bluuebunny/crossref_metadata_2025 huggingface dataset:
Last Advances on Hydrogel Nanoparticles Composites in Medicine: An Overview with Focus on Gold Nanoparticles
Authors: Molinelli Alessandro , Schirato Andrea , Moretti Luca , Della Valle Giuseppe , Maiuri Margherita , Rossi Filippo
Published: March 2024

Hydrogel nanocomposites have lately taken part in the biomaterials scenario for several applications in the biomedical field, e. g., drug delivery, biosensing and cancer therapy. The inclusion of a broad variety of nanomaterials inside the hydrogel matrix leads to the successful development of hybrid platforms with superior and advantageous features. In this way, finely designed nano‐systems can be obtained, which are able to overcome the intrinsic limitations of conventional hydrogels, such as weak mechanical properties, burst drug delivery, extremely high hydrophilicity and lack of multifunctionality. This review aims to outline the last advances in the manufacturing of nanocomposite systems and their novel applications to the biomedical field, providing an overview of the most used nanoparticles with a special focus on gold nanoparticles.
Probing the Dynamic Landscape: From Static to Time‐Resolved X‐Ray Absorption Spectroscopy to Investigate Copper Redox Chemistry in Neurodegenerative Disorders
Authors: De Santis Emiliano , Alleva Stefania , Minicozzi Velia , Morante Silvia , Stellato Francesco
Published: March 2024

Copper (Cu), with its ability to exist in various oxidation states, notably Cu(I) and Cu(II), plays a crucial role in diverse biological redox reactions. This includes its involvement in pathways associated with oxidative stress in neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and Transmissible Spongiform Encephalopathies. This paper offers an overview of X‐ray Absorption Spectroscopy (XAS) studies designed to elucidate the interactions between Cu ions and proteins or peptides associated with these neurodegenerative diseases. The emphasis lies on XAS specificity, revealing the local coordination environment, and on its sensitivity to Cu oxidation states. Furthermore, the paper focuses on XAS applications targeting the characterization of intermediate reaction states and explores the opportunities arising from recent advancements in time‐resolved XAS at ultrabright synchrotron and Free Electron Laser radiation sources.
Perylene Diimide‐Based Dimeric Electron Acceptors with Molecular Conformations for Perovskite Solar Cells
Authors: Saltan Gözde Murat , Yeşil Tamer , Ötken Aysun Albayrak , Zafer Ceylan , Dinçalp Haluk
Published: March 2024

This paper reports five novel PDI dimer type electron transport materials (ETMs) employing o‐indoloquinoxaline (o‐Iq), m‐indoloquinoxaline (m‐Iq), and cibalackrot (Ci) groups as the core building blocks and presents the twisted structures of PDI dimers coded as PDI‐NHR‐o‐Iq, PDI‐o‐Iq, PDI‐NHR‐m‐Iq, PDI‐m‐Iq and PDI‐NHR‐Ci dyes (see Scheme 1 and 2). We have systematically compared their photophysical, electrochemical, and optoelectronic properties with respect to the reference dye (2PDI‐NHR), which is directly connected of two PDI planes. Their calculated HOMO‐LUMO energy levels are sufficient for charge transfer to the perovskite material so that structure‐photovoltaic performance relationship of synthesized ETM dyes can be evaluated. When the binding position of indoloquinoxaline group between PDI rings are changed from o‐ to m‐ positions, most of the photophysical and electrochemical properties of PDI dimer are dramatically changed, finally improving the photovoltaic performances.
Development and validation of a practical clinical risk prediction model for post‐endoscopic retrograde cholangiopancreatography pancreatitis
Authors: Meng Zhao Wu , Ruan Yibing , Fisher Stacey , Bishay Kirles , Chau Millie , Howarth Megan , Cartwright Shane , Chen Yen‐I , Dixon Elijah , Heitman Steven J. , Brenner Darren R. , Forbes Nauzer
Published: March 2024

Background

Pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP) can lead to significant morbidity and mortality. We aimed to develop an accurate post‐ERCP pancreatitis risk prediction model using easily obtainable variables.

Methods

Using prospective multi‐center ERCP data, we performed logistic regression using stepwise selection on several patient‐, procedure‐, and endoscopist‐related factors that were determined a priori. The final model was based on a combination of the Bayesian information criterion and Akaike's information criterion performance, balancing the inclusion of clinically relevant variables and model parsimony. All available data were used for model development, with subsequent internal validation performed on bootstrapped data using 10‐fold cross‐validation.

Results

Data from 3021 ERCPs were used to inform models. There were 151 cases of post‐ERCP pancreatitis (5.0% incidence). Variables included in the final model included female sex, pancreatic duct cannulation, native papilla status, pre‐cut sphincterotomy, increasing cannulation time, presence of biliary stricture, patient age, and placement of a pancreatic duct stent. The final model was discriminating, with a receiver operating characteristic curve statistic of 0.79, and well‐calibrated, with a predicted risk‐to‐observed risk ratio of 1.003.

