bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative decomposition of resonance‐assisted hydrogen bond energy in β‐diketones into resonance and hydrogen bonding (π‐ and σ‐) components using molecular tailoring and function‐based approaches
Authors: Afonin Andrei V. , Vashchenko Alexander V.
Published: February 2020

Using the molecular tailoring and function‐based approaches allows one to divide the energy of the O─H⋯O═C resonance‐assisted hydrogen bond in a series of the β‐diketones into resonance and hydrogen bonding components. The magnitude of the resonance component is assessed as about 6 kcal mol−1. This value increases by ca. 1 kcal mol−1 on going from the weak to strong resonance‐assisted hydrogen bonding. The magnitude of the hydrogen bonding component varies in the wide range from 2 to 20 kcal mol−1 depending on the structure of the β‐diketone in question.
Classification of skew‐Hadamard matrices of order 32 and association schemes of order 31
Authors: Hanaki Akihide , Kharaghani Hadi , Mohammadian Ali , Tayfeh‐Rezaie Behruz
Published: February 2020

Using a backtracking algorithm along with an essential change to the rows of representatives of known 13 710 027 equivalence classes of Hadamard matrices of order 32, we make an exhaustive computer search feasible and show that there are exactly 6662 inequivalent skew‐Hadamard matrices of order 32. Two skew‐Hadamard matrices are considered SH‐equivalent if they are similar by a signed permutation matrix. We determine that there are precisely 7227 skew‐Hadamard matrices of order 32 up to
SH‐equivalence. This partly settles a problem posed by Kim and Solé. As a consequence, we provide the classification of association schemes of order 31.
Association between BTLA polymorphisms and susceptibility to esophageal squamous cell carcinoma in the Chinese population
Authors: Cao Rui , Tang Weifeng , Chen Shuchen
Published: February 2020

Background

Growing evidence suggested that B‐ and T‐lymphocyte attenuator (BTLA) polymorphisms raised the susceptibility to a wide range of cancers. This study aimed to evaluate whether BTLA variants were related to the risk of esophageal squamous cell carcinoma (ESCC).

Methods

A total of 721 ESCC patients and 1208 matched non‐cancer controls were included in this research, and four tagging BTLA polymorphisms (rs2171513 G > A, rs3112270 A > G, rs1982809 G > A, and rs16859629 T > C) were selected and genotyped using SNPscan™ Assays.

Results

In the present study, no significant relationship between BTLA polymorphisms and ESCC was observed. However, stratified analyses suggested that the variant of BTLA rs3112270 A > G reduced the risk of ESCC in the male subgroup (AG vs AA: adjusted OR = 0.78, 95% CI = 0.61‐0.99, P = .042), BMI < 24 kg/m2 subgroup (AG vs AA: adjusted OR = 0.72, 95% CI = 0.55‐0.93, P = .012; AG/GG vs AA: adjusted OR = 0.77, 95% CI = 0.60‐0.98, P = .032), and ever drinking subgroup (AG vs AA: adjusted OR = 0.61, 95% CI = 0.38‐0.97, P = .037). But when stratified by BMI ≥ 24 kg/m2, the rs3112270 A > G polymorphism increased the susceptibility to ESCC (GG vs AA: adjusted OR = 1.91, 95% CI = 1.02‐3.59, P = .045). Besides, we demonstrated that BTLA rs2171513 G > A polymorphism was protective of ESCC in the ever drinking subgroup (GA/AA vs GG: adjusted OR = 0.62, 95% CI = 0.39‐0.97, P = .037).

Conclusion

Taken together, our initial investigation postulated that the rs3112270 A > G and rs2171513 G > A variants in the BTLA gene are candidates for the risk of ESCC, which might be helpful for the early diagnosis and treatment of ESCC.
Handgrip strength and muscle quality in Australian women: cross‐sectional data from the Geelong Osteoporosis Study
Authors: Sui Sophia X. , Holloway‐Kew Kara L. , Hyde Natalie K. , Williams Lana J. , Tembo Monica C. , Mohebbi Mohammadreza , Gojanovic Marlene , Leach Sarah , Pasco Julie A.
Published: February 2020

Background

Low handgrip strength (HGS) is a measure of poor skeletal muscle performance and a marker of ill health and frailty. Muscle quality (MQ) is a measure of muscle strength relative to muscle mass. We aimed to develop normative data for HGS and MQ, report age‐related prevalence of low HGS and MQ, and determine the relationship with age, anthropometry, and body composition for women in Australia.

Methods

This cross‐sectional analysis included data from 792 women (ages 28–95 years) assessed by the Geelong Osteoporosis Study. Duplicate measures of HGS were performed for each hand with a dynamometer (Jamar) and the mean of maximum values used for analyses. Dual energy X‐ray absorptiometry‐derived lean mass for the arms was used to calculate MQ as HGS/lean mass (kg/kg). Body mass index (BMI) was categorized as normal (BMI < 25.0 kg/m2), overweight (25.0–29.9 kg/m2), and obese (>30.0 kg/m2). Fat mass index (FMI) was calculated as whole body fat/height2 (kg/m2) and appendicular lean mass index (ALMI) as lean mass of arms and legs/height2 (kg/m2).

