全文获取类型
收费全文 | 5103篇 |
免费 | 221篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 132篇 |
妇产科学 | 24篇 |
基础医学 | 672篇 |
口腔科学 | 107篇 |
临床医学 | 319篇 |
内科学 | 1369篇 |
皮肤病学 | 111篇 |
神经病学 | 276篇 |
特种医学 | 141篇 |
外科学 | 1147篇 |
综合类 | 30篇 |
一般理论 | 1篇 |
预防医学 | 153篇 |
眼科学 | 43篇 |
药学 | 289篇 |
中国医学 | 8篇 |
肿瘤学 | 406篇 |
出版年
2022年 | 60篇 |
2021年 | 107篇 |
2020年 | 44篇 |
2019年 | 54篇 |
2018年 | 71篇 |
2017年 | 55篇 |
2016年 | 87篇 |
2015年 | 85篇 |
2014年 | 95篇 |
2013年 | 144篇 |
2012年 | 243篇 |
2011年 | 244篇 |
2010年 | 153篇 |
2009年 | 146篇 |
2008年 | 219篇 |
2007年 | 271篇 |
2006年 | 269篇 |
2005年 | 248篇 |
2004年 | 238篇 |
2003年 | 249篇 |
2002年 | 247篇 |
2001年 | 124篇 |
2000年 | 133篇 |
1999年 | 147篇 |
1998年 | 88篇 |
1997年 | 49篇 |
1996年 | 50篇 |
1995年 | 38篇 |
1994年 | 47篇 |
1993年 | 34篇 |
1992年 | 108篇 |
1991年 | 94篇 |
1990年 | 81篇 |
1989年 | 95篇 |
1988年 | 86篇 |
1987年 | 100篇 |
1986年 | 93篇 |
1985年 | 78篇 |
1984年 | 52篇 |
1983年 | 56篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 49篇 |
1978年 | 26篇 |
1977年 | 25篇 |
1972年 | 24篇 |
1970年 | 31篇 |
1969年 | 24篇 |
1968年 | 27篇 |
1967年 | 27篇 |
排序方式: 共有5335条查询结果,搜索用时 531 毫秒
1.
2.
Koji Matsumoto Masahiro Hoshino Keita Omori Hidetoshi Igarashi Hiromi Matsuzaki Yasuaki Tokuhashi 《Journal of orthopaedic science》2021,26(4):538-542
BackgroundAdjacent vertebral fracture (AVF) is a major complication following Balloon Kyphoplasty (BKP). There is no scoring system for predicting AVF using only preoperative elements. The purposes of this study were to develop a scoring system for predicting early AVF after BKP based on preoperative factors and to investigate the appropriate surgical indication for BKP.MethodsOf 220 patients who underwent BKP at a single institution since 2011, 65 patients over the age of 60 who had undergone a standing whole spine X-ray preoperatively were enrolled. Factors affecting the occurrence of early AVF were examined. A scoring system was created consisting of the factors exhibiting significant differences, and the correlation between the total score and the incidence of early AVF was investigated.ResultsTwenty of the 65 patients (30.8%) had early AVF. In a univariate analysis, age, previous vertebral fracture, pelvic tilt, and Local kyphosis significantly influenced early AVF. In a multivariate logistic regression analysis, age had an odds ratio of 1.136 (95% CI 1.001–1.289), previous vertebral fractures 4.181 (1.01–17.309), and Local kyphosis 1.103 (1.021–1.191). The scoring system was set as follows: ①Age (<75 years: 0 points(P), 75years≦: 1P), ②The number of previous vertebral fractures (0: 0 P, 1: 1P, 2: 2P, 3 or more: 3P), and ③Local kyphosis (<10°: 0P, 10°≦: 1P). There was a correlation between the total score and the incidence of early AVF (r = 0.812, 1P = 0.05). The incidence of early AVF was 6.4% (2 cases/31 cases) for a score of ≦1P and 54.5% (18 cases/33 cases) for a score of ≧2P.ConclusionsThere was a correlation between the total score and the incidence of early AVF. A score of 1 point or less may represent the appropriate surgical indication for BKP. 相似文献
3.
