全文获取类型
收费全文 | 26156篇 |
免费 | 1647篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 179篇 |
儿科学 | 821篇 |
妇产科学 | 626篇 |
基础医学 | 3926篇 |
口腔科学 | 465篇 |
临床医学 | 3741篇 |
内科学 | 4805篇 |
皮肤病学 | 440篇 |
神经病学 | 2716篇 |
特种医学 | 607篇 |
外科学 | 2123篇 |
综合类 | 173篇 |
一般理论 | 26篇 |
预防医学 | 3009篇 |
眼科学 | 445篇 |
药学 | 1892篇 |
1篇 | |
中国医学 | 56篇 |
肿瘤学 | 1833篇 |
出版年
2024年 | 23篇 |
2023年 | 213篇 |
2022年 | 386篇 |
2021年 | 716篇 |
2020年 | 470篇 |
2019年 | 639篇 |
2018年 | 785篇 |
2017年 | 554篇 |
2016年 | 614篇 |
2015年 | 804篇 |
2014年 | 917篇 |
2013年 | 1459篇 |
2012年 | 2041篇 |
2011年 | 2188篇 |
2010年 | 1139篇 |
2009年 | 1074篇 |
2008年 | 1786篇 |
2007年 | 1839篇 |
2006年 | 1792篇 |
2005年 | 1678篇 |
2004年 | 1590篇 |
2003年 | 1454篇 |
2002年 | 1281篇 |
2001年 | 173篇 |
2000年 | 140篇 |
1999年 | 179篇 |
1998年 | 222篇 |
1997年 | 169篇 |
1996年 | 163篇 |
1995年 | 117篇 |
1994年 | 127篇 |
1993年 | 106篇 |
1992年 | 74篇 |
1991年 | 92篇 |
1990年 | 76篇 |
1989年 | 81篇 |
1988年 | 50篇 |
1987年 | 49篇 |
1986年 | 50篇 |
1985年 | 51篇 |
1984年 | 69篇 |
1983年 | 75篇 |
1982年 | 70篇 |
1981年 | 49篇 |
1980年 | 51篇 |
1979年 | 35篇 |
1978年 | 22篇 |
1977年 | 25篇 |
1976年 | 25篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Cobo T Borrell A Fortuny A Hernández S Pérez M Palacio M Pereira A Coll O 《Prenatal diagnosis》2007,27(11):1024-1027
OBJECTIVE: To assess the amniopatch procedure when premature rupture of membranes occurs after first-trimester chorionic villus sampling (CVS). STUDY DESIGN: From May 2001 to June 2004, the amniopatch procedure was offered in cases of premature rupture of membranes after CVS when severe oligohydramnios was present (largest vertical pocket < 2 cm) and persistent (more than 1 week). RESULTS: The amniopatch was placed in five pregnancies at 12-18 weeks of gestation, resulting in amniotic fluid restoration in all but one pregnancy. In three pregnancies, fetal demise was observed at 1, 2 and 36 days after the procedure. The last procedure resulted in a healthy newborn. CONCLUSION: Although the amniopatch restored normal amniotic fluid levels in all cases, 4 of the 5 cases resulted in fetal demise. 相似文献
992.
Utility of screening for other causes of infertility in women with "known" polycystic ovary syndrome
McGovern PG Legro RS Myers ER Barnhart HX Carson SA Diamond MP Carr BR Schlaff WD Coutifaris C Steinkampf MP Nestler JE Gosman G Leppert PC Giudice LC;National Institutes for Child Health Human Development-Reproductive Medicine Network 《Fertility and sterility》2007,87(2):442-444
We investigated the prevalence of abnormal screening results (questionnaire and testing for other causes of oligo-ovulation, male or tubal factor infertility) in a group of 1,313 oligo-ovulatory women (included and excluded subjects) whose condition was screened for inclusion in the Pregnancy in Polycystic Ovary Syndrome trial, a multicenter clinical trial that was conducted at 13 sites in the United States. Other than failure to demonstrate laboratory evidence of hyperandrogenemia, the most common reasons for subject exclusion were persistent oligospermia and tubal factor infertility. 相似文献
993.
Sandra Bärnreuther 《Medical anthropology》2016,35(1):73-89
ABSTRACTIn 1978, the year the first in vitro fertilization (IVF) baby was born in the United Kingdom, a research team in Kolkata reported that it too had successfully produced an IVF baby in India. However, the claim was dismissed at the time, because the experiment was conducted outside authorized institutions and recognized centers of innovation—in short, because it was an innovation ‘out of place.’ Tracing controversies over the case between 1978 and 2005, I show the importance of space or place in processes of knowledge production and recognition. Further, I explain the initial repudiation and subsequent partial recognition of the claim through shifts in the landscape of legitimate spaces of innovation. By discussing this specific case of the production of science and technology in the Global South, I challenge conventional narratives of diffusion that are prevalent in studies on the worldwide proliferation of reproductive technologies. 相似文献
994.
995.
