Publications by authors named "Zhuo Xu"

144 Publications

Single-path electro-optic coefficients measurement approach using multiple reflection interference.

Appl Opt 2021 Nov;60(33):10372-10376

An electro-optic coefficient (EOC) is an important optical property of optical crystals. In this work, a single-path multiple reflection interferometer is proposed to measure the components of signed EOCs with high precision. With the help of the normalization method, the influence of incident light was removed, and repeatability of the experimental results was improved. The signed EOCs of a congruent crystal were determined under a small external electric field as =+9.6±0.3/ and =+29.5±0.5/. This study may contribute to the development of potential anisotropic devices of optical crystals.
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http://dx.doi.org/10.1364/AO.441951DOI Listing
November 2021

Hole-Pinned Defect Clusters for a Large Dielectric Constant up to GHz in Zinc and Niobium Codoped Rutile SnO.

ACS Appl Mater Interfaces 2021 Nov 2;13(45):54124-54132. Epub 2021 Nov 2.

Research School of Chemistry, The Australian National University, Canberra, Australian Capital Territory 2601, Australia.

High permittivity materials for a gigahertz (GHz) communication technology have been actively sought for some time. Unfortunately, in most materials, the dielectric constant starts to drop as frequencies increase through the megahertz (MHz) range. In this work, we report a large dielectric constant of ∼800 observed in defect-mediated rutile SnO ceramics, which is nearly frequency and temperature independent over the frequency range of 1 mHz to 35 GHz and temperature range of 50-450 K. Experimental and theoretical investigations demonstrate that the origin of the high dielectric constant can be attributed to the formation of locally well-defined Zn-Nb defect clusters, which create hole-pinned defect dipoles. We believe that this work provides a promising strategy to advance dipole polarization theory and opens up a direction for the design and development of high frequency, broadband dielectric materials for use in future communication technology.
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http://dx.doi.org/10.1021/acsami.1c09632DOI Listing
November 2021

High Frequency 0.36BiScO3-0.64PbTiO3 Ultrasonic Transducer for High Temperature Imaging Application.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Oct 27;PP. Epub 2021 Oct 27.

(1-x)BiScO3-xPbTiO3 (BS-PT) ceramics have excellent piezoelectricity and high Curie temperature at its morphotropic phase boundary (x=0.64), so it is a promising piezoelectric material for fabricating high temperature ultrasonic transducer (HTUT). Electric properties of 0.36BS-0.64PT ceramics were characterized at different temperature, and a HTUT with the center frequency of about 15 MHz was designed by PiezoCAD based on the measuring results. The prepared HTUT was tested in a silicone oil bath at different temperature systematically. The test results show that the HTUT can maintain a stable electrical resonance until 290 °C, and get a clear echo response until 250 °C with slight changes of the center frequency. Then a stepped metal block submerged in silicone oil was imaged by the HTUT until 250 °C. Velocity of silicone oil and axial resolution of the HTUT at different temperature were calculated. The results verify the capability of 0.36BS-0.64PT based HTUT for high temperature ultrasonic imaging applications.
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http://dx.doi.org/10.1109/TUFFC.2021.3123331DOI Listing
October 2021

[The application progress of cone beam computed tomography in cochlear implantation].

Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2021 Sep;35(9):845-849

Cochlear implantation has become the primary treatment of choice for the patients with severe or profound sensorineural hearing loss. However, the outcomes of cochlear implantation are affected by many factors which need multi-disciplinary evaluation such as imaging, audiology and linguistics. Cone beam computed tomography, a novel imaging technique, has been increasingly used in the study of cochlear morphology, accurate location of electrode and evaluation of inner ear trauma after cochlear implantation. The aim of this review is to describe the advantages and application prospects of cone beam computed tomography, which is meaningful for the wider application of cone beam computed tomography in cochlear implantation.
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http://dx.doi.org/10.13201/j.issn.2096-7993.2021.09.018DOI Listing
September 2021

Observing two-photon subwavelength interference of broadband chaotic light in a polarization-selective Michelson interferometer.

Opt Express 2021 Sep;29(19):30094-30103

We demonstrated a method to achieve the two-photon subwavelength effect of true broadband chaotic light in polarization-selective Michelson interferometer based on two-photon absorption detection. To our knowledge, it is the first time that this effect has been observed with broadband chaotic light. In theory, the two-photon polarization coherence matrix and probability amplitudes matrix are combined to develop polarized two-photon interference terms, which explains the experimental results well. To make better use of this interferometer to produce the subwavelength effect, we also make a series of error analyses to find out the relationship between the visibility and the degree of polarization error. Our experimental and theoretical results contribute to the understanding of the two-photon subwavelength interference, which shed light on the development of the two-photon interference theory of vector light field based on quantum mechanics. The characteristic of the two-photon subwavelength effect have significant applications in temporal ghost imaging, such as it helps to improve the resolution of temporal objects.
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http://dx.doi.org/10.1364/OE.434733DOI Listing
September 2021

High-Quality-Factor AlON Transparent Ceramics for 5 GHz Wi-Fi Aesthetically Decorative Antennas.

