bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoluminescence and laser properties of active media based on ZnSe doped with Cr, Al, Na from spray pyrolysis deposited films
Authors: Savin D V , Tomilova T S , Kurashkin S V , Ikonnikov V B , Gavrishchuk E M
Published: November 2020

The prospects for using multicomponent films produced by aerosol spray pyrolysis for doping bulk ZnSe crystals with optically and electrically active impurities are shown for the first time. Lasing was obtained on ZnSe:Cr active elements doped during hot isostatic pressing treatment from CrS and CdS:Cr films. The lasing efficiency with respect to the absorbed radiation energy at a wavelength of 1.94 μm was about 54% for ZnSe:Cr doped from CrS film and 50% for ZnSe:Cr doped from CdS:Cr film, respectively. The luminescence and lasing characteristics of ZnSe:Cr active elements co-doped with Al and Na impurities were investigated. A high diffusion rate of Cr2+ ions into polycrystalline ZnSe doping process from sulfide films was observed.
Natural forests loss and tree plantations: large-scale tree cover loss differentiation in a threatened biodiversity hotspot
Authors: Altamirano Adison , Miranda Alejandro , Aplin Paul , Carrasco Jaime , Catalán Germán , Cayuela Luis , Fuentes-Castillo Taryn , Hernández Angela , Martínez-Harms María J , Peluso Franco , Prado Marco , Reyes-Riveros Rosa , Van Holt Tracy , Vergara Cristian , Zamorano-Elgueta Carlos , Di Bella Carlos
Published: November 2020

Distinguishing between natural forests from exotic tree plantations is essential to get an accurate picture of the world’s state of forests. Most exotic tree plantations support lower levels of biodiversity and have less potential for ecosystem services supply than natural forests, and differencing them is still a challenge using standard tools. We use a novel approach in south-central of Chile to differentiate tree cover dynamics among natural forests and exotic tree plantations. Chile has one of the world’s most competitive forestry industry and the region is a global biodiversity hotspot. Our collaborative visual interpretation method combined a global database of tree cover change, remote sensing from high-resolution satellite images and expert knowledge. By distinguishing exotic tree plantation and natural forest loss, we fit spatially explicit models to estimate tree-cover loss across 40 millions of ha between 2000 and 2016. We were able to distinguish natural forests from exotic tree plantations with an overall accuracy of 99% and predicted forest loss. Total tree cover loss was continuous over time, and the disaggregation revealed that 1 549 909 ha of tree plantations were lost (mean = 96 869 ha year−1), while 206 142 ha corresponded to natural forest loss (mean = 12 884 ha year−1). Mostly of tree plantations lost returned to be plantation (51%). Natural forests were converted mainly (75%) to transitional land covers (e.g. shrubland, bare land, grassland), and an important proportion of these may finish as tree plantation. This replacement may undermine objectives of increasedcarbon storage and biodiversity. Tree planting as a solution has gained increased attention in recen years with ambitious commitments to mitigate the effects of climate change. However, negative outcomes for the environment could result if strategies incentivize the replacement of natural forests into other land covers. Initiatives to reduce carbon emissions should encourage differentiating natural forests from exotic tree plantations and pay more attention on protecting and managing sustainably the former.
Quantum engine based on general measurements
Authors: Behzadi Naghi
Published: November 2020

In this work, we introduce a three-stroke quantum engine with a single-qubit working substance whose cycle consists of two strokes arise due to performing two distinct general quantum measurements and it is completed by thermalization through contact with a finite temperature thermal reservoir. It is demonstrated that energy is imported into the engine by first measurement channel and work (useful energy) is extracted from it, in a frictionless isentropic manner, by the second measurement channel. It is particularly shown that the engine is capable to have perfect efficiency. In continuation, we equip the engine cycle with two additional adiabatic strokes. As illustrated, the presence of adiabatic strokes in the cycle provide an improved lower bound for the parametrized efficiency range of the engine.
Review on the damage behavior of metal laminated composite
Authors: Huang Tao , Pei Yanbo , Chen Fuxiao , Xiang Nan
Published: November 2020

Metal laminated composite (MLC) have attracted widespread attention for their potential in achieving excellent properties. However, damage and failure are more likely to occur during the plastic deformation due to the existence of the interface region, leading to serious safety disasters. Thus, it is essential to research the damage mechanism accurately in order to instruct the practical design of the composite structures. This paper provides a comprehensive review of the experimental methods, various failure criteria and the finite element analysis for studying the damage behavior of the MLC. Some advanced failure criteria such as the cohesive theory and the Gurson-Tvergaard-Needleman (GTN) model which are used to predict the damage behavior of interface region and metal matrix of the MLC are discussed. The establishment of exponential cohesive/shear modified GTN mixed model are expected to accelerate the damage mechanism analysis of the MLC.
Fabrication of high quantum efficiency p-i-n AlGaN detector and optimization of p-layer and i-layer thickness
Authors: Cao Zikun , Zhao Degang , Liang Feng , Liu Zongshun
Published: November 2020

In this paper, the fabrication process and structure of AlGaN based p-i-n photodetectors with different layer thicknesses are described. The maximum external quantum efficiency (EQE) of back illumination is 87.87% at zero bias. According to the Poisson equation, the electric field distribution of the devices is analysed, and a detailed method to estimate the reverse bias voltage required for the p-layer and i-layer to be completely depleted is proposed. The reliability of the method is also well proven by the responsivity measurement results under zero bias and reverse bias. Finally, based on the experimental data and theoretical calculation, the optimization method of p-layer and i-layer thickness in p-i-n photodetector is analysed.
Plasmon modulation in three-dimensional periodic structure of graphene ribbons
Authors: Liu Daqing , Zhuo Fulin , Chen Shuyue , Ma Ning , Zhao Xiang
Published: November 2020

