全文获取类型
收费全文 | 208篇 |
免费 | 13篇 |
国内免费 | 13篇 |
专业分类
化学 | 140篇 |
力学 | 3篇 |
数学 | 57篇 |
物理学 | 34篇 |
出版年
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 14篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1969年 | 2篇 |
1937年 | 1篇 |
1918年 | 1篇 |
排序方式: 共有234条查询结果,搜索用时 33 毫秒
131.
132.
Steven Murkli Jared Klemm Dr. Adam T. Brockett Michael Shuster Prof. Dr. Volker Briken Prof. Dr. Matthew R. Roesch Prof. Dr. Lyle Isaacs 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(9):3098-3105
We report investigations of the use of cucurbit[8]uril (CB[8]) macrocycles as an antidote to counteract the in vivo biological effects of phencyclidine. We investigate the binding of CB[8] and its derivative Me4CB[8] toward ten drugs of abuse ( 3 – 9 , 12 – 14 ) by a combination of 1H NMR spectroscopy and isothermal titration calorimetry in phosphate buffered water. We find that the cavity of CB[8] and Me4CB[8] are able to encapsulate the 1-amino-1-aryl-cyclohexane ring system of phencyclidine (PCP) and ketamine as well as the morphinan skeleton of morphine and hydromorphone with Kd values ≤50 nm . In vitro cytotoxicity (MTS metabolic and adenylate kinase cell death assays in HEK293 and HEPG2 cells) and in vivo maximum tolerated dose studies (Swiss Webster mice) which were performed for Me4CB[8] indicated good tolerability. The tightest host⋅guest pair (Me4CB[8]⋅PCP; Kd=2 nm ) was advanced to in vivo efficacy studies. The results of open field tests demonstrate that pretreatment of mice with Me4CB[8] prevents subsequent hyperlocomotion induction by PCP and also that treatment of animals previously dosed with PCP with Me4CB[8] significantly reduces the locomotion levels. 相似文献
133.
Ashley E. Truxal Dr. Liping Cao Prof. Dr. Lyle Isaacs Prof. Dr. David E. Wemmer Prof. Dr. Alexander Pines 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(24):6108-6112
Advancement of hyperpolarized 129Xe MRI technology toward clinical settings demonstrates the considerable interest in this modality for diagnostic imaging. The number of contrast agents, termed biosensors, for 129Xe MRI that respond to specific biological targets, has grown and diversified. Directly functionalized xenon-carrying macrocycles, such as the large family of cryptophane-based biosensors, are good for localization-based imaging and provide contrast before and after binding events occur. Noncovalently functionalized constructs, such as cucurbituril- and cyclodextrin-based biosensors, benefit from commercial availability and optimal exchange dynamics for CEST imaging. In this work, we report the first directly functionalized cucurbituril used as a xenon biosensor. Biotinylated cucurbit[7]uril (btCB7) gives rise to a 129Xe hyperCEST response at the unusual shift of δ=28 ppm when bound to its protein target with substantial CEST contrast. We posit that the observed chemical shift is due to the deformation of btCB7 upon binding to avidin, caused by proximity to the protein surface. Conformational searches and molecular dynamics (MD) simulations support this hypothesis. This construct combines the strengths of both families of biosensors, enables a multitude of biological targets through avidin conjugation, and demonstrates the advantages of functionalized cucurbituril-based biosensors. 相似文献
134.
Christiana M. Adeyemi Heinrich C. Hoppe Michelle Isaacs Rosalyn Klein Kevin A. Lobb Perry T. Kaye 《Tetrahedron》2019,75(16):2371-2378
An efficient synthetic pathway to a series of novel “reverse” fosmidomycin analogues has been developed, commencing from substituted benzylamines. In these analogues, the fosmidomycin hydroxamate moiety is reversed and the tetrahedral methylene carbon adjacent to the phosphonate moiety is replaced by a nitrogen atom bearing different benzyl groups. The resulting phosphonate esters were designed as potential antimalarial “pro-drugs”. 相似文献
135.
