全文获取类型
收费全文 | 5343篇 |
免费 | 505篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 90篇 |
妇产科学 | 144篇 |
基础医学 | 538篇 |
口腔科学 | 236篇 |
临床医学 | 371篇 |
内科学 | 612篇 |
皮肤病学 | 63篇 |
神经病学 | 308篇 |
特种医学 | 199篇 |
外国民族医学 | 2篇 |
外科学 | 356篇 |
综合类 | 446篇 |
现状与发展 | 1篇 |
预防医学 | 450篇 |
眼科学 | 70篇 |
药学 | 1606篇 |
中国医学 | 194篇 |
肿瘤学 | 302篇 |
出版年
2024年 | 18篇 |
2023年 | 119篇 |
2022年 | 215篇 |
2021年 | 257篇 |
2020年 | 216篇 |
2019年 | 223篇 |
2018年 | 210篇 |
2017年 | 208篇 |
2016年 | 198篇 |
2015年 | 217篇 |
2014年 | 333篇 |
2013年 | 458篇 |
2012年 | 313篇 |
2011年 | 307篇 |
2010年 | 269篇 |
2009年 | 269篇 |
2008年 | 282篇 |
2007年 | 297篇 |
2006年 | 220篇 |
2005年 | 189篇 |
2004年 | 193篇 |
2003年 | 126篇 |
2002年 | 120篇 |
2001年 | 93篇 |
2000年 | 72篇 |
1999年 | 67篇 |
1998年 | 54篇 |
1997年 | 49篇 |
1996年 | 42篇 |
1995年 | 31篇 |
1994年 | 40篇 |
1993年 | 38篇 |
1992年 | 33篇 |
1991年 | 30篇 |
1990年 | 29篇 |
1989年 | 27篇 |
1988年 | 26篇 |
1987年 | 21篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1973年 | 3篇 |
排序方式: 共有6017条查询结果,搜索用时 15 毫秒
91.
《Medical engineering & physics》2014,36(11):1515-1520
The pulse pressure waveform has, for long, been known as a fundamental biomedical signal and its analysis is recognized as a non-invasive, simple, and resourceful technique for the assessment of arterial vessels condition observed in several diseases. In the current paper, waveforms from non-invasive optical probe that measures carotid artery distension profiles are compared with the waveforms of the pulse pressure acquired by intra-arterial catheter invasive measurement in the ascending aorta. Measurements were performed in a study population of 16 patients who had undergone cardiac catheterization. The hemodynamic parameters: area under the curve (AUC), the area during systole (AS) and the area during diastole (AD), their ratio (AD/AS) and the ejection time index (ETI), from invasive and non-invasive measurements were compared. The results show that the pressure waveforms obtained by the two methods are similar, with 13% of mean value of the root mean square error (RMSE). Moreover, the correlation coefficient demonstrates the strong correlation. The comparison between the AUCs allows the assessment of the differences between the phases of the cardiac cycle. In the systolic period the waveforms are almost equal, evidencing greatest clinical relevance during this period. Slight differences are found in diastole, probably due to the structural arterial differences. The optical probe has lower variability than the invasive system (13% vs 16%). This study validates the capability of acquiring the arterial pulse waveform with a non-invasive method, using a non-contact optical probe at the carotid site with residual differences from the aortic invasive measurements. 相似文献
92.
目的 研究面部三维光学测量系统在面部外形重建和测量中的实用性和可靠性。方法 利用自行研制的面部三维光学测量系统扫描45名正常人面形,结合Geomagic studio软件反求重建面部外形。比较面部内眦间距、鼻长、鼻宽、鼻高、鼻深等的反求测量结果与手工测量结果间的差异。结果 基于面部三维光学测量系统结合反求软件直接重建了45名正常人的面部三维外形,面部测量项目的 反求测量结果与手工测量结果在统计学上无明显差异(P>0.05)。结论 面部三维光学测量系统在面部外形采集、反求重建、三维测量中具有较高的可靠性和较好的实用性。 相似文献
93.
94.
