全文获取类型
收费全文 | 5051篇 |
免费 | 649篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 135篇 |
妇产科学 | 384篇 |
基础医学 | 456篇 |
口腔科学 | 256篇 |
临床医学 | 1227篇 |
内科学 | 696篇 |
皮肤病学 | 110篇 |
神经病学 | 400篇 |
特种医学 | 353篇 |
外科学 | 585篇 |
综合类 | 150篇 |
一般理论 | 1篇 |
预防医学 | 422篇 |
眼科学 | 67篇 |
药学 | 286篇 |
中国医学 | 6篇 |
肿瘤学 | 155篇 |
出版年
2023年 | 66篇 |
2021年 | 65篇 |
2020年 | 81篇 |
2019年 | 85篇 |
2018年 | 147篇 |
2017年 | 152篇 |
2016年 | 132篇 |
2015年 | 154篇 |
2014年 | 200篇 |
2013年 | 211篇 |
2012年 | 205篇 |
2011年 | 202篇 |
2010年 | 185篇 |
2009年 | 190篇 |
2008年 | 152篇 |
2007年 | 189篇 |
2006年 | 181篇 |
2005年 | 151篇 |
2004年 | 143篇 |
2003年 | 140篇 |
2002年 | 157篇 |
2001年 | 147篇 |
2000年 | 122篇 |
1999年 | 146篇 |
1998年 | 139篇 |
1997年 | 144篇 |
1996年 | 137篇 |
1995年 | 119篇 |
1994年 | 103篇 |
1993年 | 81篇 |
1992年 | 98篇 |
1991年 | 104篇 |
1990年 | 74篇 |
1989年 | 101篇 |
1988年 | 94篇 |
1987年 | 78篇 |
1986年 | 88篇 |
1985年 | 75篇 |
1984年 | 53篇 |
1983年 | 49篇 |
1982年 | 49篇 |
1981年 | 28篇 |
1980年 | 33篇 |
1979年 | 36篇 |
1978年 | 42篇 |
1977年 | 36篇 |
1976年 | 30篇 |
1975年 | 25篇 |
1973年 | 36篇 |
1972年 | 22篇 |
排序方式: 共有5710条查询结果,搜索用时 15 毫秒
71.
C KAPPAGODA DN SCHELL RM HANSON & P HUTCHINS 《Journal of paediatrics and child health》1998,34(6):508-512
72.
Linda Cardozo Professor Christopher Benness Consultant Denise Abbott Research Nurse 《BJOG : an international journal of obstetrics and gynaecology》1998,105(4):403-407
Objective To assess the efficacy of oral oestriol in the prevention of recurrent Urinary tract infections in elderly women.
Design Double-blind, randomised, parallel group, placebo controlled trial
Setting Urogynaecology Unit at King's College Hospital with some women recruited from the geriatric units of St. Pancras Hospital and Dulwich Hospital, London (UK).
Participants Seventy-two postmenopausal women older than 60 years of age (mean 73.2 years) suffering from recurrent urinary tract infections.
Intervention Oral oestriol (3 mg per day) or placebo for six months.
Main outcome measures Urinary tract infection rates.
Results The study was difficult to conduct because of its design and the age of the participants. Oral oestriol (3 mg per day) was not shown to be superior to placebo in the prevention of recurrent urinary tract infections, but both oestriol and placebo improved urinary symptoms during the trial.
Conclusion The power of the study might have been too low to detect a significant difference between the groups, or oral oestriol(3 mg per day) may have been either the wrong dose or the wrong route of administration for this indication. 相似文献
Design Double-blind, randomised, parallel group, placebo controlled trial
Setting Urogynaecology Unit at King's College Hospital with some women recruited from the geriatric units of St. Pancras Hospital and Dulwich Hospital, London (UK).
Participants Seventy-two postmenopausal women older than 60 years of age (mean 73.2 years) suffering from recurrent urinary tract infections.
Intervention Oral oestriol (3 mg per day) or placebo for six months.
Main outcome measures Urinary tract infection rates.
Results The study was difficult to conduct because of its design and the age of the participants. Oral oestriol (3 mg per day) was not shown to be superior to placebo in the prevention of recurrent urinary tract infections, but both oestriol and placebo improved urinary symptoms during the trial.
Conclusion The power of the study might have been too low to detect a significant difference between the groups, or oral oestriol(3 mg per day) may have been either the wrong dose or the wrong route of administration for this indication. 相似文献
73.
