bluuebunny/crossref_metadata_2025 huggingface dataset:
Topological structures of river networks and their regional‐scale controls: A multivariate classification approach
Authors: Walley Yasmin , Henshaw Alexander J. , Brasington James
Published: June 2020

Landscape evolution is governed by the interplay of uplift, climate, erosion, and the discontinuous pattern of sediment transfer from the proximal source of erosion to distal sedimentary sinks. The transfer of sediment through the catchment system is often referred to as a cascade, the pattern of which is modulated by the interaction of key network characteristics such as the distribution of transport capacity and resultant zones of sediment storage. An understanding of how sediment production is modulated through river networks with different topological structures at the associated timescales has remained elusive but presents significant implications for the knowledge of river response to disturbance events, and floodplain asset management.

A multivariate method of identifying representative topological structures from a range of river networks is presented. Stream networks from 59 catchments in the South Island of New Zealand were extracted from a digital elevation model and their key topological parameters quantified. A principal component analysis was implemented to reduce these to two‐dimensional axes that represent the magnitude of network branching and the topographic structure of each catchment, respectively. An agglomerative hierarchical clustering analysis revealed five network ‘types’, which are examined in terms of their internal structural characteristics and relationships to potential regional‐scale controls. Implications for sediment transfer in these network ‘types’, and their use as representative networks for further analysis, are discussed. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
Proxy re‐encryption with equality test for secure data sharing in Internet of Things‐based healthcare systems
Authors: Li Wenchao , Jin Chuanjie , Kumari Saru , Xiong Hu , Kumar Sachin
Published: June 2020

The integration of the Internet of Things (IoT) and cloud computing brings tremendous convenience and efficiency to process and store growing sensor data in healthcare systems. For the security of sensor data collected by healthcare systems, encrypting data before uploading is necessary. Nevertheless, these encrypted form sensor data make it a research challenge to achieve efficient data search and data sharing on the cloud‐assisted IoT simultaneously. Encrypting data by public key encryption with equality test (PKE‐ET) scheme, identified as a viable solution, is capable to search data encrypted with different keys efficiently. However, how to efficiently share searched healthcare record on the cloud server is still an unsettled problem. To address this problem, we combine the concepts of proxy re‐encryption (PRE) and PKE‐ET to obtain proxy re‐encryption with equality test (PRE‐ET). Inheriting the advantages of PKE‐ET and PRE, the user can search the required healthcare record data from data encrypted under different public keys. Meanwhile, the searched healthcare record can be shared securely and flexibly without disclosing the secret key and plaintext. We prove the security of our PRE‐ET construction based on divisible computation Diffie‐Hellman assumption in the random oracle model. Eventually, the proposed scheme is proven useful according to extensive efficiency analysis and comparison.
Joint subchannel assignment and power control in OFDMA in‐band full‐duplex heterogeneous networks
Authors: Rajabi Hamed , Rasti Mehdi , Pedram Hossein , Yousefpour Rohollah
Published: June 2020

Among the emerging technologies for the fifth‐generation (5G) cellular networks, in‐band full‐duplex (FD) wireless communication and heterogeneous networks (HetNets) are two promising technologies, which can significantly improve the network capacity. Due to self‐interference (SI) and multiple sources of intercell interference, base station (BS)‐BS interference and user equipment (UE)‐UE interference in FD HetNets, interference management is a significant and challenging issue in such a network. To this end, in this article, we study the joint subchannel assignment and power control problem in the OFDMA FD HetNet. The joint subchannel assignment and power control problem in this network is formulated as an optimization problem to maximize the uplink and downlink sum throughput of the femtocell user equipments (FUEs) taking into account the maximum interference constraint imposed on the macrocell user equipments (MUEs) and the minimum throughput constraint of FUEs. Since the formulated problem is a nonconvex and intractable mixed integer nonlinear programming (MINLP) problem, we invoke variable change and linear approximation to reformulate and convert the problem into a tractable mixed‐integer linear programming (MILP) problem. Numerical results show that the optimal solution of the new MILP problem is very close to the optimal objective value of the original MINLP problem. The results also demonstrate that in an OFDMA FD HetNet, when all the UEs and the BSs are FD, approximately 50% improvement in the network throughputcan be achieved compared with a half‐duplex HetNet.
Measuring human perceptions of developing room fires: The influence of situational and dispositional factors
Authors: Bonny Justin W. , Leventon Isaac T.
Published: June 2020

Studies of human behavior during emergencies have observed that when presented with situational cues that a hazard may be present, humans can fail to act on this information in a timely manner. Some models of human behavior in response to fire‐related emergencies can explicitly account for potential delays in identifying and acting on the presented risk of a fire. Past research has indicated that variations in the disposition of individuals, such as psychological traits, can also influence responses to emergencies. The present study examines the extent to which responses to images of growing room fires are influenced by situational and dispositional factors. Participants judged whether words reflecting normalcy, risk, or protective action applied to images of developing room fires that varied in intensity. Psychophysical models of responses revealed that, as room fires developed, deviation from normalcy words were first reliably judged to apply, then risk, and finally protective action, in line with models of human evacuation behavior. Individual differences in specific dispositional traits influenced when participants identified that protective action applied to the growing fire. The evidence in the present study suggests that psychophysical and observational data can contribute to understanding human evacuation behavior during fire emergencies.
An Optimized Model for Predicting Kinematic Viscosities of Biodiesel Fuels▴
Authors: Wang S. , Sui M. , Luo H. , Li F.
Published: June 2020

