bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of a 3D CT imaging method for quantifying implant migration following anatomic total shoulder arthroplasty
Authors: Jun Bong‐Jae , Ricchetti Eric T. , Haladik Jeffrey , Bey Michael J. , Patterson Thomas E. , Subhas Naveen , Li Zong‐Ming , Iannotti Joseph P.
Published: August 2021

Glenoid component loosening remains a common complication following anatomic total shoulder arthroplasty (TSA); however, plain radiographs are unable to accurately detect early implant migration. The purpose of this study was to validate the accuracy of a method of postoperative, three‐dimensional (3D) computed tomography (CT) imaging with metal artifact reduction (MAR) to detect glenoid component migration following anatomic TSA. Tantalum bead markers were inserted into polyethylene glenoid components for implant detection on 3D CT. In‐vitro validation was performed using a glenoid component placed into a scapula sawbone and incrementally translated and rotated, with MAR 3D CT acquired at each test position. Accuracy was evaluated by root mean square error (RMSE). In‐vivo validation was performed on six patients who underwent anatomic TSA, with two postoperative CT scans acquired in each patient and marker‐based radiostereometric analysis (RSA) performed on the same days. Glenoid component migration was calculated relative to a scapular coordinate system for both MAR 3D CT and RSA. Accuracy was evaluated by RMSE and paired Student's t‐tests. The largest RMSE on in‐vitro testing was 0.24 mm in translation and 0.11° in rotation, and on in‐vivo testing was 0.47 mm in translation and 1.04° in rotation. There were no significant differences between MAR 3D CT and RSA measurement methods. MAR 3D CT imaging is capable of quantifying glenoid component migration with a high level of accuracy. MAR 3D CT imaging is advantageous over RSA because it is readily available clinically and can also be used to evaluate the implant‐bone interface.
Prognostic factors, disparity, and equity variables impacting prognosis in bone sarcomas of the hand: SEER database review
Authors: Jawad Muhammad Umar , Bayne Christopher O. , Farhan Saif , Haffner Max R. , Carr‐Ascher Janai , Alvarez Elysia , Thorpe Steven W. , Randall R. Lor
Published: August 2021

Background

Primary sarcomas originating from the bones of hand and wrist are rare but carry a significant burden of morbidity.

Methods

National Cancer Institute's Surveillance, Epidemiology and End Result database from 1975 to 2017 was queried to report incidence and survival data in 237 patients in the United States. Kaplan–Meier and Cox regression were used to determine the prognostic factors affecting survival. χ2 test was used to assess the correlation.

Results

Incidence of hand and wrist sarcoma was 0.017 per 100 000 persons in 2017 and has not significantly changed since 1975 (p > 0.05). Disease‐specific 5‐year and 10‐year survival for the entire cohort was 90% and 84%, respectively. On multivariate analysis race “others,” histology other than “osteosarcoma,” “undifferentiated” grade, and size “≥6 cm” were predictors of worse disease‐specific survival. Cross‐tabulation of race with other significant prognostic factors on univariate analysis revealed a significant correlation of race with every other significant prognostic factor except for grade.

Conclusions

The current study is an analysis of a population‐based registry reporting incidence and survival data for patients with sarcoma of hand and wrist. Independent prognostic factors include race, histology, grade, and size. There is a lack of improvement in survival over the last four decades.
Effects of livestock grazing on soil health and recovery of a degraded Andean Araucaria forest
Authors: Crovo Oscar , Aburto Felipe , da Costa‐Reidel Clara , Montecino Francisco , Rodríguez Rolando
Published: August 2021

Araucaria araucana is an iconic long‐lived endangered tree species native to Southern Chile and Argentina. Araucaria forests and soils provide a myriad of ecosystem benefits to local communities, which are threatened by increasing anthropic‐driven disturbances like fire and livestock overgrazing. The main objectives of this study were: (i) to evaluate the effect of uncontrolled livestock grazing on soil health; and (ii) to identify a set of sensitive soil health indicators to grazing pressure. Twenty soil health indicators in two contiguous degraded forest areas with contrasting grazing pressure were considered. A substantial shift in forest structure and a 12% reduction in tree coverage on the overgrazed sites were observed. Overgrazing has substantially affected soil physical, chemical, and biological health indicators, making soil conditions less suitable for forest regeneration. Significant increments in C:P and N:P ratios were observed due to overgrazing (p < 0.01). Soil chemical properties such as Kjeldahl nitrogen, P‐fractions (total, inorganic, and available), cation exchange capacity (CEC), and pH were identified as the best indicators of overgrazing activity in these soils. Additionally, forest cover reduction and overgrazing altered soil physical indicators (e.g., saturated hydraulic conductivity, infiltration, and aggregate stability), suggesting changes in hydrological behavior with potential consequences in water storage and availability. Our results show that uncontrolled grazing in native protected forests degrades soils and forests, restricting forest regeneration and potentially accelerating erosive processes. These results emphasize the need for improved conservation plans for these endangered forests that systematically evaluates and monitors the direct and indirect effects of livestock grazing on soil health.
Acetylene Dicarboxylic Acid Diallyl Ester: A Versatile Monomer for Thiol–Ene Photocured Networks
Authors: Daglar Ozgun , Çakmakçi Emrah , Gunay Ufuk Saim , Hizal Gurkan , Tunca Umit , Durmaz Hakan
Published: August 2021

