bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation and calculation of the Mott phase transition and magnetroelectric performance of Magnli phase titanium suboxides
Authors: Hou Qing-Yu  , Wu Yun  , Zhao Chun-Wang  ,   College of Sciences, Inner Mongolia University of Technology, Hohhot 010051, China;,   Chemistry department, Inner Mongolia Vocational College of chemistry Engineering, Hohhot 010071, China
Published: December 2020

The pure and Magnli phase titanium suboxides for both rutile and anatase supercell models of TiO1.9375 were structured by using first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory; the geometry optimizations, the band structures, and density of states of these models were calculated. Results show that the volumes become greater for Magnli phase titanium suboxides in both rutile and anatase; meanwhile, the stability may reduce slightly, leading to a Mott transition. The nonmagnetic property of anatase titanium suboxides, and the magnetic property of rutile titanium suboxides, as wall as the conductive property of anatase titanium suboxides are higher than rutile titanium suboxides, in agreement with the experimental results.
Mn2+ induced luminescence regulation and enhancement of Lu-based nanocrystals
Authors: He En-Jie  , Zheng Hai-Rong  , Gao Wei  , Lu Ying  , Li Jun-Na  , Wei Ying  , Wang Deng  , Zhu Gang-Qiang  ,   School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062, China;,   School of Science, Anhui Science and Technology University, Bengbu 233100, China
Published: December 2020

Transformation from Lu-based nanocrystals in hexagonal and cubic mixed phases to pure cubic phase was observed through adjusting the doping concentration of Mn2+. The mechanism for the phase transformation was discussed in detail. Studies on the time and frequency domain spectra indicated that the semi-pure red emissions in cubic Na5Lu9F32: 40% Mn2+, 20% Yb3+, 2% Ln3+ (Ln=Er3+, Ho3+) nanocrystals were caused by a two-step energy transfer between Mn2+ and Ln3+ ions. After incorporating of Mn2+ ions into the host lattices, the local symmetry around the luminescent ion was reduced, which induced the increase of radiative rates for transitions that were mainly contributed by electric dipole radiations. Considerable enhancements in upconversion and downconversion luminescence were accompanied. The result of the current study has great application potential in bioimaging and solar cells.
Generalized projective lag synchronization between delay-coupled networks under circumstance noise
Authors: Zhang Li  , Yang Xiao-Li  , Sun Zhong-Kui  ,   College of Mathematics and Information Science, Shaanxi Normal University, Xi’an 710062, China;,   Department of Applied Mathematics, Northwestern Polytechnical University, Xi’an 710072, China
Published: December 2020

It is well known that time delay and random noise are universal in complex networks. However, the research on the synchronization of coupled networks that are subjected to delay-coupling and noise perturbation is very rare. In this paper, for two delay-coupled complex networks with different node dynamics, different topological structures and different numbers of nodes, under circumstance noise, the generalized projective lag synchronization between two networks is proposed for the first time. First, a more realistic theoretical framework is constructed for the drive-response network synchronization. Second, according to the LaSalle-type theorem for stochastic differential delay equations, we rigorously prove that the generalized projective lag synchronization between the drive-response networks can be achieved almost surely, by introducing an appropriate controller. Furthermore, numerical simulation is employed to verify the theoretical analysis. The results indicate that the drive-response networks can indeed achieve generalized projective lag synchronization, and that the synchronization is independent of time delay and scaling factor. Moreover, the remarkable influences of the update gain and the coupling delay on synchronization speed are revealed through the numerical results.
Influence of the functional layer thickness on the light output property of tandem organic light emitting diode：a numerical study
Authors: Lu Fei-Ping  , Li Jian-Feng  , Sun Shuo  ,   College of Physics and Information Science, Tianshui Normal University, Tianshui 741000, China;,   Key Laboratory of Optoelectronic Technology and Intelligent Control, Lanzhou Jiaotong University, Lanzhou 730070, China;,   National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Published: December 2020

Based on the principle of thin film optics, the theory of electric dipole radiation, and the principle of Fabry-Prot microcavity, an optical model is built for the tandem organic light emitting diode (OLED) with the structure of Glass/ITO/N, N0-bis(naphthalen-1-yl)-N, N0-bis (phenyl)-benzidine(NPB)/tris(8-hydroxyquinoli-ne) aluminum (Alq3)/molybdenum trioxide (MoO3)/NPB/Alq3/LiF/Al. The influence of the functional layer thickness on the light output intensity of device is systematically studied, the laws of light output intensity for tandem OLEDs under different thickness values of functional layer are obtained. This model and the results obtained in this paper can present an in-depth understanding of the working mechanism of tandem OLED and help ones fabricate high efficiency OLED.
Entropy in voltage mode controlled discontinuous conducting mode DC-DC converters
Authors: Xu Hong-Mei  , Jin Yong-Gao  , Guo Shu-Xu  ,   College of Electronic Science and Engineeing, Jilin University, Changchun 130012, China;,   College of Engineeing, Yanbian University, Yanji 133002, China
Published: December 2020

