全文获取类型
收费全文 | 2583篇 |
免费 | 232篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 145篇 |
妇产科学 | 73篇 |
基础医学 | 255篇 |
口腔科学 | 107篇 |
临床医学 | 314篇 |
内科学 | 604篇 |
皮肤病学 | 49篇 |
神经病学 | 138篇 |
特种医学 | 66篇 |
外科学 | 595篇 |
综合类 | 43篇 |
预防医学 | 103篇 |
眼科学 | 61篇 |
药学 | 127篇 |
中国医学 | 5篇 |
肿瘤学 | 62篇 |
出版年
2024年 | 7篇 |
2023年 | 43篇 |
2022年 | 77篇 |
2021年 | 107篇 |
2020年 | 56篇 |
2019年 | 67篇 |
2018年 | 89篇 |
2017年 | 72篇 |
2016年 | 116篇 |
2015年 | 137篇 |
2014年 | 154篇 |
2013年 | 253篇 |
2012年 | 146篇 |
2011年 | 139篇 |
2010年 | 169篇 |
2009年 | 102篇 |
2008年 | 112篇 |
2007年 | 87篇 |
2006年 | 111篇 |
2005年 | 105篇 |
2004年 | 90篇 |
2003年 | 58篇 |
2002年 | 93篇 |
2001年 | 53篇 |
2000年 | 33篇 |
1999年 | 48篇 |
1998年 | 25篇 |
1997年 | 29篇 |
1996年 | 27篇 |
1995年 | 6篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1984年 | 4篇 |
1966年 | 5篇 |
1965年 | 6篇 |
1937年 | 5篇 |
1931年 | 10篇 |
1930年 | 12篇 |
1928年 | 6篇 |
1927年 | 6篇 |
1926年 | 7篇 |
1925年 | 5篇 |
1924年 | 9篇 |
1923年 | 4篇 |
1906年 | 3篇 |
排序方式: 共有2826条查询结果,搜索用时 15 毫秒
991.
Locked Nucleic Acid Oligonucleotides 总被引:2,自引:0,他引:2
992.
Adriana Balduzzi Jean-Hugues Dalle Jacek Wachowiak Isaac Yaniv Akif Yesilipek Petr Sedlacek Marc Bierings Marianne Ifversen Sabina Sufliarska Krzysztof Kalwak Arjan Lankester Jacek Toporski Lucia Di Maio Evgenia Glogova Ulrike Poetschger Christina Peters 《Biology of blood and marrow transplantation》2019,25(11):2197-2210
Eligibility criteria for hematopoietic stem cell transplantation (HSCT) in acute lymphoblastic leukemia (ALL) vary according to disease characteristics, response to treatment, and type of available donor. As the risk profile of the patient worsens, a wider degree of HLA mismatching is considered acceptable. A total of 138 children and adolescents who underwent HSCT from HLA-identical sibling donors (MSDs) and 210 who underwent HSCT from matched donors (MDs) (median age, 9 years; 68% male) in 10 countries were enrolled in the International-BFM ALL SCT 2007 prospective study to assess the impact of donor type in HSCT for pediatric ALL.The 4-year event-free survival (65 ± 5% vs 61 ± 4%; P = .287), overall survival (72 ± 4% versus 68 ± 4%; P = .235), cumulative incidence of relapse (24 ± 4% versus 25 ± 3%; P = .658) and nonrelapse mortality (10 ± 3% versus 14 ± 3%; P = .212) were not significantly different between MSD and MD graft recipients. The risk of extensive chronic (cGVHD) was lower in MD graft recipients than in MSD graft recipients (hazard ratio [HR], .38; P = .002), and the risks of severe acute GVHD (aGVHD) and cGVHD were higher in peripheral blood stem cell graft recipients than in bone marrow graft recipients (HR, 2.06; P = .026). Compared with the absence of aGVHD, grade I-II aGVHD was associated with a lower risk of graft failure (HR, .63; P = .042) and grade III-IV aGVHD was associated with a higher risk of graft failure (HR, 1.85; P = .020) and nonleukemic death (HR, 8.76; P < .0001), despite a lower risk of relapse (HR, .32; P = .021). Compared with the absence of cGVHD, extensive cGVHD was associated with a higher risk of nonleukemic death (HR, 8.12; P < .0001).Because the outcomes of transplantation from a matched donor were not inferior to those of transplantation from an HLA-identical sibling, eligibility criteria for transplantation might be reviewed in pediatric ALL and possibly in other malignancies as well. Bone marrow should be the preferred stem cell source, and the addition of MTX should be considered in MSD graft recipients. 相似文献
993.