In this work, the empirical correlations for viscosity and temperature of biodiesel fuels have been optimized. In order to achieve this, an optimized empirical correlation is proposed and the predicted values are found to be in good agreement with the experimental data. The optimized empirical correlation has the advantages of small relative error, small error range and no obvious error fluctuations. On the basis of the proposed correlation, the concepts of viscosity gradient of biodiesels and critical preheating temperature of biodiesels are proposed in this paper. The viscosity gradient, the critical preheating temperature and the range of applications for three kinds of biodiesel fuels are obtained by analyzing their viscosity data.
Truncated tests for combining evidence of summary statistics
Authors: Bu Deliang , Yang Qinglong , Meng Zhen , Zhang Sanguo , Li Qizhai
Published: June 2020

To date, thousands of genetic variants to be associated with numerous human traits and diseases have been identified by genome‐wide association studies (GWASs). The GWASs focus on testing the association between single trait and genetic variants. However, the analysis of multiple traits and single nucleotide polymorphisms (SNPs) might reflect physiological process of complex diseases and the corresponding study is called pleiotropy association analysis. Modern day GWASs report only summary statistics instead of individual‐level phenotype and genotype data to avoid logistical and privacy issues. Existing methods for combining multiple phenotypes GWAS summary statistics mainly focus on low‐dimensional phenotypes while lose power in high‐dimensional cases. To overcome this defect, we propose two kinds of truncated tests to combine multiple phenotypes summary statistics. Extensive simulations show that the proposed methods are robust and powerful when the dimension of the phenotypes is high and only part of the phenotypes are associated with the SNPs. We apply the proposed methods to blood cytokines data collected from Finnish population. Results show that the proposed tests can identify additional genetic markers that are missed by single trait analysis.
δ scores predict multiple neuropsychiatric symptoms
Authors: Royall Donald R. , Palmer Raymond F.
Published: June 2020

Objectives

Dementia severity is strongly related to Spearman's general intelligence factor “g”, via the latent dementia phenotype “δ” and is distinct from domain‐specific cognitive impairments arising from disease‐specific regional pathologies. It is an empiric question whether behavioral and psychological symptoms of dementia (BPSD) are associated with δ or with domain‐specific constructs.

Methods

A recently developed δ homolog (”dDx”) was tested as a predictor of 1 year prospective BPSD in n = 723 Mexican‐American and non‐Hispanic White participants in the Texas Alzheimer's Research and Care Consortium (TARCC). The informant‐rated frequencies of 12 BPSD were rated by the neuropsychiatric inventory (NPI‐Q). Baseline BPSD, demographic features, selected biomarkers, and treatment exposure to acetylcholinesterase inhibitors were used as covariates. Composite scores derived from orthogonal latent measures of domain‐specific memory (MEM) and executive function (EF) were also tested as predictors.

Results

“Functionally salient cognitive impairment (FSCI)” that is, categorical “dementia” as diagnosed by dDx was associated with increased prospective frequency of 11/12 BPSD, independently of baseline behavior and covariates. Age, depressive symptoms, and EF were associated with individual BPSD. MEM was not associated with any. Dementia severity, as measured by dDx, was also associated with a prospective increase in total NPI‐Q scores.

Conclusion

δ is associated non‐specifically with multiple BPSD. This suggests the existence of a dementia‐specific behavioral profile, arising from insults to general intelligence, and unrelated to disease‐specific regional pathology(ies).
Baseline sensorimotor GABA levels shape neuroplastic processes induced by motor learning in older adults
Authors: King Bradley R. , Rumpf Jost‐Julian , Verbaanderd Elvire , Heise Kirstin F. , Dolfen Nina , Sunaert Stefan , Doyon Julien , Classen Joseph , Mantini Dante , Puts Nicolaas A. J. , Edden Richard A. E. , Albouy Geneviève , Swinnen Stephan P.
Published: June 2020

Previous research in young adults has demonstrated that both motor learning and transcranial direct current stimulation (tDCS) trigger decreases in the levels of gamma‐aminobutyric acid (GABA) in the sensorimotor cortex, and these decreases are linked to greater learning. Less is known about the role of GABA in motor learning in healthy older adults, a knowledge gap that is surprising given the established aging‐related reductions in sensorimotor GABA. Here, we examined the effects of motor learning and subsequent tDCS on sensorimotor GABA levels and resting‐state functional connectivity in the brains of healthy older participants. Thirty‐six older men and women completed a motor sequence learning task before receiving anodal or sham tDCS to the sensorimotor cortex. GABA‐edited magnetic resonance spectroscopy of the sensorimotor cortex and resting‐state (RS) functional magnetic resonance imaging data were acquired before and after learning/stimulation. At the group level, neither learning nor anodal tDCS significantly modulated GABA levels or RS connectivity among task‐relevant regions. However, changes in GABA levels from the baseline to post‐learning session were significantly related to motor learning magnitude, age, and baseline GABA. Moreover, the change in functional connectivity between task‐relevant regions, including bilateral motor cortices, was correlated with baseline GABA levels. These data collectively indicate that motor learning‐related decreases in sensorimotor GABA levels and increases in functional connectivity are limited to those older adults with higher baseline GABA levels and who learn the most. Post‐learning tDCS exerted no influence on GABA levels, functional connectivity or the relationships among these variables in older adults.
Phenylboronic acid‐functionalized F127‐oligochitosan conjugate micelles for doxorubicin encapsulation
Authors: Feng Runliang , Wang Wanqiu , Zhu Li , Xu Hongmei , Chen Shiyu , Song Zhimei
Published: June 2020

