全文获取类型
收费全文 | 21174篇 |
免费 | 1925篇 |
国内免费 | 660篇 |
专业分类
耳鼻咽喉 | 248篇 |
儿科学 | 365篇 |
妇产科学 | 482篇 |
基础医学 | 2584篇 |
口腔科学 | 342篇 |
临床医学 | 1536篇 |
内科学 | 4652篇 |
皮肤病学 | 460篇 |
神经病学 | 1155篇 |
特种医学 | 349篇 |
外国民族医学 | 2篇 |
外科学 | 2930篇 |
综合类 | 2477篇 |
一般理论 | 1篇 |
预防医学 | 1273篇 |
眼科学 | 239篇 |
药学 | 2298篇 |
4篇 | |
中国医学 | 733篇 |
肿瘤学 | 1629篇 |
出版年
2023年 | 354篇 |
2022年 | 487篇 |
2021年 | 1220篇 |
2020年 | 1071篇 |
2019年 | 1524篇 |
2018年 | 1585篇 |
2017年 | 977篇 |
2016年 | 703篇 |
2015年 | 840篇 |
2014年 | 1484篇 |
2013年 | 1339篇 |
2012年 | 1127篇 |
2011年 | 1308篇 |
2010年 | 1037篇 |
2009年 | 916篇 |
2008年 | 893篇 |
2007年 | 929篇 |
2006年 | 747篇 |
2005年 | 627篇 |
2004年 | 555篇 |
2003年 | 557篇 |
2002年 | 334篇 |
2001年 | 280篇 |
2000年 | 255篇 |
1999年 | 243篇 |
1998年 | 323篇 |
1997年 | 250篇 |
1996年 | 161篇 |
1995年 | 156篇 |
1994年 | 131篇 |
1993年 | 92篇 |
1992年 | 95篇 |
1991年 | 81篇 |
1990年 | 52篇 |
1989年 | 57篇 |
1988年 | 68篇 |
1987年 | 43篇 |
1986年 | 47篇 |
1985年 | 93篇 |
1984年 | 114篇 |
1983年 | 73篇 |
1982年 | 98篇 |
1981年 | 78篇 |
1980年 | 80篇 |
1979年 | 74篇 |
1978年 | 49篇 |
1977年 | 32篇 |
1976年 | 29篇 |
1975年 | 28篇 |
1974年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
Cadmium is a toxic metal that can damage the brain and other organs. This study aimed to explore the protective effects of Potentilla anserine L. polysaccharide (PAP) against CdCl2-induced neurotoxicity in N2a and SH-SY5Y cells and in the cerebral cortex of BALB/c mice. In addition, we aimed to identify the potential mechanisms underlying these protective effects. Relative to CdCl2 treatment alone, pretreatment with PAP prevented the reduction in cell viability evoked by CdCl2, decreased rates of apoptosis, promoted calcium homeostasis, decreased ROS accumulation, increased mitochondrial membrane potential, inhibited cytochrome C and AIF release, and prevented the cleavage of caspase-3 and PARP. In addition, PAP significantly decreased the CdCl2-induced phosphorylation of CaMKII, Akt, and mTOR. In conclusion, PAP represents a potential therapeutic agent for the treatment of Cd-induced neurotoxicity, functioning in part via attenuating the activation of the mitochondrial apoptosis pathway and the Ca2+-CaMKII-dependent Akt/mTOR pathway. 相似文献
2.
《Drug discovery today》2022,27(4):1108-1114
This project demonstrates the use of the IEEE 2791–2020 Standard (BioCompute Objects [BCO]) to enable the complete and concise communication of results from next generation sequencing (NGS) analysis. One arm of a clinical trial was replicated using synthetically generated data made to resemble real biological data and then two independent analyses were performed. The first simulated a pharmaceutical regulatory submission to the US Food and Drug Administration (FDA) including analysis of results and a BCO. The second simulated an FDA review that included an independent analysis of the submitted data. Of the 118 simulated patient samples generated, 117 (99.15%) were in agreement in the two analyses. This process exemplifies how a template BCO (tBCO), including a verification kit, facilitates transparency and reproducibility, thereby reinforcing confidence in the regulatory submission process. 相似文献
3.
《Drug discovery today》2022,27(6):1733-1742
Compounds that exhibit assay interference or undesirable mechanisms of bioactivity are routinely encountered in assays at various stages of drug discovery. We observed that assays for the investigation of thiol-reactive and redox-active compounds have not been collected in a comprehensive review. Here, we review these assays and subject them to experimental optimization to improve their reliability. We demonstrate the usefulness of our assay cascade by assaying a library of bioactive compounds, chemical probes, and a set of approved drugs. These high-throughput assays should complement the array of wet-lab and in silico assays during the initial stages of hit discovery campaigns to pursue only hit compounds with tractable mechanisms of action. 相似文献
4.
