bluuebunny/crossref_metadata_2025 huggingface dataset:
Warning signals promote morphological diversification in fossorial uropeltid snakes (Squamata: Uropeltidae)
Authors: Cyriac Vivek Philip , Kodandaramaiah Ullasa
Published: May 2020

Many species possess warning colourations that signal unprofitability to predators. Warning colourations are also thought to provide prey with a ‘predator-free space’ and promote niche expansion. However, how such strategies release a species from environmental constraints and facilitate niche expansion is not clearly understood. Fossoriality in reptiles imposes several morphological limits on head and body size to facilitate burrowing underground, but many fossorial snakes live close to the surface and occasionally move above ground, exposing them to predators. In such cases, evolving antipredator defences that reduce predation on the surface could potentially relax the morphological constraints associated with fossoriality and promote morphological diversification. Fossorial uropeltid snakes possess varying degrees of conspicuous warning colourations that reduce avian predation when active above ground. We predicted that species with more conspicuous colourations will exhibit more robust body forms and show faster rates of morphological evolution because constraints imposed by fossoriality are relaxed. Using a comparative phylogenetic approach on the genus Uropeltis, we show that more conspicuous species tend to have more robust morphologies and have faster rates of head-shape evolution. Overall, we find that the evolution of warning colourations in Uropeltis can facilitate niche expansion by influencing rates of morphological diversification.
An Innovative Educational Trio for Physical Assessment in an Undergraduate Nursing Course
Authors: Weaver Kendra , Jones Allison R.
Published: May 2020

Effective teaching methods are critical to the acquisition of physical assessment skills. This article describes the combined use of deliberate practice, standardized patient simulation, and peer evaluation in improving physical assessment skills among first-semester nursing students. Students prepared for a physical assessment check-off by using deliberate practice throughout the semester; they then received peer feedback after a standardized patient simulation. Students felt the integrated experience improved their physical assessment performance. Incorporating this innovative educational trio can provide opportunities for physical assessment skill enhancement.
Long-term Outcomes of Glaucoma Drainage Implants in Uveitic Eyes With Fluocinolone Acetonide Implants
Authors: Cao Jessica L. , Srivastava Sunil K. , Lowder Careen Y. , Sharma Sumit , Baynes Kimberly , Eisengart Jonathan
Published: May 2020

Precis:

In eyes with uveitis and a history of fluocinolone acetonide (FA) implantation, glaucoma drainage implants (GDIs) provides excellent long-term control of intraocular pressure (IOP).

Purpose:

The purpose of this study was to evaluate the long-term control of IOP achieved by GDIs in uveitic eyes with glaucoma and a FA implant.

Patients and Methods:

Retrospective case series of 56 eyes from 37 patients with a history of noninfectious posterior uveitis who underwent both FA implantation and GDI surgery at the Cleveland Clinic Cole Eye Institute between April 2001 and April 2017. Patients were excluded if they did not undergo FA implantation before, or concurrently with, a GDI. Data was collected up to 10 years after GDI surgery. Outcome measures included IOP, number of IOP-lowering medications, and surgical success rate at each timepoint. Success was defined as IOP between 6 and 21 mm Hg at the most recent follow-up visit, without need for GDI removal or additional IOP-lowering surgeries, or loss of light perception.

Results:

The mean follow-up time was 71.0 months (median 72.0 mo). IOP was reduced by a mean of 52.9% (range: 43.1% to 62.3%) and the number of IOP-lowering medications decreased by a mean of 69.0% (range: 56.3% to 93.8%) between 1 and 10 years postoperatively. The percentage of eyes with IOP <21 mm Hg was 32.1% at baseline and ranged between 76.8% and 100% at follow-up. The percentage of eyes with IOP <18 mm Hg was 21.4% at baseline and ranged between 67.9% and 100% at follow-up. The surgical success rate was 71.4% at 10 years.

Conclusions:

In eyes with uveitis that undergo FA implantation, concurrent or subsequent GDI surgery offers excellent long-term control of IOP. Postoperative IOP and number of IOP-lowering medications dropped considerably and remained stable.
The effect of Ramadan fasting on ambulatory blood pressure in treated hypertensive patients using diuretics
Authors: Aslan Serkan , Riza Demir Ali , Kahraman Serkan , Memiç Kadriye , Avci Yalçin , Gürbak İsmail , Karabulut Enes , Ertürk Mehmet
Published: May 2020

Objective

The influence of the Ramadan fasting on blood pressure (BP) in patients taking diuretics therapy has not been addressed specifically yet. The aim of this study was to examine the effect of long Ramadan fasting on BP with ambulatory BP monitoring in hypertensive patients using diuretics.

Methods

This prospective, observational study was done on 129 hypertensive patients and was carried out in two groups: 73 treated hypertensive patients were assigned to the diuretic group and 56 treated hypertensive patients were allocated to the non-diuretic group. Twenty-four-hour ambulatory BP monitoring was performed during and after Ramadan. Mean overall, daytime and nighttime BP were measured and compared in both groups. The differences in mean SBP and DBP were recorded between the two monitoring periods.

