bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Thermodynamic Process in the Bulk-Flow Model for the Estimation of the Dynamic Coefficients of Labyrinth Seals
Authors: Cangioli Filippo , Pennacchi Paolo , Vannini Giuseppe , Ciuchicchi Lorenzo , Vania Andrea , Chatterton Steven , Dang Phuoc Vinh
Published: September 2017

The impact of sealing equipment on the stability of turbomachineries is a crucial topic because the power generation market is continuously requiring high rotational speed and high performance, leading to the clearance reduction in the seals. The accurate characterization of the rotordynamic coefficients generated by the seals is pivotal to mitigate instability issues. In the paper, the authors propose an improvement of the state-of-the-art one-control volume (1CV) bulk-flow model (Childs and Scharrer, 1986, “An Iwatsubo-Based Solution for Labyrinth Seals: Comparison to Experimental Results,” ASME J. Eng. Gas Turbines Power, 108(2), pp. 325–331) by considering the energy equation in the steady-state problem. Thus, real gas properties can be evaluated in a more accurate way because the enthalpy variation, expected through the seal cavities, is evaluated in the model. The authors assume that the enthalpy is not a function of the clearance perturbation; therefore, the energy equation is considered only in the steady-state problem. The results of experimental tests of a 14 teeth-on-stator (TOS) labyrinth seal, performed in the high-pressure seal test rig owned by GE Oil&Gas, are presented in the paper. Positive and negative preswirl ratios are used in the experimental tests to investigate the effect of the preswirl on the rotordynamic coefficients. Overall, by considering the energy equation, a better numerical estimation of the rotordynamic coefficients for the tests with the negative preswirl ratio has been obtained (as it results from the comparison with the experiments). Finally, the numerical results are compared with a reference bulk-flow model proposed by Thorat and Childs (2010, “Predicted Rotordynamic Behavior of a Labyrinth Seal as Rotor Surface Speed Approaches Mach 1,” ASME J. Eng. Gas Turbines Power, 132(11), p. 112504), highlighting the improvement obtained.
On the Influence of Lubricant Supply Conditions and Bearing Configuration to the Performance of (Semi) Floating Ring Bearing Systems for Turbochargers
Authors: San Andrés Luis , Yu Feng , Gjika Kostandin
Published: September 2017

Engine oil-lubricated (semi) floating ring bearing ((S)FRB) systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermomechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. The paper details a model to predict the pressure and temperature fields and the distribution of thermal energy flows in a bearing system. The impact of lubricant supply conditions, bearing film clearances, and oil supply grooves is quantified. Either a low oil temperature or a high supply pressure increases the generated shear power. Either a high supply pressure or a large clearance allows more flow through the inner film and draws more heat from the hot journal, thought it increases the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat from the shaft. The results identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.
New Operational Matrix for Solving Multiterm Variable Order Fractional Differential Equations
Authors: Nagy A. M. , Sweilam N. H. , El-Sayed Adel A.
Published: September 2017

The multiterm fractional variable-order differential equation has a massive application in physics and engineering problems. Therefore, a numerical method is presented to solve a class of variable order fractional differential equations (FDEs) based on an operational matrix of shifted Chebyshev polynomials of the fourth kind. Utilizing the constructed operational matrix, the fundamental problem is reduced to an algebraic system of equations which can be solved numerically. The error estimate of the proposed method is studied. Finally, the accuracy, applicability, and validity of the suggested method are illustrated through several examples.
Nonlinear Analysis of Shape Memory Devices With Duffing and Quadratic Oscillators
Authors: Rajendra Gaikwad Shantanu , Kumar Pandey Ashok
Published: September 2017

In this paper, we investigate the linear and nonlinear response of shape memory alloy (SMA)-based Duffing and quadratic oscillator under large deflection conditions. In this study, we first present thermomechanical constitutive modeling of SMA with a single degree-of-freedom system. Subsequently, we solve equation to obtain linear frequency and nonlinear frequency response using the method of harmonic balance and validate it with numerical solution as well as averaging method under the isothermal condition. However, for nonisothermal condition, we analyze the influence of cubic and quadratic nonlinearity on nonlinear response based on method of harmonic balance. Analysis of results leads to various ways of controlling the nature and extent of nonlinear response of SMA-based oscillators. Such findings can be effectively used to control external vibration of different systems.
Feedback Control of Grazing-Induced Chaos in the Single-Degree-of-Freedom Impact Oscillator
Authors: Shen Yongkang , Yin Shan , Wen Guilin , Xu Huidong
Published: September 2017

