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Recognition of the key text of the Chinese seal can speed up the approval of documents, and improve the office efficiency of enterprises or government administrative departments. Due to image blurring and occlusion, the accuracy of Chinese seal recognition is low. In addition, the real dataset is very limited. In order to solve these problems, we improve the differentiable binarization detection algorithm (DBnet) to construct a model DB-ECA for text region detection, and propose a model named LSTR (Lightweight Seal Text Recognition) for text recognition. The efficient channel attention module is added to the differentiable binarization network to solve the feature pyramid conflict, and the convolutional layer network structure is improved to delay downsampling for reducing semantic feature loss. LSTR uses a lightweight CNN more suitable for small-sample generalization, and dynamically fuses positional and visual information through a self-attention-based inference layer to predict the label distribution of feature sequences in parallel. The inference layer not only solves the weak discriminative power of CNN in the shallow layer, but also facilitates CTC (Connectionist Temporal Classification) to accurately align the feature region with the target character. Experiments on the homemade dataset in this paper, DB-ECA compared with the other five commonly used detection models, the precision, recall, F-measure are the best effect of 90.29, 85.17, 87.65, respectively. LSTR compared with the other five kinds of recognition models in the last three years, to achieve the highest effect of accuracy 91.29%, and has the advantages of a small number of parameters and fast inference. The experimental results fully prove the innovation and effectiveness of our model. [ABSTRACT FROM AUTHOR]

We develop two neural network models for computing the quaternion singular value decomposition (QSVD), which can be shown to arise as gradient flows or Riemannian-gradient flows on the product of Stiefel manifold over the quaternion skew-field and their geometric and dynamical properties are investigated. Numerical experiments including color image compression indicate the feasibility and effectiveness of the proposed neural network models. • Establish the parameterization optimization formula for computing QSVD. • Propose the neutral network models and algorithms for solving the optimization model, and give the convergence analysis. • The neutral network models have the local asymptotically stable under suitable assumptions. • The color image compression illustrates the effectiveness of the QSVD neutral dynamical system models. [ABSTRACT FROM AUTHOR]

In this work, we propose a preconditioned tensor splitting iteration method for solving the multilinear system with Einstein product and give the corresponding theoretical analysis. Then we give a global correction method and theoretically prove that the proposed global correction method accelerates the convergence of the existing algorithm. These studies give some new accelerated iterative techniques which are not appeared in the previously published works. Some numerical results are disclosed to experimentally illustrate the effectiveness of the preconditioned method and the global correction technique. [ABSTRACT FROM AUTHOR]

In this paper, we establish some efficient iteration methods for solving the general coupled discrete-time periodic matrix equation. More concretely, we propose some structure preserving matrix versions of subspace methods, such as bi-conjugate gradient, bi-conjugate residual, conjugate gradient squared, bi-conjugate gradient stabilized, generalized minimal residual and restarted generalized minimal residual methods. We demonstrate experimentally that the proposed iteration methods are feasible and efficient for the periodic matrix equation. [ABSTRACT FROM AUTHOR]

In this paper, we propose a feasible and effective iteration method for solving the tensor equation A ∗ N X ∗ M B = C with a tensor inequality constraint D ∗ N X ∗ M E ≥ F . The global convergence is established. Numerical examples are provided to illustrate the feasibility and efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

We develop a conjugate gradient-type method for solving a class of tensor linear system with a T-product structure. The finite termination of the proposed method is proven without considering the rounding error. As an application, we obtain the numerical approximation of the tensor Moore-Penrose inverse based on the tensor T-product by solving the tensor linear system that are considered. Some numerical experiments are given to show the performance of the proposed method including the application in the numerical calculation of the tensor Moore-Penrose inverse and the color image deblurring. • Propose a conjugate gradient-type method for solving the tensor linear system, and give the convergence analysis. • Provide a perspective for the numerical calculation of the tensor Moore-Penrose inverse under the tensor T-product. • The color image deblurring problem illustrates the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The notation of Moore-Penrose inverse of matrices has been extended from matrix space to even-order tensor space with Einstein product. In this paper, we give the numerical study on the Moore-Penrose inverse of tensors via the Einstein product. More precisely, we transform the calculation of Moore-Penrose inverse of tensors via the Einstein product into solving a class of tensor equations via the Einstein product. Then, by means of the conjugate gradient method, we obtain the approximate Moore-Penrose inverse of tensors via the Einstein product. Finally, we report some numerical examples to show the efficiency of the proposed methods and testify the conclusion suggested in this paper. [ABSTRACT FROM AUTHOR]

In this article, we propose some subspace methods such as the conjugate residual, generalized conjugate residual, biconjugate gradient, conjugate gradient squared and biconjugate gradient stabilized methods based on the tensor forms for solving the tensor equation involving the Einstein product. These proposed algorithms keep the tensor structure. The convergence analysis shows that the proposed methods converge to the solution of the tensor equation for any initial value. Some numerical results confirm the feasibility and applicability of the proposed algorithms in practice. [ABSTRACT FROM AUTHOR]

