Publications by authors named "Yuanli Cai"

34 Publications

Effects of dietary corticosterone on the central adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in broiler chickens.

J Anim Sci 2020 Jul;98(7)

Department of Biosystems, Division of Animal and Human Health Engineering, KU Leuven, Leuven, Belgium.

Glucocorticoids (GCs) induce the activation of the central adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway in birds. In this study, we aimed to investigate the effects of corticosterone (CORT) supplemented in diet on the central AMPK signaling pathway in broilers. The average daily gain was reduced by CORT treatment, and the average daily feed intake remained unchanged. Plasma glucose, triglyceride, total cholesterol, and CORT contents were increased by CORT administration. In addition, CORT treatment decreased the relative weights of heart, spleen, and bursa and increased the relative weights of liver and abdominal fat. The glycogen contents in the liver and breast muscle were higher in the chicks treated with CORT. CORT treatment upregulated the gene expression of mammalian target of rapamycin, glucocorticoid receptor, AMPKα2, neuropeptide Y(NPY), liver kinase B1 (LKB1), AMPKα1, and fatty acid synthase in the hypothalamus. Moreover, CORT treatment increased the protein levels of acetyl-coenzyme A carboxylase (ACC) phosphorylation and total AMPK and phosphorylated AMPK in the hypothalamus. Hence, CORT administration in the diet activated the LKB1-AMPK-NPY/ACC signaling pathway in the hypothalamus of broiler.
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http://dx.doi.org/10.1093/jas/skaa202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7373321PMC
July 2020

Noncovalent structural locking of thermoresponsive polyion complex micelles, nanowires, and vesicles via polymerization-induced electrostatic self-assembly using an arginine-like monomer.

Chem Commun (Camb) 2020 May 2;56(36):4954-4957. Epub 2020 Apr 2.

State-Local Joint Engineering Laboratory for Novel Functional Polymer Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.

The noncovalent structural locking of thermoresponsive polyion complex micelles, nanowires, and vesicles can be implemented via hydrogen bonding assisted polyion complexation through polymerization-induced electrostatic self-assembly (PIESA) using an arginine-like cationic monomer.
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http://dx.doi.org/10.1039/d0cc00427hDOI Listing
May 2020

Adaptive Estimation and Cooperative Guidance for Active Aircraft Defense in Stochastic Scenario.

Sensors (Basel) 2019 Feb 25;19(4). Epub 2019 Feb 25.

School of Information and Navigation, Air Force Engineering University, Xi'an 710077, China.

The active aircraft defense problem is investigated for the stochastic scenario wherein a defending missile (or a defender) is employed to protect a target aircraft from an attacking missile whose pursuit guidance strategy is unknown. For the purpose of identifying the guidance strategy, the static multiple model estimator (sMME) based on the square-root cubature Kalman filter is proposed, and each model represents a potential attacking missile guidance strategy. Furthermore, an estimation enhancement approach is provided by using pseudo-measurement. For each model in the sMME, the model-matched cooperative guidance laws for the target and defender are derived by formulating the active defense problem as a constrained linear quadratic problem, where an accurate defensive interception and the minimum evasion miss distance are both considered. The proposed adaptive cooperative guidance laws are the result of mixing the model-matched optimal cooperative guidance laws in the criterion of maximum a posteriori probability in the framework of the sMME. By adopting the adaptive cooperative guidance laws, the target can facilitate the defender's interception with the attacking missile with less control effort. Also, simulation results show that the proposed guidance laws increase the probability of successful target protection in the stochastic scenario compared with other defensive guidance laws.
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http://dx.doi.org/10.3390/s19040979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412683PMC
February 2019

Adaptive Fifth-Degree Cubature Information Filter for Multi-Sensor Bearings-Only Tracking.

Sensors (Basel) 2018 Sep 26;18(10). Epub 2018 Sep 26.

School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China.

Standard Bayesian filtering algorithms only work well when the statistical properties of system noises are exactly known. However, this assumption is not always plausible in real target tracking applications. In this paper, we present a new estimation approach named adaptive fifth-degree cubature information filter (AFCIF) for multi-sensor bearings-only tracking (BOT) under the condition that the process noise follows zero-mean Gaussian distribution with unknown covariance. The novel algorithm is based on the fifth-degree cubature Kalman filter and it is constructed within the information filtering framework. With a sensor selection strategy developed using observability theory and a recursive process noise covariance estimation procedure derived using the covariance matching principle, the proposed filtering algorithm demonstrates better estimation accuracy and filtering stability. Simulation results validate the superiority of the AFCIF.
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http://dx.doi.org/10.3390/s18103241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6209913PMC
September 2018

Synthesis of Low-Dimensional Polyion Complex Nanomaterials via Polymerization-Induced Electrostatic Self-Assembly.

