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   17362篇
  免费   1136篇
  国内免费   114篇
耳鼻咽喉   267篇
儿科学   405篇
妇产科学   293篇
基础医学   2488篇
口腔科学   1765篇
临床医学   1385篇
内科学   3675篇
皮肤病学   419篇
神经病学   1238篇
特种医学   524篇
外科学   1831篇
综合类   137篇
一般理论   4篇
预防医学   1970篇
眼科学   175篇
药学   1309篇
中国医学   177篇
肿瘤学   550篇
  2023年   152篇
  2022年   416篇
  2021年   657篇
  2020年   449篇
  2019年   549篇
  2018年   686篇
  2017年   568篇
  2016年   539篇
  2015年   697篇
  2014年   869篇
  2013年   976篇
  2012年   1425篇
  2011年   1585篇
  2010年   868篇
  2009年   665篇
  2008年   1019篇
  2007年   1068篇
  2006年   837篇
  2005年   712篇
  2004年   599篇
  2003年   500篇
  2002年   415篇
  2001年   291篇
  2000年   261篇
  1999年   207篇
  1998年   141篇
  1997年   117篇
  1996年   101篇
  1995年   84篇
  1994年   94篇
  1993年   68篇
  1992年   94篇
  1991年   92篇
  1990年   71篇
  1989年   78篇
  1988年   73篇
  1987年   47篇
  1986年   59篇
  1985年   53篇
  1984年   33篇
  1983年   43篇
  1982年   18篇
  1980年   34篇
  1979年   34篇
  1978年   19篇
  1977年   21篇
  1976年   21篇
  1975年   21篇
  1973年   20篇
  1968年   32篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
991.
An open, randomized, controlled study with two parallel treatment groups was done to evaluate the efficacy of a Lippia sidoides essential oil (EO) 1% mouthrinse compared with chlorhexidine 0.12% mouthrinse, applied two times daily for 1 week, in the treatment of dental plaque and gingivitis. Fifty‐five patients were included in the study. The efficacy variables were the colony count of Streptococcus mutans from the stimulated saliva and periodontal indices on days 0, 7 and 30 after commencement of therapy. Twenty eight patients received chlorhexidine mouthrinse (Periogard®) and 27 Lippia sidoides essential oil mouthrinse (Cepakill®). The clinical and microbiological parameters were significantly reduced by both mouthrinses. No significant difference was seen between the two groups (p > 0.05). There was a significant reduction in the colony count of S. mutans in both groups (p < 0.05). Chlorhexidine treatment reduced more efficiently than L. sidoides, however, no statistical difference was seen, the efficacy of both groups was similar (p = 0.3). The results indicate that Chlorhexidine mouthrinse reduced plaque index, gingival bleeding and the number of CFU (colonies forming units) more efficiently than L. sidoides but did not reach statistical significance. This study demonstrated that Lippia sidoides EO mouthrinse is effective in reducing microbial plaque and gingival inflammation. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
992.
Therapeutic strategies directed at the tumor surfaceome (TS), including checkpoint inhibitor blocking antibodies, antibody drug conjugates (ADCs), and chimeric antigen receptor T (CAR-T) cells, provide a new armament to fight cancer. However, a remaining bottleneck is the lack of strategies to comprehensively interrogate patient tumors for potential TS targets. Here, we have developed a platform (tumor surfaceome mapping [TS-MAP]) integrated with a newly curated TS classifier (SURFME) that allows profiling of primary 3D cultures and intact patient glioma tumors with preserved tissue architecture. Moreover, TS-MAP specifically identifies proteins capable of endocytosis as tractable targets for ADCs and other modalities requiring toxic payload internalization. In high-grade gliomas that remain among the most aggressive forms of cancer, we show that cellular spatial organization (2D vs. 3D) fundamentally transforms the surfaceome and endocytome (e.g., integrins, proteoglycans, semaphorins, and cancer stem cell markers) with general implications for target screening approaches, as exemplified by an ADC targeting EGFR. The TS-MAP platform was further applied to profile the surfaceome and endocytome landscape in a cohort of freshly resected gliomas. We found a highly diverse TS repertoire between patient tumors, not directly associated with grade and histology, which highlights the need for individualized approaches. Our data provide additional layers of understanding fundamental to the future development of immunotherapy strategies, as well as procedures for proteomics-based target identification and selection. The TS-MAP platform should be widely applicable in efforts aiming at a better understanding of how to harness the TS for personalized immunotherapy.

