bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of mPEGA/EHA Ratio and Copolymer Composition on the Solution Behavior of Amphiphilic, Comb‐Shape Copolymers Synthesized via Cu(0)‐Mediated SET‐LRP for Potential Drug Delivery Applications
Authors: Pourdakheli Hamedani Yasaman , Çakırefe Semanur , Fietz Agnes , Hurst José , Schnichels Sven , Adams Friederike 
Published: September 2023

AbstractComb‐shape, block copolymers from hydrophilic poly(ethylenglycol) monomethyl ether acrylate (mPEGA, A) and hydrophobic 2‐ethylhexyl acrylate (EHA, B) are synthesized by copper(0)‐mediated single‐electron transfer living radical polymerization (SET‐LRP) via sequential addition of the two monomers, resulting in different compositions (AB, ABA, BAB, BA), molar masses, and mPEGA/EHA ratios. All polymers show narrow molar mass distributions and molecular weights of 7.7–25.50 kg mol−1, demonstrating precise control over the polymerization and molecular weights through the utilization of SET‐LRP. Kinetic experiments are conducted to investigate the polymerization behavior of mPEGA and EHA in N,N‐dimethylformamide as a rather uncommon solvent for SET‐LRP further underlining a living‐type polymerization. Amphiphilic properties are investigated by critical micelle concentration (CMC) measurements and formation of micelles in water. A reverse relation between mPEGA/EHA ratio and CMC values reveals that an increased hydrophobicity leads to decreased CMC values. The self‐assembly behavior of polymers in water confirms the formation of uniform and stable micelles in water with a size between 12 and 184 nm depending on the composition of the polymers. With increased hydrophilicity, micelle sizes increase as well. In vitro tests of the obtained polymers show excellent biocompatibility even at high concentrations further affirming their suitability for drug delivery applications.
Dual‐energy head cone‐beam CT using a dual‐layer flat‐panel detector: Hybrid material decomposition and a feasibility study
Authors: Wang Zhilei , Zhou Hao , Gu Shan , Xia Yingxian , Liao Haiyue , Deng Yifan , Gao Hewei 
Published: September 2023

AbstractBackgroundFlat panel detector (FPD) based cone‐beam computed tomography (CT) has made tremendous progress in the last two decades, with many new and advanced medical and industrial applications keeping emerging from diagnostic imaging and image guidance for radiotherapy and interventional surgery. The current cone‐beam CT (CBCT), however, is still suboptimal for head CT scan which requires a high standard of image quality. While the dual‐layer FPD technology is under extensive development and is promising to further advance CBCT from qualitative anatomic imaging to quantitative dual‐energy CT, its potential of enabling head CBCT applications has not yet been fully investigated.PurposeThe relatively moderate energy separation from the dual‐layer FPD and the overall low signal level especially at the bottom‐layer detector, could raise significant challenges in performing high‐quality dual‐energy material decomposition (MD). In this work, we propose a hybrid, physics and model guided, MD algorithm that attempts to fully use the detected x‐ray signals and prior‐knowledge behind head CBCT using dual‐layer FPD.MethodsFirstly, a regular projection‐domain MD is performed as initial results of our approach and for comparison as conventional method. Secondly, based on the combined projection, a dual‐layer multi‐material spectral correction (dMMSC) is applied to generate beam hardening free images. Thirdly, the dMMSC corrected projections are adopted as a physics‐model based guidance to generate a hybrid MD. A set of physics experiments including fan‐beam scan and cone‐beam scan using a head phantom and a Gammex Multi‐Energy CT phantom are conducted to validate our proposed approach.ResultsThe combined reconstruction could reduce noise by about 10% with no visible resolution degradation. The fan‐beam studies on the Gammex phantom demonstrated an improved MD performance, with the averaged iodine quantification error for the 5–15 mg/ml iodine inserts reduced from about 5.6% to 3.0% by the hybrid method. On fan‐beam scan of the head phantom, our proposed hybrid MD could significantly reduce the streak artifacts, with CT number nonuniformity (NU) in the selected regions of interest (ROIs) reduced from 23 Hounsfield Units (HU) to 4.2 HU, and the corresponding noise suppressed from 31 to 6.5 HU. For cone‐beam scan, after scatter correction (SC) and cone‐beam artifact reduction (CBAR), our approach can also significantly improve image quality, with CT number NU in the selected ROI reduced from 24.2 to 6.6 HU and the noise level suppressed from 22.1 to 8.2 HU.ConclusionsOur proposed physics and model guided hybrid MD for dual‐layer FPD based head CBCT can significantly improve the robustness of MD and suppress the low‐signal artifact. This preliminary feasibility study also demonstrated that the dual‐layer FPD is promising to enable head CBCT spectral imaging.
Real‐time automatic image‐based slice tracking of gadolinium‐filled balloon wedge catheter during MR‐guided cardiac catheterization: A proof‐of‐concept study
Authors: Vidya Shankar Rohini , Huang Li , Neji Radhouene , Kowalik Grzegorz , Neofytou Alexander Paul , Mooiweer Ronald , Moon Tracy , Mellor Nina , Razavi Reza , Pushparajah Kuberan , Roujol Sébastien 
Published: September 2023