Angew Chem Int Ed Engl 2018 01 20;57(4):1053-1056. Epub 2017 Dec 20.

Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State-Local Joint Engineering Laboratory for Novel Functional Polymer Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Nanostructured polyion complexes (PICs) are appealing in biomaterials applications. Yet, conventional assembly suffers from the weakness in scale-up and reproducibility. Only a few low-dimensional PICs are available to date. Herein we report an efficient and scalable strategy to prepare libraries of low-dimensional PICs. It involves a visible-light-mediated RAFT polymerization of ionic monomer in the presence of a polyion of the opposite charge at 5-50 % w/w total solids concentration in water at 25 °C, namely, polymerization-induced electrostatic self-assembly (PIESA). A Vesicle, multi-compartmental vesicle, and large-area unilamellar nanofilm can be achieved in water. A long nanowire and porous nanofilm can be prepared in methanol/water. An unusual unimolecular polyion complex (uPIC)-sphere-branch/network-film transition is reported. This green chemistry offers a general platform to prepare various low-dimensional PICs with high reproducibility on a commercially viable scale under eco-friendly conditions.
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http://dx.doi.org/10.1002/anie.201710811DOI Listing
January 2018

Metal-Folded Single-Chain Nanoparticle: Nanoclusters and Self-Assembled Reduction-Responsive Sub-5-nm Discrete Subdomains.

Macromol Rapid Commun 2017 Sep 10;38(17). Epub 2017 Jul 10.

State-Local Joint Engineering Laboratory of Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Easy access to discrete nanoclusters in metal-folded single-chain nanoparticles (metal-SCNPs) and independent ultrafine sudomains in the assemblies via coordination-driven self-assembly of hydrophilic copolymer containing 9% imidazole groups is reported herein. H NMR, dynamic light scattering, and NMR diffusion-ordered spectroscopy results demonstrate self-assembly into metal-SCNPs (>70% imidazole-units folded) by neutralization in the presence of Cu(II) in water to pH 4.6. Further neutralization induces self-assembly of metal-SCNPs (pH 4.6-5.0) and shrinkage (pH 5.0-5.6), with concurrent restraining residual imidazole motifs and hydrophilic segment, which organized into constant nanoparticles over pH 5.6-7.5. Atomic force microscopy results evidence discrete 1.2 nm nanoclusters and sub-5-nm subdomains in metal-SCNP and assembled nanoparticle. Reduction of metal center using sodium ascorbate induces structural rearrangement to one order lower than the precursor. Enzyme mimic catalysis required media-tunable discrete ultrafine interiors in metal-SCNPs and assemblies have hence been achieved.
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http://dx.doi.org/10.1002/marc.201700269DOI Listing
September 2017

Underestimation of phosphorus fraction change in the supernatant after phosphorus adsorption onto iron oxides and iron oxide-natural organic matter complexes.

J Environ Sci (China) 2017 May 8;55:197-205. Epub 2016 Sep 8.

Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Department of Environmental Science and Engineering, Southwest University, Chongqing 400716, China. Electronic address:

The phosphorus (P) fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid (HA) complexes were analyzed using the ultrafiltration method in this study. With an initial P concentration of 20mg/L (I=0.01mol/L and pH=7), it was shown that the colloid (1kDa-0.45μm) component of P accounted for 10.6%, 11.6%, 6.5%, and 4.0% of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite (FH), goethite (GE), ferrihydrite-humic acid complex (FH-HA), goethite-humic acid complex (GE-HA), respectively. The <1kDa component of P was still the predominant fraction in the supernatant, and underestimated colloidal P accounted for 2.2%, 55.1%, 45.5%, and 38.7% of P adsorption onto the solid surface of FH, FH-HA, GE and GE-HA, respectively. Thus, the colloid P could not be neglected. Notably, it could be interpreted that Fe hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant. And colloidal adsorbent particles co-existing in the supernatant were another important reason for it. Additionally, dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant. Ultimately, we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P, even when considering other contaminants such as organic pollutants, heavy metal ions, and arsenate at the sediment/soil-water interface in the real environment.
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http://dx.doi.org/10.1016/j.jes.2016.08.005DOI Listing
May 2017

Chelation-Induced Polymer Structural Hierarchy/Complexity in Water.

Macromol Rapid Commun 2016 Aug 24;37(15):1275-81. Epub 2016 May 24.

Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Understanding nanoscale structural hierarchy/complexity of hydrophilic flexible polymers is imperative because it can be viewed as an analogue to protein-alike superstructures. However, current understanding is still in infancy. Herein the first demonstration of nanoscale structural hierarchy/complexity via copper chelation-induced self-assembly (CCISA) is presented. Hierarchically-ordered colloidal networks and disks can be achieved by deliberate control of spacer length and solution pH. Dynamic light scattering, transmission electron microscopy, and atomic force microscopy demonstrate that CCISA underwent supramolecular-to-supracolloidal stepwise-growth mechanism, and underline amazing prospects to the hierarchically-ordered superstructures of hydrophilic flexible polymers in water.
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http://dx.doi.org/10.1002/marc.201600214DOI Listing
August 2016

Construction and Self-Assembly of Single-Chain Polymer Nanoparticles via Coordination Association and Electrostatic Repulsion in Water.

