379 results on '"Xu, Rongrong"'
Search Results
152. 2 μm spectroscopic investigation of Tm3+-doped tellurite glass fiber
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Xu, Rongrong, primary, Tian, Ying, additional, Hu, Lili, additional, and Zhang, Junjie, additional
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- 2011
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153. Structural Origin and Energy Transfer Processes of 1.8 μm Emission in Tm3+ Doped Germanate Glasses
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Xu, Rongrong, primary, Tian, Ying, additional, Hu, Lili, additional, and Zhang, Junjie, additional
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- 2011
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154. Enhanced emission of 27 μm pumped by laser diode from Er^3+/Pr^3+-codoped germanate glasses
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Xu, Rongrong, primary, Tian, Ying, additional, Hu, Lili, additional, and Zhang, Junjie, additional
- Published
- 2011
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155. 2.05 µm emission properties and energy transfer mechanism of germanate glass doped with Ho3+, Tm3+, and Er3+
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Xu, Rongrong, primary, Wang, Meng, additional, Tian, Ying, additional, Hu, Lili, additional, and Zhang, Junjie, additional
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- 2011
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156. Diffraction characteristics of spatial and temporal Gaussian-shaped femtosecond laser pulse by rectangle reflection grating
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Liu, Guohua, primary, Xu, Rongrong, additional, Yu, Wenbing, additional, and Wu, Hanping, additional
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- 2011
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157. Observation of 27μm emission from diode-pumped Er^3+/Pr^3+-codoped fluorophosphate glass
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Tian, Ying, primary, Xu, Rongrong, additional, Zhang, Liyan, additional, Hu, Lili, additional, and Zhang, Junjie, additional
- Published
- 2011
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158. 1.8 μm emission of highly thulium doped fluorophosphate glasses
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Tian, Ying, primary, Xu, Rongrong, additional, Zhang, Liyan, additional, Hu, Lili, additional, and Zhang, Junjie, additional
- Published
- 2010
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159. 2.0μm Emission properties of transparent oxyfluoride glass ceramics doped with Yb3+–Ho3+ ions
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Pan, Jiajia, primary, Xu, Rongrong, additional, Tian, Ying, additional, Li, Kefeng, additional, Hu, Lili, additional, and Zhang, Junjie, additional
- Published
- 2010
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160. 2μm Emission of Ho3+-doped fluorophosphate glass sensitized by Yb3+
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Tian, Ying, primary, Zhang, Liyan, additional, Feng, Suya, additional, Xu, Rongrong, additional, Hu, Lili, additional, and Zhang, Junjie, additional
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- 2010
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161. Influence of phospholipase A2 (PLA2)-treated dried egg yolk on wheat dough rheological properties
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Zhao, Xiaoguang, primary, Shi-Jian, Dong, additional, Tao, Guanjun, additional, Xu, Rongrong, additional, Wang, Miao, additional, Reuhs, Brad, additional, and Yang, Yanjun, additional
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- 2010
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162. Enhanced 2.0 μm emission in codoped transparent oxyfluoride glass ceramics containing nano-crystals
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Pan, Jiajia, primary, Xu, Rongrong, additional, Wang, Meng, additional, Gao, Guojun, additional, Chen, Jimeng, additional, Hu, Lili, additional, and Zhang, Junjie, additional
- Published
- 2010
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163. A real time memory manager for the real time specification for Java
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Xu, Rongrong, primary
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164. Study on microchannel fabrication technology by femtosecond laser micromachining in transparent materials
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Xu, Rongrong, primary, Liu, Deming, additional, Liu, Guohua, additional, and Cao, Feng, additional
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- 2009
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165. L1-estimation for spatial nonparametric regression
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Xu, Rongrong, primary and Wang, Jinde, additional
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- 2008
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166. The Convergence of RFID with Wi-Fi and on the Applications in Logistics System
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Ouyang, Ye, primary and Xu, Rongrong, additional
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- 2007
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167. Mid-infrared luminescence and energy transfer of Dy3+/Tm3+ doped fluorophosphate glass
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Tian, Ying, Xu, Rongrong, Guo, Yanyan, Li, Ming, Hu, Lili, and Zhang, Junjie
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LUMINESCENCE spectroscopy , *THULIUM isotopes , *ENERGY transfer , *PARAMETER estimation , *FLUOROPHOSPHINE , *METALLIC glasses , *PHOTOLUMINESCENCE , *THERMAL analysis - Abstract
Abstract: This work reports the observation of emissions at 2.9μm, 1.8μm and 1.47μm from Dy3+/Tm3+ codoped fluorophosphate glass upon excitation of a conventional 800nm laser diode. Judd–Ofelt intensity parameters and radiative properties of Dy3+ ions in present glasses were calculated using the Judd–Ofelt theory. The mechanism and microparameters of energy transfer processes were investigated based on photoluminescence performance and lifetime measurements. The Dy3+/Tm3+ codoped fluorophosphate glass possessing advantageous spectroscopic characteristics as well as excellent thermal stability is a promising candidate for an efficient 2.9μm laser. [Copyright &y& Elsevier]
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- 2012
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168. Synthesis and infrared photoluminescence around 2.9μm from Dy3+/Tm3+ codoped fluorophosphate glass
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Tian, Ying, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
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PHOTOLUMINESCENCE , *RARE earth ions , *GLASS , *PHOSPHATES , *ENERGY transfer , *ABSORPTION , *ELECTRONIC excitation , *FLUORESCENCE spectroscopy - Abstract
Abstract: Fluorophosphate glasses co-doped with Dy3+ and Tm3+ ions have been synthesized with low OH content. Photoluminescence around 2.9μm is successfully obtained in present glass excited by a conventional 808nm laser diode. The luminescence characteristics and energy transfer mechanism are investigated. Based on the absorption, fluorescence spectra and lifetime measurements, Tm3+ ions can effectively absorb excitation energy and then play an important role in getting 2.9μm emission. Besides, it is found that Tm3+ ions can transfer their energy to Dy3+ ions with high efficiency. Hence, the results indicate that Dy3+/Tm3+ co-doped fluorophosphate glass possessing advantageous spectroscopic characteristics is a potential cost-effective host for the mid-infrared solid state lasers. [Copyright &y& Elsevier]
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- 2012
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169. 2.7μm fluorescence radiative dynamics and energy transfer between Er3+ and Tm3+ ions in fluoride glass under 800nm and 980nm excitation
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Tian, Ying, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
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FLUORESCENCE , *ENERGY transfer , *ERBIUM , *FLUORIDE glasses , *LASERS , *RADIATIVE transfer - Abstract
Abstract: A detailed study of the fluorescence radiative dynamics and energy transfer processes between Er and Tm ions in the Er3+/Tm3+ doped fluoride glass is reported. The fluorescence properties of 2.7μm emission, other infrared and visible emissions are investigated under different selective laser excitations. Three Judd–Ofelt intensity parameters, energy transfer microparameters and efficiency have been determined and discussed. It is found that present Er3+/Tm3+ doped fluoride glass possesses large calculated emission cross section (8.98×10–21 cm2) around 2.7μm. The more suitable pumping scheme for laser applications at 2.7μm laser is 980nm excitation for Er3+/Tm3+ doped fluoride glass. [Copyright &y& Elsevier]
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- 2012
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170. Broadband 2.84μm luminescence properties and Judd–Ofelt analysis in Dy3+ doped ZrF4–BaF2–LaF3–AlF3–YF3 glass
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Tian, Ying, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
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LUMINESCENCE spectroscopy , *POTENTIAL theory (Physics) , *DYSPROSIUM , *OPTICAL properties of metals , *ENERGY transfer , *LASER beams - Abstract
