65 results on '"Xin Duan"'
Search Results
2. Effect of a preoperative mobilization program on perioperative complications and function recovery in older adults with femoral neck fracture
- Author
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Jiaxin, Liu, Li, Chen, Cheng, Long, Xiang, Zhang, Feng, Gao, Xin, Duan, and Zhou, Xiang
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Treatment Outcome ,Humans ,Pneumonia ,Recovery of Function ,Gerontology ,Aged ,Femoral Neck Fractures ,Retrospective Studies - Abstract
To assess the effectiveness of a preoperative mobilization program for preventing perioperative complications and improving function in older adults with femoral neck fracture who delayed surgery.In this controlled, quasi-experimental study, a total of 150 older patients with femoral neck fracture who waited more than 2 days before surgery were assigned to the Intervention group or control group. Perioperative complications were recorded. The change of physical function was assessed using the modified Barthel index (MBI).The overall perioperative complication rate (52.2% vs. 73.5%), pulmonary infection (6.0% vs. 16.9%), delirium (9.0% vs. 24.1%) in the intervention group were lower than those in the control group. The intervention group had significantly better improvement in MBI score preoperatively and postoperatively.A preoperative mobilization program was shown to have advantages in preventing perioperative complications and promoting early functional recovery in older adults with delayed surgery of femoral neck fracture.
- Published
- 2022
3. Novel mechanistic role of Kif26b in adipogenic differentiation of murine multipotent stromal cells
- Author
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Mingming Yan, Lei Cai, Xin Duan, and Muhammad Farooq Rai
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Adipogenesis ,Multipotent Stem Cells ,Cell Cycle ,Biophysics ,Kinesins ,Cell Biology ,Biochemistry ,Cell Line ,PPAR gamma ,Mice ,Gene Knockdown Techniques ,Adipocytes ,Animals ,Stromal Cells ,Molecular Biology ,Signal Transduction - Abstract
Emerging evidence delineates that obesity, a complex metabolic disorder, impairs the structure and function of stromal cells residing in various tissues. The exuberant adipose tissue mass observed in obesity is, in part, associated with hyperplasia of adipocytes resulting from recruitment of multipotent stromal cells within the stromal vascular fraction of adipose tissues. However, a clear understanding of the causal role of stromal cells and biological factors in obesity is lacking. In our quest to understanding the role of kinesin family member 26B (KIF26B), we found that KIF26B regulates osteogenic and chondrogenic differentiation of stromal/progenitor cells. In this study, we sought to examine the effects of Kif26b loss-of-function on adipogenic differentiation of murine C3H10T1/2 multipotent stromal cells. In vitro loss-of-function studies demonstrated that Kif26b knockdown by lentivirus mediated shRNA markedly dampened the differentiation potential of C3H10T1/2 cells to adipocytes and suppressed the expression of adipogenesis-related genes e.g., Pparg, C/ebpα, Fabp4 and Adipoq. Analysis of cell cycle revealed that Kif26b knockdown resulted in elevated expression of cyclins (Ccnd1, Ccnb1, Ccna2) along with rapid cell cycle progression from G0/G1 to S and G2 phases. Mechanistically, reduced adipogenic differentiation of Kif26b-deficient cells was partly dependent on PPARγ, a key transcription factor implicated in adipogenesis. This observation was experimentally supported as loss of adipogenesis was partially rescued by the addition of PPARγ agonist, rosiglitazone in Kif26b-deficient cells. We further found that silencing of Kif26b lessened the protein levels of phospho-AKT(Ser473), phospho-S6(Ser235/236), and phospho-mTOR(Ser2448), the major component of AKT/mTOR complex 1 (mTORC1) signaling at the basal level. Together, these data define a novel role of Kif26b in regulating the commitment of C3H10T1/2 multipotent stromal cells to the adipocyte lineage and provide a practical framework for further experiments to establish its therapeutic potential for the treatment of problems associated with adipogenesis such as obesity at the cellular and molecular level.
- Published
- 2022
4. Recent advances in biofabrication strategies based on bioprinting for vascularized tissue repair and regeneration
- Author
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Fei Xing, Jiawei Xu, Peiyun Yu, Yuxi Zhou, Man Zhe, Rong Luo, Ming Liu, Zhou Xiang, Xin Duan, and Ulrike Ritz
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2023
5. Recent progress on the electroreduction of carbon dioxide to C1 liquid products
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Yan-Xin Duan, Rong-Chao Cui, and Qing Jiang
- Subjects
Electrochemistry ,Analytical Chemistry - Published
- 2023
6. Accelerated rehabilitation in treating neer type V distal clavicle fractures using anatomical locking plates with coracoclavicular ligament augmentation
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Min Zou, Xin Duan, Mufan Li, and Jiachen Sun
- Subjects
Multidisciplinary - Published
- 2023
7. Integrated design and fabrication strategies based on bioprinting for skeletal muscle regeneration: Current status and future perspectives
- Author
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Hong Ma, Fei Xing, Peiyun Yu, Jiawei Xu, Xinyu Wu, Rong Luo, Zhou Xiang, Pol Maria Rommens, Xin Duan, and Ulrike Ritz
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2023
8. RNA-seq analysis of chondrocyte transcriptome reveals genetic heterogeneity in LG/J and SM/J murine strains
- Author
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Muhammad Farooq Rai, Lei Cai, Eric J. Schmidt, Jie Shen, Regis J. O'Keefe, Xin Duan, James M. Cheverud, and Eric Tycksen
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Cartilage, Articular ,Candidate gene ,Quantitative Trait Loci ,Biomedical Engineering ,Mice, Inbred Strains ,Quantitative trait locus ,Biology ,Real-Time Polymerase Chain Reaction ,Carbonic Anhydrase II ,Polymorphism, Single Nucleotide ,Article ,Receptors, Tumor Necrosis Factor ,Chondrocyte ,Cartilage condensation ,Transcriptome ,Mice ,Chondrocytes ,Rheumatology ,Osteoarthritis ,Gene expression ,medicine ,Animals ,Regeneration ,Genetic Predisposition to Disease ,Orthopedics and Sports Medicine ,RNA-Seq ,Gene ,Gene Expression Profiling ,Cartilage ,Molecular biology ,medicine.anatomical_structure ,Ear Cartilage ,Ear Auricle - Abstract
Summary Objective To investigate the transcriptomic differences in chondrocytes obtained from LG/J (large, healer) and SM/J (small, non-healer) murine strains in an attempt to discern the molecular pathways implicated in cartilage regeneration and susceptibility to osteoarthritis (OA). Design We performed RNA-sequencing on chondrocytes derived from LG/J (n = 16) and SM/J (n = 16) mice. We validated the expression of candidate genes and compared single nucleotide polymorphisms (SNPs) between the two mouse strains. We also examined gene expression of positional candidates for ear pinna regeneration and long bone length quantitative trait loci (QTLs) that display differences in cartilaginous expression. Results We observed a distinct genetic heterogeneity between cells derived from LG/J and SM/J mouse strains. We found that gene ontologies representing cell development, cartilage condensation, and regulation of cell differentiation were enriched in LG/J chondrocytes. In contrast, gene ontologies enriched in the SM/J chondrocytes were mainly related to inflammation and degeneration. Moreover, SNP analysis revealed that multiple validated genes vary in sequence between LG/J and SM/J in coding and highly conserved noncoding regions. Finally, we showed that most QTLs have 20–30% of their positional candidates displaying differential expression between the two mouse strains. Conclusions While the enrichment of pathways related to cell differentiation, cartilage development and cartilage condensation infers superior healing potential of LG/J strain, the enrichment of pathways related to cytokine production, immune cell activation and inflammation entails greater susceptibility of SM/J strain to OA. These data provide novel insights into chondrocyte transcriptome and aid in identification of the quantitative trait genes and molecular differences underlying the phenotypic differences associated with individual QTLs.
- Published
- 2020
9. Protective immunity against spring viremia of carp virus by mannose modified chitosan loaded DNA vaccine
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Zhao, Zhao, Fu-Yi, Jiang, Guo-Qing, Zhou, Hui-Xin, Duan, Jun-Yao, Xia, and Bin, Zhu
- Subjects
Chitosan ,Fish Diseases ,Cancer Research ,Carps ,Infectious Diseases ,Virology ,Vaccines, DNA ,Animals ,Viral Vaccines ,Viremia ,Rhabdoviridae ,Mannose - Abstract
Spring viremia of carp virus (SVCV) usually be considered as one of the serious in viral diseases of aquaculture, and DNA vaccine with novel delivery mechanism or adjuvant has proven to be a promising and effective strategy to control aquatic animal diseases. In this study, the mannose-modified chitosan, a carrier system for vaccine delivery, were used to developed a chitosan-encapsulated DNA vaccine (CS-M-G) against SVCV, then investigated immune response induced by the vaccine. Our results showed that CS-M-G was confirmed the spherical or elliptical with even distribution and ranging from approximately 50 to 150 nm in size, the expression of the antigen gene could still be detected after 21 d post vaccination. The CS-M-G induces the highest antibody levels in the 20 μg dose group which is about 3 times than naked plasmid group at 21 d post vaccination, and still hold a higher level than control group at 28 d post vaccination. On the side, strongest protection with relative percent survival of 62.1% in the 20 μg CS-M-G group, which could produce significantly higher enzyme activities and up-regulated expression of immune-associated genes than control group. Thus, our results indicate that DNA vaccine loaded with mannose-modified chitosan induces strong immune response and provided an effective protection against SVCV infection, may be helpful and extended for developing more aquatic animal vaccines in the future.