AbstractPurposeMR‐guided cardiac catheterization procedures currently use passive tracking approaches to follow a gadolinium‐filled catheter balloon during catheter navigation. This requires frequent manual tracking and repositioning of the imaging slice during navigation. In this study, a novel framework for automatic real‐time catheter tracking during MR‐guided cardiac catheterization is presented.MethodsThe proposed framework includes two imaging modes (Calibration and Runtime). The sequence starts in Calibration mode, in which the 3D catheter coordinates are determined using a stack of 10–20 contiguous saturated slices combined with real‐time image processing. The sequence then automatically switches to Runtime mode, where three contiguous slices (acquired with partial saturation), initially centered on the catheter balloon using the Calibration feedback, are acquired continuously. The 3D catheter balloon coordinates are estimated in real time from each Runtime slice stack using image processing. Each Runtime stack is repositioned to maintain the catheter balloon in the central slice based on the prior Runtime feedback. The sequence switches back to Calibration mode if the catheter is not detected. This framework was evaluated in a heart phantom and 3 patients undergoing MR‐guided cardiac catheterization. Catheter detection accuracy and rate of catheter visibility were evaluated.ResultsThe automatic detection accuracy for the catheter balloon during the Calibration/Runtime mode was 100%/95% in phantom and 100%/97 ± 3% in patients. During Runtime, the catheter was visible in 82% and 98 ± 2% of the real‐time measurements in the phantom and patients, respectively.ConclusionThe proposed framework enabled real‐time continuous automatic tracking of a gadolinium‐filled catheter balloon during MR‐guided cardiac catheterization.
Benchmark computations of dynamic poroelasticity
Authors: Anselmann Mathias , Bause Markus , Margenberg Nils , Shamko Pavel 
Published: September 2023

AbstractWe present benchmark computations of dynamic poroelasticity modeling fluid flow in deformable porous media by a coupled hyperbolic–parabolic system of partial differential equations. A challenging benchmark setting and goal quantities of physical interest for this problem are proposed. Computations performed by space–time finite element approximations with continuous and discontinuous discretizations of the time variable are summarized. By this work, we intend to stimulate comparative studies by other research groups for the evaluation of dynamic poroelasticity solver regarding the accuracy of discretization techniques, the efficiency and robustness of iterative methods for the linear systems, and the arrangement of the model equations in terms of their variables (two‐field or multifield formulations).
Benchmarking solution methods for parameter identification in dynamical systems
Authors: Wiesner Marek , Büskens Christof 
Published: September 2023

