bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuroinflammation: The next target of exosomal microRNAs derived from mesenchymal stem cells in the context of neurological disorders
Authors: Hajinejad Mehrdad , Sahab‐Negah Sajad
Published: July 2021

Among different types of mechanisms involved in neurological disorders, neuroinflammation links initial insults to secondary injuries and triggers some chronic outcomes, for example, neurodegenerative disorders. Thus, anti‐inflammatory substances can be targeted as a novel therapeutic option for translational and clinical research to improve brain disease outcomes. In this review, we propose to introduce a new insight into the anti‐inflammatory effects of mesenchymal stem cells (MSCs) as the most frequent source for stem cell therapy in neurological diseases. Our insight incorporates a bystander effect of these stem cells in modulating inflammation and microglia/macrophage polarization through exosomes. Exosomes are nano‐sized membrane vesicles that carry cell‐specific constituents, including protein, lipid, DNA, and RNA. microRNAs (miRNAs) have recently been detected in exosomes that can be taken up by other cells and affect the behavior of recipient cells. In this article, we outline and highlight the potential use of exosomal miRNAs derived from MSCs for inflammatory pathways in the context of neurological disorders. Furthermore, we suggest that focusing on exosomal miRNAs derived from MSCs in the course of neuroinflammatory pathways in the future could reveal their functions for diverse neurological diseases, including brain injuries and neurodegenerative diseases. It is hoped that this study will contribute to a deep understanding of stem cell bystander effects through exosomal miRNAs.
Healthcare worker training to improve quality of care for sexual and gender minority people in sub‐Saharan Africa: learning from efforts in Uganda
Authors: Keuroghlian Alex S , Mujugira Andrew , Mayer Kenneth H
Published: July 2021

Introduction

Training in care for sexual and gender minority (SGM) populations is critical for ending the HIV epidemic. SGM people, particularly men who have sex with men (MSM) and transgender women, experience disproportionate HIV infection across the globe. The objective of this commentary was to synthesize facilitators of and barriers to SGM health training efforts for healthcare workers in Uganda, in order to help inform potential priorities, strategies and next steps to advance culturally responsive HIV‐related care for SGM communities across Uganda and sub‐Saharan Africa.

Discussion

SGM health training often includes education on: foundational concepts and language; stigma, discrimination and SGM health disparities; understanding and addressing implicit bias; sensitive and effective communication and building SGM‐inclusive and welcoming healthcare environments. Clinicians’ education includes sexual and gender histories, sex‐positive HIV counselling, sexually transmitted infections, HIV pre‐exposure prophylaxis and gender‐affirming hormone therapy. SGM communities in sub‐Saharan Africa have often experienced discrimination, persecution, incarceration and physical violence, and they encounter unique barriers to engagement in sexual health services and HIV prevention and treatment. SGM health training efforts in Uganda reveal challenges to and opportunities for advancing equity for SGM communities in sexual health and HIV medical care across the region. In Uganda, SGM community advocacy, as well as policies and programmes of the Ministry of Health and US President’s Emergency Plan for AIDS Relief, have increased readiness and need for scaling up training and skills‐sharing in SGM‐focused HIV and sexual healthcare, including Ugandan‐led and international initiatives.

Conclusions

Numerous challenges exist to widespread culturally responsive HIV and sexual healthcare for SGM communities in sub‐Saharan Africa. Lessons learned from healthcare worker training efforts in Uganda may inform future replication, adaptation and dissemination initiatives to meet the needs of more SGM communities in the region. Evaluation of SGM health training programmes to determine the impact on HIV virological suppression and sexual health outcomes will be critical for identifying best practices and strategies that may support advancing HIV epidemic control for SGM communities in Uganda and across sub‐Saharan Africa.
Unraveling the MRI‐Based Microstructural Signatures Behind Primary Progressive and Relapsing–Remitting Multiple Sclerosis Phenotypes
Authors: Boscolo Galazzo Ilaria , Brusini Lorenza , Akinci Muge , Cruciani Federica , Pitteri Marco , Ziccardi Stefano , Bajrami Albulena , Castellaro Marco , Salih Ahmed M.A. , Pizzini Francesca B. , Jovicich Jorge , Calabrese Massimiliano , Menegaz Gloria
Published: July 2021

Background

The mechanisms driving primary progressive and relapsing–remitting multiple sclerosis (PPMS/RRMS) phenotypes are unknown. Magnetic resonance imaging (MRI) studies support the involvement of gray matter (GM) in the degeneration, highlighting its damage as an early feature of both phenotypes. However, the role of GM microstructure is unclear, calling for new methods for its decryption.

Purpose

To investigate the morphometric and microstructural GM differences between PPMS and RRMS to characterize GM tissue degeneration using MRI.

Study Type

Prospective cross‐sectional study.

Subjects

Forty‐five PPMS (26 females) and 45 RRMS (32 females) patients.

Field Strength/Sequence

3T scanner. Three‐dimensional (3D) fast field echo T1‐weighted (T1‐w), 3D turbo spin echo (TSE) T2‐w, 3D TSE fluid‐attenuated inversion recovery, and spin echo‐echo planar imaging diffusion MRI (dMRI).

Assessment

T1‐w and dMRI data were employed for providing information about morphometric and microstructural features, respectively. For dMRI, both diffusion tensor imaging and 3D simple harmonics oscillator based reconstruction and estimation models were used for feature extraction from a predefined set of regions. A support vector machine (SVM) was used to perform patients' classification relying on all these measures.

Statistical Tests

Differences between MS phenotypes were investigated using the analysis of covariance and statistical tests (P < 0.05 was considered statistically significant).

