全文获取类型
收费全文 | 21667篇 |
免费 | 1522篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 350篇 |
儿科学 | 586篇 |
妇产科学 | 422篇 |
基础医学 | 2598篇 |
口腔科学 | 325篇 |
临床医学 | 2215篇 |
内科学 | 4685篇 |
皮肤病学 | 480篇 |
神经病学 | 2055篇 |
特种医学 | 747篇 |
外科学 | 3190篇 |
综合类 | 316篇 |
现状与发展 | 1篇 |
一般理论 | 18篇 |
预防医学 | 2103篇 |
眼科学 | 524篇 |
药学 | 1420篇 |
中国医学 | 25篇 |
肿瘤学 | 1202篇 |
出版年
2023年 | 108篇 |
2022年 | 163篇 |
2021年 | 478篇 |
2020年 | 295篇 |
2019年 | 451篇 |
2018年 | 562篇 |
2017年 | 397篇 |
2016年 | 448篇 |
2015年 | 504篇 |
2014年 | 730篇 |
2013年 | 1035篇 |
2012年 | 1501篇 |
2011年 | 1558篇 |
2010年 | 851篇 |
2009年 | 811篇 |
2008年 | 1340篇 |
2007年 | 1468篇 |
2006年 | 1379篇 |
2005年 | 1365篇 |
2004年 | 1355篇 |
2003年 | 1196篇 |
2002年 | 1064篇 |
2001年 | 256篇 |
2000年 | 233篇 |
1999年 | 264篇 |
1998年 | 265篇 |
1997年 | 188篇 |
1996年 | 178篇 |
1995年 | 170篇 |
1994年 | 144篇 |
1993年 | 125篇 |
1992年 | 166篇 |
1991年 | 142篇 |
1990年 | 123篇 |
1989年 | 149篇 |
1988年 | 114篇 |
1987年 | 107篇 |
1986年 | 122篇 |
1985年 | 120篇 |
1984年 | 128篇 |
1983年 | 87篇 |
1982年 | 104篇 |
1981年 | 118篇 |
1980年 | 82篇 |
1979年 | 87篇 |
1978年 | 72篇 |
1977年 | 79篇 |
1976年 | 52篇 |
1975年 | 54篇 |
1971年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Neil H Pliskin Alia N Ammar Joseph W Fink S Kristian Hill Aaron C Malina Alona Ramati Kathleen M Kelley Raphael C Lee 《Journal of the International Neuropsychological Society》2006,12(1):17-23
The clinical presentation of electrical injury commonly involves physical, cognitive, and emotional complaints. Neuropsychological studies, including case reports, have indicated that electrical injury (EI) survivors may experience a broad range of impaired neuropsychological functions, although this has not been clarified through controlled investigation. In this study, we describe the neuropsychological test findings in a series of 29 EI patients carefully screened and matched to a group of 29 demographically similar healthy electricians. Participants were matched by their estimated premorbid intellectual ability. Multivariate analysis of variance was used to assess group differences in the following neuropsychological domains: attention and mental speed, working memory, verbal memory, visual memory, and motor skills. EI patients performed significantly worse on composite measures of attention/mental speed and motor skills, which could not be explained by demographic differences, injury parameters, litigation status, or mood disturbance. Results suggest that cognitive changes do occur in patients suffering from electrical injury. 相似文献
12.
