全文获取类型
收费全文 | 8181篇 |
免费 | 481篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 167篇 |
妇产科学 | 79篇 |
基础医学 | 873篇 |
口腔科学 | 111篇 |
临床医学 | 912篇 |
内科学 | 2020篇 |
皮肤病学 | 144篇 |
神经病学 | 432篇 |
特种医学 | 196篇 |
外国民族医学 | 1篇 |
外科学 | 1520篇 |
综合类 | 211篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 505篇 |
眼科学 | 149篇 |
药学 | 787篇 |
中国医学 | 159篇 |
肿瘤学 | 419篇 |
出版年
2024年 | 16篇 |
2023年 | 171篇 |
2022年 | 524篇 |
2021年 | 646篇 |
2020年 | 386篇 |
2019年 | 469篇 |
2018年 | 460篇 |
2017年 | 280篇 |
2016年 | 305篇 |
2015年 | 334篇 |
2014年 | 397篇 |
2013年 | 468篇 |
2012年 | 727篇 |
2011年 | 657篇 |
2010年 | 312篇 |
2009年 | 291篇 |
2008年 | 426篇 |
2007年 | 400篇 |
2006年 | 339篇 |
2005年 | 312篇 |
2004年 | 241篇 |
2003年 | 229篇 |
2002年 | 104篇 |
2001年 | 42篇 |
2000年 | 28篇 |
1999年 | 19篇 |
1998年 | 19篇 |
1997年 | 7篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1980年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1972年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有8728条查询结果,搜索用时 15 毫秒
991.
992.
Abdul Ghafur Muhammad Raza Wendy Labbett Anuradha Chawla Colette Smith Siew Lin Ngui Andrew Davenport Anna Maria Geretti 《Nephrology, dialysis, transplantation》2007,22(9):2640-2644
BACKGROUND: It has been proposed that hepatitis C virus (HCV)-infected patients with end-stage renal disease undergoing maintenance haemodialysis may lack HCV antibody (anti-HCV) despite chronic HCV viraemia. This carries important implications for the design of surveillance policies. METHODS: To characterize the prevalence of antibody-negative/RNA-positive HCV infection, patients attending seven haemodialysis units underwent anti-HCV testing using a third-generation assay and HCV RNA testing using real-time PCR. RESULTS: At screening, anti-HCV prevalence was 12/360 (3.3%; 95% CI 1.7-5.8%); 7/12 (58.3%) anti-HCV positive samples were HCV RNA positive. Among anti-HCV-negative samples, 2/348 (0.6%; 95% CI 0.2-2.1%) tested HCV RNA positive (genotype 1a). Retrospective testing of stored sera dated the infections to a period of holiday in the Indian subcontinent. The two infections were unrelated by HCV-NS5B sequencing. Only one of the two newly infected persons showed raised transaminases. Both developed anti-HCV within 8-13 weeks of follow-up. Prospective surveillance of travellers to resource-limited countries returning to the units showed a HCV incidence of 4/153 travel episodes (2.6%; 95% CI 0.7-6.6%) among 131 persons (3.1%; 95% CI 0.8-7.6%). CONCLUSIONS: Among haemodialysis patients in the United Kingdom, antibody-negative/RNA-positive HCV status is associated with newly acquired infection, rather than lack of antibody responses in chronic HCV infection. There is a significant risk of HCV infection associated with travel to resource-limited countries. Given that transaminase levels may be normal, HCV RNA testing is recommended in patients re-entering a dialysis unit following haemodialysis in settings where suboptimal infection control policies pose a risk of exposure to blood-borne viruses. 相似文献
993.
Joseph K. Muhammad Michael A. O. Lewis St. John Crean 《Journal of oral pathology & medicine》2002,31(2):121-124
There have been few reports describing the occurrence of pemphigus vulgaris (PV) during pregnancy. The patient described in this case report is interesting because the PV that developed during her pregnancy was confined to her mouth. It has been suggested that prompt treatment with systemic steroids prevents development of PV in cutaneous tissues. In this case, early control of the condition is believed to have eliminated the need for high dose steroids throughout the remainder of the pregnancy. In addition, this therapeutic approach could have contributed to the birth of a baby free of PV. Resolution of the presenting oral symptoms allowed the mother to resume a normal diet, allaying her anxiety about the possible effects of poor nutritional intake on foetal development. Aspects of clinical management considered in this report include the choice of immunosuppressive therapy and the multidisciplinary care involving both dental and obstetric specialists. 相似文献
994.
Muhammad Imran Malik Bernd Trathnigg C. Oliver Kappe 《Macromolecular chemistry and physics.》2007,208(23):2510-2524
Diblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) were synthesized by the anionic ring‐opening polymerization of propylene oxide (PO), with controlled microwave heating in sealed vessels. A detailed study was carried out to investigate the effects of different parameters on the formation of unwanted byproducts. Parameters that were considered include temperature; the concentration of NaH, monomer and hydroxy groups in the feed; and the polarity of the reaction medium. A continuous decrease of internal pressure during the sealed‐vessel experiment reflected the consumption of PO monomer and the completion of the reaction was confirmed by a drop of the internal pressure to zero when reactions were performed in bulk. The products were characterized by using different chromatographic techniques. A comparison of the reaction times and composition of the polymers prepared by microwave and conductive heating is given.