Kinta Beaver PhD MRes BA DPSN RGN David Jones MD FRCS † Shabbir Susnerwala MD FRCR ‡ Olive Craven MSc RGN RM Onc.Cert § Mary Tomlinson BA RGN ¶ Gary Witham BA RGN Onc.Cert PG.Cert Karen A Luker PhD BNurs FMedSci †† 《Health expectations》2005,8(2):103-113
OBJECTIVES: To explore patient views on participation in treatment, physical care and psychological care decisions and factors that facilitate and hinder patients from making decisions. DESIGN: Qualitative study using semi-structured interviews with patients. SETTING AND PARTICIPANTS: Three NHS Trusts in the north-west of England. Theoretical sampling including 41 patients who had been treated for colorectal cancer. RESULTS: For patients, participation in the decision-making process was about being informed and feeling involved in the consultation process, whether patients actually made decisions or not. The perceived availability of treatment choices (surgery, radiotherapy, chemotherapy) was related to type of treatment. Factors that impacted on whether patients wanted to make decisions included a lack of information, a lack of medical knowledge and trust in medical expertise. Patients perceived that they could have a more participatory role in decisions related to physical and psychological care. CONCLUSION: This study has implications for health professionals aiming to implement policy guidelines that promote patient participation and shared partnerships. Patients in this study wanted to be well informed and involved in the consultation process but did not necessarily want to use the information they received to make decisions. The presentation of choices and preferences for participation may be context specific and it cannot be assumed that patients who do not want to make decisions about one aspect of their care and treatment do not want to make decisions about other aspects of their care and treatment. 相似文献
74.
The effect of anticoagulation on antenatal ultrasound findings in pregnant women with thrombophilia.
Urania Magriples Tulin Ozcan Anita Karne Joshua Abbott Copel 《The journal of maternal-fetal & neonatal medicine》2006,19(1):27-30
OBJECTIVE: To assess whether treatment with heparin alters ultrasound findings in pregnant women with inherited thrombophilia. METHODS: This was a retrospective study of a cohort of patients referred for pregnancy complications who were found to have genetic thrombophilia. Ultrasounds were reviewed in treated and untreated pregnancies for the presence of growth restriction, oligohydramnios or abnormal Doppler results. RESULTS: There were a total of 178 pregnancies in 51 patients. The overall percentage of abnormal ultrasounds was significantly greater in the untreated compared with treated pregnancies (52.8% vs. 27.9%; p = 0.024.) Growth restriction and abnormal Doppler results were more common in untreated pregnancies. There was a significantly decreased risk of oligohydramnios with treatment (27.3% vs. 7%; p = 0.03). Overall outcomes were significantly improved with the use of anticoagulation ( p < 0.0001). CONCLUSIONS: Treatment markedly improves ultrasound parameters of growth, fluid and feto-placental blood flow in patients with thrombophilia. The presence of abnormalities despite treatment reinforces the need for close antenatal surveillance. 相似文献
75.
76.
Differences in the accommodation stimulus response curves of adult myopes and emmetropes 总被引:5,自引:2,他引:5
Meredith L. Abbott Katrina L. Schmid Niall C. Strang 《Ophthalmic & physiological optics》1998,18(1):13-20
While the accommodation system has been implicated in myopia development, the nature of this relationship remains obscure. This study investigated the differences in accommodation stimulus response curves between adult myopes and emmetropes. Myopic subjects were classified according to age of onset and stability of their myopia. Accommodation stimulus response curves were measured using three different methods: (i) real targets presented at viewing distances of 4 m to 0.25 m, (ii) a target at 4 m viewed through negative lenses of increasing power, and (iii) a target at 0.25 m viewed through positive lenses of decreasing power. A Canon Autoref R-1 measured the accommodation responses at 5 levels of demand (increasing from 0 D to 4 D in 1 D steps). We found significant differences between the three methods used to stimulate an accommodation response in all subject groups, for example, accommodation lags at high accommodative demands were greatest for the negative lens series and least for the positive lens series. In addition, while differences between early-onset myopes, late-onset myopes and emmetropes were not observed, we did observe differences when myopic subjects were reclassified according to whether their myopia was progressing or stable. A reduced accommodation response to negative lens-induced accommodative demand was found in progressing myopes but not in stable myopes. These results provide further evidence for the link between myopia progression and inaccurate accommodation. The data also suggest that adult myopes with stable refractive errors show accommodation responses similar to that of emmetropes. 相似文献
77.
Six phakic patients with unilateral corneal edema and clinically normal-appearing fellow eyes were examined with specular microscopy and found to have endothelial pleomorphism and reduced cell counts in the nonedematous cornea. None of these patients had any previous eye disease, trauma, inflammation, or surgery. Clinically unrecognized endothelial disease was proposed as a cause for the unilateral corneal edema and was verified by light and electron microscopic studies in five patients. These pathologic findings vary somewhat from those found in Fuchs' dystrophy and may represent either a variant or a form of endothelial cell degeneration of as yet undetermined etiology. Our studies suggest that this condition is not detectable in the nonedematous cornea by standard high magnification biomicroscopy and requires the use of the clinical specular microscope to confirm the diagnosis in suspected cases. 相似文献
78.
79.
80.