, the On-X, and the
MIRA valves maintain a relatively high velocity through the central orifice. The curved leaflets of the JR valve generate
higher velocities with a divergent flow during the accelerating and peak flow phases when the valve is installed in the anatomical
orientation. In the velocity field directly below the mitral valve and normal to the previous measuring plane (B-B section),
where characteristic differences in valve design on the three-dimensional flow should be visible, the symmetrical divergent
nature of the flow generated by the two inclined half-disks installed in the antianatomical orientation was evident. The SJM
valve, with a central downward flow near the valve, is contrasted with the JR valve, which has a peripherally strong downward
circulation with higher turbulent stresses. The On-X valve has a strong central downward flow attributable to its large opening
angle and flared inlet shape. The MIRA valve also has a relatively strong downward central flow. The MIRA valve, however,
diverts the flow three-dimensionally due to its peripherally curved leaflets. 相似文献
54.
Mary Gwo-Shu Lee Frances T. Yen Yuhong Zhang Bernard E. Bihain 《Molecular and biochemical parasitology》1999,100(2):117-162
The procyclic form of Trypanosoma brucei binds and internalizes bovine high density lipoprotein (HDL) particles in a saturable process; the binding and uptake of 125I-labeled HDL are inhibited by excess unlabeled HDL. We calculated that each procyclic trypanosome exposes ≈1.0×106 binding sites for bovine HDL, with an equilibrium dissociation constant (Kd) of ≈1.26×10−7 M. Uptake of HDL particles does not occur at 4°C. At 28°C, a significant amount of the internalized HDL particles were efficiently degraded through a process that is sensitive to the presence of 50 μM chloroquine. These results suggested that the uptake of HDL particles in procyclic T. brucei may occur via receptor mediated endocytosis, leading to proteolytic degradation of the particles in an acidic and endocytic compartment. 相似文献
55.
Wei Lv PhD Tao Chen ME Yifan Zeng BE Weihong Liu BE Chuying Huang BE 《Journal of Cosmetic Dermatology》2023,22(9):2565-2578
Background
Deep-learning object detection has been applied in various industries, including healthcare, to address hair loss.Methods
In this paper, YOLOv5 object detection algorithm was used to detect hair follicles in a small and specific image dataset collected using a specialized camera on the scalp of individuals with different ages, regions, and genders. The performance of YOLOv5 was compared with other popular object detection models.Results
YOLOv5 performed well in the detection of hair follicles, and the follicles were classified into five classes based on the number of hairs and the type of hair contained. In single-class object detection experiments, a smaller batch size and the smallest YOLOv5s model achieved the best results, with an map of 0.8151. In multiclass object detection experiments, the larger YOLOv5l model was able to achieve the best results, and batch size affected the result of model training.Conclusion
YOLOv5 is a promising algorithm for detecting hair follicles in a small and specific image dataset, and its performance is comparable to other popular object detection models. However, the challenges of small-scale data and sample imbalance need to be addressed to improve the performance of target detection algorithms. 相似文献56.
Yongheon Kim BE Hyunseon Yu MS Sunghwan An MD Donghoon Ha BE Byungjo Jung PhD 《Journal of Cosmetic Dermatology》2023,22(11):2982-2988
Objective
Although focused ultrasound modalities have achieved positive clinical results in noninvasive skin rejuvenation, they presented various side effects and particularly severe pain during treatment. This study introduces a microfocused ultrasound (MFU) device, ULTIGHT, to overcome the severe pain issue, providing quasi-facial lifting.Materials and Methods
Transducer surface was imaged with a scanning electron microscope. The energies of four treatment cartridges were measured using an ultrasound power meter. In vitro experiments were performed to quantitatively evaluate the MFU thermal zones (MFUTZs) and treatment line (TL) of 10 MFUTZs. Ex vivo experiments were performed to evaluate the MFUTZs and temperature rise in tissue. Clinical trials using eight volunteers were performed to qualitatively evaluate facial lifting.Results
The MFU transducer clearly showed a smooth and no air gap surface. ULTIGHT produced 10 discrete MFUTZs in a TL of length 10 mm. In ex vivo tissue, discrete linear MFUTZs were clearly observed at lower number of TLs; however, they started to aggregate at higher number of TLs. The temperature rise was linearly increased as a function of the number of treatments. A single MFUTZ resulted in a temperature rise of 3°C–10°C that could cause hyperthermia for body temperature. In the clinical trials, the volunteers showed quasi-facial lifting right after treatment on the lower facial region.Conclusions
ULTIGHT provides relatively low energy, which may be advantageous or disadvantageous depending on clinical applications. Additionally, it has the advantage of being pain-free even without anesthetic during treatment, providing quasi-facial lifting right after treatment. 相似文献57.
