bluuebunny/crossref_metadata_2025 huggingface dataset:
Separation of the collagen protein by ultrafiltration: Effects of concentration on the membrane's characteristics
Authors: Scutariu Roxana‐Elena , Batrinescu Gheorghe , Nechifor Gheorghe , Popescu Mariana , Tenea Anda G.
Published: August 2020

Collagen is one of the predominant proteins found in all multicellular animals. In this paper, the performance of the ultrafiltration process (UF) for concentrating the collagen protein was studied by performing batch experiments using a membrane module with an effective area of 28 cm2 and equipped with a regenerated cellulose membrane with a molecular weight cut‐off of 5 kDa. The feed solution consisted of aqueous solutions of bovine collagen hydrolysate with a molecular weight of 10 kDa. The effects of feed concentration (1%, 2%, 3%, 4%, and 5%) on the performance were determined. The optimum operating conditions were: a transmembrane pressure of 5 bar and a temperature of 25°C. The results showed that the permeability decreases with the increase of the volumetric concentration factor (VCF) for all five concentrated solutions of collagen tested. Also, the rejection of proteins increases with the increase in the concentration of the collagen solutions. The study confirms that the clogging phenomenon was dependent on the increase of concentration. Further, a mathematical modeling of fouling mechanism was analyzed based on Hermia's model. The concentration of the collagen solutions was also highlighted by viscosity measurements.
Sometimes hot, sometimes not: the relations between selected situational vocational interests and situation perception
Authors: Roemer Lena , Horstmann Kai T. , Ziegler Matthias
Published: August 2020

Vocational interests are traditionally conceived as stable preferences for different activities. However, recent theorizing suggests their intraindividual variability. This preregistered experience sampling study examined intraindividual variation in selected vocational interests states and related situation and person factors ( N = 237). Results indicate that the three interest dimensions Investigative, Artistic, and Social interests did vary intraindividually but less so than other phenomena’s dimensions (e.g., personality and happiness). At the within-person level, the focused interest states were related to specific situation characteristics, also after controlling for related personality dimensions and happiness. These relations were either specified a priori, based on the concept of congruence or person-environment fit, and tested in a strictly confirmatory manner, or identified using a more exploratory approach. Furthermore, aggregated states of the three selected interest dimensions mainly varied below their corresponding trait levels. This suggests that interest trait levels could represent an upper limit for aggregated interest states that could be due to method-related or construct-related reasons. The results demonstrate the situational character of interests and provide novel approaches for studying vocational interest in daily life.
Agreement between spirometry and impulse oscillometry for lung function assessment in 6‐year‐old children born extremely preterm and at term
Authors: Lundberg Björn , Melén Erik , Thunqvist Per , Norman Mikael , Hallberg Jenny
Published: August 2020

Background

Extremely preterm birth is a risk factor for reduced lung function later in life, and clinical follow‐up from early childhood is recommended. Dynamic spirometry is the most widely used method to assess airway obstruction, but impulse oscillometry (IOS) may be an alternative method that is easier to perform in young children. The feasibility and agreement between spirometry and IOS outcome variables has not been investigated in children born extremely preterm.

Aim

To determine the feasibility of and correlation between spirometry and IOS in pre‐school children born extremely preterm.

Methods

Spirometry and IOS were performed in 6‐year‐old children born extremely preterm (n = 88) and age‐matched term controls (n = 84) in Stockholm, Sweden. Correlations between spirometry and IOS outcome variables were analyzed using Pearson's partial correlation, adjusting for height.

Results

Success rate for spirometry (60%) was lower than for IOS (93%) but did not differ significantly between the preterm and term groups (56% and 64% for spirometry, P = .25; and 92% and 94% for IOS, P = .61). Correlations between spirometry and IOS outcomes were at best moderate (Spearman's r = −0.31 to −0.56). Normal IOS identified 69% to 90% of those with normal spirometry. A negative predictive value of 90% was found for R5‐R20 versus FEV0.75/FVC, suggesting that IOS may be used to exclude obstructive airway disease as measured by spirometry.

Conclusion

IOS is a more feasible method than spirometry to assess lung function in young children irrespective of gestational age at birth and could be considered an alternative in children who cannot perform spirometry.
Atopy and pulmonary function among healthy‐weight and overweight/obese children with asthma
Authors: Farhat Lara , de Vos Gabriele , De Aliva , Lee Diana S. , Rastogi Deepa
Published: August 2020

Introduction

Epidemiologic studies have found low/absence of atopy in obese asthmatic children, but the association or lack thereof of atopy with disease morbidity, including pulmonary function, in obese asthma is not well understood. We sought to define the association of atopy with pulmonary function in overweight/obese minority children with asthma.

Methods

In a retrospective chart review of 200 predominantly minority children evaluated at an academic Pediatric Asthma Center over 5 years, we compared the prevalence of atopy, defined as 1 positive skin prick test or serum‐specific immunoglobulin E quantification to environmental allergens, and its association with pulmonary function in overweight/obese (body mass index [BMI] > 85th percentile) (n = 99) to healthy‐weight children (BMI, 5th‐85th percentile for age) (n = 101).

