bluuebunny/crossref_metadata_2025 huggingface dataset:
Zimmermann–Laband syndrome in monozygotic twins with a mild neurobehavioral phenotype lacking gingival overgrowth—A case report of a novel KCNN3 gene variant
Authors: Schwarz Martin , Ryba Lukáš , Křepelová Anna , Moslerová Veronika , Zelinová Michaela , Turnovec Marek , Martinková Júlia , Kratochvílová Lenka , Drahanský Martin , Macek Milan , Havlovicová Markéta
Published: December 2021

Zimmermann–Laband syndrome is a rare, heterogeneous disorder characterized by gingival hypertrophy or fibromatosis, aplastic/hypoplastic nails, hypoplasia of the distal phalanges, hypertrichosis, various degrees of intellectual disability, and distinctive facial features. Three genes are considered causative for ZLS: KCNH1, KCNN3, and ATP6V1B2. We report on a pair of female concordant monozygotic twins, both carrying a novel pathogenic variant in the KCNN3 gene, identified using exome sequencing. Only six ZLS patients with the KCNN3 pathogenic variant have been reported so far. The twins show facial dysmorphism, hypoplastic distal phalanges, aplasia or hypoplasia of nails, and hypertrichosis. During infancy, they showed mild developmental delays, mainly speech. They successfully completed secondary school education and are socio‐economically independent. Gingival overgrowth is absent in both individuals. Our patients exhibited an unusually mild phenotype compared to published cases, which is an important diagnostic finding for proper genetic counseling for Zimmermann–Laband syndrome patients and their families.
Review of morphology, development, and evolution of the notarium in birds
Authors: Aires Alex S. , Reichert Leici M. , Müller Rodrigo T. , Andrade Marco B.
Published: December 2021

The notarium is a rigid bony structure, which resulted from the fusion of thoracic vertebrae of some pterosaurs and birds. It is high variable, ranging from two to six fused thoracic vertebrae. In this study, we reviewed and analyzed approximately 270 specimens of neornithine birds (representing 80% of the living orders) and some fossils in order to identify the number of fused vertebrae, degree and sites of vertebral fusion, occurrence of sutures, and other structures of potential phylogenetic and functional significance. These data were analyzed using a recent time‐calibrated molecular phylogenetic tree and principal component analyses analysis evaluating the relationship with long bones in order to reconstruct macroevolutionary trends related to the evolution of the notarium. The occurrence of this structure shows a mosaic distribution over neornithine phylogeny, originating several times independently, especially during the Paleogene, in predominantly ground‐dwelling forms. The notarium of these groups is characterized by: neural spines fused into single structure, intervertebral openings small to absent, large ventral keels forming ventral plates, and fused transverse processes. Derived neornithines, such as aquatic forms and long‐legged birds, have a tendency to display a decreased degree of fusion between the vertebrae, which may indicate a reduction or disappearance of the notarium.
Invasive cribriform carcinoma of the breast detected incidentally on computed tomography: A case report
Authors: Adachi Yasuhiro , Katsuki Takefumi , Sasaguri Takakazu , Hirata Keiji , Nagata Naoki
Published: December 2021

Invasive cribriform carcinoma is a rare type of invasive breast carcinoma, and a few cases have been reported. Its features are a cribriform pattern resembling the histological structures of cribriform ductal carcinoma in situ and an excellent prognosis. However, the extent of progress for intraductal extension must be carefully evaluated.
S‐Scheme Heterojunction and Defect Site Engineering on CuxIn5S8−Cu2‐ySe for Highly Efficient Photoreduction of CO2 to methanol
Authors: Zhao Hui , Duan Jihai , Zhang Zisheng , Wang Weiwen
Published: December 2021

The conversion and utilization of CO2 is imminent. Herein, the CuxIn5S8−CuySe S‐scheme heterojunction catalyst was successfully synthesized by the MOF‐derived method and the strategy of surface hydrogenation. In a photocatalytic performance test, Cu1.5In4.5S7.5−Cu1.45Se has excellent catalytic activity, and the production rate of methanol is 5.250 umol g−1 h−1, and the methanol selectivity is about 100 %. In addition, through DFT calculation and in situ FT‐IR, a new mechanism for the catalytic reduction of CO2 to methanol by bimetallic sites or variable valence metal sites is revealed, which opens up a new strategy to conversion of CO2 into energy fuel. This research couples charge accumulation centers, active sites and adsorption sites on the exposed active interface to enhance the visible light‐driven photocatalytic performance of the catalyst through defect engineering, morphology engineering and heterojunction engineering, which provides a promising approach to facilitate the selective photocatalytic reduction of CO2 to methanol.
Rearrangements in Scholl Reaction
Authors: Ponugoti Nagaraju , Parthasarathy Venkatakrishnan
Published: December 2021

Rearrangements in Scholl reaction are mostly serendipitous. The design of molecular precursors is what seems to guide the course of rearrangement. This review consolidates different classes of precursors used in Scholl reaction and their accompanying rearrangements that include aryl migration, migration followed by cyclization and skeletal rearrangements involving ring expansion, ring contraction and both, under the reaction conditions. The attempt in collating heretofore‐reported examples in this review is to guide designing appropriate precursors to predictably achieve complex molecular structures or nanographenes or defect‐nanographenes via rearrangement.
Photochemical Sandmeyer‐type Halogenation of Arenediazonium Salts
Authors: Sivendran Nardana , Belitz Florian , Sowa Prendes Daniel , Manu Martínez Ángel , Schmid Rochus , Gooßen Lukas J.
Published: December 2021