Abstract: 2.84μm luminescence with a bandwidth of 213nm is obtained in Dy3+ doped (ZrF4–BaF2–LaF3–AlF3–YF3) ZBLAY glass. Three intensity parameters and radiative properties have been determined from the absorption spectrum based on the Judd–Ofelt theory. The 2.84μm emission characteristics and energy transfer mechanism upon excitation of a conventional 808nm laser diode are investigated. The prepared Dy3+ doped ZBLAY glass possessing high predicted spontaneous transition probability (45.92s−1) along with large calculated emission cross section (1.17×10−20 cm2) has potential applications in 2.8μm laser. [Copyright &y& Elsevier]
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- 2012
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171. Spectroscopic properties and energy transfer process in Er3+ doped ZrF4-based fluoride glass for 2.7μm laser materials
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Tian, Ying, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
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ENERGY transfer , *RARE earth ions , *FLUORIDES , *OPTICAL materials , *ELECTRONIC excitation , *ABSORPTION spectra , *PHASE transitions , *RADIATIVE transfer - Abstract
Abstract: Intense 2.7μm emission from Er3+ doped in a new type of ZrF4-based fluoride glass is reported. 2.7μm emission characteristics and energy transfer process upon excitation of a conventional 980nm laser diode are investigated. Based on the absorption spectra, the Judd–Ofelt parameters and radiative properties were calculated and compared with those of other glass hosts. The prepared glass possesses higher predicted spontaneous transition probability (29.04s−1) along with larger calculated emission cross section (9.16×10−21 cm2). Besides, the energy transfer coefficient of laser upper level (4I11/2) can reach as high as 6.56×10−39 cm6/s. Hence, these results indicate that this Er3+ doped ZrF4-based fluoride glass has potential applications in 2.7μm laser. [Copyright &y& Elsevier]
- Published
- 2011
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172. 2μm spectroscopic investigation of Tm3+-doped tellurite glass fiber
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Xu, Rongrong, Tian, Ying, Hu, Lili, and Zhang, Junjie
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GLASS fibers , *THULIUM , *TELLURITES , *SEMICONDUCTOR doping , *METAL quenching , *ENERGY transfer , *METAL castings , *FLUORESCENCE , *EMISSION spectroscopy , *STRENGTH of materials , *RADIATIVE transitions - Abstract
Abstract: TmF3 doped TeO2–ZnO–La2O3 (TZL) glasses and fibers have been prepared by the conventional melt-quenching and suction casting methods, respectively. 2μm emission properties and energy transfer mechanisms of the TZL glasses and fibers have been analyzed and discussed. The oscillator strength, Judd–Ofelt parameters, radiative transition probability and radiative lifetime of Tm3+ have been calculated based on the absorption spectra and Judd–Ofelt theory. The maximum emission cross-section of Tm3+ is 6.9×10−21 cm2 near 2μm. Emission spectra have been obtained from both TZL fibers and bulk glass when excited with a 794nm pump. The results of 2μm emission spectra indicate that the line width of Tm3+ measured in fibers is narrower than that in the bulk glass sample. The peak position of the emission spectra shifts to longer wavelength with increment of the fiber length. [Copyright &y& Elsevier]
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- 2011
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173. Investigation on broadband near-infrared emission and energy transfer in Er3+–Tm3+ codoped germanate glasses
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Xu, Rongrong, Tian, Ying, Wang, Meng, Hu, Lili, and Zhang, Junjie
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INFRARED radiation , *ENERGY transfer , *RARE earth ions , *GERMANIUM compounds , *METALLIC glasses , *OPTICAL materials , *OPTICAL amplifiers , *WAVELENGTH division multiplexing - Abstract
Abstract: Broadband near-infrared emission has been investigated in a new type host composition of Er3+–Tm3+ codoped germanate glass. A broadband emission extend from 1350 to 1675nm with the full width at half maximum (FWHM) around 138nm is obtained in the germanate glass which codoped with 0.2 wt.% Er2O3 and 0.8 wt.% Tm2O3. The energy transfer between Er3+ and Tm3+ plays an important role in the emission mechanism, which is evidenced by the visible upconversion and the lifetime of Er3+:4I13/2 level effected by the addition of Tm2O3. And energy transfer efficiency from Er3+ to Tm3+ reaches 76% for the highest Tm3+ concentration of 0.8 wt.%. These results suggest that this glass would be a promising material for broadband light source and broadband amplifier for the wavelength division multiplexing transmission systems. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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174. 2.0μm Emission properties of transparent oxyfluoride glass ceramics doped with Yb3+–Ho3+ ions
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Pan, Jiajia, Xu, Rongrong, Tian, Ying, Li, Kefeng, Hu, Lili, and Zhang, Junjie
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FLUORIDE glasses , *CERAMICS , *METAL ions , *HOLMIUM , *EMISSIONS (Air pollution) , *HEAT treatment of metals , *METAL absorption & adsorption - Abstract
Abstract: Transparent oxyfluoride glass and glass ceramics doped with 3.0mol% Yb3+ and 0.5mol% Ho3+ ions have been prepared. The investigated samples show efficient 2.0μm emission. The absorption and emission cross sections corresponding to the 5I7–5I8 transitions of Ho3+ (at 2.0μm) have been calculated according to the McCumber theory. Glass sample heat-treated at 470°C has the maximum absorption and emission cross sections of 5.58×10−21 cm2 at 1949nm and 6.64×10−21 cm2 at 2034nm. The Yb3+–Ho3+ doped oxyfluoride glass ceramic exhibits an advantage for application in 2.0μm laser devices. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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175. An Improved Isotope Labelling Method for Quantifying Deamidated Cobratide Using High-Resolution Quadrupole-Orbitrap Mass Spectrometry.
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Liu, Bo, Huang, Lu, Xu, Rongrong, Fan, Huihong, and Wang, Yue
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RADIOLABELING , *MASS spectrometry , *TANDEM mass spectrometry , *AMINO acid sequence , *DEAMINATION , *AMIDATION , *CAPILLARY electrophoresis , *PEPTIDES - Abstract
Protein deamidation can severely alter the physicochemical characteristics and biological functions of protein therapeutics. Cobratide is a non-addictive analgesic with wide clinical acceptance. However, the Asn residue at position 48 from the N-terminus of the cobratide amino acid sequence (N48) tends to degrade during purification, storage, and transport. This characteristic could severely affect the drug safety and clinical efficacy of cobratide. Traditional methods for quantitating deamidation reported in previous research are characterised by low efficiency and accuracy; the quality control of cobratide via this method is limited. Herein, we developed an improved 18O-labelling method based on the detection of a unique peptide (i.e., the protein fragment of cobratide containing the N48 deamidation hotspot after enzymolysis) using an Orbitrap high-resolution mass spectrometer to quantify deamidated cobratide. The limits of detection and quantification of this method reached 0.02 and 0.025 μM, respectively, and inter- and intra-day precision values of the method were <3%. The accuracy of the 18O-labelling strategy was validated by using samples containing synthesised peptides with a known ratio of deamidation impurities and also by comparing the final total deamidation results with our previously developed capillary electrophoresis method. The recoveries for deamidation (Asp), deamidation isomerisation (iso-Asp), and total deamidation were 101.52 ± 1.17, 102.42 ± 1.82, and 103.55 ± 1.07, respectively. The robustness of the method was confirmed by verifying the chromatographic parameters. Our results demonstrate the applicability of the 18O-labelling strategy for detecting protein deamidation and lay a robust foundation for protein therapeutics studies and drug quality consistency evaluations. [ABSTRACT FROM AUTHOR]
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- 2022
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176. Effect of chloride ion introduction on structural and 1.5?μm emission properties in Er^3+-doped fluorophosphate glass
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Tian, Ying, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
- Abstract
Effects of chloride ion introduction on structural and 1.5?μm emission properties in Er^3+-doped fluorophosphate have been investigated. The structural changes revealed by the measured Raman spectra indicate that the chloride ions have an important influence on the phonon density of host glasses. With increasing chloride content, the phonon density of fluorophosphate glasses decreases. The chloride modified fluorophosphate glasses possessing higher thermal stability are suitable for broadband amplifier fiber fabrication. Desirable thermal resistance properties and spectroscopic characteristics of Er^3+-doped chloride fluorophosphate glass indicate that it is a promising material for 1.5?μm lasers.