Conclusions

We successfully developed and internally validated a promising post‐ERCP pancreatitis clinical prediction model using easily obtainable variables that are known at baseline or observed during the ERCP procedure. The model achieved an area under the curve of 0.79. External validation is planned as additional data becomes available.
An easily implemented single‐visit survey method for intermittently available and imperfectly detectable wildlife applied to the Florida east coast diamondback terrapin (Malaclemys terrapin tequesta)
Authors: Stolen Eric D. , Breininger David R. , Breininger Daniel J. , Breininger Robert D.
Published: March 2024

Single‐visit surveys of plots are often used for estimating the abundance of species of conservation concern. Less‐than‐perfect availability and detection of individuals can bias estimates if not properly accounted for. We developed field methods and a Bayesian model that accounts for availability and detection bias during single‐visit visual plot surveys. We used simulated data to test the accuracy of the method under a realistic range of generating parameters and applied the method to Florida's east coast diamondback terrapin in the Indian River Lagoon system, where they were formerly common but have declined in recent decades. Simulations demonstrated that the method produces unbiased abundance estimates under a wide range of conditions that can be expected to occur in such surveys. Using terrapins as an example we show how to include covariates and random effects to improve estimates and learn about species‐habitat relationships. Our method requires only counting individuals during short replicate surveys rather than keeping track of individual identity and is simple to implement in a variety of point count settings when individuals may be temporarily unavailable for observation. We provide examples in R and JAGS for implementing the model and to simulate and evaluate data to validate the application of the method under other study conditions.
On the distribution and habitat use of the sub‐Antarctic fly Hyadesimyia clausa Bigot (Diptera, Tachinidae) according to citizen science
Authors: Barahona‐Segovia Rodrigo M. , Mulieri Pablo R. , González Christian R. , Osorio Zúñiga Felipe , Pañinao‐Monsálvez Laura
Published: March 2024

Hyadesimyia clausa Bigot is a morphologically striking tachinid that inhabits the Sub‐Antarctic Ecoregion of the Magallanes Region in Chile and Tierra del Fuego province in Argentina. Much of the distributional information about this species is restricted to the Cape Horn islands, which have extreme environmental conditions, but the species' natural history, range limits, and habitat use have never been described or confirmed. Our goals were to describe the distributional limits of this sub‐Antarctic fly with the help of citizen science and use this information type to describe this tachinid's habitat use and potential biological interactions with nonvascular and vascular flora. We found that citizen science significantly increased our understanding of the extent of occurrence, expanding the known distributional range by 195 km to the north and 153 km to the west. On the contrary, the values for the area of occupancy were not significant, but the occupancy overlap between different records was very low. We confirmed that H. clausa's habitat uses peatlands and although we have not provided evidence of pollination or movement of spores, we hypothesized, that the walking activity of H. clausa could help move sperm from mosses and pollen from the flowers of vascular plants, so they could act as potential pollinators. Citizen science can reduce and eliminate some scientific knowledge shortfalls and propose new ecological questions that could increase our knowledge of extreme ecosystems.
Exchange Couplings and Magneto‐Structural Correlations of Trinuclear MII‐UIV‐MII (MII=Co, Ni, Cu) Complexes
Authors: Belkhiri Lotfi , Maurice Rémi , Le Guennic Boris , Boucekkine Abdou , Ephritikhine Michel
Published: March 2024

The magnetic properties of the trinuclear Schiff base complexes M2UL7 (MII=Co, Ni, Cu; L7=N,N’‐bis(3‐hydroxysalicylidene)‐2,2‐dimethyl‐1,3‐propanediamine), exhibiting the [M(μ‐O)2]2U core structure (3d‐5 f‐3d subsystem), have been investigated theoretically using scalar relativistic ZORA/DFT computations combined with the broken symmetry (BS) approach. The calculated coupling constants JMU between the adjacent M1−U and M2−U agree with the observed ferromagnetic (Ferro) character observed in the case of the Cu2UL7 complex, the antiferromagnetic (AF) character of the Ni2UL7 one is consistent with the experimentally observed AF behaviour for Co2UL7. The structural parameters, in particular the M−U distances and the M−Ob−U angles, as well as the electronic factors driving the superexchange couplings are discussed. The bond orders and the magnetic molecular orbital analyses reveal that the U(5 f) covalent contribution to the bonding within the M−O−U coordination is more important in the Co2UL7 and Ni2UL7 complexes than in the Cu2UL7 congener, thus favouring AF coupling between the transition metal and the uranium magnetic centers, in the first complexes. The analyses are supported by the study of the mixed ZnMUL7 and M2ThL7 systems, where the CoII (3d7) and NiII (3d8) paramagnetic ions are replaced by the diamagnetic ZnII(3d10) one, whereas in the second complex, the UIV(5f2) paramagnetic center is replaced by the diamagnetic ThIV(5f0) one. The Natural Populations Analyses confirm the crucial role of spin delocalization that is at work in favour of the AF vs. Ferro magnetic character of the M−U−M (M=Ni, Co) and Cu−U−Cu coordination, respectively.
Review of borehole thermal energy storage systems in unsaturated soils: Materials, mechanism, and future development
Authors: Zeng Shu , Cheng Xiaohui , Yang Jun
Published: March 2024

