10 results on '"Junjie Quan"'
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2. Dimensional Gradient Structure of CoSe2@CNTs–MXene Anode Assisted by Ether for High-Capacity, Stable Sodium Storage
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Enze Xu, Pengcheng Li, Junjie Quan, Hanwen Zhu, Li Wang, Yajing Chang, Zhenjie Sun, Lei Chen, Dabin Yu, and Yang Jiang
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CoSe2@CNTs–MXene ,Ether electrolyte ,In situ XRD ,DFT calculation ,Sodium-ion full battery ,Technology - Abstract
Abstract Recently, abundant resources, low-cost sodium-ion batteries are deemed to the new-generation battery in the field of large-scale energy storage. Nevertheless, poor active reaction dynamics, dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved. Herein, dimensional gradient structure of sheet–tube–dots is constructed with CoSe2@CNTs–MXene. Gradient structure is conducive to fast migration of electrons and ions with the association of ether electrolyte. For half-cell, CoSe2@CNTs–MXene exhibits high initial coulomb efficiency (81.7%) and excellent cycling performance (400 mAh g−1 cycling for 200 times in 2 A g−1). Phase transformation pathway from crystalline CoSe2–Na2Se with Co and then amorphous CoSe2 in the discharge/charge process is also explored by in situ X-ray diffraction. Density functional theory study discloses the CoSe2@CNTs–MXene in ether electrolyte system which contributes to stable sodium storage performance owing to the strong adsorption force from hierarchical structure and weak interaction between electrolyte and electrode interface. For full cell, CoSe2@CNTs–MXene//Na3V2 (PO4)3/C full battery can also afford a competitively reversible capacity of 280 mAh g−1 over 50 cycles. Concisely, profiting from dimensional gradient structure and matched electrolyte of CoSe2@CNTs–MXene hold great application potential for stable sodium storage.
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- 2021
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- View/download PDF
3. Alternating double t-values and T-values
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Junjie Quan
- Subjects
Multiple zeta values ,Multiple t-values ,Multiple T-values ,Odd harmonic numbers ,Contour integration ,Mathematics ,QA1-939 - Abstract
Abstract Recently, Hoffman (Commun. Number Theory Phys. 13:529–567, 2019), Kaneko and Tsumura (Tsukuba J. Math. (in press), 2020) introduced and systematically studied two variants of multiple zeta values of level two, i.e., multiple t-values and multiple T-values, respectively. In this paper, by the contour integration and residue theorem, we establish two general identities, which further reduce to the expressions of the alternating double t-values and T-values. Some examples are also provided.
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- 2020
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4. Some results on q-multiple harmonic sums
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Junjie Quan
- Subjects
General Mathematics ,Mathematical analysis ,Harmonic (mathematics) ,Mathematics - Abstract
In this paper the author present some new identities for q-analogues of multiple harmonic (star) sums whose indices are the sequences ({p}a) and ({p}a, p+1, {p}b). Then we use these formulas to establish some relations between multiple harmonic (star) sums and classical harmonic numbers and binomial coefficients. As an application we give some explicit formulas involving multiple zeta star values. Some interesting consequences and illustrative examples are also given.
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- 2021
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5. Dimensional Gradient Structure of CoSe
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Enze, Xu, Pengcheng, Li, Junjie, Quan, Hanwen, Zhu, Li, Wang, Yajing, Chang, Zhenjie, Sun, Lei, Chen, Dabin, Yu, and Yang, Jiang
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Ether electrolyte ,In situ XRD ,DFT calculation ,CoSe2@CNTs–MXene ,Sodium-ion full battery ,Article - Abstract
Highlights Dimensional gradient structure of sheet–tube–dots was constructed with CoSe2@CNTs–MXene for fast ion and electron transportation.Density functional theory study discloses the electrochemical difference of CoSe2@CNTs–MXene in ether/ester electrolyte system.Phase transformation of CoSe2@CNTs–MXene was analyzed by in situ XRD. The full cell based on CoSe2@CNTs–MXene anode was also assembled. Electronic supplementary material The online version of this article (10.1007/s40820-020-00562-7) contains supplementary material, which is available to authorized users., Recently, abundant resources, low-cost sodium-ion batteries are deemed to the new-generation battery in the field of large-scale energy storage. Nevertheless, poor active reaction dynamics, dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved. Herein, dimensional gradient structure of sheet–tube–dots is constructed with CoSe2@CNTs–MXene. Gradient structure is conducive to fast migration of electrons and ions with the association of ether electrolyte. For half-cell, CoSe2@CNTs–MXene exhibits high initial coulomb efficiency (81.7%) and excellent cycling performance (400 mAh g−1 cycling for 200 times in 2 A g−1). Phase transformation pathway from crystalline CoSe2–Na2Se with Co and then amorphous CoSe2 in the discharge/charge process is also explored by in situ X-ray diffraction. Density functional theory study discloses the CoSe2@CNTs–MXene in ether electrolyte system which contributes to stable sodium storage performance owing to the strong adsorption force from hierarchical structure and weak interaction between electrolyte and electrode interface. For full cell, CoSe2@CNTs–MXene//Na3V2 (PO4)3/C full battery can also afford a competitively reversible capacity of 280 mAh g−1 over 50 cycles. Concisely, profiting from dimensional gradient structure and matched electrolyte of CoSe2@CNTs–MXene hold great application potential for stable sodium storage. Electronic supplementary material The online version of this article (10.1007/s40820-020-00562-7) contains supplementary material, which is available to authorized users.
