bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐confidence as a predictor of senior dental student academic success
Authors: Meisha Dalia E. , Al‐dabbagh Raghad A.
Published: April 2021

Purpose

Noncognitive indicators, such as personality type and self‐confidence, have been used as predictors of achievement. Accordingly, we investigated whether self‐confidence in clinical skills predicts academic success among predoctoral senior dental students.

Methods

Two consecutive cohorts (N = 336) of predoctoral senior dental students were invited to rate their self‐confidence in clinical procedures twice: at the beginning and at the end of the academic year. Academic performance in clinical assessments was retrieved from scholastic records. Multiple linear regression models were constructed to predict clinical assessment grades using self‐confidence scores as a predictor after controlling for possible confounders.

Results

Self‐confidence scores in clinical procedures were positively correlated with clinical and academic performance. Self‐confidence in clinical procedures and grade point averages were consistent predictors of student performance. Additionally, self‐confidence had improved at the end of the senior year (p = 0.003).

Conclusions

Self‐confidence in clinical procedures was a predictor of future clinical success. Therefore, fostering and nurturing the confidence of students and integrating self‐confidence assessment into the curricula at relevant timepoints should be a goal in dental education. Moreover, self‐assessment of confidence in clinical skills could be used to guide students and graduates in developing their own personal development plan.
Residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and its metabolites during tea growing and tea brewing
Authors: Bai Aijuan , Chen Ang , Chen Wuying , Liu Shaowen , Luo Xiangwen , Liu Yong , Zhang Deyong
Published: April 2021

BACKGROUND

Tolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup.

RESULTS

An effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1–106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first‐order kinetics models with half‐lives of 4.30–7.33 days and 4.65–5.50 days, respectively. With application amounts of 112.5–168.75 g a.i. ha–1 once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg−1, respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4–2.3% and 93.7–98.1%, respectively.

CONCLUSION

Tolfenpyrad and dinotefuran in tea were easily degraded. The RQc and RQa values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.
Breeding Habitat Associations of Eastern Whip‐Poor‐Wills in Managed Forests
Authors: SPILLER KIMBERLY J. , KING DAVID I.
Published: April 2021

Populations of the eastern whip‐poor‐will (Antrostomus vociferus; whip‐poor‐will) have declined throughout most of its range, making it a species of high conservation concern in nearly every state and province where it occurs. Researchers have reported whip‐poor‐wills are associated with forest stands with open canopies, and thus silviculture may be a promising means for promoting their populations, yet the ecological literature does not quantify fine‐scale habitat relationships capable of assisting with silviculture prescriptions. Our objective was to quantify the associations between whip‐poor‐wills, canopy openness, and other vegetation characteristics to provide managers with guidance for whip‐poor‐will management. Based on prior research, we hypothesized that whip‐poor‐wills may be associated with intermediate levels of canopy retention and that their numbers would also be affected by understory characteristics. We surveyed whip‐poor‐wills with point counts in managed forest at the Fort Drum Army installation in New York, USA, during 2015 and 2016 and collected vegetation measurements at each point count location to relate whip‐poor‐will occupancy with vegetation structure and composition. Whip‐poor‐will occupancy was strongly related to intermediate levels of basal area, with peak occupancy at 13.8 m2/ha, a value that corresponds to forest denser than most shrublands but more open than closed‐canopy forest. Whip‐poor‐will presence was negatively related to understory height, which is consistent with prior studies. These findings provide managers with quantitative targets that can be used to increase or maintain whip‐poor‐will numbers and abundance of other disturbance‐associated species similarly unable to persist in unmanaged forests stands. © 2021 The Wildlife Society.
All‐Dielectric Fiber Meta‐Tip Enabling Vortex Generation and Beam Collimation for Optical Interconnect
Authors: Zhou Changyi , Lee Woo‐Bin , Gao Song , Li Hongliang , Park Chul‐Soon , Choi Duk‐Yong , Lee Sang‐Shin
Published: April 2021

“Lab‐on‐fiber” technology, which combines the unique merits of optical fibers with nanophotonic platforms, has received significant investigation due to its profound ability to control light at the nanoscale, which has significantly boosted the functionalities of conventional fibers. Previous plasmonic‐based fiber meta‐tips (FMTs) have been inhibited by the intrinsic ohmic losses of the metallic structures, resulting in limited light manipulation efficiency. In addition, to become prominent candidates for integrated photonics, their functional diversity needs to be enhanced. In this study, an FMT constructed by tethering an all‐dielectric metasurface to a single‐mode fiber for bifunctional light manipulation is implemented. Distinct light manipulation, including vortex generation and beam collimation, is executed by tailoring the phase profiles encoded in the metasurface for transverse electric and transverse magnetic polarized light. To build the proposed FMT, a polarization‐selective metasurface is first created via lithography nanofabrication and then attached to an optical fiber with the aid of a vision system. Moreover, as a proof‐of‐concept, the feasibility of exploiting the established FMT for applications such as optical interconnects is demonstrated. The resulting fiber optics and metasurface‐based meta‐tip represent a major breakthrough in the lab‐on‐fiber technology roadmap for applications such as optical communication, optical trapping, and biological sensing.
Research Progress of All Organic Polymer Dielectrics for Energy Storage from the Classification of Organic Structures
Authors: Luo Jiaming , Mao Jiale , Sun Wenjie , Wang Shuang , Zhang Lei , Tian Liliang , Chen Yu , Cheng Yonghong
Published: April 2021

