全文获取类型
收费全文 | 33484篇 |
免费 | 1907篇 |
国内免费 | 335篇 |
专业分类
耳鼻咽喉 | 550篇 |
儿科学 | 349篇 |
妇产科学 | 462篇 |
基础医学 | 5564篇 |
口腔科学 | 875篇 |
临床医学 | 2675篇 |
内科学 | 6344篇 |
皮肤病学 | 1317篇 |
神经病学 | 2450篇 |
特种医学 | 2246篇 |
外国民族医学 | 1篇 |
外科学 | 4130篇 |
综合类 | 166篇 |
一般理论 | 5篇 |
预防医学 | 1578篇 |
眼科学 | 583篇 |
药学 | 3318篇 |
中国医学 | 444篇 |
肿瘤学 | 2669篇 |
出版年
2024年 | 23篇 |
2023年 | 244篇 |
2022年 | 774篇 |
2021年 | 1238篇 |
2020年 | 559篇 |
2019年 | 798篇 |
2018年 | 974篇 |
2017年 | 798篇 |
2016年 | 1155篇 |
2015年 | 1528篇 |
2014年 | 1802篇 |
2013年 | 2061篇 |
2012年 | 3076篇 |
2011年 | 3017篇 |
2010年 | 1723篇 |
2009年 | 1512篇 |
2008年 | 2093篇 |
2007年 | 1889篇 |
2006年 | 1686篇 |
2005年 | 1559篇 |
2004年 | 1204篇 |
2003年 | 1054篇 |
2002年 | 896篇 |
2001年 | 787篇 |
2000年 | 720篇 |
1999年 | 511篇 |
1998年 | 201篇 |
1997年 | 129篇 |
1996年 | 113篇 |
1995年 | 78篇 |
1994年 | 90篇 |
1993年 | 74篇 |
1992年 | 145篇 |
1991年 | 153篇 |
1990年 | 171篇 |
1989年 | 133篇 |
1988年 | 119篇 |
1987年 | 110篇 |
1986年 | 93篇 |
1985年 | 64篇 |
1984年 | 43篇 |
1983年 | 38篇 |
1982年 | 28篇 |
1981年 | 36篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 23篇 |
1975年 | 18篇 |
1974年 | 17篇 |
1970年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Riëm El Tahry Susana Ferrao Santos Pascal Vrielynck Marianne de Tourtchaninoff Thierry Duprez Geraldo Ribeiro Vaz Christian Raftopoulos Joon Yul Choi Zhong Irene Wang 《Epileptic Disord》2020,22(2):156-164
Aims: Magnetic resonance imaging is of paramount importance in the presurgical evaluation of drug resistant epilepsy. Detection of a potentially epileptogenic lesion significantly improves seizure outcome after surgery. To optimize the detection of subtle lesions, MRI post‐processing techniques may be of essential help. Methods: In this study, we aimed to evaluate the detection rate of the voxel‐based morphometric analysis program (MAP) in a prospective trial. We aimed to study the MAP+ findings in terms of their clinical value in the decision‐making process of the presurgical evaluation. Results: We included, prospectively, 21 patients who had negative MRI by visual analysis. In a first step, results of the conventional non‐invasive presurgical evaluation were discussed, blinded to the MAP results, in multidisciplinary patient management conferences to determine the possible seizure onset zone and to set surgical or invasive evaluation plans. Thereafter, MAP results were presented, and the change of initial clinical plan was recorded. All MAP detections were reaffirmed by a neuroradiologist with epilepsy expertise. For the 21 patients included, mean age at the time of patient management conference was 26 years (SD 15 +/‐ years, range: 5–54 years). In total, 4/21 had temporal lobe epilepsy and 17/21 had extra‐temporal lobe epilepsy. MAP was positive in 10/21 (47%) patients and in 6/10 (60%) a diagnosis of focal cortical dysplasia was confirmed after neuroradiologist review, corresponding to a 28% detection rate. MAP+ findings had a clear impact on the initial management in 7/10 patients (7/21, 33% of all patients), which included an adaptation of the intracranial EEG plan (6/7 patients), or the decision to proceed directly to surgery (1/7 patients). Conclusion: MRI post‐processing using the MAP method yielded an increased detection rate of 28% for subtle dysplastic lesions in a prospective cohort of MRI‐negative patients, indicating its potential value in epilepsy presurgical evaluation. 相似文献
992.