Considering that the variation of nonlinear characteristics of DC-DC converter with parameter k and the fact that entropy can reflect the statistical characteristic of numerical sequence, in this paper we propose a new method to estimate the nonlinear characteristics of DC-DC converter based on the information about entropy. In this study, taking one-order DCM Buck and Boost converter for example, the distributions of numerical sequences and entropies are analysed under different values of feedback gain k and initial values of x0. The results prove that the entropy of DC-DC converter is determined by feedback gain k and irrelevant to initial value x0, and its final value is smaller than the theoretical maximum value log2N (N is the number of partition), and that entropy can discriminate the period-doubling bifurcation and chaos. So a quantifiable nonlinear dynamical behavior index is obtained which can provide theoretical basis for understanding chaos characteristic and chaos control, and perfect the theoretical analysis method in DC-DC converters.
Experimental measurement of aluminium diffuser applied to calibration system of space-borne differential optical absorption spectrometer
Authors: Zhao Min-Jie  , Si Fu-Qi  , Lu Yi-Huai  , Wang Shi-Mei  , Jiang Yu  , Zhou Hai-Jin  , Liu Wen-Qing  ,   Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
Published: December 2020

In a space-borne differential optical absorption spectrometer, which has a large field in nadir push-broom mode the “Sun+Diffuser” method is adopted for onboard spectral calibration. Therefore the aluminium diffuser used in the space-borne spectral calibration system is required to have a good Lambert feature to ensure the full field spectral calibration accuracy of the space-borne differential optical absorption spectrometer. And it can provide a uniform source in the observing view-field of the instrument. Using bidirectional reflectance distribution function measurement instrument, bidirectional reflectance distribution function of aluminium diffuser is measured by the relative measurement method. Experimental results show that in a wavelength range of 180–880 nm and an observing view range from -70° to +70°, the bidirectional reflectance distribution function declines from middle to both sides and approximates the cosine distribution, showing that the aluminium diffuser has a good Lambert feature. The spectral calibration of the space-borne instrument is also presented with the system: high calibration accuracy is reached by the calibration system, with the maximum deviation being 0.022 nm, which meets the requirements for the accuracy better than 0.05 nm. The aluminium diffuser measured in laboratory can be chosen for the spectral calibration system.
Design and Implementation of Induction Coil for Case Hardening of a Carbon Steel Gear
Authors: Sabeeh H. F. , Abdlbaqi I. M. , Mahdi S. M.
Published: December 2020

Abstract: This work includes a design of an induction coil as a guide to design an induction furnace as a part of a production line suitable for achieving case hardening of a CK-45 carbon steel gear in a mass production factory. Such a workpiece requires certain hardening profile in that the periphery including the gear teeth must be hardened for certain depth to withstand against corrosion, while the rest volume must be of low hardness in order to overcome mechanical stresses due to the coupled shaft. Induction heating technology adopted for achieving such a complex hardness profile in one workpiece. A numerical simulation intended to design the induction coil, then the induction furnace able to perform this hardening requirement. A three dimensional (3-D) electromagnetic-thermal coupled analysis using Finite Element Method (FEM) is intended to design this coil. This design must determine the required frequency, current, and temperature required for this process at certain required time. These parameters are the guide to build the suitable induction furnace power supply for this task. This work proves the truth that this simulation is quite accurate to implement a pioneer system.
Malignant Warty Lesion at Cervix in Asymptomatic Postmenopausal Woman- A Case Report
Authors: Jha Sangam , Vanya Vidhi , Kumar Tarun
Published: December 2020

Verrucous carcinoma is a rare variant of cervical carcinoma, usually occurs in postmenopausal group. Aetiology is still not understood but it is thought to be associated with chronic irritation and inflammation. Histological diagnosis is usually difficult since the pathologic findings may be benign especially if biopsy specimen contains only surface epithelium. Prognosis of this histological subtype is better compared to the well-differentiated Squamous Cell Carcinoma (SCC) of cervix. Author present a case of verrucous carcinoma where patient came for routine check-up and on pelvic examination; cervix was replaced by friable, cauliflower like warty growth, clinically staged as stage 1B. Punch biopsy was taken from the growth and it reported benign pathology but due to high index of suspicion, repeat biopsy was taken and second histopathology also reported benign pathology. Contrast Enhanced Computed Tomography (CECT) whole abdomen was advised as clinical picture and Histopathological Examination (HPE) was not matching. CECT reported mass confined to the cervix, features consistent with carcinoma cervix. So, the patient underwent radical hysterectomy with pelvic lymphadenectomy. Final histopathology reported verrucous carcinoma of cervix. Patient is under regular follow-up and free of disease since 1 year.
Procedure for optimal implementation of automatic tube potential selection in pediatric CT to reduce radiation dose and improve workflow
Authors: Browne Jacinta E. , Bruesewitz Michael R. , Thomas Vrieze , Thomas Kristen B. , Hull Nathan C. , McCollough Cynthia H. , Yu Lifeng
Published: December 2020

It is important to employ radiation dose reduction techniques in pediatric computed tomography (CT) to reduce potential risks of radiation‐induced malignancy. Automatic tube potential (kV) selection tools have been developed and become available on many CT scanners, which select the optimum kV based on the patient size and clinical task to improve the radiation dose efficiency. However, its use in pediatric CT has been mostly empirical, following manufacturer’s default recommendation without solid demonstration for quality improvement. This study aimed to implement an automatic tube potential tool (CAREkV, Siemens Healthcare) into routine pediatric CT practice, using the “Plan‐Do‐Study‐Act” quality improvement process, in place of an existing kV/mAs technique chart. The design of this quality improvement project involved Plan‐Do‐Study‐Act stages. Plan and Do stages identified the criteria for optimal automatic kV selection; a range of phantoms representing typical pediatric groups were scanned on a dual‐source 128‐slice scanner using a fast‐pitch scanning mode. The identified CAREkV settings were implemented into the CT protocol and evaluated after a 6‐month period. In the Study stage, an objective evaluation of the image metrics and radiation dose for two similar patient cohorts using CAREkV and the technique‐chart, respectively, were compared. The kV selected, image quality and radiation dose determined by CAREkV were comparable to those obtained while using the technique‐chart. The CAREkV was successfully implemented into our pediatric abdominopelvic CT practice. By utilizing the “PDSA” process optimal image quality and radiation dose reduction were achieved with an automatic kV selection tool to improve CT workflow.
Clinical experience of MRI4D QUASAR motion phantom for latency measurements in 0.35T MR‐LINAC
Authors: Kim Taeho , Lewis Benjamin , Lotey Rajiv , Barberi Enzo , Green Olga
Published: December 2020

