bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect and mechanism of high‐fat diet on the preference for sweeteners on mice
Authors: Yin Kai‐Jing , Ren Jing‐Nan , Li Xiao , Fan Gang , Zhao Lei , Li Zhi , Zhang Lu‐Lu , Xie Ding‐Yuan , Pan Si‐Yi , Yuan Fang
Published: September 2020

BACKGROUND

Male Kunming mice were divided into a normal diet group (control group) and a high‐fat diet group (HF group) (185 g·kg−1 protein, 600 g·kg−1 fat and 205 g·kg−1 carbohydrate). After 8 weeks' feeding, behavioral indicators and biochemical indicators in serum were determined. The double‐bottle preference experiment was used to study the preferences of mice for five sweeteners. The monoamine neurotransmitter content, gene expression related to dopamine (DA), and opioid receptors were also determined.

RESULTS

The body weight of the mice in the HF group increased significantly (P < 0.05) after 36 days compared with the control group. The feed intake of the HF group increased sharply in the first 12 days, and then it became basically unchanged. The preference of the HF group for all of the five sweeteners was highly significantly lower (P < 0.01) than that of the control group. Depression‐related behavior was observed in the HF group mice. The triglyceride (TG), total cholesterol (TC), and low‐density lipoprotein cholesterol (LDLC) content in the HF group were very much higher (P < 0.01) than those of the control group. The gene expression related to DA and opioid receptor in the HF group was significantly lower than that of the control group, except for preproenkephalin (PENK).

CONCLUSIONS

In summary, this study suggested that a long‐term high‐fat diet could result in a decrease in the preference for sweeteners and could result in a state of reward hypofunction in mice. © 2020 Society of Chemical Industry
Improving the digestibility of cereal fractions of wheat, maize, and rice by a carbohydrase complex rich in xylanases and arabinofuranosidases: an in vitro digestion study
Authors: Vangsøe Cecilie T , Bonnin Estelle , Joseph‐Aime Maud , Saulnier Luc , Neugnot‐Roux Virginie , Bach Knudsen Knud E
Published: September 2020

BACKGROUND

Cereal co‐products rich in dietary fibres are increasingly used in animal feed. The high fibre content decreases the digestibility and reduces the nutrient and energy availability, resulting in lower nutritive value. Therefore, this study investigated the ability of two carbohydrase complexes to solubilize cell‐wall polysaccharides, in particular arabinoxylan (AX), from different cereal fractions of wheat, maize, and rice using an in vitro digestion model of the pig gastric and small intestinal digestive system. The first complex (NSPase 1) was rich in cell‐wall‐degrading enzymes, whereas the second complex (NSPase 2) was additionally enriched with xylanases and arabinofuranosidases. The extent of solubilization of insoluble cell‐wall polysaccharides after in vitro digestion was evaluated with gas–liquid chromatography and an enzymatic fingerprint of the AX oligosaccharides was obtained with high‐performance anion‐exchange chromatography with pulsed amperometric detection.

RESULTS

The addition of carbohydrase increased the digestibility of dry matter and solubilized AX in particular, with the greatest effect in wheat fractions and less effect in maize and rice fractions. The solubilization of AX (expressed as xylose release) ranged from 6% to 41%, and there was an increased effect when enriching with xylanases and arabinofuranosidases in wheat aleurone and bran of 19% and 14% respectively. The enzymatic fingerprint of AX oligosaccharides revealed several non‐final hydrolysis products of the enzymes applied, indicating that the hydrolysis of AX was not completed during in vitro digestion.

CONCLUSION

These results indicate that the addition of a carbohydrase complex can introduce structural alterations under in vitro digestion conditions, and that enrichment with additional xylanases and arabinofuranosidases can boost this effect in wheat, maize, and rice. © 2020 Society of Chemical Industry
Calcium applications throughout fruit development enhance olive quality, oil yield, and antioxidant compounds' content
Authors: Morales‐Sillero Ana , Lodolini Enrico María , Suárez María Paz , Navarrete Víctor , Jiménez María Rocío , Casanova Laura , Gregori Luca , Rallo Pilar , Martín‐Vertedor Daniel
Published: September 2020

BACKGROUND

Calcium is a preservative and firming agent largely used in the table olive industry. Foliar applications of calcium (as calcium chloride, CaCl2) before harvest have been proposed in other fruits to increase firmness and reduce physiological disorders or internal damage. However, there is still a shortage of information regarding the source, the concentration, the number, and the period of calcium application onto the canopy to get an effective response of olive quality. In this study, we aimed to investigate the effect of two concentrations of CaCl2 foliar treatments (0.5% and 1.0%), applied at different stages of fruit development (at the end of fruit set, end of pit hardening, and prior to harvesting), on olive quality for two varieties (‘Manzanilla de Sevilla’ and ‘Ascolanta tenera’), cultivated in two different geographical areas (Spain and Italy respectively).

RESULTS

The calcium concentrations applied enhanced the fruit calcium content and decreased sodium and potassium. They also improved the mechanical properties without modifying fruit morphology or cuticle thickness; nor did they cause phytotoxicity. Foliar treatments increased the oil content in the pulp (dry weight basis) and the amount of hydroxytyrosol, tyrosol, and oleuropein, among other phenols.