Macromol Rapid Commun 2015 Aug 3;36(16):1521-7. Epub 2015 Jul 3.

Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Simultaneous coordination-association and electrostatic-repulsion interactions play critical roles in the construction and stabilization of enzymatic function metal centers in water media. These interactions are promising for construction and self-assembly of artificial aqueous polymer single-chain nanoparticles (SCNPs). Herein, the construction and self-assembly of dative-bonded aqueous SCNPs are reported via simultaneous coordination-association and electrostatic-repulsion interactions within single chains of histamine-based hydrophilic block copolymer. The electrostatic-repulsion interactions are tunable through adjusting the imidazolium/imidazole ratio in response to pH, and in situ Cu(II)-coordination leads to the intramolecular association and single-chain collapse in acidic water. SCNPs are stabilized by the electrostatic repulsion of dative-bonded block and steric shielding of nonionic water-soluble block, and have a huge specific surface area of function metal centers accessible to substrates in acidic water. Moreover, SCNPs can assemble into micelles, networks, and large particles programmably in response to the solution pH. These unique media-sensitive phase-transformation behaviors provide a general, facile, and versatile platform for the fabrication of enzyme-inspired smart aqueous catalysts.
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http://dx.doi.org/10.1002/marc.201500281DOI Listing
August 2015

Simultaneous determination of two amino bisphosphonates drugs by micellar electrokinetic chromatography.

J Chromatogr Sci 2015 Nov-Dec;53(10):1794-800. Epub 2015 Jun 25.

College of Chemical Engineering, Sichuan University, Chengdu 610065, Sichuan, China

A sensitive micellar electrokinetic chromatographic method with laser-induced fluorescence detection was developed for the determination of alendronate sodium (ALN) and pamidronate disodium (PAM) after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole. The developed method was first used for the determination of ALN and PAM in pharmaceutical preparations. After optimization, baseline separation of the analytes could be obtained in <10 min in a running buffer composed of 10 mM sodium borate and 30 mM sodium dodecyl sulfate (pH 9.0) at a voltage of 15 kV with 25°C cartridge temperature and the samples were injected by pressure (3447.5 Pa × 3 s). The method has linearity range of 0.05-70 µg/mL for the analytes (correlation coefficients: 0.9995 and 0.9997), the detection limits were 4 and 10 ng/mL for ALN and PAM, respectively. In intraday precision experiment, the relative standard deviation (RSD) values for migration time were 0.30% (ALN) and 0.27% (PAM), and the RSD values for peak areas were 1.19% (ALN) and 1.32% (PAM). The ranges of recovery were 95.5-101.8 and 94.6-105.3% for ALN and PAM, respectively. This method is not only rapid and accurate but also has the potential to be used for the quality control in pharmaceutical preparations of the two drugs.
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http://dx.doi.org/10.1093/chromsci/bmv074DOI Listing
June 2016

Directional supracolloidal self-assembly via dynamic covalent bonds and metal coordination.

Soft Matter 2015 Jul;11(27):5546-53

The Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.

An emerging strategy towards the sophistication of supramolecular nanomaterials is the use of supracolloidal self-assembly, in which micelles or colloids are used as building blocks. Binding directionality can produce nanostructures with attractive properties. Herein, we present a new directional supracolloidal self-assembly by virtue of dynamic covalent bonds and metal coordination in water. Conjugation of a ligand precursor to a water-soluble block copolymer through dynamic covalent bonds leads to the dehydration and micellization of the functionalized polymer. Reversible reaction facilitates the permeation of metal ions into core-shell interfaces. Conversely, metal-coordination promotes reaction over the interfaces. Cu(ii)-coordination occurs overwhelmingly inside each isolated micelle. However, Zn(ii)-coordination induced a directional self-assembly whose nanostructures evolve stepwise from nanorods, nanowires, necklaces, and finally to supracolloidal networks scaling-up to several tens of micrometres. Post-reactions of simultaneous dynamic covalent bond conversion and Zn(ii)-coordination over the core-shell interfaces endow these supracolloidal networks with a huge specific surface area for hydrophobic dative metal centres accessible to substrates in water. Water-soluble shells play important roles in directional supracolloidal assembly and in the stabilization of nanostructures. Thus the directional self-assembly provides a versatile platform to produce metallo-hybridized nanomaterials that are promising as enzyme-inspired aqueous catalysts.
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http://dx.doi.org/10.1039/c5sm00546aDOI Listing
July 2015

Reconstruction of Block Copolymer Micelles to Long-Range Ordered Dense Nanopatterns Via Light-Tunable Hydrogen-Bonding Association.