Results

In a cohort comprised of 47.5% Hispanics and 39.5% African Americans, 81% of overweight/obese and 74% of healthy‐weight children were atopic. While atopic healthy‐weight children had lower percent‐predicted forced expiratory volume in the first second (FEV1) (93 ± 13.6 vs 107% ± 33.2%, P = .03) and lower percent‐predicted forced vital capacity (FVC) (93% ± 12.2% vs 104% ± 16.1%, P = .01) as compared to nonatopic children, atopy was not associated with FEV1 (P = .7) or FVC (P = .17) in overweight/obese children. Adjusting for demographic and clinical variables, atopy was found to be an independent predictor of FEV1 and FVC in healthy‐weight (β = −2.4, P = .07 and β = −1.7, P = .04, respectively) but not in overweight/obese children (β = .6, P = .5 and β = .8, P = .3).

Conclusions

Atopy is associated with lower lung function in healthy‐weight asthmatics but not in overweight/obese asthmatics, supporting the role of nonallergic mechanisms in disease burden in pediatric obesity‐related asthma.
An increasing public health burden arising from children infected with SARS‐CoV2: A systematic review and meta‐analysis
Authors: Zheng Baojia , Wang Hui , Yu Cuixiang
Published: August 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV2) is spreading all over the world and poses a great threat to humans. This study aimed to systematically review the current situation and public health burden associated with children infected with SARS‐CoV2.

Methods

We searched four electronic databases without language limitations. The pooled proportion or odds ratio (OR) and 95% CI confidence interval (CI) were calculated for each analysis to explore the prevalence of asymptomatic infection and coinfection, as well as to assess the sex of SARS‐CoV‐2‐infected children.

Results

We obtained data from 14 eligible studies with 410 patients for the meta‐analysis. The pooled proportion of asymptomatic infection was 40.45% (95% CI, 24.04‐56.85), while coinfection was 10.14% (95% CI, 3.97‐16.30), of which Mycoplasma pneumonia (50%; 95% CI, 28.24‐71.76) and influenza virus or parainfluenza virus (22.76%; 95% CI, 4.76‐40.77) were the most common pathogens. Both male and female children were susceptible to SARS‐CoV2 infection. And the pooled proportion of family clustering infection was 83.63% (95% CI, 77.54‐89.72).

Conclusion

A high proportion of asymptomatic infections occurs in children infected with SARS‐CoV2, who are also susceptible to coinfection regardless of sex. These data affirm the increasing public health burden arising from infected children regarding the causation of asymptomatic infection or misdiagnosis and as a significant contributor to virus spread. The public should pay more attention to children during epidemics and conduct multimethod detection to further effectively identify infected children and control the source of infection.
Calculation and Experimental Study on Extrusion Pressure of Resin in 3D Carbon Fiber Preform
Authors: Ma Yuqin , Wang Jie , Chen Yi , Zhao Yatao , Li Kaifu , Jin Hao
Published: August 2020

Three‐dimensional carbon fiber reinforced resin matrix composite can effectively overcome the defects of traditional composite in the interlayer strength and stiffness, and has been widely used. Herein, the threshold infiltration pressure of resin in three‐dimensional carbon fiber preform is respectively calculated as 0.170 and 0.973 MPa from the perspective of statics and dynamics. The static calculation ignores the additional pressure caused by the viscous resistance of the resin during the infiltration process, which deviated greatly from the actual value. Therefore, the dynamics calculation value is used as a reference to extrusion pressure in the experiment. The composites with extrusion pressure of 1, 2, 3, 4, and 5 MPa are prepared by vacuum infiltration hot pressing process. Through the study of the infiltration microstructure and bending fracture morphology of the composite, it is found that when the extrusion pressure is 3 MPa, the preparation effect is the best. At this time, the bending strength of the composite is 540 MPa, which is 92.86% and 71.43% higher than that at 1 and 5 MPa, respectively. It is indicated that the extrusion pressure is a key parameter in the composite preparation process and needs to be selected reasonably.
Protective effect of ginsenoside Rh2 on scopolamine‐induced memory deficits through regulation of cholinergic transmission, oxidative stress and the ERK‐CREB‐BDNF signaling pathway
Authors: Lv Jingwei , Lu Cong , Jiang Ning , Wang Haixia , Huang Hong , Chen Ying , Li Yujiao , Liu Xinmin
Published: August 2020