In the article the spectra of plasmon-polariton in a three-dimensional periodic structure of graphene ribbons embedded in a medium were studied at the first time and for a fixed carrier concentration, influences on the spectra from ribbon width, interface distance and period of ribbon were shown. Compared to those in monolayer periodic structure of graphene ribbons, sharp differences occur. Furthermore, there always exist a match point where frequencies of the plasmon-polarition and the electromagnetic radiation are the same. The study improved our basic knowledge on plasmon dynamics in graphene and was important in the design of high efficiency optoelectronic devices.
Root biomass and root traits ofAlnus glutinosashow size-dependent and opposite patterns in a drained and a rewetted forest peatland
Authors: Schwieger Sarah , Blume-Werry Gesche , Ciesiolka Felix , Anadon-Rosell Alba
Published: November 2020

Background and Aims

Forest peatlands represent 25 % of global peatlands and store large amounts of carbon (C) as peat. Traditionally they have been drained in order to increase forestry yield, which may cause large losses of C from the peat. Rewetting aims to stop these losses and to restore the initial storage function of the peatlands. As roots represent major peat-forming elements in these systems, we sampled roots with diameter <5 mm in a drained and a rewetted forest peatland in north-east Germany to evaluate differences in tree biomass investments below ground, root functional characteristics and root age.

Methods

We cored soil next to Alnus glutinosa stems and sorted root biomass into <1, 1–2 and 2–5 mm diameter classes. We measured biomass distribution and specific root area (SRA) in 10-cm depth increments down to 50 cm, and estimated root age from annual growth rings.

Key Results

Root biomass in the rewetted site was more than double that in the drained site. This difference was mostly driven by very fine roots <1 mm, which accounted for 51 % of the total root biomass and were mostly (75 %) located in the upper 20 cm. For roots <1 mm, SRA did not differ between the sites. However, SRA of the 1–2 mm and 2–5 mm diameter roots was higher in the drained than in the rewetted site. Root age did not differ between sites.

Conclusions

The size-dependent opposite patterns between root biomass and their functional characteristics under contrasting water regimes indicate differences between fine and coarse roots in their response to environmental changes. Root age distribution points to similar root turnover rates between the sites, while higher root biomass in the rewetted site clearly indicates larger tree C stocks below ground under rewetting, supporting the C sink function of the ecosystem.
Bioinformatics and machine learning methodologies to identify the effects of central nervous system disorders on glioblastoma progression
Authors: Rahman Md Habibur , Rana Humayan Kabir , Peng Silong , Hu Xiyuan , Chen Chen , Quinn Julian M W , Moni Mohammad Ali
Published: November 2020

Glioblastoma (GBM) is a common malignant brain tumor which often presents as a comorbidity with central nervous system (CNS) disorders. Both CNS disorders and GBM cells release glutamate and show an abnormality, but differ in cellular behavior. So, their etiology is not well understood, nor is it clear how CNS disorders influence GBM behavior or growth. This led us to employ a quantitative analytical framework to unravel shared differentially expressed genes (DEGs) and cell signaling pathways that could link CNS disorders and GBM using datasets acquired from the Gene Expression Omnibus database (GEO) and The Cancer Genome Atlas (TCGA) datasets where normal tissue and disease-affected tissue were examined. After identifying DEGs, we identified disease-gene association networks and signaling pathways and performed gene ontology (GO) analyses as well as hub protein identifications to predict the roles of these DEGs. We expanded our study to determine the significant genes that may play a role in GBM progression and the survival of the GBM patients by exploiting clinical and genetic factors using the Cox Proportional Hazard Model and the Kaplan–Meier estimator. In this study, 177 DEGs with 129 upregulated and 48 downregulated genes were identified. Our findings indicate new ways that CNS disorders may influence the incidence of GBM progression, growth or establishment and may also function as biomarkers for GBM prognosis and potential targets for therapies. Our comparison with gold standard databases also provides further proof to support the connection of our identified biomarkers in the pathology underlying the GBM progression.
Covariate adaptive familywise error rate control for genome-wide association studies
Authors: Zhou Huijuan , Zhang Xianyang , Chen Jun
Published: November 2020

The familywise error rate has been widely used in genome-wide association studies. With the increasing availability of functional genomics data, it is possible to increase detection power by leveraging these genomic functional annotations. Previous efforts to accommodate covariates in multiple testing focused on false discovery rate control, while covariate-adaptive procedures controlling the familywise error rate remain underdeveloped. Here, we propose a novel covariate-adaptive procedure to control the familywise error rate that incorporates external covariates which are potentially informative of either the statistical power or the prior null probability. An efficient algorithm is developed to implement the proposed method. We prove its asymptotic validity and obtain the rate of convergence through a perturbation-type argument. Our numerical studies show that the new procedure is more powerful than competing methods and maintains robustness across different settings. We apply the proposed approach to the UK Biobank data and analyse 27 traits with 9 million single-nucleotide polymorphisms tested for associations. Seventy-five genomic annotations are used as covariates. Our approach detects more genome-wide significant loci than other methods in 21 out of the 27 traits.
Geographical structure of genetic diversity inLoudetia simplex(Poaceae) in Madagascar and South Africa
Authors: Hagl Peter Anton , Gargiulo Roberta , Fay Michael F , Solofondranohatra Cédrique , Salmona Jordi , Suescun Uxue , Rakotomalala Nantenaina , Lehmann Caroline E R , Besnard Guillaume , Papadopulos Alexander S T , Vorontsova Maria S
Published: November 2020

