bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical process fault detection and trend analysis based on KESN
Authors: Cao Yuping , Cheng Ruikang , Deng Xiaogang , Wang Ping
Published: June 2024

Fault detection has great significance for chemical process safety with the development of science and technology. The conventional echo state network‐based fault detection method does not highlight key fault features, and cannot forecast future fault trend after the occurrence of faults. For the above problems, a chemical process fault detection and trend analysis strategy based on key feature enhanced echo state network (KESN) is proposed. First, dynamic features are extracted by a detecting echo state network. Then, a weighting strategy is designed to enhance key features and increase fault detection rates. After detecting a fault, independent component analysis is utilized to extract independent key features. Future fault trend is forecasted based on the forecasting multi‐KESN. Simulation results on the Tennessee Eastman process demonstrate the effectiveness of the proposed method.
Branching‐Chain Propagation of Parahydrogen‐Derived Nuclear Spin Order on a Catalyst Surface
Authors: Pokochueva Ekaterina V. , Burueva Dudari B. , Salnikov Oleg G. , Koptyug Igor V.
Published: June 2024

This study reveals that, when two hydrogen atoms are produced on the surface of a catalyst (e. g., a metal nanoparticle) upon dissociation of a parahydrogen molecule, their initial nuclear spin correlation can propagate in a branching‐chain fashion as they diffuse and combine with random H atoms to produce H2 molecules, which subsequently dissociate. This process leads to a gradual dilution of the non‐equilibrium nuclear spin order, but the number of involved H atoms that share the spin order becomes larger. These conclusions, confirmed by the spin density matrix calculations, may be relevant in the context of parahydrogen‐induced polarization (PHIP) in heterogeneous hydrogenations catalyzed by supported metal catalysts, the observation of which apparently contradicts the accepted non‐pairwise mechanism of the addition of hydrogen to an unsaturated substrate over such catalysts. The potential consequences of the reported findings are discussed in the context of PHIP effects and beyond.
Rare presentations of small bowel endometriosis
Authors: Sakiris Anthony , Fraz Ezaam Naik , Rajandran Arvinf , Smith Jason , Allen Benjamin , Pillai Sooraj , Ramaswamy Pradeep Kakkadasam , John Sneha
Published: June 2024

Despite endometriosis being a relatively common chronic gynecological condition in women of childbearing age, small bowel endometriosis is rare. Presentations can vary from completely asymptomatic to reported symptoms of abdominal pain, bloating, and diarrhea. The following two cases depict very atypical manifestations of ileal endometriosis that presented as obscure intermittent gastrointestinal bleeding and bowel obstruction requiring surgical intervention. The first case describes a previously healthy 40‐year‐old woman with severe symptomatic iron deficiency anemia and intermittent melena. A small bowel enteroscopy diagnosed multiple ulcerated strictures in the distal small bowel as the likely culprit. Despite nonsteroidal anti‐inflammatory drug‐induced enteropathy being initially considered as the likely etiology, histopathological examination of the resected distal ileal segment revealed evidence of endometriosis. The second case describes a 66‐year‐old with a presumptive diagnosis of Crohn's disease who reported a 10‐year history of intermittent perimenstrual abdominal pain, diarrhea, and nausea with vomiting. Following two subsequent episodes of acute bowel obstruction and surgical resection of the patient's stricturing terminal ileal disease, histopathological examination demonstrated active chronic inflammation with endometriosis. Small bowel endometriosis should be considered as an unusual differential diagnosis in women who may present with obscure gastrointestinal bleeding from the small bowel or recurrent bowel obstruction.
Low‐temperature chemical vapor deposition growth of 2D materials
Authors: Lei Minting , Wang Peijian , Ke Xiaofeng , Xie Jun , Yue Min , Zhao Mei , Zhang Kenan , Dong Youqing , Xu Quanlong , Zou Chao , Wang Shun , Zhang Lijie
Published: June 2024

Two‐dimensional (2D) materials have atomic thickness, and thickness‐dependent electronic transport, optical and thermal properties, highlighting great promise applications in future semiconductor devices. Chemical vapor deposition (CVD) is considered as an industry‐oriented method for macro‐synthesis of 2D materials. In conventional CVD, high temperatures are required for the synthesis of high‐quality large‐size 2D materials, which is incompatible with of back‐end‐of‐line of the complementary metal oxide semiconductor (CMOS) techniques. Therefore, low‐temperature synthesis of 2D materials is of critical importance for the advancement toward practical applications of 2D materials with the CMOS technologies. In this review, we focus on strategies for the low‐temperature growth of 2D materials, including the use of low‐melting‐point precursors, metal‐organic CVD, plasma‐enhanced CVD, van der Waals‐substrate vapor phase epitaxy, tellurium‐assisted CVD, salt‐assisted CVD, etc., with discussions of their reaction mechanisms, applications, associated advantages, and limitations. We also provide an outlook and perspectives of future low‐temperature chemical vapor deposition growth of 2D materials.
Astrocytic PAR1 and mGluR2/3 control synaptic glutamate time course at hippocampal CA1 synapses
Authors: Roh Woo Suk , Yoo Jae Hong , Dravid Shashank M. , Mannaioni Guido , Krizman Elizabeth N. , Lee Myunghoon , Wahl Philip , Robinson Michael B. , Traynelis Stephen F. , Lee C. Justin , Han Kyung‐Seok
Published: June 2024