《Cirugía espa?ola》2023,101(2):116-122
IntroductionMetastasis is remaining one of the major problems in cancer treatment. Like many other malignancies, urogenital tumors originating from kidney, prostate, testes, and bladder tend to metastasize to the lungs.The aim of this retrospective study is to evaluate the operative results and prognosis of pulmonary metastasectomy in patients with primary urogenital tumors.MethodsThis study was approved by the local ethical committee. We retrospectively analyzed the surgical and oncological results of patients who underwent lung resections for urogenital cancer metastases in our department between 2002 and 2018. Demographic data and clinicopathological features were extracted from the medical records. Survival outcomes according to cancer subtypes and early postoperative results of VATS and thoracotomy were analyzed.Results22 out of 126 patients referred for pulmonary metastasectomy to our department had metastases from urogenital tumors. These patients consisted of 17 males and five females. Their metastasis originated from renal cell carcinoma (RCC; n = 9), bladder tumor (n = 7), testis tumors (n = 4), and prostate cancer (n = 2). There was no intraoperative complication. Postoperative complications were seen in 2 patients.ConclusionsAlthough pulmonary metastasectomy in various types of tumors is well known and documented, the data is limited for metastases of urogenital cancers in the literature. Despite the limitations of this study, we aim to document our promising results of pulmonary metastasectomy in patients with primary urogenital tumors and wanted to emphasize the role of minimally invasive approaches. 相似文献
5.
《Injury》2023,54(7):110767
AimThis network meta-analysis aims to compare functional outcomes and complications between conservative treatment and surgery for distal radius fractures in patients aged 60 years and over.MethodsWe searched the PubMed, EMBASE, and Web of Science databases for randomized controlled trials (RCTs) assessing the effect of conservative treatment and surgery for distal radius fractures in patients aged 60 years and over. Primary outcomes included grip strength and overall complications. Secondary outcomes included Disabilities of the Arm, Shoulder, and Hand (DASH) scores, Patient-Rated Wrist Evaluation (PRWE) scores, wrist range of motion and forearm rotation, and radiographic assessment. All continuous outcomes were assessed using standardized mean differences (SMDs) with 95% confidence intervals (CIs), and binary outcomes were assessed using odds ratio (OR) with 95% CIs. The surface under the cumulative ranking curve (SUCRA) was used to determine a hierarchy of treatments. Cluster analysis was performed for grouping treatments based on the SUCRA values of primary outcomes.ResultsFourteen RCTs were included to compare conservative treatment, volar lockedplate (VLP), K-wires fixation, and external-fixation. VLP outperformed conservative treatment for 1-year and minimum 2-year grip strength (SMD; 0.28 [0.07 to 0.48] and 0.27 [0.02 to 0.53], respectively). VLP yielded the optimal grip strength at 1-year and minimum 2-year follow-up (SUCRA; 89.8% and 86.7%, respectively). In a subgroup analysis of patients aged 60 to 80 years old, VLP outperformed conservative treatment in DASH and PRWE scores (SMD, 0.33 [0.10, 0.56] and 0.23 [0.01, 0.45], respectively). In addition, VLP had the fewest complications (SUCRA = 84.3%). Cluster analysis suggested that VLP and K-wire fixation were more effective treatment groups.ConclusionEvidence to date demonstrates that VLP provides measurable benefits in grip strength and fewer complications to those 60 years of age and over, and that benefit is not reflected in current practice guidelines. There is a subgroup of patients where K-wire fixation outcomes are similar to those of VLP; defining this subgroup may yield substantial societal benefits. 相似文献
6.
《Revista portuguesa de cardiologia》2022,41(6):445-452
Introduction and ObjectivesThe 2019 ESC guidelines on chronic coronary syndromes updated the method for estimating the pre-test probability (PTP) of obstructive coronary artery disease (CAD). We aimed to compare the performance of the new PTP method against the 2013 prediction model in patients with stable chest pain undergoing coronary computed tomography angiography (CCTA) for suspected CAD.MethodsWe conducted a single-center cross-sectional study enrolling 320 consecutive patients undergoing CCTA for suspected CAD. Obstructive CAD was defined as any ≥50% luminal stenosis on CCTA. Whenever invasive coronary angiography was subsequently performed, patients were reclassified accordingly. The two PTP prediction models were assessed for calibration, discrimination and the ability to change the downstream diagnostic pathway.ResultsThe observed prevalence of obstructive CAD was 16.3% (n=52). The 2013 prediction model significantly overestimated the likelihood of obstructive CAD (relative overestimation of 130%, p=0.005), while the updated 2019 method showed good calibration (relative underestimation of 6.5%, p=0.712). The two approaches showed similar discriminative power, with C-statistics of 0.73 (95% CI: 0.66-0.80) and 0.74 (95% CI: 0.66-0.81) for the 2013 and 2019 methods, respectively (p=0.933). Reclassification of PTP using the new method resulted in a net reclassification improvement of 0.10 (p=0.001).ConclusionsThe updated 2019 prediction model provides a more accurate estimation of pre-test probabilities of obstructive CAD than the previous model. Adoption of this new score may improve disease prediction and influence the selection of non-invasive testing. 相似文献
7.
