bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiobiologically derived biphasic fractionation schemes to overcome the effects of tumour hypoxia
Authors: Joseph Nuradh , Kirkby Norman F. , Hoskin Peter J , West Catharine M L , Choudhury Ananya , Dale Roger G. 
Published: May 2020

Objective:
As a fractionated course of radiotherapy proceeds tumour shrinkage leads to resolution of hypoxia and the initiation of accelerated proliferation of radioresistant cancer cells with better repair capacity. We hypothesise that, in tumours with significant hypoxia, improved tumour control could be achieved with biphasic fractionation schedules that either use acceleration after 3–4 weeks of conventional radiotherapy or deliver a higher proportional dose towards the end of a course of treatment. We conducted a modelling study based on the concept of biological effective dose (BED) comparing such novel regimens with conventional fractionation.

Methods:
The comparator conventional fractionation schedule 70 Gy in 35 fractions delivered over 7 weeks was tested against the following novel regimens, both of which were designed to be isoeffective in terms of late normal tissue toxicity.
40 Gy in 20 fractions over 4 weeks followed by 22.32 Gy in 6 consecutive daily fractions (delayed acceleration)
30.4 Gy in 27 fractions over 4 weeks followed by 40 Gy in 15 fractions over 3 weeks (temporal dose redistribution)
The delayed acceleration regimen is exactly identical to that of the comparator schedule over the first 28 days and the BED gains with the novel schedule are achieved during the second phase of treatment when reoxygenation is complete. For the temporal redistribution regimen, it was assumed that the reoxygenation fraction progressively increases during the first 4 weeks of treatment and an iterative approach was used to calculate the final tumour BED for varying hypoxic fractions.

Results:
Novel fractionation with delayed acceleration or temporal fractionation results in tumour BED gains equivalent to 3.5–8 Gy when delivered in 2 Gy fractions.

Conclusion:
In hypoxic tumours, novel fractionation strategies result in significantly higher tumour BED in comparison to conventional fractionation.

Advances in knowledge:
We demonstrate that novel biphasic fractionation regimens could overcome the effects of tumour hypoxia resulting in biological dose escalation.
A simple model for calculating relative biological effectiveness of X-rays and gamma radiation in cell survival
Authors: Vassiliev Oleg N. , Peterson Christine B. , Grosshans David R. , Mohan Radhe 
Published: May 2020

Objectives:
The relative biological effectiveness (RBE) of X-rays and γ radiation increases substantially with decreasing beam energy. This trend affects the efficacy of medical applications of this type of radiation. This study was designed to develop a model based on a survey of experimental data that can reliably predict this trend.

Methods:
In our model, parameters α and β of a cell survival curve are simple functions of the frequency-average linear energy transfer (LF) of delta electrons. The choice of these functions was guided by a microdosimetry-based model. We calculated LF by using an innovative algorithm in which LF is associated with only those electrons that reach a sensitive-to-radiation volume (SV) within the cell. We determined model parameters by fitting the model to 139 measured (α,β) pairs.

Results:
We tested nine versions of the model. The best agreement was achieved with α and β being linear functions of LF .The estimated SV diameter was 0.1–1 µm. We also found that α, β, and the α/β ratio increased with increasing LF .

Conclusions:
By combining an innovative method for calculating LF with a microdosimetric model, we developed a model that is consistent with extensive experimental data involving photon energies from 0.27 keV to 1.25 MeV.

Advances in knowledge:
We have developed a photon RBE model applicable to an energy range from ultra-soft X-rays to megaelectron volt γ radiation, including high-dose levels where the RBE cannot be calculated as the ratio of α values. In this model, the ionization density represented by LF determines the RBE for a given photon spectrum.
Undergraduate medical education: a national survey of consultant radiologists
Authors: Chew C , O’Dwyer PJ 
Published: May 2020

Objective:
Rising clinical demand and changes to Radiologists’ job plans mean it is becoming ever more difficult for Radiologists to teach medical students.
The aim of this study was to assess the current role of Radiologists in undergraduate medical education in Scotland.

Methods:
Consultant Radiologists working across all 14 Scottish Health Boards were invited by email to participate in an anonymous short online survey. The survey ran for 6 weeks from November 2019. One reminder email was sent a week before the survey closed.