Ecologically dominant species are primary determinants of ecosystem function, especially in grassy ecosystems, but the history and biology of grassy ecosystems in Madagascar are poorly understood compared to those of Africa. Loudetia simplex is a C4 perennial grass that is adapted to fire and common to dominant across Africa. It is also widespread across central Madagascar in what are often thought to be human-derived grasslands, leading us to question how recently L. simplex arrived and how it spread across Madagascar. To address this, we collected population genetic data for 11 nuclear and 11 plastid microsatellite loci, newly developed for this study, for > 200 accessions from 78 populations of L. simplex, primarily from Madagascar and South Africa. Malagasy and African populations are genetically differentiated and harbour distinct plastid lineages. We demonstrate distinct geographically clustered diploid, tetraploid and hexaploid groups. The Malagasy hexaploid populations cluster into northern and southern types. In South Africa, diploid populations in the Drakensberg are distinct from tetraploid populations in north-eastern South Africa. Different genetic clusters are associated with significantly different precipitation and temperature. We conclude that L. simplex is native to both Madagascar and South Africa, probably with a single colonization event from Africa to Madagascar followed by pre-human diversification of L. simplex populations in Madagascar.
Effectiveness of Meningococcal Vaccines at Reducing Invasive Meningococcal Disease and Pharyngeal Neisseria meningitidis Carriage: A Systematic Review and Meta-analysis
Authors: McMillan Mark , Chandrakumar Abira , Wang Hua Lin Rachael , Clarke Michelle , Sullivan Thomas R , Andrews Ross M , Ramsay Mary , Marshall Helen S
Published: November 2020

Background

Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, leads to significant morbidity and mortality worldwide. This review aimed to establish the effectiveness of meningococcal vaccines at preventing IMD and N. meningitidis pharyngeal carriage.

Methods

A search within PubMed, Embase, Scopus, and unpublished studies up to 1 February 2020 was conducted.

Results

After removal of duplicates, 8565 studies were screened and 27 studies included. Protection was provided by meningococcal C vaccines for group C IMD (odds ratio [OR], 0.13 [95% confidence interval {CI}, .07–.23]), outer membrane vesicle (OMV) vaccines against group B IMD (OR, 0.35 [95% CI, .25–.48]), and meningococcal A, C, W, Y (MenACWY) vaccines against group ACWY IMD (OR, 0.31 [95% CI, .20–.49]). A single time series analysis found a reduction following an infant 4CMenB program (incidence rate ratio, 0.25 [95% CI, .19–.36]). Multivalent MenACWY vaccines did not reduce carriage (relative risk [RR], 0.88 [95% CI, .66–1.18]), unlike monovalent C vaccines (RR, 0.50 [95% CI, .26–.97]). 4CMenB vaccine had no effect on group B carriage (RR, 1.12 [95% CI, .90–1.40]). There was also no reduction in group B carriage following MenB-FHbp vaccination (RR, 0.98 [95% CI, .53–1.79]).

Conclusions

Meningococcal conjugate C, ACWY, and OMV vaccines are effective at reducing IMD. A small number of studies demonstrate that monovalent C conjugate vaccines reduce pharyngeal N. meningitidis carriage. There is no evidence of carriage reduction for multivalent MenACWY, OMV, or recombinant MenB vaccines, which has implications for immunization strategies.

Clinical Trials Registration

CRD42018082085 (PROSPERO).
Theoretical Estimation on the Success Rate of the Asymptotic Higher Order Optimal Distinguisher
Authors: Zhang Hailong , Yang Wei
Published: November 2020

Since its first publication at ASIACRYPT 2014, higher order optimal distinguisher (HOOD) has been the most efficient style of higher order side channel attacks that can be used to evaluate the physical security of a masking device. In practice, the efficiency of HOOD can be empirically evaluated with the success rate (SR) metric. In the empirical evaluation, a large number of power traces are needed, and HOOD should be repeated thousands of times under the values of different parameters, which can make the evaluation process cumbersome and the evaluation price high. In light of this, the exact relationship between the SR of the asymptotic HOOD and the values of different parameters is theoretically built, and the soundness of the theoretical analysis is empirically verified in both the simulated scenario and the real scenario. Then, by setting the values of different parameters, the SR of the asymptotic HOOD can be theoretically estimated. Here, as the signal-to-noise ratio of a masking device approaches to zero, the SR of the asymptotic HOOD approaches to the SR of HOOD. Overall, this contribution may help evaluators to efficiently evaluate the physical security of a masking device with HOOD.
Metarhizium Entomopathogenic Fungi Against the Beetle Brontispa longissima (Coleoptera: Hispidae): Isolation and Species Identification
Authors: Lian Tao , Qiu Hua-long , Qin Chang-sheng , Fox Eduardo G P , Zhao Dan-yang , Fang Tian-song , Yang Hua , Tian Long-yan , Xu Jin-zhu
Published: November 2020

