bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic skin effect in Pb(Fe

_{1/2}$

Nb

_{1/2}$

)O3
Authors: Giles-Donovan N , Hillier A D , Ishida K , Hampshire B V , Giblin S R , Roessli B , Gehring P M , Xu G , Li X , Luo H , Cochran S , Stock C
Published: July 2024

Relaxor-ferroelectrics display exceptional dielectric properties resulting from the underlying random dipolar fields induced by strong chemical inhomogeneity. An unusual structural aspect of relaxors is a skin-effect where the near-surface region in single crystals exhibit structures and critical phenomena that differ from the bulk. Relaxors are unique in that this skin effect extends over a macroscopic lengthscale of ∼100 

μ
m

whereas usual surface layers only extend over a few unit cells (or ∼nm). We present a muon spectroscopy study of Pb(Fe

_{1/2}

Nb

_{1/2}

)O3 (PFN) which displays ferroelectric order, including many relaxor-like dielectric properties such as a frequency broadened dielectric response, and antiferromagnetism with spatially short-range polar correlations and hence can be termed a multiferroic. In terms of the magnetic behavior determined by the Fe3+ (

S
=
5

/

2

, L ≈ 0) ions, PFN has been characterized as a unique example of a ‘cluster spin-glass’. We use variable momentum muon spectroscopy to study the depth dependence of the slow magnetic relaxations in a large 1 cm3 crystal of PFN. Zero-field positive muon spin relaxation is parameterized using a stretched exponential, indicative of a distribution of relaxation rates of the Fe3+ spins. This bandwidth of frequencies changes as a function of muon momentum, indicative of a change in the Fe3+ relaxation rates as a function of muon implantation depth in our single crystal. Using negative muon elemental analysis, we find small-to-no measurable change in the Fe3+/Nb5+ concentration with depth implying that chemical concentration alone cannot account for the change in the relaxational dynamics. PFN displays an analogous magnetic skin effect reported to exist in the structural properties of relaxor-ferroelectrics.
A novel method to obtain the characteristic constant of a measurement chain
Authors: Yang Jing , Cui Zhitong , Cao Fei , Zhu Zhizhen , Dong Yayun , Qiu Mengtong
Published: July 2024

The characteristic constant is commonly used to reconstruct the measured signal when a measurement chain with flat wideband frequency response is applied. The characteristic constant is often calibrated by a standard pulse that follows a rectangular pulse behavior. However, a pulse that is more than similar to the measured signal is more suitable theoretically than a rectangular pulse as the calibration waveform. To reduce the measurement error caused by the calibration waveform, a novel method to optimize the calibration waveform is proposed in this paper. A dataset is constructed based on the prior information of the signal to be measured. Criterions for better calibration waveforms are also discussed. Dataset construction along with this criterion makes the calibration waveform optimization a solvable mathematical problem. The calibration waveform can then be quantitively evaluation and optimized. The optimized calibration waveform will make the error caused by the fluctuations in the frequency response of a proportional sensor as small as possible statistically. As an actual application case, simulation results are also provided to intuitively explain the method. The procedure to obtain the characteristic constant based on the optimized calibration waveform is then outlined. A calibration system for the given application case is built. Finally, an experiment is designed and executed. The experimental results approved the method proposed in this paper well.
Assessment of the accuracy and reliability of clinical thermometers for body temperature measurements at the hospital: a laboratory study
Authors: Shinsuphan Nikorn , Phanthi Aphinan , Leeudomwong Theera , Sanponpute Tassanai
Published: July 2024

This study aims to assess the accuracy and reliability of two different types of thermometers: contact thermometers (CT) and non-contact thermometers (NCIRT) at Maharaj Nakorn Chiang Mai Hospital. The comparison method was carried out in a hospital laboratory setting and followed a specific calibration procedure. The mean readings, errors, and measurement uncertainties were reported and categorized according to the manufacturer’s labeling models. The maximum permissible errors were defined by international standards and clinical acceptances for contact and NCIRTs, respectively. The results showed that thermometers of temperature probes (PTs) provided the highest level of accuracy. When compared to a reference standard thermometer (STD), the mean errors were only 0.04 °C at the calibration point of 37.0 °C. For digital CTs, the mean error at the calibration points of 37.0 °C was 0.24 °C. Most CT models exhibited high accuracy and reliability. However, the forehead (IRFTs) and ear (IRETs) readings significantly differed from the STD, with over half of all units not meeting the ISO 80601–2–56/ASTM E1965–98 standard requirements. These results suggest that CTs and PTs are highly accurate and reliable devices for measuring body temperature. However, both IRFTs and IRETs could be useful in certain situations, such as screening many people in a short amount of time, but their accuracy should be interpreted with caution and confirmed using a more precise method if necessary.
CMDS-SLAM: real-time efficient centralized multi-robot dense surfel SLAM
Authors: Zuo Chenle , Feng Zhao , Xiao Xiaohui
Published: July 2024

