全文获取类型
收费全文 | 4089篇 |
免费 | 382篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 123篇 |
妇产科学 | 105篇 |
基础医学 | 439篇 |
口腔科学 | 95篇 |
临床医学 | 377篇 |
内科学 | 799篇 |
皮肤病学 | 82篇 |
神经病学 | 392篇 |
特种医学 | 272篇 |
外国民族医学 | 1篇 |
外科学 | 508篇 |
综合类 | 140篇 |
一般理论 | 5篇 |
预防医学 | 445篇 |
眼科学 | 51篇 |
药学 | 370篇 |
中国医学 | 2篇 |
肿瘤学 | 262篇 |
出版年
2021年 | 31篇 |
2020年 | 30篇 |
2019年 | 49篇 |
2018年 | 59篇 |
2017年 | 56篇 |
2016年 | 59篇 |
2015年 | 73篇 |
2014年 | 80篇 |
2013年 | 126篇 |
2012年 | 213篇 |
2011年 | 199篇 |
2010年 | 111篇 |
2009年 | 126篇 |
2008年 | 184篇 |
2007年 | 174篇 |
2006年 | 170篇 |
2005年 | 136篇 |
2004年 | 147篇 |
2003年 | 133篇 |
2002年 | 105篇 |
2001年 | 100篇 |
2000年 | 112篇 |
1999年 | 124篇 |
1998年 | 84篇 |
1997年 | 104篇 |
1996年 | 91篇 |
1995年 | 88篇 |
1994年 | 80篇 |
1993年 | 74篇 |
1992年 | 79篇 |
1991年 | 87篇 |
1990年 | 98篇 |
1989年 | 63篇 |
1988年 | 78篇 |
1987年 | 82篇 |
1986年 | 72篇 |
1985年 | 43篇 |
1984年 | 37篇 |
1983年 | 50篇 |
1982年 | 51篇 |
1981年 | 35篇 |
1980年 | 39篇 |
1979年 | 30篇 |
1978年 | 35篇 |
1977年 | 41篇 |
1976年 | 33篇 |
1974年 | 31篇 |
1972年 | 32篇 |
1968年 | 30篇 |
1967年 | 26篇 |
排序方式: 共有4482条查询结果,搜索用时 31 毫秒
81.
AIMS: Long acting subcutaneous testosterone pellets are of proved efficacy for the treatment of hypogonadal men, but have not been reported as a treatment modality in adolescent boys. Pharmacodynamic studies of subcutaneous testosterone release have shown prolonged normalisation of testosterone levels for at least four months. Administration of a long acting, safe, effective, and convenient form of treatment is desirable when life-long treatment is indicated. PATIENTS AND METHODS: Eighteen boys (aged 13.9-17.5 years at the start of treatment)-seven with primary hypogonadism, nine with secondary hypogonadism, and two boys being treated with testosterone for tall stature--were given testosterone pellets (8-10 mg/kg) every six months for 18 months. Height, weight, pubertal status, and psychosocial parameters were assessed and follicle stimulating hormone, luteinising hormone, testosterone, prolactin, and lipids were measured at 0, 1, 3, 6, 12, and 18 months. Bone age was measured at 0 and 12 months. RESULTS: In all boys growth velocity continued appropriately for bone age. Puberty continued to progress in all boys and in two boys the amount of virilisation exceeded that seen with previous treatment with intramuscular testosterone. After testosterone administration, follicle stimulating hormone and luteinising hormone suppressed incompletely in the boys with primary hypogonadism. Serum testosterone ranged from 4.3 to 26.7 nmol/l at three months to less than 10 nmol/l at six months after implantation. Prolactin and lipid levels were normal throughout the study. By report, there was an improvement in mood and emotional wellbeing. No pellet extrusions occurred in a total of 156 pellet insertions. CONCLUSIONS: All boys preferred this mode of testosterone administration to intramuscular injections. Long acting subcutaneous testosterone pellets are safe, efficacious, well tolerated, and convenient, and result in normal physical growth and improved psychological outlook in adolescent hypogonadal boys. 相似文献
82.
Kangaroo Care with a ventilated preterm infant 总被引:4,自引:0,他引:4
83.
Bauman Glenn S. Fisher Barbara J. Cairncross J. Gregory Macdonald David 《Journal of neuro-oncology》1998,38(1):83-89
Recurrence of malignant glioma following radiotherapy most commonly occurs in close proximity to the original contrast enhancing CT/MRI tumor volume. For this reason current radiation planning favors focal radiotherapy fields designed to cover the preoperative tumor contrast enhancing volume ± surrounding edema with a 2–4 centimetre margin. Two patients with bifrontal malignant gliomas treated with such radiotherapy fields experienced out of field tumor progression while on treatment. Posterior extension along the corpus callosum, not evident on pretreatment imaging, was hypothesized as the cause of the geographic miss. The literature documenting recurrence patterns of malignant glioma following radiotherapy support focal field radiotherapy fields for most patients with malignant glioma. Reporting bias may exist in the literature, however, due to the whole brain radiotherapy used in older series reporting recurrence patterns and exclusion of patients with bihemispheric or more locally extensive tumors in more modern series. Tumor location and pattern of growth at presentation may be important factors in predicting patterns of spread and relapse after radiotherapy. 相似文献
84.