Shinichiro Uchiyama Takao Hoshino Leila Sissani Monteiro Tavares Linsay Kenji Kamiyama Taizen Nakase Kazuo Kitagawa Kazuo Minematsu Kenichi Todo Yasushi Okada Jyoji Nakagawara Ken Nagata Hiroshi Yamagami Takenori Yamaguchi Pierre Amarenco 《Journal of stroke and cerebrovascular diseases》2019,28(8):2232-2241
BackgroundTIAregistry.org is an international cohort of patients with transient ischemic attack (TIA) or minor stroke within 7 days before enrollment in the registry. Main analyses of 1-year follow-up data have been reported.5 We conducted subanalysis on the baseline and 1-year follow-up data of Japanese patients.MethodsThe patients were classified into 2 groups based on Japanese ethnicity, Japanese (345) and non-Japanese (3238), and their baseline data and 1-year event rates were compared. We also determined risk factors and predictors of 1-year stroke.ResultsCurrent smoking, regular alcohol drinking, intracranial arterial stenosis, and small vessel occlusion; and hypertension, dyslipidemia, coronary artery disease, and extracranial arterial stenosis were more and less common among Japanese patients, respectively. Stroke risk was higher and TIA risk was lower at 1-year follow-up among Japanese patients. The baseline risk factors for recurrent stroke were diabetes, alcohol drinking, and large artery atherosclerosis. Independent predictors of 1-year stroke risk were prior congestive heart failure and alcohol consumption.ConclusionsThe two populations of patients featured differences in risk factors, stroke subtypes, and outcome events. Predictors of recurrent stroke among Japanese patients included congestive heart failure and regular alcohol drinking. Strategies to attenuate residual risk of stroke aside from adherence to current guidelines should take our Japanese-patient specific findings into account. 相似文献
4.
Endoscopic anterior cruciate ligament reconstruction using a computer-assisted fluoroscopic navigation system 总被引:3,自引:0,他引:3
Hisatada Hiraoka Sou Kuribayashi Akira Fukuda Naoshi Fukui Kozo Nakamura 《Journal of orthopaedic science》2006,11(2):159-166
Background During anterior cruciate ligament (ACL) reconstruction, placement of the reconstructed ligament affects the clinical results.
To accomplish accurate and reproducible placement of the tibial bone tunnel, we employed a fluoroscopic navigation system
for endoscopic ACL reconstruction. In this study, preciseness of the tibial tunnel placement was evaluated, and the advantages
and disadvantages of this navigation system for endoscopic ACL reconstruction are discussed.
Methods Altogether, 16 knees of 16 patients who had undergone ACL reconstruction using this system (navi group) were evaluated regarding
the positioning of the tibial tunnel against Blumensaat's line using X-p and the route of the graft by magnetic resonance
imaging (MRI). Another 16 knees of 16 patients who underwent endoscopic ACL reconstruction without the navigation system were
the controls (control group).
Results At the 1-year follow-up, maximally extended lateral knee X-p revealed that the anterior edge of the tibial tunnel and Blumensaat's
line were almost aligned and that roof impingement was avoided; the T2-weighted MR images showed that the graft was placed
close to and parallel to the intercondylar roof in all the knees of the navi group. The ratio of the distance between Blumensaat's
line and the anterior edge of the tibial tunnel at the level of the tibial plateau to the anteroposterior width in fully extended
true lateral radiographs was 2.7% ± 3.4% in the navi group and 8.4% ± 7.4% in the control group.
Conclusions The computer-assisted fluoroscopic navigation system improves accuracy and decreases dispersion of the tibial tunnel placement
against Blumensaat's line in single-bundle ACL reconstruction. This innovative device renders the reconstruction procedure
more reliable, eliminating the problem of skeletal variation among patients. However, the function of this navigation system
for femoral tunnel placement is insufficient at present. Further refinement of the system is necessary, and the method of
application requires improvement. 相似文献
5.
Yasuyuki Suzuki Kazuyuki Daitoku Masahito Minakawa Kozo Fukui Ikuo Fukuda 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(1):44-46
We report the case of a 4-year-old girl who had quadricuspid aortic valve regurgitation with tetralogy of Fallot and pulmonary
atresia. This combination is very uncommon. Aortic valve replacement was performed successfully due to aortic regurgitation
which had progressed one year after the total repair. The dilated aortic annulus plus quadricuspid aortic valve may result
in progressive aortic regurgitation for a short period. 相似文献
6.