Results

Mean (±SD) of HGS values for normal BMI, overweight, and obese groups were 25 (±7), 24 (±7), and 24 (±7) kg, P = 0.09, and for MQ, 12 (±3), 11 (±3), and 10 (±3) kg/kg, P < 0.001. Our data indicated a quadratic relationship between age and HGS or MQ. Mean HGS and MQ remained stable until the fifth age decade then declined steadily with increasing age; therefore, we used data for women (n = 283) aged 28–49 years as the young adult reference group, with mean (SD) values for HGS 28 (±6) kg and MQ 12 (±3) kg/kg. The prevalence of low (T‐score < −2) HGS and MQ for women 80 years and older was 52.2% and 39.6%, respectively. In multivariable models, age‐adjusted HGS was associated with FMI (B = −0.13, P = 0.004) and ALMI (1.03, <0.001) while age‐adjusted MQ was associated with BMI (−0.15, <0.001) but not with FMI. In a sensitivity analysis, the same pattern remained after the removal of 129 women who reported hand and/or arm pain.

Conclusions

Mean HGS and MQ declined with advancing age in older women. Our data suggest that while mean HGS increased with appendicular lean mass and decreased with body fat mass, there was no association with BMI. By contrast, MQ decreased with increasing BMI, but not with increasing adiposity.
Reproductive phenotype predicts adult bite‐force performance in sex‐reversed dragons (Pogona vitticeps)
Authors: Jones Marc E. H. , Pistevos Jennifer C. A. , Cooper Natalie , Lappin A. Kristopher , Georges Arthur , Hutchinson Mark N. , Holleley Clare E.
Published: February 2020

Sex‐related differences in morphology and behavior are well documented, but the relative contributions of genes and environment to these traits are less well understood. Species that undergo sex reversal, such as the central bearded dragon (Pogona vitticeps), offer an opportunity to better understand sexually dimorphic traits because sexual phenotypes can exist on different chromosomal backgrounds. Reproductively female dragons with a discordant sex chromosome complement (sex reversed), at least as juveniles, exhibit traits in common with males (e.g., longer tails and greater boldness). However, the impact of sex reversal on sexually dimorphic traits in adult dragons is unknown. Here, we investigate the effect of sex reversal on bite‐force performance, which may be important in resource acquisition (e.g., mates and/or food). We measured body size, head size, and bite force of the three sexual phenotypes in a colony of captive animals. Among adults, we found that males (ZZm) bite more forcefully than either chromosomally concordant females (ZWf) or sex‐reversed females (ZZf), and this difference is associated with having relatively larger head dimensions. Therefore, adult sex‐reversed females, despite apparently exhibiting male traits as juveniles, do not develop the larger head and enhanced bite force of adult male bearded dragons. This pattern is further illustrated in the full sample by a lack of positive allometry of bite force in sex‐reversed females that is observed in males. The results reveal a close association between reproductive phenotype and bite force performance, regardless of sex chromosome complement.
Detection and analysis of autophagy in the American alligator (Alligator mississippiensis)
Authors: Hale Amber , Merchant Mark , White Mary
Published: February 2020

In response to environmental temperature depression in the fall and winter, American alligators (Alligator mississippiensis) brumate. Brumation is characterized by lethargy, fasting, decreased metabolism, and decreased body temperature. During brumation, alligators will periodically emerge for basking or other encounters when environmental conditions permit. This sporadic activity and lack of nutrient intake may place strain on nutrient reserves. Nutrient scarcity, at the cellular and/or organismal level, promotes autophagy, a well‐conserved subcellular catabolic process used to maintain energy homeostasis during periods of metabolic or hypoxic stress. An analysis of the putative alligator autophagy‐related proteins has been conducted, and the results will be used to investigate the physiological role of autophagy during the brumation period. Using published genomic data, we have determined that autophagy is highly conserved, and alligator amino acid sequences exhibit a high percentage of identity with human homologs. Transcriptome analysis conducted using liver tissue derived from alligators confirmed the expression of one or more isoforms of each of the 34 autophagy initiation and elongation genes assayed. Five autophagy‐related proteins (ATG5, ATG9A, BECN1, ATG16L1, and MAP1‐LC3B), with functions spanning the major stages of autophagy, have been detected in alligator liver tissue by western blot analysis. In addition, ATG5 was detected in alligator liver tissue by immunohistochemistry. This is the first characterization of autophagy in crocodylians, and the first description of autophagy‐related protein expression in whole blood.
Isolation and characterization of two satellite DNAs in Atlantolacerta andreanskyi (Werner, 1929) (Reptilia, Lacertidae)
Authors: Giovannotti Massimo , S'Khifa Abderrahim , Nisi Cerioni Paola , Splendiani Andrea , Slimani Tahar , Fioravanti Tatiana , Olmo Ettore , Caputo Barucchi Vincenzo
Published: February 2020

Two satellite DNAs (satDNAs) have been isolated and characterized from three populations of Atlantolacerta andreanskyi. One satDNA (AAN‐TaqI) has been isolated here from the first time. It is characterized by a tendency to AT enrichment (AT = 54.2%) and monomer length ranging from 187 to 199 bp. FISH experiments showed that this element occurs in subterminal position on the short arms of all chromosomes of the complement. The analyses of genetic variability of AAN‐TaqI showed that the concerted evolution is acting effectively on these repeats that form separate clusters consistent with the geographic origin in the phylogenetic tree, thus supporting the hypothesis that A. andreanskyi would be a species complex. In addition, in the population from Jbel Aoulime this satDNA is already differentiated into two subfamilies. The other satDNA belongs to the family of IMO‐TaqI already isolated in other lacertids. Differently from AAN‐TaqI, concerted evolution does not seem to act effectively on this element that is not differentiated between populations. These results confirm that IMO‐TaqI (AT = 53.4%) is conserved in both chromosomal position and most of its sequence in the lacertids from which it has been characterized so far. Its remarkable evolutionary conservation for about 45 million years could indicate that this satDNA may have a functional role that future investigations could unveil. Once again, this study shows how satDNAs coexisting in the same genome may differ in their evolutionary pattern, even though the reasons underlying this phenomenon in the species here studied have still to be fully understood.
Colorings versus list colorings of uniform hypergraphs
Authors: Wang Wei , Qian Jianguo , Yan Zhidan
Published: February 2020

