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Lei Jiang

Publications and source records attributed to Lei Jiang.

At least 73 records · Page 4Linked to original sources
PubMed2004

Reversible wettability of a chemical vapor deposition prepared ZnO film between superhydrophobicity and superhydrophilicity.

A superhydrophobic ZnO thin film was fabricated by the Au-catalyzed chemical vapor deposition method. The surface of the film exhibits hierarchical structure with nanostructures on sub-microstructures. The water contact angle (CA) was 164.3 degrees, turning into a superhydrophilic one (CA < 5 degrees) after UV illumination, which can be recovered through being placed in the dark or being heated. The film was attached tightly to the substrate, showing good stability and durability. The surface structures were characterized by scanning electron microscopy and atomic force microscopy.

Journal Article↗
PubMed2004

Property influence of polyanilines on photovoltaic behaviors of dye-sensitized solar cells.

The influence of polyanilines (PANIs) as hole conductors on the photovoltaic behaviors of dye-sensitized solar cells is studied. The current-voltage (I-V) characteristics and the incident photon to current conversion efficiency (IPCE) curves of the devices are determined as the function of different conductivities and morphologies of PANIs. The results show that the conductivity of PANIs affects the performance of the devices greatly, and PANI with the intermediate conductivity value (3.5 S/cm) is optimum. In addition, the effects of both the film formation property and the cluster size of polyanilines on the photovoltaic behaviors of the devices are also discussed.

Aniline Compounds↗
PubMed2004

Polyelectrolyte multilayer as matrix for electrochemical deposition of gold clusters: toward super-hydrophobic surface.

This communication describes the use of polyelectrolyte multilayer as a preformed matrix in electrochemical deposition to adjust the morphology of gold clusters, and only the surface covered with dendritic gold clusters shows a super-hydrophobic property, with the contact angle above 150 degrees and the tilt angle less than 1.5 degrees , after the surface further chemisorbed with a self-assembled monolayer of n-dodecanethiol.

Journal Article↗
PubMed2004

Comparison of protein precipitation methods for sample preparation prior to proteomic analysis.

Protein samples should be free of salt and other disturbing agents and have an appropriate concentration to be suitable for two-dimensional (2D) electrophoresis, the principal step of proteomics. To find the most efficient method for sample preparation, we used human plasma and compared four widely applied precipitation methods, using trichloroacetic acid (TCA), acetone, chloroform/methanol and ammonium sulfate, as well as ultrafiltration. Precipitation with TCA and acetone and ultrafiltration resulted in an efficient sample concentration and desalting. We also found that ammonium sulfate fractionation can efficiently remove albumin, which represents more than 50% of plasma proteins.

Ammonium Sulfate↗
PubMed2004

Reversible super-hydrophobicity to super-hydrophilicity transition of aligned ZnO nanorod films.

Remarkable surface wettability transition occurs with an inducement of ultraviolet (UV) for aligned ZnO nanorod films. The inorganic oxide films, which show super-hydrophobicity (left), become super-hydrophilic (right) when exposed to UV illumination. After the films are placed in the dark, the wettability evolves back to super-hydrophobicity. This reversible effect is ascribed to the cooperation of the surface photosensitivity and the aligned nanostructure. Such special property will greatly extend the applications of ZnO films.

Journal Article↗
PubMed2004

[Inhibitory effect of siRNA on bcr-abl gene expression in K562 cell line].

To explore a new way to treat CML, inhibitory effect of small interfering RNA (SiRNA) on bcr-abl fusion gene expression of K562 cell line was studied. SiRNA for bcr-abl gene was designed and transfected into K562 cells, bcr-abl gene expression was tested by RT-PCR. The results showed that bcr-abl gene expression was inhibited by using siRNA in dose-dependent manner and reduced to 19.9% and 26.6% of the control at 24 and 48 hours after transfection with 0.2 micro g siRNA respectively. K562 cells proliferation was suppressed finally, but bcr-abl gene expression restored at 72 hours. In conclusion, anti-bcr-abl siRNA can effectively inhibit bcr-abl gene expression of K562 cell line.

Dose-Response Relationship, Drug↗
PubMed2004

[The protective effect of amifostine on hydroquinone-induced apoptosis in bone marrow].

