全文获取类型
收费全文 | 4612篇 |
免费 | 178篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 130篇 |
儿科学 | 221篇 |
妇产科学 | 125篇 |
基础医学 | 317篇 |
口腔科学 | 160篇 |
临床医学 | 358篇 |
内科学 | 1123篇 |
皮肤病学 | 86篇 |
神经病学 | 310篇 |
特种医学 | 186篇 |
外科学 | 1021篇 |
综合类 | 100篇 |
一般理论 | 1篇 |
预防医学 | 206篇 |
眼科学 | 101篇 |
药学 | 187篇 |
中国医学 | 9篇 |
肿瘤学 | 187篇 |
出版年
2023年 | 44篇 |
2022年 | 63篇 |
2021年 | 129篇 |
2020年 | 73篇 |
2019年 | 103篇 |
2018年 | 127篇 |
2017年 | 77篇 |
2016年 | 147篇 |
2015年 | 135篇 |
2014年 | 162篇 |
2013年 | 262篇 |
2012年 | 347篇 |
2011年 | 340篇 |
2010年 | 183篇 |
2009年 | 164篇 |
2008年 | 343篇 |
2007年 | 361篇 |
2006年 | 373篇 |
2005年 | 324篇 |
2004年 | 300篇 |
2003年 | 225篇 |
2002年 | 198篇 |
2001年 | 29篇 |
2000年 | 29篇 |
1999年 | 28篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 15篇 |
1987年 | 13篇 |
1986年 | 16篇 |
1985年 | 24篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 13篇 |
1978年 | 8篇 |
1976年 | 5篇 |
1974年 | 8篇 |
1972年 | 8篇 |
1970年 | 4篇 |
1969年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有4828条查询结果,搜索用时 0 毫秒
51.
Fadlullah Aksoy Remzi Dogan Orhan Ozturan Selahattin Tugrul Bayram Veyseller Omer Faruk Ozer Alev Pektas 《Clinical and experimental otorhinolaryngology》2015,8(4):312-319
Objectives
In this study we investigated the probable protective effects of thymoquinone on amikacin-induced ototoxicity in rats.Methods
Thirty-two healthy rats were divided into four groups (amikacin, amikacin+thymoquinone, thymoquinone, and no treatment). Thymoquinone was fed to the rats via oral gavage in a dose of 40 mg/kg/day throughout the study period of 14 days. Amikacin was given by the intramuscular route in a dose of 600 mg/kg/day. Audiological assessment was conducted by the distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) tests, administered to all rats at the beginning of the study, and also on days 7 and 15. Biochemical parameters were calculated at the termination of the study to evaluate the oxidative status.Results
There were significant decreases in DPOAE values and significant increases in ABR thresholds of the amikacin group on days 7 and 15, as compared to the amikacin+thymoquinone group. While ABR thresholds of the amikacin group increased significantly on days 7 and 15 as compared to their initial values, there were no significant differences between the initial and the 7th and 15th day values of ABR thresholds in the amikacin+thymoquinone group. Total oxidant status and oxidative stress index values of the amikacin+thymoquinone group were significantly lower than those of the amikacin group. Total antioxidant status values of the amikacin+thymoquinone group were significantly higher than those of the amikacin group.Conclusion
Our study has demonstrated that the ototoxic effect brought forth by amikacin could be overcome with the concurrent use of thymoquinone. 相似文献52.
