bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotating machinery dynamics simulation. I. Rigid systems with ball bearing nonlinearities and outer ring ovality under rotating unbalance excitation
Authors: El-Saeidy Fawzi M. A.
Published: July 2002

The radial clearance in rolling bearing systems, required to compensate for dimensional changes associated with thermal expansion of the various parts during operation, may cause dimensional attrition and comprise bearing life, if unloaded operation occurs and balls skid [D. Childs and D. Moyer, ASME J. Eng. Gas Turb. Power 107, 152–159 (1985)]. Also, it can cause jumps in the response to unbalance excitation. These undesirable effects may be eliminated by introducing two or more loops into one of the bearing races so that at least two points of the ring circumference provide a positive zero clearance [D. Childs, Handbook of Rotordynamics, edited by F. Ehrich (McGraw-Hill, NY, 1992)]. The deviation of the outer ring with two loops, known as ovality, is one of the bearing distributed defects. Although this class of imperfections has received much work, none of the available studies has simulated the effect of the outer ring ovality on the dynamic behavior of rotating machinery under rotating unbalance with consideration of ball bearing nonlinearities, shaft elasticity, and speed of rotation. To fill this gap, the equations of motion of a rotor–ball bearing system are formulated using finite-elements (FE) discretization and Lagrange’s equations. The analyses are specialized to a rigid-rotor system, by retaining the rigid body modes only in the FE solution. Samples of the results are presented in both time domain and frequency domain for a system with and without outer ring ovality. It is found that with ideal bearings (no ovality), the vibration spectrum is qualitatively and quantitatively the same in both the horizontal and vertical directions. When the ring ovality is introduced, however, the spectrum in both orthogonal planes is no longer similar. And magnitude of the bearing load has increased in the form of repeated random impacts, between balls and rings, in the horizontal direction (direction of maximum clearance) compared to a continuous contact along the vertical direction (direction of positive zero clearance). This underlines the importance of the vibration measuring probe’s direction, with respect to the outer ring axes, to capture impact-induced vibrations. Moreover, when the harmonic excitation is increased for a system with ideal bearings, the spectral peaks above forcing frequency have shifted to a higher-frequency region, indicating some sort of a hard spring mechanism inherent in the system. Another observation, is that for the same external excitation, vibration amplitude at forcing frequency in the bearing force spectrum is the same for systems with or without outer ring ovality.
Acoustic hybrid junction in a rectangular waveguide
Authors: Kwon Jae Y. , Eom Hyo J.
Published: July 2002

Acoustic scattering from a hybrid junction in a rectangular waveguide is studied. The Fourier transform and mode matching is used to represent the scattered wave and the simultaneous equations for the modal coefficients are formulated. A residue calculus is utilized to obtain a solution to the simultaneous equations in fast-converging series. Numerical computations are performed to show the behavior of transmission in terms of junction geometry and operating frequency. The utility of acoustic hybrid junction is discussed in terms of its decoupling characteristics.
A generic matrix representation of configuration tensor rheological models
Authors: Jongschaap R. J. J. , de Haas K. H. , Damen C. A. J.
Published: July 2002

A general framework for microrheological modeling is provided and elaborated for the case of configuration tensor models. It is an extension and partial revision of our earlier work on a specific matrix representation for a thermodynamic treatment in microrheological modeling. The extension consists in a more detailed discussion of the fundamentals and some particular aspects of that representation, such as the implications of frame indifference and isotropy and a more complete discussion of its thermodynamic context. The revision has to do with the extension to nonlinear cases. Finally, the application to particular types of rheological models is discussed in some detail.
Use of coupled birefringence and LDV studies of flow through a planar contraction to test constitutive equations for concentrated polymer solutions
Authors: Quinzani L. M. , Armstrong R. C. , Brown R. A.
Published: July 2002

Laser Doppler velocimetry and flow-induced birefringence are used to measure the rate of deformation and the principal components of the refractive index tensor in a 5% polyisobutylene (PIB) solution in tetradecane (C14) flowing along the centerplane of an abrupt 3.97:1 planar contraction. The stress optical law is used to interpret the birefringence data in terms of the normal stress difference, which is used to calculate a transient elongational viscosity defined along the centerplane. These measurements are compared directly to predictions of six multimode, differential constitutive models (Oldroyd-B, White–Metzner, Acierno et al., Giesekus, Bird–DeAguiar, and Phan-Thien–Tanner) that are fit to steady and small amplitude oscillatory shear flow data for the PIB/C14 solution. The fluid exhibits slight elongational thickening followed by apparent extensional thinning at higher elongation rates. We believe that this ‘‘thinning’’ behavior is due to the decreased residence time of the polymer molecules in the high-strain-rate region as the flow rate (and maximum elongation rate) is increased. The nonlinear constitutive equations, except for the White–Metzner model, are virtually indistinguishable in their description of the dynamical response of the fluid in this experiment; however, the Phan-Thien–Tanner model gives the best quantitative fit to the data. These results point to the need for experiments in which the fluid flowing along the centerline is subjected to a greater total elongational strain.
Synthesis and X-ray powder diffraction data of transition metal derivatives of maleic acid. I. M2+(C4H3O4−)2⋅4H2O (M2+=Mn, Fe, Co, Ni, and Zn)
Authors: Briceño A. , González T. , de Delgado G. Díaz , Guevara R. , Delgado J. M.
Published: July 2002