Cell-surface proteins have a key role in drug development, and approximately two-thirds of approved human drugs target a cell-surface protein (1). Recently, tumor cell–surface proteins integrated with the plasma membrane (tumor surfaceome [TS]) have attracted considerable attention as targets for immunotherapies in cancer. Immune checkpoint-blocking antibodies (e.g., ipilimumab and nivolumab), antibody drug conjugates (ADCs, e.g., trastuzumab emtansin), radioimmunotherapy (RIT, e.g., 90Y ibritumomab tiuxetan), and chimeric antigen receptor T (CAR-T) cells are all directed at the TS and currently revolutionize cancer treatment (26). With the impressive development of creative methods for antibody and T cell engineering, a remaining challenge is the lack of strategies to comprehensively map potential TS target antigens for the design of more rational, individualized treatments (7). Although advancements in DNA and RNA sequencing provide high throughput data for prediction algorithms, e.g., personalized peptide vaccine trials (8, 9), the predicted proteome derived from these platforms is not necessarily expressed and available for targeting. Moreover, proteomics-based strategies involve analysis of the bulk from disintegrated tumor tissue, resulting in loss of spatial information and limited coverage of the less abundant and hydrophobic TS proteins (10, 11). Of particular relevance, ADC, RIT, and other intracellular drug delivery strategies rely on TS targets that functionally engage in endocytic internalization (12). Clearly, despite its great targeting potential in cancer immunotherapy, the TS remains an elusive treasure for further discovery.Procedures for unbiased mapping of the TS and target identification should include specific labeling of the TS in freshly resected patient tumors with preserved tissue architecture. Enrichment of TS proteins and reduction of noise from intracellular proteins as well as abundant extracellular matrix collagens and glycoproteins would greatly improve downstream mass spectrometry analysis. Moreover, the approach should allow functional and dynamic profiling of TS internalization in an intact tissue environment. With the aim to address these challenges and to provide insight into the complexity of the TS, we have developed a versatile technology for TS mapping (TS-MAP). As proof of concept, we focused on primary brain tumors that remain among the most aggressive forms of cancer and for which attempts to conquer the most common variant, glioblastoma (GBM) (World Health Organization [WHO] grade IV) have failed so far (13). TS-MAP is compatible with spheroids from primary human stem cell–like GBM cultures, as well as mouse and patient brain tumors, and separately profiles surface resident and internalized TS proteins. Moreover, a TS classifier (SURFME) was curated for filtering and categorization of bona fide membrane proteins exposed to the extracellular space. We find significant differences in the TS between the 2D and 3D spheroid format, which underlines the importance of cellular spatial organization. In strong support of the need of individualized approaches, our findings suggest substantial intertumoral heterogeneity in the relative abundance of TS proteins in a cohort of freshly resected patient gliomas.  相似文献   
993.
Given the increase in life expectancy indeveloped countries,nonagenarian population will become clinically and numerically relevant in our daily routine practice in the near future.Age has been observed to exert a profound influence on the prevalence of severe mitral regurgitation (MR) in the population.[1]Mitral valve surgery remains the gold standard of care for patients with symptomatic severe MR.  相似文献   
994.
Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare and aggressive condition that is associated with the SMARCA4 mutation and has a dismal prognosis. It is generally diagnosed in young women. Here, we report a case of a young woman with SCCOHT harboring a rare molecular finding with a highly aggressive biological behavior. The patient had a somatic SMARCB1 mutation instead of an expected SMARCA4 alteration. Even though the patient was treated with high-dose chemotherapy followed by stem cell transplantation, she evolved with disease progression and died 11 months after her first symptoms appeared. We present a literature review of this rare disease and discuss the findings in the present patient in comparison to expected molecular alterations and options for SCCOHT treatment.  相似文献   
995.
Traumatic brain injury (TBI) is among the leading causes of death and disability all over the globe. TBI is also commonly associated with clinical sequelae of posttraumatic depression, and reports of other subsequent affective distress are common. Similarly, posttraumatic changes in chemoreceptive sensory functions, primarily due to coup-contrecoup injury induced shearing of the olfactory nerve fibers, leading to anosmia and ageusia are also well documented in the literature. However, the current literature is limited in addressing the intersections between said variables. The aim of this study was to provide a focused narrative review of the literature, to address these intersections found in clinical sequelae of TBI. As chemoreceptive sensory deficits are also linked to significant affective distress of their own, this review addresses the bidirectionality between sensory deficit and affective distress. Prevalence, demographics, mechanisms, and clinical implications are presented. Previous research is presented and discussed, in an effort to highlight the importance of consideration for all factors in TBI patient care and future research.  相似文献   
996.
