PubMed Health⌕ Search

Biomedical subjects

Jianlin Shi

Publications and source records attributed to Jianlin Shi.

17 recordsLinked to original sources
PubMed2006

Photocatalytic activity of a Bi-based oxychloride Bi(3)O(4)Cl.

A Bi-based oxychloride Bi(3)O(4)Cl with a layered structure as a novel efficient photocatalyst was studied in the present paper. The compound synthesized by a solid-state reaction method has a band gap of 2.79 eV. The material possesses a fair visible-light-induced photocatalytic activity. Generally, the photocatalytic efficiency of Bi(3)O(4)Cl for degrading methyl orange (MO) is higher than that of anatase TiO(2) under UV light illumination. The dispersion of Ag over Bi(3)O(4)Cl leads to an obvious increase in the photocatalytic performance. The MO decolorization over Bi(3)O(4)Cl is mainly initiated by a photocatalytic process. The photocatalytic activity is discussed in close connection with the crystal structure and the electronic structure in details.

Journal Article↗
PubMed2006

A reverse cation-exchange route to hollow PbSe nanospheres evolving from Se/Ag2Se core/shell colloids.

A reverse cation-exchange approach for the synthesis of hollow PbSe nanospheres is successfully established. This route involves a new strategy of a stepwise, in-situ template-based evolution from spherical amorphous Se colloids to Se/Ag(2)Se core/shell colloids, then to hollow PbSe nanospheres. Se colloids are prepared as the initial product by utilizing the chelation of ethylenediamine to bulk Se. They are converted into Se/Ag(2)Se core/shell colloids through the reaction with Ag(+) in ethylene glycol. During the conversion from Ag(2)Se shell to PbSe shell, a small amount of tributylphosphine is crucial as the capping agent. The characterization results, including XRD, SEM, TEM, HRTEM, and EDX, reveal that hollow PbSe nanospheres with polycrystalline and cubic structure are prepared. The corresponding optical band gap is calculated to be 0.56 eV. This conformation is potentially beneficial to the improvement concerning the applications of PbSe nanostructures.

Journal Article↗
PubMed2006

MnO2-embedded-in-mesoporous-carbon-wall structure for use as electrochemical capacitors.

We present an in situ reduction method to synthesize a novel structured MnO(2)/mesoporous carbon (MnC) composite. MnO(2) nanoparticles have been synthesized and embedded into the mesoporous carbon wall of CMK-3 materials by the redox reaction between permanganate ions and carbons. Thermogravimetric analysis (TG), X-ray photoelectron spectrum (XPS), X-ray diffraction (XRD), nitrogen sorption, transmission electron microscopy (TEM), and cyclic voltammetry were employed to characterize these composite materials. The results show that different MnO(2) contents could be introduced into the pores of CMK-3 treated with different concentrations of potassium permanganate aqueous solution, while retaining the ordered mesostructure and larger surface area. Increasing the MnO(2) content did not result in a decrease in pore size from the data of nitrogen sorption isotherms, indicating that MnO(2) nanoparticles are embedded in the pore wall, as evidenced by TEM observation. We obtained a large specific capacitance over 200 F/g for the MnC composite and 600 F/g for the MnO(2), and these materials have high electrochemical stability and high reversibility.

Journal Article↗
PubMed2006

[Clinical investigation of the combined therapy on deformed fingers after burn injury].