In this paper, some accelerated iterative algorithms are developed to find the minimal positive solution of the nonsymmetric algebraic Riccati equation arising in transport theory. The convergence analysis shows that the sequences of vectors generated by iterative algorithms with the initial vector (e , e) are monotonically increasing and converge to the minimal positive solution of the vector equations. Numerical examples are provided to illustrate the efficiency of the proposed algorithms and testify the conclusions suggested in this paper. [ABSTRACT FROM AUTHOR]

The function of Latexin (LXN) in inflammation has attracted attention. However, no data are available regarding its role in colitis. We report that LXN is a suppressor of colitis. LXN deficiency leads to the severity of colitis in DSS-induced mice, and LXN is required for the therapeutic effect of retinoic acid on colitis. Using a proteomics approach, we demonstrate that LXN interacts and forms a functional complex with HECTD1 (an E3 ubiquitin ligase) and ribosomal protein subunit3 (Rps3). IκBα is one of the substrates of HECTD1. Ectopic expression of LXN leads to IκBα accumulation in intestinal epithelial cells, however, LXN knockdown enhances the interaction of HECTD1 and Rps3, contributing to the ubiquitination degradation of IκBα, and subsequently enhances inflammatory response. Thus, our findings provided a novel mechanism underlying LXN modulates colitis via HECTD1/Rps3/NF-κB pathway and significant implications for the development of novel strategies for the treatment of colitis by targeting LXN. [ABSTRACT FROM AUTHOR]

This paper is concerned with the conjugate gradient least squares algorithm to solve a class of tensor equations via the Einstein product. The proposed algorithm uses tensor computations with no matricizations involved. We prove that the solution (or the least squares solution) of the tensor equation can be obtained within a finite number of iterative steps in the absence of round-off errors. By selecting the appropriate initial tensor, the least Frobenius norm solution (or the least Frobenius norm least squares solution) of the tensor equation can be obtained. Numerical examples are provided to illustrate the efficiency of the proposed algorithm and testify the conclusions suggested in this paper. [ABSTRACT FROM AUTHOR]

Summary: The rhamnosyl group of naringin dihydrochalcone, neohesperidin dihydrochalcone, naringin and hesperidin was selectively removed by enzymatic hydrolysis using an immobilised α‐L‐rhamnosidase. Monoglycosylated products, including trilobatin, hesperetin dihydrochalcone‐7‐O‐glucoside, prunin and hesperetin‐7‐O‐glucoside, were isolated and characterised by 1H and 13C NMR and ESI‐MS. To optimise the enzymatic reaction conditions and its process costs, the hydrolysis of neohesperidin dihydrochalcone to produce trilobatin was selected as a model reaction. Using a ratio of neohesperidin dihydrochalcone: immobilised α‐L‐rhamnosidase equal to 1:0.6, the trilobatin yields was over 98%. The recycle of enzyme was also investigated, obtaining trilobatin with a yields of 80% even when the twentieth reaction cycle was conducted. Moreover, antiradical and antimicrobial activities of the obtained flavonoid monoglucosides were examined by DPPH, FRAP and ORAC methods, and compared with the efficacy of parental flavonoid glycosides and their aglycone. The results highlight that some of the obtained flavonoid monoglucosides show significant improvement in the antioxidant activity. [ABSTRACT FROM AUTHOR]

A MnO2/rGO composite with a novel yarn-rod shape was fabricated by a simple, economic and environmentally friendly electrodeposition method. The as-prepared MnO2/rGO composite was systematically characterized via X-ray Diffraction, X-ray Photoelectron Spectroscopy, Raman Spectra, Scanning Electron Microscope, Transmission Electron Microscope, and Specific Surface Area measurement. The experimental results indicate that the MnO2 nanoparticles with rod-like morphology scatter over the yarn-shaped rGO sheet through the electrodeposition procedure. The current density of O2 reduction on the MnO2/rGO composite modified electrode is higher than those on MnO2 and rGO. The initial oxygen-reduction peak potential and half-wave potential of the MnO2/rGO composite are more positive than those of MnO2 and rGO. The MnO2/rGO composite, as a non-noble metal oxide catalyst, not only exhibits superior electrocatalytic activity for oxygen-reduction reaction (ORR) in an alkaline medium compared with MnO2 and rGO but also shows better ORR stability, higher electron transfer numbers, and stronger methanol-tolerant ability than the commercial Pt/C catalyst. These considerable results enable the development of a cheap and efficient non-noble metal electrocatalyst for ORR in fuel cells. The MnO2/RGO composite prepared by the facile electrodeposition method shows the comparable electrocatalytic ORR performance with Pt/C [ABSTRACT FROM AUTHOR]