Dielectric films are the foundation of power electronic equipment for energy storage in capacitors. However, typical dielectric films exhibit undesirable energy storage density and thermal stability, limiting its further application in the advanced field. For both pure polymers and composites‐based dielectrics, the macromolecular matrix greatly determines the performances. This paper summarizes the research progress of all‐organic polymer materials for the dielectric application from the perspective of molecular structure design. Systematic comparisons on properties, including dielectric constant and dielectric loss, glass transition temperature, and energy density are given, expecting to inspire researchers to devote further efforts in this area. An outlook for the future of all‐polymer dielectrics is also presented.
Michael Polyaddition Approach Towards Sulfur Enriched Nonaromatic Polymers with Fluorescence‐Phosphorescence Dual Emission
Authors: Kausar Fahmeeda , Zhao Zihao , Yang Tianjia , Hou Wubeiwen , Li Yuxuan , Zhang Yongming , Yuan Wang Zhang
Published: April 2021

Nonaromatic photoluminescent polymers have attracted great attention due to their intriguing photophysical properties and promising implications in optoelectronic and biological areas. The luminescence from these nonconventional luminophores can be well rationalized by the clustering‐triggered emission mechanism. Sulfur, although as an n‐electron‐rich element with big radius, is not been widely utilized in construction of nonconventional luminophores despite of its potential competitiveness in nonaromatic photoluminescent polymers. Herein, the “click” type Michael polyaddition is utilized to construct sulfur‐bearing nonconventional luminophores, and two sulfur enriched nonaromatic poly(thioether sulfone)s (PES) are obtained, which demonstrate fluorescence‐phosphorescence dual emission. More investigations concerning the monomer of bis(vinylsulfonyl)methane are further proceeded to support acquired results. Finally, the application of explosive detection by the prepared PES is also conducted.
Toward Olefin Multiblock Copolymers with Tailored Properties: A Molecular Perspective
Authors: Mohammadi Yousef , Saeb Mohammad Reza , Penlidis Alexander , Jabbari Esmaiel , Stadler Florian J. , Zinck Philippe , Vivaldo‐Lima Eduardo
Published: April 2021

Recent progress in macromolecular reaction engineering has enabled the synthesis of sequence‐controlled polymers. The advent of olefin block copolymers (OBCs) via chain shuttling polymerization of ethylene with α‐olefins has opened new horizons for the synthesis of polyolefins having a dual character of thermoplastics and elastomers. Nevertheless, the use of two catalysts with different comonomer selectivities and a chain shuttling agent, dragging and dropping live chains between active catalyst centers, made precise tailoring of OBCs microstructure containing hard and soft units a feasible challenge. This work discusses the possibility of predicting properties of OBCs from its simulated molecular patterns. The microstructural characteristics of OBCs are discussed in terms of topology‐related and property‐related features. An intelligent tool, which combines the benefits of kinetic Monte Carlo simulation and artificial neural network modeling, is used to explore the connection between polymerization recipe (catalyst composition, ethylene to 1‐octene monomer ratio, and chain shuttling agent level) and topology‐related as well as property‐related microstructural features. The properties of target OBCs are reflected in the hard block percent, the number of 1‐octene units in the copolymer chains, and the longest ethylene sequence length of the hard and soft segments.
Cluster based nonuniform transformation field analysis: An efficient homogenization for inelastic heterogeneous materials
Authors: Ri Jun‐Hyok , Hong Hyon‐Sik , Ri Sung‐Gyu
Published: April 2021

In this article, the authors propose an efficient numerical homogenization method, the so‐called cluster based nonuniform transformation field analysis (NTFA), for inelastic heterogeneous material. The method enables to predict the effective properties directly from the local constitutive relations for microstructural phases of heterogeneous material, thus no requiring preliminary assumptions and any derivations for the effective constitutive relation as in the conventional NTFA. Evolution of plastic strain field is expressed by combination of nonuniform plastic strain modes evaluated from the nonlinear finite element analysis for training directions previously given and snapshot proper orthogonal decomposition. Eventually, microscopic stress and strain field are represented by scalar reduced variables and plastic strain modes. A simple maximization of minimum distance is proposed in order to choose uniformly distributed training directions on a unit sphere in the load space. Also, scalar reduced variables are directly determined from the integration of local constitutive relation, where material points are compressed into a number of clusters by clustering scheme. Thus, evolution of reduced variables is evaluated by the integration of local constitutive relation only in clusters. Numerical examples that consider material models followedJ2plasticity and pressure‐dependent non‐associated flow rule show that the current approach may predict the effective properties of inelastic heterogeneous material accurately and efficiently. It should be noted that the current approach can be available for material followed not only associated flow rule but also non‐associated flow one.
Unexpected decline in pediatric asthma morbidity during the coronavirus pandemic
Authors: Ulrich Lisa , Macias Charlie , George Ashish , Bai Shasha , Allen Elizabeth
Published: April 2021

