全文获取类型
收费全文 | 540篇 |
免费 | 35篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 22篇 |
妇产科学 | 11篇 |
基础医学 | 57篇 |
口腔科学 | 27篇 |
临床医学 | 80篇 |
内科学 | 120篇 |
皮肤病学 | 1篇 |
神经病学 | 105篇 |
特种医学 | 19篇 |
外科学 | 32篇 |
综合类 | 2篇 |
预防医学 | 46篇 |
眼科学 | 1篇 |
药学 | 38篇 |
肿瘤学 | 13篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 6篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 18篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 18篇 |
2013年 | 21篇 |
2012年 | 36篇 |
2011年 | 43篇 |
2010年 | 22篇 |
2009年 | 16篇 |
2008年 | 31篇 |
2007年 | 40篇 |
2006年 | 17篇 |
2005年 | 30篇 |
2004年 | 31篇 |
2003年 | 26篇 |
2002年 | 28篇 |
2001年 | 13篇 |
2000年 | 20篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 13篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有575条查询结果,搜索用时 15 毫秒
1.
In the oomycete, Phytophthora infestans, mating type is determined by a locus that segregates in a non-Mendelian manner consistent with its linkage to a system of
balanced lethals. The significance of this unusual phenomenon was addressed by studying the segregation patterns of DNA markers
linked to mating type in the related species, P. parasitica. This was done using loci identified by either RAPD analysis of P. parasitica crosses or by cross-hybridization with RFLP markers linked to mating type in P. infestans. The resulting data revealed that, unlike P. infestans, mating type in P. parasitica was regulated by a locus displaying Mendelian segregation. An improved model for mating-type determination in Phytophthora is presented.
Received: 21 October 1996 / 7 April 1997 相似文献
2.
P. Hartikainen H. Soininen K. J. Reinikainen J. Sirviö R. Soikkeli P. J. Riekkinen 《Journal of neural transmission (Vienna, Austria : 1996)》1991,84(1-2):103-117
Summary We have investigated neurotransmitter-related markers of the cerebrospinal fluid (CSF) in a carefully screened series of normally aging subjects in standardized conditions in order to find out the influence of age and other confounding factors on CSF measures. The levels of 3-methoxy-4-hydroxyglycol (MHPG) and the activity of acetylcholinesterase (AChE) also increased with age, while homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5 HIAA) and immunoreactivities of somatostatin (SLI), beta-endorphin (BLI) and adrenocorticotropic hormone (ACTH) were unrelated to age. The gender of subjects had no significant effect on the levels of neurotransmitter markers, while seasonal changes, as well as height and weight of the subjects seemed to cause some variations in the levels of HVA, dopamine--hydroxylase (DBH) and ACTH. The study underscores the importance of standardized conditions and matched patient groups in the CSF studies. 相似文献
3.
Transient interference of right hemispheric function due to automatic emotional processing 总被引:4,自引:0,他引:4
We examined the effects of emotional stimuli on right and left hemisphere detection performance in a hemifield visual discrimination task. A group of 18 healthy subjects were asked to discriminate between upright and inverted triangles (target). Targets were randomly presented in the left or right visual hemifield (150 ms target duration). A brief emotional picture (pleasant or unpleasant; 150 ms stimulus duration) or neutral picture selected from the International Affective Picture System was randomly presented either in the same (47%) or the opposite (47%) spatial location to the subsequent target. Emotional or neutral stimuli offset 150 ms prior to the subsequent target. Subjects were instructed to ignore the pictures and respond to the targets as quickly and accurately as possible. Independent of field of presentation, emotional stimuli prolonged reaction times (P < 0.01) to LVF targets, with unpleasant stimuli showing a greater effect than pleasant stimuli. The current study shows that brief emotional stimuli selectively impair right hemispheric visual discrimination capacity. The findings suggest automatic processing of emotional stimuli captures right hemispheric processing resources and transiently interferes with other right hemispheric functions. 相似文献
4.