Abstract In this work, some weaker convergent conditions of the generalized Newton method for solving absolute value equation associated with second order cone are obtained, which are superior to the conditions appeared in previously published works. [ABSTRACT FROM AUTHOR]

In this paper, we establish some criteria for strong -tensors. The results obtained in this paper extend the corresponding conclusions for strong -matrices and improve the existing results for strong -tensors. As an application, some sufficient conditions of the positive definiteness for an even-order real symmetric tensor are presented. Some numerical results show the feasibility and effectiveness of the results which are obtained in this paper. [ABSTRACT FROM AUTHOR]

Abstract Strong H -tensors play an important role in the theories and applications of numerical linear algebra. It is necessary to identify whether a given tensor is a strong H -tensor or not. In this paper, we establish some iterative criteria for identifying strong H -tensors. These criteria depend on the elements of the tensors; therefore, they are easy to be verified. The results obtained in this paper extend the corresponding conclusions for strictly generalized diagonally dominant matrices. As an application, some sufficient conditions for the positive definiteness of an even-order real symmetric tensor are presented. Some numerical experiments show the feasibility and efficiency of the results which are obtained in this paper. [ABSTRACT FROM AUTHOR]

The present work proposes a finite iterative algorithm to find the least squares solutions of periodic matrix equations over symmetric ξ-periodic matrices. By this algorithm, for any initial symmetric ξ-periodic matrices, the solution group can be obtained in finite iterative steps in the absence of round-off errors, and the solution group with least Frobenius norm can be obtained by choosing a special kind of initial matrices. Furthermore, in the solution set of the above problem, the unique optimal approximation solution group to a given matrix group in the Frobenius norm can be derived by finding the least Frobenius norm symmetric ξ-periodic solution of a new corresponding minimum Frobenius norm problem. Finally, numerical examples are provided to illustrate the efficiency of the proposed algorithm and testify the conclusions suggested in this paper. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we are concerned with the Shamanskii-like self-adaptive Levenberg–Marquardt methods for nonlinear equations. We consider two choices of Levenberg–Marquardt parameter. One of them is the standard self-adaptive Levenberg–Marquardt parameter, the other is nonmonotone self-adaptive Levenberg–Marquardt parameter by using the nonmonotone technique of Grippo, Lampariello and Lucidi. Under the error bound condition which is weaker than nonsingularity, we show that the Shamanskii-like self-adaptive Levenberg–Marquardt methods converge with Q -order (m + 1). Numerical experiments show the new algorithms are efficient and promising. [ABSTRACT FROM AUTHOR]

Abstract Vine tea has been used as a medicinal herb in traditional Chinese medicine for hundreds of years. As the most abundant ingredient in vine tea, Dihydromyricetin (DHM) has been reported to exert anti-inflammatory, antioxidant, and anti-cardiovascular disease. However, the role of DHM in injury-induced neointimal formation remains poorly characterized. We determined the effects of DHM on ligation-induced carotid artery neointimal formation. We found that ligation-induced carotid artery neointimal formation could be significantly attenuated by DHM treatment. We provide evidence that DHM increases orphan nuclear receptor TR3 expression in smooth muscle cell (SMC) and carotid artery. Moreover, overexpression and loss-of-function strategies of TR3 were done to overexpression and knockdown of TR3, and demonstrate that DHM promotes SMC differentiation, however, inhibits SMC proliferation and migration, via regulating expression of TR3. Collectively, we reveal that DHM may be a therapeutic agent for the treatment of injury-induced vascular diseases. [ABSTRACT FROM AUTHOR]

Summary: An efficient and cost‐effective enzymatic production method for preparation of a high‐valued natural sweetener (dihydrochalcone glucoside trilobatin) was developed by the combination of hydrogenation and enzymatic hydrolysis reactions with α‐ l‐rhamnosidase as the catalyst in aqueous medium. This technology is adopting the cheap and largely available citrus flavanone naringin as the starting material for trilobatin synthesis, and the present enzymatic technology is possibly utilised by commercial for scale‐up production. The production is a straightforward two‐step process, in which naringin was hydrogenated into naringin dihydrochalcone and followed by removal of the rhamnosyl group of naringin dihydrochalcone by enzymatic hydrolysis using immobilised α‐ l‐rhamnosidase as the catalyst. Under optimised conditions, an overall yield of 96% was achieved with a very low loading of α‐ l‐rhamnosidase catalyst at 60 °C in a neutral aqueous buffer solution within 2 h. The immobilised α‐ l‐rhamnosidase catalyst can be recycled for 10 reactions (90% yield retained). [ABSTRACT FROM AUTHOR]