Results

All the dMRI indices showed significant microstructural alterations between the considered MS phenotypes, for example, the mode and the median of the return to the plane probability in the hippocampus. Conversely, thalamic volume was the only morphometric feature significantly different between the two MS groups. Ten of the 12 features retained by the selection process as discriminative across the two MS groups regarded the hippocampus. The SVM classifier using these selected features reached an accuracy of 70% and a precision of 69%.

Data Conclusion

We provided evidence in support of the ability of dMRI to discriminate between PPMS and RRMS, as well as highlight the central role of the hippocampus.

Level of Evidence

2

Technical Efficacy Stage

3
Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2‐Mapping: Initial Experience With 3‐Year Follow‐Up
Authors: Tao Hongyue , Zhang Yuyang , Hu Yiwen , Li Qianru , Hua Yinghui , Lu Rong , Xie Yuxie , Li Xiangwen , Zhang Bo , Chen Shuang
Published: July 2021

Background

Anatomic repair is widely accepted as the primary surgical treatment for chronic lateral ankle instability (CLAI). T2‐mapping is a powerful tool for quantitative assessment of biochemical changes in cartilage matrix.

Purpose

To longitudinally evaluate cartilage matrix changes in the hindfoot joints of CLAI patients before and after anatomic repair by using T2‐mapping with magnetic resonance imaging (MRI).

Study Type

Prospective.

Subjects

Thirty‐two CLAI patients (males/females = 20/12) and 21 healthy controls (males/females = 13/7).

Field Strength/Sequence

3 T; sagittal multi‐echo spin‐echo technique (T2‐mapping), coronal, sagittal, and axial spin‐echo PD‐FS, and sagittal T1WI sequences.

Assessment

MRI examinations were performed in CLAI patients at baseline (prior to surgery) and 3 years after anatomic repair and in healthy controls. On T2‐maps, the hindfoot joints were segmented into 16 cartilage subregions. The T2 value of each subregion was measured. All patients were evaluated with the American Orthopedic Foot and Ankle Society (AOFAS) scale at baseline and after surgery.

Statistical Tests

Analysis of variance (ANOVA) and Student's t‐test were used. The differences corresponding to P < 0.05 were considered statistically significant.

Results

At baseline, the T2 values in most cartilage subregions of talar dome and medial posterior subtalar joint (pSTJ) were higher in CLAI patients than in healthy controls. After surgery, only the T2 value of anteriomedial talar dome decreased from that at baseline (31.11 ± 3.88 msec vs. 34.27 ± 5.30 msec). The T2 values of other subregions with elevated T2 values remained higher than healthy controls. There were no significant differences in T2 values in the midtarsal joints between CLAI patients and healthy controls (P = 0.262, 0.104, 0.169, 0.103). Postoperatively, the patients' AOFAS scores improved significantly from 67.81 to 89.13.

Data Conclusion

CLAI patients exhibited elevated T2 values in most subregions of talar dome and medial pSTJ. After anatomic repair, although the patients exhibited good clinical outcomes, the elevated T2 values could not be fully recovered.

Level of Evidence

2

Technical Efficacy Stage

4
Variation in the patellar tendon moment arm identified with an improved measurement framework
Authors: Dandridge Oliver , Garner Amy , Amis Andrew A. , Cobb Justin P. , van Arkel Richard J.
Published: July 2021

The mechanical advantage of the knee extensor mechanism depends heavily on the patellar tendon moment arm (PTMA). Understanding which factors contribute to its variation may help improve functional outcomes following arthroplasty. This study optimized PTMA measurement, allowing us to quantify the contribution of different variables. The PTMA was calculated about the instantaneous helical axis of tibiofemoral rotation from optical tracked kinematics. A fabricated knee model facilitated calculation optimization, comparing four data smoothing techniques (raw, Butterworth filtering, generalized cross‐validated cubic spline‐interpolation and combined filtering/interpolation). The PTMA was then measured for 24 fresh‐frozen cadaveric knees, under physiologically based loading and extension rates. Combined filtering/interpolation enabled sub‐mm PTMA calculation accuracy throughout the range of motion (root‐mean‐squared error 0.2 mm, max error 0.4 mm), whereas large errors were measured for raw, filtered‐only and interpolated‐only techniques at terminal flexion/extension. Before scaling, the mean PTMA was 46 mm; PTMA magnitude was consistently larger in males (mean differences: 5 to 10 mm, p < .05) and was strongly related to knee size: larger knees have a larger PTMA. However, while scaling eliminated sex differences in PTMA magnitude, the peak PTMA occurred closer to terminal extension in females (female 15°, male 29°, p = .01). Knee size accounted for two‐thirds of the variation in PTMA magnitude, but not the flexion angle where peak PTMA occurred. This substantial variation in angle of peak PTMA has implications for the design of musculoskeletal models and morphotype‐specific arthroplasty. The developed calculation framework is applicable both in vivo and vitro for accurate PTMA measurement.
Interaction of loading and ligament injuries in subtalar joint instability quantified by 3D weightbearing computed tomography
Authors: Burssens Arne , Krähenbühl Nicola , Lenz Amy L. , Howell Kalebb , Zhang Chong , Sripanich Yantarat , Saltzman Charles L. , Barg Alexej
Published: July 2021