Let be an integer with and be a connected ‐uniform hypergraph with edges. By refining the broken cycle theorem for hypergraphs, we show that if , then the ‐list assignment of admitting the fewest colorings is the constant list assignment. This extends the previous results of Donner, Thomassen, and the current authors for graphs.
Titrating a modified ketogenic diet for patients with McArdle disease: A pilot study
Authors: Løkken Nicoline , Hansen Kit K. , Storgaard Jesper H. , Ørngreen Mette C. , Quinlivan Ros , Vissing John
Published: February 2020

Glycogen storage disease type V (GSDV) is a rare inborn error of carbohydrate metabolism. Patients present with exercise intolerance due to blocked glycogen breakdown in skeletal muscle. Introducing alternative fuel substrates, such as ketone bodies (KBs), could potentially alleviate muscle symptoms. This pilot study investigates which of three different modified ketogenic diet regimes is optimal for GSDV‐patients to follow in a future large‐scale study. Participants were randomised to follow one of three diet regimes for 3 weeks (#1: 65%/15%/20%; #2: 75%/15%/10%, or #3: 80%/15%/5%, fat/protein/carbohydrate). The primary outcome was exercise tolerance assessed by heart rate (HR) changes during constant load cycling. Secondary outcomes included levels of ketosis, and changes in perceived exertion and indirect calorimetry measures during exercise. Ten GSDV‐patients were included. Eight completed the study. The other two were excluded. Diet #3 showed the highest average KB level (1.1 mmol/L) vs #2 (0.5 mmol/L) and #1 (0.3 mmol/L). Five patients reported subjective symptom relief, all of whom were on diets #2 and #3. All diet regimes seemed to improve fatty acid oxidation rates and exercise capacity as indicated by a small decrease in HR and perceived exertion. The results of this open‐label pilot study show that diets #2 and #3 induce ketosis and improve symptoms and exercise capacity in GSDV‐patients. Diet #2 had the highest acceptability score and was superior or equal to diet #3 in all other parameters, except level of ketosis. Based on this, we suggest testing diet #2 in a large‐scale, placebo‐controlled study in GSDV.
Specific monitoring of aflatoxin M1 in real samples using aptamer binding to DNFS based on turn‐on method: A novel biosensor
Authors: Kordasht Houman Kholafazad , Hasanzadeh Mohammad
Published: February 2020

In the present work, a novel biocompatible scaffold was fabricated for the DNA aptamer immobilization. For the first time, amino‐functionalized dendritic fibrous nanosilica (KCC‐1‐nPr‐NH2) and gold nanoparticle supported by chitosan (AuNPs‐CS) were synthesized and electrodeposited successfully on the surface of the glassy carbon electrode by chronoamperometry technique. Unique oligonucleotide of aflatoxin M1 (5′‐ATC CGT CAC ACC TGC TCT GAC GCT GGG GTC GAC CCG GAG AAA TGC ATT CCC CTG TGG TGT TGG CTC CCG TAT) labeled by toluidine blue was immobilization on the prepared interface. Hence, a novel aptamer‐based bioassay was formed for highly sensitive quantitation of AFM1 using cyclic voltammetry and differential plus voltammetry. The structure and morphology of GQDs‐CS/KCC‐1‐nPr‐NH2 were investigated by Fourier‐transform infrared spectroscopy, X‐ray diffraction, atomic force, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy. The achieved low limit of quantification of apta‐assay for detection of AFM1 was 10fM. Also, calibration curve was linear from 0.1μM to 10fM in real samples. The proposed apta‐assay has acceptable long‐term stability. Designed aptasensor has a lot of remarkable advantages including excellent selectivity, sensitivity, and stability that could be used as facile bio‐device for the determination of AFM1 in milk samples.
Magnetic Resonance Angiography of the Thoracic Vasculature: Technique and Applications
Authors: Ludwig Daniel R. , Shetty Anup S. , Broncano Jordi , Bhalla Sanjeev , Raptis Constantine A.
Published: February 2020

Magnetic resonance angiography (MRA) is a powerful clinical tool for evaluation of the thoracic vasculature. MRA can be performed on nearly any magnetic resonance imaging (MRI) scanner, and provides images of high diagnostic quality without the use of ionizing radiation. While computed tomographic angiography (CTA) is preferred in the evaluation of hemodynamically unstable patients, MRA represents an important tool for evaluation of the thoracic vasculature in stable patients. Contrast‐enhanced MRA is generally performed unless there is a specific contraindication, as it shortens the duration of the exam and provides images of higher diagnostic quality than noncontrast MRA. However, intravenous contrast is often not required to obtain a diagnostic evaluation for most clinical indications. Indeed, a variety of noncontrast MRA techniques are used for thoracic imaging, often in conjunction with contrast‐enhanced MRA, each of which has a differing degree of reliance on flowing blood to produce the desired vascular signal. In this article we review contrast‐enhanced MRA, with a focus on contrast agents, methods of bolus timing, and considerations in imaging acquisition. Next, we cover the mechanism of contrast, strengths, and weaknesses of various noncontrast MRA techniques. Finally, we present an approach to protocol development and review representative protocols used at our institution for a variety of thoracic applications. Further attention will be devoted to additional techniques employed to address specific clinical questions, such as delayed contrast‐enhanced imaging, provocative maneuvers, electrocardiogram and respiratory gating, and phase‐contrast imaging. The purpose of this article is to review basic techniques and methodology in thoracic MRA, discuss an approach to protocol development, and illustrate commonly encountered pathology on thoracic MRA examinations.