Trihalide salts were found to efficiently promote photochemical dediazotizing halogenations of diazonium salts. In contrast to classical Sandmeyer reactions, no metal catalysts are required to achieve high yields and outstanding selectivities for halogenation over competing hydridodediazotization. Convenient protocols are disclosed for synthetically meaningful brominations, iodinations, and chlorinations of diversely functionalized derivatives.
The effect of population and tourism factors on Covid‐19 cases in Italy: Visual data analysis and forecasting approach
Authors: Uğuz Sezer , Yağanoğlu Mete , Özyer Barış , Özyer Gülşah Tümüklü , Tokdemir Gül
Published: December 2021

At the beginning of 2020, the new coronavirus disease (Covid‐19), a deadly viral illness, is declared as a public health emergency situation by WHO. Consequently, it is accepted as pandemic that affected millions of people worldwide. Italy is one of the most affected countries by Covid‐19 disease among the world. In this article, our main goal is to investigate the effect of intensity of Covid‐19 cases based on the population size and tourism factors in certain regions of Italy by visual data analysis. The regions of Lombardia, Veneto, Campania, Emilia‐Romagna, Piemonte are the top five regions covering 58.50% of the total Covid‐19 cases diagnosed in Italy. It has been shown by visual data analysis that population and tourism factors play an important role in the spread of Covid‐19 cases in these five regions. In addition, a prediction model was created using Bi‐LSTM and ARIMA algorithms to forecast the number of Covid‐19 cases occurring in these five regions in order to take early action. We can conclude that these northern regions have been affected mostly by Covid‐19 and the distribution of the resident population and tourist flow factors affected the number of Covid‐19 cases in Italy.
Implementation and verification of a conservative,multi‐species,gyro‐averaged, full‐f,Lenard‐Bernstein/Dougherty collision operator in the gyrokinetic codeGENE‐X
Authors: Ulbl Philipp , Michels Dominik , Jenko Frank
Published: December 2021

Gyrokinetic simulations are among the main tools to predict turbulent transport in the core of fusion devices. Unlike the core, the plasma edge and scrape‐off layer are characterized by lower temperature and higher collisionality. To allow for realistic gyrokinetic modelling of edge and scrape‐off layer turbulence, it is crucial to include collisional effects into the simulations. In this work, we present a full‐f, gyro‐averaged, multi‐species, Lenard‐Bernstein/Dougherty (LBD) collision operator, for the use in the gyrokinetic turbulence codeGENE‐X. The operator accounts for exact particle density, momentum, and energy conservation, with collision frequencies chosen such that the momentum or temperature relaxation rates of the Boltzmann collision operator are recovered. We provide a conservative second‐order finite‐volume implementation of the operator and present a thorough verification. Due to the excellent conservation properties of the finite‐volume implementation, it is possible to use a coarser velocity space grid, save computational resources and, as a consequence, perform simulations of larger fusion devices.
Beyond illness: Variation in haemosporidian load explains differences in vocal performance in a songbird
Authors: Lopez‐Serna Salome , Gonzalez‐Quevedo Catalina , Rivera‐Gutierrez Hector Fabio
Published: December 2021

In animal communication, signals are expected to evolve to be honest, so that receivers avoid being manipulated by signalers. One way that signals can evolve to be honest is for them to be costly, with only high‐quality individuals being able to bear the costs of signal expression. It has been proposed that parasites can introduce costs that affect the expression of sexually selected traits, and there is evidence to support the role of parasitism in modulating animal behavior. If host infection status or intensity is found to relate to differences in signal expression, it may indicate a fitness cost that mediates honesty of signals. Birdsong is a good model for testing this, and physically challenging songs representing complex motor patterns provide a good example of sexually selected traits indicating individual condition. We performed a field study to evaluate the relationship between song performance and avian malaria infection in a common songbird. Previous work on this subject has almost always evaluated avian malaria in terms of binary infection status; however, parasitemia—infection intensity—is rarely assessed, even though differences in parasite load may have profound physiological consequences. We estimated parasitemia levels by using real‐time PCR. We found that birds with higher parasitemia displayed lower vocal performance, providing evidence that this song trait is an honest signal of parasitic load of haemosporidian parasites. To our knowledge, this study links parasite load and the expression of a sexually selected trait in a way that has not been addressed in the past. Studies using song performance traits and parasitemia offer an important perspective for understanding evolution of characters via sexual selection.
Geographic variation in the matching between call characteristics and tympanic sensitivity in the Weeping lizard
Authors: Labra Antonieta , Reyes‐Olivares Claudio , Moreno‐Gómez Felipe N. , Velásquez Nelson A. , Penna Mario , Delano Paul H. , Narins Peter M.
Published: December 2021

