297 results on '"Lei, Teng"'
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2. Research on motion target detection based on infrared biomimetic compound eye camera
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Li, Linhan, Wang, Xiaoyu, Lei, Teng, Yue, Juan, Gao, Sili, Yu, Yang, and Su, Haifeng
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- 2024
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3. Thermally driven phase transition of halide perovskites revealed by big data-powered in situ electron microscopy
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Luo, Xin, Liu, Weiyan, Wang, Zeyu, Lei, Teng, Yang, Peidong, and Yu, Yi
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Affordable and Clean Energy ,Physical Sciences ,Engineering ,Chemical Physics ,Chemical sciences ,Physical sciences - Abstract
Halide perovskites are promising light-absorbing materials for high-efficiency solar cells, while the crystalline phase of halide perovskites may influence the device's efficiency and stability. In this work, we investigated the thermally driven phase transition of perovskite (CsPbIxBr3-x), which was confirmed by electron diffraction and high-resolution transmission electron microscopy results. CsPbIxBr3-x transitioned from δ phase to α phase when heated, and the γ phase was obtained when the sample was cooled down. The γ phase was stable as long as it was isolated from humidity and air. A template matching-based data analysis method enabled visualization of the thermally driven phase evolution of perovskite during heating. We also proposed a possible atomic movement in the process of phase transition based on our in situ heating experimental data. The results presented here may improve our understanding of the thermally driven phase transition of perovskite as well as provide a protocol for big-data analysis of in situ experiments.
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- 2023
4. Unilateral hemilaminectomy vs. laminoplasty for the resection of spinal schwannomas: an analysis of 100 patients
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Xiaofeng Chen, Dianhui Han, Tie Mao, Huilong Xu, Hua Guo, Haitao Ge, Xiangyi Meng, Lei Teng, Liankun Wang, Qingchun Mu, and Jiabin Wang
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unilateral hemilaminectomy ,spinal schwannoma ,laminoplasty ,spine ,surgery ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
ObjectiveSpinal schwannomas are the most common intradural extramedullary tumors, and their complete removal is recommended to avoid tumor recurrence. Although laminoplasty provides a sufficient window for tumor resection, this approach may increase tissue trauma and cause postoperative instability compared with unilateral hemilaminectomy. This study aimed to compare the efficacy and clinical outcomes of the two approaches.Materials and methodsWe included 100 consecutive patients who underwent unilateral hemilaminectomy or laminoplasty for resection of spinal schwannomas between January 2015 and February 2023. The patients' baseline characteristics, including sex, age, tumor location, percentage of tumor occupying the intradural space, operative time, postoperative length of hospital stay, intraoperative bleeding volume, visual analog scale score, and neurologic results, were retrospectively analyzed.ResultsHemilaminectomy patients who underwent unilateral hemilaminectomy had smaller intraoperative bleeding (p = 0.020) volume, shorter operative time (p = 0.012), and shorter postoperative length of hospital stay (p = 0.044). The mean VAS scores at the last follow-up were similar between the two groups (p = 0.658). Although the postoperative McCormick and Karnofsky Performance scores were not significantly different between the laminoplasty and unilateral hemilaminectomy groups (p = 0.687 and p = 0.649, respectively), there was a statistically significant improvement based on postoperative neurological results compared to preoperative neurological results for both groups. The incidence of postoperative complications was 5% and 11.7% in the unilateral hemilaminectomy and laminoplasty groups, respectively (p = 0.308).ConclusionsFor spinal schwannoma resection, unilateral hemilaminectomy has more advantages than laminoplasty, including a shorter postoperative hospital stay, faster procedure, and less intraoperative blood loss while achieving the same desired result.
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- 2024
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5. Ferroelectricity in a semiconducting all-inorganic halide perovskite
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Zhang, Ye, Parsonnet, Eric, Fernandez, Abel, Griffin, Sinéad M, Huyan, Huaixun, Lin, Chung-Kuan, Lei, Teng, Jin, Jianbo, Barnard, Edward S, Raja, Archana, Behera, Piush, Pan, Xiaoqing, Ramesh, Ramamoorthy, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Affordable and Clean Energy ,MSD-General ,MSD-PChem - Abstract
Ferroelectric semiconductors are rare materials with both spontaneous polarizations and visible light absorptions that are promising for designing functional photoferroelectrics, such as optical switches and ferroelectric photovoltaics. The emerging halide perovskites with remarkable semiconducting properties also have the potential of being ferroelectric, yet the evidence of robust ferroelectricity in the typical three-dimensional hybrid halide perovskites has been elusive. Here, we report on the investigation of ferroelectricity in all-inorganic halide perovskites, CsGeX3, with bandgaps of 1.6 to 3.3 eV. Their ferroelectricity originates from the lone pair stereochemical activity in Ge (II) that promotes the ion displacement. This gives rise to their spontaneous polarizations of ~10 to 20 μC/cm2, evidenced by both ab initio calculations and key experiments including atomic-level ionic displacement vector mapping and ferroelectric hysteresis loop measurement. Furthermore, characteristic ferroelectric domain patterns on the well-defined CsGeBr3 nanoplates are imaged with both piezo-response force microscopy and nonlinear optical microscopic method.
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- 2022
6. An adjustable and customised finger splint to improve mallet finger treatment compliance and outcomes
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Shi Lei Teng, Yoke Rung Wong, Peggy Poh Hoon Lim, and Duncan Angus McGrouther
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Finger splint ,3D printing ,Mallet finger ,Medical technology ,R855-855.5 - Abstract
Objective: Tendinous mallet finger injuries are normally treated conservatively by finger splinting, whereby the injured finger is immobilised in extension to allow the ruptured extensor tendon to heal. However, current splints including the Stack and Zimmer reported high failure rates of almost 50 %. Reasons are attributed to poor splint fit, skin complications and discomfort which cause non-compliance to splint regimens. To address the above mentioned issues, we designed and developed a 3D printed adjustable and customised finger splint. Participants and interventions: The 3D printed finger splint, Zimmer and Stack splint were worn by 24 healthy volunteers on their middle fingers for 24 h. Main outcome measures: The finger extension angle, splint fit, splint comfort and skin maceration were assessed via angle measurement and subjects’ feedback using a questionnaire. Results: The 3D printed finger splint was capable to maintain the distal interphalangeal joint at an extended angle of 8.1° However, 70.8 % of the subjects reported that the 3D printed finger splint shifted or came off wholly during 24 h of wear. This proportion is higher compared to the Zimmer (45.8 %) and the Stack (37.5 %). While 91.7 % of the subjects were satisfied with the ease of wearing and removing the 3D printed finger splint, subjects experienced difficulty performing work and washing activities owing to the design and material. Conclusion: Our proposed design fulfils its function of holding the fingertip in extension and improves ease of application. The design of 3D printed finger splint could be further refined to provide better splint fit and comfort, so as to achieve better treatment compliance.