Fifty-seven patients with low back pain and sciatica of various causes were reviewed with reference to problems associated with pedicle plate fixation of the lumbar spine. Eleven percent of patients had neurologic problems postoperatively and 3.5% (two patients) had severe sensory impairments. All patients had this complication in the early phases of the study. Of 297 screws, 17 broke, ie, 5.7%. These breakages occurred in 12 of 57 patients (21%). In patients with spondylolisthesis, the degree of slip correction averaged 53% postoperatively, which decreased to 35% at the 1-year follow-up. Slip angle was maintained after correction. Pedicle screw plate fixation is an effective form of immobilization of the lumbar spine used in achieving arthrodesis. The surgeon must be fully trained in methodology. It is recommended that screw and plate materials be improved to prevent screw breakage. 相似文献
7.
Ung-il Chung Hiroshi Kawaguchi Tsuyoshi Takato Kozo Nakamura 《Journal of orthopaedic science》2004,9(4):410-414
Mammalian bones have three distinct origins (paraxial mesoderm, lateral plate mesoderm, and neural crest) and undergo two different modes of formation (intra-membranous and endochondral). Bones derived from the paraxial mesoderm and lateral plate mesoderm mainly form through the endochondral process. During this process, hypertrophic chondrocytes play a vital role in inducing both osteogenesis and angiogenesis. One of the essential osteogenic factors secreted from hypertrophic chondrocytes is Indian hedgehog (Ihh). In contrast, bones derived from the neural crest mainly form through the intramembranous pro-cess and do not require Ihh. Thus, depending on their origin, bones have distinct signaling properties, which need to be considered in the research and application of bone biology.Presented at the 18th Annual Research Meeting of the Japanese Orthopaedic Association, Kitakyushu, Japan, October 17, 2003 相似文献
8.
When the neural tube of avian embryos is separated from the notochord and floor plate, motoneurons in the spinal cord fail to develop. In order to investigate the factors involved in this phenomenon, cell proliferation activity and cell death were observed following paramedian incision of the neural tube at the level of the segmental plate using colchicine, BrdU, and TUNEL methods. If the notochord and/or floor plate produces a substance(s) that promotes cell division in the basal plate neuroepithelium or that supports the survival of the motoneuron's neuroblasts, mitotic figures should not be present in the neuroepithelium nor should substantial cell death be observed in the ventral aspect of the notochord- and floor plate-deprived neural tube. Surprisingly, however, neither result was observed in the present experiments, with the exception of a considerable amount of homogeneously distributed cell death. Neuroepithelial cells continued to proliferate and gave rise to neuroblasts. Nevertheless, motoneurons failed to develop, and the neural tube was enveloped by only the basement membrane of the alar plate (S. Hirano and H. Tanaka, 1994,Dev. Growth Differ.36, 481–488). These morphological results revealed that the cause of the development of the anterior horn lacking a neural tube in the notochord- and neural tube-eliminated embryos is not the elimination of the source of the surviving factor(s) of the motoneuron's neuroblasts, but rather the elimination of the signals to induce the motoneurons, derived from the notochord and/or floor plate. The larger amount of cell death in the neural tube on the experimental side suggests that a nonspecific survival factor(s), necessary for the survival of a variety of types of neuroblasts, is also produced by the notochord and/or floor plate. 相似文献
9.
Kozo Yamada Seiji Hayasaka Yukari Yamamoto Tomoichi Setogawa 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1990,228(1):1-4
We examined 62 patients with acute herpes zoster involving the trigeminal nerve; 13 had eruptions only and 49 (51 eyes) had
eruptions with ocular complications. Bilateral involvement was found in two patients. The frequency of the disease appeared
to increase with age, and the disease was least active in November. Patients with eruptions only demonstrated affected areas
along the first, second, and/or third divisions of the trigeminal nerve. Ocular complications occurred in patients who had
eruptions along the first and/or second divisions of the nerve, and they were usually noted in patients with eruptions on
the tip and one side of the node. The ocular complications and associated systemic conditions varied. 相似文献
10.
The ion recombination loss is one of the most important correction factors for dosimetry using ionization chamber especially for the measurement of high-intensity pulsed radiation beam. The two-voltage method has been used frequently for the correction of ion recombination loss. Several ways to approximate the method are presented. Comparisons were carried out to check the validity of the approximation. Using four ionization chambers of different types and shapes, measurements were made to obtain the optimal value of the ratio for the two voltages. 相似文献