全文获取类型
收费全文 | 3984篇 |
免费 | 223篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 110篇 |
妇产科学 | 94篇 |
基础医学 | 403篇 |
口腔科学 | 91篇 |
临床医学 | 397篇 |
内科学 | 883篇 |
皮肤病学 | 88篇 |
神经病学 | 314篇 |
特种医学 | 129篇 |
外科学 | 674篇 |
综合类 | 89篇 |
一般理论 | 3篇 |
预防医学 | 338篇 |
眼科学 | 76篇 |
药学 | 293篇 |
中国医学 | 20篇 |
肿瘤学 | 172篇 |
出版年
2024年 | 5篇 |
2023年 | 60篇 |
2022年 | 158篇 |
2021年 | 185篇 |
2020年 | 135篇 |
2019年 | 160篇 |
2018年 | 178篇 |
2017年 | 113篇 |
2016年 | 133篇 |
2015年 | 132篇 |
2014年 | 152篇 |
2013年 | 189篇 |
2012年 | 303篇 |
2011年 | 349篇 |
2010年 | 161篇 |
2009年 | 138篇 |
2008年 | 225篇 |
2007年 | 236篇 |
2006年 | 216篇 |
2005年 | 186篇 |
2004年 | 178篇 |
2003年 | 161篇 |
2002年 | 154篇 |
2001年 | 23篇 |
2000年 | 20篇 |
1999年 | 30篇 |
1998年 | 25篇 |
1997年 | 24篇 |
1996年 | 14篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 17篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 13篇 |
1986年 | 10篇 |
1985年 | 13篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1937年 | 4篇 |
排序方式: 共有4244条查询结果,搜索用时 15 毫秒
11.
12.
Sami R Achem MD Alexander Klaus MD Ronald A Hinder MD PhD Kenneth R DeVault MD 《The American journal of medicine》2004,116(10):717-718
13.
14.
C. M. Lazaro W. Y. Guo M. Sami T. Hindmarsh K. Ericson A. L. Hulting J. Wersäll 《Neuroradiology》1994,36(2):111-114
In a group of 69 patients with pituitary tumours, 12 were found to have evidence of intratumoral haemorrhage on MRI, characterized by high signal intensity on short TR/TE sequences. This was verified in all but 1 patient. The majority of the bleedings occurred in macroadenomas. Five (42%) were prolactinomas and 4 (33%) were non-functioning adenomas. There were 2 GH- and 1 ACTH-secreting tumours. All 5 patients with prolactinomas were on bromocriptine medication. Two of the patients had a clinical picture of pituitary apoplexy. The haemorrhage was not large enough to prompt surgery in any of the patients. However, surgical verification of the diagnosis was obtained in 5 cases, while 6 patients were examined with follow-up MRI. 相似文献
15.
Innate immunity and its role against infections. 总被引:5,自引:0,他引:5
Suwannee Uthaisangsook Noorbibi K Day Sami L Bahna Robert A Good Soichi Haraguchi 《Annals of allergy, asthma & immunology》2002,88(3):253-64; quiz 265-6, 318
LEARNING OBJECTIVES: This article reviews current concepts of the innate immune system that offers protection against infections. It offers an overview for the readers to understand how innate immunity, consisting of different receptors, cells, and mediators recognizes pathogens and exerts protective function against pathogens. DATA SOURCES AND STUDY SELECTION: MEDLINE-search articles including original research papers, review articles, textbooks, and references identified from bibliographies of relevant articles. RESULTS AND CONCLUSIONS: The innate immune system is nonspecific immunity present since birth not requiring repeated exposure to pathogens. It is capable of differentiation between self and nonself. Because of its nonspecificity, it has a broad spectrum of resistance to infection. Further, it is thought to play an important role in the control of adaptive immunity by regulating co-stimulatory molecules and effector cytokines. Innate immunity includes pattern recognition molecules/receptors, antimicrobial peptides, the complement system, inflammatory mediators, and cytokines produced by immune cells. Pattern recognition molecules/receptors recognize pathogen-associated molecular patterns that are essential for microorganisms' survival and pathogenicity. Although innate immunity has recently gained increasing importance, further studies are necessary for a better understanding of its role. 相似文献
16.
17.
The effect of calcium dobesilate on venous function following saphenectomy in coronary artery bypass grafting 总被引:1,自引:0,他引:1
Kerim Cagli Kanat Ozisik Mustafa Emir Okan Yurdakok Sami Gurkahraman Vedat Bakuy Muharrem Tola Mustafa Pac Adnan Cobanoglu 《Cardiovascular Revascularization Medicine》2006,7(4):212-216
BACKGROUND: The aim of this study was to determine whether prophylactic use of calcium dobesilate (CD) can improve venous function after saphenous vein harvest in coronary artery bypass graft (CABG). MATERIALS AND METHODS: A total of 100 patients who underwent elective CABG were divided into four equal groups. In Group A, the greater saphenous vein (GSV) was harvested below the knee and, in Group B, through the knee till the groin. These patients remained untreated. Group C received CD in a dosage of 1500 mg po daily after the GSV was harvested below the knee. Group D received same dosage of CD after the GSV was harvested through the knee till the groin. Venous function of ipsilateral leg was evaluated clinically and by Doppler ultrasonography in the postoperative first week and second month. RESULTS: Clinical findings of venous insufficiency were observed with a similar rate between groups at both early and late periods. In Groups A and B, after 2 months, flow velocities decreased and reflux periods increased significantly. In groups C and D, treatment with CD for 2 months after saphenectomy resulted in a significant increase in flow velocities and a significant decrease in reflux periods. Patients in Groups B and D have significantly more impaired venous functions. CONCLUSION: Saphenectomy results in ipsilateral leg venous dysfunction, which seems to be unrelated to leg swelling and to be more prominent in patients with high-level saphenectomy. In addition, to be careful about the restriction of the saphenectomy procedure into the most appropriate level, prophylactic use of CD can prevent this deterioration when it was added to varice socks. 相似文献
18.
