全文获取类型
收费全文 | 2324篇 |
免费 | 95篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 87篇 |
妇产科学 | 122篇 |
基础医学 | 208篇 |
口腔科学 | 83篇 |
临床医学 | 176篇 |
内科学 | 537篇 |
皮肤病学 | 19篇 |
神经病学 | 168篇 |
特种医学 | 125篇 |
外科学 | 526篇 |
综合类 | 32篇 |
预防医学 | 46篇 |
眼科学 | 97篇 |
药学 | 69篇 |
中国医学 | 8篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 4篇 |
2023年 | 15篇 |
2022年 | 25篇 |
2021年 | 44篇 |
2020年 | 33篇 |
2019年 | 32篇 |
2018年 | 63篇 |
2017年 | 46篇 |
2016年 | 80篇 |
2015年 | 94篇 |
2014年 | 98篇 |
2013年 | 133篇 |
2012年 | 153篇 |
2011年 | 151篇 |
2010年 | 110篇 |
2009年 | 74篇 |
2008年 | 202篇 |
2007年 | 193篇 |
2006年 | 190篇 |
2005年 | 188篇 |
2004年 | 151篇 |
2003年 | 156篇 |
2002年 | 100篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 15篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1939年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
1928年 | 1篇 |
排序方式: 共有2452条查询结果,搜索用时 0 毫秒
81.
Süheyla Kirmizigül Hüseyin Anil Füsun Uar Kemal Akdemir 《Phytotherapy research : PTR》1996,10(3):274-276
The antimicrobial and antifungal activities of the MeOH extract of the flowers of Cephalaria transsylvanica and three triterpenic acid glycosides, transsylvanoside A–C from the flowers of the plant were assayed using an agar-disc diffusion method. The results showed that both the MeOH extract and the glycosides possess antimicrobial and antifungal activities against Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Corynebacterium xerosis, Klebsiella pneumoniae, Candida utilis, Kluyveromyces fragilis, Aspergillus oryzae and Aspergillus flavus respectively. 相似文献
82.
83.
84.
Emre A Ucer E Yesilcimen K Bilsel T Oz D Sayar N Terzi S Akbulut T Ersek B 《Cardiology》2006,106(4):264-269
BACKGROUND/AIMS: The timing of GpIIb/IIIa inhibitor administration may be important in achieving early epicardial and myocardial reperfusion. We evaluated the effect of early tirofiban on myocardial salvage and cardiovascular outcome in patients with acute myocardial infarction (AMI) undergoing infarct-related artery stenting. METHODS: Patients (n = 66) with a first AMI presenting <6 h from onset of symptoms were randomized to either early administration of tirofiban in the emergency room (n = 32) or later administration in the catheterization laboratory (n = 34) (tirofiban bolus dose of 10 microg/kg, followed by 0.15 microg/kg for 24 h). The primary end-point was the degree of myocardial salvage, determined by means of serial scintigraphic studies with technetium-99m sestamibi. Thirty-day major adverse cardiac events were also assessed. RESULTS: There were no significant differences in patient characteristics or in their presentation. The mean door-to-balloon time was similar in both groups (43 +/- 12 and 53 +/- 9 min, p = 0.08). The early and late treatment groups received tirofiban 18 +/- 4 and 52 +/- 10 min after admission, respectively. Angiographic analysis revealed a higher initial frequency of TIMI grade 3 flow in the early group (31% vs. 12%, p = 0.04). Procedural success was achieved in all patients. Myocardial risk area were comparable between early and late treatment groups (35.6 +/- 12.2% vs. 39.3 +/- 14.0%, p = 0.6). Scintigraphic outcomes demonstrated a significant reduction in the final infarction size (11.8 +/- 5.2% vs. 22.4 +/- 6.2%, p = 0.01), and improvement in salvage index (0.68 +/- 0.22 vs. 0.44 +/- 0.18, p = 0.003) in favor of the early tirofiban group. The thirty-day composite end-point of death, recurrent MI or rehospitalization also favored the early group (6% early, 15% late, p = 0.06). CONCLUSION: Early tirofiban administration enhanced the degree of myocardial salvage and clinical outcome in patients with AMI undergoing infarct-related artery stenting. 相似文献
85.
Combined human papillomavirus typing and TP53 mutation analysis in distinguishing second primary tumors from lung metastases in patients with head and neck squamous cell carcinoma 下载免费PDF全文
Tamas Daher MD Mehmet Kemal Tur DMS Alexander Brobeil MD Benjamin Etschmann DVM Biruta Witte MD Rita Engenhart‐Cabillic MD Gabriele Krombach MD Wolfgang Blau MD Friedrich Grimminger MD Werner Seeger MD Jens Peter Klussmann MD Andreas Bräuninger PhD Stefan Gattenlöhner MD 《Head & neck》2018,40(6):1109-1119
86.
