bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse
Authors: Scott Hayden , Alvarez Paola E. , Howell Rebecca M. , Riegel Adam , Sun Ryan , Liu Kevin , Kry Stephen F.
Published: June 2024

Background

Optically stimulated luminescent dosimeters (OSLDs) can be bleached and reused, but questions remain about the effects of repeated bleaching and fractionation schedules on OSLD performance.

Purpose

The aim of this study was to investigate how light sources with different wavelengths and different fractionation schemes affect the performance of reused OSLDs.

Methods

OSLDs (N = 240) were irradiated on a cobalt‐60 beam in different step sizes until they reached an accumulated dose of 50 Gy. Between irradiations they were bleached using light sources of different wavelengths: the Imaging and Radiation Oncology Core (IROC) bleaching system (our control); monochromatic red, green, yellow, and blue lights; and a polychromatic white light. Sensitivity and linearity‐based correction factors were determined as a function of dose step‐size. The rate of signal removal from different light sources was characterized by sampling these OSLDs at various time points during their bleaching process. Relative doses were calculated according to the American Association of Physicists in Medicine Task Group‐191. Signal repopulation was investigated by irradiating OSLDs (N = 300) to various delivered doses of 2, 10, 20, 30, 40, and 50 Gy in a single fraction, bleached with one of the colors, and read over time. Fractionation effects were evaluated by irradiating OSLDs up to 30 Gy in different size steps. After reading, the OSLDs were bleached following IROC protocol. OSLDs (N = 40) received irradiations in 5, 10, 15, 30 Gy fractions until they had an accumulated dose of 30 Gy; The sensitivity response of these OSLDs was compared with reference OSLDs that had no accumulated dose.

Results

Light sources with polychromatic spectrums (IROC and white) bleached OSLDs faster than did sources with monochromatic spectra. Polychromatic light sources (white light and IROC system) provided the greatest dose stability for OSLDs that had larger amounts of accumulated dose. Signal repopulation was related to the choice of bleaching light source, timing of bleaching, and amount of accumulated dose. Changes to relative dosimetry were more pronounced in OSLDs that received larger fractions. At 5‐Gy fractions and above, all OSLDs had heightened sensitivity, with OSLDs exposed to 30‐Gy fractions being 6.4% more sensitive than reference dosimeters.

Conclusions

The choice of bleaching light plays a role in how fast an OSLD is bleached and how much accumulated dose an OSLD can be exposed to while maintaining stable signal sensitivity. We have expanded upon investigations into signal repopulation to show that bleaching light plays a role in the migration of deep traps to dosimetric traps after bleaching. Our research concludes that the bleaching light source and fractionation need to be considered when reusing OSLD.
Novel radiation quality metrics accounting for proton energy spectra for RBE proton models
Authors: Kalholm Fredrik , Toma‐Dasu Iuliana , Traneus Erik , Bassler Niels
Published: June 2024

Background

For proton therapy, a relative biological effectiveness (RBE) of 1.1 is widely applied clinically. However, due to abundant evidence of variable RBE in vitro, and as suggested in studies of patient outcomes, RBE might increase by the end of the proton tracks, as described by several proposed variable RBE models. Typically, the dose averaged linear energy transfer () has been used as a radiation quality metric (RQM) for these models. However, the optimal choice of RQM has not been fully explored.

Purpose

This study aims to propose novel RQMs that effectively weight protons of different energies, and assess their predictive power for variable RBE in proton therapy. The overall objective is to identify an RQM that better describes the contribution of individual particles to the RBE of proton beams.

Methods

High‐throughput experimental set‐ups of in vitro cell survival studies for proton RBE determination are simulated utilizing the SHIELD‐HIT12A Monte Carlo particle transport code. For every data point, the proton energy spectra are simulated, allowing the calculation of novel RQMs by applying different power levels to the spectra of LET or effective () values. A phenomenological linear‐quadratic‐based RBE model is then applied to the in vitro data, using various RQMs as input variables, and the model performance is evaluated by root‐mean‐square‐error (RMSE) for the logarithm of cell surviving fractions of each data point.

Results

Increasing the power level, that is, putting an even higher weight on higher LET particles when constructing the RQM is generally associated with an increased model performance, with dose averaged (i.e., dose averaged cubed LET, ) resulting in a RMSE value 0.31, compared to 0.45 for a model based on (linearly weighted) , with similar trends also observed for track averaged and ‐based RQMs.

Conclusions

The results indicate that improved proton variable RBE models can be constructed assuming a non‐linear RBE(LET) relationship for individual protons. If similar trends hold also for an in vitro‐environment, variable RBE effects are likely better described by or tracked averaged cubed LET (), or corresponding ‐based RQM, rather than linearly weighted or which is conventionally applied today.
Use of a pressure sensor array for multifunctional patient monitoring in radiotherapy: A feasibility study
Authors: Jeon Hosang , Kim Dong Woon , Joo Ji Hyeon , Park Dahl , Kim Wontaek , Nam Jiho , Kim Dong Hyeon , Ki Yongkan
Published: June 2024

Background

Modern radiotherapeutic techniques, such as intensity‐modulated radiation therapy or stereotactic body radiotherapy, require high‐dose delivery precision. However, the precise localization of tumors during patient respiration remains a challenge. Therefore, it is essential to investigate effective methods for monitoring respiration to minimize potential complications. Despite several systems currently in clinical use, there are drawbacks, including the complexity of the setup, the discomfort to the patient, and the high cost.