The iterative method of the generalized coupled Sylvester-conjugate matrix equations ∑j=1lAijXjBij+CijX¯jDij=Ei(i=1,2,⋯,s) over Hermitian and generalized skew Hamiltonian solution is presented. When these systems of matrix equations are consistent, for arbitrary initial Hermitian and generalized skew Hamiltonian matrices Xj(1), j = 1,2,⋯, l, the exact solutions can be obtained by iterative algorithm within finite iterative steps in the absence of round-off errors. Furthermore, we provide a method for choosing the initial matrices to obtain the least Frobenius norm Hermitian and generalized skew Hamiltonian solution of the problem. Finally, numerical examples are presented to demonstrate the proposed algorithm is efficient. [ABSTRACT FROM AUTHOR]

The iterative algorithm of a class of generalized coupled Sylvester-transpose matrix equations is presented. We prove that if the system is consistent, a solution can be obtained within finite iterative steps in the absence of round-off errors for any initial matrices; if the system is inconsistent, the least squares solution can be obtained within finite iterative steps in the absence of round-off errors. Furthermore, we provide a method for choosing the initial matrices to obtain the least Frobenius norm least squares solution of the problem. Finally, numerical examples are presented to demonstrate that the algorithm is efficient. [ABSTRACT FROM AUTHOR]

• Effective and green enzymatic glucosylation of citrus flavonoids as new food additives. • The water solubility and bioactivity of the flavonoids modified by glucosylation are enhanced. • Citrus flavonoids after glucosylation show good anti-inflammatory and antioxidant effects. • Amelioration of flavonoid taste is found mainly attributed to the addition of glycosyl groups. Cyclodextrin glucosyltransferase (CGTase) is commonly used to produce cyclodextrins but its utility in flavonoids modification is rarely found. In the present study, an enzymatic transformation of citrus flavonoids by applying CGTase as the catalyst was investigated to produce a number of novel polyglucosylated derivatives from monoglucoside metabolites of citrus flavonoid diglycosides. Under the optimized conditions, the yield of glucosylated products achieved 80%. The water solubility and water partition coefficient of citrus flavonoids before and after the structural modification were compared. The results revealed that the water solubility of the flavonoids modified by glucosylation was significantly increased while the oil-water partition coefficient was just slightly reduced. Moreover, after glucosylation, the products have good anti-inflammatory and antioxidant effects. Interestingly, the taste property (bitterness and sweetness) of the glucosylated products was ameliorated. An evaluation with a Taste-Sensing System showed that the taste of the glucosylated products was strongly correlated with the attached rhamnosyl group (bitter taste) and glucosyl group (sweet taste), indicating that the amelioration of taste of flavonoids could be mainly attributed to the addition of glycosyl groups. The present study demonstrated a novel molecular engineering approach for the enhancement of water solubility and amelioration of taste for some citrus flavonoids, which may have potential applications in the functional food industry. [Display omitted] [ABSTRACT FROM AUTHOR]

Oneof the important criteria for achieving efficient nanoparticle-basedtargeted drug delivery is that the drug is not prematurely releasedat off-target sites. Here we report the preclinical evaluation ofa serum-stable dendrimer-based drug conjugate capable of activelytargeting into prostate cancer (PC) cells, delivered through the prostate-specificmembrane antigen (PSMA). Multiple molecules of PSMA-binding smallmolecule glutamate urea (GLA; targeting agent) and the drug methotrexate(MTX) were conjugated to generation 5 PAMAM dendrimer (G5) throughCu-free “click” chemistry. The GLA was conjugated througha stable amide bond, and the MTX was conjugated either through ester(Es)- or amide (Am)-coupling, to generate G5-GLAm-(Es)MTXnand G5-GLAm-(Am)MTXn, respectively.In serum-containing medium, free MTX was slowly released from “G5-GLAm-(Es)MTXn”,with ∼8% MTX released from the dendrimer in 72 h, whereas theMTX on G5-GLAm-(Am)MTXnwas completely stable. The G5-GLAm-(Am)MTXnbound and internalized intoPSMA-expressing LNCaP cells, but not into PSMA-negative PC3 cells.The conjugate-inhibited recombinant dihydrofolate reductase and inducedpotent cytotoxicity in the LNCaP cells, but not in the PC3 cells.Similar to the action of free GLA, stable amide-linked dendrimer-GLAwas capable of inhibiting the enzyme N-acetylated α-linked acidicdipeptidase (NAALADase) activity of PSMA. The G5-GLAm-MTXnmay serve as a serum-stablenanoparticle conjugate to specifically and effectively target andtreat PSMA-overexpressing prostate tumors. [ABSTRACT FROM AUTHOR]

In this paper, we propose a modified SOR-like method for solving absolute value equations associated with second order cones (SOCAVE in short), which is obtained by reformulating the SOCAVE as a two-by-two block nonlinear equation. The convergence analysis and error estimation of this method are established under mild assumptions on system matrix and iteration parameters. And, the optimal iteration parameters and the corresponding optimal convergence factor are studied. In particular, we present the approximate optimal iteration parameters which are independent of the number of iterations. Numerical results are given to show the efficiency of the proposed iteration method with suitable parameters. [ABSTRACT FROM AUTHOR]