CONCLUSION

Calcium foliar applications during fruit development effectively increase olive quality. © 2020 Society of Chemical Industry
Impacts of soil use and management on water quality in agricultural watersheds in Southern Brazil
Authors: Martíni Aline F. , Favaretto Nerilde , De Bona Fabiano D. , Durães Matheus F. , de Paula Souza Luiz C. , Goularte Gabriel D.
Published: September 2020

Worldwide, agriculture is considered one of the main activities that influence water quality. The objective of this work was to evaluate the influence of soil use and management on water quality at the small watershed scale, in Southern Brazil. One watershed is characterized by production of annual crop seeds under no‐tillage (zero tillage), with crop rotation and with terraces (Sarandi watershed—SW), while the other is characterized by production of grains in the summer and pasture with grazing in the winter, under no‐tillage, without crop rotation and without terraces (Coxilha watershed—CW). Flow and climatic data were measured during 2 years. Water samples were manually taken at precipitation events and base flow over 1 year for laboratory analysis. During events of high volume, most of the rainfall was converted to base flow in SW, while in CW, most of the rainfall was transformed into overland flow. Overall, higher concentrations and losses of sediments and nutrients occurred in the CW, mainly during precipitation events in the winter crops season. Of the total nitrogen concentration in water, approximately 3% was ammonium‐N and 58% was nitrate‐N, on average, in both watersheds. For total phosphorus concentration in water, more than 75% was particulate in both watersheds, however, the bioavailable phosphorus accounted for 70% of the total phosphorus in the SW and for 35% in the CW. The higher concentration of bioavailable phosphorus in the SW indicates a short‐term pollution potential, but in both watersheds, the water quality was impaired by the high concentrations of total phosphorus. In general, even with no‐tillage, the results highlight the importance of best management practices as terracing, riparian vegetation, crop rotation, better crop systems and fertilizer management to avoid degradation of water resources.
Predicting the sediment transport capacity from flow condition and particle size in the presence of vegetation cover
Authors: Mu Hongli , Fu Suhua , Yu Bofu , Zhang Guanghui
Published: September 2020

The sediment transport capacity plays a pivotal role in erosion research, and is usually predicted using hydraulic variables. The transport capacity and hydraulic variables are affected by vegetation cover. Our understanding of the effect of vegetation cover, including the size, density, and arrangement of vegetation stems, on the relationship between the sediment transport capacity and hydraulic variables were rather limited. The objectives of this study were to investigate the effect vegetation stem cover on the relationship between hydraulic variables and the sediment transport capacity and to derive an equation for predicting the sediment transport capacity in the presence of vegetation cover. Five data sets from 288 flume experiments with a wide range of discharge (0.25–2 × 10−3 m3 s−1), slope (8.8–42.3%), median sediment diameter (0.11–1.16 × 10−3 m), stem cover (0–30%), stem diameter (2–36 mm), and stem arrangement (bead, tessellation, zigzag, random, and banding) were compiled for this study. Extensive regression analysis has shown that the sediment transport capacity could be expressed as a power function of flow velocity, shear stress, stream power, or unit stream power. Predictors of the sediment transport capacity were ranked from the unit stream power as the strongest, followed by the stream power, flow velocity, and the shear stress. Vegetation stem cover had no apparent and direct effect on the relationship between hydraulic variables and the sediment transport capacity so long as the unit stream power or stream power was used as its predictor. Vegetation cover became a significant factor only when the shear stress was used to predict the sediment transport capacity. Finally, a new equation involving the slope gradient, flow velocity, and median sediment diameter in a nondimensional form was shown to be a superior predictor of the sediment transport capacity with the Nash–Sutcliffe coefficient of efficiency of 0.92. The product of slope and flow velocity, that is, the unit stream power, captures the effect of vegetation stem cover and surface roughness and was shown to be an effective predictor of the transport capacity in the presence of vegetation cover.
Effect of head roll‐tilt on the subjective visual vertical in healthy participants: Towards better clinical measurement of gravity perception
Authors: Wada Yoshiro , Yamanaka Toshiaki , Kitahara Tadashi , Kurata Junichi
Published: September 2020

Objective

Gravity perception is an essential function for spatial orientation and postural stability; however, its assessment is not easy. We evaluated the head‐tilt perception gain (HTPG, that is, mean perceptual gain [perceived/actual tilt angle] during left or right head roll‐tilt conditions) and head‐upright subjective visual vertical (SVV) using a simple method developed by us to investigate the characteristics of gravity perception in healthy participants.

Methods

We measured the SVV and head roll‐tilt angle during head roll‐tilt within ±30° of vertical in the sitting and standing positions while the participant maintained an upright trunk (sitting, 434 participants; standing, 263 participants). We evaluated the head‐upright SVV, HTPG, and laterality of the HTPG.

Results

We determined the reference ranges of the absolute head‐upright SVV (<2.5°), HTPG (0.80‐1.25), and HTPG laterality (<10%) for the sitting position. The head‐upright SVV and HTPG laterality were not influenced by sex or age. However, the HTPG was significantly greater in women than in men and in middle‐aged (30‐64 years) and elderly (65‐88 years) participants than in young participants (18‐29 years). The HTPG, but not the head‐upright SVV or HTPG laterality, was significantly higher in the standing vs sitting position.

Conclusion

The HTPG is a novel parameter of gravity perception involving functions of the peripheral otolith and neck somatosensory systems to the central nervous system. The HTPG in healthy participants is influenced by age and sex in the sitting position and immediately increases after standing to reinforce the righting reflex for unstable posture, which was not seen in the head‐upright SVV, previously considered the only parameter.

