Read by QxMD icon Read


Selma M Cuya, Mary-Ann Bjornsti, Robert C A M van Waardenburg
To resolve the topological problems that threaten the function and structural integrity of nuclear and mitochondrial genomes and RNA molecules, human cells encode six different DNA topoisomerases including type IB enzymes (TOP1 and TOP1mt), type IIA enzymes (TOP2α and TOP2β) and type IA enzymes (TOP3α and TOP3β). DNA entanglements and the supercoiling of DNA molecules are regulated by topoisomerases through the introduction of transient enzyme-linked DNA breaks. The covalent topoisomerase-DNA complexes are the cellular targets of a diverse group of cancer chemotherapeutics, which reversibly stabilize these reaction intermediates...
May 20, 2017: Cancer Chemotherapy and Pharmacology
Peter Fulde, Hermann Stoll
An alternative to the density functional theory is the use of wavefunction based electronic structure calculations for solids. In order to perform them, the Exponential Wall (EW) problem has to be resolved. It is caused by an exponential increase of the number of configurations with increasing electron number N. There are different routes one may follow. One is to characterize a many-electron wavefunction by a vector in Liouville space with a cumulant metric rather than in Hilbert space. This removes the EW problem...
May 21, 2017: Journal of Chemical Physics
Peng Xue, Xian Zhan, Zhihao Bian
We experimentally demonstrate a photonic quantum simulator: by using a two-spin Ising chain (an isolated dimer) as an example, we encode the wavefunction of the ground state with a pair of entangled photons. The effect of magnetic fields, leading to a critical modification of the correlation between two spins, can be simulated by just local operations. With the ratio of simulated magnetic fields and coupling strength increasing, the ground state of the system changes from a product state to an entangled state and back to another product state...
May 19, 2017: Scientific Reports
Sina Saravi, Thomas Pertsch, Frank Setzpfandt
We propose the use of nonlinear periodic waveguides for direct and fully integrated generation of counterpropagating photon pairs by spontaneous parametric down-conversion. Using the unique properties of Bloch modes in such periodic structures, we furthermore show that two counterpropagating phase-matching conditions can be fulfilled simultaneously, allowing for the generation of path-entangled Bell states in a single periodic waveguide. To demonstrate the feasibility of our proposal, we design a photonic crystal slab waveguide made of lithium niobate and numerically demonstrate Bell-state generation...
May 5, 2017: Physical Review Letters
Jugal Kishore Sahoo, Calvin Nazareth, Michael A VandenBerg, Matthew J Webber
Supramolecular chemistry enables the creation of a diversity of nanostructures and materials. Many of these have been explored for applications as biomaterials and therapeutics. Among them, self-assembling peptides have been broadly applied. The structural diversity afforded from the library of amino acid building blocks has enabled control of emergent properties across length-scales. Here, we report on a family of amphiphilic tripeptides with sequence-controlled nanostructure. By altering one amino acid in these peptides, we can produce a diversity of nanostructures with different aspect-ratio and geometry...
May 18, 2017: Biomaterials Science
Ting-Ting Song, Xiaoqing Tan, Tianyin Wang
Cluster states, whose model are a remarkably rich structure in measurement-based quantum computation, hold high degree of entanglement, while entanglement is very fragile during the process of transmission because of the inevitable interaction with the environment. We propose two entanglement concentration protocols for four-particle linear cluster states which and are susceptible to the decoherence and the imperfect communication setups. In the first protocol, POVM operators are introduced to maximize the success probability, and the second protocol is based on cross-Kerr nonlinearity which is utilized to check the parity between the original particle and the ancillary particle...
May 16, 2017: Scientific Reports
Qiting Li, Jianlian Cui, Shuhao Wang, Gui-Lu Long
By introducing an arbitrary-dimensional multipartite entanglement measure, which is defined in terms of the reduced density matrices corresponding to all possible two partitions of the entire system, we prove that multipartite entanglement cannot be freely shared among the parties in both n-qubit systems and three-qutrit systems. Furthermore, our result implies that the satisfaction of the entanglement monogamy is related to the number of particles in the quantum system. As an application of three-qutrit monogamy inequality, we give a condition for the separability of a class of two-qutrit mixed states in a 3 ⊗ 3 system...