Five transition metal derivatives of maleic acid with general formula, M2+(C4H3O4−)2⋅4H2O (M2+=Mn, Fe, Co, Ni, and Zn) were prepared by slow evaporation of the aqueous solution at room temperature. Their X-ray powder diffraction patterns were recorded and evaluated. These materials are isostructural and crystallize in a triclinic unit cell. The volume of the cells vary linearly between that of the Ni complex [V=314.65(7) Å3: a=5.1769(8) Å, b=7.317(1) Å, c=9.140(2) Å, α=108.42(2)°, β=104.61(1)°, γ=92.87(1)°] and the volume of the Mn-derivative [V=330.30(8) Å3: a=5.322(1) Å, b=7.375(1) Å, c=9.752(2) Å, α=115.48(2)°, β=106.64(2)°, γ=86.63(2)°].
The cryo‐EM structure of full‐length RAD52 protein contains an undecameric ring
Authors: Kinoshita Chiaki , Takizawa Yoshimasa , Saotome Mika , Ogino Shun , Kurumizaka Hitoshi , Kagawa Wataru
Published: January 2023

The human RAD52 protein, which forms an oligomeric ring structure, is involved in DNA double‐strand break repair. The N‐terminal half of RAD52 is primarily responsible for self‐oligomerisation and DNA binding. Crystallographic studies have revealed the detailed structure of the N‐terminal half. However, only low‐resolution structures have been reported for the full‐length protein, and thus the structural role of the C‐terminal half in self‐oligomerisation has remained elusive. In this study, we determined the solution structure of the human RAD52 protein by cryo‐electron microscopy (cryo‐EM), at an average resolution of 3.5 Å. The structure revealed an undecameric ring that is nearly identical to the crystal structures of the N‐terminal half. The cryo‐EM map for the C‐terminal half was poorly defined, indicating that the region is intrinsically disordered. The present cryo‐EM structure provides important insights into the mechanistic roles played by the N‐terminal and C‐terminal halves of RAD52 during DNA double‐strand break repair.
The NLRP3 inflammasome – interleukin 1β axis in uveal melanoma
Authors: Correa Victor S. M. C. , Efstathiou Nikolaos E. , Ntentakis Dimitrios P. , Yu Zhen , Narimatsu Toshio , Gragoudas Evangelos , Kim Ivana K. , Vavvas Demetrios G.
Published: January 2023

Uveal melanoma (UM) is the most common primary intraocular cancer in the adult population. Recent studies suggested that the NLRP3 inflammasome could be a therapeutic target for cutaneous melanoma (CM), but the role of NLRP3 in UM remains unknown. Here, we analyzed the NLRP3‐IL‐1β axis in 5 UM and 4 CM cell lines. Expression of NLRP3 mRNA in UM and CM was low, and expression in UM was lower than in CM (P < 0.001). NLRP3 protein levels were below detection limit for all cell lines. UM exhibited lower baseline IL‐1β secretion than CM, especially when compared to the Hs294t cell line (P < 0.05). Bioinformatic analysis of human tumor samples showed that UM has significantly lower expression of NLRP3 and IL‐1β compared with CM. In conclusion, our work shows evidence of extremely low NLRP3 expression and IL‐1β secretion by melanoma cells and highlight differences between CM and UM.
The Role of Bismuth as Trace Element on the Solidification Path and Microstructure of Na‐Modified AlSi7Mg Alloys
Authors: Gursoy Ozen , Timelli Giulio
Published: January 2023

The effects of Bi content as a trace element on the microstructure and the solidification path of A356.2 alloy have been investigated. The alloys containing different Bi levels (0, 20, and 200 ppm) have been modified by sodium. The experimental alloys have been thermally analyzed by using the two‐thermocouple method. Metallographic and image analysis techniques have been used to quantitatively examine the microstructural changes occurring at different Bi and Na concentrations. The results indicate how the presence of Bi as a trace element affects the eutectic structure. Upon increasing the Bi level, the nucleation and growth temperatures of eutectic Si raise, and the eutectic Si particles appear coarser in Na‐modified alloys. The EBSD analyses show that the crystallographic orientation between eutectic Al and surrounding primary Al dendrites becomes identical in Na‐modified Bi‐containing alloy. Furthermore, an irregular Bi + (Mg,Na)3Bi2 eutectic is formed prior to the precipitation of the eutectic Si, thus reducing the efficiency of Na addition to fully modify the eutectic Si.
Engineering Materials for Neurotechnology
Authors: Ghezzi Diego
Published: January 2023

Neurotechnology applies methods and devices to mitigate the burden of neurological and mental disorders. In particular, neural interfaces establish a long‐term, seamless, symbiotic integration between implants and neural tissue. Materials play a pivotal role in neurotechnology. Advanced materials and materials engineering are crucial to achieving the desired function and outcome. Recently, neural interfaces extended their range of applications with the emergence of flexible, conformable, stretchable, injectable, and transient electronics. However, despite this enormous advancement in materials science and engineering, clinical devices still rely on old‐fashioned but reliable materials and processes. The gap between research development and industry adoption has recently gained high interest. This article analyzes recent developments, discusses roadblocks, and provides a roadmap for materials engineering applied to neurotechnology.
A State‐of‐Art Review on Prediction Model for Fatigue Performance of Welded Joints via Data‐Driven Method
Authors: Feng Chao , Xu Lianyong , Zhao Lei , Han Yongdian , Hao Kangda
Published: January 2023