ACS Appl Mater Interfaces 2021 Oct 24;13(39):46866-46874. Epub 2021 Sep 24.

Multifunctional Materials and Structures, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.

Transparent material has been widely used in product design and has seen a large increase in its use. In this paper, a kind of aesthetically decorative 5 GHz Wi-Fi dielectric resonator antenna (DRA) of aluminum oxynitride (AlON) transparent ceramic has been designed. High-quality-factor AlON transparent dielectric ceramics were fabricated by presintering at 1780 °C and further cold isostatic pressing (CIP) under a 200 MPa argon atmosphere. For a 9.0 mm thick specimen, the in-line light transmittance reached 83%. Optimum dielectric constant (ε = 9.32), quality factor ( = 47 960) and temperature coefficient (TCF = -51.7 ppm/°C) was achieved in the AlON transparent ceramic by cold isostatic pressing. As a result, the proposed aesthetically decorative DRA can achieve an impedance bandwidth of 32% (4.48-6.19 GHz), a high radiation efficiency of 85%, and a low cross-polarization discrimination (XPD) of -30 dB. To achieve a broad bandwidth, the proposed antenna was excited in its dominant TE mode and higher-order TE mode. The proposed antenna is thus an excellent candidate for an indoor decoration Wi-Fi antenna.
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http://dx.doi.org/10.1021/acsami.1c12223DOI Listing
October 2021

Application and advantages of zebrafish model in the study of neurovascular unit.

Eur J Pharmacol 2021 Nov 2;910:174483. Epub 2021 Sep 2.

State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address:

The concept of "Neurovascular Unit" (NVU) was put forward, so that the research goal of Central Nervous System (CNS) diseases gradually transitioned from a single neuron to the structural and functional integrity of the NVU. Zebrafish has the advantages of high homology with human genes, strong reproductive capacity and visualization of neural circuits, so it has become an emerging model organism for NVU research and has been applied to a variety of CNS diseases. Based on CNKI (https://www.cnki.net/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/about/) databases, the author of this article sorted out the relevant literature, analyzed the construction of a zebrafish model of various CNS diseases,and the use of diagrams showed the application of zebrafish in the NVU, revealed its relationship, which would provide new methods and references for the treatment and research of CNS diseases.
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http://dx.doi.org/10.1016/j.ejphar.2021.174483DOI Listing
November 2021

Segmentation of the urothelium in optical coherence tomography images with dynamic contrast.

J Biomed Opt 2021 08;26(8)

Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, Ohio, United States.

Significance: Speckle variation induced by intracellular motion (IM) in the urothelium was observed in optical coherence tomography (OCT) images. IM can be used as a dynamic contrast to segment the urothelium by comparing two sequential OCT images. This method opens the possibility of specifically tracking the distribution of urothelial cancerous cells for identifying the microinvasion of bladder tumors.

Approach: OCT images were acquired ex vivo with fresh porcine bladder tissue. IM was analyzed by tracking speckle variation using autocorrelation function, then quantified with constrained regularization method for inverting data (CONTIN method) to identify the decorrelation time (DT) of the speckle variations. Variance analysis was also conducted to show IM amplitude and distribution in the urothelium. The segmentation of the urothelium was demonstrated with OCT images with a visible urothelial layer and OCT images with an invisible urothelial layer.

Results: Significant speckle variation induced by IM was observed in the urothelium. However, the distribution of the IM is heterogeneous. The DTs are mostly concentrated between 1 and 30 ms. With the IM as a dynamic contrast, the urothelium can be accurately and exclusively segmented, even the urothelial layer is invisible in normal OCT images.

Conclusions: IM can be used as a dynamic contrast to exclusively track urothelial cell distribution. This contrast may provide a new mechanism for OCT to image the invasion depth and pattern of urothelial cancerous cells for accurately substaging of bladder cancer.
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http://dx.doi.org/10.1117/1.JBO.26.8.086002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8363479PMC
August 2021

Highly Luminescent Metal-Free Perovskite Single Crystal for Biocompatible X-Ray Detector to Attain Highest Sensitivity.

Adv Mater 2021 Sep 26;33(36):e2102190. Epub 2021 Jul 26.

Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, Institute for Advanced Energy Materials, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.

