全文获取类型
收费全文 | 2520篇 |
免费 | 121篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 108篇 |
妇产科学 | 76篇 |
基础医学 | 389篇 |
口腔科学 | 29篇 |
临床医学 | 253篇 |
内科学 | 446篇 |
皮肤病学 | 43篇 |
神经病学 | 144篇 |
特种医学 | 135篇 |
外科学 | 417篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 151篇 |
眼科学 | 109篇 |
药学 | 209篇 |
中国医学 | 10篇 |
肿瘤学 | 105篇 |
出版年
2022年 | 22篇 |
2021年 | 40篇 |
2020年 | 16篇 |
2019年 | 28篇 |
2018年 | 35篇 |
2017年 | 29篇 |
2016年 | 40篇 |
2015年 | 48篇 |
2014年 | 68篇 |
2013年 | 90篇 |
2012年 | 104篇 |
2011年 | 120篇 |
2010年 | 65篇 |
2009年 | 79篇 |
2008年 | 134篇 |
2007年 | 140篇 |
2006年 | 104篇 |
2005年 | 103篇 |
2004年 | 92篇 |
2003年 | 90篇 |
2002年 | 74篇 |
2001年 | 71篇 |
2000年 | 51篇 |
1999年 | 68篇 |
1998年 | 49篇 |
1997年 | 42篇 |
1996年 | 40篇 |
1995年 | 34篇 |
1994年 | 34篇 |
1993年 | 37篇 |
1992年 | 52篇 |
1991年 | 45篇 |
1990年 | 35篇 |
1989年 | 33篇 |
1988年 | 47篇 |
1987年 | 42篇 |
1986年 | 36篇 |
1985年 | 38篇 |
1984年 | 31篇 |
1983年 | 19篇 |
1982年 | 18篇 |
1980年 | 21篇 |
1979年 | 19篇 |
1978年 | 21篇 |
1976年 | 17篇 |
1975年 | 17篇 |
1974年 | 18篇 |
1971年 | 14篇 |
1970年 | 19篇 |
1967年 | 14篇 |
排序方式: 共有2671条查询结果,搜索用时 15 毫秒
1.
There is some evidence suggesting that Parkinson's disease (PD) patients exhibit lower body weight when compared to age-matched healthy subjects. Low body mass index (BMI) is correlated with low bone mineral density, both of which are major risk factors for hip fractures. Possible determinants of weight loss in PD patients include hyposmia, impaired hand-mouth coordination, difficulty chewing, dysphagia, intestinal hypomotility, depression, decreased reward processing of dopaminergic mesolimbic regions, nausea, and anorexia as the side effects of medication, and increased energy requirements due to muscular rigidity and involuntary movements. It is unclear whether PD patients in general, or only a subgroup of those affected, definitely show lower BMI in the advanced stages of the disease. We therefore recommend that the body weight of PD patients be monitored monthly as the disease progresses, and that a patient's nutrition should be supplemented with sufficient amounts of vitamin D and calcium to reduce the risk of hip fractures and strengthen bone density. Because meal times may coincide with unpredictable off periods associated with akinesia and impaired hand-mouth coordination, PD patients also need flexible food schedules that accommodate the associated symptoms of this disease. 相似文献
2.
3.
OBJECTIVE: The aim of this study was to assess the severity of epilepsy and
its effect on patients lives, and to describe patients' use of and
attitudes to health care. METHOD: A questionnaire was sent to 595 people
with epilepsy identified from 14 general practices in north-west Bristol.
All patients aged 16 years and over receiving anti-epileptic medication for
their epilepsy were included in the study. Areas investigated included
severity of epilepsy and its effect on quality of life, anti-epileptic
medication and its perceived effect, health care utilization and
preferences for health care. RESULTS: Seizure frequency was strongly
associated with adverse effects of epilepsy. Attacks of epilepsy were
experienced at least monthly by 20.4% (95% confidence intervals (Cl)
17.0-23.7%) of patients, 29.4% (25.4-33.4%) took more than one
anti-epileptic drug, 56.1% (50.1-62.2%) reported drug side effects, 74.1%
(70.3-77.8%) would prefer to receive all or most of their epilepsy care in
a general practice setting, and 69.8% (63.5- 76.2%) would like contact with
a primary care-based epilepsy specialist nurse. During the previous year
42.4% (35.9-48.8%) of patients had not seen a doctor about their epilepsy.