Real-time dense mapping technology for multi-robot systems is crucial in scenarios like search and rescue. This paper presents CMDS-SLAM, a centralized multi-robot dense surfel SLAM system aimed at overcoming limitations in hardware constraints, data transmission, and real-time creation and updating of dense maps in multi-robot SLAM. CMDS-SLAM reduces the transmission of dense information by employing a dense information filtering mechanism based on co-visual keyframes, in conjunction with the extraction and compression of superpixels. Additionally, the method employs a three-stage superpixel segmentation approach to optimize transmission and enhance the efficiency of surfel map generation. Finally, a surfel co-visibility graph is established, and multi-robot surfel map maintenance and updates are achieved through co-visibility graph and map optimization. A comprehensive evaluation of CMDS-SLAM indicates that the method enables multi-robot surfel mapping and significantly alleviates data transmission pressures while achieving real-time updates and maintenance of the surfel map.
Crystal structure identification with 3D convolutional neural networks with application to high-pressure phase transitions in SiO2
Authors: Erhard Linus C , Utt Daniel , Klomp Arne J , Albe Karsten
Published: July 2024

Efficient, reliable and easy-to-use structure recognition of atomic environments is essential for the analysis of atomic scale computer simulations. In this work, we train two neuronal network (NN) architectures, namely PointNet and dynamic graph convolutional NN (DG-CNN) using different hyperparameters and training regimes to assess their performance in structure identification tasks of atomistic structure data. We show benchmarks on simple crystal structures, where we can compare against established methods. The approach is subsequently extended to structurally more complex SiO2 phases. By making use of this structure recognition tool, we are able to achieve a deeper understanding of the crystallization process in amorphous SiO2 under shock compression. Lastly, we show how the NN based structure identification workflows can be integrated into OVITO using its python interface.
Prevention of infinite-time blowup by slightly super-linear degradation in a Keller–Segel system with density-suppressed motility
Authors: Xiao Yamin , Jiang Jie
Published: July 2024

An initial-Neumann boundary value problem for a Keller–Segel system with density-suppressed motility and source terms is considered. Infinite-time blowup of the classical solution was previously observed for its source-free version when dimension

N
⩾
2

. In this work, we prove that with any source term involving a slightly super-linear degradation effect on the density, of a growth order of

s
log
⁡
s

at most, the classical solution is uniformly-in-time bounded when

N
⩽
3

, thus preventing the infinite-time explosion detected in the source-free counter-part. The cornerstone of our proof lies in an improved comparison argument and a construction of an entropy inequality.
An interpretable ensemble trees method with joint analysis of static and dynamic features for myocardial infarction detection
Authors: Liang Chunmiao , Sun Qinghua , Li Jiali , Ji Bing , Wu Weiming , Zhang Fukai , Chen Yuguo , Wang Cong
Published: July 2024

Objective. In recent years, artificial intelligence-based electrocardiogram (ECG) methods have been massively applied to myocardial infarction (MI). However, the joint analysis of static and dynamic features to achieve accurate and interpretable MI detection has not been comprehensively addressed. Approach. This paper proposes a simplified ensemble tree method with a joint analysis of static and dynamic features to solve this issue for MI detection. Initially, the dynamic features are extracted by modeling the intrinsic dynamics of ECG via dynamic learning in addition to extracting classical static features. Secondly, a two-stage feature selection strategy is designed to identify a few significant features, which substitute the original variables that are employed in constructing the ensemble tree. This approach enhances the discriminative ability by selecting significant static and dynamic features. Subsequently, this paper presents an interpretable classification method named StackTree by introducing a stacked ensemble scheme to modify the ensemble tree simplification algorithm. The representative rules of the raw ensemble trees are selected as the intermediate training data that is used to retrain a decision tree with performance close to that of the source ensemble model. Using this scheme, the significant precision and interpretability of MI detection are thus comprehensively addressed. Main results. The effectiveness of our method in detecting MI is evaluated using the Physikalisch-Technische Bundesanstalt (PTB) and clinical database. The findings suggest that our algorithm outperforms the traditional methods based on a single type of feature. Additionally, it is comparable to the conventional random forest, achieving 97.1% accuracy under the inter-patient framework on the PTB database. Furthermore, feature subsets trained on PTB are validated using the clinical database, resulting in an accuracy of 84.5%. The chosen important features demonstrate that both static and dynamic information have crucial roles in MI detection. Crucially, the proposed method provides clear internal workings in an easy-to-understand visual manner.
Identification of new gold lines in the 350–1000 nm spectral region using laser produced plasmas
Authors: Charlwood M , Chaurasia S , McCann M , Ballance C , Riley D , Keenan F P
Published: July 2024

We present results from a pilot study, using a laser-produced plasma, to identify new lines in the 350–1000 nm spectral region for the r-process element gold (Au), of relevance to studies of neutron star mergers. This was achieved via optical-IR spectroscopy of a laser-produced Au plasma, with an Au target of high purity (99.95%) and a low vacuum pressure to remove any air contamination from the experimental spectra. Our data were recorded with a spectrometer of 750 mm focal length and 1200 lines mm−1 grating, yielding a resolution of 0.04 nm. We find 54 lines not previously identified and which are not due to the impurities (principally copper (Cu) and silver (Ag)) in our Au sample. Of these 54 lines, we provisionally match 21 strong transitions to theoretical results from collisional-radiative models that include energy levels derived from atomic structure calculations up to the 6s level. Some of the remaining 33 unidentified lines in our spectra are also strong and may be due to transitions involving energy levels which are higher-lying than those in our plasma models. Nevertheless, our experiments demonstrate that laser-produced plasmas are well suited to the identification of transitions in r-process elements, with the method applicable to spectra ranging from UV to IR wavelengths.
Internal dosimetry assessment of beta, beta/auger, and alpha decaying radionuclides in targeted radionuclide therapy for prostate cancer: a simulation study
Authors: Karadeniz-Yildirim Ayşe
Published: July 2024