Purpose: Design and evaluate the in vitro and in vivo efficacy of two extended release morphine formulations developed for IV administration by complexing esterase activated morphine prodrugs to surface-modified, generation 5 (G5) poly(amidoamine) (PAMAM) dendrimer. Methods: Prodrugs were synthesized, complexed with PAMAM dendrimer, characterized via ultra performance liquid chromatography (UPLC), nuclear magnatic resonance (NMR), and tested in vitro using rat plasma vs. saline control and in an in vivo rat and guinea pig pain model (modified Randall and Selitto test). Results: We demonstrated that complexation with dendrimer allowed the solubilization of the prodrugs for in vivo applications without the need for salt, and that the structural design of the morphine prodrugs allowed the controlled release of morphine which extended the action of morphine-induced analgesia in an animal pain model from 2 h (control) to 6 h (Morphine Prodrug A). Conclusion: The concept of complexing/solubilizing appropriately designed esterase-sensitive prodrugs with dendrimer to enhance the sustained release of these drugs may be a useful pharmacokinetic strategy for a range of therapeutics. [ABSTRACT FROM AUTHOR]

Abstract: The facile conjugation of three azido modified functionalities, namely a therapeutic drug (methotrexate), a targeting moiety (folic acid), and an imaging agent (fluorescein) with a G5 PAMAM dendrimer scaffold with cyclooctyne molecules at the surface through copper-free click chemistry is reported. Mono-, di-, and tri-functional PAMAM dendrimer conjugates can be obtained via combinatorial mixing of different azido modified functionalities simultaneously or sequentially with the dendrimer platform. Preliminary flow cytometry results indicate that the folic acid targeted nanoparticles are efficiently binding with KB cells. [Copyright &y& Elsevier]

Abstract: Polyamidoamine (PAMAM) dendrimers have unique attributes that have led to their use in a wide variety of biomedical applications. However, the complex synthesis of this polymer leads to variations in the structure and consistency of the final product, and makes scale-up of manufacturing difficult. This has limited the clinical translation of PAMAM-based materials. Here we describe a rapid and highly efficient two-step method for the synthesis of novel Poly(EThyleneAmidoAmine) (PETAA) dendrimers that have many of the favorable characteristics of PAMAM dendrimers. Generation 0 (G0) to 5 (G5) PETAA dendrimers were synthesized using a 3-(bis(2-(2,2,2,-trifluoroacetamido)ethyl)amino)propanoic acid AB 2 (compound 1) building block via a divergent approach. An ethylenediamine core was coupled with the AB 2 building block via O-(7-Azabenzotriazol-1-yl)N,N,N’,N’-tetramethyluronium hexafluorophosphate (HATU) in the presence of diisopropylethyl amine to give a G0 trifluoroacetamide surface dendrimer. The G0 amine surface dendrimer was then obtained by treating the G0 trifluoroacetamide surface dendrimer with potassium carbonate. Repetitions of these two coupling/deprotection reactions were then used to build the dendrimer by coupling the surface amino groups to the carboxyl moiety of the AB 2 building block, followed by the deprotection step with potassium carbonate. The resulting PETAA dendrimers have the same number of surface primary amino groups, the same number of chemical bonds between the dendrimer core and the surface, and the same number of tertiary amino groups throughout the structures as similar generations of PAMAM dendrimers. In contrast, the structure of the PETAA dendrimers is more complete and more uniform than PAMAM dendrimers, especially at higher generations. This unique synthetic process for PETAA dendrimers also offers the potential for large-scale production, therefore providing inherently more uniform and complete structures for exacting biomedical applications. [Copyright &y& Elsevier]

Abstract: The synthesis of a generation 5 (G5) poly(amidoamine) (PAMAM) dendrimer platform having cyclooctyne ligands that were subsequently be used for a copper-free Huisgen 1,3-dipolar cycloaddition (click reaction) with azido modified methotrexate is described. The G5 PAMAM dendrimer was first partially (70%) acetylated and then coupled with 20 cyclooctyne ligands through amide bonds. The remaining primary amine groups on the dendrimer surface were neutralized by acetylation. The platform was then ‘clicked’ with different numbers (5, 10, and 17) of γ-azido functionalized methotrexate. The copper-free click reactions were stoichiometric with excellent yields. [Copyright &y& Elsevier]

Abstract: Two morphine prodrugs (‘PDA’ and ‘PDB’) were synthesized and the kinetics of esterase-mediated morphine release from these prodrugs were determined when incubated with plasma from different animal species. Morphine was rapidly released from PDA by all species plasma with the maximum reached within 5–10min; the released morphine was biologically active as determined by an in vitro cAMP assay. The morphine was released from PDB at a slower and species-dependent rate (mouse>rat>guinea pig>human). Morphine’s release from PDB appeared to be mediated by carboxyl esterases as the release was inhibited by the carboxyl esterase inhibitor benzil. PDA nor PDB induce cytotoxicity in the neuronal cell lines SK-NSH and SH-SY5Y. The carboxyl and amino functional moieties present on the linker portions of PDA and PDB, respectively, may facilitate their conjugation to nanoparticles to tailor morphine pharmacokinetics and specific targeting. These studies suggest the potential clinical utility of these prodrugs for morphine release at desired rates by administration of their mixture at selected ratios. [ABSTRACT FROM AUTHOR]