- Published
- 2022
10. A β-tubulin dsRNA derived from Fusarium asiaticum confers plant resistance to multiple phytopathogens and reduces fungicide resistance
- Author
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Xue-Mei Xiao, Yiping Hou, Yabing Duan, Xiao-Xin Duan, Kai-Xin Gu, Mingguo Zhou, Xiu-Shi Song, and Jianxin Wang
- Subjects
0106 biological sciences ,0301 basic medicine ,Fusarium ,Carbendazim ,Health, Toxicology and Mutagenesis ,fungi ,food and beverages ,Virulence ,General Medicine ,Biology ,biology.organism_classification ,01 natural sciences ,Microbiology ,Fungicide ,010602 entomology ,03 medical and health sciences ,RNA silencing ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Colletotrichum truncatum ,Agronomy and Crop Science ,Mycelium ,Botrytis cinerea - Abstract
Crops are attacked by a large number of pathogens which are responsible for an approximately 30% loss in global crop production at pre- and post-harvest levels. In light of the continuing emergence of fungicide resistance, the needs for new agricultural drugs turn out to be much more critical. Here we demonstrated a Faβ2Tub-3 dsRNA derived from Fusarium asiaticum had broad-spectrum antifungal activity against Fusarium spp., Botrytis cinerea, Magnaporthe oryzae and Colletotrichum truncatum, with an additional function of reducing the dosage of carbendazim (MBC) fungicide. RNAi molecules derived from different regions of β2-tubulin gene had different effects on mycelial growth, asexual reproduction and virulence. Faβ2Tub-3 (one of β2-tubulin segments) exhibited a strong silencing efficacy both on β1-tubulin and β2-tubulin genes in F. asiaticum. Faβ2Tub-3 sequence was found to be highly conserved among Fusarium spp., Botrytis cinerea, Magnaporthe oryzae and Colletotrichum truncatum. The Faβ2Tub-3 dsRNA demonstrated a broad-spectrum antifungal activity against these fungi in vitro and on living plant. More importantly, Faβ2Tub-3 dsRNA increased the fungal sensitivity to MBC, while MBC increased the duration of Faβ2Tub-3 dsRNA. Our findings suggest a new anti-fungal agent (Faβ2Tub-3 dsRNA) for plant protection against diverse pathogens and for fungicide reduction.
- Published
- 2019
11. Roasted modified lead-zinc tailings using alkali as activator and its mitigation of Cd contaminated: Characteristics and mechanisms
- Author
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Shaojun, Jiang, Tao, Chen, Junhao, Zhang, Lian Xin, Duan, and Bo, Yan
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Alkalies ,Pollution ,Kinetics ,Soil ,Zinc ,Lead ,Spectroscopy, Fourier Transform Infrared ,Environmental Chemistry ,Adsorption ,Cadmium - Abstract
To comprehensively reuse lead-zinc tailings, leaching residue (LR) of solid by-products was produced after the recovery of valuable metals. This study provided a "waste-ecology" strategy by a simple, inexpensive method of roasting prepared highly active silicon modified tailing (HAST) to eliminate the environment risk of LR, and investigates performance and mechanism of HAST as sorbents and passivators. The results indicated that HAST possesses high pH, abundant mineral content, microporous structure and high stability. The adsorption kinetic experiment revealed that chemisorption is the main reaction and the Q
- Published
- 2022
12. A parallel shape formation method for swarm robotics
- Author
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Hong-an Yang, Yuhua Li, Xin Duan, Gaopan Shen, and Shaohua Zhang
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Control and Systems Engineering ,General Mathematics ,Software ,Computer Science Applications - Published
- 2022
13. Shear response of circular-in-square CFDST members: Experimental investigation and finite element analysis
- Author
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Li-Xin Duan, Wen-Da Wang, Wei Xian, and Yan-Li Shi
- Subjects
Mechanics of Materials ,Metals and Alloys ,Building and Construction ,Civil and Structural Engineering - Published
- 2022
14. Periostin-null mice are protected from post-traumatic and age-related osteoarthrtis
- Author
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Lei Cai, S.B. Abramson, Weili Zhang, Mukundan Attur, Muhammad Farooq Rai, Tianzhen Han, Jonathan Samuels, Xin Duan, and R.H. Brophy
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Null mice ,medicine.medical_specialty ,Endocrinology ,Rheumatology ,business.industry ,Internal medicine ,Age related ,Biomedical Engineering ,medicine ,Orthopedics and Sports Medicine ,Periostin ,business - Published
- 2021
15. Colorimetric and fluorometric dual sensing of trace water in methanol based on a Schiff Base-Al3+ ensemble probe
- Author
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Jian Bin Chao, Yu Wang, Li Xin Duan, Zhuo Bin Shang, Jia Feng, and Wei Jun Jin
- Subjects
Detection limit ,Schiff base ,Trace Amounts ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Fluorescence ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Bathochromic shift ,Titration ,Methanol ,0210 nano-technology ,Instrumentation ,Julolidine ,Spectroscopy - Abstract
A new julolidine based Schiff base receptor (L) was synthesized and characterized. L forms a 1:1 complex with Al3+ in methanol, resulting in an immediate color change from chartreuse to orange and a remarkable enhancement in its emission intensity along with a bathochromic shift from 540 nm to 570 nm. Addition of trace amounts of water significantly quenches the fluorescence emission, where a decomplexation of Al3+ from the L-Al3+ complex takes place. The significant quenching effect indicated that the L-Al3+ ensemble system can be used to detect trace water in commercial methanol. From the fluorescence titration, the detection limit for sensing water in methanol was estimated to be 0.0047%. We have also made an easy-to-prepare test strip of L-Al3+ to detect water in methanol through naked-eye observation, which is possible to realize in situ monitoring.
- Published
- 2018
16. Heterophilic Type II Cadherins Are Required for High-Magnitude Synaptic Potentiation in the Hippocampus
- Author
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Raunak Basu, Xin Duan, Matthew R. Taylor, E. Anne Martin, Shruti Muralidhar, Yueqi Wang, Luke Gangi-Wellman, Sujan C. Das, Masahito Yamagata, Peter J. West, Joshua R. Sanes, and Megan E. Williams
- Subjects
General Neuroscience - Published
- 2018
17. Acclimation-induced metabolic reprogramming contributes to rapid desiccation tolerance acquisition in Boea hygrometrica
- Author
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Yue-Hua Gong, Xiao-Fei Zhang, Chih-Ta Lin, Xin Deng, Xiao-Quan Qi, Li-Xin Duan, and Run-Ze Sun
- Subjects
0106 biological sciences ,0301 basic medicine ,chemistry.chemical_classification ,ved/biology ,fungi ,ved/biology.organism_classification_rank.species ,food and beverages ,Resurrection plant ,Plant Science ,Biology ,01 natural sciences ,Acclimatization ,Amino acid ,Desiccation tolerance ,Transcriptome ,03 medical and health sciences ,Protein catabolism ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Agronomy and Crop Science ,Gene ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
The acquisition of rapid desiccation tolerance for the resurrection plant Boea hygrometrica requires a cycle of drought acclimation. Here, a gas chromatography-mass spectrometry based global untargeted metabolite profiling analysis was conducted on leaves of B. hygrometrica during dehydration and rehydration. Metabolic profiles between non-acclimated and drought acclimated plants were clearly distinguished in principal-component and hierarchical cluster analysis, indicating that drought acclimation response required the process in metabolic reprogramming. Accumulation of numerous metabolites involved in carbon and energy metabolism as well as amino acid and fatty acid biosynthesis was observed to be significantly changed upon drought acclimation and dehydration treatments. Using partial least-squares discriminant analysis, 25 known metabolites and 51 compounds with unknown structures were identified as putative biomarkers contributed to the discrimination between drought acclimated and non-acclimated plants. Remarkably, as revealed by transcriptome data analysis, some up-accumulated metabolites in acclimated plants, such as maltose, glutaric acid, L-tryptophan and α-tocopherol, which are in good correlation with the increased desiccation tolerance, and were precisely controlled by the transcript changes in multigene family members of related enzymes. Furthermore, genes positively correlated with the up-accumulated biomarkers in transcription abundances were enriched in multiple biological processes, such as “ubiquitin-dependent protein catabolism” and “abscisic acid-activated signaling pathway”. Taken together, our observations indicate that the accumulation of important metabolites correlates with the transcriptional activity of biosynthetic related enzymes and putative regulators involved in ubiquitination and ABA signal transduction during a short period of drought acclimation might contribute to the acquisition of rapid desiccation tolerance in B. hygrometrica.
- Published
- 2018
18. Tetherless near-infrared control of brain activity in behaving animals using fully implantable upconversion microdevices
- Author
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Xi Chen, Feng Wang, Peng Shi, Xian Chen, Xin Wang, Ying Wang, Zhen Xu, Ming Liu, Wenchong Zhang, Qinghai Liao, Xudong Lin, Jufang He, and Xin Duan
- Subjects
0301 basic medicine ,Materials science ,Infrared Rays ,Brain activity and meditation ,Transducers ,Biophysics ,Bioengineering ,02 engineering and technology ,Optogenetics ,Prosthesis Implantation ,Biomaterials ,Mice ,03 medical and health sciences ,medicine ,Animals ,Behavior, Animal ,Near-infrared spectroscopy ,Temperature ,Brain ,Prostheses and Implants ,021001 nanoscience & nanotechnology ,Electric Stimulation ,Photon upconversion ,030104 developmental biology ,Transducer ,Visual cortex ,medicine.anatomical_structure ,Mechanics of Materials ,Modulation ,Neural stimulation ,Ceramics and Composites ,0210 nano-technology ,Biomedical engineering - Abstract
Many nanomaterials can be used as sensors or transducers in biomedical research and they form the essential components of transformative novel biotechnologies. In this study, we present an all-optical method for tetherless remote control of neural activity using fully implantable micro-devices based on upconversion technology. Upconversion nanoparticles (UCNPs) were used as transducers to convert near-infrared (NIR) energy to visible light in order to stimulate neurons expressing different opsin proteins. In our setup, UCNPs were packaged in a glass micro-optrode to form an implantable device with superb long-term biocompatibility. We showed that remotely applied NIR illumination is able to reliably trigger spiking activity in rat brains. In combination with a robotic laser projection system, the upconversion-based tetherless neural stimulation technique was implemented to modulate brain activity in various regions, including the striatum, ventral tegmental area, and visual cortex. Using this system, we were able to achieve behavioral conditioning in freely moving animals. Notably, our microscale device was at least one order of magnitude smaller in size (∼100 μm in diameter) and two orders of magnitude lighter in weight (less than 1 mg) than existing wireless optogenetic devices based on light-emitting diodes. This feature allows simultaneous implantation of multiple UCNP-optrodes to achieve modulation of brain function to control complex animal behavior. We believe that this technology not only represents a novel practical application of upconversion nanomaterials, but also opens up new possibilities for remote control of neural activity in the brains of behaving animals.