The study employs the Monte Carlo method to calculate the internal dosimetry of beta, beta/Auger and alpha-type decaying radionuclides used in the treatment of prostate cancer. The distributions of dose to the prostate and critical organs were simulated on a virtual phantom using GATE MC software. In GATE simulation, geometric parameters and densities were determined for the prostate as the source organ and the kidneys, liver, testicles, and bladder as critical organs. In the prostate geometry, Lu-177, Ac-225, and Tb-161 with an activity of 370 MBq were identified. Using the DoseActors command, the S values, instant absorbed doses (Gy/s), uncertainties, and total absorbed doses (Gy) were computed and saved as an output file in the TXT format. Dosimetric comparison was made between different TRTs according to the absorbed doses in the source and critical organs. The prostate was found to be the tissue that received the highest instant absorbed dose with 8.397E-03, 1.594E+00 and 1.195E-02 Gy/s for Lu-177, Ac-225 and Tb-161, respectively. The kidney, liver, and testicles were taken lowest instant absorbed doses with 3.888E-08 (mean), 5.679E-08, and 4.302E-07 (mean) Gy/s by Tb-161. Lu-177 gave the lowest instant absorbed doses of 5.731E-07 Gy/s for the bladder. It was found that there was no overdose in any critical organ according to the critical threshold values given to protect the organs from radiation-related toxic effects. However, testicles were additionally evaluated in terms of fertility. Ac-225 and Tb-161 were radionuclides that produced optimal doses for TRT.
Investigation of structural, morphological, optical and electronic properties of Cu-doped PbS thin films: a comparative experimental and theoretical study
Authors: Ramay Shahid M , Aldosary Mohammed H
Published: July 2024

Thin film technology has emerged as a cornerstone in optoelectronics, enabling the fabrication of compact, lightweight devices with enhanced performance and efficiency through precise control of the nanoscale thicknesses of functional materials. The current study explores the impact of copper (Cu) doping (3.125%, 6.25%, and 12.5%) on lead (Pb) sites in PbS to examine the structural, morphological, electronic, optical, and thermoelectric characteristics, employing both experimental and theoretical approaches. Polycrystalline thin films of PbS are deposited by spin coating technique on glass substrates. The XRD study discloses the cubic crystal structure of pristine and Cu-doped PbS with nominal variation in d-spacing. Surface morphological investigations reveal that Cu-doping transforms the coffee beans like grains to nanoplates that significantly affect the surface homogeneity and porosity. The tuning of band structure in the visible range, 1.64–2.21 eV is witnessed in the band structure analysis. Moreover, the experimental results are complemented by a theoretical study using WIEN2k software. Theoretical study exhibits the direct bandgap nature and with the incorporation of Cu, it increases from 0.89 to 2.11 eV. The density of states spectra for Cu-doped PbS exhibits strong hybridization between p-states of Pb and S, and d-states of Cu. Optical findings demonstrate significant variations in the absorption spectrum, which result in modifications in the optical energy band gap and peculiar optical parameters of doped samples. At room temperature, the increase in electrical conductivity (σ/τ) from 0.2 × 1020 (Ω.m.s)−1 for PbS to 0.3 × 1020, 3.1 × 1020 and 7.8 × 1020 (Ω.m.s)−1, thermal conductivity from 0.25 × 1014 W m.K.s−1 to 0.30 × 1014, 2.4 × 1014 and 5.2 × 1014 W m.K.s−1 and decrease in Seebeck coefficient from 72 to 35, 13 and 8 μV/K with the inclusion of Cu up to 3.125, 6.25 and 12.5% offer the potential for advancing thermoelectric technology. This could lead to improved efficiency and practical utilization in energy harvesting and waste heat recovery.
On the validity of using spectrophotometry of cuvettes to provide a dose-response calibration for radiochromic optical computed tomography-based three-dimensional dosimetry
Authors: Jensen M B , Balling P , Vindbæk S H , Doran S J , Jensen M L , Petersen J B B , Muren L P
Published: July 2024

The dose response of materials used in radiochromic three-dimensional (3D) dosimeters is often characterised via spectrophotometry of small cuvette samples as it is less time-consuming and cheaper. However, spatially-resolved dose measurements for clinical purposes are obtained using 3D optical computed tomography (CT). Hence, the link between the method of characterisation and the method for extracting 3D dose information must be established. The aim of this study was to investigate if spectrophotometry-based dose-response characterisation using cuvette-sized samples is valid for calibration of 3D optical CT readout systems using a silicone-based radiochromic dosimeter. Additionally, the uniformity of 3D optical CT dose-response readout of larger samples was investigated. We found the dose response of cuvette-sized samples read out by spectrophotometry to agree with the averaged dose response across cuvette-sized samples read out by optical CT and with the response near the edges of larger samples scanned using the same apparatus. Thus, cuvette-based dose-response spectrophotometry can be used to calibrate 3D optical CT readout using silicone-based radiochromic dosimeters. However, caution should be taken when considering larger samples as they exhibit a gradual radial increase in dose response from the centre and outwards.
Mapping 3D doses in water with a cable robot equipped with plastic scintillator
Authors: Archambault Louis , Mersi Ramin , Foucault Simon , Berthiaume Frédérik , Lessard Boby , Therriault-Proulx Francois , Cardou Philippe
Published: July 2024

