全文获取类型
收费全文 | 1861篇 |
免费 | 62篇 |
国内免费 | 83篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 69篇 |
妇产科学 | 13篇 |
基础医学 | 157篇 |
口腔科学 | 44篇 |
临床医学 | 304篇 |
内科学 | 436篇 |
皮肤病学 | 49篇 |
神经病学 | 69篇 |
特种医学 | 289篇 |
外科学 | 250篇 |
综合类 | 44篇 |
预防医学 | 84篇 |
眼科学 | 24篇 |
药学 | 93篇 |
中国医学 | 15篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 19篇 |
2022年 | 30篇 |
2021年 | 35篇 |
2020年 | 12篇 |
2019年 | 22篇 |
2018年 | 40篇 |
2017年 | 24篇 |
2016年 | 30篇 |
2015年 | 38篇 |
2014年 | 51篇 |
2013年 | 68篇 |
2012年 | 78篇 |
2011年 | 71篇 |
2010年 | 91篇 |
2009年 | 87篇 |
2008年 | 76篇 |
2007年 | 94篇 |
2006年 | 79篇 |
2005年 | 64篇 |
2004年 | 46篇 |
2003年 | 55篇 |
2002年 | 44篇 |
2001年 | 39篇 |
2000年 | 37篇 |
1999年 | 20篇 |
1998年 | 89篇 |
1997年 | 78篇 |
1996年 | 64篇 |
1995年 | 53篇 |
1994年 | 47篇 |
1993年 | 47篇 |
1992年 | 35篇 |
1991年 | 23篇 |
1990年 | 24篇 |
1989年 | 39篇 |
1988年 | 40篇 |
1987年 | 28篇 |
1986年 | 27篇 |
1985年 | 23篇 |
1984年 | 20篇 |
1983年 | 12篇 |
1982年 | 18篇 |
1981年 | 9篇 |
1980年 | 15篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1900年 | 2篇 |
排序方式: 共有2006条查询结果,搜索用时 0 毫秒
101.
102.
Jaber AJ Murín J Hricák V Tomasovic B Kinová S Kozlíková K Ghanem W Radman A 《Vnitr?ní lékar?ství》2003,49(2):109-114
It is known that local and systemic inflammatory processes play an important role in the genesis and development of atheroclerotic lesions and in the pathophysiology of acute coronary syndromes. This hypothesis is supported by findings of elevated parameters of the "inflammatory" reaction in the affected blood vessels but also in the blood of atherosclerotic patients. Known risk factors do not explain quite satisfactorily epidemiological cardiovascular phenomena and different manifestations of coronary heart disease. It is very probable that also Chlamydia pneumoniae is a risk factor. This assumption is based on evaluation of seroepidemiological data, examination of atherosclerotic plaques not only in humans but also in animal models with chlamydial infection. Based on retrospective and prospective evaluation of case-records the authors analyzed the incidence of cardiovascular complications in 83 patients with acute myocardial infarction (AIM), incl. 51 patients (31 men and 20 women, mean age 64.4 +/- 3.4 years who had a non-specific inflammation and chlamydial infection, and 32 patients (24 men and 8 women, mean age 64.7 +/- 3.6 years) who had chlamydial infections but no non-specific inflammation (in the blood). These patients were selected from all patients hospitalized during 1998-2001. When diagnosing acute myocardial infarction we applied WHO criteria, and the presence of at least two of three criteria was necessary: a history of prolonged (more than 20 min). stenocardia, electrocardiographic changes typical for ischaemia and/or necrosis and elevation of myocardial enzymes in serum, Non-specific inflammatory activity was present in patients (i.e. positive) if the following laboratory parameters were recorded: C-reactive protein > 5 mg/l assessed by the radial immunodiffusion method; fibrinogen > 4 mg/l assessed by the coagulation method according to Claus; leukocytes > 9.6 x 10(3)/microliter, leukocytes were counted automatically in a Coulter chamber; lymphocytes > 3.4 x 10(3)/microliter. Red cell sedimentation rate > 20 mm/hour. The activity was evaluated as positive when all parameters were elevated. The presence of chronic infection with Chlamydia pneumoniae was assessed qualitatively by antibody positivity (IgG) in serum using the microimmunoflurescent method (using a set from Labsystems Co.). The incidence of associated risk factors (obesity, smoking, diabetes, hyperlipidaemia and hypertension) is higher in the sub-group of patients with Chlamydia infections without inflammation, however, the difference is not statistically significant. The incidence of cardiovascular attacks was higher in the sub-group of patients with chlamydial infection and concurrent inflammation as compared with the sub-group of patients with chlamydial infection without inflammation. In case of re-infarction of the myocardium, a sudden cerebrovascular attack, death and arrhythmia the difference was statistically significant, while in case of cardiac failure and cardiogenic shock the difference was not significant. Patients with acute myocardial infarction with chlamydial infection and a concurrent non-specific inflammation had to be treated more often by combined (i.e. more intense) treatment, thrombolytic treatment, PTCA and surgery (bypass) of the coronary vessels as compared with patients with Chlamydia infections but without inflammation. The authors assume therefore that not only different risk factors but also the effect of non-specific inflammation and Chlamydia infection contribute towards the increased number of cardiovascular postinfarction complications. Therefore a therapeutic approach involving eradication of infection and suppression of the inflammatory reaction should be considered. 相似文献
103.
