26 results on '"Ya-meng Li"'
Search Results
2. A learning model for improving in-service teachers’ course completion in MOOCs
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Ning Ma, Ya-Meng Li, Jia-Hui Guo, Diana Laurillard, and Min Yang
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Computer Science Applications ,Education - Published
- 2022
3. Identification of circ_0058357 as a regulator in non‐small cell lung cancer cells resistant to cisplatin by miR‐361‐3p/ABCC1 axis
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Jiang Shi, Dan Chu, Pengpeng Li, Peng-Fei Jiao, Ya-Meng Li, and Siyuan Huang
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Pulmonary and Respiratory Medicine ,Lung Neoplasms ,endocrine system diseases ,Cell Survival ,ABCC1 ,Antineoplastic Agents ,Apoptosis ,NSCLC ,Flow cytometry ,Mice ,Carcinoma, Non-Small-Cell Lung ,circ_0058357 ,Medicine ,Cytotoxic T cell ,Animals ,Humans ,MTT assay ,RC254-282 ,Cell Proliferation ,Cisplatin ,Reporter gene ,Mice, Inbred BALB C ,medicine.diagnostic_test ,business.industry ,Cell growth ,chemoresistance ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,General Medicine ,Original Articles ,RNA, Circular ,Xenograft Model Antitumor Assays ,In vitro ,miR‐361‐3p ,MicroRNAs ,Oncology ,A549 Cells ,Drug Resistance, Neoplasm ,Cancer research ,Original Article ,Female ,Multidrug Resistance-Associated Proteins ,business ,medicine.drug - Abstract
Background Drug resistance is a major clinical drawback behind the failure of chemotherapy in non‐small cell lung cancer (NSCLC). In this study, we undertook to identify the precise role of circular RNA (circRNA) circ_0058357 in the functional properties of DDP‐resistant NSCLC cells. Methods Circ_0058357, miR‐361‐3p and ATP‐binding cassette (ABC) subfamily C member 1 (ABCC1) were quantified by qRT‐PCR and western blot. Cell survival and viability were gauged by MTT assay. Cell proliferation, apoptosis, invasion and migration were measured by EdU, flow cytometry, transwell and wound‐healing assays, respectively. The direct relationship between miR‐361‐3p and circ_0058357 or ABCC1 was validated by dual‐luciferase reporter assay. Results Our data showed that circ_0058357 was highly expressed in DDP‐resistant NSCLC tissues and cells. Inhibition of circ_0058357 repressed cell growth, invasion, migration, and promoted DDP sensitivity and cell apoptosis of H1299/DDP and A549/DDP cells in vitro. Moreover, inhibition of circ_0058357 diminished the growth of A549/DDP cells and sensitized them to the cytotoxic effect of DDP in vivo. Mechanistically, circ_0058357 contained a miR‐361‐3p binding site and miR‐361‐3p was identified as a molecular mediator of circ_0058357 regulation. MiR‐361‐3p suppressed ABCC1 expression by binding to ABCC1 3′UTR, and miR‐361‐3p‐mediated inhibition of ABCC1 affected the growth, invasion, migration, apoptosis and DDP sensitivity of H1299/DDP and A549/DDP cells. Furthermore, circ_0058357 regulated ABCC1 expression by competitively binding to shared miR‐361‐3p. Conclusions Our findings identified that inhibition of circ_0058357 suppresses the growth and metastasis of H1299/DDP and A549/DDP cells and sensitizes them to DDP therapy partially by targeting the miR‐361‐3p/ABCC1 axis., Circ_0058357 affects ABCC1 expression through miR‐361‐3p. H1299/DDP (a) and A549/DDP (b) cells were transfected with si‐circ_0058357 + anti‐miR‐361‐3p, si‐circ_0058357 + anti‐miR‐NC, si‐circ_0058357 or si‐NC and checked for ABCC1 protein level by western blot.
