bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods and timing of curricular integration in U.S. dental education in preparation for the Integrated National Board Dental Examination
Authors: van der Hoeven Dharini , Hachem Lea El , Chaudhry Samyia , Holland Julian Nathaniel , Shepherd Kathi R.
Published: October 2020

Purpose

To characterize methods, timing, faculty training, and barriers pertaining to curricular integration in preparation for the Integrated National Board Dental Examination (INBDE) at U.S. dental schools

Methods

Academic deans at 67 U.S. dental schools were emailed an online survey consisting of questions on the time frame and methods of curricular integration, faculty training, and barriers to curricular integration

Results

Approximately 86% of schools have implemented (∼39%) or will implement (∼61%) changes in curriculum in preparation for the INBDE. Curricular integration was completed in 3‐4 years in most schools, with those schools with larger class sizes taking longer. While 56% of respondents reported avoiding a complete curricular overhaul, 79% reported course sequencing changes, adding, subtracting, or combining courses, and making some changes in existing courses. Curriculum committees had the most input in curricular changes, while individual instructors had the least influence. Sixty seven percent of respondents reported faculty being trained to teach in an integrated curriculum. Problem/case‐based learning and clinical case presentations are being used more for incorporation of biomedical sciences in clinical curriculum; use of clinical examples was the most used mechanism to integrate clinical information in biomedical sciences curriculum. Eighty two percent of respondents indicated that lack of faculty time to prepare courses as the primary barrier for implementing an integrated curriculum.

Conclusions

Our results show that most U.S. dental schools are implementing integrated teaching models to prepare their students for the INBDE. However, lack of faculty time and training need to be addressed for more successful curricular integration.
Psychometry and estimation of cutoff points of Jefferson Scale of empathy in dental students
Authors: Díaz Víctor P. , Reyes Alejandro , Calzadilla Aracelis , Torres Pilar A. , González Eugenia , Bilbao Jorge L. , González Farith , Estrada Nuvia , Fortich Natalia , Sepúlveda Wilmer , Silva‐Vetri María G. , Bullen Miriam , Erazo Ana M.
Published: October 2020

Objective

The objective of this study was to determine the psychometric properties of the 3‐dimensional latent model of empathy on the Jefferson Scale of Physician Empathy instrument (version S), and to verify the existence of cutoff points capable of differentiating empathy measures classified as: “high,” “medium,” and “low” using data collected from observations of students from 11 dental faculties of 5 Central American and Caribbean countries (n = 3082) between 2015 and 2019.

Methods

This is an exploratory, “a posteriori,” and non‐experimental study. Factor structure and factor invariance by country and gender were analyzed. Hierarchical cluster analysis and bifactorial analysis were applied, and the data were normalized by cluster and by percentiles within them.

Results

Confirmatory factor analysis showed that the original model was replicable and fit the data, while multigroup analysis allowed assuming an invariant factor structure by country and by gender. There is reliability in the measurement made by the scale and its dimensions.

Conclusions

The instrument has adequate psychometric properties, and cutoff values obtained allow people with lower or higher levels of empathy and its components to be classified. Therefore, these results solve the problem of comparing the scores and observed levels of empathy between dental schools within and between countries and between genders. Such comparisons were only possible since the original data of each study were made available for traditional statistical methods.
A longitudinal study of the relation between creative potential and academic achievement at an engineering university in Korea
Authors: Kim Jin‐Young
Published: October 2020

Background

Future scientists in engineering fields are expected, and even demanded, to be creative and innovative. Longitudinal studies pertaining to how creativity and academic achievement grow and develop over time remain limited.

Purpose

This study examines (a) relationships between the creative potential of first‐year engineering students and their graduation grades as well as between the creative potential and graduation grades in nonmajor liberal arts courses, (b) the role of gender in creative potential, and (c) changes in creative potential after 4 years of college life.

Method

In this exploratory study, the participants included 57 students from an engineering college in Korea. Data were first collected from 90 first‐year engineering students in August 2013. More than 4 years later in October 2017, 57 of these students were contacted again for follow‐up.

Results

A positive relationship was found between the creative potential of engineering students and their academic achievement. Female students exhibited higher creative potential scores than the male students at both time points. Creative potential increased after 4 years, particularly in total creativity score, fluency, and originality.

Conclusions

The findings from this study are different from the findings of Western engineering schools in their depiction of a positive relationship between creative potential and grades. This study indicated the possibility of developing creative potential even in adulthood. However, the results should be carefully interpreted not only because of the small sample size but also because of limitations of the Torrance Tests of Creative Thinking.
Enhancement Characteristics of Middle Cerebral Arterial Atherosclerotic Plaques Over Time and Their Correlation With Stroke Recurrence
Authors: Zhang Xuefeng , Chen Luguang , Li Shuai , Shi Zhang , Tian Xia , Peng Wenjia , Chen Shiyue , Zhan Qian , Liu Qi , Lu Jianping
Published: October 2020

Background

The progression of atherosclerotic plaque is a dynamic process; however, the natural evolution process of plaque enhancement on MRI remains unclear.

Purpose

To evaluate changes in enhancement characteristics of middle cerebral arterial (MCA) atherosclerotic plaques over time using MRI and to explore the relationship between the changes in plaque enhancement and stroke recurrence.

Study Type

Prospective.