- Published
- 2017
19. Full-range behavior of FRP-to-concrete bonded joints subjected to combined effects of loading and temperature variation
- Author
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Jian-Guo Dai, De Xin Duan, Jian Yang, Dong Ge Jia, and Wan-Yang Gao
- Subjects
Bond length ,Substrate (building) ,Materials science ,Mechanics of Materials ,Mechanical Engineering ,Service life ,General Materials Science ,Adhesive ,Composite material ,Fibre-reinforced plastic ,Deformation (engineering) ,Material properties ,Joint (geology) - Abstract
Concrete structures strengthened with externally bonded fiber-reinforced polymer (FRP) composites are likely to experience significant temperature variations (i.e., thermal loadings) due to daily and seasonal temperature changes or possible fire exposure during service life. Such thermal loadings may lead to changes in the mechanical properties of components (including FRP, bonding adhesive and concrete substrate) and induce interfacial thermal stress due to the thermal incompatibility between FRP and concrete. A limited bond length is usually adopted to investigate the bond behavior (e.g., the local bond-slip characteristics) of the FRP-to-concrete interface under temperature variations. This paper presents an analytical study for the first time to predict the full-range deformation behavior of a mechanically loaded FRP-to-concrete bonded joint with a limited bond length under temperature variations. The solution is in a closed-form manner and has enabled isolation of the interfacial thermal stress effect from the temperature-induced changes of material properties, thereby leading to an accurate calibration of the bond-slip characteristics and the interfacial fracture energy. The closed-form analytical solution has been verified by comparing the analytical predictions with the existing experimental and numerical results in the literature. To further understand the mechanism of the FRP-to-concrete interface under combined thermal and mechanical loadings, the effects of thermal stress and bond length on the interfacial responses and the full-range deformation behavior of the FRP-to-concrete interface are comprehensibly analyzed.
- Published
- 2021
20. 125 COMBINATION OF IMMUNE, STROMAL AND EPITHELIAL-MESENCHYMAL TRANSITION RELATED GENES TO PREDICT THE PROGNOSIS OF STAGE II-III COLORECTAL CANCER
- Author
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Min-Yi Lv, Wei Wang, Feng Gao, Wei-Bin Kou, Min-Er Zhong, Ze-Ping Huang, Du Cai, Dejun Fan, Xiaojian Wu, Chuling Hu, Cheng-Hang Li, Xin Duan, and Qiqi Zhu
- Subjects
Immune system ,Stromal cell ,Hepatology ,Colorectal cancer ,business.industry ,Gastroenterology ,medicine ,Cancer research ,Epithelial–mesenchymal transition ,Stage ii ,medicine.disease ,business ,Gene - Published
- 2021
21. Diverse Central Projection Patterns of Retinal Ganglion Cells
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Mariah Evarts, Yang Li, Karla E. Hirokawa, Julie A. Harris, Quanxin Wang, Lydia Ng, Joshua R. Sanes, Xin Duan, Benjamin Ouellette, Seung Wook Oh, Joshua J. Royall, Michelle Stoecklin, Hongkui Zeng, Emily M. Martersteck, and Amy Bernard
- Subjects
0301 basic medicine ,Retinal Ganglion Cells ,Central projection ,Superior Colliculi ,genetic structures ,Transgene ,Cre recombinase ,Mice, Transgenic ,retinal ganglion cell types ,Biology ,Retinal ganglion ,General Biochemistry, Genetics and Molecular Biology ,Retina ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Geniculate ,Animals ,Visual Pathways ,Projection (set theory) ,lcsh:QH301-705.5 ,Integrases ,Superior colliculus ,axon projections ,Retinal ,Anatomy ,connectivity mapping ,eye diseases ,030104 developmental biology ,chemistry ,Cre driver ,lcsh:Biology (General) ,sense organs ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Understanding how >30 types of retinal ganglion cells (RGCs) in the mouse retina each contribute to visual processing in the brain will require more tools that label and manipulate specific RGCs. We screened and analyzed retinal expression of Cre recombinase using 88 transgenic driver lines. In many lines, Cre was expressed in multiple RGC types and retinal cell classes, but several exhibited more selective expression. We comprehensively mapped central projections from RGCs labeled in 26 Cre lines using viral tracers, high-throughput imaging, and a data processing pipeline. We identified over 50 retinorecipient regions and present a quantitative retina-to-brain connectivity map, enabling comparisons of target-specificity across lines. Projections to two major central targets were notably correlated: RGCs projecting to the outer shell or core regions of the lateral geniculate projected to superficial or deep layers within the superior colliculus, respectively. Retinal images and projection data are available online at http://connectivity.brain-map.org.
- Published
- 2017
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22. Defect-related photoluminescence of gallium nitride/silicon nanoporous pillar array modulated by ammonia gas flow rate
- Author
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Bing-Xin Duan, Zhi-Hua Wang, and Xinjian Li
- Subjects
010302 applied physics ,Materials science ,Photoluminescence ,Silicon ,business.industry ,Nanoporous ,Mechanical Engineering ,chemistry.chemical_element ,Gallium nitride ,02 engineering and technology ,Chemical vapor deposition ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Vacancy defect ,0103 physical sciences ,Optoelectronics ,General Materials Science ,Gallium ,0210 nano-technology ,Luminescence ,business - Abstract
The structural and physical properties of silicon nanoporous pillar array (Si-NPA) make it an ideal template for preparing Si-based gallium nitride (GaN) optoelectronic devices with promising performances. For satisfying the spectral requirements in different devices, the control of the luminescence is of key importance. Here we report that utilizing Si-NPA as substrates, high-purity metal gallium as gallium source and ammonia gas as nitrogen source, GaN nanostructures were grown on Si-NPA by a chemical vapor deposition method. It was demonstrated that the photoluminescence (PL) properties of GaN/Si-NPA can be tuned effectively by changing the ammonia flow rate used during the growing process. Through analyzing the evolution of the PL spectra of GaN/Si-NPA with ammonia flow rate, the origins of the observed ultraviolet and visible PL were attributed to the near band edge emission and the emissions from Ga vacancy and N interstitial point defects, respectively. Therefore the variation of the PL spectra of GaN/Si-NPA with ammonia flow rate is actually a reflection of the change of the types and concentrations of point defects. The results might provide an efficient path for preparing Si-based GaN with controlled properties.
- Published
- 2021
23. Fe3O4/carbonized cellulose micro-nano hybrid for high-performance microwave absorber
- Author
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Nian Chen, Yuan Yuan, Weihong Zhou, Juncai Song, Xin Duan, and Chuan Jiang
- Subjects
chemistry.chemical_classification ,Materials science ,Fabrication ,Polymers and Plastics ,Annealing (metallurgy) ,Organic Chemistry ,Reflection loss ,02 engineering and technology ,Dielectric ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Graphite ,Composite material ,Cellulose ,0210 nano-technology ,Microwave - Abstract
A novel microwave absorber of Fe3O4/carbonized cellulose micro-nano hybrid with self-assembly porous structure has been fabricated through a facile process of loading of hydrolyzed Fe3+ polymers, freeze drying and annealing. Annealing temperature has effect on the microstructural defects and growth of Fe3O4 and graphite nanocrystals, and further affects the dielectric properties of Fe3O4/carbonized cellulose micro-nano hybrid. The Fe3O4/carbonized cellulose micro-nano hybrid annealed at 700 ℃ (FC-700) presents the most excellent microwave absorption properties. The effective adsorption bandwidth of FC-700 reaches up to 6.72 GHz with the thickness of 2.3 mm. The minimum reflection loss of FC-700 reaches -42.25 dB in frequency of 12.27 GHz. The delta-function method proves the Fe3O4/carbonized cellulose micro-nano hybrid has good impedance match with the free space. Cole-Cole plots validate the polarization relaxation. The novel carbon- based micro-nano hybrid with excellent performance, easy fabrication, and low cost has good prospects for microwave absorption application.
- Published
- 2020
24. Polyphenols from the flower of Hibiscus syriacus Linn ameliorate neuroinflammation in LPS-treated SH-SY5Y cell
- Author
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Shi-Jie Zhang, Xin-Yi Lu, Li-Xin Duan, Rong-Rong Zhang, Guo-Yong Huang, Rui-Dan Hu, and Xiao-Ying Ding
- Subjects
Lipopolysaccharides ,0301 basic medicine ,LPS ,SH-SY5Y ,Cell ,Anti-Inflammatory Agents ,Flowers ,RM1-950 ,Pharmacology ,Neuroprotection ,Antioxidants ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Neuritis ,Neuroinflammation ,Neurotrophic factors ,Cell Line, Tumor ,medicine ,Humans ,Hibiscus syriacus ,Nerve Growth Factors ,RNA, Messenger ,Natural product ,biology ,Plant Extracts ,Fatty Acids ,Polyphenols ,General Medicine ,biology.organism_classification ,Oxidative Stress ,Neuroprotective Agents ,030104 developmental biology ,medicine.anatomical_structure ,Hibiscus ,chemistry ,Polyphenol ,030220 oncology & carcinogenesis ,Cytokines ,Therapeutics. Pharmacology - Abstract
The flower of Hibiscus syriacus Linn is a well-known traditional Chinese medicine (TCM) and health food in China, which has been used to treat dysentery, vaginal discharge, and hemorrhoids. In this study, five polyphenols (compounds 1–5) and five fatty acids (compounds 6–10) were isolated from the ethanol extract of the flower of H. syriacus. The isolated compounds were characterized by spectroscopic techniques. Polyphenols, an important type of natural product, have variety of biological activities. Here, we employed LPS or H2O2-treated SH-SY5Y cell models to test the neuroprotective effect of compounds 1–10. Results found compounds 1–5 (concentration range was around 20 μM on LPS model, concentration range was around 13 μM on H2O2 model), not compounds 6–10, exhibited neuroprotective effect in LPS or H2O2-treated SH-SY5Y cell. PCR analysis showed that compounds 1–5 can effectively improve the mRNA expression of synapse-related gene and neurotrophic factors (Syp, NGF and BDNF) in LPS-treated SH-SY5Y cell. In addition, compounds 1–5 decreased the levels of ROS and MDA and increased the activities of SOD, GSH-Px and CAT in LPS-treated SH-SY5Y cell. Furthermore, compounds 1–5 inhibited neuroinflammation (TNF-α, IL-1β and IL-6) in LPS-treated SH-SY5Y cell. In conclusion, the polyphenols in the flower of H. syriacus could be a promising candidate for preventive effect of neuroinflammation.