Undar A Ji B Rider A Lukic B Kunselman AR Weiss WJ Myers JL 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2007,53(6):778-784
We compared four commercially available 10F pediatric aortic cannulae with different geometric designs (DLP-Long tip, DLP-Short tip, RMI-Long tip, and Surgimedics-Short tip) during pulsatile versus nonpulsatile perfusion in terms of pressure drops and surplus hemodynamic energy (SHE) levels in an in vitro neonatal model of cardiopulmonary bypass. The pseudo patient was subjected to seven pump flow rates at 100 ml/min increments in the 400-1,000 ml/min range. A total of 44 experiments (n = 22, nonpulsatile; n = 22, pulsatile) were performed at each of the seven flow rates. Surgimedics had significantly higher pressure drops than the other three cannulae at various flow rates during nonpulsatile and pulsatile perfusion, respectively. When the perfusion mode was changed from nonpulsatile to pulsatile flow, SHE levels at both precannula and postcannula sites increased seven to nine times at all flow rates in all four cannulae. Surgimedics generated a significant lower SHE level when compared with the other three cannulae at all flow rates at both precannula and postcannula sites. The results suggest that different geometries of aortic cannulae have a significant impact on pressure drops of the cannulae as well as hemodynamic energy generation and delivery. Pulsatile perfusion generates more "extra" hemodynamic energy when compared with the nonpulsatile perfusion mode with all four cannulae used in this study. 相似文献
994.
Undar A Ji B Kunselman AR Myers JL 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2007,53(6):725-729
We compared the effects of perfusion modes (pulsatile vs. nonpulsatile) on gaseous microemboli delivery using the Emboli Detection and Classification (EDAC) Quantifier at postpump, postoxygenator, and postarterial filter sites in a simulated pediatric cardiopulmonary bypass (CPB) model. The mock loop was subjected to five different pump flow rates of equal 100 ml/min intervals, ranging from 400 to 800 ml/min. When the target pump flow rate was achieved, 5 cc air was introduced into the venous line. The EDAC system recorded gaseous microemboli counts simultaneously at three locations in 5-minute intervals. Regardless of the type of perfusion mode, when the pump flow rate was increased, more gaseous microemboli were generated at postpump site. Compared with nonpulsatile flow, pulsatile flow did deliver significantly more gaseous microemboli at postpump site, but there was no difference between two groups at postoxygenator and postarterial filter sites. Capiox Baby-RX hollow-fiber membrane oxygenator significantly reduced the gaseous microemboli counts in both groups at all five pump flow rates with either pulsatile flow or nonpulsatile flow in this model. Our results suggest that using this novel EDAC system, we could detect the size of gaseous microemboli, as small as 10 microm, and the percentage of detected gaseous microemboli, <40 microm, was about 90% in total gaseous microemboli counts at any flow rate with pulsatile or nonpulsatile flow. 相似文献
995.
One of the important implications of the rights given to children by Article 12 of UN Convention on the Rights of Children 1989 is the inclusion of children in research on issues related to their lives. However, studies on father involvement are still conducted for young children not with them and there are no data-gathering techniques available that can be used specifically with young children. Within this context the main aim of this study is to develop new techniques to gather qualitative data from children aged between 50 and 72 months to understand how they perceive their fathers’ involvement. Findings of the present study were consistent with the results of previous studies that depended on adult reports of father involvement. Both the findings and the techniques used with children in the present study have implications for future research into father involvement and its application. 相似文献
996.
Rupture of the urinary collecting system associated with peripelvic extravasation of the urine is an unusual condition and commonly associated with obstructing calculus. We report a patient, recently given chemotherapy due to lymphoma, with acute abdomen symptoms. He had a renal pelvis rupture with perirenal extravasation of urine, an uncommon condition due to a stone in the ureter. Diagnosis was suspected on serial ultrasonography, and confirmed by computed tomograhy. Diagnosis, follow-up, and therapeutic approach are discussed. 相似文献
997.
