bluuebunny/crossref_metadata_2025_split huggingface dataset:
Donor–Acceptor Stenhouse Adduct‐Polydimethylsiloxane‐Conjugates for Enhanced Photoswitching in Bulk Polymers
Authors: Clerc Michèle , Tekin Cem , Ulrich Sebastian , Freire Rafael V. M. , Salentinig Stefan , Bruns Nico , Boesel Luciano F. 
Published: April 2022

AbstractDonor–acceptor Stenhouse adducts (DASAs) are a rapidly emerging class of visible light‐activated photochromes and DASA‐functionalized polymers hold great promise as biocompatible photoresponsive materials. However, the photoswitching performance of DASAs in solid polymer matrices is often low, particularly in materials below their glass transition temperature. To overcome this limitation, DASAs are conjugated to polydimethylsiloxanes which have a glass transition temperature far below room temperature and which can create a mobile molecular environment around the DASAs for achieving more solution‐like photoswitching kinetics in bulk polymers. The dispersion of DASAs conjugated to such flexible oligomers into solid polymer matrices allows for more effective and tunable DASA photoswitching in stiff polymers, such as poly(methyl methacrylate), without requiring modifications of the matrix. The photoswitching of conjugates with varying polymer molecular weight, linker type, and architecture is characterized via time‐dependent UV–vis spectroscopy in organic solvents and blended into polymethacrylate films. In addition, DASA‐functionalized polydimethylsiloxane networks, accessible via the same synthetic route, provide an alternative solution for achieving fast and efficient DASA photoswitching in the bulk owing to their intrinsic softness and flexibility. These findings may contribute to the development of DASA‐functionalized materials with better tunable, more effective, and more reversible modulation of their optical properties.
Characteristic analysis of Omicron‐included SARS‐CoV‐2 variants of concern
Authors: Yang Hao , Liu Penghui , Zhang Yong , Du Tingfu , Zhou Yanan , Lu Shuaiyao , Peng Xiaozhong 
Published: April 2022

AbstractIn view of the rapid development of the COVID‐19 pandemic and SARS‐CoV‐2 mutation, we characterized the emerging SARS‐CoV‐2 variants of concern (VOCs) by both bioinformatics methods and experiments. The representative genomic sequences of SARS‐CoV‐2 VOCs were first downloaded from NCBI, including the prototypic strain, Alpha (B.1.1.7) strain, Beta (B.1.351) strain, Delta (B.1.617.2), and Omicron (B1.1.529) strain. Bioinformatics analysis revealed that the D614G mutation led to formation of a protruding spike (S) in the tertiary structure of spike protein, which could be responsible for the enhanced binding to angiotensin‐converting enzyme 2 (ACE2) receptor. The epitope analysis further showed that the S protein antigenicity of the Omicron variant changed dramatically, which was possibly associated with its enhanced ability of immune escape. To verify the bioinformatics results, we performed experiments of pseudovirus infection and protein affinity assay. Notably, we found that the spike protein of Omicron variant showed the weakest infectivity and binding ability among all tested strains. Finally, we also proved this through virus infection experiments, and found that the cytotoxicity of Omicron seems to be not strong enough. The results in this study provide guidelines for prevention and control of COVID‐19.
Antigenicity comparison of SARS‐CoV‐2 Omicron sublineages with other variants contained multiple mutations in RBD
Authors: Li Qianqian , Zhang Mengyi , Liang Ziteng , Zhang Li , Wu Xi , Yang Chaoying , An Yimeng , Tong Jincheng , Liu Shuo , Li Tao , Cui Qianqian , Nie Jianhui , Wu Jiajing , Huang Weijin , Wang Youchun 
Published: April 2022