Of patients who had attended the general practice only 13.4% (9.6-17.2%)
had regular arrangements to see their GP about epilepsy. Patients receiving
both primary and secondary care had the greatest needs and wants for
improved care. CONCLUSIONS: Structured care, including regular
appointments, co-ordination of primary and secondary care, and increased
monitoring and discussion, may improve the quality of life of people with
epilepsy, but requires evaluation.
相似文献
4.
K Bachmann T J Sullivan L S Mauro M Martin L Jauregui L Levine 《Journal of clinical pharmacology》1992,32(5):476-482
The influence of usual regimens of the H2 blocking drugs, cimetidine, ranitidine, and nizatidine on the steady-state plasma concentrations and pharmacokinetic characteristics of theophylline was studied in seventeen patients with chronic obstructive pulmonary disease (COPD). Patients were dosed to steady-state with an oral, sustained-release formulation of theophylline given in therapeutic doses twice daily for 2 weeks. Over the next 4 weeks, each patient received a week-long regimen of each H2 blocker concomitantly with theophylline, and a week-long regimen of theophylline alone (control). At the end of each of the latter 4 weeks the steady-state pharmacokinetics of theophylline were assessed. Neither ranitidine nor nizatidine treatment altered the steady-state pharmacokinetics of theophylline relative to the control phase (i.e. no H2 blocker treatment). Values for theophylline C(ave), Cssmax, AUC0-12, and CLoral were significantly different during cimetidine treatment compared with all other treatments (ranitidine, nizatidine, and control). Cimetidine increased theophylline Cssmax, AUC0-12 and Cave by approximately 32%, and decreased theophylline oral clearance by approximately 23%. The authors conclude that cimetidine alters the steady-state pharmacokinetics of theophylline in COPD patients, whereas ranitidine and nizatidine are without effect. 相似文献
5.
The role of various subfamilies of rat hepatic cytochrome P450 in the oxidation of ethosuximide was evaluated by comparing ethosuximide clearance in control rats and those pretreated with relatively selective P450 inducers and/or inhibitors. Clotrimazole pretreatment increased ethosuximide clearance threefold (p less than 0.005). Dexamethasone increased ethosuximide clearance twofold (p less than 0.001), and the dexamethasone effect was completely abolished by a single dose of triacetyloleandomycin. These results suggest a prominent role for cytochrome P450IIIA in ethosuximide metabolism in the rat. Isoniazid increased ethosuximide clearance twofold (p less than 0.001), and this effect was abolished by a single dose of diallylsulfide, suggesting that ethosuximide is also processed by cytochrome P450IIE1 in rats. Phenobarbital pretreatment increased ethosuximide clearance 2-2.7 fold (p less than 0.001); an effect that was only partially reversed by orphenadrine, an inhibitor of cytochrome P450IIB/IIC enzymes. This suggests a quantitatively less important role for the IIB/IIC subfamilies in processing ethosuximide, since phenobarbital is an inducer of P450 subfamilies IIB, IIC, IIE, and IIIA. Neither the cytochrome P450IA inducer, beta-naphthoflavone, nor the inhibitor, alpha-naphthoflavone altered ethosuximide clearance. Ajmaline, an inhibitor of cytochrome P450IID, had no effect on ethosuximide clearance. Together, these findings suggest that ethosuximide is principally oxidized by cytochrome P450IIIA, and that cytochrome P450IIE may play an important role. Cytochromes P450IIB/C play less prominent roles in ethosuximide oxidation, and neither cytochrome P450IA nor cytochrome P450IID is involved. 相似文献
6.
7.
M. O. Bachmann M. O'Brien † C. Husbands ‡ A. Shreeve § N. Jones ¶ J. Watson § R. Reading J. Thoburn † M. Mugford the National Evaluation of Children's Trusts Team 《Child: care, health and development》2009,35(2):257-265
Background Poor co‐ordination of services can have severe consequences for disadvantaged children with complex needs. Since 2003 national and local governments in England embarked on sweeping reforms aimed at improving and integrating local health, education and social services for children. These were to be organized locally by children's trusts and piloted by 35 children's trust pathfinders. Methods This study described and compared the experience of integrating children's services in all 35 children's trust pathfinders, covering 20% of children in England. It had a prospective mixed‐methods design. Over 3 years we interviewed 147 managers and professionals working in the children's trusts, including 172 semi‐structured interviews, carried out two questionnaire surveys of the 35 children's trusts and analysed official documents. Results In most areas different agencies jointly commissioned children's services, especially for mental health, disabilities and multi‐purpose children's centres, and increasingly pooled finances. Provision of multi‐agency and multi‐professional services was increasing. Professionals generally supported these changes but found them stressful. All children's trusts appointed directors of children's services and established boards representing multiple agencies. Systems for sharing information about individual children were mostly in place but were still underused. Health services were generally less involved in joint work than were local authorities' education and social care services, with notable exceptions. Areas where local authorities and health authorities shared geographical boundaries made most progress. Some children's trusts made few changes beyond their statutory obligations. Conclusion Children's trusts enabled major changes to services in areas where local actors and organizations were motivated and empowered. In other areas the remit of children's trusts was often too broad and vague to overcome entrenched organizational and professional divisions and interests. Policymakers need to balance facilitation of change in areas with dynamic change agents with methods for ensuring that dormant areas and agencies are not left behind. 相似文献
8.