Seven entomopathogenic fungi strains (M1−7) were isolated from field-obtained dead coconut hispine beetles Brontispa longissima (Gestro), identified to species, and bioassayed for their pathogenicity. According to ITS sequences, all isolates belong in the genus Metarhizium, mainly M. flavoviride and M. anisopliae. Measured median lethal times (LT50) of 1×107 conidia/ml of M1−7 against fourth-instar B. longissima larvae within 15 d following exposure were, respectively: 5.43, 10.64, 11.26, 10.93, 6.62, 4.73, and 5.95 d. The isolate M6 yielded the highest mortality to fourth-instar larvae, and was thus selected to be tested against other larval instars and adults of B. longissima, after Time–Dose–Mortality (TDM) models. M6 proved more pathogenic against larvae than adults. The obtained bioassays data produced a good fit to the TDM models, yielding estimated LC50 and LT50 for each of the tested developmental stages of B. longissima. Both the obtained dose (β) and time effect (ri) parameters from TDM models suggest that first-instar larvae are the most susceptible life stage of the pest insect, while adults are more resistant to M6 infection. Calculated LC50 values were, respectively, 1.23×103 and 1.15×106 conidia/ml for first-instar larvae and adults, on the 15th day following M6 inoculation. Estimated LT50 were 3.3 and 5.9 d for first-instar larvae and adults, respectively, at 1×108 conidia/ml. Taken together, these results would suggest Metarhizium M6 as an option for the biological control of B. longissima in the field.
Minimally invasive surgery versus thoracotomy for resectable stage II and III non-small-cell lung cancers: a systematic review and meta-analysis
Authors: Shen Haifeng , Wang Xin , Nie Yuntao , Zhang Kai , Wei Zihan , Yang Fan , Wang Jun , Chen Kezhong
Published: November 2020

OBJECTIVES

The study aimed to compare the long-term oncological efficacy and perioperative outcomes of patients with locally advanced non-small-cell lung cancers who underwent minimally invasive surgery (MIS) or thoracotomy.

METHODS

Cochrane Library, PubMed and EMBASE databases, ClinicalTrials.gov and reference lists were searched for relevant studies. Two reviewers independently assessed the quality of the studies. Recurrence-free survival (RFS) and overall survival (OS) and perioperative outcomes were synthesized. Random-effects models were used to summarize hazard ratios (HRs), relative risks and standardized mean differences (SMDs) with 95% confidence intervals (CIs).

RESULTS

Twenty-three retrospective cohort studies were reviewed with a total of 3281 patients, of whom 1376 (41.9%) received MIS and 1905 (58.1%) received thoracotomy. Meta-analysis showed no significant differences in both RFS (HR, 1.02; 95% CI, 0.89–1.17; P = 0.78) and OS (HR, 0.91; 95% CI, 0.80–1.03; P = 0.15) between MIS versus thoracotomy approaches. Similar results were observed in propensity score matched studies (RFS, HR, 0.94; 95% CI, 0.73–1.20; P = 0.62; OS, HR, 0.96; 95% CI, 0.72–1.30; P = 0.81). No significant difference was found in lymph node clearance and margin positivity. As for perioperative outcomes, MIS was associated with a significant reduction in postoperative complications (relative risk, 0.83; P = 0.01), intraoperative blood loss (standardized mean difference, −0.68; P = 0.007), chest tube drainage (standardized mean difference, −0.38; P = 0.03) and length of hospital stay (standardized mean difference, −0.79; P = 0.002) when compared with thoracotomy.

CONCLUSIONS

The use of MIS for resectable stage II and III non-small-cell lung cancers is an eligible alternative to conventional thoracotomy without compromising the long-term survival and short-term outcomes.
Genetic characterization of extended-spectrum β-lactamase-producing Enterobacteriaceae from a biological industrial wastewater treatment plant in Tunisia with detection of the colistin-resistance mcr-1 gene
Authors: Hassen Bilel , Abbassi Mohamed Salah , Ruiz-Ripa Laura , Mama Olouwafemi M , Ibrahim Chourouk , Benlabidi Saloua , Hassen Abdennaceur , Torres Carmen , Hammami Salah
Published: November 2020

This study evaluated the occurrence of extended-spectrum β-lactamases (ESBL) and associated resistance genes, integrons, and plasmid types, as well as the genetic relatedness of enterobacterial isolates in the wastewater treatment plant (WWTP) of La Charguia, Tunis City (Tunisia). A total of 100 water samples were collected at different points of the sewage treatment process during 2017–2019. Antimicrobial susceptibility was conducted by the disc-diffusion method. blaCTX-M, blaTEM and blaSHV genes as well as those encoding non-β-lactam resistance, the plasmid types, occurrence of class1 integrons and phylogenetic groups of Escherichia coli isolates were determined by PCR/sequencing. Genomic relatedness was determined by multi-locus sequence typing (MLST) for selected isolates. In total, 57 ESBL-producer isolates were recovered (47 E. coli, eight Klebsiella pneumoniae, 1 of the Citrobacter freundii complex and 1 of the Enterobacter cloacae complex). The CTX-M-15 enzyme was the most frequently detected ESBL, followed by CTX-M-27, CTX-M-55 and SHV-12. One E. coli isolate harboured the mcr-1 gene. The following phylogroups/sequence types (STs) were identified among ESBL-producing E. coli isolates: B2/ST131 (subclade-C1), A/ST3221, A/ST8900, D/ST69, D/ST2142, D/ST38, B1/ST2460 and B1/ST6448. High numbers of isolates harboured the class 1 integrons with various gene cassette arrays as well as IncP-1 and IncFIB plasmids. Our findings confirm the importance of WWTPs as hotspot collectors of ESBL-producing Enterobacteriaceae with a high likelihood of spread to human and natural environments.
Unbiased Subgenome Evolution in Allotetraploid Species ofEphedraand Its Implications for the Evolution of Large Genomes in Gymnosperms
Authors: Wu Hui , Yu Qiong , Ran Jin-Hua , Wang Xiao-Quan
Published: November 2020