Thiol–ene photopolymerization (TEP) is a highly advantageous method for the curing of unsaturated monomers, and the design of novel monomers to be used in TEP is an active area of research. The feasibility and the versatility of novel acetylene dicarboxylic acid diallyl ester (ACDAE)‐based monomers are synthesized and demonstrated. The electron deficient acetylenic core in ACDAE allows to apply three different click reactions, aza‐Michael, thio‐Michael, and metal‐free azide–alkyne cycloaddition reactions, efficiently on it. Thus, three novel allylic monomers are synthesized and are used to prepare thiol–ene photopolymerized networks. All monomers are synthesized in good yields and structurally characterized by 1H NMR and Fourier‐transform infrared spectroscopy (FTIR) measurements. Thermal, thermomechanical, and mechanical properties, flame retardancy, transmittance, and the wettability of the networks are determined.
Impact of preconception weight loss on fasting glucose and pregnancy outcomes in women with obesity: A randomized trial
Authors: Price Sarah A. L. , Sumithran Priya , Nankervis Alison J. , Permezel Michael , Prendergast Luke A. , Proietto Joseph
Published: August 2021

Objective

This study examined the effectiveness of a nonsurgical, preconception weight loss intervention on pregnancy outcomes in women with obesity.

Methods

This was a two‐arm, parallel‐group randomized controlled trial. A total of 164 women with BMI 30 to 55 kg/m2 who were aged 18 to 38 years and planning pregnancy were randomized to a 12‐week standard dietary intervention (SDI; n = 79) or a modified very low‐energy diet (VLED; n = 85). Participants were observed for ≤48 weeks while trying for pregnancy and then during pregnancy. The primary outcome was maternal fasting plasma glucose at 26 to 28 weeks’ gestation. Exploratory outcomes were individual and composite obesity‐related adverse pregnancy outcomes.

Results

Weight loss was greater in the VLED group (SDI 3.2 [0.6] kg vs. VLED 13.0 [0.5] kg, p < 0.01). In completers who had a singleton live birth (SDI 22/79 vs. VLED 35/85, p = 0.10), there was no difference in fasting glucose at 26 to 28 weeks’ gestation (SDI 4.8[0.2] mmol/L vs. VLED 4.6 [0.1] mmol/L, p = 0.42). However, the composite of adverse pregnancy outcomes was significantly lower in the VLED group (p < 0.001).

Conclusions

Substantial prepregnancy weight loss in women with obesity does not alter fasting glucose at 26 to 28 weeks’ gestation but does reduce a composite of adverse pregnancy outcomes. A better understanding of metabolic changes in pregnancy after preconception weight loss may assist in improving maternal and neonatal health outcomes.
A Potential Iterative Approach to 1,4‐Dihydro‐N‐Heteroacene Arrays
Authors: Plater M. John , Harrison William T. A.
Published: August 2021

A new method for the synthesis of substituted 1,4‐dihydrophenazines is reported and the structure of N‐butyl‐5‐methyl‐3‐nitro‐5,10‐dihydrophenazine is proven by an X‐ray single‐crystal structure determination.
Factors associated with self‐rated difficulty to descend stairs in persons with knee osteoarthritis
Authors: Stensdotter Ann‐Katrin , Vårbakken Kjartan , Roeleveld Karin
Published: August 2021

Background

Difficulty descending stairs is common in persons with knee osteoarthritis (OA). Clinically, it is important to know if and how this is explained by objectively measured difficulty to descend stairs, muscle weakness, pain, fear of movement, or knee joint status.

Objective

To identify the potential of these factors to explain self‐reported difficulty descending stairs.

Design

Cross sectional, case‐control.

Setting

Hospital outpatient and physiotherapy clinic.

Participants

Twenty‐eight men and women with knee OA (age 62.2 SD 5.9 years) and 31 controls (age 50.0 SD 8.5 years).

Intervention

Not applicable.

Main outcome measures

Using multivariate statistics, group comparisons were made for lower extremity kinematics (incorporating hip, knee, and ankle angles) and stance time in stair descent and lower extremity muscle strength. Then, a stepwise linear regression analysis was performed within the OA group to explain self‐reported difficulties in stair descent where pain, kinesiophobia, radiographic signs, and outcomes that differed from controls for stair‐descent kinematics and muscle strength were independent variables.

Results

Multivariate statistics showed that the OA group displayed different all‐over lower extremity kinematics (F8,42 = 2.44 p = .029, η2 = 0.32) and a longer stance time (F3,50 = 6.46; p = .001, η2 = 0.28) in stair descent and lower muscle strength (F7,47 = 2.39; p = .035, η2 = 0.26) compared to controls. Regression analysis within the OA group to explain self‐rated difficulties to descend stairs showed that the strongest association with kinesiophobia (ß = 0.607, p = .001) that combined with pain last week and radiographic signs explained almost 100% (ß = 0.972). Stair descent kinematics and strength variables that differed between groups did not explain self‐rated difficulties to descend stairs.