R Bachmann B Genin P Bugmann D Belli S Hanquinet P Liniger C Le Coultre 《Zeitschrift für Kinderchirurgie》2003,13(4):280-284
Although benign, hepatic haemangioendotheliomas (HHE) are rare vascular tumours of the infant which have a high mortality rate secondary to high output congestive heart failure. The management of these tumours is still controversial and none of the different medical or surgical options has been unanimously accepted. We report the case of a neonate with congestive heart failure (CHF) due to a localized HHE, treated successfully by selective ligation of the left hepatic artery branch irrigating the tumour, under perioperative ultrasound Doppler control. A review of the literature showed 35 cases of HHE treated by hepatic artery ligation (HAL) with a survival rate of 80 %. 相似文献
9.
Michael Sørensen M.D. Michael Bachmann Nielsen M.D. Jan Fog Pedersen M.D. Ph.D. John Christiansen M.D. Ph.D. 《Diseases of the colon and rectum》1994,37(2):138-143
PURPOSE: The aim of our study was to investigate internal anal sphincter electromyographic signals. METHODS: Electromyography of the internal anal sphincter was performed with platinum wire electrodes in six healthy volunteers (three males and three females), inserted under endosonographic guidance. Platinum wire electrodes were also inserted into the external anal sphincter. Activity of both the internal and external anal sphincter in a 40-second period was measured. RESULTS: Internal anal sphincter median activity was 22.1 (range, 5.5–67.6) μ V. Slow-wave activity was 47 cycles/minute (range, 34–55 cycles/minute). After inflation of a rectal balloon with air until a constant relaxation of the anal canal was obtained, a decrease in internal anal sphincter activity to 15.9 (1.2–31.3) μV as well as a decrease in slow-wave activity to 34 cycles/minute (range, 27–40 cycles/minute) was found. The original internal anal sphincter EMG was resumed after deflation of the rectal balloon. External anal sphincter median activity was 31 (range, 0.77–18.6)μV. During inflation of the rectal balloon, a reflex increase in external sphincter EMG activity was found. With the rectal balloon fully inflated a part of this increase was still present, 11.0 (1.9–24.6)μV. In some of the subjects, this increased activity was superimposed on the internal anal sphincter recordings as well. During a voluntary squeeze it was not possible to identify internal anal sphincter activity due to activity of the external anal sphincter totally overriding the internal anal sphincter signal. CONCLUSION: Precise EMG recordings from the internal anal sphincter is possible with endosonographic guidance of the electrodes, except during voluntary squeezing of the external anal sphincter. 相似文献
10.
Hans Knecht Pierre Brousset Edith Bachmann Gorm Pallesen Bernhard F. Odermatt 《Leukemia & lymphoma》1994,15(5):399-403
Two recently discovered genes, the recombination activating genes 1 and 2 (RAG-1 and RAG-2), are necessary to perform variable (V), diversity (D), and joining (J) recombination. They synergistically activate VDJ recombination to generate immunocompetent lymphocytes. Disruption of either gene results in a maturation arrest at a very early B and T cell progenitor stage. Expression and downregulation of RAG's are closely associated with interleukin 7, sIgM and TCR-CD3 complex, respectively. Assessment of RAG mRNA expression is a valuable marker in identifying the genotypic maturation status of leukemias and lymphomas. Persistent RAG expression in otherwise mature lymphoid proliferations may explain puzzling biological and clinical observations such as multiple rearrangements in lymphomas with a mature phenotype. Lack of RAG expression in Hodgkin's disease with abundant Reed-Stern-berg cells is consistent with a mature phenotype of the latter. Availability of a anti-RAG-1 monoclonal antibody in the near future will facilitate RAG analysis of lymphomas. 相似文献