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- 2021
4. Thermally activated microstructural evolution of metallic heterophase nanoparticles: insights from molecular dynamics simulations
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Yu-Hua Wen, Ya-Meng Li, Wei-Hua Yang, Kai-Wen Huang, and Rao Huang
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General Materials Science - Abstract
A crystal phase is a key factor to determine the physical and chemical properties of crystalline materials. As a new class of nanoscale structures, heterophase nanoparticles, which assemble conventional and unconventional phases, exhibit exceptional properties in comparison with their single-phase counterparts. In this work, we explored the thermodynamic stability of Au, Co, and AuCo heterophase nanoparticles with fcc and hcp phases by using molecular dynamics simulations. These heterostructured nanoparticles were continuously heated to examine their thermally activated structural evolutions. Au and Co single-phase nanoparticles were also considered for comparison. The results show that the phase transition between fcc and hcp is absent in these heterophase nanoparticles despite the existence of an unconventional phase. Although the melting of Au and Co heterophase nanoparticles is homogeneous, AuCo heterophase nanoparticles show heterogeneous melting
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- 2022
5. Spatial distribution and environmental significance of phytoliths in the surface soil of the Xilingol Grassland in Inner Mongolia, China
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Feng Qin, Hua Su, Chong-Xiao Sun, Cai-Qing Guo, Zhi-Wei Liu, Ya-Meng Li, and Hai-Ming Liu
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Palynology ,010506 paleontology ,Global and Planetary Change ,geography ,geography.geographical_feature_category ,Ecology ,Steppe ,Paleontology ,Geology ,Vegetation ,010502 geochemistry & geophysics ,medicine.disease_cause ,01 natural sciences ,Grassland ,Altitude ,Phytolith ,Canonical correspondence analysis ,Pollen ,medicine ,Physical geography ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
Reconstruction of grassland ecosystems and their vegetation succession is an important issue in palaeoenvironmental research. Phytoliths and pollen are two common proxies for palaeovegetation reconstruction, and their importance can be evaluated based on investigations of the relationships between modern vegetation and phytolith/pollen assemblages in surface-soil samples. The correlations between phytolith assemblages and environmental variables were analysed based on 34 surface-soil samples from the Xilingol Grassland, Inner Mongolia, North China, and a palynological analysis was carried out on the same samples, enabling a comparison between their sensitivity to vegetation and climate change. The results show that the phytolith assemblages mainly consist of blocky and rondel phytoliths, while other short-cell phytolith types, such as saddle and bilobate types, are scarce. The pollen assemblages were characterised by a high abundance of Artemisia and Amaranthaceae. Canonical correspondence analysis (CCA) indicated that the most important environmental factors affecting the distribution of phytoliths are altitude and latitude, while the mean warmest monthly temperature (MWMT) and altitude were the most significant environmental factors affecting the distribution of the pollen assemblages. CCA of the phytoliths and pollen assemblages separated both samples into two groups: broadleaf forest/scrub and steppe/meadow groups, but it appeared that phytoliths were more sensitive in arid grasslands. This case study could be used as a baseline for interpreting fossil phytolith/pollen assemblages from the grasslands of Inner Mongolia and indicates that multiproxy analysis of the same samples can provide reliable information on palaeovegetation and palaeoclimate reconstruction.
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- 2021
6. The effect of S-functionalized and vacancies on V2C MXenes as anode materials for Na-ion and Li-ion batteries
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Zhaoyong Jiao, Yongliang Guo, and Ya-Meng Li
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Adsorption ,chemistry ,Diffusion barrier ,Vacancy defect ,Inorganic chemistry ,Monolayer ,General Physics and Astronomy ,Vanadium ,chemistry.chemical_element ,General Materials Science ,MXenes ,Electrochemistry ,Anode - Abstract
The electrochemical properties of V2C and V2CT2 (T = O, S) MXenes with and without vacancy as anode materials for Na-ion and Li-ion batteries, have been studied using first-principles calculation. The present results indicate that the adsorption strength of Li-ion and Na-ion on V2CS2 are less than that of O-functionalized, together with a lower diffusion barrier. Simultaneously, V2CS2 monolayer exhibits lower open-circuit voltage (OCV) values of 0.72 and 0.49 V for Li- and Na-ion, respectively. Interestingly, the presence of atomic vanadium vacancy on V2CS2 monolayer exerts more prominent effects on enhancing adsorption strength than that of carbon vacancy for Li-ion and Na-ion, but with an exception for the diffusion of Li-ion and Na-ion on V2CS2 monolayer. The finding suggests that the V2CS2 monolayer is expected to be a potential candidate as anode material for Li-ion and Na-ion battery due to its lower open-circuit voltages and diffusion barriers.
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- 2020
7. Thermally Driven Structural Evolution and Diverse Melting Modes of Metallic Heterophase Nanoparticles
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Yuhua Wen, Ya-Meng Li, Wei-Hua Yang, Kai-Wen Huang, and Rao Huang
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
8. Long Non-Coding RNA THOR Depletion Inhibits Human Non-Small Cell Lung Cancer Cell Growth
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Dan Chu, Peng-Fei Jiao, Ya-Meng Li, Wei-hua Xu, Gao-Fei Ren, and Pei-jun Tang
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Cancer Research ,IGF2BP1 ,Cell growth ,Lnc-THOR ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Biology ,NSCLC ,respiratory tract diseases ,Small hairpin RNA ,Downregulation and upregulation ,Oncology ,Apoptosis ,GLI1 ,Cell culture ,Cancer research ,biology.protein ,Gene silencing ,cell growth ,Viability assay ,signaling ,RC254-282 ,Original Research - Abstract
Long non-coding RNA (LncRNA) THOR (Lnc-THOR) is expressed in testis and multiple human malignancies. Lnc-THOR association with IGF2BP1 (IGF2 mRNA-binding protein 1) is essential for stabilization and transcription of IGF2BP1 targeted mRNAs. We tested its expression and potential functions in non-small cell lung cancer (NSCLC). In primary NSCLC cells and established cell lines, Lnc-THOR shRNA or CRISPR/Cas9-mediated knockout (KO) downregulated IGF2BP1 target mRNAs (IGF2, Gli1, Myc and SOX9), inhibiting cell viability, growth, proliferation, migration and invasion. Significant apoptosis activation was detected in Lnc-THOR-silenced/-KO NSCLC cells. Conversely, ectopic overexpression of Lnc-THOR upregulated IGF2BP1 mRNA targets and enhanced NSCLC cell proliferation, migration and invasion. RNA-immunoprecipitation and RNA pull-down assay results confirmed the direct binding between Lnc-THOR and IGF2BP1 protein in NSCLC cells. Lnc-THOR silencing and overexpression were ineffective in IGF2BP1-KO NSCLC cells. Forced IGF2BP1 overexpression failed to rescue Lnc-THOR-KO NSCLC cells. In vivo, intratumoral injection of Lnc-THOR shRNA adeno-associated virus potently inhibited A549 xenograft tumor growth in nude mice. At last we show that Lnc-THOR is overexpressed in multiple NSCLC tissues and established/primary NSCLC cells. Collectively, these results highlighted the ability of Lnc-THOR in promoting NSCLC cell growth by associating with IGF2BP1, suggesting that Lnc-THOR represents a promising therapeutic target of NSCLC.
