287 results on '"Qiao Guan"'
Search Results
252. Fabrication of SiC Dense-Porous Laminates by Electrophoretic Deposition Process
- Author
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Li, Yuan, Gao, Ji Qiang, Yang, Jian Feng, Wang, Hong Jie, and Qiao, Guan Jun
- Abstract
In order to obtain dense-porous laminated structure in green bodies of SiC ceramics, rapid aqueous electrophoretic deposition (EPD) was introduced. The suspension for the electrophoretic deposition was prepared using silicon carbide, silicon and carbon powders as the starting materials. During the electrophoretic deposition process, the intending dense and porous layers were deposited alternately to form the green body. After drying, the green bodies were reaction-bonded at 1550°C in vacuum atmosphere. Pore fraction of the porous layers could be adjusted by changing process preferences of EPD and suspension composition. Pore size and size distribution could be controlled by using different sized starting powders. Using this process, no additional substance is necessary to generate the pores via burnt-off, and the dense/porous laminated structure can be obtained by one-step sintering process.
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- 2008
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253. Multilayer SiC/Si Composites Derived from Papers
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Yang, Gang Bin, Liu, Yin Juan, Qiao, Guan Jun, and Jin, Zhi Hao
- Abstract
The SiC/Si multilayer composites were fabricated successfully by reaction sintering method with normal stacked papers as the raw materials. Paper was cut into rectangular sheets and stacked, then infiltrated with phenolic resin to get a laminar structure. This paper /resin laminar composite was transformed into porous carbon with laminar structure after heating at 800 oC for 2h in N2 atmosphere. Finally this porous laminar carbon was reheated with silicon powder at 1450-1650oC for 1-2h in a vacuum furnace and SiC/Si multilayer composites can be obtained through the in-situ reaction between carbon and liquid silicon. The microstructure, reaction mechanism, phase composition and mechanical properties of these multilayer composites were researched. The final material shows a distingished laminar structure with alternating arrangement of SiC thick layers and silicon thin layers. SiC layer was composed by beta-SiC and a little of free silicon and carbon not reacted. The capillarity infiltration and in-situ reaction of liquid silicon act key roles in this process. Higher strength and non-catastrophic failure mode for this material were observed.
- Published
- 2007
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254. 03:27 PM Abstract No. 115 Clinical and imaging factors predictive of high lung shunt fraction: a useful reference.
- Author
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Azeze, S., Qiao-Guan, G., Radzinsky, E., and Patel, I.
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- 2019
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255. 18.8 Gbps real-time quantum random number generator with a photonic integrated chip.
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Bai, Bing, Huang, Jianyao, Qiao, Guan-Ru, Nie, You-Qi, Tang, Weijie, Chu, Tao, Zhang, Jun, and Pan, Jian-Wei
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RANDOM number generators , *QUANTUM numbers , *INTEGRATED circuit design , *FIELD programmable gate arrays , *ANALOG-to-digital converters , *SUCCESSIVE approximation analog-to-digital converters , *BINARY sequences - Abstract
Quantum random number generators (QRNGs) can produce true random numbers. Yet, the two most important QRNG parameters highly desired for practical applications, i.e., speed and size, have to be compromised during implementations. Here, we present the fastest and miniaturized QRNG with a record real-time output rate as high as 18.8 Gbps by combining a photonic integrated chip and the technology of optimized randomness extraction. We assemble the photonic integrated circuit designed for vacuum state QRNG implementation, an InGaAs homodyne detector, and a high-bandwidth transimpedance amplifier into a single chip using hybrid packaging, which exhibits the excellent characteristics of integration and high-frequency response. With a sample rate of 2.5 GSa/s in a 10-bit analog-to-digital converter and subsequent paralleled postprocessing in a field programmable gate array, the QRNG outputs ultrafast random bitstreams via a fiber optic transceiver, whose real-time speed is validated in a personal computer. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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256. Tooth Surface Modification for Helical Gear Pairs considering Mesh Misalignment Tolerance.
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Han, Guosheng, Yuan, Bing, and Qiao, Guan
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HELICAL gears , *TEETH - Abstract
Mesh misalignment in mating the gear tooth surface is common and difficult to be determined accurately because of system deformation and bearing clearances, as well as manufacturing and assembly errors. It is not appropriate to consider the mesh misalignment as a constant value or even completely ignore it in the tooth surface modification design. Aiming to minimize the expectation and variance of static transmission error (STE) fluctuations in consideration of mesh misalignment tolerance, a multiobjective optimization model of tooth surface modification parameters is proposed through coupling the NSGA-II algorithm and an efficient loaded tooth contact analysis (LTCA) model. The modified tooth flank of helical gear pairs is defined using 6 design variables which are related to profile modification, lead modification, and bias modification. The influences of mesh misalignment on time-dependent meshing stiffness (TDMS) and STE of unmodified and modified helical gear pairs are investigated. Then, the dynamic transmission error (DTE) of modified helical gears in consideration of mesh misalignment is discussed. The results indicate that the designed modified tooth surface shows good robustness to mesh misalignment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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257. Reliability Analysis of Dynamic Fault Tree Based on Binary Decision Diagrams for Explosive Vehicle.
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Jiang, Guang-Jun, Li, Zong-Yuan, Qiao, Guan, Chen, Hong-Xia, Li, Hai-Bin, and Sun, Hong-Hua
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FAULT trees (Reliability engineering) , *LOGIC circuits , *RELIABILITY in engineering , *AUTOMATED guided vehicle systems , *PROBLEM solving , *FAULT diagnosis , *MARKOV processes - Abstract
Dynamic fault tree is often used to analyze system reliability. The Markov model is a commonly used method, which can accurately reflect the relationship between the state transition process and the dynamic logic gate transfer in the dynamic fault tree. When the complexity or scale of system is increasing, the Markov model encountered a problem of state space explosion leading to increase troubles. To solve the above problems, a modular approach is needed. Based on the modular approach, a hybrid fault module was researched in this paper. Firstly, the stackable fault subtree containing complex static/dynamic logic gate is transformed into four common combinational logic gates through preprocessing of the dynamic gate in the module. Then, the complexity of the model was reduced by incorporating four common combinational logic gates and using the binary decision graph to solve variable ordering in the calculation of failure probability of static subtree. Moreover, the calculating process of complex mixed logic gate fault tree can be simplified. An example of the ammonium nitrate/fuel explosive production system for BCZH-15 explosive vehicle was used to verify the feasibility of the presented method. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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258. Variational Analysis of High-Frequency Effect on Moving Electromagnetic Interface.