Based on the special dynamical property of continuous transition at certain degenerate grazing points in the single-degree-of-freedom impact oscillator, the control problem of the grazing-induced chaos is investigated in this paper. To design degenerate grazing bifurcations, we show how to obtain the degenerate grazing points of the 1/n impact periodic motions by the existence and stability analysis first. Then, a discrete-in-time feedback control strategy is used to suppress the grazing-induced chaos into the 1/n impact periodic motions precisely by the desired degenerate grazing bifurcation. The feasibility of the control strategy is verified by numerical simulations.
Lean-Premixed, Swirl-Stabilized Flame Response: Flame Structure and Response as a Function of Confinement
Authors: De Rosa Alexander J. , Peluso Stephen J. , Quay Bryan D. , Santavicca Domenic A.
Published: September 2017

The effect of confinement (flame–wall interactions) on the response of a turbulent, swirl-stabilized flame is experimentally examined, with a focus on the shape and structure of these flames. A series of three cylindrical combustors of 0.11, 0.15, and 0.19 m diameter are used to vary the degree of confinement experienced by the flame. Using CH* chemiluminescence images, the shape of the flame in each combustor is described. These images are then further analyzed and reveal marked similarities in the geometry and location of these flames in a defined “flame base” region near the combustor inlet. This similarity in location of the flame base leads to a similarity in the response of this portion of the flame to imposed oscillations. In particular, the phase of the fluctuations in this region is shown to be the same in each confinement. The nature of the fluctuations in the mean flame position is also shown to be similar in each confinement. These results indicate that the geometry of the flame in the base region is not a function of confinement and that the flames are responding to the same convective mechanisms, and in the same manner, in this region of the flame.
Theoretical Model of Buoyancy-Induced Heat Transfer in Closed Compressor Rotors
Authors: Tang Hui , Michael Owen J.
Published: September 2017

The cavities between the rotating compressor disks in aero-engines are open, and there is an axial throughflow of cooling air in the annular space between the center of the disks and the central rotating compressor shaft. Buoyancy-induced flow occurs inside these open rotating cavities, with an exchange of heat and momentum between the axial throughflow and the air inside the cavity. However, even where there is no opening at the center of the compressor disks—as is the case in some industrial gas turbines—buoyancy-induced flow can still occur inside the closed rotating cavities. The closed cavity also provides a limiting case for an open cavity when the axial clearance between the cobs—the bulbous hubs at the center of compressor disks—is reduced to zero. Bohn and his co-workers at the University of Aachen have studied three different closed-cavity geometries, and they have published experimental data for the case where the outer cylindrical surface is heated and the inner surface is cooled. In this paper, a buoyancy model is developed in which it is assumed that the heat transfer from the cylindrical surfaces is analogous to laminar free convection from horizontal plates, with the gravitational acceleration replaced by the centripetal acceleration. The resulting equations, which have been solved analytically, show how the Nusselt numbers depend on both the geometry of the cavity and its rotational speed. The theoretical solutions show that compressibility effects in the core attenuate the Nusselt numbers, and there is a critical Reynolds number at which the Nusselt number will be a maximum. For the three cavities tested, the predicted Nusselt numbers are in generally good agreement with the measured values of Bohn et al. over a large range of Raleigh numbers up to values approaching 1012. The fact that the flow remains laminar even at these high Rayleigh numbers is attributed to the Coriolis accelerations suppressing turbulence in the cavity, which is consistent with recently published results for open rotating cavities.
Numerical and Experimental Study of Clearance Nonlinearities Based on Nonlinear Response Reconstruction
Authors: Liu Jie , Li Bing , Miao Huihui , He Anqi , Zhu Shangkun
Published: September 2017