The Coronavirus disease 2019 (COVID‐19) pandemic profoundly impacted health care utilization. We evaluated asthma‐related emergency department (ED) and inpatient health care utilization by a county‐specific Medicaid population, ages 2–18, during the COVID‐19 pandemic and compared it to utilization from a 3‐year average including 2017–2019. All‐cause ED utilization and asthma medication fill rates were evaluated during the same timeframes. Relative to the 2017–2019 3‐year average, cumulative asthma‐related ED visits from January through June decreased by 45.8% (p = .03) and inpatient admission rates decreased by 50.5% (p = .03). The decline in asthma‐related ED utilization was greater than the reduction of overall ED use during the same time period, suggesting that the decline involved factors specific to asthma and was not due solely to avoidance of health care facilities. Fill rates for asthma controller medications decreased during this time (p = .03) and quick relief medication fill rates had no significant change (p = .31). Multiple factors may have contributed to the decrease in acute asthma health care visits. Locally, decreased air pollution and viral exposures coincided with the “Stay‐at‐home” order in Ohio, and increased utilization of telehealth for assessment during exacerbations may have impacted outcomes. Identification of the cause of the decline in visit rates could spur new interventions to limit the need for ED and inpatient visits for asthma patients, leading to both economic and health‐associated benefits.
An adaptive finite‐time stable control law for manipulator robots with unknown parameters
Authors: Boutalbi Oussama , Benmahammed Khier , Boukezata Boualem
Published: April 2021

This article develops an adaptive finite‐time stable control algorithm for an accurate manipulation of robot arms considering unknown model parameters and external disturbances. First, a state‐dependent twisting control algorithm is developed for the robust manipulation of robot arms under the consideration of bounded unknown uncertainties conditions. The more challenging problem of robust control design under consideration of totally unknown dynamical parameters is investigated in a second stage by supporting the control law with a suitable online parameters estimator. The objective of the parameters estimator is to drive the vector of estimated parameters to some level that ensures the establishment of real second‐order sliding mode without overloading the discontinuous controller gains. This approach based on combining both techniques of robust and adaptive algorithms allows overcoming large levels of uncertainties while preserving a high level of tracking accuracy without exciting the unwanted phenomena of chattering. The system finite‐time stability is proven by using Lyapunov theory and the weighted homogeneity principle. Practical tests are reported to support theoretical study results.
Reading Anxiety, Engagement, and Achievement: A Comparison of Emergent Bilinguals and English Monolinguals in the Elementary Grades
Authors: Taboada Barber Ana , Klauda Susan Lutz , Wang Weimeng
Published: April 2021

Socioemotional constructs have been receiving increased attention as contributors to individuals’ literacy development. However, in comparison with positive socioemotional constructs, negative socioemotional constructs have been understudied with respect to their role in reading achievement in both emergent bilinguals (EBs) and English monolinguals (EMs). In the present study, we addressed this gap by examining reading anxiety in 339 EBs, who primarily spoke Spanish as their first language, and 178 EMs in grades 3–5, using a latent variable approach. We used structural equation modeling to form latent variables for reading anxiety, reading engagement, and reading achievement; compare latent variable means for EBs and EMs; and examine relations among the three focal constructs across the two language groups. The EBs and EMs showed similar levels of reading engagement, whereas the EBs showed a trend toward greater reading anxiety and statistically significantly lower reading achievement. Further, for both EBs and EMs, reading anxiety related negatively to reading achievement, both directly and indirectly through reading engagement, controlling for grade level. However, both the direct and indirect effects were greater for EBs than EMs. We interpret these results in the context of theoretical views of potential mechanisms linking reading anxiety and achievement, giving attention especially to the multidimensional nature of reading engagement. Based on the current findings and those of other research, we conclude by contending that reading anxiety merits increased scrutiny by researchers and educators endeavoring to understand and strengthen students’ reading achievement and socioemotional development during the elementary school years.
Cost‐efficient clinical studies with continuous time survival outcomes
Authors: Sandoval Grecio J. , Bebu Ionut , Lachin John M.
Published: April 2021

