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The identification of small numbers of leukemic cells in the cerebrospinal fluid (CSF) presents a diagnostic problem in the treatment of children with acute lymphoblastic leukemia (ALL). We adapted a latex sphere rosetting technique to allow us to identify simultaneously cell surface markers and cell morphology in 199 CSF samples from 34 patients and 14 control subjects. In patients without leukemic meningitis, the majority of CSF lymphocytes (69%) were found to be mature T cells positive for OKT11. A much smaller number of cells (8%) were found to be B cells positive for la. In these children, only 3% of CSF lymphoid cells expressed the common acute lymphoblastic leukemia antigen (CALLA). Similar results were found in the control subjects. By contrast, 28 CSF samples from nine children with varying numbers of CSF lymphoblasts had much greater proportions of CALLA- and la-positive CSF cells (24% to 96%). Leukemic meningitis was present in one of these patients and later developed in four others. However, three patients with small numbers of lymphoblasts present but with low proportions of CALLA-positive CSF cells (less than 5%) subsequently had normal CSF examinations. We found the use of this rosetting technique valuable in providing information complementary to that obtained from cell morphology alone about the possible malignant nature of small numbers of lymphoblast-like CSF cells seen on cytocentrifuge preparations in children with ALL. 相似文献
44.
Optical imaging and electrophysiology of rat barrel cortex. I. Responses to small single-vibrissa deflections 总被引:2,自引:2,他引:0
A study was undertaken to investigate the response of the rodent
somatosensory barrel cortex to single-whisker, near-threshold vibrissal
stimuli. Cortical responses to controlled whisker deflections were recorded
by (i) conventional multi-unit extracellular recording within the
cytochrome oxidase rich barrels centers and the interbarrel septa, and (ii)
intrinsic signal optical imaging, a technique that provides a spatial view
of cortical activation thought to be related to the deoxygenation of
hemoglobin in activated areas. Barrel cortex neurons responded weakly to
whisker deflections of 0.04 degrees. Their response to a series of small
stimuli of increasing amplitude was well-fitted by a logarithmic function.
Responses to larger stimuli declined monotonically with distance from the
center of the barrel column, and were characterized by greater onset and
offset firing rates, by greater post-excitatory reduction of firing to
below spontaneous levels, and by shorter response latency. In comparison to
measurements taken previously from primary vibrissal afferent fibers, we
conclude that cortical cells can respond to activity in a very small
fraction of first-order sensory neurons.
相似文献
45.
Maturo VG; Zusmer NR; Gilson AJ; Smoak WM; Janowitz WR; Bear BE; Goddard J; Dick DE 《Radiology》1980,137(2):457-463
Innovations in design of a dedicated breast scanner resulted in automation of the scanning process, the production of high resolution images of the whole breast and an efficient mode of image review. The results of clinical evaluation of the prototype of this breast scanner investigating normal breasts as well as benign and malignant breast lesions are presented. 相似文献
46.
Rajasekaran S Thapar V Dave H Huang CH 《Journal of clinical monitoring and computing》2005,19(4-5):351-359
Multiple sequence alignment (MSA) is a vital problem in biology. Optimal alignment of multiple sequences becomes impractical
even for a modest number of sequences [1] since the general version of the problem is NP-hard. Because of the high time complexity
of traditional MSA algorithms, even today's fast computers are not able to solve the problem for large number of sequences.
In this paper we present a randomized algorithm to calculate distance matrices, which is a major step in many multiple sequence
alignment algorithms. The basic idea employed is sampling (along the lines of [2]). We also illustrate how to parallelize
this algorithm.
In Section 1 we introduce the problem of multiple sequence alignments. In Section 2 we provide a discussion on various methods
that have been employed in the literature for Multiple Sequence Alignment. In this section we also introduce our new sampling
approach. We extend our randomized algorithm to the case of non-uniform length sequences as well. We show that our algorithms
are amenable to parallelism in Section 3. In Section 4 we back up our claim of speedup and accuracy with empirical data and
examples. In Section 5 we provide some concluding remarks. 相似文献
47.
48.
AAEM Van Alfen‐van der Velden C Noordam BE De Galan JJG Hoorweg‐Nijman PG Voorhoeve C Westerlaken 《Pediatric diabetes》2010,11(6):380-382
van Alfen‐van der Velden AAEM, Noordam C, de Galan BE, Hoorweg‐Nijman JJG, Voorhoeve PG, Westerlaken C. Successful treatment of severe subcutaneous insulin resistance with inhaled insulin therapy. The potential of inhaled insulin therapy for severe resistance to subcutaneous insulin was tested in a 7‐yr old boy with type 1 diabetes mellitus. The efficiency of 1 mg inhaled insulin (Exubera®) was examined by a 4‐h euglycemic clamp study. During the clamp, the glucose infusion rate started to increase 25 min after inhalation and peaked 120 min after inhalation. Subsequently, a trial of inhaled insulin monotherapy was initiated consisting of pre‐meal inhalations and one inhalation during the night. Since glycemic control remained fair (HbA1c ~8.5%), this therapy was continued. Over the ensuing 18 months, mild keto‐acidosis occurred twice during gastro‐enteritis. Inhaled insulin was well tolerated and pulmonary function did not deteriorate. We conclude that severe resistance to subcutaneous insulin does not preclude sufficient absorption of insulin delivered by pulmonary. 相似文献
49.
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
50.
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