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- 2024
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7. Phase transition dynamics in one-dimensional halide perovskite crystals
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Lai, Minliang, Lei, Teng, Zhang, Ye, Jin, Jianbo, Steele, Julian A, and Yang, Peidong
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Engineering ,Materials Engineering ,Affordable and Clean Energy ,Macromolecular and Materials Chemistry ,Mechanical Engineering ,Applied Physics ,Materials engineering ,Nanotechnology - Abstract
Abstract: Triiodide perovskites CsPbI 3, CsSnI 3, and FAPbI 3 (where FA is formamidinium) are highly promising materials for a range of optoelectronic applications in energy conversion. However, they are thermodynamically unstable at room temperature, preferring to form low-temperature (low-T) non-perovskite phases with one-dimensional anisotropic crystal structures. While such thermodynamic behavior represents a major obstacle toward realizing high-performance devices based on their high-temperature (high-T) perovskite phases, the underlying phase transition dynamics are still not well understood. Here we use in situ optical micro-spectroscopy to quantitatively study the transition from the low-T to high-T phases in individual CsSnI 3 and FAPbI 3 nanowires. We reveal a large blueshift in the photoluminescence (PL) peak (~38 meV) at the low-T/high-T two-phase interface of partially transitioned FAPbI 3 wire, which may result from the lattice distortion at the phase boundary. Compared to the experimentally derived activation energy of CsSnI3 (~1.93 eV), the activation energy of FAPbI 3 is relatively small (~0.84 eV), indicating a lower kinetic energy barrier when transitioning from a face-sharing octahedral configuration to a corner-sharing one. Further, the phase propagation rate in CsSnI3 is observed to be relatively high, which may be attributed to a high concentration of Sn vacancies. Our results could not only facilitate a deeper understanding of phase transition dynamics in halide perovskites with anisotropic crystal structures, but also enable controllable manipulation of optoelectronic properties via local phase engineering. Impact Statement: Metal halide perovskites are a new class of semiconductors with great promise for a variety of optoelectronic applications. Owing to their soft ionic lattice, halide perovskites often exhibit rich phase transitions between different crystal structures, frequently from the “active” perovskite phases to undesirable “inactive” non-perovskite phases. Understanding and controlling this transition is vital for developing stable, high-performance devices. However, there is limited understanding on how different symmetry, crystal structure, and defect would impact such a phase transition process. In this report, in situ optical micro-spectroscopy is used to systematically investigate the phase transitions from non-perovskite to perovskite phases in individual CsSnI3 and FAPbI3 wires. Compared to the transition from an edge-sharing octahedral non-perovskite structure to a corner-sharing perovskite structure in CsSnI3, the activation energy for the FAPbI3 phase transition is relatively small, indicating a lower energy barrier when starting from a face-sharing octahedral structure in FAPbI3. The high concentration of Sn vacancies is probably responsible for the much higher phase propagation rate in CsSnI3 when compared to a CsPbBrxI3-x system with the same crystal structure but different halide vacancies. Our experimental results expand theknowledge of phase transition in halide perovskites and offer important guidance toward rationally designing more stable and efficient perovskite devices.
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- 2021
8. Liquid-Like Interfaces Mediate Structural Phase Transitions in Lead Halide Perovskites
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Bischak, Connor G., Lai, Minliang, Lu, Dylan, Fan, Zhaochuan, David, Philippe, Dong, Dengpan, Chen, Hong, Etman, Ahmed S., Lei, Teng, Sun, Junliang, Grünwald, Michael, Limmer, David T., Yang, Peidong, and Ginsberg, Naomi S.
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Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Materials Science ,Condensed Matter - Statistical Mechanics ,Physics - Applied Physics ,Physics - Chemical Physics - Abstract
Microscopic pathways of structural phase transitions are difficult to probe because they occur over multiple, disparate time and length scales. Using $in$ $situ$ nanoscale cathodoluminescence microscopy, we visualize the thermally-driven transition to the perovskite phase in hundreds of non-perovskite phase nanowires, resolving the initial nanoscale nucleation and subsequent mesoscale growth and quantifying the activation energy for phase propagation. In combination with molecular dynamics computer simulations, we reveal that the transformation does not follow a simple martensitic mechanism, and proceeds via ion diffusion through a liquid-like interface between the two structures. While cations are disordered in this liquid-like region, the halide ions retain substantial spatial correlations. We find that the anisotropic crystal structure translates to faster nucleation of the perovskite phase at nanowire ends and faster growth along the long nanowire axis. These results represent a significant step towards manipulating structural phases at the nanoscale for designer materials properties., Comment: 8 pages, 3 figures, ancilliary supplementary information
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- 2019
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9. Morphology-controlled transformation of Cu@Au core-shell nanowires into thermally stable Cu3Au intermetallic nanowires
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Niu, Zhiqiang, Chen, Shouping, Yu, Yi, Lei, Teng, Dehestani, Ahmad, Schierle-Arndt, Kerstin, and Yang, Peidong
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Engineering ,Chemical Sciences ,Nanotechnology ,intermetallic nanocrystal ,shape control ,nanowire ,Cu-Au ,stability ,Nanoscience & Nanotechnology - Abstract
Multimetallic nanowires with long-range atomic ordering hold the promise of unique physicochemical properties in many applications. Here we demonstrate the synthesis and study the stability of Cu3Au intermetallic nanowires. The synthesis is achieved by using Cu@Au core-shell nanowires as precursors. With appropriate Cu/Au stoichiometry, the Cu@Au core-shell nanowires are transformed into fully ordered Cu3Au nanowires under thermal annealing. Thermally-driven atom diffusion accounts for this transformation as revealed by X-ray diffraction and electron microscopy studies. The twin boundaries abundant in the Cu@Au core-shell nanowires facilitate the ordering process. The resulting Cu3Au intermetallic nanowires have uniform and accurate atomic positioning in the crystal lattice, which enhances the nobility of Cu. No obvious copper oxides are observed in fully ordered Cu3Au nanowires after annealing in air at 200 °C, a temperature that is much higher than those observed in Cu@Au core-shell and pure Cu nanowires. This work opens up an opportunity for further research into the development and applications of intermetallic nanowires. [Figure not available: see fulltext.].
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- 2020
10. Liquid-like Interfaces Mediate Structural Phase Transitions in Lead Halide Perovskites
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Bischak, Connor G, Lai, Minliang, Fan, Zhaochuan, Lu, Dylan, David, Philippe, Dong, Dengpan, Chen, Hong, Etman, Ahmed S, Lei, Teng, Sun, Junliang, Grünwald, Michael, Limmer, David T, Yang, Peidong, and Ginsberg, Naomi S
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,cond-mat.mes-hall ,cond-mat.mtrl-sci ,cond-mat.stat-mech ,physics.app-ph ,physics.chem-ph ,Macromolecular and materials chemistry ,Materials engineering ,Nanotechnology - Abstract
Microscopic pathways of structural phase transitions in metal halide perovskites are difficult to probe because they occur over disparate time and length scales and because electron-based microscopies typically used to directly probe nanoscale dynamics of phase transitions often damage metal halide perovskite materials. Using in situ nanoscale cathodoluminescence microscopy with low electron beam exposure, we visualize nucleation and growth in the thermally driven transition to the perovskite phase in hundreds of non-perovskite phase nanowires. In combination with molecular dynamics simulations, we reveal that the transformation does not follow a simple martensitic mechanism, but proceeds despite a substantial energy barrier via ion diffusion through a liquid-like interface between the two structures. While cations are disordered in this liquid-like region, the halide ions retain substantial spatial correlations. This detailed picture not only reveals how phase transitions between disparate structures can proceed, but also opens the possibility to control such processes.
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- 2020
11. Lead-free Cesium Europium Halide Perovskite Nanocrystals
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Huang, Jianmei, Lei, Teng, Siron, Martin, Zhang, Ye, Yu, Sunmoon, Seeler, Fabian, Dehestani, Ahmad, Quan, Li Na, Schierle-Arndt, Kerstin, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,rare earth ,nanocrystals ,blue emission ,lead-free halide perovskites ,Nanoscience & Nanotechnology - Abstract
Because of the toxicity of lead, searching for a lead-free halide perovskite semiconducting material with comparable optical and electronic properties is of great interest. Rare-earth-based halide perovskite represents a promising class of materials for this purpose. In this work, we demonstrate the solution-phase synthesis of single-crystalline CsEuCl3 nanocrystals with a uniform size distribution centered around 15 nm. The CsEuCl3 nanocrystals have photoluminescence emission centered at 435 nm, with a full width at half-maximum of 19 nm. Furthermore, CsEuCl3 nanocrystals can be embedded in a polymer matrix that provides enhanced stability under continuous laser irradiation. Lead-free rare-earth cesium europium halide perovskite nanocrystals represent a promising candidate to replace lead halide perovskites.