- Published
- 2020
25. Induction of tetraploids in ‘Red Flash’ caladium using colchicine and oryzalin: Morphological, cytological, photosynthetic and chilling tolerance analysis
- Author
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Jin-Jin Chen, Yuan-Shan Zhang, Yun-Mei Cao, Jia-Xin Duan, and Xiao-Dong Cai
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0106 biological sciences ,0301 basic medicine ,Stomatal conductance ,Caladium ,fungi ,food and beverages ,Horticulture ,Biology ,Oryzalin ,biology.organism_classification ,01 natural sciences ,Petiole (botany) ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Polyploid ,chemistry ,Cultivar ,Ploidy ,010606 plant biology & botany ,Transpiration - Abstract
In vitro pre-cultured leaf segments of ‘Red Flash’ Caladium (Caladium × hortulanum Birdsey) were treated with 0.1%, 0.2% and 0.3% (w/v) colchicine, or 0.001%, 0.002% and 0.003% (w/v) oryzalin for 2, 4 and 6 days, respectively, with the aim to develop an efficient polyploid induction protocol for caladium, and to identify promising caladium variants for cultivar development and chilling tolerance breeding. A total of 206 out of 723 plants were found to exhibit stable and remarkable morphological changes, and were grouped into 10 variant types based on differences in leaf shape, color, and/or coloration. As many as 93 plants were identified preliminary as tetraploids by flow cytometry, and the most efficient way for chromosome doubling seemed to be exposed to 0.002% oryzalin for 6 days. Chromosome counting were performed to further determine the ploidy level of the variants as extensive variation of mean fluorescence intensity (MFI) were recorded among them, and results showed that chromosome gains or losses occurred frequently in the established variants. As compared to the wild type, tetraploidization resulted in plants with rounder and thicker leaves, larger petiole diameter, higher plant height, lower leaf number per plant, and lower stomatal density, and significantly increased the net photosynthesis rate, transpiration rate, and stomatal conductance. Furthermore, enhanced chilling tolerance were observed in the tetraploids (T1), as evidenced by their higher superoxide dismutase (SOD) activity, peroxidase (POD) activity and proline (Pro) content, and a lower relative electrical conductivity (REC) and malondialdehyde (MDA) content in the leaves compared with those of the diploid counterparts and the diploid aneuploids (SVT1) during chilling stress. The variants associated with valuable phenotypic traits including the tetraploids, diploid variants, diploid aneuploids, and tetraploid aneuploids hold considerable potential for cultivar development, genetic study and chromosome engineering in caladium.
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- 2020
26. The protective effect of the earthworm active ingredients on hepatocellular injury induced by endoplasmic reticulum stress
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Leng-xin Duan, Qi Wang, Shou-min Xi, Jian-gang Wang, and Zheng-shun Xu
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0301 basic medicine ,Eukaryotic Initiation Factor-2 ,Down-Regulation ,Apoptosis ,Pharmacology ,Biology ,Protective Agents ,Models, Biological ,Cell Line ,Eukaryotic translation initiation factor 2A ,eIF-2 Kinase ,03 medical and health sciences ,0302 clinical medicine ,Enhancer binding ,medicine ,Animals ,Humans ,RNA, Messenger ,Oligochaeta ,Protein kinase A ,education ,Cell Proliferation ,Transcription Factor CHOP ,education.field_of_study ,EIF-2 kinase ,Tunicamycin ,Endoplasmic reticulum ,ATF4 ,General Medicine ,Endoplasmic Reticulum Stress ,Activating Transcription Factor 4 ,Up-Regulation ,030104 developmental biology ,medicine.anatomical_structure ,Liver ,030220 oncology & carcinogenesis ,Hepatocyte ,Immunology ,biology.protein - Abstract
The earthworm is a widely used Chinese herbal medicine. There are more than 40 prescriptions including earthworms in the "Compendium of Materia Medica". TCM theory holds that earthworms exert antispasmodic and antipyretic effects through the liver meridian to calm the liver. However, the clinical effect of earthworms on liver injury has not been clearly demonstrated. We have previously established a method to extract the active ingredients from earthworms (hereinafter referred to as EWAs) [1]. In the present study, we observed protective effect of the EWAs on tunicamycin-induced ERS (endoplasmic reticulum stress) model in human hepatic L02 cells. The results showed that the EWAs promote proliferation and reduced apoptosis of ERS model in L02 cells (P
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- 2016
27. Theoretical investigation of structure diversity and electronic properties in the series isomeric [26]hexaphyrin (1.1.1.1.1.1) and [28]hexaphyrin (1.1.1.1.1.1)
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Gang Sun, Xiang-Shuai Liu, Xi-Xin Duan, E. Lei, Chun-Guang Liu, and Chun-Hui Yu
- Subjects
010405 organic chemistry ,Chemistry ,Hyperpolarizability ,Aromaticity ,Time-dependent density functional theory ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Computational chemistry ,Molecule ,Density functional theory ,Molecular orbital ,Physical and Theoretical Chemistry ,HOMO/LUMO ,Antiaromaticity - Abstract
In this work, [26]hexaphyrin (1.1.1.1.1.1) and corresponding [28]hexaphyrin (1.1.1.1.1.1) with different structures have been investigated using density functional theory (DFT) and time-dependent DFT. The frontier molecular orbitals (FMOs), aromaticity, electronic spectra and nonlinear optical properties were systematically investigated. Significantly, thienyls groups on the meso -carbon have great influence on the electronic properties. Based on an analysis of orbital composition, contribution of the thienyls to FMOs concentrates primarily on HOMO and third highest occupied molecular orbital (HOMO−2) to aromatic molecules, and focuses on second highest occupied molecular orbital (HOMO−1) to antiaromatic molecules. In addition, the first hyperpolarizability ( β 0 ) values of dumbbell-shape and rectangular-shape molecules are significantly lower than those of the other three molecules. For the other three molecules with both aromatic molecules and antiaromatic molecules, their β 0 values have the same regularities that are in the orders of triangular-shape β 0 value of antiaromatic molecules is greater than that of aromatic molecules because of their different transition properties. We hope that this work will provide valuable information for adjusting electro-optical properties by changing substituent group on the meso -carbon, aromaticity and configuration.
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- 2016
28. Isotopic effect on the dynamics of the H/D + LiH/LiD reactions
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Pei-Yu Zhang, Zhi-Xin Duan, and Xiaohu He
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010304 chemical physics ,Chemistry ,Wave packet ,Rotational–vibrational spectroscopy ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Cross section (physics) ,Reaction rate constant ,Excited state ,0103 physical sciences ,Potential energy surface ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state ,Quantum - Abstract
The H/D + LiH/LiD (v = 0, j = 0) → H2/HD/D2 + Li reactions are studied using the time-dependent wave packet (TDWP) and quasi-classical trajectory (QCT) methods on a ground state potential energy surface (PES). Integral cross sections and rate constants are calculated. The present quantum and classical integral cross sections are in good agreement with each other. The total integral cross sections and rate constants are found to be in reasonable agreement with the available literature results. We compare the dynamics among different isotopic variants of the reactions: the integral cross section of the D + LiH reaction is largest among the four reactions, and the rate constant of the H + LiH reaction is the largest one. We also analyze the state-to-state rate constants in detail, and find that not only the products are preferentially formed in their excited rovibrational states, but also the favored final state varies with temperature. Besides, the favored final states of the title reactions are different with each other because of the isotopic effect.
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- 2016
29. MicroR-760 suppresses cancer stem cell subpopulation and breast cancer cell proliferation and metastasis: By down-regulating NANOG
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Guangcheng Guo, Fang Wang, Yuanting Gu, Mingzhi Zhu, Xin Ge, Lin Li, Mingli Han, Yimeng Wang, Xinhong Pei, and Xin Duan
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0301 basic medicine ,Homeobox protein NANOG ,Rex1 ,Down-Regulation ,Breast Neoplasms ,Metastasis ,03 medical and health sciences ,Antigens, CD ,Cell Movement ,Cancer stem cell ,medicine ,Humans ,Gene Silencing ,Neoplasm Metastasis ,skin and connective tissue diseases ,Cell Proliferation ,Pharmacology ,biology ,Cell growth ,CD44 ,Nanog Homeobox Protein ,General Medicine ,medicine.disease ,Molecular biology ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030104 developmental biology ,MCF-7 ,Gene Knockdown Techniques ,MCF-7 Cells ,Neoplastic Stem Cells ,biology.protein ,Cancer research ,Female - Abstract
Background and objective Emerging evidences suggest that cancer stem cells are responsible for tumor aggressive, metastasis and therapeutic resistance. To data, the mechanism underlying breast cancer stem cell (BCSC) population within tumor metastasis remains to be fully elucidated. The current study was to investigate the potential role of microRNA-760 (miR-760) and its associated target gene in population and metastasis of BCSC. Methods Characteristic BCSCs surface markers (CD44+/CD24−/low) were determined by flow cytometry in breast cancer MCF-7 and BT-549 cells. Quantitative RT-PCR was used to evaluate miR-760 and NANOG mRNA expression. Expression of NANOG protein was determined using western blot. Cell proliferation was determined by MTT assay. The model of breast cancer cell xenograft was used to evaluate the effect of miR-760 on tumor growth. Results BT-549 cell has substantially more CD44+/CD24−/low subpopulation than MCF-7 cell. Moreover, BT-549 cell expressed lower level of miR-760 and higher level of NANOG than MCF-7cell. By result from cellular miR-760 modulation, we found that miR-760 overexpression suppressed CD44+/CD24−/low population as well as inhibited cell proliferation and migration of BT-549. On the contrary, knockdown of miR-760 promoted CD44+/CD24−/low population and migration of MCF-7 cells. By luciferase reporter assay, miR-760 was proved to be functional associated with NANOG via regulating its expression. This functional interaction was showed to be involved in controlling proliferation and migration of MCF-7 and BT-549 cell. Conclusion These data suggest that the target of miR-760/NANOG axis may represent a new therapeutic approach to suppress breast cancer stem cell subpopulation thereby prevent cancer metastasis.