Level of Evidence

4.
Effect of oil‐air lubrication on contact temperature and sliding tribological properties
Authors: Liu Cong , Yin Yanguo , Tong Baohong , Zhang Guotao
Published: September 2020

This paper investigated the effect of oil‐air lubrication on contact temperature and sliding tribological properties. On the basis of heat transfer theory, a numerical simulation model of forced convection was established. Experiments were conducted using the tribology machine. Results show that in oil‐air lubrication, forced convection can significantly reduce the temperature at the contact position. Nonlinear decline and decrease in the descent rate of contact temperature were observed with the increase in convective heat transfer coefficient. The convective heat transfer between friction pairs increased with air supply velocity, whereas the sliding friction coefficient initially decreased and then increased. The friction flash temperature reached its lowest value with proper heat dissipation capacity. With the increase in ambient temperatures of the friction pairs, the sliding friction coefficient decreased, whereas the friction flash temperature increased. Influenced by the oil‐air lubrication heat dissipation in the test, the wear mechanism of point contact sliding friction was abrasive wear.
Melt Electrospinning Polyethylene Fibers in Inert Atmosphere
Authors: Morikawa Kai , Vashisth Aniruddh , Bansala Taruna , Verma Pawan , Green Micah J. , Naraghi Mohammad
Published: September 2020

Electrospinning is commonly used for fabrication of polymer fibers. Melt electrospinning, instead of the commonly used solution electrospinning, offers many advantages in generating polymer fibers without using solvents. However, polymer melts have high viscosity which poses major limitations in producing low diameter fibers. Here, melt electrospinning is investigated at elevated temperatures in inert atmosphere to reduce fiber diameters while suppressing thermal degradation. Two types of spinneret configurations, syringe and wire, with two distinct outcomes are studied. In syringe‐based electrospinning, increasing the nozzle temperature from 300 to 360 °C in nitrogen reduced fiber diameter significantly from 33 ± 5 to 10 ± 4 µm. Electrospinning in nitrogen leads to formation of fibers even at a high nozzle temperature of 360 °C, while this temperature leads to thermal degradation when spinning in air. In contrast, increasing the temperature of wire electrospinning setup do not lead to a noticeable reduction in diameter. This is attributed to the viscosity‐dependent flow rate in this method. Increasing the temperature leads to increased flow rates, promoting the formation of thicker fibers, while the increased stretchability promotes the formation of thinner fibers. The results clearly demonstrate advantages of developing polymer microfibers in inert atmosphere to avoid thermal degradation with a temperature‐independent flow control.
Nanomechanical Properties of a Supramolecular Helix Stabilized by Non‐Covalent Interactions
Authors: Wang Huijie , Shen Bowen , Song Yu , Lee Myongsoo , Zhang Wenke
Published: September 2020

Supramolecular helices have unique properties and many potential applications, such as chiral separation and asymmetric catalysis. Mechanical property (stability) of the supramolecular helix plays important roles in their functions. Due to the limitation of detection method, it is quite challenging to investigate nanomechanical properties of individual supramolecular helices stabilized by pure supramolecular interactions. Here atomic force microscopy (AFM)‐based single molecule force spectroscopy (SMFS) is used to study the nanomechanical properties of a thermal‐responsive supramolecular helix. The unwinding force plateau is observed in the force‐extension curve, and the rupture force of the helix is dependent on the loading rate. In addition, the force‐induced unwinding process is reversible and there is almost no energy dissipation in the process. Furthermore, the result of thermal shape‐fluctuation analysis shows that the persistence length of the supramolecular helix is about 222 nm, which is much larger than helical structure formed by double‐stranded DNA (dsDNA). However, because of its unique backbone structure, the supramolecular helix exhibits higher dynamic flexibility during force‐induced deformation, since the persistence length determined from the stretching experiment is much smaller (1.1 nm).
Analysis of Heterozygous PRKN Variants and Copy‐Number Variations in Parkinson's Disease
Authors: Yu Eric , Rudakou Uladzislau , Krohn Lynne , Mufti Kheireddin , Ruskey Jennifer A. , Asayesh Farnaz , Estiar Mehrdad A. , Spiegelman Dan , Surface Matthew , Fahn Stanley , Waters Cheryl H. , Greenbaum Lior , Espay Alberto J. , Dauvilliers Yves , Dupré Nicolas , Rouleau Guy A. , Hassin‐Baer Sharon , Fon Edward A. , Alcalay Roy N. , Gan‐Or Ziv
Published: September 2020

Background

Biallelic PRKN mutation carriers with Parkinson's disease (PD) typically have an earlier disease onset, slow disease progression, and, often, different neuropathology compared to sporadic PD patients. However, the role of heterozygous PRKN variants in the risk of PD is controversial.

Objectives

Our aim was to examine the association between heterozygous PRKN variants, including single‐nucleotide variants and copy‐number variations (CNVs), and PD.

Methods

We fully sequenced PRKN in 2809 PD patients and 3629 healthy controls, including 1965 late‐onset (63.97 ± 7.79 years, 63% men) and 553 early‐onset PD patients (43.33 ± 6.59 years, 68% men). PRKN was sequenced using targeted next‐generation sequencing with molecular inversion probes. CNVs were identified using a combination of multiplex ligation‐dependent probe amplification and ExomeDepth. To examine whether rare heterozygous single‐nucleotide variants and CNVs in PRKN are associated with PD risk and onset, we used optimized sequence kernel association tests and regression models.

