bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abelian sections of the symmetric groups with respect to their index
Authors: Sabatini Luca 
Published: October 2021

AbstractWe show the existence of an absolute constant $$\alpha >0$$

α
>
0

such that, for every $$k \ge 3$$

k
≥
3

, $$G:= \mathop {\mathrm {Sym}}(k)$$

G
:
=
Sym
(
k
)

, and for every $$H \leqslant G$$

H
⩽
G

of index at least 3, one has $$|H/H'| \le |G:H|^{\alpha / \log \log |G:H|}$$

|
H
/

H
′

|
≤
|
G
:
H
|

α
/
log
log
|
G
:
H
|

. This inequality is the best possible for the symmetric groups, and we conjecture that it is the best possible for every family of arbitrarily large finite groups.
Type 2 diabetes burden among migrants in Europe: unravelling the causal pathways
Authors: Agyemang Charles , van der Linden Eva L. , Bennet Louise 
Published: October 2021

AbstractEuropean populations are ethnically and culturally diverse due to international migration. Evidence indicates large ethnic inequalities in the prevalence of type 2 diabetes. This review discusses the burden of type 2 diabetes and its related complications, and the potential explanatory mechanisms among migrants in Europe. The current available data suggest that the rate of type 2 diabetes is higher in all migrant groups and that they develop this disease at an earlier age than the host European populations. The level of diabetes awareness among migrant populations is high, but glycaemic control remains suboptimal compared with Europeans. The culturally adapted lifestyle modification intervention trials to prevent type 2 diabetes mainly focus on South Asian adults in Europe. Diabetes-related microvascular and macrovascular complications remain a major burden among migrant populations in Europe. Earlier studies found higher mortality rates among migrants, but recent studies seem to suggest a shifting trend in favour of first-generation migrants. However, the extent of the burden of type 2 diabetes varies across migrant groups and European countries. Despite the higher burden of type 2 diabetes among migrants, the key underlying factors are not well understood mainly due to limited investment in basic science research and development of prospective cohort studies. We hypothesise that the underlying risk factors for the high burden of type 2 diabetes and its related complications in migrants are multifaceted and include pre-migration factors, post-migration factors and genetic predispositions. Given the multi-ethnic nature of the current European population, there is a clear need for investment in research among migrant populations to gain insight into factors driving the high burden of type 2 diabetes and related complications to facilitate prevention and treatment efforts in Europe.
Graphical abstract
An inverse problem on determining second order symmetric tensor for perturbed biharmonic operator
Authors: Bhattacharyya Sombuddha , Ghosh Tuhin 
Published: October 2021

AbstractThis article offers a study of the Calderón type inverse problem of determining up to second order coefficients of higher order elliptic operators. Here we show that it is possible to determine an anisotropic second order perturbation given by a symmetric matrix, along with a first order perturbation given by a vector field and a zero-th order potential function inside a bounded domain, by measuring the Dirichlet to Neumann map of the perturbed biharmonic operator on the boundary of that domain.
Microalgal biomass as renewable biofiller in natural rubber compounds
Authors: Bellinetto Emanuela , Ciapponi Riccardo , Contino Marco , Marano Claudia , Turri Stefano 
Published: October 2021

AbstractMicroalgal biomasses, consisting of micronized Spirulina Platensis and its low protein fraction, were investigated in this work as possible renewable biofillers in natural rubber compounds, with the aim of replacing the commonly used carbon black. Natural rubber, in some cases blended with 10% of epoxidized natural rubber to improve the matrix-filler affinity, was compounded with 25, 35, 50 and 75 phr of each biomass. Compounds with 25, 35 and 50 phr of carbon black N990 were also prepared as benchmarks. After compounding, vulcanization times were determined by dynamic mechanical analysis. Rubbers were vulcanized by compression moulding and characterized by means of morphological analysis (scanning electron microscopy), thermal analysis (thermogravimetric analysis, dynamic mechanical thermal analysis) and mechanical tests (tensile tests, strain induced crystallization detection by X-ray diffraction, pure shear fracture tests). Microalgal biomass turned out to be homogeneously dispersed in natural rubber matrix and the materials obtained required lower curing times compared to carbon black compounds. It was found that, up to 50 phr, Spirulina has the ability to increase rubber tensile strength and modulus, acting similarly to N990, while decreasing rubber thermal stability and fracture toughness.
Could Norwegian fjords serve as an analogue for the future of the Svalbard fjords? State and fate of high latitude fjords in the face of progressive “atlantification”
Authors: Kujawa Agnieszka , Łącka Magdalena , Szymańska Natalia , Pawłowska Joanna , Telesiński Maciej M. , Zajączkowski Marek 
Published: October 2021

