bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dosimetry with a clinical linac adapted to FLASH electron beams
Authors: Szpala Stanislaw , Huang Vicky , Zhao Yingli , Kyle Alastair , Minchinton Andrew , Karan Tania , Kohli Kirpal 
Published: May 2021

AbstractPurposeTo assess dosimetric properties and identify required updates to commonly used protocols (including use of film and ionization chamber) pertaining to a clinical linac configured into FLASH (ultra‐high dose rate) electron mode.MethodsAn 18MV photon beam of a Varian iX linac was converted to FLASH electron beam by replacing the target and the flattening filter with an electron scattering foil. The dose was prescribed by entering the MUs through the console. Fundamental beam properties, including energy, dose rate, dose reproducibility, field size, and dose rate dependence on the SAD, were examined in preparation for radiobiological experiments. Gafchromic EBT‐XD film was evaluated for usability in measurements at ultra‐high dose rates by comparing the measured dose to the inverse square model. Selected previously reported models of chamber efficiencies were fitted to measurements in a broad range of dose rates.ResultsThe performance of the modified linac was found adequate for FLASH radiobiological experiments. With exception of the increase in the dose per MU on increase in the repetition rate, all fundamental beam properties proved to be in line with expectations developed with conventional linacs. The field size followed the theorem of similar triangles. The highest average dose rate (2 × 104 Gy/s) was found next to the internal monitor chamber, with the field size of FWHM = 1.5 cm. Independence of the dose readings on the dose rate (up to 2 × 104 Gy/s) was demonstrated for the EBT‐XD film. A model of recombination in an ionization chamber was identified that provided good agreement with the measured chamber efficiencies for the average dose rates up to at least 2 × 103 Gy/s.ConclusionDosimetric measurements were performed to characterize a linac converted to FLASH dose rates. Gafchromic EBT‐XD film and dose rate‐corrected cc13 ionization chamber were demonstrated usable at FLASH dose rates.
Effect of auto flash margin on superficial dose in breast conserving radiotherapy for breast cancer
Authors: Wang Lu , Qiu Gang , Yu Jianhe , Zhang Qunhui , Man Li , Chen Li , Zhang Xiaoxiao , Ren Qun , Xu Hongxia , Hua Xiaolong 
Published: May 2021

AbstractPurposeTo investigate the dose‐effect of Auto Flash Margin (AFM) on breast cancer's superficial tissues based on the Treatment Planning System (TPS) in the breast‐conserving radiotherapy plan.MethodsA total of 16 breast‐conserving patients with early stage breast cancer were selected, using the X‐ray Voxel Monte Carlo (XVMC) algorithm. Then, every included case plan was designed using a 2 cm‐AFM (the value of AFM is 2 cm) and N‐AFM (without AFM). Under the condition of ensuring the same configuration of #MU and collimator, the absorbed dose after a simulated inspiratory motion was calculated again using the new plan center, which moved backward to the linac source. The dose difference between the measurement points between AFM and N‐AFM groups was compared.ResultsIn the dose results, PTVV50Gy of the AFM group was superior to that of the N‐AFM group, PTVD2%, PTVDmean, Lung_IpsiV20Gy, Lung_IpsiDmean, and BodyDmax. Also, the dose results of the N‐AFM group were significantly higher than those of the AFM group. However, there was no significant difference between Lung_ContraV5Gy, HeartDmean, and Breast_ContraV10Gy in the two groups. In the collimator alignments at the same angle between groups, the AFM group formed an apparent air region outside the collimator compared with the N‐AFM group. In the XVMC algorithm feature parameter, the AFM group had less #MU, higher QE, and slightly longer optimization time. The #segments of both groups were close to the 240 control points preset by the plan. The validation results of EBT3 film in both groups were more significant than 95%, meeting the clinical plan's application requirements. The difference in film results between groups was mainly reflected in the dose distribution at the near‐source. 4DCT was used to summarize the maximum and minimum inspiratory motion distances of 7.31 ± 0.45 and 3.42 ± 0.91 mm respectively.ConclusionsThese results suggest that the AFM function application could significantly reduce the possibility of insufficient tumor target caused by inspiratory motion and ensure sufficient tumor target exposure.
Adaptive sliding mode control with guaranteed performance based on monitoring and barrier functions
Authors: Rodrigues Victor Hugo Pereira , Hsu Liu , Oliveira Tiago Roux , Fridman Leonid 
Published: May 2021