Time‐to‐event outcomes are common in clinical studies. For example, the time to a first major adverse cardiovascular event (MACE, defined as CVD death, nonfatal myocardial infarction, or stroke) is a commonly used outcome in cardiovascular outcome trials. Owing to the lengthy time frame and other factors, the high costs of conducting such studies has been identified as one of the major obstacles in conducting clinical trials in the United States. However, typical approaches for designing clinical trials with time‐to‐event outcomes do not consider study costs. For a given effect size (eg, hazard ratio), the power to detect differences between two groups is typically a function of the total number of events observed in the study. Therefore, the same level of power will be achieved based on various combinations of the total number of participants, length of enrollment and total follow‐up times, and group allocation probability. Herein, we provide a general framework for designing cost‐efficient studies comparing treatments with respect to continuous time‐to‐event outcomes. Among the various designs that achieve the desired level of power to detect a given effect size for a fixed type‐I error level, the optimal cost‐efficient design is the design that minimizes the expected total study cost. The method is general and can be used for Cox proportional hazards models or Aalen additive models, and under various recruitment and censoring assumptions. The proposed approach for designing cost‐efficient studies is illustrated for a Weibull time‐to‐event outcome with uniform recruitment and exponentially distributed censoring time. The case of an additive hazards model is also described. A Shiny web application implementation of the proposed methods is presented.
Throttle: An efficient approach to mitigate distributed denial of service attacks on software‐defined networks
Authors: Olakanmi Oladayo Olufemi , Odeyemi Kehinde Oluwasesan
Published: April 2021

Recently, different approaches such as statistical methods, genetic algorithm, hidden Markov, fuzzy logic, and blockchain have been adopted to detect and prevent distributed denial of services (DDoS) on software‐defined networks. However, most of these methods are not only complex but are also not adaptive, therefore adversaries with high computational resources can successfully launch DDoS attacks. In this work, we propose a security scheme capable of detecting DDoS attacks and throttling down traffics coming from the suspected hosts irrespective of their computational power. To achieve this, we develop three essential models for the scheme for predicting the volume of traffics from different hosts, determining the processing load of the network, and throttling down traffics from the suspicious hosts. We also develop a time tracking digital signature for determining the traffic pattern and sources of traffics. The simulation results show that the scheme is adaptive, efficient, and capable of detecting identity theft and resource exhaustion‐based DDoS attacks without denying services to a legitimate host.
Cyclic behavior of beams rehabilitated by reinforced concrete layers
Authors: Aykaç Sabahattin , Özbek Eray , Tankut Ali Tugrul
Published: April 2021

One of the well‐known methods for rehabilitation of insufficient or damaged reinforced concrete (RC) beams is to add a new RC layer. Although RC beams strengthened or repaired in this way have proved themselves under monotonic and repeated loads, the behavior under cyclic loads has not been adequately investigated yet. In this experimental research, beams were strengthened, repaired, or revived (repaired after heavy damage) using familiar RC layer adding methods and tested under reversal cyclic loading. Ten half‐scaled specimens, composed of columns and a beam, were prepared and 18 tests were conducted on these specimens. The obtained results showed that the strengthened and repaired beams mostly could achieve the monolithic behavior. However, sufficient ductility could not be maintained for the revived ones.
Supporting Young Students’ Word Study During the COVID‐19 Quarantine: ABC Scavenger Hunt
Authors: Chen Xiufang , Greenwood Kaitlyn
Published: April 2021

The COVID‐19 pandemic has dramatically affected U.S. schools since March 2020. K–12 schools have put in place various forms of remote learning to continue the education of students. In trying times like these, young students face unique unprecedented challenges. Often, they need parents’ and/or guardians’ supervision and guidance at home. How can teachers work with young students and their parents or guardians to ensure high‐quality and equitable teaching and learning during the COVID‐19 pandemic? More specifically, how can teachers support young students’ word study from home during trying times? An ABC scavenger hunt can be a great activity to support young students’ word study while bridging home and school and fostering a positive home learning environment. We share teaching tips developed by a first‐grade teacher over the past several months.
Retrospective analysis of hibernation parameters and breeding success in captive Vancouver Island marmots (Marmota vancouverensis): 1997–2018
Authors: Aymen Jessica , Freedman Megan , Delnatte Pauline , McAdie Malcolm , Beaufrère Hugues
Published: April 2021

Vancouver Island marmots (Marmota vancouverensis) have been managed in a captive‐breeding program since 1997, as in situ conservation efforts were insufficient in raising the numbers of this critically endangered species. The success of captive‐breeding programs centers on sustainable reproduction and survival of individuals once released into the wild. Captive‐born Vancouver Island marmots released to the wild have lower survival rates than their wild‐born counterparts; this difference may arise from compromised hibernation patterns or behaviors. Hibernation duration, body weight over the hibernation season, and reproductive success of captive Vancouver Island marmots were reviewed to assess the effect of these variables on each other. Data from a total of 1782 hibernations and 456 breeding attempts were compiled from 1997 to 2018. The number of winters spent in captivity, the origin of the marmot (captive‐born or wild‐born), the facility at which hibernation occurred, and the body weight all had a significant effect on hibernation length (all p < .001). Increased weight was associated with increased hibernation length by 0.4 ± 0.1 day/kg on average (p = .0015). Captive, wild‐born marmots hibernated for significantly longer than their captive‐born counterparts by about 21 ± 2 days (p < .001). The odds of successful breeding were significantly increased with increasing hibernation length by approximatively 20% for every 10 additional days of hibernation. This study provides information on the intrinsic relationship between body weight, reproduction, and hibernation in captive Vancouver Island marmots.
Dark matter annihilation into leptons through gravity portals
Authors: Sun Xudong , Dai Ben-Zhong
Published: April 2021