Fatigue fracture of welded joints is an important cause for engineering accidents. Due to the coexistence of so many influencing factors, the current prediction model of fatigue behavior cannot be used for all service conditions. The progress of each module (database establishment, data processing, data augmentation, dimension reduction, and comprehensive consideration of influencing factors) during the process of constructing a prediction model is summarized herein. Specifically, the state‐of‐art prediction models of fatigue strength, fatigue crack growth rate, fatigue life, and fatigue reliability are introduced. Moreover, suggestions for future work are given at the end of each section. Finally, according to the influential prediction methods, the establishment of fatigue performance prediction methods of welded joints via data‐driven method is summarized.
Numerical Macroscale Modeling of a Magnetized Ferromagnetic Fiber in Viscous Fluidic Environments
Authors: De Schryver Cédric , Vanoost Dries , Buffel Bart , Pissoort Davy , Desplentere Frederik
Published: January 2023

Herein, the experimental results of discontinuous ferromagnetic‐fiber manipulation using magnetic‐field interaction are presented. High‐aspect‐ratio steel fibers are realigned in viscous polydimethylsiloxanes (PDMSs) with electromagnets. The influence of the matrix viscosity, magnetic‐field strength, and fiber‐aspect ratio on the dynamics of the realignment process is investigated. To predict the fiber behavior under static magnetic fields, two commonly used theoretical models (hereinafter referred to as the torque model and the exponential model) are compared to a nonlinear regression model proposed by the authors. The latter model focuses on the alignment rate of a fiber as a function of the physical process parameters. To indicate the best fitting model for the experimental results, the statistical root‐mean‐square error (RMSE) values of the fitted models are assessed. A total of 54 comparisons are made between the exponential model and the authors’ nonlinear regression model. In 50 cases, the nonlinear regression model provides a better fit.
Microstructure and Solidification Behavior of Co30Ni30Fe30Zr10 Eutectic Multi‐Principal Element Alloy
Authors: An Xulong , Zhang Wei , Li Yanhao , Zhang Lantian , Zhang Yong , Wei Wei , Chu Chenglin
Published: January 2023

Herein, the Co30Ni30Fe30Zr10 eutectic multi‐principal element alloy is prepared by vacuum arc melting. The phase composition and microstructure of eutectic alloy are analyzed by X‐ray diffraction (XRD) and scanning electron microscope (SEM). It is showed in the results that the eutectic multi‐component alloy is composed of primary phase and eutectic structure, in which the primary phase is Fe‐rich phase, and the eutectic structure is mainly composed of face‐centered cubic (FCC) and body‐centered cubic (BCC) phases. Co30Ni30Fe30Zr10 eutectic multi‐component alloy possesses good room‐temperature mechanical properties. Its yield strength, compressive strength, and compression ratio are 700, 1000 MPa, and 22%, respectively.
Effect of Shot Peening Strengths on Microstructure and Mechanical Properties of 316L Stainless Steel Prepared by 3D Printing
Authors: Pan Haijun , Tao Wenyu , Zhang Bin , Jiang Peng , Wang Zhizhi , Wu Wangping , Liu Lin , Li Jing , Wu Zhiqiang , Cai Zhihui
Published: January 2023

Herein, the influence of shot peening (SP) on the microstructure and mechanical properties of 3D printed 316L stainless steel is studied by optical microscopy (OM), electron backscattered diffraction (EBSD), and mechanical properties testing. The changes in microstructure and mechanical properties of 316L stainless steel by 3D printing under different SP strengths are explored, which are drawn as follows: 1) the microstructure of 3D‐printed 316L stainless steel is greatly refined, and the thickness of ultrafine microstructure in the surface layer increases from 0 to 112.5 μm with the increase in peening strengths from 0 to 0.4 MPa; 2) with the increase of peening strengths from 0 to 0.4 MPa, the hardness increases from 236 to 518 HV, and yield strength increases from 547.3 to 740.7 MPa; and 3) based on the EBSD results, the enhanced hardness and yield strength are caused by refinement hardening and dislocation hardening for the SP samples. In addition, it should be noted that the SP decreases the elongation of 3D‐printed 316L stainless steel up to 9%, and makes the ultimate tensile strength reach the maximum value of 871.2 MPa at 0.2 MPa SP strength.
Fabrication and Mechanical Properties of Tri‐Layer B4C‐Reinforced Al–Zn Functionally Graded Foam Having Higher Energy Absorption Efficiency
Authors: Sharma Ankit , Ravindran Sujith , Gupta Amit Kumar
Published: January 2023

Metal foams are lightweight and have a higher impact energy absorption ability, making them suitable for various dynamic load applications. However, thin cell walls having higher porosity and lower compressive strength limit the foam's application. Density‐graded foams have superior compressive properties to uniform foam, making them a suitable lightweight candidate for dynamic loading applications. The tri‐layer functionally graded foam material (FGFM) is fabricated using the hot pressure‐assisted sintering and dissolution route by varying the porosity and B4C reinforcement. The density gradation enhances the load‐bearing capacity compared to uniform foam, and the maximum compressive strength achieved is 142 MPa. Also, the densification strain is 26% higher compared to uniform foam. B4C (9 vol%)‐reinforced FGFM shows the highest energy absorption efficiency of ≈67% due to their stabilized plateau region.
Grain Refinement and Phase Transformation of Pure Titanium Foils During Asymmetrical Rolling
Authors: Xiao Guizhi , Cheng Xumin , Xue Shaobo , Zeng Xiangkang , Zhu Wenguang , Wang Yuexiang
Published: January 2023