Population

Fifty‐four patients with MCA atherosclerotic plaque underwent initial and follow‐up examinations with a median interval of 519 days (range 84–1820 days), including 37 males and 16 patients with recurrent stroke.

Field Strength/Sequence

Time‐of‐flight magnetic resonance angiography, diffusion‐weighted imaging, T2‐weighted imaging, pre‐ and postcontrast T1‐weighted imaging at 3 T.

Assessment

Clinical characteristics and differences in the changes in plaque enhancement among acute, subacute and chronic stroke groups and the changes in the degree of stenosis and plaque enhancement between the patients with and without recurrent stroke were compared. Risk factors for patients with recurrent stroke were assessed. Intra‐ and interobserver agreement in initial and the changes in plaque enhancement and stenosis, and the correlation between changes in plaque enhancement and recurrent stroke, were evaluated.

Statistical Tests

Independent‐samples t‐test, Mann–Whitney U‐test, chi‐squared test, Spearman correlation, logistic regression and Cohen's kappa test.

Results

There were significant differences in the changes in stenosis and plaque enhancement (P < 0.05) between the patients with and without recurrent stroke. A significant correlation was observed between the changes in plaque enhancement and stroke recurrence (r = 0.415, P < 0.05). Multivariate regression analysis showed that a change in plaque enhancement was an independent factor for stroke recurrence after adjusting for confounding factors (odds ratio [OR] = 5.797, P < 0.05). There was excellent intra‐ and interobserver agreement in evaluating plaque enhancement and stenosis.

Data Conclusion

Stable or increased enhancement of MCA plaque was related to recurrent stroke events at follow‐up. Change in plaque enhancement on MRI may be an important indicator for predicting recurrent stroke.

Level of Evidence

2

Technical Efficacy Stage

2
Impact of the Choice of Native T1 in Pixelwise Myocardial Blood Flow Quantification
Authors: Kräuter Corina , Reiter Ursula , Reiter Clemens , Nizhnikava Volha , Schmidt Albrecht , Stollberger Rudolf , Fuchsjäger Michael , Reiter Gert
Published: October 2020

Background

Quantification of myocardial blood flow (MBF) from dynamic contrast‐enhanced (DCE) MRI can be performed using a signal intensity model that incorporates T1 values of blood and myocardium.

Purpose

To assess the impact of T1 values on pixelwise MBF quantification, specifically to evaluate the influence of 1) study population‐averaged vs. subject‐specific, 2) diastolic vs. systolic, and 3) regional vs. global myocardial T1 values.

Study Type

Prospective.

Subjects

Fifteen patients with chronic coronary heart disease.

Field Strength/Sequence

3T; modified Look–Locker inversion recovery for T1 mapping and saturation recovery gradient echo for DCE imaging, both acquired in a mid‐ventricular short‐axis slice in systole and diastole.

Assessment

MBF was estimated using Fermi modeling and signal intensity nonlinearity correction with different T1 values: study population‐averaged blood and myocardial, subject‐specific systolic and diastolic, and segmental T1 values. Myocardial segments with perfusion deficits were identified visually from DCE series.

Statistical Tests

The relationships between MBF parameters derived by different methods were analyzed by Bland–Altman analysis; corresponding mean values were compared by t‐test.

Results

Using subject‐specific diastolic T1 values, global diastolic MBF was 0.61 ± 0.13 mL/(min·g). It did not differ from global MBF derived from the study population‐averaged T1 (P = 0.88), but the standard deviation of differences was large (0.07 mL/(min·g), 11% of mean MBF). Global diastolic and systolic MBF did not differ (P = 0.12), whereas global diastolic MBF using systolic (0.62 ± 0.13 mL/(min·g)) and diastolic T1 values differed (P < 0.05). If regional instead of global T1 values were used, segmental MBF was lower in segments with perfusion deficits (bias = −0.03 mL/(min·g), −7% of mean MBF, P < 0.05) but higher in segments without perfusion deficits (bias = 0.01 mL/(min·g), 1% of mean MBF, P < 0.05).

Data Conclusion

Whereas cardiac phase‐specific T1 values have a minor impact on MBF estimates, subject‐specific and myocardial segment‐specific T1 values substantially affect MBF quantification.

Level of Evidence

3

Technical Efficacy Stage

3
The mode‐conversion coefficient of ELF wave propagation due to land‐to‐sea transition
Authors: Xu Hong Lei , Gu Ting Ting , Zhu Yong , Yin Hong Cheng , Yang Li Xia
Published: October 2020

The mode‐conversion coefficient is studied to investigate the ELF wave propagation over a mixed land‐to‐sea path. As partition by the consideration of reflection influence from the ionosphere layer, we assume the propagation can be regarded as being subjected to two different models over mixed paths, in terms of the propagation distance in the range of ELF far‐field and near‐field regions, respectively. Both of the mentioned stratified models can be represented as cascaded transmission networks at the abrupt junctions. In conformity with previous study to formulate the far‐field propagation as a cascaded terrestrial waveguide with abrupt height and ground impedance changes, the presented study proposed an equivalent cascaded network to exploit the concept of mode‐conversion for near‐field propagation across discontinuity. Representative parameters of ground types in contrast are supportive to demonstrate the interference of abrupt impedance‐change at ELF band. The presented analysis provide with computational schemes to obtain synthetic fields of ELF wave propagation, which could be extended to more realistic model over multi‐segmental mixed paths.
Interdecadal summer warming of the Tibetan Plateau potentially regulated by a sea surface temperature anomaly in the Labrador Sea
Authors: Gao Kailun , Duan Anmin , Chen Deliang
Published: October 2020

