bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissemination mechanisms of NDM genes in hospitalized patients
Authors: Zhai Yuting , Lee Shinyoung , Teng Lin , Ma Zhengxin , Hilliard Nicole B , May Robert J , Brown Scott A , Yu Fahong , Desear Kathryn E , Cherabuddi Kartik , Rand Kenneth H , Morris J Glenn , Iovine Nicole M , Jeong KwangCheol C 
Published: February 2021

Abstract

Background
NDM-producing Enterobacteriaceae are a major clinical concern worldwide. We characterized NDM-positive pathogens isolated from patients and assessed the dissemination patterns of the blaNDM genes in a hospital setting.

Methods
Eleven NDM-positive Enterobacteriaceae (three Enterobacter hormaechei, six Klebsiella pneumoniae and two Escherichia coli) were isolated from nine patients over a 1 year period. Antimicrobial susceptibility was assessed by MICs. A combination of short- and long-read WGS was used for genome analysis. Clinical treatment history of patients was linked with genetic features of individual isolates to investigate the dissemination patterns of the blaNDM genes and NDM-positive strains.

Results
bla NDM in clonal K. pneumoniae were transmitted between two patients. In other instances, an identical IncC plasmid encoding NDM-1 was transmitted between E. coli and K. pneumoniae isolated from the same patient, and an IncX3 plasmid, carrying blaNDM-1 or blaNDM-5, was harboured in non-clonal E. hormaechei. Varying patterns of IS elements were identified as a critical transmission mechanism in association with blaNDM genes.

Conclusions
Multiple transmission patterns were identified in hospitalized patients, including dissemination of clonal bacterial strains carrying resistance genes and horizontal transfer of resistance genes among divergent bacterial strains. Controlling spread of NDM is complex: while attention to standard infection control practices is critically important, this needs to be matched by aggressive efforts to limit unnecessary antimicrobial use, to minimize the selection for and risk of transfer of ‘high mobility’ resistance genes among Enterobacteriaceae.
Comparison of Lethal Doses Calculated Using Logit/Probit–Log(Dose) Regressions With Arbitrary Slopes Using R
Authors: Peng Xiaowei , Lei Chengfeng , Sun Xiulian 
Published: February 2021

AbstractThe median lethal dose (LD50) is commonly used to indicate acute toxicity of an insecticide to an insect species. Approximate confidence intervals for LD50s are often calculated using the Fieller and delta methods. It is often necessary to compare the relative potencies of several insecticides with a population or of one insecticide with different populations. Comparing the LD50s using probit/logit–log(dose) regressions with parallel slopes can be implemented in many software packages, but for the cases with arbitrary slopes are not generally available. We used the glm function in R to calculate and compare lethal doses without assuming equal slopes. Bioassay datasets from the literature fitted using the logit model gave the 95% confidence limits (95% CLs) for the lethal doses using Fieller’s theorem and incorporating a heterogeneity factor identical to the 95% CLs determined using the PoloPlus software. The delta method gave 95% CLs identical to the 95% CLs determined using the R drc package. The same datasets fitted using the probit model gave 95% CLs similar to the 95% CLs determined using PoloPlus and the drc package. The natural response rates for the control group were included using Abbott’s equation. When the potency ratio method and the z-test were used to identify differences between two lethal doses, and when the χ2 and log likelihood ratio tests were used to determine whether the regression lines were parallel, the conclusions were the same as those gave by PoloPlus and the drc package.
Geophysical investigations for stability and safety mitigation of regional crude-oil pipeline near abandoned coal mines
Authors: Butchibabu B , Khan Prosanta Kumar , Jha P C 
Published: February 2021