Purpose

This study investigated the feasibility of using a novel pressure sensor array (PSA) as a tool to monitor respiration during radiotherapy treatments. The PSA was positioned between the treatment couch and the back of the patient lying on it and was intended to overcome some limitations of current methods. The main objectives included assessing the PSA's capability in monitoring respiratory behavior and to investigate prospective applications that extend beyond respiratory monitoring.

Methods

A PSA with 31 pressure‐sensing elements was used in 12 volunteers. The participants were instructed to breathe naturally while lying on a couch without any audio or visual guidance. The performance of the PSA was compared to that of a camera‐based respiratory monitoring system (RPM, Varian, USA), which served as a reference. Several metrics, including pressure distribution, weight sensitivity, and correlations between PSA and RPM signals, were analyzed. The PSA's capacity to provide information on potential applications related to patient stability was also investigated.

Results

The linear relationship between the weight applied to the PSA and its output was demonstrated in this study, confirming its sensitivity to pressure changes. A comparison of PSA and RPM curves revealed a high correlation coefficient of 0.9391 on average, indicating consistent respiratory cycles. The PSA also effectively measured the weight distribution at the volunteer's back in real‐time, which allows for monitoring the patient's movements during the radiotherapy.

Conclusion

PSA is a promising candidate for effective respiratory monitoring during radiotherapy treatments. Its performance is comparable to the established RPM system, and its additional capabilities suggest its multifaceted utility. This paper shows the potential use of PSA for patient monitoring in radiotherapy and suggests possibilities for further research, including performance comparisons with other existing systems and real‐patient applications with respiratory training.
Presentation of microstructural diffusion components by color schemes in abdominal organs
Authors: Wittsack Hans‐Jörg , Thiel Thomas Andreas , Valentin Birte , Stabinska Julia , Benkert Thomas , Schimmöller Lars , Antoch Gerald , Ljimani Alexandra
Published: June 2024

Purpose

Development of a color scheme representation to facilitate the interpretation of tri‐exponential DWI data from abdominal organs, where multi‐exponential behavior is more pronounced.

Methods

Multi‐exponential analysis of DWI data provides information about the microstructure of the tissue under study. The tri‐exponential signal analysis generates numerous parameter images that are difficult to analyze individually. Summarized color images can simplify at‐a‐glance analysis. A color scheme was developed in which the slow, intermediate, and fast diffusion components were each assigned to a different red, green, and blue color channel. To improve the appearance of the image, histogram equalization, gamma correction, and white balance were used, and the processing parameters were adjusted. Examples of the resulting color maps of the diffusion fractions of healthy and pathological kidney and prostate are shown.

Results

The color maps obtained by the presented method show the merged information of the slow, intermediate, and fast diffusion components in a single view. A differentiation of the different fractions becomes clearly visible. Fast diffusion regimes, such as in the renal hilus, can be clearly distinguished from slow fractions, such as in dense tumor tissue.

Conclusion

Combining the diffusion information from tri‐exponential DWI analysis into a single color image allows for simplified interpretation of the diffusion fractions. In the future, such color images may provide additional information about the microstructural nature of the tissue under study.
Recovering high‐quality fiber orientation distributions from a reduced number of diffusion‐weighted images using a model‐driven deep learning architecture
Authors: Bartlett Joseph J. , Davey Catherine E. , Johnston Leigh A. , Duan Jinming
Published: June 2024

Purpose

The aim of this study was to develop a model‐based deep learning architecture to accurately reconstruct fiber orientation distributions (FODs) from a reduced number of diffusion‐weighted images (DWIs), facilitating accurate analysis with reduced acquisition times.

Methods

Our proposed architecture, Spherical Deconvolution Network (SDNet), performed FOD reconstruction by mapping 30 DWIs to fully sampled FODs, which have been fit to 288 DWIs. SDNet included DWI‐consistency blocks within the network architecture, and a fixel‐classification penalty within the loss function. SDNet was trained on a subset of the Human Connectome Project, and its performance compared with FOD‐Net, and multishell multitissue constrained spherical deconvolution.

Results

SDNet achieved the strongest results with respect to angular correlation coefficient and sum of squared errors. When the impact of the fixel‐classification penalty was increased, we observed an improvement in performance metrics reliant on segmenting the FODs into the correct number of fixels.

