全文获取类型
收费全文 | 899782篇 |
免费 | 62272篇 |
国内免费 | 2333篇 |
专业分类
耳鼻咽喉 | 12474篇 |
儿科学 | 28681篇 |
妇产科学 | 26146篇 |
基础医学 | 126593篇 |
口腔科学 | 24686篇 |
临床医学 | 74752篇 |
内科学 | 183154篇 |
皮肤病学 | 18989篇 |
神经病学 | 71388篇 |
特种医学 | 36448篇 |
外国民族医学 | 336篇 |
外科学 | 142112篇 |
综合类 | 19030篇 |
一般理论 | 247篇 |
预防医学 | 64564篇 |
眼科学 | 20083篇 |
药学 | 63808篇 |
中国医学 | 1798篇 |
肿瘤学 | 49098篇 |
出版年
2018年 | 9048篇 |
2017年 | 7160篇 |
2016年 | 7674篇 |
2015年 | 8722篇 |
2014年 | 12368篇 |
2013年 | 19210篇 |
2012年 | 25649篇 |
2011年 | 27257篇 |
2010年 | 16575篇 |
2009年 | 15782篇 |
2008年 | 26132篇 |
2007年 | 27734篇 |
2006年 | 27915篇 |
2005年 | 27448篇 |
2004年 | 26296篇 |
2003年 | 25462篇 |
2002年 | 25052篇 |
2001年 | 41358篇 |
2000年 | 42552篇 |
1999年 | 36268篇 |
1998年 | 9968篇 |
1997年 | 9149篇 |
1996年 | 9085篇 |
1995年 | 8445篇 |
1994年 | 8081篇 |
1993年 | 7584篇 |
1992年 | 28198篇 |
1991年 | 26979篇 |
1990年 | 26408篇 |
1989年 | 25348篇 |
1988年 | 23553篇 |
1987年 | 23174篇 |
1986年 | 22254篇 |
1985年 | 21152篇 |
1984年 | 15808篇 |
1983年 | 13477篇 |
1982年 | 8087篇 |
1979年 | 14589篇 |
1978年 | 10208篇 |
1977年 | 8627篇 |
1976年 | 8147篇 |
1975年 | 8960篇 |
1974年 | 10697篇 |
1973年 | 10182篇 |
1972年 | 9661篇 |
1971年 | 8917篇 |
1970年 | 8584篇 |
1969年 | 8025篇 |
1968年 | 7684篇 |
1967年 | 7087篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
962.
B Kerboul J Le Saout C Lefevre D Miroux L Fabre J F Le Noac'h J M Rogero B Courtois 《Journal de chirurgie》1986,123(6-7):428-434
Results of three therapeutic modalities used for the treatment of a homogeneous series of patients with a Pouteau Colles fracture are analyzed. Orthopedic treatment provided deceiving results. Pinning was, on the contrary, very effective, intrafocal pinning with immediate mobilization of the wrist appearing perfectly effective. Few complications were reported in contrast to plastered immobilizations. Good results were obtained in 80% of cases and functional recovery was rapid, indicating that this method represents undoubted progress when compared with conventional therapies. 相似文献
963.
Allografts of CNS tissue possess a blood-brain barrier. II. Angiogenesis in solid tissue and cell suspension grafts 总被引:2,自引:0,他引:2
R D Broadwell H M Charlton P S Ebert W F Hickey Y Shirazi J Villegas A L Wolf 《Experimental neurology》1991,112(1):1-28
Angiogenesis and patency of blood vessels were analyzed qualitatively in solid CNS and peripheral tissue syngeneic, allogeneic, and xenogeneic grafts and in individual cell suspension grafts of astrocytes, fibroblasts, PC12, and three additional tumor cell lines placed intracerebrally in adult host mice. Postgrafting survival times were 1 day through 4 weeks. The patency of graft vessels was determined in sections from immersion-fixed tissues incubated to reveal the endogenous peroxidase activity of host red cells trapped within the lumen of blood vessels. Additionally, horseradish peroxidase (HRP) was administered intravenously to live hosts; HRP labels host brain and graft vessels on the luminal surface and reveals the presence or absence of a blood-brain barrier (BBB) within the grafts. The origins of blood vessels supplying solid tissue xenografts were identified immunohistochemically with primary antibodies against host (athymic AKR mice) and donor (fetal Lewis rats) major histocompatibility complex (MHC) class I. Blood vessels supplying solid CNS grafts at 1-7 days post-transplantation were identified ultrastructurally and possessed interendothelial tight junctional complexes; however, they were not perfused with either host blood or blood-borne HRP prior to 8 days. Graft vessels at 10 days were outlined consistently by peroxidase-positive red cells in immersion-fixed material and labeled with blood-borne HRP. These vessels provided a BBB to the circulating HRP and exhibited interendothelial tight junctions. Evidence of angiogenesis within solid anterior pituitary grafts and the variety of cell suspension grafts was obtained prior to 3 days post-transplantation in immersion-fixed preparations; the vessels, with the notable exception of those supplying astrocyte cell suspensions, failed to present a BBB to blood-borne peroxidase. Endothelia in the solid pituitary allografts and the PC12 cell grafts were highly fenestrated and exhibited open interendothelial junctions; those in the tumor and fibroblast cell grafts, for the most part, appeared nonfenestrated, and many possessed open interendothelial junctional complexes. Immunostaining for host and donor MHC class I revealed that donor blood vessels predominate over host vessels in CNS xenografts and supply pituitary xenografts exclusively; in both preparations, donor vessels were not identified within the host CNS. Because cell suspension grafts were derived from endothelia-free preparations grown in culture, blood vessels supplying these grafts were necessarily of host CNS origin and manifested a morphological transformation from a BBB to a non-BBB endothelium. The data suggest that angiogenesis in solid CNS grafts placed into the adult host CNS, compared to similarly placed solid peripheral tissue/cell suspension grafts, is not rapid.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
964.
