全文获取类型
收费全文 | 640篇 |
免费 | 37篇 |
国内免费 | 1篇 |
专业分类
678篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 20篇 |
2021年 | 25篇 |
2020年 | 34篇 |
2019年 | 58篇 |
2018年 | 40篇 |
2017年 | 28篇 |
2016年 | 29篇 |
2015年 | 21篇 |
2014年 | 48篇 |
2013年 | 63篇 |
2012年 | 52篇 |
2011年 | 48篇 |
2010年 | 20篇 |
2009年 | 25篇 |
2008年 | 26篇 |
2007年 | 31篇 |
2006年 | 24篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 4篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 2篇 |
排序方式: 共有678条查询结果,搜索用时 15 毫秒
541.
Mehrzad Hajialilo Sanam Dolati Samaneh Abdolmohammadi-Vahid Majid Ahmadi Amin Kamrani Shadi Eghbal-Fard Arezou Ghassembaglou Amir Valizadeh Mohammad Hossein Musavi Shenas Leili Aghebati-Maleki Hossein Samadi Kafil Amir Mehdizadeh Mehdi Yousefi 《Journal of cellular biochemistry》2019,120(7):12027-12038
542.
Majid Alizadeh Mahdi Ghorbani Abbas Haghparast Naser Zare Toktam Ahmadi Moghaddas 《Reports of Practical Oncology and Radiotherapy》2015,20(3):204-209
Aim
The aim of this study is to evaluate the dose distribution of the Flexisource 192Ir source.Background
Dosimetric evaluation of brachytherapy sources is recommended by task group number 43 (TG. 43) of American Association of Physicists in Medicine (AAPM).Materials and methods
MCNPX code was used to simulate Flexisource 192Ir source. Dose rate constant and radial dose function were obtained for water and soft tissue phantoms and compared with previous data on this source. Furthermore, dose rate along the transverse axis was obtained by simulation of the Flexisource and a point source and the obtained data were compared with those from Flexiplan treatment planning system (TPS).Results
The values of dose rate constant obtained for water and soft tissue phantoms were equal to 1.108 and 1.106, respectively. The values of the radial dose function are listed in the form of tabulated data. The values of dose rate (cGy/s) obtained are shown in the form of tabulated data and figures. The maximum difference between TPS and Monte Carlo (MC) dose rate values was 11% in a water phantom at 6.0 cm from the source.Conclusion
Based on dosimetric parameter comparisons with values previously published, the accuracy of our simulation of Flexisource 192Ir was verified. The results of dose rate constant and radial dose function in water and soft tissue phantoms were the same for Flexisource and point sources. For Flexisource 192Ir source, the results of TPS calculations in a water phantom were in agreement with the simulations within the calculation uncertainties. Furthermore, the results from the TPS calculation for Flexisource and MC calculation for a point source were practically equal within the calculation uncertainties. 相似文献543.
Jazireian Parham Sasani Soheila Talesh Assarzadegan Farhad Azimian Mojtaba 《Molecular biology reports》2020,47(12):9659-9665
Molecular Biology Reports - Multiple sclerosis (MS) is an autoimmune-type inflammatory disorder in human central nervous system. Recombinant interferon beta (IFN-β) decreases the number of... 相似文献
544.
Lotfi Ramin Davoodi Akram Mortazavi Seyed Hamidreza Gorgin Karaji Ali Tarokhian Hanieh Rezaiemanesh Alireza Salari Farhad 《Molecular biology reports》2020,47(10):7745-7754
Molecular Biology Reports - Timely and successful resolution of acute inflammation plays a crucial role in preventing the development of chronic airway inflammation in allergic rhinitis (AR). This... 相似文献
545.
Narges Rostami Afshin Nikkhoo Yalda Khazaei-poul Shohreh Farhadi Melika Sadat Haeri Sadaf Moghadaszadeh Ardebili Nasimeh Aghaei Vanda Fatemeh Atyabi Afshin Namdar Masoumeh Baghaei Navideh Haghnavaz Tohid Kazemi Mehdi Yousefi Ghasem Ghalamfarsa Gholamabas Sabz Farhad Jadidi-Niaragh 《Journal of cellular physiology》2020,235(12):9702-9717
546.
547.