Effective communication requires a match among signal characteristics, environmental conditions, and receptor tuning and decoding. The degree of matching, however, can vary, among others due to different selective pressures affecting the communication components. For evolutionary novelties, strong selective pressures are likely to act upon the signal and receptor to promote a tight match among them. We test this prediction by exploring the coupling between the acoustic signals and auditory sensitivity in Liolaemus chiliensis, the Weeping lizard, the only one of more than 285 Liolaemus species that vocalizes. Individuals emit distress calls that convey information of predation risk to conspecifics, which may respond with antipredator behaviors upon hearing calls. Specifically, we explored the match between spectral characteristics of the distress calls and the tympanic sensitivities of two populations separated by more than 700 km, for which previous data suggested variation in their distress calls. We found that populations differed in signal and receptor characteristics and that this signal variation was explained by population differences in body size. No precise match occurred between the communication components studied, and populations differed in the degree of such correspondence. We suggest that this difference in matching between populations relates to evolutionary processes affecting the Weeping lizard distress calls.
Pathophysiology of Takotsubo syndrome – a joint scientific statement from the Heart Failure Association Takotsubo Syndrome Study Group and Myocardial Function Working Group of the European Society of Cardiology – Part 1: overview and the central role for catecholamines and sympathetic nervous system
Authors: Omerovic Elmir , Citro Rodolfo , Bossone Eduardo , Redfors Bjorn , Backs Johannes , Bruns Bastian , Ciccarelli Michele , Couch Liam S. , Dawson Dana , Grassi Guido , Iacoviello Massimo , Parodi Guido , Schneider Birke , Templin Christian , Ghadri Jelena R. , Thum Thomas , Chioncel Ovidiu , Tocchetti C. Gabriele , van der Velden Jolanda , Heymans Stephane , Lyon Alexander R.
Published: December 2021

This is the first part of a scientific statement from the Heart Failure Association (HFA) of the European Society of Cardiology focused upon the pathophysiology of Takotsubo syndrome and is complimentary to the previous HFA position statement on Takotsubo syndrome which focused upon clinical management. In part 1 we provide an overview of the pathophysiology of Takotsubo syndrome and fundamental questions to consider. We then review and discuss the central role of catecholamines and the sympathetic nervous system in the pathophysiology, and the direct effects of high surges in catecholamines upon myocardial biology including β‐adrenergic receptor signalling, G‐protein coupled receptor kinases, cardiomyocyte calcium physiology, myofilament physiology, cardiomyocyte gene expression, myocardial electrophysiology and arrhythmogenicity, myocardial inflammation, metabolism and energetics. The integrated effects upon ventricular haemodynamics are discussed and integrated into the pathophysiological model.
Iridium‐Catalyzed β‐C(sp2)−H Borylation of Enamides – Access to 3,3‐Dihalogeno‐2‐methoxypiperidines
Authors: Gillaizeau Isabelle , Dondasse Ismaël , Nicolas Cyril , Mimoun Liliane , Sukach Volodymyr , Meudal Hervé
Published: December 2021

An efficient catalytic preparation of synthetically useful new β‐borylated enamides was achieved under relatively mild conditions via a regioselective iridium‐catalyzed C(sp2)−H borylation. The method features broad substrate scope, good functional group tolerance and efficient scale‐up. These C‐3 borylated enamides can be advantageously exploited in cross‐coupling reactions and converted into valuable 3,3‐dihalogeno‐2‐methoxypiperidines in very short reaction times.
Experimental Research on the Forward and Reverse Rotation Characteristics of a Pneumatic Motor for a Microscale Compressed Air Energy Storage System
Authors: Xu Yonghong , Zhang Hongguang , Yang Fubin , Tong Liang , Yan Dong , Yang Yifan , Wang Yan , Wu Yuting
Published: December 2021

Microscale compressed air energy storage is not dependent on geographical environment, exhibits a flexible layout, and is especially suitable for distributed energy systems. Herein, a test bench of microscale compressed air energy storage is established. The effects of key parameters, such as regulated pressure, current, voltage, and rotating speed, on the output performance of a pneumatic motor (PM) and generator are examined. The power performance, economic performance, and energy efficiency of the PM in forward and reverse rotations are also investigated. The differences in the output performances of the PM and generator under the forward and reverse rotations of the PM are analyzed. Experimental results show that the PM's power performance, economy, and efficiency in forward rotation are greater than those in reverse rotation. The power output of the generator with the PM in forward rotation is greater than that in reverse rotation. The maximum values of the power output and efficiency and the minimum compressed air consumption rate of the PM are 650 W, 6.92%, and 0.165 g J−1, respectively. The maximum efficiency of the generator is 94.35%.
The evolutionary significance of human brown adipose tissue: Integrating the timescales of adaptation
Authors: Levy Stephanie B. , Leonard William R.
Published: December 2021

While human adaptability is regarded as a classical topic in anthropology, recent work provides new insight into metabolic adaptations to cold climates and the role of phenotypic plasticity in human evolution. A growing body of literature demonstrates that adults retain brown adipose tissue (BAT) which may play a role in non‐shivering thermogenesis. In this narrative review, we apply the timescales of adaptation framework in order to explore the adaptive significance of human BAT. Human variation in BAT is shaped by multiple adaptive modes (i.e., allostasis, acclimatization, developmental adaptation, epigenetic inheritance, and genetic adaptation), and together the adaptive modes act as an integrated system. We hypothesize that plasticity in BAT facilitated the successful expansion of human populations into circumpolar regions, allowing for selection of genetic adaptations to cold climates to take place. Future research rooted in human energetics and biocultural perspectives is essential for understanding BAT's adaptive and health significance.
Allocation of Opportunities to Participate in Clinical Trials during the Covid‐19 Pandemic and Other Public Health Emergencies
Authors: Spector‐Bagdady Kayte , Lynch Holly Fernandez , Bierer Barbara E. , Gelinas Luke , Hull Sara Chandros , Magnus David , Meyer Michelle N. , Sharp Richard R. , Sugarman Jeremy , Wilfond Benjamin S. , Yearby Ruqaiijah , Mohapatra Seema
Published: December 2021