8.
《Revista espa?ola de cardiología》2022,75(12):1059-1069
Left ventricular noncompaction is a poorly defined and controversial entity, with wide phenotypic expression: from a simple anatomical trait to a disease with overt cardiac affection. Current diagnostic criteria rely exclusively on morphologic features of hypertrabeculation, which have low specificity for identifying true cardiomyopathy cases. The management of left ventricular noncompaction is also heterogeneous, and there are no dedicated clinical practice guidelines. The most common cardiovascular complications are heart failure, ventricular arrhythmias, and systemic embolisms. In this review, we discuss the diagnostic limitations of the available criteria, and propose a comprehensive alternative approach (including functional imaging variables, tissue characterization, genetics, and family screening) that may help in the differential diagnosis of hypertrabeculation cases. We also describe the genetic background of the disease and discuss the overlap with other cardiomyopathies. Finally, we focus on controversial issues in clinical management and suggest the use of the previously-mentioned variables for risk stratification and for individualization of patient follow-up. 相似文献
9.
《Revista espa?ola de cardiología》2022,75(11):949-959
Introduction and objectivesThis document includes cardiac pacing activity performed in Spain in 2021: figures for implanted devices, demographic and clinical factors, characteristics of the implanted material, and remote monitoring data.MethodsThe European Pacemaker Patient Card, the CardioDispositivos.es online platform, the centers’ own databases and the data provided by the supplier companies are used as sources of information.Results17.360 procedures were registered from 95 hospitals, which represents 43% of the activity. The implantation rates of conventional and resynchronization pacemakers were 822 and 31 units per million population, respectively. 652 leadless pacemakers were implanted. The mean age of implantation is high (78.8 years), and atrioventricular block is the most frequent electrocardiographic abnormality. Dual-chamber pacing mode predominated, nonetheless single-chamber pacing was performed in 19% of patients in sinus rhythm, mainly in the elderly. 28.5% of implanted conventional pacemakers and 56,2% of low-energy resynchronization pacemakers were included in the remote monitoring program.ConclusionsIn 2021 the number of conventional pacemakers increased by 8.3% and resynchronizers by 18.9%, despite the decrease in low-energy resynchronization, probably attributable to the development of physiological pacing. Leadless pacemakers increased by 25%. The expansion of remote monitoring continued, consolidating as a fundamental follow-up method. 相似文献
10.
D. R. Frei R. Beasley D. Campbell A. Forbes K. Leslie D. Mackle C. Martin A. Merry M. R. Moore P. S. Myles L. Ruawai-Hamilton T. G. Short P. J. Young 《Anaesthesia》2023,78(10):1272-1284
International recommendations encourage liberal administration of oxygen to patients having surgery under general anaesthesia, ostensibly to reduce surgical site infection. However, the optimal oxygen regimen to minimise postoperative complications and enhance recovery from surgery remains uncertain. The hospital operating theatre randomised oxygen (HOT-ROX) trial is a multicentre, patient- and assessor-blinded, parallel-group, randomised clinical trial designed to assess the effect of a restricted, standard care, or liberal peri-operative oxygen therapy regimen on days alive and at home after surgery in adults undergoing prolonged non-cardiac surgery under general anaesthesia. Here, we report the findings of the internal vanguard feasibility phase of the trial undertaken in four large metropolitan hospitals in Australia and New Zealand that included the first 210 patients of a planned overall 2640 trial sample, with eight pre-specified endpoints evaluating protocol implementation and safety. We screened a total of 956 participants between 1 September 2019 and 26 January 2021, with data from 210 participants included in the analysis. Median (IQR [range]) time-weighted average intra-operative FiO2 was 0.30 (0.26–0.35 [0.20–0.59]) and 0.47 (0.44–0.51 [0.37–0.68]) for restricted and standard care, respectively (mean difference (95%CI) 0.17 (0.14–0.20), p < 0.001). Median time-weighted average intra-operative FiO2 was 0.83 (0.80–0.85 [0.70–0.91]) for liberal oxygen therapy (mean difference (95%CI) compared with standard care 0.36 (0.33–0.39), p < 0.001). All feasibility endpoints were met. There were no significant patient adverse events. These data support the feasibility of proceeding with the HOT-ROX trial without major protocol modifications. 相似文献