Borehole thermal energy storage (BTES) is an innovative renewable energy technology for building heating and cooling. The lack of studies about BTES in unsaturated soils acts as a barrier to further implementation. In this study, the research obstacles, progress, hotspots, and differences between countries of BTES systems in unsaturated soils were described in detail based on a literature review, bibliometric analysis, technology roadmap, and data visualizations. The results show that the process of coupled heat and moisture transfer has been a research hotspot in recent years, and the thermo‐hydraulic properties increase the complexity of analysis. There are few studies on experimental data and engineering practices of BTES systems in unsaturated soils. China is leading in publications number, but European and North American countries perform better in international cooperation and policy incentives. Technology development will be directly driven by policy momentum, followed by the gradual establishment of a complete research, design, and evaluation system, which helps accelerate the replacement of traditional fossil energy with renewable energy. In an attempt to improve society's awareness and move forward with scientific foresight of BTES systems in unsaturated soils, this review has revealed the evolutionary process, identified its current status, and depicted the future development from political, economic, social, and other dimensions.
Glycation reactions of methylglyoxal during digestion in a dynamic, in vitro model of the upper gastrointestinal tract (TIM‐1)
Authors: Treibmann Stephanie , Venema Koen , Henle Thomas
Published: March 2024

The 1,2‐dicarbonyl compound methylglyoxal (MGO) can react with and thereby impair the function of proteins and DNA, leading to pathophysiological pathways in vivo. However, studies on the bioavailability of dietary MGO and its reactions during digestion have diverging results. Therefore, simulated digestion experiments of MGO, protein, and creatine were performed in the dynamic, in vitro model of the upper gastrointestinal tract (TIM‐1). This multicompartment model continuously adjusts pH values and has realistic gastrointestinal transit times while also removing water and metabolites by dialysis. Samples were analyzed with HPLC‐UV for MGO and HPLC–MS/MS for creatine and glycated amino compounds. MGO reacted with creatine during simulated digestion in TIM‐1 to form the hydroimidazolone MG‐HCr in similar amounts as in a human intervention study. 28%–69% of MGO from the meal were passively absorbed in TIM‐1, depending on the addition of creatine and protein. Simultaneous digestion of MGO with ovalbumin led to the formation of the lysine adduct Nε‐carboxyethyllysine (CEL) and the methylglyoxal‐derived hydroimidazolone of arginine (MG‐H1). The formation of both compounds decreased with added creatine. Hence, glycation compounds are formed during digestion and significantly contribute to other ingested dietary glycation compounds, whose physiological consequences are critically discussed.
Blood biomarkers in dynamic prediction of conversion to Alzheimer's disease: An application of joint modeling
Authors: Yuan Manqiong , Lian Shuli , Li Xueru , Long Xianxian , Fang Ya ,   Alzheimer's Disease Neuroimaging Initiative (ADNI)
Published: March 2024

Objectives

To investigate the accuracy of longitudinal trajectories of blood biomarkers for predicting future onset of AD among MCI participants as well as to demonstrate dynamic prediction of the individual conversion risk applying joint modeling.

Methods

A total of 446 participants with MCI at baseline from the Alzheimer's Disease Neuroimaging Initiative database were included. We introduced joint modeling to analyze the effects of the longitudinal blood biomarkers on the conversion risk to AD, and further to build individual‐specific prediction risk model.

Results

During the follow‐up, 345 participants remained with MCI and 101 progressed to AD, and were categorized as non‐progression and progression group, respectively. Longitudinally, the positive association of the concentration dynamics of plasma p‐tau181 and NfL with the conversion risk to AD from MCI was also demonstrated, with Hazard Ratio (HR) = 5.83 and HR = 4.18, respectively. When incorporating plasma p‐tau181 and NfL together to predict AD progression, we observed improved performance (AUC = 0.701, Brier Score = 0.119). Two participants were chosen to exemplify the individual‐specific risk prediction at different follow‐up time for comparative analysis.

Conclusions

Plasma p‐tau181 and NfL could serve as biomarkers for the prediction of AD onset, and the individualized prediction opens up the possibility to provide clinical information at a personal level.
High expression of ACTL6A leads to poor prognosis of oral squamous cell carcinoma patients through promoting malignant progression
Authors: Liu Yi , Liu Yisha , Li Ying , Wang Tong , Li Bolong , Kong Xianchen , Li Changyi
Published: March 2024

Objective

The aim was to research ACTL6A's role in oral squamous cell carcinoma (OSCC).

Methods

OSCC and normal samples were obtained from patients and public databases. GSEA was performed. CIBERSORT was utilized to analyze immune landscape. Kaplan–Meier survival analysis and multivariate Cox regression analysis were conducted. After knocking down ACTL6A, we performed MTT assay, transwell assays, and flow cytometry to detect the impact of knockdown.

Results

ACTL6A expressed higher in OSCC samples than normal samples. The CNV and mutation rate of TP53 was higher in ACTL6A high‐expression group. TFs E2F7 and TP63 and miRNA hsa‐mir‐381 were significantly related to ACTL6A. ACTL6A could influence immune microenvironment of OSCC. Knockdown of ACTL6A inhibited OSCC cells' proliferation, migration, and invasion. ACTL6A was able to predict OSCC prognosis independently.