Purpose

In MRgRT, accuracy of treatment depends on the gating latency, when real‐time targeting and gating is enabled. Gating latency is dependent on image acquisition, processing time, accuracy, efficacy of target tracking algorithms, and radiation beam delivery latency. In this report, clinical experience of the MRI4D QUASAR motion phantom for latency measurements on a 0.35‐T magnetic resonance‐linear accelerator (MR‐LINAC) with two imaging speeds and four tracking algorithms was studied.

Materials/Methods

Beam‐control latency was measured on a 0.35‐T MR‐LINAC system with four target tracking algorithms and two real‐time cine imaging sequences [four and eight frames per second (FPS)]. Using an MR‐compatible motion phantom, the delays between phantom beam triggering signal and linac radiation beam control signal were evaluated for three motion periods with a rigid target. The gating point was set to be 8 mm above the full exhalation position. The beam‐off latency was measured for a total of 24 combinations of tracking algorithm, imaging FPS, and motion periods. The corresponding gating target margins were determined using the target motion speed multiplied by the beam‐off latency.

Results

The largest measured beam‐off latency was 302 ± 20 ms with the Large Deforming Targets (LDT) algorithm and 4 s motion period imaged with 8‐FPS cine MRI. The corresponding gating uncertainty based on target motion speed was 3.0 mm. The range of the average beam‐off latency was 128–243 ms in 4‐FPS imaging and 47–302 ms in 8‐FPS imaging.

Conclusions

The gating latency was measured using an MRI4D QUASAR motion phantom in a 0.35‐T MR‐LINAC. The latency measurements include time delay related to MR imaging method, target tracking algorithm and system delay. The gating uncertainty was estimated based on the beam‐off latency measurements and the target motion.
Clinical and imaging characteristics of breast ductal carcinoma in situ with microinvasion
Authors: Han Sijia , Qiu Fang , Han Ye , Xu Yongqing , Yin Jianqiao , Xing Fei , Bian Xiaobo , He Guijin
Published: December 2020

Background

We analyzed the clinical and imaging characteristics of patients with breast ductal carcinoma in situ with microinvasion (DCISM) and breast ductal carcinoma in situ (DCIS).

Methods

We analyzed the records of 40 patients diagnosed with DCISM and 61 patients with DCIS who were hospitalized at Shengjing Hospital (Shenyang, China) from January 2009 to June 2016. The size, hardness, and degree of calcification of tumors were determined by mammography and ultrasonography.

Results

In all, 37 DCISM patients and 45 DCIS patients showed clinical palpable masses (92.5% vs 73.77%, P = 0.018). Mammography showed that the mean size of tumor was larger in DCISM patients than that of DCIS patients (3.13 ± 1.51 vs 2.68 ± 1.77, P = 0.030). Ultrasound examination revealed calcification shadows in the solid tumor mass in 17 DCISM cases and 11 DCIS patients (42.5 vs 18.03%, P = 0.007). Furthermore, estrogen receptor positivity and progesterone receptor positivity were more common in DCIS patients (32.5% vs 54.10%, P = 0.033; 22.5% vs 45.90%, P = 0.017), and the percentage of menopausal patients were higher in DCISM patients than that of DCIS patients (70.00% vs 47.54%, P = 0.026).

Conclusion

Clinically palpable and calcified tumor masses on sonography are more commonly encountered in DCISM lesions.
Exploring Structural Changes, Manufacturing, Joining, and Repair of Intermetallic γ‐TiAl‐Based Alloys: Recent Progress Enabled by In Situ Synchrotron X‐Ray Techniques
Authors: Spoerk-Erdely Petra , Staron Peter , Liu Jie , Kashaev Nikolai , Stark Andreas , Hauschildt Katja , Maawad Emad , Mayer Svea , Clemens Helmut
Published: December 2020

Intermetallic γ‐TiAl‐based alloys are a promising class of materials for lightweight high‐temperature applications. Following intensive research and development activities, they have recently entered service in the automotive and aircraft engine industries. In the course of the past decades, the development of these complex multiphase alloys has benefited considerably from the application of (in situ) X‐ray scattering and diffraction techniques. Herein, a practical introduction and overview of recent progress in this field of research are provided. In particular, four case studies taken from various stages in the alloy development (i.e., fundamental research—manufacturing, joining, and repair—and application) illustrate current prospects at modern synchrotron radiation sources, including detailed information on available setups for in situ high‐energy X‐ray diffraction and small‐angle X‐ray scattering experiments and a discussion of potential limitations in the use of these techniques.
Selective Laser Melting of a Near‐α Ti6242S Alloy for High‐Performance Automotive Parts
Authors: Fleißner-Rieger Christian , Pfeifer Tanja , Jörg Tanja , Kremmer Thomas , Brabetz Manfred , Clemens Helmut , Mayer Svea
Published: December 2020