Ultrafine‐grained microstructure and face center cubic (FCC) phase are produced in the pure titanium foils through asymmetrical rolling (ASR) to explore the mechanical properties of pure titanium foils with different thicknesses. Herein, the grain refinement process and phase transformation behavior are systematically investigated. The grain refinement process can be described as: 1) coarse equiaxed grains are elongated along RD due to the compressive strain and shear strain caused by the ASR process. 2) elongated grains are split into thin laths and subgrains by dislocation walls under greater strain. 3) thin laths and subgrains are further refined and ultrafine‐grained microstructures are obtained. In addition, hexagonal close‐packed (HCP)‐FCC phase transformation is also discovered during the ASR process. The orientation relationship between the HCP and FCC phases is determined as [0001]HCP//[001]FCC, (100)HCP//(20)FCC and the phase transformation is caused by Shockley partial dislocation with Burgers vector 1/6[110] gliding on each (100) plane. Uniaxial tensile tests on heat‐treated pure titanium foils of different thicknesses show a size effect on tensile properties. As the thickness decreases, tensile strength and elongation are reduced, with fewer/single‐layer equiaxed grains at the section of the specimen.
Improved Antifouling Ability for Double‐Network Hydrogel Coatings with Excellent Elastic and Toughness under Marine Tidal Environment
Authors: Li Xinglinmao , Gou Jianglin , Feng Huimeng , Sun Xiao , Qin Xude , Wang Wei , Li Wen , Chen Shougang
Published: January 2023

The marine coating in the tidal zone is crucial to restoring its protective function in the case of coating defects, mainly due to the structural damage of the coating by the alternation of wet and dry in the tidal zone and the surface damage of the coating by the impact of sand and gravel. Hydrophilic materials such as hydrogel transformed the tidal zone into an entire immersion zone. Due to the complexation of copper, the fouling problem can be effectively reduced. The coating (AAm/Alginate‐Ca/Cu‐BTA) has excellent mechanical properties (modulus: 200 kPa, toughness 128 J m−2) and significant adhesion (138 J m−2). Otherwise, herein, simultaneously mechanical tests of hydrogels at different temperatures and excellent mechanical properties (modulus: 160 kPa, toughness 100 J m−2) after 7 days of use in alternating dry and wet environments every 6 h are shown. It's proved that the coating has an excellent antifouling and anticorrosion effect. Meanwhile, theoretical study reveals the nature of the weak mechanical properties of hydrogel materials at low temperatures. This work provides an effective strategy for preparing hydrogel coatings with excellent mechanical properties and marine anticorrosion and antifouling. It also proves that hydrogels have broad application prospects in marine tidal zone by excellent water retention performance.
Evaluation of Dislocation Density of Coarse and Fine Grains in Bimodal Harmonic Structured Steel Observed by Diffraction Contrast Tomography using Ultrabright Synchrotron Radiation
Authors: Nakai Yoshikazu , Kikuchi Shoichi , Shiozawa Daiki , Hase Takumi , Nakazawa Issei , Fujita Keisuke , Kawabata Mie O. , Ameyama Kei
Published: January 2023

Austenitic stainless steels with a bimodal harmonic structure, in which the fine grain structure (Shell) exists around the coarse grain structure (Core), are prepared by powder metallurgy to improve both strength and ductility. Herein, X‐ray diffraction contrast tomography, a 3D grain mapping technique for polycrystalline materials using ultrabright synchrotron radiation X‐rays, is used to reconstruct the grain shape and location and to evaluate the average excess dislocation density of the Core and Shell structures. This technique allows one to evaluate the excess dislocation density not only on the surface, but also inside the sample where damage occurs in tensile tests. The results show that the excess dislocation density of the Shell structure is higher than that of the Core structure. The excess dislocation density of homogeneous austenitic stainless steels with grain sizes similar to the Core structure of the harmonic structured stainless steel is higher than that at comparable stresses, indicating that the deformation of the bimodal harmonic structured alloy is localized in the fine grain structure. This is consistent with the results obtained from electron backscatter diffraction analysis, in which the surface grains are evaluated.
Targeted Delivery of Apoptotic Cell‐Derived Nanovesicles prevents Cardiac Remodeling and Attenuates Cardiac Function Exacerbation
Authors: Lee Ju‐Ro , Sim Woo‐Sup , Park Hun‐Jun , Park Bong‐Woo , Joung Yoon Ki
Published: January 2023

The modulation of inflammatory responses plays an important role in the pathobiology of cardiac failure. In a natural healing process, the ingestion of apoptotic cells and their apoptotic bodies by macrophages in a focal lesion result in resolution of inflammation and regeneration. However, therapeutic strategies to enhance this natural healing process using apoptotic cell‐derived biomaterials have not yet been established. In this study, apoptotic bodies‐mimetic nanovesicles derived from apoptotic fibroblasts (ApoNVs) conjugated with dextran and ischemic cardiac homing peptide (CHP) (ApoNV‐DCs) for ischemia‐reperfusion (IR)‐injured heart treatment are developed. Intravenously injected ApoNV‐DCs actively targeted the ischemic myocardium via conjugation with CHP, and are selectively phagocytosed by macrophages in an infarcted myocardium via conjugation with dextran. ApoNV‐DCs polarized macrophages from the M1 to M2 phenotype, resulting in the attenuation of inflammation. Four weeks after injection, ApoNV‐DCs attenuated cardiac remodeling, preserved blood vessels, and prevented cardiac function exacerbation in IR‐injured hearts. Taken together, the findings may open a new avenue for immunomodulation using targeted delivery of anti‐inflammatory nanovesicles that can be universally applied for various inflammatory diseases.
A Self‐Enhancing Nanoreactor Reinforces Radioimmunotherapy by Reprogramming Nutrients and Redox Metabolisms
Authors: Hou Mengfei , Su Haiyang , Wu Qinghe , Sun Wenshe , Zhang Pengli , Jiang Yifei , Qian Kun , Zhang Chunfu
Published: January 2023

