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   9467篇
  免费   569篇
  国内免费   71篇
耳鼻咽喉   67篇
儿科学   249篇
妇产科学   259篇
基础医学   1334篇
口腔科学   139篇
临床医学   708篇
内科学   2419篇
皮肤病学   120篇
神经病学   1397篇
特种医学   373篇
外科学   860篇
综合类   16篇
一般理论   3篇
预防医学   380篇
眼科学   125篇
药学   744篇
中国医学   10篇
肿瘤学   904篇
  2023年   155篇
  2022年   101篇
  2021年   342篇
  2020年   260篇
  2019年   372篇
  2018年   406篇
  2017年   308篇
  2016年   357篇
  2015年   378篇
  2014年   543篇
  2013年   618篇
  2012年   817篇
  2011年   856篇
  2010年   490篇
  2009年   444篇
  2008年   627篇
  2007年   571篇
  2006年   561篇
  2005年   489篇
  2004年   354篇
  2003年   301篇
  2002年   268篇
  2001年   41篇
  2000年   39篇
  1999年   49篇
  1998年   38篇
  1997年   33篇
  1996年   30篇
  1995年   24篇
  1994年   24篇
  1993年   15篇
  1992年   16篇
  1991年   24篇
  1990年   20篇
  1989年   23篇
  1988年   25篇
  1987年   14篇
  1986年   14篇
  1985年   7篇
  1984年   7篇
  1983年   7篇
  1982年   3篇
  1981年   8篇
  1980年   4篇
  1979年   8篇
  1978年   4篇
  1977年   2篇
  1968年   1篇
  1967年   2篇
  1966年   3篇
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
1.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
2.
3.
We investigated the occurrence and management of therapy‐related hematological disorders (tr‐HDs) in women with epithelial ovarian cancer (EOC) exposed to poly‐ADP‐ribose polymerase inhibitors (PARPi), after previous chemotherapy. We analyzed 130 consecutive EOC patients treated with PARPi at the European Institute of Oncology, Milan. In line with the literature, overall survival of the entire population was 37% at 5.5 years (89% were advanced stages). Cell blood counts were collected prior to start PARPi, at each new cycle and at monthly intervals. Patients displaying persistent and/or marked hematological abnormalities underwent bone marrow evaluation, with cytogenetic and molecular analysis. Nine patients (6,9%) developed tr‐HDs, after a median 22.8 months of PARPi exposure. Two patients died early and could not be treated. Two patients have no indication for active treatment and are presently under close hematological monitoring. Five patients underwent chemotherapy followed, in three cases, by allogeneic hematopoietic transplantation: three patients are in complete remission of their hematological and gynecological malignancies at 13, 19, and 25 months; the remaining two patients died due to progression of their hematological disease. We show the potential risk of hematological disorders in EOC patients treated with chemotherapy and prolonged PARPi therapy. In our series, tr‐HDs incidence was higher compared to recent reports in large series. Our observations suggest careful monitoring in order to conclusively define, on large series and prolonged follow‐up, the actual risk of tr‐HDs in patients under PARPi. Notably, prompt diagnosis of hematological abnormalities and appropriate management allow achievement of remission from severe hematological complications, at least in most patients.  相似文献   
4.
Journal of Neurology - Diagnostic delay of hereditary transthyretin amyloidosis (ATTRv, v for variant) prevents timely treatment and, therefore, concurs to the mortality of the disease. The aim of...  相似文献   
5.
Digestive Diseases and Sciences - Haemorrhoids, a common ailment afflicting mostly Western patients, can produce bothersome symptoms, in particular pain, pruritus, and bleeding. There is a wide...  相似文献   
6.
Although antibody levels progressively decrease following SARS-CoV-2 infection, the immune memory persists for months. Thus, individuals who naturally contracted SARS-CoV-2 are expected to develop a more rapid and sustained response to COVID-19 vaccines than naïve individuals. In this study, we analyzed the dynamics of the antibody response to the BNT162b2 mRNA COVID-19 vaccine in six healthcare workers who contracted SARS-CoV-2 in March 2020, in comparison to nine control subjects without a previous infection. The vaccine was well tolerated by both groups, with no significant difference in the frequency of vaccine-associated side effects, with the exception of local pain, which was more common in previously infected subjects. Overall, the titers of neutralizing antibodies were markedly higher in response to the vaccine than after natural infection. In all subjects with pre-existing immunity, a rapid increase in anti-spike receptor-binding domain (RBD) IgG antibodies and neutralizing antibody titers was observed one week after the first dose, which seemed to act as a booster. Notably, in previously infected individuals, neutralizing antibody titers 7 days after the first vaccine dose were not significantly different from those observed in naïve subjects 7 days after the second vaccine dose. These results suggest that, in previously infected people, a single dose of the vaccine might be sufficient to induce an effective response.  相似文献   
7.