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- 2020
12. Phase transition dynamics in one-dimensional halide perovskite crystals
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Lai, Minliang, Lei, Teng, Zhang, Ye, Jin, Jianbo, Steele, Julian A, and Yang, Peidong
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Engineering ,Materials Engineering ,Affordable and Clean Energy ,Macromolecular and Materials Chemistry ,Mechanical Engineering ,Applied Physics ,Materials engineering ,Nanotechnology - Abstract
Triiodide perovskites CsPbI3, CsSnI3, and FAPbI3(where FA is formamidinium) are highly promising materials for a range of optoelectronic applications in energy conversion. However, they are thermodynamically unstable at room temperature, preferring to form low-temperature (low-T) non-perovskite phases with one-dimensional anisotropic crystal structures. While such thermodynamic behavior represents a major obstacle toward realizing high-performance devices based on their high-temperature (high-T) perovskite phases, the underlying phase transition dynamics are still not well understood. Here we use in situ optical micro-spectroscopy to quantitatively study the transition from the low-T to high-T phases in individual CsSnI3and FAPbI3nanowires. We reveal a large blueshift in the photoluminescence (PL) peak (∼38 meV) at the low-T/high-T two-phase interface of partially transitioned FAPbI3wire, which may result from the lattice distortion at the phase boundary. Compared to the experimentally derived activation energy of CsSnI3(∼1.93 eV), the activation energy of FAPbI3is relatively small (∼0.84 eV), indicating a lower kinetic energy barrier when transitioning from a face-sharing octahedral configuration to a corner-sharing one. Further, the phase propagation rate in CsSnI3is observed to be relatively high, which may be attributed to a high concentration of Sn vacancies. Our results could not only facilitate a deeper understanding of phase transition dynamics in halide perovskites with anisotropic crystal structures, but also enable controllable manipulation of optoelectronic properties via local phase engineering.
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- 2020
13. Opportunistic Routing Aided Cooperative Communication MRC Network With Energy-Harvesting Nodes
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Lei Teng, Wannian An, Chen Dong, Xiaodong Xu, and Boxiao Han
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Energy-harvesting ,opportunistic routing ,maximal ratio combining ,state transition matrix ,Telecommunication ,TK5101-6720 ,Transportation and communications ,HE1-9990 - Abstract
In this research, we present a cooperative communication network based on two energy-harvesting (EH) decode-and-forward (DF) relays that contain the harvest-store-use (HSU) architecture and may harvest energy from the surrounding environment by utilizing energy buffers. To improve the performance of this network, an opportunistic routing (OR) algorithm is presented that takes into account channel status information, relay position, and energy buffer status, as well as using the maximal ratio combining (MRC) at the destination to combine the signals received from the source and relays. The theoretical expressions for limiting distribution of energy stored in infinite-size buffers are derived from the discrete-time continuous-state space Markov chain model (DCSMC). In addition, the theoretical expressions for outage probability, throughput, and per-packet time slot cost in the network are obtained utilizing both the limiting distributions of energy buffers and the probabilities of transmitter candidates set. Through numerous simulation results, it is demonstrated that simulation results match with corresponding theoretical results.
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- 2023
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14. Dose of intra‐operative opioids has no impact on recurrence or survival in primary liver cancer
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Liuyuan Zhao, Lei Teng, Wenhui Zhang, Shiyan Lin, Xuejiao Liu, Junzhu Dai, Hongxue Shao, Xiaoshi Li, Quan Liu, and Huichao Zou
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hepatectomy ,intro‐operative opioid ,overall survival ,primary liver cancer ,recurrence‐free survival ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Intra‐operative use of opioid analgesics might have an impact on cancer recurrence and survival after surgery. The objective of this study was to investigate the association between the intra‐operative fentanyl equivalents and survival outcomes in patients with primary liver cancer after receiving hepatectomy. Methods This was a retrospective single‐center cohort study, and clinical data of 700 patients with primary liver cancer who underwent hepatectomy in Harbin Medical University Cancer Hospital from September 2013 to August 2018 were reviewed. After propensity matching, 376 patients were included. Patients were divided into high‐dose and low‐dose groups according to the median intra‐operative fentanyl equivalents (1.500 mg). Kaplan Meier curve and Cox proportional hazards regression model were used. Results Results of univariable analysis showed there were no significant differences in recurrence‐free survival (RFS) (p = 0.136) and overall survival (OS) (p = 0.444) between high‐dose fentanyl equivalents and low‐dose fentanyl equivalents group. The multivariable Cox regression analysis found that the dose of intra‐operative fentanyl equivalents was not associated with RFS (HR: 1.119, 95%CI: 0.851–1.472, p = 0.422) or OS (HR: 0.939, 95%CI: 0.668–1.319, p = 0.715). Conclusions The amounts of intra‐operative fentanyl equivalents had no impact on recurrence‐free or overall survival in patients with primary liver cancer after curative hepatectomy.
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- 2022
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15. Calcaneous interlocking nail treatment for calcaneous fracture: a multiple center retrospective study
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Ye Peng, Junsong Wang, Bo Feng, Yunshou Li, Yunlong Zhu, Weiqing Yuan, Lei Teng, Chengming Zhu, Bin Shi, and Lihai Zhang
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Calcaneal fracture ,Sinus tarsi approach ,Calcaneal interlocking nail ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Minimally invasive treatments for calcaneous fractures have the same outcomes and fewer complications. However, they are technically demanding, and there are a lack reduction tools. To overcome these problems, a calcaneous interlocking nail system was developed that can make reduction and fixation minimally invasive and effective. We retrospectively studied the calcaneous fracture variables intraoperatively and followed up to evaluate the outcomes of patients treated with the calcaneous interlocking nail system. Methods All patients in 7 institutions between October 2020 and May 2021 who had calcaneous fractures treated with calcaneous interlocking nails were retrospectively analyzed. The patient characteristics, including age, sex, injury mechanism, Sanders type classification, smoking status, and diabetes were recorded. The calcaneous interlocking nail and standard surgical technique were introduced. The intraoperative variables, including days waiting for surgery, surgery time, blood loss, incision length, and fluoroscopy time, were recorded. The outcomes of complications, AOFAS scores and VAS scores were recorded and compared with other similar studies. Results Fifty-nine patients were involved in this study; 54 were male; 5 were female; and they had an average age of 47.5 ± 9.2 years (range 25–70). 2 of these fractures were Sanders type I, 28 of these fractures were Sanders type II, 27 of these fractures were Sanders type III, and 2 of these were Sanders type IV. The surgery time was 131.9 ± 50.5 (30–240) minutes on average. The blood loss was 36.9 ± 41.1 (1-250) ml. The average incision length was 3.5 ± 1.8 (1–8) cm; 57 were sinus tarsi incisions; and 2 were closed fixations without incisions. The average fluoroscopy time was 12.3 ± 3.6 (10–25) seconds during the surgery. The VAS score of patients on the day after surgery was 2.4 ± 0.7 (1–3). The AOFAS ankle-hindfoot score in patients who had a follow-up of at 12 months was 93.3 ± 3.6(85–99). During the follow-up, all patients’ functional outcomes were good. One patient had a superficial infection. The rate of complications of the 59 patients was 1.7% (1/59). Conclusion The calcaneous interlocking nail system can have satisfactory reduction and fixation in calcaneous fractures, even in Sanders type IV. The outcomes of follow-up showed good function. The calcaneous interlocking nail could be an alternative method for minimally invasive calcaneous fracture fixation.
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- 2022
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16. Pressure-induced semiconductor-to-metal phase transition of a charge-ordered indium halide perovskite
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Lin, Jia, Chen, Hong, Gao, Yang, Cai, Yao, Jin, Jianbo, Etman, Ahmed S, Kang, Joohoon, Lei, Teng, Lin, Zhenni, Folgueras, Maria C, Quan, Li Na, Kong, Qiao, Sherburne, Matthew, Asta, Mark, Sun, Junliang, Toney, Michael F, Wu, Junqiao, and Yang, Peidong
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Inorganic Chemistry ,Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,charge ordered ,inorganic ,halide perovskite ,phase transition ,high pressure - Abstract
Phase transitions in halide perovskites triggered by external stimuli generate significantly different material properties, providing a great opportunity for broad applications. Here, we demonstrate an In-based, charge-ordered (In+/In3+) inorganic halide perovskite with the composition of Cs2In(I)In(III)Cl6 in which a pressure-driven semiconductor-to-metal phase transition exists. The single crystals, synthesized via a solid-state reaction method, crystallize in a distorted perovskite structure with space group I4/m with a = 17.2604(12) Å, c = 11.0113(16) Å if both the strong reflections and superstructures are considered. The supercell was further confirmed by rotation electron diffraction measurement. The pressure-induced semiconductor-to-metal phase transition was demonstrated by high-pressure Raman and absorbance spectroscopies and was consistent with theoretical modeling. This type of charge-ordered inorganic halide perovskite with a pressure-induced semiconductor-to-metal phase transition may inspire a range of potential applications.