Olak J Mändar R Karjalainen S Söderling E Saag M 《International journal of paediatric dentistry / the British Paedodontic Society [and] the International Association of Dentistry for Children》2007,17(2):92-97
Objective. The aim of this study was to assess the dental health and presence of mutans streptococci (MS) in 2–4‐year‐old Estonian children. Methods. The dental health of 472 2–4‐year‐old children was examined using a mirror and a penlight in 14 daycare centres representing seven communities around Estonia. The mean (± SD) age of the children was 41.4 ± 4.1 months (n = 222). Plaque samples of 222 children were employed to determine the presence of MS using the Dentocult® SM Strip mutans test. Results. Caries was diagnosed in 42% of the children, and the average (± SD) dmft index was 1.6 ± 2.5, ranging from 1.1 ± 1.2 in Tartu to 2.4 ± 3.1 in Võru. The proportion of caries‐free children decreased from 82% in the younger to 63% in the older group (P = 0.001). Among the tested subjects, 58% were colonized with MS, and those with caries were colonized more often than children with no visible caries (80% and 51%, respectively; P = 0.001). Conclusions. The prevalence of dental caries in Estonian 2–4‐year‐olds is higher than in the Nordic countries, but similar to other Baltic nations. Colonization by MS was associated with dental caries. 相似文献
998.
Although heart-lung machines and cardiac assist devices have been used successfully for acute and chronic cardiac support for decades, controversies still remain concerning the benefits of pulsatile and non-pulsatile perfusion. The core of the debate is whether enough energy is generated by the artificial pulse to keep capillary beds open and cell metabolism stabilized during acute or chronic cardiac support. In other words, does artificial pulsatility exist in the microcirculation: small vessels of less than 100 microm in diameter? Many investigators have tried to use different tools and biomarkers to reflect directly or indirectly the state of the microcirculation when comparing the two different perfusion modes during acute and chronic cardiac support. However, the results are controversial. First, direct observation of the state of the microcirculation during acute and chronic cardiac support is limited; and reports concerning direct observation of the microcirculation with different perfusion modes in contemporary literature are rare. Secondly, different investigators have used their own criteria to define pulsatile flow. Therefore, it is necessary to develop more efficient methodologies, enabling direct observation of the microcirculation during acute and chronic cardiac support and also establish common criteria that will precisely quantify the pulsatile flow in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels. Using these critical parameters may explain how excess energy is created by pulsatile flow and maintains perfusion through the microcirculation by ensuring capillary patency. 相似文献
999.
The effects of weight loss after sleeve gastrectomy on left ventricular systolic function in men versus women
下载免费PDF全文
![点击此处可从《Journal of clinical ultrasound : JCU》网站下载免费的PDF全文](/ch/ext_images/free.gif)
1000.
Ümmügülsüm Gaygısız Melike Badoğlu Nazlıhan Boyacı Zuhal Güllü Gül Gürsel 《Scandinavian journal of clinical and laboratory investigation》2016,76(2):143-150
Background In critical care patients, the diagnosis of subclinical acute kidney injury (AKI) might be difficult with measurements of serum creatinine and estimated glomerular filtration rate (eGFR). Their ‘sensitive kidneys’ can easily be affected from sepsis, underlying diseases, medications and volume status and if they can be detected earlier, some preventive measures might be taken. In this study we aimed to determine whether admission serum cystatin C (sCys-C) and other clinical parameters can identify subclinical AKI in medical intensive care unit (ICU) patients with normal creatinine-based eGFR at admission. Methods A prospective cohort study, performed in an adult ICU of a university hospital between January 2008 and March 2013. The blood samples were obtained within the first 24-48 hours of admission and sCys-C levels were analyzed with particle-enhanced immunonephelometric assay. AKI development was assessed according to RIFLE criteria. The cutoff value of sCys-C for the prediction of AKI was determined with receiver operating characteristic (ROC) curve analysis. Results A total of 72 patients were included in the study and 19 (26%) of them developed AKI. Among the patients with AKI admission sCys-C levels were significantly higher when compared with non-AKI patients (1.06?±?0.29 vs. 0.89?±?0.28 respectively, p?=?0.026). With ROC curve analysis, the threshold level for sCys-C was 0.94?mg/L with 63% sensitivity and 66% specificity [AUC: 0.67, p?=?0.026]. With logistic regression analysis ‘high sCys-C levels at admission’ (OR?=?4.73; 95%CI 1.03–21.5, p?=?0.044) was found as one of the independent variables for the prediction of AKI development, in addition to ‘being intubated before ICU admission’ (OR?=?10.2; 95%CI 1.72–60.4, p?=?0.01) and ‘hypotension during ICU follow-up’ (OR?=?12.3; 95%CI 2.5–60.1, p?=?0.002). Conclusion In this cohort of patients, a high sCys-C level at admission was found to be a predictor of subclinical AKI arising during their ICU stay. If supported with further studies, it might be used to provide more accurate and earlier knowledge about renal dysfunction and to take appropriate preventive measures. 相似文献