Abstract
This study aims for the protection of a crude-oil pipeline, buried at a shallow depth, against a probable environmental hazard and pilferage. Both surface and borehole geophysical techniques such as electrical resistivity tomography (ERT), ground penetrating radar (GPR), surface seismic refraction tomography (SRT), cross-hole seismic tomography (CST) and cross-hole seismic profiling (CSP) were used to map the vulnerable zones. Data were acquired using ERT, GPR and SRT along the pipeline for a length of 750 m, and across the pipeline for a length of 4096 m (over 16 profiles of ERT and SRT with a separation of 50 m) for high-resolution imaging of the near-surface features. Borehole techniques, based on six CSP and three CST, were carried out at potentially vulnerable locations up to a depth of 30 m to complement the surface mapping with high-resolution imaging of deeper features. The ERT results revealed the presence of voids or cavities below the pipeline. A major weak zone was identified at the central part of the study area extending significantly deep into the subsurface. CSP and CST results also confirmed the presence of weak zones below the pipeline. The integrated geophysical investigations helped to detect the old workings and a deformation zone in the overburden. These features near the pipeline produced instability leading to deformation in the overburden, and led to subsidence in close vicinity of the concerned area. The area for imminent subsidence, proposed based on the results of the present comprehensive geophysical investigations, was found critical for the pipeline.
The influence of advance speed on overburden movement characteristics in longwall coal mining: insight from theoretical analysis and physical simulation
Authors: Han Penghua , Zhang Cun , Ren Zhaopeng , He Xiang , Jia Sheng 
Published: February 2021

Abstract
The advance speed of a longwall face is an essential factor affecting the mining pressure and overburden movement, and an effective approach for choosing a reasonable advance speed to realise coal mine safety and efficient production is needed. To clarify the influence of advance speed on the overburden movement law of a fully mechanised longwall face, a time-space subsidence model of overburden movement is established by the continuous medium analysis method. The movement law of overburden in terms of the advance speed is obtained, and mining stress characteristics at different advance speeds are reasonably explained. The theoretical results of this model are further verified by a physical simulation experiment. The results support the following conclusions. (i) With increasing advance speed of the longwall face, the first (periodic) rupture interval of the main roof and the key stratum increase, while the subsidence of the roof, the fracture angle and the rotation angle of the roof decrease. (ii) With increasing advance speed, the roof displacement range decreases gradually, and the influence range of the advance speed on the roof subsidence is 75 m behind the longwall face. (iii) An increase in the advance speed of the longwall face from 4.89 to 15.23 m/d (daily advancing of the longwall face) results in a 3.28% increase in the impact load caused by the sliding instability of the fractured rock of the main roof and a 5.79% decrease in the additional load caused by the rotation of the main roof, ultimately resulting in a 9.63% increase in the average dynamic load coefficient of the support. The roof subsidence model based on advance speed is proposed to provide theoretical support for rational mining design and mining-pressure-control early warning for a fully mechanised longwall face.
Formal Hierarchies and Informal Networks: How Organizational Structure Shapes Information Search in Local Government
Authors: Whetsell Travis A , Kroll Alexander , DeHart-Davis Leisha 
Published: February 2021

Abstract
Attention to informal communication networks within public organizations has grown in recent decades. While research has documented the role of individual cognition and social structure in understanding information search in organizations, this article emphasizes the importance of formal hierarchy. We argue that the structural attributes of bureaucracies are too important to be neglected when modeling knowledge flows in public organizations. Empirically, we examine interpersonal information-seeking patterns among 143 employees in a small city government, using exponential random graph modeling (ERGM). The results suggest that formal structure strongly shapes information search patterns while accounting for social network variables and individual-level perceptions. We find that formal status, permission pathways, and departmental membership all affect employees’ information search. Understanding the effects of organizational structure on information search networks will offer opportunities to improve information flows in public organizations via design choices.
Short overview on the relevance of microRNA–reactive oxygen species (ROS) interactions and lipid peroxidation for modulation of oxidative stress-mediated signalling pathways in cancer treatment
Authors: Ulker Ozge Cemiloglu , Panieri Emiliano , Suzen Sibel , Jaganjac Morana , Zarkovic Neven , Saso Luciano 
Published: February 2021

Abstract

Objectives
Modulation of oxidative stress-mediated signalling pathways is constantly getting more attention as a valuable therapeutic strategy in cancer treatment. Although complexity of redox signalling pathways might represent a major hurdle, the development of advanced -omics technologies allow thorough studies on cancer-specific biology, which is essential to elucidate the impact of these signalling pathways in cancer cells. The scope of our review is to provide updated information about recent developments in cancer treatment.

