首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4811篇
  免费   217篇
  国内免费   28篇
耳鼻咽喉   99篇
儿科学   54篇
妇产科学   40篇
基础医学   570篇
口腔科学   156篇
临床医学   338篇
内科学   1111篇
皮肤病学   100篇
神经病学   361篇
特种医学   264篇
外科学   809篇
综合类   17篇
预防医学   183篇
眼科学   131篇
药学   268篇
中国医学   7篇
肿瘤学   548篇
  2024年   4篇
  2023年   43篇
  2022年   57篇
  2021年   116篇
  2020年   66篇
  2019年   101篇
  2018年   103篇
  2017年   77篇
  2016年   105篇
  2015年   106篇
  2014年   155篇
  2013年   173篇
  2012年   305篇
  2011年   339篇
  2010年   170篇
  2009年   152篇
  2008年   301篇
  2007年   310篇
  2006年   376篇
  2005年   335篇
  2004年   353篇
  2003年   317篇
  2002年   305篇
  2001年   46篇
  2000年   40篇
  1999年   57篇
  1998年   63篇
  1997年   67篇
  1996年   50篇
  1995年   42篇
  1994年   59篇
  1993年   38篇
  1992年   33篇
  1991年   27篇
  1990年   26篇
  1989年   24篇
  1988年   12篇
  1987年   13篇
  1986年   12篇
  1985年   11篇
  1984年   16篇
  1983年   8篇
  1982年   8篇
  1981年   7篇
  1980年   6篇
  1979年   4篇
  1978年   5篇
  1973年   2篇
  1969年   3篇
  1965年   2篇
排序方式: 共有5056条查询结果,搜索用时 15 毫秒
81.
Laparoscopic appendectomy is now widely practiced for the treatment of acute appendicitis. As result of increased demand for minimally invasive surgery, single-incision access was introduced and is being performed in various abdominal surgeries. Conventional laparoscopic appendectomy (LA) is gradually being performed in pregnant women. A 33-year-old woman was referred to our department at 39 weeks and 1 day of gestation due to abdominal pain. She was aware of her gastroepiploic pain even after the delivery. Though it was past 2 days, she was not recovering from right lower abdominal pain, so she was transferred to the Department of Gynecology at our hospital on the same day. Although an antibiotic was administered, the right abdominal pain did not improve, and she was referred to our department from the Department of Gynecology. We performed single-port LA (SP-LA). The total operation time was 63 minutes, and the estimated blood loss was 0 mL. She was discharged with no complications on postoperative day 7. We report our initial experience with single-port LA (SP-LA) using the glove technique for treatment of acute appendicitis in a postpartum woman. SP-LA using the glove technique was performed successfully during the puerperium without prolongation of operation time. This approach is less invasive, offers a much better cosmetic result than with conventional methods, and can be performed safely and at low cost.Key words: PLA (single-port laparoscopic appendectomy), PuerperiumThe advantages of laparoscopic appendectomy (LA) over open appendectomy (OA) are widely known and include decreased pain, shorter convalescence, and earlier return to work. Especially, LA is advantageous for treating acute appendicitis in pregnant women. Because the appendix of a pregnant woman is shifted from its normal position, OA may leave a larger operative scar than normal. In recent years, efforts of laparoscopic surgeons have resulted in a reduction in both the diameter of the access ports and the number of ports needed.1 In addition, natural orifice transluminal endoscopic surgery (NOTES) is being developed as another form of minimally invasive surgery.2 As a part of this process, the single-incision laparoscopic surgery (SILS) technique is presently being developed for various laparoscopic surgeries.3 SILS is a virtually scarless technique in which the single-port access site is hidden in the umbilicus. We think that the primary advantage of single-port laparoscopic appendectomy (SP-LA) is the superior cosmetic result compared with multi-port access LA. We report a very rare case in which SP-LA was performed to treat acute appendicitis during the puerperium. This approach is less invasive, offers a much better cosmetic result than with conventional methods, and can be performed safely and at low cost.  相似文献   
82.
83.
84.
85.
86.
Levels of lipoprotein (a) (Lp[a]) and various hemostatic factors were studied in 132 Japanese aged >75 years (mean 83). The group consisted of 50 healthy persons, 36 hypertensive subjects, 31 patients with chronic cerebral infarction, and 15 with coronary artery disease. Lp(a) levels were slightly lower in the healthy “old old” subjects than in the 184 healthy younger adults (mean ± SD: 10.7 ± 7.9 vs 12.1 ± 10.1 mg/dl). There were no gender-related differences in the Lp(a) levels of healthy adults and healthy old old subjects. Lp(a) levels were higher in the hypertensive old old subjects (14.6 ± 15.4 mg/dl) and the old old patients with cerebral infarction (21.3 ± 16.2 mg/dl) and coronary artery disease (26.5 ± 20.4 mg/dl). The prevalence of subjects with high Lp(a) levels (>30 mg/dl) was the greatest among old old patients with coronary artery disease (27%). Lp(a) levels in the 132 old old subjects showed positive correlations with sialic acid, fibrinogen, factor VII activity, and D-dimer levels. These results indicate a close association between Lp(a) levels and atherothrombotic disease as well as the characteristics of Lp(a) as an acute phase reactant in old old Japanese. Subjects with higher Lp(a) levels may develop cardiovascular disease later in life, whereas the remaining healthy old old subjects have lower Lp(a) levels.  相似文献   
87.