58.
Role of nitric oxide in regulation of coronary blood flow during myocardial ischemia in dogs 总被引:6,自引:0,他引:6
Masafumi Kitakaze Md Koichi Node MD Tetsuo Minamino MD Hiroaki Kosaka MD Yoshiro Shinozaki BE Hidezo Mori MD Michitoshi Inoue MD Masatsugu Hori MD Takenobu Kamada MD 《Journal of the American College of Cardiology》1996,27(7):1804-1812
Objectives. This study was undertaken to examine whether nitric oxide released in ischemic myocardium decreases the coronary vascular resistance and attenuates the severity of contractile and metabolic dysfunction.Background. Endothelium-derived relaxing factor, recently identified as nitric oxide, is a potent relaxant of coronary smooth muscle.Methods. The left anrterior descending coronary artery was perfused through an extracorporeal bypass tube placed in the carotid artery in 56 open chest dogs. After hemodynamic stabilization, we occluded this bypass tube to decrease coronary blood flow to one third of the control flow. Thereafter, we maintained a constant coronary perfusion pressure(40.9 ± 3.1mm Hg).Results. Under ischemic conditions, the coronary arteriovenous differences in nitrate and nitrite (end products of nitric oxide) increased (from 3.5 ± 0.4 [mean ± SEM] to 12.9 ± 2.1 μmol/liter, p < 0.01).
0-Monomethyl
-arginine (3 μg/kg body weight per min, intracoronary) decreased the coronary arteriovenous differences in nitrate and nitrite (5.0 ± 0.9 μmol/liter, p < 0.05) and coronary blood flow (from 29.8 ± 0.5 to 18.1 ± 1.1 ml/100 g per min, p < 0.001). Fractional shortening (from 3.7 ± 1.0 to −1.3 ± 0.7%, p < 0.001) and lactate extraction ration (from −44.0 ± 4.1 to −59.2 ± 4.9%, p < 0.005) of the perfused area also decreased. These values were restored by the concomitant administration of
-arginine. Blood flow to the endomyocardium was decreased relative to the epimyocardium. A reduction in coronary blood flow and worsening of myocardial contractile and metabolic functions due to the administration of
G-monomethyl
-arginine during ischemia were observed in denervated hearts. A reduction in coronary blood flow in ischemic myocardium was observed with the administration of
W-nitro-
-arginene methyl ester as well, although neither
W-nitro-
-arginine methyl ester nor
G-monomethyl
-arginine changed coronary blood flow and myocardial contractile and metabolic functions in the nonischemic myocardium. The cyclic guanosine monophosphate content of epicardial coronary artery increased due to myocardial ischemia; this increased was attenuated with
G-monomethyl
-arginine treatment.Conclusions. We conclude that endogenous nitric oxide predominantly decreases the coronary vascular resistance of ischemic endomyocardium, thereby improving myocardial contractility and metabolic function. 相似文献
59.
Impact of Insurance Provider on Overall Costs in Failed Back Surgery Syndrome: A Cost Study of 122,827 Patients 下载免费PDF全文
60.
The Influence of Skin Redness on Blinding in Transcranial Direct Current Stimulation Studies: A Crossover Trial 下载免费PDF全文