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Kang-Bo Tan, Hong-Min Lu, Qiao Guan, Guang-Shuo Zhang, and Chong-Chong Chen
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ELECTROMAGNETISM ,SPECIAL relativity (Physics) ,FRAMES of reference (Relativity) ,QUANTUM information science ,MATHEMATICAL models - Abstract
Based on Fermat’s principle and the special relativity, the transmission of high-frequency electromagnetics is unified by variational formulation on the moving interface. Applying the theoretical model, we investigate the detailed practices of transmission of high-frequency electromagnetic under relativistic conditions. The deduced results illustrate that the effective estimation of the super high-speed effect on a moving interface supports the valuable frame of reference in controlling precision. The results also show that the theoretical model has potential applications in electromagnetically controlled precision in the quantum information, ray sensor, controllable environment, etc. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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259. Stereotactic body radiotherapy for the treatment of oligometastatic gynecological malignancy in the abdomen and pelvis: A singleinstitution experience.
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Smile, Timothy D., Reddy, Chandana A., Qiao-Guan, George, Winter, Ian W., Stephans, Kevin L., Woody, Neil M., Balagamwala, Ehsan H., Amarnath, Sudha R., Magnelli, Anthony, AlHilli, Mariam M., Michener, Chad M., Mahdi, Haider, DeBernardo, Robert L., Rose, Peter G., and Cherian, Sheen S.
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STEREOTACTIC radiotherapy , *PELVIS , *POSITRON emission tomography , *ABDOMEN , *DRUG efficacy , *GYNECOLOGIC cancer - Abstract
Purpose/Objectives: Metastasis-directed therapy with stereotactic body radiotherapy (SBRT) in the setting of oligometastatic disease is a rapidly evolving paradigm given ongoing improvements in systemic therapies and diagnostic modalities. However, SBRT to targets in the abdomen and pelvis is historically associated with concerns about toxicity. The purpose of this study was to evaluate the safety and efficacy of SBRT to the abdomen and pelvis for women with oligometastases from primary gynecological tumors. Materials/Methods: From our IRB-approved registry, all patients who were treated with SBRT between 2014 and 2020 were identified. Oligometastatic disease was defined as 1 to 5 discrete foci of clinical metastasis radiographically diagnosed by positron emission tomography (PET) and/or computerized tomography (CT) imaging. The primary endpoint was local control at 12 months. Local and distant control rates were estimated using the Kaplan-Meier method. Time intervals for development of local progression and distant progression were calculated based on follow up visits with re-staging imaging. Acute and late toxicity outcomes were determined based on Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Results: We identified 34 women with 43 treated lesions. Median age was 68 years (range 32- 82), and median follow up time was 12 months (range 0.2-54.0). Most common primary tumor sites were ovarian (n=12), uterine (n=11), and cervical (n=7). Median number of previous lines of systemic therapy agents at time of SBRT was 2 (range 0-10). Overall, SBRT was delivered to 1 focus of oligometastasis in 29 cases, 2 foci in 2 cases, 3 foci in 2 cases, and 4 foci in 1 case. All patients were treated comprehensively with SBRT to all sites of oligometastasis. Median prescription dose was 24 Gy (range 18-54 Gy) in 3 fractions (range 3-6) to a median prescription isodose line of 83.5% (range 52-95). Local control by lesion at 12 and 24 months was 92.5% for both time points. Local failure was observed in three treated sites among two patients, two of which were at 11 months in one patient, and the other at 30 months. Systemic control rate was 60.2% at 12 months. Overall survival at 12 and 24 months was 85% and 70.2%, respectively. Acute grade 2 toxicities included nausea (n=3), and there were no grade > 3 acute toxicities. Late grade 1 toxicities included diarrhea (n=1) and fatigue (n=1), and there were no grade > 2 toxicities. Conclusion: SBRT to oligometastatic gynecologic malignancies in the abdomen and pelvis is feasible with encouraging preliminary safety and local control outcomes. This approach is associated with excellent local control and low rates of toxicity during our follow-up interval. Further investigations into technique, dose-escalation and utilization are warranted. [ABSTRACT FROM AUTHOR]
- Published
- 2021
260. Nano-Wedge IrO2/MnO2Hybrid Film Electrode for Electrochemical Supercapacitors
- Author
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Ye, Zhi-Guo, Liu, Gui-Wu, Huang, Guang-Bin, Wang, Ke, and Qiao, Guan-Jun
- Abstract
A simple and large-scale synthesis technique was developed to fabricate a nano-wedge IrO2/MnO2hybrid film electrode for high-performance electrochemical supercapacitors. When the galvanostatic charge/discharge rate was increased from 2.96 to 296 A g−1, the specific capacitance of the electrode declined from 573.5 to 379.2 F g−1with a relatively limited loss of 34%. In particular, the hybrid film electrode presents a loss of only 4.9% in the specific capacitance after 1000 cycles.
- Published
- 2013
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261. All position-independent and position-dependent geometric error measurement and identification of the precision of a horizontal boring machine tool.
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Guo, Shijie, Tang, Shufeng, Wu, Jianxin, and Qiao, Guan
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MACHINE tools , *MEASURING instruments , *MEASUREMENT errors - Abstract
Geometric error is the main obstacle that affects the quasi-static accuracy of horizontal boring machine tools. To improve quasi-static performance, the error terms of all position-independent geometric errors (PIGEs) and position-dependent geometric errors (PDGEs) must be measured and identified precisely. This study proposes a novel method for measuring and identifying the above two types of geometric errors based on double ballbar for the rotary axis. The error terms of the linear axis are identified from the measurement model based on the exponential product method and a preset measure trajectory, and the measure coordinate system is combined with the reference coordinate to lower the uncertainty in the identification accuracy. Then, the elastic net method and improved weight function IGG3-LTS method are established to identify the PIGEs and PDGEs of the rotary and linear axes, respectively. This method has the advantage that measurement with the built-in sensor method synchronously does not interfere with the running state of the machine tool, and neither the inaccuracy of reference-frame misalignment nor installation error of the measuring instrument affects the geometric error identification results of the linear axis. Moreover, all PIGEs and PDGEs, particular to the rotary axis of the horizontal boring machine tool, are determined accurately. The measurement and identification strategy is demonstrated by experimental comparison on a four-axis precision horizontal boring machine tool. The minimum compensation rate of each precision index of the test specimen is 40.0%, the average compensation rate is 52.7%, and the maximum compensation rate is 62.5%. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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262. Assembly deviation modelling to predict and trace the geometric accuracy of the precision motion system of a CNC machine tool.