Abstract: Hypoxia is known to occur in tissues in response to narcotic analgesic therapy using as a result of respiratory depression. The aim of this study was to synthesize a narcotic antagonist pro-drug that can be activated by tissue hypoxia to prevent the damage associated with respiratory depression. We synthesized three different pro-drugs of the narcotic antagonist naloxone utilizing indolequinone as the hypoxia-sensitive moiety. The indolequinone structure in the pro-drugs was designed to have an open reactive point at the N-1 position offering the possibility of further conjugation with macromolecules to modify the bio-availability of these pro-drugs in vivo. A pro-drug (labeled 1) where naloxone and the indolequinone moiety were linked through a carbonate bond was rapidly hydrolyzed in phosphate buffered saline. However, two additional pro-drugs (labeled 2 and 3) having carbamate linkers were stable in phosphate buffered saline for 24h. The reductive release of naloxone from the pro-drugs was achieved in the presence of the bio-reductive enzyme DT-Diaphorase, with about 80% release occurring from the two pro-drugs in 24h. More than 99% of naloxone was released from pro-drug 2 in 30% human plasma, however the release only occurred under hypoxic conditions. This system provides a potential means for feedback control to counter critical respiratory depression induced by narcotic analgesics. [Copyright &y& Elsevier]

Abstract: Hydroxyl terminated, poly(alkyl ether) dendrons possessing single site phosphine functional groups at their focal points have been synthesized. These single site reactive dendrons are then used in ligand exchange reactions to produce stabilized surface capped CdSe/core CdS-shell quantum dots that exhibit high quantum yield, non-quenching photoluminescence (PL) properties. These enhanced features are in sharp contrast to quantum dots capped with analogous single site thiol functionalized dendrons that exhibit substantially quenched photoluminescence. These new dendron constructions begin with protected pentaerythritol moieties which are used as the initiator core as well as the branch cells. By protecting one of the four hydroxyl groups in the pentaerythritol moiety, the remaining three hydroxyl groups are utilized as divergent growth sites for the poly(ether) dendron construction. Desired generation levels (i.e., generations 1, 2) are synthesized, followed by deprotection of the focal point hydroxyl group to expose appropriate functional groups suitable for conversion to sulfhydryl, phosphine or other desired functional groups. [Copyright &y& Elsevier]

Abstract: Poly(amidoamine) (PAMAM) dendrimers containing disulfide cores (i.e., cystamine) and possessing carboxylic acid or hydroxyl terminal groups were reduced with dithiothreitol (DTT) to yield single site, thiol core, functionalized PAMAM dendron reagents. These thiol functionalized dendron reagents were used to surface modify (dendronize) both gold nanoparticles, as well as CdSe/CdS (core–shell) quantum dots (QDs). Dendronization involved self-assembly of the focal point thiol functional dendrons at the metal interface of both gold and CdSe/CdS QDs by ligand exchange of protective surfactants used for their synthesis. The synthesis, characterization and preliminary luminescence studies of these new dendritic hybrids are reported. [Copyright &y& Elsevier]

The effect of nonlocal Interactions on the local structural propensities of folded dendrimers was evaluated In this work by comparing, under identical conditions, the conformational properties of isomeric dendrimers differing in their global packing efficiency. Accordingly, a modular synthesis of two series of dendrimers up to the third generation was developed to provide efficient access to isomeric dendrimers displaying different levels of overall compaction. Dendrimer compaction levels were adjusted by connecting the folded dendrons to 1,3,5-benzenetricarbonyl chloride, as the central core, via either a 2- or a 4-aminobenzamide linkage to induce relatively "compacted" or "expanded' conformations, respectively. The hydrodynamic volumes of the dendrimers were measured by time-resolved fluorescence anisotropy (TRFA) measurements as a function of the dendrimer series, generation level, and solvent. Packing efficiencies (compaction levels) were estimated by the ratio (V[suph]/V[subvw]) of the experimental hydrodynamic volume (V[subh]) to the calculated van der Waals volume (V[subvw]). The extent and stability of local helical bias was measured using circular dichroism and correlated with the packing efficiency (V[subh]/V[subvw]). These studies suggested that compaction plays an extremely important role in determining the secondary structural preferences of the dendrimers; however, the nature of compaction was more important than the extent of compaction. [ABSTRACT FROM AUTHOR]

Tests the roles of the C-terminal residues of bovine pancreatic phospholipase A2 (PLA2) overexpressed in Escherichia coli using the approaches of multiple mutation and deletion. Construction and purification of mutants; Conformational stability; X-ray crystallographic analysis of K120A/K121A; Restoration of activity toward DC8PC micelles by sodium chloride.