Dehghan G Dolatabadi JE Jouyban A Zeynali KA Ahmadi SM Kashanian S 《DNA and cell biology》2011,30(3):195-201
The interaction of native calf thymus DNA (CT-DNA) with quercetin-terbium(III) [Q-Tb(III)] complex at physiological pH was monitored by UV absorption spectrophotometry, circular dichroism, fluorescence spectroscopy, and viscosimetric techniques. The complex displays binding properties to the CT-DNA and was found to interact with CT-DNA through outside binding, demonstrated by a hypochromic effect of Q-Tb(III) on the UV spectra of CT-DNA and the calculated association constants (K). Also, decrease in the specific viscosity of CT-DNA, decrease in the fluorescence intensity of Q-Tb(III) solutions in the presence of increasing amounts of CT-DNA, and detectable changes in the circular dichroism spectrum of CT-DNA are other evidences to indicate that Q-Tb(III) complex interact with CT-DNA through outside binding. 相似文献
548.
Farhad Mashayekhi Elham Dianati Lotfali Masomi Moghadam 《Saudi Journal of Biological Sciences》2011,18(2):209-212
Nerve growth factor (NGF) and most neurotrophic factors support the proliferation and survival of particular types of neurons. Besidesthe pivotal role of NGF in the development of neuronal cells, it also has important functions on non-neuronal cells. The amnion surrounds the embryo, providing an aqueous environment for the embryo. A wide range of proteins has been identified in human amniotic fluid (AF). In this study, total protein concentration (TPC) and NGF level in AF samples from chick embryos were measured using a Bio-Rad protein assay, enzyme linked immunosorbent assay (ELISA) and Western blot. TPC increased from days E10 to day E18. There was a rapid increase in AF TPC on day E15 when compared to day E16. No significant changes in NGF levels have been seen from day E10 to day E14. There was a rapid increase in NGF content on days E15 and E16, and thereafter the levels decreased from day E16 to day E18. Since, NGF is important in brain development and changes in AF NGF levels have been seen in some CNS malformations, changes in the TPC and NGF levels in AF during chick embryonic development may be correlated with cerebral cortical development. It is also concluded that NGF is a constant component of the AF during chick embryogenesis. 相似文献
549.
Peptide hydrogels show immense promise as therapeutic materials. Here we present a rationally designed multidomain peptide that self-assembles into nanofibers approximately 8 nm wide, 2 nm high, and micrometers in length in the presence of Mg(2+). At a concentration of 1% by weight, the peptide forms an extensive nanofibers network that results in a physically cross-linked viscoelastic hydrogel. This hydrogel undergoes shear thinning and then quickly recovers nearly 100% of its elastic modulus when the shearing force is released, making it ideal for use as an injectable material. When placed in the presence of human embryonic stem cells (ESCs), the nanofibrous hydrogel acts like a sponge, soaking up the vast array of growth factors and cytokines released by the ESCs. The peptide hydrogel sponge can then be removed from the presence of the ESCs and placed in a therapeutic environment, where it can subsequently release these components. In vitro experiments demonstrate that release of stem cell secretome from these hydrogels in the presence of glomerular epithelial cells treated with high glucose significantly decreased protein permeability in a model of diabetes-induced kidney injury. Tracking experiments were then performed to determine the fate of the hydrogel upon injection in vivo. Hydrogels labeled with a Gd(3+) MRI contrast agent were injected into the abdominal cavity of mice and found to remain localized over 24 h. This implies that the hydrogel possesses sufficient rigidity to remain localized and release stem cell secretome over time rather than immediately dissolving in the abdominal cavity. Together, the shear thinning and recovery as observed by rheometry as well as secretome absorption and release in vivo demonstrate the potential of the nanofibrous multidomain peptide hydrogel as an injectable delivery agent. 相似文献
550.
Nicholson G Rantalainen M Li JV Maher AD Malmodin D Ahmadi KR Faber JH Barrett A Min JL Rayner NW Toft H Krestyaninova M Viksna J Neogi SG Dumas ME Sarkans U;MolPAGE Consortium Donnelly P Illig T Adamski J Suhre K Allen M Zondervan KT Spector TD Nicholson JK Lindon JC Baunsgaard D Holmes E McCarthy MI Holmes CC 《PLoS genetics》2011,7(9):e1002270
We have performed a metabolite quantitative trait locus (mQTL) study of the (1)H nuclear magnetic resonance spectroscopy ((1)H NMR) metabolome in humans, building on recent targeted knowledge of genetic drivers of metabolic regulation. Urine and plasma samples were collected from two cohorts of individuals of European descent, with one cohort comprised of female twins donating samples longitudinally. Sample metabolite concentrations were quantified by (1)H NMR and tested for association with genome-wide single-nucleotide polymorphisms (SNPs). Four metabolites' concentrations exhibited significant, replicable association with SNP variation (8.6×10(-11)
相似文献