http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Huebsch, Nathaniel,Kearney, Cathal J.,Zhao, Xuanhe,Kim, Jaeyun,Cezar, Christine A.,Suo, Zhigang,Mooney, David J. National Academy of Sciences 2014 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.111 No.27
<P>Biological systems are exquisitely sensitive to the location and timing of physiologic cues and drugs. This spatiotemporal sensitivity presents opportunities for developing new therapeutic approaches. Polymer-based delivery systems are used extensively for attaining localized, sustained release of bioactive molecules. However, these devices typically are designed to achieve a constant rate of release. We hypothesized that it would be possible to create digital drug release, which could be accelerated and then switched back off, on demand, by applying ultrasound to disrupt ionically cross-linked hydrogels. We demonstrated that ultrasound does not permanently damage these materials but enables nearly digital release of small molecules, proteins, and condensed oligonucleotides. Parallel in vitro studies demonstrated that the concept of applying temporally short, high-dose “bursts” of drug exposure could be applied to enhance the toxicity of mitoxantrone toward breast cancer cells. We thus used the hydrogel system in vivo to treat xenograft tumors with mitoxantrone, and found that daily ultrasound-stimulated drug release substantially reduced tumor growth compared with sustained drug release alone. This approach of digital drug release likely will be applicable to a broad variety of polymers and bioactive molecules, and is a potentially useful tool for studying how the timing of factor delivery controls cell fate in vivo<I>.</I></P>
Yiyang Zhou,Andrew M. Cox,Christopher M. Kearney 한국식물생명공학회 2017 Plant biotechnology reports Vol.11 No.3
Agroinoculation transient expression systems are commonly accompanied with elevated pathogenesisrelated (PR) protein production and leaf necrosis. We identified the major PR proteins in Nicotiana benthamiana in response to agroinoculation and determined that their occurrence was mainly due to agrobacterium infection and the method of inoculation, rather than due to viral vectors overexpressing foreign proteins. A spray-on inoculation method was optimized in this research and used to obviate the leaf necrosis and PR proteins induced by agrobacterium. Subsequently, this method also increased the yield and purity of the protein-of-interest. A further investigation of PR protein induction by a necrosis-inducing protein, Jun a 1, suggested that the plant pathogenic response was related to biochemical integrity of plant cell wall, which was also confirmed by an osmo-stabilizing mannitol ex vivo culture experiment. These findings provide insight into the response of plants to agroinoculation and suggested a connection between cell wall weakening and PR protein elicitation.
Induced quadrupolar singlet ground state of praseodymium in a modulated pyrochlore
van Duijn, J.,Kim, K. H.,Hur, N.,Ruiz-Bustos, R.,Adroja, D. T.,Bridges, F.,Daoud-Aladine, A.,Fernandez-Alonso, F.,Wen, J. J.,Kearney, V.,Huang, Q. Z.,Cheong, S.-W.,Perring, T. G.,Broholm, C. American Physical Society 2017 Physical Review B Vol.96 No.9
<P>The complex structure and magnetism of Pr2-xBixRu2O7 was investigated by neutron scattering and extended x-ray absorption fine structure. Pr has an approximate doublet ground state and the first excited state is a singlet. While the B-site (Ru) is well ordered throughout, this is not the case for the A-site (Pr/Bi). A broadened distribution for the Pr-O-2 bond length at low temperature indicates the Pr environment varies from site to site even for x = 0. The environment about the Bi site is highly disordered ostensibly due to the 6s lone pairs on Bi3+. Correspondingly, we find that the non-Kramers doublet ground-state degeneracy, otherwise anticipated for Pr in the pyrochlore structure, is lifted so as to produce a quadrupolar singlet ground statewith a spatially varying energy gap. For x = 0, below TN, the Ru sublattice orders antiferromagnetically, with propagation vector k = (0,0,0) as forY(2)Ru(2)O(7). No ordering associated with the Pr sublattice is observed down to 100 mK. The low-energy magnetic response of Pr2-xBixRu2O7 features a broad spectrum of magnetic excitations associated with inhomogeneous splitting of the Pr quasidoublet ground state. For x = 0 (x = 0.97), the spectrum is temperature dependent (independent). It appears disorder associated with Bi alloying enhances the inhomogeneous Pr crystal-field level splitting so that intersite interactions become irrelevant for x = 0.97. The structural complexity for the A-site may be reflected in the hysteretic uniform magnetization of B-site ruthenium in the Neel phase.</P>