BACKGROUND: Recent guidelines suggest supplementation with ergocalciferol (vitamin D(2)) in chronic kidney disease stages 3 and 4 patients with elevated parathyroid hormone (PTH) levels and 25-hydroxyvitamin D (25OHD) levels <75 nmol/l. These guidelines are also applied to renal transplant patients. However, the prevalence rates of 25OHD deficiency and its association with PTH levels in renal transplant populations have not been extensively examined. We aimed to document the prevalence rates of 25OHD deficiency [defined by serum levels <40 nmol/l (<16 ng/ml)] and insufficiency [<75 nmol/l (<30 ng/ml)] in a single renal transplant centre, and examine its relationship with PTH levels. METHODS: Serum 25OHD and PTH concentrations were measured in 419 transplant patients attending a single renal transplant clinic over a 4-month period. Demographic and biochemical data were also collected, including serum creatinine, calcium, phosphate and albumin. Simple and multiple linear regression analysis were performed. RESULTS: In 27.3% of the patients, 25OHD deficiency was present, and 75.5% had insufficiency. On univariate analysis, 25OHD, serum albumin and estimated glomerular filtration rate (eGFR) were significantly associated with PTH levels (P < 0.0001, P = 0.004 and P < 0.0001, respectively). Multiple linear regression demonstrated that only 25OHD, eGFR and serum phosphate were significantly predictive of PTH levels (R(2) = 0.19, P < 0.0001). In this model, a 75 nmol/l increase in 25OHD will only result in a maximal reduction in PTH of 2.0 pmol/l. CONCLUSIONS: We conclude that 25OHD deficiency and insufficiency are common in renal transplant patients and may exacerbate secondary hyperparathyroidism. However, 25OHD, eGFR and phosphate only account for 19% of the variability in PTH levels. In addition, even a large increase in serum 25OHD levels is likely to result in only a small reduction in PTH. Therefore, alternative approaches to managing hyperparathyroidism in renal transplant recipients rather than supplementation with ergocalciferol are warranted. 相似文献
13.
S F Wong A Lee-Tannock D Amaraddio F Y Chan H D McIntyre 《Ultrasound in obstetrics & gynecology》2006,28(7):934-938
OBJECTIVE: To assess the effect of glucose control on the rate of growth of fetuses in women with pregestational diabetes mellitus (Types 1 and 2). METHODS: All pregestational diabetic women booked at Mater Mothers' Hospital, Brisbane, Australia, between 1 January 1994 and 31 December 2002, were included. Pregnancies with congenital fetal anomalies, multiple pregnancies, and pregnancies terminated prior to 20 weeks' gestation were excluded. Dating scans were performed before 14 weeks' gestation and serial scans were performed at 18, 24, 28, 32 and 36 weeks. Fetal parameters, including biparietal diameter, femur length and abdominal circumference, were recorded. The daily growth rates for biparietal diameter, femur length, and fetal abdominal area were calculated and compared with those in a low-risk (non-diabetic) population. The growth rates in fetuses of women with satisfactory diabetic control (HbA1c < 6.5%) and unsatisfactory control (HbA1c > or = 6.5%) in the three trimesters were compared. RESULTS: A total of 174 diabetic pregnancies were included and a total of 997 ultrasound scans were performed. The growth rates for fetuses of mothers with diabetes mellitus were significantly higher than for those in the low-risk population. The z-scores for biparietal diameter, femur length, and fetal abdominal area were 0.18, 0.59 and 1.44, respectively. Fetuses of diabetic mothers with high HbA1c in the first trimester had significantly greater fetal abdominal area growth rate than those with normal HbA1c (fetal abdominal area z-score of 1.7 vs. 0.75, P = 0.009). Although the fetal abdominal area z-scores in fetuses of diabetic mothers with high HbA1c in the second or third trimesters were also higher than those with normal HbA1c levels, the differences did not reach statistical significance. Maternal obesity did not influence the fetal growth rate. CONCLUSION: The rate of growth of fetuses of diabetic mothers differs from that of the normal population. Growth acceleration persists until the late third trimester. Moreover, periconceptional glucose control appears to have a significant effect on accelerated growth of the fetal abdominal area. 相似文献
14.
Caroline A. Harrison BMedSci MRCS ; Martin J. Heaton MD FRCS ; Christopher M. Layton PhD ; Sheila Mac Neil PhD 《Wound repair and regeneration》2006,14(2):203-209
To produce a stable epidermis, keratinocytes need to be firmly attached to the basement membrane. However, following wounding, keratinocytes are required to develop a migratory phenotype in order to reepithelialize the wound. To investigate some of the issues underlying reepithelialization, we have developed a three-dimensional in vitro model of tissue-engineered skin, comprising sterilized human dermis seeded with human keratinocytes and dermal fibroblasts. Using this model, we have shown that the inclusion of fibroblasts within the model increases the stability of keratinocyte attachment. We have also demonstrated that keratinocyte migration occurs most effectively in the absence of a basement membrane and following the inclusion of fibroblasts in the model. In addition, subjecting the keratinocyte layer to mechanical trauma induces a migratory phenotype. We conclude that this three-dimensional in vitro wound model can be used to increase our understanding of the factors that enhance keratinocyte migration and hence wound healing in vivo. 相似文献
15.