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- 2019
17. Self-Assembly of Two-Dimensional Perovskite Nanosheet Building Blocks into Ordered Ruddlesden–Popper Perovskite Phase
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Liu, Yong, Siron, Martin, Lu, Dylan, Yang, Jingjing, dos Reis, Roberto, Cui, Fan, Gao, Mengyu, Lai, Minliang, Lin, Jia, Kong, Qiao, Lei, Teng, Kang, Joohoon, Jin, Jianbo, Ciston, Jim, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Nanotechnology ,Bioengineering ,General Chemistry ,Chemical sciences ,Engineering - Abstract
The self-assembly of nanoparticles, a process whereby nanocrystal building blocks organize into even more ordered superstructures, is of great interest to nanoscience. Here we report the layer-by-layer assembly of 2D perovskite nanosheet building blocks. Structural analysis reveals that the assembled superlattice nanocrystals match with the layered Ruddlesden-Popper perovskite phase. This assembly proves reversible, as these superlattice nanocrystals can be reversibly exfoliated back into their building blocks via sonication. This study demonstrates the opportunity to further understand and exploit thermodynamics to increase order in a system of nanoparticles and to study emergent optical properties of a superlattice from 2D, weakly attracted, perovskite building blocks.
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- 2019
18. Quantitative imaging of anion exchange kinetics in halide perovskites
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Zhang, Ye, Lu, Dylan, Gao, Mengyu, Lai, Minliang, Lin, Jia, Lei, Teng, Lin, Zhenni, Quan, Li Na, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Benzofurans ,Halogens ,Kinetics ,Light ,Luminescence ,Nanostructures ,Semiconductors ,Single Molecule Imaging ,Solar Energy ,halide perovskites ,anion exchange and diffusion ,reaction kinetics ,quantitative imaging ,2D heterostructures - Abstract
Ion exchange, as a postsynthetic transformation strategy, offers more flexibilities in controlling material compositions and structures beyond direct synthetic methodology. Observation of such transformation kinetics on the single-particle level with rich spatial and spectroscopic information has never been achieved. We report the quantitative imaging of anion exchange kinetics in individual single-crystalline halide perovskite nanoplates using confocal photoluminescence microscopy. We have systematically observed a symmetrical anion exchange pathway on the nanoplates with dependence on reaction time and plate thickness, which is governed by the crystal structure and the diffusion-limited transformation mechanism. Based on a reaction-diffusion model, the halide diffusion coefficient was estimated to be on the order of [Formula: see text] This diffusion-controlled mechanism leads to the formation of 2D perovskite heterostructures with spatially resolved coherent interface through the precisely controlled anion exchange reaction, offering a design protocol for tailoring functionalities of semiconductors at the nano-/microscale.
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- 2019
19. Limited Variation in Codon Usage across Mitochondrial Genomes of Non-Biting Midges (Diptera: Chironomidae).
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Lei, Teng, Zheng, Xiaojun, Song, Chao, Jin, Haobo, Chen, Lingjun, and Qi, Xin
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MITOCHONDRIAL DNA , *NATURAL selection , *CHIRONOMIDAE , *GENOMES , *PHYLOGENY - Abstract
Simple Summary: There are thousands of species of non-biting midges. They face various living pressures which may influence their codon usage in mitochondrial genomes. Codon usage analysis has been conducted on only a few species, and the codon usage across Chironomidae is still unclear. In this study, we sequenced a new mitochondrial genome and compared codon usage across as many genera as possible. Limited variation was observed in most genera, except one which presented a weaker codon usage bias. We speculated that most of its mitochondrial genes experienced natural selection. Additionally, three genes, ND1, ND2 and ND3, were found to have experienced natural selection across most genera. To some extent, this work adds to our understanding of the evolution and phylogeny of non-biting midges. The codon usage patterns of mitochondrial genomes offer insights into the evolutionary and phylogenetic studies of species. Codon usage analysis has been conducted in a few Chironomidae species, and the codon usage patterns in other species remain ambiguous. We aim to reveal the codon usage differences in the mitochondrial genomes across this family. We sequenced the first mitochondrial genome of the genus Conchapelopia and the third mitochondrial genome of the subfamily Tanypodinae. Then, we analyzed its relative synonymous codon usage and effective number of codons with registered mitochondrial genomes from 28 other genera. The results indicated that there was limited variation in codon usage across five subfamilies, Chironominae, Orthocladiinae, Diamesinae, Prodiamesinae and Tanypodinae. While Parochlus steinenii from Podonominae presented a weaker codon bias, P. steinenii possessed the most genes experiencing natural selection. Additionally, ND1, ND2 and ND3 were found to be the most frequently selected genes across all species. Our findings contribute to further understanding the evolutionary and phylogenetic relationships of Chironomidae. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Intrinsic anion diffusivity in lead halide perovskites is facilitated by a soft lattice
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Lai, Minliang, Obliger, Amael, Lu, Dylan, Kley, Christopher S, Bischak, Connor G, Kong, Qiao, Lei, Teng, Dou, Letian, Ginsberg, Naomi S, Limmer, David T, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,halide perovskite nanowire ,anion diffusivity ,nanoscale imaging ,molecular simulation ,soft lattice - Abstract
Facile ionic transport in lead halide perovskites plays a critical role in device performance. Understanding the microscopic origins of high ionic conductivities has been complicated by indirect measurements and sample microstructural heterogeneities. Here, we report the direct visualization of halide anion interdiffusion in CsPbCl3-CsPbBr3 single crystalline perovskite nanowire heterojunctions using wide-field and confocal photoluminescence measurements. The combination of nanoscale imaging techniques with these single crystalline materials allows us to measure intrinsic anionic lattice diffusivities, free from complications of microscale inhomogeneity. Halide diffusivities were found to be between 10-13 and ∼10-12 cm2/second at about 100 °C, which are several orders of magnitudes lower than those reported in polycrystalline thin films. Spatially resolved photoluminescence lifetimes and surface potential measurements provide evidence of the central role of halide vacancies in facilitating ionic diffusion. Vacancy formation free energies computed from molecular simulation are small due to the easily deformable perovskite lattice, accounting for the high equilibrium vacancy concentration. Furthermore, molecular simulations suggest that ionic motion is facilitated by low-frequency lattice modes, resulting in low activation barriers for vacancy-mediated transport. This work elucidates the intrinsic solid-state ion diffusion mechanisms in this class of semisoft materials and offers guidelines for engineering materials with long-term stability in functional devices.
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- 2018
21. Giant Light-Emission Enhancement in Lead Halide Perovskites by Surface Oxygen Passivation
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Lu, Dylan, Zhang, Ye, Lai, Minliang, Lee, Alex, Xie, Chenlu, Lin, Jia, Lei, Teng, Lin, Zhenni, Kley, Christopher S, Huang, Jianmei, Rabani, Eran, and Yang, Peidong
- Subjects
Quantum Physics ,Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Physical Sciences ,Perovskites ,surface passivation ,photoluminescence ,quantum efficiency ,size effect ,Nanoscience & Nanotechnology - Abstract
Surface condition plays an important role in the optical performance of semiconductor materials. As new types of semiconductors, the emerging metal-halide perovskites are promising for next-generation optoelectronic devices. We discover significantly improved light-emission efficiencies in lead halide perovskites due to surface oxygen passivation. The enhancement manifests close to 3 orders of magnitude as the perovskite dimensions decrease to the nanoscale, improving external quantum efficiencies from
- Published
- 2018
22. Phase-transition–induced p-n junction in single halide perovskite nanowire
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Kong, Qiao, Lee, Woochul, Lai, Minliang, Bischak, Connor G, Gao, Guoping, Wong, Andrew B, Lei, Teng, Yu, Yi, Wang, Lin-Wang, Ginsberg, Naomi S, and Yang, Peidong
- Subjects
Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,halide perovskite nanowire ,heterostructure ,phase transition ,p-n junction ,electrical transport - Abstract
Semiconductor p-n junctions are fundamental building blocks for modern optical and electronic devices. The p- and n-type regions are typically created by chemical doping process. Here we show that in the new class of halide perovskite semiconductors, the p-n junctions can be readily induced through a localized thermal-driven phase transition. We demonstrate this p-n junction formation in a single-crystalline halide perovskite CsSnI3 nanowire (NW). This material undergoes a phase transition from a double-chain yellow (Y) phase to an orthorhombic black (B) phase. The formation energies of the cation and anion vacancies in these two phases are significantly different, which leads to n- and p- type electrical characteristics for Y and B phases, respectively. Interface formation between these two phases and directional interface propagation within a single NW are directly observed under cathodoluminescence (CL) microscopy. Current rectification is demonstrated for the p-n junction formed with this localized thermal-driven phase transition.