Macromol Rapid Commun 2015 Aug 1;36(16):1505-10. Epub 2015 Jun 1.

Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Controlling the orientation and long-range order of nanostructures is a key issue in the self-assembly of block copolymer micelles. Herein, a versatile strategy is presented to transform one-component oxime-based block copolymer micelles into long-range ordered dense nanopatterns. Photoisomerization provides a straightforward and versatile approach to convert the hydrogen-bonding association from inward dimerization (E-type oxime motifs, slightly desolvated in ethyl acetate) into outward interchain association (Z-type ones, highly desolvated in ethyl acetate). This increases the glass transition temperature in bulk and converts swollen micelles into compact spherical micelles in solution. The reconstruction of these micelles on various substrates demonstrates that the phase transformation enables reconstruction of spherical micelles into mesoscopic sheets, nanorods, nanoworms, nanowires, networks, and eventually into long-range ordered and densely packed textile-like and lamellar nanopatterns on a macroscopic scale by adjusting E/Z-oxime ratio and solvent-evaporation rate.
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http://dx.doi.org/10.1002/marc.201500219DOI Listing
August 2015

Determination of Gabapentin in Human Plasma and Urine by Capillary Electrophoresis with Laser-Induced Fluorescence Detection.

J Chromatogr Sci 2015 Jul 27;53(6):986-92. Epub 2014 Oct 27.

College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China

A simple and reliable method based on capillary electrophoresis with laser-induced fluorescence detection was developed for the analysis of the antiepileptic drug Gabapentin in human plasma and urine. 4-Chloro-7-nitrobenzofurazan was used for precolumn derivatization of the drug. With an uncoated fused silica capillary (40.0 cm effective length, 50.2 cm total length and 75 μm internal diameter), optimal separation was achieved with 30 mM sodium dodecyl sulfate, 40 mM sodium borate (pH 10.25) and acetonitrile 10% (v/v) as running buffer. The applied voltage was 20 kV and the samples were injected by pressure (3.45 kPa × 3 s). The method was fully validated with regard to linear range, sensitivity, precision, limit of detection and limit of quantification in human plasma and urine samples. Linear ranges were 0.1-15 μg mL(-1) for plasma and urine. The intra- and interday precisions were ≤9.02 and 13.90%, respectively. The recoveries were 96.0-109.3% for plasma and 94.3-98.0% for urine. The method was successfully applied for the determination of Gabapentin in human plasma and urine.
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http://dx.doi.org/10.1093/chromsci/bmu134DOI Listing
July 2015

Acceleration and selective monomer addition during aqueous RAFT copolymerization of ionic monomers at 25 °C.

Macromol Rapid Commun 2014 Aug 2;35(16):1430-5. Epub 2014 Jun 2.

Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

An acceleration effect and selective monomer addition during RAFT copolymerization of the oppositely-charged ionic monomers in dilute aqueous solution at 25 °C are reported. The reaction is conducted using a non-ionic water-soluble polymer as a macromolecular chain transfer agent under visible light irradiation. A fast iterative polymerization can be induced, even in dilute solution, by the favorable ionic interactions and in situ self-assembly of zwitterionic growing chains. Selelctive monomer addition is achieved in the statistical copolymerization due to the ion-pairing of the oppositely-charged monomers, such as precisely the same reaction rates at a 1:1 of monomer ratio, otherwise a faster reaction of the minor monomer component over the major one. These behaviors open up an avenue towards the rapid synthesis of sequence-controlled zwitterionic polyelectrolytes that can satisfy the demands of emerging biological applications.
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http://dx.doi.org/10.1002/marc.201400153DOI Listing
August 2014

Visible light mediated fast iterative RAFT synthesis of amino-based reactive copolymers in water at 20 °C.

Macromol Rapid Commun 2013 Dec 11;34(23-24):1827-32. Epub 2013 Nov 11.

Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

The attempts to mediate iterative RAFT polymerization of ionic monomers through visible light irradiation in water at 20 °C is reported, in which complete conversions are attained in several tens of minutes and the propagation suspends/restarts immediately for multiple times on cycling irradiation. This technique suits the one-pot synthesis of NH2 /imidazole-based polymers with tuned structures from homo to random, block, random-block, and block-random-block, thus is robust and promising to control the sequence of the ionized water-soluble reactive copolymers.
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http://dx.doi.org/10.1002/marc.201300697DOI Listing
December 2013

Simultaneous determination of amino acids in tea leaves by micellar electrokinetic chromatography with laser-induced fluorescence detection.

