全文获取类型
收费全文 | 27277篇 |
免费 | 1953篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 1111篇 |
妇产科学 | 1085篇 |
基础医学 | 3144篇 |
口腔科学 | 328篇 |
临床医学 | 4371篇 |
内科学 | 5078篇 |
皮肤病学 | 488篇 |
神经病学 | 2575篇 |
特种医学 | 443篇 |
外国民族医学 | 1篇 |
外科学 | 2308篇 |
综合类 | 363篇 |
一般理论 | 30篇 |
预防医学 | 3846篇 |
眼科学 | 443篇 |
药学 | 1671篇 |
中国医学 | 36篇 |
肿瘤学 | 1830篇 |
出版年
2023年 | 186篇 |
2022年 | 253篇 |
2021年 | 429篇 |
2020年 | 362篇 |
2019年 | 585篇 |
2018年 | 682篇 |
2017年 | 538篇 |
2016年 | 576篇 |
2015年 | 642篇 |
2014年 | 881篇 |
2013年 | 1390篇 |
2012年 | 2064篇 |
2011年 | 2016篇 |
2010年 | 1153篇 |
2009年 | 1059篇 |
2008年 | 1735篇 |
2007年 | 1886篇 |
2006年 | 1779篇 |
2005年 | 1834篇 |
2004年 | 1735篇 |
2003年 | 1561篇 |
2002年 | 1506篇 |
2001年 | 279篇 |
2000年 | 248篇 |
1999年 | 256篇 |
1998年 | 318篇 |
1997年 | 238篇 |
1996年 | 209篇 |
1995年 | 214篇 |
1994年 | 185篇 |
1993年 | 177篇 |
1992年 | 130篇 |
1991年 | 144篇 |
1990年 | 141篇 |
1989年 | 151篇 |
1988年 | 106篇 |
1987年 | 117篇 |
1986年 | 111篇 |
1985年 | 132篇 |
1984年 | 124篇 |
1983年 | 87篇 |
1982年 | 110篇 |
1981年 | 83篇 |
1980年 | 82篇 |
1979年 | 87篇 |
1978年 | 73篇 |
1977年 | 59篇 |
1975年 | 55篇 |
1973年 | 43篇 |
1972年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
The meaning of spirituality: a literature review 总被引:1,自引:0,他引:1
Jane Dyson MEd BA RGN DipN RNT Mark Cobb BSc Dawn Forman MBA PGDip TDCR MDCR 《Journal of advanced nursing》1997,26(6):1183-1188
This paper presents a literature review in relation to the meaning of spirituality. It is proposed that meeting the spiritual needs of patients is a fundamental part of providing holistic nursing care, but that the assessment and meeting of those needs is impeded by inadequate definitions and conceptual frameworks. It should not be assumed that spirituality is either synonymous, or coterminous, with religion, and it is suggested that to adopt this restrictive view is unhelpful in the provision of individualized care. Reflection on the literature reveals that the self, others and 'God' provide the key elements within a definition of spirituality, and that other emerging themes namely meaning, hope, relatedness/connectedness, beliefs/belief systems and expressions of spirituality, can be articulated in the context of those three key elements. In particular, it is proposed that the nature of 'God' may take many forms and, essentially, is whatever an individual takes to be of highest value in his/her life. It is suggested that the themes emerging from the literature can be utilized as a framework to give practitioners and researchers a direction for future exploration of the concept of spirituality. 相似文献
93.
Jane Farmer Patrick Dawson Elizabeth Martin Janet Tucker 《Health services management research》2007,20(1):59-68
There is a wealth of material on 'how to do' change plus empirical work revealing change process complexity. In health care, the relevance of context is highlighted, but studies of rural health-care change have focused on community impacts. There is little to inform health-care managers of how remoteness and rurality impact upon change processes. This study considered Scottish maternity units and aimed to identify issues in the change process associated with rurality and remoteness. Six units were purposively selected and 131 interviews were conducted with managers, staff and community members over 15 months. Analysis induced themes pertinent to remoteness and rurality. These included: perceived 'distance' between senior managers imposing change and the wider community of staff and residents; perceptions of community vulnerability; and tensions arising from working in small teams and living in small communities. The study provides useful insights for rural managers at a time of considerable service reconfiguration. 相似文献
94.
Evidence from both experimental carcinogenesis and studies in human cirrhotic liver suggest that defective repair of the
promutagenic DNA base lesion, O
6-methylguanine, is a factor in the multistep process of hepatocellular carcinogenesis. Ubiquitous environmental alkylating
agents such as N-nitroso compounds can produce O
6-methylguanine in cellular DNA. Unrepaired, O
6-methylguanine can lead to the formation of G ? A transition mutations, a known mechanism of human oncogene activation and
tumour suppressor gene inactivation. Combined treatment of rodents with an agent producing O
6-methylguanine in DNA, and an agent promoting cell proliferation, leads to development of hepatic nodules and hepatocellular
carcinoma (HCC), cell division, hence DNA replication, being required for the propagation of tumorigenic mutation(s) in hepatocyte
DNA. The paramount importance of O
6-methylguanine in hepatocellular carcinogenesis is indicated by the observation that transgenic mice engineered to have increased
hepatic levels of repair enzyme O
6-methylguanine-DNA methyltransferase (MGMT) are significantly less prone to hepatocellular carcinogenesis following alkylating
agent treatment. Cirrhosis is a universal risk factor for development of human HCC, and a condition that is characterized
by increased hepatocyte proliferation as a result of tissue regeneration. Levels of the human repairing enzyme for O
6-methylguanine were found to be significantly lower in cirrhotic liver than in normal tissue. In accord with findings from
animal models, this suggested a mechanism in which persistence of O
6-methylguanine due to defective DNA repair by MGMT, together with increased hepatocyte proliferation, might lead to specific
gene mutation(s) and hepatocellular carcinogenesis. Screening for the presence and persistence of O
6-methylguanine in human DNA presently involves formidable technical difficulty. Indications are that such limitations might
be overcome by the use of an ultrasensitive method such as immuno-polymerase chain reaction (PCR). This approach should allow
parallel measurement of DNA adduct and repair enzyme in routine liver biopsy samples. It might also enable investigation of
O
6-methylguanine in human genes specifically associated with hepatocellular carcinogenesis. Given the wide variation in human
MGMT levels observed between individuals, tissues, and cells, this technology should be adapted to permit the ultrasensitive
localisation and measurement of adducts and repairing enzyme in liver biopsy tissue sections. Ability to ultrasensitively
measure O
6-methylguanine, and its repair enzyme, should prove valuable in the risk assessment of cirrhotic patients for developing hepatocellular
carcinoma.