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- 2011
177. Development of histidine-tagged cyclic peptide functionalized monolithic material for the affinity purification of antibodies in biological matrices.
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Xu, Rongrong, Lu, Li, Sun, Lingjue, Liu, Xiao, Lei, Yutian, Huang, Shengfeng, Huang, Hao, Crommen, Jacques, Han, Hai, Wang, Qiqin, and Jiang, Zhengjin
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TRYPSIN , *IMMUNOGLOBULINS , *RITUXIMAB , *CELL culture , *SEPHAROSE , *MONOCLONAL antibodies , *DIGESTION - Abstract
• A cyclic peptide functionalized monolith was fabricated to purify antibodies. • This material exhibited excellent antibody-specific selectivity and good binding capacity. • The novel material exhibited acceptable resistance to trypsin digestion. • It can highly selectively capture antibodies from multiple bio-samples. The rapidly increasing applications of monoclonal antibodies (mAbs) in therapy have necessitated the development of mAb production and purification technologies for both academic and industrial usage. Herein, a histidine-tagged cyclic peptide (HHHHHHGSGSGSDC*AWHLGELVWC*T, the disulfide-bonded cysteines of which are indicated by asterisks, named HT25-cyclopeptide) functionalized monolithic material was developed by the metal ion chelation-based approach. The resulting material possessed suitable affinity and peptide ligand density (13.8 mg peptide ligand per mL of material), good porosity (67.1 %), acceptable specific surface area (52.95 m2/g), and lots of macropores (4.13 μm). Moreover, excellent antibody-specific selectivity, comparable or even better binding capacity (for dried material, maximum static binding capacity and dynamic binding capacity are about 119.3 mg/g and 17.05 mg/g, respectively) for antibody compared to previously developed affinity materials, acceptable resistance to trypsin digestion, and negligible nonspecific protein adsorption, were also achieved on this novel monolithic material. Compared with the corresponding cyclic peptide-based sepharose material, milder elution conditions were employed for the HT25-cyclopeptide-based monolithic material, which could effectively prevent the aggregation and denaturation of the enriched antibodies. This novel material was then successfully applied to the affinity enrichment and purification of mAbs (including infliximab and rituximab) in different cell culture media or IgG in human serum. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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178. Ion-exchange controlled surface engineering of cobalt phosphide nanowires for enhanced hydrogen evolution.
- Author
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Xu, Rongrong, Jiang, Tengfei, Fu, Zheng, Cheng, Ningyan, Zhang, Xingxiu, Zhu, Kun, Xue, Huaiguo, Wang, Wenjun, Tian, Jingqi, and Chen, Peng
- Abstract
Transition metal phosphides are promising alternatives to the precious metal catalysts for various electrocatalysis applications. Controllable and precise surface engineering of electrocatalysts is the key challenge to enhance their performance. Herein, we demonstrate an ion-exchange strategy to produce cobalt phosphide nanowires which have a conductive core and a thickness-controlled surface layer with sulfur dopants, phosphorus vacancies, and amorphous domains. They are applied for hydrogen evolution reaction with high stability, achieving a current density of 100 mA cm
-2 at an overpotential of 114 mV. Based on both comprehensive state-of-the-art experimental characterizations and theoretical investigations, the excellent catalytic performance is attributed to increased active sites, facilitated charge transfer and transport, as well as weakened H adsorption and strengthened H 2 O adsorption due to the synergistic effects of S dopants and P vacancies. A controllable surface-layer-confined doping strategy to engineer the surface composition and structure of cobalt phosphide nanowire arrays based on an ion-exchange mechanism is developed toward superior electrocatalytic hydrogen evolution. Image 1 • A controllable ion-exchange strategy to produce sulfur doped-cobalt phosphide nanowires (S-CoP) has been developed. • S-CoP has conductive core and thickness-controlled surface layer with sulfur dopants, phosphorus vacancies, and amorphous domains. • S-CoP can achieve the current density of 100 mA cm-2 at a low overpotential of 114 mV, much is lower than that of CoP (η 100 = 134 mV). • We demonstrate a new strategy to precisely engineer a nanostructured catalyst based on state-of-the-art experimental characterization and theoretical analyses. • Mechanistic insights on interplays between dopants, vacancies and active centers have been provided. [ABSTRACT FROM AUTHOR]- Published
- 2020
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179. Detection and analysis of comE and luxS genes in quorum sensing signal pathway from Streptococcus oralis.
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Xu Rongrong, Wang Bin, and Ge Jiuyu
- Abstract
Objective To detect and analyze two important genes, comE and luxS, in quorum sensing signal pathway from Streptococcus oralis (S.oralis). Methods The total genomic DNA of S.oralis NH521 (a clinically isolated strain) was firstly extracted. The comE and luxS genes were then amplified by polymerase chain reaction (PCR) and further sequenced. The obtained sequences were compared with related sequences in GenBank. Results Target bands of both comE and luxS genes were detected by electrophoresis. The obtained gene sequences were similar to the corresponding sequences from another S.oralis strain (luxS, 95.0%; comE, 99.6%); however, comparing to gene sequences of another species Streptococcus mutans, comE was more divergent (12.7%) than luxS gene (74.1%). Conclusion This study successfully amplified and sequenced comE and luxS genes from S.oralis NH521 strain. The luxS gene accumulated more mutations than comE gene did between two S.oralis strains, but comE gene is more divergent than luxS gene between two Streptococcus species. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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180. High-precision time transfer over a local ring fiber link.
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Xu, Rongrong, Zuo, Faxing, Hu, Liang, Chen, Jianping, and Wu, Guiling
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LOCAL rings (Algebra) , *OPTICAL fibers , *FIBERS - Abstract
We propose a low-cost scheme for multi-access time transfer with high-precision over a local ring fiber link. The time signals are delivered to both the clockwise and anticlockwise directions over a single optical fiber by employing the same wavelengths. The proposed scheme is validated in experiment over a fiber–optic loop link with different lengths. The results demonstrate that the time deviation (TDEV) of less than 20 ps/s and 2 ps/10 4 s can be achieved for the fiber link up to 70 km. The evaluated uncertainty is less than 354 ps, which is mainly limited by the employed time interval counters. The maximum number of accommodated nodes is also theoretically evaluated based on the conditions of signal attenuation and backscattering effect. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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181. The combination of Ilexhainanoside D and ilexsaponin A1 reduces liver inflammation and improves intestinal barrier function in mice with high-fat diet-induced non-alcoholic fatty liver disease.