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- 2016
30. 414P Identification of a stemness-related gene signature for predicting prognosis of patients with adjuvant chemotherapy in colorectal cancer
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Cheng-Hang Li, Xin Duan, Du Cai, Y. Chen, Jia Ke, X. Wu, Zhaoliang Yu, and Feng Gao
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Oncology ,medicine.medical_specialty ,Colorectal cancer ,business.industry ,Adjuvant chemotherapy ,Internal medicine ,medicine ,Identification (biology) ,Hematology ,Related gene ,medicine.disease ,business - Published
- 2020
31. Knowledge map of environmental crisis management based on keywords network and co-word analysis, 2005–2018
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Xin Duan, Shengli Dai, and Wei Zhang
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Management theory ,Renewable Energy, Sustainability and the Environment ,Spatial structure ,020209 energy ,Strategy and Management ,Corporate governance ,05 social sciences ,Climate change ,02 engineering and technology ,Building and Construction ,Industrial and Manufacturing Engineering ,Environmental crisis ,Harm ,050501 criminology ,0202 electrical engineering, electronic engineering, information engineering ,Management research ,Business ,Environmental planning ,Human society ,0505 law ,General Environmental Science - Abstract
Currently, the whole world is facing various environmental crises, which have caused serious harm to human society. Environmental crisis management is extremely important in tackling environmental crises. A large number of scholars have conducted extensive research on environmental crisis management, but the knowledge map about the environmental crisis management research is unknown. Therefore, analyzing the spatial structure of environmental crisis management not only helps to understand the specific distribution of the research paradigm of environmental crisis management but is also helpful in understanding the important topics. Based on the Web of Science (WOS) database. The software of NoteExpress, Bibexcel, and Ucinet and the analysis methods of social network (SN), K-core, co-word analysis, and multi-dimensional scaling (MDS) were employed to explore the spatial structure of keywords in environmental crisis management literature. The study revealed that climate change is the hotspot of environmental crisis management. Moreover, the five main research topics on environmental crisis management have been identified, which are, respectively, different types of environmental crisis, the impact areas of the environmental crisis, the governance of environmental crisis, the application of technology in environmental crisis management, the characteristics of environmental crisis, and micro-governance. The spatial structure in the research field of environmental crisis management can be divided into application of environmental crisis management technology, management practice of environmental crisis, specific types of environmental crisis, and management theory of environmental crisis management. Finally, this study puts forward four research topics which should be attached importantly in the future.
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- 2020
32. Roscovitine enhances All-trans retinoic acid (ATRA)-induced leukemia cell differentiation: Novel effects on signaling molecules for a putative Cdk2 inhibitor
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Mengsu Yang, Feng Gao, Asif Rashid, Andrew Yen, and Xin Duan
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0301 basic medicine ,Cell signaling ,MAP Kinase Signaling System ,Cellular differentiation ,Retinoic acid ,Down-Regulation ,HL-60 Cells ,Tretinoin ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Differentiation therapy ,Cyclin-dependent kinase ,LYN ,Proto-Oncogene Proteins ,hemic and lymphatic diseases ,Roscovitine ,Humans ,Myeloid Cells ,Proto-Oncogene Proteins c-cbl ,Phosphorylation ,Proto-Oncogene Proteins c-vav ,Protein Kinase Inhibitors ,neoplasms ,Cell Proliferation ,Respiratory Burst ,Mitogen-Activated Protein Kinase Kinases ,Principal Component Analysis ,biology ,Kinase ,organic chemicals ,NADPH Oxidases ,Myeloid leukemia ,Cell Differentiation ,Cell Cycle Checkpoints ,Cell Biology ,biological factors ,Up-Regulation ,Cell biology ,Proto-Oncogene Proteins c-raf ,Leukemia, Myeloid, Acute ,src-Family Kinases ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,biology.protein ,Signal Transduction - Abstract
All-trans retinoic acid (ATRA)-based differentiation therapy has been unsuccessful in treating t(15;17) negative acute myeloid leukemia (AML) patients, motivating interest in combination therapies using ATRA plus other agents. Using the t (15, 17) negative HL-60 human myeloblastic leukemia model, we find that the cyclin-dependent kinase (CDK) inhibitor, roscovitine, augments signaling by an ATRA-induced macromolecular signalsome that propels differentiation and enhances ATRA-induced differentiation. Roscovitine co-treatment enhanced ATRA-induced expression of pS259- pS289/296/301- pS621-c-Raf, pS217/221-Mek, Src Family Kinases (SFKs) Lyn and Fgr and SFK Y416 phosphorylation, adaptor proteins c-Cbl and SLP-76, Vav, and acetylated 14-3-3 in the signalsome. Roscovitine enhanced ATRA-induced c-Raf interaction with Lyn, Vav, and c-Cbl. Consistent with signalsome hyper-activation, roscovitine co-treatment enhanced ATRA-induced G1/0 arrest and expression of differentiation markers, CD11b, ROS and p47 Phox. Because roscovitine regulated Lyn expression, activation and partnering, a stably transfected Lyn knockdown was generated from wt-parental cells to investigate its function in ATRA-induced differentiation. Lyn-knockdown enhanced ATRA-induced up-regulation of key signalsome molecules, c-Raf, pS259-c-Raf, pS289/296/301-c-Raf, Vav1, SLP-76, and Fgr, but with essentially total loss of pY416-SFK. Compared to ATRA-treated wt-parental cells, differentiation markers p47 phox, CD11b, G1/G0 arrest and ROS production were enhanced in ATRA-treated Lyn-knockdown stable transfectants, and addition of roscovitine further enhanced these ATRA-inducible markers. The Lyn-knockdown cells expressed slightly higher c-Raf, pS259-c-Raf, pS289/296/301-c-Raf, and SLP-76 than wt-parental cells, and this was associated with enhanced ATRA-induced upregulation of Fgr and cell differentiation, consistent with heightened signaling, suggesting that enhanced Fgr may have compensated for loss of Lyn to enhance differentiation in the Lyn-knockdown cells.
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- 2020
33. The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review
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Xin Duan, Zhou Xiang, Zhao Xu, Xixun Yu, X. Dong, and Hao Wang
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Morton's neuroma ,Sensitivity and Specificity ,Likelihood ratios in diagnostic testing ,Foot Diseases ,Neuroma ,Young Adult ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Statistical analysis ,Aged ,Ultrasonography ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Ultrasound ,Reproducibility of Results ,Magnetic resonance imaging ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Meta-analysis ,Female ,Radiology ,business - Abstract
Aim To determine the accuracy of MRI versus ultrasound for Morton's neuroma. Materials and methods A search was undertaken for clinical studies published in any language in PubMed up to the date of December 2013. Studies assessing the accuracy of the ultrasound or MRI for the diagnosis of Morton's neuroma were included. Data were pooled for meta-analysis. Study selection, data collection, and extraction were performed independently by two authors. Meta-disc 1.4 and Revman 5.2 software were applied for statistical analysis. Results The study included 12 studies; 217 patients underwent MRI and 241 underwent ultrasound examinations. There appeared greater diagnostic accuracy for ultrasound than MRI for the diagnosis of Morton's neuroma (ultrasound sensitivity 90%, specificity 88%, positive likelihood ratio 2.77, negative likelihood ratio 0.16 versus MRI sensitivity 93%, specificity 68%, positive likelihood ratio 1.89, negative likelihood ratio 0.19). Conclusions The available evidence suggests that ultrasound can provide better accuracy for the diagnosis of Morton's neuroma than MRI.
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- 2015
34. Metallogenic events and tectonic setting of the Duobaoshan ore field in Heilongjiang Province, NE China
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Qun Yang, Chao Li, Yujie Hao, Kuang-Yin Tong, Cong Chen, Yun-Sheng Ren, and Ming-Xin Duan
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Isochron ,Porphyritic ,Petrography ,Geochronology ,Ordovician ,Geochemistry ,Geology ,Radiometric dating ,Skarn ,Petrology ,Earth-Surface Processes ,Zircon - Abstract
The Duobaoshan ore field, a major center of metal production in Northeast China, is located in the northeast of the Xing’an–Mongolia Orogenic Belt (the eastern part of the Central Asian Orogenic Belt) and within the northern Greater Xing’an Mountains. Several types of ore deposits are mined in the Duobaoshan region, including the Duobaoshan and Tongshan porphyry copper–molybdenum deposits, the Sankuanggou skarn iron–copper deposit, and the Zhengguang epithermal gold deposit. Zircon grains from the Tongshan granodiorite and porphyritic granite yield laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) U–Pb weighted mean ages of 475.9 ± 0.8 Ma and 230.9 ± 0.9 Ma to 240.7 ± 0.8 Ma, respectively. The Re–Os isochron age of molybdenites from the Tongshan deposit is 473 ± 4 Ma. Because both field observations and petrographic analysis identified disseminated chalcopyrite, pyrite, and malachite in the porphyritic granite, the isotope dating indicates that the Tongshan deposit underwent at least two magmatic–mineralization events, during the Ordovician and the Triassic. Zircon grains from the metallogenic granodiorite of the Sankuanggou skarn deposit yield an age of 176.1 ± 0.3 Ma, and Re–Os dating of molybdenite gives an age of 173 ± 6 Ma, indicating a Jurassic event. Based on previous research and the new geochemical analysis presented in this study, it is inferred that the magmatism and mineralization of the Sankuanggou deposit were associated with the subduction of the Paleo-Pacific Plate. The Duobaoshan region has therefore experienced at least three major magmatic and mineralization events, during the Ordovician (470–480 Ma), the Triassic (230–240 Ma), and the Early Jurassic (170–180 Ma).