Abstract

Dark matter (DM) constitutes 85% of the matter in the Universe. However, its specific particle property is still unclear. The fundamentals of DM particles subject to gravitational interaction, and that the lepton excess in cosmic rays may originate from DM particles, inspired us to investigate DM particle properties beyond the standard model. We assume that a leptophilic SU(2) doublet exists in nature as the mediator connecting DM with visible leptons. Since general relativity is not renormalizable at the quantum level, it should be regarded as an effective field theory’s leading order term. One species of the next-to-leading-order term should be operators linear to the Ricci scalar and containing scalar fields, such as the Higgs field, scalar DM, or the newly introduced SU(2) scalar doublet. These operators can cause DM annihilation through gravity portals. We analyzed constraints from the cosmic antiproton flux, DM relic abundance, cosmic positron flux, cosmic microwave background, and direct detection experiments. The result shows that there is a vast parameter space that is compatible with current experiments. DM with a mass of electroweak scale is only allowed to annihilate into leptons. We further show that the purely gravitational DM better explains the DArk Matter Particle Explorer cosmic lepton excess. Our work provides a promising mechanism for DM particles to connect with standard model particles.
Hairy magnetic and dyonic black holes in the Standard Model
Authors: Bai Yang , Korwar Mrunal
Published: April 2021

Abstract

Spherically symmetric magnetic and dyonic black holes with a magnetic charge Q = 2 are studied in the Standard Model and general relativity. A magnetically charged black hole with mass below 9.3 × 1035 GeV has a “hairy” cloud of electroweak gauge and Higgs fields outside the event horizon with 1/mW in size. An extremal magnetic black hole has a hair mass of 3.6 TeV, while an extremal dyonic black hole has an additional mass of q2 × 1.6 GeV for a small electric charge q ≪ 2π/e2. A hairy dyonic black hole with an integer charge is not stable and can decay into a magnetic one plus charged fermions. On the other hand, a hairy magnetic black hole can evolve via Hawking radiation into a nearly extremal one that is cosmologically stable and an interesting object to be searched for.
A relatively light, highly bino-like dark matter in the Z3-symmetric NMSSM and recent LHC searches
Authors: Abdallah Waleed , Datta AseshKrishna , Roy Subhojit
Published: April 2021

Abstract

A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably ‘natural’, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable to meet the stringent experimental upper bound on its abundance unless its self-annihilation hits a funnel involving either the Z-boson or the Standard Model (SM)-like Higgs boson. We demonstrate that, in such a realistic situation, a highly bino-like DM of the popular Z3-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) is viable over an extended range of its mass, from our targeted maximum in the vicinity of the mass of the top quark down to about 30 GeV. This is facilitated by the presence of comparably light singlet-like states that could serve as funnel (scalars) and/or coannihilating (singlino) states even as the bino-like LSP receives a minimal (but optimal) tempering triggered by suitably light higgsino states that, in the first place, evade stringent lower bounds on their masses that can be derived from the Large Hadron Collider (LHC) experiments only in the presence of a lighter singlino-like state. An involved set of blind spot conditions is derived for the DM direct detection rates by considering for the very first time the augmented system of neutralinos comprising of the bino, the higgsinos and the singlino which highlights the important roles played by the NMSSM parameters ‘λ’ and tan β in delivering a richer phenomenology.
Imaging Artifacts of Nonadhesive Liquid Embolic Agents in Conventional and Cone-beam CT in a Novel in Vitro AVM Model
Authors: Schmitt Niclas , Floca Ralf O , Paech Daniel , El Shafie Rami A , Neuberger Ulf , Bendszus Martin , Möhlenbruch Markus A , Vollherbst Dominik F
Published: April 2021

Background

A major drawback of liquid embolic agents (LEAs) is the generation of imaging artifacts (IA), which may represent a crucial obstacle for the detection of periprocedural hemorrhage or subsequent radiosurgery of cerebral arteriovenous malformations (AVMs). This study aimed to compare the IAs of Onyx, Squid and PHIL in a novel three-dimensional in vitro AVM model in conventional computed tomography (CT) and cone-beam CT (CBCT).