Conclusion

ACTL6A expressed higher in OSCC than normal samples and it could be used as an independent prognostic marker in OSCC patients.
Impact of soil compaction and irrigation practices on salt dynamics in the presence of a saline shallow groundwater: An experimental and modelling study
Authors: Nick Sina Maghami , Copty Nadim K. , Saygın Selen Deviren , Öztürk Hasan Sabri , Demirel Burak , Emadian S. Mehdi , Erpul Günay , Sedighi Majid , Babaei Masoud
Published: March 2024

Soil salt accumulation is a widespread problem leading to diminished crop yield and threatening food security in many regions of the world. The soil salinization problem is particularly acute in areas that lack adequate soil water drainage and where a saline shallow water table (WT) is present. In this study, we present laboratory‐scale column experiments, extending over a period of more than 400 days that focus on the processes contributing to soil salinization. We specifically examine the combined impact of soil compaction, surface water application model and water quality on salt dynamics in the presence of a saline shallow WT. The soil columns (60 cm height and 16 cm diameter) were packed with an agricultural soil with bulk densities of 1.15 and 1.34 g/cm−3 for uncompacted and compacted layers, respectively, and automatically monitored for water content, salinity and pressure. Two surface water compositions are considered: fresh (deionized, DI) and saline water (~3.4 mS/cm). To assess the sensitivity of compaction on salt dynamics, the experiments were numerically modelled with the HYDRUS‐1D computer program. The results show that the saline WT led to rapid salinization of the soil column due to capillarity, with the salinity reaching levels much higher than that at the WT. However, compaction layer provided a barrier that limited the downwards moisture percolation and solute transport. Furthermore, the numerical simulations showed that the application of freshwater can temporarily reverse the accumulation of salts in agricultural soils. This irrigation strategy can help, in the short‐term, alleviate soil salinization problem. The soil hydraulic properties, WT depth, water quality, evaporation demand and the availability of freshwater all play a role in the practicability of such short‐term solutions. The presence of a saline shallow WT would, however, rapidly reverse these temporary measures, leading to the recurrence of topsoil salinization.
Optimization of sprinkler irrigation scheduling scenarios for reducing irrigation energy consumption
Authors: Pang Yiyuan , Tang Pan , Li Hong , Marinello Francesco , Chen Chao
Published: March 2024

In recent years, traditional sprinkler irrigation scheduling scenarios have no longer been applicable to modern agriculture because of the increase in energy prices and the rapid development of smart agriculture. This paper proposes a new irrigation scheduling scenario in which a sprinkler is used as the minimum optimization unit for sectoring design. The main challenge of the proposed approach lies in obtaining the most energy‐efficient sectoring and pump operating frequencies, and the high complexity of the optimization problem requires considerable computational effort. To compare the irrigation performance before and after optimization, seven scheduling scenarios are established to analyse the performance of the unified control method, branch scheduling method and sprinkler scheduling method. Through numerical calculations and experimental verification, it was found that sprinkler scheduling can not only meet the pressure requirements of sprinklers without using pressure‐regulating valves but also minimize energy consumption. Compared with optimal branch pipe scheduling, optimal sprinkler scheduling can reduce the sprinkler pressure variance from 792 to 180 kPa2 and reduce the irrigation cost by approximately 18%. In addition, by analysing the uniformity coefficient and distribution uniformity under different scenarios, it was found that sprinkler scheduling optimization does not substantially improve irrigation uniformity.
Lessons contemporary counselors can learn from the exploratory therapies
Authors: Hansen James T.
Published: March 2024

The history of talk therapy is characterized by ideological trends rather than incremental progress. When a new trend is ascendant, insights from prior eras may be forgotten or lost. Currently, counseling is arguably dominated by an ideology of symptom reduction. Therefore, insights from the prior exploratory phase of talk therapy may be difficult for modern practitioners to access. I discuss eight important lessons that contemporary counselors can learn from exploratory therapies.
Music therapy for therapeutic development in personality disorders: A qualitative case study
Authors: van Sprang Irene , Haeyen Suzanne
Published: March 2024

People with personality disorders (PDs) are often difficult to reach emotionally in therapy. As music therapy (MT) provides an entry point to emotions and facilitates contact and communication, it is regularly used with this target group. This study presents a case study of a 40‐year‐old woman diagnosed with a PD not otherwise defined. “Nina” experienced depressive and physical symptoms, including severe anxiety. Previous treatments had failed. In MT, she experienced a sense of safety. Over the course of the treatment, she experimented with making herself heard, learned to listen to herself and recognize her own physical signals, permitted closeness and cooperation, and began setting boundaries and taking initiative. She got in touch with and learned to regulate emotions such as sadness and fear. Self‐criticism gave way to a more compassionate self. Nina began to experience positive feelings and showed progress in her work and social interactions. The findings suggest that MT can directly connect to clients' emotions, behaviors, and thoughts in a way they perceive as safe. This is of the utmost importance for clients who are hard to reach. The use of MT can potentially prevent dropout and further entrapment in personality problems.
The impact of a prophylactic skin dressing on surface‐guided patient positioning in chest wall Radiation Therapy
Authors: Cumming James , Thompson Kenton , Woodford Katrina , Panettieri Vanessa , Sapkaroski Daniel
Published: March 2024

Introduction

Surface‐guided radiation therapy (SGRT) has emerged as a powerful tool to improve patient setup accuracy in radiation therapy (RT). Combined with the goal of increasing RT accuracy is an ongoing effort to decrease RT side effects. The application of a prophylactic skin dressing to the treatment site is a well‐documented method of reducing skin‐related side effects from RT. This paper aims to investigate whether the application of Mepitel, a prophylactic skin dressing, has an impact on the accuracy of surface‐guided patient setups in chest wall RT.