Solution-processed metal-based halide perovskites have taken a dominant position for perovskite optoelectronics including light emission and X-ray detection; however, the toxicity of the included heavy metals severely restricts their applications for wearable, lightweight, and transient optoelectronic devices. Here, the authors describe investigations of large (4 × 6 × 2 mm ) 3D metal-free perovskite MDABCO-NH I (MDBACO = methyl-N'-diazabicyclo[2.2.2]octonium) single crystal and its charge recombination and extraction behavior for light emission and X-ray detection. Unlike conventional 3D metal-based perovskites, this lightweight and biocompatible perovskite large crystal is processed from aqueous solution at room temperature, and can achieve both an extremely long carrier lifetime up to ≈1.03 µs and the formation of self-trapped excited states for luminescence. These features contribute to a photoluminescence quantum yield (PLQY) as high as ≈53% at room temperature and an X-ray sensitivity up to 1997 ± 80 μC Gy cm at 50 V bias (highest among all metal-free detectors). The ability to tune the perovskite band gap by modulating the structure under high pressure is also demonstrated, which opens up applications for the crystal as colored emitters. These attributes make it a molecular alternative to metal-based perovskites for biocompatible and transient optoelectronics.
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http://dx.doi.org/10.1002/adma.202102190DOI Listing
September 2021

A natural product of acteoside ameliorate kidney injury in diabetes db/db mice and HK-2 cells via regulating NADPH/oxidase-TGF-β/Smad signaling pathway.

Phytother Res 2021 Sep 8;35(9):5227-5240. Epub 2021 Jul 8.

Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, and Key Laboratory of Chinese Medicinal Resources Recycling Utilization, State Administration of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, China.

This study was designed to investigate the protective effects and mechanisms of acteoside on DKD in diabetes male db/db mice and high glucose-induced HK-2 cells. The diabetes db/db mice were divided randomly into model group, metformin group, irbesartan group, and acteoside group. We observed the natural product of acteoside exhibiting a significant effect in renal protection through analyzing of biochemical indicators and endogenous metabolites, histopathological observations, and western blotting. HK-2 cells subjected to high glucose were used in invitro experiments. The molecular mechanisms of them were investigated by RT-PCR and western blot. Acteoside prevents high glucose-induced HK-2 cells and diabetes db/db mice by inhibiting NADPH/oxidase-TGF-β/Smad signaling pathway. Acteoside regulated the disturbed metabolic pathway of lipid metabolism, glyoxylate and dicarboxylate metabolism, and arachidonic acid metabolism. We discovered the natural product of acteoside exhibiting a significant effect in renal protection. This study paved the way for further exploration of pathogenesis, early diagnosis, and development of a new therapeutic agent for DKD.
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http://dx.doi.org/10.1002/ptr.7196DOI Listing
September 2021

Self-compassion and the Mitigation of Negative Affect in the Era of Social Distancing.

Mindfulness (N Y) 2021 Jun 28:1-12. Epub 2021 Jun 28.

Department of Psychology, Tsinghua University, Beijing, China.

Objectives: The outbreak of contagious diseases and their associated non-pharmaceutical interventions can lead to negative mental health consequences. This study aimed to investigate online self-compassion exercises' effectiveness in alleviating people's negative affect (anxiety and negative emotions) during the COVID-19 pandemic lockdown.

Methods: Study 1 examined the associations between self-compassion and negative affect using an anonymous online survey. In study 2, two pilot experiments were conducted to examine online self-compassion exercises' (i.e., instructor-guided meditation and self-guided writing) effectiveness to mitigate individuals' negative affect. In study 3, a randomized controlled study was conducted to further examine online self-compassion writing's effectiveness in reducing people's negative affect.

Results: The results of study 1 indicated a significant negative association between self-compassion and participants' negative affect. Participants in study 2a reported significant decreases in negative affect after completing the self-compassion meditation. Study 2b showed that participants who completed the self-compassion writing reported significantly more self-compassion and less anxiety when compared to participants who did not. Study 3 showed substantial pre/post-test changes in participants who completed self-compassion writing. Importantly, there were significant increases in participants' self-compassion and decreases in negative affect when compared to participants in the control condition.

Conclusions: Self-compassion exercises were effective to alleviate individuals' anxiety and reduce negative emotions (even within a brief session) during the pandemic lockdown.

Supplementary Information: The online version contains supplementary material available at 10.1007/s12671-021-01674-w.
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http://dx.doi.org/10.1007/s12671-021-01674-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8236748PMC
June 2021

Tapered Coaxial Arrays for Photon- and Plasmon-Enhanced Light Harvesting in Perovskite Solar Cells: A Theoretical Investigation Using the Finite Element Method.

Chempluschem 2021 May 14;86(6):858-864. Epub 2021 May 14.

Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China.

Although there have been reports of separate studies of photon-enhanced and plasmon-enhanced light harvesting to improve perovskite solar cell (PSC) efficiency, there are none that have achieved simultaneous enhancement in both photonic and plasmonic effects in PSCs. In this work, we designed a layer of tapered coaxial humps (TCHs) to harvest both in PSCs. The light absorption behavior of the textured perovskite layer in PSCs was systematically investigated through the finite element method (FEM). The calculation results show that the TCH-textured perovskite layer absorbs 67.6 % of visible light under AM 1.5G solar irradiation, a 21.8 % increase relative to the planar reference cell without TCHs. Using this design, a perovskite thickness of only 106 nm is needed to realize the full light absorption that normally requires 300-nm-thick perovskite without TCHs. To reveal the mechanism of light absorption enhancement, the specific field distributions were studied. We demonstrated that different photonic modes and plasmonic modes collectively result in remarkable light absorption enhancement in the 500-800 nm wavelength range. The textured PSCs reported herein provide an effective method to decrease Pb-based perovskite consumption and realize angle-insensitive and ultrathin PSCs.
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http://dx.doi.org/10.1002/cplu.202100157DOI Listing
May 2021

Large-Area Piezoelectric Single Crystal Composites via 3-D-Printing-Assisted Dice-and-Insert Technology for Hydrophone Applications.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 10 27;68(10):3241-3248. Epub 2021 Sep 27.