Covid‐19 raised many novel ethical issues including regarding the allocation of opportunities to participate in clinical trials during a public health emergency. In this article, we explore how hospitals that have a scarcity of trial opportunities, either overall or in a specific trial, can equitably allocate those opportunities in the context of an urgent medical need with limited therapeutic interventions. We assess the three main approaches to allocating trial opportunities discussed in the literature: patient choice, physician referral, and randomization/lottery. As, we argue, none of the three typical approaches are ethically ideal for allocating trial opportunities in the pandemic context, many hospitals have instead implemented hybrid solutions. We offer practical guidance to support those continuing to face these challenges, and we analyze options for the future.
Crystalline Supramolecular Polymers: Dynamics, Chirality, and Function
Authors: Stupp Samuel I. , Palmer Liam C. , Sai Hiroaki
Published: December 2021

Inspired by biological systems, supramolecular polymers have emerged over the past three decades as an important way to form functional structures with potential to tune the internal order and dynamics and to create materials with the potential for responsiveness, reconfigurability, and recyclability. We focus here on several recent examples of ordered supramolecular polymers with a significant extent of internal order that results in crystalline molecular packing, or with dynamics that allow them to undergo structural reconfiguration. These examples highlight the spectrum of molecular mobility that the noncovalently bound constituents can experience. These materials have found interesting functions in their interaction with chiral biological systems and in their ability to form materials with interesting optoelectronic and photocatalytic behavior.
Osteodentin in the Atlantic wolffish (Anarhichas lupus): Dentin or bone?
Authors: Thangadurai Senthil , Brumfeld Vlad , Milgram Joshua , Li Ling , Shahar Ron
Published: December 2021

The teeth of actinopterygian fish, like those of mammals, consist of a thin outer hyper‐mineralized layer (enamel or enameloid) that surrounds a core of dentin. While all mammalian species have a single type of dentin (called orthodentin), various dentin types have been reported in the teeth of actinopterygian fish. The most common type of actinopterygian fish dentin is orthodentin. However, the second most common type of actinopterygian fish dentin, called osteodentin, found in several teleost species and in many Selachians, is structurally radically different from orthodentin. Osteodentin, comprising denteons and inter‐denteonal matrix, is characterized by an appearance that is similar to mammalian osteonal bone, however, it lacks cells and a lacuno‐canalicular system. The current consensus is that although osteodentin is morphologically different from orthodentin, it is a true dentinal material, the product of odontoblast cells. We present the results of a study of osteodentin found in the teeth of the Atlantic wolffish, Anarhichas lupus. Using a variety of microscopy techniques, high‐resolution microCT scans, and micro‐indentation we describe the three‐dimensional structure of both its components (denteons and inter‐denteonal matrix), as well as their mineral density distribution and mechanical properties, at several length‐scales. We show that wolffish osteodentin is remarkably similar to the anosteocytic bone of the swords of several swordfish species. We also describe the three‐dimensional network of canals found in mature osteodentin. The high density of these canals in a metabolically inactive, acellular tissue casts doubt upon the accepted paradigm, that the canals house a vascular network.
Synthesis and Characterization of Functional Monomer N‐Vinyl Formamide (NVF)
Authors: Yao Kai , Wang Songlin , Wang Qian , Yang Xuxu
Published: December 2021

N‐vinyl formamide (NVF) is successfully synthesized by using the intermediate polystyrene maleic anhydride ester. The prepared NVF owns high purity and the diacid as a by‐product of synthesis can be reused. N‐a‐hydroxyethyl formamide (NHEF) is synthesized by using acetaldehyde and formamide as raw materials in the presence of basic catalyst. Acetaldehyde is purified by distillation under reduced pressure and dried with anhydrous magnesium sulfate. Low molecular weight styrene/maleic anhydride copolymer (SMA) is synthesized by the reaction of styrene and maleic anhydride in the presence of benzoyl peroxide initiator using acetone as solvent. The intermediate polystyrene maleic anhydride ester (NHEF–ADDUCT) is synthesized with SMA and NHEF as raw materials. Finally, the obtained NHEF–ADDUCT is cracked and the target product NVF is isolated and purified. The NVF is characterized by Fourier transform infrared spectroscopy, gas chromatography (GC), 1H‐NMR, and 13C‐NMR. The purity of NVF is 86.7% as measured by iodometric method and GC internal standard method, indicating the small amount of impurity formamide in it.
Thermodynamic analysis of nanocrystalline solid solutions formation in copper‐lead‐tin ternary immiscible system during mechanical alloying
Authors: Wu Z.F. , Zhu Z.Y. , Wu R.
Published: December 2021