Downward clear‐sky longwave radiation, which is related to atmospheric water vapour content, has been suggested as an important factor causing an interdecadal increase in boreal summer surface temperature over the Tibetan Plateau (TP). We reveal the relationship between the 2 m air temperature (t2m) and water vapour over the TP in boreal summer, as well as the mechanism modulating the change in atmospheric water vapour. In recent decades, spatiotemporal variations between water vapour and t2m in boreal summer over the TP have shown synchronicity at the decadal scale. Moreover, Rossby wave trains which originate over the Northwest Atlantic and trigger an anomalous anticyclone between the northeastern TP and Baikal Lake are suggested to play a crucial role in decadal warming over the TP. First, the anomalous anticyclone, with an equivalent barotropic structure, can directly heat near‐surface air across the northeastern TP. Second, it promotes net water vapour input into the northeastern TP, leading to an increase of the total water vapour content over the entire TP, ultimately contributing to warming. Finally, a linear baroclinic model experiment further indicates that the Rossby wave trains are mainly associated with interdecadal increases in sea surface temperature (SST) in the Labrador Sea, with the SST in Baffin Bay playing a secondary role.
Molecular profiling of bone remodeling occurring in musculoskeletal tumors
Authors: Nakajima Kosei , Kidani Teruki , Miura Hiromasa
Published: October 2020

Musculoskeletal malignancy is often accompanied by aberrant bone remodeling, leading to tumor cell invasion into skeletal tissues and causing severe pain. BMPs, FGF‐2, and RANKL have been identified as promising regulators in physiological bone remodeling. In this study, we explored the expressional profile of BMPs, FGF‐2, and RANKL in 1361 patients with 22 varieties of musculoskeletal tumors. Notably, the expression of FGF‐2 and RANKL was under detected in all patients. Among BMP1 to BMP15, we found that BMP1, BMP2, BMP4, BMP5, BMP6, and BMP7 were prevalent. In comparison with normal bones, osteosarcoma highly expressed BMP1, BMP2, BMP4, and BMP7 with statistical significance. Synovial sarcoma upregulated BMP4, BMP5, and BMP7; rhabdomyosarcoma increased BMP1 and BMP4; and alveolar soft part sarcoma upregulated BMP1, BMP4, and BMP7. To visualize the BMP‐oriented interactions in a bone tumor microenvironment, we have developed novel software that analyzes numerous cell‐to‐cell and ligand‐to‐receptor interactions, that is, Environmentome, delineating that osteosarcoma‐secreted BMP‐4 and synovial sarcoma‐secreted BMP7 potently interact with osteoblasts, osteocytes, osteoclast precursors, and mature osteoclasts. Specifically, quantification analysis revealed that the relationship between osteosarcoma and mature osteoclast/precursor, BMP4–BMPR2 and BMP4–ACVR2A interactions were most potent. Regarding the association between osteosarcoma and osteocyte/osteoblast, BMP4–ACVR1 and BMP4–BMPR2 were the key interactions. In the connection between synovial sarcoma and mature osteoclast/precursor, BMP7–ACVR2A and BMP7–BMPR2 interactions were most remarkable. With regard to the cellular link between synovial sarcoma and osteocyte/osteoblast, BMP7–BMPR2 was identified as a potent interaction. In conclusion, our new outlook suggests delivering the pathological events that clinically underlie behind severe skeletal pain or fracture in musculoskeletal tumors.
Approach for using measured soil gas diffusion coefficients in Hydrus 1D with examples from forest soils
Authors: Haas Christoph , Paulus Sinikka , Maier Martin , Jochheim Hubert , Gerke Horst H.
Published: October 2020

The use of Hydrus‐1D for modeling soil gas fluxes can be improved by introducing a parameter f obtained by fitting the Millington–Quirk (MQ) tortuosity model to measured gas diffusion coefficients. The approach was tested for data from soil horizons of two sandy forest sites located in Northeast‐Germany. f‐values ranged between 0.41 and 0.54, indicating a more tortuous pore systems than predicted by MQ model (f = 1). The parameter optimization procedure can be carried out by using the statistical software R and the enclosed R‐script.
Effects of mid‐stage nitrogen application timing on the morphological structure and physicochemical properties of japonica rice starch
Authors: Hu Qun , Liu Qiuyuan , Jiang Weiqin , Qiu Shi , Wei Haiyan , Zhang Hongcheng , Liu Guodong , Xing Zhipeng , Hu Yajie , Guo Baowei , Gao Hui
Published: October 2020

BACKGROUND

Nitrogen management of crops, especially when mid‐stage nitrogen is applied, is a key factor affecting the yield and grain quality of rice (Oryza sativa). Here, the timing of mid‐stage nitrogen application was evaluated for its effect on rice grain quality by assessing the morphological structure and physicochemical properties of starch from two japonica rice cultivars growing in fields (Nangeng 9108 and Nangeng 5055).