- Author
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Zhao, Wenwen, Xiao, Meng, Yang, Jie, Zhang, Li, Ba, Yinying, Xu, Rongrong, Liu, Zongyang, Zou, Haiyan, Yu, Ping, Wu, Xia, and Chen, Xiaoqing
- Abstract
Background: Non-alcoholic fatty liver disease (NAFLD) is becoming a major health concern worldwide. Ilex hainanensis Merr. extract was proved to have anti-inflammation effect on NAFLD, and Ilexhainanoside D (IhD) and ilexsaponin A1 (IsA) were the main triterpenoid saponins extracted from it.Purposes: To investigate the hepatoprotective effect of the combination of IhD and IsA (IIC) against NAFLD and discuss the potential mechanisms.Methods: Male C57BL/6 mice were fed a high-fat diet (HFD) to induce NAFLD and were treated with IIC (60, 120 or 240 mg/kg) for 8 weeks. Growth parameters, abdominal fat content, serum biochemical markers, hepatic lipid accumulation and insulin tolerance were assessed. Quantitative real-time PCR was used to determine the hepatic gene expression of TLR2, TLR4, TNF-α, IL-6, and IL-1β. Western blot analysis was performed to determine the expression of the epidermal tight junction proteins ZO-1 and occludin. Gut microbiota profiles were established via high-throughput sequencing of the V3-V4 region of the bacterial 16S rRNA gene.Results: IIC significantly reduced the severity of NAFLD induced by HFD in a dose-dependent manner. IIC decreased the ratio of Firmicutes/Bacteroidetes, reduced the relative abundance of Desulfovibrio and increased the relative abundance of Akkermansia. The intestinal barrier was improved as evidenced by the upregulation of the expression of ZO-1 and occludin in the ileum. IIC thus reduced the entry of LPS into the circulation and decreased the hepatic gene expression levels of proinflammatory cytokines.Conclusion: This approach demonstrated the positive effects of IIC in a mouse model of NAFLD, indicating that it possibly acts by reducing inflammation and improving the intestinal barrier function. [ABSTRACT FROM AUTHOR]- Published
- 2019
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182. Piperine promotes PI3K/AKT/mTOR-mediated gut-brain autophagy to degrade α-Synuclein in Parkinson's disease rats.
- Author
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Yu, Lan, Hu, Xiaolu, Xu, Rongrong, Zhao, Yimeng, Xiong, Lijuan, Ai, Jiaxuan, Wang, Xing, Chen, Xiaoqing, Ba, Yinying, Xing, Zhikai, Guo, Chongye, Mi, Shuangli, and Wu, Xia
- Subjects
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PARKINSON'S disease diagnosis , *PROTEINS , *BRAIN , *GASTROINTESTINAL system , *MEDICINAL plants , *ALKALOIDS , *PHOSPHOTRANSFERASES , *AUTOPHAGY , *ANIMAL experimentation , *IMMUNOHISTOCHEMISTRY , *WESTERN immunoblotting , *CELLULAR signal transduction , *RATS , *GAS chromatography , *ELECTRON microscopy , *SYNUCLEINS , *HUMAN microbiota , *MASS spectrometry , *FLUORESCENT antibody technique , *PLANT extracts , *METABOLITES , *PHOSPHORYLATION - Abstract
Piper longum L., a medicinal and food homologous herb, has a traditional history of use in treating gastrointestinal and neurological disorders. Piperine (PIP) the main alkaloid of P. longum , exists neuroprotective effects on various animal models of Parkinson's disease (PD). Nevertheless, the underlying mechanism, particularly the role of PIP in promoting gut-brain autophagy for α-Synuclein (α-Syn) degradation in PD, remains incompletely understood. To explore the role of PIP in regulating the gut-brain autophagy signaling pathway to reduce α-Syn levels in both the colon and substantia nigra (SN) of PD model rats. Behavioral experiments were conducted to assess the impact of PIP on 6-hydroxydopamine (6-OHDA)-induced PD rats. The intestinal microbiome composition and intestinal metabolites were analyzed by metagenomics and GC-MS/MS. The auto-phagosomes were visualized by transmission electron microscopy. Immunohistochemistry, immunofluorescence, and western blotting were performed to assess the levels of tyrosine hydroxylase (TH), α-Syn, LC3II/LC3I, p62, and the PI3K/AKT/mTOR pathway in both the SN and colon of the rats. The pathway-related inhibitor and agonist were used to verify the autophagy mechanism in the SH-SY5Y cells overexpressing A53T mutant α-Syn (A53T-α-Syn). PIP improved autonomic movement and gastrointestinal dysfunctions, reduced α-Syn aggregation and attenuated the loss of dopaminergic neurons in 6-OHDA-induced PD rats. After oral administration of PIP, the radio of LC3II/LC3I increased and the expression of p62 was degraded, as well as the phosphorylation levels of PI3K, AKT and mTOR decreased in the SN and colon of rats. The effect of PIP on reducing A53T-α-Syn through the activation of the PI3K/AKT/mTOR-mediated autophagy pathway was further confirmed in A53T-α-Syn transgenic SH-SY5Y cells. This effect could be inhibited by the autophagy inhibitor bafilomycin A1 and the PI3K agonist 740 Y–P. Our findings suggested that PIP could protect neurons by activating autophagy to degrade α-Syn in the SN and colon, which were related to the suppression of PIP on the activation of PI3K/AKT/mTOR signaling pathway. [Display omitted] • PIP improved behavioral impairments and gastrointestinal dysfunctions in 6-OHDA-induced PD rats. • PIP attenuated α-Synuclein accumulation in the colon and substantia nigra (SN) of PD rats. • PIP degraded pathological α-Syn by promoting gut-brain autophagy via suppressing PI3K/AKT/mTOR pathway. [ABSTRACT FROM AUTHOR]
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- 2024
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183. Enhanced emission of 2.7?μm pumped by laser diode from Er^3+/Pr^3+-codoped germanate glasses
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Xu, Rongrong, Tian, Ying, Hu, Lili, and Zhang, Junjie
- Abstract
A novel Er^3+/Pr^3+ codoped germanate glass was fabricated and analyzed. Efficient emission at 2.7?μm from the glass was observed upon excitation of a conventional 980?nm laser diode. The 2.7?μm emission characteristics and energy transfer (ET) were investigated. Population inversions between I_13/24 and I_11/24 levels have been achieved, and an enhanced emission from 2550 to 2800?nm was obtained. Large ET efficiency of 95% indicates that the ET process from Er^3+ to Pr^3+(I4_13/2,H3_4)?(I4_15/2,F3_3) is efficient and that Pr^3+ can enhance the emission of 2.7?μm by quenching the lower laser level of Er^3+ via ET.
- Published
- 2011
184. Changing footprint of the Pacific Decadal Oscillation on global land surface air temperature.
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Liang, Lili, Ziegler, Alan D., Chen, Deliang, Ciais, Philippe, Li, Laurent Z.X., Liang, Shijing, Wang, Dashan, Xu, Rongrong, and Zeng, Zhenzhong
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LAND surface temperature , *OSCILLATIONS - Published
- 2024
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185. Impacts of anemometer changes, site relocations and processing methods on wind speed trends in China.
