全文获取类型
收费全文 | 3498篇 |
免费 | 256篇 |
国内免费 | 93篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 79篇 |
妇产科学 | 56篇 |
基础医学 | 343篇 |
口腔科学 | 129篇 |
临床医学 | 328篇 |
内科学 | 849篇 |
皮肤病学 | 32篇 |
神经病学 | 165篇 |
特种医学 | 244篇 |
外科学 | 474篇 |
综合类 | 303篇 |
一般理论 | 4篇 |
预防医学 | 299篇 |
眼科学 | 48篇 |
药学 | 199篇 |
4篇 | |
中国医学 | 78篇 |
肿瘤学 | 206篇 |
出版年
2023年 | 33篇 |
2022年 | 45篇 |
2021年 | 61篇 |
2020年 | 49篇 |
2019年 | 46篇 |
2018年 | 75篇 |
2017年 | 57篇 |
2016年 | 62篇 |
2015年 | 86篇 |
2014年 | 120篇 |
2013年 | 166篇 |
2012年 | 168篇 |
2011年 | 217篇 |
2010年 | 172篇 |
2009年 | 208篇 |
2008年 | 176篇 |
2007年 | 202篇 |
2006年 | 141篇 |
2005年 | 120篇 |
2004年 | 127篇 |
2003年 | 102篇 |
2002年 | 103篇 |
2001年 | 80篇 |
2000年 | 75篇 |
1999年 | 90篇 |
1998年 | 48篇 |
1997年 | 53篇 |
1996年 | 52篇 |
1995年 | 35篇 |
1994年 | 40篇 |
1993年 | 42篇 |
1992年 | 62篇 |
1991年 | 50篇 |
1990年 | 52篇 |
1989年 | 56篇 |
1988年 | 56篇 |
1987年 | 45篇 |
1986年 | 29篇 |
1985年 | 38篇 |
1984年 | 28篇 |
1983年 | 28篇 |
1982年 | 20篇 |
1980年 | 24篇 |
1979年 | 32篇 |
1978年 | 32篇 |
1977年 | 29篇 |
1976年 | 31篇 |
1975年 | 22篇 |
1974年 | 23篇 |
1971年 | 20篇 |
排序方式: 共有3847条查询结果,搜索用时 15 毫秒
101.
Lars Engesæter Stein Atle Lie Birgitte Espehaug Ove Furnes Stein Emil Vollset Leif Ivar Havelin 《Acta orthopaedica》2013,84(6):644-651
We studied the effects of antibiotic prophylaxis, systemically and in bone cement, on the revision rate of cemented total hip arthroplasties (THAs) in data from the Norwegian Arthroplasty Register during the period 1987-2001. To have comparable groups, only THAs performed because of primary osteoarthritis, using cemented implants with documented good results, and high-viscosity cement were included. If systemic antibiotic prophylaxis had been given, only operations with cephalosporin or penicillin were selected. Cox-estimated survival relative revision risks (RR) are presented with adjustment for differences among groups in gender, age, cement brand, type of systemic antibiotic prophylaxis, type of prosthesis, type of operating room, and duration of the operation. Of 22,170 THAs studied, 696 THAs (3.1%) were revised, 440 (2.0%) for aseptic loosening and 102 (0.5%) for deep infection. We found the lowest risk of revision when the antibiotic prophylaxis was given both systemically and in the cement (15,676 THAs). Compared to this combined regime, patients who received antibiotic prophylaxis only systemically (5,960 THAs) had a 1.4 times higher revision rate with all reasons for revision as endpoint (p= 0.001), 1.3 times higher with aseptic loosening (p= 0.02) and 1.8 times higher with infection as the endpoint (p= 0.01). With the combined antibiotic regime, the results were better if antibiotics were given 4 times on the day of surgery (2,194 THAs), as compared to once (1,424 THAs) (p<0.001), twice (2,680 THAs) (p<0.001), or 3 times (5,522 THAs) (p= 0.02). Those who received systemic prophylaxis a single day 1, 2 or 3 times, as compared to 4 times, had a revision rate 1.8-3.5 times higher with all reasons for revision as endpoint, 1.5-3.1 times higher with aseptic loosening, and 2.7-6.8 times higher with infection. When we compared systemic prophylaxis 4 times in 1 day, no further improvement resulted in those given systemic prophylaxis for 2 days (1,928 THAs) or 3 days (717 THAs). In a subset of data including only the Charnley prosthesis, we obtained similar results. This observational study shows that the best results were recorded when antibiotic prophylaxis was given both systemically and in the bone cement, and if the systemic antibiotic was given 4 times on the day of surgery. 相似文献
102.