Key findings
In recent years identifying oxidative stress-mediated signalling pathways is a major goal of cancer research assuming it may provide novel therapeutic approaches through the development of agents that may have better tissue penetration and therefore affect specific redox signalling pathways. In this review, we discuss some recent studies focussed on the modulation of oxidative stress-related signalling pathways as a novel anti-cancer treatment, with a particular emphasis on the induction of lipid peroxidation.

Conclusions
Characterization and modulation of oxidative stress-mediated signalling pathways and lipid peroxidation products will continue to foster novel interest and further investigations, which may pave the way for more effective, selective, and personalized integrative biomedicine treatment strategies.
Measuring neck circumference to predict and detect haemorrhage following thyroid surgery. A case series and literature review
Authors: Ezzy Mohsen A , Elshafei Moustafa H , Sharaan Mohamed A 
Published: February 2021

Abstract
Post-thyroidectomy bleeding is a fortunately rare but potentially life-threatening complication that may increase postoperative morbidity and hospital stay. In this case series, we demonstrate the relation between the measurement of neck circumference and haemorrhage following thyroid surgery and the value of this measurement in predicting post-thyroidectomy haemorrhage.
Currently, there is no simple and reliable method available for the early detection of post-thyroidectomy bleeding. Continuous pressure measurement could be a potential tool for the early detection of haemorrhage but is invasive, and more data are required to recommend threshold values for revision surgery. Early recognition and prompt surgical intervention are key to the management of cervical haematoma. Measurement of the neck circumference is a valuable adjunct tool in the early recognition of post-thyroidectomy bleeding. In this case series, we concluded that a 4-cm increase in neck circumference may trigger the clinical decision for cervical exploration.
In vivo study of hypericin-loaded poloxamer-based mucoadhesive in situ gelling liquid crystalline precursor system in a mice model of vulvovaginal candidiasis
Authors: de Araújo Patricia Rocha , Calixto Giovana Maria Fioramonti , Araújo Victor Hugo Sousa , Sato Mariana Rillo , Rodero Camila Fernanda , Oshiro-Junior João Augusto , Bauab Taís Maria , Chorilli Marlus 
Published: February 2021

Abstract
The present study reports the performance of the pigment hypericin (HYP)-loaded poloxamer-based mucoadhesive in situ gelling liquid crystalline precursor system (LCPS) for the treatment of vulvovaginal candidiasis (VVC) in mice. LCPS composed of 40% of ethoxylated and propoxylated cetyl alcohol, 30% of oleic acid and cholesterol (7:1), 30% of a dispersion of 16% poloxamer 407 and 0.05% of HYP (HYP-LCPS) was prepared and characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS) and ex vivo permeation and retention studies across vaginal porcine mucosa were performed. In addition, the antifungal properties of the HYP-LCPS were evaluated in a murine in vivo model; for this, infected C57BL female mice groups were treated with both HYP in solution and HYP-LCPS, and after 6 days colony forming unit (CFU)/ml count was performed. PLM and SAXS confirmed that HYP-LCPS is a microemulsion situated in boundary transition region confirming its action as an LCPS. When in contact with simulated vaginal fluid, HYP-LCPS became rigid and exhibited maltase crosses and bragg peaks characteristics of lamellar phase. Ex vivo permeation and retention studies showed that HYP-LCPS provides a localized treatment on the superficial layers of porcine vaginal mucosa. HYP-LCPS induced a significant reduction in the number of CFU/ml in the mice; thus this formulation indicated it is as effective as a commercial dosage form. It was concluded that LCPS maintains the biological activity of HYP and provides an adequate drug delivery system for this lipophilic molecule at the vaginal mucosa, being a promising option in cases of VVC.
New members of Cygnus OB2 from Gaia DR2
Authors: Orellana R B , De Biasi M S , Paíz L G 
Published: February 2021