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Liu, Yi, Zhou, Lihong, Qin, Yingzuo, Azorin-Molina, Cesar, Shen, Cheng, Xu, Rongrong, and Zeng, Zhenzhong
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WIND speed , *QUALITY control standards , *VORONOI polygons , *ANEMOMETER , *QUALITY control , *ROBUST control - Abstract
In situ surface wind observation is a critical meteorological data source for various research fields. However, data quality is affected by factors such as surface friction changes, station relocations and anemometer updates. Previous methods to address discontinuities have been insufficient, and processing methods have not always adhered to World Meteorological Organization (WMO) World Climate Programme guidelines. We analyzed data discontinuity caused by anemometer changes and station relocations in China's daily in situ near-surface (∼ 10 m) wind speed observations and the impact of the processing methods on wind speed trends. By comparing the wind speed discontinuities with the recorded location changes, we identified 90 stations that showed abnormally increasing wind speeds due to relocation. After removing those stations, we followed a standard quality control method recommended by the World Meteorological Organization to improve the data reliability and applied Thiessen polygons to calculate the area-weighted average wind speed. The result shows that China's recent reversal of wind speed was reduced by 41 % after removing the problematic stations, with an increasing trend of 0.017 m s -1 yr -1 (R2 = 0.64, P < 0.05), emphasizing the importance of robust quality control and homogenization protocols in wind trend assessments. [ABSTRACT FROM AUTHOR]
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- 2024
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186. Compliant-Control-Based Assisted Walking with Mobile Manipulator.
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Li, Weihua, Li, Pengpeng, Jin, Lei, Xu, Rongrong, Guo, Junlong, and Wang, Jianfeng
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MANIPULATORS (Machinery) , *HUMAN-robot interaction , *SOCIAL interaction , *WALKING speed - Abstract
In this paper, a new approach involving the use of a mobile manipulator to assist humans with mobility impairments to walk is proposed. First, in order to achieve flexible interaction between humans and mobile manipulators, we propose a variable admittance controller that can adaptively regulate the virtual mass and damping parameters based on the interaction forces and the human motion intention predicted using the fuzzy theory. Moreover, a feedforward velocity compensator based on a designed state observer is proposed to decrease the inertia resistance of the manipulator, effectively enhancing the compliance of the human–robot interaction. Then, the configuration of the mobile manipulator is optimized based on a null-space approach by considering the singularity, force capacity, and deformation induced by gravity. Finally, the proposed assisted walking approach for the mobile manipulator is implemented using the human–robot interaction controller and the null-space controller. The validity of the proposed controllers and the feasibility of assisted human walking are verified by conducting a set of tests involving different human volunteers. [ABSTRACT FROM AUTHOR]
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- 2024
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187. Exposure to ambient air pollution from the preconceptional period and risk of gestational hypertension.
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Guo, Chen, Qian, Yan, Xu, Rongrong, Li, Zhigang, Wang, Zhanshan, Zhu, Xiaojing, Peng, Jianhao, Su, Qiaoqiao, and Wei, Yongjie
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- 2023
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188. Mutation, food-grade expression, and characterization of a lactonase for zearalenone degradation.
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Qiu, Yangyu, Xu, Huidong, Ji, Qinyi, Xu, Rongrong, Zhu, Mulan, Dang, Yali, Shi, Xizhi, Zhang, Lili, and Xia, Yu
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KLUYVEROMYCES marxianus , *ZEARALENONE , *FEED industry , *CORN - Abstract
Zearalenone (ZEN) is a mycotoxin that causes serious threats to human health. People are exposed to ZEN contamination externally and internally through many ways, while environmental-friendly strategies for efficient elimination of ZEN are urgently needed worldwide. Previous studies revealed that the lactonase Zhd101 from Clonostachys rosea can hydrolyze ZEN to low toxicity compounds. In this work, the enzyme Zhd101 was conducted with combinational mutations to enhance its application properties. The optimal mutant (V153H-V158F), named Zhd101.1, was selected and introduced into the food-grade recombinant yeast strain Kluyveromyces lactis GG799(pKLAC1-Zhd101.1), followed by induced expression and secretion into the supernatant. The enzymatic properties of this mutant were extensively examined, revealing a 1.1-fold increase in specific activity, as well as improved thermostability and pH stability, compared to the wild-type enzyme. The ZEN degradation tests and the reaction parameters optimization were carried out in both solutions and the ZEN-contaminated corns, using the fermentation supernatants of the food-grade yeast strain. Results showed that the degradation rates for ZEN by fermentation supernatants reached 96.9% under optimal reaction conditions and 74.6% in corn samples, respectively. These new results are a useful reference to zearalenone biodegradation technologies and indicated that the mutant enzyme Zhd101.1 has potential to be used in food and feed industries. Key points: • Mutated lactonase showed 1.1-fold activity, better pH stability than the wild type. • The strain K. lactis GG799(pKLAC1-Zhd101.1) and the mutant Zhd101.1 are food-grade. • ZEN degradation rates by supernatants reached 96.9% in solution and 74.6% in corns. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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189. Influence of different concentrations of ozone on the alteration of mitochondrial DNA copy numbers in human peripheral blood.
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Li, Zhigang, Su, Qiaoqiao, Xu, Rongrong, Peng, Jianhao, Zhu, Xiaojing, and Wei, Yongjie
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- 2023
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190. Amide alkaloids characterization and neuroprotective properties of Piper nigrum L.: A comparative study with fruits, pericarp, stalks and leaves.
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Yu, Lan, Hu, Xiaolu, Xu, Rongrong, Ba, Yinying, Chen, Xiaoqing, Wang, Xing, Cao, Bing, and Wu, Xia
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PETIOLES , *SUPERCRITICAL fluid chromatography , *PERICARP , *NEUROPROTECTIVE agents , *BLACK pepper (Plant) , *FRUIT - Abstract
• 42 amide alkaloids were identified and characterized by UHPLC-LTQ-Orbitrap HRMS. • 8 amide alkaloids were firstly reported in P. nigrum. • 9 constituents in different parts of P. nigrum were determined by UHPSFC-MS. • The extracts of different parts of P. nigrum showed neuroprotective effects in vitro. Piper nigrum L. is commonly used worldwide and its pericarp, stalks, leaves will be major wastes materials. 42 amide alkaloids were identified in black, white pepper and pericarp by UHPLC-LTQ-Orbitrap HRMS method, followed by 40 constituents in stalks and 36 constituents in leaves. 8 amide alkaloids were reported for the first time in P. nigrum. An ultra-high-performance supercritical fluid chromatography (UHPSFC)-MS method was firstly applied to simultaneously determine 9 characteristic constituents (piperine, piperlonguminine, piperanine, pipercallosine, dehydropipernonaline, pipernonatine, retrofractamide B, pellitorine and guineensine). The most abundant compound in each extract was piperine with a concentration from 0.10 to 12.37 mg/g of dry weight. The fruits, pericarp and leaves extracts could improve cell viability in 6-OHDA-induced SK- N -SH and SH-SY5Y cells. The results showed the characteristics of amide alkaloids of different parts of P. nigrum and evaluated their neuroprotective activities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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191. Spatiotemporal variation of power law exponent on the use of wind energy.
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Yang, Xinrong, Jiang, Xin, Liang, Shijing, Qin, Yingzuo, Ye, Fan, Ye, Bin, Xu, Jiayu, He, Xinyue, Wu, Jie, Dong, Tianyun, Cai, Xitian, Xu, Rongrong, and Zeng, Zhenzhong
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WIND power , *ENERGY consumption , *POWER resources , *EXPONENTS , *WIND speed , *GEOGRAPHY - Abstract
The power law, a common method in wind energy assessments, often assumes a global power law exponent (α) of 1/7, potentially leading to inaccuracies in estimating wind conditions and energy potential. This study uses high-frequency measurements from eight wind towers to assess the power law's reliability and demonstrates its general applicability, except in complex topography. The α value is found to differ significantly from 1/7 in validation sites, yet it can be reliably used in ERA5 data based on regional verification. To evaluate the global spatiotemporal variation of α, we analyze the hourly α from 1980 to 2022 using ERA5 wind speed data at 10 m and 100 m. Our findings reveal varying α value with time and geography, with particular disparities between land and ocean. Additionally, we observe changes related to diurnal cycles, seasons, and latitudes. This analysis of α value carries significant implications for a global-scale wind energy resource assessment, site selection, and turbine design. • Assess the spatiotemporal variation of the power law exponent (α) in global wind energy assessments. • The power law exponent α values vary with geography, seasons, diurnal cycles, latitudes, land and ocean. • The power law is generally applicable and has important implications for wind energy resource assessments and turbine design. [ABSTRACT FROM AUTHOR]
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- 2024
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192. Evaluation of Global Reanalysis Land Surface Wind Speed Trends to Support Wind Energy Development Using In Situ Observations.