- Author
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Guo, Shijie, Yang, Jun, Qiao, Guan, and Mei, Xuesong
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NUMERICAL control of machine tools , *PERIODIC functions , *TEST methods - Abstract
• The mapping between assembly deviation and the geometric accuracy of a linear axis are clarified. • The measurement and geometric accuracy characterization are united in a uniform datum. • The effect of different assembly deviation on geometric accuracy of the single linear axis is quantified. Geometric accuracy is the direct embodiment of the assembly deviation of a precision motion system. This paper proposes a novel methodology for predicting the geometric accuracy induced by assembly deviation of a precision motion system and tracing the sensitivity of the assembly deviation with respect to geometric accuracy terms. The small displacement torsor is first characterized as the periodic function of the assembly deviation and dimension parameters of the components of ball-screw feeding system, the vector constraint relationship of the parallel assembly of the feeding system is established, and a spatial propagate model of the assembly deviation for the feeding system is then constructed. A random balance design and Fourier amplitude sensitivity test method are introduced to trace the effect of each assembly feature on the geometric accuracy. The experiments were performed on a single-axis feeding system to verify the effectiveness of the proposed method. This method has the advantage that the mapping relationship between the assembly deviation and geometric accuracy with respect to the instructed position is quantified, and the assembly and adjustment is pertinent to the traceability analysis. The model has the potential to accurately allocate and maintain the machining centre. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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263. Plasma active sintering of silicon carbide
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Jin, Hai-Yun, Ishiyama, Masaaki, Qiao, Guan-Jun, Gao, Ji-Qiang, and Jin, Zhi-Hao
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SILICON carbide , *SINTERING , *CERAMICS , *IRON metallurgy - Abstract
Abstract: Silicon carbide (SiC) ceramics were fabricated by plasma-activated sintering. The sintering was accomplished at relatively low temperatures within a short time. The grain growth of the SiC ceramics was considerably inhibited, and finally SiC ceramics with a higher bending strength (853.7MPa) and fracture toughness (8.34MPam1/2) could be fabricated. [Copyright &y& Elsevier]
- Published
- 2008
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264. Study of machinable silicon carbide–boron nitride ceramic composites
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Jin, Hai-Yun, Xu, Hui, Qiao, Guan-Jun, Gao, Ji-Qiang, and Jin, Zhi-Hao
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SILICON carbide , *BORON nitride , *SINTER (Metallurgy) , *CRYSTAL grain boundaries - Abstract
Abstract: Silicon carbide (SiC) particles coated with nano-boron nitride (BN) were synthesized. The SiC/BN ceramic nano-composites and micro-composites were sintered by plasma-activated sintering. For the nano-composites, due to the homogeneous dispersion of the nano-BN crystals around the SiC grains of the matrix, the grain size of nano-composites was smaller than the monolithic SiC and micro-composites. As a result, the bending strength of the nano-composites decreased slowly (for SiC/20% h-BN nano-composite, about 18% decrease), while their hardness decreased sharply and the machinability properties were improved noticeably. [Copyright &y& Elsevier]
- Published
- 2008
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265. Stereotactic Body Radiotherapy for the Treatment of Oligometastatic Gynecological Malignancy in the Abdomen and Pelvis: A Single-Institution Experience.
- Author
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Smile, T., Reddy, C.A., Qiao-Guan, G., Amarnath, S.R., Stephans, K.L., Woody, N.M., Balagamwala, E.H., AlHilli, M.M., Michener, C., Mahdi, H., DeBernardo, R., Rose, P.G., and Cherian, S.
- Subjects
- *
STEREOTACTIC radiotherapy , *PELVIS , *ABDOMEN - Published
- 2020
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266. Clinical Assessment of Prostate Displacement and Planning Target Volume Margins for Stereotactic Body Radiotherapy of Prostate Cancer
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Rebecca Levin-Epstein, George Qiao-Guan, Jesus E. Juarez, Zhouhuizi Shen, Michael L. Steinberg, Dan Ruan, Luca Valle, Nicholas G. Nickols, Patrick A. Kupelian, Christopher R. King, Minsong Cao, and Amar U. Kishan
- Subjects
prostate cancer ,stereotactic body radiation therapy ,SBRT ,prostate motion ,planning target volume ,margins ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Purpose: To assess the optimal planning target volume (PTV) margins for stereotactic body radiotherapy (SBRT) of prostate cancer based on inter- and intra-fractional prostate motion determined from daily image guidance.Methods and Materials: Two hundred and five patients who were enrolled on two prospective studies of SBRT (8 Gy × 5 fractions) for localized prostate cancer treated at a single institution between 2012 and 2017 had complete inter- and intra-fractional shift data available. All patients had scheduled kilovoltage planar imaging during SBRT with rigid registration to intraprostatic fiducials prior to each of four half-arcs delivered per fraction, as well as cone beam CT verification of anatomy prior to each fraction. Inter- and intra- fractional shift data were obtained to estimate the required PTV margins based on the classic van Herk formula. Inter- and intra-fractional motion were compared between patients with and without severe toxicities using the independent two-sample Wilcoxon test.Results: The margins required to account for inter-fractional motion were estimated to be 0.99, 1.52, and 1.45 cm in lateral (LR), longitudinal (SI), and vertical (AP) directions, respectively. The margins required to account for intra-fractional motion were estimated to be 0.19, 0.27, and 0.31 cm in LR, SI and AP directions, respectively. Large intra-fractional shifts were mostly observed in the SI and AP directions, with 2.0 and 5.4% of patients experiencing average intra-fractional motion >3 mm in the SI and AP directions, respectively, compared with none experiencing mean shifts >3 mm in the LR direction. Six patients experienced grade 3 gastrointestinal or genitourinary toxicity. There were no significant differences in mean inter- or intra-fractional motion in any of the cardinal directions compared to patients without severe toxicity (inter-fractional p = 0.46–0.99, intra-fractional p = 0.10–0.84).Conclusion: The inter- and intra-fractional margins estimated from this study are in line with prior reported values. Intra-fractional prostate motion was generally small with larger margins required for the SI and AP directions, notably just slightly exceeding the commonly used 3 mm posterior PTV margin even with realignment between half-arcs. Development of severe toxicity was not significantly associated with the degree of inter- or intra-fractional motion.
- Published
- 2020
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267. Prognosability study of ball screw degradation using systematic methodology.
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Li, Pin, Jia, Xiaodong, Feng, Jianshe, Davari, Hossein, Qiao, Guan, Hwang, Yihchyun, and Lee, Jay
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FAULT tolerance (Engineering) , *SCREWS , *ROTATIONAL motion , *ENERGY dissipation , *DATA quality - Abstract
As a critical mechanical component that converts rotary motion to linear motion with high precision, the ball screw has drawn a lot of attention in the field of Prognostics and Health Management (PHM). However, prognosis of the ball screw degradation has not been fully discussed yet in the current literature. This paper first justifies the prognosability of a ball screw via experimental studies, then proposes a systematic methodology for ball screw prognosis to implement the fault diagnosis, early diagnosis, health assessment and remaining useful life (RUL) prediction. Meanwhile, sensor-less and sensor-rich strategies are investigated and benchmarked in the experimental studies. The results demonstrate that the ball screw degradation behavior is available for prognosis and the proposed methodology can effectively help users to implement PHM analysis. Besides, the benchmark studies between sensor-less and sensor-rich strategies also achieve several practical conclusions that are valuable for real-world applications. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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268. Porous Si loaded with Ag nanoparticles for ultra-broadband infrared absorption and detection.