《Physical & occupational therapy in pediatrics》2013,33(4):59-68
A statewide service delivery project which provides specialized adaptive equipment to multi-handicapped persons living in rural communities is described. In addition to client consultation regarding motor programs, the adaptive equipment project provided specialized equipment such as adaptive chairs, standing and walking aids, feeding utensils, bathing aids, etc. to handicapped client of all ages. Services were delivered via an itinerant approach and relied on parents and others in the community as primary intervention agents. The project is viewed as an important activity in maintaining recently deinstitutionalized clients in community settings. 相似文献
95.
《Gait & posture》2019
BackgroundComplex clinical gait analysis results can be expressed as single number gait deviations by applying multivariate processing methods. The original Movement Deviation Profile (MDP) quantifies the deviation of abnormal gait using the most trusted nine dynamic joint angles of lower limbs.Research questionWhich subset of joint angles maximises the ability of the MDP to separate abnormal gait from normality? What is the effect of using the best subset in a large group of patients, and in individuals?MethodsA self-organising neural network was trained using normal gait data from 166 controls, and then the MDP of 1923 patients with cerebral palsy (3846 legs) was calculated. The same procedure was repeated with 511 combinations of the nine joint angles. The standardised distances of abnormal gait from normality were then calculated as log-transformed Z-scores to select the best combination. A mixed design ANOVA was used to assess how removing the least discriminating angle improved the separation of patients from controls. The effect of using the optimal subset of angles was also quantified for each individual leg by comparing the change in MDP to the independent FAQ levels of patients.ResultsRemoval of hip rotation significantly (p<0.0005) increased the separation of the patient group from normality (ΔZ-score 0.24) and also at FAQ levels 7-10 (ΔZ-score 0.38, 0.27, 0.22, 0.14). The MDP of individual patients changed in a wider range of -4.65 to 1.12 Z-scores and their change matched their independent FAQ scores, with less functional patients moving further from, and more functional patients moving closer to normality.SignificanceIn existing gait databases we recommend excluding hip rotation from data used to calculate the MDP. Alternatively, the calculation of hip rotation can be improved by post-hoc correction, but the ultimate solution is to use more accurate and reliable models of hip rotation. 相似文献
96.
97.
《Drug and chemical toxicology》2013,36(2):123-131
Adiponitrile (ADN) has moderate acute toxicity with an oral LD50 in rats of 100 to 500 mg/kg and a 4‐hr LC50 in rats of 1.71 mg/L (vapor plus aerosol). ADN produced slight eye but no skin irritation in rabbits. Repeated exposures by inhalation produced changes in the hematologic profile with effects seen at 100 or 300 mg/m3. The hematologic changes were reversible upon cessation of further inhalation exposures. Dogs fed up to 500 ppm (equivalent to 12–15 mg/kg) showed no effects but 1,000 ppm produced vomiting and nausea which limited further testing at that concentration. ADN was not a genetic toxin, developmental toxin, reproductive toxin nor did it produce an increase in tumors in a 2‐yr drinking water study in rats. Human experience reports are limited to one accidental poisoning case and a few skin exposures resulting in transient irritation and inflammation. ADN is rapidly absorbed and excreted by mammals, and is metabolized to some extent although unchanged ADN is readily detected in urine, and does not bioaccumulate. 相似文献
98.
《Diabetes & Metabolic Syndrome: Clinical Research & Reviews》2022,16(4):102448
Background and aimsLDL-cholesterol (LDL-C), being the primary predictor of cardiovascular disease in Type 2 diabetes (T2D), is associated with cardiovascular risk stratification and requires to be estimated with better accuracy with minimal bias. Different formulae have been devised to calculate the LDL-C from the measured lipid profile parameters.MethodsIn this analytical cross-sectional study, a total of 150 patients with T2D were studied, and blood samples were subjected for lipid profile analysis at the Central Biochemistry laboratory. Different formulae assessed calculated LDL-C.ResultsWe observed that all formulae, except Ahmadi, underestimated the LDL-C compared to direct assay. A significant difference was observed between all calculated LDL-C and directly measured LDL-C. On linear regression analysis, the newer formula Martin's has a better approximation with direct assay (slope: 0.9708) than Friedewald (slope: 0.9477). Similarly, Martin's formula exhibited lesser bias (?13.56) in calculating LDL-C in patients with T2D compared with Friedewald's formula.ConclusionsThe study demonstrated that in patients with T2D, all formulae except Ahmadi significantly underestimated the LDL-C when compared with the direct assay. The newer Martin's formula appeared to more precisely calculate LDL-C in T2D when compared with the traditional Friedewald's formula. 相似文献
99.
