全文获取类型
收费全文 | 4596篇 |
免费 | 329篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 58篇 |
儿科学 | 85篇 |
妇产科学 | 43篇 |
基础医学 | 763篇 |
口腔科学 | 98篇 |
临床医学 | 453篇 |
内科学 | 1266篇 |
皮肤病学 | 28篇 |
神经病学 | 395篇 |
特种医学 | 284篇 |
外国民族医学 | 1篇 |
外科学 | 529篇 |
综合类 | 14篇 |
一般理论 | 3篇 |
预防医学 | 290篇 |
眼科学 | 22篇 |
药学 | 335篇 |
中国医学 | 1篇 |
肿瘤学 | 263篇 |
出版年
2023年 | 36篇 |
2022年 | 51篇 |
2021年 | 122篇 |
2020年 | 67篇 |
2019年 | 82篇 |
2018年 | 103篇 |
2017年 | 112篇 |
2016年 | 134篇 |
2015年 | 152篇 |
2014年 | 175篇 |
2013年 | 210篇 |
2012年 | 309篇 |
2011年 | 357篇 |
2010年 | 204篇 |
2009年 | 211篇 |
2008年 | 269篇 |
2007年 | 319篇 |
2006年 | 238篇 |
2005年 | 214篇 |
2004年 | 205篇 |
2003年 | 192篇 |
2002年 | 157篇 |
2001年 | 77篇 |
2000年 | 89篇 |
1999年 | 77篇 |
1998年 | 52篇 |
1997年 | 34篇 |
1996年 | 35篇 |
1995年 | 32篇 |
1994年 | 29篇 |
1993年 | 29篇 |
1992年 | 65篇 |
1991年 | 46篇 |
1990年 | 55篇 |
1989年 | 34篇 |
1988年 | 47篇 |
1987年 | 46篇 |
1986年 | 37篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 22篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1979年 | 15篇 |
1978年 | 19篇 |
1977年 | 8篇 |
1975年 | 14篇 |
1973年 | 10篇 |
1972年 | 12篇 |
1971年 | 14篇 |
排序方式: 共有4931条查询结果,搜索用时 31 毫秒
1.
Paul C. Willems Leon Elmans Patricia G. Anderson Wilco C. H. Jacobs Dick B. van der Schaaf Marinus de Kleuver 《European spine journal》2006,15(10):1487-1494
The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, χ
2 test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery. 相似文献
2.
G Harry Van Lenthe Marieke M. M. Willems Nico Verdonschot Maarten C De Waal Malefijt Rik Huiskes 《Acta orthopaedica》2002,73(6):630-637
Although the revision rates for modern knee prostheses have decreased drastically, the total number of revisions a year is increasing because many more primary knee replacements are being done. At the time of revision, bone loss is common, which compromises prosthetic stability. To improve stability, intramedullary stems are often used. The aim of this study was to estimate the effects of a stem, its diameter and the interface bonding conditions on patterns of the bone remodeling in the distal femur.
We created finite element models of the distal half of a femur in which 4 types of knee prostheses were placed. The bone remodeling process was simulated using a strain-adaptive bone remodeling theory. The amount of such remodeling was determined by calculating the changes in bone mineral density in 9 regions of interest from simulated DEXA scans.
The computer simulation model showed that revision prostheses tend to cause more bone resorption than primary ones, especially in the most distal regions. Predicted long-term bone loss due to a revision prosthesis with a thin stem equalled that around a prosthesis with an intercondylar box. However, strong regional differences were found- the stemmed prostheses having more bone loss in the most distal areas and some bone gain in the more proximal ones. A prosthesis with a thick stem led to an increase in bone loss. When the prosthesis-cement interface was bonded, more bone loss was predicted than with an unbonded interface. These results suggest that a stem which increases stability initially may reduce stability in the long term. This is due to an increase in stress shielding and bone resorption. 相似文献
We created finite element models of the distal half of a femur in which 4 types of knee prostheses were placed. The bone remodeling process was simulated using a strain-adaptive bone remodeling theory. The amount of such remodeling was determined by calculating the changes in bone mineral density in 9 regions of interest from simulated DEXA scans.
