全文获取类型
收费全文 | 7490篇 |
免费 | 760篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 228篇 |
妇产科学 | 223篇 |
基础医学 | 1202篇 |
口腔科学 | 331篇 |
临床医学 | 703篇 |
内科学 | 1460篇 |
皮肤病学 | 108篇 |
神经病学 | 791篇 |
特种医学 | 269篇 |
外科学 | 964篇 |
综合类 | 218篇 |
一般理论 | 5篇 |
预防医学 | 731篇 |
眼科学 | 91篇 |
药学 | 514篇 |
中国医学 | 1篇 |
肿瘤学 | 394篇 |
出版年
2021年 | 90篇 |
2020年 | 64篇 |
2019年 | 67篇 |
2018年 | 100篇 |
2017年 | 75篇 |
2016年 | 90篇 |
2015年 | 97篇 |
2014年 | 171篇 |
2013年 | 247篇 |
2012年 | 336篇 |
2011年 | 366篇 |
2010年 | 204篇 |
2009年 | 195篇 |
2008年 | 295篇 |
2007年 | 340篇 |
2006年 | 269篇 |
2005年 | 278篇 |
2004年 | 274篇 |
2003年 | 241篇 |
2002年 | 256篇 |
2001年 | 256篇 |
2000年 | 240篇 |
1999年 | 196篇 |
1998年 | 119篇 |
1997年 | 108篇 |
1996年 | 90篇 |
1995年 | 95篇 |
1994年 | 100篇 |
1993年 | 109篇 |
1992年 | 173篇 |
1991年 | 200篇 |
1990年 | 147篇 |
1989年 | 183篇 |
1988年 | 169篇 |
1987年 | 168篇 |
1986年 | 160篇 |
1985年 | 148篇 |
1984年 | 131篇 |
1983年 | 93篇 |
1982年 | 79篇 |
1981年 | 76篇 |
1980年 | 66篇 |
1979年 | 112篇 |
1978年 | 78篇 |
1977年 | 58篇 |
1975年 | 65篇 |
1974年 | 80篇 |
1973年 | 68篇 |
1972年 | 62篇 |
1970年 | 54篇 |
排序方式: 共有8282条查询结果,搜索用时 0 毫秒
61.
Results of treatment in 72 children with a relapse of acute lymphoblastic leukaemia were analysed. A second remission was induced in 57 children (79%). Remission rates were significantly higher in males, and in patients with white cell counts less than 30 X 10(9)/L. The median duration of the second remission was only four months, and the median duration of survival from the time of relapse was nine months. The median duration of survival from the time of diagnosis was 27 months. Among children who suffered a relapse was a small group who had prolonged survival and prolonged second remissions. It is uncertain whether some of these may have a chance of "cure". 相似文献
62.
Environmental monitoring of anaesthetic gases was carried out in theatre areas in eight hospitals as well as in Delivery suites, radiology, radiotherapy and Dental suites. High staff exposures occurred in nontheatre areas although exposures in theatres were generally satisfactory. Environmental control measures are required where staff exposures exceed legal standards. 相似文献
63.
Abstract: Despite advances in therapy for acute leukemia, relapse continues to be the major cause of treatment failure. Hematopoietic stem cell transplant can rescue some patients after relapse, but the ability to escalate the intensity of preparative regimens is limited by toxicity to normal organs. Radiolabeled monoclonal antibodies against hematopoietic antigens have emerged as an alternative to deliver targeted supplemental radiation to sites of leukemic involvement while relatively sparing normal organs. This paper will review the rationale for using this approach, our current experience with radiolabeled anti-CD45 antibody, and the potential challenges encountered in treating children with radiolabeled antibodies. 相似文献
64.
A 5 1/2 month old male infant who had suffered three acute life threatening episodes was admitted for overnight sleep studies but was found dead after their completion while still in hospital. A necropsy classified the cause of death as sudden infant death syndrome (SIDS). The sleep studies had shown no periods of apnoea (> 20 seconds) or bradycardia (< 90 beats/min), and a rapid response to nasal occlusion (5 seconds). However, autonomic function during sleep was poor, with reduced heart rate variability (6 beats/min v control 24 beats/min, SD 6.2) and postural hypotension (a 12-14% fall in resting systolic blood pressure) associated with a fall in heart rate when tilted to a vertical position. Postural hypotension with bradycardia occurs in adults with unexplained syncopal episodes and is called a neurocardiac reflex. It involves poor vasomotor tone with peripheral pooling of blood, a consequent reduction in central venous return and cardiac distension, and in some individuals a neurally mediated bradycardia, as seen in this infant, rather than the expected tachycardia. A progressive bradycardia is the predominant mechanism of death seen in SIDS infants dying on cardiorespiratory monitors at home. This case suggests that a neurocardiac reflex occurs in infants, may have been involved in this infant's death, and deserves further study in the context of SIDS. 相似文献
65.
