全文获取类型
收费全文 | 1269篇 |
免费 | 158篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 49篇 |
妇产科学 | 23篇 |
基础医学 | 137篇 |
口腔科学 | 30篇 |
临床医学 | 173篇 |
内科学 | 252篇 |
皮肤病学 | 13篇 |
神经病学 | 80篇 |
特种医学 | 40篇 |
外科学 | 215篇 |
综合类 | 39篇 |
预防医学 | 157篇 |
眼科学 | 62篇 |
药学 | 58篇 |
肿瘤学 | 82篇 |
出版年
2020年 | 16篇 |
2019年 | 23篇 |
2018年 | 27篇 |
2017年 | 13篇 |
2016年 | 19篇 |
2015年 | 19篇 |
2014年 | 35篇 |
2013年 | 40篇 |
2012年 | 49篇 |
2011年 | 54篇 |
2010年 | 34篇 |
2009年 | 22篇 |
2008年 | 46篇 |
2007年 | 43篇 |
2006年 | 34篇 |
2005年 | 43篇 |
2004年 | 31篇 |
2003年 | 44篇 |
2002年 | 31篇 |
2001年 | 37篇 |
2000年 | 45篇 |
1999年 | 30篇 |
1998年 | 24篇 |
1996年 | 12篇 |
1995年 | 14篇 |
1993年 | 17篇 |
1992年 | 47篇 |
1991年 | 28篇 |
1990年 | 26篇 |
1989年 | 29篇 |
1988年 | 23篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 38篇 |
1984年 | 23篇 |
1983年 | 19篇 |
1982年 | 16篇 |
1981年 | 17篇 |
1979年 | 17篇 |
1978年 | 23篇 |
1977年 | 27篇 |
1976年 | 20篇 |
1975年 | 22篇 |
1974年 | 19篇 |
1973年 | 21篇 |
1972年 | 20篇 |
1971年 | 11篇 |
1970年 | 17篇 |
1969年 | 15篇 |
1968年 | 12篇 |
排序方式: 共有1431条查询结果,搜索用时 15 毫秒
101.
102.
Bob Phillips Karen Selwood Sheila M Lane Roderick Skinner Faith Gibson Julia C Chisholm 《Archives of disease in childhood》2007,92(6):495-498
OBJECTIVE: To assess the variation in the current UK management strategies for the treatment of febrile neutropenia in childhood. Design and SETTING: A postal survey of all 21 United Kingdom Children's Cancer Study Group (UKCCSG) centres assessing and collating local policies, protocols or guidelines relating to the management of febrile neutropenia. Further direct contact was undertaken to clarify any uncertainties. RESULTS: All 21 centres provided information. The policies used to manage febrile neutropenia in the centres around the UK vary in almost every aspect of management. Definitions of fever ranged from a persistent temperature of >37.5 degrees C to a single reading of >39 degrees C. Neutropenia was inconsistently defined as an absolute neutrophil count of <1x10(9), <0.75x10(9 )or <0.5x10(9). Choices of antibiotic approaches, empirical modifications and antistaphylococcal treatment were different in each protocol. The use of risk stratification was undertaken in 11 centres, with six using a policy of reduced intensity therapy in low risk cases. Empirical antifungal treatment was very poorly described and varied even more widely. CONCLUSIONS: There was a great deal of variation in definitions and treatment of febrile neutropenia in the UKCCSG children's cancer treatment centres. A degree of variation as a result of local microbiological differences is to be expected, but beyond this we should seek to standardise the core of our approach to defining fever and neutropenia, risk stratification and duration of empirical therapy in a way that maintains safety, minimises resource utilisation and maximises quality of life. 相似文献
103.
Chapman BA Frampton CM Wilson IR Chisholm RJ Allan RB Burt MJ 《The New Zealand medical journal》2000,113(1104):46-48
AIMS: To determine the frequency, risk factors and clinical significance of gallstones in a New Zealand population. METHODS: One thousand names were randomly selected from the Christchurch electoral rolls to recruit controls for a study on the prevalence of gallstones in diabetics. Three hundred and eighteen subjects (169 females, 149 males) were recruited and in this study we analyse this control group for gallstone disease. All subjects completed a questionnaire, provided a fasting blood sample and underwent an ultrasound examination of their gallbladder unless they had previously undergone a cholecystectomy. RESULTS: Overall gallstone disease, defined as previous cholecystectomy or a positive scan for gallstones was seen in 20.75% of the 318 subjects recruited. Gallstone disease was more frequent in females (23.1%) compared to males (18.1%) but this difference was not statistically significant. For both genders there was a significant increase in gallstones with age. On univariate analysis, risk factors for gallstone disease included age, increased body mass index, family history of gallstones and decreased alcohol intake in females. However, only age and family history were significant on multiple logistic regression. There was no difference in the frequency of dyspeptic symptoms or abdominal pain between those with or without gallstones confirmed on scanning. The ratio of cholecystectomy to silent gallstones was higher in females (46.2%) than in males (22.2%). CONCLUSION: Gallstones are prevalent in the New Zealand Community (20.8% overall). Risk factors are increasing age and family history. Gallstones detected on scanning were not associated with an increased incidence of dyspeptic symptoms or abdominal pain. 相似文献
104.