RESULTS

The experiment was arranged in a split‐plot design, with the two rice cultivars as the main plot factor and three timings of mid‐stage nitrogen application as the within‐plot factor. Briefly, three applications were made: at the emergence of the top‐sixth‐leaf (ahead), the top‐fourth‐leaf (normal), and the top‐second‐leaf (delayed) of the main stem. Delaying mid‐stage nitrogen application caused the starch granule surface to become uneven and significantly reduced its particle size, whereas it increased the polished rice rate, chalkiness degree, and protein content. Furthermore, the apparent amylose content decreased with a delay in mid‐stage nitrogen application, thereby resulting in higher relative crystallinity, swelling power, water solubility, gelatinization enthalpy, and low retrogradation. Finally, we also found that delaying this nitrogen application lowered the characteristic values of rice flour viscosities, leading to cooking quality deterioration.

CONCLUSION

These results therefore suggest that delaying mid‐stage nitrogen application enhances the processing and nutritional qualities of japonica rice but evidently has an adverse effect upon its appearance and cooking qualities. © 2020 Society of Chemical Industry
Prediction of Stress Urinary Incontinence Using the Retrovesical (β) Angle in Transperineal Ultrasound
Authors: Keshavarz Elham , Pouya Ensi Khalili , Rahimi Maryam , Bozorgan Tayebeh Jahed , Saleh Masoumeh , Tourzani Zahra Mehdizadeh , Kabir Kourosh , Bakhtiyari Mahmood
Published: October 2020

Objectives

The accurate, rapid diagnosis of stress urinary incontinence (SUI) in women can profoundly improve their sexual and psychosocial life. In this study, the diagnostic power of SUI was assessed by transperineal ultrasound.

Methods

In this hospital‐based case‐control study, married women who were referred to the gynecologic and ultrasound wards with negative urinalysis and culture results were enrolled by random sampling. Patients with positive cough signs based on the urodynamic testing data were considered cases, whereas control women showed no cough symptoms and were recruited from the same ward.

Results

There was a significant difference (P < .001) in bladder neck descent (mean ± SD, 10.89 ± 5.51 versus 7.08 ± 2.60 mm, respectively; P = .0001) and the retrovesical (β) angle with the Valsalva maneuver (144.22° ± 19.63° versus 111.81° ± 24.47°; P < .001) between the case and control groups. Also, the β angle without the Valsalva maneuver was higher in the case group (112.35° ± 23.10°) than the control group (120.17° ± 25.16°; P = .001). There was no case of a urinary leak, urethral diverticulitis, a bladder stone or mass, and cystourethrocele in the patients of each group. The results of multivariate logistic regression with a backward method showed that bladder neck descent (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.09–1.40), the β angles with and without the Valsalva maneuver (OR, 1.1; 95% CI, 1.06–1.13; and OR, 1.04; 95% CI, 1.01–1.06) were the predictors of SUI. A β angle higher than 127° with the Valsalva maneuver, with an area under the curve of 0.89 (95% CI, 0.75–0.96), could very well predict the SUI response. This finding shows that it can be very well used to distinguish between normal and non‐normal responses, with 89% sensitivity and 79% specificity.

Conclusions

The β angle with the Valsalva maneuver could very well predict the SUI response.
Investigating equations for measuring dissolved inorganic nutrient uptake in oligotrophic conditions
Authors: Stukel Michael R.
Published: October 2020

Multiple different equations have been used to quantify nutrient uptake rates from stable isotope tracer label incorporation experiments. Each of these equations implicitly assumes an underlying model for phytoplankton nutrient uptake behavior within the incubation bottle and/or pelagic environment. However, the applicability of different equations remains in question and uncertainty arising from subjective choices of which equation to use is never reported. In this study, I use two approaches to investigate the conditions under which different nutrient uptake equations should be used. First, I utilized a moderate‐complexity pelagic ecosystem model that explicitly models the δ15N values of all model compartments (NEMURO + 15N) to conduct simulated nitrate uptake and ammonium uptake incubations and quantify the accuracy of different nutrient uptake equations. Second, I used results of deckboard diel nutrient uptake experiments to quantify the biases of 24‐h incubations relative to six consecutive 4‐h incubations. Using both approaches, I found that equations that account for nutrient regeneration (i.e., isotope dilution) are more accurate than equations that do not, particularly when nutrient concentrations are low but uptake is relatively high. Furthermore, I find that if the goal is to estimate in situ uptake rates it is appropriate to use an in situ correction to standard equations. I also present complete equations for quantifying uncertainty in nutrient uptake experiments using each nutrient uptake equation and make all of these calculations available as Excel spreadsheets and Matlab scripts.
Creating a flexible business credit rating model using multicriteria decision analysis
Authors: Katsimperis Valentinos , Andrikopoulos Athanasios
Published: October 2020

To decide for the approval or rejection of a business loan application, banks are following a rating procedure. However, in many cases this procedure is not simply and properly structured. This may lead to unpleasant results so, for a long time, banks are struggling to find quite flexible and simple rating methods, widely applicable, easily comprehensible, and modifiable from their analysts. This study presents an empirical model of mass business rating with the use of multicriteria analysis (AHP method) and other techniques. Two main scenarios of a two‐stage evaluation procedure will be analysed that demonstrate its flexibility, stability, and simplicity. The performance of this method is measured for both presented scenarios showing its capability. Furthermore, this method saves time and sources while ensuring the quality of the produced results. The outcome will be a list of rated businesses which, depending on the score they succeed in each of the two scenarios, will be approved or rejected for a business loan.
Advances and current challenges in non‐invasive wearable sensors and wearable biosensors—A mini‐review
Authors: dos Santos Caio Carvalho , Lucena Guilherme N. , Pinto Gabriel C. , Júnior Miguel J. , Marques Rodigo F.C.
Published: October 2020