Despite decades of research since its first description, subtalar joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two‐dimensional measurements. Therefore, we used weightbearing computed tomography imaging to quantify three‐dimensional displacement associated with subtalar joint instability. Three‐dimensional models were generated in seven paired cadaver specimens to compute talocalcaneal displacement after different patterns of axial load (85 kg) combined with torque in internal and external rotation (10 Nm). Sequential imaging was repeated in the subtalar joint containing intact ligaments to determine reference displacement. Afterward, the interosseus talocalcaneal ligament (ITCL) or calcaneofibular ligament (CFL) was sectioned, then the ITCL with CFL and after the ITCL, CFL with the deltoid ligament (DL). The highest translation could be detected in the dorsal direction and the highest rotation occurred in the internal direction when external torque was applied to the foot without load. These displacements differed significantly from the condition containing intact ligaments, with a mean difference of 1.6 mm (95% CI, 1.3 to 1.9) for dorsal translation and a mean of 12.4° (95% CI, 10.1 to 14.8) for internal rotation. Clinical relevance: Our study provides a novel and noninvasive analysis to quantify subtalar joint instability based on three‐dimensional WBCT imaging. This approach overcomes former studies using trans‐osseous fixation to determine three‐dimensional subtalar joint displacement and implements an imaging device and software modalities that are readily available. Based on our findings, we recommend applying torque in external rotation to the foot to optimize the detection of subtalar joint instability.
MRI‐based synthetic CT shows equivalence to conventional CT for the morphological assessment of the hip joint
Authors: Florkow Mateusz C. , Willemsen Koen , Zijlstra Frank , Foppen Wouter , van der Wal Bart C. H. , van der Voort van Zyp Jochem R. N. , Viergever Max A. , Castelein René M. , Weinans Harrie , van Stralen Marijn , Sakkers Ralph J. B. , Seevinck Peter R.
Published: July 2021

This study evaluated the accuracy of synthetic computed tomography (sCT), as compared to CT, for the 3D assessment of the hip morphology. Thirty male patients with asymptomatic hips, referred for magnetic resonance (MR) imaging and CT, were included in this retrospective study. sCT images were generated from three‐dimensional radiofrequency‐spoiled T1‐weighted multi‐echo gradient‐echo MR images using a commercially available deep learning‐enabled software and were compared with CT images through mean error and surface distance computation and by means of eight clinical morphometric parameters relevant for hip care. Parameters included center‐edge angle (CEA), sharp angle, acetabular index, extrusion index, femoral head center‐to‐midline distance, acetabular version (AV), and anterior and posterior acetabular sector angles. They were measured by two senior orthopedic surgeons and a radiologist in‐training on CT and sCT images. The reliability and agreement of CT‐ and sCT‐based measurements were assessed using intraclass correlation coefficients (ICCs) for absolute agreement, Bland–Altman plots, and two one‐sided tests for equivalence. The surface distance between CT‐ and sCT‐based bone models were on average submillimeter. CT‐ and sCT‐based measurements showed moderate to excellent interobserver and intraobserver correlation (0.56 < ICC < 0.99). In particular, the inter/intraobserver agreements were good for AV (ICC > 0.75). For CEA, the intraobserver agreement was good (ICC > 0.75) and the interobserver agreement was moderate (ICC > 0.69). Limits of agreements were similar between intraobserver CT and intermodal measurements. All measurements were found statistically equivalent, with average intermodal differences within the intraobserver limits of agreement. In conclusion, sCT and CT were equivalent for the assessment of the hip joint bone morphology.
Optimizing outcomes of ACL surgery—Is autograft reconstruction the only reasonable option?
Authors: Murray Martha M.
Published: July 2021

Anterior cruciate ligament (ACL) injuries occur at a high frequency in the United States with approximately 400,000 ACL reconstructions being performed each year. While ACL reconstruction is our current gold standard of treatment, it does not restore joint motion, or prevent the premature development of posttraumatic osteoarthritis (PTOA) in many patients. Thus, new treatments for an ACL injury, which are less invasive and minimize patient morbidity, including cartilage damage, are highly desirable. We have used a tissue‐engineered approach to stimulate ligament healing, to improve upon current treatment options. In this review, we describe and discuss our work moving a tissue engineering strategy from the concept to bench, preclinical, clinical trials and ultimately FDA 510(k) de Novo approval, providing clinicians and patients with a viable alternative to ACL reconstruction.
State of the mineralized tissue comprising the femoral ACL enthesis in young women with an ACL failure
Authors: Patton Daniella M. , Ochocki Danielle N. , Martin Colin T. , Casden Michael , Jepsen Karl J. , Ashton‐Miller James A. , Wojtys Edward M. , Schlecht Stephen H.
Published: July 2021

Despite poor graft integration among some patients that undergo an anterior cruciate ligament (ACL) reconstruction, there has been little consideration of the bone quality into which the ACL femoral tunnel is drilled and the graft is placed. Bone mineral density of the knee decreases following ACL injury. However, trabecular and cortical architecture differences between injured and non‐injured femoral ACL entheses have not been reported. We hypothesize that injured femoral ACL entheses will show significantly less cortical and trabecular mass compared with non‐injured controls. Femoral ACL enthesis explants from 54 female patients (13–25 years) were collected during ACL reconstructive surgery. Control explants (n = 12) were collected from seven donors (18−36 years). Injured (I) femoral explants differed from those of non‐injured (NI) controls with significantly less (p ≤ 0.001) cortical volumetric bone mineral density (vBMD) (NI: 736.1–867.6 mg/cm3; I: 451.2–891.9 mg/cm3), relative bone volume (BV/TV) (NI: 0.674–0.867; I: 0.401–0.792) and porosity (Ct.Po) (NI: 0.133–0.326; I: 0.209–0.600). Injured explants showed significantly less trabecular vBMD (p = 0.013) but not trabecular BV/TV (p = 0.314), thickness (p = 0.412), or separation (p = 0.828). We found significantly less cortical bone within injured femoral entheses compared to NI controls. Lower cortical and trabecular bone mass within patient femoral ACL entheses may help explain poor ACL graft osseointegration outcomes in the young and may be a contributor to the osteolytic phenomenon that often occurs within the graft tunnel following ACL reconstruction.
Identifying alternative antibiotics that elute from calcium sulfate beads for treatment of orthopedic infections
Authors: Levack Ashley E. , Turajane Kathleen , Driscoll Daniel A. , Yang Xu , Miller Andy O. , Bostrom Mathias P. , Wellman David S. , Carli Alberto V.
Published: July 2021

