全文获取类型
收费全文 | 28189篇 |
免费 | 1858篇 |
国内免费 | 277篇 |
专业分类
耳鼻咽喉 | 540篇 |
儿科学 | 353篇 |
妇产科学 | 373篇 |
基础医学 | 4639篇 |
口腔科学 | 828篇 |
临床医学 | 2528篇 |
内科学 | 5476篇 |
皮肤病学 | 1041篇 |
神经病学 | 2106篇 |
特种医学 | 1645篇 |
外科学 | 3472篇 |
综合类 | 140篇 |
现状与发展 | 3篇 |
一般理论 | 8篇 |
预防医学 | 1131篇 |
眼科学 | 497篇 |
药学 | 2651篇 |
中国医学 | 426篇 |
肿瘤学 | 2467篇 |
出版年
2023年 | 210篇 |
2022年 | 735篇 |
2021年 | 1090篇 |
2020年 | 587篇 |
2019年 | 805篇 |
2018年 | 945篇 |
2017年 | 751篇 |
2016年 | 1103篇 |
2015年 | 1501篇 |
2014年 | 1574篇 |
2013年 | 1878篇 |
2012年 | 2694篇 |
2011年 | 2496篇 |
2010年 | 1515篇 |
2009年 | 1190篇 |
2008年 | 1652篇 |
2007年 | 1455篇 |
2006年 | 1248篇 |
2005年 | 1176篇 |
2004年 | 936篇 |
2003年 | 826篇 |
2002年 | 677篇 |
2001年 | 406篇 |
2000年 | 390篇 |
1999年 | 311篇 |
1998年 | 143篇 |
1997年 | 125篇 |
1996年 | 85篇 |
1995年 | 68篇 |
1994年 | 72篇 |
1993年 | 64篇 |
1992年 | 112篇 |
1991年 | 130篇 |
1990年 | 111篇 |
1989年 | 97篇 |
1988年 | 90篇 |
1987年 | 76篇 |
1986年 | 78篇 |
1985年 | 62篇 |
1984年 | 42篇 |
1983年 | 38篇 |
1979年 | 53篇 |
1978年 | 37篇 |
1975年 | 52篇 |
1974年 | 29篇 |
1972年 | 39篇 |
1971年 | 49篇 |
1970年 | 34篇 |
1969年 | 27篇 |
1968年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
61.
Disc replacement using Pro-Disc C versus fusion: a prospective randomised and controlled radiographic and clinical study 总被引:4,自引:0,他引:4
A. Nabhan F. Ahlhelm T. Pitzen W. I. Steudel J. Jung K. Shariat O. Steimer F. Bachelier D. Pape 《European spine journal》2007,16(3):423-430
Anterior cervical discectomy and fusion (ACDF) may be considered to be the gold standard for treatment of symptomatic degenerative
disc disease within the cervical spine. However, fusion of the segment may result in progressive degeneration of the adjacent
segments. Therefore, dynamic stabilization procedures have been introduced. Among these, artificial disc replacement by disc
prosthesis seems to be promising. However, to be so, segmental motion must be preserved. This, again, is very difficult to
judge and has not yet been proven. The aim of the current study was to first analyse the segmental motion following artificial
disc replacement using a disc prosthesis. A second aim was to compare both segmental motion as well as clinical result to
the current gold standard (ACDF). This is a prospective controlled study. Twenty-five patients with cervical disc herniation
were enrolled and assigned to either study group (receiving a disc prosthesis) or control group (receiving ACDF, using a cage
with bone graft and an anterior plate.) Radiostereometric analysis was used to quantify intervertebral motion immediately
as well as 3, 6, 12 and 24 weeks postoperatively. Further, clinical results were judged using visual analogue scale and neuro-examination.
Cervical spine segmental motion decreased over time in the presence of disc prosthesis or ACDF. However, the loss of segmental
motion is significantly higher in the ACDF group, when looked at 3, 6, 12 and 24 weeks after surgery. We observed significant
pain reduction in neck and arm postoperatively, without significant difference between both groups (P > 0.05). Cervical spine disc prosthesis preserves cervical spine segmental motion within the first 6 months after surgery.
The clinical results are the same when compared to the early results following ACDF. 相似文献
62.
Recessive dystrophic epidermolysis bullosa (RDEB) is an uncommon and severe disorder characterised by trauma-induced blisters, intractable skin ulcers, scarring, milia, and nail dystrophy. We report the good result of both surgical release of fingers allowing spontaneous epithelisation without skin grafting and post-operative meticulous skin care without splinting, followed-up for one year. 相似文献
63.