With the growing structural complexity and growing demands on structural reliability, nonlinear parameters identification is an efficient approach to provide better understanding of dynamic behaviors of the nonlinear system and contribute significantly to improve system performance. However, the dynamic response at nonlinear location, which cannot always be measured by the sensor, is the basis for most of these identification algorithms, and the clearance nonlinearity, which always exists to degrade the dynamic performance of mechanical structures, is rarely identified in previous studies. In this paper, based on the thought of output feedback which the nonlinear force is viewed as the internal feedback force of the nonlinear system acting on the underlying linear model, a frequency-domain nonlinear response reconstruction method is proposed to reconstruct the dynamic response at the nonlinear location from the arbitrary location where the sensor can be installed. For the clearance nonlinear system, the force graph method which is based on the reconstructed displacement response and nonlinear force is presented to identify the clearance value. The feasibility of the reconstruction method and identification method is verified by simulation data from a cantilever beam model with clearance nonlinearity. A clearance test-bed, which is a continuum structure with adjustable clearance nonlinearity, is designed to verify the effectiveness of proposed methods. The experimental results show that the reconstruction method can precisely reconstruct the displacement response at the clearance location from measured responses at reference locations, and based on the reconstructed response, the force graph method can also precisely identify the clearance parameter.
Effects of Fuel Molecular Weight on Emissions in a Jet Flame and a Model Gas Turbine Combustor
Authors: Makwana Anandkumar , Iyer Suresh , Linevsky Milton , Santoro Robert , Litzinger Thomas , O'Connor Jacqueline
Published: September 2017

The objective of this study is to understand the effects of fuel volatility on soot emissions. This effect is investigated in two experimental configurations: a jet flame and a model gas turbine combustor. The jet flame provides information about the effects of fuel on the spatial development of aromatics and soot in an axisymmetric, co-flow, laminar flame. The data from the model gas turbine combustor illustrate the effect of fuel volatility on net soot production under conditions similar to an actual engine at cruise. Two fuels with different boiling points are investigated: n-heptane/n-dodecane mixture and n-hexadecane/n-dodecane mixture. The jet flames are nonpremixed and rich premixed flames in order to have fuel conditions similar to those in the primary zone of an aircraft engine combustor. The results from the jet flames indicate that the peak soot volume fraction produced in the n-hexadecane fuel is slightly higher as compared to the n-heptane fuel for both nonpremixed and premixed flames. Comparison of aromatics and soot volume fraction in nonpremixed and premixed flames shows significant differences in the spatial development of aromatics and soot along the downstream direction. The results from the model combustor indicate that, within experiment uncertainty, the net soot production is similar in both n-heptane and n-hexadecane fuel mixtures. Finally, we draw conclusions about important processes for soot formation in gas turbine combustor and what can be learned from laboratory-scale flames.
Asymptotic Stabilization of Fractional Permanent Magnet Synchronous Motor
Authors: Guo Yuxiang , Ma Baoli
Published: September 2017

This paper is mainly concerned with asymptotic stability for a class of fractional-order (FO) nonlinear system with application to stabilization of a fractional permanent magnet synchronous motor (PMSM). First of all, we discuss the stability problem of a class of fractional time-varying systems with nonlinear dynamics. By employing Gronwall–Bellman's inequality, Laplace transform and its inverse transform, and estimate forms of Mittag–Leffler (ML) functions, when the FO belongs to the interval (0, 2), several stability criterions for fractional time-varying system described by Riemann–Liouville's definition is presented. Then, it is generalized to stabilize a FO nonlinear PMSM system. Furthermore, it should be emphasized here that the asymptotic stability and stabilization of Riemann–Liouville type FO linear time invariant system with nonlinear dynamics is proposed for the first time. Besides, some problems about the stability of fractional time-varying systems in existing literatures are pointed out. Finally, numerical simulations are given to show the validness and feasibleness of our obtained stability criterions.
On Finite Part Integrals and Hadamard-Type Fractional Derivatives
Authors: Ma Li , Li Changpin
Published: September 2017

This paper is devoted to investigating the relation between Hadamard-type fractional derivatives and finite part integrals in Hadamard sense; that is to say, the Hadamard-type fractional derivative of a given function can be expressed by the finite part integral of a strongly singular integral, which actually does not exist. Besides, our results also cover some fundamental properties on absolutely continuous functions, and the logarithmic series expansion formulas at the right end point of interval for functions in certain absolutely continuous spaces.
Chaotic Behavior and Feedback Control of Magnetorheological Suspension System With Fractional-Order Derivative
Authors: Zhang Chengyuan , Xiao Jian
Published: September 2017

The fractional differential equations of the single-degree-of-freedom (DOF) quarter vehicle with a magnetorheological (MR) suspension system under the excitation of sine are established, and the numerical solution is acquired based on the predictor–corrector method. The analysis of phase trajectory, time domain response, and Poincaré section shows that the nonlinear dynamic characteristics between fractional and integer-order suspension systems are quite different, which proves the superiority of using fractional order to describe the physical properties. By discussing the influence of each parameter on the vibration, the range of parameters to avoid the chaotic vibration is obtained. The variable feedback control is used to control the chaotic vibration effectively.
Functionally Distinct Tendons From Elastin Haploinsufficient Mice Exhibit Mild Stiffening and Tendon-Specific Structural Alteration
Authors: Eekhoff Jeremy D. , Fang Fei , Kahan Lindsey G. , Espinosa Gabriela , Cocciolone Austin J. , Wagenseil Jessica E. , Mecham Robert P. , Lake Spencer P.
Published: September 2017