A study was carried out to find out the effects of prior physical activity, sports participation and prior military training on the incidence of stress fractures among Gentlemen Cadets (GC''s) undergoing military training at Indian Military Academy (IMA). One thousand and fourteen GC''s were followed up for a period of 12 weeks. Thirty-seven GC''s developed stress fractures during the study period. The incidence of stress fractures was significantly higher in GC''s without any prior military training (p=0.0009). They were compared with 100 healthy controls drawn from the study population to study the influence of the other mentioned factors. There was no significant association between prior physical activity and stress fractures (OR=0.74, 95% CL=0.26 to 2.05, p=0.688). There was also no significant relationship between sports participation and stress fractures (OR=0.79. 95% CCL=0.35 to 1.81, p=0.684).KEY WORDS: Risk factors, Stress fractures 相似文献
66.
Fetal hypothalamo-pituitary-adrenal (HPA) activity increases dramatically at term in sheep, however, little is known about the regulation of glucocorticoid feedback in the developing brain. Heat shock protein 70 (hsp70) is closely associated with glucocorticoid actions within the cell. We hypothesized that there is a decrease in glucocorticoid negative feedback in the brain, near term, resulting from changes in the expression of glucocorticoid receptors (GR) and hsp70. Brains were removed at various stages of development. GR mRNA levels in the paraventricular nucleus (PVN) and cortex, and hsp70 mRNA in the PVN were determined by in situ hybridization. In the hippocampus, GR mRNA levels were measured by Northern analysis. In the PVN, GR mRNA was present by d60. GR mRNA levels reached a peak at d100-110, but then decreased significantly with progression of gestation, and were lowest at term. Hippocampal GR mRNA levels were highest on day 130 of gestation, decreasing to low levels at term. In the cerebral cortex, GR mRNA levels were expressed at high levels in all layers of the cortex by day 110 of gestation with levels decreasing to term. Hsp70 mRNA was present in both parvocellular and magnocellular regions of the PVN, and there was no significant change in late gestation. In conclusion, (1) The high levels of GR mRNA present in the PVN, hippocampus and cerebral cortex during fetal life are likely important in development of these structures at a time when circulating glucocorticoids are low. (2) Changes in GR mRNA levels in the PVN are not associated with alterations in the expression of hsp70. (3) The decrease in GR mRNA in the hippocampus and PVN in late gestation, at a time when fetal plasma cortisol is increasing, likely facilitates maintained hypothalamic drive to the pituitary corticotroph. 相似文献
67.
68.
69.
McCombe D MacGill K Ainslie J Beresford J Matthews J 《The Australian and New Zealand journal of surgery》2000,70(5):358-361
BACKGROUND: Squamous cell carcinoma (SCC) of the lower lip is a common malignancy in Australia. Surgical excision and/or radiotherapy are used in treatment, and are regarded as equally effective. METHODS: A retrospective review of 323 patients treated at the Peter MacCallum Cancer Institute with either surgical excision and/or radiotherapy, evaluated disease recurrence, cause-specific mortality, and the incidence of metachronous lesions. RESULTS: Recurrence-free survival at 10 years was estimated to be 92.5%, and cause-specific survival at 10 years was estimated to be 98.0%. Equivalent rates of local control were obtained with surgery and radiotherapy. Recurrence was related to tumour stage and differentiation. A high incidence of metachronous lesions was noted, 25 patients had a lesion prior to presentation and 33 patients developed second lip lesions during the study period. CONCLUSIONS: Squamous cell carcinoma of the lower lip is well treated with surgery or radiotherapy. The preferred treatment for most patients with SCC of the lower lip in the Australian population is surgical excision. This study has shown a significant incidence of metachronous lip neoplasia, except in those patients whose whole lip had been resurfaced. 相似文献
70.
Joan SK Ng FRCS William Wong FRCP Ricky WK Law FRCS Joannie Hui MRCP Esther N Wong MRCP Dennis SC Lam FRCOphth 《Clinical & experimental ophthalmology》2001,29(4):239-243
Purpose : To investigate ocular complications arising from nephrotic syndrome and/or its treatments in children. Methods : A cross‐sectional study was conducted in a teaching hospital. A total of 31 paediatric patients with nephrotic syndrome were studied. Comprehensive ophthalmic assessments on best‐corrected visual acuity, intraocular pressure, slit‐lamp and fundus examination were taken. Information regarding histological diagnosis of nephrotic syndrome and its treatment regimen in each patient was reviewed and analysed. Results : Bilateral posterior subcapsular cataracts were detected in three of 29 patients (10.3%) who received steroid therapy. Two had normal vision while one had visual acuity reduced to 6/15 in both eyes. The age of onset of the nephrotic syndrome in these three patients was 2 years, which was significantly younger than those without cataract (5.4 ± 3.2 years, P < 0.001). Three patients (9.7%) had isolated asymptomatic fundal findings of tortuous and dilated retinal vessels. Hypertensive retinopathy was found in one patient (3.2%). No steroid‐induced glaucoma, uveitis, ocular infection, or other eye complications related to the use of steroids or other immunosuppressive agents were noted. Conclusions : Children who have nephrotic syndrome often require prolonged, intermittent high dose of systemic corticosteroid therapy. Paediatricians should be aware of the potential risk of developing steroid‐related complications, especially posterior subcapsular cataract. It appears to have a higher risk when steroid therapy is used in very young patients. Early detection would help to prevent amblyopia development, particularly in the group of immature eyes. 相似文献