Doxorubicin shows good anticancer activity, but poor pharmacokinetic property and high organ toxicity restrict its clinical application. The synthesized phenylboronic acid‐modified F127‐chitosan conjugate was used to prepare doxorubicin‐loaded micelles through dialysis method. The physicochemical properties of the doxorubicin‐loaded micelles were characterized. These micelles were further evaluated for in vitro release/cytotoxicity, in vivo activity/biosafety, and pharmacokinetic studies. in vitro release experiment demonstrated that the release of doxorubicin from drug‐loaded micelles was pH‐dependent. in vitro cytotoxic study showed that the introduction of phenylboronic acid resulted in lower IC50 against B16 cells than that in non‐modified F127‐chitosan micelles group, and the doxorubicin‐loaded micelles displayed lower in vitro activity against B16, A549, and HT‐29 cells than free doxorubicin did. However, in vivo experiments confirmed that the doxorubicin‐loaded micelles were safe for mouse main organs, obviously improved pharmacokinetic parameters of doxorubicin in rat and achieved comparable inhibition of tumor growth with no animal death in B16‐bearing mice models throughout the experiment when compared with free doxorubicin. The phenylboronic acid‐sialic acid interaction and pH‐sensitive drug release might play important roles in increased tumor targeting and therapeutic effect of the doxorubicin‐loaded micelles.
Subjective experience of the origin and development of avoidant personality disorder
Authors: Sørensen Kristine D. , Wilberg Theresa , Berthelsen Eivind , Råbu Marit
Published: June 2020

Objective

To better understand how persons diagnosed with avoidant personality disorder (AVPD) make sense of the origin and development of their current everyday struggles.

Methods

Persons with AVPD (N = 15) were interviewed twice using semi‐structured qualitative interviews, which were analyzed through interpretative‐phenomenological analysis. Persons with the first‐hand experience of AVPD were included in the research.

Results

The superordinate theme, “a story of becoming forlorn,” encompassed three main themes: “it goes all the way back to when I was little,” “there was a distance between others and me,” and “transitions made it worse.”

Conclusions

Though the results are not necessarily specific to AVPD, the findings clarify how people with AVPD can make sense of their current struggles by constructing developmental life stories in the interplay between themselves as persons and the growing demands of their social world. Furthermore, childhood relational vulnerabilities may challenge the ongoing development of social cognition and skills.
LINC01426 contributes to clear cell renal cell carcinoma progression by modulating CTBP1/miR‐423‐5p/FOXM1 axis via interacting with IGF2BP1
Authors: Jiang YuFeng , Zhang HaiMin , Li Wei , Yan Yang , Yao XuDong , Gu WenYu
Published: June 2020

Increasing evidence suggests that long noncoding RNAs (lncRNAs) are pivotal regulators in oncogenesis. However, the role of numerous lncRNAs has never been unmasked in clear cell renal cell carcinoma (ccRCC). Presently, we investigated the function of long intergenic nonprotein coding RNA 1426 (LINC01426) in ccRCC, as The Cancer Genome Atlas data indicated that LINC01426 was highly expressed in ccRCC tissues and its overexpression was correlated with disappointing prognosis. First, we verified that LINC01426 was indeed upregulated in ccRCC cell lines and its depletion restrained ccRCC cell proliferation and migration. Besides, we proved that LINC01426 facilitated ccRCC tumorigenesis via forkhead box M1 (FOXM1). Moreover, it was revealed that miR‐423‐5p was downregulated and directly targeted FOXM1 in ccRCC, and that LINC01426 positively regulated FOXM1 via its inhibition on miR‐423‐5p. Notably, we also uncovered that miR‐423‐5p was transcriptionally silenced by CTBP1 and HDAC2. Of importance, LINC01426 was certified to distribute both in the cytoplasm and the nucleus of ccRCC cells, and it increased CTBP1 expression through recruiting insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) in cytoplasm whereas interacted with CTBP1 protein to improve the transcriptional repression on miR‐423‐5p in nucleus. Jointly, our observations unveiled that LINC01426 aggravates ccRCC progression via IGF2BP1/CTBP1/HDAC2/miR‐423‐5p/FOXM1 axis, highlighting LINC01426 as a novel promising target for ccRCC treatment.
Effects of photobiomodulation combined with MSCs transplantation on the repair of spinal cord injury in rat
Authors: Chen Hongli , Wang Yunhao , Tu Wenjun , Wang Hong , Yin Huijuan , Sha Hong , Li Yingxin
Published: June 2020