In this paper, copper‐15 wt.%‐lead‐1 wt.%‐tin (Cu‐15wt %Pb‐1wt %Sn), copper‐15 wt.%‐lead‐2 wt.%‐tin (Cu‐15wt %Pb‐2wt %Sn) and copper‐15 wt.%‐lead‐3 wt.%‐tin (Cu‐15wt %Pb‐3wt %Sn) powder mixtures were mechanically alloyed in order to study the solid solubility extension during the alloying process. Nanocrystalline supersaturated solid solutions have been prepared in copper‐lead‐tin (Cu−Pb−Sn) ternary immiscible system by mechanical alloying (MA). Based on the thermodynamic model, the Gibbs free energy changes in these alloys during the formation of solid solutions are calculated to be positive, which means that there are no driving force to form solid solutions in copper‐lead‐tin ternary immiscible system. It was found that a large fraction of grain boundaries and a high density of dislocations play a significant role in the solid solubility extension in copper‐lead‐tin ternary immiscible system.
The effects of laser machining parameters on roughness and contact angle for boron carbide ceramic surface
Authors: Canel T. , Gölbaşi F. , Gezer Z.
Published: December 2021

Hydrophobicity or Hydrophilicity properties of boron carbide ceramic surface can be controlled by manipulating the roughness of the surface and thus the contact angle. In this study, the wettability of the boron carbide surface was manipulated by laser with different parameters. The contact angle was measured at 9th seconds after the droplet was dropped onto the laser‐treated surface. Also, the change in contact angle in the first 9 seconds after the droplet was dropped was examined. For a more hydrophobic surface, it was aimed to have the largest contact angle at 9th seconds after the droplet was dropped and the smallest change with time in contact angle. The effects of laser scan speed, power, frequency and overlap rate on the contact angle of the treated surface were investigated using the Taguchi method. It was calculated to what extent each examined parameter affected the result. The effectiveness rates of the two most effective parameters which were scan speed and overlap rate were obtained. Since the results of the verification tests performed to confirm the results obtained are quite compatible with the results predicted by the Taguchi method, the Taguchi method can be regarded as a reliable method in optimizing laser parameters.
Relationship of Genotype, Phenotype, and Treatment in Dopa‐Responsive Dystonia: MDSGene Review
Authors: Weissbach Anne , Pauly Martje G. , Herzog Rebecca , Hahn Lisa , Halmans Sara , Hamami Feline , Bolte Christina , Camargos Sarah , Jeon Beomseok , Kurian Manju A. , Opladen Thomas , Brüggemann Norbert , Huppertz Hans‐Jürgen , König Inke R. , Klein Christine , Lohmann Katja
Published: December 2021

Background

Pathogenic variants in 5 genes (GCH1, TH, PTS, SPR, and QDPR), involved in dopamine/tetrahydrobiopterin biosynthesis or recycling, have been linked to Dopa‐responsive dystonia (DRD). Diagnosis and treatment are often delayed due to high between‐ and within‐group variability.

Objectives

Comprehensively analyzed individual genotype, phenotype, treatment response, and biochemistry information.

Methods

734 DRD patients and 151 asymptomatic GCH1 mutation carriers were included using an MDSGene systematic literature review and an automated classification approach to distinguish between different forms of monogenic DRDs.

Results

Whereas dystonia, L‐Dopa responsiveness, early age at onset, and diurnal fluctuations were identified as red flags, parkinsonism without dystonia was rarely reported (11%) and combined with dystonia in only 18% of patients. While sex was equally distributed in autosomal recessive DRD, there was female predominance in autosomal dominant DYT/PARK‐GCH1 patients accompanied by a lower median age at onset and more dystonia in females compared to males. Accordingly, the majority of asymptomatic heterozygous GCH1 mutation carriers (>8 years of age) were males. Multiple other subgroup‐specific characteristics were identified, showing high accuracy in the automated classification approach: Seizures and microcephaly were mostly seen in DYT/PARK‐PTS, autonomic symptoms appeared commonly in DYT/PARK‐TH and DYT/PARK‐PTS, and sleep disorders and oculogyric crises in DYT/PARK‐SPR. Biochemically, homovanillic acid and 5‐hydroxyindoleacetic acid in CSF were reduced in most DRDs, but neopterin and biopterin were increased only in DYT/PARK‐PTS and DYT/PARK‐SPR. Hyperphenylalaninemia was seen in DYT/PARK‐PTS, DYT/PARK‐QDPR, and rarely reported in autosomal recessive DYT/PARK‐GCH1.

Conclusions

Our indicators will help to specify diagnosis and accelerate start of treatment. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
Integrated MRI‐guided proton therapy planning: Accounting for the full MRI field in a perpendicular system
Authors: Burigo Lucas N , Oborn Bradley M
Published: December 2021

Purpose

To present a first study on the treatment planning feasibility in perpendicular field MRI‐integrated proton therapy that considers the full transport of protons from the pencil beam scanning (PBS) assembly to the patient inside the MRI scanner.

Methods

A generic proton PBS gantry was modeled as being integrated with a realistic split‐bore MRI system in the perpendicular orientation. MRI field strengths were modeled as 0.5, 1, and 1.5 T. The PBS beam delivery and dose calculation was modeled using the TOPAS Monte Carlo toolkit coupled with matRad as the optimizer engine. A water phantom, liver, and prostate plans were evaluated and optimized in the presence of the full MRI field distribution. A simple combination of gantry angle offset and small PBS nozzle skew was used to direct the proton beams along a path that closely follows the reference planning scenario, that is, without magnetic field.

Results

All planning metrics could be successfully achieved with the inclusion of gantry angle offsets in the range of 8–29 when coupled with a PBS nozzle skew of 1.6–4.4. These two hardware‐based corrections were selected to minimize the average Euclidean distance (AED) in the beam path enabling the proton beams to travel inside the patient in a path that is close to the original path (AED smaller than 3 mm at 1.5 T). Final dose optimization, performed through further changes in the PBS delivery, was then shown to be feasible for our selection of plans studied yielding comparable plan quality metrics to reference conditions.