SummaryThis paper proposes a new adaptive sliding mode control approach via output feedback for a class of nonlinear systems. The sliding‐mode based controller can deal with parametric uncertainties and (un)matched disturbances with unknown upper bounds. Finite‐time convergence of the tracking error to a predefined neighborhood of the origin of the closed‐loop system is proved with guaranteed transient and steady‐state performance. Basically, the novelty of our result lies on combining two important adaptation tools: monitoring and barrier functions. The adaptation process is divided into two stages, where an appropriate monitoring function allows for the specification of performance criteria during the transient phase, while the barrier function ultimately confines the tracking error within a small residual set in steady state. Simulation results including an application to Anti‐lock Braking System illustrate the advantages of the proposed adaptive control strategy.
Tissue Regeneration through Cyber‐Physical Systems and Microbots
Authors: Kumar Prasoon , Mirza Khalid Baig , Choudhury Kaushik , Cucchiarini Magali , Madry Henning , Shukla Pratyoosh 
Published: May 2021

AbstractTissue engineering is a systematic approach of assembling cells onto a 3D scaffold to form a functional tissue in the presence of critical growth factors. The scaffolding system guides stem cells through topological, physiochemical, and mechanical cues to differentiate and integrate to form a functional tissue. However, cellular communication during tissue formation taking place in a reactor needs to be understood properly to enable appropriate positioning of the cells in a 3D environment. Hence, sensors and actuators integrated with cyber‐physical system (CPS) may be able to sense the tissue microenvironment and direct cells/cellular aggregates to an appropriate position, respectively. This can facilitate better cell‐to‐cell communication and cell–extracellular matrix communication for proper tissue morphogenesis. Advancements are made in the field of smart scaffolds that can morph cells/cellular aggregates after sensing the cellular microenvironment in a desired 3D architecture by providing appropriate cues. Recent scientific developments in the additive manufacturing technology have enabled the fabrication of smart scaffolds to create structural and functional tissue constructs. Sensors/actuators, cyber‐systems, smart materials, and additive manufacturing put together is expected to lead to improved tissue‐engineered medical products. The present review aims to highlight the possibilities of advancement of BioCPS for tissue engineering and regenerative medicine.
Strategies Toward Efficient Blue Perovskite Light‐Emitting Diodes
Authors: Ren Zhenwei , Wang Kai , Sun Xiao Wei , Choy Wallace C. H. 
Published: May 2021

AbstractSubstantial progress has been made in blue perovskite light‐emitting diodes (PeLEDs). In this review, the strategies for high‐performance blue PeLEDs are described, and the main focus is on the optimization of the optical and electrical properties of perovskites. In detail, the fundamental device working principles are first elucidated, followed by a systematical discussion of the key issues for achieving high‐quality perovskite nanocrystals (NCs) and quasi‐2D perovskites. These involve ligand optimization and metal doping in enhancing the carrier transport and reducing the traps of perovskite NCs, as well as the perovskite phase modulation and defect passivation in improving energy transfer and emission efficiency of quasi‐2D perovskites. The strategies for efficient 3D mixed‐halide perovskite and lead‐free perovskite blue LEDs are then briefly introduced. After that, other strategies, including effective charge transport layer, efficient perovskite emission system, and effective device architecture for high light outcoupling efficiency, are further discussed to boost the blue PeLED performances. Meanwhile, the testing standard of blue PeLED lifetime is suggested to enable the direct comparisons of the device operational stability. Finally, challenges and future directions for blue PeLEDs are addressed.
HtrA3‐Mediated Endothelial Cell–Extracellular Matrix Crosstalk Regulates Tip Cell Specification
Authors: Guo Yaru , Ma Siqin , Xu Mingming , Wei Yan , Zhang Xuehui , Huang Ying , He Ying , Heng Boon Chin , Chen Lili , Deng Xuliang 
Published: May 2021