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- 2018
23. Electrical and Optical Tunability in All-Inorganic Halide Perovskite Alloy Nanowires
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Lei, Teng, Lai, Minliang, Kong, Qiao, Lu, Dylan, Lee, Woochul, Dou, Letian, Wu, Vincent, Yu, Yi, and Yang, Peidong
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Macromolecular and Materials Chemistry ,Chemical Sciences ,Physical Chemistry ,Engineering ,Nanotechnology ,Semiconductor alloy ,tunability ,halide perovskite ,nanowires ,Nanoscience & Nanotechnology - Abstract
Alloying different semiconductors is a powerful approach to tuning the optical and electronic properties of semiconductor materials. In halide perovskites (ABX3), alloys with different anions have been widely studied, and great band gap tunability in the visible range has been achieved. However, perovskite alloys with different cations at the "B" site are less understood due to the synthetic challenges. Herein, we first have developed the synthesis of single-crystalline CsPb xSn1- xI3 nanowires (NWs). The electronic band gaps of CsPb xSn1- xI3 NWs can be tuned from 1.3 to 1.78 eV by varying the Pb/Sn ratio, which leads to the tunable photoluminescence (PL) in the near-infrared range. More importantly, we found that the electrical conductivity increases as more Sn2+ is alloyed with Pb2+, possibly due to the increase of charge carrier concentration when more Sn2+ is introduced. The wide tunability of the optical and electronic properties makes CsPb xSn1- xI3 alloy NWs promising candidates for future optoelectronic device applications.
- Published
- 2018
24. Design principles for high transition metal capacity in disordered rocksalt Li-ion cathodes
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Kitchaev, Daniil A, Lun, Zhengyan, Richards, William D, Ji, Huiwen, Clément, Raphaële J, Balasubramanian, Mahalingam, Kwon, Deok-Hwang, Dai, Kehua, Papp, Joseph K, Lei, Teng, McCloskey, Bryan D, Yang, Wanli, Lee, Jinhyuk, and Ceder, Gerbrand
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Engineering ,Materials Engineering ,Chemical Sciences ,Physical Chemistry ,Affordable and Clean Energy ,Energy - Abstract
The discovery of facile Li transport in disordered, Li-excess rocksalt materials has opened a vast new chemical space for the development of high energy density, low cost Li-ion cathodes. We develop a strategy for obtaining optimized compositions within this class of materials, exhibiting high capacity and energy density as well as good reversibility, by using a combination of low-valence transition metal redox and a high-valence redox active charge compensator, as well as fluorine substitution for oxygen. Furthermore, we identify a new constraint on high-performance compositions by demonstrating the necessity of excess Li capacity as a means of counteracting high-voltage tetrahedral Li formation, Li-binding by fluorine and the associated irreversibility. Specifically, we demonstrate that 10-12% of Li capacity is lost due to tetrahedral Li formation, and 0.4-0.8 Li per F dopant is made inaccessible at moderate voltages due to Li-F binding. We demonstrate the success of this strategy by realizing a series of high-performance disordered oxyfluoride cathode materials based on Mn2+/4+ and V4+/5+ redox.
- Published
- 2018
25. Therapeutic effect of natural polyphenols against glioblastoma
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Ozal Beylerli, Aferin Beilerli, Alina Shumadalova, Xiaoxiong Wang, Mingchun Yang, Hanran Sun, and Lei Teng
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glioblastoma ,anticancer therapy ,polyphenols ,flavonoids ,curcumin ,Biology (General) ,QH301-705.5 - Abstract
Glioblastoma (GBM) is the most common and aggressive tumor of the central nervous system, which has a highly invasive growth pattern, which creates poor prospects for patient survival. Chemotherapy and tumor surgery are limited by anticancer drug resistance and tumor invasion. Evidence suggests that combinations of treatments may be more effective than single drugs alone. Natural polyphenolic compounds have potential as drugs for the treatment of glioblastoma and are considered as potential anticancer drugs. Although these beneficial effects are promising, the efficacy of natural polyphenolic compounds in GBM is limited by their bioavailability and blood-brain barrier permeability. Many of them have a significant effect on reducing the progression of glioblastoma through mechanisms such as reduced migration and cell invasion or chemosensitization. Various chemical formulations have been proposed to improve their pharmacological properties. This review summarizes natural polyphenolic compounds and their physiological effects in glioblastoma models by modulating signaling pathways involved in angiogenesis, apoptosis, chemoresistance, and cell invasion. Polyphenolic compounds are emerging as promising agents for combating the progression of glioblastoma. However, clinical trials are still needed to confirm the properties of these compounds in vitro and in vivo.
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- 2022
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26. Control of Architecture in Rhombic Dodecahedral Pt–Ni Nanoframe Electrocatalysts
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Becknell, Nigel, Son, Yoonkook, Kim, Dohyung, Li, Dongguo, Yu, Yi, Niu, Zhiqiang, Lei, Teng, Sneed, Brian T, More, Karren L, Markovic, Nenad M, Stamenkovic, Vojislav R, and Yang, Peidong
- Subjects
Chemical Sciences ,General Chemistry - Abstract
Platinum-based alloys are known to demonstrate advanced properties in electrochemical reactions that are relevant for proton exchange membrane fuel cells and electrolyzers. Further development of Pt alloy electrocatalysts relies on the design of architectures with highly active surfaces and optimized utilization of the expensive element, Pt. Here, we show that the three-dimensional Pt anisotropy of Pt-Ni rhombic dodecahedra can be tuned by controlling the ratio between Pt and Ni precursors such that either a completely hollow nanoframe or a new architecture, the excavated nanoframe, can be obtained. The excavated nanoframe showed ∼10 times higher specific and ∼6 times higher mass activity for the oxygen reduction reaction than Pt/C, and twice the mass activity of the hollow nanoframe. The high activity is attributed to enhanced Ni content in the near-surface region and the extended two-dimensional sheet structure within the nanoframe that minimizes the number of buried Pt sites.
- Published
- 2017
27. Cd248a and Cd248b in zebrafish participate in innate immune responses
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Xianpeng Li, Ruitong Guo, Shuaiqi Yang, Xiangmin Zhang, Xiu Yin, Lei Teng, Shicui Zhang, Guangdong Ji, and Hongyan Li
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zebrafish ,cd248a ,cd248b ,immune ,LPS ,inflammatory cytokines ,Immunologic diseases. Allergy ,RC581-607 - Abstract
CD248, also known as endosialin or tumor endothelial marker 1, is a type I single transmembrane glycoprotein. CD248 has been demonstrated to be upregulated in cancers, tumors and many fibrotic diseases in human and mice, such as liver damage, pulmonary fibrosis, renal fibrosis, arthritis and tumor neovascularization. However, no definite CD248 orthologs in fish have been documented so far. In this study, we report the identification of cd248a and cd248b in the zebrafish. Both the phylogenetic analysis and the conserved synteny strongly suggested that zebrafish cd248a and cd248b are orthologs of the human CD248. Both cd248a and cd248b exhibited similar and dynamic expression pattern in early development, both genes had weak maternal expression, the zygotic transcripts were first seen in anterior somites and head mesenchyme, then shifted to eyes and head mesenchyme, later expanded to branchial arches, and gradually declined with development. The expression profiles of cd248a and cd248b were upregulated upon LPS (Lipopolysaccharide) challenge. Both Cd248a protein and Cd248b protein were localized on the cell membrane and cytoplasm, and overexpression of cd248a and cd248b induced the expression of pro-inflammatory cytokines, in vitro and in vivo. Moreover, deficiency of cd248a or cd248b both downregulated the expression of pro-inflammatory cytokines and upregulated anti-inflammatory cytokine. Additionally, loss of cd248a or cd248b both downregulated the expression of pro-inflammatory cytokines after LPS treatment. Taken together, these results indicated that cd248a and cd248b in zebrafish were involved in immune response and would provide further information to understand functions of Cd248 protein in innate immunity of fish.