Compared with Pb(Zr,Ti)O (PZT) ceramics, piezoelectric ceramic composites (PCCs), and piezoelectric polyvinylidene fluoride (PVDF) polymer, piezoelectric single crystal composites (PSCCs) are thought to be the promising candidates for hydrophone applications because of their superior hydrostatic performance. However, due to the brittleness and small dimensions of single crystals, the preparation of large-area or conformal PSCCs is to be challenged. Herein, we prepared a large-area PSCC with dimensions of 50 mm × 50 mm × 5 mm using 3-D-printing-assisted dice-and-insert technology. The hydrostatic piezoelectric performances for PSCC were investigated using a quasi-static method. The hydrostatic figure-of-merit (HFOM) of PSCC is approximately [Formula: see text]/N, which is higher by 69.4% than that of PCC. Furthermore, PSCC shows advantages in the dielectric loss, frequency constant, electromechanical coupling coefficient, and hydrostatic pressure stability. The results suggest that PSCCs have great potential in substantially improving the sensitivity of hydrophones. In addition, 3-D-printing-assisted dice-and-insert technology breaks through the restriction of as-grown piezoelectric crystal size so as to make it possible for the applications where large-scale piezoelectric composites are required.
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http://dx.doi.org/10.1109/TUFFC.2021.3085842DOI Listing
October 2021

Effective Phase-Alignment for 2D Halide Perovskites Incorporating Symmetric Diammonium Ion for Photovoltaics.

Adv Sci (Weinh) 2021 Jul 24;8(13):e2001433. Epub 2021 May 24.

Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.

New structural type of 2D AA' M X type halide perovskites stabilized by symmetric diammonium cations has attracted research attention recently due to the short interlayer distance and better charge-transport for high-performance solar cells (PSCs). However, the distribution control of quantum wells (QWs) and its influence on optoelectronic properties are largely underexplored. Here effective phase-alignment is reported through dynamical control of film formation to improve charge transfer between quantum wells (QWs) for 2D perovskite (BDA)(MA) Pb I (BDA = 1,4-butanediamine, 〈n〉 = 4) film. The in situ optical spectra reveal a significantly prolonged crystallization window during the perovskite deposition via additive strategy. It is found that finer thickness gradient by n values in the direction orthogonal to the substrate leads to more efficient charge transport between QWs and suppressed charge recombination in the additive-treated film. As a result, a power conversion efficiency of 14.4% is achieved, which is not only 21% higher than the control one without additive treatment, but also one of the high efficiencies of the low-n (n ≤ 4) AA' M X PSCs. Furthermore, the bare device retains 92% of its initial PCE without any encapsulation after ambient exposure for 1200 h.
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http://dx.doi.org/10.1002/advs.202001433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8327467PMC
July 2021

Corrigendum to "Umbilical Cord Tissue-Derived Mesenchymal Stem Cells Induce T Lymphocyte Apoptosis and Cell Cycle Arrest by Expression of Indoleamine 2, 3-Dioxygenase".

Stem Cells Int 2021 16;2021:9817948. Epub 2021 Apr 16.

The Scientific Research Center, China-Japan Union Hospital, Jilin University, 126 Xiantai Street, Changchun, Jilin 130033, China.

[This corrects the article DOI: 10.1155/2016/7495135.].
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http://dx.doi.org/10.1155/2021/9817948DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8088360PMC
April 2021

Band-Pass Filtering Cross-Polarization Converter Using Transmitarrays.

Materials (Basel) 2021 Apr 22;14(9). Epub 2021 Apr 22.

The Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China.

Microwave devices with polarization conversion and band-pass filtering response have great application prospects on radomes. Here, the concepts of band-pass filters and cross-polarization converters are combined to realize a band-pass filtering cross-polarization converter with an extremely high polarization-conversion ratio. Most importantly, the device has an excellent out-of-band rejection level, above 30 and 40 dB for the lower and upper edges, respectively. In addition, the transmission zeros of the passband can be flexibly tuned independently. The band-pass filtering polarization converter was simulated, fabricated, and measured, and the measured results were found to be in good agreement with the simulation results.
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http://dx.doi.org/10.3390/ma14092109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8122630PMC
April 2021

Textured ferroelectric ceramics with high electromechanical coupling factors over a broad temperature range.

Nat Commun 2021 Mar 3;12(1):1414. Epub 2021 Mar 3.

Electronic Materials Research Laboratory (Key Lab of Education Ministry), State Key Laboratory for Mechanical Behavior of Materials and School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, China.