Astrocytes play an essential role in regulating synaptic transmission. This study describes a novel form of modulation of excitatory synaptic transmission in the mouse hippocampus by astrocytic G‐protein‐coupled receptors (GPCRs). We have previously described astrocytic glutamate release via protease‐activated receptor‐1 (PAR1) activation, although the regulatory mechanisms for this are complex. Through electrophysiological analysis and modeling, we discovered that PAR1 activation consistently increases the concentration and duration of glutamate in the synaptic cleft. This effect was not due to changes in the presynaptic glutamate release or alteration in glutamate transporter expression. However, blocking group II metabotropic glutamate receptors (mGluR2/3) abolished PAR1‐mediated regulation of synaptic glutamate concentration, suggesting a role for this GPCR in mediating the effects of PAR1 activation on glutamate release. Furthermore, activation of mGluR2/3 causes glutamate release through the TREK‐1 channel in hippocampal astrocytes. These data show that astrocytic GPCRs engage in a novel regulatory mechanism to shape the time course of synaptically‐released glutamate in excitatory synapses of the hippocampus.
In vitro exposure of porcine spermatozoa to methylparaben, and propylparaben, alone or in combination adversely affects sperm quality
Authors: Barraza J. , Cleofas P. , Villamil S. , García M. , López A. , Casas E. , Salazar Z. , Pichardo F. , Barajas‐Salinas A. , Núñez‐Macías E. , Ramírez Y. , Bonilla E. , Bahena I. , Ortíz‐Muñíz R. , Cortés‐Barberena E. , Betancourt M. , Casillas F.
Published: June 2024

Parabens (PBs) are widely used in the cosmetic, pharmaceutical, and food industries as preservatives of products. Because of its great use, humans and other organisms are highly exposed daily. However, little is known about the effect of PBs on male infertility. Therefore, the aim of the present study was to evaluate the effect of methylparaben (MePB) and propylparaben (PrPB), alone or in combination, on the physiological characteristics of pig in vitro exposed sperm to different concentrations (0, 200, 500, and 700 μM) for viability, motility, and acrosome integrity evaluation and (0, 200, 500, 700, 1000, and 2000 μM) for DNA fragmentation index evaluation, after 4 h of exposure. The results showed that sperm viability decreased after exposure to MePB from the concentration of 500 μM. In the PrPB and mixture groups, viability decreased at all concentrations except for the control. The decrease in viability of sperm exposed to PrPB was greater than that of the mixture and MePB groups. Sperm motility decreased in all the experimental groups exposed to PBs, at all concentrations, except for the control group. Acrosome integrity was not decreased in the MePB group; however, in the PrPB group, it decreased at a concentration of 200 μM and in the mixture at 500 μM. All groups exhibited DNA damage at different concentrations, except for the control group. Additionally, the effect of PBs on sperm quality was concentration‐dependent. The results demonstrated that MePB and PrPB alone or in combination can have adverse effects on sperm quality parameters. MePB had lower toxicity than did both PrPB and the mixture. The mixture did not have an additive effect on any of the parameters evaluated. This could partially explain the link between PB exposure and infertility.
How scanning probe microscopy can be supported by artificial intelligence and quantum computing?
Authors: Pregowska Agnieszka , Roszkiewicz Agata , Osial Magdalena , Giersig Michael
Published: June 2024

The impact of Artificial Intelligence (AI) is rapidly expanding, revolutionizing both science and society. It is applied to practically all areas of life, science, and technology, including materials science, which continuously requires novel tools for effective materials characterization. One of the widely used techniques is scanning probe microscopy (SPM). SPM has fundamentally changed materials engineering, biology, and chemistry by providing tools for atomic‐precision surface mapping. Despite its many advantages, it also has some drawbacks, such as long scanning times or the possibility of damaging soft‐surface materials. In this paper, we focus on the potential for supporting SPM‐based measurements, with an emphasis on the application of AI‐based algorithms, especially Machine Learning‐based algorithms, as well as quantum computing (QC). It has been found that AI can be helpful in automating experimental processes in routine operations, algorithmically searching for optimal sample regions, and elucidating structure–property relationships. Thus, it contributes to increasing the efficiency and accuracy of optical nanoscopy scanning probes. Moreover, the combination of AI‐based algorithms and QC may have enormous potential to enhance the practical application of SPM. The limitations of the AI‐QC‐based approach were also discussed. Finally, we outline a research path for improving AI‐QC‐powered SPM.

Research Highlights

Artificial intelligence and quantum computing as support for scanning probe microscopy.

The analysis indicates a research gap in the field of scanning probe microscopy.

The research aims to shed light into ai‐qc‐powered scanning probe microscopy.
Developmental morpho‐analysis of the caecum in Japanese quail embryos (Coturnix coturnix japonica)
Authors: Abdelhakeem Fatma
Published: June 2024

In the current study, we are focusing on the microanatomical structure of quail caecum during the prehatching time to try to understand the function and the role of each cell‐built quail caecum reaching how caecum plays an essential role in immunity and absorption. The morpho‐developmental features of the quail caecum were described in detail daily from the third incubation day (ID) till hatching time, investigating the gross morphology, microscopic, and ultrastructure using light and scanning electron microscope. The embryonic caecum appeared grossly as two lateral outpocketings with blinded ends, emerging laterally at the junction between the small and large intestine (the ileocaecal junction). The primordia of two caeca, represented by two lateral swellings from the hindgut on the fourth ID, continued growing till the day of hatching, where the caecal wall consisted of three apparent layers: mucosa, musculosa, and serosa. At the time of hatching, the quail caecum was still not fully mature and will continue growing posthatching. The findings in this study can be applied in further studies intended to understand the physiological mechanisms of the caecum during prehatching and posthatching periods.