Methods

A retrospective analysis of daily image‐guided Online Corrections (OLCs) from patients undergoing chest wall irradiation with SGRT was performed. Translational (superior–inferior, lateral, and anterior–posterior) OLC magnitude and direction were compared between patients treated with Mepitel applied and those treated without. Systematic and random errors were calculated and compared between groups.

Results

OLCs from 275 fractions were analysed. Mean OLCs were larger for patients with Mepitel applied in the superior_inferior axis (0.34 vs. 0.22 cm, P = 0.049) and for the combined translational vector (0.54 vs. 0.43 cm, P = 0.043). Combined translational systematic error was slightly larger for patients with Mepitel applied (0.15 vs. 0.09 cm).

Conclusion

Mepitel can impact the accuracy of SGRT patient‐positioning in chest wall RT. The variation however is small and unlikely to have any clinical impact if SGRT is coupled with image guidance and appropriate PTV margins. Further investigation is required to assess the effect of Mepitel on SGRT accuracy in other treatment sites, as well as any potential dosimetric impacts.
A fluorescence detection method for postharvest tomato epidermal defects based on improved YOLOv5m
Authors: Huang Yuhua , Xiong Juntao , Yao Zhaoshen , Huang Qiyin , Tang Kun , Jiang Dandan , Yang Zhengang
Published: March 2024

BACKGROUND

Tomato quality visual grading is greatly affected by the problems of smooth skin, uneven illumination and invisible defects that are difficult to identify. The realization of intelligent detection of postharvest epidermal defects is conducive to further improving the economic value of postharvest tomatoes.

RESULTS

An image acquisition device that utilizes fluorescence technology has been designed to capture a dataset of tomato skin defects, encompassing categories such as rot defects, crack defects and imperceptible defects. The YOLOv5m model was improved by introducing Convolutional Block Attention Module and replacing part of the convolution kernels in the backbone network with Switchable Atrous Convolution. The results of comparison experiments and ablation experiments show that the Precision, Recall and mean Average Precision of the improved YOLOv5m model were 89.93%, 82.33% and 87.57%, which are higher than YOLOv5m, Faster R‐CNN and YOLOv7, and the average detection time was reduced by 47.04 ms picture−1.

CONCLUSION

The present study utilizes fluorescence imaging and an improved YOLOv5m model to detect tomato epidermal defects, resulting in better identification of imperceptible defects and detection of multiple categories of defects. This provides strong technical support for intelligent detection and quality grading of tomatoes. © 2024 Society of Chemical Industry.
Phytic Acid, Protein, and Oil Contents and Their Relationship With Seed Quality During Seed Maturation of Bambara Nut (Vigna subterranea (L.) Verdc.) Landraces
Authors: Oballim Gerard , Opile Wilson R. , Ochuodho Julius O.
Published: March 2024

Phytic acid, proteins, and oils are seed storage compounds that play a role in germination and seedling growth and may determine seed quality. The pattern of accumulation of these compounds and the relationship of their contents with the seed quality of the Bambara nut (BN) are poorly understood. Seeds of three BN landraces, AbiBam001 (black/cream), LocalBam (brown speckled), and TVSU544 (cream), were harvested from two field experiments at different maturation stages and tested for final germination percentage (FGP), germination velocity index (GVI), and seedling dry weight (SDW). Seed samples from the same experiments were analyzed for phytic acid and proximate composition. Kendall's ranked correlation was used to describe relationships between phytic acid, protein, and oil contents and the seed quality of the landraces. Results showed no differences in the phytate, protein, and oil contents of landraces during seed maturation (p > 0.05), except for the phytate content of AbiBam001 (p < 0.05), which increased in the first experiment. At mass maturity, AbiBam001 and LocalBam had higher phytate and less protein and oil contents than TVSU544, implying that seed coat color may influence the phytate, protein, and oil contents of BN landraces. Higher phytate content in landraces appeared to relate positively with FGP, GVI, and SDW and vice versa. Phytic acid may positively affect seed germinability in BN landraces with high phytate content but may affect it negatively in low‐phytate landraces. The oil content of all landraces had negative correlations with most seed quality characteristics, suggesting that BN oils either are not priority reserves or play a minimal role in germination and seedling growth.
A vendor‐neutral EPI sequence for hyperpolarized 13C MRI
Authors: Blazey Tyler , Shaw Ashley , von Morze Cornelius
Published: March 2024

Purpose

To develop a flexible, vendor‐neutral EPI sequence for hyperpolarized 13C metabolic imaging.

Methods

An open‐source EPI sequence consisting of a metabolite‐specific spectral‐spatial RF excitation pulse and a customizable EPI readout was created using the Pulseq framework. To explore the flexibility of our sequence, we tested several versions of the sequence including a symmetric 3D readout with different spatial resolutions for each metabolite (1.0 cm3 and 1.5 cm3). A multichamber phantom constructed with a Shepp‐Logan geometry, containing two chambers filled with either natural abundance 13C compounds or hyperpolarized (HP) [1–13C]pyruvate, was used to test each sequence. For experiments involving HP [1–13C]pyruvate, a single chamber was prefilled with nicotinamide adenine dinucleotide hydride and lactate dehydrogenase to facilitate the conversion of [1–13C]pyruvate to [1–13C]lactate. All experiments were performed on a Siemens Prisma 3T scanner.

