全文获取类型
收费全文 | 134474篇 |
免费 | 43173篇 |
国内免费 | 670篇 |
专业分类
耳鼻咽喉 | 2431篇 |
儿科学 | 4789篇 |
妇产科学 | 1407篇 |
基础医学 | 25371篇 |
口腔科学 | 6321篇 |
临床医学 | 17275篇 |
内科学 | 32885篇 |
皮肤病学 | 9212篇 |
神经病学 | 17095篇 |
特种医学 | 5441篇 |
外科学 | 21151篇 |
综合类 | 853篇 |
现状与发展 | 2篇 |
一般理论 | 38篇 |
预防医学 | 7232篇 |
眼科学 | 2603篇 |
药学 | 10754篇 |
中国医学 | 1646篇 |
肿瘤学 | 11811篇 |
出版年
2023年 | 464篇 |
2022年 | 1419篇 |
2021年 | 3359篇 |
2020年 | 5910篇 |
2019年 | 11836篇 |
2018年 | 11494篇 |
2017年 | 12382篇 |
2016年 | 13570篇 |
2015年 | 14236篇 |
2014年 | 14584篇 |
2013年 | 15502篇 |
2012年 | 9538篇 |
2011年 | 9051篇 |
2010年 | 11629篇 |
2009年 | 7591篇 |
2008年 | 5619篇 |
2007年 | 4094篇 |
2006年 | 3687篇 |
2005年 | 3210篇 |
2004年 | 2996篇 |
2003年 | 2695篇 |
2002年 | 2454篇 |
2001年 | 2289篇 |
2000年 | 2057篇 |
1999年 | 1316篇 |
1998年 | 513篇 |
1997年 | 387篇 |
1996年 | 250篇 |
1995年 | 217篇 |
1994年 | 183篇 |
1993年 | 186篇 |
1992年 | 392篇 |
1991年 | 348篇 |
1990年 | 304篇 |
1989年 | 292篇 |
1988年 | 268篇 |
1987年 | 265篇 |
1986年 | 188篇 |
1985年 | 176篇 |
1984年 | 128篇 |
1983年 | 122篇 |
1982年 | 62篇 |
1981年 | 68篇 |
1980年 | 59篇 |
1979年 | 87篇 |
1978年 | 75篇 |
1975年 | 56篇 |
1974年 | 61篇 |
1973年 | 55篇 |
1970年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
K. K. Adamama‐Moraitou G. D. Brellou T. S. Rallis N. Zavros D. Pardali A. Dinopoulos I. Vlemmas 《Transboundary and Emerging Diseases》2006,53(2):81-84
A 3.5‐year‐old intact male American Pit Bull was presented because of urinary incontinence and dysuria. Constipation, followed by diarrhoea, ocular disturbances and finally regurgitation developed over the next 4 years. Autonomic dysfunction was evidenced by clinical presentation, as well as positive ophthalmic pilocarpine test and subnormal Schirmer tear test. Diagnosis, however, was established through histopathological and immunohistochemical examination. Lesions attributable to inflammatory degenerative neuropathy of the autonomic ganglia, which represents one of the various types of human autonomic failure, were detected. 相似文献
102.
103.
T. W. Boesgaard S. I. Castella G. Andersen A. Albrechtsen T. Spars K. Borch‐Johnsen T. Jrgensen T. Hansen O. Pedersen 《Diabetic medicine》2007,24(7):702-706
AIMS: The glutamate decarboxylase gene (GAD2) encodes GAD65, an enzyme catalysing the production of the gamma-aminobutyric acid (GABA) which interacts with neuropeptide Y to stimulate food intake. It has been suggested that in pancreatic islets, GABA serves as a functional regulator of pancreatic hormone release. Conflicting results have been reported concerning the potential impact of GAD2 variation on estimates of energy metabolism. The aim of this study was to elucidate potential associations between the GAD2-243A-->G polymorphism and levels of body mass index (BMI) and estimates of glycaemia. METHODS: Using high-throughput chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the GAD2-243A-->G (rs2236418) polymorphism was genotyped in a population-based sample (Inter99) of 5857 middle-aged, unrelated Danish White subjects. RESULTS: The G-allele was associated with modestly lower BMI (P = 0.01). In a case-control study of obesity, the G-allele frequency in 2582 participants with BMI < 25 kg/m2 was 19.5% (18.4-20.6) compared with 17.1% (15.5-18.8) in 968 participants having BMI > or = 30 kg/m2 (P = 0.03), odds ratio 0.9 (0.7-1.0). Of the 5857 subjects, GG carriers had lower fasting plasma glucose levels (mmol/l) [AA (n = 3859) 5.6 +/- 0.8; AG (n = 1792) 5.5 +/- 0.8; GG (n = 206) 5.5 +/- 0.8, P = 0.008] and lower 30-min oral glucose tolerance test (OGTT)-related plasma glucose levels (AA 8.7 +/- 1.9; AG 8.6 +/- 1.9; GG 8.6 +/- 2.0, P = 0.04), adjusted for sex, age and BMI. Analysing subjects who were both normoglycaemic and glucose tolerant (n = 4431) GG carriers still had lower fasting plasma glucose concentrations: AA (n = 2895) 5.3 +/- 0.4; AG (n = 1383) 5.3 +/- 0.4; GG (n = 153) 5.2 +/- 0.4 (P = 9.10(-5)). CONCLUSION: The present study suggests that the GAD2-243A-->G polymorphism in a population of middle-aged White people associates with a modest reduction in BMI and fasting and OGTT-related plasma glucose levels. 相似文献
104.