AbstractAccurate models are crucial for simulating, optimizing, and controlling real‐world processes. Parameter identification—the task of estimating the unknown parameters of a dynamical system based on measurements—is challenging and there exist various methods to approach it. Integration‐based methods, such as shooting methods and full discretization, approximate the model output by numerically solving the dynamical system. Gradient matching methods, on the other hand, avoid solving the dynamical system and focus on minimizing the error between the measurement slope and the state derivatives instead. All approaches have advantages and disadvantages and a recipe for which method is best in a particular situation does not exist. In this paper, we present the results of a benchmark comparing single shooting, multiple shooting, full discretization, and gradient matching using a comprehensive database of test problems. We investigate if there is a notable difference in the performance of the various methods and if one approach is superior to the others. From the benchmark, we conclude that the integration‐based methods outperform gradient matching. While full discretization exhibits robustness, single and multiple shooting provide higher precision. Additionally, we observe that finding an optimal configuration of the methods across a diverse set of parameter identification problems remains challenging and often requires fine‐tuning.
A review on electrically conductive polyurethane nanocomposites: From principle to application
Authors: Jafarzadeh Shahabaldin , Farzaneh Arman , Haddadi‐Asl Vahid , Jouibari Iman Sahebi 
Published: September 2023

AbstractPolyurethanes (PUs) thanks to the occurrence of phase separation and biphasic structure prevail over other polymer matrixes for impregnation of conductive fillers and production of conductive composites. A number of carbonous fillers including carbon black, carbon fiber, carbon nanotube, graphite and its derivatives, and fullerene can be loaded into the PU matrixes to impart electrical conductivity. The properties of the carbonous fillers, the filler/PU interactions, and the method of compositing determine the conductive performance of the composite. It is possible to modulate the properties of the conductive PU composites and employ them for a number of electronic applications including but not limited to the strain sensors, electromagnetic interference shielding materials, supercapacitors, and tissue engineering scaffolds. In the present review, first, the distinctive properties of PU as a matrix of conductive composites have been discussed. Then, various carbon fillers loaded into the PU matrixes and their structural and conductive properties have been debated. Thereafter, the fabrication methods of the conductive composites as well as the influential parameters on the electrical properties of the composites have been reviewed to provide an insight into how fulfill a PU composite with the desired electrical performance. And finally, a number of applications of conductive PU composites have been put forward.Highlights
Polyurethanes are very capable matrixes for conductive composites.
Carbonous fillers can be loaded into the PU matrixes to impart conductivity.
Conductive PU composites are employed for a number of electronic applications.
Herein, properties, fillers, and applications of PU composites are reviewed.
Ethnolinguistic and genetic diversity of fonio (Digitaria exilis) in Senegal
Authors: Diop Baye Magatte , Guèye Mame Codou , Leclerc Christian , Deu Monique , Zekraoui Leila , Calatayud Carolina , Rivallan Ronan , Kaly Justin Raymond , Cissé Momar , Piquet Marie , Diack Omar , Ngom Ablaye , Berger Angélique , Ndoye Ibrahima , Ndir Khadidiatou , Vigouroux Yves , Kane Ndjido Ardo , Barnaud Adeline , Billot Claire 
Published: September 2023

Societal Impact StatementFonio (Digitaria exilis—Kippist—Stapf) is a neglected cereal crop that plays a crucial role in the food and nutritional security of sub‐Saharan populations. Currently threatened with extinction in many countries, fonio, like other minor species, could help give insights into the history of African agriculture and provide clues to past social interactions. Highlighting and preserving genetic diversity that can be used to develop improved varieties improves food security. By recognizing the role of indigenous people and local communities (IPLCs) in agrobiodiversity creation and management, this study provides support for strengthening the rights of rural communities and promoting their food and seed sovereignty as outlined in the United Nations UNDROP Declaration.Summary
Fonio (Digitaria exilis) is a neglected cereal crop that plays a crucial role in the food and nutritional security of sub‐Saharan populations. It is an excellent candidate to diversify agricultural and food systems beyond Africa because of its adaptability and hardiness. However, fonio is threatened with extinction and the factors that organize its genetic diversity remain unknown, despite the fact that this knowledge is necessary to define conservation strategies and uses to achieve sustainable agriculture.
Here, we combined social anthropology and population genetics analysis of 158 fonio landraces, thereby generating insight into the genetic diversity, population structure and evolutionary history of fonio cultivation in Senegal.
We noted a spatial structure of genetic diversity at two embedded levels, with the first corresponding to the genetic differentiation between ethnic groups and the second to the demographic history of the Mande and Atlantic Congo linguistic families. Selection and seed exchange practices have contributed to shaping fonio genetic diversity at the ethnic level, while the migration of Fulani people over the last 500 years has fragmented the Mandinka kingdom, hence leaving a fonio diversity imprint.
Our study highlighted that social factors are pivotal in structuring diversity and should be taken into greater consideration in research and conservation projects to dovetail local and regional scales. It also showed that neglected species such as fonio—which are seldom used in breeding and dissemination programmes—are key markers of the history of African agriculture.
Modeling of the photophysical and photovoltaic properties of an active layer based on the organic composite poly(2‐methoxy‐5‐(2‐ethyl‐hexyloxy)‐1,4‐phenylene‐vinylene) (MEH‐PPV)–poly(3‐hexylthiophene) (P3HT): (6,6)‐phenyl C61 butyric acid methyl ester (PCBM)
Authors: Ltayef M. , Mbarek M. , Almoneef M. M. , Alimi K. 
Published: September 2023