J.-S. Kim J.-K. Cha H.W. Nah M.-J. Kang D.-H. Kim H.-S. Park J.-H. Choi H.-K. Suh 《Journal of stroke and cerebrovascular diseases》2018,27(11):3266-3271
Recent studies demonstrated that modified thrombolysis in cerebral infarction (TICI) 3 reperfusion have better functional outcomes than modified TICI 2b after mechanical thrombectomy in acute ischemic stroke with large vessel occlusion. The purpose of this study was to determine significant factors to forecast the presence of complete reperfusion after mechanical thrombectomy based on multimodal magnetic resonance imaging (MRI). We investigated 96 consecutive patients with acute large intracranial artery occlusion of anterior circulation who based on multimodal MRI. Also, we compared clinical and radiologic parameters between patients with modified TICI 3 and those with modified TICI 0-2b. Among 96 eligible subjects received mechanical thrombectomy, 39 patients (40.6%) showed complete reperfusion and 57 partial or nonreperfusion (mTICI 2b-26, mTICI 2a-9, mTICI 1-8, and mTICI 0-14) after mechanical thrombectomy. Patients with mTICI 3 had significantly smaller initial Diffusion weighted images (DWI) lesion volume (P < .01) and much shorter time interval from onset to reperfusion (P < .01) than those patients with mTICI (0-2b). In multivariate analysis, smaller initial DWI volume (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.23-2.57; P < .01) and faster reperfusion time (OR, 1.07; 95% CI 1.01-1.14; P = .015) had an independence significance for complete reperfusion after mechanical thrombectomy. In this study, the ischemic lesion volume on DWI and faster processing time are critical factor to predict the state of complete reperfusion after mechanical thrombectomy. 相似文献
993.
Eun Sol Lee Vin Ryu Jungwon Choi Yunhye Oh Jin Woong Yoon Hyeree Han Hyeon Hong Hye Jung Son Ji Hyun Lee Subin Park 《Psychiatry investigation》2022,19(11):884
Objective Disruptive behavior disorder (DBD) adversely impacts children and adolescents. However, a comprehensive and cost-effective scale to assess DBD is lacking in Korea. Therefore, this study translated the Disruptive Behavior Disorders Rating Scale (DBDRS) into Korean and analyzed its psychometric properties. Methods Parents and primary caregivers of non-clinical (n=429) and clinical (n=28) children and adolescents aged 6–15 years were included in the analysis. Confirmatory factor analysis was conducted; further, concurrent validity and internal consistency were investigated using correlation analysis and Cronbach’s alpha, respectively. Furthermore, discriminative capacity was estimated using receiver operating characteristic curve analysis. Results The four-factor model of K-DBDRS showed good model fit indices and factor loadings, which supported the construct validity of the scale. Strong correlations between K-DBDRS and related measurements were observed, and a robust level of Cronbach’s alpha was confirmed (0.891–0.933). The discriminative capacity of the scale was good, based on the area under the curve values (0.933–0.953). Conclusion This study indicated that the K-DBDRS is an appropriate screening tool for Korean children and adolescents. Thus, this scale can be applied in clinical and community settings to identify children and adolescents with disruptive behavior disorders. 相似文献
994.
Alan S. L. Wong Gigi C. G. Choi Cheryl H. Cui Gabriela Pregernig Pamela Milani Miriam Adam Samuel D. Perli Samuel W. Kazer Aleth Gaillard Mario Hermann Alex K. Shalek Ernest Fraenkel Timothy K. Lu 《Proceedings of the National Academy of Sciences of the United States of America》2016,113(9):2544-2549
The orchestrated action of genes controls complex biological phenotypes, yet the systematic discovery of gene and drug combinations that modulate these phenotypes in human cells is labor intensive and challenging to scale. Here, we created a platform for the massively parallel screening of barcoded combinatorial gene perturbations in human cells and translated these hits into effective drug combinations. This technology leverages the simplicity of the CRISPR-Cas9 system for multiplexed targeting of specific genomic loci and the versatility of combinatorial genetics en masse (CombiGEM) to rapidly assemble barcoded combinatorial genetic libraries that can be tracked with high-throughput sequencing. We applied CombiGEM-CRISPR to create a library of 23,409 barcoded dual guide-RNA (gRNA) combinations and then perform a high-throughput pooled screen to identify gene pairs that inhibited ovarian cancer cell growth when they were