Conclusion

Inclusion of DWI‐consistency blocks improved reconstruction performance, and the fixel‐classification penalty term offered increased control over the angular separation of fixels in the reconstructed FODs.
Viscosity‐coupled curing simulation model for L‐shaped composites considering flow and compaction
Authors: Ye Yaoyao , Zhang Fan , Chen Qisen , Xu Qiang , Ke Yinglin
Published: June 2024

Computational methods provide effective tools for the prediction of the curing behavior of composites, especially for large‐scale complex composite structures. The flow‐compaction analysis during curing receives insufficient attention in current studies. In this work, an integrated framework considering the heat transfer, the cross‐linking reaction, the flow and compaction, and the stress–strain module is established. A comprehensive resin flow termination criterion is proposed. L‐shaped composites with a stacking layer of [45/90/−45/0]s were fabricated, and the good agreement between the experimentally measured and the numerically predicted contour data validated the current model. Compared with Hubert's model, the prediction accuracy of the thickness and fiber volume content increases by 4.24% and 3.92%, respectively. Correlation analysis between the fiber volume ratio predicted by numerical methods and experimental results (94% for this method, −41% for Hubert's model) demonstrates the well‐capture of nonuniform fiber distribution in curved composites for the current strategy. The overall framework provides an accurate and promising tool for the prediction of the curing behavior of complex composite components.

Highlights

An integrated numerical methodology is proposed considering the resin flow and compaction.

The viscosity‐temperature coupled feature of resin is considered in the permeability coefficients.

A comprehensive resin flow termination criterion is proposed for an accurate prediction.

The resin content, thickness, and spring‐in angle of L‐shaped laminates are characterized.

The good correlation between the experimental and numerical results validates this method.

Compared with the model proposed by Hubert, the prediction accuracy improves.
Data blanks by design: Intellectual property and restrictions on genetic diversity assessments of the maize standing crop in the USA Upper Midwest
Authors: McCluskey Cathleen A. , Tracy William F.
Published: June 2024

Societal Impact Statement

All US commercial maize (Zea mays) is a single race, “Corn Belt Dent,” and its genetic base has been in decline for at least 40 years. Independent genotyping can only be conducted after patent and licensing restrictions have expired, a period of 20 years. These restrictions also impede a molecular based assessment of the standing crop by the United States Department of Agriculture (USDA) as recommended by experts. Data blanks about landscape vulnerability put farmers at risk of crop failure and the public at risk of food insecurity. Understanding maize diversity experts' perspectives and analysis helps describe the contours of these data blanks and inform policy recommendations.

Recommendations by the Maize Crop Germplasm Committee to the United States Department of Agriculture (USDA) for a molecular based vulnerability assessment on the US standing maize (Zea mays) crop have not been acted on because of intellectual property and licensing restrictions. This research explores maize diversity experts' access to data and perceptions and analysis of the standing crop.

The data come from semi‐structured interviews conducted with 44 maize diversity experts in the public and private sectors.

Experts explain that genetic data blanks restrict non‐industry research, describe public sector concerns that standing diversity is narrow(ing), and find historic sources of pedigree data in Plant Variety Protection and patent records are no longer reliable. Some interviewees perceive that industry monitoring of standing diversity is in their best financial interest. Industry participants describe concentration in US maize allows them to control diversity over time, while public researchers discuss efficiency of scale narrowing genetic diversity and global concentration spreading this trend.

Knowledge gaps about genetic diversity in US commercial maize are designed through patents, contracts, non‐disclosure agreements, and confidentiality agreements by patent holders who do not want their inbred lines genotyped by competitors. This restricts research and knowledge flow about genetic information into public networks. The Maize Crop Germplasm Committee is a node for knowledge flow; however, the lack of mechanisms for action suggests it is performative. We recommend all protections used on seed include exemptions for research, breeding, and seed saving; an independent assessment of how industry monitors standing diversity; and a molecular analysis of the standing crop conducted by the USDA.
The strongest protein binder is surprisingly labile
Authors: Fernandez‐Calvo Alba , Reifs Antonio , Saa Laura , Cortajarena Aitziber L. , De Sancho David , Perez‐Jimenez Raul
Published: June 2024

Bacterial adhesins are cell‐surface proteins that anchor to the cell wall of the host. The first stage of infection involves the specific attachment to fibrinogen (Fg), a protein found in human blood. This attachment allows bacteria to colonize tissues causing diseases such as endocarditis. The study of this family of proteins is hence essential to develop new strategies to fight bacterial infections. In the case of the Gram‐positive bacterium Staphylococcus aureus, there exists a class of adhesins known as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Here, we focus on one of them, the clumping factor A (ClfA), which has been found to bind Fg through the dock‐lock‐latch mechanism. Interestingly, it has recently been discovered that MSCRAMM proteins employ a catch‐bond to withstand forces exceeding 2 nN, making this type of interaction as mechanically strong as a covalent bond. However, it is not known whether this strength is an evolved feature characteristic of the bacterial protein or is typical only of the interaction with its partner. Here, we combine single‐molecule force spectroscopy, biophysical binding assays, and molecular simulations to study the intrinsic mechanical strength of ClfA. We find that despite the extremely high forces required to break its interactions with Fg, ClfA is not by itself particularly strong. Integrating the results from both theory and experiments we dissect contributions to the mechanical stability of this protein.
Targeting the protein folding transition state by mutation: Large scale (un)folding rate accelerations without altering native stability
Authors: Campos Luis A. , Muñoz Victor
Published: June 2024