The figure-of-merits of ferroelectrics for transducer applications are their electromechanical coupling factor and the operable temperature range. Relaxor-PbTiO ferroelectric crystals show a much improved electromechanical coupling factor k (88~93%) compared to their ceramic counterparts (65~78%) by taking advantage of the strong anisotropy of crystals. However, only a few relaxor-PbTiO systems, for example Pb(InNb)O-Pb(MgNb)O-PbTiO, can be grown into single crystals, whose operable temperature range is limited by their rhombohedral-tetragonal phase transition temperatures (T: 60~120 °C). Here, we develop a templated grain-growth approach to fabricate <001>-textured Pb(InNb)O-Pb(ScNb)O-PbTiO (PIN-PSN-PT) ceramics that contain a large amount of the refractory component ScO, which has the ability to increase the T of the system. The high k of 85~89% and the greatly increased T of 160~200 °C are simultaneously achieved in the textured PIN-PSN-PT ceramics. The above merits will make textured PIN-PSN-PT ceramics an alternative to single crystals, benefiting the development of numerous advanced piezoelectric devices.
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http://dx.doi.org/10.1038/s41467-021-21673-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7977148PMC
March 2021

van der Waals Interaction-Induced Tunable Schottky Barriers in Metal-2D Perovskite Contacts.

J Phys Chem Lett 2021 Feb 10;12(6):1718-1725. Epub 2021 Feb 10.

Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Key Laboratory for Advanced Energy Devices; Shaanxi Engineering Lab for Advanced Energy Technology; Institute for Advanced Energy Materials; School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, China.

We systematically study the bonding and electronic properties of metal-BAPbI contacts, which play a crucial role in affecting the device performance, based on density functional theory calculations. Tunable Schottky barrier heights (SBHs) are observed in metal-BAPbI contacts by using different metals with a moderate Fermi level pinning (FLP) effect. An interfacial van der Waals interaction-induced Pauli-exclusion effect is found to be responsible for the FLP. The unique structure of BAPbI ensures the interfacial interaction has a limited influence on the band energy of BAPbI, since the spacer cation can be seen as a naturally formed buffer layer. We also found the SBHs depend on the thickness of inorganic layers in quasi-two-dimensional (2D) BAMAPbI. A high tunneling barrier and low interfacial charge density are also observed in all contacts. The thorough understanding of the underlying mechanisms of bonding and electronic properties in these contacts is beneficial for us to promote the performance of 2D perovskite-related devices.
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http://dx.doi.org/10.1021/acs.jpclett.0c03635DOI Listing
February 2021

Circ_LDLR Knockdown Suppresses Progression of Hepatocellular Carcinoma via Modulating miR-7/RNF38 Axis.

Cancer Manag Res 2021 13;13:337-349. Epub 2021 Jan 13.

Department of Hepatobiliary Surgery, Fourth Hospital of Hebei Medical University, Shijiazhuang 050035, Hebei, People's Republic of China.

Background: Hepatocellular carcinoma (HCC) is a horrible malignancy derived from liver. Circular RNAs (circRNAs) act important roles in the pathogenesis and progression of human diseases, including HCC. The current assay intended to investigate the function of circRNA low-density lipoprotein receptor (circ_LDLR) in HCC and clarify the underlying mechanism.

Materials And Methods: Expression of circ_LDLR, microRNA (miR)-7 and ring finger protein 38 (RNF38) was determined by quantitative real-time PCR (qRT-PCR) or Western blot analysis. Flow cytometry was used to detect cell cycle distribution and apoptosis. Cell colony formation ability and viability were examined by colony formation and methyl thiazolyl tetrazolium (MTT) assays, respectively. Levels of cell proliferation and epithelia-mesenchymal transition (EMT) biomarker proteins were analyzed via Western blot assay. Cell migration and invasion were monitored by Transwell assay, and target relationship between miR-7 and circ_LDLR or RNF38 was validated by dual-luciferase reporter assay. Xenograft model was established to explore the role of circ_LDLR in vivo.

Results: Expression of circ_LDLR and RNF38 was upregulated, but miR-7 expression was downregulated in HCC tissues and cells. Circ_LDLR knockdown significantly inhibited cell proliferation, migration, invasion and EMT in HCC cells. Circ_LDLR acted as a sponge of miR-7, and interference of miR-7 could attenuate circ_LDLR knockdown-induced inhibitory effects on malignant behaviors of HCC cells. Besides, miR-7 also repressed cell proliferation and metastasis of HCC cells, by targeting RNF38. Depletion of circ_LDLR could suppress tumor growth in vivo.

Conclusion: Depletion of circ_LDLR restrained HCC cell proliferation, metastasis and tumorigenesis through the regulation on miR-7/RNF38 axis, affording a promising therapeutic target for HCC.
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http://dx.doi.org/10.2147/CMAR.S275003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813465PMC
January 2021

Overcome chromatism of metasurface via Greedy Algorithm empowered by self-organizing map neural network.