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- 2021
9. Theoretical investigations of TiNbC MXenes as anode materials for Li-ion batteries
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Ya-Meng Li, Zhaoyong Jiao, Yongliang Guo, and Wan-Gao Chen
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Materials science ,Mechanical Engineering ,Diffusion ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Ion ,Anode ,Adsorption ,Chemical engineering ,chemistry ,Mechanics of Materials ,Monolayer ,Materials Chemistry ,Lithium ,0210 nano-technology ,MXenes - Abstract
The electronic properties and electrochemical performance of double-metal MXenes: TiNbC and TiNbCT2 (T = O, F and OH) as anode materials for Li-ion batteries (LIBs) have been studied to understand the effects of Nb(Ti)-layer inserting in Ti2C (Nb2C) monolayer and terminated functional-group (T = O, F, and OH) on the electrochemical performance. The results demonstrate that all the TiNbC and TiNbCT2 monolayers are metallic conductivity, while the adsorption of lithium-ion on TiNbC(OH)2 is unstable, and TiNbCF2 is unfavorable as anode material for LIBs due to the F-groups and Li-ions forming ring structure. Specifically, TiNbC and TiNbCO2 nanosheets exhibit such distinctive features as moderate adsorption energies and quite low diffusion barriers of lithium, theoretical storage capacities comparable to Ti2C monolayer, which manifest the double-metal TiNbC and TiNbCO2 monolayers as excellent anode materials for LIBs.
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- 2019
10. Reversible hydrogen storage behaviors of Ti2N MXenes predicted by first-principles calculations
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Ya-Meng Li, Wan-Gao Chen, Yongliang Guo, Zhaoyong Jiao, and Shu-Hong Ma
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education.field_of_study ,Materials science ,020502 materials ,Mechanical Engineering ,Population ,Ab initio ,02 engineering and technology ,Nitride ,Hydrogen storage ,Adsorption ,0205 materials engineering ,Mechanics of Materials ,Chemical physics ,Monolayer ,Density of states ,General Materials Science ,education ,MXenes - Abstract
The hydrogen storage behaviors of the nitride-based MXenes Ti2N have been investigated by performing density functional calculations. It is observed that H2-molecules could be adsorbed on and desorbed from Ti2N monolayer with suitable adsorption strength under ambient conditions. Moreover, the stability and hydrogen adsorption behaviors are analyzed by computing adsorption energy, charge population and ab initio molecular dynamic simulations. The Kubas-type interaction of the H2-molecules with Ti2N monolayer is investigated according to the charge transfer and electronic projected density of states. Specifically, it is found that the maximum hydrogen storage capacity of Ti2N reaches up to 8.555 wt%, in which the reversible hydrogen storage capacity is of 3.422 wt%. In addition, OH-group-decorated Ti2N has great advantages on hydrogen storage, and the reversible hydrogen storage capacity is of 2.656 wt%. Therefore, the 2D Ti2N MXenes are expected for a potential candidate as reversible hydrogen storage materials under ambient conditions.
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- 2018
11. First-principles investigations of phase stability, mechanical, thermal and optical properties of Ti3(Al1-Si )C2 solid solutions
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Zhaoyong Jiao, Shuhong Ma, and Ya-Meng Li
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Materials science ,Mechanical Engineering ,Metals and Alloys ,02 engineering and technology ,Photon energy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Carbide ,Metal ,Brittleness ,Thermal conductivity ,Mechanics of Materials ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Physical chemistry ,0210 nano-technology ,Ternary operation ,Anisotropy ,Solid solution - Abstract
By means of first-principles calculation, we explored the physical properties of substituting Al with Si atom in layered ternary carbide Ti 3 AlC 2 . Present results revealed that the Ti 3 (Al 1- x Si x )C 2 ( x = 0.0–1.0) compounds under study are thermodynamically stable brittle materials, and the mechanical properties can be improved to some extent by Si-doping. Moreover, all the compounds show metallic character with a strong Ti C bonding and possess a rather stiff lattice and good thermal conductivity. It is notable that these compounds show highly anisotropic at photon energies lower than 18.0 eV. Specifically, all the Ti 3 (Al 1- x Si x )C 2 compounds exhibit high reflectivity, nearly reaching the maximum of ∼98%, in the photon energy range of 0–12.5 eV. Therefore, we expect that Si-doped Ti 3 (Al 1- x Si x )C 2 solid solutions are possibly a good candidate for coating materials in ultraviolet region.
