bluuebunny/crossref_metadata_2025_split huggingface dataset:
How Safe Is the Use of Ultrasound in Prenatal Medicine? Facts and Contradictions. Part 1 – Ultrasound-Induced Bioeffects
Authors: Dudwiesus Heiko , Merz Eberhard 
Published: October 2020

AbstractThe “Ordinance on Protection Against the Harmful Effects of Non-Ionizing Radiation in Human Applications” will go into effect at the beginning of 2021 1. § 10 of this ordinance prohibits non-medical fetal ultrasound exposure thereby resulting in uncertainty, particularly among affected patients, with respect to the generally accepted theory regarding the lack of ultrasound side effects. Although not a single study has shown a detrimental effect on fetal or child development following exposure to ultrasound, the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety has justified the ban with the purely hypothetical possibility of an unidentified side effect. The first part of the following study shows which ultrasound-induced biophysical effects are known and which dose-dependent threshold values must be taken into consideration. In particular, the study focuses on the well-researched heat effect with some in vivo measurements in humans showing that the actual temperature increase is less than the theoretically calculated values. The planned second part of this study will discuss the non-thermal effects and present the most important epidemiological studies.
Screening, Management and Delivery in Twin Pregnancy
Authors: von Kaisenberg Constantin , Klaritsch Philipp , Ochsenbein-Kölble Nicole , Hodel Markus Eugen , Nothacker Monika , Hecher Kurt 
Published: October 2020

AbstractThe following AWMF guideline (DGGG/AGG & DEGUM responsible) deals with the diagnosis, screening and management of twins as well as the timing and mode of birth.Twin pregnancies can be classified as dichorionic diamniotic (DC DA), monochorionic diamniotic (MC DA) and monochorionic monoamniotic (MC MA) which are always monochorionic.Twin pregnancies can be concordant (both twins are affected) or discordant (only one twin is affected) for chromosomal defects, malformations, growth restriction and hemodynamic disorders.Chorionicity is the prognostically most significant parameter. Monochorial twins have significantly higher risks of intrauterine morbidity and mortality compared to dichorial twins.In particular, general aspects of twin pregnancies such as dating, determination of chorionicity and amnionicity, the labeling of twin fetuses and the perinatal switch phenomenon are discussed.Routine monitoring of MC and DC twin pregnancies with ultrasound at 11–13+ 6 weeks of gestation for chromosomal defects, invasive prenatal diagnosis, first-trimester NT or CRL discrepancies, early diagnosis of fetal anatomical defects, and management of twins with abnormalities, including selective fetocide, is described.Second trimester screening and management for preterm birth, intrauterine selective growth restriction (sFGR), classification of monochorial twins with sFGR, and management of the surviving twin after the death of the co-twin are described.Complications exclusively affecting MC twins include Twin to Twin Transfusion Syndrome (TTTS) with the important topics screening, prognosis, complications of laser therapy, timing of delivery, risks for brain abnormalities and delayed neurological development, Twin Anemia-Polycythemia Sequence (TAPS) and Twin Reversed Arterial Perfusion (TRAP) Sequence. This also includes MC MA twins as well as conjoined twins.Finally, the birth mode and time for DC and MC twin pregnancies are described.The information is summarized in 62 recommendations for action, 4 tables and 8 illustrations with comprehensive background texts.The guideline is an international guideline adaptation (ISUOG, NICE) as well as a systematic literature search and is up-to-date.
Highly Functionalized Pyrrolylpyridines from 2-(Acylethynyl)-pyrroles
Authors: Trofimov Boris A. , Tomilin Denis N. , Sobenina Lyubov N. , Ushakov Igor A. 
Published: October 2020

AbstractA novel family of pharmaceutically prospective, densely functionalized (aryl-, hetaryl-, acyl-, and vinyl-substituted) pyrrolylpyridines has been assembled in up to 95% yields via the amination (NH4Cl/K2CO3/DMSO system, 90 °C, 16 h) of 2-(acylethynyl)pyrroles, followed by cyclization (MeOH, reflux, 6 h, up to 90% yield) of the formed intermediate 1-(pyrrol-2-yl)-1-aminoenones with acetylenic ketones (Bohlmann–Rahtz reaction). The intermediate pyrrolyl aminodienones, prospective building blocks for organic synthesis, can be separately synthesized (DMSO, 90 °C, 6 h) in 70–86% yields. A novel facet of this chemistry is stereoselective synthesis of C-vinylated pyridines, (E)-3-[5-acyl-2-aryl-6-(pyrrol-2-yl)pyridin-3-yl]-1-arylprop-2-en-1-ones, by involving the second molecule of acylacetylene into the reaction.
Synthesis, Spectral Characterization and Crystal Structure of Chlororhodibalamin: A Synthesis Platform for Rhodium Analogues of Vitamin B12 and for Rh-Based Antivitamins B12
Authors: Kräutler Bernhard , Widner Florian J. , Kieninger Christoph , Wurst Klaus , Deery Evelyne , Lawrence Andrew D. , Warren Martin J. 
Published: October 2020