Results

We did not find any associations between all types of PRKN variants and risk of PD. Pathogenic and likely‐pathogenic heterozygous single‐nucleotide variants and CNVs were less common among PD patients (1.52%) than among controls (1.8%, false discovery rate‐corrected P = 0.55). No associations with age at onset and in stratified analyses were found.

Conclusions

Heterozygous single‐nucleotide variants and CNVs in PRKN are not associated with PD. Molecular inversion probes allow for rapid and cost‐effective detection of all types of PRKN variants, which may be useful for pretrial screening and for clinical and basic science studies targeting specifically PRKN patients. © 2020 International Parkinson and Movement Disorder Society
Hessian Schatten‐norm and adaptive dictionary for image recovery
Authors: Wang Qian , Qu Gangrong , Ji Dongjiang
Published: September 2020

From many fewer acquired measurements than that suggested by the Nyquist sampling theory, compressive sensing (CS) theory demonstrates that a signal can be reconstructed with high probability when it exhibits sparsity in a certain domain. Recent CS methods have employed analytical sparsifying transforms such as wavelets, curvelets, and finite differences. In this paper, we propose a novel algorithm for image recovery, which minimizes a linear combination of three terms corresponding to least square data fitting, adaptive dictionary, and Hessian Schatten‐norm regularization. We split the problem into some subproblems which turn the minimization task into much simpler. Numerical experiments are conducted on several test images with a variety of sampling patterns and ratios in both noiseless and noise scenarios. The results demonstrate the superior performance of the proposed algorithm.
Frequency agile multiple‐input‐multiple‐output antenna design for 5G dynamic spectrum sharing in cognitive radio networks
Authors: Hussain Rifaqat , Khan Muhammad U. , Iqbal Naveed , AlMajali Eqab , Alja'Afreh Saqer S. , Johar Umar , Shamim Atif , Sharawi Mohammad S.
Published: September 2020

In this work, 2‐element slot‐based frequency reconfigurable (FR) multiple‐input‐multiple‐output (MIMO) antenna design antenna with a very wide‐sweep is proposed for dynamic spectrum sharing (DSS) in 5G technologies. FR is achieved using varactor diode with frequency tuning range from 1655 to 2605 MHz. The design is a low profile with planar structure having a single element footprint of 19.5 × 20 mm2. The two slot antenna elements of the MIMO configuration are etched out from a ground (GND) plane of dimensions of 60 × 120 mm2. The proposed antenna is narrow‐band and hence it is suitable for RF front‐end in the 5G‐enabled DSS in cognitive radio (CR) applications.
Toward improved 3D carotid artery imaging with Adaptive CaRdiac cOne BEAm computed Tomography (ACROBEAT)
Authors: Reynolds Tess , Dillon Owen , Prinable Joseph , Whelan Brendan , Keall Paul J. , O’Brien Ricky T.
Published: September 2020

Purpose

Interventional treatments of aneurysms in the carotid artery are increasingly being supplemented with three‐dimensional (3D) x‐ray imaging. The 3D imaging provides additional information on device sizing and stent malapposition during the procedure. Standard 3D x‐ray image acquisition is a one‐size fits all model, exposing patients to additional radiation and results in images that may have cardiac‐induced motion blur around the artery. Here, we investigate the potential of a novel dynamic imaging technique Adaptive CaRdiac cOne BEAm computed Tomography (ACROBEAT) to personalize image acquisition by adapting the gantry velocity and projection rate in real‐time to changes in the patient’s electrocardiogram (ECG) trace.

Methods

We compared the total number of projections acquired, estimated carotid artery widths and image quality between ACROBEAT and conventional (single rotation fixed gantry velocity and acquisition rate, no ECG‐gating) scans in a simulation study and a proof‐of‐concept physical phantom experimental study. The simulation study dataset consisted of an XCAT digital software phantom programmed with five patient‐measured ECG traces and artery motion curves. The ECG traces had average heart rates of 56, 64, 76, 86, and 100 bpm. To validate the concept experimentally, we designed and manufactured the physical phantom from an 8‐mm diameter silicon rubber tubing cast into Phytagel. An artery motion curve and the ECG trace with an average heart rate of 56 bpm was passed through the phantom. To implement ACROBEAT on the Siemens ARTIS pheno angiography system for the proof‐of‐concept experimental study, the Siemens Test Automation Control System was used. The total number of projections acquired and estimated carotid artery widths were compared between the ACROBEAT and conventional scans. As the ground truth was available for the simulation studies, the image quality metrics of Root Mean Square Error (RMSE) and Structural Similarity Index (SSIM) were also utilized to assess image quality.

Results

In the simulation study, on average, ACROBEAT reduced the number of projections acquired by 63%, reduced carotid width estimation error by 65%, reduced RMSE by 11% and improved SSIM by 27% compared to conventional scans. In the proof‐of‐concept experimental study, ACROBEAT enabled a 60% reduction in the number of projections acquired and reduced carotid width estimation error by 69% compared to a conventional scan.