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- 2017
12. Safety and effectiveness of a Tai Chi-based cardiac rehabilitation programme for chronic coronary syndrom patients: study protocol for a randomised controlled trial
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Tian ming Gao, Zai hao Chen, Hua Li, Cui han Li, Jing Ma, Ai ying Guo, Mei ze Cui, Heng chan Yin, Lian shan Zhao, Ya meng Li, Qiu yang Wei, Shao jun Lyu, Yu long Lu, Wen Yuan, Hong wei Wang, Jianwei Zhang, and Bo Song
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Male ,Sports medicine ,medicine.medical_treatment ,lcsh:Medicine ,Perceived Stress Scale ,Coronary Disease ,Anxiety ,law.invention ,Pittsburgh Sleep Quality Index ,Randomized controlled trial ,law ,complementary medicine ,Multicenter Studies as Topic ,Randomized Controlled Trials as Topic ,Aged, 80 and over ,Cardiac Rehabilitation ,Rehabilitation ,rehabilitation medicine ,General Medicine ,Middle Aged ,Exercise Therapy ,Research Design ,Female ,Adult ,medicine.medical_specialty ,Adolescent ,Angina Pectoris ,Young Adult ,Respiratory muscle ,medicine ,Humans ,Sports and Exercise Medicine ,coronary heart disease ,Aged ,clinical trials ,sports medicine ,business.industry ,lcsh:R ,Patient Acceptance of Health Care ,education & training (see medical education & training) ,Clinical trial ,Berg Balance Scale ,Chronic Disease ,Quality of Life ,Physical therapy ,Tai Ji ,business ,Stress, Psychological - Abstract
IntroductionPreliminary evidence from clinical observations suggests that Tai Chi exercise may offer potential benefits for patients with chronic coronary syndrom (CCS). However, the advantages for CCS patients to practice Tai Chi exercise as rehabilitation have not been rigorously tested and there is a lack of consensus on its benefits. This study aims to develop an innovative Tai Chi Cardiac Rehabilitation Program (TCCRP) for CCS patients and to assess the efficacy, safety and acceptability of the programme.Methods and analysisWe propose to conduct a multicentre randomised controlled clinical trial comprising of 150 participants with CCS. The patients will be randomly assigned in a 1:1 ratio into two groups. The intervention group will participate in a supervised TCCRP held three times a week for 3 months. The control group will receive supervised conventional exercise rehabilitation held three times a week for 3 months. The primary and secondary outcomes will be assessed at baseline, 1 month, 3 months after intervention and after an additional 3-month follow-up period. Primary outcome measures will include a score of 36-Item Short Form Survey and Chinese Perceived Stress Scale. The secondary outcome measures will include body composition, cardiopulmonary exercise test, respiratory muscle function, locomotor skills, echocardiogram, New York Heart Association classification, heart rate recovery time and laboratory examination. Other measures also include Seattle Angina Scale, Pittsburgh Sleep Quality Index, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7 and Berg Balance Scale. All adverse events will be recorded and analysed.Ethics and disseminationThis study conforms to the principles of the Declaration of Helsinki and relevant ethical guidelines. Ethical approval has been obtained from the Ethics Committee of Chinese People’s Libration Army General Hospital (approval number: S2019-060-02). Findings from this study will be published and presented at conferences for widespread dissemination of the results.Trial registration numberNCT03936504.
- Published
- 2020
13. The Synthesis of Mesoporous TS-1 and Its Performance for Oxidation of Diphenyl Sulfide and Dibenzyl Sulfide
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Ya-Meng Li, Hua-Qin Wang, Rong-Qiang Li, Wen-Jie Sun, Pei Yu, Hai-Xiang Gao, Meng-Die Chen, and Ya-Long Ding
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lcsh:GE1-350 ,Materials science ,010405 organic chemistry ,chemistry.chemical_element ,Microporous material ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,Hydroxide ,Fourier transform infrared spectroscopy ,Mesoporous material ,Zeolite ,lcsh:Environmental sciences ,Titanium - Abstract
TS-1 zeolite has outstanding performance in the catalytic reactions with hydrogen peroxide as catalytic promoter. However, the narrow pore size (< 1.0 nm) of traditional TS-1 makes it difficult for bulky organic compounds to contact with the active sites in the pores, which seriously limits application of TS-1. Recently, the introduction of mesoporous structure into microporous TS-1 becomes a hot research topic. Meanwhile, the huge synthesis cost of TS-1 is another main reason hindering its industrial application. In this paper, mesoporous TS-1 was successfully synthesized using sodium silicate as silicon source and titanium trichloride as titanium source under the template conditions of tetrapropylammonium hydroxide (TPAOH) and cationic polymer. The mesoporous TS-1 was characterized by X-ray diffraction (XRD), N2 adsorption, scanning electric microscopy (SEM), transmitting electric microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and UV-Vis Spectrum spectra (UV-Vis). Results show that the synthesized TS-1 zeolites have good crystallinity and tetra-coordinated framework Ti atoms, and there are abundant mesoporous structures in the zeolite crystals. The results of oxidation experiments show that conversion of diphenyl sulfide and dibenzyl sulfide with mesoporous TS-1 are 97.3 % and 85.3 % respectively, while that conversion with microporous TS-1 are 75.7 % and 63.5 respectively.