Aaron S. Farberg Mary A. Hall Leah Douglas Kyle R. Covington Sarah J. Kurley Robert W. Cook 《Current medical research and opinion》2020,36(8):1301-1307
AbstractObjective: To integrate gene expression profiling into the management of high-risk cutaneous squamous cell carcinoma (cSCC) within the National Comprehensive Cancer Network (NCCN) guidelines to improve risk-aligned management recommendations.Methods: A cohort of 300 NCCN-defined high-risk cSCC patients, along with the American Joint Committee on Cancer (AJCC) T stage, Brigham and Women’s Hospital (BWH) T stage, and known patient outcomes were analyzed. Risk classifications using a validated 40-gene expression profile (40-GEP) test and T stage were applied to NCCN patient management guidelines. Risk-directed patient management recommendations within the NCCN guidelines framework were aligned based on risk for metastasis.Results: Of the 300 NCCN high-risk cSCC patients, 159 (53.0%) were 40-GEP Class 1 and AJCC T1-T2, and 173 (57.7%) were Class 1 and BWH T1-2a, indicating low risk for metastasis and, thereby, suggesting low management intensity. The 40-GEP integration suggested high intensity management for only 24 (8.0%) patients (all Class 2B), and moderate intensity management for the remainder of the cohort.Conclusions: The 40-GEP test can be integrated within existing NCCN guideline recommendations for managing cSCC patients to help refine risk-directed management decisions. Integration of the 40-GEP test would allow >50% of this NCCN-defined high-risk cohort to be managed with the lowest intensity recommendations within the broad NCCN guidelines. High intensity management was deemed risk-appropriate for a small subpopulation (8.0%). This study demonstrates that the 40-GEP test, in combination with T stage, has clinical utility to impact patient management decisions in NCCN high-risk cSCC for improving risk-aligned management within the NCCN guidelines framework. 相似文献
100.
《The Egyptian Rheumatologist》2020,42(3):237-240
Aim of the workIt was to estimate the carotid intima-media thickness (CIMT), lipid profile, serum amyloid A and vitamin D in Familial Mediterranean Fever (FMF) patients and to explore the relationship between CIMT and FMF.Patients and methodsThe study comprised forty-five FMF patients diagnosed during the attack free period and 40 healthy children with similar demographic features as control. The diagnosis of the FMF cases was confirmed by clinical, laboratory assessments and confirmed by the molecular diagnosis. The CIMT, lipid profile, complete blood picture, serum amyloid A (SAA) levels, vitamin D and the growth pattern were investigated.ResultsThe study showed no significant difference of CIMT among patients and controls, significant decrease of vitamin D levels, while lipid profile parameters, triglyceride (TG) to HDL-Cholesterol (HDL-C) ratio, serum amyloid A were significantly increased. A significant correlation was present between the CIMT with the serum cholesterol, low density lipoprotein and triglycerides as well as between SAA and the number of attacks. In addition, vitamin D levels showed significant negative correlation with colchicine. M694I mutation was the most prevalent among FMF patients. Growth parameters were normal in FMF cases.ConclusionThis study sheds light that the normal CIMT in the FMF patients makes it difficult to describe the children as having subclinical atherosclerosis although the higher TG/HDL ratio reflects their risk of atherosclerosis. Moreover, significant decrease of vitamin D in FMF patients was observed. The growth parameters of the FMF patients on regular treatment of colchicine were not affected. 相似文献