Conclusions

For the first time, we have shown a robust method to account for the full proton beam deflection in a perpendicular orientation MRI‐integrated proton therapy. These results support the ongoing development of the current prototype systems.
Three‐dimensional reduced field‐of‐view imaging (3D‐rFOVI)
Authors: Sun Kaibao , Zhong Zheng , Dan Guangyu , Karaman Muge , Luo Qingfei , Zhou Xiaohong Joe
Published: December 2021

Purpose

This study aimed at developing a 3D reduced field‐of‐view imaging (3D‐rFOVI) technique using a 2D radiofrequency (RF) pulse, and demonstrating its ability to achieve isotropic high spatial resolution and reduced image distortion in echo planar imaging (EPI).

Methods

The proposed 3D‐rFOVI technique takes advantage of a 2D RF pulse to excite a slab along the conventional slice‐selection direction (i.e., z‐direction) while limiting the spatial extent along the phase‐encoded direction (i.e., y‐direction) within the slab. The slab is phase‐encoded in both through‐slab and in‐slab phase‐encoded directions. The 3D‐rFOVI technique was implemented at 3T in gradient‐echo and spin‐echo EPI pulse sequences for functional MRI (fMRI) and diffusion‐weighted imaging (DWI), respectively. 3D‐rFOVI experiments were performed on a phantom and human brain to illustrate image distortion reduction, as well as isotropic high spatial resolution, in comparison with 3D full‐FOV imaging.

Results

In both the phantom and the human brain, image voxel dislocation was substantially reduced by 3D‐rFOVI when compared with full‐FOV imaging. In the fMRI experiment with visual stimulation, 3D isotropic spatial resolution of (2 × 2 × 2 mm3) was achieved with an adequate signal‐to‐noise ratio (81.5) and blood oxygen level‐dependent (BOLD) contrast (2.5%). In the DWI experiment, diffusion‐weighted brain images with an isotropic resolution of (1 × 1 × 1 mm3) was obtained without appreciable image distortion.

Conclusion

This study indicates that 3D‐rFOVI is a viable approach to 3D neuroimaging over a zoomed region.
Characterization and correction of time‐varying eddy currents for diffusion MRI
Authors: Valsamis Jake J. , Dubovan Paul I. , Baron Corey A.
Published: December 2021

Purpose

To develop and test a method for reducing artifacts due to time‐varying eddy currents in oscillating gradient spin‐echo (OGSE) diffusion images.

Methods

An in‐house algorithm (TVEDDY), that for the first time retrospectively models eddy current decay, was tested on pulsed gradient spin echo and OGSE brain images acquired at 7 T. Image pairs were acquired using opposite polarity diffusion gradients. A three‐parameter exponential decay model (two amplitudes and a time constant) was used to characterize and correct eddy current distortions by minimizing the intensity difference between image pairs. Correction performance was compared with conventional correction methods by evaluating the mean squared error (MSE) between diffusion‐weighted images acquired with opposite polarity diffusion gradients. As a ground‐truth comparison, images were corrected using field dynamics up to third order in space, measured using a field monitoring system.

Results

Time‐varying eddy currents were observed for OGSE, which introduced blurring that was not reduced using the traditional approach but was diminished considerably with TVEDDY and field monitoring–informed model‐based reconstruction. No MSE difference was observed between the conventional approach and TVEDDY for pulsed gradient spin echo, but for OGSE TVEDDY resulted in significantly lower MSE than the conventional approach. The field‐monitoring reconstruction had the lowest MSE for both pulsed gradient spin echo and OGSE.

Conclusion

This work establishes that it is possible to estimate time‐varying eddy currents from the actual diffusion data, which provides substantial image‐quality improvements for gradient‐intensive diffusion MRI acquisitions like OGSE.
Biotic and Abiotic Factors Affecting Feeding Success of Early Juvenile Lake Whitefish in Lakes Michigan and Huron
Authors: Pothoven Steven , Olds Chris
Published: December 2021

Feeding success is associated with increased growth and survival during early life stages for fish, and understanding the factors that influence feeding success is a critical step toward predicting future recruitment to the fishery. The goal of our study was to test whether various biotic and abiotic factors, including prey abundance, fish abundance, and water temperature, affected the feeding success of early juvenile Lake Whitefish Coregonus clupeaformis from Lakes Michigan and Huron. Higher feeding success, which was determined using residuals from average weights of consumed prey for a given length fish, was associated with more rapid growth rates in length and depended on multiple factors. Although the relationships were not overly strong, one factor that was most consistently associated with increased feeding success was available zooplankton biomass in combination with some other factor(s) such as water temperature and/or total fish or Lake Whitefish density. There was no difference in diet composition or the available zooplankton community composition among four different levels of feeding success. Feeding success measures help integrate complex environmental factors that can vary with fish ontogeny. In turn, feeding success has the potential to be an important metric for Lake Whitefish fishery management strategies that critically need to account for the myriad factors influencing survival and growth of prerecruits to the fishery.
Mesoporous Silica Nanoparticles Functionalized with Amino Groups for Biomedical Applications
Authors: Estevão Bianca Martins , Miletto Ivana , Hioka Noboru , Marchese Leonardo , Gianotti Enrica
Published: December 2021

