全文获取类型
收费全文 | 56365篇 |
免费 | 3506篇 |
国内免费 | 492篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 962篇 |
妇产科学 | 1770篇 |
基础医学 | 12960篇 |
口腔科学 | 1381篇 |
临床医学 | 3761篇 |
内科学 | 9913篇 |
皮肤病学 | 1302篇 |
神经病学 | 4945篇 |
特种医学 | 1775篇 |
外国民族医学 | 2篇 |
外科学 | 4872篇 |
综合类 | 1339篇 |
现状与发展 | 7篇 |
一般理论 | 2篇 |
预防医学 | 2896篇 |
眼科学 | 708篇 |
药学 | 4298篇 |
5篇 | |
中国医学 | 377篇 |
肿瘤学 | 6883篇 |
出版年
2024年 | 39篇 |
2023年 | 2287篇 |
2022年 | 2897篇 |
2021年 | 3102篇 |
2020年 | 3299篇 |
2019年 | 2084篇 |
2018年 | 1970篇 |
2017年 | 2689篇 |
2016年 | 2660篇 |
2015年 | 3174篇 |
2014年 | 5064篇 |
2013年 | 3667篇 |
2012年 | 2397篇 |
2011年 | 2064篇 |
2010年 | 3640篇 |
2009年 | 3474篇 |
2008年 | 1452篇 |
2007年 | 1568篇 |
2006年 | 1225篇 |
2005年 | 934篇 |
2004年 | 827篇 |
2003年 | 860篇 |
2002年 | 892篇 |
2001年 | 894篇 |
2000年 | 662篇 |
1999年 | 833篇 |
1998年 | 720篇 |
1997年 | 639篇 |
1996年 | 684篇 |
1995年 | 637篇 |
1994年 | 448篇 |
1993年 | 376篇 |
1992年 | 227篇 |
1991年 | 264篇 |
1990年 | 256篇 |
1989年 | 212篇 |
1988年 | 196篇 |
1987年 | 78篇 |
1986年 | 66篇 |
1985年 | 86篇 |
1984年 | 89篇 |
1983年 | 60篇 |
1982年 | 64篇 |
1981年 | 58篇 |
1980年 | 60篇 |
1979年 | 52篇 |
1978年 | 50篇 |
1977年 | 56篇 |
1976年 | 44篇 |
1974年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
《Ticks and Tick》2022,13(3):101934
Anaplasmosis is a tick-transmitted disease due to several species of the genus Anaplasma. In 2019, we demonstrated the presence of Anaplasma capra in two deer species at a zoological park in mainland France. As we suspected its presence in Corsica, we surveyed 11 geographically distant sheep or goat farms. Using molecular tools such as nested PCR targeting 16S ribosomal RNA (rRNA), citrate synthase (gltA) and heat-shock protein (groEL) genes, we detected the presence of A. capra on 5/11 farms, in 26/108 blood samples (24%), in sheep as well as in goats. Genotyping and phylogenetic analysis of A. capra revealed that isolates from Corsica island grouped closely with A. capra isolates reported in red deer and swamp deer from a zoological reserve in mainland France, as well as in roe deer from Spain, in a separate and well supported clade within A. capra clade II. This third report of the tick-borne bacterium A. capra in Europe suggests a potentially larger presence of this pathogen on the European continent, on domestic, native as well as wild ruminants, a broad host range already described in Asian countries for this species. 相似文献
12.
《HPB : the official journal of the International Hepato Pancreato Biliary Association》2022,24(8):1201-1216
BackgroundPancreatic ductal adenocarcinoma (PDAC) has poor survival. Current treatments offer little likelihood of cure or long-term survival. This systematic review evaluates prognostic models predicting overall survival in patients diagnosed with PDAC.MethodsWe conducted a comprehensive search of eight electronic databases from their date of inception through to December 2019. Studies that published models predicting survival in patients with PDAC were identified.Results3297 studies were identified; 187 full-text articles were retrieved and 54 studies of 49 unique prognostic models were included. Of these, 28 (57.1%) were conducted in patients with advanced disease, 17 (34.7%) with resectable disease, and four (8.2%) in all patients. 34 (69.4%) models were validated, and 35 (71.4%) reported model discrimination, with only five models reporting values >0.70 in both derivation and validation cohorts. Many (n = 27) had a moderate to high risk of bias and most (n = 33) were developed using retrospective data. No variables were unanimously found to be predictive of survival when included in more than one study.ConclusionMost prognostic models were developed using retrospective data and performed poorly. Future research should validate instruments performing well locally in international cohorts and investigate other potential predictors of survival. 相似文献
13.
《European journal of medical genetics》2021,64(12):104345
BackgroundEpidermolysis bullosa (EB) is a genodermatosis characterized by skin fragility and blisters with variable severity. Patients with Dystrophic EB (DEB) or Junctional EB (JEB) mainly present to clinic due to greater functional impairment. Pathogenic sequence variations in COL7A1 are implicated in DEB.ObjectiveWe have tried to decipher the molecular spectrum and genotype phenotype correlation of 21 Indian patients with EB.MethodsNext generation sequencing (NGS) was performed to determine the pathogenic variants. Sanger sequencing was also done for validation of the variants in eleven individuals.ResultsPathogenic variants were detected in 20 individuals (diagnostic yield of 95%). Majority of them (90%) had sequence variation in COL7A1 while two had pathogenic variants in ITGB4 and KRT14 respectively. Out of the 18 patients confirmed to have DEB, 3 had Dominant DEB (DDEB) whereas 15 patients had Recessive DEB (RDEB). Amongst 23 sequence variations identified, 12 were found to be novel (3 were missense, 5 were premature termination codon variants while 4 were splice-site changes).ConclusionGenotype phenotype correlation was noted with milder manifestations in those with dominant inheritance types. Exact molecular diagnosis can be ascertained by NGS in majority of cases. 相似文献
14.