The evolutionary dynamics of polyploid genomes and consequences of polyploidy have been studied extensively in angiosperms but very rarely in gymnosperms. The gymnospermous genus Ephedra is characterized by a high frequency of polyploidy, and thus provides an ideal system to investigate the evolutionary mode of allopolyploid genomes and test whether subgenome dominance has occurred in gymnosperms. Here, we sequenced transcriptomes of two allotetraploid species of Ephedra and their putative diploid progenitors, identified expressed homeologs, and analyzed alternative splicing and homeolog expression based on PacBio Iso-Seq and Illumina RNA-seq data. We found that the two subgenomes of the allotetraploids had similar numbers of expressed homeologs, similar percentages of homeologs with dominant expression, and approximately equal numbers of isoforms with alternative splicing, showing an unbiased subgenome evolution as in a few polyploid angiosperms, with a divergence of the two subgenomes at ∼8 Ma. In addition, the nuclear DNA content of the allotetraploid species is almost equal to the sum of two putative progenitors, suggesting limited genome restructuring after allotetraploid speciation. The allopolyploid species of Ephedra might have undergone slow diploidization, and the unbiased subgenome evolution implies that the formation of large genomes in gymnosperms could be attributed to even and slow fractionation following polyploidization.
Relating force balances and flow length scales in geodynamo simulations
Authors: Schwaiger T , Gastine T , Aubert J
Published: November 2020

In fluid dynamics, the scaling behaviour of flow length scales is commonly used to infer the governing force balance of a system. The key to a successful approach is to measure length scales that are simultaneously representative of the energy contained in the solution (energetically relevant) and also indicative of the established force balance (dynamically relevant). In the case of numerical simulations of rotating convection and magnetohydrodynamic dynamos in spherical shells, it has remained difficult to measure length scales that are both energetically and dynamically relevant, a situation that has led to conflicting interpretations, and sometimes misrepresentations of the underlying force balance. By analysing an extensive set of magnetic and non-magnetic models, we focus on two length scales that achieve both energetic and dynamical relevance. The first one is the peak of the poloidal kinetic energy spectrum, which we successfully compare to crossover points on spectral representations of the force balance. In most dynamo models, this result confirms that the dominant length scale of the system is controlled by a previously proposed quasi-geostrophic (QG-) MAC (Magneto-Archimedean-Coriolis) balance. In non-magnetic convection models, the analysis generally favours a QG-CIA (Coriolis-Inertia-Archimedean) balance. Viscosity, which is typically a minor contributor to the force balance, does not control the dominant length scale at high convective supercriticalities in the non-magnetic case, and in the dynamo case, once the generated magnetic energy largely exceeds the kinetic energy. In dynamo models, we introduce a second energetically relevant length scale associated with the loss of axial invariance in the flow. We again relate this length scale to another crossover point in scale-dependent force balance diagrams, which marks the transition between large-scale geostrophy (the equilibrium of Coriolis and pressure forces) and small-scale magnetostrophy, where the Lorentz force overtakes the Coriolis force. Scaling analysis of these two energetically and dynamically relevant length scales suggests that the Earth’s dynamo is controlled by a QG-MAC balance at a dominant scale of about $200 \, \mathrm{km}$, while magnetostrophic effects are deferred to scales smaller than $50 \, \mathrm{km}$.
On the origin of apparently negative minimum susceptibility of hematite single crystals calculated from low-field anisotropy of magnetic susceptibility
Authors: Hrouda František , Ježek Josef , Chadima Martin
Published: November 2020

As shown in the literature several times, the calculation of the anisotropy of magnetic susceptibility (AMS) of hematite single crystals using standard linear AMS theory reveals that the calculated minimum principal susceptibility is parallel to the crystallographic c-axis, but is negative, which is however not due to diamagnetism as evidenced by direct measurements of susceptibility along the principal directions. Susceptibility of a few hematite single crystals from Minas Gerais, Brazil, was measured in 320 directions using a special 3-D rotator and the measurements were processed through AMS calculation by means of standard linear theory and through constructing contour diagrams in equal-area projection. In addition, the susceptibility was in detail measured in three perpendicular planes approximately passing through the main crystallographic directions. The crystals show extremely high anisotropy, the susceptibility measured along the basal plane is several hundred times higher than that along the c-axis and the AMS ellipsoids are very oblate. The contour diagrams show relatively simple patterns of directional susceptibilities, similar to those of the second-rank tensor. Fitting tensor to measured hematite grains results in small but negative minimum principal susceptibility. Nevertheless, summation of many oriented grains filters out the non-tensorial parts of the grain susceptibility in multicrystal assemblages, the AMS of which is well represented by a tensor.
A stacked frequency approach for inhomogeneous time-dependent MRE: an inverse problem for the elastic shear modulus
Authors: Davies Penny J , Sack Ingolf
Published: November 2020