Rh2 is a rare ginsenoside and there are few reports of its effect on cognition compared with other similar molecules. This study aimed to establish the impact of Rh2 treatment on improving scopolamine (Scop)‐induced memory deficits in mice and illuminate the underlying mechanisms. First, memory‐related behavior was evaluated using two approaches: object location recognition (OLR), based on spontaneous activity, and a Morris water maze (MWM) task, based on an aversive stimulus. Our results suggested that Rh2 treatment effectively increased the discrimination index of the mice in the OLR test. In addition, Rh2 elevated the crossing numbers and decreased the escape latency during the MWM task. Moreover, Rh2 markedly upregulated the phosphorylation of the extracellular signal‐regulated kinase (ERK)‐cAMP response element binding (CREB)‐brain derived neurotrophic factor (BDNF) pathway in the hippocampus. Meanwhile, the administration of Rh2 significantly promoted the cholinergic system and dramatically suppressed oxidative stress in the hippocampus. Taken together, Rh2 exhibited neuroprotective effects against Scop‐induced memory dysfunction in mice. Rh2 activity might be ascribed to several underlying mechanisms, including its effects on modulating the cholinergic transmission, inhibiting oxidative stress and activating the ERK‐CREB‐BDNF signaling pathway. Consequently, the ginsenoside Rh2 might serve as a promising candidate compound for Alzheimer's disease.
Fructus Ligustri Lucidi preserves bone quality through induction of canonical Wnt/β‐catenin signaling pathway in ovariectomized rats
Authors: Liu Haixia , Guo Yubo , Zhu Ruyuan , Wang Lili , Chen Beibei , Tian Yimiao , Li Rui , Ma Rufeng , Jia Qiangqiang , Zhang Hao , Xia Bingke , Li Yu , Wang Xinxiang , Zhu Xiaofeng , Zhang Ronghua , Brӧmme Dieter , Gao Sihua , Zhang Dongwei , Pei Xiaohua
Published: August 2020

Fructus Ligustri Lucidi (FLL) has been preclinically and clinically used to treat musculoskeletal diseases. However, whether and how FLL affect the canonical Wnt/β‐catenin signaling in the management of osteoporosis remains largely unknown. To this end, ovariectomized (OVX) rats and primary osteoblasts were administrated with FLL aqueous extract and medicated serum, respectively. Supplement of FLL to OVX rats maintains bone quality by attenuating the reduction in bone mineral density, strength and microstructure. The maintenance may be associated with upregulating the expression of insulin‐like growth factor‐1, osteoprotegerin, phospho (p)‐low‐density lipoprotein receptor‐related protein 6, p‐glycogen synthase kinase 3 beta (GSK3β), β‐catenin, Runx2 and c‐Myc, and downregulating the expressions of sclerostin (SOST), dickkopf‐related protein 1 (DKK1), GSK3β and p‐β‐catenin in rat femurs and tibias. In addition, the medicated serum promotes osteoblastic bone formation through activation of Wnt/β‐catenin signaling via inhibition of DKK1 and SOST overexpression. Salidroside may be one of the active ingredients in FLL that are beneficial for bone homeostasis. In summary, our results suggest that FLL may preserve bone quality through induction of canonical Wnt/β‐catenin signaling via inhibition of DKK1 and SOST overexpression. And FLL may offer a new source of the DKK1 or SOST inhibitors in protection against osteoporosis.
Specific migration of caprolactam and infrared characteristics of a polyamide/polyethylene composite film for food packaging under conditions of long‐term storage before use
Authors: Ritter Milena , Schlettwein Derck , Leist Ulrich
Published: August 2020

Caprolactam is the monomer typically used for the production of polyamide 6 films. Originating from incomplete polymerization reactions, caprolactam can remain part of the final food packaging and has the potential to migrate from the plastic packaging into the packed good. For film and food producers as well as for end users, it is of great interest that the conformity of a film with migration limits is ensured over its lifetime and that environmental conditions do not affect the migration behavior inadequately. In this work, we have investigated the long‐term storage characteristics of a polyamide/polyethylene (PA/PE) film over a storage period of 40.5 months with respect to the specific migration rate of caprolactam. Within statistical indicators, this rate is stable over the complete storage period. Different exposure conditions were applied to the same PA/PE film to accelerate the aging process. Alterations under forced aging conditions (elevated temperature and ultraviolet radiation) were studied by Fourier transform infrared (FTIR) spectroscopy to detect possible chemical changes in the polymer bulk and, by the use of the attenuated total reflection method, on the sample surface. The film was subjected to an extraction study to verify the results obtained using FTIR. Additionally, mechanical tensile tests were carried out. Indication for alterations regarding caprolactam under the different storage conditions were found. The results clearly show that photo‐oxidative conditions led to changes in the chemical and mechanical properties of the film. New chemical species occurred caused by degradation of the polymers and their contribution to chemical migration is discussed.
Assimilating synthetic land surface temperature in a coupled land–atmosphere model
Authors: Sgoff Christine , Schomburg Annika , Schmidli Juerg , Potthast Roland
Published: August 2020

A realistic simulation of the atmospheric boundary layer (ABL) depends on an accurate representation of the land–atmosphere coupling. Land surface temperature (LST) plays an important role in this context and the assimilation of LST can lead to improved estimates of the boundary layer and its processes. We assimilated synthetic satellite LST retrievals derived from a nature run as truth into a fully coupled, state‐of‐the‐art land–atmosphere numeric weather prediction model. As assimilation system a local ensemble transform Kalman filter was used and the control vector was augmented by the soil temperature and humidity. To evaluate the concept of the augmented control vector, two‐day case‐studies with different control vector settings were conducted for clear‐sky periods in March and August 2017. These experiments with hourly LST assimilation were validated against the nature run and overall, the RMSE of atmospheric and soil temperature of the first‐guess (and analysis) were reduced. The temperature estimate of the ABL was particularly improved during daytime as was the estimate of the soil temperature during the whole diurnal cycle. The best impact of LST assimilation on the soil and the ABL was achieved with the augmented control vector. Through the coupling between the soil and the atmosphere, the assimilation of LST can have a positive impact on the temperature forecast of the ABL even after 15 hr because of the memory of the soil. These encouraging results motivate further work towards the assimilation of real satellite LST retrievals.
Impact of subchorionic hematoma in early pregnancy on obstetric complications: A retrospective cohort study in women who had live births after frozen‐thawed embryo transfer
Authors: So Shuhei , Mochizuki Osamu , Yamaguchi Wakasa , Murabayashi Nao , Miyano Naomi , Tawara Fumiko
Published: August 2020

Purpose

We investigated the contribution of subchorionic hematoma (SCH) involvement in early pregnancy to the risk of pregnancy complications in women who underwent frozen‐thawed embryo transfer (FET).

