全文获取类型
收费全文 | 1471篇 |
免费 | 91篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 39篇 |
妇产科学 | 81篇 |
基础医学 | 191篇 |
口腔科学 | 50篇 |
临床医学 | 247篇 |
内科学 | 261篇 |
皮肤病学 | 56篇 |
神经病学 | 106篇 |
特种医学 | 31篇 |
外科学 | 102篇 |
综合类 | 8篇 |
一般理论 | 2篇 |
预防医学 | 194篇 |
眼科学 | 13篇 |
药学 | 70篇 |
中国医学 | 19篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 33篇 |
2020年 | 15篇 |
2019年 | 35篇 |
2018年 | 30篇 |
2017年 | 44篇 |
2016年 | 33篇 |
2015年 | 43篇 |
2014年 | 50篇 |
2013年 | 114篇 |
2012年 | 138篇 |
2011年 | 106篇 |
2010年 | 70篇 |
2009年 | 51篇 |
2008年 | 93篇 |
2007年 | 82篇 |
2006年 | 94篇 |
2005年 | 93篇 |
2004年 | 83篇 |
2003年 | 62篇 |
2002年 | 63篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1998年 | 21篇 |
1997年 | 11篇 |
1996年 | 9篇 |
1995年 | 17篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1974年 | 4篇 |
1967年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1569条查询结果,搜索用时 15 毫秒
61.
BACKGROUND: Gastric lipase contributes significantly to overall lipolysis and is regulated by interacting neuro-hormonal mechanisms. Patients with alcoholic chronic pancreatitis (ACP) have low, or even absent, activity of pancreatic lipases. In that state the secretion of gastric lipase could be essential and compensate for the pancreatic defect. However, conflicting studies have not resolved the order of magnitude of gastric lipase secretion in these patients. This could be explained by differences in regulatory mechanisms, gastric mucosal changes, and abdominal vagal tone. METHODS: Nasogastric intubation with modified sham feeding and upper endoscopy including biopsies for histologic classification and Helicobacter pylori infection status were performed in eight ACP patients, and eight healthy volunteers were studied on separate occasions. Vagal nerve function was assessed by calculation of heart rate variability in ACP patients. Gastric lipase was measured in aspirates by means of enzyme-linked immunosorbent assay and an enzyme kinetic assay. Plasma concentrations of gastrin, secretin, cholecystokinin, and pancreatic polypeptide were measured throughout the study. RESULTS: Sham feeding rapidly and significantly increased gastric lipase secretion in healthy volunteers, whereas ACP patients did not respond to sham feeding. Two of eight patients were infected with H. pylori and had mucosal changes accordingly. The lack of lipase response could not be ascribed to dysfunction of the abdominal vagus. CONCLUSIONS: The cephalic phase of gastric lipase secretion is impaired in ACP patients. Although their fundic cells continue to secrete gastric lipase, they are not subject to normal neuro-hormonal regulation. 相似文献
62.
Background
In this study the focus is on social insurance officers judging applications for disability pensions. The number of applications for disability pension increased during the late 1990s, which has resulted in an increasing number of disability pensions in Sweden. A more restrictive attitude towards the clients has however evolved, as societal costs have increased and governmental guidelines now focus on reducing costs. As a consequence, the quantitative and qualitative demands on social insurance officers when handling applications for disability pensions may have increased. The aim of this study was therefore to describe the social insurance officers' experiences of assessing applications for disability pensions after the government's introduction of stricter regulations. 相似文献63.
Psoriasis is one of the most common chronic skin diseases. The author presented results from a qualitative study focusing on patients with severe psoriasis in an acute phase and their experience of living with the disease. Twenty-two hospitalized patients with psoriasis were interviewed in depth. The interviews were consecutively analyzed according to grounded theory methodology. Bodily suffering emerged as a core variable in the data. Bodily suffering includes the following categories: the visible body, staying on an even keel, coping with an all-consuming disease, and social vulnerability. The results of this study indicate that the criterion for the management of soriasis should be the patients' own perception of the consequences of the disease. 相似文献
64.