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- 2020
14. Diatom-inferred salinity changes from the Yushe paleolake indicate an aridification during the Pliocene–Pleistocene transition in north China
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Yu-Fei Wang, David K. Ferguson, Ya-Meng Li, Rui-Xia Wang, Cheng-Sen Li, and Qi Zhao
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biology ,Pleistocene ,fungi ,Paleontology ,Oceanography ,biology.organism_classification ,Paleolimnology ,Salinity ,Diatom ,Benthic zone ,Aridification ,Glacial period ,Global cooling ,Ecology, Evolution, Behavior and Systematics ,Geology ,Earth-Surface Processes - Abstract
The global climate changed significantly during the Pliocene–Pleistocene transition, and a worldwide aridification occurred. In order to investigate the influence of the aridification during the Pliocene–Pleistocene transition in the East Asian interior, diatom assemblages from the Upper Zhangcun Formation, north China, deposited during 2.7–2.5 Ma BP were analyzed, and the lake salinity was reconstructed using diatom–environment transfer functions. A total of 74 diatom taxa were found in the sediments, belonging to 21 families and 32 genera. Four zones were established from the bottom to the top, based on the changes in the diatom assemblages over the 15.7 m sediment sequence. In Zone 1, Cyclotella iris dominated in assemblage while Caloneis westii and Staurosira construens were less presented among representative species. In Zone 2, C. iris dominated, which indicates carbonate-rich water. But in Zone 3, benthic pennate taxa such as C. westii and Anomoeoneis sphaerophora became more abundant, indicating a significant increase in water salinity, from carbonate type to sulfate type, caused by climatic change. In Zone 4, C. iris became dominant again, with abundant Gomphonema intricatum and rare Pinnularia rathsbergiana and Martyana martyi species. The salinity inferred by conductivity reconstruction increased from 1.9 ppt in Zone 2 to 4.1 ppt in Zone 3. The significant changes of anion ratio (Alk / (Cl− + SO42−)) indicate an abrupt change from carbonate-rich to a sulfatic type water. The increase of salinity reflects changes in the precipitation –evaporation balance. The change from carbonate to sulfatic water inferred from the diatom assemblages could indicate a significant aridification around ca. 2.6 Ma BP on the eastern edge of the Loess Plateau. This is the most easterly record of aridification across the Eastern Asian interior and may be related with the global cooling and the development of the Northern Hemisphere glaciation.
- Published
- 2015
15. A Low-Capacitance and Fast-Response Bidirectional SCR for RFICs ESD Protection Applications
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Ya-meng Li, Ting Li, and Kang-ming Sun
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Engineering ,Electrostatic discharge ,business.industry ,Electrical engineering ,Integrated circuit ,Capacitance ,law.invention ,Silicon-controlled rectifier ,Parasitic capacitance ,law ,Radio frequency ,business ,Effective response ,Voltage - Abstract
For the radio frequency integrated circuits (RFICs) electrostatic discharge (ESD) protection special applications, a novel low-capacitance and fast-response bidirectional silicon controlled rectifier (LFBSCR) is developed. The low capacitance is achieved by changing the series-parallel relationship of parasitic capacitances located in the electrostatic discharge path. Moreover, the fast-response-time (Ton) and the low triggering voltage (Vt1) parameters are obtained due to gate-assistant triggering mechanism. The experimented results show excellences of the LFBSCR in ESD protection critical performance: low parasitic capacitance CESD~100fF, fast effective response Ton~100ps, low triggering voltage Vt1~4.06V, and low leakage current Ileak~0.016nA. With aforementioned excellences, a high rbustness, and a small ESD design windows, the proposed LFBSCR is very suitable for RFICs ESD protection applications.
- Published
- 2017
16. A Method to Determine Relative Vehicle Positioning for Safety Warning
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Xiang-hui Song, Jiahai Zhao, Xin-ke Wang, and Ya-meng Li
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Transport engineering ,Vehicle positioning ,Engineering ,business.industry ,Position (vector) ,Global Positioning System ,Margin of error ,Poison control ,business ,Intelligent transportation system ,Field (computer science) ,Automotive engineering ,Reference frame - Abstract
Determining relative vehicle positioning for vehicle safety warning services requires high level of accuracy. Positioning based on general satellite information has a large margin of error due to cost constraints. This paper proposes a method to determine relative vehicle position for vehicle safety warning, based on conditional extremum and relative vehicle history positioning. Special attention is paid to improve not only the computational efficiency but also the accuracy of determining the relative position of two vehicles or a vehicle and reference frame. Field test results demonstrate the significance of improved accuracy in determining relative vehicle position. Theoretical analysis and realistic systematic tests provide useful insights into potential applications in safety warning.
