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22. Homologous recombination and gene‐specific selection co‐shape the vertical nucleotide diversity of mangrove sediment microbial populations.

Author

Ding, Jijuan, Liu, Fei, Zeng, Jiaxiong, Gu, Hang, Zhang, Dandan, Yang, Xueqin, Wu, Bo, Shu, Longfei, He, Zhili, and Wang, Cheng

Subjects
BIOLOGICAL evolution, HOMOLOGOUS recombination, GENETIC variation, GENE frequency, ENERGY metabolism, MICROORGANISM populations
Abstract

Mangrove sediments host a diverse array of microbial populations and are characterized by high heterogeneity along their vertical depths. However, the genetic diversity within these populations is largely unknown, hindering our understanding of their adaptive evolution across the sediment depths. To elucidate their genetic diversity, we utilized metagenome sequencing to identify 16 high‐frequency microbial populations comprised of two archaea and 14 bacteria from mangrove sediment cores (0–100 cm, with 10 depths) in Qi'ao Island, China. Our analysis of the genome‐wide genetic variation revealed extensive nucleotide diversity in the microbial populations. The genes involved in the transport and the energy metabolism displayed a high nucleotide diversity (HND; 0.0045–0.0195; an indicator of shared minor alleles with the microbial populations). By tracking the processes of homologous recombination, we found that each microbial population was subjected to different purification selection levels at different depths (44.12% genes). This selection resulted in significant differences in synonymous/non‐synonymous mutation ratio between 0–20 and 20–100 cm layers, indicating the adaptive evolutionary process of microbial populations. Furthermore, our assessment of differentiation in the allele frequencies between these two layers showed that the functional genes involved in the metabolic processes of amino acids or cofactors were highly differential in more than half of them. Together, we showed that the nucleotide diversity of microbial populations was shaped by homologous recombination and gene‐specific selection, finally resulting in the stratified differentiation occurring between 0–20 and 20–100 cm. These results enhance our cognition of the microbial adaptation mechanisms to vertical environmental changes during the sedimentation process of coastal blue carbon ecosystems. [ABSTRACT FROM AUTHOR]

Published
2024
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28. Magnetoresistance and doping effects in conjugated polymer-based organic light emitting diodes

Author

Gu, Hang

Subjects
621.34, Physics, Magnetoconductance, Magnetoresistance, Light emitting diodes
Abstract

Magnetoresistance (MR) and doping effects have been investigated in a poly(3-hexylthiophene-2,5-diyl) (P3HT) based organic light emitting diodes. In single device of fixed composition (Au/P3HT/Al as spun and processed in air), the measured MR strongly depends on the drive conditions. The magnetoconductance (MC) varies from negative to positive (-0.4% ≤ MC ≤ 0.4%) with increasing current density, depending on which microscopic mechanism dominates. The negative MC is due to bipolaron based interactions and the positive MC to triplet-polaron based interactions (as confirmed by light emission). Oxygen doping is prevalent in P3HT devices processed in air and the effect of de-doping (by annealing above the glass transition temperature) is investigated on the MC of an Au/P3HT/Al diode. De-doping reduces the current through the device under forward bias by ~3 orders of magnitude, but increases the negative (low current) MC from a maximum of -0.5% pre-annealing to -3% post-annealing. This increased negative MC is consistent with bipolaron theory predictions based on Fermi level shifts and density of states (DoS) changes due to de-doping. The decrease in current density is explained by increased injection barriers at both electrodes also resulting from de-doping. Deliberate chemical doping of P3HT is carried out using pentacene as a hole trap centre. The trapping effect of pentacene is confirmed by reproducible and significant hole mobility-pentacene concentration behaviour, as measured by dark injection (DI) transient measurements. The enhanced carrier injection resulting from the pentacene doping also leads to increased electroluminescence (EL). The resultant MC in pentacene doped devices is strongly dependent on carrier injection and can be significantly enhanced by doping, for example from -0.2% to -0.6% depending on device and drive conditions. Throughout this thesis Lorentzian and non-Lorentzian function fitting is carried out on the measured MC, although the underlying microscopic mechanisms cannot always be discerned.