Conclusion

A simulation and proof‐of‐concept experimental study was completed applying a novel dynamic imaging protocol, ACROBEAT, to imaging the carotid artery. The ACROBEAT results showed significantly improved image quality with fewer projections, offering potential applications to intracranial interventional procedures negatively affected by cardiac motion.
Technical Note: Automatic segmentation of CT images for ventral body composition analysis
Authors: Fu Yabo , Ippolito Joseph E. , Ludwig Daniel R. , Nizamuddin Rehan , Li Harold H. , Yang Deshan
Published: September 2020

Purpose

Body composition is known to be associated with many diseases including diabetes, cancers, and cardiovascular diseases. In this paper, we developed a fully automatic body tissue decomposition procedure to segment three major compartments that are related to body composition analysis — subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and muscle. Three additional compartments — the ventral cavity, lung, and bones — were also segmented during the segmentation process to assist segmentation of the major compartments.

Methods

A convolutional neural network (CNN) model with densely connected layers was developed to perform ventral cavity segmentation. An image processing workflow was developed to segment the ventral cavity in any patient’s computed tomography (CT) using the CNN model, then further segment the body tissue into multiple compartments using hysteresis thresholding followed by morphological operations. It is important to segment ventral cavity firstly to allow accurate separation of compartments with similar Hounsfield unit (HU) inside and outside the ventral cavity.

Results

The ventral cavity segmentation CNN model was trained and tested with manually labeled ventral cavities in 60 CTs. Dice scores (mean ± standard deviation) for ventral cavity segmentation were 0.966 ± 0.012. Tested on CT datasets with intravenous (IV) and oral contrast, the Dice scores were 0.96 ± 0.02, 0.94 ± 0.06, 0.96 ± 0.04, 0.95 ± 0.04, and 0.99 ± 0.01 for bone, VAT, SAT, muscle, and lung, respectively. The respective Dice scores were 0.97 ± 0.02, 0.94 ± 0.07, 0.93 ± 0.06, 0.91 ± 0.04, and 0.99 ± 0.01 for non‐contrast CT datasets.

Conclusion

A body tissue decomposition procedure was developed to automatically segment multiple compartments of the ventral body. The proposed method enables fully automated quantification of three‐dimensional (3D) ventral body composition metrics from CT images.
Water calorimetry in MR‐linac: Direct measurement of absorbed dose and determination of chamber
Authors: D'Souza Mark , Nusrat Humza , Iakovenko Viktor , Keller Brian , Sahgal Arjun , Renaud James , Sarfehnia Arman
Published: September 2020

Purpose

To use a portable 4°C cooled MR‐compatible water calorimeter to measure absorbed dose in a magnetic resonance‐guided radiation therapy (MRgRT) system. Furthermore, to use the calorimetric dose results and direct cross‐calibration to experimentally measure the combined beam quality and magnetic field correction factor () of a clinically used reference‐class ionization chamber placed under the same radiation field.

Methods

An Elekta Unity MR‐linac (7 MV FFF, B = 1.5 T) was used in this study. Measurements were taken using the in‐house designed and built water calorimeter. Following preparation and cooling of the system, the MR‐compatible calorimeter was positioned using a combination of MR and EPID imaging and the dose to water was measured by monitoring the radiation‐induced temperature change. Immediately after the calorimetric measurements, an A1SL ionization chamber was placed inside the calorimeter for direct cross‐calibration. The results allowed for a direct and absolute experimental measurement of for this chamber and comparison against existing Monte Carlo values.

Results

The calorimeter was successfully positioned using imaging in under an hour. The 1‐hour setup time is from the time the calorimeter leaves storage to the first calorimetric measurement. Absorbed dose was successfully measured with a relative combined standard uncertainty of 0.71 % (k = 1). Through a cross‐calibration, the for an Exradin A1SL ionization chamber, set up perpendicular to the incident photon beam and opposite to the direction of the Lorentz force, was directly determined in water in absolute terms to be 0.977 ± 0.010. The currently published results, obtained via Monte Carlo calculations, agree with experimental measurements in this work within combined uncertainties.

Conclusions

A novel design of an MR‐compatible water calorimeter was successfully used to measure absorbed dose in an MR‐linac and determine an experimental value of for a clinically used ionization chamber.
Evaluation of differences and dosimetric influences of beam models using golden and multi‐institutional measured beam datasets in radiation treatment planning systems
Authors: Tani Kensuke , Wakita Akihisa , Tohyama Naoki , Fujita Yukio , Kito Satoshi , Miyasaka Ryohei , Mizuno Norifumi , Uehara Ryuzo , Takakura Toru , Miyake Shunsuke , Shinoda Kazuya , Oka Yoshitaka , Saito Yasunori , Kojima Hideki , Hayashi Naoki
Published: September 2020

Purpose

The beam model in radiation treatment planning systems (RTPSs) plays a crucial role in determining the accuracy of calculated dose distributions. The purpose of this study was to ascertain differences in beam models and their dosimetric influences when a golden beam dataset (GBD) and multi‐institution measured beam datasets (MBDs) are used for beam modeling in RTPSs.

Methods

The MBDs collected from 15 institutions, and the MBDs' beam models, were compared with a GBD, and the GBD’s beam model, for Varian TrueBeam linear accelerator. The calculated dose distributions of the MBDs' beam models were compared with those of the GBD’s beam model for simple geometries in a water phantom. Calculated dose distributions were similarly evaluated in volumetric modulated arc therapy (VMAT) plans for TG‐119 C‐shape and TG‐244 head and neck, at several dose constraints of the planning target volumes (PTVs), and organs at risk.