AbstractChlororhodibalamin (ClRhbl), a rhodium analogue of vitamin B12 (cyanocobalamin), was prepared in 84% yield by metalation of the metal-free B12 ligand hydrogenobalamin using the RhI-complex [Rh(CO)2Cl]2. ClRhbl was identified and characterized by UV/Vis, circular dichroism, high-resolution mass and heteronuclear NMR spectra. The RhIII-corrin ClRhbl features the ‘base-on’ architecture of vitamin B12. X-ray analysis of single crystals of ClRhbl have revealed its detailed 3D-geometry and close structural similarity to the CoIII-analogue chlorocobalamin (ClCbl). ClRhbl is a versatile starting material for the preparation of other rhodibalamins, among them the organometallic derivatives adenosylrhodibalamin and methylrhodibalamin, the Rh analogues of the important coenzyme and cofactor forms of B12, adenosylcobalamin and methylcobalamin.
Synthesis of Catenanes from a BMP32C10-Based Cryptand Tuned by the Linkage Length of Paraquat Salts
Authors: Li Shijun , Yan Feng-Zhi , Shao Yuan-Guang , Zhang Zibin , Shen Yan-Feng , Huang Xue-Chun , Zhang Pei-Ling 
Published: October 2020

AbstractA series of catenanes have been synthesized through olefin metathesis from a BMP32C10-based cryptand and paraquat guests attached with two terminal alkenes. Distribution of the catenane products can be significantly affected by the linkage length on the paraquat guests. In the presence of BMP32C10-based cryptand, the paraquat salt with a long linkage facilitates intramolecular olefin metathesis to release a [2]catenane as the sole catenation product, while the use of a paraquat salt with a shorter linkage leads to the simultaneous generation of [2]-, [3]-, and [4]-catenanes.
Predicting Anticoagulation Need for Otogenic Intracranial Sinus Thrombosis: A Machine Learning Approach
Authors: Kaufmann Matthew R. , Camilon Philip Ryan , Levi Jessica R. , Devaiah Anand K. 
Published: October 2020

AbstractObjective The role of anticoagulation (AC) in the management of otogenic cerebral venous sinus thrombosis (OCVST) remains controversial. Our study aims to better define when AC is used in OCVST.Methods MEDLINE, EMBASE, and The Cochrane Library were searched from inception to February 14, 2019 for English and English-translated articles. References cited in publications meeting search criteria were searched. Titles and abstracts were screened and identified in the literature search, assessing baseline risk of bias on extracted data with the methodological index for nonrandomized studies (MINORS) scale. Random effects meta-regression followed by random forest machine learning analysis across 16 moderator variables between AC and nonanticoagulated (NAC) cohorts was conducted.Results A total of 92% of treated patients were free of neurologic symptoms at the last follow-up (mean 29.64 months). Four percent of AC and 14% of NAC patients remained symptomatic (mean 18.72 and 47.10 months). 3.5% of AC patients experienced postoperative wound hematomas. AC and NAC recanalization rates were 81% (34/42) and 63% (five-eights), respectively. OCVST was correlated with cholesteatoma and intracranial abscess. Among the analyzed covariates, intracranial abscess was most predictive of AC and cholesteatoma was most predictive of NAC. Comorbid intracranial abscess and cholesteatoma were predictive of AC.Conclusion The present study is the first to utilize machine learning algorithms in approaching OCVST. Our findings support the therapeutic use of AC in the management of OCVST when complicated by thrombophilia, intracranial abscess, and cholesteatoma. Patients with intracranial abscess and cholesteatoma may benefit from AC and surgery. Patients with cholesteatoma can be managed with NAC and surgery.
The Role of CD68 (+) Histiocytic Macrophages in Nasal Polyp Development
Authors: Bayar Muluk Nuray , Arikan Osman Kürşat , Atasoy Pınar , Kiliç Rahmi , Tuna Yalçinozan Eda 
Published: October 2020