Altered metabolism of cancer cells reshapes the unique tumor microenvironment (TME) with glucose addiction and high antioxidant levels, resulting in a strong alliance to promote tumor progression and treatment failure. Herein, a Pd/Pt/Au tri‐metallic mesoporous nanoparticle coated with pH‐responsive tannic acid‐iron ion (FeIIITA) network (PdPtAu@TF) is fabricated, aiming at reinforcing radioimmunotherapy by reprogramming nutrients and redox metabolisms. PdPtAu@TF has a fine hierarchical structure and demonstrates high glucose oxidase, peroxidase‐, catalase‐ and glutathione peroxidase‐mimic activities, acting as a self‐enhancing nanoreactor to consume endogenous glucose and break redox homeostasis in the harsh TME. As a result, cancer cells accelerate the uptake of lipids, especially polyunsaturated fatty acids when glucose is deficient, and then fall into lipid peroxidation‐induced ferroptosis trap to sensitize radiotherapy (RT), inhibiting tumor progression. More significantly, combined treatment with PdPtAu@TF can promote the polarization of pro‐inflammatory M1‐type macrophages as well as inhibit the proliferation of cancer‐associated fibroblasts to overcome RT‐induced immunosuppression and eliminate excessive tissue fibrosis, thereby eliciting antitumor immunity and suppressing tumor metastasis. Consequently, this study describes a promising strategy to enhance the efficacy of radioimmunotherapy by reprogramming tumor nutrients and redox metabolisms, which has great potential to benefit cancer treatments.
Encapsulating and Operating a Stable Li3ErBr6‐Based Solid Li–SeS2 Battery at Room Temperature
Authors: Shi Xiaomeng , Zeng Zhichao , Zhang Hongtu , Huang Yunhui , Yan Chun‐Hua , Du Yaping
Published: January 2023

Rare earth‐based halide solid electrolytes (RE‐HSEs) are noted due to their comprehensive properties of good ionic conductivity, electrochemical window, and deformability. However, the types and applications of RE‐HSEs need to be further expanded. Here, a highly purified RE‐HSE Li3ErBr6 (LErB) is synthesized successfully by a vacuum evaporation method. The prepared LErB possesses a high ionic conductivity of 1.0 mS cm−1 with an electrochemical window of 1.5–3.4 V. The LErB is applied in a solid Li–SeS2 battery, which can realize stable cycling performance for 300 cycles and good rate performance at room temperature. Moreover, to evaluate the practicability of the LErB‐based Li–SeS2 battery, a pouch‐type cell is assembled, which can light a diode array even after bending and cutting. These results demonstrate that LErB‐based solid Li–SeS2 cells possess advantages in battery packaging and operation, which can improve the practicability of all‐solid‐state lithium batteries.
Histone Deacetylase‐Triggered Self‐Immolative Peptide‐Cytotoxins for Cancer‐Selective Drug Delivery
Authors: Bai Haoyu , Wang Huifang , Zhou Zhuha , Piao Ying , Liu Xiangrui , Tang Jianbin , Shen Xian , Shen Youqing , Zhou Zhuxian
Published: January 2023

Precise delivery and release of therapeutics in the subcellular targets are critical for tumor‐selective chemotherapy. Self‐immolative structures are sophisticatedly designed to achieve stimuli‐responsive drug delivery. Herein, the facile fabrication of self‐immolative peptide‐camptothecin (CPT) nanoassemblies is reported for cancer‐selective drug delivery by utilizing the dual‐mode peptide targeting design and amine‐catalyzed intramolecular hydrolysis. The dual‐mode peptide targeting design is realized by co‐assembly of tumor targeting and nuclei‐localizing peptide‐CPT prodrugs, rendering the nanoassemblies with efficient cancer cell‐selective capability. When the nanoassemblies enter cancer cell, the overexpressed endonuclear histone deacetylases (HDACs) cleave the acetyl group to generate primary amines, triggers amine‐catalyzed intramolecular hydrolysis, and fast‐release drug in the cell nuclei. The peptide‐CPT prodrugs release up to 68% CPT in 1 h in the presence of HDACs, while no detectable CPT release is observed in the absence of HDACs at the same time. The peptide‐CPT prodrugs selectively kill cancer cells with high HDACs levels. The dual targeting peptide‐CPT nanoassemblies exhibit extended blood circulation, excellent tumor accumulation, and potent antitumor activity by inhibiting tumor progression and metastasis in mice bearing 4T1 aggressive breast tumors. Overall, the HDAC‐triggered self‐immolative strategy is promising for developing cancer‐selective drug delivery systems.
A Biomimetic Lubricating Nanosystem with Responsive Drug Release for Osteoarthritis Synergistic Therapy
Authors: Li Cheng , Gong Peiwei , Chao Mianran , Li Juan , Yang Liyan , Huang Yan , Wang Dandan , Liu Jianxi , Liu Zhe
Published: January 2023