Methods

Tubes with different diameters were configured in a container resembling an AVM with an artificial nidus at its center. Subsequently, the AVM models were filled with Onyx 18, Squid 18, PHIL 25% or saline and inserted into an imaging phantom (n = 10/LEA). Afterwards CT and CBCT scans were acquired. The degree of IAs was graded quantitatively (Hounsfield units in a defined region of interest) and qualitatively (feasibility of defining the nidus)—Onyx vs. Squid vs. PHIL vs. saline, respectively.

Results

Quantitative density evaluation demonstrated more artifacts for Onyx compared to Squid and PHIL, e.g. 48.15 ± 14.32 HU for Onyx vs. 7.56 ± 1.34 HU for PHIL in CT (p < 0.001) and 41.88 ± 7.22 density units (DU) for Squid vs. 35.22 ± 5.84 DU for PHIL in CBCT (p = 0.044). Qualitative analysis showed less artifacts for PHIL compared to Onyx and Squid in both imaging modalities while there was no difference between Onyx and Squid regarding the definition of the nidus (p > 0.999).

Conclusion

In this novel three-dimensional in vitro AVM model, IAs were higher for the EVOH/tantalum-based LEAs Onyx and Squid compared to iodine-based PHIL. Onyx induced the highest degree of IAs with only minor differences to Squid.
Correction: Ribociclib in Kombination mit endokriner Therapie verbessert Überleben von prä-/perimenopausalen Mammakarzinom-Patientinnen
Authors: Krug David , Fabian Alexander , Dunst Jürgen
Published: April 2021

Eine Correction zu dieser Publikation wurde veröffentlicht: 10.1007/s00066-019-01574-y
Die Rolle der HabilitandInnen in der chirurgischen Lehre
Authors: Paasch Christoph , Meißner Carl , Meyer Frank
Published: April 2021

Ziel

Die kompakte Übersicht skizziert die Verantwortung und das breite Aufgabenfeld der/s HabilitandIn in der chirurgischen Lehre im Rahmen des Humanmedizinstudiums.

Methode

Narrative Kurzübersicht auf der Basis gewonnener individueller und einrichtungsspezifischer Lehrerfahrungen.

Ergebnisse (Eckpunkte)

Rolle der/des HabilitandIn in (Auswahl): (i) Abgrenzung zum nichthabilitierten ärztlichen Kollegen: Die im Rahmen des Habilitationsvorhabens gesammelten administrativen und wissenschaftlichen als auch Lehrerfahrungen lassen den/die HabilitandIn als geeigneteren, motivierteren und kompetenteren Promotionsverantwortlichen und -betreuer im Gegensatz zu Kollegen, die sich nicht habilitiert haben oder habilitieren möchten, erscheinen. (ii) Abhängigkeit medizinischer Disziplinen: Die Rolle, die in der Lehre eingenommen werden kann, ist durchaus stark fachabhängig. So bestehen die Möglichkeit und die Pflicht, in chirurgischen Fächern neben theoretischem Wissen stets auch kompetente praktische Fertigkeiten zu vermitteln. (iii) Universitäten und nichtuniversitäre Krankenhäuser: In nichtuniversitären (Lehr‑)Krankenhäusern können die/der chirurgische HabilitandIn die Aufgaben der chirurgischen Lehre durch eine komplette PJ- und Famulaturbetreuung erfüllen. An universitären Kliniken steht das Abhalten von Lehrveranstaltungen eher im Vordergrund.

Schlussfolgerung

Die/der HabilitandIn spielt in der chirurgischen Lehre eine zentrale Rolle. Ein breites Aufgabenspektrum mit Abhaltung und Gestaltung von Vorlesungen, Seminaren, Blockpraktika bis hin zu direkter studentischer Betreuung im Rahmen der Famulatur, des Praktischen Jahrs und der Promotion kann von der Habilitandin/vom Habilitand suffizient erfüllt werden neben der ideenreichen Gestaltung fakultativer Lehrkonzepte.
Erworbener Chylothorax im Säuglingsalter
Authors: Hickmann D. , Maiberger T. , von der Wense A. , Reinshagen K.
Published: April 2021

Es wird über den Fall eines 8‑monatigen Säuglings mit einem Chylothorax unklarer Genese berichtet. Ein Stridor, zunehmende respiratorische Beeinträchtigung und, bedingt durch den hohen Eiweißverlust, ausgeprägte Ödeme waren die relevantesten klinischen Merkmale. Die bekannten konservativen Therapien wie fettfreie enterale Ernährung unter Substitution von „medium-chain triglycerides“(MCT)-Fetten, gefolgt von Nahrungskarenz und parenteraler Ernährung sowie die Gabe des Somatostatinanalogons Octreotid konnten trotz langer Therapiedauer keine Besserung erzielen. Erst der Einsatz von thorakoskopisch eingebrachten Titan-Clips brachte letztlich den gewünschten Erfolg.
The Society for Integrative Oncology Practice Recommendations for online consultation and treatment during the COVID-19 pandemic
Authors: Ben-Arye Eran , Paller Channing J. , Lopez Ana Maria , White Shelley , Pendleton Eva , Kienle Gunver S. , Samuels Noah , Abbawaajii Nuria , Balneaves Lynda G.
Published: April 2021

Objective

The Society for Integrative Oncology (SIO) Online Task Force was created in response to the challenges facing continuity of integrative oncology care resulting from the COVID-19 pandemic. The Task Force set out to guide integrative oncology practitioners in providing effective and safe online consultations and treatments for quality-of-life-concerns and symptom management. Online treatments include manual, acupuncture, movement, mind-body, herbal, and expressive art therapies.