Elastic fibers are present in low quantities in tendon, where they are located both within fascicles near tenocytes and more broadly in the interfascicular matrix (IFM). While elastic fibers have long been known to be significant in the mechanics of elastin-rich tissue (i.e., vasculature, skin, lungs), recent studies have suggested a mechanical role for elastic fibers in tendons that is dependent on specific tendon function. However, the exact contribution of elastin to properties of different types of tendons (e.g., positional, energy-storing) remains unknown. Therefore, this study purposed to evaluate the role of elastin in the mechanical properties and collagen alignment of functionally distinct supraspinatus tendons (SSTs) and Achilles tendons (ATs) from elastin haploinsufficient (HET) and wild type (WT) mice. Despite the significant decrease in elastin in HET tendons, a slight increase in linear stiffness of both tendons was the only significant mechanical effect of elastin haploinsufficiency. Additionally, there were significant changes in collagen nanostructure and subtle alteration to collagen alignment in the AT but not the SST. Hence, elastin may play only a minor role in tendon mechanical properties. Alternatively, larger changes to tendon mechanics may have been mitigated by developmental compensation of HET tendons and/or the role of elastic fibers may be less prominent in smaller mouse tendons compared to the larger bovine and human tendons evaluated in previous studies. Further research will be necessary to fully elucidate the influence of various elastic fiber components on structure–function relationships in functionally distinct tendons.
Passive Regulation of Thermally Induced Axial Force and Displacement in Microbridge Structures
Authors: Hassanpour Pezhman , Nieva Patricia M. , Khajepour Amir
Published: September 2017

The analytical model of a mechanism for regulating the thermally induced axial force and displacement in a fixed–fixed microbeam is presented in this article. The mechanism which consists of a set of parallel chevron beams replaces one of the fixed ends of the microbeam. The thermomechanical behavior of the system is modeled using Castigliano’s theorem. The effective coefficient of thermal expansion is used in the analytical model. The analytical model takes into account both the axial and bending deformations of the chevron beams. The model provides a closed-form equation to determine the thermally induced axial force and displacement in the microbeam. In addition, the model is used to derive the equations for the sensitivities of the microbeam’s axial force and displacement to the variations of the design parameters involved. Moreover, the model produces the stiffness of the chevron beams. The effect of the stiffness of the chevron beams on the dynamic behavior of the microbeam is discussed. The analytical model is verified by finite element modeling using a commercially available software package. Using the analytical model, two special cases are highlighted: a system with thermally insensitive axial force and a system with thermally insensitive axial displacement. The main application of the model presented in this article is in the design of sensors and resonators that require robustness against changes of temperature in the environment. The analytical model and the sensitivity equations can be easily integrated into optimization algorithms.
Ontology-Based Representation of Design Decision Hierarchies
Authors: Ming Zhenjun , Wang Guoxin , Yan Yan , Panchal Jitesh H. , Goh Chung Hyun , Allen Janet K. , Mistree Farrokh
Published: September 2017

The design of complex engineering systems requires that the problem is decomposed into subproblems of manageable size. From the perspective of decision-based design (DBD), typically this results in a set of hierarchical decisions. It is critically important for computational frameworks for engineering system design to be able to capture and document this hierarchical decision-making knowledge for reuse. Ontology is a formal knowledge modeling scheme that provides a means to structure engineering knowledge in a retrievable, computer-interpretable, and reusable manner. In our earlier work, we have created ontologies to represent individual design decisions (selection and compromise). Here, we extend the selection and compromise decision ontologies to an ontology for hierarchical decisions. This can be used to represent workflows with multiple decisions coupling together. The core of the proposed ontology includes the coupled decision support problem (DSP) construct, and two key classes, namely, Process that represents the basic hierarchy building blocks wherein the DSPs are embedded, and Interface to represent the DSP information flows that link different Processes to a hierarchy. The efficacy of the ontology is demonstrated using a portal frame design example. Advantages of this ontology are that it is decomposable and flexible enough to accommodate the dynamic evolution of a process along the design timeline.
Design of a Novel, Adjustable Flow Rate, Reusable, Electricity-Free, Low-Cost Syringe Infusion Pump
Authors: Guelig Dylan , Bauer James , Wollen Alec , Schiller Chelsea , Sherman-Konkle Jill , Roche Anthony , Weyrauch Karl , Eisenstein Mike
Published: September 2017