Proteins are constantly undergoing folding and unfolding transitions, with rates that determine their homeostasis in vivo and modulate their biological function. The ability to optimize these rates without affecting overall native stability is hence highly desirable for protein engineering and design. The great challenge is, however, that mutations generally affect folding and unfolding rates with inversely complementary fractions of the net free energy change they inflict on the native state. Here we address this challenge by targeting the folding transition state (FTS) of chymotrypsin inhibitor 2 (CI2), a very slow and stable two‐state folding protein with an FTS known to be refractory to change by mutation. We first discovered that the CI2's FTS is energetically taxed by the desolvation of several, highly conserved, charges that form a buried salt bridge network in the native structure. Based on these findings, we designed a CI2 variant that bears just four mutations and aims to selectively stabilize the FTS. This variant has >250‐fold faster rates in both directions and hence identical native stability, demonstrating the success of our FTS‐centric design strategy. With an optimized FTS, CI2 also becomes 250‐fold more sensitive to proteolytic degradation by its natural substrate chymotrypsin, and completely loses its activity as inhibitor. These results indicate that CI2 has been selected through evolution to have a very unstable FTS in order to attain the kinetic stability needed to effectively function as protease inhibitor. Moreover, the CI2 case showcases that protein (un)folding rates can critically pivot around a few key residues‐interactions, which can strongly modify the general effects of known structural factors such as domain size and fold topology. From a practical standpoint, our results suggest that future efforts should perhaps focus on identifying such critical residues‐interactions in proteins as best strategy to significantly improve our ability to predict and engineer protein (un)folding rates.
Force‐regulated chaperone activity of BiP/ERdj3 is opposite to their homologs DnaK/DnaJ
Authors: Banerjee Souradeep , Chowdhury Debojyoti , Chakraborty Soham , Haldar Shubhasis
Published: June 2024

Polypeptide chains experience mechanical tension while translocating through cellular tunnels, which are subsequently folded by molecular chaperones. However, interactions between tunnel‐associated chaperones and these emerging polypeptides under force is not completely understood. Our investigation focused on mechanical chaperone activity of two tunnel‐associated chaperones, BiP and ERdj3 both with and without mechanical constraints and comparing them with their cytoplasmic homologs: DnaK and DnaJ. While BiP/ERdj3 have been observed to exhibit robust foldase activity under force, DnaK/DnaJ showed holdase function. Importantly, the tunnel‐associated chaperones (BiP/ERdj3) transitioned to a holdase state in the absence of force, indicating a force‐dependent chaperone behavior. This chaperone‐driven folding event in the tunnel generated an additional mechanical energy of up to 54 zJ, potentially aiding protein translocation. Our findings align with strain theory, where chaperones with higher intrinsic deformability act as mechanical foldases (BiP, ERdj3), while those with lower deformability serve as holdases (DnaK and DnaJ). This study thus elucidates the differential mechanically regulated chaperoning activity and introduces a novel perspective on co‐translocational protein folding.
Ligation of multiple protein domains using orthogonal inteins with non‐native splice junctions
Authors: Romero‐Casañas Alejandro , García‐Lizarribar Andrea , Castro Jessica , Vilanova Maria , Benito Antoni , Ribó Marc
Published: June 2024

Protein splicing is a self‐catalyzed process in which an internal protein domain (the intein) is excised from its flanking sequences, linking them together with a canonical peptide bond. Trans‐inteins are separated in two different precursor polypeptide chains that must assemble to catalytically self‐excise and ligate the corresponding flanking exteins to join even when expressed separately either in vitro or in vivo. They are very interesting to construct full proteins from separate domains because their common small size favors chemical synthesis approaches. Therefore, trans‐inteins have multiple applications such as protein modification and purification, structural characterization of protein domains or production of intein‐based biosensors, among others. For many of these applications, when using more than one trans‐intein, orthogonality between them is a critical issue to ensure the proper ligation of the exteins. Here, we confirm the orthogonality (lack of cross‐reactivity) of four different trans‐ or split inteins, gp41‐1, gp41‐8, IMPDH‐1 and NrdJ‐1 both in vivo and in vitro, and built different constructs that allow for the sequential fusion of up to four protein fragments into one final spliced product. We have characterized the splicing efficiency of these constructs. All harbor non‐native extein residues at the splice junction between the trans‐intein and the neighboring exteins, except for the essential Ser + 1. Our results show that it is possible to ligate four different protein domains using inteins gp41‐1, IMPDH‐1 and NrdJ‐1 with non‐native extein residues to obtain a final four‐domain spliced product with a not negligible yield that keeps its native sequence.
Graphene Oxide as Novel Visible Light Active Photocatalyst: Synthesis, Modification by Nitrogen and Boron Doping, and Photocatalytic Application
Authors: Samriti  , Thakur Sahil , Ojha Abhijeet , Gupta Rajeev , Bechelany Mikhael , Kuznetsov A.Yu. , Swart Hendrik C. , Prakash Jai
Published: June 2024