Jouko Hartikainen Jukka Antila Matti Varpula Pauli Puukka Heikki Sepp Reidar Grnman 《The Laryngoscope》1998,108(12):1861-1866
Objectives and Study Design: The advent of the rigid endonasal endoscope and the development of functional endoscopic sinus surgery (FESS) technique have awakened interest in an endonasal endoscopic dacryocystorhinostomy (EESC-DCR) in treating nasolacrimal obstruction. This prospective, randomized study compares EESC-DCR with traditional external dacryocystorhinostomy (EXT-DCR) for their success rates, surgical duration, and postoperative symptoms. Patients and Methods: Sixty-four cases in 60 patients with primary acquired nasolacrimal sac or duct obstruction were divided into two subgroups by symptoms (simple epiphora/ chronic dacryocystitis). These patients were randomized within both subgroups into two operation groups. Altogether 32 EESC-DCRs and 32 EXT-DCRs were performed. The final follow-up visit was at 1 year. The patency of the lacrimal passage was investigated by irrigation and patients were questioned about their symptoms. Results: The success rate at 1 year after surgery was 75% for EESC-DCR and 91% for EXT-DCR after primary surgery. The difference was not statistically significant (P = .18). The success rate after secondary surgery with a follow-up time of 1 year was 97% in both study groups. The average duration for EESC-DCR was 38 minutes, and 78 minutes for EXT-DCR, (P < .001). Conclusions: EXT-DCR, when compared with EESC-DCR, appears to give a higher, although not statistically significant, primary success rate, but the secondary success rates are equal, indicating that these two different DCR techniques are acceptable alternatives. 相似文献
5.
Kaija Komulainen DDS Pekka Ylöstalo DDS PhD Anna‐Maija Syrjälä DDS PhD Piia Ruoppi DDS Matti Knuuttila DDS PhD Raimo Sulkava MD PhD Sirpa Hartikainen MD PhD 《Special care in dentistry》2014,34(1):19-26
The aim was to study the determinants of preventive oral health care need among community‐dwelling old people. The study population consisted of 165 participants, a subpopulation in the Geriatric Multidisciplinary Strategy for Good Care of Elderly People (GeMS) study. Fifty‐five percent of the edentate participants with full dentures and 82% of the dentate had a need for preventive oral health care. In the total study population, the need for preventive care was associated with co‐morbidity (measured by means of the Modified Functional Co‐morbidity Index) odds ratios (OR) 1.2 (confidence intervals [CI] 1.0–1.5), being pre‐frail or frail, OR 2.5 (CI 1.2–5.1), presence of natural teeth, OR 4.8 (CI 2.2–10.4), and among dentate participants, the use of a removable partial denture, OR 12.8 (CI 1.4–114.4). Primary care clinicians should be aware of the high need for preventive care and the importance of nonoral conditions as determinants of preventive oral health care need. 相似文献
6.
7.
Kuittinen T Husso-Saastamoinen M Sipola P Vuolteenaho O Ala-Kopsala M Nousiainen T Jantunen E Hartikainen J 《Bone marrow transplantation》2005,36(12):1077-1082
Cardiotoxicity is potentially the most threatening nonhaematological side effect of high-dose CY. We prospectively evaluated the very acute cardiac effects of high-dose CY in 17 adult non-Hodgkin's lymphoma (NHL) patients receiving CY 1500 mg/m2/day as a part of BEAC high-dose therapy (HDT). Magnetic resonance imaging (MRI) and plasma natriuretic peptide (NT-proBNP, NT-proANP) measurements were performed prior to HDT (d-7) and just after completing HDT (d-2). After the high-dose CY left atrial end-systolic area increased from 15.2+/-1.2 to 18.5+/-1.4 cm2 (P=0.001), left ventricular end-diastolic volume from 136.1+/-12.3 to 156.6+/-11.1 cm3 (P=0.04) and left ventricular end-systolic volume from 67.4+/-7.8 to 75.3+/-7.1 cm3 (P=0.018). However, no significant change in left ventricular ejection fraction (LVEF) was observed. At the same time, plasma levels of NT-proBNP increased from 134.9+/-53.3 to 547.1+/-168.4 pmol/l (P=0.003) and NT-proANP from 481.1+/-105.5 to 1056.6+/-193.1 pmol/l (P=0.001), respectively. To conclude, high-dose CY results in very acute cardiac toxicity characterised by enlargement of the heart chambers in NHL patients previously treated with anthracyclines. This toxicity can be detected with increased concentrations of circulating natriuretic peptides but not with LVEF measurement. 相似文献
8.
Bennett AJ Sovio U Ruokonen A Martikainen H Pouta A Hartikainen AL Franks S Elliott P Järvelin MR McCarthy MI 《Diabetologia》2008,51(1):82-85
Aims/hypothesis The P12A variant in the PPARG gene and the E23K polymorphism in KCNJ11 are both known to influence individual predisposition to type 2 diabetes. If the effect of these variants on insulin secretion
and action were to extend to an influence on early growth (which is largely mediated by insulin), it would offer an explanation
for observed associations between low birthweight and subsequent diabetes. Since previous studies of the effects of these
variants on early growth have been limited and conflicting, we examined these associations in a large, well-characterised
birth cohort.
Methods The P12A and E23K variants were genotyped in (respectively) 5,652 and 5,632 individuals from the Northern Finland Birth Cohort
of 1966 and we sought associations with early growth phenotypes.