105.
The main goal of the present work was to longitudinally examine consequences of long‐term moderately elevated levels of stress for various health outcomes. To address this issue, data covering 10 years was used from the ongoing Swedish population‐based prospective Betula Study. Based on the ratings on a validated self‐reported stress scale, matched subsamples between 40 and 65 years of age were divided into a high (n = 137) and low (n = 211) stress group. The reported incidence of cardiovascular, diabetes, psychiatric, tumour and musculoskeletal diseases was assessed 5 and 10 years after baseline (baseline = 1993–1995) without contaminating effects of past health history. The incidence of diseases 5 years after baseline assessment showed no differences between the groups. After 10 years, there was a significantly higher incidence of psychiatric diseases, mainly depression in the high‐stress group as well as a significant effect for tumours, although the number of cases was low. Although moderately elevated stress level may have a possible impact on psychiatric diseases especially depression and some tumours, it seems that prolonged moderate stress does not appear to be harmful to other stress‐related diseases. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
106.
Jun Suk Huh Sang Keun Park Jun Jae Shin Tae Hong Kim 《Journal of Korean Neurosurgical Society》2007,42(4):342-345
The azygos anterior cerebral artery, a rare anomaly in the circle of Willis in which only a single vessel supplies the medial aspects of both anterior cerebral hemispheres, is closely associated with saccular aneurysms. We present three cases of azygos anterior cerebral artery aneurysms among the 781 cerebral aneurysms surgically treated at our institution in an 11-year period. These three cases all involved elderly women who presented with subarachnoid hemorrhage. Conventional cerebral angiography and CT angiography revealed small saccular aneurysms at the distal ends of the azygos anterior cerebral arteries. These aneurysms were clipped successfully using a bifrontal interhemispheric approach. Hence, the pathogenesis of these particular aneurysms relating to hemodynamic change, associated anomalies, and surgical pitfalls is discussed with review of literature. 相似文献
107.
Jeffrey A Morgan Ranjit John Yookyung Park Linda J Addonizio Mehmet C Oz Niloo M Edwards Jan M Quaegebeur Ralph S Mosca 《The Journal of heart and lung transplantation》2005,24(1):58-62
BACKGROUND: Many cardiac transplant programs have liberalized donor eligibility criteria in an attempt to maximize donor supply and to accommodate increasing demand. Although many studies have evaluated the potential adverse effects of prolonged donor ischemic time (DIT) in adults undergoing cardiac transplantation, relatively few have focused specifically on pediatric recipients that include a substantial number of patients and long-term follow-up. The focus of this study was to examine the effect of extended DIT on mortality after pediatric heart transplantation. METHODS: We conducted a retrospective review of our pediatric cardiac transplant experience in the past 11 years, comparing patients who received allografts and had ischemic times >240 minutes with those who had ischemic times <240 minutes. RESULTS: A total of 129 pediatric patients (<19 years) underwent orthotopic heart transplantation, of whom 78 (60.5%) had DIT <240 minutes and 51 (39.5%) had DIT >240 minutes. We found no statistically significant difference in age, sex, race, height, weight, or donor age between the groups (p = not significant). Post-transplant survival at 1, 5, and 10 years was similar for both groups: 91.2%, 88.0%, and 85.2%, respectively, for patients with DIT <240 minutes vs 89.6%, 87.2%, and 79.8%, respectively, for patients with DIT >240 minutes (p = 0.433). Additionally, using Cox proportional hazard models, extended DIT >240 minutes was not a statistically significant independent predictor of post-transplant mortality (odds ratio, 0.655; 95% confidence interval, 0.518-0.972; p = 0.684; standard error = 0.468). CONCLUSION: Procurement of hearts from distant locations with associated extended DIT is justified in the setting of increased demand and a fixed donor population. 相似文献
108.