This work presents the first use of a cable robot for 3D dosimetry. Its design was optimized to operate in water and offer five degrees of freedom. It was equipped with a plastic scintillation detector. The cables and the end effector were made of plastic, thus making all components inside the phantom water equivalent. Feasibility and reproducibility was demonstrated using a 6MV beam. The cable robot prototype had a usable workspace of 40 cm in each direction and could rotate over 90 degrees in both the polar and azimuthal directions. It was tested at speeds of up to 120.8 mm/s. Position precision was within 2.5 mm for translation and within 1.1 mm for rotations about a fixed point. This new robotic dosimetry system is more versatile and can address limitations of current water phantoms that are constrained to only 3 translation axes.
Preliminary study on a bifunctional, elastic NBT–PVA radiochromic gel acting as a bolus and dosimeter in radiotherapy
Authors: Jaszczak-Kuligowska M. , Maras P. , Kozicki M.
Published: July 2024

This work presents a new elastic radiochromic gel containing a radiation-sensitive nitro blue tetrazolium chloride (NBT) embedded in a poly(vinyl alcohol) (PVA) matrix, which can simultaneously function as a bolus and a dosimeter in radiotherapy.
A heterogeneous-cavity model for miniaturized detectors of orthovoltage X-rays
Authors: Thevenet F. , Keshmiri S. , Moussaoui M. , Huffschmidt B. , Esteves J. , Lu G-N. , Adam J-F , Pittet P.
Published: July 2024

To meet the needs of modelling small-sized detectors of orthovoltage X-rays, for spatially fractionated radiotherapy, we propose a model to determine responses of the detectors in cases of highly heterogeneous cavity. The model was applied to a detector whose cavity features a sparse high-Z perovskite scintillation layer embedded in an epoxy resin. Irradiations were carried out using the Small Animal Radiation Research Platform. Local photon and electron spectra were computed by the SpekPy toolbox and Penelope Monte Carlo simulations, respectively. The detector model considers that X-ray photons mainly interact with medium surrounding the scintillation layer, and that the output of the detector mainly results from secondary electrons in this layer. Results from model computations are compared with measurement data, showing differences less than 16% for beam energies in the 60 kVp −220 kVp range.
Applications of Polarization Imaging for Conventional and FLASH Radiotherapy Dosimetry
Authors: Cloutier Émily , Lalonde Arthur , Zerouali Karim , Beaulieu Luc , Archambault Louis
Published: July 2024

The application of Cherenkov radiation in radiation therapy dosimetry has been limited by the anisotropic nature of the signal. Recently, polarization imaging was investigated as a method to correct Cherenkov anisotropy and allow precise dose measurements directly in a water tank. The aim of this study is to present polarization imaging as method for the measurement of ultra-high dose rate (UHDR) intra-operative electron beams. In this new approach, the polarized Cherenkov signal was isolated and utilized as a surrogate to evaluate the quality and consistency of both UHDR and conventional electron beams. Percent depth Cherenkov signal were measured for different energies, field sizes and dose rates. The results demonstrate high linearity (R
2 > 0.99) of the Cherenkov signal with the number of pulses and pulse width. The wide dynamic range of the device enabled measurement for both conventional and UHDR radiation beams making it a promising candidate for real-time quality assurance devices.
Real-time Plastic Scintillation Dosimetry of Ultra-High Dose Rate Very High Energy Electrons (VHEE) at CERN CLEAR Facility
Authors: Giguère Cloé , Hart Alexander , Bateman Joseph , Korysko Pierre , Farabolini Wilfrid , LeChasseur Yoan , Bazalova-Carter Magdalena , Beaulieu Luc
Published: July 2024

Very High Energy Electrons (VHEE) that can theoretically treat deep-seated tumours and be delivered at ultra-high dose rates (UHDR) could be the solution to translate FLASH radiotherapy into the clinic. Standard dosimeters have limited application in those extreme conditions, but dose-rate independent and fast-response plastic scintillation detectors (PSDs) are a potential alternative to overcome this. In this work, response of a 4-channel PSD to the 200 MeV VHEE UHDR beam delivered with doses and dose rates in pulse up to 90 Gy and 4.6 × 109 Gy/s, respectively, at the CLEAR facility in CERN was characterized, using the Hyperscint RP200 platform. Scintillation light linearity with dose was observed for three scintillators from ∼5-50 Gy, while clear eiber output was linear up to 90 Gy. While linearity on this dose range was conserved even after radiation damage by exposure to 37.2 kGy total accumulated dose, light output signieicantly decreased. This work proves the potential of plastic scintillators for real-time dosimetry of UHDR VHEE beams.
On the use of Al2O3:C and plastic scintillators for small-field dosimetry in MR-linacs
Authors: Andersen Claus E. , Klavsen Mads F. , Ankjærgaard Christina
Published: July 2024

Fiber coupled luminescence detectors based on organic plastic scintillators or inorganic materials such as Al2O3:C are suitable for dosimetry in strong magnetic fields as found in MR-linacs. The main finding of this work was that field-output factor measurements at the maximum dose point are less variable than if measured at the central beam axis (CAX). In contrast to plastic scintillators, Al2O3:C was found to have a yield of radioluminescence per dose that (within uncertainty) is independent of the magnetic field strength.
Dosimetric Evaluation of an Adaptive Planning Strategy for Implant Shift in HDR Prostate Brachytherapy
Authors: Wallace Jordan , Hanlon Maximilian , Smith Ryan L , Franich Rick
Published: July 2024

