全文获取类型
收费全文 | 2257篇 |
免费 | 155篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 83篇 |
妇产科学 | 36篇 |
基础医学 | 227篇 |
口腔科学 | 230篇 |
临床医学 | 197篇 |
内科学 | 585篇 |
皮肤病学 | 65篇 |
神经病学 | 108篇 |
特种医学 | 126篇 |
外科学 | 265篇 |
综合类 | 18篇 |
预防医学 | 193篇 |
眼科学 | 69篇 |
药学 | 132篇 |
中国医学 | 16篇 |
肿瘤学 | 77篇 |
出版年
2023年 | 15篇 |
2022年 | 48篇 |
2021年 | 68篇 |
2020年 | 46篇 |
2019年 | 92篇 |
2018年 | 104篇 |
2017年 | 69篇 |
2016年 | 70篇 |
2015年 | 79篇 |
2014年 | 102篇 |
2013年 | 122篇 |
2012年 | 159篇 |
2011年 | 157篇 |
2010年 | 86篇 |
2009年 | 73篇 |
2008年 | 119篇 |
2007年 | 110篇 |
2006年 | 111篇 |
2005年 | 84篇 |
2004年 | 98篇 |
2003年 | 65篇 |
2002年 | 55篇 |
2001年 | 42篇 |
2000年 | 29篇 |
1999年 | 41篇 |
1998年 | 23篇 |
1997年 | 28篇 |
1996年 | 23篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 20篇 |
1992年 | 26篇 |
1991年 | 17篇 |
1990年 | 21篇 |
1989年 | 25篇 |
1988年 | 28篇 |
1987年 | 13篇 |
1986年 | 27篇 |
1985年 | 14篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1971年 | 4篇 |
1970年 | 5篇 |
1968年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有2445条查询结果,搜索用时 15 毫秒
1.
2.
J. Oliveira-Santos R. Santos C. Moreira S. Abreu L. Lopes C. Agostinis-Sobrinho G. Stratton J. Mota 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(8):783-792
Background and aimsThe long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence.Methods and resultsRetrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents.ConclusionA high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes. 相似文献
3.
Intratemporal vascular tumors: detection with CT and MR imaging 总被引:1,自引:0,他引:1
Lo WW; Shelton C; Waluch V; Solti-Bohman LG; Carberry JN; Brackmann DE; Wade CT 《Radiology》1989,171(2):445-448
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion. 相似文献
4.
To study the effect of sorbinil on the alteration of the blood-retinal barrier, 32 adult-onset, non-insulin-dependent diabetic patients with minimal or no retinopathy were randomly assigned to receive either oral sorbinil (250 mg once a day) or a placebo for 6 mo. All patients underwent fundus photography, fluorescein angiography, and vitreous fluorophotometry before treatment and at 3 and 6 mo after treatment. Vitreous fluorophotometry data showed that the alteration of the blood-retinal barrier increased significantly less in the sorbinil-treated group compared with the placebo group during the 6-mo study period. Side effects were limited to hypersensitivity reactions, with skin rash and fever, in only 2 of the 16 patients who received the drug. These hypersensitivity reactions disappeared with discontinuation of the medication. Aldose-reductase inhibition may play an important role in stabilization of the blood-retinal barrier in early diabetic retinopathy. 相似文献
5.
6.
7.
Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献
8.
G P Gerrits A A Haagen R A De Abreu L A Monnens F J Gabre?ls F J Trijbels A L Theeuwes J M van Baal 《Clinical chemistry》1988,34(7):1439-1442
Disturbances in the metabolism of purines and pyrimidines in neurologically affected patients can be reflected by aberrant concentrations of nucleosides and nucleobases in cerebrospinal fluid (CSF). However, normal values, especially for children at different ages, are lacking. We collected 1000 specimens of CSF from subjects ranging in age from newborn to 18 years, who were undergoing a diagnostic lumbar puncture for several clinical indications. Of these, 78 samples could be used retrospectively as a reference according to our criteria. The analyses were performed with a modified HPLC procedure. None of the substances shows age-dependency except uridine and uric acid. Uridine increases with age, and uric acid increases with age in boys older than 12 years. 相似文献
9.
10.
Melatonin is a pineal hormone that regulates the human cycle of sleep and wakefulness. Plasma melatonin levels were investigated in patients with obstructive sleep apnoea syndrome (OSAS). In total, 20 patients with OSAS and 11 healthy controls were studied. OSAS patients were tested twice: on the night of diagnostic polysomnography and the night of continuous positive airway pressure (CPAP) titration. Controls were tested on one occasion. Plasma melatonin levels were determined at 23:00 h (light period), at 02:00 h (dark period) and at 06:00 h (light period) in patients and control subjects using the radioimmunoassay method. The control subjects showed a nocturnal melatonin peak value at 02:00 h (70.6+/-14 pg.mL(-1)). However, this nocturnal melatonin peak was absent in the OSAS patients. The highest melatonin value was found in OSAS patients on the night of diagnosis, at 06:00 h (49.3+/-36.8 pg.mL(-1)). It was found that the melatonin level in OSAS patients at 06:00 h was significantly lower in the night of titration (35.6+/-37.9 pg.mL(-1)) than in the diagnosis night. However, the melatonin levels at either 23:00 h or 02:00 h in OSAS patients did not differ significantly when comparing levels in the night of diagnostic polysomnography (23:00 h: 31.6+/-29.8 pg.mL(-1); 02:00 h: 47.4+/-33.8 pg.mL(-1)) with levels in the night of CPAP titration (23:00 h: 20.2+/-10.3 pg.mL(-1); 02:00 h: 37.7+/-27.5 pg.mL(-1)). Patients with obstructive sleep apnoea syndrome have an abnormal melatonin secretion pattern. The absence of a nocturnal serum melatonin peak could be partially related to the difficulty that these patients have in achieving a normal sleep-wakefulness pattern. 相似文献