May 16, 2017: Scientific Reports
Gufei Zhang, Tomas Samuely, Zheng Xu, Johanna K Jochum, Alexander Volodin, Shengqiang Zhou, Paul W May, Oleksandr Onufriienko, Jozef Kačmarčík, Julian A Steele, Jun Li, Johan Vanacken, Jiri Vacík, Pavol Szabó, Haifeng Yuan, Maarten B J Roeffaers, Dorin Cerbu, Peter Samuely, Johan Hofkens, Victor V Moshchalkov
Superconductivity and ferromagnetism are two mutually antagonistic states in condensed matter. Research on the interplay between these two competing orderings sheds light not only on the cause of various quantum phenomena in strongly correlated systems but also on the general mechanism of superconductivity. Here we report on the observation of the electronic entanglement between superconducting and ferromagnetic states in hydrogenated boron-doped nanodiamond films, which have a superconducting transition temperature Tc ~ 3 K and a Curie temperature TCurie > 400 K...
May 16, 2017: ACS Nano
Dylan J Saunders, Adam J Bennet, Cyril Branciard, Geoff J Pryde
Quantum mechanics admits correlations that cannot be explained by local realistic models. The most studied models are the standard local hidden variable models, which satisfy the well-known Bell inequalities. To date, most works have focused on bipartite entangled systems. We consider correlations between three parties connected via two independent entangled states. We investigate the new type of so-called "bilocal" models, which correspondingly involve two independent hidden variables. These models describe scenarios that naturally arise in quantum networks, where several independent entanglement sources are used...
April 2017: Science Advances
Kamel Ourabah, Mouloud Tribeche
In this paper, we consider entanglement in a system out of equilibrium, adopting the viewpoint given by the formalism of superstatistics. Such an approach yields a good effective description for a system in a slowly fluctuating environment within a weak interaction between the system and the environment. For this purpose, we introduce an alternative version of the formalism within a quantum mechanical picture and use it to study entanglement in the Heisenberg XY model, subject to temperature fluctuations. We consider both isotropic and anisotropic cases and explore the effect of different temperature fluctuations (χ^{2}, log-normal, and F distributions)...
April 2017: Physical Review. E
Masoumeh Keshavarz, Hans Engelkamp, Jialiang Xu, Onno I Van Den Boomen, Jan C Maan, Peter C M Christianen, Alan E Rowan
We directly track the tube-like motion of individual fluorescently labeled polymer molecules in a concentrated solution of unlabeled polymers. We use a single molecule wide-field fluorescence microscopy technique that is able to determine characteristic properties of the polymer dynamics, such as the confining potential, the tube diameter and the Rouse time. The use of synthetic polymers allows us to investigate the confined motion of the polymer chains not only as a function of polymer concentration (mesh size) but also versus the persistence length of the matrix polymers...
May 15, 2017: Journal of Physical Chemistry. B
Andreea Luca, Vasilica Maier, Stelian S Maier, Maria Butnaru, Maricel Danu, Constanta Ibanescu, Mariana Pinteala, Marcel Popa
Mixed crosslinked networks of ionic-covalent entanglement type were prepared starting from ternary mixtures of atelocollagen (aK; as fibrillary matrix generator), sodium hyaluronate (NaHyal; a microfibrillation assistant), and oxidized polysaccharides (OxPolys; as both cross-linkers and matrix fillers), and were tested as hydrogels for eukaryotic cell encapsulation. Either oxidized gellan (GellOx) or pullulan (PullOx) were used. An original procedure and optimal hydrogel recipes were developed to encapsulate fibroblasts and adipose-derived stem cells, while preserving their viability and proliferative ability during ex vivo temporarily storage...
August 1, 2017: Carbohydrate Polymers
Masashi Saitoh, Yukiyasu Kashiwagi, Masaya Chigane
The recent growing interest in the applications of gold nanowires (AuNWs) as flexible materials has raised the fundamental issue of how their mechanical properties are related to their morphology. In this work, to address this issue, the systematic synthesis of AuNWs, their structural analysis, and their rheological investigation were demonstrated. The structural analysis of AuNWs was performed based on TEM observations and light-scattering experiments. From these observations, it was found that the length of AuNWs varies from nanometer to micrometer depending on the reaction time while a constant width of 1...
May 12, 2017: Soft Matter
Zongchen Liu, Irfan Ahmed, Garuma Abdisa, Zihai Jiang, Shuwei Fan, Hongxing Wang, Yanpeng Zhang
We report the generation of three-mode hybrid intensity-noise correlation and intensity-difference squeezing of spontaneous parametric four-wave mixing (SP-FWM) and fourth-order fluorescence (FL) signals in the heteronuclear-like (three-level Λ-type) molecular structure of a Pr(3+):Y2SiO5 (Pr(3+):YSO) crystal using the nonlinear cross-Kerr effect under a polarized dressing effect. In the semi-classical view of a Kerr nonlinear medium, the amplitude of two-mode hybrid correlations of this kind is subject to a limit determined by the hybrid maximally entangled state...