Results

In diuretic group, 24-h SBP decreased from 128.2 ± 17.9 to 119.3 ± 9.5 mmHg during Ramadan (8.9 units; P < 0.001). DBP decreased from 79.4 ± 10.9 to 75.3 ± 7.6 mmHg (4.1 units; P < 0.001). On the other hand, SBP and DBP were lower insignificantly in the non-diuretic group. The reduction in SBP was significantly higher in the diuretic group (overall: P = 0.005, daytime: P = 0.011, nighttime: P = 0.022). Thiazide-like diuretics lowered BP more than thiazide-type diuretic despite an insignificant difference.

Conclusion

This study suggested that Ramadan fasting might cause significant reductions in mean SBP and DBP measurements in patients using diuretics. Despite decreasing in BP, diuretics generally well tolerated and can be safe in well-controlled hypertensive patients during Ramadan fasting.
Pelvic Leiomyosarcoma With Splenic Metastasis and Response Assessment by 18F-FDG PET/CT
Authors: Yadav Divya , Kumar Rakesh , Rastogi Sameer , Shamim Shamim Ahmed
Published: May 2020

The pelvis is a rare site for the origin of soft tissue sarcomas, and leiomyosarcoma remains the most common soft tissue sarcoma arising in the pelvis. Pelvic leiomyosarcomas are frequently aggressive tumors, and metastatic recurrence rates are high, with the lung, peritoneum, bone, and liver being the most frequent sites. We describe the findings of serial 18F-FDG PET/CT in a 53-year-old woman having pelvic leiomyosarcoma with uncommon site of metastasis, emphasizing the role of 18F-FDG PET/CT in response assessment.
Post Contusion Breast Hematoma Mimicking Malignancy on FDG PET/CT
Authors: Levin Daniel , Lantsberg Sophie , Giladi Maia Rosenthal , Kazap Dina Ezroh , Hod Nir
Published: May 2020

A 32-year-old woman was treated for breast carcinoma. Posttreatment FDG PET/CT scan revealed complete response, but in the contralateral breast, unexpected incidental intense FDG uptake was seen with a differential diagnosis of both malignant and benign causes. Medical history revealed recent breast contusion. The lesion was further evaluated by mammogram and ultrasound, which were compatible with deep breast bruise. Histopathology showed no malignancy. Subsequent FDG PET/CT study showed breast uptake normalization. This case shows that postcontusion breast hematoma can cause a potential pitfall mimicking breast malignancy on FDG PET/CT.
Variations in Volume and Costs of Inpatient Admissions for Female Pelvic Reconstructive Procedures Across the United States
Authors: Wang Rui , Tulikangas Paul , Hacker Michele R.
Published: May 2020

Objectives

We aim to describe the volume and cost of female pelvic reconstructive surgeries across the United States and evaluate the relationship between volume and cost of inpatient care for these surgeries.

Methods

Medicare Severity Diagnosis Related Group was used to identify admissions for female pelvic reconstructive procedures and aggregated at the state and census region levels using the 2016 Inpatient Medicare Provider Utilization and Payment Data. Total hospital charges were converted to cost using the cost-to-charge ratios for each state. For context and comparison with another benign gynecologic procedure, we replicated the analysis for benign uterine and adnexal surgeries.

Results

We identified 2133 patients admitted for female pelvic reconstructive procedures. Across all states, the average cost was US $11,857, and the average number of procedures per 100,000 Medicare beneficiaries was 4.4. The Northeast had the lowest cost, and the West had the highest. The regression model showed that, for each additional admission per 100,000 Medicare beneficiaries, the cost of inpatient care decreased (US $549, P = 0.04). In comparison, we identified 8340 admissions for benign uterine and adnexal surgeries and found a minimal, nonsignificant decrease in cost for each additional admission.

Conclusions

There are variations in the volume and cost of admissions for female pelvic reconstructive surgeries across the United States. We identified that an inverse association between volume and cost for female pelvic reconstructive surgery was not seen in benign uterine and adnexal surgeries.
On the thermodynamical restrictions in isothermal deformations of fractional Burgers model
Authors: Atanacković Teodor M. , Janev Marko , Pilipović Stevan
Published: May 2020

We investigate, in the distributional setting, the restrictions on the constitutive equation for a fractional Burgers model of viscoelastic fluid that follow from the weak form of the entropy inequality under isothermal conditions. The results are generalized, from the Burgers model, to an arbitrary class of linear constitutive equations with fractional derivatives. Our results show that the restrictions obtained here on the coefficients of constitutive equations are weaker when compared with the restrictions obtained by Bagley–Torvik method. We show the precise relation between restrictions derived here and those derived by Bagley–Torvik. We deal with the creep test, for the case when Bagley–Torvik conditions are violated, and new conditions obtained in this work are satisfied. The results show a qualitative difference in the form of creep function.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Fractional-order heat conduction models from generalized Boltzmann transport equation
Authors: Li Shu-Nan , Cao Bing-Yang
Published: May 2020