- Author
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Ma, Xing H., Hou, Hai G., Yang, Jian, Liu, Jun L., Liu, Gui W., Du, Feng, and Qiao, Guan J.
- Subjects
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INFRARED absorption , *POROUS silicon , *POROUS materials , *LIGHT propagation , *ABSORPTION spectra , *FREE electron lasers , *PHOTOTHERMAL effect - Abstract
With the rapid development of semiconductor technology, silicon based infrared detector chips have been greatly optimized with the help of MEMS process. The infrared absorber, as the core part of thermal detector, requires infrared absorption characteristics such as wide spectrum and high absorption. In this paper, two kinds of porous silicon materials loaded with Ag nanoparticles (Si@AgNPs), honeycomb-like and forest-like, were constructed by chemical etching method. The experimental results and corresponding analyses illustrated that micro- and nano-porous structures of silicon with arbitrary sizes and random spatial positions can have a great guiding effect on the light waves, providing multiple reflections and scattering, allowing increased light propagation paths and generating light trapping effect, leading to enhanced infrared absorption in a wide spectral range. AgNPs are loaded, and the collective oscillation of free electrons resonates with incident photons, thereby exciting plasmon resonance effect, which can further improve the infrared absorption properties of the material. Benefiting from the synergistic effect of light trapping and plasmon resonance, the porous Si@AgNPs with honeycomb-like or forest-like structure both exhibited high absorption properties at 2.5–20 μm. Moreover, the honeycomb-like Si@AgNPs also possessed optical interference effect, which can further enhance the absorption, compared with the forest-like Si@AgNPs. • Two kinds of porous silicon materials loaded with Ag nanoparticles (Si@AgNPs), honeycomb-like and forest-like, were constructed as ultra-broadband infrared absorbers by two different chemical etching methods. • Benefiting from the synergistic effect of light trapping and plasmon resonance, the porous Si@AgNPs with honeycomb-like or forest-like structure both exhibited high absorption properties at 2.5–20 μm. • The honeycomb-like Si@AgNPs also possessed optical interference effect, which can further enhance the absorption, compared with the forest-like Si@AgNPs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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269. Fabrication of highly dense pure SiC ceramics via the HTPVT method
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Dai, Pei Yun, Wang, Yan Zhong, Liu, Guang Liang, Wang, Bo, Shi, Yong Gui, Yang, Jian Feng, Qiao, Guan Jun, and Wang, Hong Jie
- Subjects
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SILICON carbide , *RECRYSTALLIZATION (Metallurgy) , *CERAMICS , *SINTERING , *MOLECULAR structure , *BENDING (Metalwork) , *HARDNESS , *STRENGTH of materials - Abstract
Abstract: A high-temperature physical vapor transport (HTPVT) method was used to grow highly dense SiC ceramics free of sintering aids, and the effects of growth time and temperature upon the grain size, growth rate, thickness and orientation of silicon carbide were explored. Silicon carbide ceramics with a thickness of 8mm and a bulk density of 3.208g/cm−3 were obtained after 4h of growth. The silicon carbide texture exhibited a preferred orientation along (000 l) planes. The degree of grain size and orientation of the silicon carbide increased with increased growth time, and the growth rate increased with the growth temperature and temperature gradient. Silicon carbide ceramics exhibited a bending strength of only 290±34MPa, primarily due to the large grain size (average grain size: 2mm), and a Vickers hardness of 29.7±0.6GPa. [Copyright &y& Elsevier]
- Published
- 2011
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270. Supramolecular-macrocycle-based functional organic cocrystals.
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Ren S, Qiao GY, and Wu JR
- Abstract
Supramolecular macrocycles, renowned for their remarkable capabilities in molecular recognition and complexation, have emerged as pivotal elements driving advancements across various innovative research fields. Cocrystal materials, an important branch within the realm of crystalline organic materials, have garnered considerable attention owing to their simple preparation methods and diverse potential applications, particularly in optics, electronics, chemical sensing and photothermal conversion. In recent years, macrocyclic entitles have been successfully brought into this field, providing an essential and complementary channel to create novel functional materials, especially those with multiple functionalities and smart stimuli-responsiveness. In this Review, we present an overview of the research efforts on functional cocrystals constructed with macrocycles, covering their design principles, preparation strategies, assembly modes, and diverse functions and applications. Finally, the remaining challenges and perspectives are outlined. We anticipate that this review will serve as a valuable and timely reference for researchers interested in supramolecular crystalline materials and beyond, catalyzing the emergence of more original and innovative studies in related fields.
- Published
- 2024
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271. Pleiotropy of positive selection in ancient ACE2 suggests an alternative hypothesis for bat-specific adaptations to host coronaviruses.
- Author
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Guo YT, Jiang JB, Qiao GR, Luo RH, Zhou X, Hua R, Zheng CB, and Liu Z
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- Animals, Mice, Genetic Pleiotropy, Evolution, Molecular, SARS-CoV-2 genetics, COVID-19 virology, COVID-19 genetics, Coronavirus genetics, Humans, Phylogeny, Chiroptera virology, Chiroptera genetics, Angiotensin-Converting Enzyme 2 genetics, Angiotensin-Converting Enzyme 2 metabolism, Selection, Genetic
- Abstract
Angiotensin-convertingenzyme 2 (ACE2) has dual functions, regulating cardiovascular physiology and serving as the receptor for coronaviruses. Bats, the only true flying mammals and natural viral reservoirs, have evolved positive alterations in traits related to both functions of ACE2. This suggests significant evolutionary changes in ACE2 during bat evolution. To test this hypothesis, we examine the selection pressure in ACE2 along the ancestral branch of all bats (AncBat-ACE2), where powered flight and bat-coronavirus coevolution occurred, and detect a positive selection signature. To assess the functional effects of positive selection, we resurrect AncBat-ACE2 and its mutant (AncBat-ACE2-mut) created by replacing the positively selected sites. Compared to AncBat-ACE2-mut, AncBat-ACE2 exhibits stronger enzymatic activity, enhances mice's performance in exercise fatigue, and shows lower affinity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our findings indicate the functional pleiotropy of positive selection in the ancient ACE2 of bats, providing an alternative hypothesis for the evolutionary origin of bats' defense against coronaviruses., Competing Interests: Competing interests statement:The authors declare no competing interest.