There has been increasing interest in the use of a synthetic absorbable calcium sulfate (CaSO4) for local antibiotic delivery in orthopaedic infections. The purpose of this study was to quantify elution kinetics of six antibiotics (amikacin, meropenem, fosfomycin, minocycline, cefazolin, and dalbavancin) from a clinically relevant CaSO4 bead model and compare elution and antimicrobial activity to the current clinical gold standards: vancomycin and tobramycin. Antibiotic‐loaded synthetic CaSO4 beads were immersed in phosphate buffered saline and incubated at 37°C. Eluent was harvested at eight time points over 28 days. Antibiotic concentrations were measured by high performance liquid chromatography to quantify elution rates. CaSO4 beads demonstrated burst release kinetics. Dalbavancin, cefazolin, and minocycline all demonstrated similar elution profiles to vancomycin. Amikacin and meropenem demonstrated favorable elution profiles and durations of above‐minimum inhibitory concentration when compared to tobramycin.

Clinical Significance: This study provides important novel data regarding the utility of amikacin, meropenem and dalbavancin as alternative choices to place in CaSO4 carriers when treating orthopaedic infections.
MRI‐­ and CT‐­based metrics for the quantification of arthroscopic bone resections in femoroacetabular impingement syndrome
Authors: Guidetti Martina , Malloy Philip , Alter Thomas D. , Newhouse Alexander C. , Espinoza Orías Alejandro A. , Inoue Nozomu , Nho Shane J.
Published: July 2021

The purpose of this in vitro study was to quantify the bone resected from the proximal femur during hip arthroscopy using metrics generated from magnetic resonance imaging (MRI) and computed tomography (CT) reconstructed three­dimensional (3D) bone models. Seven cadaveric hemi­pelvises underwent both a 1.5 T MRI and CT scan before and following an arthroscopic proximal femoral osteochondroplasty. The images from MRI and CT were segmented to generate 3D proximal femoral surface models. A validated 3D‐­3D registration method was used to compare surface‐­to­‐surface distances between the 3D models before and following surgery. The new metrics of maximum height, mean height, surface area and volume, were computed to quantify bone resected during osteochondroplasty. Stability of the metrics across imaging modalities was established through paired sample t‐­tests and bivariate correlation. Bivariate correlation analyses indicated strong correlations between all metrics (r = 0.728­–0.878) computed from MRI and CT derived models. There were no differences in the MRI‐ and CT‐based metrics used to quantify bone resected during femoral osteochondroplasty. Preoperative­ and postoperative MRI and CT derived 3D bone models can be used to quantify bone resected during femoral osteochondroplasty, without significant differences between the imaging modalities.
Meta‐regression methods to characterize evidence strength using meaningful‐effect percentages conditional on study characteristics
Authors: Mathur Maya B. , VanderWeele Tyler J.
Published: July 2021

Meta‐regression analyses usually focus on estimating and testing differences in average effect sizes between individual levels of each meta‐regression covariate in turn. These metrics are useful but have limitations: they consider each covariate individually, rather than in combination, and they characterize only the mean of a potentially heterogeneous distribution of effects. We propose additional metrics that address both limitations. Given a chosen threshold representing a meaningfully strong effect size, these metrics address the questions: “For a given joint level of the covariates, what percentage of the population effects are meaningfully strong?” and “For any two joint levels of the covariates, what is the difference between these percentages of meaningfully strong effects?” We provide semiparametric methods for estimation and inference and assess their performance in a simulation study. We apply the proposed methods to meta‐regression analyses on memory consolidation and on dietary behavior interventions, illustrating how the methods can provide more information than standard reporting alone. To facilitate implementing the methods in practice, we provide reporting guidelines and simple R code.
The finite subsets and the permutations with finitely many non‐fixed points of a set
Authors: Nuntasri Jukkrid , Panasawatwong Supakun , Vejjajiva Pimpen
Published: July 2021

We write and for the cardinalities of the set of finite subsets and the set of permutations with finitely many non‐fixed points, respectively, of a set which is of cardinality . In this paper, we investigate relationships between and for an infinite cardinal in the absence of the Axiom of Choice. We give conditions that make and comparable as well as give related consistency results.
Impulse Control Disorders in Parkinson's Disease: Has COVID‐19 Related Lockdown Been a Trigger?
Authors: Rábano‐Suárez Pablo , Martínez‐Fernández Raúl , Natera‐Villalba Elena , Pareés Isabel , Martínez‐Castrillo Juan Carlos , Alonso‐Canovas Araceli
Published: July 2021

Background

Parkinson's disease (PD) patients, especially those on dopamine agonists (DA), are at risk of impulse control disorders (ICD). Little attention has been paid to the influence of environmental factors.

