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   1388篇
  免费   92篇
  国内免费   7篇
耳鼻咽喉   22篇
儿科学   44篇
妇产科学   114篇
基础医学   193篇
口腔科学   55篇
临床医学   106篇
内科学   235篇
皮肤病学   26篇
神经病学   124篇
特种医学   17篇
外科学   125篇
综合类   13篇
预防医学   100篇
眼科学   50篇
药学   62篇
中国医学   2篇
肿瘤学   199篇
  2023年   10篇
  2022年   48篇
  2021年   67篇
  2020年   32篇
  2019年   57篇
  2018年   67篇
  2017年   43篇
  2016年   37篇
  2015年   42篇
  2014年   35篇
  2013年   83篇
  2012年   106篇
  2011年   87篇
  2010年   74篇
  2009年   49篇
  2008年   85篇
  2007年   85篇
  2006年   92篇
  2005年   67篇
  2004年   53篇
  2003年   48篇
  2002年   67篇
  2001年   24篇
  2000年   19篇
  1999年   15篇
  1998年   10篇
  1997年   7篇
  1996年   9篇
  1995年   4篇
  1994年   3篇
  1993年   4篇
  1992年   4篇
  1991年   4篇
  1990年   6篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1980年   3篇
  1979年   3篇
  1978年   3篇
  1975年   2篇
  1974年   3篇
  1973年   1篇
  1966年   1篇
  1965年   2篇
  1963年   1篇
排序方式: 共有1487条查询结果,搜索用时 31 毫秒
1.
ImportanceImmunotherapy has emerged as an effective treatment option for the management of advanced cancers. The effects of these immune checkpoint inhibitors in the older patient population has not been adequately assessed.ObjectiveTo understand the impact of aging on CTLA-4 and PDL-1 inhibitors efficacy and immune-related adverse events (irAE) in the context of real-world management of advanced solid cancers.Design, Setting, and ParticipantsThis retrospective study involved all non-study patients with histologically-confirmed metastatic or inoperable solid cancers receiving immunotherapy at Kingston Health Sciences Centre. We defined ‘older patient’ as age ≥ 75. All statistical analyses were conducted under SPSS IBM for Windows version 24.0.Main Outcomes and MeasuresStudy outcomes included immunotherapy treatment response, survival, as well as number, type, and severity of irAEs.ResultsOur study (N = 78) had 29 (37%) patients age <65, 26 (33%) patients age 65–74, and 23 (30%) patients age ≥75. Melanoma, non-small cell lung cancer, and renal cell carcinoma accounted for 70%, 22%, and 8% of the study population, respectively. Distributions of ipilimumab (32%), nivolumab (33%), and pembrolizumab (35%) were similar in the study. The response rates were 28%, 27%, and 39% in the age <65, age 64–74, age ≥75 groups, respectively (P = 0.585). Kaplan-Meier curve showed a median survival of 28 months (12.28–43.9, 95% CI) and 17 months (0–36.9, 95% CI) in the age <65 and age 64–74 groups, respectively; the estimated survival probability did not reach 50% in the age ≥75 group (P = 0.319). There were no statistically significant differences found in terms of irAEs, multiple irAEs, severity of grade 3 or higher, types of irAEs, and irAEs resolution status when comparing between different age groups.Conclusion and RelevanceOur results suggest that patients age ≥75 are able to gain as much benefit from immunotherapy as younger patients, without excess toxicity. Our findings suggest that single agent immunotherapy is generally well-tolerated across different age groups with no significant difference in the type, frequency or severity of irAEs. Future studies evaluating aging and combination immunotherapy are warranted.  相似文献   
2.
Purpose: To study the prevalence and time of onset of ocular complications in intermediate uveitis (IU) and to assess their effects on visual outcome in short-term and long-term follow-up.

Methods: A retrospective cohort study of patients with IU who had a minimal follow-up of one year.

Results: 96 patients (174 eyes, 70% females) were included with a mean age at presentation of 30 years. Children constituted 38% of all patients. Mean follow- up was 64.9 months. Pars planitis was the most common form followed by sarcoidosis and multiple sclerosis. Cystoid macular edema (CME), cataract, epiretinal membrane and posterior synechiae were the most prevalent complications. Posterior synechiae, band keratopathy, cataract and papillitis at presentation were associated with worse presenting visual acuity (VA). Of the late-onset complications, glaucoma/ocular hypertension (OHT) was the most significantly associated with worse long-term VA. Most sight-threatening complications (namely CME and glaucoma) were diagnosed at presentation while late complications predominantly affected the posterior segment and included among others peripheral retinal elevations, vasoproliferative tumors, and vitreous hemorrhage. Median LogMAR VA improved at short-term and long-term follow-up, from 0.2 to 0.1 (p<0.001). Subgroup analysis revealed significant VA improvement for eyes with all the different complications except for eyes with glaucoma/OHT.