Level of Evidence

5

Technical Efficacy Stage

3
Low‐Dose, Contrast‐Enhanced Mammography Compared to Contrast‐Enhanced Breast MRI: A Feasibility Study
Authors: Clauser Paola , Baltzer Pascal A.T. , Kapetas Panagiotis , Hoernig Mathias , Weber Michael , Leone Federica , Bernathova Maria , Helbich Thomas H.
Published: February 2020

Background

Contrast‐enhanced MRI (CE‐MRI) is the most sensitive technique for breast cancer detection. Contrast‐enhanced mammography (CEM) is emerging as a possible alternative to CE‐MRI.

Purpose

To evaluate the diagnostic performance of a low radiation dose contrast‐enhanced mammography (L‐CEM) in women with suspicious findings on conventional imaging compared to CE‐MRI of the breast.

Study Type

Prospective, single center.

Population

Women with suspicious findings on mammography, tomosynthesis, or ultrasound, and no contraindications for L‐CEM or CE‐MRI. Eighty women were included.

Field Strength/Sequence

1.5 and 3T CE‐MRI, standard protocol for breast, with dedicated coils, according to international guidelines. L‐CEM was performed using a dedicated prototype.

Assessment

Three, off‐site, blinded readers evaluated the images according to the BI‐RADS lexicon in a randomized order, each in two separate reading sessions. Histology served as a gold standard.

Statistical Test

Lesion detection rate, sensitivity, specificity, and negative and positive predictive values (NPV, PPV) were calculated and compared with multivariate statistics.

Results

Included were 80 women (mean age, 54.3 years ±11.2 standard deviation) with 93 lesions (32 benign, 61 malignant). The detection rate was significantly higher with CE‐MRI (92.5–94.6%; L‐CEM 79.6–91.4%, P = 0.014). Sensitivity (L‐CEM 65.6–90.2%; CE‐MRI 83.6–93.4%, P = 0.086) and NPV (L‐CEM 59.6–71.4%; CE‐MRI 63.0–76.5%, P = 0.780) did not differ between the modalities. Specificity (L‐CEM 46.9–96.9%; CE‐MRI 37.5–53.1%, P = 0.001) and PPV (L‐CEM 76.4–97.6%; CE‐MRI 73.3–77.3%, P = 0.007) were significantly higher with L‐CEM. Variations between readers were significant for sensitivity and NPV. The accuracy of L‐CEM was as good as CE‐MRI (75.3–76.3% vs. 72.0–75.3%, P = 0.514).

Data Conclusion

L‐CEM showed a high sensitivity and accuracy in women with suspicious findings on conventional imaging. Compared to CE‐MRI, L‐CEM has the potential to increase specificity and PPV. L‐CEM might help to reduce false‐positive biopsies while obtaining sensitivity comparable to that of CE‐MRI

Level of Evidence

1

Technical Efficacy Stage

2 J. Magn. Reson. Imaging 2020;52:589–595.
Evaluating Biventricular Myocardial Velocity and Interventricular Dyssynchrony in Adult Patients During the First Year After Heart Transplantation
Authors: Sarnari Roberto , Blake Allison M. , Ruh Alexander , Abbasi Muhannad A. , Pathrose Ashitha , Blaisdell Julie , Dolan Ryan S. , Ghafourian Kambiz , Wilcox Jane E. , Khan Sadiya S. , Vorovich Esther E. , Rich Jonathan D. , Anderson Allen S. , Yancy Clyde W. , Carr James C. , Markl Michael
Published: February 2020

Background

Magnetic resonance tissue phase mapping (TPM) measures three‐directional myocardial velocities of the left and right ventricle (LV, RV). This noninvasive technique may supplement endomyocardial biopsy (EMB) in monitoring grafts post‐heart transplantation (HTx).

Purpose

To assess biventricular myocardial velocity alterations in grafts and investigate the relationship between velocities and acute cellular rejection (ACR) episodes.

Study Type

Prospective.

Subjects

Twenty‐seven patients within 1 year post‐HTx (49 ± 13 years, 19 M) and 18 age‐matched controls (49 ± 15 years, 12 M).

Field Strength/Sequence

1.5T, 2D balanced steady‐state free precession, and TPM.

Assessment

Ventricular function: end‐diastolic and end‐systolic volumes, stroke volumes, ejection fraction (EF), and myocardial mass. TPM velocities: peak‐systolic and peak‐diastolic velocities, cardiac twist, and interventricular dyssynchrony. ACR rejection episodes: International Society for Heart and Lung Transplantation grading of EMB specimens.

Statistical Tests

The Lilliefors test for normality, unpaired t‐tests, and Wilcoxon rank‐sum tests for normally and nonnormally distributed data, respectively, were used, as well as multivariate regression for confounding variables and Pearson's correlation for associations between TPM velocities and global function.

Results

Compared to controls, HTx patients demonstrated reduced biventricular systolic longitudinal velocities (LV: 5.2 ± 2.1 vs. 4.0 ± 1.5 cm/s, P < 0.05; RV: 4.2 ± 1.3 vs. 3.1 ± 1.2 cm/s, P < 0.01). Correlation analysis revealed significant positive relationships for biventricular EF with radial peak velocities of the same ventricle in both systole and diastole (LV systole: r = 0.48, P < 0.01; LV diastole: r = 0.28, P < 0.05; RV systole: r = 0.35, P < 0.01; RV diastole: r = 0.36, P < 0.01). Segmentally, longitudinal velocities were impaired in 7/16 LV segments and 5/10 RV segments in systole and 7/10 RV segments in diastole. TPM analysis in studies with >4 preceding ACR episodes showed globally reduced RV and LV systolic radial velocity, and segmentally reduced radial and longitudinal systolic velocities.