Methods

A hypoechogenic area surrounding the gestational sac at early pregnancy on ultrasound was defined as SCH. Simultaneously, the presence of vaginal bleeding was evaluated. We included 1416 women with live births after FET between March 2015 and September 2018 in this study. The frequency of pregnancy complications was compared between the SCH (n = 340) and non‐SCH (n = 1076) groups.

Results

The adjusted odds ratio of abnormal placental adhesion and placenta previa for the SCH group relative to the non‐SCH group was 7.01 [2.96‐18.00] and 3.77 [1.24‐11.91], respectively. In contrast, hypertensive disorders of pregnancy, non‐reassuring fetal status, fetal growth restriction, chorioamnionitis, and premature rupture of the membrane showed no differences between both groups. Furthermore, the frequency of abnormal placental adhesion was higher in the SCH group with vaginal bleeding than in the SCH group without vaginal bleeding.

Conclusions

Subchorionic hematoma in early pregnancy may cause abnormal placental adhesion and placenta previa in pregnant women with FET. SCH presence should be carefully noted, particularly in cases with vaginal bleeding during early pregnancy after FET.
The Mechanism of High Reactivity of Benzyl Carbocation, C6H5CH2+, during Interaction with Benzene
Authors: Stoyanov Evgenii S. , Stoyanova Irina V.
Published: August 2020

The first two stages of the chemical interaction of a benzyl cation with a weak base, benzene, have been established. A key point in the reactivity of this cation is its ability to act as a strong protonating agent, turning itself to highly reactive carbene molecule, which then interacts with the available initial carbocation. The second step is mostly responsible for the high reactivity of the unsaturated carbocation. Further studies will show whether this mechanism is typical for saturated alkane and allyl‐type carbocations.
An Early Devonian actinostelic euphyllophyte with secondary growth from the Emsian of Gaspé (Canada) and the importance of tracheid wall thickening patterns in early euphyllophyte systematics
Authors: Pfeiler Kelly C. , Tomescu Alexandru M. F.
Published: August 2020

Secondary growth is a tracheophyte structural feature whose earliest known occurrence dates to the late Pragian – early Emsian. Armoricaphyton, Franhueberia and an unnamed plant from eastern Canada represent the only instances of secondary growth documented to date for the Early Devonian. Here, we describe a new Early Devonian euphyllophyte exhibiting secondary growth, from the Emsian (c. 400–395 Ma) Battery Point Formation (Québec, Canada): Gmujij tetraxylopteroides gen. et sp. nov., which is characterized by a mesarch actinostele with Psilophyton‐type (P‐type) tracheid wall thickening, and which exhibits a new type of anatomical organization in Early Devonian wood‐producing euphyllophytes. Gmujij differs from coeval euphyllophytes, but lack of data on branching patterns, reproductive structures and other traditional diagnostic features precludes classification in previously recognized euphyllophyte groups. We experiment with a numerical approach to tracheid size distributions, to compare Gmujij with younger euphyllophytes exhibiting secondary growth. Comparisons indicate similarity between Gmujij and aneurophytalean progymnosperms, such as Tetraxylopteris. However, its plesiomorphic P‐type tracheids set Gmujij apart from younger actinostelic euphyllophytes, questioning the importance of tracheid thickening patterns as diagnostic characters separating major lineages. Answers to this question hinge on whether transitions between wall thickening patterns require simple or complex changes in developmental regulation, a matter that requires improved understanding of regulatory programs that determine tracheid thickening patterns. Irrespective of these, Gmujij adds a new component to the diversity of anatomically preserved plants known in the Early Devonian, an incompletely explored interval of tracheophyte anatomical diversification, contributing information that will facilitate understanding of the evolutionary origins of secondary growth.
Chinchilla (Chinchilla lanigera) behavioral responses to a visual signal preceding handling
Authors: Baskir Eli A. , Kucharski Sarah , Powell David M.
Published: August 2020

Zoos use ambassador animals in educational programs featuring close contact with humans. Chinchillas (Chinchilla lanigera) at the Saint Louis Zoo are retrieved for programs by a keeper wearing brown handling gloves, but green cleaning gloves are worn during normal husbandry when physical contact with the animal is only incidental. The chinchillas’ primary keeper anecdotally reported more reactivity and movement from chinchillas when approached with handling gloves. Animals’ behavioral reactions to the presence of humans often include locomotion and vigilance, but these responses may be attenuated by predictability. To investigate these behaviors, handling trials involving brief contact attempts with both cleaning and handling gloves were filmed. Results indicated that chinchillas responded to disturbances by moving, jumping, and adopting more alert body postures. Surprisingly, movement was recorded in longer durations when the keeper attempted to touch the animals with cleaning gloves. This higher arousal may indicate that the animal was not expecting to be handled, yet an attempt to do so was being made. This reaction provides evidence that potentially aversive events should be reliably and consistently signaled.
Healthcare, Well-being, and the Regulation of Diversity in Healing
Authors: Cloatre Emilie , Urquiza-Haas Nayeli
Published: August 2020