- Published
- 2015
35. Rational Design of Small Molecule Inhibitors Targeting the Ras GEF, SOS1
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Jaroslaw Meller, Chris R. Evelyn, Xin Duan, Jacek Biesiada, Yi Zheng, and William L. Seibel
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Models, Molecular ,Clinical Biochemistry ,Drug Evaluation, Preclinical ,Biology ,Biochemistry ,Article ,Receptor tyrosine kinase ,Small Molecule Libraries ,Mice ,Structure-Activity Relationship ,Catalytic Domain ,Cell Line, Tumor ,Anti-apoptotic Ras signalling cascade ,Drug Discovery ,Animals ,Humans ,Structure–activity relationship ,Molecular Biology ,Cell Proliferation ,Pharmacology ,Cell growth ,Rational design ,General Medicine ,Fibroblasts ,Small molecule ,Mutagenesis ,Drug Design ,biology.protein ,Cancer research ,Molecular Medicine ,Guanine nucleotide exchange factor ,SOS1 Protein ,Intracellular ,Signal Transduction - Abstract
SummaryRas GTPases regulate intracellular signaling involved in cell proliferation. Elevated Ras signaling activity has been associated with human cancers. Ras activation is catalyzed by guanine nucleotide exchange factors (GEFs), of which SOS1 is a major member that transduces receptor tyrosine kinase signaling to Ras. We have developed a rational approach coupling virtual screening with experimental screening in identifying small-molecule inhibitors targeting the catalytic site of SOS1 and SOS1-regulated Ras activity. A lead inhibitor, NSC-658497, was found to bind to SOS1, competitively suppress SOS1-Ras interaction, and dose-dependently inhibit SOS1 GEF activity. Mutagenesis and structure-activity relationship studies map the NSC-658497 site of action to the SOS1 catalytic site, and define the chemical moieties in the inhibitor essential for the activity. NSC-658497 showed dose-dependent efficacy in inhibiting Ras, downstream signaling activities, and associated cell proliferation. These studies establish a proof of principle for rational design of small-molecule inhibitors targeting Ras GEF enzymatic activity.
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- 2014
36. Type II Cadherins Guide Assembly of a Direction-Selective Retinal Circuit
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Irina De la Huerta, Arjun Krishnaswamy, Xin Duan, and Joshua R. Sanes
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Cell type ,Retinal Bipolar Cells ,genetic structures ,Biology ,Visual system ,Optogenetics ,Direction selective ,General Biochemistry, Genetics and Molecular Biology ,Retina ,chemistry.chemical_compound ,Mice ,medicine ,Animals ,Visual Pathways ,Gene Knock-In Techniques ,Electronic circuit ,Cadherin ,Biochemistry, Genetics and Molecular Biology(all) ,Retinal ,Anatomy ,Cadherins ,Axons ,medicine.anatomical_structure ,chemistry ,Synapses ,Neuroscience - Abstract
SummaryComplex retinal circuits process visual information and deliver it to the brain. Few molecular determinants of synaptic specificity in this system are known. Using genetic and optogenetic methods, we identified two types of bipolar interneurons that convey visual input from photoreceptors to a circuit that computes the direction in which objects are moving. We then sought recognition molecules that promote selective connections of these cells with previously characterized components of the circuit. We found that the type II cadherins, cdh8 and cdh9, are each expressed selectively by one of the two bipolar cell types. Using loss- and gain-of-function methods, we showed that they are critical determinants of connectivity in this circuit and that perturbation of their expression leads to distinct defects in visually evoked responses. Our results reveal cellular components of a retinal circuit and demonstrate roles of type II cadherins in synaptic choice and circuit function.
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- 2014
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37. Total shoulder arthroplasty versus hemiarthroplasty in patients with shoulder osteoarthritis: A meta-analysis of randomized controlled trials
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Xingxing Dong, Wei Zhang, Jian Li, Ming Liu, Xin Duan, Yu Gao, Zhou Xiang, and Fuguo Huang
- Subjects
Shoulder ,medicine.medical_specialty ,medicine.medical_treatment ,MEDLINE ,Osteoarthritis ,law.invention ,Rheumatology ,Randomized controlled trial ,law ,medicine ,Shoulder arthritis ,Humans ,Arthroplasty, Replacement ,Randomized Controlled Trials as Topic ,Shoulder Joint ,business.industry ,Incidence (epidemiology) ,medicine.disease ,Arthroplasty ,Clinical trial ,Treatment Outcome ,Anesthesiology and Pain Medicine ,Meta-analysis ,Physical therapy ,Hemiarthroplasty ,business - Abstract
Objectives Total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) are treatment choices for end-stage shoulder osteoarthritis. The decision of whether to use TSA or HA is controversial. The objective of this study was to compare the effects of TSA and HA for shoulder osteoarthritis. Methods We conducted a search for clinical studies that had been published in any language in December 2012 or before. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and several other databases. Randomized and quasi-randomized controlled clinical studies that evaluated different methods were included. At least two review authors independently performed the study selection, data collection, and data extraction. The software Revman 5.1 was used for the statistical analysis. Results This study included 4 clinical trials. Two of the trials were published clinical trials, and the other 2 clinical trials were presented as unpublished abstracts. A total of 146 patients with 153 shoulders were included in the trials. Compared with HA, TSA presents with a higher UCLA shoulder scale (MD 3.10, 95% CI 1.13–5.08) and a higher ASES (MD 10.17, 95% CI 1.40–18.87). There was no significant difference between TSA and HA for revision (RR 0.35, 95% CI 0.10–1.19), WOOS (MD 9.10, 95% CI −2.72 to 20.92), and incidence of instability (RR 0.88, 95% CI 0.19–3.98). HA had a lower operation time (MD 39.00, 95% CI 17.05–60.95). Conclusion The available evidence suggests that TSA is more effective than HA for patients with shoulder arthritis.
- Published
- 2013
38. Quasiclassical state-to-state dynamics of the F+HCl reaction on a ground 12A′ potential energy surface
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Zhi-Xin Duan, Cui-Xia Yao, and Ming-Hui Qiu
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Angular momentum ,Stripping (chemistry) ,Chemistry ,Excited state ,Potential energy surface ,Dynamics (mechanics) ,State (functional analysis) ,Physical and Theoretical Chemistry ,Atomic physics ,Condensed Matter Physics ,Polarization (waves) ,Biochemistry - Abstract
Quasi-classical trajectories have been evaluated to study the state-to-state dynamic for the title reaction on a recent DHTSN PES of the ground 1(2)A' electronic state [Deskevich et al., J. Chem. Phys. 124 (2006) 224303]. State resolved integral and differential cross sections (DCSs), as well as product rotational polarization, have been obtained for F + HCl (nu = 0, j = 0) -> Cl + HF(nu', j') reaction at E-col = 10.0 and 50.0 kcal/mol. Both the vibrational and the rotational distributions are found to be inverted, with the peaks locating at excited final states. At E-col = 10.0 kcal/mol, the vibrational resolved DCSs are mainly directed backward and correspond to a simple direct-rebound mechanism. However, for E-col = 50.0 kcal/mol, the HF(nu' = 0) products are preferentially backward-scattered, while the vibrationally excited HF(nu' = 1, 2, 3) are forward-scattered. These results can be interpreted by increasing of reactive collisions with high-b, which corresponds to a "stripping" dynamics. The P(theta(r)) and P(Phi(r)) distributions and the polarization parameters, a(1-)({1}), a(0)({2}) are also obtained to gain insights into the chemical stereodynamics of the title reaction. The HF rotational angular momentum has been found to be both aligned and oriented, and depends sensitively on the product rotational level. Difference in polarization behavior is discussed by means of the reactive mechanism. (C) 2013 Elsevier B.V. All rights reserved.
- Published
- 2013
39. Repair of large osteochondral defects in a beagle model with a novel type I collagen/glycosaminoglycan-porous titanium biphasic scaffold
- Author
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Jing Yang, Xin Duan, Frankie Leung, Xingxing Dong, Fuguo Huang, Xiangdong Zhu, Hongsong Fan, Zhou Xiang, and Shiqiang Cen
- Subjects
Cartilage, Articular ,Male ,Materials science ,X-ray microtomography ,Bone Marrow Cells ,Bioengineering ,Osteoarthritis ,Collagen Type I ,Biomaterials ,Glycosaminoglycan ,Dogs ,medicine ,Animals ,Cell Proliferation ,Glycosaminoglycans ,Titanium ,Wound Healing ,Staining and Labeling ,Tissue Scaffolds ,Stem Cells ,Cartilage ,Bone Marrow Stem Cell ,X-Ray Microtomography ,Anatomy ,medicine.disease ,Disease Models, Animal ,medicine.anatomical_structure ,Mechanics of Materials ,Cattle ,Stem cell ,Wound healing ,Porosity ,Type I collagen ,Biomedical engineering - Abstract
The limited repair potential of articular cartilage, which hardly heals after injury or debilitating osteoarthritis, is a clinical challenge. The aim of this work was to develop a novel type I collagen (Col)/glycosaminoglycan (GAGs)-porous titanium biphasic scaffold (CGT) and verify its ability to repair osteochondral defects in an animal model with bone marrow stem cells (bMSCs) in the chondral phase. The biphasic scaffold was composed of Col/GAGs as chondral phasic and porous titanium as subchondral phasic. Twenty-four full-thickness defects through the articular cartilage and into the subchondral bone were prepared by drilling into the surface of the femoral patellar groove. Animals were assigned to one of the three groups: 1) CGT with bMSCs (CGTM), 2) only CGT, and 3) no implantation (control). The defect areas were examined grossly, histologically and by micro-CT. The most satisfied cartilage repairing result was in the CGTM group, while CGT alone was better than the control group. Abundant subchondral bone formation was observed in the CGTM and CGT groups but not the control group. Our findings demonstrate that a composite based on a novel biphasic scaffold combined with bMSCs shows a high potential to repair large osteochondral defects in a canine model.