Stem cell transplantation has shown promising regenerative effects against neural injury, and photobiomodulation (PBM) can aid tissue recovery. This study aims to evaluate the therapeutic effect of human umbilical cord mesenchymal stem cells (hUCMSCs) and laser alone or combined on spinal cord injury (SCI). The animals were divided into SCI, hUCMSCs, laser treatment (LASER) and combination treatment (hUCMSCs + LASER) groups. Cell‐enriched grafts of hUCMSCs (1 × 106 cells/ml) were injected at the site of antecedent trauma in SCI model rats. A 2 cm2 damaged area was irradiated with 630 nm laser at 100 mW/cm2 power for 20 min. Locomotion was evaluated using Basso–Beattie–Bresnahan (BBB) scores, and neurofilament repair were monitored by histological staining and diffusion tensor imaging (DTI). First, after SCI, the motor function of each group was restored with different degrees, the combination treatment significantly increased the BBB scores compared to either monotherapy. In addition, Nissl bodies were more numerous, and the nerve fibers were longer and thicker in the combination treatment group. Consistent with this, the in situ expression of NF‐200 and glial fibrillary acidic protein in the damaged area was the highest in the combination treatment group. Finally, DTI showed that the combination therapy optimally improved neurofilament structure and arrangement. These results may show that the combination of PBM and hUCMSCs transplantation is a feasible strategy for reducing secondary damage and promoting functional recovery following SCI.
Macro‐ and microscopic study on the tongue and lingual papillae of Bison bonasus hybrid as an interspecific species (Bos taurus × Bison bonasus)
Authors: Plewa Barbara , Jackowiak Hanna
Published: June 2020

Nowadays the processes of crossing of different mammalian species are well characterized in light of genetics, and possibility of reproduction. Generally, lack detailed studies on changes in anatomy and histology of internal systems of hybrids. Bison bonasus hybrid is an interspecific species between the bull of European bison (Bison bonasus), and female of domesticated cattle (Bos taurus). To study the anatomy of tongue and distribution of lingual papillae on Bison bonasus hybrid tongue, a stereomicroscopic and scanning electron microscopic observations was conducted. We aimed to study the appearance of macro‐ and microscopic traits in relation to parental species and other bovids. Results indicate that Bison bonasus hybrid tongue possesses characteristic traits for parental species and ruminants from Bovidae family and also species‐specific features differ from mentioned animals. Specific new traits in hybrid are: V‐shaped arrangement of lingual papillae on ventral surface of the tongue, rosette arrangement of conical papillae on the top of lingual prominence, bigger number of vallate papillae and closer arrangement of vallate papillae. In hybrid observed also the appearance of combination of parental traits. Similar to European bison are rectangular shape of lingual prominence and absence of filiform papillae on the root of tongue. Presence of lateral processes of filiform papillae on the apex of tongue, and arrangement of vallate papillae into two rows corresponded to cattle. Development of new morphological features of tongue and its mucosal papillae in Bison bonasus hybrid opens new issue for future studies on organs of digestive system in animals after hybridization.
“Patients are not the same, so we cannot treat them the same” – A qualitative content analysis of provider, patient and implementer perspectives on differentiated service delivery models for HIV treatment in South Africa
Authors: Pascoe Sophie J S , Scott Nancy A , Fong Rachel M , Murphy Joshua , Huber Amy N , Moolla Aneesa , Phokojoe Mokgadi , Gorgens Marelize , Rosen Sydney , Wilson David , Pillay Yogan , Fox Matthew P , Fraser‐Hurt Nicole
Published: June 2020

Introduction

In 2014, the South African government adopted a differentiated service delivery (DSD) model in its “National Adherence Guidelines for Chronic Diseases (HIV, TB and NCDs)” (AGL) to strengthen the HIV care cascade. We describe the barriers and facilitators of the AGL implementation as experienced by various stakeholders in eight intervention and control sites across four districts.

Methods

Embedded within a cluster‐randomized evaluation of the AGL, we conducted 48 in‐depth interviews (IDIs) with healthcare providers, 16 IDIs with Department of Health and implementing partners and 24 focus group discussions (FGDs) with three HIV patient groups: new, stable and those not stable on treatment or not adhering to care. IDIs were conducted from August 2016 to August 2017; FGDs were conducted in January to February 2017. Content analysis was guided by the Consolidated Framework for Implementation Research. Findings were triangulated among respondent types to elicit barriers and facilitators to implementation.

Results

New HIV patients found counselling helpful but intervention respondents reported sub‐optimal counselling and privacy concerns as barriers to initiation. Providers felt insufficiently trained for this intervention and were confused by the simultaneous rollout of the Universal Test and Treat strategy. For stable patients, repeat prescription collection strategies (RPCS) were generally well received. Patients and providers concurred that RPCS reduced congestion and waiting times at clinics. There was confusion though, among providers and implementers, around implementation of RPCS interventions. For patients not stable on treatment, enhanced counselling and tracing patients lost‐to‐follow‐up were perceived as beneficial to adherence behaviours but faced logistical challenges. All providers faced difficulties accessing data and identifying patients in need of tracing. Congestion at clinics and staff attitude were perceived as barriers preventing patients returning to care.

Conclusions

Implementation of DSD models at scale is complex but this evaluation identified several positive aspects of AGL implementation. The positive perception of RPCS interventions and challenges managing patients not stable on treatment aligned with results from the larger evaluation. While some implementation challenges may resolve with experience, ensuring providers and implementers have the necessary training, tools and resources to operationalize AGL effectively is critical to the overall success of South Africa’s HIV control strategy.
Automatic T Staging Using Weakly Supervised Deep Learning for Nasopharyngeal Carcinoma on MR Images
Authors: Yang Qing , Guo Ying , Ou Xiaomin , Wang Jiazhou , Hu Chaosu
Published: June 2020

Background

Recent studies have shown that deep learning can help tumor staging automatically. However, automatic nasopharyngeal carcinoma (NPC) staging is difficult due to the lack of large and slice‐level annotated datasets.