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Fan, Wenxin, Liu, Yi, Chappell, Adrian, Dong, Li, Xu, Rongrong, Ekström, Marie, Fu, Tzung-May, and Zeng, Zhenzhong
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Global reanalysis products are important tools across disciplines to study past meteorological changes and are especially useful for wind energy resource evaluations. Studies of observed wind speed show that land surface wind speed declined globally since the 1960s (known as global terrestrial stilling) but reversed with a turning point around 2010. Whether the declining trend and the turning point have been captured by reanalysis products remains unknown so far. To fill this research gap, a systematic assessment of climatological winds and trends in five reanalysis products (ERA5, ERA-Interim, MERRA-2, JRA-55, and CFSv2) was conducted by comparing gridcell time series of 10-m wind speed with observational data from 1439 in situ meteorological stations for the period 1989–2018. Overall, ERA5 is the closest to the observations according to the evaluation of climatological winds. However, substantial discrepancies were found between observations and simulated wind speeds. No reanalysis product showed similar change to that of the global observations, although some showed regional agreement. This discrepancy between observed and reanalysis land surface wind speed indicates the need for prudence when using reanalysis products for the evaluation and prediction of winds. The possible reasons for the inconsistent wind speed trends between reanalysis products and observations are analyzed. The results show that wind energy production should select different products for different regions to minimize the discrepancy with observations. [ABSTRACT FROM AUTHOR]
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- 2021
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193. In-Situ polymerized polypyrrole Janus cotton fabric for Solar-driven water evaporation in Textile-dying wastewater.
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Wang, Hongjie, Yao, Lan, Zhang, Menghan, Xu, Rongrong, Ye, Fan, Zhu, Kexin, Wang, He, Zuo, Hongmei, Ruan, Fangtao, and Feng, Quan
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COTTON textiles , *POLYPYRROLE , *PHOTOTHERMAL conversion , *LIGHT absorbance , *WATER purification - Abstract
• The JCF is designed through a one-side deposition followed by in-situ polymerization. • JCF-60 possessed a good vapor generation rate and photothermal conversion efficiency. • JCF shows great potential in solar-driven water evaporation applications. Herein, a Janus cotton fabric (JCF) with polypyrrole (PPy) layer was prepared through one-side ultrasonic atomization deposition followed by the in-situ polymerization. The PPy layer was robust on the fabric and showed excellent light absorbance ability (∼99%). And the JCF with 60 min one-side deposition (JCF-60) showed good photothermal conversion ability with the vapor generation rate of 1.45 kg m−2h−1 and the photothermal conversion efficiency of 91.0% in dyed water purification. It can be expected to large scale applications in solar-driven water evaporation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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194. Phase separation behavior and structural analysis of ovalbumin–gum arabic complex coacervation.
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Niu, Fuge, Dong, Yiting, Shen, Fei, Wang, Jiaqi, Liu, Yuntao, Su, Yujie, Xu, Rongrong, Wang, Junwei, and Yang, Yanjun
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PHASE separation , *OVALBUMINS , *GUM arabic , *COACERVATION , *BIOPOLYMERS , *PROTEIN structure - Abstract
Phase separation behavior and structure between ovalbumin (OVA) and gum arabic (GA) were investigated at pH 1.5–6.5; 2:1 OVA:GA mixing ratio, total biopolymer concentration 0.05 wt%. Soluble and insoluble complexes were observed as a function of pH. The biopolymers particles had a tiny diameter ( d ≤ 500 nm) at pH above 4.0 or below 2.5, and increased sharply at pH 4.0 together with the turbidity under the same conditions. As the biopolymers mixing ratios increased from 1:3 to 24:1, critical pHs shifted towards higher pH. However, monovalent ions had a same influence on OVA–GA complex formation; the divalent cations reduced the formation of complex compared with same concentration monovalent ions. Second-derivative UV spectra and intrinsic fluorescence results indicated that the unfolding of the tertiary conformation was induced by GA, and more tryptophan residues were buried inside the OVA protein after complexation. [ABSTRACT FROM AUTHOR]
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- 2015
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195. Evaluation of combined detection of multigene mutation and SDC2/SFRP2 methylation in stool specimens for colorectal cancer early diagnosis.
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Lin, Jie, Zhang, Lijing, Chen, Mengshi, Chen, Juan, Wu, Yijuan, Wang, Tao, Lu, Yan, Ba, Zhaofen, Cheng, Xiaowei, Xu, Rongrong, Tian, Tian, Sun, Aijuan, Zhang, Tiantian, and Chen, Minghong
- Abstract
Purpose: Molecular diagnostics of colorectal cancer (CRC) can be used as an auxiliary approach for patients recommended for colonoscopy, providing more CRC supplemental diagnosis options. This study investigated whether combined detection of KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation can serve as auxiliary diagnostics in clinical management.KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation in stool samples from healthy donors, patients with CRC, advanced adenoma (AA), non-advanced adenoma (NAA), or other gastroenterological diseases were evaluated using quantitative PCR (qPCR) or methylation-specific quantitative PCR (MSP). Test accuracy was determined by evaluating the tests’ sensitivity, specificity, positive/negative predictive value (PPV/NPV), or positive/negative likelihood ratio (PLR/NLR).The combined fecal
KRAS/BRAF/APC mutation andSFRP2/SDC2 methylation detection test achieved a sensitivity of 88.57% with a PPV of 93.64% and a PLR of 7.10 for CRC patients. In comparison, the corresponding parameters for multigene mutation were 46.67%, 92.59%, and 36.26 and 83.81%, 93.94%, and 7.47, for DNA methylation, separately. The sensitivity of the combined test, gene mutation test, and DNA methylation test approach was 75%, 28.26%, and 72.83%. Furthermore, the specificity of this approach in the NAA group was 79.49%. Meanwhile, the overall diagnostic specificity for the combined test in NAA, healthy control, and interference groups was 88.42%. In addition, the sensitivity of the combined detection method increased with the disease stage in CRC patients and elevated along with the lesion size (≥ 1 cm) in AA patients.Combined detection of fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation has potential application value for the auxiliary diagnosis of CRC and AA.Methods: Molecular diagnostics of colorectal cancer (CRC) can be used as an auxiliary approach for patients recommended for colonoscopy, providing more CRC supplemental diagnosis options. This study investigated whether combined detection of KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation can serve as auxiliary diagnostics in clinical management.KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation in stool samples from healthy donors, patients with CRC, advanced adenoma (AA), non-advanced adenoma (NAA), or other gastroenterological diseases were evaluated using quantitative PCR (qPCR) or methylation-specific quantitative PCR (MSP). Test accuracy was determined by evaluating the tests’ sensitivity, specificity, positive/negative predictive value (PPV/NPV), or positive/negative likelihood ratio (PLR/NLR).The combined fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation detection test achieved a sensitivity of 88.57% with a PPV of 93.64% and a PLR of 7.10 for CRC patients. In comparison, the corresponding parameters for multigene mutation were 46.67%, 92.59%, and 36.26 and 83.81%, 93.94%, and 7.47, for DNA methylation, separately. The sensitivity of the combined test, gene mutation test, and DNA methylation test approach was 75%, 28.26%, and 72.83%. Furthermore, the specificity of this approach in the NAA group was 79.49%. Meanwhile, the overall diagnostic specificity for the combined test in NAA, healthy control, and interference