Data Conclusion

Biventricular global and segmental velocities were reduced in HTx patients. Patients with >4 rejection episodes showed reduced myocardial velocities. The TPM sequence may add functional information for monitoring graft dysfunction.

Level of Evidence

2

Technical Efficacy Stage

2 J. Magn. Reson. Imaging 2020;52:920–929.
Improving Spatial Normalization of Brain Diffusion MRI to Measure Longitudinal Changes of Tissue Microstructure in the Cortex and White Matter
Authors: Jacobacci Florencia , Jovicich Jorge , Lerner Gonzalo , Amaro Edson , Armony Jorge L. , Doyon Julien , Della‐Maggiore Valeria
Published: February 2020

Background

Fractional anisotropy (FA) and mean diffusivity (MD) are frequently used to evaluate longitudinal changes in white matter (WM) microstructure. Recently, there has been a growing interest in identifying experience‐dependent plasticity in gray matter using MD. Improving registration has thus become a major goal to enhance the detection of subtle longitudinal changes in cortical microstructure.

Purpose

To optimize normalization of diffusion tensor images (DTI) to improve registration in gray matter and reduce variability associated with multisession registrations.

Study Type

Prospective longitudinal study.

Subjects

Twenty‐one healthy subjects (18–31 years old) underwent nine MRI scanning sessions each.

Field Strength/Sequence

3.0T, diffusion‐weighted multiband‐accelerated sequence, MP2RAGE sequence.

Assessment

Diffusion‐weighted images were registered to standard space using different pipelines that varied in the features used for normalization, namely, the nonlinear registration algorithm (FSL vs. ANTs), the registration target (FA‐based vs. T1‐based templates), and the use of intermediate individual (FA‐based or T1‐based) targets. We compared the across‐session test–retest reproducibility error of these normalization approaches for FA and MD in white and gray matter.

Statistical Tests

Reproducibility errors were compared using a repeated‐measures analysis of variance with pipeline as the within‐subject factor.

Results

The registration of FA data to the FMRIB58 FA atlas using ANTs yielded lower reproducibility errors in white matter (P < 0.0001) with respect to FSL. Moreover, using the MNI152 T1 template as the target of registration resulted in lower reproducibility errors for MD (P < 0.0001), whereas the FMRIB58 FA template performed better for FA (P < 0.0001). Finally, the use of an intermediate individual template improved reproducibility when registration of the FA images to the MNI152 T1 was carried out within modality (FA–FA) (P < 0.05), but not via a T1‐based individual template.

Data Conclusion

A normalization approach using ANTs to register FA images to the MNI152 T1 template via an individual FA template minimized test–retest reproducibility errors both for gray and white matter.

Level of Evidence

1

Technical Efficacy Stage

1 J. Magn. Reson. Imaging 2020;52:766–775.
Radiomics Based on Multimodal MRI for the Differential Diagnosis of Benign and Malignant Breast Lesions
Authors: Zhang Qian , Peng Yunsong , Liu Wei , Bai Jiayuan , Zheng Jian , Yang Xiaodong , Zhou Lijuan
Published: February 2020

Background

MRI‐based radiomics has been used to diagnose breast lesions; however, little research combining quantitative pharmacokinetic parameters of dynamic contrast‐enhanced MRI (DCE‐MRI) and diffusion kurtosis imaging (DKI) exists.

Purpose

To develop and validate a multimodal MRI‐based radiomics model for the differential diagnosis of benign and malignant breast lesions and analyze the discriminative abilities of different MR sequences.

Study Type

Retrospective.

Population

In all, 207 female patients with 207 histopathology‐confirmed breast lesions (95 benign and 112 malignant) were included in the study. Then 159 patients were assigned to the training group, and 48 patients comprised the validation group.

Field Strength/Sequence

T2‐weighted (T2W), T1‐weighted (T1W), diffusion‐weighted MR imaging (b‐values = 0, 500, 800, and 2000 seconds/mm2) and quantitative DCE‐MRI were performed on a 3.0T MR scanner.

Assessment

Radiomics features were extracted from T2WI, T1WI, DKI, apparent diffusion coefficient (ADC) maps, and DCE pharmacokinetic parameter maps in the training set. Models based on each sequence or combinations of sequences were built using a support vector machine (SVM) classifier and used to differentiate benign and malignant breast lesions in the validation set.

Statistical Tests

Optimal feature selection was performed by Spearman's rank correlation coefficients and the least absolute shrinkage and selection operator algorithm (LASSO). Receiver operating characteristic (ROC) curves were used to assess the diagnostic performance of the radiomics models in the validation set.

Results

The area under the ROC curve (AUC) of the optimal radiomics model, including T2WI, DKI, and quantitative DCE‐MRI parameter maps was 0.921, with an accuracy of 0.833. The AUCs of the models based on T1WI, T2WI, ADC map, DKI, and DCE pharmacokinetic parameter maps were 0.730, 0.791, 0.770, 0.788, and 0.836, respectively.

Data Conclusion

The model based on radiomics features from T2WI, DKI, and quantitative DCE pharmacokinetic parameter maps has a high discriminatory ability for benign and malignant breast lesions.