- Published
- 2020
6. MicroRNA-539 inhibits glioma cell proliferation and invasion by targeting DIXDC1
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Le Zhou, Jianqiang Qu, and Junjie Quan
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0301 basic medicine ,Untranslated region ,Pathology ,medicine.medical_specialty ,Glioma cell ,Biology ,Cell Line ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Cell Line, Tumor ,Glioma ,microRNA ,medicine ,Humans ,Neoplasm Invasiveness ,Inverse correlation ,3' Untranslated Regions ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Pharmacology ,Gene knockdown ,Brain Neoplasms ,Microfilament Proteins ,Intracellular Signaling Peptides and Proteins ,Wnt signaling pathway ,General Medicine ,medicine.disease ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer research ,Signal Transduction - Abstract
Dysregulation of microRNAs (miRNAs) has been suggested to contribute to malignant progression of glioma. Previous studies have demonstrated that miR-539 is dysregulated in malignant progression of cancers. However, the potential role and mechanism of miR-539 in the progression of glioma remains unclear. In this study, we aimed to investigate the expression status and functional significance of miR-539 in glioma. We found that miR-539 expression was significantly decreased in glioma cell lines and tissues. Overexpression of miR-539 markedly inhibited glioma cell proliferation and invasion, while miR-539 suppression exhibited the opposite effect. Bioinformatics analysis and dual-luciferase reporter assays showed that miR-539 directly targeted the 3′-untranslated region of Disheveled-axin domain containing 1 (DIXDC1). DIXDC1 expression was negatively regualted by miR-539 overexpression. An inverse correlation between DIXDC1 mRNA expression and miR-539 expression was found in glioma specimens. Furthermore, knockdown of DIXC1 significantly inhibited proliferation, invasion and Wnt signaling in glioma cells. Overexpression of DIXDC1 partially reversed the inhibitory effect of miR-539 on glioma cell proliferation and invasion. Overall, these findings demonstrate that miR-539 inhibits glioma cell proliferation and invasion by targeting DIXDC1. Our study suggests that the miR-539 may serve as a potential target for the clinical diagnosis and treatment of glioma.
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- 2017
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7. The microstructure and reasonable management of the arachnoid during the infrafloccular approach for microvascular decompression of the facial nerve
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Le Zhou, Yan Xianxia, Junjie Quan, Yanbing Ma, Jianqiang Qu, Jiehua Xu, and Mengyao Sun
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congenital, hereditary, and neonatal diseases and abnormalities ,business.industry ,medicine.medical_treatment ,Cranial nerves ,Microvascular decompression ,Dissection (medical) ,Anatomy ,Nerve injury ,medicine.disease ,Cerebellopontine angle ,Facial nerve ,nervous system diseases ,body regions ,cardiovascular system ,medicine ,Surgery ,Arachnoid Membrane ,Neurology (clinical) ,medicine.symptom ,business ,Hemifacial spasm - Abstract
Aim Arachnoid dissection is a basic step during facial nerve microvascular decompression (MVD). However, the literature focusing on the arachnoid microstructure in this region is scarce, and there are different views on how to handle the arachnoid around the cochlea nerve in order to protect the cochlea nerve. To provide a valuable reference for minimal invasion during facial nerve MVD, the arachnoid microstructure during the infrafloccular approach was studied in this paper. Material and methods This study recruited 55 patients with hemifacial spasm who underwent MVD. Retrospective analyses of the MVD surgical videos were performed to reveal the arachnoid microstructure during the procedures. Cadaveric head specimens (n = 8, on 16 sides) were dissected for observation of the microstructure of the arachnoid in the cerebellopontine angle. Results The arachnoid membrane surrounding the facio-cochleovestibular and lower cranial nerves forms two arachnoid sheaths. Both arachnoid sheaths contain two parts: the outer membranous and inner trabecular part. The membranous part is an intact and translucent membrane that wraps around nerves. The inner trabecular part is located beneath the membranous part and forms a trabecular network that connects the membranous arachnoid, nerves, and blood vessels to form a physical structure. Conclusion The arachnoid connects the facio-cochleovestibular and lower cranial nerves, blood vessels, and cerebellum as a complex physical entity. Therefore, during MVD surgery, sharply dissecting the arachnoid before retracting the flocculus and relocating the offending vessels helps reduce nerve injury.