groups was 88.42%. In addition, the sensitivity of the combined detection method increased with the disease stage in CRC patients and elevated along with the lesion size (≥ 1 cm) in AA patients.Combined detection of fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation has potential application value for the auxiliary diagnosis of CRC and AA.Results: Molecular diagnostics of colorectal cancer (CRC) can be used as an auxiliary approach for patients recommended for colonoscopy, providing more CRC supplemental diagnosis options. This study investigated whether combined detection of KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation can serve as auxiliary diagnostics in clinical management.KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation in stool samples from healthy donors, patients with CRC, advanced adenoma (AA), non-advanced adenoma (NAA), or other gastroenterological diseases were evaluated using quantitative PCR (qPCR) or methylation-specific quantitative PCR (MSP). Test accuracy was determined by evaluating the tests’ sensitivity, specificity, positive/negative predictive value (PPV/NPV), or positive/negative likelihood ratio (PLR/NLR).The combined fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation detection test achieved a sensitivity of 88.57% with a PPV of 93.64% and a PLR of 7.10 for CRC patients. In comparison, the corresponding parameters for multigene mutation were 46.67%, 92.59%, and 36.26 and 83.81%, 93.94%, and 7.47, for DNA methylation, separately. The sensitivity of the combined test, gene mutation test, and DNA methylation test approach was 75%, 28.26%, and 72.83%. Furthermore, the specificity of this approach in the NAA group was 79.49%. Meanwhile, the overall diagnostic specificity for the combined test in NAA, healthy control, and interference groups was 88.42%. In addition, the sensitivity of the combined detection method increased with the disease stage in CRC patients and elevated along with the lesion size (≥ 1 cm) in AA patients.Combined detection of fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation has potential application value for the auxiliary diagnosis of CRC and AA.Conclusion: Molecular diagnostics of colorectal cancer (CRC) can be used as an auxiliary approach for patients recommended for colonoscopy, providing more CRC supplemental diagnosis options. This study investigated whether combined detection of KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation can serve as auxiliary diagnostics in clinical management.KRAS/BRAF/APC mutation and SDC2/SFRP2 methylation in stool samples from healthy donors, patients with CRC, advanced adenoma (AA), non-advanced adenoma (NAA), or other gastroenterological diseases were evaluated using quantitative PCR (qPCR) or methylation-specific quantitative PCR (MSP). Test accuracy was determined by evaluating the tests’ sensitivity, specificity, positive/negative predictive value (PPV/NPV), or positive/negative likelihood ratio (PLR/NLR).The combined fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation detection test achieved a sensitivity of 88.57% with a PPV of 93.64% and a PLR of 7.10 for CRC patients. In comparison, the corresponding parameters for multigene mutation were 46.67%, 92.59%, and 36.26 and 83.81%, 93.94%, and 7.47, for DNA methylation, separately. The sensitivity of the combined test, gene mutation test, and DNA methylation test approach was 75%, 28.26%, and 72.83%. Furthermore, the specificity of this approach in the NAA group was 79.49%. Meanwhile, the overall diagnostic specificity for the combined test in NAA, healthy control, and interference groups was 88.42%. In addition, the sensitivity of the combined detection method increased with the disease stage in CRC patients and elevated along with the lesion size (≥ 1 cm) in AA patients.Combined detection of fecalKRAS/BRAF/APC mutation andSFRP2/SDC2 methylation has potential application value for the auxiliary diagnosis of CRC and AA. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
196. Effectiveness of protected areas in preventing forest loss in a tropical mountain region.
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Liu, Yang, Ziegler, Alan D., Wu, Jie, Liang, Shijing, Wang, Dashan, Xu, Rongrong, Duangnamon, Decha, Li, Hailong, and Zeng, Zhenzhong
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TROPICAL forests , *PROTECTED areas , *FOREST conversion , *LOGGING laws , *WILDLIFE refuges , *MOUNTAIN soils - Abstract
[Display omitted] • Most protected areas are effective in controlling forest loss. • Forest loss accelerates at protected area boundaries. • Accessibility and demographic variables are direct drivers of forest loss in protected areas. • International maize prices affect the extent of forest loss with a two-year lag. As forest loss is accelerating in tropical mountains globally, protected areas (PAs) are seen as bastions to protect sensitive ecosystems, preserve biodiversity, and safeguard headwater catchments from degradation. However, the effectiveness of PAs in preventing forest conversion has rarely been determined. Complicating the issue is that many PAs are inhabited to some extent by long-standing residents, causing illegal logging that is commonly reported. To assess the effectiveness of PAs in preserving forests, as well as investigate the drivers of forest loss in/near PAs, we compare forest loss rates inside and outside PAs before and after their establishment in a tropical mountain region (northern Thailand, the epicenter of mainland Southeast Asia, including 84 PAs). Over the 17-year period from 2000 to 2016, we found that the percentage of forest loss was lower within the PAs than outside (1.69% versus 4.94%). Mean annual forest loss in the PAs was 20% of that in unprotected area. Total forest loss inside PAs included 888.12 km2 (1.93%) in national parks, 325.18 km2 (1.34%) in wildlife sanctuaries/conservation areas and 16.37 km2 (0.65%) in no hunting areas. Forest loss also tended to be highest along boundaries within a 300-m buffer both inside and outside the PAs. Using gradient boosting decision trees, we determined that accessibility variables (elevation, and distance to road) and population were key drivers associated with forest loss in PAs. Further, we found a two-year lagged correlation between forest loss in PAs and international maize price (R2 = 0.73, p < 0.001), indicating the sensitivity of forest loss in some locations to commodity agriculture trends. Finally, we acknowledge the difficulty of managing forest loss in PAs because of the large populations of people living within the boundaries who rely on forest products to support their livelihoods, as well as difficulties in enforcing illegal logging laws. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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197. 2μm Emission of Ho3+-doped fluorophosphate glass sensitized by Yb3+
- Author
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Tian, Ying, Zhang, Liyan, Feng, Suya, Xu, Rongrong, Hu, Lili, and Zhang, Junjie
- Subjects
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METALLIC glasses , *YTTERBIUM , *EMISSIONS (Air pollution) , *MICROMETERS , *CROSS-sectional method - Abstract
Abstract: Two micrometer emission of Ho3+-doped new fluorophosphate glass sensitized by Yb3+ upon excitation of a conventional 980nm laser diode is reported. Based on the measured absorption spectra, the Judd–Ofelt parameters and radiative properties were calculated and discussed. For Yb3+/Ho3+ codoped fluorophosphate glass, the predicted spontaneous transition probability and emission cross-section of Ho3+:5I7→5I8 reaches 73.54s−1 and 4.66×10−21 cm2 , respectively, are much higher than other reported glasses. Larger product of emission cross-section (σem ) and radiative lifetime (τrad ) in the prepared glass shows the prepared glass is expected to be better laser material. In addition, the σem and maximum gain coefficient of Ho3+ in Yb3+/Ho3+ codoped fluorophosphate glass is 12.02% and 12.12% larger than those of Ho3+ singly-doped sample, respectively. The results suggest Yb3+/Ho3+ fluorophosphate glass is a good candidate for efficient 2μm laser. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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198. Rapid preparation of 1-vinylimidazole based non-affinity polymers for the highly-selective purification of antibodies from multiple biological sources.