Opt Express 2020 Nov;28(24):35724-35733

Chromatism generally exists in most metasurfaces. Because of this, the deflected angle of metasurface reflectors usually varies with frequency. This inevitably hinders wide applications of metasurfaces to broadband signal scenarios. Therefore, it is of great significance to overcome chromatism of metasurfaces. With this aim, we firstly analyze necessary conditions for achromatic metasurface deflectors (AMD) and deduce the ideal dispersions of meta-atoms. Then, we establish a Self-Organizing Map (SOM) Neural Network as a prepositive model to obtain a diversified searching map, which is then applied to Greedy Algorithm to search meta-atoms with the required dispersions. Using these meta-atoms, an AMD was designed and simulated, with a thickness about 1/15 the central wavelength. A prototype was fabricated and measured. Both the simulation and measurement show that the proposed AMD can achieve an almost constant deflected angle of 22° under normal incidence within 9.5-10.5GHz. This method may find wide applications in designing functional metasurfaces for satellite communications, mobile wireless communications and others.
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http://dx.doi.org/10.1364/OE.405856DOI Listing
November 2020

An Efficient Optimization Design of Liquid Lens for Acoustic Pattern Control.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 05 26;68(5):1546-1554. Epub 2021 Apr 26.

In order to effectively and flexibly control acoustic pattern, an efficient optimization design method of acoustic liquid lens (ALL) is developed by the frame of particle swarm optimization (PSO) algorithm. The ALL is composed of ethanol and dimethicone, and its parameters include ethanol concentration (EC), volume fraction of dimethicone (VFD), and total volume (TV). Based on the established finite element model and orthogonal design method, the data of acoustic pattern and ALL can be obtained by using COMSOL Multiphysics. Based on the simulation data, the neural network models are constructed to characterize the relationship between the parameters of ALL and the performance of acoustic pattern. The optimization design criteria of ALL are constructed based on the performance parameters of acoustic pattern, including focal distance (FD), transverse resolution (TR), and longitudinal resolution (LR). Based on the optimization criteria, the modified PSO algorithm is utilized to optimize the design parameters of ALL in the developed method. According to the desired FD, TR, and LR of acoustic pattern (20, 1, and 17 mm), the optimized EC, VFD, and TV of ALL are about 0.838, 0.165, and 164.4 [Formula: see text]. The performance parameters of acoustic pattern verified by simulation and experiments agree with the desired ones. In addition, using 6 MHz ultrasonic transducer with the optimized ALL, the ultrasonic imaging of tungsten wires and porcine eyeball further demonstrates the effectiveness and feasibility of the developed method.
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http://dx.doi.org/10.1109/TUFFC.2020.3040174DOI Listing
May 2021

High-Efficiency Perovskite Solar Cells with Imidazolium-Based Ionic Liquid for Surface Passivation and Charge Transport.

Angew Chem Int Ed Engl 2021 Feb 23;60(8):4238-4244. Epub 2020 Dec 23.

Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.

Surface defects have been a key constraint for perovskite photovoltaics. Herein, 1,3-dimethyl-3-imidazolium hexafluorophosphate (DMIMPF ) ionic liquid (IL) is adopted to passivate the surface of a formamidinium-cesium lead iodide perovskite (Cs FA PbI ) and also reduce the energy barrier between the perovskite and hole transport layer. Theoretical simulations and experimental results demonstrate that Pb-cluster and Pb-I antisite defects can be effectively passivated by [DMIM] bonding with the Pb ion on the perovskite surface, leading to significantly suppressed non-radiative recombination. As a result, the solar cell efficiency was increased to 23.25 % from 21.09 %. Meanwhile, the DMIMPF -treated perovskite device demonstrated long-term stability because the hydrophobic DMIMPF layer blocked moisture permeation.
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http://dx.doi.org/10.1002/anie.202010987DOI Listing
February 2021

Morphology Evolution of a High-Efficiency PSC by Modulating the Vapor Process.

Small 2020 Oct 30;16(43):e2003582. Epub 2020 Sep 30.

Key Laboratory for Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710062, China.

The morphological quality of the photoactive layer is the key component affecting the performance metrics of a photovoltaic device. Therefore, fine adjustment of the crystallization dynamics is urgently required. By manipulating the amount of dimethyl sulfoxide (DMSO) remaining in the spin-coated perovskite films during the annealing treatment, an obvious morphological evolution arises. The crystallization kinetics is significantly altered due to the formation of intermediate phases and the variation of DMSO vapor pressure via producing the semienclosed space with a covering. On the one hand, the obviously formed intermediate phase MA Pb I (DMSO) retards the crystallization process. On the other hand, the DMSO vapor in the semienclosed space intrigues the recrystallization process and results in Ostwald ripening to produce large-aspect-ratio grains with fewer defect states, decreased carrier doping, and longer carrier lifetimes. Thus, nonradiative processes are greatly suppressed. Besides, combined with X-ray photoelectron spectroscopy measurement and the surface energy of MAI- and PbI-terminated surface model calculated by density functional theory, the defect states are identified and the causes of Pb defect states are explained. Using this strategy, a high power conversion efficiency of 20.09% is achieved based on MAPbI photovoltaic solar cell, and the long-term ambient shelf and thermal stability are obviously improved.
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http://dx.doi.org/10.1002/smll.202003582DOI Listing
October 2020

2D Perovskite Single Crystals with Suppressed Ion Migration for High-Performance Planar-Type Photodetectors.