AbstractAngiogenesis is critical in tissue engineering and regenerative medicine. Once initiated, outgrowing capillaries are spearheaded by specialized endothelial cells (ECs) termed tip cells. Specification of tip cells from ECs during angiogenesis is greatly influenced by the surrounding extracellular matrix (ECM). However, the crosstalk between ECs and the ECM in tip cell specification is poorly understood. Here, this study shows that the high‐temperature requirement A3 (HtrA3) protein is deeply involved in this process. Specifically, HtrA3 is upregulated in the frontal area of tissue repair and cancer progression through VEGFR2 activation by VEGF in ECs. Secreted HtrA3 degrades the surrounding Collagen IV, which provides space for tip cell morphogenesis and exposes integrin β1‐related ligands. Integrin β1‐ligand binding activates PI3K/AKT/mTOR signaling, which subsequently suppresses the Notch signaling pathway, eventually promoting tip cell specification. Moreover, local administration of exogeneous recombinant HtrA3 in rat cranial bone defects significantly increases blood vessel formation. Conversely, injection of HtrA3 siRNA decreases developmental retinal angiogenesis. These data show that HtrA3 mediated crosstalk between ECs and the ECM enhances tip cell specification of ECs. Hence, HtrA3 can act as a therapeutic agent for improving angiogenesis in situations in need, as well as serve as a therapeutic target for pathological angiogenesis.
Surface Hydrophobicity Modulates the Key Characteristics of Cancer Spheroids through the Interaction with the Adsorbed Proteins
Authors: Lee Minseok , Kim Yesol , Yu Seung Jung , Lee Sun Young , Son Jin Gyeng , Lee Tae Geol , Cho Youngbin , Shin Jennifer H. , Lee Eunjung , Im Sung Gap 
Published: May 2021

AbstractThree‐dimensional in vitro cancer models have emerged as a promising tool for various cancer‐related applications. However, the limited availability of the in vitro model capable of adequately recapitulating the active interactions between the cancer cells and the surrounding tumor microenvironment (TME) hampers their use for therapeutic applications. Here, it is demonstrated that the proteins adsorbed on the culture substrate significantly influence the characteristics of the cancer cells, thereby suggesting that the modulation of cell–protein interaction can be a powerful tool to construct an advanced cancer model. A series of polymers are prepared for the precise control of the surface hydrophobicity of the culture plate. Cancer cells cultured on the polymers exhibit distinct morphological transitions ranging from monolayer to spheroids with entirely different characteristics depending on the surface hydrophobicity. The poly (cyclohexyl methacrylate) surface of the highest hydrophobicity tested in this study strongly attracts albumin from the media for enhanced adsorption and induces conformational changes in albumin upon binding, leading to the formation of spheroid with the most enriched tumorigenic properties. It is believed that this finding can provide new insights when selecting the experimental strategy to appropriately mimic the complex interplay between the cancer cells and the TME.
pH‐Sensitive, Cerebral Vasculature‐Targeting Hydroxyethyl Starch Functionalized Nanoparticles for Improved Angiogenesis and Neurological Function Recovery in Ischemic Stroke
Authors: Yang Hang , Luo Yan , Hu Hang , Yang Sibo , Li Yanan , Jin Huijuan , Chen Shengcai , He Quanwei , Hong Candong , Wu Jiehong , Wan Yan , Li Man , Li Zifu , Yang Xiangliang , Su Ying , Zhou Yifan , Hu Bo 
Published: May 2021

AbstractAngiogenesis, an essential restorative process following ischemia, is a promising therapeutic approach to improve neurological deficits. However, overcoming the blood–brain barrier (BBB) and effective drug enrichment are challenges for conventional drug delivery methods, which has limited the development of treatment strategies. Herein, a dual‐targeted therapeutic strategy is reported to enable pH‐sensitive drug release and allow cerebral ischemia targeting to improve stroke therapeutic efficacy. Targeted delivery is achieved by surface conjugation of Pro‐His‐Ser‐Arg‐Asn (PHSRN) peptides, which binds to integrin α5β1 enriched in the cerebral vasculature of ischemic tissue. Subsequently, smoothened agonist (SAG), an activator of sonic hedgehog (Shh) signaling, is coupled to PHSRN‐HES by pH‐dependent electrostatic adsorption. SAG@PHSRN‐HES nanoparticles can sensitively release more SAG in the acidic environment of ischemic brain tissue. More importantly, SAG@PHSRN‐HES exerts the synergistic mechanisms of PHSRN and SAG to promote angiogenesis and BBB integrity, thus improving neuroplasticity and neurological function recovery. This study proposes a new approach to improve the delivery of medications in the ischemic brain. Dual‐targeted therapeutic strategies have excellent potential to treat patients suffering from cerebral infarction.
Hybrid Poly(AMPS‐CS)‐Au Microneedle Arrays to Enrich Metabolites from Skin for Early Disease Diagnosis
Authors: Tang Yuyin , Li Su , Hu Linyu , Sun Xuetong , Zhang Bei , Ji Wenwen , Ma Lijuan , Qian Wenhui , Kang An , Zhu Dong 
Published: May 2021