Research Highlights

Caecum is one of the hindgut derivatives that started as two lateral swellings.

The caecal wall consisted of three layers; mucosa, musculosa, and serosa.

The caecum plays an essential role in immunity maintenance.

Caecum continues to grow posthatching as it is not fully mature at hatching time.
Some results and problems on clique coverings of hypergraphs
Authors: Rödl Vojtech , Sales Marcelo
Published: June 2024

For a ‐uniform hypergraph we consider the parameter , the minimum size of a clique cover of the edge set of . We derive bounds on for belonging to various classes of hypergraphs.
Muscle and joint function in the rotator cuff deficient shoulder
Authors: Yeung Angus , Fernando Ashen , Patel Minoo , Gatto Laura , Ackland David C.
Published: June 2024

Full‐thickness rotator cuff tears can lead to poor coaptation of the humeral head to the glenoid, disrupting muscle forces required for glenohumeral joint stability, ultimately leading to joint subluxation. The aim of this study was to evaluate muscle forces and glenohumeral joint translations during elevation in the presence of isolated and combined full‐thickness rotator cuff tears. Eight fresh‐frozen upper limbs were mounted to a computer‐controlled testing apparatus that simulated joint motion by simulated muscle force application. Scapular‐plane abduction was performed, and glenohumeral joint translations were measured using an optoelectronic system. Testing was performed in the native shoulder, a following an isolated tear to the supraspinatus, as well as combined tears involving the supraspinatus and subscapularis, as well as supraspinatus, infraspinatus, and teres minor. Rotator cuff tears significantly increased middle deltoid force at 30°, 60°, and 90° of abduction relative to that in the native shoulder (p < 0.05). Significantly greater superior translations were observed relative to the intact shoulder due to combined tears to the supraspinatus and infraspinatus at 30° of abduction (mean increase: 1.6 mm, p = 0.020) and 60° of abduction (mean increase: 4.8 mm, p = 0.040). This study illustrates the infraspinatus‐teres minor complex as a major humeral head depressor and contributor to glenohumeral joint stability. An increase in deltoid force during abduction occurs in the presence of rotator cuff tears, which exacerbates superior migration of the humeral head. The findings may help in the development of clinical tests in rotator cuff tear diagnostics, in surgical planning of rotator cuff repair, and in planning of targeted rehabilitation.
Inferior vena cava filter thromboprophylaxis in surgical cancer patients
Authors: Makary Mina S. , Koso Mensur , Yoder Matthew
Published: June 2024

Background and Objectives

This study evaluated the utilization and outcomes of inferior vena cava (IVC) filters as thromboprophylaxis in cancer patients undergoing surgery.

Methods

This single‐center retrospective study analyzed baseline patient characteristics and clinical outcomes of surgical cancer patients who received perioperative prophylactic IVC filters. Primary clinical endpoints included venous thromboembolism (VTE) incidence and filter complications. A statistical correlative analysis was conducted to identify risk factors related to pulmonary embolism (PE), deep vein thrombosis (DVT), and filter thrombi, as well as advanced technique filter removal and mortality at 6 months.

Results

A total of 252 surgical oncology patients (median age, 59; female 51%) received IVC filters for the perioperative prevention of PE. Primary surgical sites included spine (n = 91, 36%), orthopedic extremity/joint (n = 49, 19%), genitourinary (n = 47, 19%), brain/cranial (n = 40, 16%), abdominal (n = 18, 7%), multisite (n = 4, 2%), and chest (n = 3, 1%). Moreover, 15% of patients experienced DVTs in the postplacement preretrieval period, while 2% (n = 6) of patients experienced definitive PEs. A total of 36% of IVC filters were ultimately retrieved, with an average filter dwell time of 7.4 months. Complications occurred in one retrieval.

Conclusion

Prophylactic perioperative IVC filters in surgical cancer patients resulted in minimal complications while ultimately resulting in a low incidence of PE.
Individualised compared to off‐the‐shelf total knee arthroplasty results in lower and less variable patellar tilt
Authors: Beel Wouter , Sappey‐Marinier Elliot , Latifi Roshan ,   ReSurg, Aït‐Si‐Selmi Tarik , Bonnin Michel P.
Published: June 2024

Purpose

The purpose of this study was to compare postoperative patellar tilt at 4 months follow‐up in a consecutive series of randomised patients that received individualised or off‐the‐shelf (OTS) primary total knee arthroplasty (TKA). The hypothesis was that patellar tilt would be lower and less variable in patients who received individualised TKA compared to patients who received OTS TKA.

Methods

A consecutive series of 385 patients randomised (1:1) to receive either OTS TKA or individualised TKA were analysed. Pre‐ and postoperative radiographs at 4 months were obtained of weight‐bearing long leg, anterior–posterior and lateral knee views and a skyline view at 30° of flexion. Postoperative patellar tilt was measured between the anterior femoral line and patellar resection surface (β) and the anterior femoral line and mediolateral patellar axis (σ). Postoperative patellar tilt (absolute value) was compared between the individualised and OTS TKA groups based on preoperative phenotypes of their femoral mechanical angle, tibial mechanical angle and hip–knee–ankle angle. Variability in postoperative patellar tilt was compared using the 95% confidence intervals (CIs).

