全文获取类型
收费全文 | 18540篇 |
免费 | 827篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 212篇 |
儿科学 | 494篇 |
妇产科学 | 164篇 |
基础医学 | 2220篇 |
口腔科学 | 644篇 |
临床医学 | 1082篇 |
内科学 | 4689篇 |
皮肤病学 | 284篇 |
神经病学 | 1355篇 |
特种医学 | 839篇 |
外科学 | 3320篇 |
综合类 | 90篇 |
预防医学 | 495篇 |
眼科学 | 429篇 |
药学 | 1092篇 |
中国医学 | 29篇 |
肿瘤学 | 2005篇 |
出版年
2023年 | 86篇 |
2022年 | 159篇 |
2021年 | 300篇 |
2020年 | 159篇 |
2019年 | 224篇 |
2018年 | 307篇 |
2017年 | 287篇 |
2016年 | 325篇 |
2015年 | 327篇 |
2014年 | 449篇 |
2013年 | 587篇 |
2012年 | 866篇 |
2011年 | 1014篇 |
2010年 | 586篇 |
2009年 | 560篇 |
2008年 | 943篇 |
2007年 | 1015篇 |
2006年 | 1039篇 |
2005年 | 985篇 |
2004年 | 1009篇 |
2003年 | 967篇 |
2002年 | 943篇 |
2001年 | 457篇 |
2000年 | 449篇 |
1999年 | 504篇 |
1998年 | 287篇 |
1997年 | 232篇 |
1996年 | 232篇 |
1995年 | 190篇 |
1994年 | 176篇 |
1993年 | 181篇 |
1992年 | 326篇 |
1991年 | 290篇 |
1990年 | 290篇 |
1989年 | 322篇 |
1988年 | 245篇 |
1987年 | 230篇 |
1986年 | 233篇 |
1985年 | 206篇 |
1984年 | 175篇 |
1983年 | 142篇 |
1982年 | 103篇 |
1981年 | 89篇 |
1980年 | 65篇 |
1979年 | 93篇 |
1978年 | 75篇 |
1977年 | 63篇 |
1975年 | 58篇 |
1974年 | 63篇 |
1973年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Resolution of homonymous visual field loss documented with functional magnetic resonance and diffusion tensor imaging. 总被引:5,自引:0,他引:5
Masaki Yoshida Masahiro Ida Thien Huong Nguyen Marie-Therese Iba-Zizen Luc Bellinger Jean Louis Stievenart Takehiko Nagao Shinsuke Kikuchi Takaaki Hara Takuya Shiba Kenji Kitahara Emmanuel Alain Cabanis 《Journal of neuro-ophthalmology》2006,26(1):11-17
A 68-year-old man developed right homonymous hemianopic paracentral scotomas from acute infarction of the left extrastriate area. He was studied over the ensuing 12 months with visual fields, conventional MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI). As the visual field defect became smaller, fMRI demonstrated progressively larger areas of cortical activation. DTI initially showed that the lesioned posterior optic radiations were completely interrupted. This interruption lessened in time and had disappeared by one year after onset. fMRI and DTI are innovative measures to follow functional and structural recovery in the central nervous system. This is the first reported application of these imaging techniques to acute cerebral visual field disorders. 相似文献
22.
Kazuo Yamakawa Masashi Takanashi Masao Watanabe Noriyuki Nakamura Tomonori Kobayashi Masato Hasegawa Yoshikuni Mizuno Shigeki Tanaka Hideo Mori 《Neuropathology》2006,26(6):586-591
We report on a male patient with Pick disease who had shown severe white matter atrophy and dilatation of the lateral ventricle in the frontal lobe from an early stage. Upon admission to our hospital 2 years after disease onset, the patient showed apathy, and MRI revealed severe atrophy of the cortex and white matter of the frontal lobe. He died at age 74, 11 years after disease onset. Autopsy revealed severe atrophy of the frontal and temporal lobes, severe loss of white matter in the frontal lobe, dilatation of the lateral ventricles, and cortical thinning. Histopathological examination showed severe loss of myelinated fibers in the frontal white matter and severe neuronal loss with gliosis in the frontal and temporal cortices. Many Pick bodies were seen. Our patient had a rare case of Pick disease predominantly affecting the frontal lobe with severe involvement of the white matter from an early stage. This case suggests that myelinated fibers in the white matter as well as cerebral neurons are primarily affected in Pick disease. 相似文献
23.