OBJECTIVE: To investigate the benefit of the combined therapy for deformed fingers after burn injury by comparing with the conventional one, and to sum up some experience. METHODS: From June 1999 to June 2004, 56 patients with deformed fingers entered the trial. In 28 patients of treatment group who received combined therapy (operation with post operational systematic convalescent care, group A), there were 20 males and 8 females (14-47 years), 129 fingers of 47 hands were involved. In 28 of conventional group who received conventional therapy (the same operational principle, and self-convalescent-care with out-patient service guidance, group B), there were 17 males and 11 females (18-51 years), 107 fingers of 42 hands were involved. Before and after the therapy, the finger's motor function were assessed according to the Swanson method. The hand's motor function was assessed through the Nine Hole Peg Test. RESULTS: The follow-up was 12-19 months in group A and 13-20 months in group B. The index of ankylosis (IA) of group A before therapy was 82% +/- 20%, and 45% +/- 13% after therapy; while the IA of group B before therapy was 78% +/- 17%, and 52% +/- 14% after therapy. The decreased of IA between before therapy and after therapy was 37% +/- 15% in group A, and 26% +/- 15% in group B, showing significant difference between the two groups (P<0.05). The Nine Hole Peg Test value of group A was 28.34 +/- 5.62 s before therapy, and 20.73 +/- 4.25 s after therapy; while that of group B was 27.47 +/- 5.78 s before therapy, and 21.86 +/- 4.12 s after therapy. The decrease of the Nine Hole Peg Test value between before therapy and after therapy was 7.61 +/- 2.27 s in group A, and 5.61 +/- 2.94 s in group B, showing statistically significant difference (P<0.05). CONCLUSION: The combined therapy is more effective than the conventional one.

Adolescent↗
PubMed2005

Epitaxial synthesis of uniform cerium phosphate one-dimensional nanocable heterostructures with improved luminescence.

Uniform CePO(4)@LaPO(4) and CePO(4):Tb(3+)@LaPO(4) one-dimensional single-crystalline nanocable heterostructures with highly enhanced photoluminescent emission have been synthesized via a mild and simple hydrothermal approach. The resulting one-dimensional single-crystalline nanocable heterostructures have smooth and uniform LaPO(4) sheaths, which is of great significance in effectively eliminating surface trap-states and suppressing the energy quenching in energy-transfer processes. The photoluminescence results for these one-dimensional nanocable heterostructures illustrate that the uniform LaPO(4) sheaths remarkably increase the luminescent efficiency.

Journal Article↗
PubMed2005

Fabrication of uniform magnetic nanocomposite spheres with a magnetic core/mesoporous silica shell structure.

A novel kind of magnetic core/mesoporous silica shell nanospheres with a uniform particle diameter of ca. 270 nm was synthesized. The inner magnetic core endues the whole nanoparticle with magnetic properties, while the outer mesoporous silica shell shows high enough surface area and pore volume. The synthesized material is expected to be applied to targeted drug delivery and multiphase separation. The storage and release of ibuprofen into and from the pore channels of the mesoporous silica shell, as a typical example, are demonstrated.

Magnetics↗
PubMed2005

Enhancement of third-order optical nonlinearities in 3-dimensional films of dielectric shell capped Au composite nanoparticles.

The composite nanoparticles of Au-core capped by CdS shells of different thickness were prepared and assembled into densely packed 3-dimensional films by the layer-by-layer self-assembly (LBL) technique. These films exhibited the 3-dimensional structure of densely packed Au@CdS composite nanoparticles and the shell thickness was tunable by changing the concentration of Cd2+-thiourea complexes. These multilayer films exhibited enhanced third-order optical nonlinear responses and ultrafast response times (several picoseconds). The third-order nonlinear optical susceptibility of the film with the CdS shell thickness of 4.4 nm was estimated to be 1.48 x 10(-9) esu and the value decreases with the increase of the CdS shell thickness. The enhancement of the optical nonlinearity was explained based on the calculation according to the electrostatic approximation by the solution of Laplace's equation under the boundary conditions appropriate to the model of core-shell nanoparticles, and mainly attributed to localized electric field effects in the CdS shell region. Additionally, the nonlinearity was optimized by determination of the values of the dielectric constant and thickness of the different shell.

Journal Article↗
PubMed2005

A mesoporous template route to the low-temperature preparation of efficient green light emitting Zn2SiO4:Mn phosphors.

Green light emitting Zn2SiO4:Mn phosphors have been prepared via a low-temperature solid-state reaction using mesoporous silica SBA-15 template. This mesoporous silica template method features low-temperature formation of phosphors and easy doping. The structure and morphology of the phosphors were characterized by XRD, SEM, TEM, and N2 adsorption/desorption techniques, which confirmed the single crystallinity, ordered mesostructure, closed pore channels, and elongated ropelike morphology. The luminescent properties were examined by photoluminescence spectroscopy at room temperature, and the results of fluorescence decay time measurements show non-single-exponential decay behavior and a decrease of the decay time with an increase of the Mn concentration.

