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61.
Gliomatosis cerebri with good prognosis 总被引:4,自引:0,他引:4
Seiji Kannuki Hideki Hondo Kunio Ii Takanori Hirose Keizo Matsumoto 《Brain tumor pathology》1997,14(1):53-57
A 52-year-old man was admitted to our clinic with severe headache and bilateral papilledema. Magnetic resonance (MR) images
on admission demonstrated diffuse swelling of the cerebral cortex without formation of a tumor mass. Biopsy revealed diffuse
infiltration with neoplastic glial cells. After radiation and chemotherapy, the MR images returned to normal. The morphological
and neurological features of the present case met the criteria for gliomatosis cerebri. However, this patient showed an unusually
good response to radiation and chemotherapy. 相似文献
62.
核素显像对小儿消化道出血的病因诊断 总被引:5,自引:0,他引:5
目的探讨核素显像对小儿消化道出血,特别是对Meckel憩室、肠重复畸形的病因诊断的价值。方法对26例腹痛、便血为主要症状的患儿行99m锝酸盐(99mTcO-4)显像,其中12例显像阴性者于检查后24小时有活动性出血者,再行99m锝标记红细胞显像。所有病例的诊断均经手术、病理及内窥镜等检查所证实。结果99mTcO-4显像诊断Meckel憩室和肠重复畸形的敏感性、特异性、准确性分别为85.7%(12/14)、91.7%(11/12)及88.5%(23/26)。结论核素显像具有无创、方法简单易行等特点,特别是对异位胃粘膜诊断具有较好的灵敏性和特异性。核素显像可作为下消化道出血病因诊断的有效方法。 相似文献
63.
Khema R. Sharma Jane Kent-Braun Mark A. Mynhier Michael W. Weiner Robert G. Miller 《Muscle & nerve》1995,18(12):1403-1411
The goals of this study were to investigate muscle fatigue in patients with multiple sclerosis (MS), and to determine the relationships between muscle fatigue, clinical status, and perceived fatigue. The fatigability of the anterior tibial muscle was quantitated in patients and controls during 9 min of intermittent stimulation (used to eliminate central sources of muscle fatigue). During exercise, the decline in tetanic force, phosphocreatine, and intracellular pH was greater in patients than in controls. The compound muscle action potential amplitude did not decrease during exercise, indicating that there was no failure of neuromuscular transmission during fatigue. Thus, the excessive fatigue in MS developed from sources beyond the muscle membrane. Following exercise, the recovery of tetanic force was delayed in patients (a pattern that suggests abnormal excitation–contraction coupling), whereas the recovery of metabolites was complete in both groups. Muscular fatigue was correlated with clinical disability but not with perceived fatigue. These results suggests that fatigue in MS has both central (perception, upper motor neuron dysfunction) and peripheral (impaired metabolism and excitation–contraction coupling) components.© 1995 John Wiley &Sons, Inc. 相似文献
64.
Juhani Trmnen Osmo Tervonen Antero Koivula Juhani Junila Ilkka Suramo 《Journal of magnetic resonance imaging : JMRI》1996,6(5):805-811
The purpose of this study was to explore systematically the effect of the imaging parameters changeable by the user in spin-echo (SE) imaging sequences to minimize image distortion when imaging joint prostheses. A titanium alloy hip joint prosthesis was studied at 1.0 T. The SE imaging parameters were bandwidth/pixel (BW/p), TE, strength of encoding gradients (matrix size), echo train length (ETL), and direction of phase and frequency encoding. The effect of ETL in rapid acquisition relaxation enhanced (RARE) sequences was also evaluated with a turbo-SE sequence using a different ETL with the same TR and an effective TE. It is concluded that an optimized image quality can be achieved in SE imaging by using a high bandwidth/pixel value (at least 130 Hz/pixel), a high resolution matrix (256–512), sequences with multiple refocusing, and a frequency-encoding axis parallel to the long axis of the prosthesis. The degree of distortion is reduced with this optimized technique. 相似文献
65.
A case of MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) which presented as migraine
complicated by stroke is reported. Strokes associated with migraine have often been reported, but the mechanism remains unclear
and may include a variety of pathologies. MELAS also presents with migrainous headache, vomiting, and stroke-like symptoms.
Magnetic resonance imaging demonstrates characteristic findings. MELAS should be considered in the differential diagnosis
of infarct-like lesions with migrainous headaches in young adults, especially if the symptoms fluctuate and are accompanied
by a homonymous hemianopia.
Received: 23 September 1996 Accepted: 19 February 1997 相似文献
66.