AbstractIn this work, two different composite architectures have been investigated. These materials are formed by the block and ramified MEHPPV‐P3HT copolymers mixing with the PCBM. Density Functional Theory (DFT) and Time‐Dependent Density Functional Theory (TD‐DFT) calculation methods have been used to simulate the properties of the photo‐physical and photovoltaic material. The results show that adding the PCBM decreases the HOMO–LUMO gap energy to approximately 1.4 eV compared to the basic copolymers. This reduction implies a higher charge transfer between the donor and acceptor materials. Therefore, these composites can be implemented as an active layer in bulk heterojunction organic solar cells. Furthermore, the coupling between the polymers MEH‐PPV and P3HT improves their performance order by 5.2%.
Dereplication of tropane alkaloids from four Erythroxylum species using liquid chromatography coupled with ESI‐MSn and HRESIMS
Authors: Gonçalves Dantas César Augusto , Abreu Lucas Silva , Viana Vinicius Ferreira , Gouveia Veloso Carlos Arthur , Agra Maria de Fátima , da Silva Marcelo Sobral , Tavares Josean Fechine 
Published: September 2023

RationaleTropane alkaloids represent an important class of secondary metabolites, but many of these compounds are already described in the scientific literature, so the use of guided identification and isolation strategies, such as dereplication, represent a fast and safe alternative.MethodsFor the annotation of the tropane alkaloids the chloroform phases of the four Erythroxylum species were analyzed by high‐performance liquid chromatography coupled to mass spectrometry with positive‐mode electrospray ionization, then the ions of their protonated molecules, molecular formulas and fragmentation patterns were observed and a comparison of the obtained data with those present in the scientific literature was performed. The compounds not fully annotated were isolated and characterized by 1H and 13C nuclear magnetic resonance spectroscopy.ResultsThe annotation of 29 tropane alkaloids was performed, some being described for the first time in the family Erythroxylaceae. The chemical profiles of these secondary metabolites in the four Erythroxylum species analyzed were traced and compared. Isolation of three compounds whose mass spectral data were not sufficient for their full annotation was performed. They were 6‐(benzoyloxy)‐3‐(3,5‐dimethoxy‐4‐hydroxybenzoyloxy)tropane, 6‐(benzoyloxy)‐3‐(3,4,5‐trimethoxybenzoyloxy)tropane and 6‐(benzoyloxy)‐3‐(3,4,5‐trimethoxycinamoyloxy)tropane, first reported in the species Erythroxylum revolutum Mart.ConclusionsThis work contributes to the phytochemical knowledge of the genus Erythroxylum, and demonstrates the efficiency and importance of using guided isolation methodologies of secondary metabolites in natural products research. Since safe results were presented in the annotation of the compounds evidenced, employing small quantities of organic solvents, when compared to classical methodologies, besides promoting an optimization in the research time.
Confidence bounds for threshold similarity graph in random variable network
Authors: Koldanov P. A. , Koldanov A. P. , Semenov D. P. 
Published: September 2023