Flexible wearable sensors and wearable biosensors have attracted considerable interest in the scientific community. They have shown relevant potential for continuous monitoring of physiological functions in real‐time and non‐invasively using biofluids. Recent nanotechnology advances in sensor miniaturization and lower costs have driven the development of new flexible sensors. These new materials make sensors and biosensors promising and will cause a substantial impact on society by providing an improvement in the quality of life, as well as in a faster diagnosis and early treatment. However, considerable challenges still need to be overcome for these sensors to reach their totality, as such as improving available power supplies, low power data transmission mode, problems with device deformation and contaminated, continuous wear, understanding the correlations between analytes in biofluids and blood to validate results, and issues of security and privacy. Overcoming these challenges will allow, through the diffusion of this technology, to modify how the disease can be monitored in the future. Due to this, systematic studies should be conducted to elucidate and enhance the understanding of the current challenges for the development and implementation of wearable sensors (WS) and wearable biosensors (WBS). In this mini‐review, we discuss the state of the art of these devices, critically addressing the advances by debating the current gaps and the challenges that need to overcome this science area.
Tiny‐RainNet: a deep convolutional neural network with bi‐directional long short‐term memory model for short‐term rainfall prediction
Authors: Zhang Chang‐Jiang , Wang Hui‐Yuan , Zeng Jing , Ma Lei‐Ming , Guan Li
Published: October 2020

Rainfall is not only related to current and previous meteorological conditions but also to meteorological conditions of the current location and surrounding regions. Existing short‐term rainfall prediction methods mainly focus on radar echo extrapolation to predict the future radar echo maps, and then retrieve rainfall based on the predicted radar echo maps. These methods obtain rainfall through two separate steps usually leading to large accumulated errors. However, Tiny‐RainNet is proposed by combining convolutional neural networks (CNNs) with bi‐directional long short‐term memory (BiLSTM) to directly predict future rainfall based on sequential radar echo maps. The structure of Tiny‐RainNet is simpler than existing rainfall prediction models combining CNNs with LSTM. In order to further reduce computational complexity of the Tiny‐RainNet and obtain good rainfall prediction results, 10 × 10, not the original 101 × 101, sequential radar maps are used as inputs of the Tiny‐RainNet after making many tests considering temporal–spatial meteorological conditions. The proposed model takes into account the influence of temporal–spatial meteorological conditions on rainfall prediction. This avoids the accumulated error caused by multi‐step prediction methods. The overall performance of the Tiny‐RainNet model performs better than fully connected LSTM, LSTM and convolutional LSTM.
Design of high‐efficiency continuous resistive‐reactive class‐J power amplifier
Authors: Liu Guohua , Zhao Zhong , Cheng Zhiqun , Li Sudong
Published: October 2020

This paper presents an ultra‐wideband, high‐efficiency continuous resistive‐reactive class‐J power amplifier. The design space is extended by controlling the second harmonic with impedance component and multiple harmonics of a continuous class‐J PA, enabling it to achieve efficient output in multiple octave bandwidths. Based on this theory, a GaN HEMT transistor CGH40010F is used to achieve a 0.6 to 3.2 GHz, average efficiency of 65%, ultra‐wideband PA with output power greater than 40 dBm. The simulation results are consistence with the measurement results and respond to the expectations.
Chemical shift encoding using asymmetric readout waveforms
Authors: Rydén Henric , Norbeck Ola , Avventi Enrico , Skorpil Mikael , van Niekerk Adam , Skare Stefan , Berglund Johan
Published: October 2020

Purpose

To describe a new method for encoding chemical shift using asymmetric readout waveforms that enables more SNR‐efficient fat/water imaging.

Methods

Chemical shift was encoded using asymmetric readout waveforms, rather than conventional shifted trapezoid readouts. Two asymmetric waveforms are described: a triangle and a spline. The concept was applied to a fat/water separated RARE sequence to increase sampling efficiency. The benefits were investigated through comparisons to shifted trapezoid readouts. Using asymmetric readout waveforms, the scan time was either shortened or maintained to increase SNR. A matched in‐phase waveform is also described that aims to improve the SNR transfer function of the fat and water estimates. The sequence was demonstrated for cervical spine, musculoskeletal (MSK), and optic nerve applications at 3T and compared with conventional shifted readouts.

Results

By removing sequence dead times, scan times were shortened by 30% with maintained SNR. The shorter echo spacing also reduced
blurring. Maintaining the scan times and using asymmetric readout waveforms achieved an SNR improvement in agreement with the prolonged sampling duration.