In the differentiated state, the testicular excurrent duct system of the sturgeon begins as a longitudinal marginal network of the testis, extending along the entire length of the male gonad. From here, mesorchial transversal ducts travel to the ventral aspect of the pars sexualis of the opisthonephros where they merge behind the dorsal coelomic wall to form the longitudinal marginal network of the kidney. Then, the seminal pathways enter the confines of the pars sexualis of the opisthonephros and divide into a complicated, multipartite system consisting of (1) centropapillary ducts, situated in the center of a group of urinary collecting ducts, (2) lacunary basal sinuses, located on the bases of opisthonephric columns and (3) intracolumnar ducts running inside the renal columns, the latter representing typical functional units of the adult sturgeon kidney. The contacts between intracolumnar ducts and the vascular poles of corresponding renal corpuscles represent the urogenital junction in the sturgeon. The nephrons of the pars sexualis involved in sperm transport do not lose their urinary functions, but are histologically identical to those of the pars excretoria which are solely urinary. The opisthonephros of sturgeons grows continuously by the formation of new nephrons from an opisthonephric blastema located on the base of each renal column. A close topographical association between this blastema tissue and the lacunary basal sinuses of the testicular excurrent duct system guarantees that new renal corpuscles in the pars sexualis are included in the seminal passage from their beginning. From the urogenital junctions, on their way to the exterior, the spermatozoa have to travel through Bowman's capsules and tubules of the nephrons involved, then through the urinary collecting ducts, the wolffian duct and finally the sinus urogenitalis. The development of the testicular excurrent duct system begins in 8-month-old animals in the pregonadal area of the gonadal fold. Here, a primary gonoductal blastema proliferates to form a longitudinal network of anastomosing strands, situated in the dorsal mesogonadal attachment. From this primary longitudinal network, small tubules grow into the direction of the opisthonephros and into the direction of the testis. In the period from 8 to 18 months, the testicular excurent duct system reaches the adult state. In conclusion, the testicular excurrent ducts of sturgeons initially develop similar to those of Polypterus and in modern teleosts from a primary longitudinal system, beginning in the pregonadal area, localized in the mesogonadal attachment and extending caudally. Then, in a second step of development, the phylogenetically older situation, using parts of the kidney as passage, already seen in Chondrichthyes, but preserved also in higher vertebrates, is achieved in Acipenser. For this, seminal ducts grow into the opisthonephros and establish here the urogenital junctions with corresponding renal corpuscles. Furthermore, the initially longitudinally oriented ducts in the mesogonadal attachment partly lose their continuity and become integrated into the course of the transversal mesorchial ducts, represented by their portions with the widest lumina and the thickest walls. 相似文献
19.
Totally extra-peritoneal (TEP) laparoscopic repair of an inguinalhernia involves the creation of an extra-peritoneal space by blunt dissection or the use of commercial balloons. This new technique demonstrates the use of a device to create this extra-peritoneal space, without the need for any commercial balloons. The extra-peritoneal space was created using a glove-balloon. A total of 107 consecutive TEP repairs were carried out using the glove-balloon technique, these included ten bilateral and 17 recurrent inguinal hernias. This method is simple, cost-effective and easy to teach. 相似文献
20.
Klaus-Dietrich Wolff Sami Swaid Dirk Nolte Roland A B?ckmann Frank H?lzle Christian Müller-Mai 《Journal of cranio-maxillo-facial surgery》2004,32(2):71-79
BACKGROUND: A carbonated apatite cement (NORIAN SRS) was used as a bone mineral substitute for the calvaria or viscerocranium in 27 patients. It has the consistency of a paste and hardens at physiologic pH and body temperature due to dahllite crystallization, which has the stoichiometric formula Ca(8.8)(HPO(4))(0.7)(PO(4))(4.5)(CO(3))(0.7)(OH)(1.3). MATERIAL AND METHODS: The cement was used for posttraumatic bone defects in the orbital, periorbital or malar regions (nine patients), posttraumatic deformities of the frontal bone (six patients), tumour-dependent bony defects of the calvaria (two patients) and posttraumatic or cystic defects of the mandible (five patients). In another five patients, the material was used to augment the atrophic anterior mandible in combination with the insertion of dental implants. Follow-up varied between 6 and 40 months (mean: 29 months). RESULTS: There was no inflammatory reaction surrounding the implanted material. There was no sign of infection in any of the patients and only one case of partial wound dehiscence with superficially exposed material. The defect fillings and augmentations were successful in all patients. None of the 19 dental implants which were inserted in combination with the material showed any sign of infection or loosening. Also, there was no loosening of the implants after loading (mean follow-up: 15 months). From the check-up radiographs, the material could be seen as a dense, radio-opaque structure. There were no material fractures or dislocations. Radiologically, the material seemed to be completely replaced by bony tissue after 30 months. CONCLUSION: Our 5-year clinical experience suggests that the material is a suitable bone mineral substitute for cranio-maxillofacial surgery especially for moderate-sized defects of the calvaria and forehead bone. It has advantages over preformed, solid bone substitute materials, and, due to its initial plasticity and eventual great compressive strength, it can also stabilize dental endosseous implants in the atrophic mandible. 相似文献