D. G. Kim C.-Y. Kim S. H. Paek D. S. Lee J.-K. Chung H.-W. Jung B.-K. Cho 《Acta neurochirurgica》1998,140(7):665-674
Summary
Background To determine its roles in the diagnosis and the systemic evaluation of metastatic brain tumours, whole-body positron emission
tomography (PET) using [18F]FDG was performed in 20 consecutive patients.
Methods
All patients were thought to be suffering or needing to be differentiated from metastatic brain tumours. Nine patients had
multiple brain lesions; six were older and showed a rim-enhancing lesion with surrounding oedema; seven had homogeneously
enhancing periventricular lesion(s) on computed tomography (CT) and/or magnetic resonance (MR) imaging, thought to be central
nervous system lymphomas. Two patients had skull mass(es) and two patients had a solid mass suspected to be, respectively,
a haemorrhagic metastasis and a metastatic malignant melanoma. All of them received whole-body [18F]FDG PET and conventional systemic work-up for metastasis in order to compare the results of the two methods.
Results
Metastatic brain tumours were diagnosed on whole-body [18F]FDG PET in eleven patients who had extracranial and intracranial hypermetabolic lesions. In nine of these, a conventional
work-up also detected primary lesions which on whole-body [18F]FDG PET were seen to be hypermetabolic foci. Systemic lymph node metastases were detected by whole-body [18F]FDG PET only in two patients and histological diagnosis was possible by biopsy of lymph nodes rather than of brain lesions.
In the remaining nine patients who had only intracranial hypermetabolic foci, histological diagnosis was made by craniotomy
or stereotactic biopsy. It was confirmed that seven of nine patients were suffering from a primary brain tumour and two from
metastatic carcinoma. None of the nine showed evidence of systemic cancer on conventional work-up. Histological diagnoses
of the primary brain tumours were four cases of primary central nervous system lymphoma and one each of multifocal glioblastoma,
Ewing's sarcoma, and cavernous angioma.
Patients felt no discomfort during the whole-body [18F]FDG PET procedure and there were no complications. The false negative rate in [18F]FDG PET and in conventional work-up was 15.4% and 30.7% respectively. There were no false positives on either [18F]FDG PET or conventional work-up.
Conclusion
It is suggested that whole-body [18F]FDG PET is a safe, reliable, and convenient method for the diagnosis and systemic evaluation of patients thought to be suffering
or needing to be differentiated from a metastatic brain tumour. 相似文献
64.
Zhao Canxi Wu Yan Lei Ying Ruan Heqiu Wolfgang Voelter Albrecht Jung Miriam Schick 《华中科技大学学报(医学英德文版)》1996,16(4):203-204
Zusammenfassung Die Wirkung des ?thylazetatextraktes von Chrysanthemum morifolium auf P. falciparum wurde in vitro untersucht. W?hrend sich
die Parasit?mie bei der Kontrollgruppe bis zu 10. 90 % entwickelte, wurde bei dem mit ?thylazetatextrakt in einer Konzentration
von 100 μg/ml Medium am 5. Tag der Kultur eine signifikante Hemmwirkung auf die Parasiten beobachtet. Die Parasit?mie blieb
bei 1. 00 %.
Diese Arbeit wurde durch die Stiftung von “National Nature Science Foundation of China” finanziert (No. 39260066) 相似文献
65.
Marion Jung EvaMaria Krämer Thomas Müller Horst Antonicek Jacqueline Trotter 《The European journal of neuroscience》1998,10(10):3246-3256
The immortalization of progenitor cells from embryonic murine hippocampus using oncogene‐carrying retroviral vectors is described. Use of a vector encoding the oncogene v‐myc results in lines of nestin‐positive progenitor cells. Limited differentiation ensues if the cells are cultured in the presence of dibutyryl cyclic adenosine monophosphate. In contrast, use of a vector in which the extracellular portion of the epidermal growth factor (EGF) receptor is fused to the neu tyrosine kinase generates lines of pluripotential nestin‐positive progenitor cells, which differentiate upon withdrawal of EGF into neurons and glia. Differentiated neurons expressing action potentials and neurotransmitter receptors make up a high proportion of the cells. These cell lines are useful tools to investigate the characteristics of differentiating neurons and glia, as well as to screen neuroactive drugs. This work has been reported in preliminary form as an abstract (1996 Society for Neuroscience Abstract, #606.20, p. 1537). 相似文献
66.
E G Jung 《Der Hautarzt; Zeitschrift für Dermatologie, Venerologie, und verwandte Gebiete》1989,40(12):761-762
"Schnyder's rule" states that multiple tumours of the skin are dominantly inherited, whereas solitary tumours of the same histological type are noninherited. This rule may be extended to cover segmental cases representing somatic mutations. 相似文献
67.