The occurrence of significant implant shifts between CT simulation planning and first fraction delivery is a frequent challenge for HDR prostate brachytherapy treatment. Here, we present evidence supporting the viability of a first-order adaptation strategy as a viable alternative to the conventional practice of re-scanning and re-planning. Our findings underscore the potential of this approach to enhance workflow efficiency in HDR prostate brachytherapy.
Three-dimensional dosimetry of dose degradations around gold markers in spot-scanning proton therapy
Authors: Valdetaro Lia B , Stolarczyk Liliana , Skyt Peter S , Petersen Stine E , Rønde Heidi S , Balling Peter , Petersen Jørgen B B , Muren Ludvig P
Published: July 2024

Fiducial markers are necessary for some tumor sites to ensure safe and accurate delivery of radiotherapy including proton therapy (PT). However, the high metal content of the markers may lead to shadowing of the proton beam. The aim of this study was to investigate the dose degradations around three fiducial marker types implanted in different configurations into a 3D dosimeter. The dosimeters were irradiated with a clinically relevant prostate cancer PT plan. Gamma comparisons (2%-2mm) between the control (no marker) and marker dosimeters resulted in a pass rate of 97%, and no significant differences were observed in the isodoses, indicating that markers did not affect dose coverage to the target. However, due to optical artifacts, the 3D dosimeter was unable to resolve the regions within a few millimeters from the markers.
Extension of a radiation transport model for water-equivalent, portal imaging dose applications
Authors: Kutuzov Ivan , Rivest Ryan , Van Uytven Eric , McCurdy Boyd
Published: July 2024

The amorphous-silicon based design of electronic portal imaging device (a-Si EPID) is commonly available on medical linear accelerators, and thus presents enormous potential as a radiotherapy dosimetry tool. One of the recognized technical challenges with using the device is it’s lack of water equivalency when measuring dose. In this work a radiation transport model, previously used to predict dose to the phosphor of an a-Si EPID, was modified to predict dose to a water-equivalent planar detector as well as to a 3D water-tank. Initial testing was performed for a 6MV beam using a variety of simple square fields and clinically relevant intensity modulated fields. Using a 2% criterion, the predicted versus measured image comparisons had pass rates between 95.9-98.2% for the square fields, and 89.2-96.3% for the modulated fields. The predicted 3D dose distribution showed a percentage depth dose agreement within 1% of that measured in a water tank (beyond 5 mm depth). These initial validation results provide confidence that the radiation transport model could be used for water-equivalent dosimetric applications in clinical radiotherapy.
Advancements in stimulation therapies for peripheral nerve regeneration
Authors: Bordett Rosalie , Danazumi Khadija B , Wijekoon Suranji , Garcia Christopher J , Abdulmalik Sama , Kumbar Sangamesh G
Published: July 2024

Soft-tissue injuries affecting muscles, nerves, vasculature, tendons, and ligaments often diminish the quality of life due to pain, loss of function, and financial burdens. Both natural healing and surgical interventions can result in scarring, which potentially may impede functional recovery and lead to persistent pain. Scar tissue, characterized by a highly disorganized fibrotic extracellular matrix, may serve as a physical barrier to regeneration and drug delivery. While approaches such as drugs, biomaterials, cells, external stimulation, and other physical forces show promise in mitigating scarring and promoting regenerative healing, their implementation remains limited and challenging. Ultrasound, laser, electrical, and magnetic forms of external stimulation have been utilized to promote soft tissue as well as neural tissue regeneration. After stimulation, neural tissues experience increased proliferation of Schwann cells, secretion of neurotropic factors, production of myelin, and growth of vasculature, all aimed at supporting axon regeneration and innervation. Yet, the outcomes of healing vary depending on the pathophysiology of the damaged nerve, the timing of stimulation following injury, and the specific parameters of stimulation employed. Increased treatment intensity and duration have been noted to hinder the healing process by inducing tissue damage. These stimulation modalities, either alone or in combination with nerve guidance conduits and scaffolds, have been demonstrated to promote healing. However, the literature currently lacks a detailed understanding of the stimulation parameters used for nerve healing applications. In this article, we aim to address this gap by summarizing existing reports and providing an overview of stimulation parameters alongside their associated healing outcomes.
Design of gelatin cryogel scaffolds with the ability to release simvastatin for potential bone tissue engineering applications
Authors: Yaman Suzan Melis , Demir Didem , Bölgen Nimet
Published: July 2024

Tissue engineering aims to improve or restore damaged tissues by using scaffolds, cells and bioactive agents. In tissue engineering, one of the most important concepts is the scaffold because it has a key role in keeping up and promoting the growth of the cells. It is also desirable to be able to load these scaffolds with drugs that induce tissue regeneration/formation. Based on this, in our study, gelatin cryogel scaffolds were developed for potential bone tissue engineering applications and simvastatin loading and release studies were performed. Simvastatin is lipoliphic in nature and this form is called inactive simvastatin (SV). It is modified to be in hydrophilic form and converted to the active form (SVA). For our study’s drug loading and release process, simvastatin was used in both inactive and active forms. The blank cryogels and drug-loaded cryogels were prepared at different glutaraldehyde concentrations (1, 2, and 3%). The effect of the crosslinking agent and the amount of drug loaded were discussed with morphological and physicochemical analysis. As the glutaraldehyde concentration increased gradually, the pores size of the cryogels decreased and the swelling ratio decreased. For the release profile of simvastatin in both forms, we can say that it depended on the form (lipophilic and hydrophilic) of the loaded simvastatin.
MXene reinforced microporous bacterial cellulose/sodium alginate dual crosslinked cryogel for bone tissue engineering
Authors: Hu Tongzhou , Cai Pengfei , Xia Chenggen
Published: July 2024