Conclusions

Asymmetric readout waveforms offer an additional degree of freedom in pulse sequence designs where chemical shift encoding is desired. This can be used to significantly shorten scan times or to increase SNR with maintained scan time.
On solution of a class of nonlinear variable order fractional reaction–diffusion equation with Mittag–Leffler kernel
Authors: Pandey Prashant , Gómez‐Aguilar José Francisco
Published: October 2020

In this article, an efficient variable‐order Chebyshev collocation method which is based on shifted fifth‐kind Chebyshev polynomials is applied to solve a nonlinear variable‐order fractional reaction–diffusion equation with Mittag–Leffler kernel. The operational matrix of shifted fifth‐kind Chebyshev polynomials is derived for variable‐order ABC derivatives. The Chebyshev operational matrix together with the collocation method are applied to concerned nonlinear physical model with Mittag–Leffler kernel which is converted into a system of nonlinear algebraic equations, this system can be solved by using Newton method. The main focus of this paper is finding the convergence analysis of the approximation and high convergence order for small grid approximation. Few test examples with a comparison of maximum absolute error between the obtained numerical solution and existing known solution are being reported to show the accuracy and stability of the scheme. The physical presentation of the absolute errors for considered nonlinear variable‐order reaction–diffusion equations involving the Mittag–Leffler kernel with their exact solutions shows that the method is good for finding the solution of these kind of problems.
A stabilizer free weak Galerkin finite element method with supercloseness of order two
Authors: Al‐Taweel Ahmed , Wang Xiaoshen , Ye Xiu , Zhang Shangyou
Published: October 2020

The weak Galerkin (WG) finite element method is an effective and flexible general numerical technique for solving partial differential equations. A simple WG finite element method is introduced for second‐order elliptic problems. First we have proved that stabilizers are no longer needed for this WG element. Then we have proved the supercloseness of order two for the WG finite element solution. The numerical results confirm the theory.
Epoxy resins with high heat resistance and flame retardancy via a new process
Authors: Kimura Hajime , Ohtsuka Keiko , Yonekawa Morio
Published: October 2020

To develop highly heat‐resistant and flame‐retardant epoxy resins, the curing behavior of an epoxy resin and the properties of the resulting cured product were investigated using two compounds as curing agents, an acid anhydride containing a phenylethynylcarbonyl group and an imide compound with a phenylethynylcarbonyl group at both ends. The results indicated that reaction between the acid anhydride group and the epoxy group first proceeded at about 150°C to 170°C, followed by reaction between the phenylethynylcarbonyl groups at about 250°C to 300°C. The reaction between the acid anhydride and the epoxy group proceeded more efficiently in the presence of a small amount of the imide compound. The resulting product exhibited very good heat resistance and flame retardancy. The crosslink density was increased by polymerization of the phenylethynylcarbonyl group, and the resulting polyene structure and intramolecular imide skeleton strengthened intermolecular interactions, likely due to the limited freedom of movement of the molecular chains.
Assessment of nutritional status in children with cancer: Significance of arm anthropometry and serum visceral proteins
Authors: Yaprak Deniz Sül , Yalçın Bilgehan , Pınar Aslı Akhun , Büyükpamukçu Münevver
Published: October 2020

Background

Arm anthropometry is a better indicator of nutritional status in children with cancer. The value of serum albumin and prealbumin in nutritional assesment is debatable. We investigated the nutritional status of children with cancer and their serum albumin and prealbumin levels.

Patients and Methods

At diagnosis and following induction therapies, weight, height, body mass index (BMI), mid‐upper arm circumference (MUAC), and triceps skin‐fold thickness (TSFT) were measured; serum albumin and prealbumin levels were determined. Prevalences of malnutrition defined by anthropometric indices were calculated. Correlations of anthropometric indices with each other, with serum albumin/prealbumin levels, and clinicopathological parameters were analyzed.

Results

In 81 patients, median age was 7.5 years (males/females = 50/31), tumors were located mostly in the abdomen, and abdominal tumors were more common under 5 years. Prevalence of malnutrition according to weight for age, BMI, MUAC, TSFT z scores were 14.8%, 23.5%, 27.2%, 21%, respectively. Defined by combined BMI/MUAC/TSFT measurements, 33/81 cases (40.7%) had malnutrition (z scores < −1, 23 mild; z scores < −2, 10 moderate). Malnutrition was more prevalent under 5 years (P = .03), also in abdominal tumors (P = .03) and advanced disease (P < .001). Younger age and advanced disease were risk factors for malnutrition. At diagnosis, prevalences of low serum albumin and prealbumin levels were 7.4% and 54%, respectively. Cases with malnutrition had significantly lower survival rates.

Conclusions

Nutritional status is assessed best by MUAC and TSFT measurements. Serum prealbumin levels can be used to identify patients at risk of undernutrition. Presence of malnutrition is a significant poor prognostic factor. All children with cancer should undergo nutritional evaluation and active nutritional support.
Personality and emerging adults' friend selection on social networking sites: A social network analysis perspective
Authors: Zhou Yixin , Zhang Zheng , Wang Kexin , Chen Shuang , Zhou Mingjie , Zhang Jianxin
Published: October 2020

Personality affects how emerging adults select friends and how they are selected on social networking sites (SNSs). Big Five personality traits and frequency of contacts on SNSs were collected from 160 college freshmen (M = 18 years) under a round‐robin design over 2 months. Using social network analyses, we examined how personality and dyadic similarity affect online friend selections among new acquaintances. Our results show that people with high extraversion, neuroticism, and agreeableness and low openness selected more friends, verifying both the social enhancement hypothesis and the social compensation hypothesis. People with low extraversion, conscientiousness, and neuroticism and high openness were selected as online friends more often. Only openness dissimilarity had a salutary effect. We discuss the role of personality in social networking friend selection.
Bioactivity improvement via display of the hydrophobic core of HYD1 in a cyclic β‐hairpin‐like scaffold, MTI‐101
Authors: Jain Priyesh , Badger David B. , Liang Yi , Gebhard Anthony W. , Santiago Daniel , Murray Philip , Kaulagari Sridhar R. , Gauthier Ted J. , Nair Rajesh , Kumar MohanRaja , Guida Wayne C. , Hazlehurst Lori A. , McLaughlin Mark L.
Published: October 2020