While the diversity of healing practices and knowledges is not new, controversies triggered by non-conventional medicines have intensified over the years. Contemporary regulation tends to rely on a core difference between proven and unproven therapies, and on scientific logics, to adjudicate questions of legitimacy, authority and funding. But such focus on science does not easily map onto the multiple ontologies at play in how patients and healers approach healthcare, and has limited the ability of law to adequately engage with non-biomedical healing systems. In the contemporary context, plagued with scarcity and neoliberal logics, such disalignment has become more visible, creating ongoing pressures for the regulation of healthcare. Meanwhile, self-proclaimed healers thrive in this highly commercialised environment, where people seek healthcare outside the state-regulated healthcare system. In this chapter, we analyse these tensions and challenges as emerging, in part, from the difficulty for law to respond to multiple ontological worlds. At the same time, we draw on scholarship on vulnerability and care to explore how healing could be ordered and regulated if we were to decentre the idea of evidence from one of pure rationale.
Tumor-Treating Fields at EMBC 2019: A Roadmap to Developing a Framework for TTFields Dosimetry and Treatment Planning
Authors: Bomzon Ze’ev , Wenger Cornelia , Proescholdt Martin , Mohan Suyash
Published: August 2020

Tumor Treating Fields (TTFields) are electric fields known to exert an anti-mitotic effect on cancerous tumors. TTFields have been approved for the treatment of glioblastoma and malignant pleural mesothelioma. Recent studies have shown a correlation between TTFields doses delivered to the tumor bed and patient survival. These findings suggest that patient outcome could be significantly improved with rigorous treatment planning, in which numerical simulations are used to plan treatment in order to optimize delivery of TTFields to the tumor bed.

Performing such adaptive planning in a practical and meaningful manner requires a rigorous and scientifically proven framework defining TTFields dose and showing how dose distribution influences disease progression in different malignancies (TTFields dosimetry). At EMBC 2019, several talks discussing key components related to TTFields dosimetry and treatment planning were presented. Here we provide a short overview of this work and discuss how it sets the foundations for the emerging field of TTFields dosimetry and treatment planning.
Simplifying the Numerical Human Model with k-means Clustering Method
Authors: Fujimoto Kyoko , Angelone Leonardo M. , Rajan Sunder S. , Iacono Maria Ida
Published: August 2020

Currently, the safety assessment of radio-frequency (RF) heating using computational modeling is limited by the available numerical models which are not patient specific. However, RF-induced heating depends on the physical characteristics of the patient. The numerical model generation is difficult due to the highly time-consuming segmentation process. Therefore, having fewer types of segmented structures simplifies the generation of numerical models and reduces computational burden as a result. In this study, we used the k-means clustering method to reduce the number of dielectric properties of an existing numerical model and investigated the resulting difference in specific absorption rate (SAR) with respect to the number of clusters.
RF-Induced Unintended Stimulation for Implantable Medical Devices in MRI
Authors: Brown James E. , Qiang Rui , Stadnik Paul J. , Stotts Larry J. , Von Arx Jeffrey A.
Published: August 2020

Historically, patients with implantable medical devices have been denied access to magnetic resonance imaging (MRI) due to several potentially hazardous interactions. There has been significant interest in recent years to provide access to MRI to patients with implantable medical devices, as it is the preferred imaging modality for soft tissue imaging. Among the potential hazards of MRI for patients with an active implantable medical device is radio frequency (RF)-induced unintended stimulation. RF energy incident on the device may be rectified by internal active components. Any rectified waveform present at the lead electrodes may stimulate nearby tissue. In order to assess the risk to the patient, device manufacturers use computational human models (CHMs) to quantify the incident RF on the device and perform in vitro testing to determine the likelihood of unintended stimulation. The use of CHMs enables the investigation of millions of scenarios of scan parameters, patient sizes and anatomies, and MR system technologies.
Estimating Electric Field and SAR in Tissue in the Proximity of RF Coils
Authors: Lemdiasov Rosti , Venkatasubramanian Arun , Jegadeesan Ranga
Published: August 2020

Medical implants that require recharging typically use magnetic resonant coupling of transmit (external) and receive (internal) RF coils. Apart from magnetic field, the transmit coil creates a time-varying electric field that excites currents not only in the receive coil but also in the surrounding tissues. Radio frequency (RF) exposure assessment for inductive systems used in wireless powering and telemetry is done using electric field, specific absorption rate (SAR), and induced current as metrics. Full-wave analysis using RF simulation tools such as Ansys HFSS is generally used to estimate these metrics, and the results are widely accepted. However, such simulation-based analysis is quite rigorous and time-consuming, let alone the complexities with setting up the simulation.