The entangled assembly of bacterial cellulose (BC) nanofibers does not provide a three-dimensional (3D) macroporous structure for cellular infiltration thus hindering its use as a scaffold for bone tissue engineering. In addition, it is difficult to achieve uniform dispersion of bioactive agents in entangled BC nanofibers. To address this, the BC nanofibers were integrated with MXene, a two-dimensional nanomaterial known for its electrical signaling and mechanical strength, along with sodium alginate to form cryogel. The cryogel was fabricated using a cross-linking to enhance its mechanical properties, pores for cellular infilteration. MXene incorporation not only increased water absorption (852%–1446%) and retention (692%–973%) ability but also significantly improved the compressive stress (0.85 MPa–1.43 MPa) and modulus (0.22 MPa–1.17 MPa) confirming successful MXene reinforcement in cryogel. Biological evaluation revealed that the optimum concentration of MXene increased the cell proliferation and the osteogenic role of fabricated scaffolds was also confirmed through osteogenic gene expressions. The macropores in reconstructed MXene-BC-based cryogel provided ample space for cellular proliferation. The osteogenic role of the scaffold was examined through various gene expressions. The Quantitative polymerase chain reaction revealed that MXene-loaded scaffolds especially in low concentration, had an obvious osteogenic effect hence concluding that BC can not only be reconstructed into the desired form but osteogenic property can be induced. These findings can open a new way of reconstructing BC into a more optimal structure to overcome its structural limitations and retain its natural bioactivities.
Improving estimations of GHG emissions and removals from land use change and forests in Brazil
Authors: Zimbres Barbara , Shimbo Julia , Lenti Felipe , Brandão Amintas , Souza Edriano , Azevedo Tasso , Alencar Ane
Published: July 2024

Brazil ranks fifth in greenhouse gas emissions globally due to land use change. As a signatory to the Paris Agreement, Brazil must periodically report its GHG emissions as well as present mitigation targets set in the Nationally Determined Contribution (NDC). The SEEG Brazil Initiative (Greenhouse Gas Emission and Removal Estimating System) generates independent estimates of GHG emissions and removals since 2013, and in 2020, the estimation method for the land use change sector has been improved. This study aimed to (1) present these methodological advancements, including the spatial allocation of annual emissions and removals due to land use change (LUC) in Brazil at a 30 m spatial scale, and (2) explore the emission and removal patterns observed in Brazil from 1990 to 2019. The method presented here is built upon—but improves—the approach used by Brazil’s official National Inventories to estimate GHG emissions and removals. The improvements presented here include exploring emissions to the municipality level and using an annual updated time series of land use and land cover maps. Estimated greenhouse gas emissions from the LUC sector ranged from 687 Mt of CO2e in 2011 to a peak of 2150 Mt of CO2e in 2003. In 2010, removals nearly offset gross emissions in the sector, with a net emission of 116 Mt of CO2e. The trend observed in recent years was an increase in emissions, decreasing Brazil’s likelihood of meeting its NDC targets. Emission profiles vary across the country, but in every biome, the conversion of primary native vegetation is the predominant transition type. If Brazil managed to curb deforestation, the total GHG emissions from the land use change sector would decrease by 96%, mitigating around 44% of total emissions.
Tribology of Mg-B4C nanocomposites fabricated following powder metallurgy route
Authors: Hazra Samrat , Chattopadhyay Subhajit , Chakravarty Soumyabrata , kumar Mandal Nirmal
Published: July 2024

In this experimental work, magnesium nanocomposite reinforced with various percentage of boron carbide (0.5%, 1.0%, 1.5%, 2.0% by volume) is fabricated using conventional powder metallurgy technique. Characterisation and wear test of the fabricated composite have been performed using scanning electron microscopy, tribology test monitor respectively. It is observed that addition of B4C increases the hardness and wear resistance linearly. Addition of 2% B4C produces the hardness of the nanocomposites as high as 57.93 ± 4.9 Hv. Furthermore, the nanocomposites displayed improved wear resistance and lower friction coefficient compared to the base magnesium. The influence of sliding speed on these properties has been systematically presented. The paper provides an in-depth exploration of wear mechanisms through a meticulous analysis of SEM micrographs of worn surfaces. This work offers valuable insights into the microstructural characteristics and tribological behaviour of Mg-B4C nanocomposites. These findings underscore the potential application of Mg-B4C nanocomposites in the development of lightweight wear-resistant materials. The impact of incorporating minute amounts of nano-sized boron carbide into Mg, on its behaviour under small loads and repeated scratching has been investigated in this study. Moreover, introspection of the wear mechanisms and the effectiveness of the powder metallurgy technique in fabricating composite materials is presented.
Utilizing deep learning via computer vision for agricultural production quality control: jackfruit growth stage identification
Authors: Krishnan Sreedeep , Karuppasamypandiyan M , Chandran Ranjeesh R , Devaraj D
Published: July 2024