The relationship between fractional-order heat conduction models and Boltzmann transport equations (BTEs) lacks a detailed investigation. In this paper, the continuity, constitutive and governing equations of heat conduction are derived based on fractional-order phonon BTEs. The underlying microscopic regimes of the generalized Cattaneo equation are thereafter presented. The effective thermal conductivityκeffconverges in the subdiffusive regime and diverges in the superdiffusive regime. A connection between the divergence and mean-square displacement 〈|Δx|2〉 ∼ tγis established, namely,κeff ∼ tγ−1, which coincides with the linear response theory. Entropic concepts, including the entropy density, entropy flux and entropy production rate, are studied likewise. Two non-trivial behaviours are observed, including the fractional-order expression of entropy flux and initial effects on the entropy production rate. In contrast with the continuous time random walk model, the results involve the non-classical continuity equations and entropic concepts.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Effect of adsorption, radioactive decay and fractal structure of matrix on solute transport in fracture
Authors: Chugunov Vladimir , Fomin Sergei
Published: May 2020

Reservoir contamination by various contaminants including radioactive elements is an actual environmental problem for all developed countries. Analysis of mass transport in a complex environment shows that the conventional diffusion equation based on Fick's Law fails to model the anomalous character of the diffusive mass transport observed in the field and laboratory experiments. These complex processes can be modelled by non-local advection–diffusion equations with temporal and spatial fractional derivatives. In the present paper, fractional differential equations are used for modelling the transport of radioactive materials in a fracture surrounded by the porous matrix of fractal structure. A new form of fractional differential equation for modelling migration of the radioactive contaminant in the fracture is derived and justified. Solutions of particular boundary value problems for this equation were found by application of the Laplace transform. Through the use of fractional derivatives, the model accounts for contaminant exchange between fracture and surrounding porous matrix of fractal geometry. For the case of an arbitrary time-dependent source of radioactive contamination located at the inlet of the fracture, the exact solutions for solute concentration in the fracture and surrounding porous medium are obtained. Using the concept of a short memory, an approximate solution of the problem of radioactive contaminant transport along the fracture surrounded by the fractal type porous medium is also obtained and compared with the exact solution.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Mathematical modelling with experimental validation of viscoelastic properties in non-Newtonian fluids
Authors: Ionescu C. M. , Birs I. R. , Copot D. , Muresan C. I. , Caponetto R.
Published: May 2020

The paper proposes a mathematical framework for the use of fractional-order impedance models to capture fluid mechanics properties in frequency-domain experimental datasets. An overview of non-Newtonian (NN) fluid classification is given as to motivate the use of fractional-order models as natural solutions to capture fluid dynamics. Four classes of fluids are tested: oil, sugar, detergent and liquid soap. Three nonlinear identification methods are used to fit the model: nonlinear least squares, genetic algorithms and particle swarm optimization. The model identification results obtained from experimental datasets suggest the proposed model is useful to characterize various degree of viscoelasticity in NN fluids. The advantage of the proposed model is that it is compact, while capturing the fluid properties and can be identified in real-time for further use in prediction or control applications.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Thermo-poromechanics of fractal media
Authors: Li Jun , Ostoja-Starzewski Martin
Published: May 2020

This article advances continuum-type mechanics of porous media having a generally anisotropic, product-like fractal geometry. Relying on a fractal derivative, the approach leads to global balance laws in terms of fractal integrals based on product measures and, then, converting them to integer-order integrals in conventional (Euclidean) space. Proposed is a new
line transformation coefficient
that is frame invariant, has no bias with respect to the coordinate origin and captures the differences between two fractal media having the same fractal dimension but different density distributions. A continuum localization procedure then allows the development of local balance laws of fractal media: conservation of mass, microinertia, linear momentum, angular momentum and energy, as well as the second law of thermodynamics. The product measure formulation, together with the angular momentum balance, directly leads to a generally asymmetric Cauchy stress and, hence, to a micropolar (rather than classical) mechanics of fractal media. The resulting micropolar model allowing for conservative and/or dissipative effects is applied to diffusion in fractal thermoelastic media. First, a mechanical formulation of Fick’s Law in fractal media is given. Then, a complete system of equations governing displacement, microrotation, temperature and concentration fields is developed. As a special case, an isothermal model is worked out.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Fractional thermoelasticity problem for an infinite solid with a penny-shaped crack under prescribed heat flux across its surfaces
Authors: Povstenko Y. , Kyrylych T.
Published: May 2020

The time-nonlocal generalization of the Fourier law with the ‘long-tail’ power kernel can be interpreted in terms of fractional calculus and leads to the time-fractional heat conduction equation with the Caputo derivative. The theory of thermal stresses based on this equation was proposed by the first author (
J. Therm. Stresses
28
, 83–102, 2005 (
doi:10.1080/014957390523741
)). In the present paper, the fractional heat conduction equation is solved for an infinite solid with a penny-shaped crack in the case of axial symmetry under the prescribed heat flux loading at its surfaces. The Laplace, Hankel and cos-Fourier integral transforms are used. The solution for temperature is obtained in the form of integral with integrands being the generalized Mittag-Leffler function in two parameters. The associated thermoelasticity problem is solved using the displacement potential and Love’s biharmonic function. To calculate the additional stress field which allows satisfying the boundary conditions at the crack surfaces, the dual integral equation is solved. The thermal stress field is calculated, and the stress intensity factor is presented for different values of the order of the Caputo time-fractional derivative. A graphical representation of numerical results is given.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Variable-order particle dynamics: formulation and application to the simulation of edge dislocations
Authors: Patnaik Sansit , Semperlotti Fabio
Published: May 2020