Canjia Zhai Prof. Lyle Isaacs 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(56):e202201743
We report that the direct macrocyclization of naphthalene monomers bearing ethyl ester functional groups delivers prism[5]arene derivatives, which can be deprotected to yield water-soluble prism[5]arenes ( H1 and H3 ). 1H NMR spectroscopy showed that dicationic guests bind with the hydrophobic cores buried inside the anisotropic magnetically shielding cavity. Isothermal titration calorimetry measurements showed that H1 and H3 are high-affinity hosts in PBS-buffered water with Ka values exceeding 109 M−1 for a select guest. The complexation events are driven by the non-classical hydrophobic effect, CH⋅⋅⋅π interactions, and electrostatic interactions. Host H1 displays somewhat higher affinity toward a common guest than pillar[6]arene bearing carboxylic acid functional groups but is significantly less potent than pillar[6]arene bearing sulfate groups. H1 and H3 should be considered alongside other high affinity hosts for a variety of chemical and biological applications. 相似文献
136.
Inside Back Cover: A Nexus between Theory and Experiment: Non‐Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]uril⋅Guest Binding Interactions (Chem. Eur. J. 48/2016) 下载免费PDF全文
Jiří Hostaš Dr. David Sigwalt Marina Šekutor Haresh Ajani Dr. Matúš Dubecký Prof. Jan Řezáč Dr. Peter Y. Zavalij Dr. Liping Cao Christian Wohlschlager Prof. Kata Mlinarić‐Majerski Prof. Lyle Isaacs Prof. Robert Glaser Prof. Pavel Hobza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17487-17487
137.
J. A. Isaacs A. Tanwani M. L. Healy L. J. Dahlben 《Journal of nanoparticle research》2010,12(2):551-562
The carbon nanotube market is steadily growing and projected to reach $1.9 billion by 2010. This study examines the economics
of manufacturing single-walled carbon nanotubes (SWNT) using process-based cost models developed for arc, CVD, and HiPco processes.
Using assumed input parameters, manufacturing costs are calculated for 1 g SWNT for arc, CVD, and HiPco, totaling $1.9 billion by 2010. This study examines the economics
of manufacturing single-walled carbon nanotubes (SWNT) using process-based cost models developed for arc, CVD, and HiPco processes.
Using assumed input parameters, manufacturing costs are calculated for 1 g SWNT for arc, CVD, and HiPco, totaling 1,906,
1,706, and1,706, and 485, respectively. For each SWNT process, the synthesis and filtration steps showed the highest costs, with direct
labor as a primary cost driver. Reductions in production costs are calculated for increased working hours per day and for
increased synthesis reaction yield (SRY) in each process. The process-based cost models offer a means for exploring opportunities
for cost reductions, and provide a structured system for comparisons among alternative SWNT manufacturing processes. Further,
the models can be used to comprehensively evaluate additional scenarios on the economics of environmental, health, and safety
best manufacturing practices. 相似文献
138.
Huang WH Liu S Zavalij PY Isaacs L 《Journal of the American Chemical Society》2006,128(46):14744-14745
The condensation of glycoluril and formaldehyde in concentrated HCl at 50 degrees C delivers nor-seco-cucurbit[10]uril (ns-CB [10]). 1H NMR and X-ray crystallographic evidence indicates that the two cavities of ns-CB[10] accommodate guests that are typically bound within CB[6] or CB[7]. Several interesting types of selectivity are possible within these ternary complexes-top/center isomerism, diastereoselective complexation of chiral (but racemic) guest pairs, and guest size controlled homotropic allosterism. 相似文献
139.
Let p be the smallest prime divisor of the order of a finite group G. We find sufficient conditions for G to be p-nilpotent based on the existence of complements in G for p-subgroups of certain orders. In particular, we generalize a recent result of M. Asaad. 相似文献
140.
I. M. Isaacs 《Archiv der Mathematik》2012,98(5):399-401
Let A be a group acting via automorphisms on a group G, and let Ω be the set of orbits in this action. Then C = C G (A) acts on Ω in a natural manner, and using this action, we deduce some divisibility information about |Ω|. 相似文献