全文获取类型
收费全文 | 1563篇 |
免费 | 100篇 |
专业分类
1663篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 41篇 |
2020年 | 16篇 |
2019年 | 31篇 |
2018年 | 49篇 |
2017年 | 33篇 |
2016年 | 57篇 |
2015年 | 72篇 |
2014年 | 76篇 |
2013年 | 87篇 |
2012年 | 128篇 |
2011年 | 126篇 |
2010年 | 98篇 |
2009年 | 89篇 |
2008年 | 101篇 |
2007年 | 94篇 |
2006年 | 83篇 |
2005年 | 95篇 |
2004年 | 83篇 |
2003年 | 65篇 |
2002年 | 55篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 9篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1944年 | 2篇 |
排序方式: 共有1663条查询结果,搜索用时 0 毫秒
1.
Giacomo Zaccone John Maina Antonino Germanà Giuseppe Montalbano Gioele Capillo Luisa Aragona Michał J. Kuciel Eugenia Rita Lauriano José M. Icardo 《Acta zoologica》2019,100(2):160-166
Available studies that have examined O2 sensing in fish have indicated that oxygen-sensitive neuroepithelial cells (NECs) are O2 sensors in the gills and initiate cardiorespiratory reflexes in aquatic vertebrates. This is the first study describing the occurrence of NECs in accessory respiratory organs in the air-breathing catfish Clarias gariepinus. Immunocytochemical stainings with specific neuronal markers such as nNOS, VAchT, 5-HT and TH have been shown to be very useful for location and distribution of these cells in the gill fans and suprabranchial chamber that take origin from the transformation of the gill tissue. But the response of these putative O2 chemoreceptors, their role in the respiratory reflexes and their innervation await investigation. 相似文献
2.
3.
4.
Cardiolipin (CL) plays a key role in dynamic organization of bacterial and mitochondrial membranes. CL forms membrane domains in bacterial cells, and these domains appear to participate in binding and functional regulation of multi-protein complexes involved in diverse cellular functions including cell division, energy metabolism, and membrane transport. Visualization of CL domains in bacterial cells by the fluorescent dye 10-N-nonyl acridine orange is critically reviewed. Possible mechanisms proposed for CL dynamic localization in bacterial cells are discussed. In the mitochondrial membrane CL is involved in organization of multi-subunit oxidative phosphorylation complexes and in their association into higher order supercomplexes. Evidence suggesting a possible role for CL in concert with ATP synthase oligomers in establishing mitochondrial cristae morphology is presented. Hypotheses on CL-dependent dynamic re-organization of the respiratory chain in response to changes in metabolic states and CL dynamic re-localization in mitochondria during the apoptotic response are briefly addressed. 相似文献
5.
Iveković R Novak-Laus K Tedeschi-Reiner E Masnec-Paskvalin S Sarić D Mandić Z 《Collegium antropologicum》2005,29(Z1):33-36
A chief morbidity of Graves eye disease is eyelid retraction and exophthalmus. Transpalpebral orbital fat removal accomplished with full thickness anterior blepharotomy was performed in 4 patients (5 orbits). Preoperative and postoperative ocular exposure symptoms, visual acuity, upper eyelid retraction and proptosis were evaluated. In all 5 operated orbits preoperative symptoms resolved; good results were achieved from the functional and cosmetic point of view. Full-thickness anterior blepharotomy combined with fat decompression is a safe and effective surgery for patients with upper eyelid retraction and exophthalmus due to enlarged orbital fat compartment. 相似文献
6.
7.
García-Huante Yolanda Cayetano-Cruz Maribel Santiago-Hernández Alejandro Cano-Ramírez Claudia Marsch-Moreno Rodolfo Campos Jorge E. Aguilar-Osorio Guillermo Benitez-Cardoza Claudia G. Trejo-Estrada Sergio Hidalgo-Lara María Eugenia 《Extremophiles : life under extreme conditions》2017,21(1):175-186
Extremophiles - A hyperthermophilic and thermostable xylanase of 82 kDa (TtXynA) was purified from the culture supernatant of T. terrestris Co3Bag1, grown on carboxymethyl cellulose (CMC),... 相似文献
8.
9.
10.
Annarita Tullio Alessandro Magli Eugenia Moretti Francesca Valent 《Reports of Practical Oncology and Radiotherapy》2019,24(6):511-519
AimThe aim of the present study is to evaluate and quantify the bias of competing risks in an Italian oncologic cohort comparing results from different statistical analysis methods.BackgroundCompeting risks are very common in randomized clinical trials and observational studies, in particular oncology and radiotherapy ones, and their inappropriate management causes results distortions widely present in clinical scientific articles.Materials and methodsThis is a single-institution phase II trial including 41 patients affected by prostate cancer and undergoing radiotherapy (IMRT-SIB) at the University Hospital of Udine.Different outcomes were considered: late toxicities, relapse, death.Death in the absence of relapse or late toxicity was considered as a competing event.ResultsThe Kaplan Meier method, compared to cumulative incidence function method, overestimated the probability of the event of interest (toxicity and biochemical relapse) and of the competing event (death without toxicity/relapse) by 9.36%. The log-rank test, compared to Gray's test, overestimated the probability of the event of interest by 5.26%.The Hazard Ratio's and cause specific hazard's Cox regression are not directly comparable to subdistribution hazard's Fine and Gray's modified Cox regression; nonetheless, the FG model, the best choice for prognostic studies with competing risks, found significant associations not emerging with Cox regression.ConclusionsThis study confirms that using inappropriate statistical methods produces a 10% overestimation in results, as described in the literature, and highlights the importance of taking into account the competing risks bias. 相似文献