- Published
- 2014
17. A thermally stable pcu network based on ferromagnetic dinuclear Ni(II) units
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Zhan-Feng Ju, Jiandong Pang, Xu-Dong Zhang, and Ya-Meng Li
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Magnetism ,Organic Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Crystal structure ,Analytical Chemistry ,Ion ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Nickel ,chemistry ,Ferromagnetism ,Carboxylate ,Benzene ,Spectroscopy ,Benzoic acid - Abstract
A pcu network based on the dinuclear Ni(II) units, [Ni2(hfipbb)2(1,3-bix)2]n (1 )( H 2hfipbb = 4,4 0 (Hexafluoroisopropylidene)bis(benzoic Acid); 1,3-bix = 1,3-bis(imidazol-1-ylmethyl)benzene), has been hydrothermally synthesized and structurally characterized. Interestingly, the two Ni(II) cations are bridged by two carboxylate groups in the rarely-seen syn-anti mode. The magnetic data reveal the dominant ferromagnetic interactions between Ni(II) ions.
- Published
- 2014
18. A high-connected self-penetrating network supported by pentanuclear cobalt(II) secondary building units
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Ya-Meng Li, Jiandong Pang, Zhan-Feng Ju, and Xu-Dong Zhang
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Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,chemistry.chemical_element ,Antiferromagnetism ,Crystal structure ,Physical and Theoretical Chemistry ,Benzene ,Cobalt - Abstract
A 3D ten-connected self-penetrating network based on the pentacobalt(II) clusters, [Co5(1,4-ndc)4(OH)2(1,3-bix)2]n (1) (1,4-H2ndc = 1,4-naphthalenedicarboxylic acid; 1,3-bix = 1,3-bis(imidazol-1-ylmethyl)benzene), is synthesized and characterized. Topological analysis indicates that it has ile-364345362 network. The magnetic data reveals the dominant antiferromagnetic interactions between the Co(II) cations.
- Published
- 2013
19. A Water and Thermally Stable Metal–Organic Framework Featuring Selective CO2 Adsorption
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Ya-Meng Li, Ben-Lai Wu, Zhan-Feng Ju, and Daqiang Yuan
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Pore size ,Crystallography ,Chromatography ,Chemistry ,General Materials Science ,Metal-organic framework ,Thermal stability ,General Chemistry ,Microporous material ,Condensed Matter Physics ,Co2 adsorption ,Powder diffraction - Abstract
A 2-fold interpenetrated microporous MOF [Ni2(C2O4)(L)2]n·6nH2O (HL = 4,2′:4″,2′-terpyridine-4′-carboxylic acid) (1) was synthesized and structurally characterized. 1 has obvious 1D channels along the crystallographic a and c axes with a pore size of 5.7 to 6.9 A. Topological analysis shows that the framework of 1 can be interpreted as a (3,4)-connected net with point symbol (63)(65·8). 1 exhibits high water and thermal stability, which is demonstrated by TGA, PXRD, and VT-PXRD. Additionally, the high temperature structure of 1′ (433 K) undoubtedly demonstrates the stability of the framework. More importantly, 1 shows high selectivities for CO2 over N2, H2, and CH4 at low pressure and 273 K.
- Published
- 2013
20. A tetragonal molecular cage and polymeric macrocyclic complex based on a clip-like bis-pyridyl-bis-amide ligand
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Yu-Han Peng, Ben-Lai Wu, Ya-Hui Yu, Hong-Yun Zhang, and Ya-Meng Li
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Chemistry ,Coordination polymer ,Ligand ,chemistry.chemical_element ,Crystal structure ,chemistry.chemical_compound ,Nickel ,Tetragonal crystal system ,Crystallography ,Amide ,Materials Chemistry ,Physical and Theoretical Chemistry ,Chirality (chemistry) ,Cobalt - Abstract
Reactions of a bis-pyridyl-bis-amide ligand, N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide (bppdca) with nickel(II) and cobalt(II) salts resulted in a tetragonal molecular cage, [Ni2(bppdca)4(SCN)4] (1), and a 1-D polymeric macrocyclic complex, [Co(bppdca)(SO4)(CH3OH)(DMF)] n ·nCH3OH (2) (DMF = N,N′-dimethylformamide). Compound 1 features a tetragonal cage-like structure. In each cage, four bppdca ligands are twisted in the same direction, which endow the cage with chirality. However, because the twist or screw directions of adjacent cages are contrary, 1 is a mesomer and exhibits no chirality on the whole. Compound 2 possesses a 1-D, double-chain structure containing Co4(SO4)4(bppdca)2 macrocyclic subunits.