Conclusion

Kinesiophobia and pain rather than stair‐descent kinematics and reduced muscle‐strength explained self‐rated difficulties in stair descent in the OA group.
Tensile Strained Germanium Microstructures: A Comprehensive Analysis of Thermo‐Opto‐Mechanical Properties
Authors: Manganelli Costanza Lucia , Virgilio Michele , Montanari Michele , Zaitsev Ignatii , Andriolli Nicola , Faralli Stefano , Tirelli Stefano , Dagnano Fabio , Klesse Wolfgang Matthias , Spirito Davide
Published: August 2021

The influence of the thermomechanical effects on the optical properties of germanium microstructures is investigated. Finite element method (FEM) calculations allow a complete spatial assessment of mechanical deformations induced by a silicon nitride (SiN) stressor layer deposited on Ge micropillars. Simulated strain maps are confirmed by experimental maps obtained by Raman spectroscopy. The theoretical investigation on strain‐dependent band structure, including the presence of a strain gradient along the longitudinal direction, is exploited to fully capture photoluminescence spectroscopy experiments. Finally, the joint effect of temperature and strain on the fundamental bandgap is also quantified.
Chromatographic‐mass spectrometric analysis of the urinary metabolite profile of chlorphenesin observed after dermal application of chlorphenesin‐containing sunscreen
Authors: Rubio Ana , Görgens Christian , Krug Oliver , Okano Masato , Fedoruk Matthew , Ahrens Brian , Geyer Hans , Thevis Mario
Published: August 2021

Rationale:

Chlorphenesin is an approved biocide frequently used in cosmetics, and its carbamate ester is an approved skeletal muscle relaxant in certain countries for the treatment of discomfort related to skeletal muscle trauma and inflammation. A major urinary metabolite is 4‐chlorophenoxy acetic acid (4‐CPA), also known as para‐chlorophenoxyacetate, which is also employed as a target analyte in sports drug testing to detect the use of the prohibited nootropic stimulant meclofenoxate. To distinguish between 4‐CPA resulting from chlorphenesin, chlorphenesin carbamate, and meclofenoxate, urinary metabolite profiles of chlorphenesin after legitimate use were investigated.

Methods:

Human administration studies with commercially available sunscreen containing 0.25% by weight of chlorphenesin were conducted. Six study participants dermally applied 8 g of sunscreen and collected urine samples before and up to 7 days after application. Another set of six study participants applied 8 g of sunscreen on three consecutive days, and urine samples were also taken for up to 5 days after the last dosing. Urine specimens were analyzed using liquid chromatography‐high resolution (tandem) mass spectrometry, and urinary metabolites were identified in accordance with literature data by accurate mass analysis of respective precursor and characteristic product ions.

Results:

In accordance with literature data, chlorphenesin yielded the characteristic urinary metabolites, chlorphenesin glucuronide, chlorphenesin sulfate, and 3‐(4‐chlorophenoxy)‐2‐hydroxypropanoic acid (4‐CPP), as well as the common metabolite 4‐CPA. 4‐CPA and 4‐CPP were observed at similar abundances, with urinary concentrations of 4‐CPA reaching up to ~1500 and 2300 ng/mL after single and multiple sunscreen applications, respectively.

Conclusion:

4‐CPA is a common metabolite of meclofenoxate, chlorphenesin, and chlorphenesin carbamate. Monitoring the diagnostic urinary metabolites of chlorphenesin provides conclusive supporting evidence of whether chlorphenesin or the prohibited nootropic meclofenoxate was administered.
Fault‐tolerant control design for a class of nonlinear systems with actuator malfunctions
Authors: Guo Kexin , Lyu Shangke , Yu Xiang , Qiao Jianzhong , Guo Lei , Zhang Youmin
Published: August 2021

This article presents a single‐hidden‐layer feedforward network (SLFN) aided fault‐tolerant control (FTC) scheme for a class of nonlinear systems subject to actuator faults. First, the upper bounds of the norms of the unknown functions, which cover information of actuator faults and amplitude saturation degrees, are deployed. The upper bounds are approximated by SLFNs with adaptive techniques. Subsequently, a sliding mode control approach is presented to allow for prompt corrective reactions, with explicit consideration of multivariable conditions and control input constraints. Finally, simulation results based on a nonlinear Boeing 747 aircraft model are presented to demonstrate the effectiveness of the proposed FTC scheme.
The potential of “civic science education”: Theory, research, practice, and uncertainties
Authors: Levy Brett L. M. , Oliveira Alandeom W. , Harris Cornelia B.
Published: August 2021

This paper explores the potential ofcivic science education(CSE), which includes experiences that have been intentionally designed to foster or enhance individuals’ interactions with and/or engagement in science‐related public matters. To begin, we provide a theoretically‐grounded definition of CSE, including three sub‐categories: foundational, exploratory, and purposefully active. We then explore the scholarly arguments for why enacting CSE could help to support students’ science learning and civic engagement and also strengthen civil society. Next, the paper examines current educational practices related to CSE, such as citizen science, exploring socioscientific issues, and various civic education pedagogies, detailing what researchers have learned from empirical studies of these practices. Building on this prior theory and research, we argue that CSE could motivate students both to learn science and become engaged in civic issues, with slightly different expected outcomes across the three CSE categories. We conclude by encouraging educators and researchers to explore the great potential of such practices, providing specific recommendations for curriculum development and empirical studies.
19.3: Evaluation of Entrance Pupil Location in Measuring VR\AR Eyewear Displays: Theoretical and Experimental Analyses in Field of View
Authors: Wang Jianping , Mou Xi
Published: August 2021