We derive and analyse a new way to calculate the shear modulus of an inhomogeneous elastic material from time-dependent magnetic resonance elastography (MRE) measurements of its interior displacement. Even with such a rich data source, this is a challenging inverse problem because the coefficient of the shear modulus in the governing equations can be small (or potentially zero). Our approach overcomes this by combining different data sets into an overdetermined matrix–vector equation. It uses finite differences to approximate space derivatives and a Fourier interpolant in time, and we do not need to assume that the inhomogeneous material is ‘locally homogeneous’. Crucially, our construction ensures that the computed value of the (real) shear modulus is real: approximation methods based on the frequency domain version of the problem often give a complex shear modulus for the elastic case and this can be hard to interpret, especially if its imaginary part dominates. We carry out careful numerical tests on a one (space) dimensional analogue of the problem and on experimental MRE data for an inhomogeneous gel phantom.
Paracoccin Overexpression in Paracoccidioides brasiliensis Enhances Fungal Virulence by Remodeling Chitin Properties of the Cell Wall
Authors: Gonçales Relber Aguiar , Ricci-Azevedo Rafael , Vieira Vanessa C S , Fernandes Fabrício F , Thomaz Sandra M de O , Carvalho Agostinho , Vendruscolo Patrícia E , Cunha Cristina , Roque-Barreira Maria Cristina , Rodrigues Fernando
Published: November 2020

Background

The thermodimorphic fungi Paracoccidioides spp. are the etiological agents of paracoccidioidomycosis. Although poorly studied, paracoccin (PCN) from Paracoccidioides brasiliensis has been shown to harbor lectinic, enzymatic, and immunomodulatory properties that affect disease development.

Methods

Mutants of P. brasiliensis overexpressing PCN (ov-PCN) were constructed by Agrobacterium tumefaciens–mediated transformation. ov-PCN strains were analyzed and inoculated intranasally or intravenously to mice. Fungal burden, lung pathology, and survival were monitored to evaluate virulence. Electron microscopy was used to evaluate the size of chito-oligomer particles released by ov-PCN or wild-type strains to growth media.

Results

ov-PCN strains revealed no differences in cell growth and viability, although PCN overexpression favored cell separation, chitin processing that results in the release of smaller chito-oligomer particles, and enhanced virulence. Our data show that PCN triggers a critical effect in the cell wall biogenesis through the chitinase activity resulting from overexpression of PCN. As such, PCN overexpression aggravates the disease caused by P. brasiliensis.

Conclusions

Our data are consistent with a model in which PCN modulates the cell wall architecture via its chitinase activity. These findings highlight the potential for exploiting PCN function in future therapeutic approaches.
Safety and Antiviral Effects of Nebulized PC786 in a Respiratory Syncytial Virus Challenge Study
Authors: DeVincenzo John , Cass Lindsey , Murray Alison , Woodward Kathy , Meals Elizabeth , Coates Matthew , Daly Leah , Wheeler Vicky , Mori Julie , Brindley Charlie , Davis Amanda , McCurdy Meabh , Ito Kazuhiro , Murray Bryan , Strong Pete , Rapeport Garth
Published: November 2020

Background

PC786 is a nebulized nonnucleoside respiratory syncytial virus (RSV) polymerase inhibitor designed to treat RSV, which replicates in the superficial layer of epithelial cells lining the airways.

Methods

Fifty-six healthy volunteers inoculated with RSV-A (Memphis 37b) were randomly dosed with either nebulized PC786 (5 mg) or placebo, twice daily for 5 days, from either 12 hours after confirmation of RSV infection or 6 days after virus inoculation. Viral load (VL), disease severity, pharmacokinetics, and safety were assessed until discharge. RSV infection was confirmed by reverse-transcription quantitative polymerase chain reaction with any positive value (intention-to-treat infected [ITT-I] population) or RSV RNA ≥1 log10 plaque-forming unit equivalents (PFUe)/mL (specific intention-to-treat infection [ITT-IS] population) in nasal wash samples.

Results

In the ITT-I population, the mean VL area under the curve (AUC) was lower in the PC786 group than the placebo group (274.1 vs 406.6 log10 PFUe/mL × hour; P = .0359). PC786 showed a trend toward reduction of symptom score and mucous weight. In ITT-IS (post hoc analysis), the latter was statistically significant as well as VL AUC (P = .0126). PC786 showed an early time to maximum plasma concentration, limited systemic exposure, and long half-life and consequently a 2-fold accumulation over the 5-day dosing period. PC786 was well tolerated.

Conclusions

Nebulized PC786 demonstrated a significant antiviral effect against RSV, warranting further clinical study.

Clinical Trials Registration

ClinicalTrials.gov: NCT03382431; EudraCT: 2017-002563-18.
Genetic Background Amplifies the Effect of Immunodeficiency in Antibiotic Efficacy Against Borrelia burgdorferi
Authors: Sharma Bijaya , McCarthy Julie E , Freliech Cecily A , Clark Morgen M , Hu Linden T
Published: November 2020

Unrecognized immunodeficiency has been proposed as a possible cause of failure of antibiotics to resolve symptoms of Lyme disease. Here, we examined the efficacy of doxycycline in different immunodeficient mice to identify defects that impair antibiotic treatment outcomes. We found that doxycycline had significantly lower efficacy in the absence of adaptive immunity, specifically B cells. This effect was most pronounced in immunodeficient C3H mice compared with C57BL/6 mice, suggesting a role for genetic background beyond immunodeficiency. Addition of a single dose of ceftriaxone to doxycycline treatment effectively cleared infection in C3H mice with severe combined immunodeficiency.
Multilocus Phylogeny Support the Nonbioluminescent FireflyChespiritoas a New Subfamily in the Lampyridae (Coleoptera: Elateroidea)
Authors: Ferreira Vinicius S , Keller Oliver , Branham Marc A
Published: November 2020