We correlated MRI features with histopathological findings in an HIV-positive patient with vacuolar myelopathy. On MRI symmetrical
nonenhancing high-signal areas in the posterior columns on T2-weighted images result from extensive vacuolation visible on
histological sections.
Received: 18 November 1997 Accepted: 23 March 1997 相似文献
67.
A. Rimmelin P. L. Clouet S. Salatino P. Kehrli D. Maitrot M. Stephan J. L. Dietemann 《Neuroradiology》1997,39(3):203-206
Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal which may communicate with the subarachnoid
space. Usually in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report
cases of thoracic and lumbar arachnoid cysts studied by cystography, myelography, CT and MRI. These techniques showed extradural
cystic lesions containing cerebrospinal fluid, with variable communication with the subarachnoid space, causing anterior displacement
and flattening of the spinal cord.
Received: 3 November 1995 Accepted: 16 April 1996 相似文献
68.
Neurosarcoma is a rare tumour originating from the sheath of peripheral nerves. Facial lesions have been reported in about
20 patients. We describe the MRI appearances of neurosarcoma with histological correlation in three patients. The lesions
lay in the submandibular region, the left parapharyngeal space and the right orbit. MRI showed a well-defined mass with mixed
components. The lesions were moderately heterogeneous on T1-weighted images in two cases and on T2-weighted images in all
cases. Gadolinium enhancement occurred in all cases to variable degrees. In two cases, small high signal foci were seen on
T2-weighted sequences. MRI appearances of neurosarcoma are not specific.
Received: 3 September 1996 Accepted: 26 November 1996 相似文献
69.
H. Bonél A. Frick H. Sittek A. Heuck M. Steinborn R. G. H. Baumeister M. Reiser 《Der Radiologe》1997,37(10):785-793
Summary
Purpose of this study was to evaluate the diagnostic value of a low field dedicated MRI system in hand and wrist imaging.
All 308 exams of the hand and wrist, that were performed on a low-field dedicated MRI system (Artoscan, Esaote Biomedica,
Italy) in our institution in 1996, and high-field MRI exams performed in addition as part of the diagnostic work-up, were
evaluated and correlated to final operative (n = 64) and histologic (n = 12) reports. 90 % of all low-field MRI scans stated a diagnosis according to clinical suspicion. In 62 % the clinical question
was answered, and in 26 % additional pathologies were identified. An MR-diagnosis completely different from the clinical suspicion
was stated in 2 %. High field exams contributed additional information in 6 of 36 patients. In 3 patients a tumor was not
shown completely in the limited field-of-view of the dedicated low-field MRI-system. Frequency-selective fat-suppression pulse
sequences and a better spatial resolution were the reasons for the additional information obtained in the other three patients.
Low-field dedicated MR-imaging is a valuable method in the extensive work-up of the hand and wrist. Osseous, ligamentous and
tendinous pathologies are well depicted. Large or infiltrative tumors should be referred to a high-field system.
相似文献
70.
Summary
High-resolution computed tomography (HRCT) provides excellent contrast between osseous structures, air and soft tissue in
conjunction with high spatial resolution. Therefore, thin-section HRCT with bone window setting is the method of choice for
the examination of the middle ear structures. The indications are acute and chronic inflammatory changes, cholesteatoma and
tumor, the “postoperative middle ear”, and malformations. In most cases, HRCT enables differentiation between inflammatory
changes, cholesteatoma, and tumor. The excellent depiction of subtle osseous details enables the identification of erosions
of the ossicles or of the bony walls of the mastoid cells, of osseous defects of the tegmen, of the bony labyrinth, and of
the tympanic course of the facial canal. In addition, HRCT enables excellent depiction of reconstructions of the ossicles
or prosthesis of the ossicles. Although HRCT is the first method of choice, magnetic resonance imaging (MRI) may provide additional
information and lead to a more accurate diagnosis in some cases. This is explained by the excellent soft tissue contrast provided
by MRI. In addition, MRI offers the possibility of using various pulse sequences and the administration of IV contrast material.
Therefore, MRI may allow the differentiation between inflammatory changes, cholesteatoma, and tumor in those cases in which
accurate diagnosis cannot be made by HRCT. The differentiation between a meningocele or meningoencephalocele and other entities
such as tumors or cholesteatoma can be established by MRI. Furthermore, MRI can accurately depict cases of labyrinthitis or
of neuritis of the facial nerve or of intracranial disease caused by middle ear processes, while this is not always possible
by HRCT.
In summary, HRCT of the middle ear is the method of choice, but MRI may provide supplementary information in those cases in
which accurate diagnosis cannot be established by HRCT.
相似文献