Results

Comparisons of baseline patient characteristics revealed no difference between the individualised and OTS TKA groups. Comparison of absolute postoperative patellar tilt revealed significant differences between individualised and OTS TKA (|β|, 1.0° ± 1.0° and 2.5° ± 2.2°, respectively, p < 0.001; |σ|, 1.7° ± 1.6° and 2.8° ± 2.3°, respectively, p < 0.001). The 95% CI of postoperative patellar tilt (|β|) was narrower in patients that received individualised compared to OTS TKA (0.0° to 3.8° and 0.1° to 8.3°, respectively), irrespective of their preoperative phenotype.

Conclusion

Patients who underwent individualised TKA had lower and less variable postoperative patellar tilt than those with OTS TKA, irrespective of preoperative phenotype. Individualised TKA allows the decoupling of the tibiofemoral and patellofemoral joints, replicating anatomical trochlear orientation and improving patellar tilt, which could facilitate better clinical outcomes.

Clinical Trial Registration

This study constitutes a part of a larger registered randomised controlled trial comparing patient satisfaction following OTS versus individualised TKA (NCT04460989).

Level of Evidence

Level II.
Long‐term preservation of lean mass and sustained loss of fat mass after completion of an intensive lifestyle intervention in older adults with obesity and type 2 diabetes
Authors: Memelink Robert G , Hijlkema Aveline , Valentin Bas , Streppel Martinet T , Pasman Wilrike J , Wopereis Suzan , de Vogel‐van den Bosch Johan , Tieland Michael , Schoufour Josje D , Bautmans Ivan , Weijs Peter JM
Published: June 2024

Introduction

Lifestyle interventions combining caloric restriction with resistance exercise have the potential to preserve lean mass during weight loss. Additional protein intake can further improve lean mass. However, it is unclear whether these effects are sustained after completion of the intervention. This study aimed to evaluate the long‐term effect of a 3‐month lifestyle intervention, with or without supplementation of a protein drink, to preserve lean mass in older adults with obesity and type 2 diabetes at 6 months post‐intervention.

Methods

Adults (n = 123) aged ≥55 years with obesity and type 2 diabetes were enrolled in a 3‐month intensive lifestyle intervention including a hypocaloric diet, resistance exercise and high‐intensity interval training. Participants were randomized to either receive a leucine and vitamin D‐enriched protein drink or an isocaloric control drink. The 3‐month intervention was followed by a 6‐month phase without intervention. At baseline, 3 and 9 months (follow‐up) body composition, physical functioning, physical activity and quality of life were assessed. Statistical analyses were performed using linear mixed models.

Results

Body weight loss was largely sustained at follow‐up (−2.1 kg compared to baseline, 95% CI [−2.8, −1.5]) and comprised a sustained loss of fat mass (−2.6 kg, 95% CI [−3.2, −2.0]) with a simultaneous gain of lean mass (+0.7 kg, 95% CI [+0.2, +1.2]). Improvements in 400 m walk speed (+0.05 m/s, 95% CI [+0.03, +0.08]) and chair stand test time (−1.5 s, 95% CI [−1.9, −1.1]) were sustained at follow‐up. There were no differences in these changes between the protein supplementation group and the control group at follow‐up.

Conclusions

Older adults with obesity and type 2 diabetes preserved their lean mass, their loss of fat mass and their improvements in physical functioning at 6 months post‐intervention. Protein supplementation during intervention did not affect outcomes at follow‐up.
Highly Efficient Two‐Photon Photodynamic Therapy Using Light‐Sheet Excitation
Authors: Pang Wen , Wang Chen , Wu Wenbo , Wei Xunbin , Gu Bobo
Published: June 2024

Two‐photon photodynamic therapy (TP‐PDT), which utilizes near‐infrared light to excite photosensitizer via two‐photon excitation (TPE), is a promising modality in the treatment of deeply seated tumors or thick tumors. However, the TPE domain is much smaller than the tumor volume, significantly limiting the therapeutical outcomes of TP‐PDT. Here, a light‐sheet TPE system is designed and constructed using a cylindrical lens for highly efficient TP‐PDT. The light‐sheet TPE performance is characterized and optimized via theoretical analysis and experimental studies in solution, phantom, and tumor. The optimized excitation system can reach a large TPE domain of 2.6 × 2.7 × 0.09 mm in the tumor, which is not achievable using conventional TPE methods, enabling TPE and subsequently generated reactive oxygen species to cover the whole tumor under line‐scanning. Outstanding TP‐PDT therapeutic performance of 70% tumor growth inhibition rate is achieved under line‐scanned light‐sheet TPE, making the proposed light‐sheet excited TP‐PDT a potential therapeutic tool for future translational research.
Trends in predicted age at maturity of Sablefish from 22 years of surveys
Authors: Rodgveller C. J. , Echave K. B.
Published: June 2024

Objective

Our aim was to predict the maturity (will spawn or immature) of Sablefish Anoplopoma fimbria in Alaska for past years during a period when macroscopic data are not of utility and histological observations are not available.

Methods

In a previous study, female maturity was determined using histology and a model was developed that predicted maturity using maternal length, age, and relative condition. We used this published model to predict the maturity of individual Sablefish collected annually in the same area on the same dates. The maturity predictions were used to create predicted time series of maturity at age for surveys conducted over 22 years.