Carlo Di Mario Nuccia Morici Cosmo Godino Omer Goktekin Corrado Tamburino Rossella Barbagallo David Antoniucci Eberhard Grube Flavio Airoldi Giuseppe Biondi Zoccai Antonio Colombo Giuseppe M Sangiorgi 《Catheterization and cardiovascular interventions》2007,69(3):416-424
OBJECTIVES: The aim of the study was the assessment of the clinical, angiographic and procedural characteristics correlated with freedom from adverse events at 1 year in a real life setting of consecutive bifurcation lesions. BACKGROUND: Even if stent implantation has shown to be superior to conventional balloon angioplasty in most coronary lesions, bifurcation treatment with stent implantation both in main and in side branch (SB) still raises controversy. METHODS: We reviewed the results obtained in a prospective multicenter registry of 150 patients with 158 bifurcation lesions involving a SB of sufficient diameter to be treated, if necessary, with a polymer based paclitaxel eluting stent (PES, TAXUS). Two stents were used in 118 lesions (74.7%). Final kissing balloon inflation was performed in 87/118 lesions (73.7%) and in 30/40 lesions (75.0%) of the 2 and 1 stent group respectively. RESULTS: At 1-year clinical follow-up we observed 4 stent thromboses, all involving the SBs of the 2 stents group (2.7%). Unlike previous reports, revascularization involved the main vessel in the majority of patients (21/150, 14.0%). After an exploratory multivariable analysis the only parameter predictive of target lesion revascularization (TLR) (HR 0.52; CI 95% 0.11-0.86; p = 0.02) and target vessel revascularization (TVR) (HR 0.47; CI 95% 0.14-0.90; p = 0.03) was postprocedural main branch minimal lumen diameter (MB-MLD). CONCLUSIONS: In a real life setting of consecutive bifurcation lesions, thrombosis rate, concentrated in the SB and the 2-stents group, and need for target lesion revascularization remain higher than in less complex lesion subgroups treated with PES. No differences in immediate success and TLR were observed between 2 stents and 1 stent groups. The frequently observed suboptimal stent expansion and final MB-MLD predict 1 year revascularization. 相似文献
53.
Mehmet?DoganEmail authorView authors OrcID profile Tolga?Han?Efe Tolga?Cimen Cem?Ozisler Mehmet?Ali?Felekoglu Ahmet?Goktug?Ertem Mehmet?Erat Omer?Yiginer Murat?Tulmac 《Lung》2018,196(2):173-178
Objectives
Systemic sclerosis (SSc) is a chronic, inflammatory, and autoimmune connective tissue disease that is associated with vascular lesions, and fibrosis of the skin and visceral organs. Cardiac complications may occur as a secondary effect of SSc as a result of pulmonary arterial hypertension and interstitial lung disease. The objective of this study was to assess whether the pulmonary pulse transit time (pPTT) could serve as a diagnostic marker for pulmonary arterial alterations in patients with SSc, prior to development of pulmonary hypertension.Methods
Twenty-five SSc patients as a study group and 25 age- and sex-matched healthy volunteers for the control group were recruited to the study. Right ventricle function parameters, such as tricuspid annular plane systolic excursion (TAPSE), estimated pulmonary artery systolic pressure (ePASP), right ventricular dimensions, right ventricle fractional area changes, and myocardial perfusion index (MPI) were measured and calculated. Pulmonary pulse transit time was defined as the time interval between the R-wave peak in the ECG and the corresponding peak late systolic pulmonary vein flow velocity.Results
Right ventricle myocardial performance index (RVMPI) and eSPAP were significantly higher in the SSc group than the controls (p?=?0.032, p?=?0.012, respectively). Pulmonary pulse transit time and TAPSE was shorter in the patients with SSc (p?=?0.006, p?=?0.015, respectively). In correlation analysis, pPTT was inversely correlated with RVMPI (r?=???0.435, p?=?0.003), eSPAP (r?=???0.434, p?=?0.003), and disease duration (r?=???0.595, p?=?0.003). Conversely, it positively correlated with TAPSE (r?=?0.345, p?=?0.022).Conclusion
pPTT was found to be shorter in SSc patients. pPTT might serve as a surrogate marker of pulmonary hemodynamics in patients with SSc, even prior to the development of pulmonary hypertension.54.