Received for publication on July 6, 1998; accepted on Aug. 12, 1998 相似文献
95.
Cutaneous T-cell lymphoma 总被引:1,自引:0,他引:1
96.
Angiotensin-converting enzyme (ACE) gene polymorphism in type II diabetic patients with increased albumin excretion rate 总被引:1,自引:0,他引:1
Sianna Panagiotopoulos Trudy Jeanne Smith G. Peter Aldred Elizabeth Jane Baker Carolyn Jane Jacklin George Jerums 《Journal of diabetes and its complications》1995,9(4):272-276
Approximately one in three patients with diabetes is at risk of developing kidney disease, despite current methods of treatment. It has long been suspected that diabetic kidney disease has a genetic basis, but this has been difficult to prove. Polymorphisms of the angiotensin-converting enzyme (ACE) gene have been shown to be related to the occurrence of nephropathy in type I diabetic patients. This study showed that there was no association in the ACE genotype frequency and increased albumin excretion rate in type II diabetic patients. 相似文献
97.
Spouse Concordance for Alcohol Dependence and Heavy Drinking: Evidence from a Community Sample 总被引:2,自引:0,他引:2
Jane D. McLeod 《Alcoholism, clinical and experimental research》1993,17(6):1146-1155
Using data from a community sample of 586 married couples, levels of spouse concordance for lifetime and current alcohol dependence and heavy drinking were estimated. In addition, marital quality ratings in concordant and discordant couples were compared. Spouse concordance was significant for lifetime alcohol dependence and for both lifetime and current heavy drinking. Marital quality varied as a function of current heavy drinking and alcohol dependence such that members of couples in which neither spouse drank heavily reported better marital quality than other couples. Furthermore, although marital quality did not differ significantly between concordant and discordant couples, couples concordant for current heavy drinking consistently reported poorer marital quality than other couples. 相似文献
98.
Serotonin (5-HT) may be inhibitory to micturition at a spinal level. A potential mechanism of action for serotonergic inhibition of bladder function is a depression of the ascending limb of the supraspinal reflex mediating micturition. Ascending activity evoked by pelvic nerve stimulation was recorded in the thoracic spinal cord of anesthetized cats. For comparison, spinal reflex activity evoked by pelvic nerve stimulation was recorded on the pudendal nerve. The effects of intrathecal administration of serotonergic agents were examined to determine whether spinal and supraspinal responses to bladder afferent activation were modulated by 5-HT. Methysergide (60 nmol), a non-selective serotonergic antagonist, increased ascending activity by 61±7% and depressed spinal reflex activity by 38±6%. Zatosetron (10 nmol), a 5-HT3 antagonist had a similar effect on both activities (increased by 93±24% and decreased by 77±7%, respectively). The effect on ascending activity of blocking 5-HT3 receptors was also confirmed with ICS 205930 and MDL 72222. 2-Methyl-5-HT (800 nmol), a 5-HT3 agonist, depressed ascending activity to 46±9% of control, but enhanced spinal reflex activity by 73±92%. These results demonstrate that stimulation of 5-HT3 and methysergide-sensitive 5-HT receptors can inhibit ascending activity and facilitate spinal reflex activity elicited by activation of bladder afferents. It is suggested that descending serotonergic pathways may participate in the spinal coordination of urinary continence. 相似文献
99.
Head injury mortality in two centers with different emergency medical services and intensive care 总被引:7,自引:0,他引:7
A R Colohan W M Alves C R Gross J C Torner V S Mehta P N Tandon J A Jane 《Journal of neurosurgery》1989,71(2):202-207
The authors report data collected prospectively on 551 cases of head injury in New Delhi, India, and 822 cases in Charlottesville, Virginia. The mortality rate, adjusted for initial severity of injury, was 11.0% in New Delhi versus 7.2% in Charlottesville (p less than 0.02). There was a striking similarity in mortality rates at both centers when comparing patients with the least severe head injuries and those with the most severe injuries according to the motor score of the Glasgow Coma Scale (GCS M). However, in the group with an abnormal but purposeful motor response (GCS M = 5), the mortality rate was 12.5% in New Delhi versus 4.8% in Charlottesville (p less than 0.01). The relative absence of prehospital emergency care and the delay in admission after head injury in New Delhi are cited as two possible causes for the differences in mortality rates in this subgroup of patients with "moderate" head injuries. 相似文献
100.
Jane M Olson Sompong Vongpunsawad Helena Kuivaniemi Antti Ronkainen Juha Hernesniemi Markku Ryynänen Lee-Lian Kim Gerard Tromp 《BMC medical genetics》2002,3(1):7-7