Result

A k-means cluster analysis of annual maturity parameters revealed that data should be split into two clusters. These groups were chronologically sequential (1998–2010 and 2011–2019), with two exceptions: 2015 and 2017 were assigned to the early time period. We created two chronological time blocks by incorporating the two outlier years into the late period post hoc, as we are not aware of mechanisms that may have caused these two outliers, and it is important for stock assessment to capture the signal and not the noise. Sablefish in the later period were predicted to mature later than fish in the earlier period; age at 50% maturity was 5.5 years in the early period and 6.8 years in the later period, and the slope was shallower in the later period.

Conclusion

There are often gaps in reliable maturity data. This case study illustrates that limited histological data sets can be used to predict maturity in years without ovary samples and illustrates how these data can be grouped based on similarities and chronology for use in stock assessment. We recommend more histological studies in the future to test assumptions of the predictive model, and we recommend evaluations of other factors, such as environmental time series, that may be drivers of annual maturity.
Virtual screening of natural products to enhance melanogenosis
Authors: Bournez Colin , Gally José‐Manuel , Aci‐Sèche Samia , Bernard Philippe , Bonnet Pascal
Published: June 2024

Natural products have long been an important source of inspiration for medicinal chemistry and drug discovery. In the cosmetic field, they remain the major elements of the composition and serve as marketing asset. Recent research showed the implication of salt‐inducible kinases on the melanin production in skin via MITF regulation. Finding new potent modulators on such target could open the way to several cosmetic applications to attenuate visible signs of photoaging and improve the tan without sun. Since virtual screening can be a powerful tool for detecting hit compounds in the early stages of a drug discovery process, we applied this method on salt‐inducible kinase 2 to discover potential interesting compounds. Here, we present the different steps from the construction of a database of natural products, to the validation of a docking protocol and the results of the virtual screening. Hits from the screening were tested in vitro to confirm their efficiency and results are discussed.
Vitamin D and Atherosclerosis: Unraveling the Impact on Macrophage Function
Authors: Wang Dongxia , Sun Zhen , Yin Yajuan , Xiang Jingyi , Wei Yuzhe , Ma Yuxia , Wang Le , Liu Gang
Published: June 2024

Vitamin D plays a crucial role in preventing atherosclerosis and in the regulation of macrophage function. This review aims to provide a comprehensive summary of the clinical evidence regarding the impact of vitamin D on atherosclerotic cardiovascular disease, atherosclerotic cerebrovascular disease, peripheral arterial disease, and associated risk factors. Additionally, it explores the mechanistic studies investigating the influence of vitamin D on macrophage function in atherosclerosis. Numerous findings indicate that vitamin D inhibits monocyte or macrophage recruitment, macrophage cholesterol uptake, and esterification. Moreover, it induces autophagy of lipid droplets in macrophages, promotes cholesterol efflux from macrophages, and regulates macrophage polarization. This review particularly focuses on analyzing the molecular mechanisms and signaling pathways through which vitamin D modulates macrophage function in atherosclerosis. It claims that vitamin D has a direct inhibitory effect on the formation, adhesion, and migration of lipid‐loaded monocytes, thus exerting anti‐atherosclerotic effects. Therefore, this review emphasizes the crucial role of vitamin D in regulating macrophage function and preventing the development of atherosclerosis.
Image‐domain material decomposition for dual‐energy CT using unsupervised learning with data‐fidelity loss
Authors: Peng Junbo , Chang Chih‐Wei , Xie Huiqiao , Qiu Richard L. J. , Roper Justin , Wang Tonghe , Ghavidel Beth , Tang Xiangyang , Yang Xiaofeng
Published: June 2024

Background

Dual‐energy computed tomography (DECT) and material decomposition play vital roles in quantitative medical imaging. However, the decomposition process may suffer from significant noise amplification, leading to severely degraded image signal‐to‐noise ratios (SNRs). While existing iterative algorithms perform noise suppression using different image priors, these heuristic image priors cannot accurately represent the features of the target image manifold. Although deep learning‐based decomposition methods have been reported, these methods are in the supervised‐learning framework requiring paired data for training, which is not readily available in clinical settings.

Purpose

This work aims to develop an unsupervised‐learning framework with data‐measurement consistency for image‐domain material decomposition in DECT.

Methods

The proposed framework combines iterative decomposition and deep learning‐based image prior in a generative adversarial network (GAN) architecture. In the generator module, a data‐fidelity loss is introduced to enforce the measurement consistency in material decomposition. In the discriminator module, the discriminator is trained to differentiate the low‐noise material‐specific images from the high‐noise images. In this scheme, paired images of DECT and ground‐truth material‐specific images are not required for the model training. Once trained, the generator can perform image‐domain material decomposition with noise suppression in a single step.

Results

In the simulation studies of head and lung digital phantoms, the proposed method reduced the standard deviation (SD) in decomposed images by 97% and 91% from the values in direct inversion results. It also generated decomposed images with structural similarity index measures (SSIMs) greater than 0.95 against the ground truth. In the clinical head and lung patient studies, the proposed method suppressed the SD by 95% and 93% compared to the decomposed images of matrix inversion.