Purpose

To develop a weakly‐supervised deep‐learning method to predict NPC patients' T stage without additional annotations.

Study Type

Retrospective.

Population/Subjects

In all, 1138 cases with NPC from 2010 to 2012 were enrolled, including a training set (n = 712) and a validation set (n = 426).

Field Strength/Sequence

1.5T, T1‐weighted images (T1WI), T2‐weighted images (T2WI), contrast‐enhanced T1‐weighted images (CE‐T1WI).

Assessment

We used a weakly‐supervised deep‐learning network to achieve automated T staging of NPC. T usually refers to the size and extent of the main tumor. The training set was employed to construct the deep‐learning model. The performance of the automated T staging model was evaluated in the validation set. The accuracy of the model was assessed by the receiver operating characteristic (ROC) curve. To further assess the performance of the deep‐learning‐based T score, the progression‐free survival (PFS) and overall survival (OS) were performed.

Statistical Tests

The Sklearn package in Python was applied to calculate the area under the curve (AUC) of the ROC. The survcomp package was used for calculations and comparisons between C‐indexes. The software SPSS was employed to conduct survival analysis and chi‐square tests.

Results

The accuracy of the deep‐learning model was 75.59% in the validation set. The average AUC of the ROC curve of different stages was 0.943. There were no significant differences in the C‐indexes of PFS and OS from the deep‐learning model and those from TNM staging, with P values of 0.301 and 0.425, respectively.

Data Conclusion

This weakly‐supervised deep‐learning approach can perform fully automated T staging of NPC and achieve good prognostic performance.

Level of Evidence: 3

Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;52:1074–1082.
Resting‐state connectivity and network parameter analysis in alcohol‐dependent males. A simultaneous EEG‐MEG study
Authors: Sion Ana , Bruña Fernández Ricardo , Martínez Maldonado Andrés , Domínguez Centeno Isabel , Torrado‐Carvajal Angel , Rubio Gabriel , Pereda Ernesto , Jurado‐Barba Rosa
Published: June 2020

There is supporting evidence of alcohol negative effects on the brain: neuroimaging and psychophysiological studies finding anatomical and functional connectivity (FC) changes associated with the dependence process. Thus, the aim of this work was to evaluate brain FC and network characteristics of alcohol‐dependent individuals in resting state. For this study, we included males diagnosed with alcohol dependence (N = 25) and a group of healthy individuals (N = 23). Simultaneous EEG‐MEG (electroencephalographic and magnetoencephalographic) activity was recorded in 5 min of eyes‐closed resting state. EEG‐MEG activity was preprocessed and FC was computed through the leakage‐corrected version of phase locking value (ciPLV). Additionally, local (degree, efficiency, clustering) and global (efficiency, characteristic path length) network parameters were computed. Connectivity analysis showed an increase in phase‐lagged synchronization, mainly between frontal and frontotemporal regions, in high beta band, and a decrease in interhemispheric gamma, for alcohol‐dependent individuals. Network analysis revealed intergroup differences at the local level for high beta, indicating higher degree, clustering, and efficiency, mostly at frontal nodes, together with a decrease in these measures at more posterior sites for patients’ group. The hyper‐synchronization in beta, next to the hypo‐synchronization in gamma, could indicate an alteration in communication between hemispheres, but also a possible functional compensation mechanism in neural circuits. This could be also supported by network characteristic data, where local alterations in communication are observed.
Using collaboration networks to identify authorship dependence in meta‐analysis results
Authors: Moulin Thiago C. , Amaral Olavo B.
Published: June 2020

Meta‐analytic methods are powerful resources to summarize the existing evidence concerning a given research question and are widely used in many academic fields. Meta‐analyzes can also be used to study sources of heterogeneity and bias among results, which should be considered to avoid inaccuracies. Many of these sources can be related to study authorship, as both methodological heterogeneity and researcher bias may lead to deviations in results between different research groups. In this work, we describe a method to objectively attribute study authorship within a given meta‐analysis to different research groups by using graph cluster analysis of collaboration networks. We then provide empirical examples of how the research group of origin can impact effect size in distinct types of meta‐analyzes, demonstrating how non‐independence between within‐group results can bias effect size estimates if uncorrected. Finally, we show that multilevel random‐effects models using research group as a level of analysis can be a simple tool for correcting for authorship dependence in results.
The temporal and spatial expression of sclerostin and Wnt signaling factors during the maturation of posterolateral lumbar spine fusions
Authors: Rodriguez‐Feo John , Fernandes Lorenzo , Patel Anuj , Doan Thanh , Boden Scott D. , Drissi Hicham , Presciutti Steven M.
Published: June 2020