- Published
- 2024
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272. Unlocking Synthesis of Polyhedral Oligomeric Silsesquioxane-Based Three-Dimensional Polycubane Covalent Organic Frameworks.
- Author
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Qiao GY, Wang X, Li X, Li J, Geng K, Jin E, Xu JJ, and Yu J
- Abstract
Reticular chemistry effectively yields porous structures with distinct topological lattices for a broad range of applications. Polyhedral oligomeric silsesquioxane (POSS)-based octatopic building blocks with a rare O
h symmetric configuration and attracting inorganic features have great potential for creating three-dimensional (3D) covalent organic frameworks (COFs) with new topologies. However, the intrinsic flexibility and intensive motion of cubane-type POSS molecules make the construction of 3D regular frameworks challenging. Herein, by fastening three or four POSS cores with per aromatic rigid linker from rational steric directions, we successfully developed serial crystalline 3D COFs with unpresented "the" and scu topologies. Both the experimental and theoretical results proved the formation of target 3D POSS-based COFs. The resultant hybrid networks with designable chemical skeletons and high surface areas maintain the superiorities of both the inorganic and organic components, such as their high compatibility with inorganic salts, abundant periodic electroactive sites, excellent thermal stability, and open multilevel nanochannels. Consequently, the polycubane COFs could serve as outstanding solid electrolytes with a high ionic conductivity of 1.23 × 10-4 S cm-1 and a lithium-ion transference number of 0.86 at room temperature. This work offers a pathway to generate ordered lattices with multiconnected flexible cube motifs and enrich the topologies of 3D COFs for potential applications.- Published
- 2024
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273. Comparison of CT-derived Plaque Characteristic Index With CMR Perfusion for Ischemia Diagnosis in Stable CAD.
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Guo WF, Xu HJ, Lu YG, Qiao GY, Yang S, Zhao SH, Jin H, Dai N, Yao ZF, Yin JS, Li CG, He W, and Zeng M
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- Humans, Constriction, Pathologic, Prospective Studies, Ischemia, Tomography, X-Ray Computed, Coronary Angiography, Perfusion, Coronary Artery Disease diagnostic imaging, Fractional Flow Reserve, Myocardial
- Abstract
Background: Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) have been used to diagnose lesion-specific ischemia in patients with coronary artery disease. The aim of this study was to investigate the diagnostic performance of CCTA-derived plaque characteristic index compared with myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) derived from CMR perfusion in the assessment of lesion-specific ischemia., Methods: Between October 2020 and March 2022, consecutive patients with suspected or known coronary artery disease, who were clinically referred for invasive coronary angiography were prospectively enrolled. All participants sequentially underwent CCTA and CMR and invasive fractional flow reserve within 2 weeks. The diagnostic performance of CCTA-derived plaque characteristics, CMR perfusion-derived stress MBF, and MPR were compared. Lesions with fractional flow reserve ≤0.80 were considered to be hemodynamically significant stenosis., Results: Nighty-two patients with 141 vessels were included in this study. Plaque length, minimum luminal area, plaque area, percent area stenosis, total atheroma volume, vessel volume, lipid-rich volume, spotty calcium, napkin-ring signs, stress MBF, and MPR in flow-limiting stenosis group were significantly different from nonflow-limiting group. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of lesion-specific ischemia diagnosis were 61.0%, 55.3%, 63.1%, 35.6%, and 79.3% for stress MBF, and 89.4%, 89.5%, 89.3%, 75.6%, 95.8% for MPR; meanwhile, 82.3%, 79.0%, 84.5%, 65.2%, and 91.6% for CCTA-derived plaque characteristic index., Conclusions: In our prospective study, CCTA-derived plaque characteristics and MPR derived from CMR performed well in diagnosing lesion-specific myocardial ischemia and were significantly better than stress MBF in stable coronary artery disease., Competing Interests: Disclosures None.
- Published
- 2023
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274. Stereotactic body radiotherapy for the treatment of oligometastatic gynecological malignancy in the abdomen and pelvis: A single-institution experience.
- Author
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Smile TD, Reddy CA, Qiao-Guan G, Winter WI, Stephans KL, Woody NM, Balagamwala EH, Amarnath SR, Magnelli A, AlHilli MM, Michener CM, Mahdi H, DeBernardo RL, Rose PG, and Cherian SS
- Abstract
Purpose/objectives: Metastasis-directed therapy with stereotactic body radiotherapy (SBRT) in the setting of oligometastatic disease is a rapidly evolving paradigm given ongoing improvements in systemic therapies and diagnostic modalities. However, SBRT to targets in the abdomen and pelvis is historically associated with concerns about toxicity. The purpose of this study was to evaluate the safety and efficacy of SBRT to the abdomen and pelvis for women with oligometastases from primary gynecological tumors., Materials/methods: From our IRB-approved registry, all patients who were treated with SBRT between 2014 and 2020 were identified. Oligometastatic disease was defined as 1 to 5 discrete foci of clinical metastasis radiographically diagnosed by positron emission tomography (PET) and/or computerized tomography (CT) imaging. The primary endpoint was local control at 12 months. Local and distant control rates were estimated using the Kaplan-Meier method. Time intervals for development of local progression and distant progression were calculated based on follow up visits with re-staging imaging. Acute and late toxicity outcomes were determined based on Common Terminology Criteria for Adverse Events (CTCAE) version 5.0., Results: We identified 34 women with 43 treated lesions. Median age was 68 years (range 32-82), and median follow up time was 12 months (range 0.2-54.0). Most common primary tumor sites were ovarian (n=12), uterine (n=11), and cervical (n=7). Median number of previous lines of systemic therapy agents at time of SBRT was 2 (range 0-10). Overall, SBRT was delivered to 1 focus of oligometastasis in 29 cases, 2 foci in 2 cases, 3 foci in 2 cases, and 4 foci in 1 case. All patients were treated comprehensively with SBRT to all sites of oligometastasis. Median prescription dose was 24 Gy (range 18-54 Gy) in 3 fractions (range 3-6) to a median prescription isodose line of 83.5% (range 52-95). Local control by lesion at 12 and 24 months was 92.5% for both time points. Local failure was observed in three treated sites among two patients, two of which were at 11 months in one patient, and the other at 30 months. Systemic control rate was 60.2% at 12 months. Overall survival at 12 and 24 months was 85% and 70.2%, respectively. Acute grade 2 toxicities included nausea (n=3), and there were no grade > 3 acute toxicities. Late grade 1 toxicities included diarrhea (n=1) and fatigue (n=1), and there were no grade > 2 toxicities., Conclusion: SBRT to oligometastatic gynecologic malignancies in the abdomen and pelvis is feasible with encouraging preliminary safety and local control outcomes. This approach is associated with excellent local control and low rates of toxicity during our follow-up interval. Further investigations into technique, dose-escalation and utilization are warranted., Competing Interests: Authors’ disclosure of potential conflicts of interest The authors have nothing to disclose., (© 2021 Old City Publishing, Inc.)