Overexpression of S100A4 is closely related to the aggressiveness of gastric cancer 总被引:25,自引:0,他引:25
Cho YG Nam SW Kim TY Kim YS Kim CJ Park JY Lee JH Kim HS Lee JW Park CH Song YH Lee SH Yoo NJ Lee JY Park WS 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2003,111(5):539-545
Elevated levels of the calcium-binding protein S100A4 cause metastasis of benign rat mammary tumor cells. To investigate whether S100A4 plays an important role in the invasion and metastasis of gastric cancers, we examined the gene mutations in the coding regions and expression patterns of the S100A4 in gastric adenocarcinoma in Korea. Moderate to strong expression of S100A4 was found in 53 (68.8%) of the 77 gastric adenocarcinomas, whilst normal gastric epithelium either failed to stain or showed weak staining. Interestingly, S100A4 expression was more frequently observed in gastric cancer patients with advanced gastric cancer (p=0.039), positive lymph node metastasis (p=0.001), and peritoneal dissemination (p=0.022). No gene mutations were found in the analyzed genomic area in 77 gastric adenocarcinomas and 15 gastric cancer cell lines. We found one single nucleotide polymorphism without an amino acid change, A99G, in two cases. These data suggest that the overexpression of S100A4 may be closely related to the aggressiveness of gastric cancer in Korea. 相似文献
68.
Chu PH Yeh HI Jung SM Chien LY Cheng NF Wu HH Chu JJ Hsueh C Lee YS 《Virchows Archiv : an international journal of pathology》2004,444(4):383-386
Cardiac hamartomas are very rare and are demarcated masses of enlarged, hypertrophied, mature myocytes and collagen tissue. Cardiac hamartomas are generally circumscribed in the right ventricle or atrium, but not reported in the crista terminalis (CRT). The CRT is crucial in electrophysiology, is related to arrhythmogenesis, and is targeted by radiofrequency catheter procedures. Previous works only described the benign natures of prominent CRT using non-invasive methods. This study describes an unusual cardiac hamartoma originating from the CRT and extending toward the tricuspid valve. Microscopically, this hamartoma comprised dense collagen and adipose tissue, mixed with hypertrophy, but with disarrayed cardiomyocytes. An irregular gap junction, connexin43, was demonstrated in this cardiac hamartoma. 相似文献
69.
Combined effects of inhaled nitric oxide and a recruitment maneuver in patients with acute respiratory distress syndrome 总被引:1,自引:0,他引:1
Nitric oxide (NO) inhalation therapy has been employed in the management of acute respiratory distress syndrome (ARDS), in order to improve oxygenation. Several factors have been implicated as being responsible for the action of inhaled NO. Alveolar recruitment methods, such as prone positioning and a sufficient positive end expiratory pressure (PEEP), have been identified as having a positive impact on the NO response. A Recruitment maneuver (RM) was introduced for the treatment of ARDS, along with a lung protective strategy. Here, we hypothesized that a RM may further augment the oxygenation of patients treated with NO inhalation. Therefore, the effects of the inhalation of NO, either in combination with a RM, or separately, were evaluated on patients with ARDS for their enhancing action. 23 patients with ARDS were enrolled, and divided into three groups. The patients in group 1 (n=11) were treated with 5 ppm NO via inhalation, followed by a RM, applying a sustained inflation pressure of 30 - 35 cmH2O for 30 seconds. Group 2 (n=6) received a RM alone, while group 3 (n=3) was treated with NO inhalation alone. The oxygenation and hemodynamic parameters were obtained prior to, and 2, 12, and 24 h after, the respective treatment procedures. For group 1, the PaO2/FiO2 increased from its initial value of 171.8 +/- 67.8 to 203.2 +/- 90.0 2 h after NO inhalation. Further improvement was noted with the continual application of the RM reaching, 215.5 +/- 74.6 (p=0.05) and 254.2 +/- 109.5 (p < 0.05), after 12 and 24 h, respectively. Initially 7 of the subjects did not respond to NO inhalation, but 3 of these non-responders changed into responders 12 h after the RM. The changes in the PaO2/FiO2 from baseline at each time period were greater in group 1 than in the other groups, but with no statistical significance. The hemodynamics of the patients was not significantly altered during the entire study period. We conclude that the combined application of NO inhalation and a RM could be beneficial and safe for patients with ARDS, showing an enhancing effect in improvement of oxygenation. 相似文献
70.
To test the hypothesis that complement-mediated cell lysis and cell-mediated cytotoxicity operate by analogous mechanisms, cell membranes from two antibody-dependent cytotoxicity systems were examined by electron microscopy after negative staining. Ring-shaped membrane lesions generally similar to, but larger than, those previously described for complement lysis were observed. These findings are in agreement with recent measurements of larger functional pores for ADCC than complement. 相似文献