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- 2020
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8. Facial root entry/exit zone contact in microvascular decompression for hemifacial spasm: a historical control study
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Junxiang Gu, Chengwen Ma, Le Zhou, Qin Song, Jianqiang Qu, Yan Xianxia, Junjie Quan, and Xi Zhang
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medicine.medical_specialty ,Palsy ,Fossa ,biology ,Hearing loss ,business.industry ,Decompression ,medicine.medical_treatment ,Subdural hemorrhage ,Microvascular decompression ,General Medicine ,Neurovascular bundle ,biology.organism_classification ,medicine.disease ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,medicine ,Original Article ,medicine.symptom ,business ,030217 neurology & neurosurgery ,Hemifacial spasm - Abstract
Background Microvascular decompression (MVD) surgery is recognized as an effective treatment for hemifacial spasm (HFS). In MVD surgery, biocompatible materials are usually implanted in situ at the neurovascular conflict site in contact with the offending vessel and the facial root entry/exit zone (REZ). Another procedure of implanting the materials between the responsible vessel and the supraolivary fossa without REZ contact has also been applied. However, it is unclear whether there are any differences between these 2 procedures (REZ-contact procedure vs. REZ-non-contact procedure). Therefore, the aim of the present study was to investigate the effect of the placement of implants (contacting or not contacting the facial REZ) on surgical operations and outcomes. Methods A historical control study was performed. Clinical data of HFS patients who underwent MVD between December 2016 and November 2018 were reviewed and categorized into 1 group with the REZ-contact procedure or another group with the REZ-non-contact procedure according to the decompression strategy they received. Clinical demographics, postoperative outcomes, and complications were collected and compared between the two groups. Results Not all patients are suitable for REZ-non-contact decompression. A total of 205 patients were enrolled: 112 in the REZ-contact group and 93 in the REZ-non-contact group. In the early postoperative period, the complete cure rate in the REZ-non-contact group was significantly higher than that in the REZ-contact group. The reappearance and partial relief rates in the REZ-contact group were significantly higher than those in the REZ-non-contact group. The incidence of short-term neurological complications, especially hearing loss and transient facial palsy, was lower in the REZ-non-contact group (P=0.043). But for long-term follow-up of >1 year, there was no significant difference between the two groups in either curative effects or neurological complications. The operating time for REZ-non-contact decompression was relatively longer than for REZ-contact decompression (P=0.000). An unexpected subdural hemorrhage occurred in the REZ-non-contact group. Conclusions REZ-non-contact decompression procedure showed superiority only in short-term postoperative outcomes. Given its limitations and potential risks, the REZ-non-contact procedure can be used as an alternative individualized strategy in MVD, and there is no need to pursue REZ-non-contact during the decompression.
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- 2021
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9. Ultrafast kinetics net electrode assembled via MoSe2/MXene heterojunction for high-performance sodium-ion batteries
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Hui Wang, Pengcheng Li, Yang Jiang, Yajing Chang, Zhifeng Zhu, Enze Xu, Yan Zhang, Junjie Quan, and Dabin Yu
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Materials science ,Diffusion barrier ,General Chemical Engineering ,Kinetics ,Heterojunction ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Ion ,Chemical engineering ,Electrode ,Environmental Chemistry ,0210 nano-technology ,Hybrid material ,Faraday efficiency - Abstract
Establishing advanced sodium-ion batteries (SIBs) with high energy density and eco-friendly electrode materials are still far from satisfactory due to the large-size of sodium-ions and sluggish redox kinetics during electrochemical processes. Herein, a novel ultrafast kinetics net electrode assembled via MoSe2/MXene heterojunction is synthesized by a simple hydrothermal method followed by thermal annealing. Featuring the Van der Waals force interaction between MoSe2 and MXene, the volumetric change during the sodium ions insertion/extraction courses is effectively restrained, and the reaction kinetics is greatly enhanced further. Meanwhile, both the high electrical and ion conductivity (lower diffusion barrier between Na+/MXene ~0.066 eV) provided by the unique MXene based net heterostructure of our hybrid materials, as evidenced by DFT calculations, are beneficial to the transportation of sodium ions, thus enabling an outstanding rate and long-cycling capability. As a result, the fabricated cells exhibit high reversible capacities of 490 mAh g−1 at 1 A g−1, as well as 250 mAh g−1 at a high current of 10 A g−1 with a coulombic efficiency of 99.8%, indicating the excellent electrochemical performance of our hybrid materials, especially at high current. This novel net MoSe2/MXene heterostructure, combined with our simple synthesis strategy together, are expected to have great potential in sodium-ions storage application.
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- 2020
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10. Some Evaluations of Parametric Euler Type Sums of Harmonic Numbers
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Junjie Quan, Ce Xu, and Xixi Zhang
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Mathematics - Number Theory ,Applied Mathematics ,FOS: Mathematics ,Number Theory (math.NT) ,Analysis - Abstract
We establish some identities of Euler related sums. By using these identities, we discuss the closed form representations of sums of harmonic numbers and reciprocal parametric binomial coefficients through parametric harmonic numbers, shifted harmonic numbers and Riemann zeta function with positive integer arguments. In particular we investigate products of quadratic and cubic harmonic numbers and reciprocal parametric binomial coefficients. Some illustrative special cases as well as immediate consequences of the main results are also considered.
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- 2017
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