Food Chem 2014 Jan 29;143:82-9. Epub 2013 Jul 29.

College of Chemical Engineering, Sichuan University, Chengdu, China.

A rapid and effective method of micellar electrokinetic chromatography with laser-induced fluorescence detection was developed for the simultaneous determination of amino acids in tea leaves. Pre-column derivatization of the analytes used 4-chloro-7-nitrobenzofurazan (NDB-Cl). Optimal separation was achieved at +20kV using an uncoated fused silica capillary (40.0cm effective length, 50.2cm total length, 75μm internal diameter), as well as 20mM sodium borate (pH 8.5), 20mM Brij 35, and acetonitrile 10% (v/v) as running buffers. Within 11min, 15 amino acids were separated completely. The optimized method demonstrated good linearity (r(2)⩾0.9990), precision (⩽6.65%), accuracy (85.50-112.74%), and sensitivity (0.1ng/mL-100ng/mL). The method successfully determined the quantity of amino acids in five different tea leaves; furthermore, theanine was identified as the most abundant amino acid in teas. The proposed method showed great potential in further investigations on the biofunctions of different tea samples.
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http://dx.doi.org/10.1016/j.foodchem.2013.07.095DOI Listing
January 2014

Botryoid-shaped reactive nanoparticles through spontaneous structural reorganization of terpolymer micelles.

Macromol Rapid Commun 2013 Sep 9;34(18):1459-63. Epub 2013 Aug 9.

Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.

Botryoid-shaped reactive terpolymer nanoparticles, whose aldehyde-functional living domains are miniaturized into small-sized discrete "grapes" and attached onto the outwardly-branched scaffolds of fluorinated segments, are reported. These nanostructures can be fabricated by spontaneous structural reorganization of core-shell terpolymer micelles simply by manipulating drying conditions. The miniaturized discrete living domains are stabilized by outwardly-branched scaffolds and exhibit excellent accessibility to solution media, thus can effectively respond to solution media, which is desired in sensor-related applications.
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http://dx.doi.org/10.1002/marc.201300474DOI Listing
September 2013

Thermoresponsive synergistic hydrogen bonding switched by several guest units in a water-soluble polymer.

Macromol Rapid Commun 2013 Mar 3;34(5):411-6. Epub 2013 Jan 3.

Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.

Thermoresponsive synergistic hydrogen bonding (H-bonding) switched by several guest units in a water-soluble polymer is reported. Adjusting the distribution of guest units can effectively change the synergistic H-bonding inside polymer chains, thus widely switch the preorganization and thermoresponsive behavior of a water-soluble polymer. The synergistic H-bonding is also evidenced by converting less polar aldehyde groups into water-soluble oxime groups, which bring about the lowering-down of cloud point and an amplified hysteresis effect. This is a general approach toward the wide tunability of thermosensitivity of a water-soluble polymer simply by adjusting the distribution of several guest H-bonding units.
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http://dx.doi.org/10.1002/marc.201200685DOI Listing
March 2013

Seeding and harvest: a framework for unsupervised feature selection problems.

Sensors (Basel) 2012 Dec 27;13(1):292-333. Epub 2012 Dec 27.

School of Electronic and Information Engineering, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an 710049, China.

Feature selection, also known as attribute selection, is the technique of selecting a subset of relevant features for building robust object models. It is becoming more and more important for large-scale sensors applications with AI capabilities. The core idea of this paper is derived from a straightforward and intuitive principle saying that, if a feature subset (pattern) has more representativeness, it should be more self-organized, and as a result it should be more insensitive to artificially seeded noise points. In the light of this heuristic finding, we established the whole set of theoretical principles, based on which we proposed a two-stage framework to evaluate the relative importance of feature subsets, called seeding and harvest (S&H for short). At the first stage, we inject a number of artificial noise points into the original dataset; then at the second stage, we resort to an outlier detector to identify them under various feature patterns. The more precisely the seeded points can be extracted under a particular feature pattern, the more valuable and important the corresponding feature pattern should be. Besides, we compared our method with several state-of-the-art feature selection methods on a number of real-life datasets. The experiment results significantly confirm that our method can accomplish feature reduction tasks with high accuracy as well as low computing complexity.
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http://dx.doi.org/10.3390/s130100292DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3574678PMC
December 2012

[Determination of baclofen using micellar electrokinetic chromatography with laser induced fluorescence detection].

Se Pu 2011 Dec;29(12):1230-5

College of Chemical Engineering, Sichuan University, Chengdu 610065, China.