Conclusions

Since the invention of DECT, noise amplification during material decomposition has been one of the biggest challenges, impeding its quantitative use in clinical practice. The proposed method performs accurate material decomposition with efficient noise suppression. Furthermore, the proposed method is within an unsupervised‐learning framework, which does not require paired data for model training and resolves the issue of lack of ground‐truth data in clinical scenarios.
Calculation of intravoxel incoherent motion parameter maps using a kernelized total difference‐based method
Authors: Huang Hsuan‐Ming
Published: June 2024

Quantitative analysis of diffusion‐weighted magnetic resonance imaging (DW‐MRI) has been explored for many clinical applications since its development. In particular, the intravoxel incoherent motion (IVIM) model for DW‐MRI has been commonly utilized in various organs. However, because of the presence of excessive noise, the IVIM parameter maps obtained from pixel‐wise fitting are often unreliable. In this study, we propose a kernelized total difference‐based curve‐fitting method to estimate the IVIM parameters. Simulated DW‐MRI data at five signal‐to‐noise ratios (i.e., 10, 20, 30, 50, and 100) and real abdominal DW‐MRI data acquired on a 1.5‐T MRI scanner with nine b‐values (i.e., 0, 10, 25, 50, 100, 200, 300, 400, and 500 s/mm2) and six diffusion‐encoding gradient directions were used to evaluate the performance of the proposed method. The results were compared with those obtained by three existing methods: trust‐region reflective (TRR) algorithm, Bayesian probability (BP), and deep neural network (DNN). Our simulation results showed that the proposed method outperformed the other three comparing methods in terms of root‐mean‐square error. Moreover, the proposed method could preserve small details in the estimated IVIM parameter maps. The experimental results showed that, compared with the TRR method, the proposed method as well as the BP (and DNN) method could reduce the overestimation of the pseudodiffusion coefficient and improve the quality of IVIM parameter maps. For all studied abdominal organs except the pancreas, both the proposed method and the BP method could provide IVIM parameter estimates close to the reference values; the former had higher precision. The kernelized total difference‐based curve‐fitting method has the potential to improve the reliability of IVIM parametric imaging.
Matrix‐based implementation and GPU acceleration of hybrid FEM and peridynamic model for hydro‐mechanical coupled problems
Authors: Ni Tao , Zhang Jin , Zaccariotto Mirco , Galvanetto Ugo , Schrefler Bernhard A.
Published: June 2024

The hybrid finite element‐peridynamic (FEM‐PD) models have been evidenced for their exceptional ability to address hydro‐mechanical coupled problems involving cracks. Nevertheless, the non‐local characteristics of the PD equations and the required inversion operations when solving fluid equations result in prohibitively high computational costs. In this paper, a fast explicit solution scheme for FEM‐PD models based on matrix operation is introduced, where the graphics processing units (GPUs) are used to accelerate the computation. An in‐house software is developed in MATLAB in both CPU and GPU versions. We first solve a problem related to pore pressure distribution in a single crack, demonstrating the accuracy of the proposed method by a comparison of FEM‐PD solutions with those of PD‐only models and analytical solutions. Subsequently, several examples are solved, including a one‐dimensional dynamic consolidation problem and the fluid‐driven hydraulic fracture propagation problems in both 2D and 3D cases, to comprehensively validate the effectiveness of the proposed methods in simulating deformation and fracture in saturated porous media under the influence of hydro‐mechanical coupling. In the presented numerical results, some typical strong dynamic phenomena, such as stepwise crack advancement, crack branching, and pressure oscillations, are observed. In addition, we compare the wall times of all the cases executed on both the GPU and CPU, highlighting the substantial acceleration performance of the GPU, particularly when tackling problems with a significant computational workload.
Enhancing mechanical properties of natural waste‐based composites for automobile and plastic industry
Authors: Motaleb K. Z. M. Abdul , Repon Md. Reazuddin , Pranta Arnob Dhar , Milašius Rimvydas
Published: June 2024

Natural fiber composites are a renewable and environmentally friendly alternative to conventional synthetic materials that combine the biodegradability and essential durability of natural fibers with adaptability. Improved adhesion between fibers and matrix can be accomplished by comparing surface treatments applied to sugarcane, water hyacinth, and banana plant wastes. This will allow us to produce composite materials that are more durable and sustainable. To study the mechanical and morphological characteristics of the composites, two surface treatments were applied: gamma radiation at a dose of 1, 2, 3, 4 and 5 kGy and alkali treatment at a concentration of 5, 10, and 15%. The study revealed that with the increasing treatment of alkali solution, improvements in the composite's mechanical characteristics whereas gamma irradiation treatment enhanced the mechanical properties to a certain extent (2 kGy) after that the mechanical traits dwindled significantly. SEM, XRD, and FTIR analysis of the developed composite samples also revealed the reasons for the improvements in mechanical properties after alkali and gamma radiation treatments. As an ecofriendly and lightweight substitute for conventional materials, bio epoxy composites reinforced with natural fibers can be used for car interior panels, eco‐friendly furniture and as a replacement for any plasticware offering eco‐sustainability for contemporary living space.

Highlights

Natural fiber composites offer a renewable and eco‐friendly alternative to synthetic materials, combining biodegradability with durability.

Surface treatments like gamma radiation and alkali treatment enhance composite's mechanical properties.

Higher concentrations of alkali treatment improve mechanical characteristics, while gamma irradiation peaks at 2 kGy.