AbstractRecently, some metabolites in skin interstitial fluid (SIF) have become emerging re×sources for early disease diagnosis. However, their low level in SIF and difficulty to sampling are the biggest obstacle to further potential application. Here, a swellable microneedle array patch (MNAP) with high mechanical strength is presented, and the rapid enrichment of positively charged metabolites is achieved. The MNAP is fabricated by poly (chondroitin sulfate‐acrylamido‐2‐methylpropane sulfonic acid)‐gold nanoparticles (GNPs) composites via a micro‐molding. The negatively charged copolymer hydrogel not only enrich positively charged metabolites, but also provide swellable capacity. The in situ synthesis of GNPs in the process of copolymerization make the GNPs cross‐link to the hydrogel, which further enhance the MNAP mechanical strength and enrichment efficiency for positively charged metabolites. By using the MNAP, around 5 mg SIF in 10 min from the high fat/cholecalciferol/methimazole‐induced atherogenesis rat is extracted and 23 metabolites including 13 quaternary ammonium cationic compounds can be detected and quantified by using a LC‐QTOF‐MS. Dysregulated L‐carnitine and choline metabolism are discovered a week earlier in the SIF than in the serum, achieving early diagnosis of the metabolism syndrome disease. This MNAP also helps users complete home sampling for early disease diagnosis and monitoring.
Advances in Application of Azobenzene as a Trigger in Biomedicine: Molecular Design and Spontaneous Assembly
Authors: Cheng Hong‐Bo , Zhang Shuchun , Qi Ji , Liang Xing‐Jie , Yoon Juyoung 
Published: May 2021

AbstractAzobenzene is a well‐known derivative of stimulus‐responsive molecular switches and has shown superior performance as a functional material in biomedical applications. The results of multiple studies have led to the development of light/hypoxia‐responsive azobenzene for biomedical use. In recent years, long‐wavelength‐responsive azobenzene has been developed. Matching the longer wavelength absorption and hypoxia‐response characteristics of the azobenzene switch unit to the bio‐optical window results in a large and effective stimulus response. In addition, azobenzene has been used as a hypoxia‐sensitive connector via biological cleavage under appropriate stimulus conditions. This has resulted in on/off state switching of properties such as pharmacology and fluorescence activity. Herein, recent advances in the design and fabrication of azobenzene as a trigger in biomedicine are summarized.
Boosting the Photocatalytic Hydrogen Evolution Activity for D–π–A Conjugated Microporous Polymers by Statistical Copolymerization
Authors: Shu Chang , Han Changzhi , Yang Xiye , Zhang Chong , Chen Yu , Ren Shijie , Wang Feng , Huang Fei , Jiang Jia‐Xing 
Published: May 2021

AbstractRecently, great progress has been achieved in the design and preparation of conjugated organic polymer photocatalysts for hydrogen generation. However, it is still challenging to develop an organic polymer photocatalyst with high photoconversion efficiency. Rational structure design of organic polymer photocatalysts holds the key point to realize high photocatalytic performance. Herein, a series of donor–π–acceptor (D–π–A) conjugated organic copolymer photocatalysts is developed using statistical copolymerization by tuning the feed molar ratio of pyrene (donor) to dibenzothiophene‐S,S‐dioxide (acceptor) units. It reveals that the photocatalytic activity of the resulting copolymers is significantly dependent on the molar ratio of donor to acceptor, which efficiently changes the polymer structure and component. When the monomer feed ratio is 25:75, the random copolymer PyBS‐3 of 10 mg with Pt cocatalyst shows a high hydrogen evolution rate of 1.05 mmol h−1 under UV/Vis light irradiation using ascorbic acid as the hole‐scavenger, and an external quantum efficiency of 29.3% at 420 nm, which represents the state‐of‐the‐art of organic polymer photocatalysts. This work demonstrates that statistical copolymerization is an efficient strategy to optimize the polymer structure for improving the photocatalytic activity of conjugated organic polymer catalysts.
Digital Electrochemistry for On‐Chip Heterogeneous Material Integration
Authors: Bao Bin , Rivkin Boris , Akbar Farzin , Karnaushenko Dmitriy D. , Bandari Vineeth Kumar , Teuerle Laura , Becker Christian , Baunack Stefan , Karnaushenko Daniil , Schmidt Oliver G. 
Published: May 2021