Gokhan Soker Bozkurt Gulek Eda Soker Omer Kaya Ibrahim Inan Muhammet Arslan Kaan Esen Derya Memis Cengiz Yilmaz 《Journal of Medical Ultrasonics》2018,45(2):287-294
Purpose
In this study, we aimed to establish a quantitative threshold value in the diagnosis of subacromial impingement syndrome by measuring the thickness of the subacromial bursa during abduction and adduction.Materials and methods
Forty-five patients with subacromial impingement syndrome and 54 healthy individuals underwent dynamic shoulder ultrasonography. The subacromial bursa, between the supraspinatus tendon margin and peribursal adipose tissue, was measured between the acromion and humeral head at its widest part. The subacromial impingement ratio was calculated by dividing the subacromial bursa thickness during abduction to the subacromial bursa thickness during adduction. Shapiro–Wilk test was used in the assessment of normal distribution of parameters.Results
The mean subacromial bursa thickness in the abduction position was 1.8 ± 1.1 mm in the study group and 0.9 ± 0.3 mm in the control group. The mean subacromial bursa thickness in the adduction position was 0.9 ± 0.5 mm in the study group and 0.8 ± 0.3 mm in the control group. The subacromial impingement ratio showed a statistically significant difference between groups (p < 0.0001), and the ratio being 2.0 ± 0.5 in the study group and 1.2 ± 0.1 in the control group. For measurements performed in the abduction position, the best cut-off value was calculated as 1.3 mm, and sensitivity and specificity were 70.6 and 85.2%, respectively. The best cut-off value was 1.4 for the subacromial impingement ratio, and sensitivity and specificity were 88.2 and 96.3%, respectively.Conclusion
Subacromial impingement ratio is a very practical and reliable method in subacromial impingement syndrome diagnosis.55.
Haldun Akoglu Omer Faruk Celik Ali Celik Rabia Ergelen Ozge Onur Arzu Denizbasi 《The American journal of emergency medicine》2018,36(6):1014-1017
Introduction
The diagnostic accuracy of the FAST exam performed by EM residents were shown to be similar to radiology residents. However, in the last 2 decades, an extended-FAST (E-FAST) protocol including thoracic examination to exclude pneumo- and hemothorax was introduced. The accuracy of emergency physicians (EPs) while performing E-FAST is a less studied area, especially in Europe. The aim of this study was to compare the diagnostic accuracy of the E-FAST exam performed by EM residents with the results of CT scan as a gold standard.Methods
This was a prospective, observational, diagnostic accuracy study conducted at the ED of a Level 1 Trauma Center. All consecutive adult multiple trauma patients were eligible, and any patient in whom thoraco-abdominal CT was ordered were recruited. Unstable and unavailable patients were excluded. E-FAST examination was performed by EPs as the index test, and CT examinations reported by a blinded academic radiology faculty was the gold standard.Results
A total of 140 patients were recruited from eligible 144 patients. The final study population was 132 for abdominal and 130 for thorax examinations. In this study, AUC of E-FAST was 0.71 for abdominal free fluid, 0.87 for pneumothorax and 1.00 for pleural effusion. The sensitivity was 42.9% and specificity was 98.4%. The + LR for abdominal free fluid was 26.8 and ? LR was 0.58.Conclusion
E-FAST examination has an excellent specificity. However, the sensitivity of the test is not high enough to rule-out thoraco-abdominal injuries in trauma patients when performed by EPs. 相似文献56.
Cagla Celik Didar Tasdemir Ayse Demirbas Ahmet Kat O. Tolga Gul Behzat Cimen Ismail Ocsoy 《RSC advances》2018,8(45):25298
The discovery of functional organic–inorganic hybrid nanoflowers (FNFs) consisting of proteins/enzymes as the organic components and Cu(ii) ion as the inorganic component has made an enormous impact on enzyme immobilization studies. The FNFs synthesized by an encouraging and novel approach not only showed high stabilities but also much enhanced catalytic activities as compared to free and conventionally immobilized enzymes. A recent development demonstrated that FNF formation has moved beyond the initial discovery in which enzymes and Cu2+ ions used as the organic and inorganic parts, respectively, are replaced with new organic (chitosan, amino acid and plant extracts) and inorganic (Cu2+ and Fe2+) materials. The new organic materials incorporated into FNFs act as Fenton-like agents and then show peroxidase-like activity owing to the metal ions and the porous structure of FNFs in the presence of hydrogen peroxide (H2O2). All FNFs have been widely utilized in many different scientific and industrial fields due to their greatly enhanced activities and stabilities. This review focuses primarily on the preparation, characterization, and bioanalytical applications of FNFs and explains the mechanisms of their formation and enhanced activities and stabilities.The discovery of functional organic–inorganic hybrid nanoflowers (FNFs) consisting of proteins/enzymes as the organic components and Cu(ii) ion as the inorganic component has made an enormous impact on enzyme immobilization studies. 相似文献
57.