This study presents the application of variable-order (VO) fractional operators to modelling the dynamics of edge dislocations under the effect of a static state of shear stress. More specifically, a particle dynamic approach is used to simulate the microscopic structure of a material where the constitutive atoms or molecules are modelled via discrete masses and their interaction via inter-particle forces. VO operators are introduced in the formulation in order to capture the complex linear-to-nonlinear dynamic transitions following the translation of dislocations as well as the creation and annihilation of bonds between particles. Remarkably, the motion of the dislocation does not require anya prioriassumption in terms of either possible trajectory or sections of the model that could undergo the nonlinear transition associated with the creation and annihilation of bonds. The model only requires the definition of the initial location of the dislocations. Results will show that the VO formulation is fully evolutionary and capable of capturing both the sliding and the coalescence of edge dislocations by simply exploiting the instantaneous response of the system and the state of stress.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Application of fractional calculus methods to viscoelastic behaviours of solid propellants
Authors: Fang Changqing , Shen Xiaoyin , He Kuai , Yin Chao , Li Shasha , Chen Xiaolong , Sun Huiyu
Published: May 2020

A three-branch viscoelastic model based on fractional derivatives is proposed for the viscoelastic behaviours of solid propellants. The simulation results show a satisfactory agreement with the stress relaxation modulus and complex modulus of solid propellants. As a comparison, the static modulus is also characterized by traditional viscoelastic model with integer-order derivatives. Results show that the application of the fractional derivatives to the viscoelastic constitutive model can effectively reduce the number of the required parameters while giving an accurate prediction of viscoelastic behaviours of solid propellants. Moreover, a simple and effective direct search method based on simulated annealing and Powell's mothed is proposed for the data fitting.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives'.
Fractional-order modelling of epoxy resin
Authors: Tenreiro Machado J. A. , Lopes António M. , de Camposinhos Rui
Published: May 2020

This paper describes epoxy resins by means of electrical impedance spectroscopy (EIS) and the mathematical tool of fractional calculus (FC). Two stages are considered: first, the EIS is used for testing the samples and, second, the measured data are approximated using integer and fractional order models. The FC-based modelling describes the epoxy resins using a small number of parameters that reflect their main characteristics. The EIS data gathered for the epoxies samples are compared with those of different adhesives and sealants by means of a hierarchical clustering algorithm that unravels the relationships between the distinct materials.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Fractional-order nonlinear hereditariness of tendons and ligaments of the human knee
Authors: Bologna E. , Di Paola M. , Dayal K. , Deseri L. , Zingales M.
Published: May 2020

In this paper the authors introduce a nonlinear model of fractional-order hereditariness used to capture experimental data obtained on human tendons of the knee. Creep and relaxation data on fibrous tissues have been obtained and fitted with logarithmic relations that correspond to power-laws with nonlinear dependence of the coefficients. The use of a proper nonlinear transform allows one to use Boltzmann superposition in the transformed variables yielding a fractional-order model for the nonlinear material hereditariness. The fundamental relations among the nonlinear creep and relaxation functions have been established, and the results from the equivalence relations have been contrasted with measures obtained from the experimental data. Numerical experiments introducing polynomial and harmonic stress and strain histories have been reported to assess the provided equivalence relations.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Energy dissipation for hereditary and energy conservation for non-local fractional wave equations
Authors: Zorica Dušan , Oparnica Ljubica
Published: May 2020

Using the method of
a priori
energy estimates, energy dissipation is proved for the class of hereditary fractional wave equations, obtained through the system of equations consisting of equation of motion, strain and fractional order constitutive models, that include the distributed-order constitutive law in which the integration is performed from zero to one generalizing all linear constitutive models of fractional and integer orders, as well as for the thermodynamically consistent fractional Burgers models, where the orders of fractional differentiation are up to the second order. In the case of non-local fractional wave equations, obtained using non-local constitutive models of Hooke- and Eringen-type in addition to the equation of motion and strain,
a priori
energy estimates yield the energy conservation, with the reinterpreted notion of the potential energy.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
A novel approach to nonlinear variable-order fractional viscoelasticity
Authors: Di Paola M. , Alotta G. , Burlon A. , Failla G.
Published: May 2020

This paper addresses nonlinear viscoelastic behaviour of fractional systems with variable time-dependent fractional order. In this case, the main challenge is that the Boltzmann linear superposition principle, i.e. the theoretical basis on which linear viscoelastic fractional operators are formulated, does not apply in standard form because the fractional order is not constant with time. Moving from this consideration, the paper proposes a novel approach where the system response is derived by a consistent application of the Boltzmann principle to an equivalent system, built at every time instant based on the fractional order at that instant and the response at all the previous ones. The approach is readily implementable in numerical form, to calculate either stress or strain responses of any fractional system where fractional order may change with time.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Multi-term time fractional diffusion equations and novel parameter estimation techniques for chloride ions sub-diffusion in reinforced concrete
Authors: Chen Ruige , Wei Xiaoli , Liu Fawang , Anh Vo V.
Published: May 2020