Describes the solution structure of a soluble, biologically active mutant of the FADD death-effector domain. How activation of membrane-bound receptors for Fas and tumour-necrosis initiate programmed cell death by recruiting the death domain of the adaptor protein FADD; Examination of the structure of the FADD domain.

Presents the results of a study that describes the solution structure of the Fas death domain, as determined by NMR spectroscopy. The finding of death domains in several proteins; Uncertainty as to their three-dimensional structure and the manner in which they interact; Identification of the region of the death domain involved in self-association and binding to the downstream signalling partner (FADD).

This paper is concerned with some of well-known iterative methods in their tensor forms to solve a class of tensor equations via the Einstein product and the associated with least squares problem. Especially, the tensor forms of the LSQR and LSMR methods are presented. The proposed methods use tensor computations with no matricizations involved. We prove that the norm of residual is monotonically decreasing for the tensor form of the LSQR method. The norm of residual of normal equation is also monotonically decreasing for the tensor form of the LSMR method. We also show that the minimum-norm solution (or the minimum-norm least squares solution) of the tensor equation can be obtained by the proposed methods. Numerical examples are provided to illustrate the efficiency of the proposed methods and testify the conclusions suggested in this paper. [ABSTRACT FROM AUTHOR]

Summary: This paper is concerned with some of the well‐known iterative methods in their tensor forms to solve a class of tensor equations via the Einstein product. More precisely, the tensor forms of the Arnoldi and Lanczos processes are derived and the tensor form of the global GMRES method is presented. Meanwhile, the tensor forms of the MINIRES and SYMMLQ methods are also established. The proposed methods use tensor computations with no matricizations involved. Numerical examples are provided to illustrate the efficiency of the proposed methods and testify the conclusions suggested in this paper. [ABSTRACT FROM AUTHOR]

Stability and security are the key directions of VANET (vehicular ad hoc network) research. In order to solve the related problems in VANET, an improved AODV (ad hoc on-demand distance vector) routing protocol based on fuzzy neural network, namely, GSS-AODV (AODV with genetic simulated annealing, security and stability), is proposed. The improved scheme of the protocol analyzes the data in the movement process of the mobile node in VANET, extracts the parameters that affect the link stability, and uses the fuzzy neural network optimized by genetic simulated annealing to calculate the node stability. The improved scheme extracts the main parameters that affect the security of the nodes. After normalization, the fuzzy neural network based on genetic simulated annealing algorithm is used for fuzzy processing, and the node trust value of each node is evaluated. The improved scheme uses node stability and node trust value to control each routing process and dynamically adjusts parameters of the algorithm. The experimental results show that the improved scheme is stable and secure. [ABSTRACT FROM AUTHOR]

Stability and security are the key directions of VANET (vehicular ad hoc network) research. In order to solve the related problems in VANET, an improved AODV (ad hoc on-demand distance vector) routing protocol based on fuzzy neural network, namely, GSS-AODV (AODV with genetic simulated annealing, security and stability), is proposed. The improved scheme of the protocol analyzes the data in the movement process of the mobile node in VANET, extracts the parameters that affect the link stability, and uses the fuzzy neural network optimized by genetic simulated annealing to calculate the node stability. The improved scheme extracts the main parameters that affect the security of the nodes. After normalization, the fuzzy neural network based on genetic simulated annealing algorithm is used for fuzzy processing, and the node trust value of each node is evaluated. The improved scheme uses node stability and node trust value to control each routing process and dynamically adjusts parameters of the algorithm. The experimental results show that the improved scheme is stable and secure. [ABSTRACT FROM AUTHOR]

Developing low-cost and highly efficient non-platinum catalysts for the oxygen reduction reaction (ORR) is crucial for fuel cells. Transition metal oxide/carbon materials are important non-noble metal catalysts, and have become the focus of researchers. Herein, we report a simple one-step hydrothermal synthesis of an MoO2/C composite using Vulcan XC-72R as a support. The MoO2/C composite exhibits commendable catalytic activity for the ORR via a quasi-four-electron pathway. Compared with pure MoO2 and Vulcan XC-72R, the catalytic performance of MoO2/C composites for the ORR has been significantly improved and is very close to that of commercial Pt/C. Moreover, their methanol resistance, electron transport capacity, and electrochemical stability are superior to commercial Pt/C. [ABSTRACT FROM AUTHOR]

