10,406 research outputs found
Binary Nonlinearization of Lax pairs of Kaup-Newell Soliton Hierarchy
Kaup-Newell soliton hierarchy is derived from a kind of Lax pairs different
from the original ones. Binary nonlinearization procedure corresponding to the
Bargmann symmetry constraint is carried out for those Lax pairs. The proposed
Lax pairs together with adjoint Lax pairs are constrained as a hierarchy of
commutative, finite dimensional integrable Hamiltonian systems in the Liouville
sense, which also provides us with new examples of finite dimensional
integrable Hamiltonian systems. A sort of involutive solutions to the
Kaup-Newell hierarchy are exhibited through the obtained finite dimensional
integrable systems and the general involutive system engendered by binary
nonlinearization is reduced to a specific involutive system generated by
mono-nonlinearization.Comment: 15 pages, plain+ams tex, to be published in Il Nuovo Cimento
Antiviral treatment alters the frequency of activating and inhibitory receptor-expressing natural killer cells in chronic Hepatitis B virus infected patients
Natural killer (NK) cells play a critical role in innate antiviral immunity, but little is known about the impact of antiviral therapy on the frequency of NK cell subsets. To this aim, we performed this longitudinal study to examine the dynamic changes of the frequency of different subsets of NK cells in CHB patients after initiation of tenofovir or adefovir therapy. We found that NK cell numbers and subset distribution differ between CHB patients and normal subjects; furthermore, the association was found between ALT level and CD158b+ NK cell in HBV patients. In tenofovir group, the frequency of NK cells increased during the treatment accompanied by downregulated expression of NKG2A and KIR2DL3. In adefovir group, NK cell numbers did not differ during the treatment, but also accompanied by downregulated expression of NKG2A and KIR2DL3. Our results demonstrate that treatment with tenofovir leads to viral load reduction, and correlated with NK cell frequencies in peripheral blood of chronic hepatitis B virus infection. In addition, treatments with both tenofovir and adefovir in chronic HBV infected patients induce a decrease of the frequency of inhibitory receptor+ NK cells, which may account for the partial restoration of the function of NK cells in peripheral blood following treatment
Fitting Skeletal Object Models Using Spherical Harmonics Based Template Warping
We present a scheme that propagates a reference skeletal model (s-rep) into a particular case of an object, thereby propagating the initial shape-related layout of the skeleton-to-boundary vectors, called spokes. The scheme represents the surfaces of the template as well as the target objects by spherical harmonics and computes a warp between these via a thin plate spline. To form the propagated s-rep, it applies the warp to the spokes of the template s-rep and then statistically refines. This automatic approach promises to make s-rep fitting robust for complicated objects, which allows s-rep based statistics to be available to all. The improvement in fitting and statistics is significant compared with the previous methods and in statistics compared with a state-of-the-art boundary based method
Optimization of enantioselective production of chiral epichlorohydrin catalyzed by a novel epoxide hydrolase from domestic duck liver by response surface methodology
Enantiopure epichlorohydrin is a valuable epoxide intermediate for preparing optically active pharmaceuticals. In the present study, a novel epoxide hydrolase prepared from domestic duck liver was used as biocatalyst for producing (S)-epichlorohydrin which preparation process was optimized by response surface methodology. Response surface methodology was performed to evaluate the effects of reaction temperature, pH and reaction time on production of (S)-epichlorohydrin by the novel epoxide hydrolase. (S)-epichlorohydrin production was optimized by Box-Behnken. Three reaction parameters were optimized as follows: pH value 7.10, reaction temperature 32.44°C and reaction time11.06 h. The adequately high R2 value 0.9599 and F score 13.29 indicated the statistical significance of the model. The enantioselective excess of (S)-epichlorohydrin after optimization was 86.14% while thepredicted value was 85.55%. In conclusion, enantioselective hydrolysis conditions optimization to enhance optical purity of (S)-epichlorohydrin could be easily and effectively done by response surfacemethodology; the developed production process indicated the novel epoxide hydrolase from domestic duck liver was high efficient biocatalyst for preparing enantiopure epichlorohydrin
Spin 3/2 dimer model
We present a parent Hamiltonian for weakly dimerized valence bond solid
states for arbitrary half-integral S. While the model reduces for S=1/2 to the
Majumdar-Ghosh Hamiltonian we discuss this model and its properties for S=3/2.
Its degenerate ground state is the most popular toy model state for discussing
dimerization in spin 3/2 chains. In particular, it describes the impurity
induced dimer phase in Cr8Ni as proposed recently. We point out that the
explicit construction of the Hamiltonian and its main features apply to
arbitrary half-integral spin S.Comment: 5+ pages, 6 figures; to appear in Europhysics Letter
A highly effective <i>in vivo</i> photothermal nanoplatform with dual imaging-guided therapy of cancer based on the charge reversal complex of dye and iron oxide
To enhance the treatment efficiency of photothermal therapy (PTT) with very little light-associated side effect, we have constructed a highly effective PTT nanoplatform for fluorescence and MRI dual imaging-guided PTT of cancer, based on IR806 dye and iron oxide complex functionalized with mPEG-PCL-G2.0PAMAM-Cit, which can be for charge-conversion for targeted accumulation in tumor. Combination of iron oxide nanoparticles and IR806 improve light to thermal conversion efficiency and lower light irradiation dose. In vitro and in vivo tests demonstrated that an effective dual imaging-guided PTT as low as 0.25 W cm(-2) could be realized under a light irradiation of 808 nm. These efforts highlight the potential of this PTT nanoplatform in "precision medicine''
Bcl-2 inhibitor uploaded upconversion nanophotosensitizers to overcome the photodynamic therapy resistance of cancer through adjuvant intervention strategy
Similar to many other anticancer therapies, photodynamic therapy (PDT) also suffers from the intrinsic cancer resistance mediated by cell survival pathways. These survival pathways are regulated by various proteins, among which anti-apoptotic protein Bcl-2 plays an important role in regulation of programmed cell death and has been proved to involve in protecting against oxidative stimuli. Confronted by this challenge, we propose and validate here a novel upconversion photosensitizing nanoplatform which enables significant reduction of cancer resistance and improve PDT efficacy. The upconversion nano-photosensitizer contains the photosensitizing molecules - Zinc phthalocyanine (ZnPc) and Bcl-2 inhibitor - ABT737 small molecules, denoted as ABT737@ZnPc-UCNPs. ABT737 molecules were encapsulated, in a pH sensitive way, into the nanoplatform through Poly (ethylene glycol)-Poly (L-histidine) diblock copolymers (PEG-b-PHis). This nanosystem exhibits the superiority of sensitizing tumor cells for PDT through adjuvant intervention strategy. Upon reaching to lysosomes, the acidic environment changes the solubility of PEG-b-PHis, resulting in the burst-release of ABT737 molecules which deplete the Bcl-2 level in tumor cells and leave the tumor cells out from the protection of anti-apoptotic survival pathway in advance. Owing to the sensitization effect of ABT737@ZnPc-UCNPs, the PDT therapeutic efficiency of cancer cells can be significantly potentiated in vitro and in vivo
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