- Published
- 2012
21. Paleoenvironmental inferences from diatom assemblages of the middle Miocene Shanwang Formation, Shandong, China
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Cheng-Sen Li, Yu-Fei Wang, David K. Ferguson, and Ya-Meng Li
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Total organic carbon ,biology ,Cymbella ,Pinnularia ,Aquatic Science ,biology.organism_classification ,Paleolimnology ,Water level ,Paleontology ,Fragilaria ,Oceanography ,Diatom ,Benthic zone ,Geology ,Earth-Surface Processes - Abstract
Diatoms were analyzed in a laminated sediment sequence from the middle Miocene, lacustrine Shanwang Formation, Shandong Province, eastern China, to reconstruct past conditions in the lake and evaluate relationships between inferred changes in the aquatic and terrestrial environments. Changes in the diatom assemblages over the 22.9-m-long sediment sequence were used to assign 19 lithologic layers to five zones. In Zone 1, Aulacoseira cf. distans and Melosira youngi were dominant in diatomaceous laminations. In Zone 2, only a few Aulacoseira spp. and Cymbella spp. were found in the yellow-green mudstone samples. In Zone 3, benthic pennate taxa, such as Fragilaria, Pinnularia, and Cymbella dominated in parts of the laminites. In Zone 4, Aulacoseira taxa regained dominance, and in Zone 5, benthic diatoms were found in only one sample. Shifts in the diatom assemblages and other sedimentological evidence indicate a change in the water level from a relatively deep system (>8–12 m) to a mudflat, then fluctuating water levels (8–12 m), shallower conditions (4–8 m), and finally a terrestrial environment. Abundant Aulacoseira indicate not only cold water, but also wind-induced turbulence. Water depth fluctuations coincided with the aridity index, reflected by terrestrial plant fossils in the sediments. Water pH, total phosphorus (TP), and total organic carbon (TOC) reconstructions were undertaken using the European Diatom Database (EDDI), and results showed a correlation between fluctuating water levels and volcanic activity in Zone 3.
- Published
- 2009
22. PIGMENT DISTRIBUTION IN FRESH SHOOT TISSUES OF FOUR COLORED LEAF PRUNUS TAXA
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Ya Meng Li, Xiao Lei Li, Ling Guo, Xiang Shen, and Xiao Ling Qu
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Xylem ,Horticulture ,Biology ,Pigment ,chemistry.chemical_compound ,Prunus ,chemistry ,visual_art ,Anthocyanin ,Shoot ,Botany ,Ornamental plant ,visual_art.visual_art_medium ,Pith ,Woody plant - Abstract
P.persicaf.atropurpurea,P.mume ‘Meirenmdi',‘P.cistena Pissardii',and P.cerasifera ‘Pissardii' are popular ornamental woody plants uoody with colored-leaves during growing seasons.However,the pigment distribution,which contributes the coloration of these plants,is not clear.The distribution patterns of anthocyanin in one-year old branches,petioles and leaves from the above four taxa were examined under a microscope.Also,their morphological characteristics were documented.Each taxon has its unique distribution pattern and concentration under the different tissues.There was not anthocyanin in secondary xylem except P.cistena 'Pissardii'.Higher concentration of anthocyanin in cells of the top epidermis of P.persica f.atropurpurea and P.mume ‘Meirenmdi',while lower concentration of anthocyanin for P.Cistena ‘Pissardii' and P.cerasifera ‘Pissardii'.In general,the content of pigment was descending from the tip of branch to the base.Anthocyanin was observed at pith of branch tips for three taxa with exception of P.persica f.atropurpurea.Morphologically,leaf-color differences among the four taxa,as well as leaf-color tint and duration,were regulated by the distribution pattern and concentration of anthocyanin in epidermis cells.Based on the seasonal observation of the four taxa's color change,we found that the wider distribution of anthocyanins,the smaller of the seasonal change and the lower influence with environment.
- Published
- 2008
23. ChemInform Abstract: One-Pot Three-Component Synthesis of 1,2,3-Triazoles Using Magnetic NiFe2O4-Glutamate-Cu as an Efficient Heterogeneous Catalyst in Water
- Author
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Zhan-Hui Zhang, Li-Ping Mo, Jun Lu, Ya-Meng Li, Yu-Heng Liu, and Er‐Qian Ma
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chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,Chemistry ,Aryl ,Substrate (chemistry) ,Sodium azide ,General Medicine ,Azide ,Fourier transform infrared spectroscopy ,Heterogeneous catalysis ,Combinatorial chemistry ,Catalysis - Abstract
A novel magnetic NiFe2O4 supported glutamate–copper catalyst was prepared in a convenient and ecofriendly manner and characterized using FTIR, XRD, EDX, TEM, SEM, XPS and VSM. This magnetic catalyst exhibited excellent catalytic activity for the synthesis of a wide variety of 1,4-disubstituted-1,2,3-triazoles via one-pot three-component click reactions of sodium azide, non-activated terminal alkynes, and different azide precursors such as epoxides, benzyl chlorides, and aryl boronic acids at room temperature in water. This procedure has some advantages such as an aqueous reaction medium, ambient reaction conditions, high yields, wide substrate scope, easy separation of the catalyst using an external magnet and efficient recycling.