The RapidIO standard is a packet-switching interconnection technology similar to the Internet Protocol (IP) conceptually. It realizes the high-speed transmission of RapidIO packets at the transport layer, but this greatly increases the probability of network blocking. Therefore, it is of great significance to optimize the RapidIO routing strategy. For this problem, this paper proposes a Double-Antibody Group Multi-Objective Artificial Immune Algorithm (DAG-MOAIA), which improves the local search and global search ability of the population by adaptive crossover and adaptive mutation of the double-antibody groups, and uses co-competition of multi-antibody groups to increase the diversity of population. Through DAG-MOAIA, an optimal transmission path from the source node to multiple destination nodes can be selected to solve the Quality Of Service (QoS) problem during data transmission and ensure the QoS of the RapidIO network. Simulation results show that DAG-MOAIA could obtain high-quality solutions to select better routing transmission paths, and exhibit better comprehensive performance in all simulated test networks, which plays a certain role in solving the problem of the RapidIO routing strategy. [ABSTRACT FROM AUTHOR]

Abstract: Respiratory depression is the main obstacle for the safe administration of morphine for acute pain after injury. Due to this complication, new delivery methods are needed to insure that safe and effective doses of opioid analgesics are administered during emergencies. A depot formulation containing a naloxone pro-drug was designed to release the antidote when morphine causes dangerous hypoxic conditions in the blood. The aim of this work was to test the naloxone release in vivo in response to a severe overdose of morphine in the Sprague-Dawley rat model. Non-invasive two-chamber plethysmography was used to monitor and record respiration and to test the capability of the naloxone pro-drug to respond to and rescue morphine-induced respiratory depression in the animal. We show that the pro-drug formulation can both prevent and reverse severe morphine induced respiratory depression. The animal model demonstrates that co-administration of the naloxone pro-drug reliably antagonizes profound respiratory depressive effects of morphine. [Copyright &y& Elsevier]

BACKGROUND: The pericarp of citrus in rutaceae is rich in flavonoids that may possess diverse biological activities. Some citrus flavonoids have been used as natural bitterness inhibitors; however, many citrus flavonoid analogues that possess merit taste amelioration functions have not been reported with respect to utilization in food industry. RESULTS: The effects of 12 citrus flavonoids on the inhibition of the bitter taste of naringin, quinine hydrochloride and stevioside were evaluated both by a sensory panel and electronic tongue analysis. Among the flavonoid compounds evaluated, both neohesperidin dihydrochalcone (NHDC) and neodiosmin were identified to show an excellent bitterness inhibition effect on all three bitterness vehicles tested. The results of the electronic tongue evaluation also showed that the addition of neodiosmin, NHDC or hesperidin dihydrochalcone‐7‐o‐glucoside (HDC‐7‐G) was able to reduce significantly the bitterness response value of quinine hydrochloride, which is consistent with the sensory panel evaluation. Structure–activity relationship analysis found that the 7‐linked neohesperidosyloxy group in the A‐ring of the citrus flavonoid skeleton has the best bitterness inhibition effect. In addition, a ternary mixture of NHDC, neodiosmin and naringin, and neodiosmin/β‐cyclodextrin was formulated and it demonstrated, for the first time in the flavor improvement of citrus fruit wine, an enhancement of sweetness and a reduction of bitter taste. CONCLUSION: Twelve citrus flavonoids were found to inhibit the bitter taste of naringin, quinine hydrochloride and stevioside. With respect to the structure–activity relationship analysis, it was found that the 7‐linked neohesperidosyloxy group in the A‐ring of the citrus flavonoid skeleton possessed the best bitterness inhibition effect. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Manganese oxides (MnOx) are expected to be highly active catalysts for O2 electroreduction. However, MnOx are prone to aggregation, thus reducing their catalytic active sites. Herein, a composite of spherical MnO2 coated with reduced graphene oxide (denoted as MnO2@RGO) was fabricated by a facile and green step galvanostatic electrodeposition. The obtained MnO2@RGO is composed of a RGO lamina shell (10 nm) and spherical MnO2 core (100 nm), which were confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunner–Emmet–Teller (BET) measurement, Raman, and X-ray photoelectron spectroscopy (XPS). The obtained composite exhibited a high specific surface area of 251.3 m2 g−1. The as-prepared MnO2@RGO composite displayed a more positive onset potential of 0.86 V vs. reversible hydrogen electrode (RHE), higher kinetic current density (11.23 mA cm−2 at 0.2 V), and higher electron transfer number in OH− solution (n ≈ 3.94) for oxygen reduction reaction (ORR) compared to MnO2 NPs scattered on the surface of RGO (MnO2/RGO), bulk MnO2 NPs, and RGO. The enhanced activity was further demonstrated by the lower Tafel slope (72 mV dec−1). Moreover, MnO2@RGO exhibited greater "tolerance to methanol," "anti-CO poisoning" ability, and catalytic stability compared to commercial Pt/C catalyst. The results indicated that the prepared MnO2@RGO composite can be a potential low-cost and effective electrocatalyst for ORR. MnO2 coated with reduced graphene oxide has been firstly prepared by step galvanostatic process and shows enhanced catalytic activity and stability for oxygen reduction reaction. [ABSTRACT FROM AUTHOR]