Graphene oxide (GO) has become one of the emerging and important sole photocatalyst nanomaterials in recent years due to its exceptional/tunable optoelectronic properties, multifunctionality, and eco‐friendly nature. However, challenges remain in tuning surface chemistry, tailoring the band gap, developing doping strategies, and understanding the sole photocatalytic mechanism. This contribution investigated the synthesis of GO via the improved Hummers method by varying the ratio of the oxidizing agents (K2Cr2O7:KMnO4), as well as modifications by nitrogen (N) and boron (B) doping in view of its applications in photocatalytic degradation of organic dye pollutants. Furthermore, changes in surface chemistry, optical, compositional, morphological, and structural properties are investigated to understand the photocatalytic mechanism. The synthesized GO showed a broad spectrum of light absorption with a tunable band gap of 2.4–4.3 eV and exhibited more than 91% degradation of methylene blue dye under direct sunlight. However, the photocatalytic activity decreased after N and B doping attributed to reduced oxygen‐containing functional groups, low surface area, and dopants‐induced bonding configurations within the GO structure. This study provides a new insight into replacing metallic semiconductor photocatalysts with highly affordable, environmentally friendly, and potent metal‐free GO photocatalysts.
Characteristics of Vertical Transistors on a GaN Substrate Fabricated via Na‐Flux Method and Enlargement of the Substrate Surpassing 6 Inches
Authors: Imanishi Masayuki , Usami Shigeyoshi , Murakami Kosuke , Okumura Kanako , Nakamura Kosuke , Kakinouchi Keisuke , Otoki Yohei , Yamashita Tomio , Tsurumi Naohiro , Tamura Satoshi , Ohno Hiroshi , Okayama Yoshio , Fujimori Taku , Nagai Seiji , Moriyama Miki , Mori Yusuke
Published: June 2024

The Na‐flux method is expected to be a key GaN growth technique for obtaining ideal bulk GaN crystals. Herein, the structural quality of the latest GaN crystals grown using the Na‐flux method and, for the first time, the characteristics of a vertical transistor fabricated on a GaN substrate grown using this method are discussed. Vertical transistors exhibit normally off operation with a gate voltage threshold exceeding 2 V and a maximum drain current of 3.3 A during the on‐state operation. Additionally, it demonstrates a breakdown voltage exceeding 600 V and a low leakage current during off‐state operation. It is also described that the variation in the on‐resistance can be minimized using GaN substrates with minimal off‐angle variations. This is crucial for achieving the large‐current chips required for future demonstration of actual devices. In addition, the reverse I–V characteristics of the parasitic p–n junction diode (PND) structures indicate a reduction in the number of devices with a significant leakage current compared to commercially available GaN substrates. Finally, a circular GaN substrate with a diameter of 161 mm, surpassing 6 inches, grown using the Na‐flux method is demonstrated, making it the largest GaN substrate aside from those produced through the tiling technique.
Learning to Read Connections—Sensitivity to Collocation Frequency Links Vocabulary Size and Reading Comprehension in Middle Childhood
Authors: Schmitterer Alexandra M. A. , Gawrilow Caterina , Friedrich Claudia
Published: June 2024

The collocation frequency of words in the language environment contributes to early vocabulary development. Vocabulary size, in turn, predicts children's reading comprehension skills later in development. Both collocation frequency and reading comprehension have been connected to inferential reasoning at different time points in development. Here, it was hypothesized that 8‐year‐old children's (N = 147; 76 female) sensitivity to collocation frequency would be related to vocabulary size and reading comprehension skills of varying complexity. Participants completed an auditory thematic judgment task to assess their sensitivity to collocation frequency (response accuracy or speed). In the task, children were presented with a short sentence containing a reference word (e.g., “John sees the cloud.”) and asked to judge which of two subsequent words best fit the sentence (e.g., “rain” or “lip”). Semantic relatedness between reference words and test words was operationalized in three levels (strong, weak, and distant) based on a corpus‐based analysis of collocation frequency. Multilevel and mediation analyses confirmed that thematic judgment responses were related to corpus‐based measures of collocation frequency and were associated with vocabulary size and reading comprehension skills at the sentence and text level. Furthermore, thematic judgment predicted vocabulary size and reading comprehension when the relation of decoding and reading comprehension was taken into account. The study highlights sensitivity to collocation frequency as a link between early language comprehension development (i.e., lexical retrieval and inferential reasoning) and reading comprehension in middle childhood. It also integrates theoretical approaches from computational network or distributional semantics studies and behavioral experimental studies.
Photodynamic therapy promotes hypoxia‐activated nitrogen mustard drug release
Authors: Wang Ran , He Maomao , Zhang Zongwei , Qiu Tian , Xi Yue , Zeng Xiaolong , Fan Jiangli , Sun Wen , Peng Xiaojun
Published: June 2024

Photodynamic therapy (PDT) has become a promising method for tumor treatment due to its non‐invasive and high spatiotemporal selectivity. However, PDT is still hindered by reactive oxygen species deficiency, because solid tumors feature a hypoxic microenvironment. PDT combined with hypoxia‐activated chemotherapy drugs can effectively induce tumor death, overcoming the limitations of the sole PDT for the fight against hypoxia. Herein, we designed a nanosystem (PCe6AZOM) that enhances the release of hypoxia‐activated drugs (AZOM) by PDT. Under hypoxic conditions, the azo bond of AZOM is cleaved by azo reductase, releasing highly cytotoxic AZOM and resulting in a significant increase in intratumor drug concentration. Meanwhile, the commercial photosensitizer Ce6 can aggravate the oxygen‐poor state during the PDT process and further cause more AZOM release. Moreover, the cascade reactions in the nanosystem could activate singlet oxygen and enhance drug release through 660 nm light laser irradiation, contributing to more effective induction of tumor apoptosis and tumor growth retardation in vitro and in vivo.
Morphological Sensitivity to pH of Silica and Chalk Nanocrystalline Self‐Organized Biomorphs
Authors: Menichetti Arianna , Manzi Jeannette , Otálora Fermín , Montalti Marco , García‐Ruiz Juan Manuel
Published: June 2024