This study aims to investigate additively manufactured Ti6242S specimens compared with the widely used Ti64 alloy with a special focus on microstructure and mechanical properties as well as the impact of subsequent heat treatments. As the Ti6242S alloy, which belongs to the family of near‐α Ti‐alloys, is often used at higher service temperatures, uniaxial tensile tests are performed at a room temperature up to 500 °C. By means of optical and electron microscopy, it is found that the as‐built microstructure consists of acicular α′ martensite, which decomposes to α + β during the subsequent heat treatment. A special focus on the prior microstructure shows that the Ti6242S alloy has a small β grain size, which influences the resulting α′ microstructure after the β → α′ phase transformation. Furthermore, the mechanical properties at room temperature as well as elevated temperatures exceed the values for selective laser melted Ti64 and conventionally cast Ti6242 material. The heat‐treated Ti6242S specimens exhibit an ultimate tensile strength of about 1213 MPa including a ductility of 11.3% at room temperature. These values may path the way to a substitution of the widely used Ti64 alloy by the near‐α Ti6242S alloy, especially for highly loaded components at elevated temperatures.
Effects of Heat Input on Morphology of Thin‐Wall Components Fabricated by Wire and Arc Additive Manufacturing
Authors: Jiang Fengchun , Sun Laibo , Huang Ruisheng , Jiang Hui , Bai Guangyong , Qi Xiaopeng , Liu Chuanming , Su Yan , Guo Chunhuan , Wang Jiandong
Published: December 2020

In the process of wire and arc additive manufacturing (WAAM), it is crucial to improve the surface quality and maintain a uniform building morphology. Unacceptable morphology of components influences the surface roughness and deposition efficiency, limiting the application of WAAM in the fabrication of complex‐shaped components. Herein, linear energy density is used to estimate the applied heat input. The single‐pass single‐layer bead morphology is analyzed to establish the relationship between linear energy density and the bead width ratio to bead height. In addition, four four‐layer components under different heat inputs are deposited to reveal the process of multilayer deposition. According to the morphology and surface appearance, heat input effects on surface roughness, straightness, and deposition efficiency are investigated. Then, a relationship is established to predict the outcomes of heat input on deposition quality. It is inferred that good deposition performance can be obtained when the linear energy density lies around 600 J mm−1. A simulation based on the Simufact welding software is made on temperature field distribution and thermal cycles to illustrate the relationship, confirmed by 3D scanning results. At last, based on the investigations, a uniform and well‐formed thin‐wall component is fabricated, and its deposition efficiency can reach 80%.
Biodegradable Zwitterionic Cream Gel for Effective Prevention of Postoperative Adhesion
Authors: Zhang Ershuai , Yang Jianhai , Wang Ke , Song Boyi , Zhu Hui , Han Xiangfei , Shi Yuanjie , Yang Chengbiao , Zeng Zhipeng , Cao Zhiqiang
Published: December 2020

Postoperative peritoneal adhesions are frequent complications for almost any type of abdominal and pelvic surgery. This leads to numerous medical problems and a huge financial burden to the patients. Current anti‐adhesion strategies focus mostly on physical barriers including films and hydrogels. However, they can only alleviate or reduce adhesions to a certain level and their applying processes are far from ideal. This work reported the development of a biodegradable zwitterionic cream gel presenting a series of characters for an ideal anti‐adhesion material, including unique injectable yet malleable and self‐supporting properties, which enables an instant topical application, no curing, waiting, or suturing, no hemostasis requirement, protein/cell resistance, and biodegradability. The cream gel shows a major advancement in anti‐adhesion efficacy by completely and reliably preventing a primary and more severe recurrent adhesion in rat models.
Nanocellulose‐Reinforced Hydroxyapatite Nanobelt Membrane as a Stem Cell Multi‐Lineage Differentiation Platform for Biomimetic Construction of Bioactive 3D Osteoid Tissue In Vitro
Authors: Liu Feng , Wei Benjie , Xu Xiaoying , Ma Baojin , Zhang Shan , Duan Jiazhi , Kong Ying , Yang Hongru , Sang Yuanhua , Wang Shuhua , Tang Wei , Liu Chao , Liu Hong
Published: December 2020

Severe bone defects, especially accompanied by vascular and peripheral nerve injuries, remain a massive challenge. Most studies related to bone tissue engineering have focused on osteogenic differentiation of mesenchymal stem cells (MSCs), and ignored the formation of blood vessels and nerves in the newly generated bone owing to the lack of proper materials and methodology for tuning stem cells differentiated into osteogenic, neuronal, and endothelial cells (ECs) in the same scaffold system. Herein, a nanocellulose‐reinforced hybrid membrane with good mechanical properties and control over biodegradation by assembling ultralong hydroxyapatite nanobelts in a bacterial nanocellulose hydrogel is designed and synthesized. Osteogenic, neuronal cells are successfully differentiated on this hybrid membrane. Based on the multi‐lineage differentiation property of the membrane, a bioactive 3D osteoid tissue (osteogenic, neural, and ECs) is mimetically constructed in vitro using layer‐by‐layer culture and integration. The bone regeneration ability of the as‐prepared bioactive osteoid tissue is assessed in vivo via heterotopic osteogenesis experiments for eight weeks. The rapid new bone growth and formation of blood capillaries and nerve fibers prove that the hybrid membrane can be universally applied as a stem cell multi‐lineage differentiation platform, which has significant applications in bone tissue engineering.
Anharmonicity‐Driven Rashba Cohelical Excitons Break Quantum Efficiency Limitation
Authors: Myung Chang Woo , Kim Kwang S.
Published: December 2020