AbstractObjectives The aim of this study was to investigate the role of CD68 (+) histiocytic macrophages (H-M) in the nasal polyp pathogenesis.Materials and Methods The study group consisted of 24 adult patients with nasal polyposis. The control group consisted of 11 adult patients without nasal polyps. A total of 36 nasal polyp samples (10-nasal cavity, 10-maxillary sinus, and 16-ethmoid sinus) from the study group and 11 inferior turbinate samples from the control group were analyzed by immunohistochemical staining, with monoclonal antibodies against CD68 (+) H-M.Results CD68 positivity was significantly higher than the control group in the subepithelial (SE) layer of the ethmoid sinus, and deep layers of nasal cavity, maxillary, and ethmoid sinuses. In SE and deep layers of ethmoid and maxillary sinuses, CD68 positivity was significantly higher than that of the epithelial layer. In the deep layer, histiocytic macrophages tended to gather around eosinophils.Conclusion The high numbers of CD68 (+) histiocytic macrophages mainly located in deep layer of lamina propria may be responsible for the phagocytosis of eosinophils within the polyp tissue. Therefore, it may be concluded that increased macrophages in nasal polyps do not trigger the growth of nasal polyps. Instead, they may serve to reduce the number of eosinophils in already-developed nasal polyps.
Hormonal Contraceptives and the Risk of Venous Thrombosis
Authors: Khialani Deeksha , Rosendaal Frits , Vlieg Astrid van Hylckama 
Published: October 2020

AbstractThe risk of venous thrombosis (VT) varies according to the type of progestogen that is found in combined oral contraceptives (COCs). When combined with the estrogen component ethinylestradiol (EE), the androgenic progestogens are better able to counteract the EE-induced stimulation of liver proteins and hence are associated with a twofold decreased risk of VT compared with non- or antiandrogenic progestogens, which exert limited counteraction of EE. Because EE is responsible for the increased risk, novel estrogens such as estradiol were developed and seem to have a lower risk of VT than EE. Besides COCs, there are other methods of hormonal contraceptives, such as progestogen-only contraceptives, which do not increase VT risk, except for injectables. Other nonoral contraceptives are combined vaginal rings and patches. There is insufficient evidence regarding the risk of VT associated with these two methods compared with COCs. The increased risk associated with COCs is more pronounced in women with inherited thrombophilia. In these women, the progestogen levonorgestrel seems to be associated with the lowest risk of VT. Currently, there are no studies that have investigated the risk of VT in women who switch COCs. We hypothesize that switching COCs, even when switching from a high- to a low-risk COC, increases the risk of VT. Finally, risk prediction models in women who use COCs are lacking. Since there is a large number of VT cases associated with COC use, it is important to identify women at risk of VT and advise them on alternative contraception methods.
Subpopulations of extracellular vesicles from human metastatic melanoma tissue identified by quantitative proteomics after optimized isolation
Authors: Crescitelli Rossella , Lässer Cecilia , Jang Su Chul , Cvjetkovic Aleksander , Malmhäll Carina , Karimi Nasibeh , Höög Johanna L. , Johansson Iva , Fuchs Johannes , Thorsell Annika , Gho Yong Song , Olofsson Bagge R. , Lötvall Jan 
Published: October 2020

ABSTRACTThe majority of extracellular vesicle (EV) studies conducted to date have been performed on cell lines with little knowledge on how well these represent the characteristics of EVs in vivo. The aim of this study was to establish a method to isolate and categorize subpopulations of EVs isolated directly from tumour tissue. First we established an isolation protocol for subpopulations of EVs from metastatic melanoma tissue, which included enzymatic treatment (collagenase D and DNase). Small and large EVs were isolated with differential ultracentrifugation, and these were further separated into high and low‐density (HD and LD) fractions. All EV subpopulations were then analysed in depth using electron microscopy, Bioanalyzer®, nanoparticle tracking analysis, and quantitative mass spectrometry analysis. Subpopulations of EVs with distinct size, morphology, and RNA and protein cargo could be isolated from the metastatic melanoma tissue. LD EVs showed an RNA profile with the presence of 18S and 28S ribosomal subunits. In contrast, HD EVs had RNA profiles with small or no peaks for ribosomal RNA subunits. Quantitative proteomics showed that several proteins such as flotillin‐1 were enriched in both large and small LD EVs, while ADAM10 were exclusively enriched in small LD EVs. In contrast, mitofilin was enriched only in the large EVs. We conclude that enzymatic treatments improve EV isolation from dense fibrotic tissue without any apparent effect on molecular or morphological characteristics. By providing a detailed categorization of several subpopulations of EVs isolated directly from tumour tissues, we might better understand the function of EVs in tumour biology and their possible use in biomarker discovery.
Conflict reterritorialisation: Shifting group boundaries in the diaspora during the armed conflict in the ‘homeland’
Authors: Voytiv Sofiya 
Published: October 2020