Cases

Retrospective analysis of consecutive PD patients seen in our outpatient Movement Disorders Clinic during 2 months (September–November 2020) to explore the frequency of ICD during the preceding 2‐month lockdown period, and comparison with an equivalent control group (September–November 2019). Among 114 patients assessed, 15 (13%) presented ICD during the lockdown, versus 6 (4.5%, P 0.02) in the control group. When analyzing only patients on DA, ICD occurrence increased to 31% (vs. 9.6% pre‐lockdown, P 0.026). ICD during lockdown required drug regime adjustment in 80% (vs. 16.7% pre‐lockdown, P 0.014).

Conclusion

During COVID‐19 lockdown, the occurrence of ICD in PD patients taking DA was higher than expected, and with increased severity. Environmental stressors may play a role in ICD presentation in vulnerable patients.
Spot on: C‐H‐Aktivierung
Authors: van Gemmeren Manuel
Published: July 2021

Kohlenstoff‐Wasserstoff‐Bindungen mit Übergangsmetallen zu aktivieren ermöglicht, funktionelle Gruppen und Substituenten in ansonsten inerten Positionen eines Moleküls einzuführen. Dies eignet sich zur Naturstoffsynthese und zur Funktionalisierung in späten Synthesestadien. Dozentenpreisträger Manuel van Gemmeren entwickelt solche Methoden.
Hauptgruppenelementbasierte Lewis‐Supersäuren
Authors: Hanf Schirin
Published: July 2021

Lange haben Bor‐ und Aluminiumverbindungen die Chemie der Lewis‐Supersäuren dominiert. Inzwischen bearbeiten Forschungsgruppen auch Lewis‐Supersäuren aus den Elementen der Gruppen 13 bis 15. Eine Übersicht über deren Reaktivität und Anwendungsgebiete.
Binationale Promotion: Grenzen überschreiten
Authors: Hoffmann Jonas
Published: July 2021

In einem binationalen Promotionsverfahren können Nachwuchsforschende wie der Autor dieses Beitrags an zwei Universitäten in zwei Ländern promovieren.
Borsten und Abfallbeutel
Authors: Bulmahn Maren
Published: July 2021

Eine Broschüre zeigt Steckbriefe von Produkten, für die es sinnvoll ist, dass sie sich biologisch abbauen lassen.
Vertical alignment of carbon fibers under magnetic field driving to enhance the thermal conductivity of silicone composites
Authors: Ma Haoqi , Gao Bin , Wang Meiyu , Feng Yakai
Published: July 2021

Thermal interface materials are expected to have efficient heat conduction pathways to achieve excellent thermal conductivity under the premise of low filler filling. It is a facile strategy to build thermal pathways through filler orientation technology under external force. Herein, iron oxide nanoparticles (Fe3O4) were immobilized onto the surface of carbon fiber (CF) to prepare magnetic CF by polydopamine technology, and the oriented CF/polydimethylsiloxane composites (OCF/PDMS) were prepared through the vertically oriented cure of magnetized CF under an external magnetic field. Importantly, the thermal conductivity of OCF/PDMS reached up to 1.51 W m−1 K−1 when filling 20 wt% of CF@Fe3O4, which is 1.16 times of carbon fiber/polydimethylsiloxane composites and 5.59 times of pure PDMS matrix. In addition, OCF/PDMS also exhibits excellent tensile strength, elastic modulus and elongation at break. This strategy provides a promising attempt for the construction of thermal interface materials with high thermal conductivity and excellent mechanical properties.
CyDisCo production of functional recombinant SARS‐CoV‐2 spike receptor binding domain
Authors: Prahlad Janani , Struble Lucas R. , Lutz William E. , Wallin Savanna A. , Khurana Surender , Schnaubelt Andy , Broadhurst Mara J. , Bayles Kenneth W. , Borgstahl Gloria E. O.
Published: July 2021

The COVID‐19 pandemic caused by SARS‐CoV‐2 has applied significant pressure on overtaxed healthcare around the world, underscoring the urgent need for rapid diagnosis and treatment. We have developed a bacterial strategy for the expression and purification of a SARS‐CoV‐2 spike protein receptor binding domain (RBD) that includes the SD1 domain. Bacterial cytoplasm is a reductive environment, which is problematic when the recombinant protein of interest requires complicated folding and/or processing. The use of the CyDisCo system (cytoplasmic disulfide bond formation in E. coli) bypasses this issue by pre‐expressing a sulfhydryl oxidase and a disulfide isomerase, allowing the recombinant protein to be correctly folded with disulfide bonds for protein integrity and functionality. We show that it is possible to quickly and inexpensively produce an active RBD in bacteria that is capable of recognizing and binding to the ACE2 (angiotensin‐converting enzyme) receptor as well as antibodies in COVID‐19 patient sera.
Opening a new era of investigating unreachable cliff flora using smart UAVs
Authors: Zhou Hui , Zhu Jiaxing , Li Jiaxiang , Xu Yongfu , Li Qian , Yan Enping , Zhao Shaohua , Xiong Yujiu , Mo Dengkui
Published: July 2021

