Gold nanorods functionalized by a glutathione response near-infrared fluorescent probe as a promising nanoplatform for fluorescence imaging guided precision therapy

Huang, Yan,Liu, Qingluan,Wang, Yunqing,He, Na,Zhao, Rongfang,Choo, Jaebum,Chen, Lingxin The Royal Society of Chemistry 2019 Nanoscale Vol.11 No.25

<P>Theranostics nanoplatforms offer opportunities for imaging-guided precision therapy and hold great potential for clinical applications. In most reported works, the imaging unit has a lack of site selectivity, and is always kept in the “on” modality regardless of whether it is in normal tissues or tumor sites, increasing the risk of unsafe treatment. Herein, we designed a near-infrared (NIR) fluorescence-guided theranostics nanoplatform by integrating the functions of tumor-response and photodynamic therapy (PDT)/photothermal therapy (PTT). A novel NIR fluorescent dye, CyPT, with excellent optical and PDT/PTT properties, was synthesized and linked onto the gold nanorods (AuNRs) to form CyPT-AuNRs nanohybrids<I>via</I>a sulfur-sulfur bond that can be broken by glutathione (GSH) with high selectivity and sensitivity. In normal cells where the concentration of GSH is low, the fluorescence of CyPT is quenched by the AuNRs. By contrast, the high level of GSH in tumor cells leads to the breaking of the sulfur-sulfur bond, resulting in the release of CyPT and the accomplishment of a “off-on” fluorescence response. Followed by precise NIR tumor-imaging diagnosis, the PDT and PTT treatment which rely on the released CyPT and AuNRs, respectively, can be effectively performed. The CyPT-AuNRs nanoplatform has been successfully applied to the treatment of tumor xenograft models and no distinct damage has been observed in the nearby normal tissues. This versatile nanoplatform has potential for use in targeted tumor imaging and precision therapy.</P>

The precipitation of three Ca-P phase whiskers from an acid solution through hydrolysis of urea

Yunqing Kang,Yunshan Liu,Zhongbing Huang,Yadong Yao,Xiaoming Liao,Li Liao,Guangfu Yin 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.2

Hydroxyapatite (HA), beta-tricalcium phosphate (β-TCP) and dicalcium phosphate (DCP) whiskers with high aspect ratio and good crystallinity were successfully prepared by hydrolysis of urea in acid solutions at 90oC for 96 h. The precipitated whiskers were characterized by XRD, SEM and TEM. The lengths and aspect ratios of whiskers could be controlled by the precipitation agent, urea, with a proper incubation time. Results revealed good morphology and crystallinity of the precipitated whiskers without any impurities. TEM indicated single crystal diffraction patterns of HA and β-TCP were clearly identified. The high aspect ratio of whiskers could be potentially used as the scaffold in tissue engineering or filler in composite biomaterials to enhance mechanical properties. Hydroxyapatite (HA), beta-tricalcium phosphate (β-TCP) and dicalcium phosphate (DCP) whiskers with high aspect ratio and good crystallinity were successfully prepared by hydrolysis of urea in acid solutions at 90oC for 96 h. The precipitated whiskers were characterized by XRD, SEM and TEM. The lengths and aspect ratios of whiskers could be controlled by the precipitation agent, urea, with a proper incubation time. Results revealed good morphology and crystallinity of the precipitated whiskers without any impurities. TEM indicated single crystal diffraction patterns of HA and β-TCP were clearly identified. The high aspect ratio of whiskers could be potentially used as the scaffold in tissue engineering or filler in composite biomaterials to enhance mechanical properties.

Richardson extrapolation and defect correction of mixed finite element methods for elliptic optimal control problems

Yanping Chen,Yunqing Huang,Tianliang Hou 대한수학회 2012 대한수학회지 Vol.49 No.3

In this paper asymptotic error expansions for mixed finite element approximations to a class of second order elliptic optimal control problems are derived under rectangular meshes, and the Richardson extrapolation of two different schemes and interpolation defect correction can be applied to increase the accuracy of the approximations. As a by-product, we illustrate that all the approximations of higher accuracy can be used to form a class of a posteriori error estimators of the mixed finite element method for optimal control problems.