Closed‐shell light‐emitting diodes (LEDs) suffer from the internal quantum efficiency (IQE) limitation imposed by optically inactive triplet excitons. Here, an unrevealed emission mechanism of lead halide perovskites (LHPs) APbX3 (A = Cs/CN2H5; X = Cl/Br/I) that circumvents the efficiency limit of closed‐shell LEDs is explored. Though efficient emission is prohibited by optically inactive J = 0 in inversion symmetric LHPs, the anharmonicity arising from stereochemistry of Pb and resonant orbital‐bonding network along the imaginary A+…X−(T1u) transverse optical (TO) modes, breaks inversion symmetry, introducing disorder and Rashba–Dresselhaus spin‐orbit coupling (RD‐SOC). This results in bright cohelical and dark antihelical excitons. Many‐body theory and first‐principles calculations show that the optically active cohelical exciton is the lowest excited state in organic/inorganic LHPs. Thus, RD‐SOC can drive to achieve the ideal 50% IQE by utilizing anharmonicity, much over the 25% IQE limitation for closed‐shell LEDs.
Water‐Surface Drag Coating: A New Route Toward High‐Quality Conjugated Small‐Molecule Thin Films with Enhanced Charge Transport Properties
Authors: Deng Wei , Xiao Yanling , Lu Bei , Zhang Liang , Xia Yujian , Zhu Chenhui , Zhang Xiujuan , Guo Jinghua , Zhang Xiaohong , Jie Jiansheng
Published: December 2020

Electronic properties of organic semiconductor (OSC) thin films are largely determined by their morphologies and crystallinities. However, solution‐processed conjugated small‐molecule OSC thin films usually exhibit abundant grain boundaries and impure grain orientations because of complex fluid dynamics during solution coating. Here, a novel methodology, water‐surface drag coating, is demonstrated to fabricate high‐quality OSC thin films with greatly enhanced charge transport properties. This method utilizes the water surface to alter the evaporation dynamics of solution to enlarge the grain size, and a unique drag‐coating process to achieve the unidirectional growth of organic crystals. Using 2,8‐difluoro‐5,11‐bis(triethylsilylethynyl)anthradithiophene (Dif‐TES‐ADT) as an example, thin films with millimeter‐sized single‐crystal domains and pure crystallographic orientations are achieved, revealing a significant enhancement (4.7 times) of carrier mobility. More importantly, the resulting film can be directly transferred onto any desired flexible substrates, and flexible transistors based on the Dif‐TES‐ADT thin films show a mobility as high as 16.1 cm2 V−1 s−1, which represents the highest mobility value for the flexible transistors reported thus far. The method is general for the growth of various high‐quality OSC thin films, thus opening up opportunities for high‐performance organic flexible electronics.
Ultra‐Broadband and High‐Dynamic‐Range THz Time‐Domain Spectroscopy System Based on Organic Crystal Emitter and Detector in Transmission and Reflection Geometry
Authors: Puc Uros , Bach Tobias , Günter Peter , Zgonik Marko , Jazbinsek Mojca
Published: December 2020

The terahertz range of the electromagnetic spectrum reveals important insights when studying material properties. An ultra‐broadband terahertz time‐domain spectroscopy system based on state‐of‐the‐art, high‐stability organic nonlinear optical crystals used as both THz wave generator and detector is presented. In transmission geometry, a broad spectrum exceeding 20 THz and a high dynamic range of more than 80 dB is achieved using a compact 100 MHz femtosecond laser working at telecom wavelength 1560 nm. In the normal‐incidence reflection geometry, a similar bandwidth with a dynamic range surpassing 60 dB is reported. The experimental results are supported by a complete theoretical model, which includes the pump pulse duration, THz phonon/vibrational modes of the organic crystals and optical/THz beam path optimizations. The effectiveness of the newly developed system is demonstrated by measuring pharmaceutical samples with distinct THz features in the ultra‐broadband THz range and by measuring narrow water vapor lines at a spectral resolution of 2.7 GHz (0.090 cm−1), resulting in an excellent accuracy with a frequency deviation of less than 0.05% from the reference values.
Assessing the Applicability of Gravity Separation for Recycling of Non‐Metal Fraction from Waste Printed Circuit Boards
Authors: Kumar Amit , Holuszko Maria E. , Janke Travis
Published: December 2020

Printed circuit boards (PCB) are one of the most studied electronic waste streams due to the presence of high‐value metals. The rejects from waste PCB recycling, also known as a non‐metal fraction (NMF), are usually sent to landfill. This work explores the applicability of gravity separation, widely used in the mineral processing industry, to separate organic and inorganic components in the NMF. The float‐sink test is conducted to understand the gravity separation performance, and the results show that a 47% yield at 86% organic content with 70% combustible recovery can be obtained using dense media separation. The washability behavior of NMF is assessed using different washability indices standard in the coal industry; and the material is classified as difficult‐to‐clean. The float‐sink products show the concentration of organic stream in −1.8 g cm−3 range, fiberglass in +2.0–2.5 g cm−3 range, and metals in +2.5 g cm−3 range. The recovery of these components will facilitate the concept of the circular economy and promote sustainability.
Alloying Nickel with Molybdenum Significantly Accelerates Alkaline Hydrogen Electrocatalysis
Authors: Wang Miao , Yang Hao , Shi Jinan , Chen Yufeng , Zhou Yuan , Wang Liguang , Di Sijia , Zhao Xuan , Zhong Jun , Cheng Tao , Zhou Wu , Li Yanguang
Published: December 2020