May 11, 2017: Scientific Reports
Andrew K Mitchell, Kim G L Pedersen, Per Hedegård, Jens Paaske
Molecular electronics offers unique scientific and technological possibilities, resulting from both the nanometre scale of the devices and their reproducible chemical complexity. Two fundamental yet different effects, with no classical analogue, have been demonstrated experimentally in single-molecule junctions: quantum interference due to competing electron transport pathways, and the Kondo effect due to entanglement from strong electronic interactions. Here we unify these phenomena, showing that transport through a spin-degenerate molecule can be either enhanced or blocked by Kondo correlations, depending on molecular structure, contacting geometry and applied gate voltages...
May 11, 2017: Nature Communications
Klaus D Jöns, Lucas Schweickert, Marijn A M Versteegh, Dan Dalacu, Philip J Poole, Angelo Gulinatti, Andrea Giudice, Val Zwiller, Michael E Reimer
Global, secure quantum channels will require efficient distribution of entangled photons. Long distance, low-loss interconnects can only be realized using photons as quantum information carriers. However, a quantum light source combining both high qubit fidelity and on-demand bright emission has proven elusive. Here, we show a bright photonic nanostructure generating polarization-entangled photon pairs that strongly violates Bell's inequality. A highly symmetric InAsP quantum dot generating entangled photons is encapsulated in a tapered nanowire waveguide to ensure directional emission and efficient light extraction...
May 10, 2017: Scientific Reports
Arthur R Keith, Joseph K Bailey, Matthew K Lau, Thomas G Whitham
We examined the hypothesis that genetics-based interactions between strongly interacting foundation species, the tree Populus angustifolia and the aphid Pemphigus betae, affect arthropod community diversity, stability and species interaction networks of which little is known. In a 2-year experimental manipulation of the tree and its aphid herbivore four major findings emerged: (i) the interactions of these two species determined the composition of an arthropod community of 139 species; (ii) both tree genotype and aphid presence significantly predicted community diversity; (iii) the presence of aphids on genetically susceptible trees increased the stability of arthropod communities across years; and (iv) the experimental removal of aphids affected community network structure (network degree, modularity and tree genotype contribution to modularity)...
May 17, 2017: Proceedings. Biological Sciences
Reji Varghese, Shine K Albert, Murali Golla, Hari Veera Prasad Thelu, Nithiyanandan Krishnan
A pH-responsive DNAsome derived from the amphiphilicity-driven self-assembly of DNA amphiphile containing C-rich DNA sequence is reported. The acidification of DNAsome induces a structural change of C-rich DNA from random coil to an i-motif structure that triggers the disassembly of DNAsome and its subsequent morphological transformation into an open entangled network. The encapsulation of a hydrophobic guest into the membrane of DNAsome and its pH-triggered release upon acidification of DNAsome is also demonstrated...
May 10, 2017: Chemistry: a European Journal
Matthias Fink, Ana Rodriguez-Aramendia, Johannes Handsteiner, Abdul Ziarkash, Fabian Steinlechner, Thomas Scheidl, Ivette Fuentes, Jacques Pienaar, Timothy C Ralph, Rupert Ursin
The unification of the theory of relativity and quantum mechanics is a long-standing challenge in contemporary physics. Experimental techniques in quantum optics have only recently reached the maturity required for the investigation of quantum systems under the influence of non-inertial motion, such as being held at rest in gravitational fields, or subjected to uniform accelerations. Here, we report on experiments in which a genuine quantum state of an entangled photon pair is exposed to a series of different accelerations...
May 10, 2017: Nature Communications
Xia Cui, Yuqiao Wang, Qingyu Xu, Pingping Sun, Xiuzhen Wang, Tao Wei, Yueming Sun
A nanocomposite of Mn3O4 octahedrons entangled by carbon nanotubes (CNTs) was synthesized by a hydrothermal method assisted with a nonionic surfactant. The integration of octahedral structure and CNTs could offer many critical features, which are needed for high activity anodes, such as fast ion diffusion, good electronic conductivity, and skeleton supporting function, thus enabling the nanocomposite-based anodes with excellent electrochemical performance. In addition, CNTs can not only serve as the conductive network and structure skeleton to improve the anode performance, but also play an indispensable role in the formation of more uniform Mn3O4 octahedrons...
May 10, 2017: Nanotechnology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"