Methods

The SIO Online Practice Recommendations employed a four-phase consensus process: (1) literature review and discussion among an international panel of SIO members, identifying key elements essential in an integrative oncology visit; (2) development, testing, and refinement of a questionnaire defining challenges and strategies; (3) refinement input from integrative oncology experts from 19 countries; and (4) SIO Executive Committee review identifying the most high-priority challenges and strategies.

Results

The SIO Online Practice Recommendations address ten challenges, providing practical suggestions for online treatment/consultation. These include overcoming unfamiliarity, addressing resistance among patients and healthcare practitioners to online consultation/treatment, exploring ethical and medical-legal aspects, solving technological issues, preparing the online treatment setting, starting the online treatment session, maintaining effective communication, promoting specific treatment effects, involving the caregiver, concluding the session, and ensuring continuity of care.

Conclusions

The SIO Online Practice Recommendations are relevant for ensuring continuity of care beyond the present pandemic. They can be implemented for patients with limited accessibility to integrative oncology treatments due to geographic constraints, financial difficulties, physical disability, or an unsupportive caregiver. These recommendations require further study in practice settings.
Air pollution forecasting application based on deep learning model and optimization algorithm
Authors: Heydari Azim , Majidi Nezhad Meysam , Astiaso Garcia Davide , Keynia Farshid , De Santoli Livio
Published: April 2021

Air pollution monitoring is constantly increasing, giving more and more attention to its consequences on human health. Since Nitrogen dioxide (NO2) and sulfur dioxide (SO2) are the major pollutants, various models have been developed on predicting their potential damages. Nevertheless, providing precise predictions is almost impossible. In this study, a new hybrid intelligent model based on long short-term memory (LSTM) and multi-verse optimization algorithm (MVO) has been developed to predict and analysis the air pollution obtained from Combined Cycle Power Plants. In the proposed model, long short-term memory model is a forecaster engine to predict the amount of produced NO2 and SO2 by the Combined Cycle Power Plant, where the MVO algorithm is used to optimize the LSTM parameters in order to achieve a lower forecasting error. In addition, in order to evaluate the proposed model performance, the model has been applied using real data from a Combined Cycle Power Plant in Kerman, Iran. The datasets include wind speed, air temperature, NO2, and SO2 for five months (May–September 2019) with a time step of 3-h. In addition, the model has been tested based on two different types of input parameters: type (1) includes wind speed, air temperature, and different lagged values of the output variables (NO2 and SO2); type (2) includes just lagged values of the output variables (NO2 and SO2). The obtained results show that the proposed model has higher accuracy than other combined forecasting benchmark models (ENN-PSO, ENN-MVO, and LSTM-PSO) considering different network input variables.

Graphic abstract
Spectra: a specification language for reactive systems
Authors: Maoz Shahar , Ringert Jan Oliver
Published: April 2021

We introduce Spectra, a new specification language for reactive systems, specifically tailored for the context of reactive synthesis. The meaning of Spectra is defined by a translation to a kernel language. Spectra comes with the Spectra Tools, a set of analyses, including a synthesizer to obtain a correct-by-construction implementation, several means for executing the resulting controller, and additional analyses aimed at helping engineers write higher-quality specifications. We present the language in detail and give an overview of its tool set. Together with the language and its tool set, we present four collections of many, non-trivial, large specifications, written by undergraduate computer science students for the development of autonomous Lego robots and additional example reactive systems. The collected specifications can serve as benchmarks for future studies on reactive synthesis. We present the specifications, with observations and lessons learned about the potential use of reactive synthesis by software engineers.
Controllable and decomposable multidirectional synchronizations
Authors: Bergmann Gábor
Published: April 2021

Studying large-scale collaborative systems engineering projects across teams with differing intellectual property clearances, or healthcare solutions where sensitive patient data needs to be partially shared, or similar multi-user information systems over databases, all boils down to a common mathematical framework. Updateable views (lenses) and more generally bidirectional transformations are abstractions to study the challenge of exchanging information between participants with different read access privileges. The view provided to each participant must be different due to access control or other limitations, yet also consistent in a certain sense, to enable collaboration towards common goals. A collaboration system must apply bidirectional synchronization to ensure that after a participant modifies their view, the views of other participants are updated so that they are consistent again. While bidirectional transformations (synchronizations) have been extensively studied, there are new challenges that are unique to the multidirectional case. If complex consistency constraints have to be maintained, synchronizations that work fine in isolation may not compose well. We demonstrate and characterize a failure mode of the emergent behaviour, where a consistency restoration mechanism undoes the work of other participants. On the other end of the spectrum, we study the case where synchronizations work especially well together: we characterize very well-behaved multidirectional transformations, a non-trivial generalization from the bidirectional case. For the former challenge, we introduce a novel concept of controllability, while for the latter one, we propose a novel formal notion of faithful decomposition. Additionally, the paper proposes several novel properties of multidirectional transformations.
Towards efficient verification of population protocols
Authors: Blondin Michael , Esparza Javier , Jaax Stefan , Meyer Philipp J.
Published: April 2021