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- 2022
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28. Phase I/II trial of local interstitial chemotherapy with arsenic trioxide in patients with newly diagnosed glioma
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Dayong Han, Lei Teng, Xiaoxiong Wang, Yunbo Zhen, Xiaofeng Chen, Mingchun Yang, Ming Gao, Guang Yang, Mingyang Han, Ligang Wang, Jiajun Xu, Yue Li, Alina Shumadalova, and Shiguang Zhao
- Subjects
glioma ,arsenic trioxide ,interstitial chemotherapy ,clinical trial ,toxicity ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
BackgroundGlioma is the most common primary brain tumor in adults with poor prognosis. The glioma patients benefit from STUPP strategy, including maximum and safe resection and adjuvant radiotherapy and chemotherapy. Arsenic trioxide could inhibit various tumors. However, it is a challenge to evaluate the efficiency and safety of srsenic trioxide in glioma patients.ObjectiveThe arsenic trioxide has the potent therapeutic effect on glioma. However, the safety and efficacy of local interstitial chemotherapy with arsenic trioxide in newly diagnosed glioma patients is unclear.MethodsAll patients received partial or complete tumor resection and intraoperative implantation of Ommaya reservoirs followed by standard radiotherapy. Arsenic trioxide with the starting dose 0.3 mg was administered via an Ommaya reservoir catheter inserted into the tumor cavity for 5 consecutive days every 3 months for a total of eight cycles unless tumor progression or excessive toxicity was observed.ResultsNo hematological or grade 4 non-hematological toxicity was observed in any patient during arsenic trioxide treatment. The maximum tolerated dose of 1.5 mg of arsenic trioxide was safe and well tolerated. The median overall survival for WHO grade 3 glioma was 33.6 months, and for glioblastoma was 13.9 months. The median progression-free survival for WHO grade 2 glioma was 40.3 months, for grade 3 glioma was 21.5 months, and for glioblastoma was 9.5 months.ConclusionThese results suggest that arsenic trioxide is safe and well tolerated with local delivery into the tumor cavity of the brain, and the dose recommended for a phase II trial is 1.5 mg.
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- 2022
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29. Interfering with hyaluronic acid metabolism suppresses glioma cell proliferation by regulating autophagy
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Tao Yan, Xin Chen, Hua Zhan, Penglei Yao, Ning Wang, He Yang, Cheng Zhang, Kaikai Wang, Hong Hu, Jiafeng Li, Jingxian Sun, Yu Dong, Enzhou Lu, Zhixing Zheng, Ruotian Zhang, Xiaoxiong Wang, Jichao Ma, Ming Gao, Junyi Ye, Xinzhuang Wang, Lei Teng, Huailei Liu, and Shiguang Zhao
- Subjects
Cytology ,QH573-671 - Abstract
Abstract The tumor microenvironment plays an important role in tumor progression. Hyaluronic acid (HA), an important component of the extracellular matrix in the tumor microenvironment, abnormally accumulates in a variety of tumors. However, the role of abnormal HA accumulation in glioma remains unclear. The present study indicated that HA, hyaluronic acid synthase 3 (HAS3), and a receptor of HA named CD44 were expressed at high levels in human glioma tissues and negatively correlated with the prognosis of patients with glioma. Silencing HAS3 expression or blocking CD44 inhibited glioma cell proliferation in vitro and in vivo. The underlying mechanism was attributed to the inhibition of autophagy flux and maintaining glioma cell cycle arrest in G1 phase. More importantly, 4-methylumbelliferone (4-MU), a small competitive inhibitor of Uridine diphosphate (UDP) with the ability to penetrate the blood-brain barrier (BBB), also inhibited glioma cell proliferation in vitro and in vivo. Thus, approaches that interfere with HA metabolism by altering the expression of HAS3 and CD44 and the administration of 4-MU potentially represent effective strategies for glioma treatment.
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- 2021
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30. The combined analgesic effect of pregabalin and morphine in the treatment of pancreatic cancer pain, a retrospective study
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Junzhu Dai, Lei Teng, Liuyuan Zhao, and Huichao Zou
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morphine ,pancreatic cancer pain ,pregabalin ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Pregabalin is commonly used to relieve neuropathic pain. However, data are lacking on its efficacy for the treatment of chronic cancer pain. The purpose of this study was to determine the analgesic efficacy of pregabalin combined with morphine in the management of pancreatic cancer pain. Methods This study reviewed patients who were prescribed morphine and 150 mg/d pregabalin between 1 January 2017 and 10 November 2018 in our institute. The primary outcomes of this study were the average pain score and dose of morphine. Secondary outcomes included characters of breakthrough cancer pain, functional interference related to pain, anxiety/depression status, and incidence of treatment‐related adverse events during the study. Results A total of 240 patients with pain related to pancreatic cancer were included in the study. The results showed that patients of both combination therapy group (pregabalin+morphine) and monotherapy group (morphine) achieved similar analgesic efficacy, demonstrated by NRS (2.4 ± 0.9 vs. 2.6 ± 0.9; combination vs. monotherapy) at the end of the study. Mean daily dose of morphine used in the combination group was significant lower compared to monotherapy group (39.5 ± 16.0 mg vs. 61.5 ± 19.3 mg, net difference 23.5, 95% CI: 18.4–28.6, p
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- 2021
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31. DNA Barcoding Supports “Color-Pattern’’-Based Species of Stictochironomus from China (Diptera: Chironomidae)
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Song, Chao, primary, Chen, Guanyu, additional, Wang, Le, additional, Lei, Teng, additional, and Qi, Xin, additional
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- 2024
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32. A Super-Resolution Reconstruction Method for Infrared Polarization Images with Sparse Representation of Over-Complete Basis Sets
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Ma, Yizhe, primary, Lei, Teng, additional, Wang, Shiyong, additional, Yang, Zhengye, additional, Li, Linhan, additional, Qu, Weidong, additional, and Li, Fanming, additional
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- 2024
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33. Distributed Birefringence Measurement of a Polarization-Maintaining Fiber With an Extended Range Based on an Enhanced Brillouin Dynamic Grating
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Taofei Jiang, Dengwang Zhou, Meng Xia, Lei Teng, Dexin Ba, and Yongkang Dong
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Brillouin optical fiber sensor ,Brillouin dynamic grating ,birefringence measurement ,polarization maintaining fiber ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
A distributed birefringence measurement of a polarization-maintaining fiber (PMF) can be realized by using a Brillouin dynamic grating (BDG). However, the pump depletion decreases the intensity of the BDG along the PMF and limits the measurement range to a few hundred meters. We demonstrate a distributed birefringence measurement of the PMF with an extended range to 3030 m based on an enhanced BDG with an 18.5-ns pump-1 pulse, frequency-upshifted continuous-wave pump-2, and 4-ns read pulse (spatial resolution: 40 cm). The enhanced BDG is promising to characterize the design of a fiber coil to improve the fiber optic gyroscope performance.
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- 2020
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34. A new ɛ-Keggin polyoxometalate-based metal-organic framework: From design and synthesis to electrochemical hydrogen evolution
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Yan-Xia Ding, Qiu-Hui Zheng, Meng-Ting Peng, Chuang Chen, Kai-Feng Zou, Bao-Xia Dong, Wen-Long Liu, and Yun-Lei Teng
- Subjects
Polyoxometalate ,Metal-organic framework ,Hydrothermal ,HER ,Overpotential ,Chemistry ,QD1-999 - Abstract
A new ɛ-Keggin polyoxometalate based metal-organic framework, [TBA]3[H4PMo8VMo4VIO40Zn4](HTPT)2 (1) (H3TPT = 1,1′:4′,1″-terphenyl-3,4″,5-tricarboxylic acid, TBA+ = tetrabutylammonium ion) was synthesized under hydrothermal conditions. The tetrahedral Zn4-ε-Keggin is connected through angular HTPT2− to form a 2D entangled structure with 2-fold interpenetration. The whole network displays a staggered layer structure in AB/CD/EF/GH/AB/CD/EF/GH arrangement with extensive hydrogen bonding and intermolecular interactions. More interestingly, compound 1 exhibited good hydrogen evolution reaction (HER) activity in an acidic medium, with a Tafel slope of 68 mV·dec−1 and an η10 of 417 mV. It showed an excellent long-term stability, which could maintain its catalytic activity after 1000 cycles.