Surface treatments offer promising avenues for advancing environmentally friendly materials, contributing to sustainable innovations in material science.
Combined antibacterial and antifouling properties of polyethersulfone mixed matrix membranes with zwitterionic graphene oxide nanostructures
Authors: Castellanos Espinoza R. , Huhn Ibarra M. J. , Montes Luna A. J. , Aguilar‐Vega Manuel , Hernández Orozco M. M. , Luna Bárcenas Gabriel , Baldenegro Pérez L. A. , Guerra Balcázar Minerva , España Sánchez Beatriz Liliana
Published: June 2024

The impact of zwitterionic graphene oxide (GO‐Arg) nanostructures into polyethersulfone (PES) membranes was studied, aiming to perform mixed matrix membranes (MMMs) with combined antibacterial and antifouling properties. For this purpose, 0.25, 0.50, and 1.0 wt% of GO‐Arg were incorporated through the phase inversion method. The chemical composition reveals that the electrostatic interactions of PES, polyvinylpyrrolidone, and GO‐Arg occur by enhancing the CH/NH vibrations associated with the intrinsic MMMs and their combined antibacterial and antifouling performance. Well‐defined finger‐like morphology was observed, performing the pore distribution and the finger‐cavity inclination induced by the electrostatic charge of GO‐Arg. As a result, GO‐Arg MMM's hydrophobic properties decreased from 77.8° to 52.3°, inducing a partially hydrophilic surface and improved water flux. The isoelectric point of nanostructured membranes slightly changes by the charge modulation produced by zwitterionic GO‐Arg. The antibacterial activity against Gram (−) Escherichia coli was improved, closing the complete bacterial inhibition after 24 h. As a result, antifouling performance was improved, avoiding bacterial adhesion into the membrane surface and the possibility of promoting biofilm formation. Our results demonstrate that zwitterionic nanomaterials in MMMs perform the multifunctional capacity of materials, emerging as an effective alternative with potential application in wastewater treatment.

Highlights

The incorporation of zwitterionic GO‐Arg improves the mechanical properties of MMMs.

GO‐Arg‐enhanced well‐defined porous finger‐like morphology in MMMs.

GO‐Arg improves the antibacterial/antifouling performance of PES‐based MMMs.
Effect of graphene nanoplatelets and nano zinc oxide on gas barrier and antibacterial properties of thermoplastic nanocomposites
Authors: Ghosh Suman Kumar , Ganguly Soumya Sarathi , Paul Sangit , Ghosh Trisita , Das Amit Kumar , Das Narayan Ch.
Published: June 2024

Graphene‐loaded thermoplastic nanocomposite films must be evaluated for antibacterial activity, mechanical, and barrier properties before being utilized as food packaging. Herein, economically feasible linear low‐density polyethylene (LLDPE)‐based flexible packaging materials were developed via the melt compounding technique at 170°C temperature by taking advantage of both graphene nanoplatelets (GNP) and nano zinc oxide (ZnO) fillers. Morphological studies reveal that in composites loaded with GNP/ZnO hybrid fillers, ZnO nanoparticles form a network‐like structure throughout the polymer matrix. Simultaneously, GNPs are uniformly dispersed. The inclusion of hybrid nanofiller considerably reduces both the oxygen transmission rate and the water vapor transmission rate (WVTR) in LLDPE nanocomposites. A maximum decrease of 36% and 67%, respectively, in both oxygen transmission rate and WVTR is observed for 3 wt% of hybrid filler loading in a thermoplastic matrix containing 1 wt% of nano ZnO. The antibacterial efficacy of the derived nanocomposite films is obvious against gram‐positive (Bacillus subtilis) and gram‐negative (Escherichia coli) bacterial strains. These nanocomposite films have the potential to be successfully utilized as flexible packaging materials owing to their improved thermal, barrier, and antibacterial effectiveness.

Highlights

GNP/ZnO was used as a hybrid reinforcing filler in the LLDPE matrix.

ZnO nanoparticles establish a network‐like morphology.

LLDPE nanocomposite films exhibited excellent antibacterial activity.

Oxygen and water vapor barrier properties were significantly improved.

The thermoplastic composite films could be used as food packaging materials.
Discovery of periplasmic solute binding proteins with specificity for ketone bodies: β‐hydroxybutyrate binding proteins
Authors: Kane Bryant J. , Okuda‐Shimazaki Junko , Andrews Madelyn M. , Kerrigan Joseph A. , Murphy Kyle V. , Sode Koji
Published: June 2024

Polyhydroxyalkanoates are a class of biodegradable, thermoplastic polymers which represent a major carbon source for various bacteria. Proteins which mediate the translocation of polyhydroxyalkanoate breakdown products, such as β‐hydroxybutyrate (BHB)—a ketone body which in humans serves as an important biomarker, have not been well characterized. In our investigation to screen a solute‐binding protein (SBP) which can act as a suitable recognition element for BHB, we uncovered insights at the intersection of bacterial metabolism and diagnostics. Herein, we identify SBPs associated with putative ATP‐binding cassette transporters that specifically recognize BHB, with the potential to serve as recognition elements for continuous quantification of this analyte. Through bioinformatic analysis, we identified candidate SBPs from known metabolizers of polyhydroxybutyrate—including proteins from Cupriavidus necator, Ensifer meliloti, Paucimonas lemoignei, and Thermus thermophilus. After recombinant expression in Escherichia coli, we demonstrated with intrinsic tryptophan fluorescence spectroscopy that four candidate proteins interacted with BHB, ranging from nanomolar to micromolar affinity. Tt.2, an intrinsically thermostable protein from Thermus thermophilus, was observed to have the tightest binding and specificity for BHB, which was confirmed by isothermal calorimetry. Structural analyses facilitated by AlphaFold2, along with molecular docking and dynamics simulations, were used to hypothesize key residues in the binding pocket and to model the conformational dynamics of substrate unbinding. Overall, this study provides strong evidence identifying the cognate ligands of SBPs which we hypothesize to be involved in prokaryotic cellular translocation of polyhydroxyalkanoate breakdown products, while highlighting these proteins' promising biotechnological application.
Molecular basis for different substrate‐binding sites and chaperone functions of the BRICHOS domain
Authors: Chen Gefei , Wang Yu , Zheng Zihan , Jiang Wangshu , Leppert Axel , Zhong Xueying , Belorusova Anna , Siegal Gregg , Jegerschöld Caroline , Koeck Philip J. B. , Abelein Axel , Hebert Hans , Knight Stefan D. , Johansson Jan
Published: June 2024

