全文获取类型
收费全文 | 37257篇 |
免费 | 1809篇 |
国内免费 | 190篇 |
专业分类
耳鼻咽喉 | 449篇 |
儿科学 | 694篇 |
妇产科学 | 611篇 |
基础医学 | 4854篇 |
口腔科学 | 1259篇 |
临床医学 | 2897篇 |
内科学 | 8953篇 |
皮肤病学 | 944篇 |
神经病学 | 2700篇 |
特种医学 | 1443篇 |
外科学 | 6209篇 |
综合类 | 245篇 |
一般理论 | 2篇 |
预防医学 | 1130篇 |
眼科学 | 580篇 |
药学 | 2493篇 |
中国医学 | 54篇 |
肿瘤学 | 3739篇 |
出版年
2023年 | 203篇 |
2022年 | 450篇 |
2021年 | 806篇 |
2020年 | 389篇 |
2019年 | 544篇 |
2018年 | 798篇 |
2017年 | 573篇 |
2016年 | 646篇 |
2015年 | 723篇 |
2014年 | 916篇 |
2013年 | 1046篇 |
2012年 | 1628篇 |
2011年 | 1793篇 |
2010年 | 976篇 |
2009年 | 873篇 |
2008年 | 1512篇 |
2007年 | 1608篇 |
2006年 | 1638篇 |
2005年 | 1644篇 |
2004年 | 1624篇 |
2003年 | 1563篇 |
2002年 | 1532篇 |
2001年 | 1256篇 |
2000年 | 1417篇 |
1999年 | 1239篇 |
1998年 | 444篇 |
1997年 | 320篇 |
1996年 | 340篇 |
1995年 | 310篇 |
1994年 | 274篇 |
1993年 | 255篇 |
1992年 | 815篇 |
1991年 | 778篇 |
1990年 | 690篇 |
1989年 | 717篇 |
1988年 | 690篇 |
1987年 | 674篇 |
1986年 | 683篇 |
1985年 | 602篇 |
1984年 | 436篇 |
1983年 | 359篇 |
1979年 | 348篇 |
1978年 | 238篇 |
1977年 | 203篇 |
1975年 | 201篇 |
1974年 | 227篇 |
1973年 | 210篇 |
1971年 | 209篇 |
1970年 | 203篇 |
1969年 | 224篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The effect of external gamma-irradiation on the digestive function of rat alveolar macrophages (AM) was studied by using the in vitro assay system, where the 59Fe release from AM engulfing 59Fe-iron hydroxide colloid was measured as an indicator of their digestive capability. Graded doses of gamma-irradiation up to 100 Gy had no effect on the extracellular release of 59Fe in AM cultured at 4 and 37 degrees C for 8-72 hrs postirradiation. When 10 mM Ca-DTPA was added to the culture medium, the 59Fe release was slightly depressed by irradiation at a dose of 30 Gy. It is apparent from these results that gamma-irradiation had no effect on the 59Fe transfer between cell and medium, and little effect on the catabolism of 59Fe-colloid in rat AM. 相似文献
32.
N. Inotsume M. Nishimura M. Nakano S. Fujiyama K. Sagara T. Sato K. Matsushita Y. Imai H. Matsui 《European journal of clinical pharmacology》1990,38(3):313-314
Summary The effect of haemodialysis on the pharmacokinetics of oral famotidine has been studied in five elderly anuric patients. Famotidine 20 mg was administered in a cross-over design to patients on and not on haemodialysis.The elimination rate constant of haemodialysis (k) was 4.6-fold larger than the systemic elimination rate constant (ke). Although the mean maximum serum concentration of famotidine during haemodialysis (141.5 ng·ml–1) was not significantly lower than that without haemodialysis (195.6 ng·ml–1), the AUC up to 5 h during haemodialysis was significantly decreased to 58.1% of the value without it.The data suggest that famotidine is dialysable by haemodialysis. 相似文献
33.
Spontaneous photon emission (chemiluminescence, CL) as a monitor of free radical evolution in Drosophila melanogaster which had been maintained at 25 or 30 degrees C for 5 days after emergence was measured. When maintained at 30 degrees C the fly CL intensity was stronger than at 25 degrees C. Under the condition of the higher temperature, the fly life span was shorter (mean life span = 29 days at 30 degrees C and 63 days at 25 degrees C), and oxygen consumption (3.7 microliters/mg.h at 25 degrees C, 4.9 microliters/mg.h at 30 degrees C) and the mobility (movement distance = 25 mm/min at 25 degrees C, 700 mm/min at 30 degrees C) increased, together with augmentation of phospholipid hydroperoxide in the fly total lipids. The CL spontaneously emitted from fly homogenate was decreased by the free radical scavengers both in experiments in vivo and in vitro. The hypothesis is proposed that as the oxygen metabolism grows active, the chemiluminescent reactions that involve oxygen-dependent free radical metabolism, including membrane phospholipid hydroperoxidation, contribute to the acceleration of senescence of fly bodies. 相似文献
34.
Because of the lack of adequate strength and toughness, hydroxyapatite (HA) ceramic can not be used for a substitute for a bone and joint despite its excellent affinity for the bone. The present authors have succeeded in producing a new type of HA ceramic containing zirconia. This new ceramic material is superior to ordinary HA ceramic in quality and exceeds compact bone in bending strength and fracture toughness. The Young's modulus was about 3-4 times greater than that of compact bone. The new ceramic material contained either 1.6 or 50% of zirconia by volume and was produced using a special technique to disperse the metal dioxide. In order to assess their affinity for the bone, the new ceramic materials were implanted into rabbit femurs. Sections of the bones removed at different times after operation were prepared without decalcification and subjected to optical microscopy, scanning electronmicroscopy (SEM), and electron-probe X-ray microanalyser (EPMA). The formation of direct chemical bonds with the bone was seen without intervening membrane. Thus, the new ceramic material was shown to have an excellent affinity for the bone, comparable to that of ordinary HA ceramic. 相似文献
35.