In this paper, searching for a better chloride ions sub-diffusion system, a multi-term time-fractional derivative diffusion model is proposed for the description of the time-dependent chloride ions penetration in reinforced concrete structures exposed to chloride environments. We prove the stability and convergence of the model. We use the modified grid approximation method (MGAM) to estimate the fractional orders and chloride ions diffusion coefficients in the reinforced concrete for the multi-term time fractional diffusion system. And then to verify the efficiency and accuracy of the proposed methods in dealing with the fractional inverse problem, two numerical examples with real data are investigated. Meanwhile, we use two methods of fixed chloride ions diffusion coefficient and variable diffusion coefficient with diffusion depth to simulate chloride ions sub-diffusion system. The result shows that with the new fractional orders and parameters, our multi-term fractional order chloride ions sub-diffusion system is capable of providing numerical results that agree better with the real data than other models. On the other hand, it is also noticed from the numerical solution of the chloride ions sub-diffusion system that setting the variable diffusion coefficient with diffusion depth is more reasonable. And it is also found that chloride ions diffusion coefficients in reinforced concrete should be decreased with diffusion depth which is completely consistent with the theory. In addition, the model can be used to predict the chloride profiles with a time-dependent property.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Impact force and moment problems on random mass density fields with fractal and Hurst effects
Authors: Zhang Xian , Ostoja-Starzewski Martin
Published: May 2020

This paper reports the application of cellular automata to study the dynamic responses of Lamb-type problems for a tangential point load and a concentrated moment applied on the free surface of a half-plane. The medium is homogeneous, isotropic and linear elastic while having a random mass density field with fractal and Hurst characteristics. Both Cauchy and Dagum random field models are used to capture these effects. First, the cellular automata approach is tested on progressively finer meshes to verify the code against the continuum elastodynamic solution in a homogeneous continuum. Then, the sensitivity of wave propagation on random fields is assessed for a wide range of fractal and Hurst parameters. Overall, the mean response amplitude is lowered by the mass density field’s randomness, while the Hurst parameter (especially, for
β
 < 0.2) is found to have a stronger influence than the fractal dimension on the response. The resulting Rayleigh wave is modified more than the pressure wave for the same random field parameters. Additionally, comparisons with previously studied Lamb-type problems under normal in-plane and anti-plane loadings are given.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
Advanced materials modelling via fractional calculus: challenges and perspectives
Authors: Failla Giuseppe , Zingales Massimiliano
Published: May 2020

Fractional calculus is now a well-established tool in engineering science, with very promising applications in materials modelling. Indeed, several studies have shown that fractional operators can successfully describe complex long-memory and multiscale phenomena in materials, which can hardly be captured by standard mathematical approaches as, for instance, classical differential calculus. Furthermore, fractional calculus has recently proved to be an excellent framework for modelling non-conventional fractal and non-local media, opening valuable prospects on future engineered materials. The theme issue gathers cutting-edge theoretical, computational and experimental studies on advanced materials modelling via fractional calculus, with a focus on complex phenomena and non-conventional media.

This article is part of the theme issue ‘Advanced materials modelling via fractional calculus: challenges and perspectives’.
First hybrid complete genome of Aeromonas veronii reveals chromosome-mediated novel structural variant mcr-3.30 from a human clinical sample
Authors: Ragupathi Naveen Kumar Devanga , Sethuvel Dhiviya Prabaa Muthuirulandi , Anandan Shalini , Murugan Dhivya , Asokan Kalaiarasi , Neethi Mohan Ramya Gajaraj , Vasudevan Karthick , D Thirumal Kumar , C George Priya Doss , Veeraraghavan Balaji
Published: May 2020

Recent findings demonstrate the origin of the plasmid-mediated colistin resistance gene mcr-3 from aeromonads. The present study aimed to screen for plasmid-mediated colistin resistance among 30 clinical multidrug-resistant (MDR)

Aeromonas

spp. PCR was used to screen for the presence of mcr-1, mcr-2, mcr-3 and mcr-4, which revealed mcr-3 in a colistin-susceptible isolate (FC951). All other isolates were negative for mcr. Sequencing of FC951 revealed that the mcr-3 (mcr-3.30) identified was different from previously reported variants and had 95.62 and 95.28 % nucleotide similarity with mcr-3.3 and mcr-3.10. Hybrid assembly using IonTorrent and MinION reads revealed structural genetic information for mcr-3.30 with an insertion of ISAs18 within the gene. Due to this, mcr-3.30 was non-expressive, which makes FC951 susceptible to colistin. Further, in silico sequence and protein structural analysis confirmed the new variant. To the best of our knowledge, this is the first report on a novel mcr-3 variant from India. The significant role of mcr-like genes in different

Aeromonas

species remains unknown and requires additional investigation to obtains insights into the mechanism of colistin resistance.
A case of canine cutaneous pythiosis in Thailand
Authors: Chindamporn Ariya , Kammarnjessadakul Patcharee , Kesdangsakonwut Sawang , Banlunara Wijit
Published: May 2020

Introduction.
Pythium insidiosum causes pythiosis in humans and animals in tropical and subtropical climates. The clinical manifestations in humans are mostly systemic, vascular or ocular forms, in contrast to animals, which are cutaneous, subcutaneous and gastrointestinal forms. The highest incidence of human cases is reported in Thailand, however, no canine pythiosis has been documented yet.