- Published
- 2015
24. Expression of eosinophils be beneficial to early clinical diagnosis of brucellosis
- Author
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Peng-Fei, Jiao, Wei-Li, Chu, Gao-Fei, Ren, Jun-Na, Hou, Ya-Meng, Li, and Li-Hua, Xing
- Subjects
Original Article - Abstract
Objective: Investigate the expression and significance of eosinophils in brucellosis. Methods: Retrospective analysis of clinical data for 151 brucellosis patients (BR group), complete blood count and blood bacterial culture etc.; in addition, 150 general bacterial infection patients (BI group) and 135 persons in healthy physical condition upon testing (NC group) are selected respectively as the control groups to comparatively study expression of white blood cells and eosinophils for brucellosis patients. Adopt t test to compare measurement data. Results: In comparison with BI group, WBC, NE, EO, MO, NE% and EO% in BR group are reduced but LY, LY% and MO% are increased and such difference shows statistical significance (P0.05). NE%, EO and EO% are reduced but MO, LY% and MO% are increased and such difference shows statistical significance (P
- Published
- 2015
25. Utility of surface pollen assemblages to delimit Eastern Eurasian steppe types
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Cheng-Sen Li, Qing Wang, Hong-Zhen Ma, Feng Qin, David Kay Ferguson, Zhe Cai, Yu-Fei Wang, Ya-Meng Li, and Wen-Li Chen
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China ,Steppe ,lcsh:Medicine ,Forests ,medicine.disease_cause ,Poaceae ,Nitraria ,Zygophyllaceae ,Temperate forests ,Pollen ,medicine ,lcsh:Science ,Ecosystem ,Multidisciplinary ,geography.geographical_feature_category ,Deserts ,biology ,Ecology ,lcsh:R ,Tamarix ,Temperature ,Humidity ,Vegetation ,Mongolia ,Palynomorphs ,biology.organism_classification ,Grassland ,Geography ,Ordination ,lcsh:Q ,Pines ,Temperate rainforest ,Research Article - Abstract
Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain.
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- 2015
26. Syntheses, structures and photoluminescence of two microporous lanthanide coordination polymers
- Author
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Ben-Lai Wu, Daqiang Yuan, and Ya-Meng Li
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Lanthanide ,Thermogravimetric analysis ,Photoluminescence ,Materials science ,Crystal structure ,Chromophore ,Inorganic Chemistry ,Crystallography ,Materials Chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,Isostructural ,Luminescence ,Powder diffraction - Abstract
Article history:Received 20 April 2012Accepted 17 May 2012Available online 24 May 2012Keywords:SolvothermalLanthanideCrystal structureLuminescence Twoisostructurallanthanidecomplexes,[Ln 2 (INO) 4 (NO 3 ) 2 ] n ·2nDMF[Ln=Eu(1),Tb(2)](INO=isonicotinate-N-oxide;DMF=N,N-dimethylformamide),havebeensynthesizedunderthesolvothermalconditionandcharac-terized by single-crystal X-ray diffraction, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA)andelementalanalysis(EA).Inthesetwocomplexes,eachdinuclearLn(III)unitisconnectedwithsixneighboringdinuclear units, which finally constructs a three-dimensional (3D)framework.Along the crystallographic [0 0 1]direction,thereareone-dimensional(1D)tunnels,inwhichfreeDMFmoleculesresideasguests.Additionally,thephotoluminescent properties of 1 and 2 are also discussed.© 2012 Elsevier B.V. All rights reserved. In recent years, design and syntheses of metal-organic frame-works (MOFs) based on lanthanide ions have been under intenseinvestigation for their interesting topologies and various applicationssuch as gas separation and single-molecule magnets [1]. Especially,many lanthanide complexes offer the potential applications in medi-cal imaging, sensors and electro-optical devices since lanthanide ionshave narrow emissions in both visible and near-IR regions with rela-tively long luminescence lifetimes [2]. However, the direct excitationof the4f–4f transitionsis muchdifficult owingto theparity-forbiddentransitions in principle. To obtain efficient luminescent emission, thecommon method is the selection of suitable chromophores as anten-nas which can effectively transfer energy indirectly to the lanthanideions throughthe ligand-to-metal energy transfer (LMET) [3]. Aromat-ic carboxylic ligands, which usually have broad and strong absorptionbands in the UV region, have been proven to be good candidates asantennas or sensitizers [4]. Recently, we focus our interest on theconstruction lanthanide MOFs from carboxylic ligands. Herein wereport the syntheses, structures and photoluminescence of twolanthanide complexes.Complexes 1 and 2 were obtained via solvothermal syntheses [5]and single-crystal X-ray diffraction analyses of 1 and 2 confirmed thatthey are isostructural [6]. Therefore, in the following discussion thestructure of 1 is taken as the example to be described in detail. In theasymmetric unit of 1, there is one Eu(III) cation, two INO ligands, oneNO
- Published
- 2012
Catalog
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