A novel micellar electrokinetic chromatographic method with laser induced fluorescence detection after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) was developed for the determination of muscle relaxant drug baclofen (BAL). After optimization, baseline separation of the derivatives of BAL and gabapentin (internal standard) was obtained within 7 min in a running buffer (pH 9.75) composed of 15 mmol/L sodium borate, 20 mmol/L sodium dodecyl sulfate and 10% (v/v) acetonitrile. The separation voltage was 17.5 kV. The column temperature was 25 degrees C. The samples were injected by a pressure of 3.45 kPa (0.5 psi) for 3 s. The method has a linear range of 0.025 - 25 mg/L for BAL with the correlation coefficient of 0.999 9. The limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N = 10) were 0.90 microg/L and 6.25 microg/L, respectively. The developed method was used for the analysis of BAL pharmaceutical preparation and urine samples spiked with BAL standard. The ranges of recovery were 101.6% - 107.9% for BAL preparation and 107.0% - 109.6% for urine samples. This method can be applied to the quality assessment of baclofen drug products, and provide supplementary means for the drug metabolism research of baclofen.
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December 2011

A reliable energy-efficient multi-level routing algorithm for wireless sensor networks using fuzzy Petri nets.

Sensors (Basel) 2011 22;11(3):3381-400. Epub 2011 Mar 22.

School of Telecommunication Engineering, Air Force Engineering University, Xi'an 710077, China.

A reliable energy-efficient multi-level routing algorithm in wireless sensor networks is proposed. The proposed algorithm considers the residual energy, number of the neighbors and centrality of each node for cluster formation, which is critical for well-balanced energy dissipation of the network. In the algorithm, a knowledge-based inference approach using fuzzy Petri nets is employed to select cluster heads, and then the fuzzy reasoning mechanism is used to compute the degree of reliability in the route sprouting tree from cluster heads to the base station. Finally, the most reliable route among the cluster heads can be constructed. The algorithm not only balances the energy load of each node but also provides global reliability for the whole network. Simulation results demonstrate that the proposed algorithm effectively prolongs the network lifetime and reduces the energy consumption.
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http://dx.doi.org/10.3390/s110303381DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3231584PMC
June 2012

Mussel-inspired chemistry for robust and surface-modifiable multilayer films.

Langmuir 2011 Nov 24;27(22):13684-91. Epub 2011 Oct 24.

Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.

In this article, we report a bioinspired approach to preparing stable, functional multilayer films by the integration of mussel-inspired catechol oxidative chemistry into a layer-by-layer (LbL) assembly. A polyanion of poly(acrylic acid-g-dopamine) (PAA-dopamine) bearing catechol groups, a mussel adhesive protein-mimetic polymer, was synthesized as the building block for LbL assembly with poly(allylamine hydrochloride) (PAH). The oxidization of the incorporated catechol group under mild oxidative condition yields o-quinone, which exhibits high reactivity with amine and catechol, thus endowing the chemical covalence and retaining the assembled morphology of multilayer films. The cross-linked films showed excellent stability even in extremely acidic, basic, and highly concentrated aqueous salt solutions. The efficient chemical cross-linking allows for the production of intact free-standing films without using a sacrificial layer. Moreover, thiol-modified multilayer films with good stability were exploited by a combination of thiols-catechol addition and then oxidative cross-linking. The outstanding stability under harsh conditions and the facile functionalization of the PAA-dopamine/PAH multilayer films make them attractive for barriers, separation, and biomedical devices.
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http://dx.doi.org/10.1021/la2027237DOI Listing
November 2011

Influence of altitude on aero-optic imaging deviation.

Authors:
Liang Xu Yuanli Cai

Appl Opt 2011 Jun;50(18):2949-57

School of Electronic and Information Engineering, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, China.

Aero-optic imaging deviation is a kind of aero-optic effect. It characterizes the image position displacement on an imaging plane. This paper studies the influence of altitude on aero-optic imaging deviation. The Reynolds-averaged Navier-Stokes solver provided in FLUENT was used for flow computations. The Runge-Kutta method based ray tracing was adopted for optics calculations. The orthogonal array was brought in for the experiment arrangement. Four representative suites of imaging deviations and imaging deviation slopes were obtained in the altitude range of 10-60 km. The results show that as altitude increases, the imaging deviation decreases, and the imaging deviation slope approaches zero from a negative value.
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http://dx.doi.org/10.1364/AO.50.002949DOI Listing
June 2011

Superconcentrated hydrochloric acid.

J Phys Chem B 2011 Jun 26;115(24):7823-9. Epub 2011 May 26.

Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.

We report the discovery of a potentially useful superconcentrated HCl at ambient temperature and pressure by using a simple surfactant-based reversed micelle system. Surprisingly, the molar ratios of H(+) to H(2)O (denoted as n(H+)/n(H2O)) in superconcentrated HCl can be larger than 5, while the maximum achievable n(H+)/n(H2O) value for conventional saturated HCl aqueous solution (37 wt %) is only about 0.28. Furthermore, both NMR and FT-IR results indicate that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). The superconcentrated HCl may promote some organic reactions that are not feasible by using conventional 37 wt % HCl solution. For example, addition reaction between C═C and HCl occurs in superconcentrated HCl solution without using catalysts.
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http://dx.doi.org/10.1021/jp109551zDOI Listing
June 2011

[Determination of gabapentin using capillary electrophoresis with laser-induced fluorescence detection].