Jackfruit (Artocarpus heterophyllus), a tropical fruit renowned for its diverse culinary uses, necessitates identifying the optimal growth stage to ensure superior flavor and texture. This research investigates employing deep learning techniques, particularly convolutional neural networks (CNNs), for accurately detecting jackfruit growth stages. Despite the challenge posed by the nuanced visual differences among fruits at various maturity stages, a meticulously curated dataset of labeled jackfruit images was developed in collaboration with experts, utilizing the BBCH scale. This dataset facilitated training and evaluation. A modified version of the Places 365 GoogLeNet CNN model was proposed for classifying four distinct growth stages of jackfruit, compared with a state-of-the-art CNN model. The trained models demonstrated varying levels of accuracy in classification. Furthermore, the proposed CNN model was trained and tested using original and augmented images, achieving an impressive overall validation accuracy of 90%. These results underscore the efficacy of deep learning in automating the detection of growth stages, offering promising implications for quality control and decision-making in jackfruit production and distribution.
Molecular relaxation by reverse diffusion with time step prediction
Authors: Kahouli Khaled , Hessmann Stefaan Simon Pierre , Müller Klaus-Robert , Nakajima Shinichi , Gugler Stefan , Gebauer Niklas Wolf Andreas
Published: July 2024

Molecular relaxation, finding the equilibrium state of a non-equilibrium structure, is an essential component of computational chemistry to understand reactivity. Classical force field (FF) methods often rely on insufficient local energy minimization, while neural network FF models require large labeled datasets encompassing both equilibrium and non-equilibrium structures. As a remedy, we propose MoreRed, molecular relaxation by reverse diffusion, a conceptually novel and purely statistical approach where non-equilibrium structures are treated as noisy instances of their corresponding equilibrium states. To enable the denoising of arbitrarily noisy inputs via a generative diffusion model, we further introduce a novel diffusion time step predictor. Notably, MoreRed learns a simpler pseudo potential energy surface (PES) instead of the complex physical PES. It is trained on a significantly smaller, and thus computationally cheaper, dataset consisting of solely unlabeled equilibrium structures, avoiding the computation of non-equilibrium structures altogether. We compare MoreRed to classical FFs, equivariant neural network FFs trained on a large dataset of equilibrium and non-equilibrium data, as well as a semi-empirical tight-binding model. To assess this quantitatively, we evaluate the root-mean-square deviation between the found equilibrium structures and the reference equilibrium structures as well as their energies.
Design, synthesis and anti-oxidant activities of novel 1,2,3,4-tetrazine, 1,2,3-triazoles and coumarin derivatives and their nanoparticular encapsulation
Authors: Eyilcim Oznur , Belmen Burcu , Coksu Irem , Acar Serap , Yolacan Cigdem , Gunkara Omer Tahir
Published: July 2024

Nitrogen-containing heterocyclic compounds are currently used for a number of pharmaceutical and agricultural applications because they have biological activities such as antimicrobial, antiviral, antituberculosis, anticancer, analgesic, antioxidant, anti-inflammatory and antidepressant. 1,2,3,4-Tetrazines and 1,2,3-triazoles are examples of high-nitrogen heterocyclic compounds. Coumarins, on the other hand, are lactones that form a group of oxygenated heterocyclic compounds found in plants. In this article, two analogs of 1,2,3,4-tetrazine, two analogs of 1,2,3-triazole and five analogs of coumarin were designed and synthesized. Their chemical structures were characterized by detecting their FTIR, 1H-NMR, and 13C-NMR (APT) spectra. The antioxidant activities of all synthesized molecules were compared at a fixed concentration (0.25 mg ml−1) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Molecules 9c and 9e, which showed the highest antioxidant activity, were loaded into PLGA (poly(lactic-co-glycolic) acid) nanoparticles using the oil in water (o/w) single emulsion solvent evaporation method as a model study. Synthesized nanoparticles characterized for particle size, zeta potential, functional groups, morphology, and release properties. Particle size and zeta potential of 9c/NP were determined as 216.1 ± 8.944 nm and −14.1 ± 2.40 mV, respectively. The particle size and zeta potential for 9e/NP were measured as 222.0 ± 12.490 nm and −12.4 ± 1.42 mV respectively. The study results obtained on model nanoparticle systems with elucidated physicochemical properties may have the potential to provide a promising basis for oxidative stress-related diseases in the future.
Optical investigations of coherence and relaxation dynamics of a thulium-doped yttrium gallium garnet crystal at sub-kelvin temperatures for optical quantum memory
Authors: Das Antariksha , Falamarzi Askarani Mohsen , Davidson Jacob H , Sinclair Neil , Slater Joshua A , Marzban Sara , Oblak Daniel , Thiel Charles W , Cone Rufus L , Tittel Wolfgang
Published: July 2024

Rare-earth ion-doped crystals are of great interest for quantum memories, a central component in future quantum repeaters. To assess the promise of 1

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Tm3+-doped yttrium gallium garnet (Tm:YGG), we report measurements of optical coherence and energy-level lifetimes of its 3H

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H4 transition at a temperature of around 500 mK and various magnetic fields. Using spectral hole burning (SHB), we find hyperfine ground-level (Zeeman level) lifetimes of several minutes at magnetic fields of less than 1000 G. We also measure coherence time exceeding one millisecond using two-pulse photon echoes. Three-pulse photon echo and SHB measurements reveal that due to spectral diffusion, the effective coherence time reduces to a few µs over a timescale of around two hundred seconds. Finally, temporal and frequency-multiplexed storage of optical pulses using the atomic frequency comb protocol is demonstrated. Our results suggest Tm:YGG to be promising for multiplexed photonic quantum memory for quantum repeaters.
The LCLAT1/LYCAT acyltransferase is required for EGF-mediated phosphatidylinositol-3,4,5-trisphosphate generation and Akt signaling
Authors: Chan Victoria , Camardi Cristina , Zhang Kai , Orofiamma Laura A. , Anderson Karen E. , Hoque Jafarul , Bone Leslie N. , Awadeh Yasmin , Lee Daniel K. C. , Fu Norman J. , Chow Jonathan T. S. , Salmena Leonardo , Stephens Len R. , Hawkins Phillip T. , Antonescu Costin N. , Botelho Roberto J.
Published: July 2024