- Published
- 2013
40. Ectopic bone formation cannot occur by hydroxyapatite/β-tricalcium phosphate bioceramics in green fluorescent protein chimeric mice
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Xin Duan, Lijia Cheng, Hong Bu, Yujun Shi, Feng Ye, Xiaofeng Lu, and Zhou Xiang
- Subjects
Genetically modified mouse ,Materials science ,H&E stain ,General Physics and Astronomy ,Spleen ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Molecular biology ,Surfaces, Coatings and Films ,Staining ,Green fluorescent protein ,Chimera (genetics) ,medicine.anatomical_structure ,medicine ,Immunohistochemistry ,Bone marrow - Abstract
Many studies have shown that calcium phosphate ceramics (CP) have osteoconductive and osteoinductive properties; however, the exact mechanism of bone induction has not yet been reported. This study was performed to investigate if destroying immunological function will influence osteogenesis, to explain the mechanism which is unclear. In this study, twenty C57BL/6 mice were divided into two groups ( n = 10), in group 1, a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ceramic was implanted into both the left and right leg muscles of each mouse; in group 2, ten mice experienced lethal irradiation, then were injected bone marrow (BM) cells from green fluorescent protein (GFP) transgenic mice by tail veil, after bone marrow transplantation (BMT), heart, liver, spleen, lung, kidney, and muscle were harvested for biological analysis, after the GFP chimera model was established successfully, the same HA/β-TCP ceramic was implanted into both leg muscles of each mouse immediately after irradiation. 45 and 90 days after implantation, the ceramics of the two groups were harvested to perform with hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining; the results showed that there was no bone formation in group 2, while new bone tissues were detected in group 1. Our findings suggest that the BM cell from GFP transgenic mice is a good biomarker and it could set a good platform for chimera model; it also shows that BM cell is one of cell resources of bone induction, and destruction of immune function will impede osteoinduction by CP. Overall, our results may shed light on clear mechanism study of bone induction in the future.
- Published
- 2012
41. Interplay between DISC1 and GABA Signaling Regulates Neurogenesis in Mice and Risk for Schizophrenia
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Ju Young Kim, David St Clair, Cindy Y. Liu, Xin Duan, Emer L. Feighery, Hongjun Song, Juan Song, Bai Lu, Guo Li Ming, Dan Rujescu, Fengyu Zhang, Joseph H. Callicott, Kimberly M. Christian, Daniel R. Weinberger, and Zhexing Wen
- Subjects
Sodium-Potassium-Chloride Symporters ,Neurogenesis ,Nerve Tissue Proteins ,Hippocampal formation ,General Biochemistry, Genetics and Molecular Biology ,gamma-Aminobutyric acid ,Article ,DISC1 ,Mice ,medicine ,Animals ,Solute Carrier Family 12, Member 2 ,PI3K/AKT/mTOR pathway ,gamma-Aminobutyric Acid ,biology ,Biochemistry, Genetics and Molecular Biology(all) ,Depolarization ,Anatomy ,Dendrites ,Hyperpolarization (biology) ,Mice, Inbred C57BL ,biology.protein ,Schizophrenia ,Female ,Disease Susceptibility ,Signal transduction ,Single-Cell Analysis ,Neuroscience ,medicine.drug ,Signal Transduction - Abstract
SummaryHow extrinsic stimuli and intrinsic factors interact to regulate continuous neurogenesis in the postnatal mammalian brain is unknown. Here we show that regulation of dendritic development of newborn neurons by Disrupted-in-Schizophrenia 1 (DISC1) during adult hippocampal neurogenesis requires neurotransmitter GABA-induced, NKCC1-dependent depolarization through a convergence onto the AKT-mTOR pathway. In contrast, DISC1 fails to modulate early-postnatal hippocampal neurogenesis when conversion of GABA-induced depolarization to hyperpolarization is accelerated. Extending the period of GABA-induced depolarization or maternal deprivation stress restores DISC1-dependent dendritic regulation through mTOR pathway during early-postnatal hippocampal neurogenesis. Furthermore, DISC1 and NKCC1 interact epistatically to affect risk for schizophrenia in two independent case control studies. Our study uncovers an interplay between intrinsic DISC1 and extrinsic GABA signaling, two schizophrenia susceptibility pathways, in controlling neurogenesis and suggests critical roles of developmental tempo and experience in manifesting the impact of susceptibility genes on neuronal development and risk for mental disorders.
- Published
- 2012
- Full Text
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42. Effect of amino-functionalization on the interfacial adhesion of multi-walled carbon nanotubes/epoxy nanocomposites
- Author
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Jizhe Cai, Shanyi Du, Yunfeng Luo, Yue-Xin Duan, and Yan Zhao
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Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,Epoxy ,Carbon nanotube ,Dynamic mechanical analysis ,Surface energy ,law.invention ,Chemical engineering ,law ,visual_art ,Inverse gas chromatography ,visual_art.visual_art_medium ,Surface modification ,Composite material - Abstract
Two types of multi-walled carbon nanotubes (MWCNTs) functionalized with different amino-organics, dicyanodiamide and phenylbiguanide, respectively, were achieved in this paper. The physico-chemical properties of MWCNTs before and after amino group modification were characterized by thermogravimetric analysis (TGA), Raman spectroscopy and inverse gas chromatography (IGC). The results showed that amino-functionalization changed evidently the surface properties of MWCNTs, such as the dispersive surface energy (decreased from 122.95 mJ/m 2 to 18.65 mJ/m 2 and 25.69 mJ/m 2 , respectively) and specific surface energy (decreased from 8.84 mJ/m 2 to 0.56 mJ/m 2 and 4.60 mJ/m 2 , respectively) for two functionalized MWCNTs. And then, the interfacial adhesion states of the functionalized MWCNTs/epoxy nanocomposites were investigated using scanning electron microscope (SEM) and dynamic mechanical analysis (DMA). The results also indicated that the dispersion of MWCNTs in epoxy resin and the interfacial adhesion of MWCNTs/epoxy nanocomposites were both strongly dependent on the surface physico-chemical properties of functionalized MWCNTs, and the effect of MWCNTs functionalized by phenylbiguanide with slightly higher polarity was better.
- Published
- 2012
43. Interaction between FEZ1 and DISC1 in Regulation of Neuronal Development and Risk for Schizophrenia
- Author
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Ju Young Kim, Xin Duan, Junjie U. Guo, Anil K. Malhotra, Bai Lu, Guo Li Ming, Sungkyung Choi, Kimberly M. Christian, Katherine E. Burdick, Dimitrios Avramopoulos, Kurt A. Sailor, Eunchai Kang, Dhong Eun Jung, Dennis A. Pradhan, Hongjun Song, and Sundar Ganesan
- Subjects
Scaffold protein ,biology ,NDEL1 ,Neuroscience(all) ,General Neuroscience ,Neurogenesis ,Morphogenesis ,Hippocampus ,medicine.disease ,DISC1 ,Schizophrenia ,biology.protein ,medicine ,Neuroscience ,FEZ1 - Abstract
SummaryDisrupted-in Schizophrenia 1 (DISC1), a susceptibility gene for major mental disorders, encodes a scaffold protein that has a multifaceted impact on neuronal development. How DISC1 regulates different aspects of neuronal development is not well understood. Here, we show that Fasciculation and Elongation Protein Zeta-1 (FEZ1) interacts with DISC1 to synergistically regulate dendritic growth of newborn neurons in the adult mouse hippocampus, and that this pathway complements a parallel DISC1-NDEL1 interaction that regulates cell positioning and morphogenesis of newborn neurons. Furthermore, genetic association analysis of two independent cohorts of schizophrenia patients and healthy controls reveals an epistatic interaction between FEZ1 and DISC1, but not between FEZ1 and NDEL1, for risk of schizophrenia. Our findings support a model in which DISC1 regulates distinct aspects of neuronal development through its interaction with different intracellular partners and such epistasis may contribute to increased risk for schizophrenia.