In this paper, we present a simple approach to estimating exposure (electric field, SAR, induced current) from fundamental electromagnetic principles enabling ability to arrive at results quickly. It significantly reduces the computational time in iterative approaches where multiple simulation runs are needed.
The CAD-Compatible VHP-Male Computational Phantom
Authors: Noetscher Gregory M.
Published: August 2020

Anatomically accurate and numerically efficient computational phantoms of humans are essential to characterizing the response of a body to a variety of electromagnetic, acoustic and other types of external stimuli. In conjunction with advances in numerical simulation techniques and computational hardware, these computational phantoms enable exploration of innovative and exciting applications, from medical diagnostic techniques and therapeutic treatments to new ways of on- and in-body communications. However, in order to provide realistic estimates through simulation, the model must represent the subject as closely as possible, necessitating that all relevant anatomical features are captured. If this is not accomplished, the model will misrepresent the true physical environment, and critical information will not be captured during the simulation. This work presents a model of a male subject based on the Visible Human Project dataset. Each component of the model is constructed of triangular surface elements, making it compatible with CAD packages and facilitating its use in simulations based on major numerical methodologies. A description of the model, the procedure used for its construction and a baseline simulation are presented together with future integration and augmentation ideas.
How Do Tumor-Treating Fields Work?
Authors: Carlson Kristen W. , Tuszynski Jack A. , Dokos Socrates , Paudel Nirmal , Dreeben Thomas , Bomzon Ze’ev
Published: August 2020

Since approved by the FDA for the treatment of glioblastoma brain cancer in 2015, tumor-treating fields (TTFields) have rapidly become the fourth modality to treat cancer, along with surgery, chemotherapy, and radiation [1]. TTFields are now in clinical trials for a variety of cancer types. While efficacy has been proven in the clinic, the higher efficacy is demonstrated in vitro and in animal models, which indicates much greater clinical efficacy is possible. To attain the great promise of TTFields, uncovering the mechanisms of action (MoA) is necessary.
Analytical Solution for the Electric Field Response Generated by a Nonconducting Ellipsoid (Prolate Spheroid) in a Conducting Fluid Subject to an External Electric Field
Authors: Yakovlev Andrey B. , Federyaeva Valeriya S.
Published: August 2020

An analytical solution is presented for the electric field response generated by a nonconducting ellipsoid (prolate spheroid) in a homogeneous conducting fluid subject to an external primary electric field, including surface charge distribution. Such a solution might be useful for different purposes, including cell modeling subject to an external quasistatic electromagnetic stimulus. The solution utilizes the well-known analogy between the electrostatics of dielectrics and DC conduction. The solution obtained includes an expression for the volumetric fields and an expression for the induced surface charge density at the membrane.
A Thermal Study of Tumor-Treating Fields for Glioblastoma Therapy
Authors: Gentilal Nichal , Salvador Ricardo , Miranda Pedro Cavaleiro
Published: August 2020

Tumor-treating fields (TTFields) is an antimitotic cancer treatment technique used for glioblastoma multiforme (GBM) and malignant pleural mesothelioma. Although the frequency used is not as high as in hyperthermia, temperature increases due to the Joule effect might be meaningful given the necessary time that these fields should be applied for. Post hoc analysis of the EF-11 clinical trial showed higher median overall survival in patients whose compliance was at least 18 h per day. To quantify these temperature increases and predict the thermal impact of TTFields delivery to the head, we used a realistic model created from MR images segmented in five tissues: scalp, skull, CSF, gray matter (GM), and white matter (WM). Through COMSOL Multiphysics, we solved Laplace’s equation for the electric field and Pennes’ equation for the temperature distribution. To mimic the therapy as realistically as possible, we also considered complete current shutdown whenever any transducer reached 41 °C to allow transducers and tissues’ temperature to decrease. Our results indicate an intermittent operation of Optune due to this necessary current shutdown. Localized temperature increases were seen, especially underneath the regions where the transducers were placed. Maximum temperature values were around 41.5 °C on the scalp and 38 °C on the brain. According to the literature, significant thermal impact is only predicted for the brain where the rise in temperature may lead to an increased BBB permeability and variation in the blood flow and neurotransmitter concentration. Additionally, our results showed that if the injected current is reduced by around 25% compared to Optune’s standard way of operating, then uninterrupted treatment might be attainable. These predictions might be used to improve TTFields delivery in real patients and to increase awareness regarding possible thermal effects not yet reported elsewhere.
A Miniaturized Ultra-Focal Magnetic Stimulator and Its Preliminary Application to the Peripheral Nervous System
Authors: Colella Micol , Liberti Micaela , Apollonio Francesca , Bonmassar Giorgio
Published: August 2020