The conventional display measurements are no longer satisfying the need for eyewear displays. The measurement of VR/AR type display requires light measuring devices (LMDs) to simulate the characteristics of the human eye. Factors like the position of the pupil, field of view, and the motion of the eye are often discussed. One of the factors to be considered is the choice of entrance pupil location (aperture stop setting) of the LMD. In this paper, a preliminary study was carried out to compare the deviations of FOV and luminance with the choice of entrance pupil location. The experiment demonstrated that it exists as the most accurate eye‐viewing when the entrance pupil is located at the front focal point.
26.5: View Angle Characteristics of LCD/OLED/miniLED/microLED Panels
Authors: Liu Luning , Feng Xiaofan , Zheng Zengqiang , Zhang Shengsen , Geng Hai , Zheng Jiong
Published: August 2021

The view angle characteristics refer to the changes in the luminance that occur with varying view directions which is defined as the luminance's view angle dependence (LVAD) in this paper. Recently the LVAD of OLED/LCD/miniLED/microLED panels attracts more attention. In this paper, the LVAD of OLED/LCD/mini LED/micro LED were measured and compared. For each panel, the LVAD of three gray levels and three colors at nine positions and four azimuth angles has been measured. The gray levels are 255/128/32, the colors are red (R), green (G), blue (B) and the azimuth angles are 0/90/180/270 degrees. It was found that the LVAD of OLED/miniLED/microLED changes a lot with colors except LCD panels. And the LVAD of all panels changes with the measurement azimuth angles. Gray levels will also affect the LVAD if different gray levels are with different spectra. Besides, OLED/LCD/miniLED panels exhibit the same LVAD at different positions.
55.1: Invited Paper: FMM‐free OLED Manufacturing Enabled by Photolithographic Patterning Processes
Authors: Ke Tung-Huei , Sandeheng Calvin Mona , Alvarez Gema Molina , Vandenplas Erwin , Ciarnain Rossa Mac , Malinowski Pawel E. , Genoe Jan , Heremans Paul
Published: August 2021

Resolution and brightness are the essential figure‐of‐merits for the microdisplay development needed for AR and VR applications. In this presentation, we show our technology development toward high‐resolution FMM‐free direct R‐G‐B OLED microdisplays. We show the schematic fabrication setup and integration route to fabricate red, green, and blue OLED pixels side‐by‐side by the OLED photolithographic patterning processes. We demonstrate a 1µm line and space feature with the photoresist and transfer the pattern to an OLED stack. With the high resolution of photoresist, high aperture ratio, and high‐resolution multicolor OLED pixel arrays are demonstrated. We also investigate the possible OLED degradations induced in the photolithography process. With the innovations in the process steps, OLED stacks, process environments, and photoresists, we demonstrate a breakthrough in the reliability of photolithography patterned OLED.
P‐3.2: VR Air rescue immersive simulation system
Authors: Lv Shitao , Zhang Qichang , Wang Lijun
Published: August 2021

Developed a simulation training system based on the integration of virtual and simulation for the rescue process of aviation emergency rescue for critical illnesses. Including AR emergency and severe illness rescue process training subsystem, aiming at major disaster aviation rescue work, realize the training of emergency and severe illness rescue process by simulating the evolution process of acute and severe illness injury, vital signs display and operation recognition; AR semi‐physical equipment Operation simulation training subsystem, aiming at the research of key technology and equipment of aviation medical emergency rescue transportation, realizes the operation training of aviation rescue life support integrated machine through semi‐physical instrument workflow simulation, working status display, and operation action recognition.
P‐5.4: Design and Implementation of Mini‐LED Multi‐Screen Splicing Display System Based on FPGA
Authors: Chen Rui , Qiu ChengFeng , Liu ZhaoJun , Lv ZhiJian
Published: August 2021

Mini‐LED has developed rapidly by virtue of its advantages in display industry, including low power consumption, stability, high resolution and display effect. In this paper, a video display system based on FPGA with multiple mini‐LED displays is implemented. The system builds the circuit structure of multi‐screen splicing display with FPGA and realizes the flexible splicing display of multiple Mini‐LED displays, so that Mini‐LED display can achieve the effect of flexible expansion of display size. Multiple video images stored in the SD card are read and segmented into parts corresponding to the number of display screens and then output to the spliced Mini‐LED display screen for displaying. The main modules of the display system built by FPGA include: external storage data reading module, RAM cache module, data distribution and regulation module, RGB output module, MBI5759 module of the driver chip and infrared control module. The system is realized by using Xilinx FPGA development board and ISE development software. In addition, the corresponding PCB board is designed to connect FPGA and Mini‐LED displays.
Paper Based Low‐Cost and Portable Ultrasensitive Electroanalytical Devicefor The Detection of Uric Acid in Human Urine
Authors: Vishnu Nandimalla , Sihorwala Ahmed Z. , Sharma Chandra S.
Published: August 2021