Light↗
PubMed2005

Immobilization of hemoglobin at the galleries of layered niobate HCa2Nb3O10.

Hemoglobin (Hb) was intercalated at the galleries of layered niobate HCa(2)Nb(3)O(10) (HCNO). Two different kinds of layered phases of Hb-CNO composites Hb-CNO-1 and Hb-CNO-2 were obtained with the interlayer distances of 7.2 and 10.3nm in correspondence with the monolayer and bilayer arrangements of proteins between the niobate layers, respectively, based on the powder XRD pattern, HRTEM, UV-vis spectra and CHN analyses. FTIR spectra of Hb-CNO composites show that amide I and amide II bands were actually the same as those of the native Hb, which indicates that there is almost no structural change after immobilization. Michaelis-Menten model methods were used to study the peroxidatic activity of the reaction of 2-methoxyphenol and H(2)O(2) for the entrapped Hb in the galleries of HCNO. Compared to that of free Hb, the kinetic parameters of Hb-CNO k(cat), K(M) and k(cat)/K(M) were affected by the immobilization process. The immobilized Hb showed a higher relative activity than that of free Hb after incubated in phosphate buffer (pH = 7) at 80 degrees C for a period of time. The environments between the layers of HCNO are hydrophilic which will bind water tightly and help to stabilize the 'essential water' layer around the protein. So, immobilization of Hb between the layers of HCNO enhanced the activity of Hb in water-DMSO mixture.

Adsorption↗
PubMed2005

Template guided self-assembling two-dimensional array of Au@SiO2 core-shell nanoparticles for room-temperature single electron transistors.

The composite nanoparticles of a gold core capped by a SiO2 shell with well-controlled thickness have been synthesized and fabricated into two-dimensional array on silicon surface by a simple self-assembly method combined with an AFM nanolithography technique. Current-voltage measurements of the Au@SiO2 composite nanoparticles (shell thickness of 6 nm) show a well-pronounced Coulomb staircase with a period of 300 mV at room temperature, demonstrating single electron transistor behavior. The step width of the Coulomb staircase can be tuned by controlling the thickness of SiO2 shell. The tunable single electron tunneling properties make the 2D array of Au@SiO2 composite nanoparticles an ideal candidate for planar single electron transistor devices.

Colloids↗
PubMed2004

Enhanced catalytic activity of hemoglobin in organic solvents by layered titanate immobilization.

A simple layered titanate immobilization can significantly enhance the Hb catalytic activity in organic media relative to native Hb, especially in hydrophilic dioxane systems, where the composites have an about 100 times enhancement. The interlayer water should be responsible for the increased nonaqueous catalytic activities of the immobilized Hb due to its strengthened resistance to the distorting of the Hb surface essential water layer by organic solvents.

Catalysis↗
PubMed2004

Reversible intercalation of large-capacity hemoglobin into in situ prepared titanate interlayers with enhanced thermal and organic medium stabilities.

The exfoliated single-layer titanate can rapidly restack and reversibly release heme protein simply by adjustment of the pH value. The composites have regularly layered structure and powdery morphology by their ideal layer-to-layer assembly, which provides the titanate nanosheet an unusual specific intercalation capacity of 5900 mg g(-1) for the protein. The bound and released proteins keep active relative to the intact protein. The hemoglobin thermal and organic solvent stabilities are improved by the protective environment of the titanate host.

Hemoglobins↗
PubMed2003

A new thioether functionalized organic-inorganic mesoporous composite as a highly selective and capacious Hg2+ adsorbent.

A new thioether functionalized organic-inorganic ordered mesoporous composite as a highly selective and capacious Hg2+ adsorbent was synthesized by one-step co-condensation of (1,4)-bis(triethoxysilyl)propane tetrasufide (BTESPTS, (CH3CH2O)3Si(CH2)3S-S-S-S(CH2)3Si(OCH2CH3)3) and tetraethoxysilane (TEOS), with tri-block copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) EO20PO70EO20 as template.

Journal Article↗