Inorganic–inorganic self‐organized composite architectures resulting from the chemical coupling of alkaline‐earth carbonate and polymeric silica are a promising alternative to organic‐based hybrid bio‐mimetic systems for developing innovative multi‐functional materials. Although the importance of pH in the generation of these structures reminiscent of primitive living organisms (and for this called biomorphs) is widely acknowledged, the effect of pH is generally investigated on the basis of starting pH value. This approach inadvertently neglects the important spatial and temporal pH gradients associated with biomorph nucleation and growth. A deep understanding of the role of pH on morphogenesis requires the ability to detect locally the pH in real‐time with a non‐invasive technique and correlate pH to the different stages of biomorphic growth. This aim is achieved by combining optical and fluorescence imaging. An accurately selected pH probe suitable for ratiometric pH measurement in the silica gel is exploited during a typical counter‐diffusion experiment. The results are compared with computer simulation of the synthesis of biomorphs by counter‐diffusion experiments. The results demonstrate the existence of two main morphogenetic regimes. Interestingly, the morphogenetic process controlling the complex shaping of biomorphs results to be independent of the silica speciation.
Electrocatalytic CO2 Reduction to Alcohols: Progress and Perspectives
Authors: Long Ying , Chen Zhijie , Wu Lan , Liu Xiaoqing , Hou Ya‐Nan , Vernuccio Sergio , Wei Wei , Wong Wai‐Yeung , Ni Bing‐Jie
Published: June 2024

Utilizing renewable electricity for the electrocatalytic conversion of CO2 into alcohols represents a promising avenue for generating value‐added fuels and achieving carbon neutrality. Recently, there has been growing scientific interest in achieving high‐efficiency conversion of CO2 to alcohols, with significant advancements made in mechanism understanding, reactor design, catalyst development, and more. Herein, a thorough examination of the latest advances in electrocatalytic CO2 reduction reaction (CO2RR) to alcohols is provided. General mechanisms and pathways of electrocatalytic conversion of CO2‐to‐alcohols are systematically illustrated. Subsequently, electrolyzer configurations, electrolytes, and electrocatalysts employed in CO2RR are summarized. After that, critical operating parameters (e.g., reaction pressure, temperature, and pH) that would significantly influence the CO2RR process are also analyzed. Finally, the review addresses challenges and offers perspectives in this field to guide future studies aimed at advancing CO2‐to‐alcohols conversion technologies.
Design and Characterization of a 53.5% Efficient Gallium Indium Phosphide‐Based Optical Photovoltaic Converter under 637 nm Laser Irradiation at 10 W cm−2
Authors: Sanmartín Pablo , Fernández Eduardo F. , García‐Loureiro Antonio , Montes‐Romero Jesús , Cano Aitana , Martín Pablo , Rey‐Stolle Ignacio , García Iván , Almonacid Florencia
Published: June 2024

High‐power optical transmission (HPOT) technology has emerged as a promising alternative among far‐field wireless power transmission approaches, enabling the transfer of kilowatts of power over kilometer‐scale distances. Its exceptional adaptability allows operation in challenging scenarios where traditional electrical wiring is impractical or unfeasible, thereby opening up a vast array of potential applications previously considered utopian. An important pending assignment in enhancing the performance of laser‐based HPOT systems is achieving efficient photovoltaic conversion of high power densities (≥10 W cm−2). In this sense, there is a pressing need for the advancement of optical photovoltaic converters (OPCs) capable of enduring intense monochromatic irradiances. This work presents the design optimization, manufacturing, and characterization processes of a gallium indium phosphide (GaInP)‐based OPC under varying 637 nm laser power at room temperature. In addition, methods to evaluate the impact of temperature on performance are provided. The findings reveal a maximum efficiency of 53.5% at 10 W cm−2, surpassing literature results for GaInP converters by over 9%abs at those light intensities. Remarkably, this device withstands unmatched irradiances within GaInP OPCs up to 60 W cm−2, maintaining 42.3% efficiency. This study aims to push forward the development of wide‐bandgap power converters with recordbreaking efficiencies paving the way for new applications.
Large and Small Polarons in Highly Efficient and Stable Organic‐Inorganic Lead Halide Perovskite Solar Cells: A Review
Authors: Nandi Pronoy , Shin Sooun , Park Hyoungmin , In Yongjae , Amornkitbamrung Urasawadee , Jeong Hyeon Jun , Kwon Seok Joon , Shin Hyunjung
Published: June 2024