ABSTRACT
Due to the high quality of Gaia DR2 stellar parallaxes and proper motions, we can study the Cygnus OB2 region up to G = 17.5 mag in circular region centred at (l, b) = (79.8°, +0.8°) of radius 1°. We detect four overdensities in the Vector Point Diagram. We apply a parametric model of the proper motion distribution and determine their mean proper motions, identify their members, and estimate their distances by analysing the parallaxes of the most probable members. We confirm that one of these regions is Cygnus OB2, whose mean proper motion is (μαcosδ, μδ) = (−2.71 ± 0.02, −4.24 ± 0.02) $\mathrm{mas\, yr}^{-1}$. We identify 2767 astrometric members at an estimated distance of 1683 ± 5 pc. A detailed comparison of these members with 333 photometric and spectroscopic Cygnus OB2 members shows that 33 stars of the last group are not members, 16 of them are O-B stars. 300 members in common lead to estimate a distance to the association of 1669 ± 6 pc. One of the remaining overdensities is the open cluster UCB585 for which we find eight more members, located at ∼1460 pc. The other two groups count 179 and 188 proper motion members which are distributed throughout the region and situated at a distance of ∼1280 pc. The estimated distances of these four groups suggest the existence of different substructures in the Cygnus OB2 region along the line of sight.
The highly obscured Seyfert 2 nucleus in NGC 1448 observed with MUSE
Authors: Menezes R B , da Silva Patrícia , Steiner J E 
Published: February 2021

ABSTRACT
We present the analysis of an optical data cube of the central region of NGC 1448, obtained with the Multi Unit Spectroscopic Explorer (MUSE). Chandra X-ray data indicate that the active galactic nucleus (AGN) is not located at the apparent stellar nucleus of the galaxy, but at a projected distance of $1.75\, \pm \, 0.22$ arcsec (139 ± 17 pc). This is probably caused by the high interstellar extinction in the surroundings of the AGN, which corresponds to the true nucleus of the galaxy, as also proposed by previous studies. The morphology and classification of the optical line-emitting regions indicate two ionization cones, around an axis with a position angle of PAcones = −50° ± 7°, with emission-line spectra characteristic of Seyfert galaxies. The stellar and gas kinematics are consistent with a stellar and gas rotating disc around the nucleus, with a velocity amplitude of 125 km s−1. Two probable outflows from the AGN were detected along the region of the two ionization cones. The AGN position does not coincide with the brightest line-emitting region at the centre of NGC 1448. That may be a consequence of the high obscuration from the AGN towards the observer (the AGN is actually Compton thick), mostly caused by a nearly edge-on torus. An additional hypothesis is that the AGN reduced its luminosity, during the last 440 yr, to nearly half of the value in the past. In this case, the brightest line-emitting region corresponds to a ‘light echo’ or a ‘fossil’ of the AGN in the past.
A faint companion around CrA-9: protoplanet or obscured binary?
Authors: Christiaens V , Ubeira-Gabellini M-G , Cánovas H , Delorme P , Pairet B , Absil O , Casassus S , Girard J H , Zurlo A , Aoyama Y , Marleau G-D , Spina L , van der Marel N , Cieza L , Lodato G , Pérez S , Pinte C , Price D J , Reggiani M 
Published: February 2021

ABSTRACT
Understanding how giant planets form requires observational input from directly imaged protoplanets. We used VLT/NACO and VLT/SPHERE to search for companions in the transition disc of 2MASS J19005804-3645048 (hereafter CrA-9), an accreting M0.75 dwarf with an estimated age of 1–2 Myr. We found a faint point source at ∼0.7-arcsec separation from CrA-9 (∼108 au projected separation). Our 3-epoch astrometry rejects a fixed background star with a 5σ significance. The near-IR absolute magnitudes of the object point towards a planetary-mass companion. However, our analysis of the 1.0–3.8$\,\mu$m spectrum extracted for the companion suggests it is a young M5.5 dwarf, based on both the 1.13-μm Na index and comparison with templates of the Montreal Spectral Library. The observed spectrum is best reproduced with high effective temperature ($3057^{+119}_{-36}$K) BT-DUSTY and BT-SETTL models, but the corresponding photometric radius required to match the measured flux is only $0.60^{+0.01}_{-0.04}$ Jovian radius. We discuss possible explanations to reconcile our measurements, including an M-dwarf companion obscured by an edge-on circum-secondary disc or the shock-heated part of the photosphere of an accreting protoplanet. Follow-up observations covering a larger wavelength range and/or at finer spectral resolution are required to discriminate these two scenarios.
Self-similar adiabatic strong explosion in a medium gravitationally free falling to a point mass
Authors: Yalinewich Almog 
Published: February 2021