The synthesis and characterization of amino‐functionalized mesoporous silica nanoparticles are presented following two different synthetic methods: co‐condensation and post‐synthesis grafting of 3‐aminopropyltriethoxysilane. The amino groups’ distribution on the mesoporous silica nanoparticles was evaluated considering the aggregation state of a grafted photosensitizer (Verteporfin) by using spectroscopic techniques. The homogeneous distribution of amino groups within the silica network is a key factor to avoid aggregation during further organic functionalization and to optimize the performance of functionalized silica nanoparticles in biomedical applications. In addition, the formation of a protein corona on the external surface of both bare and amino‐functionalized mesoporous silica was also investigated by adsorbing Bovine Serum Albumin (BSA) as a model protein. The adsorption of BSA was found to be favorable, reducing the aggregation phenomena for both bare and amino‐modified nanoparticles. Nevertheless, the dispersant effect of BSA was much more evident in the case of amino‐modified nanoparticles, which reached monodispersion after adsorption of the protein, thus suggesting that amino‐modified nanoparticles can benefit from protein corona formation for preventing severe aggregation in biological media.
Differences in mortality rate among patients hospitalized with severe COVID‐19 according to their body mass index
Authors: Albarrán‐Sánchez Alejandra , Ramírez‐Rentería Claudia , Anda‐Garay Juan C. , Noyola‐García Maura E. , Alberti‐Minutti Paolo , Flores‐Padilla Guillermo , Guizar‐García Luis A. , Contreras‐García Carlos E. , Marrero‐Rodríguez Daniel , Taniguchi‐Ponciano Keiko , Mercado Moises , Ferreira‐Hermosillo Aldo
Published: December 2021

Background

Obesity has been described as a risk factor for COVID‐19 severity and mortality. Previous studies report a linear association between BMI and adverse outcomes, meanwhile in other critical illness, excessive fat tissue is related to improved survival. Whether different BMI is related with the survival of patients with severe COVID‐19 deserves further analysis.

Objective

To determine the mortality rate among hospitalized patients with severe COVID‐19 stratified according to BMI.

Methods

The clinical files of all patients hospitalized from March to December 2020 with a positive PCR test for SARS‐CoV‐2 discharged due to improvement or death, were analyzed. A mixed effects logistic regression was carried out to determine which clinical and biochemical characteristics and comorbidities were associated with in‐hospital mortality.

Results

The cohort consisted of 608 patients with a median age of 59 years (interquartile ranges, IQR 46–69 years), median BMI of 28.7 kg/m2 (IQR 25.4–32.4 kg/m2), 65.5% were male. In‐hospital mortality rate was 43.4%. Of the cohort 0.8% had low weight, 20.9% normal weight, 36.0% overweight, 26.5% obesity grade I, 10.2% obesity grade II and 5.6% obesity grade III. Mortality rate was highest in patients with low weight (80%), followed by patients with obesity grade III (58.8%) and grade II (50.0%). Overweight and underweight/obesity grade III were associated with higher mortality (OR of 9.75 [1.01–1.10] and OR 4.08 [1.64–10.14]), after adjusting by sex and age.

Conclusions

The patients in the underweight/overweight and grade 3 obesity categories are at higher risk of COVID‐19 related mortality, compared to those with grade I or II obesity.
Modeling technique for the linear‐elastic material behavior of short fiber‐reinforced composites using random fields
Authors: Rauter Natalie , Lammering Rolf
Published: December 2021

The microstructure of short fiber‐reinforced composites is probabilistic due to the manufacturing process. The induced spatial fluctuation of the material properties cannot be covered by a homogeneous modeling concept since this technique leads to a deterministic representation of the material. In this study, a numerical approach is presented that includes the fluctuation of the material properties on the component level. The modeling approach consists of two steps. First, the probabilistic characteristics of the microstructure are derived by numerical simulation on the mesoscale. The obtained effective material properties and the correlation structure of the stiffness matrix elements are used to discretize second‐order Gaussian random fields for the material representation on the component level in a second step. To validate all results nanoindentation and tensile tests are conducted. It is shown that the suggested approach leads to excellent results comprising the overall structural response as well as the spatial fluctuation of the material properties. Hence, the introduced technique is suitable for modeling the linear‐elastic behavior of short fiber‐reinforced composites.
Johannes Kepler's comments in Jost Bürgi's manuscript on “Coss”
Authors: Ullrich Peter
Published: December 2021

In the 1590ies Jost Bürgi calculated a highly precise table of the sine function with an increment of only 2 angular seconds. As a commentary to this table he wrote a manuscript on “Coss”, i.e., elementary algebra, which contains discussions of numerical methods that he used for the calculation of the table. Between 1596 and 1603, he handed the manuscript over to Johannes Kepler for editorial revision before its publication. Kepler's comments in the text are all the more interesting as he sharply criticized Bürgi's methods in his “Harmonices Mundi” in 1619.
On the influence of surface roughness on friction‐induced oscillations
Authors: Oestringer Lukas J. , Proppe Carsten
Published: December 2021