Despite the use of gold complexes in modern medicine for over 100 years and the use of gold complexes in the management of
rheumatoid disease for more than 60 years, the definitive mechanisms of action for efficacy and for toxicity have not been
established.
Gold is a group 1b metal in the periodic table with several oxidation states but it is only Au(I) which is active in the biological
milieu. Gold sodium thiomalate is not only a polymeric structure, but also has the chiral ligand, thiomalic acid. Gold sodium
thiomalate thus can exist in several different physical states which may have different biological activity. In addition the
pharmacokinetic profile of gold complexes has been of little value in the understanding of either the mechanism of action,
efficacy or toxicity for both the injectable and the oral gold complexes. Many authors have misinterpreted research data on
the activities of gold complexes because they compared gold complexes of different structures, and gold complexes which exist
at different pH.
Experimental work in our laboratory has identified that gold sodium thiomalate is a mixture and can exist as either a yellow
or a colourless solution. These have some similar but several different biological activities.
Many factors contribute to the lack of understanding of the action of gold complexes. Some of these factors are related to
the wide variation in physical structure and biological activities exhibited by these compounds. 相似文献
965.
966.
967.
Caustic injuries to the esophagus in children 总被引:2,自引:0,他引:2
F C Rothstein 《Pediatric clinics of North America》1986,33(3):665-674
The ingestion of caustic chemical agents, usually accidentally by children, produces a wide range of injuries from minor mouth burns to necrosis of the esophagus and stomach. The type of agent, amount, concentration, and duration of exposure are the determining factors. The treatment for the average burn is fairly well standardized, but the serious injuries require prompt recognition of complications and appropriate therapy to prevent more serious complications. 相似文献
968.
969.
OBJECTIVE: The aim of this study was to evaluate the relationship between the degree of conversion (DC) of composites and the light intensity using LED-curing units and also to determine the amount of exposure required to achieve optimal curing. METHOD: The light outputs of light-curing units and the depths of cure of composites exposed to these units were determined using the methods outlined in modified ISO standards, ISO/TS10650 and ISO 4049, respectively. The distributions of DC in composites were investigated by IR spectra of microareas obtained at various depths from the irradiated surface of thin specimens cut out from the cured composites. IR spectra were measured using a Fourier transform infrared spectrometer equipped with a microscopic unit. DC was calculated from the changes in the amount of C=C double bonds in the IR spectra. RESULTS: The light intensity at various depths through the cured composite was calculated from the attenuation coefficient of each material, obtained from the linear relationship between the depth of cure and the logarithm of the amount of exposure, which is defined as the product of the irradiance and irradiation time. There was a third or fourth order regression relationship between DC and the logarithm of total light energy at a particular depth. SIGNIFICANCE: The minimum light energy required to produce a saturated DC was about 1000 s mW/cm2. 相似文献
970.
Andreas Blana Stefan Denzinger Markus Lenhart Wolf F Wieland Roman Ganzer 《International journal of urology》2007,14(5):450-451
We report a case of recurrent inguinal lymphocele formation after inguinal lymphadenectomy treated by lymphographic mapping and selective ligation of the lymphatic vessels. Lymphographic mapping was performed by puncturing a lymphatic vessel at the dorsum of the foot. After isolating the vessels that drained into the lymphocele, they were clipped and divided through a small skin incision. The described technique showed an instant and complete suspension of the lymph secretion with subsequent complete healing. Lymphatic mapping and selective ligation of afferent lymphatic vessels proved to be an effective treatment of a recurrent inguinal lymphocele. 相似文献