Kazuhiko Kyoshima Susumu Oikawa Miki Kanaji Hideo Zenisaka Takeomi Takizawa Tetsuya Goto Hisayoshi Takasawa Atsushi Watanabe Kazuo Tokushige Keiichi Sakai 《Journal of clinical neuroscience》2003,10(5):571-578
Some chordomas have a very poor prognosis because of their aggressive growth nature, but the efficacy of repeat operations for these cases has not been well documented. This report concerns 3 patients with aggressive chordoma of the clivus, who underwent operations 6 to 12 times over a period of 8 to 17 years because of symptomatic regrowth. Overall mean interval between repeat operations was 18 months with a range from 5 to 57 months and survival times were 9 to19 years after the first surgery. Main symptoms before each operation were diplopia and visual disturbance. Repeat palliative operations by intentional extradural debulking of the tumour to decompress offending neural structures, as well as maximal removal of the tumour, using appropriate skull base approaches, can mitigate progressive symptoms, and may result in better quality and some prolongation of life, although our patients gradually deteriorated neurologically throughout the clinical course. 相似文献
24.
Fuyumi Yamamoto Hiroshi Kasai Tadayoshi Bessho Myung-Hee Chung Hideo Inoue Eiko Ohtsuka Tomokatsu Hori Susumu Nishimura 《Cancer science》1992,83(4):351-357
Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh8 Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh8 Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh8 Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh8 Gua from DNA is widely distributed in mammalian cells. 相似文献
25.
Y Matsuki K Suzuki M Hara A Kitani T Hirose M Harigai M Kawakami N Tanaka M Kawagoe H Nakamura 《Ryūmachi》1992,32(2):154-9; discussion 159-62
Arterial thrombosis is one of the major symptoms of antiphospholipid syndrome (APS). However, thrombosis in a primary branch of the aorta has rarely been reported in APS. We report here a case of APS complicated by thromboses in both the left subclavian artery and the left external iliac vein. A 32-year-old woman was admitted in May, 1990 complaining of no pulse in the left superficial arteries (e.g., left radial artery) for the past 5 years and acute swelling of the left lower extremity. A left ascending phlebography showed an occlusion of the external iliac vein and arteriography revealed obstruction in the left subclavian artery. Collateral circulations were developed at the site of each thrombus. Clotting and immunological studies revealed a prolonged APTT, a high titer of anticardiolipin antibody and lupus anticoagulant positive. We ruled out various diseases and clinical risk factors predisposing to both arterial and venous thromboses. Accordingly, we concluded that both thromboses were based on APS. Following treatment with anticoagulants, aspirin and corticosteroid, the swelling of her left thigh was diminished and the antibody titer was decreased within 3 months. 相似文献
26.
Hitoshi Taguchi Koh Yamada Hideo Matsumoto Akira Kato Toshihiro Imanishi Koh Shingu 《Journal of anesthesia》1997,11(3):173-178
Purpose Several case reports indicate critical respiratory complications in relation to the double-lumen endobronchial tube (DLT).
A prospective survey for the airway problems in using the DLT is presented.
Methods One hundred adult patients undergoing thoracotomy for lung cancer were investigated. Tube malposition and airway obstruction
were searched using a fiber-optic scope. The endobronchial cuff was positioned just below the trachcal carina while the trachea
was intubated with a DLT (Rüsch). The distances of displacement, from the tracheal carina to the bronchial cuff, were measured
during anesthesia using an epidural catheter, which had marks every 5 mm. The distances for correcting the tube position were
measured at both the bronchial cuff and the level of the teethPaO2,PaCO2 andSPO2 were also measured.
Results Malposition (displacement over 5 mm from the correct position) was found in 42 patients, and 40 of them were in a withdrawal
direction, occurring at the postural change and during one-lung ventilation, especially during manipulation of the lung hilum.
Correcting distances at the level of the teeth were 15.3–3-times longer than those at the bronchial cuff. Airway deformities
and gradual withdrawal of the bronchial cuff were found in association with surgical manipulation. Obstruction occurred at
the tips of the tracheal tube in four patients and the bronchial tube in six patients, and at the tip of both in two patients.