AbstractBenthic foraminifera are one of the most widely and abundantly distributed organisms in the fjords of Svalbard and Norway. Due to their short life span and quick reactivity to environmental changes they can be used as indicators of the “atlantification” process. Here, we compare the benthic foraminifera assemblages along the latitudinal gradient, from the fjords of northern Svalbard to southern Norway to assess whether the “atlantification” process may homogenise the foraminiferal assemblages in terms of their abundance and species composition. Furthermore, the previously published data on benthic foraminiferal faunas was updated to identify changes in distribution that have occurred over the last few decades. For this purpose, fjord mouths in western and northern Svalbard (Isfjorden, Wijdefjorden and Rijpfjorden) and northern and southern Norway (Balsfjorden, Raunefjorden and Hjeltefjorden) were resampled. The analysis revealed similarities between the Svalbard and Norwegian foraminiferal assemblages of up to 30%; however, there were essential differences in terms of abundance and biodiversity. These results suggest that Svalbard fjords will remain distinct in the future, even under conditions of further warming or “atlantification”. Svalbard fjords may be dominated by Atlantic Water- preferring species, whereas, in Norwegian fjords, pressure from human activity will probably be the main driver of environmental changes, leading to changes in the foraminiferal assemblages with the increasing dominance of opportunistic, hypoxia-tolerant species.
Sources of variation in multicenter rectal MRI data and their effect on radiomics feature reproducibility
Authors: Schurink Niels W. , van Kranen Simon R. , Roberti Sander , van Griethuysen Joost J. M. , Bogveradze Nino , Castagnoli Francesca , el Khababi Najim , Bakers Frans C. H. , de Bie Shira H. , Bosma Gerlof P. T. , Cappendijk Vincent C. , Geenen Remy W. F. , Neijenhuis Peter A. , Peterson Gerald M. , Veeken Cornelis J. , Vliegen Roy F. A. , Beets-Tan Regina G. H. , Lambregts Doenja M. J. 
Published: October 2021

Abstract
Objectives

To investigate sources of variation in a multicenter rectal cancer MRI dataset focusing on hardware and image acquisition, segmentation methodology, and radiomics feature extraction software.

Methods
T2W and DWI/ADC MRIs from 649 rectal cancer patients were retrospectively acquired in 9 centers. Fifty-two imaging features (14 first-order/6 shape/32 higher-order) were extracted from each scan using whole-volume (expert/non-expert) and single-slice segmentations using two different software packages (PyRadiomics/CapTk). Influence of hardware, acquisition, and patient-intrinsic factors (age/gender/cTN-stage) on ADC was assessed using linear regression. Feature reproducibility was assessed between segmentation methods and software packages using the intraclass correlation coefficient.

Results
Image features differed significantly (p < 0.001) between centers with more substantial variations in ADC compared to T2W-MRI. In total, 64.3% of the variation in mean ADC was explained by differences in hardware and acquisition, compared to 0.4% by patient-intrinsic factors. Feature reproducibility between expert and non-expert segmentations was good to excellent (median ICC 0.89–0.90). Reproducibility for single-slice versus whole-volume segmentations was substantially poorer (median ICC 0.40–0.58). Between software packages, reproducibility was good to excellent (median ICC 0.99) for most features (first-order/shape/GLCM/GLRLM) but poor for higher-order (GLSZM/NGTDM) features (median ICC 0.00–0.41).

Conclusions
Significant variations are present in multicenter MRI data, particularly related to differences in hardware and acquisition, which will likely negatively influence subsequent analysis if not corrected for. Segmentation variations had a minor impact when using whole volume segmentations. Between software packages, higher-order features were less reproducible and caution is warranted when implementing these in prediction models.