Bifunctional hydrogen electrocatalysis (hydrogen‐oxidation and hydrogen‐evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni‐based materials are the only non‐precious‐metal‐based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni4Mo alloy nanoparticles are prepared from the reduction of molybdate‐intercalated Ni(OH)2 nanosheets. The final product exhibits an apparent hydrogen‐oxidation activity exceeding that of the Pt benchmark and a record‐high mass‐specific kinetic current of 79 A g−1 at an overpotential of 50 mV. A superior hydrogen‐evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.
Synthesis and Reactivity of Multinuclear Gold Complexes with (Diphenylphosphanyl)ferrocene and Oxygen Ligands
Authors: Schulz Jiří , Císařová Ivana , Gyepes Róbert , Štěpnička Petr
Published: December 2020

AuI complexes combining hard oxygen and soft (diphenylphosphanyl)ferrocene (L) ligands in their molecules were synthesized, viz. the gold hydroxides [Au(OH)(L‐κP)] (5) and [{Au(L‐κP)}2(μ‐OH)][BF4] (4), and the oxonium cluster [{Au(L‐κP)}3(μ3‐O)][BF4] (1). In‐situ auration of 1 produced [{Au(L‐κP)}4(μ4‐O)][BF4]2 (2), which spontaneously converted into a dimeric tetragold complex featuring bridging phosphanylferrocenyl groups geminally diaurated in position 2 of the ferrocene scaffold. The same complex and its isomer incorporating ferrocene‐1,1′‐diyl bridges resulted similarly from 4. Upon crystallization, compound 5 underwent a redox reaction, producing a structurally unique, crown‐like, mixed‐valent Au0/AuI cluster, [Au7(L‐κP)6]OH. Compounds 1 and 5 were used to prepare the analogous, N‐bridged complexes, [{Au(L‐κP)}3(μ3‐NFc)][BF4] (Fc=ferrocenyl) and [{Au(L‐κP)}4(μ4‐N)][BF4]. The compounds were structurally characterized and further studied by DFT calculations.
Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution
Authors: Rey‐Tarrío Francisco , Rodríguez Rafael , Quiñoá Emilio , Riguera Ricardo , Freire Félix
Published: December 2020

Photochemical electrocyclization of poly(phenylacetylene)s (PPAs) is used for the structural elucidation of a polyene backbone. This method not only allows classification of PPAs in cis‐cisoidal (ω1<90°) or cis‐transoidal structures (ω1>90°), but also approximating ω1. A PPA solution is illuminated with visible light and monitoring the photochemical electrocyclization of the PPA helix by measuring the ECD spectra at different times. PPAs with a cis‐cisoidal structure show a reduction of the ECD signal of at least 50 % before 30 min of irradiation, while cis‐transoidal helices need much longer time because the transoidal bond must be isomerized. The different cis‐cisoidal and cis‐transoidal helices require different times to decrease their ECD signal by 50 % (t1/2), depending on the degree of compression or stretching of the helix, establishing a relationship between the secondary structure adopted by PPA (ω1) and the time required to lose the ECD vinylic signal by light irradiation.
Multimodal Imaging of Autofluorescent Sites Reveals Varied Chemical Speciation in SSZ‐13 Crystals
Authors: Omori Naomi , Candeo Alessia , Mosca Sara , Lezcano‐Gonzalez Ines , Robinson Ian K. , Li Luxi , Greenaway Alex G. , Collier Paul , Beale Andrew M.
Published: December 2020

A multimodal imaging study of chabazite is used to show the distribution of and discriminate between different emissive deposits arising as a result of the detemplation process. Confocal imaging, 3D fluorescence lifetime imaging, 3D multispectral fluorescence imaging, and Raman mapping are used to show three different types of emissive behaviours each characterised by different spatial distributions, trends in lifetime, spectral signals, and Raman signatures. A notable difference is seen in the morphology of agglomerated surface deposits and larger subsurface deposits, which experience lifetime augmentation due to spatial confinement. The distribution of organic residue throughout the crystal volume is comparable to XRF mapping that shows Si enrichment on the outer edges and higher Al content through the centre, demonstrating that a fluorescence‐based technique can also be used to indirectly comment on the compositional chemistry of the inorganic framework.
Long‐Range Exciton Migration in Coassemblies: Achieving High Photostability without Disrupting the Electron Donation of Fluorene Oligomers
Authors: Cheng Chuanqin , Gong Yanjun , Guo Yongxian , Cui Linfeng , Ji Hongwei , Yuan Hong , Jiang Lang , Zhao Jincai , Che Yanke
Published: December 2020