The bone healing environment in the posterolateral spine following arthrodesis surgery is one of the most challenging in all of orthopedics and our understanding of the molecular signaling pathways mediating osteogenesis during spinal fusion is limited. In this study, the spatial and temporal expression pattern of Wnt signaling factors and inhibitors during spinal fusion was assessed for the first time. Bilateral posterolateral spine arthrodesis with autologous iliac crest bone graft was performed on 21 New Zealand White rabbits. At 1‐, 2‐, 3‐, 4‐, and 6‐weeks, the expression of sclerostin and a variety of canonical and noncanonical Wnts signaling factors was measured by qRT‐PCR from tissue separately collected from the transverse processes, the Outer and Inner Zones of the fusion mass, and the adjancent paraspinal muscle. Immunohistochemistry for sclerostin protein was also performed. Sclerostin and many Wnt factors, especially Wnt3a and Wnt5a, were found to have distinct spatial and temporal expression patterns. For example, harvesting ICBG caused a significant increase in sclerostin expression. Furthermore, the paraspinal muscle immediately adjacent to the transplanted ICBG also had significant increases in sclerostin expression at 3 weeks, suggesting new potential mechanisms for pseudarthroses following spinal arthrodesis. The presented work is the first description of the spatial and temporal expression of sclerostin and Wnt signaling factors in the developing spine fusion, filling an important knowledge gap in the basic biology of spinal fusion and potentially aiding in the development of novel biologics to increase spinal fusion rates.
А kinеtiс аnаlysis fоr prоduсtiоn of саlсium bоrоgluсоnаtе frоm colemanite
Authors: Demir Fatih , Al‐Ani Anas Osamah Ali , Lacin Omer
Published: June 2020

In this paper, the kinetic model of colemanite dissolution in gluconic acid solutions was carried out in a batch reactor. The effects of the particle size, reaction temperature, stirring speed, gluconic acid concentration, and solid/liquid ratio on colemanite dissolution were experimentally studied. The empirical parameters were the gluconic acid concentration (0.05‐0.2 M), the temperature (20‐50°C), the solid/liquid ratio (0.05/500‐1.5/500 g⋅L−1), particle size (193.5‐1000 μm), and stirring speed (400‐700 rpm).

The kinetic models for heterogeneous solid‐liquid reactions were used with the dissolution data in evaluating the kinetic. The dissolution of colemanite in gluconic acid solutions was controlled by diffusion through the product layer. The activation energy was found to be 8.39 kJ⋅mol−1. The rate expression associated with the dissolution rate of colemanite depending on the parameters chosen may be summarized as follows:
MiRNA‐620 promotes TGF‐β1‐induced proliferation of airway smooth muscle cell through controlling PTEN/AKT signaling pathway
Authors: Chen Hui , Guo Su‐Xiang , Zhang Sai , Li Xiao‐Dan , Wang Hao , Li Xiao‐Wei
Published: June 2020

Asthma is an inflammatory syndrome characterized by airway hyperresponsiveness, bronchial inflammation, and airway remodeling. The hypertrophy and hyperplasia of airway smooth muscle cells (ASMCs) are hallmarks of bronchial remodeling in asthma. In this study, the regulatory effects of microRNA‐620 (miR‐620) on ASMC proliferation and apoptosis in response to transforming growth factor β1 (TGF‐β1) stimulation was investigated. The expression of miR‐620 was significantly upregulated in TGF‐β1‐treated ASMCs compared with vehicle‐treated cells. Downregulation of miR‐620 suppressed the proliferation and increased apoptosis in TGF‐β1‐stimulated ASMCs. Phosphatase and tensin homolog (PTEN) was predicted and confirmed as a downstream target of miR‐620. PTEN was upregulated in miR‐620‐inhibitor transfected ASMCs, but decreased in cells delivered with miR‐620 mimics. Moreover, knocking down miR‐620 alone efficiently reduced the phosphorylation of protein kinase B (AKT), decreased TGF‐β1‐induced proliferation and promoted apoptosis in ASMCs, whereas downregulation of PTEN in miR‐620 inhibitor‐transfected cells restored the activation of AKT, increased TGF‐β1‐triggered proliferation, and partially inhibited ASMC apoptosis. Taken together, the present study provided evidence that miR‐620 increased TGF‐β1‐mediated proliferation and suppressed apoptosis in ASMCs via the regulation of PTEN and AKT expression. These findings suggest that miR‐620/PTEN/AKT axis may be considered as a therapeutic target for asthma treatment.
Toward cross‐platform electronic health record‐driven phenotyping using Clinical Quality Language
Authors: Brandt Pascal S. , Kiefer Richard C. , Pacheco Jennifer A. , Adekkanattu Prakash , Sholle Evan T. , Ahmad Faraz S. , Xu Jie , Xu Zhenxing , Ancker Jessica S. , Wang Fei , Luo Yuan , Jiang Guoqian , Pathak Jyotishman , Rasmussen Luke V.
Published: June 2020

Introduction

Electronic health record (EHR)‐driven phenotyping is a critical first step in generating biomedical knowledge from EHR data. Despite recent progress, current phenotyping approaches are manual, time‐consuming, error‐prone, and platform‐specific. This results in duplication of effort and highly variable results across systems and institutions, and is not scalable or portable. In this work, we investigate how the nascent Clinical Quality Language (CQL) can address these issues and enable high‐throughput, cross‐platform phenotyping.