targeted. We validated the growth-inhibiting effects of specific gene sets, including epigenetic regulators KDM4C/BRD4 and KDM6B/BRD4, via individual assays with CRISPR-Cas–based knockouts and RNA-interference–based knockdowns. We also tested small-molecule drug pairs directed against our pairwise hits and showed that they exerted synergistic antiproliferative effects against ovarian cancer cells. We envision that the CombiGEM-CRISPR platform will be applicable to a broad range of biological settings and will accelerate the systematic identification of genetic combinations and their translation into novel drug combinations that modulate complex human disease phenotypes.New therapeutic strategies are needed to treat complex human diseases. Because disease phenotypes are often regulated by interwoven genetic networks, exploiting combination therapy to target multiple pathways, as opposed to only single ones, can enhance treatment efficacy (1). However, discovering effective combination therapies for human diseases is challenging with existing methods, due to the cost, effort, and labor required to construct and analyze each combination (2). For example, the National Cancer Institute tested ∼5,000 pairwise combinations of 100 cancer drugs against the NCI-60 panel in a study that took 2 y and cost about USD $4 million (3). Thus, there is a need for technological advances to accelerate the identification of effective combinatorial therapies. Here, we used our combinatorial genetics en masse (CombiGEM)-CRISPR platform to perform rapid pooled screening of pairwise genetic knockouts against genes coding for epigenetic regulators and then translated our screen hits into drug combinations against human ovarian cancer cells.CRISPR-Cas9 technology has been used for large-scale genetic perturbation screens with single-guide RNA (sgRNA) libraries for gene knockouts (4–7), repression, and activation (8, 9). Despite its simplicity for multiplexed genetic perturbations (10–12), new methods are needed to enable high-throughput CRISPR-Cas9–based screening with combinatorial sets of guide RNAs (gRNAs), which would be broadly useful for studying combinatorial gene functions in multigenic phenotypes and diseases. By using CombiGEM-based DNA assembly (13, 14), we developed a strategy for the simple and efficient assembly of barcoded combinatorial gRNA libraries. These libraries can be delivered into human cells by lentiviruses to create genetically ultradiverse cell populations harboring unique gRNA combinations that can be tracked via barcode sequencing in pooled assays. This strategy, termed CombiGEM-CRISPR, uses one-pot cloning steps to enable the assembly of combinatorial gRNA libraries, thus simplifying and accelerating the workflow toward systematic analysis of combinatorial gene functions. 相似文献
995.
996.
Dose-dependent pharmacokinetics of itraconazole after intravenous or oral administration to rats: intestinal first-pass effect 下载免费PDF全文
The dose-dependent pharmacokinetics of itraconazole after intravenous (10, 20, or 30 mg/kg) and oral (10, 30, or 50 mg/kg) administration and the first-pass effects of itraconazole after intravenous, intraportal, intragastric, and intraduodenal administration at a dose of 10 mg/kg were evaluated in rats. After intravenous administration at a dose of 30 mg/kg, the area under the plasma concentration-time curve from time zero to infinity (AUC(0- infinity )) was significantly greater than those at 10 and 20 mg/kg (1,090, 1,270, and 1,760 micro g. min/ml for 10, 20, and 30 mg/kg, dose-normalized at 10 mg/kg). After oral administration, the AUC(0- infinity ) was significantly different for three oral doses (380, 687, and 934 micro g. min/ml for 10, 30, and 50 mg/kg, respectively, dose-normalized at 10 mg/kg). The extent of absolute oral bioavailability (F) was 34.9% after an oral dose at 10 mg/kg. The AUC(0- infinity ) (or AUC(0-8 h)) values were comparable between intravenous and intraportal administration and between intragastric and intraduodenal administration, suggesting that the hepatic and gastric first-pass effects were almost negligible in rats. However, the AUC(0-8 h) values after intraduodenal and intragastric administration were significantly smaller than that after intraportal administration, approximately 30%, suggesting that the intestinal first-pass effect was approximately 70% of that of an oral dose of 10 mg/kg. The low F after oral administration of itraconazole at a dose of 10 mg/kg could be mainly due to the considerable intestinal first-pass effect. 相似文献
997.