Results

The agreements of the MBDs with the GBD were almost all within ±1%. The calculated dose distributions for simple geometries in a water phantom also closely corresponded between the beam models of GBD and MBDs. Nevertheless, there were considerable differences between the beam models. The maximum differences between the mean energy of the energy spectra of GBD and MBDs were −0.12 MeV (−10.5%) in AcurosXB (AXB, Eclipse) and 0.11 MeV (7.7%) in collapsed cone convolution (CCC, RayStation). The differences in the VMAT calculated dose distributions varied for each dose region, plan, X‐ray energy, and dose calculation algorithm. The ranges of the differences in the dose constraints were −5.6% to 3.0% for AXB and −24.1% to 2.8% for CCC. In several VMAT plans, the calculated dose distributions of GBD's beam model tended to be lower in high‐dose regions and higher in low‐dose regions than those of the MBDs' beam models.

Conclusions

We found that small differences in beam data have large impacts on the beam models, and on calculated dose distributions in clinical VMAT plan, even if beam data correspond within ±1%. GBD’s beam model was not a representative beam model. The beam models of GBD and MBDs and their calculated dose distributions under clinical conditions were significantly different. These differences are most likely due to the extensive variation in the beam models, reflecting the characteristics of beam data. The energy spectrum and radial energy in the beam model varied in a wide range, even if the differences in the beam data were <±1%. To minimize the uncertainty of the calculated dose distributions in clinical plans, it was best to use the institutional MBD for beam modeling, or the beam model that ensures the accuracy of calculated dose distributions.
Mechanism and quantitative assessment of saturation transfer for water‐based detection of the aliphatic protons in carbohydrate polymers
Authors: Zhou Yang , van Zijl Peter C.M. , Xu Jiadi , Yadav Nirbhay N.
Published: September 2020

Purpose

CEST MRI experiments of mobile macromolecules, for example, proteins, carbohydrates, and phospholipids, often show signals due to saturation transfer from aliphatic protons to water. Currently, the mechanism of this nuclear Overhauser effect (NOE)‐based transfer pathway is not completely understood and could be due either to NOEs directly to bound water or NOEs relayed intramolecularly via exchangeable protons. We used glycogen as a model system to investigate this saturation transfer pathway in sugar polymer solution.

Methods

To determine whether proton exchange affected saturation transfer, saturation spectra (Z‐spectra) were measured for glycogen solutions of different pH, D2O/H2O ratio, and glycogen particle size. A theoretical model was derived to analytically describe the NOE‐based signals in these spectra. Numerical simulations were performed to verify this theory, which was further tested by fitting experimental data for different exchange regimes.

Results

Signal intensities of aliphatic NOEs in Z‐spectra of glycogen in D2O solution were influenced by hydroxyl proton exchange rates, whereas those in H2O were not. This indicates that the primary transfer pathway is an exchange‐relayed NOE from these aliphatic protons to neighboring hydroxyl protons, followed by the exchange to water protons. Experimental data for glycogen solutions in D2O and H2O could be analyzed successfully using an analytical theory derived for such relayed NOE transfer, which was further validated using numerical simulations with the Bloch equations.

Conclusion

The predominant mechanism underlying aliphatic signals in Z‐spectra of mobile carbohydrate polymers is intramolecular relayed NOE transfer followed by proton exchange.
A note on the accuracy of the generalized‐α scheme for the incompressible Navier‐Stokes equations
Authors: Liu Ju , Lan Ingrid S. , Tikenogullari Oguz Z. , Marsden Alison L.
Published: September 2020

We investigate the temporal accuracy of two generalized‐ schemes for the incompressible Navier‐Stokes equations. In a widely‐adopted approach, the pressure is collocated at the time step tn + 1 while the remainder of the Navier‐Stokes equations is discretized following the generalized‐ scheme. That scheme has been claimed to be second‐order accurate in time. We developed a suite of numerical code using inf‐sup stable higher‐order non‐uniform rational B‐spline (NURBS) elements for spatial discretization. In doing so, we are able to achieve high spatial accuracy and to investigate asymptotic temporal convergence behavior. Numerical evidence suggests that only first‐order accuracy is achieved, at least for the pressure, in this aforesaid temporal discretization approach. On the other hand, evaluating the pressure at the intermediate time step recovers second‐order accuracy, and the numerical implementation is simplified. We recommend this second approach as the generalized‐ scheme of choice when integrating the incompressible Navier‐Stokes equations.
A condensed algorithm for adaptive component mode synthesis of viscoelastic flexible multibody dynamics
Authors: Tang Yixuan , Hu Haiyan , Tian Qiang
Published: September 2020