Karin T. Beuker Synnve Schjølberg Kari Kveim Lie Rogier Donders Martijn Lappenschaar Sophie H. N. Swinkels Jan K. Buitelaar 《Journal of autism and developmental disorders》2013,43(1):45-56
It is unclear whether symptoms of autism spectrum disorder (ASD) in young children in the population fit the three-factor structure of ASD as described in the DSM-IV, and cluster together in individual subjects. This study analysed questionnaire data on ASD symptoms filled in by mothers of 11,332 18-month-old children that was collected in the context of the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health. Confirmatory Factor Analyses showed that the three-factor model had a significantly better fit then the two- and one-factor model of ASD symptoms. Latent class analysis revealed four homogeneous groups of children (classes) with different scores for Social Interaction and Communication at one hand and Stereotypies/Rigidity at the other hand. 相似文献
103.
Yoshifumi Noda MD Satoshi Goshima MD PhD Kaori Tanaka MD Shinji Osada MD PhD Hiroyuki Tomita MD PhD Akira Hara MD PhD Yukio Horikawa MD PhD Jun Takeda MD PhD Kimihiro Kajita RT Haruo Watanabe MD Hiroshi Kawada MD Nobuyuki Kawai MD Masayuki Kanematsu MD Kyongtae T. Bae MD PhD 《Journal of magnetic resonance imaging : JMRI》2016,43(3):680-687
104.
Aline Moraes MENACHO Adriano REIMANN Lie Mara HIRATA Caroline GANZERELLA Flavio Heuta IVANO Ricardo SUGISAWA 《Brazilian archives of digestive surgery》2014,27(1):9-12
Background
Colonoscopy is the most frequent exam used to evaluate colonic mucosa, allowing the diagnosis and treatment of many diseases. The appropriate bowel preparation is indispensable for the realization of colonoscopy. Therefore, it is necessary the use of laxative medications, preferentially by oral administration.Aim
To compare two medications used in bowel preparation in adult patients going to ambulatory colonoscopy and to analyze the patients'' profile.Methods
A double-blind prospective study with 200 patients, randomized in two groups: one that received polyethilene glycol and another that received lactulose. The patients answered to questionnaires to data compilation, as tolerance, symptoms and complications related to preparation. Besides, it was also evaluated the prepare efficacy related to the presence of fecal residue.Results
Intestinal habit alterations and abdominal pain were the main reasons to realize the exams and hypertension was the most prevalent comorbidity. Ten percent of the ones who received lactulose didn''t get to finish the preparation and 50% considered the taste "bad, but tolerable". The most common subjective symptom after the medication was nausea, especially after lactulose. During the exam, most of the patients who used lactulose had a "light discomfort" and the ones who used polyethilene glycol considered the discomfort as "tolerable". The quality of the preparation was good in 75%, undependable of the medication that was used.Conclusion
Polyethilene glycol was more tolerable when compared to lactulose, without difference on the quality of the preparation. 相似文献105.
Ebo D. de Muinck Paolo Angelini Kathy Dougherty Bart J. Verkerke Gerhard Rakhorst Rene B. van Dijk Kong I. Lie 《Catheterization and cardiovascular interventions》1993,30(1):58-62
The effective flow rates with human blood through an autoperfusion catheter cannot be monitored in vivo and have not been experimentally determined in vitro. The manufacturers (Advanced Cardiovascular Systems [ACS], Temecula, CA) have suggested that “the flow rate” through the Stack over the wire and the RX-60 monorail catheter is 60 ml/min with a pressure gradient of 80 mmHg. We measured human blood flow rates in vitro through these catheters under different continuous pressure regimens (between 40 and 120 mmHg), with varying hematocrit levels (between 25% and 62%). Measured blood flows at a gradient of 80 mmHg were found to vary from 32 to 65 cc/min, with hematocrit levels of 62-25%. Minor variations in the circuitry, besides the viscosity of the medium, cause significant changes in observed flow rates (such as kinking of the catheter and blood sedimentation). In vitro determinations of blood flows cannot automatically be transferred to the in vivo condition, primarily because in vitro determinations do not account for the systolic intramural pressure increase (which may overcome the aortic pressure). If such a phenomenon is also considered, then the in vitro flow rates reported here should be multiplied by a factor of 0.40–0.60 to determine effective in vivo flow rates. Such information is relevant for the clinical operator of angioplasty, especially in the treatment of patients at high risk for undergoing percutaneous transluminal coronary angioplasty. © 1993 Wiiey-Liss, Inc. 相似文献
106.