ABSTRACT
We develop a generalization to the classical Sedov–Taylor explosion where the medium free falls to a point mass at the centre of the explosion. To verify our analytic results, we compare them to a suite of numerical simulations. We find that there exists a critical energy below which, instead of propagating outward the shock stalls and collapses under gravity. Furthermore, we find that the value of the critical energy threshold decreases when the adiabatic index increases and material is more evenly distributed within the shocked region. We apply this model to the problem of a shock bounce in core collapse supernova, in which the proto-neutron star serves as the point mass. The relation between the threshold energy and the distribution of mass in the shock might help explain how turbulence prevents shock stalling and recession in a core-collapse supernova explosion.
Inhomogeneous dust eclipses in young stars: the case of CQ Tauri
Authors: Dodin A V , Suslina E A 
Published: February 2021

ABSTRACT
We find that dust clouds that eclipse young stars obscure the stellar disc inhomogeneously. In the particular case of CQ Tau, we find isolated optically thick structures with sizes ≲0.6R* and derive the typical AV gradient in the plane of the sky, finding it to be as high as a few magnitudes per stellar radius. The large extinction gradients and complex structure of the obscuring clouds lead not only to a noticeable Rossiter–McLaughlin effect but also to complex and variable shaping of stellar absorption lines.
The delay time distribution of Type-Ia supernovae in galaxy clusters: the impact of extended star-formation histories
Authors: Freundlich Jonathan , Maoz Dan 
Published: February 2021

ABSTRACT
The delay time distribution (DTD) of Type-Ia supernovae (SNe Ia) is important for understanding chemical evolution, SN Ia progenitors, and SN Ia physics. Past estimates of the DTD in galaxy clusters have been deduced from SN Ia rates measured in cluster samples observed at various redshifts, corresponding to different time intervals after a presumed initial brief burst of star formation. A recent analysis of a cluster sample at z = 1.13–1.75 confirmed indications from previous studies of lower redshift clusters, that the DTD has a power-law form, DTD(t) = R1(t/Gyr)α, with amplitude R1, at delay $t=1\,\rm Gyr$, several times higher than measured in field-galaxy environments. This implied that SNe Ia are somehow produced in larger numbers by the stellar populations in clusters. This conclusion, however, could have been affected by the implicit assumption that the stars were formed in a single brief starburst at high z. Here, we re-derive the DTD from the cluster SN Ia data, but relax the single-burst assumption. Instead, we allow for a range of star-formation histories and dust extinctions for each cluster. Via MCMC modelling, we simultaneously fit, using stellar population synthesis models and DTD models, the integrated galaxy-light photometry in several bands, and the SN Ia numbers discovered in each cluster. With these more-realistic assumptions, we find a best-fitting DTD with power-law index $\alpha =-1.09_{-0.12}^{+0.15}$, and amplitude $R_1=0.41_{-0.10}^{+0.12}\times 10^{-12}\,{\rm yr}^{-1}\, {\rm M}_\odot ^{-1}$. We confirm a cluster-environment DTD with a larger amplitude than the field-galaxy DTD, by a factor ∼2–3 (at 3.8σ). Cluster and field DTDs have consistent slopes of α ≈ −1.1.
On the possibility of dust acoustic waves over sunlit lunar surface
Authors: Mishra S K 
Published: February 2021

ABSTRACTThe photoelectron sheath and floating fine positively charged dust particles constitute two-component dusty plasma in the sunlit lunar regolith’s vicinity. By including the charge fluctuation into photoelectron–dust dynamics, the lunar exospheric plasma is proposed to support the propagation of long-wavelength dust acoustic (DA) modes. Using the standard approach based on the dynamical equations for continuity, momentum, plasma potential, and dust charging along with Fowler's treatment of photoemission and non-Maxwellian nature of the sheath photoelectrons, the wave dispersion is derived. The dust charge variation modifies the usual DA wave dispersion and excites the ultralow frequency modes that propagate with sufficiently low phase speed. Such ultralow frequency modes are predicted as pronounced for smaller values of dust charge and sheath potential. The DA wave dispersion is also depicted as sensitive to the photoelectrons’ energy distribution within the sheath. The quantitative estimates suggest that the nominal exospheric plasma may exhibit DA waves propagating with frequencies of the order of unity.