The computer simulation model showed that revision prostheses tend to cause more bone resorption than primary ones, especially in the most distal regions. Predicted long-term bone loss due to a revision prosthesis with a thin stem equalled that around a prosthesis with an intercondylar box. However, strong regional differences were found- the stemmed prostheses having more bone loss in the most distal areas and some bone gain in the more proximal ones. A prosthesis with a thick stem led to an increase in bone loss. When the prosthesis-cement interface was bonded, more bone loss was predicted than with an unbonded interface. These results suggest that a stem which increases stability initially may reduce stability in the long term. This is due to an increase in stress shielding and bone resorption. 相似文献
3.
Hypomagnesemia due to isolated renal magnesium loss was demonstrated in two unrelated families with autosomal dominant mode of inheritance. Magnesium infusions performed in two patients showed not only a reduced renal magnesium threshold but also a lowered renal tubular maximum for magnesium. All members of both families who presented with hypomagnesemia had also a lowered excretion of calcium in the urine, presumably as a consequence of increased reabsorption in Henle's loop. 相似文献
4.
Marcel J. Kooy Wouter S. Dessing Esther F. Kroodsma Steven R. J. G. Smits Esther H. Fietje Martine Kruijtbosch Peter A. G. M. De Smet 《Pharmacy World & Science》2007,29(2):81-89
OBJECTIVE: According to a report published by the federation of Dutch patients' associations, patients would like to see a pharmacist, who acts more as a personal adviser. This raised the question, how often Dutch community pharmacists have personal consultations with their patients in daily practice, on which factors this depends, and what kind of topics are discussed during these meetings. SETTING: Community pharmacies in the Netherlands. METHOD: A questionnaire was distributed among 800 randomly selected pharmacies. Questions were restricted to consultations characterized by one-to-one contact, drug therapy related content, and adequate privacy. These consultations were labelled as pharmaceutical consultations in private to distinguish them from other contacts between pharmacists and patients. MAIN OUTCOME MEASURE: Number, content, and character of consultations. RESULTS: 198 (24.8%) community pharmacies responded. The pharmacists provide an average of roughly 1.2 consultations in private per working day. The vast majority of respondents provided face-to-face and telephone consultations (94.4 and 91.9%, respectively), only a minority gave consultations by e-mail (30.8%). These consultations primarily dealt with topics related to medication safety. The mean overall time spent was 290 min per month. A relatively high frequency of personal consultations was significantly associated with the absolute number of full-time equivalent pharmacists in the pharmacy. CONCLUSION: The frequency of pharmaceutical consultations in private is low, but may be improved by reorganisation of the pharmacist's activities. The possibility of personal consultations by e-mail is not yet well-developed. Further research is needed to assess the patient's view of pharmaceutical consultations in private. 相似文献
5.
Martine C M Willems L W Ernest van Heurn Geert W Schurink Frank M van der Sande Jan H M Tordoir 《Nephrology, dialysis, transplantation》2006,21(12):3583-3584
6.
7.
8.
F Stammen J Piessens J J Glazier M C Vrolix H De Geest J L Willems 《American heart journal》1992,124(5):1127-1132
The in-hospital and short-term follow-up results of a conservative coronary angioplasty approach in 354 consecutive patients treated after thrombolysis for acute myocardial infarction were compared with results obtained in 408 control noninfarcted patients treated for the classical indication of myocardial ischemia. Only 20% of the study patients underwent angioplasty during the initial hospitalization period and the clinical success rate was 93% versus 95% in the control group (p = NS). No significant differences in the total number of in-hospital untoward events were observed (10.2% and 7.6%, respectively). During a 7.4 +/- 1.5 month follow-up period, the total number of adverse events was only 16.9% in the study patients but it was 27.8% in the control group (p < 0.001). There were no significant differences in death, myocardial infarction, or coronary surgery as individual events, but repeat angioplasty was less frequent in the study group (14.0% versus 21.5%, p < 0.01). Thus in-hospital results in patients undergoing angioplasty on a deferred basis after thrombolysis for myocardial infarction were largely comparable with those results obtained in noninfarcted patients. Moreover, short-term clinical follow-up events were reduced when compared with the control group, an observation apparently largely related to the subgroup without clinical evidence of residual ischemia. 相似文献
9.