Yang PY Almofti MR Lu L Kang H Zhang J Li TJ Rui YC Sun LN Chen WS 《第二军医大学学报》2006,27(6):637-637
Polygonum multiflorum stilbeneglycoside (PMS) is a water-soluble fraction of Polygonum multiflorum Thunb. , one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White (NZW) rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS (25, 50, or 100 mg/kg). Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule (ICAM)-1 protein and the vascular endothelial growth factor (VEGF) protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells. 相似文献
85.
Inducible nitric oxide synthase (iNOS) has been reported in tangle-bearing neurons of patients with Alzheimer's disease (AD), and can be induced by tumor necrosis factor-alpha (TNFalpha). High CNS levels of TNFalpha are associated with neurodegenerative diseases such as AD, where neurons dependent on neurotrophins such as nerve growth factor (NGF) are particularly affected. In this study we determined the effect of TNFalpha on iNOS in NGF-responsive pheochromocytoma (PC12) cells. We found that while TNFalpha and NGF alone were unable to induce iNOS, their simultaneous addition resulted in iNOS induction and the release of nitric oxide. Our results suggest that synergistic iNOS induction by TNFalpha and NGF may occur in selective population of NGF-responsive neurons in the presence of elevated CNS levels of TNFalpha. 相似文献
86.
Daniel G Haller Paul J Catalano John S Macdonald Mark A O'Rourke Michael S Frontiera Don V Jackson Robert J Mayer 《Journal of clinical oncology》2005,23(34):8671-8678
PURPOSE: In 1990, fluorouracil (FU) plus levamisole for 1 year became standard adjuvant treatment for patients with high-risk stages II and III colon cancer. Intergroup (INT) 0089 assessed the relative contributions of leucovorin and levamisole in such patients. PATIENTS AND METHODS: From 1988 to 1992, 3,794 patients were randomly assigned. Experimental treatment consisted of one of three chemotherapy regimens: the low-dose leucovorin plus FU (Mayo Clinic; LDLV) regimen, the high-dose leucovorin plus FU (Roswell Park; HDLV) regimen, and the low-dose leucovorin plus levamisole plus FU (LDLV plus LEV) regimen, each administered for 30 to 32 weeks. The control arm was levamisole plus FU (LEV) for 1 year. RESULTS: After a median follow-up of 10 years, of 3,561 eligible patients, 1,691 (47%) have died and 1,330 (37%) have experienced disease recurrence; 137 (10%) of those experiencing recurrence are still alive. A total of 481 patients (13%) died without evidence of recurrence, and 1,723 (48%) are alive and disease free. Although there were toxicity differences among the four arms, none was statistically superior in disease-free or overall survival. CONCLUSION: The 6- to 8-month regimens of LDLV and HDLV without levamisole used in this trial, rather than the previous standard regimen of 12 months of LEV, have become widely used. INT-0089 has long-term follow-up of the largest clinical trial of patients with high-risk colon cancer, documenting not only the durability of the treatment effects, but also the natural history of patients with high-risk colon cancer, and analyses of treatment based on age, race, and comorbid conditions such as obesity, diabetes, and second primary cancers. 相似文献
87.
WBG Macdonald AP Patrikeos RI Thompson BD Adler AA Van Der Schaaf 《Journal of Medical Imaging and Radiation Oncology》2005,49(1):32-38
The present study compared the accuracy of ventilation perfusion scintigraphy (VQS) and CT pulmonary angiography (CTPA) for the diagnosis of pulmonary embolism. This was a prospective observational study of 112 patients with suspected pulmonary embolism (PE) who could be studied with both investigations within 24 h. Results were compared to final diagnosis at completion of 6-month follow up, using receiver operating characteristic (ROC) analysis. Pulmonary embolism was diagnosed in 27 referred patients (24%). The sensitivity and specificity of VQS and CTPA were similar to that reported from the literature. A normal VQ scan had the highest negative predictive value (100%), while a high-probability VQ scan had the highest positive predictive value (92%). There was no overall difference (area under the ROC curve (AUC)) between VQS (AUC (95% CI) = 0.82 (0.75,0.89)) and CTPA (AUC = 0.88 (0.81,0.94)) for the diagnosis of PE. Among patients with abnormal chest X-rays, CTPA (AUC 0.90 (0.83,0.97)) appeared somewhat better than VQS (AUC 0.78 (0.68,0.88)) but this difference did not reach statistical significance. In this instance, CTPA is at least as accurate as VQS and may provide an opportunity to make alternative diagnoses. 相似文献
88.
Neil Mckeganey James Mcintosh Fiona Macdonald Maria Gannon Eilish Gilvarry Paul Mcardle Steve McCarthy 《Drugs (Abingdon, England)》2004,11(4):315-327
In this paper we report the results of research on the nature and extent of legal and illegal drug use among preteens and those factors associated with illegal drug use at this young age. The paper is based upon a survey of 2318 ten to twelve year olds in Glasgow and Newcastle. Overall around 30% of children reported having been exposed to illegal drugs and 3.9% had started to use illegal drugs. There was a significant difference in the level of illegal drug use between our two cities. In most cases the illegal drug use identified on the part of preteens related to cannabis although in a small number of instances children were using heroin, cocaine and LSD. On the basis of this research we estimate that around 60 children in the ten to twelve age range will have used heroin in Glasgow and around 34 pupils will have used the drug in Newcastle. Preteen drug use was significantly associated with frequent smoking and alcohol consumption, with preteens' involvement in a range of problem behaviours, and with family difficulties including the presence of someone else within the family using illegal drugs. The paper concludes by noting some of the challenges that are likely to be faced by services seeking to support children who are using illegal drugs by their preteens. 相似文献
89.
90.