Case presentation. A female, mixed-breed, stray dog showed severe extensive ulcerative haemorrhagic dermatitis at the perineum involving the anus and tail. On cytology, there were sparse branching septate fungal hyphae. The tissue samples were subjected to polymerase chain reaction and gene sequencing for fungal identification.

Conclusion. The results of the internal transcribed spacer 1 and 2 (ITS1 and ITS2) gene had 99 % homology to Pythium insidiosum (accession no. FJ17396) and the COX2 gene (accession no. GQ451572). The phylogenetic tree of both genes was classified in clade ATH. This is the first fully documented diagnosis of canine cutaneous pythiosis in Thailand.
Two new scuticociliates from southern China: Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., with improved diagnoses of the genus Homalogastra and its type species Homalogastra setosa (Ciliophora, Oligohymenophorea)
Authors: Liu Mingjian , Li Lifang , Zhang Tengteng , Fan Xinpeng , Yi Zhenzhen , Lin Xiaofeng
Published: May 2020

The morphology of two new scuticociliates, Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., isolated from a mangrove wetland in Shenzhen, PR China, was studied using live observation and the protargol impregnation method. Uronema apomarinum is characterized by a body size of about 20–35×10–15 µm in vivo, a partly two-rowed membranelle 1, and 12 or 13 somatic kineties. Homalogastra parasetosa is distinguished by a membranelle 1 comprising two longitudinal rows of basal bodies. Three Homalogastra setosa populations are suggested as subjective synonyms of the new species. Improved diagnoses of the genus Homalogastra Kahl, 1926 and its type species Homalogastra setosa Kahl, 1926 are provided. Results of phylogenetic analyses based on 18S rRNA gene and ITS1-5.8S–ITS2 region sequences indicate that U. apomarinum is most closely related to U. marinum, while the closest relative of H. parasetosa is H. setosa.
Wickerhamiella verensis f.a. sp. nov., a novel yeast species isolated from subsoil groundwater contaminated with hydrocarbons and from a human infection
Authors: Belloch Carmela , Pelaez Ana Isabel , Sánchez Jesús , Kurtzman Cletus P.
Published: May 2020

Yeast strains belonging to a novel anamorphic yeast species were isolated from subsoil groundwater contaminated with hydrocarbons in a metal working factory located in northern Spain, and from a human infection in the USA. Comparison of ITS sequences between the isolates revealed 0.2 % divergence between the Spanish isolates and 0.46 % divergence between those and the USA isolate. Phylogenetic analysis based on the D1/D2 domains of the LSU rRNA gene showed that these isolates belong to the Wickerhamiella clade with W. sorbophila and W. infanticola as their closest relatives. Sequence divergence between the new isolates and W. sorbophila and W. infanticola was 1.97 and 1.79 %, respectively. The isolates in the novel species are not fermentative and pseudohyphae were not produced. Sexual reproduction was not observed for individual isolates or in mixtures of isolates. Conjugation between the isolates in the novel species and close relatives W. sorbophila and W. infanticola was not observed. These data support the proposal of Wickerhamiella verensis as a novel species, with CECT 12028T as the holotype.
Massilia arenae sp. nov., isolated from sand soil in the Qinghai–Tibetan Plateau
Authors: Zhang Binglin , Yang Ruiqi , Zhang Gaosen , Zhang Dongming , Zhang Wei , Chen Tuo , Liu Guangxiu
Published: May 2020

A bacterial strain, designated GEM5T, was isolated from sand soil samples from the Qinghai–Tibet Plateau. The polyphasic study confirmed the affiliation of the isolate with the genus

Massilia

. GEM5T had Gram-stain-negative, non-spore-forming and rod-shaped cells and grew at 4–30 °C, pH 6–8 and with 0–2 % (w/v) NaCl. Its cell wall contained ribose. Q8 was the predominant respiratory quinone, and summed feature 3 (C16 : 1ω6c/ω7c) and C16 : 0 were the major components of the fatty acids. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified phospholipid, an unidentified aminolipid and four unidentified lipids. The DNA G+C content was 65.1 mol%. The phylogenetic analysis based on the 16S rRNA gene showed a stable clade being formed by GEM5T,

Massilia timonae

CCUG 45783T (97.94 %) and

Massilia oculi

CCUG 43427AT (97.58 %). The average nucleotide identity (ANIb) values between GEM5T and

M. timonae

CCUG 45783T, M.oculi CCUG 43427AT were 91.3 and 91.7 %, respectively. On the basis of the morphological, physiological and chemotaxonomic pattern, it was proposed that strain GEM5T (=JCM 32744T=CICC 24458T) should be classified as representing a member of the genus

Massilia

with the name Massilia arenae sp. nov.
Cutibacterium modestum sp. nov., isolated from meibum of human meibomian glands, and emended descriptions of Cutibacterium granulosum and Cutibacterium namnetense
Authors: Dekio Itaru , Sakamoto Mitsuo , Suzuki Tomo , Yuki Masahiro , Kinoshita Shigeru , Murakami Yoshiyuki , Ohkuma Moriya
Published: May 2020