In this work, photostable coassemblies from a nonphotostable fluorene oligomer (the energy donor) and a photostable oligomer (the energy acceptor) are fabricated. Long‐range exciton migration over a net distance of about 370 energy‐donor molecules to energy acceptors is demonstrated in such coassemblies. The fast and long energy migration allows harvesting of the excitation energy of energy donors by embedding a small number of energy acceptors for photostability enhancement. Importantly, embedding a small number of energy acceptors in coassemblies causes a negligible negative influence on the electron donation of energy donors that are desired in practical applications. The advantages of the coassemblies fabricated, that is, high photostability without disrupting the electron donation of energy donors, are well illustrated in fluorescence detection of trace explosives where prolonged working life and improved detection capacity are achieved.
Convergent Total Synthesis of Yaku'amide A
Authors: Cai Yu , Ma Zhiwei , Jiang Jintao , Lo Concordia C. L. , Luo Shi , Jalan Ankur , Cardon Joseph M. , Ramos Alexander , Moyá Diego A. , Joaquin Daniel , Castle Steven L.
Published: December 2020

Total synthesis of the anticancer peptide natural product yaku'amide A is reported. Its β‐tert‐hydroxy amino acids were prepared by regioselective aminohydroxylation involving a chiral mesyloxycarbamate reagent. Stereospecific construction of the E‐ and Z‐ΔIle residues was accomplished through a one‐pot reaction featuring anti dehydration, azide reduction, and O→N acyl transfer. Alkene isomerization was negligible during this process. These methods enabled a highly convergent and efficient synthetic route to the natural product.
Current Trends in Metal–Organic and Covalent Organic Framework Membrane Materials
Authors: Hosseini Monjezi Bahram , Kutonova Ksenia , Tsotsalas Manuel , Henke Sebastian , Knebel Alexander
Published: December 2020

Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been thoroughly investigated with regards to applications in gas separation membranes in the past years. More recently, new preparation methods for MOFs and COFs as particles and thin‐film membranes, as well as for mixed‐matrix membranes (MMMs) have been developed. We will highlight novel processes and highly functional materials: Zeolitic imidazolate frameworks (ZIFs) can be transformed into glasses and we will give an insight into their use for membranes. In addition, liquids with permanent porosity offer solution processability for the manufacture of extremely potent MMMs. Also, MOF materials influenced by external stimuli give new directions for the enhancement of performance by in situ techniques. Presently, COFs with their large pores are useful in quantum sieving applications, and by exploiting the stacking behavior also molecular sieving COF membranes are possible. Similarly, porous polymers can be constructed using MOF templates, which then find use in gas separation membranes.
Cooperative Stapling of Native Peptides at Lysine and Tyrosine or Arginine with Formaldehyde
Authors: Li Bo , Tang Hong , Turlik Aneta , Wan Zhao , Xue Xiao‐Song , Li Li , Yang Xiaoxiao , Li Jiuyuan , He Gang , Houk Kendall N. , Chen Gong
Published: December 2020

Stapling of peptides by intramolecular crosslinking of two neighboring amino acid side chains offers an important tool to modulate the structure and properties of peptides. In comparison to the stapling of artificially engineered peptide substrates, methods for stapling native peptides are more desirable for easier accessibility and genetic encodability. However, the existing strategy for selectivity control in the stapling of native peptides is relatively limited: the site of anchoring is often dominated by Cys, and the means for achieving the position selectivity among the same type of residues at different locations is lacking. We have developed a simple and powerful strategy for stapling native peptides at lysine residues with formaldehyde by the cooperation of nearby tyrosine or arginine residues. The stapling reactions can proceed with high efficiency and residue selectivity under mild conditions, and generate linchpins with distinct physiochemical properties. The new method for peptide stapling enables unique control of position‐selectivity for substrates bearing multiple reaction sites by reactivity that can be readily built in the peptide sequence.
Comparison of bubble velocity, size, and holdup distribution between single‐ and double‐air inlet in jet microbubble generator
Authors: Li Xiaoheng , Su Wenbing , Liu Yu , Yan Xiaokang , Wang Lijun , Zhang Haijun
Published: December 2020

The jet microbubble generator is often used to produce bubbles in flotation equipment, which generates microbubbles by self‐absorbing or inflating. Bubble behavior is a dominant factor in froth flotation, and its velocity, size, and distribution greatly affect flotation performance. However, the asymmetry distribution of the pressure, bubble velocity, and gas holdup in generator with single inlet probably causes eccentric wear to the equipment. Therefore, in this study, using particle image velocimetry (PIV), high‐speed dynamic camera, and computational fluid dynamics (CFD) technology, the bubble behaviors in the jet microbubble generators with single inlet and double inlet was studied. The results show that under air flux of 0.4 L/min, the change of bubble diameter (D32) in two generators is obvious, reducing by 5.97% and 3.77% under circulation water flux of 1.5 and 2.5 m3/h, respectively. Comparing the influence of circulating water fluxes, the double‐inlet structure can reduce the bubble diameter more effectively. The maximum turbulent dissipation rate in the throat section of the generator with double inlet is greater than 120, while it is less than 100 in single‐inlet structure. For bubbles in generator with double inlet, velocity difference in radial direction reduces to 0.03 m/s and is more symmetrical. Meanwhile, the double‐inlet generator can also optimize the uniformity gas holdup distribution, which is beneficial to increase the collision probability of flotation and reduce the abrasion of microbubble generator.
Risk factors and their diagnostic values for ocular metastases in invasive ductal carcinoma
Authors: Liang Rong‐Bin , Yu Kang , Wu Jie‐Li , Liu Jia‐Xiang , Lin Qi , Li Biao , Zhang Yu‐Qing , Ge Qian‐Min , Li Qiu‐Yu , Shu Hui‐Ye , Shao Yi
Published: December 2020