Methods

We selected a clinically validated heart failure (HF) phenotype definition and translated it into CQL, then developed a CQL execution engine to integrate with the Observational Health Data Sciences and Informatics (OHDSI) platform. We executed the phenotype definition at two large academic medical centers, Northwestern Medicine and Weill Cornell Medicine, and conducted results verification (n = 100) to determine precision and recall. We additionally executed the same phenotype definition against two different data platforms, OHDSI and Fast Healthcare Interoperability Resources (FHIR), using the same underlying dataset and compared the results.

Results

CQL is expressive enough to represent the HF phenotype definition, including Boolean and aggregate operators, and temporal relationships between data elements. The language design also enabled the implementation of a custom execution engine with relative ease, and results verification at both sites revealed that precision and recall were both 100%. Cross‐platform execution resulted in identical patient cohorts generated by both data platforms.

Conclusions

CQL supports the representation of arbitrarily complex phenotype definitions, and our execution engine implementation demonstrated cross‐platform execution against two widely used clinical data platforms. The language thus has the potential to help address current limitations with portability in EHR‐driven phenotyping and scale in learning health systems.
Immunosuppression in Donation After Circulatory Death Liver Transplantation: Can Induction Modify Graft Survival?
Authors: Ig‐Izevbekhai Kevin , Goldberg David S. , Karp Seth J. , Foley David P. , Abt Peter L.
Published: June 2020

Recipients of donation after circulatory death (DCD) LTs historically have an increased risk of graft failure. Antibody induction (AI) with antithymocyte globulin (ATG) or anti‐interleukin 2 receptor (anti‐IL2R) immunotherapy may decrease the incidence of graft failure by mitigating ischemia/reperfusion injury. A retrospective review of the United Network for Organ Sharing (UNOS) database for LTs between 2002 and 2015 was conducted to determine whether ATG or anti‐IL2R AI was associated with graft survival in DCD. A secondary endpoint was postoperative renal function as measured by estimated glomerular filtration rate at 6 and 12 months. Among DCD recipients, ATG (hazard ratio [HR] = 0.71; P = 0.03), but not anti‐IL2R (HR = 0.82; P = 0.10), was associated with a decrease in graft failure at 3 years when compared with recipients without AI. ATG (HR = 0.90; P = 0.02) and anti‐IL2R (HR = 0.94; P = 0.03) were associated with a decreased risk of graft failure in donation after brain death (DBD) liver recipients at 3 years compared with no AI. When induction regimens were compared between DCD and DBD, only ATG (HR = 1.19; P = 0.19), and not anti‐IL2R (HR = 1.49; P < 0.01) or no AI (HR = 1.77; P < 0.01), was associated with similar survival between DCD and DBD. In conclusion, AI therapy with ATG was associated with improved longterm liver allograft survival in DCD compared with no AI. ATG was associated with equivalent graft survival between DCD and DBD, suggesting a beneficial role of immune cell depletion in DCD outcomes.
Homotopy perturbation method for N/MEMS oscillators
Authors: Anjum Naveed , He Ji‐Huan
Published: June 2020

The nano/microelectromechanical systems (N/MEMS) have caught much attention in the past few decades for their attractive properties such as small size (low mass), high reliability (high thermal conductivity and high Young's modulus), batch fabrication, and low power consumption. The dynamic oscillatory behavior of these systems is very complex due to strong nonlinearities in these systems. The basic aim of this manuscript is to investigate the nonlinear vibration property of N/MEMS oscillators arising in nanotube‐based N/MEMS and resonators by the homotopy perturbation method coupled with Laplace transform (also called as He‐Laplace method in literature). A generalized N/MEMS oscillator is systematically studied, and a fairly accurate analytic solution is obtained. Three special cases for electrically actuated MEMS, multi‐walled carbon nanotubes‐based MEMS, and MEMS subjected to van der Waals attraction are considered for comparison, and a good agreement with exact solutions is observed.
Vibration analysis of shell‐like curved carbon nanotubes using nonlocal strain gradient theory
Authors: Zare Jamal , Shateri Alireza , Beni Yaghoub Tadi , Ahmadi Afshin
Published: June 2020

The performance of nanotube‐based resonators is significantly affected by the variation of their natural frequencies. In reality, nanotubes may have some levels of initial imperfection, which definitely changes their vibrational characteristics. In the present article, the vibrational behavior of initially curved nanotubes is investigated on the basis of thin shell theory incorporating the nonlocal strain gradient theory. The three‐dimensional governing equations of motion are derived by adopting the curvilinear coordinate system through Hamilton's principle. A new formulation of Eringen's model containing the higher‐order strain gradients is employed to capture the effects of nonlocality and small scale parameter. Galerkin decomposition method is employed to acquire a bi‐cubic relation for the natural frequency of the considered nanoshell. The effects of different parameters like the ratio of radius of curvature to the cross section radius, small scale and nonlocality, and length‐to‐radius ratio on the variation of the natural frequency are presented. Excellent agreements are found in some comparative studies between the results of this work and those obtained by molecular dynamics and experimental findings in the literature. Finally, some interesting results are found by plotting the variation of natural frequency of the system versus the length‐to‐radius ratio. It is exhibited that by increasing the ratio L/r, the natural frequencies associated with different values of wavenumber m converge to the lower one and the convergence speed is highly dependent to the circumferential wavenumber n.
A generalized delta derivative on time scale with applications
Authors: Singh Negi Shekhar , Abbas Syed , Malik Muslim
Published: June 2020

