Publications by authors named "Zhongchao Duan"

Radiotherapy is one of the most effective therapeutic strategies for cervical cancer patients, although radioresistance-mediated residual and recurrent tumors are the main cause of treatment failure. However, the mechanism of tumor radioresistance is still elusive. DNA damage response pathways are key determinants of radioresistance.

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In the current study, we explored the impact of Tudor-staphylococcal nuclease (SN) on obesity induced by a high-fat diet (HFD) in mice, because the functional involvement of Tudor-SN in lipid metabolism in vivo is unknown. HFD-transgenic (Tg) mice exhibited reductions in hepatic steatosis and systemic insulin resistance. There was no difference in hepatic lipid accumulation between chow-fed wild-type (WT) and chow-fed Tg mice; consistently, no difference in activation of the lipogenic pathway was detected.

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IL-4 activates STAT6 and causes the subsequent up-regulation of Ig heavy chain germline Igε via chromatin remodeling involved in B lymphocytes development. STAT6 acts as a molecular switch to regulate the higher-order chromatin remodeling via dynamically orchestrating co-activators (CBP/Tudor-SN) and co-repressors (HDAC1/PSF). Here, we demonstrated that STAT6/Tudor-SN/PSF form a complex, balancing the acetylation and deacetylation states to co-regulate IL-4/STAT6 gene transcription.

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Soliton self-frequency shift (SSFS) and third-harmonic generation (THG) are observed in a four-hole As2S5 chalcogenide microstructured optical fiber (MOF). The As2S5 MOF is tapered to offer an ideal environment for SSFS. After tapering, the zero-dispersion wavelength (ZDW) shifts from 2.

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A chalcogenide-tellurite hybrid optical fiber with a step-index structure is fabricated by the rod-in-tube drawing technique. The core is made of 15Ge-3Ga-12Sb-70S (mol. %) glass, and the cladding is made of 78TeO₂-5ZnO-12Li₂O-5Bi₂O₃ (mol.

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Adipogenesis, in which mesenchymal precursor cells differentiate into mature adipocytes, is a well orchestrated process. In the present study we identified Tudor-SN as a novel co-activator of the transcription factor peroxisome proliferator-activated receptor γ (PPARγ). We provide the first evidence that Tudor-SN and PPARγ exist in the same complex.

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Tudor-SN is a multifunctional protein that is highly expressed in multiple cancers including breast cancer. Tudor-SN, as a component in RNA-induced splicing complex, was recently reported to regulate gene expression in a microRNA (miRNA)-dependent manner, such as let-7, miR-34a and miR-221. However, how Tudor-SN is associated with cancer development still remains largely elusive.

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The parametric amplification gain and bandwidth in highly nonlinear tellurite hybrid microstructured optical fiber (HMOF) are simulated based on four wave mixing process. The fiber core and cladding materials are made of TeO(2)–Li(2)O–WO(3)–MoO(3)–Nb(2)O(5) and TeO(2)–ZnO–Na(2)O–P(2)O(5) glass, respectively. The fiber has four zero-dispersion wavelengths and the chromatic dispersion is flattened near the zerodispersion wavelengths.

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Supercontinuum (SC) generation from a highly nonlinear tellurite microstructured optical fiber with multiple rings of holes was demonstrated by pumping with a 2 μm mode-locked picosecond fiber laser. The chromatic dispersion of the fiber was measured with a homemade white-light spectral interferometer in a wide wavelength range and agreed with the theoretical calculation. Although the pumped wavelength was far from the zero dispersion wavelength, with flat dispersion profile of the fiber in the anomalous dispersion, the SC could be expanded from 650 to 2850 nm with launched pulse energy of several hundred picojoules.

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We demonstrate the supercontinuum (SC) generation in a suspended-core As(2)S(3) chalcogenide microstructured optical fiber (MOF). The variation of SC is investigated by changing the fiber length, pump peak power and pump wavelength. In the case of long fibers (20 and 40 cm), the SC ranges are discontinuous and stop at the wavelengths shorter than 3500 nm, due to the absorption of fiber.

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A simple all-solid tellurite microstructured optical fiber which has only one layer of high-index rods in the cladding is proposed and fabricated in the paper. The core and the cladding with the low index are made from the TeO(2)-ZnO-Na(2)O-La(2)O(3) glass, and the high-index rods are made from the TeO(2)-Li(2)O-WO(3)-MoO(3)-Nb(2)O(5) glass. The guiding regime in this fiber can be explained by ARROW model.

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A new way to suppress stimulated Brillouin scattering by using an all-solid chalcogenide-tellurite photonic bandgap fiber is presented in the paper. The compositions of the chalcogenide and the tellurite glass are As(2)Se(3) and TeO(2)-ZnO-Li(2)O-Bi(2)O(3). The light and the acoustic wave are confined in the fiber by photonic bandgap and acoustic bandgap mechanism, respectively.

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We have demonstrated broad supercontinuum (SC) generation by using a highly nonlinear tapered tellurite microstructured fiber pumped by a 15-ps-pulsed laser with the peak power of 375 W. The fiber is characterized with a short section with a large diameter followed by a long section with a small diameter. The SC was mainly generated in the last 30-cm-long section which had a core diameter of 0.

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We investigate supercontinuum (SC) generation in highly nonlinear tellurite microstructured fibers pumped by a continuous wave (cw)/quasi-cw laser. We investigate two types of tellurite fibers. One type has the constant core diameter, and the other type has a longitudinally varying core diameter.

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We demonstrate theoretically and experimentally that it is feasible to draw the microstructured fiber with longitudinally varying diameter (FLVD) whose diameter varies sharply in a short fiber length. It is elucidated that during the fiber drawing process the tension is linearly proportional to the natural logarithm of the fiber drawing speed. As a result, the tension is not so sensitive to the fiber diameter.

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We try to obtain stable supercontinuum (SC) generation with broad bandwidth under relative simple pump conditions. We use a 1.3-m-long highly nonlinear tellurite microstructured fiber and pump it by a 15 ps 1064 nm fiber laser.

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Up-conversion luminescence properties of a Tm3+/Yb3+ codoped oxyfluoride glass-ceramics under 980 nm excitation are investigated. Intense blue emission centered at 476 nm, corresponding to 1G4-->3H6 transitions of Tm3+ was simultaneously observed in the transparent oxyfluoride glass ceramics at room temperature. The intensity of the blue up-conversion luminescence in a 1 mol% YbF3-containing glass-ceramic was found to be about 40 times stronger than that in the precursor oxyfluoride glass.

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Ytterbium-sensitized erbium-doped oxide-halide tellurite and germanate-niobic-lead glasses have been synthesized by conventional melting method. Intense green and red emissions centered at 525, 546 and 657 nm, corresponding to the transitions 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2, respectively, were simultaneously observed at room temperature in these glasses. The quadratic dependence of the 525, 546 and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs.

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Tm3+/Yb3+-codoped heavy metal oxide-halide glasses have been synthesized by conventional melting and quenching method. Structural properties were obtained based on the Raman spectra, indicating that halide ion has an important influence on the phonon density and maximum phonon energy of host glasses. Intense blue and weak red emissions centered at 477 and 650 nm, corresponding to the transitions 1G4-->3H6 and 1G4-->3H4, respectively, were observed at room temperature.

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