Receptor tyrosine kinases such as EGF receptor (EGFR) stimulate phosphoinositide 3 kinases to convert phosphatidylinositol-4,5-bisphosophate [PtdIns(4,5)P2] into phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P3]. PtdIns(3,4,5)P3 then remodels actin and gene expression, and boosts cell survival and proliferation. PtdIns(3,4,5)P3 partly achieves these functions by triggering activation of the kinase Akt, which phosphorylates targets like Tsc2 and GSK3β. Consequently, unchecked upregulation of PtdIns(3,4,5)P3-Akt signaling promotes tumor progression. Interestingly, 50–70% of PtdIns and PtdInsPs have stearate and arachidonate at sn-1 and sn-2 positions of glycerol, respectively, forming a species known as 38:4-PtdIns/PtdInsPs. LCLAT1 and MBOAT7 acyltransferases partly enrich PtdIns in this acyl format. We previously showed that disruption of LCLAT1 lowered PtdIns(4,5)P2 levels and perturbed endocytosis and endocytic trafficking. However, the role of LCLAT1 in receptor tyrosine kinase and PtdIns(3,4,5)P3 signaling was not explored. Here, we show that LCLAT1 silencing in MDA-MB-231 and ARPE-19 cells abated the levels of PtdIns(3,4,5)P3 in response to EGF signaling. Importantly, LCLAT1-silenced cells were also impaired for EGF-driven and insulin-driven Akt activation and downstream signaling. Thus, our work provides first evidence that the LCLAT1 acyltransferase is required for receptor tyrosine kinase signaling.
The Nature and Origins of Anti-Intellectualism
Authors: Motta Matthew
Published: July 2024

Chapter 2 proposes a novel, unified, and group-centric theory for understanding the causes and consequences of anti-intellectualism. It begins by describing anti-intellectualism as an affective (feeling-based) and group-centric (us versus them) phenomenon. It then introduces a novel theoretical model that identifies several socio-political determinants of anti-intellectualism (e.g., partisan identity) and considers how Americans’ knowledge and interest in scientific topics might inspire change in anti-intellectual attitudes over time. Importantly, Chapter 2 revives Hofstadter’s often-overlooked prediction positing a dynamic (bidirectional) relationship between opposition to experts’ policy influence and anti-intellectualism. The chapter concludes by pushing back on the idea that partisan polarization in anti-intellectual attitude endorsement began in the 1980s and either (1) has grown steadily over time or (2) arose in response to the Reagan and (W.) Bush presidencies. Instead, the Tea Party movement’s strategic efforts to denigrate experts are primarily responsible for contemporary partisan polarization of anti-intellectual attitudes.
Origin Story Part I: Explaining Between-Person Differences in Anti-Intellectual Attitude Endorsement
Authors: Motta Matthew
Published: July 2024

Chapter 5 offers an initial test of the theoretical predictions outlined in Chapter 2 by assessing the determinants of differences in anti-intellectualism between people. Across dozens of surveys spanning several decades, the chapter shows that Republicans, political conservatives, people who prefer a smaller role for government in everyday life, and highly religious people tend to be more likely to hold anti-intellectual attitudes. Critically, and contrary to previous work suggesting that anti-intellectual attitude endorsement has either steadily polarized along partisan lines since the 1980s or has grown in response to the anti-science policies of Ronald Reagan and George W. Bush, Chapter 5 shows that partisan polarization was uncommon prior to the 2010 Tea Party midterm elections. The chapter further substantiates the movement’s polarizing influence by showing that Tea Party–identifying Republicans were more likely than all other Republicans to endorse anti-intellectual sentiments throughout the Obama presidency.
Cerebral microbleeds in patients with COVID-19: is there an inevitable connection?
Authors: Wang Yuchang , Hu Yuetao , Zhao Ruichen , Wang Qi , Xu Jiarui , Yuan Jiangyuan , Dong Shiying , Liu Mingqi , Wu Chenrui , Jiang Rongcai
Published: July 2024

The COVID-19 pandemic has underscored the critical interplay between systemic infections and neurological complications, notably cerebral microbleeds. This comprehensive review meticulously aggregates and analyses current evidence on cerebral microbleeds’ prevalence, pathophysiological underpinnings and clinical implications within COVID-19 cohorts. Our findings reveal a pronounced correlation between cerebral microbleeds and increased severity of COVID-19, emphasizing the role of direct viral effects, inflammatory responses and coagulation disturbances. The documented association between cerebral microbleeds and elevated risks of morbidity and mortality necessitates enhanced neurological surveillance in managing COVID-19 patients. Although variability in study methodologies presents challenges, the cumulative evidence substantiates cerebral microbleeds as a critical illness manifestation rather than mere coincidence. This review calls for harmonization in research methodologies to refine our understanding and guide targeted interventions. Prioritizing the detection and study of neurological outcomes, such as cerebral microbleeds, is imperative for bolstering pandemic response strategies and mitigating the long-term neurological impact on survivors.