全文获取类型
收费全文 | 780篇 |
免费 | 22篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 16篇 |
妇产科学 | 40篇 |
基础医学 | 66篇 |
口腔科学 | 1篇 |
临床医学 | 33篇 |
内科学 | 169篇 |
皮肤病学 | 3篇 |
神经病学 | 158篇 |
特种医学 | 59篇 |
外科学 | 117篇 |
综合类 | 3篇 |
预防医学 | 15篇 |
眼科学 | 1篇 |
药学 | 49篇 |
肿瘤学 | 77篇 |
出版年
2024年 | 4篇 |
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 26篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 27篇 |
2017年 | 19篇 |
2016年 | 21篇 |
2015年 | 17篇 |
2014年 | 23篇 |
2013年 | 42篇 |
2012年 | 47篇 |
2011年 | 41篇 |
2010年 | 31篇 |
2009年 | 42篇 |
2008年 | 60篇 |
2007年 | 42篇 |
2006年 | 53篇 |
2005年 | 37篇 |
2004年 | 52篇 |
2003年 | 46篇 |
2002年 | 40篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1987年 | 9篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1969年 | 5篇 |
1968年 | 3篇 |
1965年 | 1篇 |
排序方式: 共有808条查询结果,搜索用时 15 毫秒
51.
52.
Caterina Clemente Silvana Elba Gianpiero Buongiorno Vito Guerra Benedetta D'Attoma Antonella Orlando Francesco Russo 《Liver international》2007,27(6):791-797
AIMS: To evaluate possible modifications in the manganese superoxide dismutase (MnSOD) activity during neoplastic transformation of a cirrhotic liver and to find out whether its assessment may have predictive value to identify cirrhotic patients at a higher risk of hepatocellular carcinoma (HCC). METHODS: Seventy-one consecutive subjects with Child-Pugh class A liver cirrhosis were recruited. At the time of enrolment, HCC was diagnosed in 20 cirrhotic patients. The 51 cirrhotic patients without HCC were followed up for the occurrence of tumour by 6-monthly screening for 7 years. During follow-up, 16 patients developed HCC. Seventy healthy subjects formed the control group. MnSOD activity was assayed spectrophotometrically. RESULTS: Serum MnSOD activity was significantly lower in 70 healthy subjects compared with 51 cirrhotic patients and 20 cirrhotic patients with HCC. Cirrhotic patients who developed HCC during follow-up showed significantly higher values of MnSOD activity than HCC-free patients. The best cut-off of MnSOD activity was 0.40 U/ml. At this cut-off, chi2 analysis revealed that MnSOD activity was significantly different between the HCC-free cirrhotic patients and cirrhotic patients who developed HCC. CONCLUSION: The present findings suggest that during neoplastic transformation of cirrhotic liver, an increase in MnSOD activity may occur already during the precancerous phase, making this enzyme a probable malignancy-associated parameter. 相似文献
53.
54.
Ruben T. Azevedo Emiliano Macaluso Alessio Avenanti Valerio Santangelo Valentina Cazzato Salvatore Maria Aglioti 《Human brain mapping》2013,34(12):3168-3181
Recent advances in social neuroscience research have unveiled the neurophysiological correlates of race and intergroup processing. However, little is known about the neural mechanisms underlying intergroup empathy. Combining event‐related fMRI with measurements of pupil dilation as an index of autonomic reactivity, we explored how race and group membership affect empathy‐related responses. White and Black subjects were presented with video clips depicting white, black, and unfamiliar violet‐skinned hands being either painfully penetrated by a syringe or being touched by a Q‐tip. Both hemodynamic activity within areas known to be involved in the processing of first and third‐person emotional experiences of pain, i.e., bilateral anterior insula, and autonomic reactivity were greater for the pain experienced by own‐race compared to that of other‐race and violet models. Interestingly, greater implicit racial bias predicted increased activity within the left anterior insula during the observation of own‐race pain relative to other‐race pain. Our findings highlight the close link between group‐based segregation and empathic processing. Moreover, they demonstrate the relative influence of culturally acquired implicit attitudes and perceived similarity/familiarity with the target in shaping emotional responses to others' physical pain. Hum Brain Mapp 34:3168–3181, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
55.
56.
Tsoumakidou Georgia Too Chow Wei Koch Guillaume Caudrelier Jean Cazzato Roberto Luigi Garnon Julien Gangi Afshin 《Cardiovascular and interventional radiology》2017,40(3):331-342
CardioVascular and Interventional Radiology - Vertebral compression fracture (VCF) is an important cause of severe debilitating back pain, adversely affecting quality of life, physical function,... 相似文献
57.
Rauch Aymeric Cazzato Roberto Luigi Garnon Julien Shaygi Behnam Tsoumakidou Georgia Caudrelier Jean Bauones Salem Koch Guillaume Lipsker Dan Gangi Afshin 《Cardiovascular and interventional radiology》2017,40(8):1285-1289
CardioVascular and Interventional Radiology - This study aims to discuss MRI-guided cryoablation (CA) of in-transit (IT) metastases from melanoma and to retrospectively present our preliminary... 相似文献
58.