Results

All the sequence variations localized natural‐abundance 13C ethylene glycol and methanol to the appropriate compartment of the multichamber phantom. [1–13C]pyruvate was detectable in both chambers following the injection of HP [1–13C]pyruvate, whereas [1–13C]lactate was only found in the chamber containing nicotinamide adenine dinucleotide hydride and lactate dehydrogenase. The conversion rate from [1–13C]pyruvate to [1–13C]lactate (kPL) was 0.01 s−1 (95% confidence interval [0.00, 0.02]).

Conclusion

We have developed and tested a vendor‐neutral EPI sequence for imaging HP 13C agents. We have made all of our sequence creation and image reconstruction code freely available online for other investigators to use.
A review of self‐supervised, generative, and few‐shot deep learning methods for data‐limited magnetic resonance imaging segmentation
Authors: Liu Zelong , Kainth Komal , Zhou Alexander , Deyer Timothy W. , Fayad Zahi A. , Greenspan Hayit , Mei Xueyan
Published: March 2024

Magnetic resonance imaging (MRI) is a ubiquitous medical imaging technology with applications in disease diagnostics, intervention, and treatment planning. Accurate MRI segmentation is critical for diagnosing abnormalities, monitoring diseases, and deciding on a course of treatment. With the advent of advanced deep learning frameworks, fully automated and accurate MRI segmentation is advancing. Traditional supervised deep learning techniques have advanced tremendously, reaching clinical‐level accuracy in the field of segmentation. However, these algorithms still require a large amount of annotated data, which is oftentimes unavailable or impractical. One way to circumvent this issue is to utilize algorithms that exploit a limited amount of labeled data. This paper aims to review such state‐of‐the‐art algorithms that use a limited number of annotated samples. We explain the fundamental principles of self‐supervised learning, generative models, few‐shot learning, and semi‐supervised learning and summarize their applications in cardiac, abdomen, and brain MRI segmentation. Throughout this review, we highlight algorithms that can be employed based on the quantity of annotated data available. We also present a comprehensive list of notable publicly available MRI segmentation datasets. To conclude, we discuss possible future directions of the field—including emerging algorithms, such as contrastive language‐image pretraining, and potential combinations across the methods discussed—that can further increase the efficacy of image segmentation with limited labels.
Optimization of electromagnetic absorption properties based on graphene, carbon nanotubes, and Fe3O4 multidimensional composites
Authors: Pang Xianke , Zhou Xinghai , Gao Yuan , Qian Yongfang , Lyu Lihua
Published: March 2024

Excellent electromagnetic wave loss and impedance matching are typical characteristics of superior‐performance electromagnetic wave (EMW) absorption materials. Changing the component ratios and multidimensional combinations of various absorbing materials is one of the best methods to improve absorption performance. This work used a convenient physical mixing approach to combine three wave‐absorbing materials with various dimensions to successfully prepare Graphene/carbon nanotubes/Fe3O4 (G/C/Fe3O4)/paraffin composites. One‐dimensional (1D) tube carbon nanotubes (CNTs) pierced two‐dimensional (2D) sheet graphene to form a strong three‐dimensional (3D) conductive network, enhancing interfacial polarization without introducing zero‐dimensional (0D) magnetic Nano‐Fe3O4. Nevertheless, because of their significant dielectric characteristics, the graphene/carbon nanotube (G/C) paraffin composites displayed low impedance matching and electromagnetic wave absorption properties. At a mass ratio of 1:1, the G/C/paraffin composites achieved an ideal reflection loss (RL) of −11.99 db and an impedance matching value of 0.59. Adding Fe3O4 improved the impedance matching and electromagnetic wave loss performance and promoted the formation of a non‐homogeneous interface, improving interfacial polarization and reflection. The G/C/Fe3O4/paraffin composite, with a mass ratio of 1:1:6 and a filler ratio of 20%, achieved an optimum reflection loss of −37.2 dB and an effective absorption bandwidth of 4.16 GHz. This work optimized and improved the performance of EMW materials practically and rapidly, providing a research method for the widespread application of superior‐performance electromagnetic wave absorption materials.

Highlights

The EMW absorption materials with various architectures.

1D CNTs pierced 2D sheet graphene to form a strong 3D conductive network.

Adding Fe3O4 promoted the formation of a non‐homogeneous interface.

Electromagnetic synergies and different structural combinations

It achieved excellent impedance matching and electromagnetic loss performance.
Cooling Performance of a Novel Ventilated Slope on Railbed in Permafrost Regions
Authors: Zhang Zhenyu , Wen Zhi , Liu Youqian , Wang Xinbin , Lu Jinxin , Chen Kun , Zhang Delong , Yu Qihao
Published: March 2024

The heat absorption of the railbed mainly originates from the embankment slope in permafrost regions. A novel ventilated slope (NVS) with a double‐layer convection channel is proposed and verified. By applying this method to the Qinghai–Tibet Railway (QTR), the annual average temperature at the 10 cm depth below the embankment slope surface under NVS was reduced by 4.95°C. The freezing index at the 10 cm depth of NVS was 1.78 times higher than that of the slope without any cooling approaches. The numerical simulation results showed that heat was accumulated for the conventional embankment, while heat was released from the railbed after the application of NVS. With the cooling effect of NVS, the 0°C isotherm would rise above the original natural ground surface in the 2nd year after the embankment construction. A low‐temperature region of −2°C would be observed in the underlying permafrost by the 10th year. The underlying permafrost would remain frozen in the 50th year. This study provides a novel method for protecting the underlying permafrost in permafrost regions.
A First‐Principles Investigation of Monolayer MoS2 Doped with Mn and V as an Excellent NO2 Sensor with High Selectivity
Authors: Tian Lei , Hu Jiahuan , He Chengyu , Ling Fei
Published: March 2024