Small 2020 Oct 29;16(42):e2003145. Epub 2020 Sep 29.

Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, Institute for Advanced Energy Materials, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.

2D Dion-Jacobson (DJ) perovskites have recently drawn much attention owing to their superior charge transport and high environmental stability. Unfortunately, their intrinsic optoelectronic properties are largely unexplored due to the lack of high-quality single crystals available for accurate measurements. Herein, a reactive, low-temperature-gradient crystallization process to grow high-quality 2D perovskite single crystal (BDAPbI ) using symmetric straight chain 1,4-butanediammonium as a short-chain insulating spacer is developed. It is found that the BDAPbI single crystal exhibits a direct bandgap with effective charge collection (μτ = 1.45 × 10 cm V ). In particular, the BDAPbI single crystal shows a high ion migration activation energy (0.88 eV) that is desired for stability. Moreover, the planar-type photodetectors made of BDAPbI single crystals demonstrate excellent photoresponse performance, including large dynamic linear range (150 dB), high responsivity (927 mA W ), fast response speed, and exceptional stability. Theoretical calculations reveal that the enhanced carrier transport properties are mainly attributed to the interlayer-induced coupling of the inorganic layers. Furthermore, the rigid structure of BDAPbI , resulting from the strong hydrogen bonds between the organic cations and the inorganic framework, will result in both low defect density and low ion migration, leading to superior carrier transport properties and detection performance.
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http://dx.doi.org/10.1002/smll.202003145DOI Listing
October 2020

Metal-Free Halide Perovskite Single Crystals with Very Long Charge Lifetimes for Efficient X-ray Imaging.

Adv Mater 2020 Oct 15;32(42):e2003353. Epub 2020 Sep 15.

Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, Institute for Advanced Energy Materials, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.

Metal-free halide perovskites, as a specific category of the perovskite family, have recently emerged as novel semiconductors for organic ferroelectrics and promise the wide chemical diversity of the ABX perovskite structure with mechanical flexibility, light weight, and eco-friendly processing. However, after the initial discovery 17 years ago, there has been no experimental information about their charge transport properties and only one brief mention of their optoelectronic properties. Here, growth of large single crystals of metal-free halide perovskite DABCO-NH Br (DABCO = N-N'-diazabicyclo[2.2.2]octonium) is reported together with characterization of their instrinsic optical and electronic properties and demonstration, of metal-free halide perovskite optoelectronics. The results reveal that the crystals have an unusually large semigap of ≈16 eV and a specific band nature with the valence band maximum and the conduction band minimum mainly dominated by the halide and DABCO , respectively. The unusually large semigap rationalizes extremely long lifetimes approaching the millisecond regime, leading to very high charge diffusion lengths (tens of μm). The crystals also exhibit high X-ray attenuation as well as being lightweight. All these properties translate to high-performance X-ray imaging with sensitivity up to 173 μC Gy cm . This makes metal-free perovskites novel candidates for the next generation of optoelectronics.
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http://dx.doi.org/10.1002/adma.202003353DOI Listing
October 2020

Frequency Dependence of Coercive Fields of [001]- and [011]-Poled Rhombohedral Pb(InNb)O₃-Pb(MgNb)O₃-PbTiO₃ Single Crystals.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Apr 26;68(4):1430-1436. Epub 2021 Mar 26.

Relaxor-PbTiO (PT-based) ferroelectric single crystals are important for many piezoelectric applications because of their outstanding performances. In order to expand their usage and avoid the failure during application, frequency dependence of coercive fields E for [001]- and [011]-poled rhombohedral Pb(InNb)O-Pb(MgNb)O-PbTiO (PIN-PMN-PT) single crystals was investigated from the frequency of 1 Hz to 300 kHz by using hysteresis loop measurement (frequency: from 1 Hz to 2 kHz) and a critical value method (frequency: from 5 to 300 kHz). The results showed that the coercive field E , remnant polarization P , and saturation polarization P strongly depended on the crystal orientation and frequency. Compared with the [001]-poled crystals, the [011]-poled PIN-PMN-PT single crystals possessed higher E , P , and P at the same testing frequencies. With increasing frequency from 1 Hz to 300 kHz, the coercive fields E of the [001]- and [011]-poled PIN-PMN-PT single crystals increased from 4.0 and 4.8 kV/cm to 11.5 and 14.9 kV/cm, respectively. Moreover, the frequency dependence of the coercive fields was found to be consistent with the growth kinetics model, where the coercive fields E were proportional to f . This work benefits to the design of piezoelectric devices based on PIN-PMN-PT single crystals operated at high frequencies and high driving fields.
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http://dx.doi.org/10.1109/TUFFC.2020.3023536DOI Listing
April 2021

Intraocular lipopolysaccharide examination for early diagnosis of endophthalmitis: a case report.