An anaerobic and aerotolerant bacterium, strain M12T, was isolated from the meibum of inflamed human meibomian glands. Cells of the strain was Gram-stain-positive, non-spore-forming and non-motile rods. Growth on trypticase soy agar plates supplemented with 5 % sheep blood was fastest at 30–37 °C under anaerobic conditions. The 16S rRNA gene sequence of the strain revealed that it belongs to the genus

Cutibacterium

with a 98.0 % similarity value to the closest species,

Cutibacterium acnes

. Genome analysis of the strain with type strains of the other

Cutibacterium

species resulted in digital DNA–DNA hybridization values of 32.3–22.3% and average nucleotide identity (OrthoANI) values of 86.7–73.6 %. Biochemical and physiological analyses using API rapid ID 32A and API Coryne kits revealed relatively low reactivity of the strain compared with

C. acnes

and

Cutibacterium namnetense

. The most abundant major cellular fatty acid was iso-C15 : 0. Fermentation end-products from glucose were propionate, lactate, succinate and acetate. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Major menaquinones were MK-9(H4), MK-9(H2) and MK-9. The major peaks of the MALDI-TOF mass spectrometry spectrum were at 3493, 3712, 6986 and 7424 Da. The DNA G+C content was 59.9 mol%. Based on these findings, we propose a novel species, Cutibacterium modestum. The type strain of C. modestum is M12T (=JCM 33380T=DSM 109769T). On the basis of further genomic analysis, we also provide emended descriptions of

Cutibacterium granulosum

(Prévot 1938) Scholz and Kilian 2016 and

Cutibacterium namnetense

(Aubin et al. 2016) Nouioui et al. 2018.
Methylicorpusculum oleiharenae gen. nov., sp. nov., an aerobic methanotroph isolated from an oil sands tailings pond
Authors: Saidi-Mehrabad Alireza , Kits Dimitri K. , Kim Joong-Jae , Tamas Ivica , Schumann Peter , Khadka Roshan , Strilets Tania , Smirnova Angela V. , Rijpstra W. Irene C. , Sinninghe Damsté Jaap S. , Dunfield Peter F.
Published: May 2020

An aerobic methane oxidizing bacterium, designated XLMV4T, was isolated from the oxic surface layer of an oil sands tailings pond in Alberta, Canada. Strain XLMV4T is capable of growth on methane and methanol as energy sources. NH4Cl and sodium nitrate are nitrogen sources. Cells are Gram-negative, beige to yellow-pigmented, motile (via a single polar flagellum), short rods 2.0–3.3 µm in length and 1.0–1.6 µm in width. A thick capsule is produced. Surface glycoprotein or cup shape proteins typical of the genera Methylococcus, Methylothermus and

Methylomicrobium

were not observed. Major isoprenoid quinones are Q-8 and Q-7 at an approximate molar ratio of 71 : 22. Major polar lipids are phosphoglycerol and ornithine lipids. Major fatty acids are C16 : 1 ω8+C16 : 1 ω7 (34 %), C16 : 1 ω5 (16 %), and C18 : 1 ω7 (11 %). Optimum growth is observed at pH 8.0 and 25 °C. The DNA G+C content based on a draft genome sequence is 46.7 mol%. Phylogenetic analysis of 16S rRNA genes and a larger set of conserved genes place strain XLMV4T within the class

Gammaproteobacteria

and family

Methylococcaceae

, most closely related to members of the genera

Methylomicrobium

and

Methylobacter

(95.0–97.1 % 16S rRNA gene sequence identity). In silico genomic predictions of DNA–DNA hybridization values of strain XLMV4T to the nearest phylogenetic neighbours were all below 26 %. On the basis of the data presented, strain XLMV4T is considered to represent a new genus and species for which the name Methylicorpusculum oleiharenae is proposed. Strain XLMV4T (=DSMZ DSM 27269=ATCC TSD-186) is the type strain.
Methicillin-resistant Staphylococcus aureus colonization in patients undergoing primary total hip arthroplasty
Authors: Schweitzer Daniel , Klaber Ianiv , García Patricia , López Felipe , Lira María Jesús , Botello Eduardo
Published: May 2020

Introduction. Nasal and skin colonization by methicillin-resistant

Staphylococcus aureus

(MRSA) are linked to a higher incidence of infection after total joint replacement. The prevalence of colonization is poorly defined in Latin American countries.

Aim. The aim of the present study was to determine the prevalence of MRSA colonization in the nostrils and groin using real-time polymerase chain reaction (RT-PCR) in patients undergoing total hip arthroplasty (THA).

Methodology. In this cross-sectional study, 146 patients undergoing THA between December 2015 and March 2017 in a tertiary-care university-affiliated hospital in Chile were screened for MRSA colonization before the procedure using RT-PCR independently in the nostrils and groin. Risk factors for colonization were documented.