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- 2021
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35. Comparative Genomics Reveals Three Genetic Groups of the Whitefly Obligate Endosymbiont Candidatus Portiera aleyrodidarum
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Lei, Teng, primary, Luo, Ning, additional, Song, Chao, additional, Yu, Junwei, additional, Zhou, Yuhang, additional, Qi, Xin, additional, and Liu, Yinquan, additional
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- 2023
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36. The level of midgut penetration of two begomoviruses affects their acquisition and transmission by two species of Bemisia tabaci
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Guo, Tao, Zhao, Jing, Pan, Li-Long, Geng, Liang, Lei, Teng, Wang, Xiao-Wei, and Liu, Shu-Sheng
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- 2018
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37. Epoxied SiO2 nanoparticles and polyethyleneimine (PEI) coated polyvinylidene fluoride (PVDF) membrane for improved oil water separation, anti-fouling, dye and heavy metal ions removal capabilities
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Lei Teng, Chuan Yue, and Ganwei Zhang
- Subjects
Biomaterials ,Colloid and Surface Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2023
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38. Complete mitochondrial genome of the non-biting midge Polypedilum henicurum Wang, 1995 (Diptera: Chironomidae)
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Di, Xuanru, primary, Lei, Teng, additional, Mou, Kunlun, additional, Song, Chao, additional, and Qi, Xin, additional
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- 2023
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39. Cation Composition Engineering of Halide Perovskite Semiconductor Nanostructures
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Lei, Teng
- Subjects
Physical chemistry ,Materials Science ,composition engineering ,halide perovskite ,nanostructure ,semiconductor - Abstract
Lead-based halide perovskites ABX3 (A= Cs, CH3NH3, CH(NH2)2; B=Pb; X = Cl, Br, I) have emerged as a promising class of semiconducting materials for optoelectronic applications because of their long carrier diffusion length, high absorption coefficient, bright photoluminescence property and the wide band-gap tunability. Lead halide perovskites are comparable in optoelectronic performance to conventional semiconductor technology, yet, they can be synthesized via solution-based methods, making their fabrication versatile and low-cost. However, due to the intrinsic toxicity of Pb, partially or completely replacing lead with other metal cations has been an important topic in recent years. This dissertation explores three approaches, substitution, alloying and doping, to replace or decrease the amount of Pb in halide perovskite, not only for reducing the toxicity of halide perovskite, but also for tuning the materials’ properties and enabling new applications. Chapter 1 provides an overview of the composition engineering in semiconductors, followed by an introduction of halide perovskites. In the subsequent chapters, the applications of the three approaches would be specifically discussed. Chapter 2 examines the optical and electrical tunability in all-inorganic halide perovskites by alloying CsPbI3 with CsSnI3. The first synthesis of single crystalline CsPbxSn1-xI3 nanowires (NWs) has been developed. The electronic band gaps of CsPbxSn1-xI3 NWs can be tuned from 1.3 eV to 1.78 eV by varying the Pb/Sn ratio, which leads to the tunable photoluminescence (PL) in the near infrared range. More importantly, the electrical conductivity increases as more Sn2+ is alloyed with Pb2+, possibly due to the increase of charge carrier concentration when more Sn2+ is introduced. The wide tunability of the optical and electronic properties makes CsPbxSn1-xI3 alloy NWs promising candidates for future optoelectronic device applications. The substitution method is discussed in Chapter 3. Due to the toxicity of lead, searching for a lead-free halide perovskite semiconducting material with comparable optical and electronic properties is of great interest. Rare-earth based halide perovskite in which Pb is replaced by rare earth metal represents a promising class of materials for this purpose. The first solution phase synthesis of single-crystalline CsEuCl3 nanocrystals with a uniform size distribution centered around 15 nm is discussed in this chapter. The CsEuCl3 nanocrystals have photoluminescence emission centered at 435 nm, with a full width at half maximum (FWHM) of 19 nm. Furthermore, CsEuCl3 nanocrystals can be embedded in a polymer matrix which provides enhanced stability under continuous laser irradiation. Lead-free rare earth cesium europium halide perovskite nanocrystals represent a promising candidate to replace lead halide perovskites. In Chapter 4, doping, the intentional addition of impurities into semiconductor crystals is discussed. A new colloidal method has been used for the synthesis of non-emissive large bandgap transparent halide perovskite Cs2SnCl6 nanocrystals with a diameter of 15 nm. As the transparent media is doped with bismuth ions, it displays strong blue emission with a photoluminescence quantum yield of 22.7 ± 3.9 %. The Density Functional Theory reveals that doping is influenced by the (111) facets of the transparent nanocrystals, which have the lowest surface energy, and that dopants tend to form on the surface of the nanocrystals, acting as luminescent centers. This study not only offers a new perspective to understand the doping mechanisms at nanoscale, but also offers a promising alternative to lead-based halide perovskites nanocrystals including promising optical performance and decreased toxicity.
- Published
- 2019
40. Publisher Correction: Insight into the microbial world of Bemisia tabaci cryptic species complex and its relationships with its host
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Wang, Hua-Ling, Lei, Teng, Xia, Wen-Qiang, Cameron, Stephen L., Liu, Yin-Quan, Zhang, Zhen, Gowda, Maruthi M. N., De Barro, Paul, Navas-Castillo, Jesús, Omongo, Christopher A., Delatte, Hélène, Lee, Kyeong-Yeoll, Patel, Mitulkumar V., Krause-Sakate, Renate, Ng, James, Wu, San-Ling, Fiallo-Olivé, Elvira, Liu, Shu-Sheng, Colvin, John, and Wang, Xiao-Wei
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- 2019
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41. Insight into the microbial world of Bemisia tabaci cryptic species complex and its relationships with its host
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Wang, Hua-Ling, Lei, Teng, Xia, Wen-Qiang, Cameron, Stephen L., Liu, Yin-Quan, Zhang, Zhen, Gowda, Maruthi M. N., De Barro, Paul, Navas-Castillo, Jesús, Omongo, Christopher A., Delatte, Hélène, Lee, Kyeong-Yeoll, Patel, Mitulkumar V., Krause-Sakate, Renate, Ng, James, Wu, San-Ling, Fiallo-Olivé, Elvira, Liu, Shu-Sheng, Colvin, John, and Wang, Xiao-Wei
- Published
- 2019
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42. Comparative proteomic analysis provides new insight into differential transmission of two begomoviruses by a whitefly
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Zhao, Jing, Chi, Yao, Zhang, Xin-Jia, Lei, Teng, Wang, Xiao-Wei, and Liu, Shu-Sheng
- Published
- 2019
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43. New Color-Patterned Species of Microtendipes Kieffer, 1913 (Diptera: Chironomidae) and a Deep Intraspecific Divergence of Species by DNA Barcodes
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Song, Chao, primary, Wang, Le, additional, Lei, Teng, additional, and Qi, Xin, additional
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- 2023
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44. Incidence of Pleural Effusion in Patients with Pulmonary Embolism
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Min Liu, Ai Cui, Zhen-Guo Zhai, Xiao-Juan Guo, Man Li, Lei-Lei Teng, Li-Li Xu, Xiao-Juan Wang, Zhen Wang, and Huan-Zhong Shi
- Subjects
Computed Tomography Pulmonary Angiography ,Pleural Effusion ,Pulmonary Embolism ,Medicine - Abstract
Background: No data on the incidence of pleural effusion (PE) in Chinese patients with pulmonary embolism are available to date. The aim of the current study was to investigate the frequency of PE in a Chinese population of patients with pulmonary embolism. Methods: This was a retrospective observational single-center study. All data of computed tomography pulmonary angiography (CTPA) performed over 6-year period on adult patients with clinically suspected pulmonary embolism were analyzed. Results: From January 2008 until December 2013, PE was identified in 423 of 3141 patients (13.5%) with clinically suspected pulmonary embolism who underwent CTPA. The incidence of PE in patients with pulmonary embolism (19.9%) was significantly higher than in those without embolism (9.4%) (P < 0.001). Majority of PEs in pulmonary embolism patients were small to moderate and were unilateral. The locations of emboli and the numbers of arteries involved, CT pulmonary obstruction index, and parenchymal abnormalities at CT were not associated with the development of PE. Conclusions: PEs are present in about one fifth of a Chinese population of patients with pulmonary embolism, which are usually small, unilateral, and unsuitable for diagnostic thoracentesis.