RICHARDSON EXTRAPOLATION AND DEFECT CORRECTION OF MIXED FINITE ELEMENT METHODS FOR ELLIPTIC OPTIMAL CONTROL PROBLEMS

Chen, Yanping,Huang, Yunqing,Hou, Tianliang Korean Mathematical Society 2012 대한수학회지 Vol.49 No.3

In this paper asymptotic error expansions for mixed finite element approximations to a class of second order elliptic optimal control problems are derived under rectangular meshes, and the Richardson extrapolation of two different schemes and interpolation defect correction can be applied to increase the accuracy of the approximations. As a by-product, we illustrate that all the approximations of higher accuracy can be used to form a class of a posteriori error estimators of the mixed finite element method for optimal control problems.

First-principles study on the doping effects of Al in a-MnO2

Zhenhua Yang,Xianyou Wang,Yunqing Huang 한국물리학회 2015 Current Applied Physics Vol.15 No.11

In this paper, first-principles calculations have been implemented to study the structural relaxation, formation energies and electronic structure of Al doped a-MnO2. Both Al insertion and Al substitution reactions in the a-MnO2 were considered. Calculated formation energies indicate that Mn atom is easier to be displaced by Al atom under the O-rich growth condition compared with Al insertion reaction. Besides, it can be found that Al doping can afford acceptor impurity level which can accommodate electrons, thus contributing to the improvement of conductivity of a-MnO2. The conductivity of a-MnO2 is gradually improved with the increasing doping concentration of Al, and Al0.0417Mn0.9583O2 exhibits the best conductivity. Lastly, the electronic structure of Al0.0417Mn0.9583O2 was further investigated by analysis of total charge density and Bader charge. It is clear that Al doping can afford more electrons for a-MnO2, which also contributes to improvement of its conductivity.

First-principles study on doping effect of Sn in BiF3 as cathode materials for Li-ion battery

Zhenhua Yang,Shuncheng Tan,Yunqing Huang 한국물리학회 2016 Current Applied Physics Vol.16 No.1

First-principles calculations were carried out to investigate the structural relaxation, formation energy, electronic structure and electrochemical properties of Sn-doped BiF3. When Sn was doped into BiF3, two common oxidation states of Sn, þ2 and þ4, were considered. In addition, some typical neutral and charge defects (Sn0 Bi,Sn1 Bi ,Sn1þ Bi ,V2 Bi1 V2 Bi2 and V0 F ) were discussed in detail. Calculated formation energies indicate that Sn4þ ion is much easier to dope into BiF3 than Sn2þ ion. When Fermi level lies at the bottom of conduction band, Sn1/32Bi30/32F3 with V2 Bi1 (Bi vacancy defect) induced by Sn4þ ion doping has the most stable structure under the rich-F growth condition. Here, DmSn, DmBi and DmF are 13.18 eV,9.71 eV and 0, respectively. What's more, the crystal structure, electronic structure and electrochemical properties of Sn1/32Bi30/32F3 with V2 Bi1 were further investigated. It is found that the crystal volume of Sn1/32Bi30/32F3 with V2 Bi1 is larger than that of pure BiF3 because the length of BieF bond around V2 Bi1 in the Sn1/32Bi30/ 32F3 becomes much longer relative to the length of BieF bond in the pure BiF3. Besides, the calculated band gap of Sn1/32Bi30/32F3 with V2 Bi1 is 2.70 eV, which is smaller than that of pure BiF3. Furthermore, Sn1/ 32Bi30/32F3 with V2 Bi1 has better theoretical voltage and theoretical capacity than pure BiF3.