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Lei, Yutian, Liu, Xiao, Lu, Li, Liu, Cuihua, Xu, Rongrong, Huang, Shengfeng, Shen, Yuan, Deng, Chunping, Yu, Jinchen, Zhang, Tingting, Crommen, Jacques, Wang, Qiqin, and Jiang, Zhengjin
- Subjects
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IMMUNOGLOBULINS , *POLYMERS , *POROUS polymers , *BINDING site assay , *LIGANDS (Biochemistry) , *MONOCLONAL antibodies - Abstract
• 1-Vinylimidazole (VIM) was proposed as the capture ligand of antibodies for the first time. • VIM-based polymers (polyVIM) can be rapidly fabricated via a facile strategy within only 1.5 h. • PolyVIM has comparable or even higher binding capacity towards antibodies than that of other materials. • PolyVIM can highly selectively capture antibodies from multiple biological sources. There is an urgent need for developing advanced purification techniques with the merits of low cost and satisfactory capacity in order to meet the challenges in the current downstream purification of monoclonal antibodies (mAbs). Herein, a simple and inexpensive nitrogen heterocycle molecule, 1-vinylimidazole (VIM), was proposed as the capture ligand of antibodies for the first time. The corresponding VIM-based non-affinity polymeric material (polyVIM) was then fabricated via a one-step polymerization for use in the highly selective purification of antibodies. Compared to the previously reported materials, this novel material exhibited many advantages without clearly sacrificing selectivity, such as a simpler and faster fabrication (within 1.5 h), comparable or even higher binding capacity (saturated static adsorption capacity > 190 mg/g polymer, dynamic binding capacity about 31.62 mg/g polymer), lower non-specific protein adsorption, and much lower cost. Notably, the polyVIM can effectively purify the antibodies from multiple biological sources with high purity (95.4% for mAbs in the cell culture medium, 93.3% for hIgG in the human serum), with an acceptable recovery (91.6% for mAbs, 77.0% for hIgG), and good reusability (> 10 times). Moreover, the target ELISA binding assay and NFAT-luc reporter gene assay demonstrated that the enriched antibodies can well maintain their binding activity and bioactivity during the whole purification process. The excellent performance of the polyVIM material may be attributed to the high recognition ability of VIM for antibodies, as well as the biocompatible and antifouling properties of the porous polymer. This study provides a promising alternative material for the purification of mAbs in downstream processes and the enrichment of hIgG in human serum. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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199. The association between maternal fruit consumption before and during pregnancy and fetal growth: The Lanzhou birth cohort study.
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Xu R, Liu Y, Cui H, Xu X, Wang F, Meng Z, and Liu Q
- Abstract
Background: The association between maternal fruit consumption and fetal growth remains inconsistent. The current study aimed to determine whether maternal fruit consumption was associated with low birth weight (LBW) or small for gestational age (SGA) babies., Methods: A large birth cohort study was conducted in Lanzhou, China, from 2010 to 2012 and included 10,076 pregnant women at the 1st, 2nd, and 3rd trimester of pregnancy for analysis. Fruit consumption in the 1st, 2nd, and 3rd trimester of pregnancy was measured by a self-designed food frequency questionnaire (FFQ) and divided into three groups: 1) inadequate fruit consumption: <200 g/d for the1st, 2nd, and 3rd trimester; 2) adequate fruit consumption: 200-350 g/d for the 1st trimester or 200-400 g/d for the 2nd and 3rd trimester; 3) excessive fruit consumption: >350 g/d for the 1st trimester or > 400 g/d for the 2nd and 3rd trimester. A case-control study was used to analyze the association between fruit intake during pregnancy and low birth weight infants., Results: Compared to adequate fruit consumption, excessive fruit consumption throughout each trimester of pregnancy was associated with a lower risk of LBW, with an odds ratio (OR) ranging from 0.70 to 0.79 (95 % confidence interval, CI: 0.57-0.98); while inadequate fruit consumption was associated with a higher risk of infant LBW, with an OR ranging from 1.26 to 1.36 (95%CI: 1.04-1.66). After stratifying by mother's pre-pregnancy body mass index (BMI), the results were similar among women with underweight BMI. No significance was found between fruit consumption and SGA in the general population. Still, stratified analyses showed that inadequate fruit consumption was associated with an increased risk of SGA in underweight mothers, with an OR ranging from 1.66 to 1.79 (95%CI: 1.13-2.64)., Conclusions: Fruit consumption during pregnancy reduces the risk of LBW in Chinese women, especially in women with low pre-pregnancy BMI., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Rongrong Xu reports financial support was provided by National 10.13039/501100004775Natural Science Foundation of Gansu Province. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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200. TFAP2A downregulation mediates tumor-suppressive effect of miR-8072 in triple-negative breast cancer via inhibiting SNAI1 transcription.
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Fang Y, Wang Y, Ma H, Guo Y, Xu R, Chen X, Chen X, Lv Y, Li P, and Gao Y
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- Humans, Female, Animals, Mice, Cell Line, Tumor, Epithelial-Mesenchymal Transition genetics, Down-Regulation, Xenograft Model Antitumor Assays, Transcription Factor AP-2 metabolism, Transcription Factor AP-2 genetics, Triple Negative Breast Neoplasms genetics, Triple Negative Breast Neoplasms pathology, Triple Negative Breast Neoplasms metabolism, Triple Negative Breast Neoplasms mortality, MicroRNAs genetics, Snail Family Transcription Factors metabolism, Snail Family Transcription Factors genetics, Gene Expression Regulation, Neoplastic, Cell Proliferation, Cell Movement genetics
- Abstract
Background: Triple-negative breast cancer (TNBC) represents a highly aggressive subset of breast malignancies characterized by its challenging clinical management and unfavorable prognosis. While TFAP2A, a member of the AP-2 transcription factor family, has been implicated in maintaining the basal phenotype of breast cancer, its precise regulatory role in TNBC remains undefined., Methods: In vitro assessments of TNBC cell growth and migratory potential were conducted using MTS, colony formation, and EdU assays. Quantitative PCR was employed to analyze mRNA expression levels, while Western blot was utilized to evaluate protein expression and phosphorylation status of AKT and ERK. The post-transcriptional regulation of TFAP2A by miR-8072 and the transcriptional activation of SNAI1 by TFAP2A were investigated through luciferase reporter assays. A xenograft mouse model was employed to assess the in vivo growth capacity of TNBC cells., Results: Selective silencing of TFAP2A significantly impeded the proliferation and migration of TNBC cells, with elevated TFAP2A expression observed in breast cancer tissues. Notably, TNBC patients exhibiting heightened TFAP2A levels experienced abbreviated overall survival. Mechanistically, TFAP2A was identified as a transcriptional activator of SNAI1, a crucial regulator of epithelial-mesenchymal transition (EMT) and cellular proliferation, thereby augmenting the oncogenic properties of TFAP2A in TNBC. Moreover, miR-8072 was unveiled as a negative regulator of TFAP2A, exerting potent inhibitory effects on TNBC cell growth and migration. Importantly, the tumor-suppressive actions mediated by the miR-8072/TFAP2A axis were intricately associated with the attenuation of AKT/ERK signaling cascades and the blockade of EMT processes., Conclusions: Our findings unravel the role and underlying molecular mechanism of TFAP2A in driving tumorigenesis of TNBC. Targeting the TFAP2A/SNAI1 pathway and utilizing miR-8072 as a suppressor represent promising therapeutic strategies for treating TNBC., (© 2024. The Author(s).)
- Published
- 2024
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