995.
Xanthogranulomatous salpingitis is an unusual inflammatory lesion of the fallopian tube, characterized by accumulation of foamy macrophages in the wall of the fallopian tube along with other chronic inflammatory cells. Only a few cases of xanthogranulomatous salpingitis have been reported in the English medical literature, some under different nomenclature. An association, most commonly with pelvic inflammatory disease and endometriosis, has been suggested. A 41-year-old woman with prior history of breast carcinoma underwent bilateral salpingoophorectomy because of hematosalpinx. The histology revealed xanthogranulomatous salpingitis in the setting of extensive fallopian tube mucosal endometriosis, endometritis, and presence of an intrauterine contraceptive device. Multiple etiologies have been linked to the xanthogranulomatous process at this location in previously reported cases. A whole spectrum of changes may exist in this lesion and probably represent a specialized form of tissue reaction secondary to multiple etiologies. Although it has been associated with pelvic endometriosis, it has never been demonstrated through progressive changes, beginning with mucosal endometriosis to the full-blown xanthogranulomatous inflammation. To the best of our knowledge, this is the first reported case that demonstrates different stages in the pathogenesis of this lesion and provides an insight into the histogenesis of this entity. 相似文献
996.
997.
Oxidative stress, glucose metabolism, and the prevention of type 2 diabetes: pathophysiological insights 总被引:1,自引:0,他引:1
With the rising epidemic of type 2 diabetes worldwide, including the United States, the death and disability due to the suboptimal control of cardiovascular disease associated with this epidemic has made prevention of type 2 diabetes emerge as a primary strategic intervention. Several modalities have been assessed in large randomized controlled trials for diabetes prevention such as lifestyle interventions and various pharmacologic agents. Included in these agents are metformin, thiazolidinediones, acarbose, angiotensin converting enzyme inhibitors, as well as angiotensin receptor blockers. Abrogation of oxidative stress appears to be a common soil hypothesis that explains the favorable effects of these agents on glucose metabolism, including the prevention of diabetes and its complications. This comprehensive review highlights the role of oxidative stress in the pathogenesis of diabetes, with emphasis on the major clinical trials conducted on prevention of type 2 diabetes. 相似文献
998.
William E. Ackerman MD ; Muhammad A. Munir MD ; Jun-Ming Zhang MS MD ; Ahmed Ghaleb MD 《Pain practice》2004,4(4):286-291
Introduction: Nonradicular low back pain can be a difficult entity to accurately diagnose and treat. Facet joints, muscle, ligaments, and fascia have all been reported to be etiologies of acute and chronic low back pain. However, the facet joint as a source of low back pain is controversial. The diagnosis of facet joint pain is made by diagnostic facet joint or median nerve branch injections with a local anesthetic. The purpose of this study was to determine if the results of diagnostic facet joint injections are influenced by the technique used to perform these injections. Methods: Seventy‐five male patients aged 45 years or younger and 18 years or older who were injured while performing heavy work with nonradicular low back pain were included in this study. Diagnostic injection therapy was performed following Institutional Review Board approval and the patient's informed consent. Patients were assigned to one of five groups to receive diagnostic injections in a double‐blinded fashion as follows: Group I: facet joint injection with continuous lidocaine administration from the skin to the facet joint as the needle was advanced; Group II: facet joint injection with saline administration from the skin to the facet joint as the needle was advanced; Group III: median nerve branch injection with a lidocaine advancing needle technique; Group IV: median nerve branch injection with saline advancing needle technique; and Group V: injection of the paraspinous muscles with local anesthetic and steroid following noted areas of pain diagnosed with saline injection and radiopaque contrast. After one week, the patients in Groups I to IV who had no pain relief with facet joint or median nerve block injections subsequently received paraspinous muscle injections, while the patients in Group V who had no long‐term relief with muscle injections were given facet joint injections. The appropriate parametric and nonparametric tests were performed with statistical significance defined as P ≤ 0.05. Results: There were no differences among the groups demographically. The incidence of pain relief was significantly higher in subjects who had a continuous injection of local anesthetic into their musculature than in those individuals who received continuous saline followed by an injection of local anesthetic into their facet joint or median nerve branch. Discussion: The results of this study demonstrated that local anesthetic injections are useful for the diagnosis of nonradicular low back pain but may yield false positive results with respect to lumbar facet pain depending upon the technique utilized. 相似文献
999.
1000.
Isolated Aneurysms of the Membranous Ventricular Septum Without Residual Shunts: Systematic Review and Description of 3 Cases in Adults 下载免费PDF全文
Ali Abdul Jabbar MD Omar Mufti MD Wojciech Mazur MD Muhammad Bilal Quraishi MD Bal K. Srivastava MD Vijay Tivakaran DO 《Journal of ultrasound in medicine》2017,36(5):869-878
A ventricular septal defect is the most common congenital cardiac abnormality encountered in infants and children. Many of them survive through adulthood before diagnosis. Two‐thirds of the cases involve the membranous part of the septum. In the absence of an interventricular shunt or concomitant cardiac surgery, guidelines for surgical intervention or resection of isolated aneurysms of the membranous septum are not well established. In this report, we discuss a multi–imaging modality approach for the diagnosis and assessment of membranous ventricular septal aneurysms and review the experts' consensuses for follow‐up and treatment strategies. 相似文献