Neil Harrington 《Cognitive therapy and research》2006,30(6):699-709
Beliefs regarding the toleration of frustration and discomfort are often described as underlying psychological disturbance, and represent a fundamental concept in Rational Emotive Behavior Therapy (REBT). Nevertheless, there has been little systematic analysis of the content of these beliefs, which are often treated as a unidimensional construct. This paper investigates the relationship between a multidimensional Frustration Discomfort Scale (FDS) and measures of depressed mood, anxiety, and anger, in a clinical population. Results indicated that FDS sub-scales were differentially related to specific emotions, independent of self-esteem and negative affect. The entitlement sub-scale was uniquely associated with anger, discomfort intolerance with depressed mood, and emotional intolerance with anxiety. These results supported the validity of the FDS, the importance of distinguishing between frustration intolerance dimensions, and of separating these beliefs from those related to self-worth.Copies of the Frustration Discomfort Scale are available from the author on request 相似文献
16.
Karen MacKinnon Marjorie McIntyre 《Revue canadienne de recherche en sciences infirmières》2006,38(2):56-72
With the recent introduction of preterm birth prevention programs there has been a shift in our understanding of what the presence of contractions during pregnancy means and a reconstituting of risk in ways that position increasing numbers of women at risk for preterm birth. This paper highlights the findings of a study exploring the influences of risk discourses on women's experiences of preterm labour. The primary goals of this institutional ethnographic study were to describe the effects of societal discourses, institutional structures, and nursing work processes on the everyday lives of childbearing women experiencing preterm labour. The findings suggest that risk discourses exert social control over pregnant women and result in fear, guilt, feelings of being judged or punished, and an overwhelming sense of personal responsibility for preventing preterm birth.The study also exposes ways in which biomedical constructions of risk and preterm labour affect the organization of health services, including nursing practice. 相似文献
17.
A wound, in the broadest sense, is a disruption of normal anatomic structure and function. Acute wounds progress through a timely and orderly sequence of repair that leads to the restoration of functional integrity. In chronic wounds, this timely and orderly sequence goes awry. As a result, people with chronic wounds often face not only physiological difficulties but emotional ones as well. The study of body image and its damage as a result of a chronic wound fits well with Selder's transition theory. This article describes interviews with seven patients with chronic wounds. The themes that emerged from those interviews were compared with Selder's theory to describe patients' experience with chronic wounds as a transition process that can be identified and better understood by healthcare providers. 相似文献
18.
Timothy Threlfall Neil Kent Peter Garcia-Webb Elizabeth Byrnes Paul Psaila-Savona 《Australian and New Zealand journal of public health》1993,17(4):379-381
Abstract: This study reports on an analysis of the lead concentrations in 123 venous blood samples collected from Perth children aged between two months and 17 years attending Princess Margaret Hospital. The overall geometric mean was 6.9 μg lead per 100 ml whole blood, with 95 per cent of results lying between 3.2 and 14.8 μg/100 ml. Among children under five years of age, those aged between 18 months and two years had the highest geometric mean blood lead (11.1 μg/100 ml). There were no consistent associations between geometric mean blood lead and area of residence, age group or sex. In this sample of Perth children, the mean blood lead concentration was lower than those reported in other studies. Less than 0.1 per cent of children of the age range studied would have been expected to have lead levels exceeding the NHMRC ‘level of concern’ (25 μg/100 ml) current at the time of the study. However, the recent adoption of goal of less than 10 μg/100 ml could mean that lead levels in up to 21 per cent of Perth children would now be regarded as excessive. 相似文献
19.
20.
Dorsal wedge osteotomy of the proximal phalanx for hallux rigidus. Long-term results 总被引:1,自引:0,他引:1
Eight women had 10 toes treated for hallux rigidus by dorsal wedge osteotomy of the proximal phalanx and were reviewed after an average follow-up of 22 years. Five toes were symptom-free, four others did not restrict walking, and only one had required metatarsophalangeal fusion. We conclude that dorsal wedge osteotomy affords long-lasting benefits for hallux rigidus in the adolescent female. 相似文献