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111.
Simeone JF; Edelman RR; Stark DD; Wittenberg J; White EM; Butch RJ; Mueller PR; Brady TJ; Ferrucci JT Jr 《Radiology》1985,157(2):437-441
Eight healthy volunteers and 11 patients with pancreatic abnormalities were studied using a conventional body coil and a prototype magnetic resonance (MR) surface coil. Final pathologic diagnoses included carcinoma of the head (six), body (one), and tail of the pancreas (two) and chronic pancreatitis (two). In surface coil images of the volunteers, the body and tail of the pancreas was visualized in all cases but one, and the pancreatic duct was seen in five of eight cases. In-plane spatial resolution of 0.9 X 0.9 mm and 5-mm section thickness was obtained. At the same time, pancreatic surface coil images had a twofold improvement in the signal-to-noise ratio (SNR) compared with body coil images. T1-weighted spin-echo images gave greater SNR, reduced motion artifacts, provided superior anatomic detail, and offered more diagnostic information than comparable T2-weighted images. Significant abnormalities detected only by surface coil imaging included a small tumor surrounded by reactive edema and periglandular tumor invasion. This study demonstrates that surface coil imaging of the pancreas not only is feasible but provides an improved method for examining the pancreas by MR. 相似文献
112.
113.
Plasma-derived vitamin D binding protein (DBP) is an important physiologic regulator of the neutrophil chemotactic response to activated complement. A cell-associated form of DBP has been observed in numerous cell types. We now report that mature, circulating human neutrophils also contain cell-associated DBP. Immunofluorescence studies of normal untreated neutrophils showed the presence of DBP on the cell surface. Western blotting of detergent-soluble neutrophil lysates with a polyclonal anti-DBP showed two major immunoreactive bands, one with an apparent molecular weight of 56 Kd (identical to purified plasma-derived DBP) and a second less prominent band at 12 to 14 Kd. Quantitation of the immunoreactive bands by video densitometry indicated that normal human neutrophils contain 1.5 +/- 0.8 ng DBP/10(6) cells (n = 9). Immunoprecipitation of detergent-soluble lysates with the polyclonal anti-DBP showed only the 56-Kd form by Western blotting. In contrast, a monoclonal anti-DBP immunoprecipitated the 12 to 14 Kd form of DBP from lysates of surface-radioiodinated cells. Western blots of subcellular fractions showed that immunoreactive bands were found in the specific (secondary) granule and plasma-membrane fractions. In addition, pretreatment of neutrophils with 10 nmol/L phorbol myristate acetate (PMA) resulted in approximately a 50% reduction in the amount of DBP in both the specific granule and plasma-membrane fractions. Finally, analysis of the cell- free supernates showed that DBP was spontaneously released into the extracellular milieu: moreover, this release was enhanced if the cells were first stimulated with C5a, formyl-norleucyl-leucyl-phenylalanine (fNLP) or PMA. 相似文献
114.
To overcome the problem of recurrence of stenosis after vascular balloon dilatations, we developed an expandable, intraluminal graft that allows dilatation of the lesion and simultaneous placement of a supportive endoprosthesis to prevent recoil of the arterial wall. The graft is made of continuous, woven, stainless steel wire. The resulting tubular mesh has a wall thickness of 200-450 micron and 80% open surface. The grafts, mounted on angioplasty catheters, are introduced through 8-12-F Teflon sheaths. Eleven grafts of 6, 8, and 10 mm in diameter by 20 mm long were placed in the aorta, common carotid, superior mesenteric, iliac, and renal arteries of dogs. Six grafts showed no stenosis in follow-up studies of up to 8 weeks. Two grafts had moderate stenosis as a result of neointimal hyperplasia. Two partial and one complete graft thrombosis occurred in nonheparinized animals in which the graft outflow was restricted. Anticoagulant was not used on a long-term basis. Light and electron microscopy studies showed complete covering of the graft's inner surface by endothelium at 3 weeks. 相似文献
115.
Adrenal abscess in the neonate is a rare complication of adrenal hemorrhage. The radiographic and clinical findings of 12 previously published cases and two new cases of adrenal abscess in the newborn are presented. Sonography was the most helpful examination in distinguishing a suprarenal lesion from an intrarenal lesion and in demonstrating the morphology of the abscess. 相似文献
116.
Anatomy of the perirenal area 总被引:2,自引:0,他引:2
The authors comment on the use of the renal bridging septa as a sign in distinguishing compartmentalization of the perinephric space. They also address new concepts regarding the spread of pancreatic effusions and provide information on other anatomic features of the perirenal area. 相似文献
117.
Edelman RR; McFarland E; Stark DD; Ferrucci JT Jr; Simeone JF; Wismer G; White EM; Rosen BR; Brady TJ 《Radiology》1985,157(2):425-430
Prototype surface coil magnetic resonance (MR) images were obtained from phantoms and 42 subjects at 0.6 T to assess the feasibility of imaging relatively deep abdominal structures. Surface coil images demonstrated a two- to fourfold improvement in signal-to-noise ratio (SNR) when compared with whole-body coil images with the same resolution elements. This improvement in SNR allowed us to obtain images with thinner sections, higher in-plane resolution, or, alternatively, a decrease in image time. Compared with body images, surface coil images demonstrated greater anatomic detail and reduction in motion artifacts. Despite the limited field of view in very large patients, the use of surface coils improves the diagnostic capability of MR imaging of the abdomen. 相似文献
118.
Rahim R. Rizi Sridhar R. Charagundla Hee Kwon Song Ravinder Reddy Alan H. Stolpen Mitchell D. Schnall John S. Leigh 《Journal of magnetic resonance imaging : JMRI》1998,8(5):1090-1096
Detection of H217O with proton T1ρ-dispersion imaging holds promise as a means of quantifying metabolism and blood flow with MRI. However, this technique requires a priori knowledge of the intrinsic T1ρ dispersion of tissue. To investigate these properties, we implemented a T1ρ imaging sequence on a 1.9-T Signa GE scanner. A series of T1ρ images for different locking frequencies and locking durations were obtained from rat brain in vivo and compared with 5 % (wt/vol) gelatin phantoms containing different concentrations of 17O ranging from .037 % (natural abundance) to 2.0 atom%. Results revealed that, although there is considerable T1ρ-dispersion in phantoms doped with H217O, the T1ρ of rat brain undergoes minimal dispersion for spin-locking frequencies between .2 and 1.5 kHz. A small degree of T1ρ dispersion is present below .2 kHz, which we postulate arises from natural-abundance H217O. Moreover, the signal-to-noise ratios of T1ρ-weighted images are significantly better than comparable T2-weighted images, allowing for improved visualization of tissue contrast. We have also demonstrated the feasibility of proton T1ρ-dispersion imaging for detecting intravenous H217O on a live mouse brain. The potential application of this technique to study brain perfusion is discussed. 相似文献
119.
Computed tomography of the normal thymus 总被引:7,自引:0,他引:7
120.