The influence of surface roughness on friction‐induced oscillations due to non‐conservative coupling is investigated. The classical non‐conservative coupling model is extended by a stochastic friction coefficient which is modeled as colored noise. Two coupled and parametrically excited stochastic differential equations are obtained. The almost sure stability is analyzed by means of the top Lyapunov exponent Λ1 which indicates instability in the case of Λ1 > 0 and asymptotic stability in the case of Λ1 < 0. An influence of the stochastic friction coefficient on stability is found which manifests in the occurrence of parametrically excited fundamental and combination resonances.
Efficient domain decomposition based reliability analysis for polymorphic uncertain material parameters
Authors: Schmidt Albrecht , Lahmer Tom
Published: December 2021

Realistic uncertainty description incorporating aleatoric and epistemic uncertainties can be described within the framework of polymorphic uncertainty, which is computationally demanding. Utilizing a domain decomposition approach for random field based uncertainty models the proposed level‐based sampling method can reduce these computational costs significantly and shows good agreement with a standard sampling technique. While 2‐level configurations tend to get unstable with decreasing sampling density 3‐level setups show encouraging results for the investigated reliability analysis of a structural unit square.
Oblique undular hydraulic jumps in turbulent free‐surface flows
Authors: Murschenhofer Dominik
Published: December 2021

Steady turbulent near‐critical free‐surface flow over a slightly inclined bottom with an oblique roughness discontinuity is considered. An asymptotic analysis for Froude numbers close to the critical value 1 and large Reynolds numbers results in an extended Korteweg–de Vries (KdV) equation describing the free‐surface elevation without the need of turbulence modeling. Two new integral relations can be derived from the extended KdV equation. For enlarged downstream bottom roughness, a new type of undular jump solutions with fully developed flow both upstream and downstream exists. Numerical solutions of the extended KdV equation show that an increasing downstream bottom roughness enhances the development of undulations.
Experimental study on cavitation in rubber vulcanizates subjected to constrained tensile deformation
Authors: Euchler Eric , Bernhardt Ricardo , Schneider Konrad , Tada Toshio , Wießner Sven
Published: December 2021

Advanced experimental techniques in terms of in situ dilatometry and X‐ray microtomography as well as microscopy have been used to investigate cavitation in unfilled and carbon black reinforced styrene‐butadiene rubber vulcanizates. The work introduces into the features of multiaxial deformation and damage behavior characterized by the formation and growth of internal defects – so‐called cavities. Experimental evidence indicates that cavitation damage occurs in rubber vulcanizates subjected to constrained tensile deformation, while the number of cavities is increasing, but the average cavity size is decreasing with increasing degree of constraints.
Modeling of dynamic behavior in saturated porous media using the Houbolt time integration scheme
Authors: Bergmann Julia Nicolina , Schwarz Alexander , Bluhm Joachim , Schröder Jörg
Published: December 2021

The following work deals with the inclusion of dynamic effects into the Theory of Porous Media (TPM) using the approach of Breuer [1] for a consolidation simulation of soil. After a rough review of the fundamental equations, a numerical boundary value problem (BVP) is shown emphasizing the importance of the choice of the time integration scheme. A drawback in the use of the Houbolt time integration scheme, regarding a change of Δt during the calculation, leads to two simple solution strategies to solve this complication.
Recent Developments in the Field of Modified Patankar‐Runge‐Kutta‐methods
Authors: Izgin Thomas , Kopecz Stefan , Meister Andreas
Published: December 2021

Modified Patankar‐Runge‐Kutta (MPRK) schemes are numerical one‐step methods for the solution of positive and conservative production‐destruction systems (PDS). They adapt explicit Runge‐Kutta schemes in a way to ensure positivity and conservation of the numerical approximation irrespective of the chosen time step size. Due to nonlinear relationships between the next and current iterate, the stability analysis for such schemes is lacking. In this work, we introduce a strategy to analyze the MPRK22(α)‐schemes in the case of positive and conservative PDS. Thereby, we point out that a usual stability analysis based on Dahlquist's equation is not possible in order to understand the properties of this class of schemes.
Design of a 3D composite structure considering data uncertainties and various failure mechanisms
Authors: Drieschner Martin , Petryna Yuri , Eichner Lukas
Published: December 2021

This study has been performed within the research project MuScaBlaDes “Multi‐scale failure analysis with polymorphic uncertainties for optimal design of rotor blades” as part of the DFG Priority Programme (SPP 1886) “Polymorphic Uncertainty Modelling for the Numerical Design of Structures” started in 2016. A three‐dimensional structure consisting of glass fiber reinforced plastic (GFRP) components glued by epoxy resin (EP) is designed considering uncertainties in geometrical and material properties. Different stresses, the vertical deflection, the global stability and the fatigue behavior should fulfill the defined restrictions in the optimization process. A global optimum is searched for four different topologies by minimizing the elastic strain energy density as well as the overall manufacturing costs.
On the evolution of residual stresses due to cooling considering martensitic phase transformation
Authors: Uebing Sonja , Brands Dominik , Scheunemann Lisa , Schröder Jörg
Published: December 2021

The direct consideration of residual stresses can positively influence the properties of a component and offers a new perspective compared to the typical strategy of avoiding residual stresses. Instead of minimizing residual stresses in forming processes, their consideration can positively influence the properties of the final component. For instance, the targeted adjustment of residual stresses can extend the service life or durability and improve the manufacturability of metal components. This is investigated in current research using experimental and numerical analyses on a cylindrical component with eccentric hole made of steel 100Cr6. Here, the cooling process after hot bulk forming is simulated to analyze the influence of microscopic phase evolution on the macroscopic stress distribution. For this purpose, different variants of the microstructural evolution described by a random process are compared.