Cepok S Zhou D Vogel F Rosche B Grummel V Sommer N Hemmer B 《Archives of neurology》2003,60(6):849-855
BACKGROUND: Borrelia burgdorferi causes a wide range of neurologic syndromes. In Europe, acute meningoradiculitis is the most common manifestation. OBJECTIVE: To address the nature of the immune response during the course of B burgdorferi meningoradiculitis, with special respect to the early and late changes in cerebrospinal fluid (CSF). METHODS: Serial immunophenotyping was performed and cytokine measurements were obtained in the peripheral blood and CSF of 12 European patients with definite B burgdorferi meningoradiculitis. RESULTS: Early during infection and before initiation of treatment, we observed high levels of interleukin (IL) 10, IL-6, and IL-8, and large numbers of B cells and plasma cells in the CSF of most patients. At the same time, we found a mainly unspecific intrathecal antibody synthesis. During resolution of the infection, cytokine levels normalized rapidly and plasma cells disappeared from the CSF. In parallel, the percentage of B cells in the CSF increased over several months, accompanied by rising levels of intrathecally produced B burgdorferi-specific antibodies. CONCLUSIONS: Our findings demonstrate that the early phase of B burgdorferi meningoradiculitis is characterized by a well-coordinated immune response involving specific cytokine release and plasma cell recruitment, followed by a long-lasting, antigen-specific B-cell response in the central nervous system. 相似文献
65.
Increased risk of stroke in hypertensive women using hormone therapy: analyses based on the Danish Nurse Study 总被引:3,自引:0,他引:3
Løkkegaard E Jovanovic Z Heitmann BL Keiding N Ottesen B Hundrup YA Obel EB Pedersen AT 《Archives of neurology》2003,60(10):1379-1384
BACKGROUND: Recent randomized clinical trials suggest an increased risk of stroke with hormone therapy (HT), whereas observational studies have suggested mixed results. Differences in design, definitions of HT exposure, and stroke outcome may explain these discrepancies. Little attention has been paid to identifying subgroups of women who are particularly sensitive to HT. OBJECTIVES: To investigate the risk of various stroke outcomes among women using HT based primarily on estradiol-17beta (unopposed or combined with norethisterone acetate) and to assess the potential modifying effect by presence of risk factors for stroke. DESIGN: Prospective cohort study. SETTING: In 1993, the Danish Nurse Study was established, and questionnaires on lifestyle and HT use were sent to all Danish nurses older than 44 years, of whom 19,898 (85.8%) replied. PARTICIPANTS: Postmenopausal women (n = 13,122) free of previous major cardiovascular and cerebrovascular disease and cancer. MAIN OUTCOME MEASURE: Ischemic or hemorrhagic stroke (n = 144) identified in the national registries of hospital discharges and cause of deaths in the total follow-up through December 31, 1998. RESULTS: In 1993, 28.0% of the 13 122 were current HT users, 14.3% were past users, and 57.7% were never users. Overall, HT exposure was not consistently associated with stroke. However, subdivision based on the presence of hypertension showed a significantly increased risk of stroke among hypertensive women. Compared with hypertensive never HT users, an increased risk of total stroke was found with current use (hazard ratio, 2.35; 95% confidence interval, 1.16-4.74) and especially with current use of estrogen-progestin (hazard ratio, 3.00; 95% confidence interval, 1.33-6.76). Normotensive women had no increased risk of stroke with HT. CONCLUSIONS: We found an increased risk of stroke among hypertensive but not normotensive women using HT. The present study suggests that HT should be avoided in hypertensive women. 相似文献
66.
Marchini G Ståbi B Kankes K Lonne-Rahm S Østergaard M Nielsen S 《Pediatric dermatology》2003,20(5):377-384
Erythema toxicum neonatorum is a common, inflammatory skin reaction in healthy newborn infants characterized by an accumulation of activated immune cells in the lesions. Its etiology and physiologic significance are still unclear. The purpose of this study was to extend the search for possible inflammatory mediators of the rash. We performed immunohistochemistry on punch biopsy cryosections from lesions of four, 1-day-old infants and from four matched controls without rash, using antibodies against the water channel proteins aquaporin-1 (AQP1) and aquaporin-3 (AQP3), psoriasin, and the nitric oxide synthase (NOS) enzymes, neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). All sections from the lesions showed a dense, nodular cellular infiltrate located near the hair follicle. The vessels in the dermis showed a high incidence of AQP1 and eNOS. Strong staining for AQP1, AQP3, and psoriasin, as well as nNOS, iNOS, and eNOS were seen in the entire epidermal layer. The infiltrate in the dermis contained numerous cells expressing AQP1, AQP3, nNOS, iNOS, and eNOS. Double immunofluorescence staining showed that AQP3 was located in CD1a-expressing Langerhans cells and other dendritic cells in the dermis, as well as in CD14-expressing macrophages, CD15-expressing neutrophils, and EG2-expressing eosinophils surrounding the hair follicle. Our findings show that AQP1 and AQP3, psoriasin, and NOSs are involved in the activation of the skin immune system at birth. 相似文献
67.
