全文获取类型
收费全文 | 1160篇 |
免费 | 98篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 28篇 |
妇产科学 | 24篇 |
基础医学 | 131篇 |
口腔科学 | 27篇 |
临床医学 | 139篇 |
内科学 | 234篇 |
皮肤病学 | 19篇 |
神经病学 | 133篇 |
特种医学 | 104篇 |
外科学 | 118篇 |
综合类 | 39篇 |
预防医学 | 134篇 |
眼科学 | 13篇 |
药学 | 62篇 |
肿瘤学 | 52篇 |
出版年
2021年 | 23篇 |
2020年 | 14篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 22篇 |
2016年 | 20篇 |
2015年 | 27篇 |
2014年 | 40篇 |
2013年 | 57篇 |
2012年 | 58篇 |
2011年 | 55篇 |
2010年 | 30篇 |
2009年 | 32篇 |
2008年 | 42篇 |
2007年 | 48篇 |
2006年 | 43篇 |
2005年 | 40篇 |
2004年 | 51篇 |
2003年 | 28篇 |
2002年 | 42篇 |
2001年 | 46篇 |
2000年 | 31篇 |
1999年 | 30篇 |
1998年 | 21篇 |
1997年 | 17篇 |
1996年 | 13篇 |
1995年 | 21篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 26篇 |
1991年 | 16篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 26篇 |
1987年 | 18篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1973年 | 14篇 |
1972年 | 12篇 |
1971年 | 11篇 |
1970年 | 13篇 |
1968年 | 15篇 |
1967年 | 7篇 |
排序方式: 共有1263条查询结果,搜索用时 15 毫秒
1.
Ketai LH; Williamson MR; Telepak RJ; Levy H; Koster FT; Nolte KB; Allen SE 《Radiology》1994,191(3):665
2.
Lipoma is a benign neoplasm composed of adult adipose tissue and occasionally fibrous stroma. These lesions occur most often in adults and rarely in the pleura. We describe a case of a lipoma in a 3 1/2 year old child that presented as a pleural-based mass. 相似文献
3.
Inter-rater reliability of the International Cooperative Ataxia Rating Scale (ICARS). 总被引:3,自引:0,他引:3
Elsdon Storey Kate Tuck Robert Hester Andrew Hughes Andrew Churchyard 《Movement disorders》2004,19(2):190-192
We assessed the inter-rater reliability of the 100-point International Cooperative Ataxia Rating Scale (ICARS). Three neurologists independently rated videotaped ICARS examinations of 22 subjects with genetically determined ataxias (spinocerebellar ataxia [SCA] Type 1 in 11; SCA Type 2 in 1; Friedreich's ataxia in 10) and 4 controls. Scores on live ICARS assessment had ranged from 0 to 7 for controls and 11 to 74 for ataxic subjects (clinically very mildly affected to wheelchair-bound). Inter-rater correlation was very high for the total score (Kendall's omega 0.994, 95% confidence interval, 0.988-0.997), and high to very high for each component subscore (0.791 for speech to 0.994 for posture/gait). All correlations were significant at P < 0.00001. The ICARS exhibits very high inter-rater reliability even without prior observer standardisation and is sensitive to a range of ataxia severities from very mild to severe. 相似文献
4.
J P Harris C Vickers D W Storey 《The Australian and New Zealand journal of surgery》1988,58(2):167-168
A 71 year old white male is reported in whom ischaemic ulceration of the lesser curve of the stomach, a variant of lesser curve necrosis, occurred after the combined procedures of highly selective vagotomy (HSV) and abdominal aortic aneurysmectomy. Other operations, particularly fundoplication and incidental splenectomy, have been implicated in the aetiology of lesser curve ischaemia, an otherwise rare complication of HSV. This case suggests that concomitant aortic surgery may also increase the risk of lesser curve ischaemia after HSV. Careful endoscopic monitoring of patients undergoing these combined procedures is therefore recommended to better define the risk. 相似文献
5.
Mesenteric cyst is one of the rarest abdominal tumours, with approximately 820 cases reported since 1507. The incidence varies from 1 per 100000 to 250000 admissions. The lack of characteristic clinical features and radiological signs may present great diagnostic difficulties. The cyst may present in one of three ways: (i) non-specific abdominal features; (ii) an incidental finding; or (iii) an acute abdomen. Abdominal pain is the major presenting symptom. Abdominal mass is found in more than 50% of cases and 40% of cases are discovered incidentally. More than one aetiological mechanism is probably involved in the development of mesenteric cysts. Mesenteric cysts have been reported from the duodenum to the rectal mesentery but are most commonly located in the ileal mesentery. Malignant cysts occur in less than 3% of cases. Enucleation of the cyst is the treatment of choice. Knowledge of these tumours is important due to the various complications associated with suboptimal surgical management. Two cases of mesenteric cysts are presented including a recurrent mesenteric cyst in a post-partum woman demonstrating the inferior technique of internal marsupialization. The association of mesenteric cyst with pregnancy is discussed. 相似文献
6.