A total of 2651 consecutive native Japanese women who underwent a glucose challenge test (GCT) were retrospectively investigated. GCT was performed between 24 and 27 weeks of gestation; each subject received a 50 g oral glucose load without regard to the fasting or fed state, followed by a determination of 1 h venous plasma glucose level. Women demonstrating GCT exceeding 130 mg/dl received a 75 g, 2 h oral glucose tolerance test to determine whether or not they had gestational diabetes mellitus (GDM). All women with GDM were treated with a strict diabetic protocol including insulin therapy. Forty-nine (1.8%) women were diagnosed to have GDM. The receiver-operator characteristic curve identified a GCT finding above 140 mg/dl as the cutoff value for detecting GDM, which showed a sensitivity and specificity of 96 and 76%, respectively. Our results suggest that the cutoff value of a 50 g GCT is 140 mg/dl to identify pregnancies with GDM in a Japanese population.  相似文献   
88.
A major challenge of targeted molecular imaging and drug delivery in cancer is establishing a functional combination of ligand-directed cargo with a triggered release system. Here we develop a hydrogel-based nanotechnology platform that integrates tumor targeting, photon-to-heat conversion, and triggered drug delivery within a single nanostructure to enable multimodal imaging and controlled release of therapeutic cargo. In proof-of-concept experiments, we show a broad range of ligand peptide-based applications with phage particles, heat-sensitive liposomes, or mesoporous silica nanoparticles that self-assemble into a hydrogel for tumor-targeted drug delivery. Because nanoparticles pack densely within the nanocarrier, their surface plasmon resonance shifts to near-infrared, thereby enabling a laser-mediated photothermal mechanism of cargo release. We demonstrate both noninvasive imaging and targeted drug delivery in preclinical mouse models of breast and prostate cancer. Finally, we applied mathematical modeling to predict and confirm tumor targeting and drug delivery. These results are meaningful steps toward the design and initial translation of an enabling nanotechnology platform with potential for broad clinical applications.A long-term goal in contemporary cancer nanomedicine has been to design and generate drug delivery systems that improve the narrow therapeutic window associated with conventional chemotherapeutics (1, 2). Conceptually, several nanotechnology-based entity candidates, including protocells (3), biosynthetic nanoparticles (NPs), viruses, and liposome-based nanoparticles, could be targeted for active delivery through a defined cell surface ligand receptor system and/or physically triggered for finely tuned cargo release (2, 4, 5).Numerous efforts have been made to functionalize NPs by combining them with antibodies, aptamers, peptides, vitamins, or carbohydrates (68), but the majority of studies involve untargeted nanoplatforms (4, 9). In practice, targeting NPs is far from trivial, and ongoing challenges include synthesis and purification, selection of an appropriate ligand receptor, and specific composition for NP conjugation. Even the conjugation reaction itself may alter the binding of the tumor-targeting moiety to its receptor through conformational changes, steric freedom restriction, or orientation distortion (10, 11). Unfortunately, the cost-to-benefit ratio of these modifications often elevate the complexity of the NP synthesis, complicating regulatory hurdles because of formulations that are heterogeneous or difficult to reproduce (10, 12, 13).To minimize such drawbacks, NPs can be functionalized via virus-based nanoplatforms as an alternative for targeted cargo delivery (1416). In particular, filamentous bacteriophage (phage)—a prokaryotic virus—is an attractive candidate to develop a bionanomedicine for cancer therapeutics because phage particles are cost-effectively produced with biological uniformity, as well as being physically robust and stable under harsh conditions (17). Notably, phage-based nanoplatforms are biocompatible and nonpathogenic with eukaryotic organisms and are able to preserve the desired cell targeting and internalization (18). Moreover, phage particles are ideal for incorporating other NPs, which can be released after reaching the tumor site. An admixture of colloidal gold NP (AuNP) with phage particles spontaneously organizes into hydrogel network-like fractal structures (19, 20). These hydrogel networks offer convenient multifunctional integration within a single entity for tumor targeting, enhanced fluorescence and dark-field microscopy, near-infrared (NIR) photon-to-heat conversion, and surface-enhanced Raman scattering (SERS)-based detection (20, 21).In the present work, we developed a tumor targeting theranostic (meaning a combination of therapeutics and diagnostics) hydrogel-based nanoplatform that enables ligand-directed tumor targeting, multimodal imaging capability, and triggered therapeutic cargo release. Our data suggest that targeted hydrogel photothermal therapy represents a functional theranostic approach (fostering “see and treat, treat and see”) in the diagnosis and management of tumors.  相似文献   
89.
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号