Maya?Rosman Orna?Rachminov Omer?Segal Gad?SegalEmail author 《BMC health services research》2015,15(1):246
Background
Prolonged, inappropriate hospital stay after patients’ eligibility for discharge from internal medicine departments is a world-wide health-care systems’ problem. Nevertheless, the extent to which such surplus hospital stays are associated with infectious complications, their time frame of appearance and their long-term implications was not previously addressed.Methods
We conducted a retrospective cohort analysis of patients experiencing an In-hospital Waiting Period (IHWP) after discharge eligibility in a single, tertiary hospital.Results
We screened the records of 245 patients out of which 104 patients fulfilled our inclusion criteria. The mean length of IHWP was 15.7?±?4.79 day during which 9(8.7 %) patients died. The study primary composite end-point, in-hospital mortality or hospital acquired infection (pneumonia, UTI or sepsis) occurred in 32(31 %) patients. The most hazardous time was during the first 3 IHWP days: 63.7 % of patients experienced a complication and 44 % of the total complications occurred during this period. The occurrence of any complication during IHWP was associated, with statistical significance, with increased risk of mortality during the first year after IHWP initiation (HR?=?6.02, p?=?0.014).Conclusion
Prolongation of hospital stay after patients are deemed to be discharged from internal medicine departments is associated with increased morbidity and mortality, mainly during the first surplus days of in-hospital stay. Efforts should be made to shorten such hospital stays as much as possible.58.
Ozdöl C Akyürek O Güldal M Karaoğuz R Oral D 《International journal of cardiology》2004,93(2-3):285-287
Congenital coronary sinus anomalies are unusual and they rarely coexist with accessory atrioventricular pathways. These anomalies are generally asymptomatic, however they can cause difficulty in mapping. The association between accessory pathway and coronary sinus anomalies may suggest an embryologic link. In this case, we report a male patient with permanent form of reciprocating tachycardia coexistent with anomalous coronary sinus. 相似文献
59.
We examined the association between serum trace elements and clinical findings such as number of sensitive tender points, severity of fatigue and functional status in patients with fibromyalgia (FM). Thirty-two patients diagnosed as having FM according to the ACR 1990 criteria and 32 normal healthy controls (NHC) were included in this study. The demographic data, disease duration, number of tender points and accompanying symptoms (fatigue, sleep disorders, headache, paresthesia, irritable bowel syndrome, sicca symptoms, Raynaud's phenomena) of the patients were noted. Visual analog scale (10 cm) was implemented to estimate daily severity of pain and fatigue. Fibromyalgia impact questionnaire was used for functional assessment. Serum selenium (mug/dL) and serum zinc (mug/dL) levels were measured by atomic absorption spectrometer. Serum magnesium (mmol/L) level was measured by the original kits of Abbott Aeroset auto-analyzer. The mean age of patients in FM group and NHC were calculated as 42.9 (SD = 7.7) years and 41.3 (SD = 9.7) years, respectively. Serum levels of zinc (P = 0.001) and magnesium (P = 0.002) were significantly decreased by FM groups, whereas there was no considerable difference with selenium levels of both groups (P > 0.05). Association between serum zinc level and number of tender points (P = 0.008) and that between fatigue and magnesium level (P = 0.003) was found as meaningful. According to the results of this study, it was asserted that serum magnesium and zinc levels may play an important role in the pathophysiology of FM. 相似文献
60.
Aktoğu S Erer OF Urpek G Soy O Tibet G 《Respiration; international review of thoracic diseases》2002,69(2):178-181
Beh?et's disease (BD) with pulmonary arterial aneurysm is rare and often associated with a poor prognosis. But there is also a chance that the aneurysm may completely resolve with medical therapy. A 39-year-old man presented with fever, malaise, bilateral chest pain, recurrent oral ulcers, and hemoptysis. The chest radiograph showed a round opacity in the right hilum. Computed tomography and magnetic resonance angiography (MRA) further revealed multiple, bilateral pulmonary arterial aneurysms consistent with the diagnosis of BD. The patient was started on a course of cyclophosphamide and corticosteroid therapy that resulted in cessation of his symptoms and complete resolution of radiologic findings. The chest radiograph and MRA reverted to normal on long-term follow-up. He is still alive and symptom-free 20 months after diagnosis. 相似文献