The electrochemical literature describes a plethora of devices for various applications. Design and development of such paper‐based analytical device(PAD) for sensing applications is paramount of interest. In this work, a PAD was developed using common office‐hold items like paper, pencil, crayons and scotch tape. On a paper, a three‐electrode system was developed by simple drawing with pencils, and the accessible area was confined by creating a hydrophobic barrier using color crayons. The newly developed PAD can hold a low‐dead volume of 25 μL for the analysis and is sealed at the bottom using scotch tape. In our preliminary approach, uric acid (UA), a critical biomarker, was demonstrated as a model analyte for the application of the developed PAD as an electrochemical sensor. The sensor exhibited better analytical performance for UA sensing in a wide range (0.1–1 mM) with appreciable reproducibility, sensitivity (0.3×10−3 A M−1) and selectivity over common interferents (ascorbic acid, urea and glucose). Furthermore, the developed electroanalytical approach was validated by testing the UA in non‐invasive bio‐sample (human urine). Such a cheap, portable, disposable, biocompatible, eco‐friendly and fully‐drawn PAD paves the way for the development of affordable ‘lab on paper’ devices for a wide range of bioanalytical applications.
A Sensitive Fluorescent Probe for Homocysteine/Cysteine in Pure Aqueous Media and Mitochondria
Authors: Su Sa , Chen Qianqian , Wang Chong , Jing Jing , Zhang Xiaoling
Published: August 2021

Biothiols, involving homocysteine (Hcy), cysteine (Cys), and glutathione (GSH), are very important in physiological and pathological processes and play critical roles in the sustainment of the cellular equilibrium. In order to grasp more information about physiological and pathological processes and make new advances in the medical industry, it′s indispensible to develop more useful tools to detect biothiols. Herein, we have successfully prepared a novel mitochondrial homocysteine/cysteine‐selective fluorescent probe. Based on nucleophilic aromatic substitution (SNAr) and intramolecular rearrangement cascade reactions, this fluorescent probe shows not only a mitochondria‐targeting property but also a stable function in pure aqueous media with rapid and sensitive responses toward Hcy/Cys. For one thing, it is able to realize fluorescence imaging of Hcy/Cys in mitochondria. For another, we can acquire information about biothiol‐relevant redox status via this potential probe. We hope this probe will help us to broaden our knowledge about the effects of biothiols especially Hcy/Cys.
Facile Ion Exchange Synthesis of Ag, Cu, and Sn Incorporated Defect Pyrochlore K2Ta2O6 towards Visible‐Light‐Responsive Photocatalytic Activity
Authors: Angineni Rani , Angineni Jyothsna , Kumar Veldurthi Naveen , Venkataswamy Perala , Vithal Muga
Published: August 2021

A novel series of Ag, Cu, and Sn ions incorporated defect pyrochlore K2Ta2O6 photocatalysts were successfully synthesized by facile ion exchange method whereas pristine K2Ta2O6 was prepared by conventional hydrothermal method. All the samples were amply characterized by powder X‐ray Diffraction (PXRD), ultraviolet‐visible diffuse reflectance spectroscopy (UV‐Vis DRS), scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDS) and X‐ray photoelectron spectroscopy (XPS) techniques to understand their phase formation, optical properties, morphology, and chemical composition. The absorption edge of ion‐exchanged samples was red‐shifted remarkably, therefore they would respond under visible light. The photocatalytic activity of all samples was assessed by studying the degradation of methylene blue (MB) dye under visible light irradiation. All samples show activity towards MB degradation and Cu−K2Ta2O6 exhibited superior photocatalytic performance (86 %) compared to others. Different scavenger tests were carried out to identify the reactive species, accountable for the decontamination of aqueous dye solution. Moreover, photoluminescence (PL) measurements were carried out to correlate the separation efficacy of photoinduced charge carriers and photocatalytic performance of all samples. This work may provide valuable information for exploring the as‐prepared photocatalysts towards more energy and environmental applications.
The impact of traceability on software maintenance and evolution: A mapping study
Authors: Tian Fangchao , Wang Tianlu , Liang Peng , Wang Chong , Khan Arif Ali , Babar Muhammad Ali
Published: August 2021

Software traceability plays a critical role in software maintenance and evolution. We conducted a systematic mapping study with six research questions to understand the benefits, costs, and challenges of using traceability in maintenance and evolution. We systematically selected, analyzed, and synthesized 63 studies published between January 2000 and May 2020, and the results show that traceability supports 11 maintenance and evolution activities, among which change management is the most frequently supported activity; strong empirical evidence from industry is needed to validate the impact of traceability on maintenance and evolution; easing the process of change management is the main benefit of deploying traceability practices; establishing and maintaining traceability links is the main cost of deploying traceability practices; 13 approaches and 32 tools that support traceability in maintenance and evolution were identified; improving the quality of traceability links, the performance of using traceability approaches, and tools are the main traceability challenges in maintenance and evolution. The findings of this study provide a comprehensive understanding of deploying traceability practices in software maintenance and evolution phase and can be used by researchers for future directions and practitioners for making informed decisions while using traceability in maintenance and evolution.
Toward Megapixel Resolution Compressed Sensing Current Mapping of Photovoltaic Devices Using Digital Light Processing
Authors: Koutsourakis George , Thompson Andrew , Blakesley James C.
Published: August 2021

Photocurrent response mapping is a powerful imaging technique for assessing defects and losses in photovoltaic devices. However, it has not enjoyed widespread application because high‐resolution measurements of large samples can last several hours, while weak signals from micrometer‐sized laser spots require lock‐in amplification. An alternative approach presented recently is the use of digital micromirror devices combined with compressed sensing theory. There are significant benefits when using such methods, such as signal amplification, undersampling options, and simplified measurement systems. Nevertheless, high computational requirements have limited the experimental application of this method to low‐resolution outputs. Herein, the mathematical background and the experimental approach toward megapixel resolution, ultrafast compressed sensing current mapping are presented, overcoming previous computational and experimental barriers. A high‐power digital light processing projection system is developed for the experimental application. Solutions to computational issues, sampling optimization, and measurement strategies are presented and the flexibility of the system regarding the sizes of photovoltaic devices that can be measured is demonstrated.
Simultaneous Improvement of Efficiency and Stability of Non‐Fullerene‐Based Organic Solar Cells Via Sequential Deposition of Single Donor and Binary Acceptor
Authors: Min Suhyun , Han Seung Hee , Park Chanju , Ryu Ka Yeon , Kim Kyungkon
Published: August 2021

Non‐fullerene acceptor (NFA)‐based organic solar cells often exhibit significant cell degradation in power conversion efficiency (PCE) in the early stages of operation, called “burn‐in.” Generally, to fabricate NFA‐based solar cells, binary blend solution deposition (binary BSD) of a conjugated polymer and an NFA is utilized. Herein, the reasons for burn‐in are investigated by aging organic photovoltaic cells with independent control of temperature and light. The results reveal that burn‐in is mainly due to a rapid increase in the interfacial resistance (R
int) rather than photo‐oxidation of the components or oxidation of the electrode. This R
int is effectively suppressed by constructing a ternary photoactive layer through the sequential deposition of a polymer solution and a binary acceptor solution consisting of an NFA and a fullerene acceptor (ternary sequential deposition [ternary SqD]). Under the illumination of 1 sun and thermal annealing at 80 °C for 500 h, the binary BSD exhibits a reduction in efficiency of 63% and 59%, respectively, whereas the ternary SqD demonstrates a reduction of only 32% and 35%, respectively. In addition, the ternary SqD improves the PCE on using fullerene acceptors to enhance light harvesting at short wavelengths.
A new way to test the WIMP dark matter models
Authors: Cheng Wei , He Yuan , Diao Jing-Wang , Pan Yu , Zeng Jun , Zhang Jia-Wei
Published: August 2021

Abstract

In this paper, we investigate the possibility of testing the weakly interacting massive particle (WIMP) dark matter (DM) models by applying the simplest phenomenological model which introduces an interaction term between dark energy (DE) and WIMP DM, i.e., Q = 3γDMHρDM. In general, the coupling strength γDE is close to 0 as the interaction between DE and WIMP DM is very weak, thus the effect of γDE on the evolution of Y associated with DM energy density can be safely neglected. Meanwhile, our numerical calculation also indicates that xf ≈ 20 is associated with DM freeze-out temperature, which is the same as the vanishing interaction scenario. As for DM relic density, it will be magnified by $$ \frac{2-3{\upgamma}_{\mathrm{DM}}}{2}{\left[2\pi {g}_{\ast }{m}_{\mathrm{DM}}^3/\left(45{s}_0{x}_f^3\right)\right]}^{\gamma_{\mathrm{DM}}} $$

2
−
3

γ
DM

2

2
π

g
∗

m
DM
3

/

45

s
0

x
f
3

γ
DM

times, which provides a new way to test WIMP DM models. As an example, we analyze the case in which WIMP DM is a scalar DM. (SGL+SNe+Hz) and (CMB+BAO+SNe) cosmological observations will give γDM = $$ {0.134}_{-0.069}^{+0.17} $$

0.134

−
0.069

+
0.17

and γDM = −0.0008 ± 0.0016, respectively. After further considering the constraints from DM direct detection experiment, DM indirect detection experiment, and DM relic density, we find that the allowed parameter space of the scalar DM model will be completely excluded for the former cosmological observations, while it will increase for the latter ones. Those two cosmological observations lead to an almost paradoxical conclusion. Therefore, one could expect more stringent constraints on the WMIP DM models, with the accumulation of more accurate cosmological observations in the near future.
5d/6d Wilson loops from blowups
Authors: Kim Hee-Cheol , Kim Minsung , Kim Sung-Soo
Published: August 2021

Abstract

We generalize Nakajima-Yoshioka’s blowup formula to calculate the partition functions counting the spectrum of bound states to half-BPS Wilson loop operators in 5d (and 6d) supersymmetric field theories. The partition function in the presence of a Wilson loop operator on the Ω-background is factorized when put on the blowup $$ \hat{\mathbb{C}} $$

ℂ
̂

2 into two Wilson loop partition functions under the localization. This structure provides a set of blowup equations for Wilson loop operators. We explain how to formulate the blowup equations and solve them to compute the partition functions of Wilson loop operators. We test this idea by explicitly calculating the Wilson loop partition functions in various 5d/6d field theories and comparing them against known results and expected dualities.
Radiotherapy for glioblastoma patients with poor performance status
Authors: Schröder Christina , Gramatzki Dorothee , Vu Erwin , Guckenberger Matthias , Andratschke Nicolaus , Weller Michael , Hertler Caroline
Published: August 2021

Purpose

There is limited information on treatment recommendations for glioblastoma patients with poor performance status. Here, we aim to evaluate the association of radiotherapy on survival in glioblastoma patients presenting with poor postoperative performance status in first-line setting.

Methods

We retrospectively analyzed data of 93 glioblastoma patients presenting with poor postoperative performance status (ECOG 2–4) at the University Hospital Zurich, Switzerland, in the years 2005–2019. A total of 43 patients received radiotherapy with or without systemic therapy in the first-line setting, whereas 50 patients received no additive local or systemic treatment after initial biopsy or resection. Overall survival was calculated from primary diagnosis and from the end of radiotherapy. In addition, factors influencing survival were analyzed.

Results

Median overall survival from primary diagnosis was 6.2 months in the radiotherapy group (95% CI 6.2–14.8 weeks, range 2–149 weeks) and 2.3 months in the group without additive treatment (95% CI 1.3–7.4 weeks, range 0–28 weeks) (p < 0.001). This survival benefit was confirmed by landmark analyses. Factors associated with overall survival were extent of resection and administration of radiotherapy with or without systemic treatment. Median survival from end of radiotherapy was 3 months (95% CI 4.3–21.7 weeks, range 0–72 weeks), with 25.6% (n = 11) early termination of treatment and 83.7% (n = 36) requiring radiotherapy as in-patients. Performance status improved in 27.9% (n = 12) of patients after radiotherapy.

Conclusion

In this retrospective single-institution analysis, radiotherapy improved overall survival in patients with poor performance status, especially in patients who were amendable to neurosurgical resection.
Effects of multiple modes of UltraPulse fractional CO2 laser treatment on extensive scarring: a retrospective study
Authors: Ge Xiaojing , Sun Yute , Lin Jing , Zhou Fang , Yao Gang , Su Xin
Published: August 2021

The main therapeutic options for extensive scarring (e.g., > 20% of the total body surface area, or TBSA) after burns and trauma have focused on conservative treatments, such as compression, moisturization, and topical agent application. However, these treatments may not achieve optimal effects due to the large size and complexity of the scars. UltraPulse fractional CO2 laser treatment is a novel approach that is currently a subject of intense interest; this treatment is most widely used to improve texture, pliability, and pigmentation in all types of scars. However, no studies on the independent use of UltraPulse fractional CO2 laser treatment for extensive scars have been reported. This retrospective study evaluated a total of 21 patients, whose scars covered 20 to 65% TBSA. Scar thickness was measured by ultrasonography before treatment. Personalized treatment modalities and parameters were set according to the scar type and thickness. Scar formation and treatment effects were evaluated by photography, the Patient and Observer Scar Assessment Scale (POSAS), and patients’ judgment of effectiveness. Where the scars covered joints, joint function was assessed by measuring the maximum range of motion (ROM). With laser therapy, scars became flatter and lighter; furthermore, pruritus, pain, and discomfort decreased significantly. POSAS scores significantly decreased after laser therapy, including the item scores for pain and pruritus. There were no instances of joint contracture, ROM reduction, apparent functional impairment, serious adverse events, or comorbidities. This study demonstrates the safety and efficiency of UltraPulse fractional CO2 laser treatment for extensive scarring.
Investigating the role of endogenous estrogens, hormone replacement therapy, and blockade of estrogen receptor-α activity on breast metabolic signaling
Authors: Arnone Alana A. , Cline J. Mark , Soto-Pantoja David R. , Cook Katherine L.
Published: August 2021

Purpose

Menopause is associated with an increased risk of estrogen receptor-positive (ER +) breast cancer. To characterize the metabolic shifts associated with reduced estrogen bioavailability on breast tissue, metabolomics was performed from ovary-intact and ovariectomized (OVX) female non-human primates (NHP). The effects of exogenous estrogen administration or estrogen receptor blockade (tamoxifen treatment) on menopause-induced metabolic changes were also investigated.

Methods

Bilateral ovariectomies were performed on female cynomolgus macaques (Macaca fascicularis) to model menopause. OVX NHP were then divided into untreated (n = 13), conjugated equine estrogen (CEE)-treated (n= 13), or tamoxifen-treated (n = 13) subgroups and followed for 3 years. Aged-matched ovary-intact female NHP (n = 12) were used as a premenopausal comparison group. Metabolomics was performed on snap-frozen breast tissue.

Results

Changes in several different metabolic biochemicals were noted, particularly in glucose and fatty acid metabolism. Specifically, glycolytic, Krebs cycle, acylcarnitines, and phospholipid metabolites were elevated in breast tissue from ovary-intact NHP and OVX + CEE in relation to the OVX and OVX + tamoxifen group. In contrast, treatment with CEE and tamoxifen decreased several cholesterol metabolites, compared to the ovary-intact and OVX NHP. These changes were accompanied by elevated bile acid metabolites in the ovary-intact group.

Conclusion

Alterations in estrogen bioavailability are associated with changes in the mammary tissue metabolome, particularly in glucose and fatty acid metabolism. Changes in these pathways may represent a bioenergetic shift in gland metabolism at menopause that may affect breast cancer risk.
Technology supported learning and pedagogy in times of crisis: the case of COVID-19 pandemic
Authors: Ahmed Vian , Opoku Alex
Published: August 2021