A condensed algorithm for adaptive component mode synthesis is proposed to compute the dynamics of viscoelastic flexible multibody systems efficiently and accurately. As studied, the continuous use of modes derived from the initial configuration will lead to poor convergence when dealing with geometric nonlinearity caused by large deformations and overall rotations. The modal reduction at a series of quasi‐static equilibrium configurations should be updated accordingly. According to the loss rate of system energy in the updating process of modal bases, an adaptive mode selection is proposed to reserve the optimal modal bases with their modal number automatically so as to achieve a high‐accuracy simulation. In the proposed condensed iteration algorithm, the order of reduced dynamic equations in the Newton‐Raphson is far less than the number of the unknowns to be discrete in generalized‐α scheme. Using an analytical mapping between the two parts of unknowns, the new algorithm solves a small part of the unknowns iteratively and solves the others noniteratively. Therefore, the saving of time cost comes not only from the proposed adaptive component mode synthesis, but also from the proposed condensed iteration algorithm. The modal bases of subsystems are updated by a series of frame‐like quasi‐static equilibrium configurations independently, in conjunction with the Craig‐Bampton method. Thus, the challenges in the model reduced of extensive ranges of stiffness and damping are removed via the successively updated modal bases. Finally, three numerical tests are made to illuminate the high accuracy and efficiency of the new algorithm proposed.
Weight Reduction Through a Cognitive Behavioral Therapy Lifestyle Intervention in PCOS: The Primary Outcome of a Randomized Controlled Trial
Authors: Jiskoot Geranne , Timman Reinier , Beerthuizen Annemerle , Dietz de Loos Alexandra , Busschbach Jan , Laven Joop
Published: September 2020

Objective

Long‐term weight loss is important and difficult to achieve for many women with polycystic ovary syndrome (PCOS). Lifestyle interventions (LS) in PCOS have shown moderate short‐term effects. Three‐component LS that combine nutrition advice, exercise, and cognitive behavioral therapy have not been tested in long‐term interventions.

Methods

Women (N = 183) with PCOS who were trying to conceive and had BMI > 25 kg/m2 were assigned to 20 group sessions of cognitive behavioral therapy combined with nutrition advice and exercise (LS with or without Short Message Service [SMS] via mobile phone) or care as usual (CAU).

Results

More weight loss was observed in LS than in CAU (P < 0.001). Adding SMS was even more effective (P = 0.017). In CAU, 13 of 60 (21.8%) succeeded in achieving a 5% weight loss, as did 32 of 60 (52.8%) in LS without SMS and 54 of 63 (85.7%) in LS with SMS. The odds of achieving a 5% weight loss were 7.0 (P < 0.001) in LS compared with CAU. More than 18 of 60 (29.0%) of the women in CAU gained weight versus 5 of 60 (8.5%) and 2 of 63 (3.1%) in LS without or with SMS, respectively. The overall dropout rate was 116 of 183 (63.4%).

Conclusions

A three‐component LS program resulted in reasonable weight loss in women with PCOS. Adding SMS resulted in more weight loss.
L−Lysine Amino Acid Adsorption on Zeolite L: a Combined Synchrotron, X‐Ray and Neutron Diffraction Study
Authors: Beltrami Giada , Martucci Annalisa , Pasti Luisa , Chenet Tatiana , Ardit Matteo , Gigli Lara , Cescon Mirco , Suard Emmanuelle
Published: September 2020

Combined neutron and X‐ray powder diffraction techniques highlighted the sorption capacity of the acidic L zeolite towards the L‐lysine amino acid. The role of zeolite channels in the stabilization of the lysine absorbed and the effect of water on protein structure are elucidated at atomistic level. The stabilization of the L α‐helical conformation is related to strong H‐bonds between the tail aminogroups of lysine molecules and the Brønsted acid site as well as to complex intermolecular H‐bond system between water molecules, zeolite and amino acid. This finding is relevant in the catalytic synthesis of polypeptide, as well as in industrial biotechnology by qualitatively predicting binding behaviour
Allopurinol use during pediatric acute lymphoblastic leukemia maintenance therapy safely corrects skewed 6‐mercaptopurine metabolism, improving inadequate myelosuppression and reducing gastrointestinal toxicity
Authors: Cohen Gordon , Cooper Stacy , Sison Edward Allan , Annesley Colleen , Bhuiyan Mariam , Brown Patrick
Published: September 2020

Background

Inadequate myelosuppression during maintenance therapy for acute lymphoblastic leukemia (ALL) is associated with an increased risk of relapse. One mechanism is skewed metabolism of 6‐mercaptopurine (6MP), a major component of maintenance therapy, which results in preferential formation of the hepatotoxic metabolite (6‐methyl mercaptopurine [6MMP]) with low levels of the antileukemic metabolite, 6‐thioguanine nucleotides (6TGN). Allopurinol can modify 6MP metabolism to favor 6TGN production and reduce 6MMP.

Methods

Patients in maintenance were considered for allopurinol treatment who had the following features: (a) Grade ≥3 hepatotoxicity; (b) Grade ≥2 nonhepatic gastrointestinal (GI) toxicity; or (c) persistently elevated absolute neutrophil count (ANC) despite >150% protocol dosing of oral chemotherapy.

Results

From 2013 to 2017, 13 ALL patients received allopurinol: nine for hepatotoxicity, five for inadequate myelosuppression, and three for nonhepatic GI toxicity (four met multiple criteria). Allopurinol was well tolerated, without significant adverse events. Allopurinol resulted in a significant decrease in the average 6MMP/6TGN ratio (mean reduction 89.1, P = .0001), with a significant increase in 6TGN (mean 550.4, P = .0008) and a significant decrease in 6MMP (mean 13 755, P = .0013). Patients with hepatotoxicity had a significant decrease in transaminase elevation after starting allopurinol (alanine transaminase [ALT] mean decrease 22.1%, P = .02), and all with nonhepatic GI toxicity had improved symptoms. Those with inadequate myelosuppression had a significant increase in the time with ANC in goal (mean increase 26.4%, P = .0004).