ABSTRACT
Research on wars, including the ethnicised armed conflicts, has focused on the territorial dimension of war, and direct and indirect actors involved therein. This paper uses concepts of deterritorialisation and reterritorialisation to explore if the symbols, narratives, and attitudes of war in the ‘homeland’ can be embedded into the ethnic boundary-making processes and shift them according to the situation in the ‘homeland’ in the diasporic setting. I focus on the Ukrainian-Russian conflict, and interview Ukrainians and Russians from Ukraine living in Sweden. I find that attitudes toward the conflict can become intertwined with subjective ethnic identification of the Self and the Other, shifting ethnic boundary-making processes in alliance with the conflict ‘back home.’
Gravitational waves in higher order teleparallel gravity
Authors: Capozziello Salvatore , Capriolo Maurizio , Caso Loredana 
Published: October 2020

Abstract
The teleparallel equivalent of higher order Lagrangians like L
□R
= −R + a
0
R
2 + a
1
R□R can be obtained by means of the boundary term B = 2∇
μ

T

μ
. In this perspective, we derive the field equations in presence of matter for higher-order teleparallel gravity considering, in particular, sixth-order theories where the □ operator is linearly included. In the weak field approximation, gravitational wave solutions for these theories are derived. Three states of polarization are found: the two standard + and × polarizations, namely 2-helicity massless transverse tensor polarizations, and a 0-helicity massive, with partly transverse and partly longitudinal scalar polarization. Moreover, these gravitational waves (GWs) exhibit four oscillation modes related to four degrees of freedom: the two classical + and × tensor modes of frequency ω
1, related to the standard Einstein waves with

k

1

2

=
0

; two mixed longitudinal-transverse scalar modes for each frequencies ω
2 and ω
3, related to two different 4-wave vectors,

k

2

2

=

M

2

2

and

k

3

2

=

M

3

2

. The four degrees of freedom are the amplitudes of each individual mode, i.e.

ϵ

̂

(

+

)

ω

1

,

ϵ

̂

(

×

)

ω

1

,

B

̂

2

k

, and

B

̂

3

k

. To describe a general teleparallel gravity model of order (2p + 2), we used the teleparallel Lagrangian

L

□

k

T

neq

=
e

T
+

a

0

T

2

+

∑

k
=
1

p

a

k

T

□

k

T

which demonstrates to be not equivalent to

L

□

k

R

=

−
g

R
+

∑

k
=
0

p

a

k

R

□

k

R

. By varying its action, the related field equations in the presence of matter are derived. Hence we obtain the GWs for these teleparallel gravity models, i.e.

L

□

k

T

neq

, that are exactly the Einstein GWs as in f(T) teleparallel gravity. In conclusion, the boundary term B generates extra polarizations and additional modes beyond the standard ones. In particular B
2 and B□B terms generate both the additional scalar polarization and the extra scalar modes.
A discussion regarding the duration of motion in a non-uniform gravitational field
Authors: Kontomaris S V , Malamou A 
Published: October 2020

Abstract
Assume that an object is thrown vertically from a planet’s surface with a low velocity. Using basic kinematics theory, it is easy to calculate the duration of the motion. In this type of problem, the acceleration due to gravity is considered to be uniform, because the motion is taking place near the planet’s surface. By contrast, if we assume that an object is launched vertically from a planet’s surface at its escape velocity, how much time does it take for the object to cover a specific distance? In addition, is it possible to find a simplified way to calculate the duration of the motion or to derive the equations of motion in a non-uniform gravitational field? In this paper, we provide a simplified analysis that can be used to answer these questions.
Pulse length effects on autoionizing states under the influence of intense SASE XUV fields
Authors: Aufleger L , Friebel P , Rupprecht P , Magunia A , Ding T , Rebholz M , Hartmann M , Stooß V , Ott C , Pfeifer T 
Published: October 2020