Conclusion: IU is a chronic low-grade uveitis that may be associated with protean early and late complications of the anterior or posterior segments or both. Optimal treatment regimens are imperative for the strict control of inflammation and proper management of complications thus allowing a favorable long-term prognosis.  相似文献   

3.
4.
Fate of micelles and quantum dots in cells.   总被引:2,自引:0,他引:2  
Micelles and quantum dots have been used as experimental drug delivery systems and imaging tools both in vitro and in vivo. Investigations of their fate at the subcellular level require different surface-core modifications. Among the most common modifications are those with fluorescent probes, dense-core metals or radionucleids. Cellular fate of several fluorescent probes incorporated into poly(caprolactone)-b-copolymer micelles (PCL-b-PEO) was followed by confocal microscopy, and colloidal gold incorporated in poly 4-vinyl pyridine-PEO micelles were developed to explore micelle fate by electron microscopy. More recently, we have examined quantum dots (QDs) as the next-generation-labels for cells and nanoparticulate drug carriers amenable both to confocal and electron microscopic analyses. Effects of QDs at the cellular and subcellular levels and their integrity were studied. Results from different studies suggest that size, charge and surface manipulations of QDs may play a role in their subcellular distribution. Examples of pharmacological agents incorporated into block copolymer micelles, administered or attached to QD surfaces show how the final biological outcome (e.g. cell death, proliferation or differentiation) depends on physical properties of these nanoparticles.  相似文献   
5.
A case of an unusual lesion from the maxilla is presented. Macroscopically, the lesion was solid and histologically consisted of 'multiple separate keratocysts' of varying size that infiltrated into the surrounding bone and soft tissues. Panoramic image and CT scans showed a multilocular honeycomb ill-defined radiolucency with infiltration into the maxillary sinus and floor of orbit. This lesion should be differentiated from similar odontogenic lesions, such as keratoameloblastoma and papilliferous keratoameloblastoma. As there was no evidence of follicles, islands of ameloblastoma, or papilliferous structures in the entire specimen, the lesion could not be diagnosed as either a keratoameloblastoma or a papilliferous keratoameloblastoma. The invasive and destructive growth behavior, the histopathological features, and the histochemical pattern of the collagen stroma imply that this solid lesion is a neoplasia. It is suggested that the proper term for this lesion is solid variant of odontogenic keratocyst.  相似文献   
6.
Detection of Clostridium difficile toxins A and B in stools by Premier Cytoclone A+B enzyme immunoassay (EIA) was compared with detection by stool culture for C. difficile followed by detection of toxigenic isolates using the same EIA. Chart reviews were performed to evaluate the likelihood of C. difficile-associated diarrhea and colitis (CADC) for all patients with at least one positive toxin assay. While the toxins were detected in 58 of 85 consecutive CADC patients by both assays, CADC in 5 patients was detected only by stool toxin assay, and in 22 patients CADC was detected only by toxigenic culture. Our results suggest that for laboratories using a rapid toxin A+B EIA, direct toxin detection in stools should be combined with toxigenic culture in cases in which there is a negative stool toxin assay.  相似文献   
7.
Metronidazole resistance among Prevotella spp. is rare. We report here the first case of bacteremia due to a high-level metronidazole-resistant Prevotella sp. responsible for treatment failure.  相似文献   
8.
Two-laser and two-color approaches were used to observe the colocalization of the calcium-binding proteins, calbindin D28k and parvalbumin, and the retrograde tracer, Fluoro-Gold (FG) in the basolateral amygdala of the rat. The study was performed on five adult rats into which FG was injected to the frontal association cortex. Then, the localization of the retrogradely labeled neurons in the basolateral amygdala was compared with the localization of the neurons labeled by calcium-binding proteins. The present study showed that most of the retrogradely labeled neurons in the posterior part of the basolateral amygdala are also calbindin-positive. Even though a lot of parvalbumin-positive endings were present at the surface of the retrogradely labeled cells, we did not observe the colocalization of the parvalbumin and projective neurons.  相似文献   
9.
10.
There has been a large amount of work done recently on small peripheral stage I adenocarcinomas that come to resection. Radiological (including proportion of ground glass opacity) and pathological features of these lesions (predominant bronchioloalveolar component, central scar with or without invasion <0.5 cm) have been shown to be prognostically favorable with cure rate approaching 100% in some series. Most of these studies emanate from Japan. The relevance of these studies to other parts of the world, particularly North America, is discussed in light of the fact that some recent chemotherapeutic studies with gefitinib have shown increased response in individuals of Asian origin, suggesting that some genetic differences may be significant. The relevance of these findings to pathologists and the pathological study of small peripheral adenocarcinomas from elsewhere in the world are discussed.  相似文献   
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