Key Points
• Features derived from T2W-MRI and in particular ADC differ significantly between centers when performing multicenter data analysis.
• Variations in ADC are mainly (> 60%) caused by hardware and image acquisition differences and less so (< 1%) by patient- or tumor-intrinsic variations.
• Features derived using different image segmentations (expert/non-expert) were reproducible, provided that whole-volume segmentations were used. When using different feature extraction software packages with similar settings, higher-order features were less reproducible.
Differences in clinical presentation and management between pre- and postsurgical diagnoses of urinary bladder paraganglioma: is there clinical relevance? A systematic review
Authors: Li Minghao , Xu Xiaowen , Bechmann Nicole , Pamporaki Christina , Jiang Jingjing , Propping Stefan , Liu Longfei , Langenhuijsen Johan F. , Pacak Karel , Eisenhofer Graeme , Lenders Jacques W. M. 
Published: October 2021

Abstract
Purpose
Paraganglioma of the urinary bladder (UBPGL) is a rare neuroendocrine tumor diagnosed in many patients only after surgery. We, therefore, assessed clinical clues relevant to presurgical diagnosis and clinical consequences in patients with a missed presurgical diagnosis of UBPGL.

Materials and methods
Case reports describing a UBPGL (published from 1–1–2001 and 31–12–2020) were identified in Pubmed. Two authors independently performed data extraction and assessed data quality according to the PRISMA guideline. Patients were divided into two groups: UBPGL diagnosis before and after surgery.

Results
We included 177 articles reporting 194 cases. In 90 (46.4%) patients, the UBPGL was diagnosed before and in 104 (53.6%) after surgery. In presurgically diagnosed UBPGL, hypertension and catecholamine-associated symptoms were 2- to 3-fold (p < 0.001) more frequent than in postsurgically diagnosed patients whereas hematuria was twofold (p = 0.003) more prevalent in those with postsurgical diagnosis. Hypertension was an independent factor for presurgical biochemical testing (OR 4.45, 95% CI 1.66–11.94) while hematuria (OR 0.23, 95% CI 0.09–0.60) was an independent factor for not performing presurgical biochemical testing. Most patients diagnosed after surgery were not pretreated with alpha-adrenoceptor blockade (95.2%), underwent more frequently transurethral resection instead of cystectomy (70.2% vs. 23.1%) and had more frequent peroperative complications and residual tumor mass.

Conclusions
In nearly half of all patients with a UBPGL, the diagnosis was not established before surgery. Hypertension and hematuria contributed independently to a presurgical diagnosis. Postsurgical diagnosis, which was associated with suboptimal presurgical and surgical management, resulted in more peroperative complications and incomplete tumor resections.
Two-year results after combined phacoemulsification and iris-fixated phakic intraocular lens removal
Authors: Gaurisankar Zoraida Solaiga , van Rijn Gwyneth A. , Cheng Yanny Y. Y. , Luyten Gregorius P. M. , Beenakker Jan-Willem M. 
Published: October 2021

Abstract

Purpose
To describe and present results after a technique for cataract surgery combined with explantation of an iris-fixated phakic intraocular lens (IF-pIOL).

Methods
The medical records of all patients, who had undergone cataract surgery combined with IF-pIOL explantation and subsequent implantation of a posterior chamber IOL by the Single Incision Technique (SIT), were reviewed. Data collection included preoperative and postoperative corrected distance visual acuity (CDVA), manifest refraction, and endothelial cell density (ECD) up to a follow-up time of 24 months.

Results
Fifty myopic eyes (34 patients) and 9 hyperopic eyes (6 patients) had undergone a SIT procedure mainly because of cataract (67%). Postoperative CDVA improved in both the myopic eyes to 0.16 ± 0.37 logMAR, as in the hyperopic eyes to − 0.10 ± 0.55 logMAR with no eyes having loss of Snellen lines. Mean postoperative spherical equivalent was − 0.34 ± 0.72 D and − 0.10 ± 0.55 D, respectively. ECD loss 6 months after surgery was 5% and remained stable thereafter.