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants, particularly those with multiple mutations in receptor‐binding domain (RBD), pose a critical challenge to the efficacy of coronavirus disease 2019 (COVID‐19) vaccines and therapeutic neutralizing monoclonal antibodies (mAbs). Omicron sublineages BA.1, BA.2, BA.3, as well as the recent emergence of C.1.2, B.1.630, B.1.640.1, and B.1.640.2, have multiple mutations in RBD and may lead to severe neutralizing antibody evasion. It is urgent to evaluate the antigenic change of the above seven variants against mAbs and sera from guinea pigs immunized with variants of concern (VOCs) (Alpha, Beta, Gamma, Delta, Omicron) and variants of interest (VOIs) (Lambda, Mu) immunogens. Only seven out of the 24 mAbs showed no reduction in neutralizing activity against BA.1, BA.2, and BA.3. However, among these seven mAbs, the neutralization activity of XGv337 and XGv338 against C.1.2, B.1.630, B.1.640.1, and B.1.640.2 were decreased. Therefore, only five neutralizing mAbs showed no significant change against these seven variants. Using VOCs and VOIs as immunogens, we found that the antigenicity of variants could be divided into three clusters, and each cluster showed similar antigenicity to different immunogens. Among them, D614G, B.1.640.1, and B.1.630 formed a cluster, C.1.2 and B.1.640.2 formed a cluster, and BA.1, BA.2, and BA.3 formed a cluster.
Tunable dual‐band filter based on monolayer black phosphorus
Authors: Oliveira Cristiano , Dmitriev Victor , Melo Geraldo , Castro Wagner 
Published: April 2022

AbstractWe propose analytical and numerical modeling of a tunable electromagnetic dual‐band filter based on a periodic structure of black phosphorus (BP) discs deposited on silicon dioxide for operating in terahertz and infrared regions. Due to BP anisotropy, single operation dipole mode bands for polarization of incident wave in the armchair or zigzag directions exist. These bands correspond to different resonant frequencies. However, for another polarization, in particular, for a polarization, a double operation band appears. The dynamic control of the proposed structure can be performed by varying the electronic doping of the BP, thus changing the operating frequency of the filter. The analytical model based on the temporal coupled‐mode theory is in good agreement with the numerical simulations by COMSOL Multiphysics.
Temporal information‐guided dynamic dual‐tracer PET signal separation network
Authors: Tong Junyi , Wang Chunxia , Liu Huafeng 
Published: April 2022

AbstractPurposeThe difficulty of dynamic dual‐tracer positron emission tomography (PET) technology is to separate the complete single‐tracer information from mixed dual‐tracer. Traditional methods cannot separate single‐injection single‐scan dynamic dual‐tracer PET images. In this paper, we propose a deep learning framework based on gated recurrent unit (GRU) network and evaluate its performance with simulation experiments and realistic monkey data.MethodsThe proposed single‐scan dynamic dual‐tracer PET image separation network consists of three parts, including encoder, separation, and decoder module. Encoder part is to map the mixed time activity curves (TACs) from the low‐dimensional space to the high‐dimensional space to get mixed weight vector matrix. Separation part is to capture the temporal information of mixed weight vector matrix using bi‐directional GRU (bi‐GRU) layer to obtain the single‐tracer masks, and the decoding part remaps the high‐dimensional single‐tracer weight vector matrix to the low‐dimensional space to obtain two separated single tracers.ResultsIn the simulation experiments under different tracers, phantoms, noise levels, arterial input function (AIF), and k‐parameter with Gaussian random, compared to the stacked auto encoder network and traditional background subtraction method, GRU‐based network has better performance with low bias and mean squared error. In the realistic study, the image results of GRU network have higher mean structural similarity and peak signal to noise ratio.ConclusionsThis study demonstrates the feasibility of temporal information‐guided neural network in single‐injection single‐scan dynamic dual‐tracer PET images separation. The GRU‐based network uses TAC temporal information without AIFs to make the separation results more robust and accurate, which significantly outperforms state‐of‐the‐art method qualitatively and quantitatively.
Deep learning‐based 3D MRI contrast‐enhanced synthesis from a 2D noncontrast T2Flair sequence
Authors: Wang Yulin , Wu Wenyuan , Yang Yuxin , Hu Haifeng , Yu Shangqian , Dong Xiangjiang , Chen Feng , Liu Qian 
Published: April 2022