- Published
- 2021
275. Paeoniflorin elicits the anti-proliferative effects on glioma cell via targeting translocator protein 18 KDa.
- Author
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Gao ZW, Huang YY, Zhang JQ, Rong JY, Qiao GY, Chen N, Yu GD, Luo M, and Liu XF
- Subjects
- Animals, Cell Line, Tumor, Disease Models, Animal, Dose-Response Relationship, Drug, Glioma metabolism, Glioma pathology, Isoquinolines pharmacology, Isoquinolines therapeutic use, Neurosteroids metabolism, Antineoplastic Agents, Phytogenic, Cell Proliferation drug effects, Cell Proliferation genetics, Glioma drug therapy, Glioma genetics, Glucosides pharmacology, Glucosides therapeutic use, Monoterpenes pharmacology, Monoterpenes therapeutic use, Phytotherapy, Receptors, GABA metabolism
- Abstract
As a natural compound isolated from Paeoniae radix, Paeoniflorin (PF) has been shown the antitumor effects in various types of human cancers including glioma, which is one of the serious tumors in central nervous system. Translocator protein 18 KDa (TSPO) has been shown to be relevant to the glioma aetiology. However, the regulation of PF in TSPO and neurosteriods biosynthesis on glioma is still unclear. In the present study, the glioma cell (U87 and U251) were cultured and used to quantify the bindings of PF on TSPO. Results indicated that there was not significant different between IC50 of PF and TSPO ligand PK11195. Moreover, PF exerted the anti-proliferative effects in glioma cell with a dose dependent inhibition from 12.5 to 100 μM in vitro. Consistent with the effects of PK11195, lowered levels on progesterone, allopregnanolone, as well as TSPO mRNA were induced by PF (25 and 50 μM). Furthermore, a xenograft mouse model with U87 cell-derived was significant inhibited by PF treatment, as well as the PK11195 administration. These results demonstrate that PF exerts its antitumor effects associated with the TSPO and neurosteroids biosynthesis in glioma cells could be a promising therapeutic agent for glioma therapy., Competing Interests: Declaration of competing interest The authors indicated no potential conflicts of interest., (Copyright © 2020 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
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276. Functionalization of Zirconium-Based Metal-Organic Layers with Tailored Pore Environments for Heterogeneous Catalysis.
- Author
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Qiao GY, Yuan S, Pang J, Rao H, Lollar CT, Dang D, Qin JS, Zhou HC, and Yu J
- Abstract
Intriguing properties and functions are expected to implant into metal-organic layers (MOLs) to achieve tailored pore environments and multiple functionalities owing to the synergies among multiple components. Herein, we demonstrate a facile one-pot synthetic strategy to incorporate multiple functionalities into stable zirconium MOLs via secondary ligand pillaring. Through the combination of Zr
6 -BTB (BTB=benzene-1,3,5-tribenzoate) layers and diverse secondary ligands (including ditopic and tetratopic linkers), 31 MOFs with multi-functionalities were systematically prepared. Notably, a metal-phthalocyanine fragment was successfully incorporated into this Zr-MOL system, giving rise to an ideal platform for the selective oxidation of anthracene. The organic functionalization of two-dimensional MOLs can generate tunable porous structures and environments, which may facilitate the excellent catalytic performance of as-synthesized materials., (© 2020 Wiley-VCH GmbH.)- Published
- 2020
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277. Clinical Assessment of Prostate Displacement and Planning Target Volume Margins for Stereotactic Body Radiotherapy of Prostate Cancer.
- Author
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Levin-Epstein R, Qiao-Guan G, Juarez JE, Shen Z, Steinberg ML, Ruan D, Valle L, Nickols NG, Kupelian PA, King CR, Cao M, and Kishan AU
- Abstract
Purpose: To assess the optimal planning target volume (PTV) margins for stereotactic body radiotherapy (SBRT) of prostate cancer based on inter- and intra-fractional prostate motion determined from daily image guidance. Methods and Materials: Two hundred and five patients who were enrolled on two prospective studies of SBRT (8 Gy × 5 fractions) for localized prostate cancer treated at a single institution between 2012 and 2017 had complete inter- and intra-fractional shift data available. All patients had scheduled kilovoltage planar imaging during SBRT with rigid registration to intraprostatic fiducials prior to each of four half-arcs delivered per fraction, as well as cone beam CT verification of anatomy prior to each fraction. Inter- and intra- fractional shift data were obtained to estimate the required PTV margins based on the classic van Herk formula. Inter- and intra-fractional motion were compared between patients with and without severe toxicities using the independent two-sample Wilcoxon test. Results: The margins required to account for inter-fractional motion were estimated to be 0.99, 1.52, and 1.45 cm in lateral (LR), longitudinal (SI), and vertical (AP) directions, respectively. The margins required to account for intra-fractional motion were estimated to be 0.19, 0.27, and 0.31 cm in LR, SI and AP directions, respectively. Large intra-fractional shifts were mostly observed in the SI and AP directions, with 2.0 and 5.4% of patients experiencing average intra-fractional motion >3 mm in the SI and AP directions, respectively, compared with none experiencing mean shifts >3 mm in the LR direction. Six patients experienced grade 3 gastrointestinal or genitourinary toxicity. There were no significant differences in mean inter- or intra-fractional motion in any of the cardinal directions compared to patients without severe toxicity (inter-fractional p = 0.46-0.99, intra-fractional p = 0.10-0.84). Conclusion: The inter- and intra-fractional margins estimated from this study are in line with prior reported values. Intra-fractional prostate motion was generally small with larger margins required for the SI and AP directions, notably just slightly exceeding the commonly used 3 mm posterior PTV margin even with realignment between half-arcs. Development of severe toxicity was not significantly associated with the degree of inter- or intra-fractional motion., (Copyright © 2020 Levin-Epstein, Qiao-Guan, Juarez, Shen, Steinberg, Ruan, Valle, Nickols, Kupelian, King, Cao and Kishan.)
- Published
- 2020
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278. An Overlapped Nano-Fe₂O₃/TiO₂ Composite Coating on Activated Carbon Fiber Membrane with Enhanced Photocatalytic Performance.