Seher Polat Yusuf Kemal Arslan 《Journal of clinical research in pediatric endocrinology》2022,14(1):56
Objective:Standard dose synacthen stimulation test (SDSST) is a gold standard screening test for evaluating adrenal gland function. Despite studies using SDSST to identify heterozygosity in CYP21A2, the reliability of the test for this purpose is still controversial. Therefore, the meta-analyses were performed to determine the differences in 17-hydroxyprogesterone (17-OHP) responses to standard dose (0.25 mg) SDSST in the diagnosis of CYP21A2 heterozygous individuals, with or without clinical signs of androgen excess disorders.Methods:PubMed and MEDLINE databases were searched. A total of 1215 subjects (heterozygous carriers n=669, mutation-free controls n=546) were included in the meta-analyses.Results:Basal 17-OHP median/mean levels were 4.156 (3.05-10.5)/5.241 (±2.59) nmol/L and 3.90 (2.20-9.74)/4.67 (±2.62) nmol/L in symptomatic heterozygous carriers and symptomatic mutation-free controls, respectively. Stimulated 17-OHP median/mean levels were 17.29 (14.22-37.2)/19.51 (±7.63) nmol/L and 9.27 (7.32-15.9)/10.77 (±3.48) nmol/L in symptomatic heterozygous carriers and symptomatic mutation-free controls, respectively. Basal 17-OHP median/mean levels were 3.21 (2.64-4.78)/3.33 (±0.84) nmol/L and 3.12 (1.82-3.6)/2.83 (±0.71) nmol/L in asymptomatic heterozygous carriers and asymptomatic mutation-free healthy controls, respectively. Stimulated 17-OHP median/mean levels were 14.16 (12.73-16.37)/14.16 (±1.37) nmol/L and 6.26 (4.9-8.23)/6.48 (±1.2) nmol/L in asymptomatic heterozygous carriers and asymptomatic mutation-free healthy controls, respectively. The cut-off levels for stimulated 17-OHP were 10.48 nmol/L and 13.48 nmol/L for asymptomatic heterozygous and symptomatic heterozygous, respectively.Conclusion:The meta-analyses support the idea that stimulated 17-OHP level has potential for use in identifying CYP21A2 carriers. Besides, considering differences in the basal and stimulated 17-OHP levels in symptomatic heterozygous individuals compared to those who were asymptomatic heterozygous could increase the accuracy of the test. 相似文献
87.
Hyperspectral image compression is an important task, where the aim is to store or transmit data in an efficient way. Hyperspectral images are mostly captured by a sensor system that includes multiple imaging sensors covering different regions of the electromagnetic spectrum. Misalignment of multiple imaging sensors produces boresight effect, and this problem can degrade band prediction performance noticeably. Another problem is prediction of blurry band images. In order to gain robustness to these problems, bimodal conventional recursive least-squares (B-CRLS) prediction method is proposed for the lossless compression of hyperspectral images. Two prediction modes are defined: spectral and spatio-spectral. B-CRLS method has a two-step process. First, mode selection is carried out for each band. Afterwards, final band image is predicted by using the selected mode, and the residual images are encoded with an arithmetic encoder. The proposed method is compared to adaptive-length CRLS, fixed-length CRLS, and other well-known prediction methods. Experiments have been performed on uncalibrated and calibrated hyperspectral images. Obtained results show that the proposed method achieves competitive compression performance with the state-of-the-art while providing relatively lower-computation times. 相似文献
88.
Gurlertop Y Yilmaz M Acikel M Bozkurt E Erol MK Senocak H Alp N 《Echocardiography (Mount Kisco, N.Y.)》2004,21(4):319-324
OBJECTIVE: The purpose of this study was to compare the left atrial appendage (LAA) tissue Doppler imaging (TDI) with the classical LAA function parameters in patients with mitral valve disease. METHODS: Twenty patients who had pure mitral regurgitation (group 1), 20 patients who had pure rheumatic mitral stenosis (group 2), and 20 healthy patients (group 3) were included in this study. All the cases were sinus rhythm. In order to determine the LAA functions, LAA late filling (LAALF), and late emptying (LAALE) flow velocities and LAA fractional area change (LAAFAC) were measured. LAA tissue Doppler evaluations were obtained from the PW Doppler, which was placed on the LAA lateral wall in a transverse basal short-axis approach. LAA late systolic (LAALSW) and late diastolic (LAALDW) wave velocities were obtained from TDI records transesophageal echocardiography (TEE). RESULTS: There were no significant differences among groups 1, 2, and 3 in terms of age, left ventricular (LV) ejection fraction, gender, and heart rate. No differences were observed between group 1 and the control group with respect to LAALE, LAALF, and LAAFAC. LAALE velocity and LAAFAC were significantly decreased in group 2 than group 1. LV diastolic diameter was significantly greater, whereas LAALSW and LAALDW velocities were significantly decreased in group 1 compared with group 3. There were no differences between groups 1 and 2 regarding to LAALSW and LAALDW velocities. LAALE, LAALF, LAALSW, LAALDW velocities, and LAAFAC were significantly decreased in group 2 than group 3. CONCLUSION: The TDI method may detect the LAA systolic dysfunctions, which cannot be detected using classical methods, on tissue level in patients with mitral regurgitation. In addition, the deterioration of the LAA functions at tissue level in patients with rheumatic mitral stenosis was also detected. 相似文献
89.
