116,662 research outputs found
Amberlite IR-120H: An improved reusable solid phase catalyst for the synthesis of nitriles under solvent free microwave irradiation
An efficient green protocol has been developed for the conversion of a range of aldehydes to the corresponding nitriles using a solid-phase reusable catalyst combined with microwave irradiation. The highlighting features of this method are short reaction time, environmentally compatible, reusability of the catalyst and good product yield
Protocol : a method to study the direct reprogramming of lateral root primordia to fertile shoots
Background: Plants have the remarkable property to elaborate entire body plan from any tissue part. The conversion of lateral root primordium (LRP) to shoot is an ideal method for plant propagation and for plant researchers to understand the mechanism underlying trans-differentiation. Until now, however, a robust method that allows the efficient conversion of LRP to shoot is lacking. This has limited our ability to study the dynamic phases of reprogramming at cellular and molecular levels. Results: Here we present an efficient protocol for the direct conversion of LRP to a complete fertile shoot system. This protocol can be readily applied to the various ecotypes of Arabidopsis. We show that, the conversion process is highly responsive to developmental stages of LRP and changes in external environmental stimuli such as temperature. The entire conversion process can be adequately analyzed by histological and imaging techniques. As a demonstration, using a battery of cell fate specific markers, we show that confocal time-lapse imaging can be employed to uncover the early molecular events, intermediate developmental phases and relative abundance of stem cell regulators during the conversion of LRP to shoot. Conclusion: Our method is highly efficient, independent of genotypes tested and suitable to study the reprogramming of LRP to shoot in intact plants as well as in excised roots.Peer reviewe
Near-perfect measuring of full-field transverse-spatial modes of light
Along with the growing interest in using the transverse-spatial modes of
light in quantum and classical optics applications, developing an accurate and
efficient measurement method has gained importance. Here, we present a
technique relying on a unitary mode conversion for measuring any full-field
transverse-spatial mode. Our method only requires three consecutive phase
modulations followed by a single mode fiber and is, in principle, error-free
and lossless. We experimentally test the technique using a single spatial light
modulator and achieve an average error of 4.2% for a set of 9 different
full-field Laguerre-Gauss and Hermite-Gauss modes with an efficiency of up to
70%. Moreover, as the method can also be used to measure any complex
superposition state, we demonstrate its potential in a quantum cryptography
protocol and in high-dimensional quantum state tomography.Comment: 7 pages, 4 figure
Pitfalls in histone propionylation during bottom-up mass spectrometry analysis
Despite their important role in regulating gene expression, posttranslational histone modifications remain technically challenging to analyze. For identification by bottom-up MS, propionylation is required prior to and following trypsin digestion. Hereby, more hydrophobic peptides are generated enabling RP HPLC separation. When histone dynamics are studied in a quantitative manner, specificity, and efficiency of this chemical derivatization are crucial. Therefore we examined eight different protocols, including two different propionylation reagents. This revealed amidation (up to 70%) and methylation (up to 9%) of carboxyl groups as a side reaction. Moreover, incomplete (up to 85%) as well as a specific propionylation (up to 63%) can occur, depending on the protocol. These results highlight the possible pitfalls and implications for data analysis when doing bottom-up MS on histones
Quantum interface between photonic and superconducting qubits
We show that optically active coupled quantum dots embedded in a
superconducting microwave cavity can be used to realize a fast quantum
interface between photonic and transmon qubits. Single photon absorption by a
coupled quantum dot results in generation of a large electric dipole, which in
turn ensures efficient coupling to the microwave cavity. Using cavity
parameters achieved in prior experiments, we estimate that bi-directional
microwave-optics conversion in nanosecond timescales with efficiencies
approaching unity is experimentally feasible with current technology. We also
outline a protocol for in-principle deterministic quantum state transfer from a
time-bin photonic qubit to a transmon qubit. Recent advances in quantum dot
based quantum photonics technologies indicate that the scheme we propose could
play a central role in connecting quantum nodes incorporating cavity-coupled
superconducting qubits
Path computation in multi-layer networks: Complexity and algorithms
Carrier-grade networks comprise several layers where different protocols
coexist. Nowadays, most of these networks have different control planes to
manage routing on different layers, leading to a suboptimal use of the network
resources and additional operational costs. However, some routers are able to
encapsulate, decapsulate and convert protocols and act as a liaison between
these layers. A unified control plane would be useful to optimize the use of
the network resources and automate the routing configurations. Software-Defined
Networking (SDN) based architectures, such as OpenFlow, offer a chance to
design such a control plane. One of the most important problems to deal with in
this design is the path computation process. Classical path computation
algorithms cannot resolve the problem as they do not take into account
encapsulations and conversions of protocols. In this paper, we propose
algorithms to solve this problem and study several cases: Path computation
without bandwidth constraint, under bandwidth constraint and under other
Quality of Service constraints. We study the complexity and the scalability of
our algorithms and evaluate their performances on real topologies. The results
show that they outperform the previous ones proposed in the literature.Comment: IEEE INFOCOM 2016, Apr 2016, San Francisco, United States. To be
published in IEEE INFOCOM 2016, \<http://infocom2016.ieee-infocom.org/\&g
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