In this study, we describe a new Lampyridae subfamily, Chespiritoinae new subfamily, its sole genus Chespirito new genus, and three new species: Chespirito zaragozai new species, Chespirito lloydi new species, and Chespirito ballantyneae new species from the Neotropical portions of Mexico. Chespirito can be readily separated from all other known Lampyridae by the unique prosternum, characterized by being very wide, divided in the middle by a distinct suture forming two plates, with the anterior margin bearing a narrow inter-coxal process, the strongly setose filiform antennae, with antennomere III much smaller than all other antennomeres, the pronotum medially constricted (not in C. ballantyneae), with area adjacent to disc strongly punctate and with the presence of a strongly developed longitudinal carina. To test the placement of the genus within the Lampyridae, we obtained three genetic markers (18S rRNA, 28SrRNA, and cox1 mitochondrial DNA) from C. zaragozai and performed a maximum likelihood (ML) and Bayesian inference (BI) analysis. Our analyses rendered nearly identical tree topologies, with C. zaragozai new species recovered as an independent lineage as sister to Pollaclasis bifaria (Say) (Coleoptera, Lampyridae) + Cyphonocerus ruficollis Kiesenwetter (Coleoptera, Lampyridae)+Luciolinae, with a posterior probability of 96 for the BI analysis and UFBoot respectively of 91 for the ML analysis with the entire clade sister to Pterotus obscuripennis LeConte (Coleoptera, Lampyridae). A detailed examination of the morphology of Chespirito indicates that this lineage is divergent from all other known Lampyridae, which combined with the results of our analyses supports the erection of a new subfamily.
Ceftazidime/avibactam in the era of carbapenemase-producing Klebsiella pneumoniae: experience from a national registry study
Authors: Karaiskos I , Daikos G L , Gkoufa A , Adamis G , Stefos A , Symbardi S , Chrysos G , Filiou E , Basoulis D , Mouloudi E , Galani L , Akinosoglou K , Arvaniti K , Masgala A , Petraki M , Papadimitriou E , Galani I , Poulakou G , Routsi C , Giamarellou H ,   the Hellenic Ceftazidime/Avibactam Registry Study Group, Papoutsaki V , Papadogeorgaki H , Tsapas C , Astriti M , Romanou V , Makronassios E , Giona P , Pontikis K , Gatselis N , Massa E , Michailidou E , Gogos C
Published: November 2020

Background

Infections caused by KPC-producing Klebsiella pneumoniae (Kp) are associated with high mortality. Therefore, new treatment options are urgently required.

Objectives

To assess the outcomes and predictors of mortality in patients with KPC- or OXA-48-Kp infections treated with ceftazidime/avibactam with an emphasis on KPC-Kp bloodstream infections (BSIs).

Methods

A multicentre prospective observational study was conducted between January 2018 and March 2019. Patients with KPC- or OXA-48-Kp infections treated with ceftazidime/avibactam were included in the analysis. The subgroup of patients with KPC-Kp BSIs treated with ceftazidime/avibactam was matched by propensity score with a cohort of patients whose KPC-Kp BSIs had been treated with agents other than ceftazidime/avibactam with in vitro activity.

Results

One hundred and forty-seven patients were identified; 140 were infected with KPC producers and 7 with OXA-48 producers. For targeted therapy, 68 (46.3%) patients received monotherapy with ceftazidime/avibactam and 79 (53.7%) patients received ceftazidime/avibactam in combination with at least another active agent. The 14 and 28 day mortality rates were 9% and 20%, respectively. The 28 day mortality among the 71 patients with KPC-Kp BSIs treated with ceftazidime/avibactam was significantly lower than that observed in the 71 matched patients, whose KPC-Kp BSIs had been treated with agents other than ceftazidime/avibactam (18.3% versus 40.8%; P = 0.005). In the Cox proportional hazards model, ultimately fatal disease, rapidly fatal disease and Charlson comorbidity index ≥2 were independent predictors of death, whereas treatment with ceftazidime/avibactam-containing regimens was the only independent predictor of survival.

Conclusions

Ceftazidime/avibactam appears to be an effective treatment against serious infections caused by KPC-Kp.
Impact of exosome-mediated feto-maternal interactions on pregnancy maintenance and development of obstetric complications
Authors: Hashimoto Ayako , Sugiura Kei , Hoshino Ayuko
Published: November 2020

Pregnancy is an immunological paradox, a phenomenon in which the foetus and the placenta, containing foreign antigens to the mother, develop without inducing rejection by the maternal immune system. Cell-to-cell communication between the foetus and the mother is mediated by secreted factors such as cytokines, hormones and extracellular vesicles (EVs) for a successful pregnancy and to avoid rejection. Exosomes, the smallest of EVs, are released extracellularly, where they are taken up by proximal or distant recipient cells. Here, we discuss the role of EVs, especially exosomes in feto-maternal communication during pregnancy. This review will provide an overview of the functional roles exosomes may play during embryo implantation, modulating immune responses during pregnancy and the onset of labour. Moreover, we will discuss exosomal function in obstetric pathology, and the development of pregnancy-associated complications such as preeclampsia and preterm birth as well as the biomarker potential of exosomes for detecting such conditions.
The logic of orthomodular posets of finite height
Authors: Chajda Ivan , Länger Helmut
Published: November 2020