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- 2015
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45. Clinical Association of Viral Tropism and Serum Cytokines in Untreated HIV-1 Infection Patients
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Na Zhang, Shuang-Mei Yu, Chang-Xin Yan, Xiao-Xiong Wang, Lei Teng, Jia-Ye Wang, and HaiZhou Zhou
- Abstract
Objective Human immunodeficiency virus type 1 (HIV-1) infection disturbs the balance of CD4+ T cells and monocytes in the immune system. In the early stage of infection, the virus stimulates the activation and proliferation of immune cells, induces the release of cytokines, destroys CD4+ T cells, and accelerates HIV-1 replication and AIDS progression. It is essential to explore cytokine changes after HIV-1 infection and further understand the underlying mechanism of HIV infection. Materials and methods In this study, we enrolled 38 HIV-infected subjects and 30 healthy subjects. We measured and compared CD4+ T cell counts, the tropism of HIV and the serum cytokine levels in different groups. Results Our results showed significantly higher serum levels of IL-1β, IL-2, IL-4, IL-7, IL-10, IL-17, IFN-γ, and TNF-α in HIV-infected patients. Higher levels of IL-6 and IL-17 were observed in the + T cell count group, and higher levels of IL-2 were observed in the CCR5-tropic HIV strain group. Conclusion In conclusion, we found that HIV infection-induced activation of the immune system. IL-6 and IL-17 may predict the severity of HIV disease and regulate HIV infection. The level of IL-2 depended on the type of virus strain.
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- 2022
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46. Evolutionary and Expression Analysis of MOV10 and MOV10L1 Reveals Their Origin, Duplication and Divergence
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Shuaiqi Yang, Xiangmin Zhang, Xianpeng Li, Xiu Yin, Lei Teng, Guangdong Ji, and Hongyan Li
- Subjects
Inorganic Chemistry ,RNA helicase ,MOV10 ,MOV10L1 ,evolution ,expression ,Organic Chemistry ,General Medicine ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Catalysis ,Computer Science Applications - Abstract
MOV10 and MOV10L1 both encode ATP-dependent RNA helicases. In mammals, MOV10 and MOV10L1 participate in various kinds of biological contexts, such as defense of RNA virus invasion, neuron system, germ cell and early development. However, mov10 and mov10l1 in zebrafish are obscure and the evolutionary relationships of mov10 among different species remain unclear. In this study, we found MOV10 and MOV10L1 had some variations despite they possessed the conserved feature of RNA helicase, however, they may originate from a single ancestor although they shared limited homology. A single MOV10L1 gene existed among all species, while MOV10 gene experienced lineage-specific intra-chromosomal gene duplication in several species. Interestingly, the mov10 gene expanded to three in zebrafish, which originating from a duplication by whole genome specific duplication of teleost lineage followed by a specific intra-chromosome tandem duplication. The mov10 and mov10l1 showed distinct expression profiles in early stages, however, in adult zebrafish, three mov10 genes exhibited similar diverse expression patterns in almost all tissues. We also demonstrated mov10 genes were upregulated upon virus challenge, highlighting they had redundant conserved roles in virus infection. These results provide valuable data for the evolution of MOV10 and MOV10L1 and they are important to the further functional exploration.
- Published
- 2022
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47. Epoxied SiO
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Lei, Teng, Chuan, Yue, and Ganwei, Zhang
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Biofouling ,Metals, Heavy ,Polyethyleneimine ,Nanoparticles ,Water ,Membranes, Artificial ,Silicon Dioxide - Abstract
Epoxied SiO
- Published
- 2022
48. Opportunistic Routing aided Cooperative Communication MRC Network with Energy-Harvesting Nodes
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Lei Teng, Wannian An, Chen Dong, Xiaodong Xu, and Boxiao Han
- Subjects
FOS: Computer and information sciences ,Computer Networks and Communications ,Information Theory (cs.IT) ,Computer Science - Information Theory ,Computer Science::Networking and Internet Architecture ,Computer Science::Information Theory - Abstract
In this paper, we consider a multi-hop cooperative network founded on two energy-harvesting (EH) decode-and-forward (DF) relays which are provided with harvest-store-use (HSU) architecture to harvest energy from the ambience using the energy buffers. For the sake of boosting the data delivery in this network, maximal ratio combining (MRC) at destination to combine the signals received from source and relays, as well as an opportunistic routing (OR) algorithm which considers channel status information, location and energy buffer status of relays is proposed. With applying discrete-time continuous-state space Markov chain model (DCSMC), the algorithm-based theoretical expression for limiting distribution of stored energy in infinite-size buffer is derived. Further more, with using both the limiting distributions of energy buffers and the probability of transmitter candidates set, the algorithm-based theoretical expressions for outage probability, throughput and timesolt cost for each data of the network are obtained. The simulation results are presented to validate the derived algorithm-based theoretical expressions., arXiv admin note: text overlap with arXiv:2205.06482
- Published
- 2022
49. Taxonomic study on the genus Stenochironomus Kieffer from the Baishanzu Nature Reserve, China (Diptera, Chironomidae)
- Author
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Song, Chao, primary, Zhu, Bin-Qing, additional, Moubayed-Breil, Joel, additional, Lei, Teng, additional, and Qi, Xin, additional
- Published
- 2022
- Full Text
- View/download PDF
50. A newly recorded Rickettsia of the Torix group is a recent intruder and an endosymbiont in the whitefly <scp> Bemisia tabaci </scp>
- Author
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Wang, Hua-Ling, Lei, Teng, Wang, Xiao-Wei, Maruthi, M. N., Zhu, Dan-Tong, Cameron, Stephen L., Rao, Qiong, Shan, Hong-Wei, Colvin, John, Liu, Yin-Quan, Liu, Shu-Sheng, Zhejiang University, China, Purdue University, USA, and Zhejiang A&F University, China
- Subjects
Male ,Asia ,S1 ,media_common.quotation_subject ,Zoology ,Insect ,Whitefly ,Biology ,Microbiology ,Hemiptera ,03 medical and health sciences ,Symbiosis ,Phylogenetics ,Animals ,Rickettsia ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,media_common ,0303 health sciences ,030306 microbiology ,Host (biology) ,biology.organism_classification ,Phenotype ,Candidatus ,bacteria ,Female - Abstract
The bacterium Rickettsia is found widely in phytophagous insects and often exerts profound effects on the phenotype and fitness of its hosts. Here, we decrypt a new, independent, phylogenetically ancient Torix Rickettsia endosymbiont found constantly in a laboratory line of an economically important insect Asia II 7, a putative species of the Bemisia tabaci whitefly complex (Hemiptera: Aleyrodidae), and occasionally in field whitefly populations. This new Rickettsia distributes throughout the body of its whitefly host. Genetically, compared to Rickettsia_bellii_MEAM1 found earlier in whiteflies, the new Rickettsia species has more gene families and pathways, which may be important factors in shaping specific symbiotic relationships. We propose the name 'Candidatus Rickettsia_Torix_Bemisia_tabaci (RiTBt)' for this new endosymbiont associated with whiteflies. Comparative genomic analyses indicate that RiTBi may be a relatively recent intruder in whiteflies given its low abundance in the field and relatively larger genome compared to Rickettsia_bellii_MEAM1.
- Published
- 2020
- Full Text
- View/download PDF
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