Cliff ecosystems are considered the ‘Last Unknown’ because cliffs may host ancient and unique species that are located in extremely hostile environments and are difficult to reach. However, comprehensive and systematic information and databases of cliff flora are unavailable; and obtaining information on these undisturbed ecosystems and cliff flora is fundamental and is of high priority for botanists. We present the first systematically sampled expert‐verified checklist of cliff flora from the ground to the top of cliffs in these harsh environments based on high‐resolution visible imagery captured with close‐range photogrammetry by a smart remote‐controlled unmanned aerial system (UAS). Using approximately 9200 records retrieved from high‐resolution images of 197 cliffs in the Wulingyuan global cultural heritage area, a mid‐subtropical region in China, we identified 267 vascular plant species, 140 genera and 58 families, excluding herbaceous plants. The maximum diversity was attributable to a few dominant families and genera, and most of the genera and families were represented by only a few species. Our findings highlight the unique floristic patterns as well as morphology on these cliffs that warrant further study and the potential for the use of a smart UAS to investigate cliff flora at large and global scales.
Using camera traps to estimate ungulate abundance: a comparison of mark–resight methods
Authors: Taylor Jace C. , Bates Steven B. , Whiting Jericho C. , McMillan Brock R. , Larsen Randy T.
Published: July 2021

Many global wildlife populations are experiencing unprecedented declines. Estimates of population abundance are needed to effectively manage common species and to conserve vulnerable species. Camera traps have advanced as wildlife monitoring tools for ungulates and can provide improved methods of estimating population abundance. Little is known, however, about how camera traps set for ungulates compare with traditional methods (e.g., ground and aerial surveys) used simultaneously. From 2012 to 2014, we captured and radio collared 34 female and 32 male bighorn sheep (Ovis canadensis) in a closed population in Utah, USA. Each collar had a unique letter and number combination. We then estimated number of young, females and yearlings, males and population abundance using multiple methods simultaneously: helicopter surveys, resight surveys performed from the ground, camera trap surveys using marked but not individually identifiable individuals and camera trap surveys using marked and individually identifiable animals. All methods estimated similar abundance. Across years, ages and sexes, however, camera trap surveys produced the most consistent and precise estimates of abundance for adult females and yearlings, lambs and the population. That method was less intrusive and safer than helicopter surveys. Our results indicate that camera trap surveys using photographs of marked animals in which the majority of the population visits a specific resource can produce precise estimates of abundance that are safer, as well as less intrusive and expensive than traditional methods. Using camera traps also creates a permanent record of photographs that can be archived and reanalyzed to answer future ecological and population questions. Finally, this method of estimating abundance can be used in other areas with ungulates that congregate around resources (e.g., watering sites or mineral licks).
Crowdsourcing usage, task assignment methods, and crowdsourcing platforms: A systematic literature review
Authors: Zhen Ying , Khan Abdullah , Nazir Shah , Huiqi Zhao , Alharbi Abdullah , Khan Sulaiman
Published: July 2021

Crowdsourcing is simply the outsourcing of different tasks or work to a diverse group of individuals in an open call for the purpose of utilizing human intelligence. Crowdsourcing nowadays used to support and enhance software engineering in different aspects. In this proposed study, a systematic literature review was conducted for the last 10 years from 2010 to 2019. During the filtering process, a total of 120 relevant studies have been identified, and then the most relevant 70 studies were selected to include as part of the current study. The proposed study shows the effect of task assignment in crowdsourcing, such as if a task is assigned to an appropriate worker or an inappropriate worker, what will be the consequences. The study also highlights crowdsourcing usage in the field of software engineering. All the existing task assignment methods used for assigning the task to make crowdsourcing activity more effective have been analyzed. The study also highlights all the available crowdsourcing platforms used for a variety of task to be performed. The study concludes by identifying the issues regarding the task assignment and to specify the methods for enhancement in the assignment of tasks for future research in crowdsourcing.
MXene and MoS3−x Coated 3D‐Printed Hybrid Electrode for Solid‐State Asymmetric Supercapacitor
Authors: Ghosh Kalyan , Pumera Martin
Published: July 2021

Recently, 2D nanomaterials such as transition metal carbides or nitrides (MXenes) and transition metal dichalcogenides (TMDs) have attracted ample attention in the field of energy storage devices specifically in supercapacitors (SCs) because of their high metallic conductivity, wide interlayer spacing, large surface area, and 2D layered structures. However, the low potential window (ΔV ≈ 0.6 V) of MXene e.g., Ti3C2Tx limits the energy density of the SCs. Herein, asymmetric supercapacitors (ASCs) are fabricated by assembling the exfoliated Ti3C2Tx (Ex‐Ti3C2Tx) as the negative electrode and transition metal chalcogenide (MoS3−x) coated 3D‐printed nanocarbon framework (MoS3−x@3DnCF) as the positive electrode utilizing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte, which provides a wide ΔV of 1.6 V. The Ex‐Ti3C2Tx possesses wrinkled sheets which prevent the restacking of Ti3C2Tx 2D layers. The MoS3−x@3DnCF holds a porous structure and offers diffusion‐controlled intercalated pseudocapacitance that enhances the overall capacitance. The 3D printing allows a facile fabrication of customized shaped MoS3−x@3DnCF electrodes. Employing the advantages of the 3D‐printing facilities, two different ASCs, such as sandwich‐ and interdigitated‐configurations are fabricated. The customized ASCs provide excellent capacitive performance. Such ASCs combining the MXene and electroactive 3D‐printed nanocarbon framework can be used as potential energy storage devices in modern electronics.
Effect of Pressure on Second Dendrite Arm Spacing and Columnar to Equiaxed Transition of 30Cr15Mo1N Ingot
Authors: He Zhi-Yu , Li Hua-Bing , Ni Zhuo-Wen , Zhu Hong-Chun , Jiang Zhou-Hua , Feng Hao , Mao Dong-Sheng
Published: July 2021