This article conducts a comprehensive investigation into the adsorption properties of both pristine MoS2 monolayers and those doped with Mn and V, wherein these dopants replace Mo atoms. By the first‐principles calculations, the research reveals a noteworthy reduction in the adsorption energy of NO2 on Mn‐doped and V‐doped MoS2 monolayers compared to pure MoS2 monolayers. Specifically, at the most favorable adsorption site, the adsorption energy decreases from −5.83 to 5.908 eV for Mn‐doped MoS2 and from −5.58 to −6.17 eV for V‐doped MoS2. Furthermore, computations of the band structure, work function, and charge density difference highlight a significant degree of charge transfer and coexistence of electrons within these systems. Additionally, post‐adsorption of NO2 molecules, a distinct shift in the density of states (DOS) toward lower energy states is observed at the adsorption sites of both MoS2/Mn and MoS2/V monolayers, underscoring their exceptional sensitivity in detecting NO2. In summary, these results demonstrate the substantial potential of Mn‐doped and V‐doped MoS2 monolayers as highly sensitive materials for NO2 detection. Their lower adsorption energies and noteworthy shifts in DOS following NO2 adsorption enhance their capabilities as NO2 sensors.
Utilizing medical thoracoscopy for the diagnosis of myelomatous pleural effusion: 2 case reports
Authors: Ng Khai Lip , Tan Sin Nee , Huan Nai‐Chien , Nasaruddin Mona Zaria , Othman Noriah , Rahaman Jamalul Azizi Abdul
Published: March 2024

Multiple myeloma (MM) is characterized by neoplastic proliferation of monoclonal antibody producing plasma cells. In clinical practice, pleural effusion is seen in up to 6% of MM patients, with many causative factors. Nevertheless, true myelomatous pleural effusion, defined as infiltration of the pleura by myeloma cells, is very rare. In this case report, we present two patients with biopsy proven myelomatous pleural effusion. The first patient developed myelomatous pleural effusion as initial presentation while the second patient's pleural effusion occurred during disease relapse. In both cases, prompt diagnosis via medical thoracoscopy (MT) followed by early commencement of myeloma specific chemotherapy led to clinical, biochemical, and radiological resolution and therefore were crucial steps in the management of myelomatous pleural effusion.
CBF‐guided iterative learning control performance optimization for switched systems
Authors: Lu Xuanhe , Qi Yiwen , Qu Ziyu , Guo Shitong
Published: March 2024

This article studies the control barrier function (CBF) guided tracking performance optimization for switched systems under iterative learning control (ILC). CBF is an effective method for handling control system state safety. If the safe set is designed as expected performance, and the unsafe set is not expected, then this may be a good choice for optimizing control system performance. We propose a tracking performance optimization method based on CBF to speed up the convergence of the tracking error. A safe set is used to describe the expected tracking performance, by utilizing CBF, safety is further transformed into a set of inequality conditions that constrain ILC controller gains, which ensures that the tracking error is always within the safe set. In addition, an event‐triggering mechanism (ETM) is considered to reduce unnecessary data transmission, and sufficient conditions for exponential stability of the tracking error of switched systems and ILC controllers design are obtained. Finally, a simulation example is given to verify the feasibility of the proposed method.
Physical‐layer security enhancement in wireless sensor networks through artificial noise optimization
Authors: Qasem Asmaa Amer , Shokair Mona , Abd El‐Samie Fathi E.
Published: March 2024

Ensuring network security is of utmost importance, especially in wireless sensor networks (WSNs), where the confidentiality of data is at risk due to eavesdropping. This paper introduces an artificial‐noise‐aided secure communication scheme for WSNs. This scheme comprises numerous sensor nodes, the sink, a friendly jammer, and an eavesdropper. The primary aim is to enhance the secrecy rate of the network by optimizing the jamming power. The friendly jammer plays a crucial role in degrading the wiretap channel between the sensor nodes and the eavesdropper. The optimization process revolves around maximizing the secrecy rate, while carefully managing the jamming power to prevent any negative impact on the main transmission link between the sink node and the sensor nodes. Due to the nonconvexity of the secrecy rate problem, the convex approximation‐based algorithm is recommened to get a safe convex approximation of the original solution. To address this optimization problem, an iterative algorithm based on quadratic transformation is proposed. Afterwards, the optimum jamming power to achieve high security is obtained. The simulation outcomes underscore the dual impact of the jammer in WSNs. The jammer diminishes the eavesdropper channel. Unfortunately, it introduces interference that consequently affects the security enhancement. In response, we concentrate on the optimization of jamming power. The proposed scheme consistently elevates secrecy rates across a spectrum of eavesdropper positions, adeptly addressing worst‐case scenarios. Notably, the algorithm showcases resilience across diverse node distributions.
Memory and relationships: A look into teachers' recollection of supervisory feedback
Authors: Clark‐Gareca Beth , Warkentin Teresa Bruno
Published: March 2024