Results Neither variant was associated with birthweight (P12A, p = 0.42; E23K, p = 0.44, additive models) or other measures of early growth. Although a previous report had suggested that the P12A effect
on adult insulin sensitivity was restricted to small babies, we were unable to reproduce this finding (p = 0.40), nor did we confirm a previous report of an association with gestational age (p = 0.23).
Conclusions/interpretation Despite a larger sample size than previous studies, we were unable to detect any effect of these variants on early growth.
These findings do not support the notion that there are shared genetic determinants of low birthweight and adult diabetes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users. 相似文献
9.
Baroreflex sensitivity and neurohormonal activation in patients with acute myocardial infarction.
下载免费PDF全文
![点击此处可从《Heart (British Cardiac Society)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J. Hartikainen F. Fyhrquist K. Tahvanainen E. Lnsimies K. Pyrl 《Heart (British Cardiac Society)》1995,74(1):21-26
OBJECTIVE--To examine the relationship between baroreflex sensitivity and neurohormonal activation in patients with an acute myocardial infarction. METHODS--Baroreflex sensitivity, plasma noradrenaline, atrial natriuretic factor, endothelin-1, and plasma renin activity were measured in 37 male patients about 10 days after their first myocardial infarction, and in 15 healthy controls. Baroreflex sensitivity was assessed from the regression line relating the change in RR interval to the change in systolic blood pressure following an intravenous bolus injection of phenylephrine. The measurements were repeated after a follow up of three months. RESULTS--There was a significant inverse correlation between baroreflex sensitivity and plasma noradrenaline measured before hospital discharge (r = -0.43, P < 0.01). Patients with increased plasma noradrenaline (> or = 2SD above the mean of the age matched control group) had significantly lower baroreflex sensitivity than patients with normal plasma noradrenaline (8.7 (SD 4.6) v 12.1 (6.1) ms/mm Hg, P < 0.05). The change in baroreflex sensitivity during the follow up showed a significant inverse correlation with the change of plasma noradrenaline (r = -0.450, P < 0.01). Furthermore, when patients with increased plasma noradrenaline before hospital discharge were analysed separately, baroreflex sensitivity at three months in patients in whom plasma noradrenaline had decreased to normal values was significantly higher than in patients in whom plasma noradrenaline had remained increased (14.6 (5.7) v 8.1 (8.1) ms/mm Hg, P < 0.05). On the other hand, baroreflex sensitivity was not related to the levels of plasma atrial natriuretic factor, plasma endothelin-1, or plasma renin activity. Neither was any relationship found between change in baroreflex sensitivity and change in plasma atrial natriuretic factor, endothelin-1, or plasma renin activity during the follow up. CONCLUSIONS--The impairment baroreflex sensitivity after myocardial infarction was associated with increased concentration of plasma noradrenaline, that is, sympathetic activation, but not with plasma atrial natriuretic factor, endothelin-1, or plasma renin activity. Baroreflex sensitivity provides information about cardiac vagal control as well as about the balance of cardiac sympathetic-parasympathetic regulation. 相似文献
10.
Anna-Liisa Svedström-Oristo Terttu Pietilä Ilpo Pietilä Hans Helenius Pentti Alanen Juha Varrela 《Acta odontologica Scandinavica》2013,71(3):160-166
There is no general agreement on criteria that could be applied to distinguish between orthodontically acceptable and non-acceptable occlusions after the completion of dental development. The aim of the present study was to analyse morphological and functional features that could be used as an index to define an acceptable occlusion in young adults. Three expert panels representing specialists in orthodontics and stomatognathic physiology participated in a modified Delphi method. Each panel responded to a questionnaire concerning the usefulness of various occlusal features, and a set of characteristics was selected on the basis of the responses; thereafter, applicability of the chosen characteristics and their cutoffs for an acceptable-non-acceptable dichotomy was tested clinically. To obtain a consensus level of 100%, the last panel session was completed with a group discussion. Assessments made using the morphological criteria were compared with those made with the dental health component of the Index of Orthodontic Treatment Need. The selected morphological characteristics consisted of overjet, overbite, canine relationship, crossbite, scissors bite and midline deviation. The functional evaluation comprised assessments of discrepancy between the centric relation and the intercuspal position, working- and non-working-side contacts and protrusion contacts. The dental health component and our morphological criteria showed different sensitivity to contact point displacements, interdigitation in buccal segments and increased overbite. This study provides a set of morphological and functional indicators reflecting the current consensus opinion of Finnish professionals. Further studies are needed to analyse the reproducibility of assessment of the characteristics included. 相似文献