Despite rapid development of adhesive hydrogels, the typical double-sided adhesives fail to adhere to wet tissues and concurrently prevent postoperative tissue adhesion, thus severely limiting their applications in repair of internal tissues. Herein, a negatively charged carboxyl-containing hydrogel is gradiently, electrostatically complexed with a cationic oligosaccharide by a one-sided dipping method to form a novel Janus hydrogel wet adhesive whose two-side faces demonstrate strikingly distinct adhesive and nonadhesive properties. The lightly complexed surface demonstrates instant robust adhesion to various wet biological tissues even under water since the phase separation induced by electrostatic complexation increases the hydrophobicity and water drainage capacity. Intriguingly, the highly complexed surface is non-adhesive due to complete neutralization of carboxyls in the hydrogels. The Janus hydrogel can be used to replace traditional sutures to treat gastric perforation of rabbits. Animal experiment outcomes reveal that one side of the Janus hydrogel is firmly glued to the stomach tissue, and other side facing outward can efficiently prevent the postoperative adhesion. Molecular simulation elucidates the importance for selecting cationic polymer species. It is believed that gradient polyelectrolyte complexation establish a new direction to create Janus adhesives for internal tissue/organ repair and simultaneous prevention of post-operative adhesion.

Two-dimensional metal-organic framework (MOF) nanosheets are utilized as effective enzyme inhibitors, providing an inspiring means to enhance the control of cellular processes as well as improve our understanding of the surface chemistry between MOFs and enzymes. In this paper, we demonstrated that the activity of α-chymotrypsin (ChT) can be effectively inhibited with 96.9% inhibition by 2-D Cu(bpy)(OTf) nanosheets, while Zn(bim) nanosheets show no significant inhibition effect toward ChT. Kinetic studies revealed that the material acts as a competitive inhibitor toward ChT. Furthermore, fluorescence and circular dichroism spectroscopy reveal that the 2-D MOF nanosheets do not change the secondary structure of the enzyme. The Cu(II) center of the 2-D nanosheets binds the 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) molecules in the buffer, leading to an electrostatic interaction between the nanosheets and the enzyme. In addition, the irreversible coordination interactions between Cu(II) center and His-57 played an important role during the inhibition process, as supported by ionic strength experiments and UV absorbance changes of Cu(II) d-d transitions. As a result, the substrate is prevented from reaching the active sites of the enzyme causing enzyme inhibition. The modulation of enzyme activity by 2-D MOF nanosheets opens up a new direction for the exploration of the MOF-bio interface in physiological and catalytic systems.

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We propose a scheme for the generation of entangled states for two atoms trapped in separate cavities coupled to each other. The scheme is based on the competition between the unitary dynamics induced by the classical fields and the collective decays induced by the dissipation of two delocalized field modes. Under certain conditions, the symmetric or asymmetric entangled state is produced in the steady state. The analytical result shows that the distributed steady entanglement can be achieved with high fidelity independent of the initial state, and is robust against parameter fluctuations. We also find out that the linear scaling of entanglement fidelity has a quadratic improvement compared to distributed entangled state preparation protocols based on unitary dynamics.There have been various practical applications for quantum entangled states, ranging from quantum teleportation [1, 2] to universal quantum computation [3,4]. The main obstacle in preserving entanglement is decoherence induced by the environment. Recently, dissipative state preparation has become a focus in quantum computation and entanglement engineering [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], which uses decoherence as a powerful resource without destroying the quantum entanglement. These schemes are robust against parameter fluctuations, obtain high fidelity entanglement with arbitrarily initial states, and do not need accurate control of the evolution time. Particularly, Kastoryano and Reiter et al. [5,6] proposed a novel scheme for dissipative preparation of entanglement for two atoms in an optical cavity which gets a qualitative improvement in the scaling of the fidelity with optimal cavity parameters as compared to any state preparation protocol with coherent unitary dynamics. However, most of the previous theoretical schemes and experiments [21] concentrate on the case in which two atoms are trapped in a single cavity.For distributed quantum information processing, it is a basic requirement to perform state transfer and quantum gate operation between separate nodes of a quantum network. To overcome the difficulty of individual addressability existing in a single cavity, efforts have been devoted to the coupled-cavity models both theoretically [22][23][24][25][26][27][28] and experimentally [29]. Most works on the coupled-cavity system focused on the traditional coherent unitary dynamics, requiring precise timing and special initial states. Clark et al. [30] proposed a scheme to entangle the internal states of atoms in separate optical cavities using technique of quantum reservoir engineering, however the scheme requires a complex atomic level configuration. Furthermore, the evolution towards the steady state slows down as the entanglement of the desired state increases.In this paper, we generalize the idea of Refs. [5, 6] * sbzheng@pub5.fz.fj.cn and propose a scheme for producing distributed entanglement for two atoms trapped in coupled cavities. Due to the coherent photon hopping between the two cavities, the system is m...

a b s t r a c tMicroRNAs (miRNAs) regulate gene expression and may contribute to HIV-1 infection. In this study, our goal was to investigate the mechanisms by which miR-34a influenced Tat-induced HIV-1 transactivation through the SIRT1/NFjB pathway. We showed that Tat induced up-regulation of miR-34a expression in TZM-bl cells. MiR-34a significantly inhibited SIRT1 expression. Overexpression of miR-34a increased Tat-induced LTR transactivation. Forced expression of miR-34a decreased SIRT1 protein expression and consequently diminished Tat-induced acetylation of p65, while treatment with a miR-34a inhibitor had the opposite effect. These results suggest that regulating SIRT1 by down-regulation of miR-34a levels may be a therapeutic strategy against HIV-1 replication.

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We propose a scheme for dissipative preparation of W-type entangled steady states of three atoms trapped in an optical cavity. The scheme is based on the competition between the decay processes into and out of the target state. By suitable choice of system parameters, we resolve the whole evolution process and employ the effective operator formalism to engineer four independent decay processes so that the target state becomes the stationary state of the quantum system. The scheme requires neither the preparation of definite initial states nor precise control of system parameters and preparation time.