Clinical Rheumatology - Our study aimed to investigate the effect of illness uncertainty on sleep quality among SLE women. Meanwhile, the role of resilience was explored in the association of... 相似文献
107.
Eva Dybvik Ove Furnes Sophie D. Foss? Clement Trovik Stein Atle Lie 《Acta orthopaedica》2014,85(6):652-656
Background and purpose —
Long-term survivors of cancer can develop adverse effects of the treatment. 60% of cancer patients survive for at least 5 years after diagnosis. Pelvic irradiation can cause bone damage in these long-term survivors, with increased risk of fracture and degeneration of the hip.Patients and methods —
Analyses were based on linkage between the Cancer Registry of Norway (CRN) and the Norwegian Arthroplasty Register (NAR). All women who had been exposed to radiation for curative radiotherapy of gynecological cancer (40–60 Gy for at least 28 days) were identified in the CRN. Radiotherapy had been given between 1998 and 2006 and only patients who were irradiated within 6 months of diagnosis were included. The control group contained women with breast cancer who had also undergone radiotherapy, but not to the pelvic area. Fine and Gray competing-risk analysis was used to calculate subhazard-rate ratios (subHRRs) and cumulative incidence functions (CIFs) for the risk of having a prosthesis accounting for differences in mortality.Results —
Of 962 eligible patients with gynecological cancer, 26 (3%) had received a total hip replacement. In the control group without exposure, 253 (3%) of 7,545 patients with breast cancer had undergone total hip replacement. The 8-year CIF for receiving a total hip replacement was 2.7% (95% CI: 2.6–2.8) for gynecological cancer patients and 3.0% (95% CI: 2.95–3.03) for breast cancer patients; subHRR was 0.80 (95% CI: 0.53–1.22; p = 0.3). In both groups, the most common reason for hip replacement was idiopathic osteoarthritis.Interpretation —
We did not find any statistically significantly higher risk of undergoing total hip replacement in patients with gynecological cancer who had had pelvic radiotherapy than in women with breast cancer who had not had pelvic radiotherapy.After approximately 5 years, two-thirds of cancer patients are still alive (Sant et al. 2009). Research on late adverse effects in cancer survivors has gained increasing interest over the last decade. However, the main interest has been on secondary cancer events (Curtis et al. 2006), cardiovascular complications, and emotional problems (Meyerowitz et al. 2008). The relationship between cancer, skeletal disorders, and treatment has rarely been investigated. Skeletal adverse effects of irradiation include cell death, cellular injury, and abnormal bone repair—although the underlying mechanisms are not fully understood (Yurut-Caloglu et al. 2010).Pelvic insufficiency fractures may be one of the possible late side effects of radiotherapy to the pelvic area. The incidence of such fractures has been reported to be 5–20% in gynecological cancer patients who have undergone radiotherapy (Kwon et al. 2008, Oh et al. 2008, Schmeler et al. 2010, Shih et al. 2013). Less common effects of pelvic irradiation include acetabular protrusion and avascular necrosis of the femoral head (Fiorino et al. 2009). Other studies have not found any increased risk of hip fracture after pelvic irradiation (Feltl et al. 2006, Elliott et al. 2011). We wanted to examine the risk of receiving a total hip replacement in patients with cancer in the pelvic area who had undergone radiotherapy compared to patients with cancer at another location who had not undergone pelvic irradiation. Our hypothesis was that patients who have had high-dose pelvic radiotherapy would have a higher risk of undergoing total hip replacement than women who have had radiotherapy with target fields in other parts of the body. 相似文献108.
Karin T. Beuker Synnve Schjølberg Kari Kveim Lie Sophie Swinkels Nanda N. J. Rommelse Jan K. Buitelaar 《European child & adolescent psychiatry》2014,23(11):1081-1091
The Modified Checklist for Autism in Toddlers (M-CHAT) and the Early Screening of Autistic Traits (ESAT) were designed to screen for autism spectrum disorders in very young children. The aim of this study was to explore proportions of children that screened positive on the ESAT or the M-CHAT and to investigate if screening positive on the ESAT and M-CHAT is associated with clinical referral by 18 months and other aspects of children’s development, health, and behavior. In this study, the mothers of 12,948 18-month-old children returned a questionnaire consisting of items from the ESAT and M-CHAT, plus questions about clinical and developmental characteristics. The M-CHAT identified more screen-positive children than the ESAT, but the ESAT was associated with more clinical referrals and tended to identify more children with medical, language, and behavioral problems. A post hoc analysis of combining the two instruments found this to be more effective than the individual instruments alone in identifying children referred to clinical services at 18 months. Further analysis at the level of single items is warranted to improve these screening instruments. 相似文献
109.
110.