Osteoarthritis (OA) is associated with lubrication failure of articular cartilage and severe inflammatory response of joint capsule. Synergistic therapy combining joint lubrication and anti‐inflammation emerges as a novel treatment of OA. In this study, bioinspired by ultralow friction of natural articular synovial fluid and mussel adhesion chemistry, a biomimetic nanosystem with dual functions of enhanced lubrication and stimuli‐responsive drug release is developed. A dopamine mediated strategy realizes one step biomimetic grafting of hyaluronic acid (HA) on fluorinated graphene. The polymer modified sheets exhibit highly efficient near‐infrared absorption, and show steady lubrication with a long time under various working conditions, in which the coefficient of friction is reduced by 75% compared to H2O. Diclofenac sodium (DS) with a high loading capacity of 29.2% is controllably loaded, and responsive and sustained drug release is adjusted by near‐infrared light. Cell experiments reveal that the lubricating nanosystem is taken up by endocytosis, and anti‐inflammation results confirm that the nanosystem inhibits osteoarthritis deterioration by upregulating cartilage anabolic gene and downregulating catabolic proteases and pain‐related gene. This work proposes a promising biomimetic approach to integrate polymer modified fluorinated graphene as a dual‐functional nanosystem for effective synergistic therapy of OA.
Strong Interlayer Coupling in Twisted Transition Metal Dichalcogenide Moiré Superlattices
Authors: Zheng Haihong , Guo Hongli , Chen Shula , Wu Biao , Li Shaofei , He Jun , Liu Zongwen , Lu Gang , Duan Xidong , Pan Anlian , Liu Yanping
Published: January 2023

Moiré superlattices in twisted van der Waals materials offer a powerful platform for exploring light–matter interactions. The periodic moiré potentials in moiré superlattices can induce strongly correlated quantum phenomena that depend on the moiré potential associated with interlayer coupling at the interface. However, moiré superlattices are primarily prepared by mechanical exfoliation and manual stacking, where the transfer methods easily cause interfacial contamination, and the preparation of high‐quality bilayer 2D materials with small twist angles by growth methods remains a significant challenge. In this work, WSe2/WSe2 homobilayers with different twist angles by chemical vapor deposition (CVD), using a heteroatom‐assisted growth technique, are synthesized. Using low‐frequency Raman scattering, the uniformity of the moiré superlattices is mapped to demonstrate the strong interfacial coupling of the CVD‐fabricated twist‐angle homobilayers. The moiré potential depths of the CVD‐grown and artificially stacked homostructures with twist angles of 1.5° are 115 and 45 meV (an increase of 155%), indicating that the depth of moiré potential can be modulated by the interfacial coupling. These results open a new avenue to study the modulation of moiré potential by strong interlayer coupling and provide a foundation for the development of twistronics.
Instantaneous Formation of Silk Protein Aerosols and Fibers with a Portable Spray Device under Ambient Conditions
Authors: Choi Jaewon , Sahoo Jugal Kishore , Hasturk Onur , Falcucci Thomas , Yao Ya , Kaplan David L.
Published: January 2023

A variety of artificial silk spinning approaches are attempted to mimic the natural spinning process found in silkworms and spiders, yet instantaneous silk fiber formation with hierarchical structure under physiological and ambient conditions without post‐treatment procedures remains unaddressed. Here, this work reports a new strategy to fabricate silk protein‐based aerosols and silk fibers instantaneously in situ using a spray device, avoiding complicated and costly advanced manufacturing techniques. The key to success is the instantaneous conformational transition of silk fibroin from random coil to β‐sheet right before spraying by mixing silk and polyethylene glycol (PEG) solutions in the spray device, allowing aerosols and silk fibers to be sprayed, with further control achieved via the molecular weight of silk. The spinning process of the spray device is based on the use of green solvents, that is, all steps of instant conformational transition of silk fibroin are carried out in aqueous conditions or with buffers at ambient conditions, in combination with shear and elongational flow caused by the hydraulic pressure generated in the spray container. The system supports a portable and user‐friendly system that could be used for drug delivery carriers, wound coating materials, and rapid silk fiber conformal coatings on surfaces.
Flexible Plasmonic Optical Tactile Sensor for Health Monitoring and Artificial Haptic Perception
Authors: Guo Jingjing , Shang Ce , Gao Shuo , Zhang Yongbiao , Fu Bo , Xu Lijun
Published: January 2023

Tactile sensors capable of quantifying mechanical stimuli through physical contact play a pivotal role in healthcare, prosthetics, and humanoid robotics. To enable conformal contact with objects of different surface morphologies, tactile sensors with high mechanical flexibility are extensively explored. Despite recent advances, most of the currently available flexible tactile sensors are based on electrical properties of functional materials, which often suffer from intrinsic limitations such as hysteresis, parasitic effects and electromagnetic interference. Herein, a flexible optical tactile sensor is presented by harnessing the unique optical properties of a soft and plasmonic optical fiber, made from composites of gold nanoparticles and elastomers. The tactile sensor is constructed by assembling the nanocomposite fiber in a sandwich structure, where sensitive and instantaneous sensing of contact force with high precision, low hysteresis, and tunable sensitivity is achieved by transducing mechanical stimuli into interpretable light signals. As demonstrations of its potential, the tactile sensor is utilized for real‐time monitoring of blood pressure, respiration, as well as providing tactile mapping of diverse hand motions. To further verify the feasibility of mimicking tactile perception of human skin, the proposed sensors integrated onto a robotic hand are demonstrated to perceive hardness, roughness, and shape of objects.
Ultra‐Stretchable, Adhesive, and Anti‐Swelling Ionogel Based on Fluorine‐Rich Ionic Liquid for Underwater Reliable Sensor
Authors: Zhao Ye , Gan Dingli , Wang Leichen , Wang Siying , Wang Wenjun , Wang Qian , Shao Jinjun , Dong Xiaochen
Published: January 2023