Orthomodular posets form an algebraic formalization of the logic of quantum mechanics. A central question is how to introduce implication in such a logic. We give a positive answer whenever the orthomodular poset in question is of finite height. The crucial advantage of our solution is that the corresponding algebra, called implication orthomodular poset, i.e. a poset equipped with a binary operator of implication, corresponds to the original orthomodular poset and that its implication operator is everywhere defined. We present here a complete list of axioms for implication orthomodular posets. This enables us to derive an axiomatization in Gentzen style for the algebraizable logic of orthomodular posets of finite height.
Population changes and limitation in the montane vole (Microtus montanus) in perennial old-field grasslands: insights from a long-term study
Authors: Sullivan Thomas P , Sullivan Druscilla S , Boonstra Rudy , Krebs Charles J
Published: November 2020

We livetrapped populations of Microtus montanus from 1982 to 2003 in semiarid perennial old-field grasslands of southern British Columbia. We evaluated two, nonmutually exclusive hypotheses (H) to explain their population dynamics: first (H1), that extended breeding during the summer or winter will drive the increase phase of population fluctuations; and second (H2), that density-dependent depression of juvenile survival will be reflected in poor early juvenile survival during high populations. Populations on 2–3 grids of 1 ha were livetrapped at 3- to 8-week intervals in summer and winter except in 5 years of very low populations. Densities ranged from 10/ha to 250/ha. Peak densities occurred in 6 years and an extended low phase occurred from 1999 to 2003. Fluctuations of 3–4 years appeared in our populations but were not always present. Breeding occurred both in summer and winter, and the best predictor of the population growth rate was the fraction of adult females lactating in summer or winter, thereby supporting H1. Juvenile production (number of juveniles/lactating female) varied greatly among years with the mean being over two times higher in low (2.41) than high (1.08) years, thereby supporting H2. There was no clear correlation between population changes and either seasonal temperatures or rainfall, or any combination of these two variables, and no obvious cause of the prolonged low from 1999 to 2003. Thus, both female reproduction and juvenile production drive montane vole dynamics demographically, similar to what is found in other vole species. However, the ultimate cause of these changes remains to be tackled experimentally.
Phase plates in the transmission electron microscope: operating principles and applications
Authors: Malac Marek , Hettler Simon , Hayashida Misa , Kano Emi , Egerton Ray F , Beleggia Marco
Published: November 2020

In this paper, we review the current state of phase plate imaging in a transmission electron microscope. We focus especially on the hole-free phase plate design, also referred to as the Volta phase plate. We discuss the implementation, operating principles and applications of phase plate imaging. We provide an imaging theory that accounts for inelastic scattering in both the sample and in the hole-free phase plate.
Symptomatic bladder metastasis of malignant melanoma: a case report
Authors: Moez Rahoui , Khaireddine Mrad Daly , Sahnoun Wajih , Zehani Alia , Bibi Mokhtar , Ouannes Yassine , Sellami Ahmed , Rhouma Sami Ben , Nouira Yassine
Published: November 2020

Bladder metastasis of cutaneous malignant melanoma is an extremely rare condition, with less than 10 cases reported in the last 30 years in the English literature. Bladder localization is most often asymptomatic, explaining the frequency of cases discovered during autopsy in multi-metastatic patients. We report a case of symptomatic malignant melanoma metastasis to the bladder in a 31-year-old patient.
Successful outcome of a giant inguinoscrotal hernia: a novel two-staged repair using preoperative progressive pneumoperitoneum and transversus abdominis release
Authors: Miller Derek B , Reed Logan
Published: November 2020

Giant inguinoscrotal hernias, defined as the extension beyond the midpoint of the inner thigh, continue to require multi-step approaches due to their complexity. Although rare in developed countries, they are commonly present in rural areas after years of neglect. This consequently allows the abdomen to maladapt to lower volumes, creating a loss of domain. Here, we present a giant left inguinoscrotal hernia managed with a unique multi-stage approach, aimed to minimize commonly encountered perioperative complications associated with abdominal hypertension. The combined two-staged approach used begins with preoperative progressive pneumoperitoneum, followed by the combined procedures of laparotomy hernia repair (Stoppa technique) and transversus abdominis release, thereby promoting a tension-free closure that is able to accommodate the reduced contents. Various modalities used in treating these hernias have been previously described; however, to our knowledge, the combined use of techniques described here has not been reported.
Sebaceous carcinoma of the axilla
Authors: Siguan Anthony Paolo T , Yray Marc Denver S
Published: November 2020

Sebaceous carcinoma is a rare cutaneous malignant neoplasm with an estimated incidence rate of approximately 1–2 per 1 000 000 per year. It rarely presents as an extra-ocular type and it affects patients in between the sixth and eighth decades of life. This is a case of a 31-year-old male with a 10-year history of a right axillary mass with an incisional biopsy of a sebaceous carcinoma. The mass was 10 × 6 cm in largest diameter, erythematous, non-tender and irregularly shaped. The patient underwent wide excision of the right axillary mass with negative margins confirmed by frozen section under general anesthesia. A parascapular fasciocutaneous flap was done in order to provide coverage for the defect. The patient was then discharged improved on the fourth postoperative day. Although there has been no established clinical protocol for the staging, medical and surgical management for extra-ocular sebaceous carcinoma, early diagnosis accompanied with the proper surgical intervention, such as oncologic wide excision with negative margins, were both adequate and paramount to the diagnosis, course and treatment of this patient, given its rarity.