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- 2011
44. Cell type and gender-dependent differential regulation of the p202 and Aim2 proteins: Implications for the regulation of innate immune responses in SLE
- Author
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Hongzhu Liu, Xin Duan, Ravichandran Panchanathan, Muthuvel Arumugam, Divaker Choubey, and Hui Shen
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Male ,Inflammasomes ,T-Lymphocytes ,Immunoblotting ,Immunology ,Biology ,Real-Time Polymerase Chain Reaction ,Article ,Mice ,AIM2 ,medicine ,Animals ,Lupus Erythematosus, Systemic ,Nuclear protein ,Molecular Biology ,Ifi202 ,Regulation of gene expression ,B-Lymphocytes ,Innate immune system ,Macrophages ,Intracellular Signaling Peptides and Proteins ,Nuclear Proteins ,Inflammasome ,Molecular biology ,Immunity, Innate ,Cell biology ,DNA-Binding Proteins ,Mice, Inbred C57BL ,Gene Expression Regulation ,TLR3 ,Female ,Signal transduction ,medicine.drug - Abstract
Upon sensing cytosolic double-stranded DNA (dsDNA), the murine Aim2 (encoded by the Aim2 gene) protein forms an inflammasome and promotes the secretion of proinflammatory cytokines, such as IL-1β and IL-18. In contrast, the p202 protein (encoded by the Ifi202 gene) does not form an inflammasome. Previously, we have reported that the interferon (IFN) and female sex hormone-induced increased nuclear levels of p202 protein in immune cells are associated with increased susceptibility to develop a lupus-like disease. However, signaling pathways that regulate the expression of Aim2 protein remain unknown. Here we report that the expression of Aim2 gene is induced in bone marrow-derived macrophages (BMDMs) by IFN-α treatment and the expression is, in part, STAT1-dependent. However, treatment of splenic T or B cells with IFN-α or their stimulation, which induced the expression of Ifi202 gene, did not induce the expression of Aim2 gene. Furthermore, treatment of cells with the male hormone androgen increased levels of Aim2 mRNA and protein. Moreover, treatment of murine macrophage cell lines (RAW264.7 and J774A.1) with IFN-α differentially induced the expression of Aim2 and p202 proteins and regulated their sub-cellular localization. Additionally, activation of Toll-like receptors (TLR3, 4, and 9) in BMDMs and cell lines also differentially regulated the expression of Aim2 and Ifi202 genes. Our observations demonstrate that cell type and gender-dependent factors differentially regulate the expression of the Aim2 and p202 proteins, thus, suggesting opposing roles for these two proteins in innate immune responses in lupus disease.
- Published
- 2011
45. Effects of heat treatment on magnetic properties of Co–Fe-plated hollow ceramic microspheres
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Yan Zhao, Xiang Li, Lei Zhu, and Yue-xin Duan
- Subjects
Diffraction ,Materials science ,heat treatment ,Magnetometer ,Annealing (metallurgy) ,Scanning electron microscope ,digestive, oral, and skin physiology ,engineering.material ,equipment and supplies ,law.invention ,Crystallinity ,hollow ceramic microspheres ,Coating ,Co–Fe ,law ,visual_art ,visual_art.visual_art_medium ,engineering ,General Materials Science ,magnetic properties ,Ceramic ,Composite material ,General ,electroless plating ,Microwave - Abstract
Functional hollow ceramic microspheres plated with Co–Fe were obtained through electroless plating technique for the application of lightweight microwave absorbers. They were treated at different temperatures by vacuum annealing method. The surface-coated hollow microspheres were characterized by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The microwave electromagnetic loss and absorbing properties of hollow microspheres plated with Co–Fe were tested by network vector analysis. The magnetic properties were tested by vibrating sample magnetometer (VSM). The results show that the annealing treatment changed the crystal phase of Co from HCP to FCC, simultaneously increased the crystallinity and crystal size of Co and Fe in coating layers. Additionally, after annealing at 800 °C or 1 000 °C, the microwave absorbing properties and soft magnetic properties of hollow microspheres plated with Co–Fe were further improved.
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- 2011
46. Characterization of the specific interaction between archaeal FHA domain-containing protein and the promoter of a flagellar-like gene-cluster and its regulation by phosphorylation
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Xin Duan and Zheng-Guo He
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Regulation of gene expression ,Operon ,Biophysics ,Sulfolobus tokodaii ,Forkhead Transcription Factors ,Promoter ,Cell Biology ,Biology ,Biochemistry ,Sulfolobus ,Flagella ,Multigene Family ,Gene cluster ,Electrophoretic mobility shift assay ,Gene Expression Regulation, Archaeal ,Phosphorylation ,Kinase activity ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor - Abstract
The mechanism and target genes of regulation by Forkhead (FHA) domain-containing transcription factors have not yet been documented in Archaea. In this study, using a bacterial one-hybrid technique, we successfully screened and identified for the first time a target gene regulated by ST0829, an FHA domain-containing potential transcriptional factor in the hyperthermophilic archaeon Sulfolobus tokodaii. We show that ST0829 could specifically bind to the promoter region of ST2519p, the archaeal flagellar protein-encoding operon (including FlaG, FlaF, FlaH, FlaI, and FlaJ) by using both in vitro electrophoretic mobility shift assay and surface plasmon resonance experiments, and invivo chromatin immunoprecipitation assays. Furthermore, phosphorylation of the FHA domain-containing protein was found to negatively regulate its specific DNA-binding activity. The interaction between ST0829 and ST2519p could be inhibited by wild-type Ser/Thr protein kinase ST1565, but was not significantly affected by its mutant variant ST1565-K166A that lacks kinase activity. These findings not only increase our knowledge about the function of an archaeal FHA domain-containing regulator but also offer important insights for further understanding the signaling mechanism of environmental adaptation in archaea.
- Published
- 2011
47. Quantum dot-antisense oligonucleotide conjugates for multifunctional gene transfection, mRNA regulation, and tracking of biological processes
- Author
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Lihong Jing, Ruirui Qiao, Xin Duan, Yilin Li, Chunhui Yang, and Mingyuan Gao
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Cell Survival ,Biophysics ,Apoptosis ,Bioengineering ,Biology ,Transfection ,Polymerase Chain Reaction ,Biomaterials ,HeLa ,Quantum Dots ,Survivin ,Humans ,RNA, Messenger ,Messenger RNA ,Oligonucleotide ,technology, industry, and agriculture ,Oligonucleotides, Antisense ,equipment and supplies ,biology.organism_classification ,Biochemistry ,Mechanics of Materials ,Covalent bond ,Ceramics and Composites ,HeLa Cells ,Conjugate - Abstract
It was demonstrated that oligonucleotides, independent of their base sequence and length, could effectively induce the cellular uptake of mercapto acid-capped CdTe QDs after the oligonucleotides were covalently attached on the surface of the QDs. Following these experimental observations, a conjugate composed of covalently linked anti-survivin antisense oligonucleotides (ASON) and CdTe QDs was designed and synthesized. Then, the survivin mRNA down-regulation and the apoptosis of HeLa cells induced by ASON were studied. Systematic experimental results revealed that CdTe-ASON could effectively induce the apoptosis of HeLa cells, while CdTe QDs offered the possibility to visualize the specific intracellular localization of the CdTe-ASON probes strongly associated with their biological functions.
- Published
- 2011
48. Electroless plating of Co-Fe on the surface of MWCNTs
- Author
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Yan Zhao, Yajuan Xue, Yue-xin Duan, and Hao Zheng
- Subjects
Materials science ,Reducing agent ,Materials Science (miscellaneous) ,Metallurgy ,chemistry.chemical_element ,Metal ,chemistry ,Electroless plating ,Molar ratio ,visual_art ,Plating ,visual_art.visual_art_medium ,General Materials Science ,Chelation ,Layer (electronics) ,Palladium ,Nuclear chemistry - Abstract
Multiwalled carbon nanotubes (MWCNTs) were electroless plated with cobalt-iron (Co-Fe) Palladium- atom centers were formed on the surface of MWCNTs by a pretreatment before the plating. Three main parameters, the molar ratio of C(subscript Co 2+:C(subscript Fe 2+), the concentration of complexing agent, and the temperature of plating bath, were changed to investigate their effects, whereas the concentrations of metal salts and reducing agent and pH were kept unchanged. A layer of metal deposited neatly with a Co-Fe content above 90% was obtained when the molar ratio of C(subscript Co2+), C(subscript Fe2+) was 9:1, the concentration of complexing agent was 0.32mol/L, and the temperature of plating bath was 60℃. Metal granules were obtained, or the content of Co-Fe was much less in the other conditions investigated.
- Published
- 2010
49. Development of neural stem cell in the adult brain
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Cindy Y. Liu, Xin Duan, Guo Li Ming, Hongjun Song, and Eunchai Kang
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Telencephalon ,Subventricular zone ,Biology ,Article ,Cell Movement ,Lateral Ventricles ,medicine ,Animals ,Humans ,Cell Lineage ,Neurons ,Stem Cells ,General Neuroscience ,Dentate gyrus ,Neurogenesis ,Cell Differentiation ,Olfactory Bulb ,Neural stem cell ,Olfactory bulb ,Neuroepithelial cell ,medicine.anatomical_structure ,Neuropoiesis ,nervous system ,Dentate Gyrus ,Stem cell ,Neuroscience - Abstract
New neurons are continuously generated in the dentate gyrus of the mammalian hippocampus and in the subventricular zone of the lateral ventricles throughout life. The origin of these new neurons is believed to be from multipotent adult neural stem cells. Aided by new methodologies, significant progress has been made in the characterization of neural stem cells and their development in the adult brain. Recent studies have also begun to reveal essential extrinsic and intrinsic molecular mechanisms that govern sequential steps of adult neurogenesis in the hippocampus and subventricular zone/olfactory bulb, from proliferation and fate specification of neural progenitors, to maturation, navigation and synaptic integration of the neuronal progeny. Future identification of molecular mechanisms and physiological functions of adult neurogenesis will provide further insight into the plasticity and regenerative capacity of the mature central nervous system.
- Published
- 2008
50. Association study of obstetrical complication and depressive disorder
- Author
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Jiajun Xu, Xin Duan, and Yanchun Yang
- Subjects
Proband ,Pediatrics ,medicine.medical_specialty ,General Computer Science ,business.industry ,Obstetric complication ,General Biochemistry, Genetics and Molecular Biology ,Low birth weight ,Medicine ,Obstetrical complications ,Sibling ,Risk factor ,medicine.symptom ,business ,Complication ,Psychiatry - Abstract
Objective To investigate the correlation between obstetrical complications and depressive disorder. Methods Depressive disorder probands and their adult sibling were diagnosed using CCMD-3 criteria. Obstetrical data from maternal reports were scored, applying published scales that take into account number and severity of complication. Results The scores of obstetric complication and prenatal complications and low birth weight were significantly worse in probands than siblings without depressive disorders. Conclusion Results suggest obstetric complications are etiologically significant in depressive disorder.
- Published
- 2007
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