Polarons, which arise from the intricate interplay between excess electrons and/or holes and lattice vibrations (phonons), represent quasiparticles pivotal to the electronic behavior of materials. This review reaffirms the established classification of small and large polarons, emphasizing its relevance in the context of recent advances in understanding lead halide perovskites' behavior. The distinct characteristics of large and small polarons stem from the electron–phonon interaction range, which exerts a profound influence on materials’ characteristics and functionalities. Concurrently, lead halides have emerged with exceptional opto‐electronic properties, featuring prolonged carrier lifetimes, low recombination rates, high defect tolerance, and moderate charge carrier mobilities; these characteristics make them a compelling contender for integration of optoelectronic devices. In this review, the formation of both small and large polarons within the lattice of lead halide perovskites, elucidating their role in protecting photogenerated charge carriers from recombination processes, is discussed. As optoelectronic devices continue to advance, this review underscores the importance of unraveling polaron dynamics to pave the way for innovative strategies for enhancing the performance of next‐generation photovoltaic technologies. Future research should explore novel polaronic effects using advanced computational and experimental techniques, enhancing our understanding and unlocking new applications in materials science and device engineering.
Thermodynamic Discussion on the Influence of the Magnesium Addition and Temperature on the Oxygen Potential in the Cast Irons
Authors: Matsushita Taishi , Ekengård Johan , Diószegi Attila
Published: June 2024

The primary objective of this study is to explore the impact of temperature and magnesium addition on the partial oxygen potential in lamellar, compacted, and spheroidal cast irons during the cooling process. The oxygen potential is assessed in large‐scale plant trials with a 1000 kg scale. Thermodynamic calculations are conducted, and the results are compared with the experimental values. There is a reasonable agreement between the experimental and calculated values, facilitating the prediction of oxygen potential in temperature ranges where measurements are challenging. According to the thermodynamic calculations, it is observed that varying amounts of added magnesium result in the formation of different types of inclusions during cooling. This, in turn, influences the temperature dependency of the oxygen potential in the molten metal.
The role of nonlocality on low and high frequency behaviors of functionally graded sandwich nanoplates
Authors: Ghazwani Mofareh Hassan , Alnujaie Ali , Eltaher Mohamed A. , Van Vinh Pham
Published: June 2024

The role of nonlocality on low and high frequency behaviors and modes of the functionally graded (FG) sandwich nanoplates is investigated in this study for the first time using simple nonlocal higher‐order shear deformation theory (HSDT). The simple HSDT consists of only four unknowns in its equation of the displacement field. The nonlocal elasticity theory is used to consider the small‐scale effects on the behaviors of the nanoplates. The governing equations of motion are established by applying Hamilton's principle, then Navier's solution technique is employed to solve these equations to achieve the free vibration behaviors of the FG sandwich nanoplates. The vibrations of the nanoplates under both low and high frequency conditions are investigated, but the high frequency vibration of the nanoplates is discussed extensively. The influences of the geometrical dimensions, material gradient index, and nonlocal parameter on the high frequency vibration of the FG nanoplates are also considered and discussed comprehensively.
Semilinear damped wave equations on the Heisenberg group with initial data from Sobolev spaces of negative order
Authors: Dasgupta Aparajita , Kumar Vishvesh , Mondal Shyam Swarup , Ruzhansky Michael
Published: June 2024

In this paper, we focus on studying the Cauchy problem for semilinear damped wave equations involving the sub-Laplacian $$\mathcal {L}$$
L
on the Heisenberg group $$\mathbb {H}^n$$

H

n

with power type nonlinearity $$|u|^p$$

|
u
|

p

and initial data taken from Sobolev spaces of negative order homogeneous Sobolev space $$\dot{H}^{-\gamma }_{\mathcal {L}}(\mathbb {H}^n), \gamma >0$$

H
˙

L

-
γ

(

H

n

)

,
γ
>
0

, on $$\mathbb {H}^n$$

H

n

. In particular, in the framework of Sobolev spaces of negative order, we prove that the critical exponent is the exponent $$p_{\text {crit}}(Q, \gamma )=1+\frac{4}{Q+2\gamma },$$

p
crit

(
Q
,
γ
)

=
1
+

4

Q
+
2
γ

,

for $$\gamma \in (0, \frac{Q}{2})$$

γ
∈
(
0
,

Q
2

)

, where $$Q:=2n+2$$

Q
:
=
2
n
+
2

is the homogeneous dimension of $$\mathbb {H}^n$$

H

n

. More precisely, we establish

A global-in-time existence of small data Sobolev solutions of lower regularity for $$p>p_{\text {crit}}(Q, \gamma )$$

p
>

p
crit

(
Q
,
γ
)

in the energy evolution space;

A finite time blow-up of weak solutions for $$1<p<p_{\text {crit}}(Q, \gamma )$$

1
<
p
<

p
crit

(
Q
,
γ
)

under certain conditions on the initial data by using the test function method.