36.
HTLV-I seroprevalence in patients with malignancy 总被引:5,自引:0,他引:5
N Asou T Kumagai S Uekihara M Ishii M Sato K Sakai H Nishimura K Yamaguchi K Takatsuki 《Cancer》1986,58(4):903-907
Since many malignancies often occur in patients with smoldering type adult T-cell leukemia (ATL) (5 of 18 cases in this report), the relationship between HTLV-I (human T-cell leukemia virus type I) infection, which is closely associated with ATL, with other malignancies in an HTLV-I endemic area was examined. Among the 394 patients with malignancies and who had not had blood cell transfusions, 61 (15.5%) tested positive for HTLV-I antibody. The prevalence was significantly higher in males older than age 40 years and females of all ages compared to age- and sex-matched healthy individuals. The overall seroprevalence (26.1%) in 291 patients with malignancies and who had had blood cell transfusions was higher than that of those who had not had blood transfusions. There was no significant correlation between the site of malignancy and antibody prevalence. These results suggest the possibility that development of malignancy may contribute to expression of latent HTLV-I infection and that HTLV-I infection may contribute to the risk of other malignancies. 相似文献
37.
Hiroki Sato Atsushi Watanabe Tamotsu Yamaguchi Nobuhiro Harada Akihiko Yamauchi Satomi Inoue Tomio Abe 《Annals of thoracic and cardiovascular surgery》2005,11(1):41-43
Intralobar pulmonary sequestration associated with asymptomatic aspergillosis is a rare case. We describe the case of a 65-year-old woman with intrapulmonary sequestration, anomalous systemic arterial supply to the left lower lobe and aspergillosis who underwent left lower lobectomy and ligation of an anomalous artery by Video-Assisted Thoracoscopic surgery (VATS). Pathological examination showed the parenchymal distortion and chronic inflammation. Aspergillus were found in the cyst. VATS lobectomy for intralobar pulmonary sequestration is a safe and valid procedure. 相似文献
38.
Yukako Sato Masahiko Aoyama Tomoko Soeda Akihiko Hoshi Mari Honma Teiji Yamamoto 《Clinical neurology》2004,44(8):527-530
A 65-year-old woman with diabetes mellitus and chronic otitis media developed headache, fever, and hoarseness, all of which did not responded to the oral antibiotics. As stiff neck and lower cranial nerve palsies appeared, bacterial meningitis was suspected. Neurological examination revealed the right hearing disturbance, right recurrent laryngeal nerve palsy, left sternocleidomastoid muscle atrophy and bilateral tongue atrophy. The CSF examination revealed mild pleocytosis and elevated protein, but no bacterial organism was cultured from the CSF. CT scans showed bilateral mastoiditis, and the right mastoid process and a posterior part of the petrous bone were eroded, indicating the exposed bony structures to the posterior fossa. MRI scans demonstrated the thickening of the dura mater of the posterior fossa and the right cerebellar tentorium. This is a rare example of bacterial pachymeningitis of the posterior fossa, the clinical symptoms and MRI findings of which resolved solely by antimicrobial agents without corticosteroid. 相似文献
39.
A case of generalized eruptive histiocytoma (GEH) was evaluated and examined histopathologically and ultrastructurally. A 24-year-old male had an episode of high fever and drug-induced eruption prior to the appearance of multiple skin lesions. Uniform, red to dark-red papular lesions appeared on his cheeks and then became generalized. The lesions were composed of a massive dermal infiltrate of histiocytes, which had oval nuclei and amphophilic cytoplasm. The cytoplasm contained unique annular structures, myeloid bodies and vacuoles. The specificity of these structures is as yet unknown. Reactive stimulation rather than neoplastic proliferation may be a causative factor in GEH. 相似文献
40.
Hidemi Yamauchi MD Kikuo Miyagawa Masamitsu Maeda Seiki Matsuno Toshio Sato 《Surgery today》1986,16(1):8-15
The findings in twenty-two patients with insulinoma were reviewed, as continuous efforts should be made to establish preoperative
localization of the tumor. Superselective arteriography and percutaneous, transhepatic portal vein and pancreatic venous catheterization
are highly recommended approaches. At the time of surgical intervention, a cautious exploration of the pancreas after thorough
mobilization is most important. Recent use of intraoperative ultrasonography increases the likelihood of finding these occult
tumors which locate deeply in the head of the pancreas. Apart from the diagnostic problems, we wish to emphasize the high
incidence of malignancy (7/22, 31.8 per cent) in our series. Althout patients with malignant isulinoma had a much better prognosis
compared to those with a pancreatic ductal malignancy, pancreatic resection with regional lymphnode dissection seems to be
a rational procedure. Enucleation can be done when intraoperative findings of the tumor and regional lymphonode indicate no
malignant features and no multiple lesions. However, at the first operation, enucleation is still a procedure of choice, even
for the malignant insulinoma in the head with a well-defined capsule and no metastatic lesions, the objective being to avoid
a duodenopancreatectomy or total pancreatectomy.
These data were reported at the 30th Congress of Société Internationale de Chirurgie, Hamburg, Germany, 1983 相似文献