Abstract
The Fano absorption line shape of an autoionizing state encodes information on its internal atomic structure and dynamics. When driven near-resonantly with intense extreme ultraviolet (XUV) electric fields, the absorption profile can be deliberately modified, including observable changes of both the line-shape asymmetry and strength of the resonance, revealing information on the underlying dynamics of the system in response to such external driving. We report on the influence of the XUV pulse parameters at high intensity that can be achieved with a free-electron laser (FEL) with statistically broadened spectra based on self-amplified spontaneous emission (SASE). More specifically, the impact of the FEL pulse duration is studied for the example of the doubly excited 2s2p resonance in helium, where line-shape modifications have been measured with XUV transient absorption spectroscopy in Fraunhofer-type transmission geometry. A computational few-level-model provides insight into the impact of different average pulse durations of the stochastic FEL pulses. These findings are supported by measurements performed at the Free-Electron Laser in Hamburg (FLASH) and provide further insight into XUV strong-coupling dynamics of resonant transitions driven by intense high-frequency FEL sources.
Fast iron oxide-induced low-field magnetic resonance imaging
Authors: Rodriguez Gonzalo G , Erro Eustaquio M , Anoardo Esteban 
Published: October 2020

Abstract
Dynamic images acquired by proton fast field-cycling magnetic resonance imaging are presented for the first time. Image contrast mediated by superparamagnetic iron oxide nanoparticles and weighted by the spin-lattice (T1) relaxation time, and both spin-lattice and spin-spin (T2) relaxation times, are discussed. Image acquisition and processing within 8 s is allowed for real-time recording of exemplary physical situations evolving in a compatible time-scale. Two simple examples are shown with the corresponding videos assembled by sequencing the acquired images. Fast iron oxide-induced low-field magnetic resonance imaging (MRI) constitutes the first step in the development of field-cycling functional MRI for biomedical and physical applications.
Hybrid functional investigation of band offsets for non-polar, Ga-polar and Al-polar interfaces in GaN/AlN heterojunction
Authors: Kaewmeechai Chaiyawat , Laosiritaworn Yongyut , Jaroenjittichai Atchara Punya 
Published: October 2020

Abstract
We investigated band alignment of non-polar and polar GaN/AlN heterojunction by using density functional theory with the Heyd–Scuseria–Ernzerhof hybrid functional. In the heterojunction model, AlN was considered as a substrate while strained GaN was grown on top. The deformation potential of GaN, were included to calculate the unstrained band offsets. For polar heterojunction, the artificial effects from an undesired interface was removed by using vacuum insertion and dipole correction. We found that the unstrained valence band offsets (VBOs) are 0.92 eV, 1.23 eV and 1.09 eV for non-polar, Ga-polar and Al-polar interfaces respectively. The variation of VBOs can be explained from the difference in both deformation and dipole potential at the interfaces. Moreover, the additional energy shift of polar VBO from non-polar VBO were extracted as 0.33 eV from considering the effect of spontaneous polarization.
Person-specific calibration of a partial body counter used for individualised Am241 skull measurements
Authors: Nogueira P , Rühm W 
Published: October 2020

Abstract
Incorporation of bone seeking alpha-emitting radionuclides such as 241Am are of special concern, due to the potential of alpha particles to damage the extremely radiation-sensitive bone marrow. In the case of an internal contamination with 241Am, direct in vivo measurements using Gamma-detectors are typically used to quantify the incorporated activity. Such detectors need to be calibrated with an anatomical phantom, for example of the skull, of known 241Am activity that reproduces the anatomy of the measured individual as closely as possible. Any difference in anatomy and material composition between phantom and individual will bias the estimation of the incorporated activity. Consequently, in this work the impact of the most important anatomical parameters on detection efficiency of one of the germanium detectors of the Helmholtz Center Munich (HMGU) partial body counter were systematically studied. For that a detailed model of the germanium detector was implemented in the Monte Carlo codes GEANT4 and MCNPX. To simulate the detector efficiency, various skull voxel phantoms were used. By changing the phantom dimensions and geometry the impact of parameters such as shape and size of the skull, thickness of tissue covering the skull bone, distribution of 241Am across the scull and within the skull bone matrix, on the detector efficiency was studied. Approaches to correct for these parameters were specifically developed for three physical skull phantoms for which Voxel phantoms were available: Case 102 USTUR phantom, Max-06 phantom, BfS phantom. Based on the impact of each parameter, correction factors for an ‘individual-specific’ calibration were calculated and applied to a real 241Am contamination case reported in 2014. It was found that the incorporated 241Am activity measured with the HMGU partial body counter was about twice as large as that estimated when using the BfS skull phantom without applying any correction factor for person-specific parameters. It is concluded that the approach developed in the present study should in the future be applied routinely for skull phantom measurements, because it allows for a considerably improved reconstruction of incorporated 241Am using partial body counters.