Published
2015

31. Crossing on hyperbolic lattices

Author

Gu, Hang and Ziff, Robert M.

Subjects
Condensed Matter - Disordered Systems and Neural Networks
Abstract

We divide the circular boundary of a hyperbolic lattice into four equal intervals, and study the probability of a percolation crossing between an opposite pair, as a function of the bond occupation probability p. We consider the {7,3} (heptagonal), enhanced or extended binary tree (EBT), the EBT-dual, and {5,5} (pentagonal) lattices. We find that the crossing probability increases gradually from zero to one as p increases from the lower p_l to the upper p_u critical values. We find bounds and estimates for the values of p_ l and p_u for these lattices, and identify the self-duality point p* corresponding to where the crossing probability equals 1/2. Comparison is made with recent numerical and theoretical results., Comment: Final published version, with some additions at the end

Published
2011
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32. Universal condition for critical percolation thresholds of kagome-like lattices

Author

Ziff, Robert M. and Gu, Hang

Subjects
Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Statistical Mechanics
Abstract

Lattices that can be represented in a kagome-like form are shown to satisfy a universal percolation criticality condition, expressed as a relation between P_3, the probability that all three vertices in the triangle connect, and P_0, the probability that none connect. A linear approximation for P_3(P_0) is derived and appears to provide a rigorous upper bound for critical thresholds. A numerically determined relation for P_3(P_0) gives thresholds for the kagome, site-bond honeycomb, (3-12^2), and "stack-of-triangle" lattices that compare favorably with numerical results., Comment: Several new figures and small changes

Published
2008
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36. High level of homocysteine is associated with pre-eclampsia risk in pregnant woman: a meta-analysis

Author

Zhang, Caihong, Hu, Jingjing, Wang, Xia, and Gu, Hang

Subjects
Endocrinology, Endocrinology, Diabetes and Metabolism, Obstetrics and Gynecology
Abstract

We aimed to investigate the correlation between blood homocysteine (Hcy) levels and pre-eclampsia (PE) risk in pregnant women. Related articles were searched using PubMed, Embase, and Web of Science databases. Methodological quality of included studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale (NOS). Cochran's Q and I2 tests were used to evaluate heterogeneity. Egger’s test was used to evaluate publication bias. A sensitivity analysis was performed to test stability of the results using a one-by-one elimination method. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess certainty of evidence. Nine studies (4384 PE and 26021 non-PE patients) were included in the meta-analysis. The methodology of them was of good quality, with NOS scores of 5–8. However, there was a significant heterogeneity among included studies. Therefore, the random effect model was generated and combined results suggested a significant association between increased level of Hcy in pregnant women and PE risk. Although a significant publication bias was found in the current study with a P value of 0.006 in the Egger test, sensitivity analysis showed that the combined results were stable and did not vary significantly from any single study. However, the GRADE evidence quality was very low, which may lower the recommendation of pooled results. Increased levels of Hcy in maternal blood were significantly associated with the risk of PE, but low certainty of evidence need to be improved by more high-quality studies.

Published
2022

39. Densification of SiCp/Al–Fe–V–Si Composites by the Wedge Rolling Method.

Author

He, Yiqiang, Huan, Changbao, Su, Qianhang, Zuo, Lijie, Feng, Wen, Ding, Yunfei, Shang, Feng, Luo, Yi, Feng, Lichao, Wang, Yan, and Gu, Hang

Subjects
STRAINS & stresses (Mechanics), POROUS metals, COMPACTING, WEDGES, EXTRUSION process, OXIDE coating, SPECIFIC gravity
Abstract