H. Coughtrey H. E. Jeffery D. J. Henderson-Smart B. Storey V. Poulos 《The Australian & New Zealand journal of obstetrics & gynaecology》1991,31(2):97-102
The cause of fetal distress and neonatal respiratory distress (RD) in association with meconium-stained liquor is not always clear. To clarify this, a prospective study was undertaken in a tertiary referral maternity hospital for 1 year. In all infants born after meconium-stained liquor who developed RD, evidence was sought for 1) fetal distress (from the cardiotocograph (CTG), the cord blood pH, the Apgar score and the asphyxial complications in the neonate) 2) causes of fetal distress (including maternal risk factors, fetal infection and fetal malnutrition) 3) causes of respiratory distress (including meconium aspiration syndrome (MAS), persistent pulmonary hypertension of the newborn (PPHN) and infection). Of 4,026 livebirths, 717 (17.8%) had meconium-stained liquor and 44 term and 5 preterm infants developed RD. In the 44 term infants, there was frequent evidence of fetal distress possibly caused by previously unrecognized factors such as fetal malnutrition with reduced neonatal skinfold thickness in 35% triceps and 41% subscapular measurements, and histological chorioamnionitis (CA) in 74%. The cause for respiratory distress was identified in only 48% of infants, and included clinical evidence of PPHN (41%), MAS (16%) and infection (2%). However in preterm infants, 80% had definite or suspected infection. The findings indicate that fetal distress is common in infants who develop respiratory distress after meconium-stained liquor. A role for histological CA and reduced nutrition in the fetus, as factors contributing to the vulnerability of the term infant to intrapartum fetal distress, is suggested. 相似文献
7.
Pippa Storey Fred J Frigo R Scott Hinks Bryan J Mock Bruce D Collick Nicole Baker Jonathan Marmurek Simon J Graham 《Magnetic resonance in medicine》2007,57(3):614-619
Partial k-space sampling is frequently used in single-shot diffusion-weighted echo-planar imaging (DW-EPI) to reduce the TE and thereby improve the SNR. However, it increases the sensitivity of the technique to bulk rotational motion, which introduces a phase gradient across the tissue that shifts the echo in k-space. If the echo is displaced into the high spatial frequencies, conventional homodyne reconstruction fails, causing intensity oscillations across the image. Zero-padding, on the other hand, compromises the image resolution and may cause truncation artifacts. We present an adaptive version of the homodyne algorithm that detects the location of the echo in k-space and adjusts the center and width of the homodyne filters accordingly. The adaptive algorithm produces artifact-free images when the echo is shifted into the high positive k-space range, and reduces to the standard homodyne algorithm in the absence of bulk motion. 相似文献
8.
Detection of clustered gastrointestinal contractions in partial intestinal obstruction by surface vibration analysis.
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gastrointestinal contraction "clusters" with alternating quiescence occur in partial intestinal obstruction and are conventionally detected by intraluminal manometry. Surface Vibration Analysis (SVA), which is a noninvasive test, was evaluated in this study in experimental and clinical situations. In the experimental situation, former SVA was assessed against simultaneous manometry in two volunteers, in whom partial obstruction had been induced by intrajejunal balloon distension. Manometry showed typical contraction "clusters" with alternating quiescence, each of two to four minutes duration, in obstructed jejunum proximal to the balloon. The distal jejunum was inhibited. SVA showed a pattern of hyperactivity and quiescence corresponding to proximal jejunal activity. In the clinical situation, SVA recordings taken after a standard meal in nine patients with suspected chronic obstruction adhesive obstruction, (subsequently proven in seven patients and disproved in two), and 36 volunteers were compared. All patients with proved obstruction showed an SVA pattern of alternating hyperactivity and quiescence. This pattern was not observed in volunteers or nonobstructed patients. 相似文献
9.
10.
The effects of aging on levels of neurotransmitters were determined in two regions of the cerebral cortex in rhesus monkeys (Macaca mulatta). Choline acetyltransferase (ChAT) activity as well as somatostatin, neuropeptide Y, and substance P immunoreactivities were analyzed in the right caudal cingulate gyrus and in the left and right inferior occipital poles in five age groups: 4-6 years; 8-11 years; 20-25 years; 26-29 years; and 31-34 years. Neuroactive amino acids and markers for monoamine transmitters were analyzed only in the youngest (4-6 years) and oldest (31-34 years) animals. Across the five age groups studied. ChAT activity as well as somatostatin and neuropeptide Y immunoreactivities were significantly decreased bilaterally in occipital poles of the 31- to 34-year-old group. There were no significant age-related differences in substance P immunoreactivity. In 4-6-year-old vs. 31-34-year-old monkeys, levels of amino acid neurotransmitters were unchanged. However, there were significant reductions in norepinephrine, serotonin and its metabolites, kynurenine, and 4-hydroxyphenyllactic acid in occipital poles of the 31- to 34-year-old monkeys. No significant neurochemical changes were detected in the cingulate cortex. These findings demonstrate that aged nonhuman primates show reductions in cortical markers for a variety of neurotransmitters, including acetylcholine, somatostatin, neuropeptide Y, norepinephrine, and serotonin but that these changes do not occur uniformly in the neocortex. 相似文献