In order to clarify the effects of pressure on the second dendrite arm spacing (SDAS) and columnar to equiaxed transition (CET) of 30Cr15Mo1N ingot, changes in solidification parameters, cooling rate and columnar dendrite tip growth rate with pressure have been investigated. A formula is proposed to obtain the quantitative correlation between pressure (≤ 2 MPa) and interfacial heat transfer coefficient: . And then, A formula is proposed to calculate SDAS with cooling rate: , which is applicable for low pressure (≤2 MPa) and low cooling rate (0.4–1.4 K · s−1). There are tiny changes in solidification mode and equilibrium partition coefficient with increasing pressure from 0.5 to 2 MPa. Therefore, increasing pressure refines SDAS mainly by enlarging cooling rate. Pressurization can increase columnar dendrite tip growth rate by enhancing undercooling, and inhibit nucleation and growth of equiaxed dendrite by decreasing constitutional undercooling. It results that the distance between the center of ingot and CET position decreased with increasing pressure from 0.5 to 2 MPa. And a formula is proposed to calculate columnar dendrite tip growth rate with undercooling: , which is suitable for low pressure (≤2 MPa).
Effect of fiber type and content on the mechanical properties and shrinkage characteristics of alkali‐activated kaolin
Authors: Matalkah Faris , Ababneh Ayman , Aqel Ruba
Published: July 2021

An experimental study was carried out to evaluate the effect of several fibers on the mechanical properties, drying shrinkage, and microstructural characteristics of alkali‐activated kaolin binders. Four different types of fibers were evaluated in this study: polypropylene (PP) fiber, discontinuous structural synthetic (DSS) fiber, brass‐coated steel (BCS) fiber, and hooked steel (HS) fiber. The fibers were added to the alkali‐activated kaolin at a volume fraction of 0%, 0.5%, 1%, and 1.5%. The experimental results revealed that the compressive strength of alkali‐activated binder increased by about 60% when 1% of PP fiber is added, whereas the addition of HS fiber substantially enhanced the flexural strength (more than 200% when 1.5% fiber volume content is added). BCS and HS fibers were found to more effective compared to PP and DSS fibers in maintaining the binder integrity prior to high temperatures exposure. All fiber‐reinforced alkali‐activated composites yielded lower drying shrinkage (≤450 microstrains), where HS fiber was found to effectively prevent the shrinkage of the binder (≤60 microstrains). The microstructural investigation revealed good interfacial bonding between the alkali‐activated binder and the fibers.
Operator complexity: a journey to the edge of Krylov space
Authors: Rabinovici E. , Sánchez-Garrido A. , Shir R. , Sonner J.
Published: July 2021

Abstract

Heisenberg time evolution under a chaotic many-body Hamiltonian H transforms an initially simple operator into an increasingly complex one, as it spreads over Hilbert space. Krylov complexity, or ‘K-complexity’, quantifies this growth with respect to a special basis, generated by H by successive nested commutators with the operator. In this work we study the evolution of K-complexity in finite-entropy systems for time scales greater than the scrambling time ts> log(S). We prove rigorous bounds on K-complexity as well as the associated Lanczos sequence and, using refined parallelized algorithms, we undertake a detailed numerical study of these quantities in the SYK4 model, which is maximally chaotic, and compare the results with the SYK2 model, which is integrable. While the former saturates the bound, the latter stays exponentially below it. We discuss to what extent this is a generic feature distinguishing between chaotic vs. integrable systems.
A master exceptional field theory
Authors: Bossard Guillaume , Kleinschmidt Axel , Sezgin Ergin
Published: July 2021

Abstract

We construct a pseudo-Lagrangian that is invariant under rigidE11and transforms as a density underE11generalised diffeomorphisms. The gauge-invariance requires the use of a section condition studied in previous work onE11exceptional field theory and the inclusion of constrained fields that transform in an indecomposableE11-representation together with theE11coset fields. We show that, in combination with gauge-invariant andE11-invariant duality equations, this pseudo-Lagrangian reduces to the bosonic sector of non-linear eleven-dimensional supergravity for one choice of solution to the section condi- tion. For another choice, we reobtain theE8exceptional field theory and conjecture that our pseudo-Lagrangian and duality equations produce all exceptional field theories with maximal supersymmetry in any dimension. We also describe how the theory entails non-linear equations for higher dual fields, including the dual graviton in eleven dimensions. Furthermore, we speculate on the relation to theE10sigma model.
Genome-wide association studies: assessing trait characteristics in model and crop plants
Authors: Alseekh Saleh , Kostova Dimitrina , Bulut Mustafa , Fernie Alisdair R.
Published: July 2021

GWAS involves testing genetic variants across the genomes of many individuals of a population to identify genotype–phenotype association. It was initially developed and has proven highly successful in human disease genetics. In plants genome-wide association studies (GWAS) initially focused on single feature polymorphism and recombination and linkage disequilibrium but has now been embraced by a plethora of different disciplines with several thousand studies being published in model and crop species within the last decade or so. Here we will provide a comprehensive review of these studies providing cases studies on biotic resistance, abiotic tolerance, yield associated traits, and metabolic composition. We also detail current strategies of candidate gene validation as well as the functional study of haplotypes. Furthermore, we provide a critical evaluation of the GWAS strategy and its alternatives as well as future perspectives that are emerging with the emergence of pan-genomic datasets.
Mundgesundheitskompetenz von Menschen mit Migrationshintergrund – Erste Auswertungen der MuMi-Studie
Authors: Spinler Kristin , Weil Marie-Theres , Valdez Richelle , Walther Carolin , Dingoyan Demet , Seedorf Udo , Heydecke Guido , Lieske Berit , Kofahl Christopher , Aarabi Ghazal
Published: July 2021

Hintergrund

Erste Studien heben den Migrationshintergrund von Menschen in Deutschland als eigenständigen Risikofaktor für eine mangelhafte Mundgesundheit hervor. Ein wichtiger Einflussfaktor könnte hierbei eine niedrigere Mundgesundheitskompetenz von Menschen mit Migrationshintergrund sein.