Objective: Tuberous sclerosis complex (TSC) is a multisystem genetic disorder associated with refractory early‐onset epilepsy. Current evidence supports surgery as the intervention most likely to achieve long‐term seizure freedom, but no specific guidelines are available on TSC pre‐surgical workup. This critical review assesses which TSC patients are suitable for surgical treatment, when pre‐surgical evaluation should start, and what degree of surgical resection is optimal for postsurgical outcome. Methods: We searched for publications from 2000 to 2020 in Pubmed and Embase using the terms “tuberous sclerosis,” “epilepsy,” and “epilepsy surgery”. To evaluate postsurgical seizure outcome, we selected only studies with at least one year of follow‐up. Results: Overall, we collected data on 1,026 patients from 34 studies. Age at surgery ranged from one month to 54 years. Mean age at surgery was 8.41 years. Of the diagnostic non‐invasive pre‐surgical tools, MRI and video‐EEG were considered most appropriate. Promising data for epileptogenic tuber detection is provided from invasive SEEG studies. Data on surgery and related outcome were available for 769 patients. Seizure freedom was seen in 64.4% of patients who underwent tuberectomy, 68.9% treated with lobectomy and 65.1% with multilobar resection. The most effective surgical approach was lobectomy, even though more recently tuberectomy associated with the resection of the perituberal area seems to be the best approach to reach seizure freedom. Published postsurgical seizure freedom rates in patients with TSC were between 65% and 75%, but reduced to 48%‐57% over longer follow‐up periods. Early surgery might positively affect neurodevelopmental trajectory in some patients, even though data on cognitive outcome are still to be confirmed with longitudinal studies. Significance: Considering the strong correlation between epilepsy duration and neurocognitive outcome, all patients with TSC ought to be referred early to a dedicated epilepsy centre for individually tailored pre‐surgical evaluation by a multi‐disciplinary epilepsy surgery team.  相似文献   
8.
Vitale  Giovanni  Dicitore  Alessandra  Barrea  Luigi  Sbardella  Emilia  Razzore  Paola  Campione  Severo  Faggiano  Antongiulio  Colao  Annamaria  Albertelli  Manuela  Altieri  Barbara  Bottiglieri  Filomena  De Cicco  Federica  Di Molfetta  Sergio  Fanciulli  Giuseppe  Feola  Tiziana  Ferone  Diego  Ferraù  Francesco  Gallo  Marco  Giannetta  Elisa  Grillo  Federica  Grossrubatscher  Erika  Guadagno  Elia  Guarnotta  Valentina  Isidori  Andrea M.  Lania  Andrea  Lenzi  Andrea  Calzo  Fabio Lo  Malandrino  Pasquale  Messina  Erika  Modica  Roberta  Muscogiuri  Giovanna  Pes  Luca  Pizza  Genoveffa  Pofi  Riccardo  Puliani  Giulia  Rainone  Carmen  Rizza  Laura  Rubino  Manila  Ruggieri  Rosa Maria  Sesti  Franz  Venneri  Mary Anna  Zatelli  Maria Chiara 《Reviews in endocrine & metabolic disorders》2021,22(3):511-525

Gut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host’s metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host’s immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microbiota and gastrointestinal adenocarcinomas, very little is known about gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). In this review, we provide an overview concerning the complex interplay between gut microbiota and GEP NENs, focusing on the potential role in tumorigenesis and progression in these tumors.

  相似文献   
9.
10.
PurposeMediastinal radiation therapy (RT) in patients with lymphoma implies involuntary coronary artery (CA) exposure, resulting in an increased risk of coronary artery disease (CAD). Accurate delineation of CAs may spare them from higher RT doses. However, heart motion affects the estimation of the dose received by CAs. An expansion margin (planning organ at risk volume [PRV]), encompassing the nearby area where CAs displace, may compensate for these uncertainties, reducing CA dose and CAD risk. Our study aimed to evaluate if a planning process optimized on CA-specific PRVs, rather than just on CAs, could provide any dosimetric or clinical benefit.Methods and MaterialsForty patients receiving RT for mediastinal lymphomas were included. We contoured left main trunk, left anterior descending, left circumflex, and right coronary arteries. An isotropic PRV was then applied to all CAs, in accordance with literature data. A comparison was then performed by optimizing treatment plans either on CAs or on PRVs, to detect any difference in CA sparing in terms of maximum (Dmax), median (Dmed), and mean (Dmean) dose. We then investigated, through risk modeling, if any dosimetric benefit obtained with the PRV-related optimization process could translate to a lower risk of ischemic complications.ResultsPlan optimization on PRVs demonstrated a significant dose reduction (range, 7%-9%) in Dmax, Dmed, and Dmean for the whole coronary tree, and even higher dose reductions when vessels were located 5- to 20-mm from PTV (range, 13%-15%), especially for left main trunk and left circumflex (range, 16%-21%). This translated to a mean risk reduction of developing CAD of 12% (P < .01), which increased to 17% when CAs were located 5- to 20-mm from PTV.ConclusionsIntegration of CA-related PRVs in the optimization process reduces the dose received by CAs and translates to a meaningful prevention of CAD risk in patients with lymphoma treated with mediastinal RT.  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