Creating flexible materials that can work underwater has the potential to broaden applications to aquatic and marine environments. Hydrogels have long been thought to be excellent ionic conductors for wearable electronics, because of their high stretchability, transparency, and excellent ionic conductivity. However, due to the huge differences between the underwater and air environments, the previously reported soft materials can rarely satisfy the critical needs of adhesive, underwater stability, and steady conductivity. Herein, an ionogel is proposed with abundant physical and chemical cross‐linked, involving ion‐dipole, electrostatic, and hydrogen bonding interactions, to achieve excellent mechanical strength, resilience, and underwater stability. The ionogel with long‐lasting underwater adherence and durability is further assembled into a high sensitivity, fast response, and excellent durability underwater wearable sensor. The ionogel sensor demonstrated high precision in various human motion detection and Morse code is used to transmit information both in the air and underwater. In addition, the tough underwater adhesion and the distinct discrepancy in electrical properties in different concentration solutions enable the ionogel sensor to adhere to the surface of marine animals and monitor the water quality in their habitats. It is identified that the designed ionogel possesses great promise in wearable devices and soft ionotronics.
High Precision Dynamic Manipulations of Large‐Volume‐Range Water‐Based Droplets by a Soft Gripper with Robust Water‐Repellent Superhydrophobic Surface
Authors: Wang Haipeng , Zhang Qingyi , Li Xinxin , Yan Peng , Guan Yingchun
Published: January 2023

Droplet manipulation has emerged as a key enabling technology in various scientific and engineering fields with great potentials in advanced applications such as bioanalysis and reagent microreactors. The current strategies generally involve external stimuli or chemical/structural surface gradients to provide the driving force for in plane droplet manipulations, which suffer from low efficiency, poor controllability, and small volume ranges (generally Vmax/Vmin < 10) due to their inherent limitations. Herein, a dynamic gripping based droplet manipulation method is proposed by employing a flexible gripper with a notch covered by superhydrophobic silicon rubber membrane (SRM) between the gripper fingers to dynamically pick up, constrain and release droplets, capable of consecutively manipulating large‐volume‐range (Vmax/Vmin >130) droplets with minimal liquid loss. The robust Cassie‐to‐Wenzel transition (CWT) resistance and mechanical stability of the produced superhydrophobic surface well support the dynamic operations of various droplets, where the superhydrophobic surface presents great water‐repellent performance during stretching and impinging experiments as well as remains superhydrophobicity even after mechanical abrasion against 600 grit SiC sandpaper for 15 m at an applied pressure of 3.2 kPa. Lossless manipulations of 3–180 µL droplets have been experimentally validated, where an application of the proposed method in droplet‐based microreactors for chemical analysis and bioassay is demonstrated.
Chemical Optimization Strategy of Rapid Additive Manufacturing via Up‐Conversion Assisted Photopolymerization Based Direct Ink Writing
Authors: Zhu Junzhe , Guo Zhenpeng , Zhou Yufan , Zou Xiucheng , Zhu Ye , Liu Yu , Liu Ren
Published: January 2023

Light‐driven 3D printing can empower the liberty of creation and concretize the original creation in versatile conditions with plenty of choices in resolution or properties. However, photopolymerization‐based 3D printing inks are facing a trade‐off between requiring processing rate and satisfying performance, and a chemical optimization strategy is proposed to achieve the ink demands of rapid direct ink writing utilizing up‐conversion assisted photopolymerization. Since acylphosphonate can generate two reactive radicals and tertiary amine can reinitiate polymerization in oxygen inhibition, the yielded active species in limited irradiation of 3D printing are maximized to accelerate the polymerization by theoretically and experimentally interpreting the roles of up‐conversion particle, photoinitiators, and co‐initiator played in printing. High print speed in depositing and in situ curing (3.56 × 104 mm3 h−1) are realized, and the manufacturing time is shortened by multi‐resolution printing which is impressive compared to current 3D printing methods. The strategy is simultaneously compatible with rigid and elastomeric materials, and will surely contribute to other light‐driven 3D printing technologies for extensive applications.
Local Structure and Self‐Defect Evolution under Nonstoichiometric Effect Unlock Zero‐Thermal‐Quenching
Authors: Ma Xilin , Wang Yuhua
Published: January 2023

Obtaining phosphors with higher quenching temperatures is a key scientific problem in developing high‐quality full‐spectrum white lighting devices. Herein, a near ultraviolet (NUV) activated orange‐yellow‐emitting single‐phase Li2Sr1‐ΔSiO4:Eu2+ phosphor is synthesized based on a nonstoichiometric ratio (Δ), and the relationship between local structure and photoluminescence (PL) is studied by electron spin resonance spectrum (ESR), Raman spectrum and density functional theory (DFT) calculations. Under the nonstoichiometric ratio effect, the local structure maintains stability by varying bond lengths, interatomic bond properties, and symmetry of coordination polyhedrons, which in turn modulates the crystal field and the PL spectra. Moreover, the optimum sample (Δ = 0.1%) specifically remains at 102%, 110%, and 114% of PL intensities at 150, 200, and 225 °C, respectively, compared with the initial at 25 °C, and the zero‐thermal‐quenching is mainly compensated by certain wide‐distributed self‐defect levels (300–550 K). Finally, a white light emitting diode with high luminous efficiency (89.61 lm W−1), low corresponding color temperature (5352 K), and good color rendering index (Ra = 95.8) is successfully fabricated. The strategy of designing self‐defect by nonstoichiometric synthesis provides a new insight for developing novel thermal‐quenching resistant phosphors and applying potential.
Recent Progress of Paclitaxel Delivery Systems: Covalent and Noncovalent Approaches
Authors: Wang Jiaoyang , Li Xueqiao , Wu Wenna , Xu Xin‐Ming , Xu Hui , Zhang Tao
Published: January 2023