Bae EJ Noh CI Choi JY Yun YS Kim WH Lee JR Kim YJ 《Pacing and clinical electrophysiology : PACE》2005,28(2):126-134
INTRODUCTION: The coexistence of two distinct atrioventricular (AV) nodes has been described in congenital heart disease requiring Fontan type palliation. The purpose of this study was to evaluate the occurrence of twin AV node according to anatomical subgroups, and to determine its relation to tachycardia. METHODS: From 2001 to 2003, we performed an electrophysiologic (EP) study upon 52 consecutive patients who had undergone cardiac catheterization after Fontan completion. Atrial pacing was performed at three or more different atrial sites. RESULTS: In 10/52 patients, two different QRS complexes were recorded at different pacing sites, suggesting twin AV node (9/20 in right isomerism, 1/8 discordance AV connections, 0/24 other complex anomalies). AV reciprocating tachycardia (AVRT), presumably involving two AV nodes and a connecting sling, was induced in 6 of 10 patients who had twin AV node (4/6 used posterior AV node as an antegrade limb, 2/6 used an anterior AV node as an antegrade limb). Heterotaxy syndrome (P < 0.001) and complete AV septal defect (P = 0.002) were found to be risk factors for twin AV node. Junctional tachycardia (JT; HR > 150/min) with either VA dissociation (7/9) or second degree VA block (2/9) were induced by pacing or isoproterenol infusion in 9/52 patients. CONCLUSION: JT induction was associated with a twin AV node (P = 0.04), or a history of early postoperative junctional ectopic tachycardia (P = 0.02). A complicated AV node conduction system such as twin AV node was frequent in heterotaxy syndrome. Both AVRT and JT with VA block may be important causes of tachyarrhythmia in this patient group. 相似文献
998.
Lee SH Park S Kang SM Jang Y Chung N Choi D 《Journal of cardiovascular pharmacology and therapeutics》2012,17(1):65-71
Postprandial triglyceride (TG) levels are easy to measure and are associated with future cardiovascular risk. The aim of this study was to compare the effects of statin monotherapy and low-dose statin/ezetimibe on lipid parameters including fasting and postprandial TG. After a 4-week dietary run-in period, 78 patients with combined hyperlipidemia were randomized into 1 of 2 treatment groups for 8 weeks: atorvastatin 20 mg or atorvastatin/ezetimibe 5 mg/5 mg. An oral fat load test was performed before and after the drug-treatment period. The low-dose combination had a tendency to decrease fasting TG more than atorvastatin monotherapy. The combination regimen showed a greater reduction in postprandial TG (-13% ± 42% and -34% ± 30%, in the atorvastatin and combination groups, respectively, P = .03) and total cholesterol (TC; P = .03). The changes in low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were not different between the 2 groups. The reduction in apo B/A1 was greater in the combination group (-32% ± 19% and -42% ± 13%, in the atorvastatin and combination groups, respectively, P = .02). In conclusion, these results demonstrated a potential beneficial effect of low-dose atorvastatin/ezetimibe combination treatment on postprandial TG control after comparable LDL-C lowering in patients with combined hyperlipidemia. 相似文献
999.
Winnie KW So Dorothy NS Chan Yan Lou Kai-Chow Choi Carmen WH Chan Kristina Shin Ava Kwong Diana TF Lee 《World Journal of Meta-Analysis》2015,3(4):193-205
AIM: To evaluate existing evidence for the association between different type of brassiere exposures and the risk of breast cancer.
METHODS: Ovid Medline, CINAHL, Cochrane Data Base of Systematic Reviews, Pubmed, Scopus, Proquest, Sciencedirect, Wiley Online Library, WanFang Data, Hong Kong Index to Chinese Periodicals, China Journal Net, Chinese Medical Current Contents, Chinese Biomedical Literature Database, China Academic Journals Full-Text database, Taiwan Electronic Periodical Services and HyRead; reference lists of published studies; original research studies published in English or Chinese examining the association between type and duration of brassiere-wearing and breast cancer risk. Data were abstracted by a first reviewer and verified by a second. Study quality was rated according to predefined criteria. “Fair” or “good” quality studies were included. Results were summarised by meta-analysis whenever adequate material was available.
RESULTS: Twelve case-control studies were included in the review. Meta-analysis showed brassiere wearing during sleep was associated with a two times of increased odds.
CONCLUSION: The present review demonstrates insufficient evidence to establish a positive association between the duration and type of brassiere wearing and breast cancer. Further research is essential; specifically, a large-scale epidemiological study of a better design is needed to examine the association between various forms of brassiere exposure in detail and breast cancer risk, with adequate control of confounding variables. 相似文献
1000.
Hemobilia occurs when injury or disease causes communication between intrahepatic blood vessels and the biliary tract. Causes of hemobilia include trauma; gallstones; inflammatory diseases; and vascular disorders such as aneurysm, tumor, and coagulopathy. Recently, with the increasing use of invasive diagnostic and therapeutic procedures involving the hepatobiliary tract, an increasing proportion of the causes of hemobilia have been of iatrogenic origin. Hemobilia may also be associated with liver abscess, but this condition is very rare. Our review of the English-language literature disclosed few cases of liver abscess associated with hemobilia. Here, we present a case of hemobilia caused by liver abscess due to intrahepatic duct stones. Liver abscess should be considered in the causes of hemobilia, especially in areas where hepatobiliary parasitic infection is endemic. 相似文献