Furthermore, to precisely characterize the blow-up time, we derive sharp upper bound and lower bound estimates for the lifespan in the subcritical case.
An inf-sup approach to $$C_0$$-semigroup generation for an interactive composite structure-Stokes PDE dynamics
Authors: Geredeli Pelin G.
Published: June 2024

In this work, we investigate the existence and uniqueness properties of a composite structure (multilayered)–fluid interaction PDE system which arises in multi-physics problems, and particularly in biofluidic applications related to the mammalian blood transportation process. The PDE system under consideration consists of the interactive coupling of 3D Stokes flow and 3D elastic dynamics which gives rise to an additional 2D elastic equation on the boundary interface between these 3D PDE systems. By means of a nonstandard mixed variational formulation, we show that the PDE system generates a $$C_0$$

C
0

-semigroup on the associated finite energy space of data. In this work, the presence of the pressure term in the 3D Stokes equation adds a great challenge to our analysis. To overcome this difficulty, we follow a methodology which is based on the necessarily non-Leray-based elimination of the associated pressure term, via appropriate nonlocal operators. Moreover, while we express the fluid solution variable via decoupling of the Stokes equation, we construct the elastic solution variables by solving a mixed variational formulation via a Babuska–Brezzi approach.
The necroptosis cell death pathway drives neurodegeneration in Alzheimer’s disease
Authors: Balusu Sriram , De Strooper Bart
Published: June 2024

Although apoptosis, pyroptosis, and ferroptosis have been implicated in AD, none fully explains the extensive neuronal loss observed in AD brains. Recent evidence shows that necroptosis is abundant in AD, that necroptosis is closely linked to the appearance of Tau pathology, and that necroptosis markers accumulate in granulovacuolar neurodegeneration vesicles (GVD). We review here the neuron-specific activation of the granulovacuolar mediated neuronal-necroptosis pathway, the potential AD-relevant triggers upstream of this pathway, and the interaction of the necrosome with the endo-lysosomal pathway, possibly providing links to Tau pathology. In addition, we underscore the therapeutic potential of inhibiting necroptosis in neurodegenerative diseases such as AD, as this presents a novel avenue for drug development targeting neuronal loss to preserve cognitive abilities. Such an approach seems particularly relevant when combined with amyloid-lowering drugs.
Repeated cognitive assessments show stable function over time in patients with ALS
Authors: Öijerstedt Linn , Foucher Juliette , Lovik Anikó , Yazdani Solmaz , Juto Alexander , Kläppe Ulf , Fang Fang , Ingre Caroline
Published: June 2024

Background

Amyotrophic lateral sclerosis (ALS) is a multisystem disorder with not only motor symptoms but also extra-motor features including cognitive impairment. The most common cognitive profile observed in patients with ALS includes deficits in executive function, language, and social cognition. However, longitudinal studies on cognitive changes over time in ALS are sparse. We aimed to investigate the presence and nature of cognitive impairment at the time of ALS diagnosis and its association with survival as well as explore longitudinal cognitive change.

Method

Patients (n = 216) were recruited at the Karolinska University Hospital in Stockholm, Sweden. Follow-up visits (n = 307 in total) were performed every 6 months. Cognitive impairment was assessed using the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and/or Montreal Cognitive Assessment (MoCA).

Results

Cognitive impairment was observed in 38% of the patients at the time of ALS diagnosis, and the majority of these patients had deficits in executive function and/or language. Patients with cognitive impairment at the time of diagnosis had a more rapid decline in ALSFRS-R at 12- and 18-months follow-up, and a shorter survival. Cognitive function was stable during the first 2 years after diagnosis, and did not follow the trajectories of decline in motor functions.

Conclusion

Cognitive impairment in ALS was associated with a faster decline of motor functions, and shorter survival. However, cognitive function did not deteriorate over time. Cognitive assessment is essential for the patients and caregivers to understand the phenotypic expression of ALS.
Cultivation modes affect the morphology, biochemical composition, and antioxidant and anti-inflammatory properties of the green microalga Neochloris oleoabundans
Authors: Baldisserotto C. , Gessi S. , Ferraretto E. , Merighi S. , Ardondi L. , Giacò P. , Ferroni L. , Nigro M. , Travagli A. , Pancaldi S.
Published: June 2024

Microalgae are considered promising sustainable sources of natural bioactive compounds to be used in biotechnological sectors. In recent years, attention is increasingly given to the search of microalgae-derived compounds with antioxidant and anti-inflammatory properties for nutraceutical or pharmacological issues. In this context, attention is usually focused on the composition and bioactivity of algae or their extracts, while less interest is driven to their biological features, for example, those related to morphology and cultivation conditions. In addition, specific studies on the antioxidant and anti-inflammatory properties of microalgae mainly concern Chlorella or Spirulina. The present work was focused on the characterization of the Chlorophyta Neochloris oleoabundans under two combinations of cultivation modes: autotrophy and glucose-induced mixotrophy, each followed by starvation. Biomass for morphological and biochemical characterization, as well as for extract preparation, was harvested at the end of each cultivation phase. Analyses indicated a different content of the most important classes of bioactive compounds with antioxidant/anti-inflammatory properties (lipids, exo-polysaccharides, pigments, total phenolics, and proteins). In particular, the most promising condition able to prompt the production of antioxidant algal biomass with anti-inflammatory properties was the mixotrophic one. Under mixotrophy, beside an elevated algal biomass production, a strong photosynthetic metabolism with high appression of thylakoid membranes and characteristics of high photo-protection from oxidative damage was observed and linked to the overproduction of exo-polysaccharides and lipids rather than pigments. Overall, mixotrophy appears a good choice to produce natural bioactive extracts, potentially well tolerated by human metabolism and environmentally sustainable.