Relationship between bone mineral density and biochemical markers of bone turnover in hemodialysis patients 总被引:1,自引:0,他引:1
End-stage renal disease is closely associated with changes in bone and mineral metabolism. In recent times, osteoporosis has become important among hemodialysis (HD) patients. In this study, the investigators sought to evaluate the relationship between bone mineral density (BMD) and biochemical markers of bone turnover among HD patients. A total of 70 uremic patients on a maintenance HD program for at least 1 y were enrolled in the study. All patients were treated with conventional bicarbonated HD for 5 h through the use of low-flux hollow-fiber dialyzers. Bone densitometry was measured by dual energy x-ray absorptiometry in the lumbar spine (LS) and the femoral neck (FN). BMD was classified according to World Health Organization criteria on the basis of BMD T scores. Biochemical bone turnover markers such as calcium, phosphorus, ionized calcium, intact parathyroid hormone, alkaline phosphatase, plasma bicarbonate, blood pH, serum albumin, and hematocrit levels were measured before the HD session in the morning. Male patients (n=37; 52.9%; mean age, 46.2+/-17.0 y) were assigned to a single study group, and female patients (n=33; 47.1%; mean age, 44.0+/-13.1 y) to another. Mean duration of HD treatment was 33.7+/-28.5 mo in females and 33.0+/-26.0 mo in males. Among all patients, BMD T scores in the osteopenia/osteoporosis range were observed at the LS in 58 patients (82.8%) and at the FN in 45 patients (64.3%). According to BMD measurements in FN T score, 10% of patients (n=7) were osteoporotic, 54.3% (n=38), osteopenic, and 35.7% (n=25), normal. On the other hand, in LS T score, the results were 47.1% (n=33) osteoporotic, 35.7% (n=25), osteopenic, and 17.1% (n=12), normal. No statistically significant association was found in osteopenia/osteoporosis between sexes according to FN and LS T score (P=.542, P=.267, respectively). No significant relationship was noted between BMD and biochemical markers of bone turnover. A positive correlation was found between FN T scores of BMD and age (r=.413, P=.000). BMD T scores within the range of scores for osteopenia/osteoporosis were observed in 78.5% of patients at the LS and in 58.5% of patients at the FN. The investigators concluded that no correlation could be found between markers of bone turnover and bone mass measurements in both skeletal regions. LS T score results were worse than FN T score results. Elevated alkaline phosphastase levels combined with high intact parathyroid hormone levels are predictive of renal osteodystrophy but not of adynamic bone disease/osteoporosis. 相似文献
90.
Gürbüz F Kotan LD Mengen E Sıklar Z Berberoğlu M Dökmetaş S Kılıçlı MF Güven A Kirel B Saka N Poyrazoğlu S Cesur Y Doğan M Ozen S Ozbek MN Demirbilek H Kekil MB Temiz F Onenli Mungan N Yüksel B Topaloğlu AK 《Journal of clinical research in pediatric endocrinology》2012,4(3):121-126
Objective: Normosmic idiopathic hypogonadotropic hypogonadism (nIHH) is characterized by failure of initiation or maintenance of puberty due to insufficient gonadotropin release, which is not associated with anosmia/hyposmia. The objective of this study was to determine the distribution of causative mutations in a hereditary form of nIHH. Methods: In this prospective collaborative study, 22 families with more than one affected individual (i.e. multiplex families) with nIHH were recruited and screened for genes known or suspected to be strong candidates for nIHH. Results: Mutations were identified in five genes (GNRHR, TACR3, TAC3, KISS1R, and KISS1) in 77% of families with autosomal recessively inherited nIHH. GNRHR and TACR3 mutations were the most common two causative mutations occurring with about equal frequency. Conclusions: Mutations in these five genes account for about three quarters of the causative mutations in nIHH families with more than one affected individual. This frequency is significantly greater than the previously reported rates in all inclusive (familial plus sporadic) cohorts. GNRHR and TACR3 should be the first two genes to be screened for diagnostic purposes. Identification of causative mutations in the remaining families will shed light on the regulation of puberty. 相似文献