- Author
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Han C, Jing MX, Yang H, Shen XQ, and Qiao GJ
- Abstract
Treatment of high concentration organic wastewater has always been a difficult problem in the field of water purification due to its high cost, low efficiency, long processing cycle and possible second pollution. An overlapped nano-Fe₂O₃/TiO₂@activated carbon fiber membrane composite was successfully prepared by hydrothermal loading method. Nano-rod-like TiO₂ and columnar Fe₂O₃ polyhedrals overlapped and formed a composite coating on the surface of activated carbon fiber membrane. This composite can absorb visible light and successfully remove the high concentration Congo red pollutant (400 mg/L) in 24 h. The enhanced photocatalytic performance should be attributed to the synergistic reaction of nano-Fe₂O₃ and nano-TiO₂, which improves the separation of photo-generated electrons and holes thus enhances the photocatalytic efficiency. This multifunctional fiber membrane is expected to be widely applied in various organic wastewater treatments.
- Published
- 2019
- Full Text
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279. Engineering self-flocculating Halomonas campaniensis for wastewaterless open and continuous fermentation.
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Ling C, Qiao GQ, Shuai BW, Song KN, Yao WX, Jiang XR, and Chen GQ
- Subjects
- Bioreactors microbiology, Cell Engineering methods, Flocculation, Halomonas genetics, Halomonas growth & development, Industrial Microbiology methods, Wastewater analysis, Water Purification methods, Fermentation, Halomonas metabolism, Hydroxybutyrates metabolism, Polyesters metabolism, Wastewater microbiology
- Abstract
Halomonas has been developed as a platform for the next generation industrial biotechnology allowing open and nonsterile growth without microbial contamination under a high-salt concentration and alkali pH. To reduce downstream cost associated with continuous centrifugation and salt containing wastewater treatment, Halomonas campaniensis strain LS21 was engineered to become self-flocculating by knocking out an etf operon encoding two subunits of an electron transferring flavoprotein in the predicted electron transfer chain. Self-flocculation could be attributed to the decrease of the surface charge and increase of the cellular hydrophobicity resulted from deleted etf. A wastewaterless fermentation strategy based on the self-flocculating H. campaniensis was developed for growth and the production of poly-3-hydroxybutyrate (PHB) as an example. Most microbial cells flocculated and precipitated to the bottom of the bioreactor within 1 min after stopping the aeration and agitation. The supernatant can be used again without sterilization or inoculation for the growth of the next batch after collecting the precipitated cell mass. The wastewaterless process was conducted for four runs without generating wastewater. PHB accumulation by the self-flocculent strain was enhanced via promoter and ribosome binding site optimizations, the productivities of cell dry weight and PHB were increased from 0.45 and 0.18 g·L
-1 ·hr-1 for the batch process compared to 0.82 and 0.33 g·L-1 ·hr-1 for the wastewaterless continuous process, respectively. This has clearly demonstrated the advantages of the wastewaterless process in that it not only reduces wastewater but also increases cell growth and product formation efficiency in a given period of time., (© 2018 Wiley Periodicals, Inc.)- Published
- 2019
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280. Discovery of Novel Retigabine Derivatives as Potent KCNQ4 and KCNQ5 Channel Agonists with Improved Specificity.
- Author
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Wang L, Qiao GH, Hu HN, Gao ZB, and Nan FJ
- Abstract
Recent research suggests that KCNQ isoforms, particularly the KCNQ4 and KCNQ5 subtypes expressed in smooth muscle cells, are involved in both establishing and maintaining resting membrane potentials and regulating smooth muscle contractility. Retigabine (RTG) is a first-in-class antiepileptic drug that potentiates neuronal KCNQ potassium channels, but poor subtype selectivity limits its further application as a pharmacological tool. In this study, we improved the subtype specificity of retigabine by altering the N-1/3 substituents and discovered several compounds that show better selectivity for KCNQ4 and KCNQ5 channels. Among these compounds, 10g is highly selective for KCNQ4 and KCNQ5 channels without potentiating KCNQ1 and KCNQ2 channels. These results are an advance in the exploration of small molecule modifiers that selectively activate different KCNQ isoforms. The developed compounds could also serve as new pharmacological tools for elucidating the function of KCNQ channels natively expressed in various tissues., Competing Interests: The authors declare no competing financial interest.
- Published
- 2018
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281. Engineering NADH/NAD + ratio in Halomonas bluephagenesis for enhanced production of polyhydroxyalkanoates (PHA).
- Author
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Ling C, Qiao GQ, Shuai BW, Olavarria K, Yin J, Xiang RJ, Song KN, Shen YH, Guo Y, and Chen GQ
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Halomonas genetics, NAD genetics, Oxygen metabolism, Halomonas metabolism, Hydroxybutyrates metabolism, Metabolic Engineering, NAD metabolism, Polyesters metabolism
- Abstract
Halomonas bluephagenesis has been developed as a platform strain for the next generation industrial biotechnology (NGIB) with advantages of resistances to microbial contamination and high cell density growth (HCD), especially for production of polyhydroxyalkanoates (PHA) including poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). However, little is known about the mechanism behind PHA accumulation under oxygen limitation. This study for the first time found that H. bluephagenesis utilizes NADH instead of NADPH as a cofactor for PHB production, thus revealing the rare situation of enhanced PHA accumulation under oxygen limitation. To increase NADH/NAD
+ ratio for enhanced PHA accumulation under oxygen limitation, an electron transport pathway containing electron transfer flavoprotein subunits α and β encoded by etf operon was blocked to increase NADH supply, leading to 90% PHB accumulation in the cell dry weight (CDW) of H. bluephagenesis compared with 84% by the wild type. Acetic acid, a cost-effective carbon source, was used together with glucose to balance the redox state and reduce inhibition on pyruvate metabolism, resulting in 22% more CDW and 94% PHB accumulation. The cellular redox state changes induced by the addition of acetic acid increased 3HV ratio in its copolymer PHBV from 4% to 8%, 4HB in its copolymer P34HB from 8% to 12%, respectively, by engineered H. bluephagenesis. The strategy of systematically modulation on the redox potential of H. bluephagenesis led to enhanced PHA accumulation and controllable monomer ratios in PHA copolymers under oxygen limitation, reducing energy consumption and scale-up complexity., (Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
282. [Retention and resuspension of atmospheric particles with two common urban greening trees].