Proteins can misfold into fibrillar or amorphous aggregates and molecular chaperones act as crucial guardians against these undesirable processes. The BRICHOS chaperone domain, found in several otherwise unrelated proproteins that contain amyloidogenic regions, effectively inhibits amyloid formation and toxicity but can in some cases also prevent non‐fibrillar, amorphous protein aggregation. Here, we elucidate the molecular basis behind the multifaceted chaperone activities of the BRICHOS domain from the Bri2 proprotein. High‐confidence AlphaFold2 and RoseTTAFold predictions suggest that the intramolecular amyloidogenic region (Bri23) is part of the hydrophobic core of the proprotein, where it occupies the proposed amyloid binding site, explaining the markedly reduced ability of the proprotein to prevent an exogenous amyloidogenic peptide from aggregating. However, the BRICHOS‐Bri23 complex maintains its ability to form large polydisperse oligomers that prevent amorphous protein aggregation. A cryo‐EM‐derived model of the Bri2 BRICHOS oligomer is compatible with surface‐exposed hydrophobic motifs that get exposed and come together during oligomerization, explaining its effects against amorphous aggregation. These findings provide a molecular basis for the BRICHOS chaperone domain function, where distinct surfaces are employed against different forms of protein aggregation.
Structural study for substrate recognition of human N‐terminal glutamine amidohydrolase 1 in the arginine N‐degron pathway
Authors: Kang Jin Mo , Park Joon Sung , Lee Jae Seok , Jang Jun Young , Han Byung Woo
Published: June 2024

The N‐degron pathway determines the half‐life of proteins by selectively destabilizing the proteins bearing N‐degrons. N‐terminal glutamine amidohydrolase 1 (NTAQ1) plays an essential role in the arginine N‐degron (Arg/N‐degron) pathway as an initializing enzyme via the deamidation of the N‐terminal (Nt) glutamine (Gln). However, the Nt‐serine‐bound conformation of hNTAQ1 according to the previously identified crystal structure suggests the possibility of other factors influencing the recognition of Nt residues by hNTAQ1. Hence, in the current study, we aimed to further elucidate the substrate recognition of hNTAQ1; specifically, we explored 12 different substrate‐binding conformations of hNTAQ1 depending on the subsequent residue of Nt‐Gln. Results revealed that hNTAQ1 primarily interacts with the protein Nt backbone, instead of the side chain, for substrate recognition. Here, we report that the Nt backbone of proteins appears to be a key component of hNTAQ1 function and is the main determinant of substrate recognition. Moreover, not all second residues from Nt‐Gln, but rather distinctive and charged residues, appeared to aid in detecting substrate recognition. These new findings define the substrate‐recognition process of hNTAQ1 and emphasize the importance of the subsequent Gln residue in the Nt‐Gln degradation system. Our extensive structural and biochemical analyses provide insights into the substrate specificity of the N‐degron pathway and shed light on the mechanism underlying hNTAQ1 substrate recognition. An improved understanding of the protein degradation machinery could aid in developing therapies to promote overall health through enhanced protein regulation, such as targeted protein therapies.
The oligomeric states of dye‐decolorizing peroxidases from Streptomyces lividans and their implications for mechanism of substrate oxidation
Authors: Lučić Marina , Allport Thomas , Clarke Thomas A. , Williams Lewis J. , Wilson Michael T. , Chaplin Amanda K. , Worrall Jonathan A. R.
Published: June 2024

A common evolutionary mechanism in biology to drive function is protein oligomerization. In prokaryotes, the symmetrical assembly of repeating protein units to form homomers is widespread, yet consideration in vitro of whether such assemblies have functional or mechanistic consequences is often overlooked. Dye‐decolorizing peroxidases (DyPs) are one such example, where their dimeric α + β barrel units can form various oligomeric states, but the oligomer influence, if any, on mechanism and function has received little attention. In this work, we have explored the oligomeric state of three DyPs found in Streptomyces lividans, each with very different mechanistic behaviors in their reactions with hydrogen peroxide and organic substrates. Using analytical ultracentrifugation, we reveal that except for one of the A‐type DyPs where only a single sedimenting species is detected, oligomer states ranging from homodimers to dodecamers are prevalent in solution. Using cryo‐EM on preparations of the B‐type DyP, we determined a 3.02 Å resolution structure of a hexamer assembly that corresponds to the dominant oligomeric state in solution as determined by analytical ultracentrifugation. Furthermore, cryo‐EM data detected sub‐populations of higher‐order oligomers, with one of these formed by an arrangement of two B‐type DyP hexamers to give a dodecamer assembly. Our solution and structural insights of these oligomer states provide a new framework to consider previous mechanistic studies of these DyP members and are discussed in terms of long‐range electron transfer for substrate oxidation and in the “storage” of oxidizable equivalents on the heme until a two‐electron donor is available.