AbstractMany modern electronic applications rely on functional units arranged in an active‐matrix integrated on a single chip. The active‐matrix allows numerous identical device pixels to be addressed within a single system. However, next‐generation electronics requires heterogeneous integration of dissimilar devices, where sensors, actuators, and display pixels sense and interact with the local environment. Heterogeneous material integration allows the reduction of size, increase of functionality, and enhancement of performance; however, it is challenging since front‐end fabrication technologies in microelectronics put extremely high demands on materials, fabrication protocols, and processing environments. To overcome the obstacle in heterogeneous material integration, digital electrochemistry is explored here, which site‐selectively carries out electrochemical processes to deposit and address electroactive materials within the pixel array. More specifically, an amorphous indium‐gallium‐zinc oxide (a‐IGZO) thin‐film‐transistor (TFT) active‐matrix is used to address pixels within the matrix and locally control electrochemical reactions for material growth and actuation. The digital electrochemistry procedure is studied in‐depth by using polypyrrole (PPy) as a model material. Active‐matrix‐driven multicolored electrochromic patterns and actuator arrays are fabricated to demonstrate the capabilities of this approach for material integration. The approach can be extended to a broad range of materials and structures, opening up a new path for advanced heterogeneous microsystem integration.
From Fundamental Understanding to Engineering Design of High‐Performance Thick Electrodes for Scalable Energy‐Storage Systems
Authors: Wu Jingyi , Zhang Xiao , Ju Zhengyu , Wang Lei , Hui Zeyu , Mayilvahanan Karthik , Takeuchi Kenneth J. , Marschilok Amy C. , West Alan C. , Takeuchi Esther S. , Yu Guihua 
Published: May 2021

AbstractThe ever‐growing needs for renewable energy demand the pursuit of batteries with higher energy/power output. A thick electrode design is considered as a promising solution for high‐energy batteries due to the minimized inactive material ratio at the device level. Most of the current research focuses on pushing the electrode thickness to a maximum limit; however, very few of them thoroughly analyze the effect of electrode thickness on cell‐level energy densities as well as the balance between energy and power density. Here, a realistic assessment of the combined effect of electrode thickness with other key design parameters is provided, such as active material fraction and electrode porosity, which affect the cell‐level energy/power densities of lithium–LiNi0.6Mn0.2Co0.2O2 (Li–NMC622) and lithium–sulfur (Li–S) cells as two model battery systems, is provided. Based on the state‐of‐the‐art lithium batteries, key research targets are quantified to achieve 500 Wh kg–1/800 Wh L–1 cell‐level energy densities and strategies are elaborated to simultaneously enhance energy/power output. Furthermore, the remaining challenges are highlighted toward realizing scalable high‐energy/power energy‐storage systems.
Directional Metastable Wetting Evolution of Droplets on Artificial Patterned Microcavity Surfaces
Authors: Xu Wenshuai , Liu Yu , Xiao Boya , Jiang Heng , Chen Meng , Wang Yuren 
Published: May 2021

AbstractControllable wetting transition on artificial microtextured surfaces has significant applications in many industrial fields. In this work, the droplet spreading and the directional wetting transition are investigated on the substrate surface with the patterned microcavities. The results show that the macroscopic inward wetting transition from the periphery to the center of the droplet strongly depends on the mesoscopic sequential transition from Cassie to Wenzel state in the microcavities on the substrate surfaces. The semiquantitative relationship between sagging depth of meniscus in the microcavities and the droplet spreading velocity is set up by utilizing scaling‐law analysis in terms of mechanical equilibrium of the meniscus. This finding is expected to help to clarify the issues on the mechanism and main affecting factors of the wetting transition on the patterned surface.