Results:
102 responses were recorded, representing 34% of the total whole time equivalent Radiologists in Scotland. All agreed Radiology should be taught to medical students. Over 70% (n = 73) taught medical students, most often during supporting professional activity time. 76 percent of Radiologists who did not teach expressed a desire to do so. The most common barrier to teaching was not having enough time in their job plan. Scottish Radiologists delivered a median of 10 h (IQR 0–22) a year of teaching to medical students. Thematic analysis of free comments revealed staffing/time constraints severely limiting ability to teach.

Conclusion:
This is the first national survey to assess the current role of Radiologists in teaching medical students. While most are teaching or want to teach, there is a large drop-off between current Scottish and previously reported UK median teaching hours. Engagement from Universities, Royal College of Radiologists and Health Boards is urgently needed to reverse this trend.

Advances in knowledge:
This is the first national survey into the current role of Radiologists in undergraduate medical education. There is a large drop-off between current Scottish and previously reported UK median teaching hours.
Fast analysis of scATAC-seq data using a predefined set of genomic regions
Authors: Giansanti Valentina , Tang Ming , Cittaro Davide 
Published: May 2020

Background: Analysis of scATAC-seq data has been recently scaled to thousands of cells. While processing of other types of single cell data was boosted by the implementation of alignment-free techniques, pipelines available to process scATAC-seq data still require large computational resources. We propose here an approach based on pseudoalignment, which reduces the execution times and hardware needs at little cost for precision. Methods: Public data for 10k PBMC were downloaded from 10x Genomics web site. Reads were aligned to various references derived from DNase I Hypersensitive Sites (DHS) using kallisto and quantified with bustools. We compared our results with the ones publicly available derived by cellranger-atac. We subsequently tested our approach on scATAC-seq data for K562 cell line. Results: We found that kallisto does not introduce biases in quantification of known peaks; cells groups identified are consistent with the ones identified from standard method. We also found that cell identification is robust when analysis is performed using DHS-derived reference in place of de novo identification of ATAC peaks. Lastly, we found that our approach is suitable for reliable quantification of gene activity based on scATAC-seq signal, thus allows for efficient labelling of cell groups based on marker genes. Conclusions: Analysis of scATAC-seq data by means of kallisto produces results in line with standard pipelines while being considerably faster; using a set of known DHS sites as reference does not affect the ability to characterize the cell populations.
Testing the effect of PAR1 inhibitors on Plasmodium falciparum-induced loss of endothelial cell barrier function
Authors: Storm Janet , Wu Yang , Davies Jill , Moxon Christopher A. , Craig Alister G. 
Published: May 2020

Background: Sequestration and cytoadherence of Plasmodium falciparum-infected erythrocytes (IE) to microvascular endothelium alters endothelial barrier function and plays a role in the pathogenesis of severe malaria. Binding of IE is mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1) and the PfEMP1 variants that binds to endothelial protein C receptor (EPCR) have, in particular, been associated with the dysregulation of the coagulation/inflammation pathways in endothelial cells. This has prompted speculation about the role of protease-activated receptor-1 (PAR1) activation and signalling in causing endothelial activation and loss of barrier function in cerebral malaria. Methods: We used a co-culture of primary human brain microvascular endothelial cells (HBMEC) with P. falciparum material, recombinant PfEMP1 or lysates from IE, and measured barrier function by trans endothelial electrical resistance (TEER). A selection of PAR1 inhibitors was tested for their ability to reverse the P. falciparum and thrombin induced decrease in barrier function. Results: An initial screen in the presence of recombinant PfEMP1 identified a few inhibitors that were able to reduce the rapid thrombin-induced barrier disruption even when activated protein C (aPC) was unable to do so. However, PAR1 inhibitors did not rescue the barrier dysfunction after co-culture with IE lysate. Conclusions: The selected PAR1 inhibitors were able to reverse the disruption of barrier function by thrombin but did not reverse the IE lysate induced disruption of barrier function, implicating a different PAR1-independent mechanism. These findings have implications for the design of adjunct therapies to reduce brain swelling in cerebral malaria.
COVID-19 and Guillain-Barre Syndrome: a systematic review of case reports
Authors: Carrillo-Larco Rodrigo M. , Altez-Fernandez Carlos , Ravaglia Sabrina , Vizcarra Joaquín A. 
Published: May 2020

Background: Guillain-Barre Syndrome (GBS) is a neurological autoimmune disease that can lead to respiratory failure and death. Whether COVID-19 patients are at high risk of GBS is unknown. Through a systematic review of case reports, we aimed to summarize the main features of patients with GBS and COVID-19. Methods: Without any restrictions, we searched MEDLINE, Embase, Global Health, Scopus, Web of Science and MedXriv (April 23rd, 2020). Two reviewers screened and studied titles, abstracts and reports. We extracted information to characterize sociodemographic variables, clinical presentation, laboratory results, treatments and outcomes. Results: Eight reports (n=12 patients) of GBS and COVID-19 were identified; one was a Miller Fisher case. Overall, the median age was 62.5 (interquartile range (IQR)=54.5-70.5) years, and there were more men (9/102). GBS symptoms started between 5 and 24 days after those of COVID-19. The median protein levels in cerebrospinal fluid samples was 101.5 mg/dl (IQR=51-145). None of the cerebrospinal fluid samples tested positive for COVID-19. Six patients debuted with ascendant weakness and three with facial weakness. Five patients had favourable evolution, four remained with relevant symptoms or required critical care and one died; the Miller Fisher case had successful resolution. Conclusions: GBS is emerging as a disease that may appear in COVID-19 patients. Although limited, preliminary evidence appears to suggest that GBS occurs after COVID-19 onset. Practitioners and investigators should have GBS in mind as they look after COVID-19 patients and conduct research on novel aspects of COVID-19. Comparison with GBS patients in the context of another viral outbreak (Zika), revealed similarities and differences that deserves further scrutiny and epidemiological studies.
Intimate Partner Violence Perpetration and Victimization Among Young Adult Sexual Minorities
Authors: Swiatlo Alison D. , Kahn Nicole F. , Halpern Carolyn T. 
Published: May 2020

CONTEXTIntimate partner violence (IPV) among sexual minority young adults has been understudied, and victimization and perpetration estimates are needed.METHODSData on 13,653 women and men aged 24–32 who participated in Wave 4 of the National Longitudinal Study of Adolescent to Adult Health were used to examine associations between sexual orientation and IPV perpetration and victimization in respondents’ current or most recent relationship. Logistic regression analyses were used to identify associations between respondent characteristics and three IPV categories (physical violence, threatened violence and forced sex).RESULTSSome 94% of males and 80% of females identified as 100% heterosexual; 4% of males and 16% of females as mostly heterosexual; 1% of males and 2% of females as bisexual; and 2% of males and females as either mostly homosexual or 100% homosexual. Compared with their heterosexual counterparts, mostly heterosexual women were more likely to report having perpetrated or been a victim of physical IPV (odds ratios, 1.9 and 1.6, respectively), having threatened violence (2.0) and having been a victim of threatened violence and forced sex (1.6 for each); mostly heterosexual males were more likely to have been a perpetrator or victim of physical IPV (3.1 and 1.8, respectively) and a perpetrator of forced sex and threatened violence (2.0 and 1.8, respectively). Bisexual males had elevated odds of physical violence victimization (3.3) and forced sex victimization (4.9) and perpetration (5.0).CONCLUSIONSSome sexual minority groups are disproportionately affected by IPV, indicating a need for increased prevention efforts and for studies exploring the mechanisms underlying these differences.
Design of infrared microspectrometer based on phase-modulated axilenses
Authors: Chen Yuyao , Britton Wesley A. , Dal Negro Luca 
Published: May 2020

We design and characterize a novel axilens-based diffractive optics platform that flexibly combines efficient point focusing and grating selectivity and is compatible with scalable top-down fabrication based on a four-level phase mask configuration. This is achieved using phase-modulated compact axilens devices that simultaneously focus incident radiation of selected wavelengths at predefined locations with larger focal depths compared with traditional Fresnel lenses. In addition, the proposed devices are polarization-insensitive and maintain a large focusing efficiency over a broad spectral band. Specifically, here we discuss and characterize modulated axilens configurations designed for long-wavelength infrared (LWIR) in the 6 µm–12 µm wavelength range and in the 4 µm–6 µm midwavelength infrared (MWIR) range. These devices are ideally suited for monolithic integration atop the substrate layers of infrared focal plane arrays and for use as compact microspectrometers. We systematically study their focusing efficiency, spectral response, and cross-talk ratio; further, we demonstrate linear control of multiwavelength focusing on a single plane. Our design method leverages Rayleigh–Sommerfeld diffraction theory and is validated numerically using the finite element method. Finally, we demonstrate the application of spatially modulated axilenses to the realization of a compact, single-lens spectrometer. By optimizing our devices, we achieve a minimum distinguishable wavelength interval of

Δ
λ
=
240

n
m

at

λ
c

=
8

µ

m

and

Δ
λ
=
165

n
m

at

λ
c

=
5

µ

m

. The proposed devices add fundamental spectroscopic capabilities to compact imaging devices for a number of applications ranging from spectral sorting to LWIR and MWIR phase contrast imaging and detection.
Video-rate lensless endoscope with self-calibration using wavefront shaping
Authors: Scharf Elias , Dremel Jakob , Kuschmierz Robert , Czarske Jürgen 
Published: May 2020

Lensless fiber endoscopes are of great importance for keyhole imaging. Coherent fiber bundles (CFB) can be used in endoscopes as remote phased arrays to capture images. One challenge is to image at high speed while correcting aberrations induced by the CFB. We propose the combination of digital optical phase conjugation, using a spatial light modulator, with fast scanning, for which a 2D galvo scanner and an adaptive lens are employed. We achieve the transmission of laser and image scanning through the CFB. Video-rate imaging at 20 Hz in 2D with subcellular resolution is demonstrated in 3D with 1 Hz. The sub-millimeter-diameter scanning endoscope has a great potential in biomedicine, for manipulation, e.g., in optogenetics, as well as in imaging.
Enhanced optical edge detection based on a Pancharatnam–Berry flat lens with a large focal length
Authors: Li Ting , Yang Yang , Liu Xinyang , Wu Yan , Zhou Yuan , Huang Sijia , Li Xiaochun , Huang Huihui 
Published: May 2020

In this Letter, we employ photo-aligned liquid crystals to record a flat lens pattern through a simple exposure method to produce a large focal length Pancharatnam-Berry (PB) lens with a film thickness of

2

µ

m

without using expensive equipment. This PB lens with a focal length of 240.6 m (at 532 nm) can transmit up to 97% across visible wavelengths and maintain high diffraction efficiency (

>

90

%

). An improved two-dimensional optical edge detection design based on this lens is proposed. We experimentally demonstrate the integrity and high efficiency of edge information that may play an important role in the application of image processing and high-contrast microscopy.
Femtosecond-written volume Bragg gratings in fluoride glasses
Authors: Talbot Lauris , Richter Daniel , Heck Maximilian , Nolte Stefan , Bernier Martin 
Published: May 2020

We report on what we believe are the first volume Bragg gratings written inside bulk multicomponent fluoride glasses. The gratings inscribed with tightly focused infrared (IR)-femtosecond pulses in combination with the phase-mask technique exhibit refractive index modulations of up to

5
×

10

−
4

with reflectivities up to 90% at a wavelength near 2.8 µm. Such highly compact and narrowband filters could have a significant impact on numerous high-end applications from the UV to the mid-IR.
On the existence of periodic oscillations for pendulum-type equations
Authors: Cid J. Ángel 
Published: May 2020

AbstractWe provide new sufficient conditions for the existence ofT-periodic solutions for theϕ-laplacian pendulum equation (ϕ(x′))′ +kx′ +asinx=e(t), wheree∈C͠T. Our main tool is a continuation theorem due to Capietto, Mawhin and Zanolin and we improve or complement previous results in the literature obtained in the framework of the classical, the relativistic and the curvature pendulum equations.
A novel motion coupling coding method for brain-computer interfaces
Authors: Yan Wenqiang , Xu Guanghua 
Published: May 2020

AbstractObjectivesThe best frequency response band for the steady-state visual evoked potential (SSVEP) stimulus for humans is limited. This results in a reduced number of encoded targets.MethodsTo circumvent these limitations, we propose a motion-coupled, steady-state motion visual evoked potential (SSMVEP) method. We designed a stimulus paradigm that couples both sinusoidal and square wave motions. The paradigm performs a spiral motion with a higher frequency in the form of sinusoidal wave, and alters the size of the lower frequency via the square wave form.ResultsThe motion-coupled SSMVEP method could simultaneously induce stable motion frequency and coupling frequency, and there was no loss of frequency component.ConclusionsThe proposed method has been evaluated to have substantial potential for increasing the number of coding targets, which is an effective supplement to the existing studies.
On birational boundedness of foliated surfaces
Authors: Hacon Christopher D. , Langer Adrian 
Published: May 2020

AbstractIn this paper we prove a result on the effective generation of pluri-canonical linear systems on foliated surfaces of general type. Fix a function{P:\mathbb{Z}_{\geq 0}\to\mathbb{Z}}, then there exists an integer{N>0}such that if{(X,{\mathcal{F}})}is a canonical or nef model of a foliation of general type with Hilbert polynomial{\chi(X,{\mathcal{O}}_{X}(mK_{\mathcal{F}}))=P(m)}for all{m\in\mathbb{Z}_{\geq 0}}, then{|mK_{\mathcal{F}}|}defines a birational map for all{m\geq N}.On the way, we also prove a Grauert–Riemenschneider-type vanishing theorem for foliated surfaces with canonical singularities.
Fabrication of highly stable and durable furfurylated wood materials. Part I: process optimization
Authors: Li Wanju , Liu Minghui , Wang Hankun , Yu Yan 
Published: May 2020

Abstract
In order to improve dimensional stability and durability of wood, furfurylation of poplar and Chinese fir wood using newly developed furfuryl alcohol (FA) formulation combined with a common vacuum and pressure impregnation process was studied. An orthogonal experiment was designed to optimize the furfurylation process for the two wood species. The weight percent gain (WPG), equilibrium moisture content (EMC), anti-swelling efficiency (ASE), modulus of rupture (MOR), modulus of elasticity (MOE), as well as resistance to mold, decay fungi, and termites were evaluated. The results showed that nearly all the properties of the furfurylated wood could be improved to various extents. The average ASE of the furfurylated Chinese fir and poplar could reach as high as 80, 71, 92% and 79, 90, 75% in tangential and radial directions, and by volume, respectively, higher than most previously reported wood modification processes. Furthermore, the modified wood had excellent biological durability, with nearly 100% mold resistance, strong decay and termite resistance. Finally, processing parameters with 50% FA, 105–115 °C curing temperature, and 5–8 h curing time were therefore recommended for pilot-scale production of furfurylated poplar and Chinese fir wood based on range analysis.
How to manage BRCA mutation carriers?
Authors: Sabiani Laura , Barrou Julien , Mathis Jérome , Eisinger Francois , Bannier Marie , Lambaudie Eric , Houvenaeghel Gilles 
Published: May 2020

Abstract
Inherited mutations in BRCA1 and BRCA2 genes increase the risk of development of cancer in organs especially in breast and ovary. Prevention and screening in BRCA mutation carriers are of high importance. Prophylactic surgeries are possible but are still insufficiently performed because they require surgical procedures in healthy patients. Guidelines for the management of BRCA mutations carriers must absolutely be part of the standard practice of all those involved in the management of these patients to increase the impact of the implementation of these preventive measures. There is no screening recommended for ovarian cancer. A risk-reducing bilateral salpingo-oophorectomy should be performed from age 35 to 40 years for BRCA1 mutation carriers and 40 to 45 years for BRCA2 mutation carriers. A screening for breast cancer should be performed annually from 30 years old by breast MRI and mammography. A risk-reducing bilateral mastectomy is recommended with nipple sparing mastectomy and immediate breast reconstruction from 30 years and before 40 years. A multidisciplinary care must be implemented for these patients with an important psychological support.