Level of Evidence

3

Technical Efficacy Stage

2 J. Magn. Reson. Imaging 2020;52:596–607.
Bipolar radiofrequency catheter ablation between the left ventricular endocardium and great cardiac vein for refractory ventricular premature complexes originating from the left ventricular summit
Authors: Tokioka Sayuri , Fukamizu Seiji , Kawamura Iwanari , Kitamura Takeshi , Hojo Rintaro
Published: February 2020

Ablation for ventricular arrhythmias originating from the left ventricular (LV) summit is sometimes challenging. Bipolar radiofrequency catheter ablation (RFCA) is effective for refractory arrhythmias; little is known about bipolar RFCA from the coronary venous system and the appropriate settings. We experienced three cases of ventricular premature complexes (VPCs) originating from the LV summit successfully treated by bipolar RFCA between the LV endocardium (irrigated catheters as active electrodes) and coronary venous system (8‐mm‐tip catheters as return electrodes). These cases showed that bipolar RFCA was effective for the VPCs originating from the LV summit; 8‐mm‐tip catheters were useful as return electrodes.
Successful hot balloon ablation for focal atrial tachycardia derived from the left superior pulmonary vein antrum
Authors: Tabata Hiroaki , Okada Ayako , Kobayashi Hideki , Shoin Wataru , Okano Takahiro , Yoshie Koji , Motoki Hirohiko , Shoda Morio , Kuwahara Koichiro
Published: February 2020

A 45‐year‐old man with paroxysmal atrial fibrillation (PAF) was admitted to our hospital for hot balloon ablation. At admission, atrial tachycardia (AT) was observed. Activation map showed focal atrial tachycardia originating from the posterior wall of the left superior pulmonary vein (LSPV) antrum. We performed hot balloon ablation at the LSPV antrum, terminated AT, and performed pulmonary vein isolation with a hot balloon. The hot balloon was successfully applied for the ablation of the focal atrial tachycardia from the pulmonary vein.
Low‐intensity pulsed ultrasound protects subchondral bone in rabbit temporomandibular joint osteoarthritis by suppressing TGF‐β1/Smad3 pathway
Authors: Yi Xin , Wu Lin , Liu Jie , Qin Yi‐Xian , Li Bo , Zhou Qing
Published: February 2020

Transforming growth factor β1(TGF‐β1)/Smad3 pathway promotes the pathological progression of subchondral bone in osteoarthritis. The aim of this study is to determine the effect of low‐intensity pulsed ultrasound (LIPUS) on the pathological progression and TGF‐β1/Smad3 pathway of subchondral bone in temporomandibular joint osteoarthritis (TMJOA). Rabbit TMJOA model was established by type II collagenase induction. The left joint in this model was continuously stimulated with LIPUS for 3 and 6 weeks (1 MHz; 30 mW/cm2) for 20 min/day. The morphological and histological features of subchondral bone were respectively examined by microcomputed tomography and Safranin‐O staining. The number of osteoclasts was quantitatively assessed by tartrate‐resistant acid phosphatase staining. Immunohistochemistry and Western blot analysis were conducted to evaluate the protein expression of Cathepsin K and TGF‐β1/Smad3 pathway. The results indicated that LIPUS could improve the trabecular microstructure and histological characteristics of subchondral bone in rabbit TMJOA. It also suppressed abnormal subchondral bone resorption and activation of TGF‐β1/Smad3 pathway, characterized by the number of osteoclasts, protein expression levels of Cathepsin K, TGF‐β1, type II TGFβ receptor, and phosphorylated Smad3 (pSmad3) were decreased. In conclusion, LIPUS promoted the quality of subchondral bone by suppressing osteoclast activity and TGF‐β1/Smad3 pathway in rabbit TMJOA.
Role of Molecular Biomarkers in Liver Transplantation for Hepatocellular Carcinoma
Authors: von Felden Johann , Villanueva Augusto
Published: February 2020

Patient selection and organ allocation for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) relies predominantly on clinical parameters, such as tumor burden (ie, radiological imaging). Patients transplanted within Milan criteria have outstanding outcomes with a 5‐ and 10‐year survival of 70% and 55%, respectively. Tumor recurrence after transplantion is rare in these patients (10%); however, treatment options upon recurrence are generally limited, and outcomes are poor. There are also several studies showing how a subgroup of patients with tumors outside the Milan criteria might achieve comparable outcomes to patients within Milan criteria. In other words, the size and number of tumor nodules does not always reflect tumor biology, which could be better captured using molecular proxies for cancer aggressiveness. Over the last decade, we have significantly improved our understanding of the molecular landscape of early stage HCC. This includes the development of molecular classification, identification of prognostic and mutational signatures, and potential mechanisms of hepatocarcinogenesis. Some molecular markers have already proven useful to predict tumor‐related outcomes in HCC patients after LT. Most of these analyses are limited to tissue‐derived biomarkers, which limits their implementation in clinical practice because tissue biopsy is not required for HCC diagnosis. Minimally invasive alternative tools, such as liquid biopsy, are being increasingly explored and could help to individualize risk stratification for patients with HCC who will benefit from LT despite being outside the accepted clinical criteria.
Lifestyle Modification Leads to Spatially Variable Reduction in Hepatic Steatosis in Potential Living Liver Donors
Authors: Park Hyo Jung , Kim Kyoung Won , Kwon Jae Hyun , Lee Jeongjin , Park Taeyong , Kwon Heon‐Ju , Song Gi‐Won , Lee Sung‐Gyu
Published: February 2020