AbstractPurposeGadolinium‐based contrast agents (GBCAs) have been successfully applied in magnetic resonance (MR) imaging to facilitate better lesion visualization. However, gadolinium deposition in the human brain raised widespread concerns recently. On the other hand, although high‐resolution three‐dimensional (3D) MR images are more desired for most existing medical image processing algorithms, their long scan duration and high acquiring costs make 2D MR images still much more common clinically. Therefore, developing alternative solutions for 3D contrast‐enhanced MR image synthesis to replace GBCAs injection becomes an urgent requirement.MethodsThis study proposed a deep learning framework that produces 3D isotropic full‐contrast T2Flair images from 2D anisotropic noncontrast T2Flair image stacks. The super‐resolution (SR) and contrast‐enhanced (CE) synthesis tasks are completed in sequence by using an identical generative adversarial network (GAN) with the same techniques. To solve the problem that intramodality datasets from different scanners have specific combinations of orientations, contrasts, and resolutions, we conducted a region‐based data augmentation technique on the fly during training to simulate various imaging protocols in the clinic. We further improved our network by introducing atrous spatial pyramid pooling, enhanced residual blocks, and deep supervision for better quantitative and qualitative results.ResultsOur proposed method achieved superior CE‐synthesized performance in quantitative metrics and perceptual evaluation. In detail, the PSNR, structural‐similarity‐index, and AUC are 32.25 dB, 0.932, and 0.991 in the whole brain and 24.93 dB, 0.851, and 0.929 in tumor regions. The radiologists’ evaluations confirmed that our proposed method has high confidence in the diagnosis. Analysis of the generalization ability showed that benefiting from the proposed data augmentation technique, our network can be applied to “unseen” datasets with slight drops in quantitative and qualitative results.ConclusionOur work demonstrates the clinical potential of synthesizing diagnostic 3D isotropic CE brain MR images from a single 2D anisotropic noncontrast sequence.
Development of a dosimetry system for therapeutic X‐rays using a flexible amorphous silicon thin‐film solar cell with a scintillator screen
Authors: Jeong Seonghoon , Cheon Wonjoong , Shin Dongho , Lim Young Kyung , Jeong Jonghwi , Kim Haksoo , Yoon Myonggeun , Lee Se Byeong 
Published: April 2022

AbstractPurposeTo evaluate the dosimetric characteristics and applications of a dosimetry system composed of a flexible amorphous silicon thin‐film solar cell and scintillator screen (STFSC‐SS) for therapeutic X‐rays.MethodsThe real‐time dosimetry system was composed of a flexible a‐Si thin‐film solar cell (0.2‐mm thick), a scintillator screen to increase its efficiency, and an electrometer to measure the generated charge. The dosimetric characteristics of the developed system were evaluated including its energy dependence, dose linearity, and angular dependence. Calibration factors for the signal measured by the system and absorbed dose‐to‐water were obtained by setting reference conditions. The application and correction accuracy of the developed system were evaluated by comparing the absorbed dose‐to‐water measured using a patient treatment beam with that measured using the ion chamber.ResultsThe responses of STFSC‐SS to energy, field size, depth, and source‐to‐surface distance (SSD) were more dependent on measurement conditions than were the responses of the ion chamber, although the former dependence was due to the scintillator screen, not the solar cell. The signals of STFSC‐SS were also dependent on dose rate, while the responses of solar cell alone and scintillator screen were not dependent on dose rate. The scintillator screen reduced the output of solar cell at 6 and 15 MV by 0.60 and 0.55%, respectively. The different absorbed dose‐to‐water measured using STFSC‐SS for patient treatment beam differed by 0.4% compared to those measured using the ionization chamber. The uncertainties of the developed system for 6 and 15 MV photon beams were 1.8 and 1.7%, respectively, confirming the accuracy and applicability of this system.ConclusionsThe thin‐film solar cell‐based detector developed in this study can accurately measure absorbed dose‐to‐water. The increased signal resulting from the use of the scintillator screen is advantageous for measuring low doses and stable signal output. In addition, this system is flexible, making it applicable to curved surfaces, such as a patient's body, and is cost‐effective.
A branch‐and‐cut algorithm for the pickup‐and‐delivery traveling salesman problem with handling costs
Authors: Radha Krishnan Devaraj , Liu Tieming 
Published: April 2022