Conclusion
SIT for combined phacoemulsification and IF-pIOL removal yields good visual and refractive results and is a safe procedure in regard to ECD loss. The technique has advantages over the conventional procedure and is easy to perform.
Drought at a coastal wetland affects refuelling and migration strategies of shorebirds
Authors: Anderson Alexandra M. , Friis Christian , Gratto-Trevor Cheri L. , Harris Christopher M. , Love Oliver P. , Morrison R. I. Guy , Prosser Sean W. J. , Nol Erica , Smith Paul A. 
Published: October 2021

AbstractDroughts can affect invertebrate communities in wetlands, which can have bottom-up effects on the condition and survival of top predators. Shorebirds, key predators at coastal wetlands, have experienced widespread population declines and could be negatively affected by droughts. We explored, in detail, the effects of drought on multiple aspects of shorebird stopover and migration ecology by contrasting a year with average wet/dry conditions (2016) with a year with moderate drought (2017) at a major subarctic stopover site on southbound migration. We also examined the effects of drought on shorebird body mass during stopover across 14 years (historical: 1974–1982 and present-day: 2014–2018). For the detailed comparison of two years, in the year with moderate drought we documented lower invertebrate abundance at some sites, higher prey family richness in shorebird faecal samples, lower shorebird refuelling rates, shorter stopover durations for juveniles, and, for most species, a higher probability of making a subsequent stopover in North America after departing the subarctic, compared to the year with average wet/dry conditions. In the 14-year dataset, shorebird body mass tended to be lower in drier years. We show that even short-term, moderate drought conditions can negatively affect shorebird refuelling performance at coastal wetlands, which may carry-over to affect subsequent stopover decisions. Given shorebird population declines and predicted changes in the severity and duration of droughts with climate change, researchers should prioritize a better understanding of how droughts affect shorebird refuelling performance and survival.
Wahrnehmungen zum Umgang mit Opioiden bei COVID-19
Authors: Peuckmann-Post Vera , Scherg Alexandra , Krumm Norbert , Hagedorn Carolin , Radbruch Lukas , Keszei Andras , Rolke Roman , Elsner Frank 
Published: October 2021

Zusammenfassung
Hintergrund
Obwohl Opioide wirksam Schmerzen und Dyspnoe lindern, findet dies in Leitlinien zur Symptomkontrolle unterschiedliche Gewichtung. Dies kann zu Unsicherheiten bezüglich Indikationen und ethischer Implikationen im Umgang mit Opioiden auch bei COVID-19 führen.

Ziel der Arbeit
Wir untersuchten bei Mitgliedern der Deutschen Gesellschaft für Palliativmedizin (DGP) die persönliche Wahrnehmung des Umgangs mit Morphin/Opioiden (M/O) zur Symptomkontrolle innerhalb und außerhalb der Palliativmedizin (PM), auch bei der Betreuung COVID-19-Erkrankter.

Material und Methoden
Mittels Survey Monkey® wurden DGP-Mitglieder anonymisiert nach ihrer eigenen Wahrnehmung des Umgangs mit M/O zur Symptomkontrolle befragt.

Ergebnisse und Diskussion
Von den 6192 DGP-Mitgliedern nahmen N = 506 teil. Den Umgang mit M/O innerhalb der PM beschrieben 98 % der befragten Ärzt:innen und Pflegekräfte als „sicher und vertraut“ bzw. 95 % als „klar geregelt“, während dies für die Bereiche außerhalb der PM von weniger als der Hälfte angegeben wurde (48 %/38 %). Bei der Betreuung COVID-19-Erkrankter wurde der Umgang mit M/O außerhalb der PM noch seltener als „sicher und vertraut“ (26 %) oder „klar geregelt“ (23 %) wahrgenommen. Dyspnoe (99 %/52 %), Erleichterung des Sterbeprozesses (62 %/37 %), Unruhe (30 %/15 %) und Angst/Panik (27 %/13 %) wurden häufiger innerhalb als außerhalb der PM als allgemeine Indikationen genannt. 89 % der Befragten wünschten sich die Einbindung eines PM-Konsilteams.

Schlussfolgerung
Mitglieder der DGP nahmen deutliche Unsicherheiten im Umgang mit M/O außerhalb der PM wahr. Einheitliche interdisziplinäre Leitlinien zur Symptomkontrolle etwa bei Dyspnoe, mehr Lehre und die Einbindung eines PM-Konsilteams sollten zukünftig mehr bedacht werden.
Unexpected ring-opening of 2,3-dihydropyridines
Authors: Hoffelner Michael-Hannes , Seebacher Werner , Kaiser Marcel , Mäser Pascal , Pferschy-Wenzig Eva-Maria , Saf Robert , Belaj Ferdinand , Kretschmer Nadine , Alajlani Muaaz , Brantner Adelheid , Bauer Rudolf , Weis Robert 
Published: October 2021