The spatial variability of hepatic fat reduction in potential living liver donors with hepatic steatosis (HS) who undergo lifestyle modification has not been investigated. Here, we aimed to examine the intrasegmental and intersegmental variability of changes in liver attenuation on computed tomography (CT) in potential living liver donors with HS after diet modification and exercise. A total of 87 living liver donor candidates (30.5 ± 7.0 years; 74 males) with biopsy‐proven macrovesicular fat (MaF) ≥10% were included. All underwent diet modification and exercise to improve HS, baseline and follow‐up unenhanced CT scans, and liver biopsies. Attenuation and its variability (mean and standard deviation, respectively, in Hounsfield units) in segmental, lobar, superficial, deep, and whole areas of the liver were measured across 32 different regions of interest on both baseline and follow‐up CT. At baseline, the right lobe and superficial areas of liver showed significantly lower and more variable attenuation than left lobe and deep areas. Greater variability was noted in patients with more severe HS. Mean interval changes in liver attenuation and variability before and after diet modification and exercise were 13.7 (range, −10.6 to 46.2) and 4.7 (1.6‐10.6), respectively. The mean interval change in liver attenuation was significantly higher in the right lobe than in the left (14.7 versus 12.7; P < 0.001), and in superficial areas than in deep areas (14.0 versus 13.4; P = 0.02). Greater variability and larger interval changes in liver attenuation were noted in those who responded (≥20% decrease in MaF) to diet modification and exercise than in those who did not. In conclusion, potential living liver donors with HS show significant intrasegmental and intersegmental variability in hepatic fat reduction on CT before and after diet modification and exercise.
Interactive music for multisensory e‐commerce: The moderating role of online consumer involvement in experiential value, cognitive value, and purchase intention
Authors: Hwang Angel Hsing‐Chi , Oh Jeeyun , Scheinbaum Angeline Close
Published: February 2020

Background music adds a multisensory element to marketing and e‐commerce. Applying interactive sensory‐enabling technologies (SETs) to online shopping websites is an area of interest in sensory marketing. This research examines interactive background music in e‐commerce and investigates how online consumer involvement moderates the effects of interactive music. Single‐factor experiments with three conditions (interactive music, static background music, and control) were conducted to investigate its impact on experiential value, cognitive value, and purchase intention of high‐ and low‐involvement consumers among both students (Study 1, N = 251) and nonstudent samples (Study 2, N = 218). Different music genres were applied to stimuli of the two studies to demonstrate the generalizability of the findings. Results find that interactive music enhances the experiential value of e‐commerce for low‐involvement consumers. By contrast, high‐involvement consumers show greater purchase intention under the interactive music condition due to a heightened level of perceived cognitive value. Involvement is an effective predictor of elaboration and purchase intention under the interactive music condition, but not under the other two conditions. The contribution is twofold: (a) it shows the impact of music as an interactive SET and, (b) demonstrates the moderating role of consumer involvement in the context of multisensory integration in e‐commerce. Theoretical and practical implications are discussed along with limitations and directions for future research.
A note on the impact of the internal organization on the accuracy of the information transmitted within the firm
Authors: Alonso‐Pauli Eduard , Bru Lluís
Published: February 2020

We investigate the incentives of sales managers to transmit information on demand conditions to headquarters under different organizational structures and its subsequent impact on firm performance. When headquarters determine quantities of production, sales managers' interests are aligned with that of the firm, and reliable information is transmitted. On the other hand, when the authority of decision making on quantities of production is delegated to sales managers, they prefer not to transmit reliable information; consequently, headquarters set transfer prices given poor information about demand. Due to such difference in the quality of the information available to headquarters, a centralized organizational structure frequently leads to the best performance.
Harnack‐type inequality for fractional elliptic equations with critical exponent
Authors: Huang Shuibo , Tian Qiaoyu
Published: February 2020

In this paper, we use the method of moving planes to derive the Harnack‐type inequality

for nonnegative solutions to fractional semilinear elliptic equations

with
,
, and
. We obtain an asymptotic blow‐up rate estimate, as an application, for solutions to the above equation with a singular set.
Numerical solution of Volterra integral equations via Szász‐Mirakyan approximation method
Authors: Usta Fuat , İlkhan Merve , Evren Kara Emrah
Published: February 2020

Szász‐Mirakyan operators are a powerful tool that can be used to approximate functions on the unbounded interval
. In this contribution, we propose a numerical solution of Volterra integral equations with the help of Szász‐Mirakyan operators. In this direction, we provide both numerical scheme and estimation of error bound of solution. Numerical experiments are also presented, highlighting the performance of the new constructions of proposed algorithm in the context of one‐dimensional approximation.
Improving modulation bandwidth and optical power of GaN‐based blue LED by hollow‐runway active area
Authors: Huang Hongyong
Published: February 2020

We demonstrate a higher‐bandwidth and optical power GaN‐based blue light‐emitting diode for visible‐light communication applications. By using a hollow‐runway active area and hollow‐runway current‐confined aperture structure, we obtain an electrical‐to‐optical (E‐O) 3 dB bandwidth (f−3 dB) significantly higher than that of a rectangle‐structure LED with the same epitaxial structure and area of active area. Meanwhile, its optical power can reach 48.65 mW, even higher than a rectangle‐structure LED (45.33 mW). Eight hollow‐runway LEDs connected in series are called hollow‐runway‐chip‐array LEDs (HRCA‐LEDs) and eight rectangle‐structure LEDs connected in series are called rectangle‐chip‐array LEDs (RCA‐LEDs), and they are fabricated into a new device on the same substrate. The f−3 dB and the optical power of the device are ~98.5 MHz and ~712.3 mW, respectively, at 50 mA. HRCA‐LEDs are used as communication module that can provide data transmission and lighting and RCA‐LEDs as a lighting module for enhancing the overall lighting capability of the device. Its luminous flux is 203.57 lm and efficacy is 87.00 lm/W at 50 mA.
A modified T‐type equivalent circuit model for stretchable microstrip line
Authors: Sang Lei , Dai Kehan , Xu Ji , Zhao Haojie , Zhang Jie , Huang Wen
Published: February 2020