Inspired by a well‐known “Hilger‐derivative” on time scale introduced by Stephan Hilger, we introduce a new derivative on the time scale, called “black delta (or in notation
)‐derivative.” It is an adaptive unified approach of derivative of continuous and discrete calculus. Several important nontrivial results concerning this derivative are obtained. Also, a necessary and sufficient condition for the existence of this new derivative and its connection with Hilger‐derivative are discussed. In addition, a new general a‐exponential function (for fixed a ≥ 1) is introduced to obtain the unique solution of the initial value problem on time scales with this derivative. Furthermore, a relation between the a‐exponential function with the existing exponential function on the time scale is obtained. We elucidate the results by considering some interesting examples. We expect that this derivative will be applicable for future investigations on various studies in the field of mathematical modeling, engineering applications.
Scintillation imaging as a high‐resolution, remote, versatile 2D detection system for MR‐linac quality assurance
Authors: Alexander Daniel A. , Zhang Rongxiao , Brůža Petr , Pogue Brian W. , Gladstone David J.
Published: June 2020

Purpose

To demonstrate the potential benefits of remote camera‐based scintillation imaging for routine quality assurance (QA) measurements for magnetic resonance guided radiotherapy (MRgRT) linear accelerators.

Methods

A wall‐mounted CMOS camera with a time‐synchronized intensifier was used to image photons produced from a scintillation screen in response to dose deposition from a 6 MV FFF x‐ray beam produced by a 0.35 T MR‐linac. The oblique angle of the field of view was corrected using a projective transform from a checkerboard calibration target. Output sensitivity and constancy was measured using the scintillator and benchmarked against an A28 ion chamber. Field cross‐plane and in‐plane profiles were measured for field sizes ranging from 1.68 × 1.66 cm2 to 20.02 × 19.92 cm2 with both scintillation imaging and using an IC profiler. Multileaf collimator (MLC) shifts were introduced to test sensitivity of the scintillation imaging system to small spatial deviations. A picket fence test and star‐shot were delivered to both the scintillator and EBT3 film to compare accuracy in measuring MLC positions and isocenter size.

Results

The scintillation imaging system showed comparable sensitivity and linearity to the ion chamber in response to changes in machine output down to 0.5 MU (R2 = 0.99). Cross‐plane profiles show strong agreement with defined field sizes using full width half maximum (FWHM) measurement of <2 mm for field sizes below 15 cm, but the oblique viewing angle was the limiting factor in accuracy of in‐plane profile widths. However, the system provided high‐resolution profiles in both directions for constancy measurements. Small shifts in the field position down to 0.5 mm were detectable with <0.1 mm accuracy. Multileaf collimator positions as measured with both scintillation imaging and EBT3 film were measured within ± 1 mm tolerance and both detection systems produced similar isocenter sizes from the star‐shot analysis (0.81 and 0.83 mm radii).

Conclusions

Remote scintillation imaging of a two‐dimensional screen provided a rapid, versatile, MR‐compatible solution to many routine quality assurance procedures including output constancy, profile flatness and symmetry constancy, MLC position verification and isocenter size. This method is high‐resolution, does not require post‐irradiation readout, and provides simple, instantaneous data acquisition. Full automation of the readout and processing could make this a very simple but effective QA tool, and is adaptable to all medical accelerators.
Pelvic floor activation upon stimulation of the sacral spinal nerves in sacral neuromodulation patients
Authors: Vaganée Donald , Voorham Jeroen , Van de Borne Sigrid , Voorham‐van der Zalm Petra , Fransen Erik , De Wachter Stefan
Published: June 2020

Purpose

To assess the activation of the different parts of the pelvic floor muscles (PFM) upon electrical stimulation of the sacral spinal nerves while comparing the different lead electrode configurations.

Material and Methods

PFM electromyography (EMG) was recorded using an intravaginal multiple array probe with 12 electrodes pairs, which allows to make a distinction between the different sides and depths of the pelvic floor. In addition concentric needle EMG of the external anal sphincter was performed to exclude far‐field recording. A medtronic InterStim tined lead (model 3889) was used as stimulation source. Standard SNM parameters (monophasic pulsed square wave, 210 microseconds, 14 Hz) were used to stimulate five different bipolar electrode configurations (3+0−/3+2−/3+1−/0+3−/1+3−) up to and around the sensory threshold. Of each EMG signal the stimulation intensity needed to evoke the EMG signals as well as its amplitude and latency were determined. Linear mixed models was used to analyse the data.

Results

Twenty female patients and 100 lead electrode configurations were stimulated around the sensory response threshold resulting in 722 stimulations and 12 times as many (8664) EMG recordings. A significant increase in EMG amplitude was seen upon increasing stimulation intensity (P < .0001). Large differences were noted between the EMG amplitude recorded at the different sides (ipsilateral>posterior>anterior>contralateral) and depths (deep>center>superficial) of the pelvic floor. These differences were noted for all lead electrodes configurations stimulated (P < .0001). Larger EMG amplitudes were measured when the active electrode was located near the entry point of the sacral spinal nerves through the sacral foramen (electrode #3). No differences in EMG latency could be withheld, most likely due to the sacral neuroanatomy (P > .05).

Conclusions

A distinct activation pattern of the PFM could be identified for all stimulated lead electrode configurations. Electrical stimulation with the most proximal electrode (electrode #3) as the active one elicited the largest PFM contractions.