Jutta Pikalo Tessa Carrau Paul Deutschmann Melina Fischer Kore Schlottau Martin Beer Sandra Blome 《Viruses》2022,14(2)
African swine fever (ASF) is a major threat to pig production, and real-time PCR (qPCR) protocols are an integral part of ASF laboratory diagnosis. With the pandemic spread of ASF, commercial kits have risen on the market. In Germany, the kits have to go through an approval process and thus, general validation can be assumed. However, they have never been compared to each other. In this study, 12 commercial PCR kits were compared to an OIE-recommended method. Samples representing different matrices, genome loads, and genotypes were included in a panel that was tested under diagnostic conditions. The comparison included user-friendliness, internal controls, and the time required. All qPCRs were able to detect ASFV genome in different matrices across all genotypes and disease courses. With one exception, there were no significant differences when comparing the overall mean. The overall specificity was 100% (95% CI 87.66–100), and the sensitivity was between 95% and 100% (95% CI 91.11–100). As can be expected, variability concerned samples with low genome load. To conclude, all tests were fit for purpose. The test system can therefore be chosen based on compatibility and prioritization of the internal control system. 相似文献
996.
Felix-Nikolai Oschinka Jegor Habermann Daniela Schmitt Thomas Failing Jann Fischer David Alexander Ziegler Laura Anna Fischer Niklas Josua Alt Julian Muster Sandra Donath Andrea Hille Markus Anton Schirmer Manuel Guhlich Rami A. El Shafie Stefan Rieken Martin Leu Leif Hendrik Drge 《Current oncology (Toronto, Ont.)》2022,29(2):1080
The pandemic raised a discussion about the postponement of medical interventions for non-small cell lung cancer (NSCLC). We analyzed the characteristics of pretreatment diagnostic assessment in the pandemic and the influence of diagnostic assessment on outcomes. A total of 96 patients with stereotactic body radiation therapy (SBRT) for NSCLC were included. The number of patients increased from mean 0.9 (2012–2019) to 1.45 per month in the COVID era (p < 0.05). Pandemic-related factors (contact reduction, limited intensive care unit resources) might have influenced clinical decision making towards SBRT. The time from pretreatment assessment (multidisciplinary tumor board decision, bronchoscopy, planning CT) to SBRT was longer during the COVID period (p < 0.05). Reduced services, staff shortage, or appointment management to mitigate infection risks might explain this finding. Overall survival, progression-free survival, locoregional progression-free survival, and distant progression-free survival were superior in patients who received a PET/CT scan prior to SBRT (p < 0.05). This supports that SBRT guidelines advocate the acquisition of a PET/CT scan. A longer time from PET/CT scan/conventional staging to SBRT (<10 vs. ≥10 weeks) was associated with worse locoregional control (p < 0.05). The postponement of diagnostic or therapeutic measures in the pandemic should be discussed cautiously. Patient- and tumor-related features should be evaluated in detail. 相似文献
997.
Rationale and design of the AdaptResponse trial: a prospective randomized study of cardiac resynchronization therapy with preferential adaptive left ventricular‐only pacing 下载免费PDF全文
Gerasimos Filippatos David Birnie Michael R. Gold Bart Gerritse Ahmad Hersi Sandra Jacobs Kengo Kusano Christophe Leclercq Wilfried Mullens Bruce L. Wilkoff 《European journal of heart failure》2017,19(7):950-957
The AdaptResponse trial is designed to test the hypothesis that preferential adaptive left ventricular‐only pacing with the AdaptivCRT® algorithm reduces the incidence of the combined endpoint of all‐cause mortality and intervention for heart failure (HF) decompensation, compared with conventional cardiac resynchronization therapy (CRT), among patients with a CRT indication, left bundle branch block (LBBB) and normal atrioventricular (AV) conduction. The AdaptResponse study is a prospective, randomized, controlled, single‐blinded, multicentre, clinical trial ( ClinicalTrials.gov Identifier: NCT02205359), conducted at up to 200 centres worldwide. Following enrolment and baseline assessment, eligible subjects will be implanted with a CRT system containing the AdaptivCRT algorithm, and randomized in a 1:1 fashion to either a treatment (‘AdaptivCRT’) or control (‘Conventional CRT’) group. The study is designed to observe a primary endpoint in 1100 patients (‘event‐driven’) and approximately 3000 patients will be randomized. The primary endpoint is the composite of all‐cause mortality and intervention for HF decompensation; secondary endpoints include all‐cause mortality, intervention for HF decompensation, clinical composite score (CCS) at 6 months, atrial fibrillation, quality of life measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), health outcome measured by the EQ‐5D instrument, all‐cause readmission after a HF admission, and cost‐effectiveness. The AdaptResponse clinical trial is powered to assess clinical endpoints and is expected to provide definitive evidence on the incremental utility of AdaptivCRT‐enhanced CRT systems. 相似文献
998.
999.
Risk factors for the development of Clostridium difficile infection in adult allogeneic hematopoietic stem cell transplant recipients: A single‐center study in Québec,Canada 下载免费PDF全文
1000.
Validation of the HFA‐PEFF score for the diagnosis of heart failure with preserved ejection fraction