997.
This paper presents a patient successfully treated for leiomyosarcoma of the vena cava, with no recurrence or symptoms on an 8-year follow-up. A 56-year-old woman presented with chronic and progressive periumbilical and right upper abdominal pain. Physical examination and laboratory tests revealed no abnormalities. Computed tomography showed a high-density image inside the vena cava. Cavography showed a filling defect with complete occlusion of the vena cava involving the renal veins and greatly developed collateral circulation through lumbar veins. Laparotomy was performed and a large caval mass involving the renal veins was dissected and resected. Venous reconstruction was undertaken using a 19-mm bovine pericardium prosthesis (Labcor, MG-Brazil) interposed as a substitute to the vena cava, and the renal veins were anastomosed to the side of the graft. Pathologic examination confirmed a leiomyosarcoma with free surgical margins. The postoperative course was uneventful and the patient was discharged on postoperative day 8. The venous flow through the inferior vena became normal, as confirmed by later cavography. This paper presents a case of successfully managed leiomyosarcoma of the vena cava with a thorough review of the literature. The treatment of such patients and the use of bovine pericardium are also discussed.  相似文献   
998.
BackgroundWe aimed to study the implications of breast cancer (BC) subtypes for the development and prognosis of leptomeningeal carcinomatosis (LC).Patients and methodsData from the breast cancer patients diagnosed with LC between 2005 and 2010 were retrieved. Patients were classified in luminal A, B, HER2 positive and triple negative (TN) and their BC diagnosis, treatment, and outcome were analyzed according to each subtype. Pearson's chi-square and Fisher's exact test were used for categorical variables. Survival analyses were performed by Kaplan–Meier method and compared with the log-rank test.ResultsA total of 38 BC patients were identified, with a median age of 54.8 years (range 36–79). The proportion of luminal A, B, HER2 positive and TN was 18.4%, 31.6%, 26.3% and 23.7%, respectively. LC was the first evidence of metastatic disease in 5 BC patients. Twenty patients received the systemic chemotherapy, with 16 (80%) whole brain radiotherapy (WBRT). Nine patients received only WBRT. TN patients had the shorter interval between metastatic breast cancer diagnosis and the development of LC. Median survival after the diagnosis of LC (OSLC) was 2.6 months (range 1.2–6.4), and did not differ across breast cancer subtypes. In univariate analysis, performance status (ECOG = 0–2) and chemotherapy were prognostic for OSLC, but only the treatment stood as an independent prognostic factor in multivariate analysis.ConclusionsBreast cancer subtype influences the timing of LC appearance, but not OSLC. Patients with LC from breast cancer should be offered systemic treatment, as it appears to associate with the improved outcome. New therapeutic strategy, including, targeted and intrathecal therapy are deserved for BC patients with LC.  相似文献   
999.
OBJECTIVE: The purpose of this study was to analyze the behavior of the mitral valve ring and the left ventricle in dilated cardiomyopathy. METHODS: We analyzed 68 fixed adult human hearts, divided into 48 hearts with dilated cardiomyopathy of ischemic or idiopathic origin and 20 hearts free of pathologic heart conditions. Digital images of the mitral ring perimeter, attachment of the anterior and posterior leaflets, and fibrous and muscular portions were collected. We also measured the internal perimeter of the left ventricle, the distance from the septum to the anterior and posterior papillary muscles, the distance between the papillary muscles, and the extension of interventricular septum. RESULTS: The analysis of the results showed proportional distribution of the ring's fibrous portion (r2 = 0.98) and muscular portion (r2 = 0.99) according to the degree of mitral valve dilation. Linear regression revealed that the perimeters of anterior and posterior leaflet attachments (r2 = 0.96 and r2 = 0.98, respectively) also had a proportional relation. We did not observe proportionality between the degree of dilation of the mitral ring and the left ventricle. It was observed that dilation of the left ventricle takes place globally in its segments. CONCLUSION: Differently from what was thought, in ischemic or idiopathic dilated cardiomyopathy, dilation of mitral ring is proportional and does not exclusively affect the posterior portion. The degree of left ventricular dilation does not determine the degree of dilation of the mitral ring because they are independent processes. These observations shed new light on the techniques used to correct mitral valve insufficiency in dilated cardiomyopathy.  相似文献   
1000.
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