- Author
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Qiao GH, Chen JW, Liu XY, Tan LS, Zheng GL, and Li P
- Subjects
- Adsorption, Plant Leaves, Air Pollutants, Environmental Monitoring, Trees
- Abstract
The purification mechanisms of plant leaves with atmospheric particles include adsorption, resuspension, rainwater leaching and absorption. However, few studies focused on the resuspension process of atmospheric particles suspending on the surface of leaves, and the correlation between content of adsorbed particles and content of elements in the leaves. Therefore, two common greening tree species, Platanus acerifolia and Magnolia grandiflora, were selected to analyze the atmospheric particles contents on the leaf surface, the leaf mineral element content, and the resuspension ratios. The results showed that the adsorption capacity of P. acerifolia (4.98 g·m
-2 ) was higher than that of M. grandiflora (2.65 g·m-2 ), which might be connected with rough leaves and dense hairs. The selected 15 elements were all detected by ICP on the leaf surface and in the leaves of two species. In general, the elemental values of the leaf surface were positively related with those in the leaves. However, the two plants showed different selective absorption capacities because positive relation between element adsorption and absorption was only found for Cr, Fe and V for P. ace-rifolia, while such relation was only not found for K, Mn, Si, Ti and Zn for M. grandiflora. The results implied that the absorption was of high selectivity to different elements. Moreover, both increase in wind speed and exposure duration in the wind significantly enhanced resuspension ratios of atmospheric particles. We suggested that resuspension should be taken into account of assessing the relationship between the atmospheric particles deposition and associated plants' function in the future.- Published
- 2017
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283. Correction for Pan et al., Later Passages of Neural Progenitor Cells from Neonatal Brain Are More Permissive for Human Cytomegalovirus Infection.
- Author
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Pan X, Li XJ, Liu XJ, Yuan H, Li JF, Duan YL, Ye HQ, Fu YR, Qiao GH, Wu CC, Yang B, Tian XH, Hu KH, Miao LF, Chen XL, Zheng J, Rayner S, Schwartz PH, Britt WJ, Xu J, and Luo MH
- Published
- 2016
- Full Text
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284. Multipotent mesenchymal stromal cells are fully permissive for human cytomegalovirus infection.
- Author
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Qiao GH, Zhao F, Cheng S, and Luo MH
- Subjects
- Cells, Cultured, Cytomegalovirus genetics, Genome, Viral, Humans, Umbilical Cord cytology, Umbilical Cord virology, Viral Plaque Assay, Viral Proteins biosynthesis, Viral Proteins genetics, Viral Proteins metabolism, Virus Internalization, Virus Replication, Cytomegalovirus physiology, Cytomegalovirus Infections virology, Mesenchymal Stem Cells cytology, Mesenchymal Stem Cells virology
- Abstract
Congenital human cytomegalovirus (HCMV) infection is a leading infectious cause of birth defects. Previous studies have reported birth defects with multiple organ maldevelopment in congenital HCMV-infected neonates. Multipotent mesenchymal stromal cells (MSCs) are a group of stem/progenitor cells that are multi-potent and can self-renew, and they play a vital role in multi-organ formation. Whether MSCs are susceptible to HCMV infection is unclear. In this study, MSCs were isolated from Wharton's jelly of the human umbilical cord and identified by their plastic adherence, surface marker pattern, and differentiation capacity. Then, the MSCs were infected with the HCMV Towne strain, and infection status was assessed via determination of viral entry, replication initiation, viral protein expression, and infectious virion release using western blotting, immunofluorescence assays, and plaque forming assays. The results indicate that the isolated MSCs were fully permissive for HCMV infection and provide a preliminary basis for understanding the pathogenesis of HCMV infection in non-nervous system diseases, including multi-organ malformation during fetal development.
- Published
- 2016
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285. Identification and BAC construction of Han, the first characterized HCMV clinical strain in China.
- Author
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Zhao F, Shen ZZ, Liu ZY, Zeng WB, Cheng S, Ma YP, Rayner S, Yang B, Qiao GH, Jiang HF, Gao S, Zhu H, Xu FQ, Ruan Q, and Luo MH
- Subjects
- Asian People, China, Cytomegalovirus Infections congenital, Cytomegalovirus Infections virology, Female, Gene Expression Profiling, Humans, Infant, Infant, Newborn, Sequence Analysis, DNA, Urine virology, Viral Proteins biosynthesis, Chromosomes, Artificial, Bacterial, Cloning, Molecular, Cytomegalovirus genetics, Cytomegalovirus isolation & purification
- Abstract
Human cytomegalovirus (HCMV) is the leading infectious cause of birth defects, and may lead to severe or lethal diseases in immunocompromised individuals. Several HCMV strains have been identified and widely applied in research, but no isolate from China has been characterized. In the present study, we isolated, characterized and sequenced the first Chinese HCMV clinical strain Han, and constructed the novel and functional HCMV infectious clone Han-BAC-2311. HCMV Han was isolated from the urine sample of a Chinese infant with multiple developmental disorders. It expresses HCMV specific proteins and contains a representative HCMV genome with minor differences compared to other strains. By homologous recombination using mini-F derived BAC vector pUS-F6, the infectious clone Han-BAC-2311 was constructed containing representative viral genes across the HCMV genome. The insertion site and orientation of BAC sequence were confirmed by restriction enzyme digestion and Southern blotting. The reconstituted recombinant virus HanBAC-2311 expresses typical viral proteins with the same pattern as that of wild-type Han, and also displayed a similar growth kinetics to wild-type Han. The identification of the first clinical HCMV strain in China and the construction of its infectious clone will greatly facilitate the pathogenesis studies and vaccine development in China., (© 2015 Wiley Periodicals, Inc.)
- Published
- 2016
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286. [The baculovirus enhancin].
- Author
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Zhang XX, Chen XH, Liang ZP, Cao SM, Xu F, Qiao GH, and Yin XM
- Subjects
- Baculoviridae genetics, Phylogeny, Viral Proteins chemistry, Viral Proteins classification, Viral Proteins genetics, Baculoviridae metabolism, Viral Proteins metabolism
- Published
- 2010
287. [Research on enhanced photocatalytic degradation of medical PVC by plasma-initiated free radicals].
- Author
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Li XJ, Qiao GJ, and Chen JR
- Subjects
- Catalysis radiation effects, Electron Spin Resonance Spectroscopy, Microscopy, Electron, Scanning, Nanotechnology, Photochemistry methods, Surface Properties, Polyvinyl Chloride chemistry, Titanium chemistry
- Abstract
Effects of plasma-initiated free radicals on photocatalytic degradation of medical PVC with anatase TiO2 were studied. Surface properties of PVC were characterized by the contact angle, surface tension, X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR). The results indicate that the surface free energy and wettability of plasma-treated PVC increase greatly. The contact angles of distilled water, glycerin and dihydroxyethylsulfide for the plasma-treated PVC decrease. ESR reveals radicals on the surface of the plasma-treated PVC film nearly increase ten times. Moreover, the photodegradation of the PVC-TiO2 was compared with that of plasma-treated PVC-TiO2 through performing weight loss monitoring, scanning electron microscopic (SEM) analysis. Weight-loss rate of the plasma-treated PVC-TiO2 increases 27.4% in comparison with that of PVC-TiO2 under UV irradiation for 60 hours. SEM of the plasma-treated PVC-TiO2 film shows a lot of crack on the surface after photodegradation. Plasma treatments aggravate the photocatalytic degradation of medical PVC.
- Published
- 2007
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