Se Pu 2010 Dec;28(12):1179-84

College of Chemical Engineering, Sichuan University, Chengdu 610065, China.

A novel method for the determination of gabapentin (an antiepileptic drug) has been developed using capillary electrophoresis with laser-induced fluorescence detection (LIFD). Gabapentin was first derived by 4-chloro-7-nitrobenzofurazan (NBD-Cl) and baseline separated within 6 min with a running buffer consisting of 10 mmol/L borate sodium and 10 mmol/L sodium dodecyl sulfate (pH 9.75). The linear range of this method was 0.01-10 mg/L (r = 0.9997) with the limit of detection (LOD) of 2 microg/L and the limit of quantification (LOQ) of 10 microg/L. The average recoveries were 100.2%-103.1% with the relative standard deviation (RSD) of 0.15%-1.00%. This method is fast, sensitive, accurate and reliable, and it has been used successfully for the quality assessment of gabapentin drug products.
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December 2010

Dexamethasone-induced hepatic lipogenesis is insulin dependent in chickens (Gallus gallus domesticus).

Stress 2011 May 6;14(3):273-81. Epub 2011 Feb 6.

Department of Animal Science, Shandong Agricultural UniversityTaian, Shandong, 271018, People's Republic of China.

Hepatic lipogenesis-induced de novo by glucocorticoids (GCs) is associated with the development of obesity and diabetes mellitus. The interaction of GCs and insulin in the regulation of hepatic lipogenesis remains unclear. The effect of exogenous GC administration on hepatic lipogenesis and fat deposition was studied in broiler chickens (Gallus gallus domesticus), and the role of insulin in the effect of GCs on hepatic lipogenesis was evaluated. Dexamethasone (DEX, 2 mg/kg body mass (BM)) administration for 3-d resulted in BM loss and increased liver and cervical adipose tissue mass compared to control and pair-fed counterparts. DEX treatment significantly (P < 0.05) increased plasma level of insulin in either the fed or fasting state, whereas plasma glucose level was only increased in the fed state. In fasted chickens, DEX treatment significantly (P < 0.01) upregulated the hepatic mRNA levels of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). In the fed state, the mRNA levels of ACC and FAS were not significantly influenced by DEX treatment, nor was FAS activity. In cultured primary hepatocytes, combined DEX and insulin significantly upregulated the transcription of the genes for FAS (1.34-fold) and malic enzyme (1.72-fold). By contrast, the expression of sterol response element-binding protein-1 (SREBP-1) was significantly upregulated by insulin (1.67-fold) regardless of DEX. In abdominal adipose tissue, DEX treatment had no significant (P>0.05) effect on the activities and transcription of FAS. The expressions of lipoprotein lipase and peroxisome proliferator-activated receptor-γ were not significantly (P>0.05) affected by DEX treatment in either the fasting or fed state. The results indicate that DEX increased hepatic de novo lipogenesis via the increased activity and expression of lipogenic enzymes. Insulin-activated gene expression for SREBP-1 is suggested to be involved in stress-augmented hepatic lipogenesis.
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http://dx.doi.org/10.3109/10253890.2010.543444DOI Listing
May 2011

Determination of uric acid in human urine by capillary zone electrophoresis with indirect laser-induced fluorescence detection.

J Sep Sci 2010 Dec;33(23-24):3710-6

College of Chemical Engineering, Sichuan University, Chengdu, PR China.

A CZE with indirect LIF detection method was used for the determination of uric acid (UA) in human urine. UA and its coexisting analytes (i.e. hypoxanthine, xanthine and ascorbic acid) could be well separated within 4.5 min at a voltage of 25 kV with 25°C cartridge temperature in a running buffer composed of 5 mM sodium borate, 10% methanol (v/v) and 0.3 μM fluorescein sodium (apparent pH of the final mixed hydro-organic solution of sodium borate, methanol and fluorescein is 9.5). Under the optimum condition, the method has good linearity relationships (correlation coefficients: 0.9973-0.9987) with ranges of 25-500, 25-350, 25-250 and 25-300 μg/mL for hypoxanthine, ascorbic acid, xanthine and UA, respectively. The detection limits for the analytes were in the range of 0.29-0.90 μg/mL. The intra-day RSD values for migration times and peak areas were less than 0.43 and 3.27%, respectively. This method was applied to the quantitation of UA in human urine with recoveries in the range of 93.1-107.3%.
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http://dx.doi.org/10.1002/jssc.201000334DOI Listing
December 2010

Increased de novo lipogenesis in liver contributes to the augmented fat deposition in dexamethasone exposed broiler chickens (Gallus gallus domesticus).