SPECTRAL-COLLOCATION METHOD FOR FRACTIONAL FREDHOLM INTEGRO-DIFFERENTIAL EQUATIONS

Yang, Yin,Chen, Yanping,Huang, Yunqing Korean Mathematical Society 2014 대한수학회지 Vol.51 No.1

We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Fredholm-Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method, which shows that the errors of the approximate solution decay exponentially in $L^{\infty}$ norm and weighted $L^2$-norm. The numerical examples are given to illustrate the theoretical results.

SPECTRAL-COLLOCATION METHOD FOR FRACTIONAL FREDHOLM INTEGRO-DIFFERENTIAL EQUATIONS

Yin Yang,Yanping Chen,Yunqing Huang 대한수학회 2014 대한수학회지 Vol.51 No.1

We propose and analyze a spectral Jacobi-collocation approx- imation for fractional order integro-differential equations of Fredholm- Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method, which shows that the errors of the approximate solution decay exponentially in L ∞ norm and weighted L²-norm. The numerical examples are given to illustrate the theoretical results.

First-principles study of Ti doping in FeF3$0.33H2O

Zhenhua Yang,Zhijuan Zhang,Yalong Yuan,Yunqing Huang,Xianyou Wang,Xiaoying Chen,Shuangying Wei 한국물리학회 2016 Current Applied Physics Vol.16 No.8

The effect of Ti doping on the geometrical and electronic structures of FeF3$0.33H2O are systematically investigated by using the first principles calculations. We focused on TixFe1-xF3$0.33H2O systems, in which x is equal to 0, 0.08, 0.17 and 0.25, respectively. Different kinds of Ti dopant sites are checked and the most stable structure can be obtained by comparison of total energy. The crystal volume of TixFe1- xF3$0.33H2O expands gradually with increasing Ti doping concentration. Calculated formation energies indicate TixFe1-xF3 is easiest to fabricate and the difficulty of Ti doping FeF3 with hexagonal-tungstenbronze( HTB) structure decreases with the increase of Ti doping concentration under the Fe-rich and Ti-rich growth conditions. Moreover, TixFe1-xF3$0.33H2O is thermodynamically stable, indicating that water molecule can preferentially occupy one-dimensional cavity in the TixFe1-xF3. The band gap of TixFe1-xF3$0.33H2O decreases with increasing Ti doping concentration and Ti0.25Fe0.75F3$0.33H2O exhibits character of half metal, indicating that the conductivity of FeF3$0.33H2O can be improved by Ti-doping. Besides, it can be confirmed that Ti-doping also can broaden the hexagonal cavity in the FeF3$0.33H2O by analyzing the crystal structure of FeF3$0.33H2O and TixFe1-xF3$0.33H2O. With excellent conductivity and larger hexagonal cavity, TixFe1-xF3$0.33H2O can afford open diffusion channels. Therefore, Li ions can remain unblocked, which is beneficial to fast charge and discharge.

Preparation and properties of the green-emitting phosphors NaCa0.98-xMgxPO4:

Bo Yue,Juan Gu,Guangfu Yin,Zhongbing Huang,Xiaoming Liao,Yadong Yao,Yunqing Kang,Panli You 한국물리학회 2010 Current Applied Physics Vol.10 No.4

In this study, a series of the green-emitting phosphors NaCa0.98-xMgxPO4:Eu2þ 0:02 was prepared through high temperature solid-state reaction. The structure and spectroscopic properties of these samples were characterized by XRD, FT-IR, reflectance spectra and photoluminescence (PL) spectra, respectively. The effect of Mg2+ co-doping concentration on the PL intensity of as-prepared samples was also investigated. The enhanced intensities of excitation and emission band of Eu2+ and a slight red-shift of the emission peak were observed due to Mg2+ co-doping. When the x value is 0.08, the phosphors possessed the maximum emission intensity monitored at 360 nm and the emission spectrum shows a single band centered at about 500 nm. The obtained phosphors had strong absorption in near-UV zone (350–400 nm), which can match the emission of near-UV light-emitting diodes. The prepared material is potential green phosphors for white LEDs.