Conclusions

Allopurinol during ALL maintenance chemotherapy is a safe, feasible, and effective intervention for those who have altered metabolism of 6MP causing toxicity or inadequate myelosuppression.
Guidance regarding COVID‐19 for survivors of childhood, adolescent, and young adult cancer: A statement from the International Late Effects of Childhood Cancer Guideline Harmonization Group
Authors: Verbruggen Lisanne C. , Wang Yuehan , Armenian Saro H. , Ehrhardt Matthew J. , van der Pal Helena J.H. , van Dalen Elvira C. , van As Jorrit W. , Bardi Edit , Baust Katja , Berger Claire , Castagnola Elio , Devine Katie A. , Gebauer Judith , Marchak Jordan Gilleland , Glaser Adam W. , Groll Andreas H. , Haeusler Gabrielle M. , den Hartogh Jaap , Haupt Riccardo , Hjorth Lars , Kato Miho , Kepák Tomáš , Koopman Maria M.W. (Rianne) , Langer Thorsten , Maeda Miho , Michel Gisela , Muraca Monica , Nathan Paul C. , van den Oever Selina R. , Pavasovic Vesna , Sato Satomi , Schulte Fiona , Sung Lillian , Tissing Wim , Uyttebroeck Anne , Mulder Renée L. , Kuehni Claudia , Skinner Roderick , Hudson Melissa M. , Kremer Leontien C.M.
Published: September 2020

Childhood, adolescent, and young adult (CAYA) cancer survivors may be at risk for a severe course of COVID‐19. Little is known about the clinical course of COVID‐19 in CAYA cancer survivors, or if additional preventive measures are warranted. We established a working group within the International Late Effects of Childhood Cancer Guideline Harmonization Group (IGHG) to summarize existing evidence and worldwide recommendations regarding evidence about factors/conditions associated with risk for a severe course of COVID‐19 in CAYA cancer survivors, and to develop a consensus statement to provide guidance for healthcare practitioners and CAYA cancer survivors regarding COVID‐19.
Interregional and intraregional variability of intergroup attitudes predict online hostility
Authors: Rosenbusch Hannes , Evans Anthony M. , Zeelenberg Marcel
Published: September 2020

To what extent are intergroup attitudes associated with regional differences in online aggression and hostility? We test whether regional attitude biases towards minorities and their local variability (i.e. intraregional polarization) independently predict verbal hostility on social media. We measure online hostility using large US American samples from Twitter and measure regional attitudes using nationwide survey data from Project Implicit. Average regional biases against Black people, White people, and gay people are associated with regional differences in social media hostility, and this effect is confounded with regional racial and ideological opposition. In addition, intraregional variability in interracial attitudes is also positively associated with online hostility. In other words, there is greater online hostility in regions where residents disagree in their interracial attitudes. This effect is present both for the full resident sample and when restricting the sample to White attitude holders. We find that this relationship is also, in part, confounded with regional proportions of ideological and racial groups (attitudes are more heterogeneous in regions with greater ideological and racial diversity). We discuss potential mechanisms underlying these relationships, as well as the dangers of escalating conflict and hostility when individuals with diverging intergroup attitudes interact. © 2020 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology
Effect of molecular weight and isotacticity distribution on hard elastic polypropylene cast films and membranes
Authors: Xu Guan , Ding Lei , Wu Tong , Yang Feng , Xiang Ming
Published: September 2020

In this study, polypropylene with different molecular structures was selected to clarify the relationship between the molecular structure and crystal structure during the extrusion of the dry process. The pore formation process was further investigated. The test results of thermal analysis, two‐dimensional wide‐angle X‐ray diffraction, two‐dimensional small‐angle X‐ray scattering and SEM show that the isotacticity distribution has a greater influence on the crystal structure than the molecular weight. The molecular weight mainly promotes the orientation of the crystalline phase; the isotacticity distribution influences both the orientation and the size of the lamellae. High molecular weight is not conducive to pore formation during stretching because of plenty of molecular entanglements between lamellae, while a narrow isotacticity distribution with longer average isotactic segment length can increase the thickness and the lateral dimension of lamellae, and the orientation of the cast film. Consequently, abundant micropores can form by the direct separation of row‐nucleating lamellae. © 2020 Society of Industrial Chemistry
Analysis for nonradiative recombination loss and radiation degradation of Si space solar cells
Authors: Yamaguchi Masafumi , Lee Kan‐Hua , Araki Kenji , Kojima Nobuaki , Okuno Yasuki , Imaizumi Mitsuru
Published: September 2020

Silicon space solar cells are currently attracting attention again for their relatively low‐cost feature with sufficient performance, and they are expected to resume into the space market especially by short‐term mission spacecraft designers. In this paper, efficiency potential of crystalline Si space solar cells is analyzed by considering external radiative efficiency (ERE), voltage and fill factor losses. Crystalline Si space solar cells have efficiency potential of more than 26% by realizing ERE of 20% from about 0.2% and normalized resistance of less than 0.05 from around 0.15. Nonradiative recombination and resistance losses in Si space solar cells are also discussed. Radiation degradation of Si space solar cells is also analyzed. Advanced Si solar cells such as passivated emitter, hetero‐junction, and back contact solar cells are expected to use as space solar cells. Potential of advanced Si solar cells for space applications is discussed from point view of radiation degradation.