With the development of wearable devices, the conventional rigid material substrates have been unable to meet the needs of development. This article proposes a model based on polydimethylsiloxane (PDMS) stretchable microstrip line, which can be used to calculate the microwave performance when the microstrip line is stretched. The deformation results of the microstrip line are obtained by simulating the microstrip line under different stretching condition. A T‐type equivalent circuit model with novel formulas is established and the parameters R, L, C, and G of the equivalent circuit of the microstrip line are calculated by using the formulas. The S‐parameters of the microstrip transmission line can then be derived. Through the comparison of S parameters, it is found that the model calculation results have a good agreement with the simulation results.
Single‐shot EPI for ASL‐CMR
Authors: Javed Ahsan , Nayak Krishna S.
Published: February 2020

Purpose

To evaluate single‐shot echo planar imaging (SS‐EPI), as an alternative to snapshot balanced steady state free precession (bSSFP) imaging, for arterial‐spin‐labeled cardiac MR (ASL‐CMR). This study presents a practical implementation SS‐EPI tailored to the needs of ASL‐CMR at 3T and demonstrates sequential multi‐slice ASL with no increase in scan time.

Methods

Reduced field of view SS‐EPI was performed using a 2DRF pulse. A spin‐echo was used with crushers optimized to maximize blood suppression and minimize myocardial signal loss, based on experiments in 4 healthy volunteers. SS‐EPI was evaluated against the widely used bSSFP reference method in single‐slice ASL‐CMR in 4 healthy volunteers, during both systole and diastole. Sequential multi‐slice ASL‐CMR with SS‐EPI was demonstrated during diastole (3 slices: basal, mid, and apical short‐axis) and during systole (2 slices: mid and apical short‐axis), in 3 volunteers.

Results

Global myocardial perfusion for diastolic SS‐EPI (1.66 ± 0.73 mL/g/min) and systolic SS‐EPI (1.50 ± 0.36 mL/g/min) were found to be statistically equivalent (2 one‐sided test with a difference of 0.4 mL/g/min) to diastolic bSSFP (duration of 1 cardiac cycle, 1.60 ± 0.80 mL/g/min) with P‐values of 0.022 and 0.031, respectively. Global myocardial perfusion for sequential multi‐slice experiments was 1.64 ± 0.47, 1.34 ± 0.29, and 1.88 ± 0.58 for basal, mid, and apical SAX slices during diastole and was 1.61 ± 0.35, and 1.66 ± 0.49 for mid and apical slice during systole. These values are comparable to published ASL‐CMR and positron emission tomography studies.

Conclusion

SS‐EPI is a promising alternative to bSSFP imaging for ASL‐CMR and can potentially improve the spatial coverage of ASL‐CMR by 3‐fold during diastole and 2‐fold during systole, without increasing scan time.
Measuring diffusion exchange across the cell membrane with DEXSY (Diffusion Exchange Spectroscopy)
Authors: Breen‐Norris James O. , Siow Bernard , Walsh Claire , Hipwell Ben , Hill Ioana , Roberts Thomas , Hall Matt G. , Lythgoe Mark F. , Ianus Andrada , Alexander Daniel C. , Walker‐Samuel Simon
Published: February 2020

Introduction

To combine numerical simulations, in vitro and in vivo experiments to evaluate the feasibility of measuring diffusion exchange across the cell membrane with diffusion exchange spectroscopy (DEXSY).

Methods

DEXSY acquisitions were simulated over a range of permeabilities in nerve tissue and yeast substrates. In vitro measurements were performed in a yeast substrate and in vivo measurements in mouse tumor xenograft models, all at 9.4 T.

Results

Diffusion exchange was observed in simulations over a physiologically relevant range of cell permeability values. In vitro and in vivo measures also provided evidence of diffusion exchange, which was quantified with the Diffusion Exchange Index (DEI).

Conclusions

Our findings provide preliminary evidence that DEXSY can be used to make in vivo measurements of diffusion exchange and cell membrane permeability.
1H‐guided reconstruction of 19F gas MRI in COPD patients
Authors: Obert Arnd Jonathan , Gutberlet Marcel , Kern Agilo Luitger , Kaireit Till Frederik , Grimm Robert , Wacker Frank , Vogel‐Claussen Jens
Published: February 2020

Purpose

To reduce acquisition time and improve image quality and robustness of ventilation assessment in a single breath‐hold using 1H‐guided reconstruction of fluorinated gas (19F) MRI.

Methods

Reconstructions constraining total variation in the image domain, L1 norm in the wavelet domain, and directional total variation between 19F and 1H images were compared in order to accelerate 19F ventilation imaging using retrospectively undersampled data from a healthy volunteer. Using the optimal constrained reconstruction in 8 patients with chronic obstructive pulmonary disease (16‐seconds breath‐hold), ventilation maps of various acceleration factors (2‐fold to 13‐fold) were compared with maps of the full data set using the Dice coefficient, difference in volume defect percentage and overlap percentage, as well as hyperpolarized 129Xe gas MRI.

Results

The reconstruction constraining total variation and directional total variation simultaneously performed best in the healthy volunteer (RMS error = 0.07, structural similarity index = 0.77) for a measurement time of 2 seconds. Using the same reconstruction in the patients with chronic obstructive pulmonary disease, the Dice coefficient of defect volumes was 0.86 ± 0.05, the mean difference in volume defect percentage was −1.0 ± 1.7 percentage points, and the overlap percentage was 87% ± 2% for a measurement time of 6 seconds. Between volume defect percentage of 19F and 129Xe, a linear correlation (r = 0.75; P = .03) was found, with 19F volume defect percentage being significantly higher (mean difference = 11%; P = .04).

Conclusion

1H‐guided reconstruction of pulmonary 19F gas MRI enables reduction of acquisition time while maintaining image quality and robustness of functional parameters.