In public schools in the United States, the work of an ESOL student teacher is characterized by relationships with multiple mentors, including a university supervisor. Through retrospective narrative accounts, this study examines what currently practicing teachers of multilingual learners retained of their supervisors' feedback from their student teaching days, and what nuggets of supervisory wisdom continue to resonate with them throughout their teaching careers. The researchers developed this qualitative study using a social constructivist lens informed by Carless and Winstone's (2023) feedback literacy dimensions. Interviews were conducted with eight current teachers to probe their recollections of supervision and integration of supervisory feedback into their practice. Findings suggest that the participants recalled a sprinkling of memories and continued to draw on a few pieces of supervisory advice in their current practice. Supervisors and student teachers demonstrated design, relational, and pragmatic dimensions of feedback literacy, though the relational (i.e., the quality of the relationship between supervisor and student teacher) was the most enduring, even if the specifics of the supervisory feedback faded. Implications suggest that teacher education programs can hone the purpose, mission, and methods of supervision by targeting the dimensions of feedback literacy to make supervisory feedback more constructive and impactful.
Performance analysis of an idealized Darrieus–Savonius combined vertical axis wind turbine
Authors: Pan Jingna , Ferreira Carlos , van Zuijlen Alexander
Published: March 2024

To investigate the effect of force distributions of each turbine component on the power performance of the Darrieus–Savonius combined vertical axis wind turbine (hybrid VAWT), the hybrid VAWT is modeled as idealized turbine under various force distributions. The goal of idealization is to simplify the intricate interactions between the Savonius and Darrieus components. The simulation actuator surfaces with uniform force distributions lead to a cost‐effective way to identify the optimal force distribution of each turbine component. The numerical model was validated against momentum theory. The results demonstrated that the numerical and theoretical results yield similar predictions in the low‐thrust cases but show differences in the high‐thrust cases. The maximum power coefficient
of an idealized hybrid VAWT with given thrust coefficient
is lower than that of a single actuator. This is a consequence of the nonoptimal loading on the actuator. The results indicate that an idealized hybrid VAWT does not show a significant power increase compared with an optimal single Darrieus rotor. Therefore, the presence of a Savonius rotor inside a Darrieus rotor leads to a lower power output in any circumstance. The hybrid configuration is primarily advantageous for the start‐up performance of the combined rotor, which is not explored in this study.
Does a language model “understand” high school math? A survey of deep learning based word problem solvers
Authors: Sundaram Sowmya S. , Gurajada Sairam , Padmanabhan Deepak , Abraham Savitha Sam , Fisichella Marco
Published: March 2024

From the latter half of the last decade, there has been a growing interest in developing algorithms for automatically solving mathematical word problems (MWP). It is a challenging and unique task that demands blending surface level text pattern recognition with mathematical reasoning. In spite of extensive research, we still have a lot to explore for building robust representations of elementary math word problems and effective solutions for the general task. In this paper, we critically examine the various models that have been developed for solving word problems, their pros and cons and the challenges ahead. In the last 2 years, a lot of deep learning models have recorded competing results on benchmark datasets, making a critical and conceptual analysis of literature highly useful at this juncture. We take a step back and analyze why, in spite of this abundance in scholarly interest, the predominantly used experiment and dataset designs continue to be a stumbling block. From the vantage point of having analyzed the literature closely, we also endeavor to provide a road‐map for future math word problem research.

This article is categorized under:

Technologies > Machine Learning

Technologies > Artificial Intelligence

Fundamental Concepts of Data and Knowledge > Knowledge Representation
Further Manifestations of Depletion Effects
Authors: Lekkerkerker Henk N. W. , Tuinier Remco , Vis Mark
Published: March 2024

In this chapter we provide examples of the manifestations of depletion effects in areas such as biology and technology. The addition of nonadsorbing polymers to colloidal suspensions can cause phase separation of the mixture into a colloid-rich and a polymer-rich phase.
Phase Transitions of Hard Sphere–Depletant Mixtures—The Basics
Authors: Lekkerkerker Henk N. W. , Tuinier Remco , Vis Mark
Published: March 2024

Phase transitions are the result of the physical properties of a collection of particles and depend on their interactions. In Chap. 2, we focused on two-body interactions. As we shall see, depletion interactions are usually not pair-wise additive. Therefore, the prediction of phase transitions of particles with depletion interaction is not straightforward. A description of the thermodynamic properties of the pure colloidal dispersion is required as a starting point. Here, the colloid–atom analogy, recognised by Einstein and exploited by Perrin in his classical experiments, is very useful. Subsequently, we explain the basics of the free volume theory for the phase behaviour of colloid–depletant systems. In this chapter, we only treat the simplest type of depletant—the penetrable hard sphere (PHS).
The Interface in Demixed Colloid–Polymer Dispersions
Authors: Lekkerkerker Henk N. W. , Tuinier Remco , Vis Mark
Published: March 2024

In Chaps. 3 and 4, the focus was on theory and experiments related to the phase behaviour of mixtures containing colloidal spheres and nonadsorbing polymers. As we have seen, when the polymer coils are sufficiently large relative to the colloidal spheres, a colloidal gas–liquid (fluid–fluid) phase separation may occur. The two phases that appear differ in composition. One phase is a dilute colloidal fluid (a colloidal ‘gas’) dispersed in a concentrated polymer solution. This phase coexists with a concentrated colloidal fluid (a colloidal ‘liquid’) dispersed in a dilute polymer solution.