Cristina?Bezzio Ilaria?Arena Massimo?Devani Barbara?Omazzi Gianpiero?Manes Simone?SaibeniEmail authorView authors OrcID profile 《International journal of colorectal disease》2017,32(7):1025-1028
Purpose
It is not clear whether aspecific ileitis may represent an early manifestation or a milder variant of Crohn’s disease or not. The aim of this study was to evaluate the clinical outcomes of aspecific ileitis.Methods
Subjects with at least one of the following signs at retrograde ileoscopy: erythema, nodularity, aftae, erosions, and ulcers were considered. They should not have had defined gastrointestinal disease, biochemical signs of inflammation, use of drugs, celiac disease, and intestinal infectious disease.Results
We enrolled 51 subjects (22 men), mean age (± SD) at colonoscopy of 41.1 ± 13.1 years. Indications to colonoscopy were overt or occult intestinal bleeding (18), diarrhoea (15), systemic signs (10), IBS-like symptoms (5), other (3). Ileal lesions were ulcers (9), erosions (26), aftae (10), nodularity (3), and erythema (3). At histological evaluation aspecific findings were observed. Forty-four out of 51 (86.3%) subjects underwent further investigations of small bowel. Second colonoscopy was performed in 31 (60.8%) persisting symptomatic subjects: ileitis was confirmed in 14 (46.6%). Ten out of 51 (19.6%) were eventually diagnosed as affected by Crohn’s disease.Conclusions
A substantial proportion of subjects with endoscopic and histological findings of aspecific ileitis is eventually diagnosed as affected by Crohn’s disease. In these subjects, a strict follow-up is strongly recommended.59.
Alessandra Parrella Mohamad Irani Derek Keating Stephen Chow Zev Rosenwaks Gianpiero D. Palermo 《Reproductive biomedicine online》2019,38(4):580-587
Research questionOoplasmic maturity has been studied for some time, but remains poorly defined. This study aimed to evaluate metaphase II (MII) oocyte competence in terms of fertilization, embryo development and cycle outcomes, according to the oocyte maturity ratio.DesignCouples treated by intracytoplasmic sperm injection (ICSI) between 1993 and 2017 with female partners ≤35 years old were included. Cycles were divided into four groups according to proportion of MII oocytes at the time of retrieval: optimal (76–100%), adequate (51–75%), partial (26–50%) and minimal (1–25%).ResultsA total of 7672 ICSI cycles (optimal: 4838; adequate: 2252; partial: 518; minimal oocyte maturity: 64) were included, in which 95,667 MII oocytes were injected using ejaculated spermatozoa. The decreasing proportion of MII significantly reduced normal fertilization (two pronuclei) (78.9% to 71.3%; P < 0.0001) with a corresponding increase in digynic three-pronuclei that rose from 2.6% in the optimal group to 4.7% in the minimal group (P = 0.003). Implantation (33% to 17%; P < 0.0001), clinical pregnancy (63.6% to 37.5%; P < 0.0001) and live birth rates (49.2% to 26.6%; P < 0.0001) were affected by the decreasing proportion of MII oocytes.ConclusionsA high proportion of immature sibling oocytes in the retrieved cohort affects the fertilization rate and embryo developmental competence of MII inseminated oocytes, clinical pregnancy and live birth rates, suggesting that, in addition to nuclear maturity, ooplasmic and membrane maturity are required for developmental competence of MII oocytes. These findings may provide guidance toward ovarian stimulation protocols aimed at achieving a greater proportion of MII oocytes, leading to higher fertilization rates and better pregnancy outcomes. 相似文献
60.
Strain and elongation of the vastus lateralis aponeurosis and tendon in vivo during maximal isometric contraction 总被引:8,自引:0,他引:8
Stafilidis S Karamanidis K Morey-Klapsing G Demonte G Brüggemann GP Arampatzis A 《European journal of applied physiology》2005,94(3):317-322
The strain and elongation of the vastus lateralis (VL) tendon, tendon plus aponeurosis, and aponeurosis were examined during maximal voluntary contractions on a Biodex-dynamometer (knee angle 115°, hip angle 140°) in 12 sprinters. Following a warm-up phase, the subjects were instructed to perform a gradual maximal knee extension and hold it for about 3 s. The kinematics of the leg were recorded using a Vicon 512 system with eight cameras operating at 120 Hz. Ultrasonography images were taken simultaneously from the VL myotendinous junction and the mid lateral part of the VL muscle belly. During the maximal isometric knee extensions, the knee joint rotated (13.6±5.9°), leading to an overestimation of the elongation of the tendinous tissues. After correcting for this, the maximal elongation of the VL tendon examined at the myotendinous junction was lower (P<0.05) than the maximal elongation of the VL tendon plus aponeurosis examined at the muscle belly (15 vs. 27 mm, respectively). The maximal estimated strains of the tendon, tendon plus aponeurosis, and aponeurosis showed no statistical differences (8±2%, 8±1%, and 7±2%, respectively, P>0.05). It is concluded that the strains of the human VL tendon, VL tendon plus aponeurosis, and VL aponeurosis, as estimated in vivo by two dimensional ultrasound during maximal isometric contractions, do not differ from each other. The displacement measured at a cross point in the VL muscle belly is significantly greater than that measured at the VL myotendinous junction. 相似文献