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique used in the clinic to treat several neurological disorders and psychiatric diseases. One of TMS’s significant limitations is its low spatial resolution, which often results in a mismatch between the target area in the brain and the stimulation site on the scalp. To enhance its spatial resolution, we designed and built a complete stimulation system complete with a millimetric-diameter coil and microscopic traces (μCoil). The first tests conducted on healthy volunteers showed that the μCoil stimulation of the radial nerve in the wrist could indeed evoke somatosensory nerve action potentials (SNAPs). In this chapter, we study this nerve stimulation system with electromagnetic and neuron simulators on a neurofunctionalized model from the Virtual Population (ViP v.4) and a μCoil figure-8 geometry. In particular, we study how changes in the μCoil geometry, such as the number of layers, shape, and length of an iron or air core, may help to promote the generation of somatosensory nerve action potentials.
Taming defects in $$ \mathcal{N} $$ = 4 super-Yang-Mills
Authors: Wang Yifan
Published: August 2020

Abstract

We study correlation functions involving extended defect operators in the four- dimensional

$$ \mathcal{N} $$

N

= 4 super-Yang-Mills (SYM). The main tool is supersymmetric localization with respect to the supercharge 𝒬 introduced in [1] which computes observables in the 𝒬- cohomology. We classify general defects of different codimensions in the

$$ \mathcal{N} $$

N

= 4 SYM that belong to the 𝒬-cohomology, which form
1
-BPS defect networks. By performing the 𝒬- localization of the

$$ \mathcal{N} $$

N

= 4 SYM on the four-dimensional hemisphere, we discover a novel defect-Yang-Mills (dYM) theory on a submanifold given by the two-dimensional hemisphere and described by (constrained) two-dimensional Yang-Mills coupled to topological quantum mechanics on the boundary circle. This also generalizes to interface defects in

$$ \mathcal{N} $$

N

= 4 SYM by the folding trick. We provide explicit dictionary between defect observables in the SYM and those in the dYM, which enables extraction of general

$$ \frac{1}{16} $$

1
16

-BPS defect network observables of the SYM from two-dimensional gauge theory and matrix model techniques. Applied to the D5 brane interface in the SU(N ) SYM, we explicitly determine a set of defect correlation functions in the large N limit and obtain precise matching with strong coupling results from IIB supergravity on AdS
5
× S
5.
Präventionsberichterstattung – neue Impulse für die Gesundheitsberichterstattung?
Authors: Reisig Veronika , Jordan Susanne , Starker Anne , Brettner Johannes , Kuhn Joseph
Published: August 2020

Das im Jahr 2015 verabschiedete „Gesetz zur Stärkung der Gesundheitsförderung und Prävention“ gibt die regelmäßige Erstellung eines Präventionsberichts durch die Nationale Präventionskonferenz vor und stimuliert auch auf Länderebene die Entwicklung einer Präventionsberichterstattung. Es existieren verschiedene Konzepte und Herangehensweisen an die Präventionsberichterstattung.

Im Jahr 2019 ist der erste Präventionsbericht der Nationalen Präventionskonferenz erschienen. Auf Länderebene verläuft die Entwicklung der Präventionsberichterstattung sehr heterogen und spiegelt die unterschiedlichen Rahmenbedingungen und Konzepte vor Ort wider. Auch die Beziehung der Präventionsberichterstattung zur Gesundheitsberichterstattung wird unterschiedlich aufgefasst: Manchenorts wird die Präventionsberichterstattung stärker im Rahmen der Gesundheitsberichterstattung gesehen, andernorts als selbstständiger betrachtet, z. B. mit Fokus auf die Berichterstattung präventiver Strukturen und Interventionen.

Einige der anstehenden Herausforderungen sind die Erschließung von Indikatoren und Datenquellen, insbesondere zur Abbildung von Ressourcen für Gesundheit, gesundheitsrelevanten Strukturen und Verhältnissen, die Entwicklung einer aussagekräftigen und mit vertretbarem Aufwand umsetzbaren Interventionsberichterstattung sowie die Weiterentwicklung von einer input- bzw. outputbezogenen zu einer wirkungsorientierten Berichterstattung.

Aus der durch das Präventionsgesetz angestoßenen Entwicklung ergeben sich inhaltliche, methodische und gesundheitspolitische Impulse auch für die Gesundheitsberichterstattung. Wünschenswert wäre eine den Aufbau der Präventionsberichterstattung unterstützende Begleitforschung.
The Rotating Rigid Body Model Based on a Non-twisting Frame
Authors: Gebhardt Cristian Guillermo , Romero Ignacio
Published: August 2020

This work proposes and investigates a new model of the rotating rigid body based on the non-twisting frame. Such a frame consists of three mutually orthogonal unit vectors whose rotation rate around one of the three axis remains zero at all times and, thus, is represented by a nonholonomic restriction. Then, the corresponding Lagrange–D’Alembert equations are formulated by employing two descriptions, the first one relying on rotations and a splitting approach, and the second one relying on constrained directors. For vanishing external moments, we prove that the new model possesses conservation laws, i.e., the kinetic energy and two nonholonomic momenta that substantially differ from the holonomic momenta preserved by the standard rigid body model. Additionally, we propose a new specialization of a class of energy–momentum integration schemes that exactly preserves the kinetic energy and the nonholonomic momenta replicating the continuous counterpart. Finally, we present numerical results that show the excellent conservation properties as well as the accuracy for the time-discretized governing equations.
A molecular brush with thermoresponsive poly(2-ethyl-2-oxazoline) side chains: a structural investigation
Authors: Kang Jia-Jhen , Shehu Kaltrina , Sachse Clemens , Jung Florian A. , Ko Chia-Hsin , Barnsley Lester C. , Jordan Rainer , Papadakis Christine M.
Published: August 2020