104.
To assess the trends in the frequency of consanguineous marriages in the Israeli Arab population in the last 40 years, we conducted a two-part study. For the first part, we re-analyzed data from a nationwide study carried out in 1992, and for the second part, we undertook a new survey in 1998 in four locations: Taibe, Tira, Kalansuwa and Kafr Bara. Data regarding the frequency of consanguineous marriage in these four locations for the years 1961-1985 was extracted from the original survey, and for the years 1986-1998, from new questionnaires. The frequency of consanguineous marriage was highest in the period 1961 1965 (50.6%), but by the period 1981-1985 it had decreased to 40.6%. Over the whole time span of the 1992 study, a significant decrease was observed between the periods 1961-1975 and 1976-1985 (p < 0.0001). In the four-location study, there was a significant decrease in the frequency of consanguineous marriage from 52.9%, in the period 1961-1970 to 32.8% in the period 1991-1998 (p = 0.0006). We conclude that the custom of consanguineous marriage in the studied population is still extremely high, and preventive measures should be taken to decrease its frequency and associated complications. 相似文献
105.
106.
Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention. 相似文献
107.
The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers 总被引:5,自引:0,他引:5
J Zschocke CA Graham JJ McKnight NC Nevin 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):41-42
We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups. 相似文献
108.
The role of divalent cations in platelet adherence to deendothelialized human arteries in flowing blood was investigated in an annular perfusion chamber. Spreading of platelets on the subendothelium was impaired below 30 microM of free Ca2+ ions (Ca2+). When Ca2+ was replaced by Mg2+, adherence was unchanged in perfusates without exogenous factor VIII-von Willebrand factor (FVIII-vWF), but the ability of FVIII-vWF to support platelet adherence was lost. Binding of FVIII-vWF to the vessel wall was independent of divalent cations, but bound FVIII-vWF was only able to mediate adherence after exposure to Ca2+. Pretreatment of FVIII-vWF with the calcium chelator EGTA (10 mM) resulted in loss of the ability to facilitate platelet adherence, while the ristocetin cofactor activity remained intact. Full restoration of the ability to mediate platelet adherence could only be obtained by prolonged dialysis against Ca2+ in the millimolar range. These data indicate that divalent cations have at least two separate roles to play in supporting platelet adherence: (1) platelet spreading on the subendothelium requires Ca2+ or Mg2+; (2) FVIII-vWF should be exposed to Ca2+ to obtain its optimal biologic activity in supporting platelet adherence. 相似文献
109.
110.
Objective : To describe the obstetric and perinatal factors, in particular the method of delivery, associated with development of a subgaleal haematoma (SGH) and to determine the outcome of survivors with this type of birth trauma. Methodology : Perinatal and obstetric data were retrospectively reviewed for 37 infants admitted to the neonatal unit of the sole tertiary paediatric referral hospital in Western Australia with an SGH, over a 24 year period from 1970 to 1993. These data were compared to data for all Western Australian births. The long-term outcome was obtained through medical and private paediatric records for 26 of these infants. Results : All except one of the neonates had instrumental deliveries; 89% had a vacuum extractor applied to the head at some stage of delivery compared to 10% of the general population of births in Western Australia. There was also a significantly increased risk of failure of attempted vacuum extraction. Of the cases where a vacuum extraction was attempted, 45% also had forceps applied to the head. Coagulopathy was associated with the severity of the SGH. There was also a high frequency of occurrence (40%) of associated head trauma such as intracranial haemorrhage, skull fracture and cerebral oedema, as well as neonatal encephalopathy (73%). The occurrence of these associated features did not correlate significantly with the severity of SGH. Minor complications of SGH included jaundice and facial bruising. There was an excess mortality associated with SGH; however, the long-term outcome for neonatal survivors with this disorder was good. None of the cases studied subsequently developed cerebral palsy or intellectual disability, and minor neurological sequelae only were documented in four infants. Conclusions : SGH is an uncommon type of birth trauma, and is associated with delivery or attempted delivery by vacuum extraction. The most commonly associated clinical problems were hypovolaemia and coagulopathy. The long-term outcome for neonates with this condition is good. 相似文献