The densification of a SiCp/Al–Fe–V–Si billet was achieved by reducing the pores and oxide film between the particles by rolling. The wedge pressing method was used to improve the formability of the composite after jet deposition. The key parameters, mechanisms, and laws of wedge compaction were studied. The results showed that the pass rate was reduced by 10 to 15 percent when using steel molds during the wedge pressing process if the distance between the two ends of the billet was about 10 mm, which was beneficial to improve the compactness and formability of the billet. The density and stress of the surface of the material were higher than those of the interior, where the distribution of density and stress tended to be uniform as the overall volume of the material shrank. During the wedge extrusion process, the material in the preforming area was thinned along the thickness direction, while the material in the main deformation area was lengthened along the length direction. Under plane strain conditions, the wedge formation of spray-deposited composites follows the plastic deformation mechanism of porous metals. The true relative density of the sheet was higher than the calculated value during the initial stamping phase, but was lower than the calculated value when the true strain exceeded 0.55. This was due to the accumulation and fragmentation of SiC particles, which made the pores difficult to remove. [ABSTRACT FROM AUTHOR]

Published
2023
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48. Perioperative Protocol of Ankle Fracture and Distal Radius Fracture Based on Enhanced Recovery after Surgery Program: A Multicenter Prospective Clinical Controlled study

Author

Li, Ting, primary, Sun, Zhi-Jian, additional, Zhou, Yan, additional, Sun, Wei-Tong, additional, Wang, Peng-Cheng, additional, Cai, Xin-Yu, additional, Liang, Jun-Bo, additional, Dong, Jing-Ming, additional, Zhou, Da-Peng, additional, Yu, Kai, additional, Wu, Ming-Xin, additional, He, Jiu-Sheng, additional, Wen, Liang-Yuan, additional, Yu, Bao-Qing, additional, Wang, Jian, additional, Yang, Jun, additional, Lin, Feng-Fei, additional, Li, Bing-Zuan, additional, Shi, Zong-Xin, additional, Wang, Bao-Jun, additional, Wang, Ai-Guo, additional, Peng, Gui-Ling, additional, Sun, Xu, additional, Xiao, Hong-Hao, additional, Mi, Meng, additional, Zhao, Xia, additional, Li, Chang-Run, additional, Liu, Gang, additional, Li, Shao-Liang, additional, Gu, Hang-Yu, additional, Zhou, Yuan, additional, Tan, Zhe-Lun, additional, and Wu, Xin-Bao, additional

Published
2022
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50. Highly interconnected porous PDMS/CNTs sandwich sponges with anti-icing/deicing microstructured surfaces

Author

Gu Hang, Wei Liu, Jinbao Xu, Anfu Chen, Guo Jiang, Jingjing Zhang, Guofeng Qin, Qiankun Wang, Han-Xiong Huang, and Zhengrong Zhang

Subjects
Toughness, Fabrication, Materials science, Polydimethylsiloxane, 020502 materials, Mechanical Engineering, 02 engineering and technology, Microstructure, Contact angle, chemistry.chemical_compound, 0205 materials engineering, chemistry, Mechanics of Materials, Specific surface area, General Materials Science, Composite material, Porosity, Layer (electronics)
Abstract

Three-dimensional flexible porous polydimethylsiloxane (pPDMS) materials are widely used in electronics due to their relatively large specific surface area, and so maintaining the electric charge at a high-humidity atmosphere is an issue that must be addressed. A method for combining centrifuging and hot embossing was proposed for rapid mass production of highly interconnected pPDMS sandwich sponges with microstructure on top layer. As optimized sacrificial templates, the salts were rearranged in the PDMS by this method, and so the high connectivity facilitated salts dissolving in 3 h, which greatly improved the efficiency of the whole fabrication period. The weight ratio of PDMS to salt was 1.0–3.5, and the porosity can be kept at ~ 70%. The combination of micron-scale truncated cones and highly interconnected pore structure endowed the sponge surface with a contact angle of up to ~ 153° and ice adhesion strength as low as ~ 6.78 kPa. The strategy to combine passive anti-icing with active deicing is to prepare PDMS/CNTs sandwich sponges with microstructure on top layer. For the PDMS/CNTs (7 wt%) sandwich sponge, the results show that the elongation at break is as high as ~ 161% and the stress is as low as ~ 23 kPa. Besides, its surface temperature rose rapidly from 25 to 100 °C in 10 s through far-infrared light (808 nm) irradiation, achieving a remote deicing effect. The superhydrophobic and anti-icing/deicing sponges with high toughness property are expected to be of use for further applications.

Published
2021

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