BACKGROUND: Activation of blood coagulation is a common complication of cancer and inflammation in both humans and experimental animals. Increased production of tissue factor--the principal initiator of the coagulation process--by endothelial cells, monocytes, and macrophages has been implicated in these conditions. AIM: To investigate whether urinary tissue factor (uTF) might reflect the state of monocyte/macrophage activation and be a useful diagnostic test. METHODS: Urine was centrifuged at 51,000 g to sediment tissue factor containing membrane vesicles. The tissue factor was then solubilised in beta-octyl-glucopyranoside and assayed in a specific chromogenic assay adapted for use in microtitre plates. RESULTS: The assay proved to be sensitive, specific, and reproducible. The normal range of uTF was relatively narrow and unaffected by age, sex, or cigarette smoking. Levels were not significantly influenced by storage of urine samples before assay or by the presence of fresh blood in the urine sample. CONCLUSIONS: This method may have diagnostic application in the study of haemostatic activation in patients with cancer and other disease states. 相似文献
105.
Leucocytes in the ejaculate from fertile and infertile men 总被引:1,自引:0,他引:1
M I el-Demiry H Young R A Elton T B Hargreave K James G D Chisholm 《British journal of urology》1986,58(6):715-720
The presence of leucocytes and their subpopulations was studied in the ejaculate from 69 men with an infertile marriage and 12 fertile men. Monoclonal antibodies specific for human leucocytes were used in an immunoperoxidase technique. In addition to the standard sperm analysis, each specimen was also tested for sperm antibodies, aerobic and anaerobic microorganisms, Ureaplasma urealyticum and Chlamydia trachomatis. Leucocytes were found in large numbers in the fertile men compared with the patients. Lymphocytes were found in 20% of the patients. Micro-organisms were cultured from a similar proportion of both groups. We found no correlation between leucocyte counts, sperm density and motility, sperm antibodies and growth of micro-organisms. Our results cast doubt on the conventional criteria of subclinical genital tract infection, namely positive culture and excess leucocyte counts. 相似文献
106.
Seventy-five patients, with uncomplicated benign prostatic hypertrophy referred for pre-prostatectomy assessment, were studied to determine whether renal tract ultrasound combined with plain films of kidney, ureters and bladder could provide an acceptable alternative to intravenous urography (IVU). All patients had both IVU and ultrasound. Bladder residual urine volumes were calculated by ultrasound measurements. Fifty-nine (78%) patients had normal IVU and ultrasound. Twelve (16%) had both abnormal IVU and abnormal ultrasound. Four (6%) had positive findings on one examination not detected on the other: two of these occurred with ultrasound and two with IVU. Measurement of residual volume of urine in the bladder by ultrasound and IVU is discussed. The combination of ultrasound and a plain radiograph of the urinary tract provides more information and should replace IVU in the preoperative assessment of patients with uncomplicated benign hypertrophy of the prostate. 相似文献
107.
Two outbreaks of Salmonella enteritidis phage type 4 infection associated with the consumption of fresh shell-egg products 总被引:4,自引:0,他引:4
J M Cowden D Chisholm M O'Mahony D Lynch S L Mawer G E Spain L Ward B Rowe 《Epidemiology and infection》1989,103(1):47-52
In 1988 there were two outbreaks of infection with Salmonella enteritidis phage type 4 in adjacent local authorities. The first affected 18 of 75 helpers and guests who attended a private function. Investigations revealed that home-made vanilla ice-cream containing uncooked eggs was the vehicle of infection and the causative organism was identified at the premises of the egg producer. The second affected 84 of 422 delegates attending a conference dinner, and 12 of 50 hotel staff at risk. A dessert made with lightly-cooked egg yolk and raw egg white was associated with infection, and the epidemic strain was cultured from the shell of an egg and an environmental sample from the producer's farm. It is of interest that one outbreak involved free-range and one battery-produced eggs, and that in one the vehicle was prepared at home and in the other in commercial premises. In neither incident was any deficiency in standards of egg production or catering practice discovered. 相似文献
108.
Fibrin sealant as a plug for the post liver biopsy needle track 总被引:1,自引:0,他引:1
Some patients are at particular risk of haemorrhage after liver biopsy. We describe the use of a two-component fibrin sealant (Tisseel, Immuno) for embolising the track left after biopsy with the 18 gauge 'Biopty' needle. In our series of five cases there have been no bleeding complications. We consider Tisseel much easier to apply than previously described embolisation materials. 相似文献
109.
Functional complementation between mutations in a yeast suppressor tRNA gene reveals potential for evolution of tRNA sequences. 总被引:7,自引:1,他引:6
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
110.