Invasive ductal carcinoma (IDC) is a major type of breast cancer. Ocular metastasis (OM) in IDC is rarely seen, but patients with OM often have a poor prognosis. Furthermore, OM is difficult to detect in the early stages by common imaging examinations. In the present study, we tried to figure out the risk factors of OM in IDC and evaluate their diagnostic values for early detection. There were 1192 IDC patients who were divided into two groups according to ocular metastasis involved in this study. Clinical parameters of those patients were used to detect differences. The binary logistic regression test was then used to determine the risk factors of OM in IDC. Furthermore, ROC curves of both single and combined risk factors were established to examine their diagnostic values. The incidence of axillary lymph node metastases was significantly higher in the OM group (p = 0.002). Higher carbohydrate antigen 153 (CA153), lower apolipoprotein A1 (ApoA1), and hemoglobin (Hb) were risk factors for OM in IDC (p < 0.001, p < 0.001, p = 0.038, respectively). In the single risk factor ROC analysis, cutoff values of CA153, ApoA1, and Hb were 43.3 u/mL (CI: 0.966–0.984, p < 0.001), 1.11 g/L (CI: 0.923–0.951, p < 0.001), and 112 g/L (CI: 0.815–0.857, p < 0.001), respectively. Among the ROC curves of combined risk factors, CA153+ApoA1+Hb had the best accuracy, with the sensitivity and specificity of 89.47% and 99.32%, respectively (CI: 0.964–0.983, p < 0.001). CA153, ApoA1, and Hb are risk factors for OM in IDC. In clinical practice, the three parameters could be used as predictive factors for the early detection of OM.
Use of Copper as a Trigger for the in Vivo Activity of E. coli Laccase CueO: A Simple Tool for Biosynthetic Purposes
Authors: Decembrino Davide , Girhard Marco , Urlacher Vlada B.
Published: December 2020

Laccases are multi‐copper oxidases that catalyze the oxidation of various electron‐rich substrates with concomitant reduction of molecular oxygen to water. The multi‐copper oxidase/laccase CueO of Escherichia coli is responsible for the oxidation of Cu+ to the less harmful Cu2+ in the periplasm. CueO has a relatively broad substrate spectrum as laccase, and its activity is enhanced by copper excess. The aim of this study was to trigger CueO activity in vivo for the use in biocatalysis. The addition of 5 mM CuSO4 was proven effective in triggering CueO activity at need with minor toxic effects on E. coli cells. Cu‐treated E. coli cells were able to convert several phenolic compounds to the corresponding dimers. Finally, the endogenous CueO activity was applied to a four‐step cascade, in which coniferyl alcohol was converted to the valuable plant lignan (−)‐matairesinol.
Synthetic Phenolic Glycolipids for Application in Diagnostic Tests for Leprosy
Authors: van Dijk J. Hessel M. , van Hooij Anouk , Groot L. Melanie , Geboers Jolijn , Moretti Rosita , Verhard‐Seymonsbergen Els , de Jong Danielle , van der Marel Gijs A. , Corstjens Paul L. A. M. , Codée Jeroen D. C. , Geluk Annemieke
Published: December 2020

Point‐of‐care (POC) diagnostic tests for the rapid detection of individuals infected with Mycobacterium leprae, the causative pathogen of leprosy, represent efficient tools to guide therapeutic and prophylactic treatment strategies in leprosy control programs, thus positively contributing to clinical outcome and reducing transmission of this infectious disease. Levels of antibodies directed against the M. leprae‐specific phenolic glycolipid I (PGL−I) closely correlate with an individual's bacterial load and a higher risk of developing leprosy. We describe herein the assembly of a set of PGL glycans carrying the characteristic phenol aglycon and featuring different methylation patterns. The PGL trisaccharides were applied to construct neoglycoproteins that were used to detect anti‐PGL IgM antibodies in leprosy patients. ELISAs and quantitative lateral‐flow assays based on up‐converting nanoparticles (UCP‐LFAs) showed that the generated PGL−I and PGL‐II trisaccharide neoglycoconjugates can be applied for the detection of anti M. leprae IgM antibodies in POC tests.
Selective immunoglobulin M deficiency in a patient with celiac disease and recurrent pneumonia
Authors: Heidarzadeh Arani Marziyeh , Razavizadeh Mohsen , ArefNezhad Reza , Motedayyen Hossein
Published: December 2020

SIgMD is a rare immune disorder that occurs in a primary or secondary condition. Patients with recurrent infectious, cancers, and autoimmune disorders should be investigated to determine SIgMD.
Chronic persistent HHV‐6B infection after sulfasalazine‐induced DRESS with demonstration of HHV‐6 encoded small noncoding RNAs (sncRNAs) in Crohn’s‐like colitis: Case report
Authors: Descamps Vincent , Gautheret‐Dejean Agnès , Pelletier Anne‐Laure , Bonnafous Pascale , Deschamps Lydia , Prusty Bhupesh K.
Published: December 2020

A sulfasalazine‐induced DRESS (Drug Reactivation with Eosinophilia and Systemic Symptoms) was complicated by a Crohn's‐like colitis. We demonstrated HHV‐6 reactivation with presence of HHV‐6 DNA and small noncoding RNA in colonic lesions. This observation confirms the major role of HHV‐6 reactivation in DRESS manifestations and the importance of looking for HHV‐6 reactivation in DRESS.