Online teaching within disciplines such as Engineering require experiential learning that equip future graduates with highly intellectual and professional skills to meet the demands of employers and the industry. The outbreak of COVID-19 however, has shifted the academic community into new landscapes that require educators and students to adapt and manage their expectations. Although literature reports on research attempts to study the implications of Covid-19 on the Higher Education curricular, little has been reported on its impact on Engineering Education. This paper therefore uses the theory of Emergency Management Life Cycle (mitigation, preparedness, response, and recover) as a lens to examine the challenges faced by students and academics and coping mechanism during the COVID period. This study adopts a mixed method approach using a case study from the College of Engineering at a Higher Education Institution in the UAE due to the sudden migration to online teaching amid COVID-19. Data is collected through interviews and surveys with both students and instructors on challenges, strategies and online delivery good practices that enhanced students’ learning experience. The results show that, Technology Supported Learning tools are capable of enhancing students’ experiential learning and associated competencies, however there were a number of pedagogical, technological and psychological challenges that faced students and instructors as a result of the sudden migration online, which are likely to play a role in the impediment of the students’ learning cycle, due to the lack of preparedness in response to the state of emergency created by Covid-19. Despite these challenges, the study found that instructors with effective communication skills and teaching style, competent use of technology, flexible, friendly and supportive attitude towards teaching, played a positive role in mitigating for the lack of preparedness in response to sudden migration online. The study also reveals that by overcoming some of the technical challenges such as slow internet connection and interruptions, lessons learnt from the sudden migration to online delivery amid COVID-19, will help create new opportunities for the use of blended learning approaches to meet the needs of the on-going COVID and future online deliveries.
The Income Gradient in Mortality during the Covid-19 Crisis: Evidence from Belgium
Authors: Decoster André , Minten Thomas , Spinnewijn Johannes
Published: August 2021

We use population-wide data from linked administrative registers to study the distributional pattern of mortality before and during the first wave of the Covid-19 pandemic in Belgium. Over the March-May 2020 study period, excess mortality is only found among those aged 65 and over. For this group, we find a significant negative income gradient in excess mortality, with excess deaths in the bottom income decile more than twice as high as in the top income decile for both men and women. However, given the high inequality in mortality in normal times, the income gradient in all-cause mortality is only marginally steeper during the peak of the health crisis when expressed in relative terms. Leveraging our individual-level data, we gauge the robustness of our results for other socioeconomic factors and decompose the role of individual vs. local effects. We provide direct evidence that geographic location effects on individual mortality are particularly strong during the first wave of the Covid-19 pandemic, channeling through the local number of Covid infections. This makes inference about the income gradient in excess mortality based on geographic variation misguided.
Post-Dropping Behavior of Potato Aphids (Macrosiphum euphorbiae)
Authors: Humphreys Rosalind K. , Ruxton Graeme D. , Karley Alison J.
Published: August 2021

Dropping behavior is an effective antipredator defense utilized by many insects including aphids, which drop from plants to lower plant parts or underlying substrates to avoid attack from predatory invertebrates. While research commonly focusses on triggers of dropping, less attention is given to what happens to prey individuals following escape drops. In this study, the duration of tonic immobility, recovery rates, and cases of “instant recovery” (re-clinging to lower plant parts) exhibited by potato aphids (Macrosiphum euphorbiae) that dropped from potted seedlings in response to introduced ladybird (Adalia bipunctata) adults, lacewing (Chrysoperla carnea) larvae, and a standardized tactile stimulus were investigated in relation to a range of environmental factors. Air temperature had a negative correlation with the duration of post-dropping tonic immobility; as temperature increased, time spent motionless decreased. Aphids also showed a pattern of increased recovery rate at higher temperatures. Aphids may be selected to move off the substrate quicker to avoid risks of overheating/desiccation at higher temperatures; and/or higher body temperature facilitates locomotion. Stimulus type also influenced recovery rate back to the original seedling, with aphids generally recovering after the standardized stimulus quicker than after dropping triggered by a real predator. Considering cases of instant recovery onto lower-reaches of the host seedling, seedling height influenced the likelihood of re-clinging, with aphids that managed to instantly recover dropping from, on average, taller seedlings than aphids that dropped to the substrate. Plant architecture could mitigate the costs of dropping for aphids, but further studies quantifying understory foliage cover are needed.
AI-Based Self-Learning System in Distributed Structural Health Monitoring and Control
Authors: Yan Kai , Lin Xin , Ma Wenfeng , Zhang Yuxiao
Published: August 2021

Artificial intelligence is predicted to play a big part in self-learning, industrial automation that will negotiate the bandwidth of structural health and control systems. The industrial structural health and control system based on discrete sensors possesses insufficient spatial coverage of sensing information, while the distributed condition monitoring has been mainly studied at the sensor level, relatively few studies have been conducted at the artificial intelligence level. This paper presents an innovative method for distributed structural health and control systems based on artificial intelligence. The structural condition was divided into regional and local features, the feature extraction and characterization are performed separately. Structural abnormality recognition and risk factor calculation method were proposed by considering the response values and the distribution patterns of both the regional and the local structural behaviours. The test results show that the method can effectively identify the full-scale and local damage of the structure, respectively. Subsequently, structural safety assessment method for long-span structures at kilometres level in view of fully length strain distributions measured by distributed fiber optic sensors were developed. A series of load tests on the long-span structure were carried out. Finite element (FE) model was developed using finite element code, ABAQUS, and an extensive parametric study was conduct to explore the effect of load cases on the structural responses. The differences in the structural response results among load test, structural safety assessment and FE simulation were investigated. It is shown that AI-based self-learning system could offer suitable speed in deployment, reliability in solution and flexibility to adjust in distributed structural health monitoring and control.