Paclitaxel (PTX) is a broad‐spectrum alkaloid anticancer drug with high therapeutic efficacy. However, PTX has a very low water solubility and its metabolism demonstrates nonlinear pharmacokinetic characteristics, resulting in systemic adverse reactions in clinical applications. Many endeavors are devoted to develop new PTX preparations in response to these obstacles, and some are used in clinical phase of cancer treatment. In particular, highly specific medical intervention at nanoscale is an emerging research field focusing on nanoapproaches to solve clinical problems. In a perspective of nanomedicine, the recent covalent and noncovalent approaches toward PTX formulation on various substrates, as well as their advantages and disadvantages during preclinical researches and clinical applications are herein summarized. It is anticipated that nanotechnology‐based drug delivery systems can further enhance therapeutic efficiencies of PTX, by reducing systemic side effects and alleviating severely negative effects on patients.
Organic Photothermal Cocrystals: Rational Design, Controlled Synthesis, and Advanced Application
Authors: Chen Ye‐Tao , Zhuo Ming‐Peng , Wen Xinyi , Chen Wenbin , Zhang Ke‐Qin , Li Ming‐De
Published: January 2023

Organic photothermal cocrystals, integrating the advantages of intrinsic organic cocrystals and the fascinating photothermal conversion ability, hold attracted considerable interest in both basic science and practical applications, involving photoacoustic imaging, seawater desalination, and photothermal therapy, and so on. However, these organic photothermal cocrystals currently suffer individual cases discovered step by step, as well as the deep and systemic investigation in the corresponding photothermal conversion mechanisms is rarely carried out, suggesting a huge challenge for their further developments. Therefore, it is urgently necessary to investigate and explore the rational design and synthesis of high‐performance organic photothermal cocrystals for future applications. This review first and systematically summarizes the organic photothermal cocrystal in terms of molecular classification, the photothermal conversion mechanism, and their corresponding applications. The timely interpretation of the cocrystal photothermal effect will provide broad prospects for the purposeful fabrication of excellent organic photothermal cocrystals toward great efficiency, low cost, and multifunctionality.
Culinary cultural immersion: A qualitative analysis of resident knowledge, attitudes, and behavioral changes following a brief Somali cultural immersion experience
Authors: Paetow Glenn , Scott Nate , Panning Ali , Hopkins Jared , Aden Muhiyadin , Hart Danielle
Published: January 2023

Background

Teaching cultural humility is required by the Accreditation Council for Graduate Medical Education and can improve patient satisfaction and health care outcomes. Because one‐third of the 150,000 Somali immigrants and refugees in the United States live in Minnesota, we aimed to determine whether a brief cultural immersion experience, where small groups of residents share a meal with Somali interpreters at a Somali restaurant, would affect resident knowledge, attitudes, and behaviors when caring for Somali patients in a Minnesota emergency department.

Methods

From October 2017 to September 2018, emergency medicine residents were invited to dinners held outside of regular clinical/academic hours. Dinners took place at a Somali restaurant and were facilitated by a Somali interpreter and a faculty physician. While they were designed as learner‐driven sessions, facilitators were encouraged to discuss specific themes. In addition to an evaluation survey, participants underwent semistructured interviews after the experiences, and a qualitative analysis of derived themes is reported.

Results

Six dinners were hosted for a total of 20 residents, with 17 (85%) completing the evaluation survey and interview. Residents strongly agreed that this experience was worth their time and would recommend the program. Residents reported an increase in their knowledge of Somali culture, health care paradigms, and diet. Behavioral changes were described, including how residents greet patients, tailor clinical visits to patient expectations, and use interpreters as cultural brokers. Attitudinal changes were reported to a lesser degree but included an increased acceptance of cultural differences and an increased sense of connectedness to this population. Finally, residents reported that the benefits of this program were due to the authenticity of the experience, the informal small‐group setting, and their sense of being in the minority during the dinners.

Conclusions

A brief immersion experience at a Somali restaurant was sufficient to result in increased knowledge, attitudinal, and behavioral changes when caring for Somali patients.
Optimizing simulator‐based training for emergency transesophageal echocardiography: A randomized controlled trial
Authors: Chenkin Jordan , Jelic Tomislav , Hockmann Edgar
Published: January 2023

Background

Resuscitative clinician‐performed transesophageal echocardiography (TEE) is a relatively novel ultrasound application; however, optimal teaching methods have not been determined. Previous studies have demonstrated that variable practice (VP), where practice conditions are changed, may improve learning of procedural skills compared with blocked practice (BP), where practice conditions are kept constant. We compared VP and BP for teaching resuscitative TEE to emergency medicine residents using a simulator.

Methods

Emergency medicine residents with no prior TEE experience were randomized to the BP or VP groups. The BP group practiced 10 repetitions of a fixed five‐view TEE sequence, while the VP group practiced 10 different random five‐view TEE sequences on a simulator. Participants completed a performance assessment immediately after training and a transfer test 2 weeks after training. Ultrasound images and transducer motion metrics were captured by the simulator for blinded analysis. The primary outcome was the percentage of successful views on the transfer test.

Results

Twenty‐eight participants completed the study (14 in the BP group, 14 in the VP group). The BP group had a higher rate of successful views compared with the VP group on the transfer test (93.6% vs. 77.6%; p = 0.002). The BP group also had higher image quality on a 5‐point scale (3.3 vs. 2.9; p = 0.01) and fewer probe angular changes (2982.5 degrees vs. 4239.8 degrees; p = 0.04). There were no statistically significant differences between the groups for the rate of correct diagnoses, confidence level, or scan time.

Conclusions

Practicing a fixed sequence of views was more effective than a variable sequence of views for learning resuscitative TEE on a simulator. These results should be validated in TEE scans performed in the clinical environment.