Population protocols are a well established model of computation by anonymous, identical finite-state agents. A protocol is well-specified if from every initial configuration, all fair executions of the protocol reach a common consensus. The central verification question for population protocols is the well-specification problem: deciding if a given protocol is well-specified. Esparza et al. have recently shown that this problem is decidable, but with very high complexity: it is at least as hard as the Petri net reachability problem, which is -hard, and for which only algorithms of non-primitive recursive complexity are currently known. In this paper we introduce the class $${ WS}^3$$

WS

3

of well-specified strongly-silent protocols and we prove that it is suitable for automatic verification. More precisely, we show that $${ WS}^3$$

WS

3

has the same computational power as general well-specified protocols, and captures standard protocols from the literature. Moreover, we show that the membership and correctness problems for $${ WS}^3$$

WS

3

reduce to solving boolean combinations of linear constraints over $${\mathbb {N}}$$
N
. This allowed us to develop the first software able to automatically prove correctness for all of the infinitely many possible inputs.
Analysis of Antimicrobial Properties of PVA-Based Coatings with Silver and Zinc Oxide Nanoparticles
Authors: Pulit-Prociak Jolanta , Staroń Anita , Prokopowicz Magdalena , Magielska Karolina , Banach Marcin
Published: April 2021

Public places such as swimming pools, saunas and jacuzzis are at high risk of developing microorganisms and are a potential source of disease. Above all, increased temperature and humidity favour this. A relatively new but effective way to combat microorganisms is to subject them to metal or metal oxide nanoparticles. The paper presents a method of obtaining nanocompositions for direct application at the place of occurrence of the microorganisms. The advantage of nanocompositions is that they can easily be removed from the infected surface in the form of a film containing dead organic matter. The article investigates the biocidal properties against common microorganisms such asAspergillus nigerandCandida albicansof nanocompositions containing silver nanoparticles and nanometric zinc oxide. The physicochemical properties of the nanocompositions were characterised and the antifungal properties of the preparations obtained determined using the suspension method. The results showed that the PVA-based compositions obtained were able effectively to inhibit the growth of the tested strains. Elongation of contact time between microorganism and nanoparticles which was changed from 5 to 60 min resulted in higher antimicrobial activity. It was manifested in reduced growth area. The same observation was made when the concentration of used nanoparticles was increased. When the concentration of nanosilver raised from 12.5 up to 200 ppm, the development ofAspergillus nigerwas slower. Increasing of zinc oxide nanoparticles concentration resulted in growth inhibition ofCandida albicansstrain.

Graphic Abstract
"Present and future of immunotherapy in Neuroendocrine Tumors"
Authors: Albertelli Manuela , Dotto Andrea , Nista Federica , Veresani Alessandro , Patti Luca , Gay Stefano , Sciallero Stefania , Boschetti Mara , Ferone Diego
Published: April 2021

Immunotherapy, so promising in many neoplasms, still does not have a precise role in the treatment of neuroendocrine neoplasms (NENs). In this article, we provide an overview on the current knowledge about immunotherapy with immune checkpoint inhibitors (ICIs) applied to NENs, evaluating future perspectives in this setting of tumors.

Evidence so far available for ICIs in gastroenteropancreatic (GEP)-NENs is definitively not as robust as for other tumors such as Small Cell Lung Cancer or Merkel Cell Carcinoma. In fact, with regard to the well-differentiated forms of NENs (NETs), the results obtained nowadays have been disappointing. However, the near future, might reserve interesting results for ICIs in GEP-NEN from a total of nine different ICI drugs, used throughout 19 randomised controlled trials. Such numbers highlight the growing attention gathering around NENs and ICIs, in response to the need of stronger evidences supporting such therapy.

For the future, the most important aspect will be to study strategies that can make NETs more susceptible to response to ICI and, thus, enhance the effectiveness of these treatments. Therefore, the combination of conventional therapy, target therapy and immunotherapy deserve attention and warrant to be explored. A sequential chemotherapy, possibly inducing an increase in tumor mutational burden and tested before immunotherapy, could be a hypothesis deserving more consideration. A radiation treatment that increases tumor-infiltrating lymphocytes, could be another approach to explore before ICIs in NENs. Equally essential will be the identification of biomarkers useful for selecting patients potentially responsive to this type of treatment.