Ziel

In diesem Artikel werden Ergebnisse zur Mundgesundheitskompetenz und Mundgesundheit aus der MuMi-Studie (Förderung der Mundgesundheit und Mundgesundheitskompetenz von Menschen mit Migrationshintergrund) vorgestellt.

Material und Methoden

In 40 Hamburger Zahnarztpraxen wurden von Patient*innen mit und ohne Migrationshintergrund Daten zu Soziodemografie, Mundgesundheit und Mundgesundheitskompetenz erhoben. Der Zusammenhang zwischen Mundgesundheitskompetenz und Mundgesundheit wurde mittels logistischer Regressionen berechnet. Potenzielle Einflussfaktoren wurden schrittweise in die Berechnungsmodelle eingefügt.

Ergebnisse

Die Gruppen mit und ohne Migrationshintergrund unterschieden sich signifikant hinsichtlich ihrer Mundgesundheitskompetenz und ausgewählter klinischer Parameter ihrer Mundgesundheit (Approximalraum-Plaqueindex und Kariessanierungsgrad). Die logistischen Regressionsanalysen zeigen einen deutlichen Zusammenhang zwischen Migrationshintergrund, Mundgesundheitskompetenz und Mundhygiene auch unter Berücksichtigung von Bildung und sozioökonomischem Status.

Diskussion

Der Migrationshintergrund stellt einen eigenständigen Indikator für eine niedrige Mundgesundheitskompetenz und schlechtere Mundgesundheit dar. Dieser Umstand sollte stärker in den Fokus von Forschung und politischen Entscheidungen rücken, um die mundgesundheitliche Chancengleichheit in Deutschland zu erhöhen.
Validation of the in vitro comet assay for DNA cross-links and altered bases detection
Authors: Muruzabal Damián , Sanz-Serrano Julen , Sauvaigo Sylvie , Treillard Bertrand , Olsen Ann-Karin , López de Cerain Adela , Vettorazzi Ariane , Azqueta Amaya
Published: July 2021

Mechanistic toxicology is gaining weight for human health risk assessment. Different mechanistic assays are available, such as the comet assay, which detects DNA damage at the level of individual cells. However, the conventional alkaline version only detects strand breaks and alkali-labile sites. We have validated two modifications of the in vitro assay to generate mechanistic information: (1) use of DNA-repair enzymes (i.e., formamidopyrimidine DNA glycosylase, endonuclease III, human 8-oxoguanine DNA glycosylase I and human alkyladenine DNA glycosylase) for detection of oxidized and alkylated bases as well as (2) a modification for detecting cross-links. Seven genotoxicants with different mechanisms of action (potassium bromate, methyl methanesulfonate, ethyl methanesulfonate, hydrogen peroxide, cisplatin, mitomycin C, and benzo[a]pyrene diol epoxide), as well as a non-genotoxic compound (dimethyl sulfoxide) and a cytotoxic compound (Triton X-100) were tested on TK-6 cells. We were able to detect with high sensitivity and clearly differentiate oxidizing, alkylating and cross-linking agents. These modifications of the comet assay significantly increase its sensitivity and its specificity towards DNA lesions, providing mechanistic information regarding the type of damage.
Correction to: Health-related quality of life after open and robot-assisted radical prostatectomy in low- and intermediate-risk prostate cancer patients: a propensity score-matched analysis
Authors: Kretschmer Alexander , Bischoff Robert , Chaloupka Michael , Jokisch Friedrich , Westhofen Thilo , Weinhold Philipp , Strittmatter Frank , Becker Armin , Buchner Alexander , Stief Christian G.
Published: July 2021

A correction to this paper has been published: https://doi.org/10.1007/s00345-021-03750-1
On the determination of the dissipation rate of turbulence kinetic energy
Authors: Lewis James M. , Koster Timothy W. , LaRue John C.
Published: July 2021

The paper presents a comparison of the dissipation rate obtained from numerical differentiation of the time-resolved velocity, analog differentiation of the hot-wire signal, integration of the velocity derivative spectra obtained from the velocity spectra, and the application of a power decay law. Hot-wire measurements downstream of an active-grid provide the time-resolved velocity with a Taylor Reynolds number in the range of 200–470, turbulence intensities in the range of 5.8–11%, and nominal mean velocities of 4, 6, and 8 m s$$^{-1}$$

-
1

. The dissipation rate calculated using a ninth-order central-difference scheme differs at most by $${\pm }$$
±
 4% from the value obtained by analog differentiation. For comparison, a 23rd-order central-difference scheme offers negligible (0.02%) difference relative to the ninth-order scheme. Correction for an apparent uncertainty in the calibration of the analog differentiator reduces the difference to $${\pm }$$
±
 2.5%. In contrast, integration of the velocity derivative spectra obtained from the velocity spectra leads to a dissipation rate 14–45% larger than the corresponding values obtained using analog differentiation. Results obtained from the application of a power decay law of turbulence kinetic energy with a nonzero virtual origin to determine the dissipation rate deviate by 1.7%, 1.6%, and 3.6% relative to the corresponding values obtained from the analog differentiator based on the ensemble average of downstream locations with a $${\pm }$$
±
5.6% scatter about the ensemble average.

Graphic abstract