Results. Seven of the 146 (5 %) patients undergoing THA were carriers of MRSA in the nostrils and/or the groin. Recent antibiotic use was identified as a risk factor for colonization, OR=4.86 [95 % confidence interval (CI): 1.56–13.96]. Patients reporting at least one of the seven surveyed risk factors had an OR of 2.39 (95 % CI: 0.37–25.77) for colonization. MRSA colonization frequency was twofold higher in the groin as opposed to the nostrils (P=0.014).

Conclusion. Five percent of the patients undergoing THA were identified as carriers of MRSA. Recent antibiotic use is a relevant risk factor for MRSA colonization in patients undergoing primary total hip arthroplasty.
Activity of mammalian peptidoglycan-targeting immunity against Pseudomonas aeruginosa
Authors: Torrens Gabriel , Escobar-Salom Maria , Oliver Antonio , Juan Carlos
Published: May 2020

Pseudomonas aeruginosa

is one of the most important opportunistic pathogens, whose clinical relevance is not only due to the high morbidity/mortality of the infections caused, but also to its striking capacity for antibiotic resistance development. In the current scenario of a shortage of effective antipseudomonal drugs, it is essential to have thorough knowledge of the pathogen’s biology from all sides, so as to find weak points for drug development. Obviously, one of these points could be the peptidoglycan, given its essential role for cell viability. Meanwhile, immune weapons targeting this structure could constitute an excellent model to be taken advantage of in order to design new therapeutic strategies. In this context, this review gathers all the information regarding the activity of mammalian peptidoglycan-targeting innate immunity (namely lysozyme and peptidoglycan recognition proteins), specifically against

P. aeruginosa

. All the published studies were considered, from both in vitro and in vivo fields, including works that envisage these weapons as options not only to potentiate their innate effects within the host or for use as exogenously administered treatments, but also harnessing their inflammatory and immune regulatory capacity to finally reduce damage in the patient. Altogether, this review has the objective of anticipating and discussing whether these innate immune resources, in combination or not with other drugs attacking certain

P. aeruginosa

targets leading to its increased sensitization, could be valid therapeutic antipseudomonal allies.
Novel genotypes of Leptospira interrogans serogroup Sejroe isolated from human patients in Okinawa Prefecture, Japan
Authors: Kakita Tetsuya , Kyan Hisako , Miyahira Masato , Takara Taketoshi , Nakama Eri , Kuba Yumani , Kato Takashi , Nidaira Minoru , Kudaka Jun , Koizumi Nobuo
Published: May 2020

Leptospirosis is a zoonotic disease caused by pathogenic spirochetes ofLeptospiraspecies. It is a public health issue in the tropics, including Okinawa, the southernmost prefecture of Japan. This study reports the first isolation ofL. interrogansserogroup Sejroe from two human patients in Japan, and describes its molecular characterization using multilocus sequence typing (MLST) and multiple-locus variable-number tandem repeat analysis (MLVA). MLST on the two isolates, 168036 and 178129, showed thatpfkBin 178129 is a novel allele, and that both isolates constitute novel sequence types (STs); ST286 for 168036 and ST287 for 178129. A minimum spanning tree based on seven alleles ofL. interrogansindicates that both isolates are genetically close, but are distinct from knownL. interrogansserogroup Sejroe strains. MLVA using 11 loci demonstrated that seven of the 11 loci were identical between the two isolates, whereas the identity between the isolates and the seven reference strains ofL. interrogansserogroup Sejroe was zero to three loci. These results indicate that the isolates investigated in this study have novel genotypes, and are genetically closest to each other among the knownL. interrogansserogroup Sejroe strains.
Delivery of antibacterial silver nanoclusters to Pseudomonas aeruginosa using species-specific DNA aptamers
Authors: Soundy Jennifer , Day Darren
Published: May 2020

Introduction. The use of silver as an antimicrobial therapeutic is limited by its toxicity to host cells compared with that required to kill bacterial pathogens.

Aim. To use aptamer targeting of DNA scaffolded silver nanoclusters as an antimicrobial agent for treating

Pseudomonas aeruginosa

infections.

Methodology. Antimicrobial activity was assessed in planktonic cultures and in vivo using an invertebrate model of infection.

Results. The aptamer conjugates that we call aptabiotics have potent antimicrobial activity. Targeted silver nanoclusters were more effective at killing

P. aeruginosa

than the equivalent quantity of untargeted silver nanoclusters. The aptabiotics have an IC50 of 1.3–2.6 µM against planktonically grown bacteria. Propidium iodide staining showed that they rapidly depolarize bacterial cells to kill approximately 50 % of the population within 10 min following treatment. In vivo testing in the Galleria mellonella model of infection prolonged survival from an otherwise lethal infection.

Conclusion. Using

P. aeruginosa

as a model, we show that targeting of DNA-scaffolded silver nanoclusters with an aptamer has effective fast-acting antimicrobial activity in vitro and in an in vivo animal model.
Smoking Prevalence is Low in Symptomatic Patients Admitted for COVID-19
Authors: Gaibazzi Nicola , Tuttolomondo Domenico , Guidorossi Angela , Botti Andrea , Tedeschi Andrea , Martini Chiara , Mattioli Maria
Published: May 2020

The authors have withdrawn this manuscript at the request of their local IRB, because the objectives outlined in this study were not specifically approved by the IRB. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.