AbstractProblem of uncertainty of graph structure identification in random variable network is considered. An approach for the construction of upper and lower confidence bounds for graph structures is developed. This approach is applied for the construction of upper and lower confidence bounds for the threshold similarity graph. The stability of confidence bounds and gaps between upper and lower confidence bounds are investigated. Theoretical results are illustrated by numerical experiments.
Charge‐Reversible Nanoparticles: Advanced Delivery Systems for Therapy and Diagnosis
Authors: Veider Florina , Sanchez Armengol Eva , Bernkop‐Schnürch Andreas 
Published: September 2023

AbstractThe past two decades have witnessed a rapid progress in the development of surface charge‐reversible nanoparticles (NPs) for drug delivery and diagnosis. These NPs are able to elegantly address the polycation dilemma. Converting their surface charge from negative/neutral to positive at the target site, they can substantially improve delivery of drugs and diagnostic agents. By specific stimuli like a shift in pH and redox potential, enzymes, or exogenous stimuli such as light or heat, charge reversal of NP surface can be achieved at the target site. The activated positive surface charge enhances the adhesion of NPs to target cells and facilitates cellular uptake, endosomal escape, and mitochondrial targeting. Because of these properties, the efficacy of incorporated drugs as well as the sensitivity of diagnostic agents can be essentially enhanced. Furthermore, charge‐reversible NPs are shown to overcome the biofilm formed by pathogenic bacteria and to shuttle antibiotics directly to the cell membrane of these microorganisms. In this review, the up‐to‐date design of charge‐reversible NPs and their emerging applications in drug delivery and diagnosis are highlighted.
Tetrahedral Occupied V Ions Enabling Reversible Three‐Electron Redox of Cr3+/Cr6+ in Layered Cathode Materials for Potassium‐Ion Batteries
Authors: Luo Rui‐Jie , Bao Jian , Li Xun‐Lu , Ma Cui , Du Chong‐Yu , Zeng Jie , Xu Xuan , Qian Zhe , Mei Zhe , Zhou Yong‐Ning 
Published: September 2023

AbstractReversible three‐electron redox of Cr3+/Cr6+ in layered cathode materials for rechargeable batteries is very attractive in layered cathode materials, which leads to high capacity and energy density for rechargeable batteries. However, the poor reversibility and Cr‐ion migration make it very challenging. In this work, by introducing V ions into tetrahedral sites of layer‐structured NaCrO2, reversible three‐electron redox of Cr3+/Cr6+ is realized successfully in NaCr0.92V0.05O2 (NCV05) cathode for potassium‐ion batteries with a cut‐off voltage of 4.0 V. V ions can weaken the attraction of Cr to electrons, leading to enhanced valence change of Cr ions. On the other hand, V in tetrahedral sites can facilitate the reversible migration of Cr between octahedral and tetrahedral sites via coulombic repulsion to realize the reversible redox between Cr3+ and Cr6+ during charge and discharge processes. In addition, V ions can inhibit the phase transition from O3 phase to O’3 phase during the charge process by adjusting the crystal lattices. As a result, the NaCr0.92V0.05O2 cathode exhibits a high reversible capacity of 130 mAh g−1 with promising cycle stability and rate capability. The strategy opens new opportunity for developing high‐capacity cathode materials for potassium‐ion batteries.
Marijuana legalization and traffic fatalities revisited
Authors: Chen Weiwei , French Michael T. 
Published: September 2023

AbstractThe legal landscape for marijuana in the United States has changed dramatically over the last three decades. While several studies have examined the relationship between marijuana legalization and traffic fatalities, some of the research is becoming outdated and existing evidence remains mixed. Our research revisits the topic with two updates. First, our study includes states that legalized marijuana more recently and provides updated evidence on the effects of marijuana legalization. Second, considering recent discussions about the limitations of difference‐in‐differences designs, we employ alternative estimators that are robust to heterogeneous and dynamic treatment effects. Overall, our alternative estimators suggest either a smaller reduction (i.e., 3.9% drop in the overall fatality rate) or no change in traffic fatalities associated with legalizing marijuana for medical use, compared to the two‐way fixed‐effect estimator. We find no significant impact on traffic fatalities associated with legalizing marijuana for recreational use.