Treatment of congenital cystic adenomatoid malformation-does resection in the early postnatal period increase surgical risk? 总被引:1,自引:0,他引:1
Young Tae Kim Jun Sung Kim June Dong Park Chang Hyun Kang Sook Whan Sung Joo Hyun Kim 《European journal of cardio-thoracic surgery》2005,27(4):658-661
OBJECTIVE: The recent development of fetal ultrasonography has allowed for an increasing number of prenatal diagnoses for congenital cystic adenomatoid malformation (CCAM). However, the appropriate surgical timing of these patients has not been studied as of yet. The aim of this study is to suggest a safe strategy for the treatment of CCAM by identifying the relationship between the timing of surgery and postoperative outcome. METHODS: Between 1987 and 2003, 40 patients (28 males, 12 females) underwent surgical resection for CCAM. The mean age was 38.6+/-9.1 (2 days-13 years) months. CCAM was diagnosed by prenatal ultrasonography in eight patients. Early operations were performed in four out of the eight. Operation was deferred until 2-12 months of age for the remaining four patients. RESULTS: Type I CCAM was found in 20 patients, type II in 20 and no patient exhibited type III. Five patients had associated pectus excavatum anomaly. There were no cases of operative mortality. Seventeen minor postoperative complications developed in 16 patients (40.0%): prolonged chest tube drain in 10, wound infection in 4, and 1 case of pneumonia, empyema and pleural space, respectively. The average hospital stay was 11.8 (6-29) days. During the mean follow-up period of 67.5 months, one patient died of accidental aspiration 7 months after operation during the postoperative recovery course of Ravich operation for pectus excavatum. The remaining patients reported doing well with normal physical activity. All five patients who underwent surgery at the age of under 1 month did not exhibit increased postoperative morbidity. CONCLUSIONS: We concluded that surgery for CCAM could be safely performed in all age groups with satisfactory long-term outcomes. It is suggested that early elective surgical correction can be recommended for a patient whose diagnosis was made in utero. 相似文献
109.
Yasushi Nishihira Chun‐Feng Tan Junko Hirato Junichi Yoshimura Kenichi Nishiyama Hideaki Takahashi Yukihiko Fujii Hitoshi Takahashi 《Neuropathology》2007,27(6):551-555
Two embryonal CNS tumors, atypical teratoid/rabdoid tumor (AT/RT) and primitive neuroectodermal tumor (PNET), may be confused with each other and misdiagnosed. Here we report an infant with a congenital supratentorial tumor, which was detected by fetal MRI at 37 weeks gestation. On routine histological examination, the tumor was composed mainly of small undifferentiated cells, among which many rhabdoid cells and occasional sickle‐shaped embracing cells were observed. No mesenchymal or epithelial areas were evident. Our impression was that the tumor was an atypical example of AT/RT. Immunohistochemically, almost all the tumor cells were strongly positive for vimentin. However, epithelial membrane antigen was notably negative, and most of the tumor cell nuclei were clearly positive for INI1. In addition, many tumor cells were positive for neurofilament protein. There were also occasional small areas containing many tumor cells positive for glial fibrillary acidic protein. Finally, a diagnosis of PNET, with a rhabdoid phenotype and expression of neuronal and glial markers, was made. In the present case, application of INI1 immunostaining was very helpful for distinguishing PNET from AT/RT. 相似文献
110.
Hyung Bin Park Mihee Koh Se Hyun Cho Brian Hutchinson Bonghee Lee 《Journal of orthopaedic research》2005,23(6):1419-1424
The anterior cruciate ligament (ACL) serves as the primary restraint to anterior tibial translation. In addition to this biomechanical function, the ACL appears to have a function in neuromuscular control. This hypothesis was formulated after the discovery of mechanoreceptors within the ACL. The full somatosensory pathway from the ACL to the cerebrum has yet to be elucidated. In order to map this sensory pathway, we conducted a viral trans-synaptic tracing experiment using the neurotropic pseudorabies virus (PRV). The pseudorabies virus was injected into the ACL of rats and allowed to replicate and spread trans-synaptically for 6-7 days. The brain and spinal cord of each sacrificed rat was then removed and processed immunohistochemically to detect the presence of PRV. PRV-immunoreactive neurons were found to be localized in several different regions from the spinal cord to the cerebrum. Four nuclei in the reticular formation of the brain stem demonstrated strong positive labeling: the mesencephalic reticular nucleus, magnocellular reticular nucleus, paragigantocellular reticular nucleus, and gigantocellular reticular nucleus. This finding suggests that the nerve endings of the rat ACL project into the cerebrum and that the reticular formation may play an important role in the afferent pathway of those nerve endings. 相似文献