BACKGROUND: Weight loss may be associated with unfavorable changes in body composition not compensated for by subsequent weight gain. OBJECTIVE: We examined the composition of weight change in relation to obesity, previous weight changes, weight-loss attempts, and physical activity. DESIGN: Part of the Danish MONICA (Monitoring Trends in Cardiovascular Disease) project, this was a longitudinal population study of changes in weight and body composition, with examinations in 1982-1983, 1987-1988, and 1993-1994. A total of 1236 men and 1200 women aged 35, 45, 55, or 65 y in 1987-1988 participated. Changes in fat and fat-free mass were measured by bioelectrical impedance. RESULTS: Before adjustment for age-related changes, fat-free mass made up 41% of weight lost and 24% of weight gained in men. In women, loss of fat-free mass (35%) was more than double that of gains (15%). After adjustment, the fractions of weight gained as fat-free mass were not significantly different from the fractions lost. These fractions were independent of age, obesity, and weight changes in the previous 5 y; successful weight-loss attempts; and physical activity. Independent of age and degree of obesity, weight changes were associated with greater changes in fat-free mass in men than in women. CONCLUSIONS: These data do not support the theory that weight loss or weight cycling may lead to an unfavorable body composition, nor do they provide a biological explanation for why long-term weight loss is often unsuccessful. However, the metabolic and health consequences of weight change may differ in men and women. 相似文献
68.
Dithiocarbamates, a class of compounds widely used in medicine and agriculture, have been reported to impair sleep structure. These effects have been attributed to the decrease in norepinephrine levels induced by these drugs. However, it has also been recently demonstrated that most of the mechanisms by which dithiocarbamates damage cell function involve changes in oxidative environment. To verify the potential relevance of the latter mechanism in the sleep impairment, we examined the sleep response of adult rats to an acute administration of diethyldithiocarbamate (DDTC). At the dose of 0.6 g/kg, DDTC induced fragmentation and a decrease in slow wave sleep (SWS), and a dramatic loss of paradoxical sleep (PS). These changes occurred soon after the treatment (day 0), persisted the following day (day 1), partially recovered on day 3, and regained near basal values on day 6. No sleep anomalies were observed with a lower dose of DDTC (0.06 mg/kg). On the other hand, when the higher dose of DDTC was given in association with either one of two antioxidants, alpha-tocopherol or melatonin, the amounts of SWS and PS significantly improved even on day 1, suggesting that the DDTC effects on sleep involved an impairment of the brain oxidative balance. Likewise, administration of the lower dose of DDTC 5 days before the higher dose induced a much earlier recovery of normal sleep, presumably due to the development of a tolerance to DDTC. On the whole, the data suggest that the brain oxidative environment may play a role in the mechanisms subserving sleep regulation. 相似文献
69.
Ingersoll-Dayton B Krause N Morgan D 《International journal of aging & human development》2002,55(1):51-70
This study examined patterns of change and stability in religiosity over the life course. Open-ended interviews with 129 adults aged 65 and older provided a rich source of data for applying a life course perspective to the study of religion. Two theoretical constructs from the life course perspective (i.e., trajectories and transitions) were used as a framework for understanding religion and aging. The interviews were content analyzed to identify: 1) dimensions of religiosity that exhibit change; 2) patterns of religious trajectories; and 3) social forces that promote changes in religiosity. These analyses revealed four distinct patterns: stable, increasing, decreasing, and curvilinear trajectories. Several forces were involved with either increasing religiosity (e.g., child rearing, adverse life experiences) or decreasing religiosity (e.g., disillusionment with church members, adverse life experiences). Directions for future research are discussed. 相似文献
70.
The help that elders provide to their adult children has received limited attention in the caregiving literature. To address this gap, data were drawn from two samples of caregiving couples: 63 focus group participants and 618 survey respondents. Survey results indicated that help from aging parents is associated with a complex pattern of benefits and costs. Focus group data identified the kinds of help provided by older parents (i.e., financial, emotional, child care, and household tasks) and illuminated why caregivers experience such help as a mixed blessing. Suggestions are offered for practitioners who work with caregivers. 相似文献