Hypoxemia (PaO2<60 mmHg) occurred in four patients and hypercapnea (PaCO2>60 mm Hg) in two patients.
Conclusion Most of the DLT obstructions were associated with withdrawal malposition. Great attention to DLT displacement and airway deformity
is advised. 相似文献
27.
Accommodative intraocular lens with spring action. Part 1. Design and placement in an excised animal eye 总被引:2,自引:0,他引:2
We designed an intraocular lens (IOL) with spring action, which we call the Spring IOL, with the idea of providing a slight but adequate accommodative power. The Spring IOL consists of two 6.0-mm optics, held 4.38 mm apart, and four flexible loops. The optics are made of polymethylmethacrylate (PMMA) and the loops of polyvinylidene fluoride. The lens's refractive power is provided by the anterior optic; the posterior optic acts as a footplate to restrict the anteroposterior movement of the anterior optic. By torsionally compressing the obliquely arranged loops, a 10.0-mm 3-dimensional IOL can be reduced to 6.0 mm and inserted in the capsular bag through a 3.5-mm capsular opening. Because the Spring IOL is made of the same materials as conventional IOLs, most of the problems hindering the development of a refilling material (which could also provide accommodation) are avoided. In this first report we discuss the design of the lens, the refractive theory involved, and our experience inserting it in an excised animal eye. 相似文献
28.
Yasuhiko Tamada Kikuka Yokochi Yoshimi Oshitani Yukiko Nitta Toshihiko Ikeya Kazuo Hara Katsushi Owaribe 《The Journal of dermatology》1995,22(3):201-204
We report a 73-year-old woman with typical clinical, histological and immunofluorescence features of pemphigoid nodularis. Direct immunofluorescence studies of prurigo nodularis-like lesions and peribullous skin showed the linear deposition of IgG and C3 at the basement membrane zone. Circulating IgG against the basement membrane was also detected by indirect immunofluorescence. The serum from the patient was shown to contain the autoantibody against 230 kDa hemidesmosomal antigen associated with bullous pemphigoid antigen. 相似文献
29.
Yasuo Miyoshi Seigoh Mizumoto MD Hideo Akashi Eiji Kurokawa Hideyuki Mishima Keisuke Iihara Kohji Takami Masayuki Ohue Yukitoshi Aoki 《Surgery today》1990,20(6):711-714
A rare case of jejunal carcinoma coexisting with adenoma, situated 120 cm distal to the ligament of Treitz in a 53 year old
male, is reported herein. We also review cases of adenoma and carcinoma in the jejunum and ileum from the Japanese literature,
and discuss the histogenesis of carcinoma of the jejunum and ileum. 相似文献
30.
Masanori Hara M.D. Reiko Yoshida M.D. Susumu Inaba M.D. Akira Higuchi M.D. Yoshifumi Suzuki M.D. Toshio Okada M.D. Takakuni Tanizawa M.D. 《Pediatrics international》1991,33(3):335-344
The aim of this study was to assess the significance of C3 deposition in IgA nephropathy in children and adolescents. One hundred and two patients aged 5–21 years (57 male and 45 female) were studied. The findings of C3 deposition were classified into 8 groups by immunofluorescent (IF) pattern and intensity as follows: group MC3+ (N = 12): mesangiocapillary pattern and 3+ in intensity; group MC2+ (N = 13): mesangiocapillary and 2+; group MC1 + (N = 4): mesangiocapillary and 1 +; group M3+ (N = 11): mesangial and 3+; group M2+ (N = 24): mesangial and 2+; group M1 + (N=18): mesangial 1 +; group S (N = 12): only segmentally positive; and group N (N = 8): negative. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration, and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, fibrous crescents, adhesion and tubulo-interstitial change). IF findings were scored semiquantitatively and laboratory findings were also studied. The following results were obtained: 1) The scores of total activity index in MC groups were higher than in the M, S or N groups, and the greater the degree of C3 deposition, the higher the score; 2) Such result was not evident in the chronicity index; 3) High IF scores of IgG and IgM were found in the MC3+ and MC2+ groups; 4) Hematuria was more severe in MC3+ and MC2+ than in other groups, and proteinuria was more prominent in the MC than other groups. Thus the degree of C3 deposition was parallel with histological activity and urinary findings. 相似文献