OBJECTIVE: To evaluate the protective effect of amifostine on hydroquinone-induced apoptosis of bone marrow mononuclear cells in vitro. METHODS: The mononuclear cells were separated and divided into four groups: blank control, amifostine group, hydroquinone group, amifostine + hydroquinone group. The cell apoptotic rate was examined in separated group at different time point, and apoptosis was detected by HT stain, then cell morphology was observed under fluorescent microscope and DNA fragments was tested by agarose gel electrophoresis. In addition, apoptotic and necrotic rate was detected by flow cytometer. RESULTS: After 10 hour culture, DNA ladder was detected in the hydroquinone group, but not in other groups. The apoptotic rate was not significantly different between amifostine group and blank control group at different culture time (P > 0.05). After 8 - 12 hour culture, the apoptotic rate in amifostine + hydroquinone group was significantly lower than that in the group of hydroquinone alone (P < 0.01). After 18 - 48 hour culture, the necrotic rate in amifostine + hydroquinone group was lower than that in the group of hydroquinone alone (P < 0.05). CONCLUSION: Amifostine can protect cell from hydroguinone-induced bone marrow damage through inhibition on cell apoptosis, and decrease in cell necrosis.

Amifostine↗
PubMed2004

[Effect of heat shock response on the cleavage of nucleolin induced by oxidative stress].

OBJECTIVE: To observe the cleavage of nucleolin (C23) during apoptosis induced by oxidative stress and to clarify the effect of heat shock response (HSR) on the cleavage of nucleolin and its possible molecular mechanism. METHODS: We added 0.5 mmol/L peroxide hydrogen (H2O2 ) into cultured cells to mimic oxidative stress. Apoptosis and cleavage of C23 were detected using caspase-3 colorimetric assay and Western blotting respectively. HSR was performed to observe the effect of HSR on cleavage of C23 induced by oxidative stress, and over-expressions of HSP70 and HSP25 were detected by Western blotting. RESULTS: Activity of caspase-3 increased significantly after 2 hours of 0.5 mmol/L H2O2 treatment, and reached the peak after 12 hours. The cleavage of C23 appeared 30 minutes to 1 hour after the treatment of H2O2 as indicated by a cleaved fragmentation of 80 kD, which was significantly inhibited by HSR. Moreover, HSR could induce HSP70 and HSP25 over-expressions. CONCLUSION: Oxidative stress can induce the activation of caspase-3, cleavage of C23, and apoptosis. HSR can significantly inhibit the cleavage of C23 induced by oxidative stress, which is related to the over-expressions of HSP70, HSP25, and other stress proteins.

Animals↗
PubMed2003

Photocurrent generation in multilayer self-assembly films fabricated from water-soluble poly(phenylene vinylene).

A novel, water-soluble, cationic PPV derivative poly[(2,5-bis(3-bromotrimethylammoniopropoxy)-phenylene-1,4-divinylene)-alt-1,4-(2,5-bis(2-(2-hydroxyethoxy)ethoxy))phenylene vinylene] (BH-PPV) has been synthesized by a Heck coupling reaction. Multilayered assemblies of the BH-PPV and the sodium salt of hexa(sulfobutyl)fullerenes (C(60)-HS) were fabricated successfully by an alternate deposition technique. The multilayer structures were studied by UV/Vis spectroscopy, small angle X-ray diffraction, and atomic force microscopy. The photoinduced charge transfer property of the self-assembled multilayer film was also measured by a three-electrode cell technique. A steady and rapid cathodic 5.5 microA cm(-2) photocurrent response was measured as the irradiation of the multilayer film was switched on and off. Importantly, the response of on/off cycling is prompt and reproducible. A possible mechanism for the electron-transfer process is proposed.

Journal Article↗
PubMed2003

Control over the wettability of an aligned carbon nanotube film.

Three-dimensional anisotropic aligned carbon nanotube microstructures were constructed by the chemical vapor deposition method on silicon templates with well-defined structure. It brought about new properties of wettability. Superhydrophobic (contact angle > 150 degrees ) and very hydrophilic (contact angle < 30 degrees ) properties can both be achieved by a simple change of structural parameter.

Journal Article↗
PubMed2003

Copper-catalyzed coupling of amides and carbamates with vinyl halides.

[reaction: see text] A general and efficient copper-catalyzed method for the amidation of vinyl bromides and iodides has been developed. This protocol uses a combination of 5 mol % copper iodide and 20 mol % N,N'-dimethyl ethylenediamine. Substrates bearing ester, silyl ether, and amino groups were successfully coupled under the reaction conditions. The double bond geometry of the vinyl halides was retained under the reaction conditions.

Amides↗