HYD1 is an all D‐amino acid linear 10‐mer peptide that was discovered by one‐bead‐one‐compound screening. HYD1 has five hydrophobic amino acids flanked by polar amino acids. Alanine scanning studies showed that alternating hydrophobic amino acid residues and N‐ and C‐terminal lysine side chains were contributors to the biological activity of the linear 10‐mer analogs. This observation led us to hypothesize that display of the hydrophobic pentapeptide sequence of HYD1 in a cyclic beta‐hairpin‐like scaffold could lead to better bioavailability and biological activity. An amphipathic pentapeptide sequence was used to form an antiparallel strand and those strands were linked via dipeptide‐like sequences selected to promote β‐turns. Early cyclic analogs were more active but otherwise mimicked the biological activity of the linear HYD1 peptide. The cyclic peptidomimetics were synthesized using standard Fmoc solid phase synthesis to form linear peptides, followed by solution phase or on‐resin cyclization. SAR studies were carried out with an aim to increase the potency of these drug candidates for the killing of multiple myeloma cells in vitro. The solution structures of 1, 5, and 10 were elucidated using NMR spectroscopy. 1H NMR and 2D TOCSY studies of these peptides revealed a downfield Hα proton chemical shift and 2D NOE spectral analysis consistent with a β‐hairpin‐like structure.
Effects of Ginkgo biloba intake on cardiometabolic parameters in patients with type 2 diabetes mellitus: A systematic review and meta‐analysis of clinical trials
Authors: Tabrizi Reza , Nowrouzi‐Sohrabi Peyman , Hessami Kamran , Rezaei Shahla , Jalali Mohammad , Savardashtaki Amir , Shahabi Saeed , Kolahi Ali‐Asghar , Sahebkar Amirhossein , Safiri Saeid
Published: October 2020

Ginkgo biloba (GKB) may have a beneficial effect on cardiometabolic parameters in type 2 diabetes mellitus (T2DM), but the data is inconsistent. Therefore, the current systematic review and meta‐analysis of clinical trials was conducted to assess the influence of GKB on cardiometabolic parameters in T2DM. Several online databases such as PubMed, Embase, Scopus, Web of Sciences, Google Scholar and Cochrane Library were systematically searched from inception up to September 2, 2019. Heterogeneity across included studies was assessed using the Cochran's Q statistic and I2 index. To pool weighted mean differences (WMDs) and the corresponding 95% confidence intervals (CIs) as summary effect size, we selected fixed or random‐effects model according to the result of heterogeneity. Seven studies comprising 768 subjects were included in the present meta‐analysis which resulted in a significant effect of GKB on hemoglobin A1c (HbA1c) (WMD = 0.26, 95% CI = [0.02, 0.50], p = .034) and serum HDL‐cholesterol levels (WMD = 1.99, 95% CI = [0.19, 3.79], p = .030) with no significant publication bias. GKB can significantly modulate HbA1c and HDL‐cholesterol levels. However, due to uncertainties related to the limited number of studies, it is too early to conclude whether GKB has any potential effects on the cardiometabolic factors in patients with T2DM or not.
Anxiolytic activity of Psidium guajava in mice subjected to chronic restraint stress and effect on neurotransmitters in brain
Authors: Sahoo Swati , Kharkar Prashant S. , Sahu Niteshkumar U. , S. Brijesh
Published: October 2020

The anxiolytic activity of Psidium guajava L. leaf ethanolic extract (PLE) and its effect on neurotransmitter systems was investigated. PLE, extracted using Soxhlet apparatus, was subjected to preliminary qualitative and quantitative (flavonoids and phenols) analyses. The anxiolytic activity at 100, 200, and 400 mg/Kg doses were assessed in mice using elevated plus maze (EPM) and light/dark transition (LDT) test models on days 1 and 16. Neurotransmitters such as monoamines (serotonin, norepinephrine, and dopamine), γ‐aminobutyric acid (GABA), and glutamate were estimated in different regions of the brain (cortex, hippocampus, and cerebellum and brain stem). Phytoconstituents identified using gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry were analyzed in silico to evaluate their potential binding mode(s) to GABAA and 5‐HT1A receptors. Phytochemical studies showed the presence of alkaloids, tannins, flavonoids, saponins, anthraquinone glycosides, carbohydrates, and proteins, whereas total flavonoid and phenol contents were estimated to be 64.96 ± 0.95 and 206.58 ± 1.60 mg/g of dried extract, respectively. PLE treatment significantly enhanced exploratory activity of mice in EPM and LDT models with significant effects on monoamines, GABA and glutamate levels in the brain. The in silico studies suggested the interaction(s) of PLE component(s) with GABAA/5‐HT1A receptors as a potential mechanism of its anxiolytic activity.
A user‐friendly, Python‐based quantum mechanics/Gromacs interface: gmx2qmmm
Authors: Götze Jan P. , Pi Yuan‐Wei , Petry Simon , Langkabel Fabian , Witte Jan Felix , Lemke Oliver
Published: October 2020