J Int Med Res 2020 Aug;48(8):300060520929865

Department of Ophthalmology, Beijing Chaoyang Hospital, affiliated with Capital Medical University, Beijing, China.

This report describes the presence of endophthalmitis after phacoemulsification in a 66-year-old woman. The patient presented with ocular redness and pain, as well as hypopyon in the anterior chamber and reduction of visual acuity to hand motion. Intraocular fluid examination revealed a lipopolysaccharide level of >2.5, which suggested bacterial endophthalmitis. The patient was promptly treated with intravitreal ceftazidime 2 mg and vancomycin 1 mg, as well as intravenous infusion of cefuroxime 750 mg, all administered simultaneously at 12-hour intervals. She also received topical levofloxacin eyedrops, once per hour. Subsequently, pathology culture confirmed the presence of the Gram-negative bacillus, . The presence of lipopolysaccharide in intraocular fluid is an important early indicator of bacterial endophthalmitis, which can provide guidance for clinical treatment.
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http://dx.doi.org/10.1177/0300060520929865DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418243PMC
August 2020

Controllable superbunching effect from four-wave mixing process in atomic vapor.

Opt Express 2020 Jul;28(15):21489-21498

Correlation property of light limits the performance in related applications such as the visibility of ghost imaging or intensity interferometry. To exceed these performance limits, we here manipulate the degree of second- and higher-order coherence of light by changing controllable variables in four-wave mixing (FWM) process. The measured degree of second- and third-order coherence of the output light beams considerably exceed those of the incident pseudothermal light. Namely superbunching effects, g(0) value up to 7.47 and g(0) value up to 58.34, are observed experimentally. In addition, strong second- and third-order cross-correlation exist between the output light beams. Further insights into the dependence of superbunching light on the temperature of Rb vapor, the laser detuning and the optical power of all the incident light beams show that it can serve as a light source with a tunable superbunching degree.
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http://dx.doi.org/10.1364/OE.394211DOI Listing
July 2020

Trifunctional metasurface based on spoof surface plasmon polaritons.

Opt Express 2020 Jul;28(14):21260-21267

In this paper, we propose the design of a metasurface that can achieve three functions in different frequency bands. The proposed metasurface is composed of two kinds of unit cells which are designed on the basis of the spatial k-dispersion engineering of spoof surface plasmon polaritons (SSPPs). By arranging these two kinds of unit cells in the chessboard configuration, the three functions of transmission, anomalous refraction and absorption can be integrated into one metasurface. High transmission and strong absorption can be achieved in 2.0-9.0 GHz and 12.6-20.0 GHz, respectively. Meanwhile, anomalous refraction can be achieved in 10-11.7 GHz due to forward scattering cancellation of two unit cells. To verify the design, a prototype was fabricated and measured. The measured results are consistent with the simulation ones. The metasurface can integrate multiple functions into one aperture and therefore has potential application values in multifunctional microwave devices such as shared-aperture antennas, etc.
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http://dx.doi.org/10.1364/OE.395123DOI Listing
July 2020

Higher neutrophil-lymphocyte ratio is associated with better prognosis of hepatocellular carcinoma.

Medicine (Baltimore) 2020 Jul;99(27):e20919

Department of Hepatobiliary Surgery.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide; its morbidity and mortality have both recently increased. Lately, the role played by the neutrophil-lymphocyte ratio (NLR) in the development of HCC has attracted attention. However, the exact relationship is not fully understood.A total of 538 participants diagnosed with HCC were recruited between 2010 and 2018. Their relevant routine blood parameters were measured, including NLR. Pearson Chi-Squared test, Spearman Rho test, and logistic regression analysis were performed to explore any correlations between NLR and HCC. A receiver operating characteristic (ROC) curve analysis was performed to determine the usefulness of NLR for predicting HCC. Univariate and multivariate Cox regression analysis for relevant routine blood parameters and any relationships with overall survival (OS) were performed. The Kaplan-Meier method was used to explore any further relationships with OS.NLR was significantly correlated with HCC tumor size by Pearson Chi-Squared test (P = .008). Furthermore, Spearman correlation coefficient showed that HCC tumor size was significantly correlated with NLR (P = .115, P = .008). NLR could sensitively and specifically predict HCC tumor size (area under the curve [AUC], 0.605; 95% confidence interval [CI], 0.429-0.743; P = .000). Higher NLR in patients with HCC was correlated with better OS (hazard ratio [HR] = 0.584; P = .000).A close correlation existed between increased NLR and HCC; NLR could sensitively and specifically predict HCC. High NLR might be an independent protective factor in the prognosis of patients with HCC.
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http://dx.doi.org/10.1097/MD.0000000000020919DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7337484PMC
July 2020
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