Patrick J. Bindels Dieke K. Mulder-Folkerts Kees Boer Maarten F. Schutte Wouter J. van der Velde Frans J. Wong Anneke J. A. R. van den Hoek Gerard J. van Doornum Roel A. Coutinho 《European journal of epidemiology》1994,10(3):331-338
The objective of the study was to monitor the HIV prevalence in the years 1988–1991 among pregnant women in the Amsterdam region, visitors to an abortion clinic and 3 outpatient infertility clinics. All women attending these clinics were asked to participate in the study on a voluntary basis and were tested with informed consent. The women were questioned about risk-bearing behaviour of themselves and their sexual partner(s). In the period 1988–1991, of the 23,827 eligible pregnant women, 22,165 women participated (93.0%). Twenty-seven women were found to be positive for HIV antibodies (0.12%, 95% CI: 0.08%–0.17%), of whom twenty belonged to a known HIV risk group or had a partner who belonged to one of these groups and 7 women had no known HIV risk. Seventeen of the 27 women had a foreign nationality. The annual HIV prevalence among pregnant women was: 1988: 0.28%; 1989: 0.10%; 1990: 0.10%; 1991: 0.11%. In the years 1990 and 1991, of the 1,128 eligible women visiting the abortion clinic 953 (84.5%) were tested. Eleven women were HIV-seropositive (1.15%, 95% CI: 0.6%–2.0%), of whom 9 were from an AIDS endemic region, 1 woman had a partner from this region and 1 woman had no known HIV risk. Four African women had HIV-2 antibodies. At the 3 outpatient infertility clinics 1 woman was found to be HIV-positive (0.13%; 95% CI: 0.02–0.9). She had no other risk than a partner from an AIDS endemic area. In the Amsterdam region there was a steady and low HIV prevalence (0.1%) among pregnant women through the years 1988–1991. The prevalence in the abortion clinic was ten times higher. The program was able to detect possible high risk groups within the population. Migration and travelling can play an important role in the spread of HIV in the general heterosexual population. 相似文献
10.
Brain glucose utilisation in acquired childhood aphasia associated with a sylvian arachnoid cyst: recovery after shunting as demonstrated by PET. 总被引:4,自引:0,他引:4 下载免费PDF全文
A G De Volder C Michel C Thauvoy G Willems G Ferrière 《Journal of neurology, neurosurgery, and psychiatry》1994,57(3):296-300
Regional brain glucose utilisation was investigated with PET and fluorodeoxyglucose (FDG) in a case of epileptic aphasia (Landau-Kleffner syndrome) associated with a left sylvian arachnoid cyst. CT and MRI had failed to disclose any mass effect of the cyst on surrounding brain structures. Sequential metabolic measurements showed a comparable pronounced hypometabolism in cortical regions around the cyst, involving speech areas, and suggested mild but chronic compression of the developing brain. After placement of a cyst-peritoneal shunt system, significant metabolic improvement occurred in all cortical regions, especially the inferior frontal gyrus and the perisylvian area, with predominant residual deficit in the left superior temporal gyrus. These findings were correlated with a pronounced increase in word fluency and slower progress in verbal auditory comprehension. This report suggests that PET is able to evaluate the functional disturbances associated with expanding arachnoid cysts, and to follow the neurological improvement after drainage. 相似文献