AbstractThe reaction of 2,3-dihydropyridines with sulfonyl halides surprisingly yielded open chain dienes with sulfonylimine structure. The products were specific out of several possible isomers and, therefore, a separation of isomers was not necessary. All new compounds were characterized using FT-IR spectroscopy, HRMS, and NMR spectroscopy. A bicyclic by-product from the reaction of a 2,3-dihydropyridine with mesyl chloride was isolated and its structure elucidated using a single X-ray crystal analysis. Some biological activities, like antimicrobial and cytotoxic properties were investigated.
Graphic abstract
Development and evaluation of a numerical simulation approach to predict metal artifacts from passive implants in MRI
Authors: Spronk Tobias , Kraff Oliver , Kreutner Jakob , Schaefers Gregor , Quick Harald H. 
Published: October 2021

Abstract
Objective
This study presents the development and evaluation of a numerical approach to simulate artifacts of metallic implants in an MR environment that can be applied to improve the testing procedure for MR image artifacts in medical implants according to ASTM F2119.

Methods
The numerical approach is validated by comparing simulations and measurements of two metallic test objects made of titanium and stainless steel at three different field strengths (1.5T, 3T and 7T). The difference in artifact size and shape between the simulated and measured artifacts were evaluated. A trend analysis of the artifact sizes in relation to the field strength was performed.

Results
The numerical simulation approach shows high similarity (between 75% and 84%) of simulated and measured artifact sizes of metallic implants. Simulated and measured artifact sizes in relation to the field strength resulted in a calculation guideline to determine and predict the artifact size at one field strength (e.g., 3T or 7T) based on a measurement that was obtained at another field strength only (e.g. 1.5T).

Conclusion
This work presents a novel tool to improve the MR image artifact testing procedure of passive medical implants. With the help of this tool detailed artifact investigations can be performed, which would otherwise only be possible with substantial measurement effort on different MRI systems and field strengths.
Dynamic flow and shear stress as key parameters for intestinal cells morphology and polarization in an organ-on-a-chip model
Authors: Fois Chiara A. M. , Schindeler Aaron , Valtchev Peter , Dehghani Fariba 
Published: October 2021

AbstractGut-on-a-chip microfluidic devices have emerged as versatile and practical systems for modeling the human intestinein vitro. Cells cultured under microfluidic conditions experience the effect of shear stress, used as a biomechanical cue to promote a faster cell polarization in Caco-2 cells when compared with static culture conditions. However, published systems to date have utilized a constant flow rate that fails to account for changes in cell shear stress ($${\tau }_{c}$$τc) resulting from changes in cell elongation that occur with differentiation. In this study, computational fluid dynamics (CFD) simulations predict that cells with villi-like morphology experience a$${\tau }_{c}$$τchigher than bulge-like cells at the initial growth stages. Therefore, we investigated the use of a dynamic flow rate to maintain a constant$${\tau }_{c}$$τcacross the experiment. Microscopic assessment of cell morphology and dome formation confirmed the initiation of Caco-2 polarization within three days. Next, adopting our dynamic approach, we evaluated whether the following decreased flow could still contribute to complete cell differentiation if compared with the standard constant flow methodology. Caco-2 cells polarized under both conditions, secreted mucin-2 and villin and formed tight junctions and crypt-villi structures. Gene expression was not impacted using the dynamic flow rate. In conclusion, our dynamic flow approach still facilitates cell differentiation while enabling a reduced consumption of reagents.
Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies
Authors: Adolph Jonas E. , Fleischhack Gudrun , Gaab Christine , Mikasch Ruth , Mynarek Martin , Rutkowski Stefan , Schüller Ulrich , Pfister Stefan M. , Pajtler Kristian W. , Milde Till , Witt Olaf , Bison Brigitte , Warmuth-Metz Monika , Kortmann Rolf-Dieter , Dietzsch Stefan , Pietsch Torsten , Timmermann Beate , Tippelt Stephan ,   for the German GPOH HIT-Network
Published: October 2021

Abstract
Purpose
Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN.

Methods
Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated.

Results
Median age at first recurrence was 7.6 years (IQR: 4.0–13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3–20.0) and 36.9 months (CI 29.7–53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74–1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found.

Conclusion
No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation.