bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbiota-mediated protection against antibiotic-resistant pathogens
Authors: Panwar Rekha B. , Sequeira Richard P. , Clarke Thomas B. 
Published: May 2021

AbstractColonization by the microbiota provides one of our most effective barriers against infection by pathogenic microbes. The microbiota protects against infection by priming immune defenses, by metabolic exclusion of pathogens from their preferred niches, and through direct antimicrobial antagonism. Disruption of the microbiota, especially by antibiotics, is a major risk factor for bacterial pathogen colonization. Restoration of the microbiota through microbiota transplantation has been shown to be an effective way to reduce pathogen burden in the intestine but comes with a number of drawbacks, including the possibility of transferring other pathogens into the host, lack of standardization, and potential disruption to host metabolism. More refined methods to exploit the power of the microbiota would allow us to utilize its protective power without the drawbacks of fecal microbiota transplantation. To achieve this requires detailed understanding of which members of the microbiota protect against specific pathogens and the mechanistic basis for their effects. In this review, we will discuss the clinical and experimental evidence that has begun to reveal which members of the microbiota protect against some of the most troublesome antibiotic-resistant pathogens: Klebsiella pneumoniae, vancomycin-resistant enterococci, and Clostridioides difficile.
Explosive fragmentation of Prince Rupert’s drops leads to well-defined fragment sizes
Authors: Kooij Stefan , van Dalen Gerard , Molinari Jean-François , Bonn Daniel 
Published: May 2021

AbstractAnyone who has ever broken a dish or a glass knows that the resulting fragments range from roughly the size of the object all the way down to indiscernibly small pieces: typical fragment size distributions of broken brittle materials follow a power law, and therefore lack a characteristic length scale. The origin of this power-law behavior is still unclear, especially why it is such an universal feature. Here we study the explosive fragmentation of glass Prince Rupert’s drops, and uncover a fundamentally different breakup mechanism. The Prince Rupert’s drops explode due to their large internal stresses resulting in an exponential fragment size distribution with a well-defined fragment size. We demonstrate that generically two distinct breakup processes exist, random and hierarchical, that allows us to fully explain why fragment size distributions are power-law in most cases but exponential in others. We show experimentally that one can even break the same material in different ways to obtain either random or hierarchical breakup, giving exponential and power-law distributed fragment sizes respectively. That a random breakup process leads to well-defined fragment sizes is surprising and is potentially useful to control fragmentation of brittle solids.
Size, microhabitat, and loss of larval feeding drive cranial diversification in frogs
Authors: Bardua Carla , Fabre Anne-Claire , Clavel Julien , Bon Margot , Das Kalpana , Stanley Edward L. , Blackburn David C. , Goswami Anjali 
Published: May 2021

AbstractHabitat is one of the most important factors shaping organismal morphology, but it may vary across life history stages. Ontogenetic shifts in ecology may introduce antagonistic selection that constrains adult phenotype, particularly with ecologically distinct developmental phases such as the free-living, feeding larval stage of many frogs (Lissamphibia: Anura). We test the relative influences of developmental and ecological factors on the diversification of adult skull morphology with a detailed analysis of 15 individual cranial regions across 173 anuran species, representing every extant family. Skull size, adult microhabitat, larval feeding, and ossification timing are all significant factors shaping aspects of cranial evolution in frogs, with late-ossifying elements showing the greatest disparity and fastest evolutionary rates. Size and microhabitat show the strongest effects on cranial shape, and we identify a “large size-wide skull” pattern of anuran, and possibly amphibian, evolutionary allometry. Fossorial and aquatic microhabitats occupy distinct regions of morphospace and display fast evolution and high disparity. Taxa with and without feeding larvae do not notably differ in cranial morphology. However, loss of an actively feeding larval stage is associated with higher evolutionary rates and disparity, suggesting that functional pressures experienced earlier in ontogeny significantly impact adult morphological evolution.
Chiral singlet superconductivity in the weakly correlated metal LaPt3P
Authors: Biswas P. K. , Ghosh S. K. , Zhao J. Z. , Mayoh D. A. , Zhigadlo N. D. , Xu Xiaofeng , Baines C. , Hillier A. D. , Balakrishnan G. , Lees M. R. 
Published: May 2021

AbstractChiral superconductors are novel topological materials with finite angular momentum Cooper pairs circulating around a unique chiral axis, thereby spontaneously breaking time-reversal symmetry. They are rather scarce and usually feature triplet pairing: a canonical example is the chiral p-wave state realized in the A-phase of superfluid He3. Chiral triplet superconductors are, however, topologically fragile with the corresponding gapless boundary modes only weakly protected against symmetry-preserving perturbations in contrast to their singlet counterparts. Using muon spin relaxation measurements, here we report that the weakly correlated pnictide compound LaPt3P has the two key features of a chiral superconductor: spontaneous magnetic fields inside the superconducting state indicating broken time-reversal symmetry and low temperature linear behaviour in the superfluid density indicating line nodes in the order parameter. Using symmetry analysis, first principles band structure calculation and mean-field theory, we unambiguously establish that the superconducting ground state of LaPt3P is a chiral d-wave singlet.
Proportion and risk factors for death by euthanasia in dogs in the UK
Authors: Pegram Camilla , Gray Carol , Packer Rowena M. A. , Richards Ysabelle , Church David B. , Brodbelt Dave C. , O’Neill Dan G. 
Published: May 2021

AbstractThe loss of a pet can be particularly distressing for owners, whether the method of death is euthanasia or is unassisted. Using primary-care clinical data, this study aimed to report the demographic and clinical factors associated with euthanasia, relative to unassisted death, in dogs. Method of death (euthanasia or unassisted) and clinical cause of death were extracted from a random sample of 29,865 dogs within the VetCompass Programme from a sampling frame of 905,544 dogs under UK veterinary care in 2016. Multivariable logistic regression modelling was used to evaluate associations between risk factors and method of death. Of the confirmed deaths, 26,676 (89.3%) were euthanased and 2,487 (8.3%) died unassisted. After accounting for confounding factors, 6 grouped-level disorders had higher odds in euthanased dogs (than dogs that died unassisted), using neoplasia as the baseline. The disorders with greatest odds included: poor quality of life (OR 16.28), undesirable behaviour (OR 11.36) and spinal cord disorder (OR 6.00). Breed, larger bodyweight and increasing age were additional risk factors for euthanasia. The results highlight that a large majority of owners will face euthanasia decisions and these findings can support veterinarians and owners to better prepare for such an eventuality.
Secure multiparty quantum key agreement against collusive attacks
Authors: Abulkasim Hussein , Mashatan Atefeh , Ghose Shohini 
Published: May 2021

AbstractQuantum key agreement enables remote participants to fairly establish a secure shared key based on their private inputs. In the circular-type multiparty quantum key agreement mode, two or more malicious participants can collude together to steal private inputs of honest participants or to generate the final key alone. In this work, we focus on a powerful collusive attack strategy in which two or more malicious participants in particular positions, can learn sensitive information or generate the final key alone without revealing their malicious behaviour. Many of the current circular-type multiparty quantum key agreement protocols are not secure against this collusive attack strategy. As an example, we analyze the security of a recently proposed multiparty key agreement protocol to show the vulnerability of existing circular-type multiparty quantum key agreement protocols against this collusive attack. Moreover, we design a general secure multiparty key agreement model that would remove this vulnerability from such circular-type key agreement protocols and describe the necessary steps to implement this model. The proposed model is general and does not depend on the specific physical implementation of the quantum key agreement.
Serial profiling of cell-free DNA and nucleosome histone modifications in cell cultures
Authors: Ungerer Vida , Bronkhorst Abel J. , Van den Ackerveken Priscilla , Herzog Marielle , Holdenrieder Stefan 
Published: May 2021

AbstractRecent advances in basic research have unveiled several strategies for improving the sensitivity and specificity of cell-free DNA (cfDNA) based assays, which is a prerequisite for broadening its clinical use. Included among these strategies is leveraging knowledge of both the biogenesis and physico-chemical properties of cfDNA towards the identification of better disease-defining features and optimization of methods. While good progress has been made on this front, much of cfDNA biology remains uncharted. Here, we correlated serial measurements of cfDNA size, concentration and nucleosome histone modifications with various cellular parameters, including cell growth rate, viability, apoptosis, necrosis, and cell cycle phase in three different cell lines. Collectively, the picture emerged that temporal changes in cfDNA levels are rather irregular and not the result of constitutive release from live cells. Instead, changes in cfDNA levels correlated with intermittent cell death events, wherein apoptosis contributed more to cfDNA release in non-cancer cells and necrosis more in cancer cells. Interestingly, the presence of a ~ 3 kbp cfDNA population, which is often deemed to originate from accidental cell lysis or active release, was found to originate from necrosis. High-resolution analysis of this cfDNA population revealed an underlying DNA laddering pattern consisting of several oligo-nucleosomes, identical to those generated by apoptosis. This suggests that necrosis may contribute significantly to the pool of mono-nucleosomal cfDNA fragments that are generally interrogated for cancer mutational profiling. Furthermore, since active steps are often taken to exclude longer oligo-nucleosomes from clinical biospecimens and subsequent assays this raises the question of whether important pathological information is lost.
Stochastic modelling of cellulose hydrolysis with Gauss and Weibull distributed transition probabilities
Authors: Duru Joseph Mcgreg , Pârvulescu Oana Cristina , Dobre Tănase , Răducanu Cristian Eugen 
Published: May 2021

AbstractTwo Markov-type stochastic models were developed to describe the kinetics of acid hydrolysis of cellulose. One of them involved a Gauss (normal) distribution of probabilities of chemical bond breaking, the other a Weibull distribution. It was considered that the random breaking of cellulose was based on the cleavage of a parent macromolecule into two descendants. Model equations and kinetics of acid hydrolysis of cellulose consisting of 10 and 100 units of cellobiose were presented. The effects of acid concentration and temperature on the kinetics of hydrolysis process were taken into account. The results obtained applying both stochastic models were in a reasonable agreement with those obtained using a deterministic kinetic model. These stochastic models can accurately describe the kinetics of acid hydrolysis and cover the drawbacks of some deterministic kinetic models, e.g., large number of model equations and parameters, modification of parameter values by changing the process conditions.
Diamine vapor treatment of viscoelastic graphene oxide liquid crystal for gas barrier coating
Authors: Choi Seung Eun , Kim Sung-Soo , Choi Eunji , Kim Ji Hoon , Choi Yunkyu , Kang Junhyeok , Kwon Ohchan , Kim Dae Woo 
Published: May 2021

AbstractA layered graphene oxide/ethylenediamine (GO/EDA) composite film was developed by exposing aqueous GO liquid crystal (GOLC) coating to EDA vapor and its effects on the gas barrier performance of GO film were systematically investigated. When a GO/EDA coating with a thickness of approximately 1 μm was applied to a neat polyethylene terephthalate (PET) film, the resultant film was highly impermeable to gas molecules, particularly reducing the gas permeance up to 99.6% for He and 98.5% for H2 in comparison to the neat PET film. The gas barrier properties can be attributed to the long diffusion length through stacked GO nanosheets. The EDA can crosslink oxygen-containing groups of GO, enhancing the mechanical properties of the GO/EDA coating with hardness and elastic modulus values up to 1.14 and 28.7 GPa, respectively. By the synergistic effect of the viscoelastic properties of GOLC and the volatility of EDA, this coating method can be applied to complex geometries and EDA intercalation can be spontaneously achieved through the scaffold of the GOLC.
Microdroplet-based system for culturing of environmental microorganisms using FNAP-sort
Authors: Saito Kanako , Ota Yuri , Tourlousse Dieter M. , Matsukura Satoko , Fujitani Hirotsugu , Morita Masamune , Tsuneda Satoshi , Noda Naohiro 
Published: May 2021

AbstractDroplet microfluidics has emerged as a powerful technology for improving the culturing efficiency of environmental microorganisms. However, its widespread adoption has been limited due to considerable technical challenges, especially related to identification and manipulation of individual growth-positive droplets. Here, we combined microfluidic droplet technology with on-chip “fluorescent nucleic acid probe in droplets for bacterial sorting” (FNAP-sort) for recovery of growth-positive droplets and droplet microdispensing to establish an end-to-end workflow for isolation and culturing of environmental microbes. As a proof-of-concept, we demonstrate the ability of our technique to yield high-purity cultures of rare microorganisms from a representative complex environmental microbiome. As our system employs off-the-shelf commercially available equipment, we believe that it can be readily adopted by others and may thus find widespread use toward culturing the high proportion of as-of-yet uncultured microorganisms in different biomes.
Application of cryopreservation to tooth germ transplantation for root development and tooth eruption
Authors: Li Xinghan , Nakamura Megumi , Tian Weidong , Sasano Yasuyuki 
Published: May 2021

AbstractWe cryopreserved mouse tooth germs with widely open cervical margins of the enamel organ to overcome difficulties in cryoprotectant permeation and tested their efficacy by transplanting them into recipient mice. The upper right first molar germs of 8-day-old donor mice were extracted and categorized into the following four groups according to cryopreservation time: no cryopreservation, 1 week, 1 month, and 3 months. The donor tooth germs were transplanted into the upper right first molar germ sockets of the 8-day-old recipient mice. The upper left first molars of the recipient mice were used as controls. The outcome of the transplantation was assessed at 1, 2, and 3 weeks after transplantation. Stereomicroscopic evaluation revealed that most of the transplanted teeth erupted by 3 weeks after transplantation. Micro-computed tomography analysis revealed root elongation in the transplanted groups as well as in the controls. There was no significant difference between the cryopreserved and non-cryopreserved transplanted teeth, but the roots of the cryopreserved teeth were significantly shorter than those of the control teeth. Histological examination revealed root and periodontal ligament formations in all the transplanted groups. These results suggest that the transplantation of cryopreserved tooth germs facilitates subsequent root elongation and tooth eruption.
Experimental study on the effects of blending PODEn on performance, combustion and emission characteristics of heavy-duty diesel engines meeting China VI emission standard
Authors: Zhao Yuwei , Geng Cong , E Weibo , Li Xiaoquan , Cheng Peiyuan , Niu Tianlin 
Published: May 2021

AbstractTo study the influence of diesel fuel blended with polyoxymethylene dimethyl ethers (PODEn), a new alternative fuel with a high oxygen content and large cetane number, on the combustion characteristics, fuel economies, and emission characteristics of heavy-duty diesel engines that meet China VI emission standards, relevant tests were conducted on a supercharged intercooled high-pressure common-rail diesel engine. The PODEn were blended with diesel fuel at three different ratios (volume fractions of 10%, 20%, and 30%). The test results showed that the PODEn could optimize the combustion process of diesel engines that met the China VI emission standards, effectively improve the thermal efficiencies of diesel engines, and reduce the emissions of hydrocarbon (HC), carbon monoxide (CO), and soot. With an increase in the PODEn blending ratio, the peak values of the in-cylinder pressure, average in-cylinder temperature, and instantaneous heat release rate gradually decreased, and each peak progressively moved forward. As the start of combustion gradually moved forward, the combustion duration was shortened by 0.7–2.8°CA, the heat release process became more concentrated, and the effective thermal efficiency was increased by up to 2.57%. The effective fuel consumption gradually increased, yet the equivalent effective fuel consumption gradually decreased, with the largest drop being as high as 4.55%. The nitrogen oxides (NOx) emission increased slightly, and the emissions of HC, CO, and soot gradually decreased. The emissions of CO and soot declined significantly under high-speed and high-load conditions, with the highest reductions reaching 66.2% and 76.3%, respectively.
The protected physiological state of intracellular Salmonella enterica persisters reduces host cell-imposed stress
Authors: Schulte Marc , Olschewski Katharina , Hensel Michael 
Published: May 2021

AbstractDuring infectious diseases, small subpopulations of bacterial pathogens enter a non-replicating (NR) state tolerant to antibiotics. After phagocytosis, intracellular Salmonella enterica serovar Typhimurium (STM) forms persisters able to subvert immune defenses of the host. Physiological state and sensing properties of persisters are difficult to analyze, thus poorly understood. Here we deploy fluorescent protein reporters to detect intracellular NR persister cells, and to monitor their stress response on single cell level. We determined metabolic properties of NR STM during infection and demonstrate that NR STM persisters sense their environment and respond to stressors. Since persisters showed a lower stress response compared to replicating (R) STM, which was not consequence of lower metabolic capacity, the persistent state of STM serves as protective niche. Up to 95% of NR STM were metabolically active at beginning of infection, very similar to metabolic capacity of R STM. Sensing and reacting to stress with constant metabolic activity supports STM to create a more permissive environment for recurrent infections. Stress sensing and response of persister may be targeted by new antimicrobial approaches.
Fracto-eutectogels: SDS fractal dendrites via counterion condensation in a deep eutectic solvent
Authors: Matthews Lauren , Ruscigno Silvia , Rogers Sarah E. , Bartlett Paul , Johnson Andrew J. , Sochon Robert , Briscoe Wuge H. 
Published: May 2021

Fracto-eutectogels comprising dendritic fractal aggregates of SDS surfactants in glyceline, a deep eutectic solvent, are observed for the first time, alluding to curious self-assembly mechanisms in such H-bonding rich, non-aqueous green solvents.
Mitochondrial and metabolic dysfunction in Friedreich ataxia: update on pathophysiological relevance and clinical interventions
Authors: Lynch David R. , Farmer Garrett 
Published: May 2021

AbstractFriedreich ataxia (FRDA) is a recessive disorder resulting from relative deficiency of the mitochondrial protein frataxin. Frataxin functions in the process of iron–sulfur (Fe–S) cluster synthesis. In this review, we update some of the processes downstream of frataxin deficiency that may mediate the pathophysiology. Based on cellular models, in vivo models and observations of patients, ferroptosis may play a major role in the pathogenesis of FRDA along with depletion of antioxidant reserves and abnormalities of mitochondrial biogenesis. Ongoing clinical trials with ferroptosis inhibitors and nuclear factor erythroid 2-related factor 2 (Nrf2) activators are now targeting each of the processes. In addition, better understanding of the mitochondrial events in FRDA may allow the development of improved imaging methodology for assessing the disorder. Though not technologically feasible at present, metabolic imaging approaches may provide a direct methodology to understand the mitochondrial changes occurring in FRDA and provide a methodology to monitor upcoming trials of frataxin restoration.
Fahrkompetenz und Morbus Parkinson
Authors: Andelfinger Vanessa , Weisbrod Matthias , Fritz Michael , Aschenbrenner Steffen 
Published: May 2021

ZUSAMMENFASSUNGDiese Arbeit gibt einen Überblick über die wissenschaftliche Studienlage zum Thema Fahrkompetenz bei Morbus Parkinson. Neben der Darstellung der geltenden Rechtslage erfolgt eine Übersicht über motorische, kognitive, visuelle und dopaminassoziierte Symptome, die Zweifel an der Fahrkompetenz von Parkinson-Patienten begründen können. In diesem Kontext findet eine differenzierte Betrachtung von Fahrverhaltensproben und Fahrsimulatoren statt. Den Abschluss bilden klinische Handlungsempfehlungen für Patienten und Behandler, die Betrachtung medikamentöser Behandlung, operative Behandlungsansätze und neuropsychologische Therapiemöglichkeiten.
Psychische Vorerkrankung der Eltern und psychische Probleme bei Kindern und Jugendlichen
Authors: Clemens Vera , Staab Marlena , Fegert Jörg M. 
Published: May 2021

ZUSAMMENFASSUNGKinder mit Eltern, die an psychischen Vorerkrankungen leiden, haben ein erhöhtes Risiko, psychische Probleme zu entwickeln. Häufiger als gesunde Elternteile sind psychisch erkrankte Eltern gestresst und belastet durch das Elternsein. Während der SARS-CoV-2-Pandemie sind Familien zusätzlich durch Einschränkungen der Pandemie belastet. Diese Studie untersucht deshalb den Zusammenhang zwischen psychischen Vorerkrankungen bei Eltern und psychischen Auffälligkeiten bei Kindern während des ersten Lockdowns der SARS-CoV-2-Pandemie. Dafür wurde eine Online-Umfrage während des ersten Lockdowns in Deutschland durchgeführt. Für die Untersuchung wurden die Daten von 687 Eltern minderjähriger Kinder analysiert. Soziodemografische Variablen sowie das Vorhandensein vorherbestehender psychischer Erkrankungen der Teilnehmenden (n = 224, 32,6 %) und deren Einschätzung zu Verhaltensauffälligkeiten ihrer Kinder vor und während des Lockdowns sowie zu dem Coping der Familie mit pandemieassoziierten Herausforderungen wurden untersucht. Die Ergebnisse zeigen, dass Kinder mit psychisch erkrankten Eltern sowohl vor als auch während des Lockdowns häufiger Verhaltensauffälligkeiten haben. Psychische Vorerkrankungen bei den Eltern waren assoziiert mit einer weniger erfolgreichen Bewältigung der Herausforderungen der Pandemie bei den Kindern sowie bei der gesamten Familie. Die Daten weisen darauf hin, dass Kinder mit psychisch vorerkrankten Eltern adäquate Behandlungs- und Unterstützungsmöglichkeiten benötigen, um die Belastungen der SARS-CoV-2-Pandemie erfolgreich meistern zu können und das Risiko für das Entwickeln von psychischen Problemen zu senken.