We introduce a Python 2.7 software called gmx2qmmm, which provides an interface between the Gaussian and Gromacs software packages in an additive quantum mechanics/molecular mechanics (QM/MM) scheme. Other QM packages will be added in future releases. The main advantage of gmx2qmmm is its simplicity in terms of input setup and configuration as it maintains the Gromacs file formats, as well as input conventions. It is also designed such that users do not need to reconfigure or recompile any of the interfaced programs. While our main goal was to provide a simplified transition from Gromacs to QM/MM using Gromacs directly as the basis for the MM part, we considered alternative ways to treat the QM/MM boundary. Our software was also developed to test a previously considered way to account for the presence of link atoms, which we term here link atom correction functions (LCFs). We show that LCFs can be good candidates to improve the forces at the QM/MM junction; however, from our data, it is also apparent that LCFs will not necessarily improve energy barriers, likely due to them being tailored to improve the situation close to potential minima. LCFs are, however, trivial to set up and can be used in the future to support the accuracy of QM/MM optimizations and dynamics. We present data on how our interface compares to a full QM description of small polypeptides; furthermore, we investigate the UV/vis spectroscopy of chlorophyll‐containing proteins depending on the employed potentials and geometries.
Binding properties of cucurbit[7]uril to neutral and protonated amino acids: A theoretical study
Authors: Ma Fenfen , Zheng Xiaoyan , Xie Jing , Li Zesheng
Published: October 2020

We systematically investigate the binding nature of cucurbit[7] (CB[7]) toward 20 amino acids in both neutral (AAs) and protonated (AAs+) states using quantum chemistry methods. The result indicates that, among AAs, Arg and Asn show the largest binding strength to CB[7], and for AAs+, Gln+ and Asn+ bind to CB[7] the strongest. The binding strength of protonated CB[7]/AA+ is much stronger than that of neutral CB[7]/AA counterpart due to the introduction of ion‐dipole interaction and the increase in number and strength of hydrogen bonds. Energy decomposition analysis indicates that electrostatic interactions play major roles in both CB[7]/AAs and CB[7]/AAs+ complexes. Moreover, we analyzed the dependence of binding strength on single AA volume and dipole moment. This study is beneficial for providing valuable information in predicting the recognition sites for a sequence‐based peptide or protein by CB[7] and rationally designing a synthetic host molecule for specific peptide or protein recognition.
Robust stability analysis for linear systems with distributed delays: A time‐domain approach
Authors: Juárez Luis , Alexandrova Irina V. , Mondié Sabine
Published: October 2020

This work is devoted to the robust stability analysis of linear systems with distributed delays. The approach is based on recent results in the Lyapunov‐Krasovskii framework, where a Lyapunov‐Krasovskii functional with prescribed negative definite derivative is applied. The stability conditions obtained in this work, are simple inequalities which depend on the so‐called delay Lyapunov matrix. The cases of matrix parameters and delays uncertainties are addressed, accurately detecting exact stability bounds when applied in an iterative manner. Our method is used successfully to tackle the challenging problem of robust predictor‐based stabilization of systems with state and input delays.
Nontracking type iterative learning control based on economic model predictive control
Authors: Long Yushen , Xie Lihua , Liu Shuai
Published: October 2020

Most existing iterative learning control algorithms are designed to improve tracking performance with respect to a given trajectory over a fixed time period. In this article, we design two iterative learning‐based economic model predictive controllers for repetitive tasks where no target trajectory is available. The controller is able to search for suboptimal trajectories with good performance by exploiting information from previous experience. Compared with existing works, the objective function is not assumed to be positive definite so it is not limited to the tracking problem but can represent more general economic performance index. The controller can learn from the previous closed‐loop trajectory, resulting in a performance which is guaranteed to be no worse than the previous one. Under some standard assumptions in model predictive control, the recursive feasibility of the algorithms is ensured. We show that the fixed operation time algorithm can guarantee that the performance is no worse than the previous iteration even without the dissipative assumption. By allowing the operation time to vary, the flexible operation time algorithm can balance the operation time and the system performance if dissipative assumption is satisfied. For both algorithms, each iteration is guaranteed to be completed within a uniformly bounded time duration.
Preparation of a Sulfonic‐Acid‐Type Ordered Mesoporous Carbon Solid Acid via Hydrothermal Synthesis for the Transesterification of Waste Frying Oil
Authors: Ma Xiuhua , Huang Zhihang , Yuan Hong , Ke Yihu
Published: October 2020

Hydrothermal carbonisation was used to synthesise hydrothermally ordered mesoporous carbon (HOMC), employing sucrose as the carbon source, a P123 block copolymer as the surfactant and tetraethyl orthosilicate as the silicon source. A high‐density sulfonic‐acid‐based solid acid catalyst (HOMC‐SO3H) was subsequently prepared via low‐temperature sulfonation of the HOMC with concentrated sulfuric acid. Transmission electron microscopy and small‐angle X‐ray diffraction analyses showed that both the HOMC and HOMC‐SO3H exhibited an ordered mesoporous structure. The N2 Brunauer‐Emmett‐Teller surface areas of the HOMC and HOMC‐SO3H were determined to be 112 and 87 m2/g, respectively, and the average pore sizes were 11.0 and 15.1 nm, respectively. X‐ray photoelectron spectroscopy data confirmed that −SO3H groups were successfully introduced onto the HOMC surface by the sulfonation process, and a surface acid concentration of 5.9 mmol/g HOMC‐SO3H was determined by acid‐base titration. The HOMC‐SO3H was applied to the transesterification of waste frying oil with methanol and a fatty acid methyl ester yield of 95 % was obtained after a 5 h reaction at 180 °C.