15.
16.
Her-Shyong Shiah Nai-Jung Chiang Chia-Chi Lin Chia-Jui Yen Hui-Jen Tsai Shang-Yin Wu Wu-Chou Su Kwang-Yu Chang Ching-Chiung Wang Jang-Yang Chang Li-Tzong Chen 《The oncologist》2021,26(4):e567-e579
Lessons Learned
- SCB01A is a novel microtubule inhibitor with vascular disrupting activity.
- This first‐in‐human study demonstrated SCB01A safety, pharmacokinetics, and preliminary antitumor activity.
- SCB01A is safe and well tolerated in patients with advanced solid malignancies with manageable neurotoxicity.
17.
《Trends in Cardiovascular Medicine》2022,32(4):221-225
Correctly diagnosing the cause of wide QRS tachycardias remain an area of difficulty for many clinicians. The authors provide a concise update to the different ECG algorithms that have been developed as well as caveats in their application. 相似文献
18.
《Journal of Medical Imaging and Radiation Sciences》2022,53(3):460-470
PurposeTo provide means for calculating the dose received by various tissues of the patient, calculate lung shield, and verify received dose using a phantom as a tool for quality assurance for a planned Total Body Irradiation (TBI) procedure in radiotherapy.MethodUsing Microsoft Visual Basic, MATLAB, and Python, a program for Total Body Irradiation Calculation in Radiotherapy (TBICR) is constructed. It uses patient translation and beam zone method for total body irradiation calculations to compute the proper dose received by the patient and determine the lung shield thickness. There are three main user-friendly interfaces in the application. The first one allows the user to upload the TBI topography and estimate the distances needed for TBI calculations. The second one enables the user to count the number of beam zones needed for each point and estimate the effective area (Aeff) for each level. The third interface estimates the velocity required to deliver the relative dose depending on patient separation, Monitor Units (MU), couch speed and travel distance. It allows the user to compute the required lung shield thickness, read any patient's CT DICOM file and acquire dose in any distinct location using machine learning model to predict the dose.ResultsThe TBICR software has been successfully validated by reproducing all of the manual calculations in an exact and timely manner. TBICR generated more accurate results and confirmed the absorbed dose to patient through measurements on Anderson phantom.ConclusionsA computer program for the calculation of total body irradiation (TBI) is described in full. The dose received at each point on the patient, the calculation of lung shield and the determination of the velocity and time required for the couch movement are all made possible using the software. The ease of use, precision, data storage and printing are some important features of the present software. 相似文献
19.
Although methadone is effective in the management of acute pain, the complexity of its absorption-distribution-metabolism-excretion profile limits its use as an opioid of choice for perioperative analgesia. Because deuteration is known to improve the pharmacokinetic, pharmacodynamic and toxicological properties of some drugs, here we characterized the single dose pharmacokinetic properties and post-operative analgesic efficacy of d9-methadone.The pharmacokinetic profiles of d9-methadone and methadone administered intravenously to CD-1 male mice revealed that deuteration leads to a 5.7- and 4.4-fold increase in the area under the time-concentration curve and maximum concentration in plasma, respectively, as well as reduction in clearance (0.9 ± 0.3 L/h/kg vs 4.7 ± 0.8 L/h/kg). The lower brain-to-plasma ratio of d9-methadone compared to that of methadone (0.35 ± 0.12 vs 2.05 ± 0.62) suggested that deuteration decreases the transfer of the drug across the blood-brain barrier. The estimated LD50 value for a single intravenous dose of d9-methadone was 2.1-fold higher than that for methadone. Moreover, d9-methadone outperformed methadone in the efficacy against postoperative pain by primarily activating peripheral opioid receptors. Collectively, these data suggest that the replacement of three hydrogen atoms in three methyl groups of methadone altered its pharmacokinetic properties, improved safety, and enhanced its analgesic efficacy. 相似文献
20.
《Practical radiation oncology》2022,12(6):e512-e516
Stereotactic body radiation therapy (SBRT) is commonly used to treat early-stage non-small cell lung cancer. Beam arrangements for SBRT include multiple entry and exit pathways resulting in irregular low-dose distributions within normal lung parenchyma. An improved understanding of posttreatment radiographic changes may improve the ability to predict clinical complications including radiation pneumonitis as well as assist in early detection of local failures. Radiation treatment planning is conducted using software systems separate from diagnostic radiology, often not accessible to the diagnostic radiologist. We developed a workflow for interfacing radiation dose information from lung SBRT treatments with a diagnostic radiology picture archiving and communication system (PACS). In an anonymized PACS study folder, SBRT dose maps depicting high-dose, low-dose, and nonirradiated lung volumes were viewable side by side with pretreatment and follow-up diagnostic computed tomography scans. Clinical utility was evaluated by 2 thoracic diagnostic radiologists reviewing posttreatment diagnostic follow-up scans in the PACS both with and without radiation dose maps available. The addition of the biologically effective dose map did not significantly change identification rates of radiation induced lung injury) (92% vs 95%; P = .32) but did significantly decrease radiologic suspicion for local recurrence (22% vs 8%; P = .003). The addition of biologically effective dose maps significantly increased confidence in identifying radiation induced lung injury (7.75 vs 8.82; P = .004) and local recurrence (5.5 vs 6.6; P = .005). The recommendation for additional workup was not significantly different (10% vs 7%; P = .41). We demonstrated the feasibility and clinical utility of a workflow generating simplified radiation dose maps that are viewable within a PACS for diagnostic radiology review. 相似文献