AbstractIn the Pickup‐and‐Delivery Traveling Salesman Problem with Handling Costs (PDTSPH), a single vehicle has to satisfy multiple customer requests, each defined by a pickup location and a delivery location. Cargo handling is performed at the rear end of the vehicle, in a Last‐In‐First‐Out (LIFO) order for PDTSPH. However, additional handling operations are permitted with a penalty if other loads that block the access to the delivery have to be unloaded and reloaded. The objective of PDTSPH is to minimize the total transportation and handling cost. In this paper, we present a new Mixed Integer Programming (MIP) model and a branch‐and‐cut algorithm to solve PDTSPH. We also present new integral separation procedures to effectively handle the exponential number of constraints in our MIP model. A family of inequalities are introduced to enhance the scalability of our implementation. The performance of our approach is compared with a compact formulation from the literature (Veenstra et al. [21]) in instances ranging from 9 to 21 customer requests. Computational results show our algorithm outperforming the compact formulation in 69% of instances with an average runtime improvement of 57%.
Thermal‐induced dielectric response in mechanically durable polyvinylidene fluoride–kapok encapsulated polyethylene glycol composite films
Authors: Gong Yutie , Li Zhenzhen , Li Hairong , Wu Wenqi , Pei Xianglin , Tu Junyang , Zhou Weijie , Jiang Ming , Gong Wei 
Published: April 2022

AbstractDielectric materials with thermally responsive property are being pursued in fields such as next‐generation sensors, smart switches, and novel actuators. These applications require that the dielectric materials have mechanical durability and stable serviceability besides thermally responsive dielectric behavior. Herein, we report a novel thermally responsive, mechanically durable, and low‐cost dielectric composite simply fabricated by vacuum impregnating polyethylene glycol (PEG) into kapok fiber and compounding them with polyvinylidene fluoride. A remarkable dielectric susceptibility, controlled dielectric transition temperature, and obvious thermal hysteresis of the composite films induced by the solid–liquid phase transition of PEG are demonstrated. The effect of molecular weights of PEG on the dielectric response behaviors is evaluated. Such thermally responsive dielectric materials with satisfactory mechanical durability will offer a chance toward constructing thermally responsive systems for reliable and stable operation.
Synthesis and characterization of block copolymers of styrene‐maleic acid with acrylamide and N,N‐dimethylacrylamide
Authors: Khaojanta Thidarat , Kalaithong Wichaya , Somsunan Runglawan , Punyamoonwongsa Patchara , Mahomed Anisa , Topham Paul D. , Tighe Brian J. , Molloy Robert 
Published: April 2022

AbstractStyrene‐maleic acid (SMA) block copolymers with either acrylamide (AM) or N,N‐dimethylacrylamide (DMA) have been synthesized via a 3‐step process comprising: (1) photopolymerization of styrene and maleic anhydride in solution to yield an alternating styrene maleic anhydride (SMAnh) copolymer, (2) copolymerization of SMAnh with either AM or DMA to yield SMAnh‐b‐AM and SMAnh‐b‐DMA block copolymers and (3) hydrolysis of the anhydride groups to yield water‐soluble SMA‐b‐AM and SMA‐b‐DMA block copolymers as the final products. With a view to their intended application in membrane protein solubilization, molecular weights are controlled to below 10,000 by the synthesis conditions employed in step (1), including using carbon tetrabromide (CBr4) as a chain transfer agent. The CBr4 also plays an important role in step (2). By terminating the SMAnh chain radicals from step (1) with C‐Br bonds that are photolytically active, SMAnh chain radicals can be regenerated to act as macroinitiators for the polymerization of AM or DMA in step (2). Finally, following step (3) and due to the pH‐dependency of the SMA chain conformation in solution, a pH of 7–8 is found to be optimal for enabling the final products to be precipitated in a solid form that is completely soluble in water.
Impact of proton pump inhibitors on sustained virologic response in veterans treated with sofosbuvir/velpatasvir for chronic hepatitis C virus: A retrospective cohort study
Authors: Rumph Danielle M. , Straley Craig M. , Kolberg Jenny L. , Jacob David A. 
Published: April 2022