Comp Biochem Physiol C Toxicol Pharmacol 2009 Aug 21;150(2):164-9. Epub 2009 Apr 21.

Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, PR China.

Effect of dexamethasone (DEX, a synthetic glucocorticoid) on lipid metabolism in broiler chickens (Gallus gallus domesticus) was investigated. Male Arbor Acres chickens (1 wk old, n=30) were injected with DEX or saline for 1 wk, and a pair-fed group was included. DEX administration resulted in enhanced lipid deposition in adipose tissues. Plasma insulin increased about 3.3 fold in DEX injected chickens as against the control and hepatic triglyceride was higher as compared with the pair-fed chickens. In DEX injected chickens, the hepatic activities of malic enzyme (ME) and fatty acid synthetase (FAS) were significantly increased, while the mRNA levels of acetyl CoA carboxylase (ACC), ME, and FAS were significantly up-regulated, compared with the control. Although the mRNA levels of lipoprotein lipase (LPL), peroxisome proliferator-activated receptor-gamma (PPARgamma) and adipose triglyceride lipase (ATGL) genes in adipose tissue were not affected by DEX injection, ME activity and mRNA levels in abdominal fat pad of chickens treated with DEX are higher than those of control chickens. The results indicated that the increased hepatic de novo lipogenesis and in turn, the increased circulating lipid flux contributes to the augmented fat deposition in adipose tissues and liver in DEX-challenged chickens. The results suggest that glucocorticoids together with the induced hyperinsulinemia should be responsible for the up-regulated hepatic lipogenesis.
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http://dx.doi.org/10.1016/j.cbpc.2009.04.005DOI Listing
August 2009

Ultra-fast RAFT polymerisation of poly(ethylene glycol) acrylate in aqueous media under mild visible light radiation at 25 degrees C.

Chem Commun (Camb) 2009 Mar 20(11):1368-70. Epub 2009 Jan 20.

College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.

Mild visible light was sufficient to activate RAFT polymerisation of poly(ethylene glycol) methyl ether acrylate in 50 wt% water at 25 degrees C, leading to an ultra-fast and well-controlled living RAFT polymerisation with more than 80% monomer conversion; this is the first example of an ultra-fast RAFT polymerisation under such environmentally friendly mild aqueous conditions.
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http://dx.doi.org/10.1039/b821486gDOI Listing
March 2009

Synthesis and "schizophrenic" micellization of double hydrophilic AB4 miktoarm star and AB diblock copolymers: structure and kinetics of micellization.

Langmuir 2007 Jan;23(3):1114-22

Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.

Poly(N-isopropylacrylamide) (PNIPAM)-based tetrafunctional atom transfer radical polymerization (ATRP) macroinitiator (1b) was synthesized via addition reaction of mono-amino-terminated PNIPAM (1a) with glycidol, followed by esterification with excess 2-bromoisobutyryl bromide. Well-defined double hydrophilic miktoarm AB4 star copolymer, PNIPAM-b-(PDEA)4, was then synthesized by polymerizing 2-(diethylamino)ethyl methacrylate (DEA) via ATRP in 2-propanol at 45 degrees C using 1b, where PDEA was poly(2-(diethylamino)ethyl methacrylate). For comparison, PNIPAM-b-PDEA linear diblock copolymer with comparable molecular weight and composition to that of PNIPAM-b-(PDEA)4 was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. The pH- and thermoresponsive "schizophrenic" micellization behavior of the obtained PNIPAM65-b-(PDEA63)4 miktoarm star and PNIPAM70-b-PDEA260 linear diblock copolymers were investigated by 1H NMR and laser light scattering (LLS). In acidic solution and elevated temperatures, PNIPAM-core micelles were formed; whereas at slightly alkaline conditions and room temperature, structurally inverted PDEA-core micelles were formed. The size of the PDEA-core micelles of PNIPAM65-b-(PDEA63)4 is much smaller than that of PNIPAM70-b-PDEA260. Furthermore, the pH-induced micellization kinetics of the AB4 miktoarm star and AB block copolymers were investigated by the stopped-flow light scattering technique upon a pH jump from 4 to 10. Typical kinetic traces for the micellization of both types of copolymers can be well fitted with double-exponential functions, yielding a fast (tau1) and a slow (tau2) relaxation processes. tau1 for both copolymers decreased with increasing polymer concentration. tau2 was independent of polymer concentration for PNIPAM65-b-(PDEA63)4, whereas it decreased with increasing polymer concentration for PNIPAM70-b-PDEA260. The chain architectural effects on the micellization properties and the underlying mechanisms were discussed in detail.
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http://dx.doi.org/10.1021/la062719bDOI Listing
January 2007