全文获取类型
收费全文 | 639篇 |
免费 | 45篇 |
专业分类
684篇 |
出版年
2024年 | 4篇 |
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 30篇 |
2020年 | 12篇 |
2019年 | 18篇 |
2018年 | 20篇 |
2017年 | 28篇 |
2016年 | 40篇 |
2015年 | 39篇 |
2014年 | 38篇 |
2013年 | 64篇 |
2012年 | 69篇 |
2011年 | 58篇 |
2010年 | 29篇 |
2009年 | 32篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 20篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1973年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
111.
112.
113.
114.
115.
En route to economical eco‐friendly solvent system in enhancing sustainable recovery of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) copolymer 下载免费PDF全文
Nik Murniati Nik Man Irdahayu Kannusamy Shantini Kai‐Hee Huong Sevakumaran Vigneswari Nursolehah Abdul Aziz Mohd. Noor Mohd. Azizan Al‐Ashraf Abdullah Amirul 《Engineering in Life Science》2017,17(9):1050-1059
Separation of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) [P(3HB‐co‐4HB)] from bacterial cell matter is a critical step in the downstream process with respect to material quality and eco‐balance as P(3HB‐co‐4HB) is widely used for biomedical applications. Therefore, an efficient and eco‐based extraction of P(3HB‐co‐4HB) using a combination of NaOH and Lysol in digesting the non‐polymeric cell material (NPCM) digestion is developed. The NaOH and Lysol show synergistic influence on the copolymer extraction at a high purity and recovery of 97 and 98 wt% respectively. The optimized cell digestion method was found applicable to a vast batch of cells containing copolymers from various 4HB monomer compositions. At the largest extraction volume of 100 L, P(3HB‐co‐4HB) with a purity of 89 wt% was extracted with a maximum recovery of 90 wt%. The method developed has also eliminated the cell pretreatment step. The extraction method developed in this research has not only produced an economic and efficient copolymer recovery but has also retained the copolymer quality, in term of its molecular weight and thermal properties. It demonstrates a practical and promising downstream processing method in recovering the copolymer effectively from the bacterial biomass. 相似文献
116.
117.
Atatreh N Stojkoski C Smith P Booker GW Dive C Frenkel AD Freeman S Bryce RA 《Bioorganic & medicinal chemistry letters》2008,18(3):1217-1222
Src signalling and transduction are directly involved in cell growth, cell cycle, malignant transformation and cell migration, providing therapeutic opportunities through inhibition of Src. Here we report virtual screening for novel compounds that inhibit the Src-SH3 protein-protein interaction with a proline-rich peptide ligand. Computational docking of the ZINC compound database was performed using GOLD. Top-scoring compounds were assayed using a fluorescence polarization-based assay. A benzoquinoline derivative showed micromolar inhibition of binding between Src-SH3 and the proline-rich peptide. Several analogues were subsequently assayed showing the requirement of a linker between the benzoquinoline and phenyl rings, and electron donating substituents on the phenyl ring. 相似文献
118.
Khalit Mohamad Yusuke Hirasawa Marc Litaudon Khalijah Awang A. Hamid A. Hadi Koichi Takeya Wiwied Ekasari Aty Widyawaruyanti Noor Cholies Zaini Hiroshi Morita 《Bioorganic & medicinal chemistry》2009,17(2):727-730
Three new limonoids, ceramicines B–D (1–3), have been isolated from the bark of Chisocheton ceramicus. Structures and stereochemistry of 1–3 were fully elucidated and characterized by 2D NMR analysis. Ceramicines exhibited a moderate antiplasmodial activity. 相似文献
119.
Kian Mau Goh Nor Muhammad Mahadi Osman Hassan Raja Noor Zaliha Raja Abdul Rahman Rosli Md Illias 《Journal of Molecular Catalysis .B, Enzymatic》2009,57(1-4):270-277
Low reaction yields and the high cost of obtaining a single type of pure CD make γ-CD costly. Using rational design and with the aid of 3D modeling structures, recombinant CGTase from Bacillus sp. G1 was molecularly engineered with the aim of producing a higher percentage of γ-CD. A single mutation at subsite −3, denoted H43T, was found to increase γ-CD production from 10% to approximately 39% using tapioca starch. This novel increment was probably the result of reduced steric hindrance to the formation of γ-CD because of the shortened side chain together with the shortened loop at positions 86–89, at substrate-binding subsite −3. A mutation (Tyr188 → Trp) and a deletion at loop 139–144 showed little effect on product specificity; however, mutagenesis at these sites affected cyclization, coupling and hydrolysis activities as well as the kinetic properties of the mutant CGTase. Based on rational design, three further mutations of the mutant H43T (denoted H43T/Δ(139–144)/S134T/A137V/L138D/V139I, H43T/S85G and H43T/Y87F) were constructed and produced γ-CD with yields of 20%, 20% and 39%, respectively. The mutant H43T/Δ(139–144)/S134T/A137V/L138D/V139I had very low cyclization and coupling activities, however their hydrolysis activity was retained. Double mutation (H43T/S85G) caused the enzyme to exhibit higher starch hydrolysis activity, approximately 26 times higher than the native CGTase G1. Although the mutants H43T and H43T/Y87F could produce the same percentage (39%) of γ-CD, the latter was more efficient as the total amount of CD produced was higher based on the Vmax and kcat values. 相似文献
120.
James S. Friedman Naushin Waseem Matthew J. Brooks Debra Breuer Daniel S. Krauth Lori S. Sullivan Lotta Gränse Edward H. Trager Dianna Hughbanks-Wheaton Noor M. Ghiasvand Christina F. Chakarova Harald H.H. Göring David G. Birch Yang Fann Stephen P. Daiger Sten Andréasson 《American journal of human genetics》2009,84(6):792-800
Retinitis pigmentosa (RP) refers to a genetically heterogeneous group of progressive neurodegenerative diseases that result in dysfunction and/or death of rod and cone photoreceptors in the retina. So far, 18 genes have been identified for autosomal-dominant (ad) RP. Here, we describe an adRP locus (RP42) at chromosome 7p15 through linkage analysis in a six-generation Scandinavian family and identify a disease-causing mutation, c.449G→A (p.S150N), in exon 6 of the KLHL7 gene. Mutation screening of KLHL7 in 502 retinopathy probands has revealed three different missense mutations in six independent families. KLHL7 is widely expressed, including expression in rod photoreceptors, and encodes a 75 kDa protein of the BTB-Kelch subfamily within the BTB superfamily. BTB-Kelch proteins have been implicated in ubiquitination through Cullin E3 ligases. Notably, all three putative disease-causing KLHL7 mutations are within a conserved BACK domain; homology modeling suggests that mutant amino acid side chains can potentially fill the cleft between two helices, thereby affecting the ubiquitination complexes. Mutations in an identical region of another BTB-Kelch protein, gigaxonin, have previously been associated with giant axonal neuropathy. Our studies suggest an additional role of the ubiquitin-proteasome protein-degradation pathway in maintaining neuronal health and in disease. 相似文献