AbstractStudy ObjectiveThe objective of this study was to determine the clinical relationship between proton pump inhibitor (PPI) use and sustained virologic response (SVR) in patients treated with sofosbuvir/velpatasvir (SOF/VEL) for chronic hepatitis C virus (HCV) infection.DesignThis was a multicenter retrospective cohort study.SettingData was collected on patients from 128 Veterans Affairs Medical Centers throughout the United States.PatientsThis study included veterans aged 18‐89 years with viremic HCV who received a full course of SOF/VEL treatment from June 2016 – July 2017.InterventionSustained viral response was compared in patients taking SOF/VEL with or without concurrent PPI prescriptions.Measurements and Main ResultsAnalysis of the primary outcome was completed utilizing logistic regression. The relationship between SVR and PPI use was adjusted for African‐American race, presence of cirrhosis, prior treatment, BMI greater than 30 kg/m2, and HCV genotype. The final analysis included 4,008 veterans, 830 with concomitant PPI use and 3,178 without PPI use. After adjustment for other variables in the logistic model, there was no statistically significant association between PPI use and lower SVR (odds ratio 0.67; 95%CI: 0.42, 1.06; p = 0.087).ConclusionConcomitant PPI treatment adjusted for other variables did not significantly impact success or failure of SOF/VEL treatment of chronic HCV. Despite the lack of significant association identified in this study, in efforts to provide the best care possible, it remains prudent to proceed with caution in patients desiring to use PPI therapy while receiving SOF/VEL, and ensure prescribing instructions are closely followed in regard to concomitant PPI use, especially in patients with other risk factors for decreased SVR.
Registration of three new bmr12 sorghum mutants from an ethyl methane sulfonate–induced BTx623 mutant population
Authors: Emendack Yves , Xin Zhanguo , Hayes Chad , Burow Gloria , Sattler Scott , Bean Scott , Smolensky Dmitriy 
Published: April 2022

AbstractThree new sorghum (Sorghum bicolor L.) brown midrib (bmr) genetic stocks BTx623bmr12‐30 (Reg. no. GS‐790, PI 699404), BTx623bmr12‐34 (Reg. no. GS‐789, PI 699405), and BTx623bmr12‐35 (Reg. no. GS‐788, PI 699406) were developed for release by USDA–ARS in Lubbock, TX. The primary purpose for the release of these stocks is to provide an extensive source of (bmr12) variants for use in forage breeding programs. The genetic stocks were isolated from the pedigreed sorghum ethyl methane sulfonate–mutagenized sorghum in BTx623 background. The derived mutations were analyzed by DNA sequencing and confirmed by KASP (Kompetitive Allele Specific PCR) markers. The confirmed bmr mutants were also analyzed for stem and leaf lignin and carbohydrate contents. Furthermore, physiological and agro‐morphological evaluations were performed under control and field conditions. All genetic stocks displayed the reddish‐brown pigmentation in the leaf midrib, confirming the bmr phenotype. The bmr12 mutants flowered 4–5 d earlier than the wild type BTx623. Physical and compositional characterization of seeds from the three genetic stocks revealed no negative consequence of bmr on grain structure. Notably, these bmr12 mutants had 14–24% greater total seed protein than wild type BTx623. The three new bmr12 alleles provide public and private breeders crucial and novel genetic stock sources for use in breeding bmr forage sorghum.
A novel 3D X‐ray computed tomography (CT) method for spatio‐temporal evaluation of waterlogging‐induced aerenchyma formation in barley
Authors: Kehoe Stephen , Byrne Tomás , Spink John , Barth Susanne , Ng Carl K. Y. , Tracy Saoirse 
Published: April 2022

AbstractIncreased precipitation during winter months in Western Europe is predicted from climate change. This is expected to increase the frequency of flooding events, with waterlogged conditions becoming more prevalent. A consequence of waterlogging is hypoxic conditions and dying back of roots, thereby negatively affecting plant nutrient uptake, growth, and development. Barley (Hordeum vulgare L.) forms lysigenous aerenchyma, which are air‐filled pockets within the root to facilitate O2 transport and support root respiration. Current methods for visualizing aerenchyma formation in roots are largely 2D and involve embedding a fixed root segment in resin, followed by destructive sectioning for microscopy. Here, we report the development of an X‐ray computed tomography (CT) acquisition and analytical method for spatio‐temporal identification and quantitation of aerenchyma in 2D and 3D in barley roots without the requirement for chemical fixation, resin embedding, followed by physical sectioning of the root. We demonstrated that the method we have developed can facilitate the identification and quantitation of aerenchyma in barley as early as 9 d post‐waterlogging. The method we have developed can be potentially applied to different plant species and has the potential to support the selection of breeding markers through X‐ray CT phenotyping of aerenchyma.