The thermoresponsive behavior of a poly(2-oxazoline)-based molecular brush is investigated in aqueous solution. The molecular brush under study, PiPOx100-g-PEtOx17, has a poly(2-isopropenyl-2-oxazoline) (PiPOx) backbone grafted with thermoresponsive poly(2-ethyl-2-oxazoline) (PEtOx) side chains. Since the backbone degree of polymerization is only a factor of ~ 6 higher than the ones of the side chains, it features an architecture between a star-like polymer and a comb-like polymer. Its aqueous solution exhibits lower critical solution temperature (LCST) behavior with a cloud point temperature Tcp = 40.5 °C at 30 g L−1. The temperature-dependent structural evolution is disclosed using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). An increase of the molecular brush size is found upon heating from room temperature to Tcp, which is attributed to the extension of the backbone resulting from the dehydration and collapse of the side chains. Above Tcp, the size decreases again, which indicates the collapse of the whole molecular brush. Large aggregates are found to be present in the solution in the temperature range 25–50 °C. These become more compact, as the temperature is increased across Tcp.
Time-space trade-offs in population protocols for the majority problem
Authors: Berenbrink Petra , Elsässer Robert , Friedetzky Tom , Kaaser Dominik , Kling Peter , Radzik Tomasz
Published: August 2020

Population protocols are a model for distributed computing that is focused on simplicity and robustness. A system of n identical agents (finite state machines) performs a global task like electing a unique leader or determining the majority opinion when each agent has one of two opinions. Agents communicate in pairwise interactions with randomly assigned communication partners. Quality is measured in two ways: the number of interactions to complete the task and the number of states per agent. We present protocols for the majority problem that allow for a trade-off between these two measures. Compared to the only other trade-off result (Alistarh et al. in Proceedings of the 2015 ACM symposium on principles of distributed computing, Donostia-San Sebastián, 2015), we improve the number of interactions by almost a linear factor. Furthermore, our protocols can be made uniform (working correctly without any information on the population size n), yielding the first uniform majority protocols that stabilize in a subquadratic number of interactions.
Pentose degradation in archaea: Halorhabdus species degrade D-xylose, L-arabinose and D-ribose via bacterial-type pathways
Authors: Sutter Jan-Moritz , Johnsen Ulrike , Reinhardt Andreas , Schönheit Peter
Published: August 2020

The degradation of the pentoses d-xylose, l-arabinose and d-ribose in the domain of archaea, in Haloferax volcanii and in Haloarcula and Sulfolobus species, has been shown to proceed via oxidative pathways to generate α-ketoglutarate. Here, we report that the haloarchaeal Halorhabdus species utilize the bacterial-type non-oxidative degradation pathways for pentoses generating xylulose-5-phosphate. The genes of these pathways are each clustered and were constitutively expressed. Selected enzymes involved in d-xylose degradation, xylose isomerase and xylulokinase, and those involved in l-arabinose degradation, arabinose isomerase and ribulokinase, were characterized. Further, d-ribose degradation in Halorhabdus species involves ribokinase, ribose-5-phosphate isomerase and d-ribulose-5-phosphate-3-epimerase. Ribokinase of Halorhabdus tiamatea and ribose-5-phosphate isomerase of Halorhabdus utahensis were characterized. This is the first report of pentose degradation via the bacterial-type pathways in archaea, in Halorhabdus species that likely acquired these pathways from bacteria. The utilization of bacterial-type pathways of pentose degradation rather than the archaeal oxidative pathways generating α-ketoglutarate might be explained by an incomplete gluconeogenesis in Halorhabdus species preventing the utilization of α-ketoglutarate in the anabolism.
Investigating voice in action teams: a critical review
Authors: Krenz Hanna L. , Burtscher Michael J.
Published: August 2020

Team communication is considered a key factor for team performance. Importantly, voicing concerns and suggestions regarding work-related topics—also termed speaking up—represents an essential part of team communication. Particularly in action teams in high-reliability organizations such as healthcare, military, or aviation, voice is crucial for error prevention. Although research on voice has become more important recently, there are inconsistencies in the literature. This includes methodological issues, such as how voice should be measured in different team contexts, and conceptual issues, such as uncertainty regarding the role of the voice recipient. We tried to address these issues of voice research in action teams in the current literature review. We identified 26 quantitative empirical studies that measured voice as a distinct construct. Results showed that only two-thirds of the articles provided a definition for voice. Voice was assessed via behavioral observation or via self-report. Behavioral observation includes two main approaches (i.e., event-focused and language-focused) that are methodologically consistent. In contrast, studies using self-reports showed significant methodological inconsistencies regarding measurement instruments (i.e., self-constructed single items versus validated scales). The contents of instruments that assessed voice via self-report varied considerably. The recipient of voice was poorly operationalized (i.e., discrepancy between definitions and measurements). In sum, our findings provide a comprehensive overview of how voice is treated in action teams. There seems to be no common understanding of what constitutes voice in action teams, which is associated with several conceptual as well as methodological issues. This suggests that a stronger consensus is needed to improve validity and comparability of research findings.