We present a proof-of-concept design and preliminary data to demonstrate a novel syringe infusion pump that is low cost, nonelectric, reusable, and adjustable. This device addresses the need for infusion therapy in low- and middle-income countries (LMIC), where intermittent electrical power precludes the use of conventional electronic infusion pumps and limited financial resources make high costs of disposable infusion pumps impractical. Our design uses a pneumatically pressurized, hydraulic (air over oil) drive piston coupled to a closed-circuit flow restriction to drive a syringe plunger at a constant velocity, thus providing a constant volumetric flow rate to the patient. The device requires no proprietary or precision consumables, significantly reducing treatment costs compared with other methods. The highly adjustable device provides constant flow rates across the range of 0.5–8 mL/h when used with a 30-mL syringe. The user interface is simple and intuitive; the hardware is robust and portable. This novel technology platform has broad applications in addressing priority health needs in LMIC.
A Moiré Pattern-Based Thread Counter
Authors: Reich Gary
Published: September 2017

Thread count is a term used in the textile industry as a measure of how closely woven a fabric is. It is usually defined as the sum of the number of warp threads per inch (or cm) and the number of weft threads per inch. (It is sometimes confusingly described as the number of threads per square inch.) In recent years it has also become a subject of considerable interest and some controversy among consumers. Many consumers consider thread count to be a key measure of the quality or fineness of a fabric, especially bed sheets, and they seek out fabrics that advertise high counts. Manufacturers in turn have responded to this interest by offering fabrics with ever higher claimed thread counts (sold at ever higher prices), sometime achieving the higher counts by distorting the definition of the term with some “creative math.” In 2005 the Federal Trade Commission noted the growing use of thread count in advertising at the retail level and warned of the potential for consumers to be misled by distortions of the definition.
Interplay between protein glycosylation pathways in Alzheimer’s disease
Authors: Frenkel-Pinter Moran , Shmueli Merav Daniel , Raz Chen , Yanku Michaela , Zilberzwige Shai , Gazit Ehud , Segal Daniel
Published: September 2017

Glycome analysis of Alzheimer’s patients reveals interplay between glycosylation pathways and suggests novel biomarkers.
Assembling oppositely charged lock and key responsive colloids: A mesoscale analog of adaptive chemistry
Authors: Mihut Adriana M. , Stenqvist Björn , Lund Mikael , Schurtenberger Peter , Crassous Jérôme J.
Published: September 2017

Oppositely charged thermoresponsive particles with complementary geometries are assembled into adaptive colloidal molecules.
Cooperative deformations of periodically patterned hydrogels
Authors: Wang Zhi Jian , Zhu Chao Nan , Hong Wei , Wu Zi Liang , Zheng Qiang
Published: September 2017

In periodically patterned gels, buckled domains mutually interact and cooperatively deform to minimize total elastic energy.
Particle-hole symmetry reveals failed superconductivity in the metallic phase of two-dimensional superconducting films
Authors: Breznay Nicholas P. , Kapitulnik Aharon
Published: September 2017

Hall effect studies in disordered superconducting films reveal particle-hole symmetry in the enigmatic quantum metallic phase.
Allochroic thermally activated delayed fluorescence diodes through field-induced solvatochromic effect
Authors: Han Chunmiao , Duan Chunbo , Yang Weibo , Xie Mingchen , Xu Hui
Published: September 2017

A novel thermally activated delayed fluorescence (TADF) allochroic diode can change emission color through adjusting voltage.
Bioinspired bright noniridescent photonic melanin supraballs
Authors: Xiao Ming , Hu Ziying , Wang Zhao , Li Yiwen , Tormo Alejandro Diaz , Le Thomas Nicolas , Wang Boxiang , Gianneschi Nathan C. , Shawkey Matthew D. , Dhinojwala Ali
Published: September 2017

A one-pot emulsion process produces noniridescent supraball inks made of core-shell melanin and silica nanoparticles.
CryoEM structure of MxB reveals a novel oligomerization interface critical for HIV restriction
Authors: Alvarez Frances J. D. , He Shaoda , Perilla Juan R. , Jang Sooin , Schulten Klaus , Engelman Alan N. , Scheres Sjors H. W. , Zhang Peijun
Published: September 2017

CryoEM structure of MxB tubes at 4.6 Å resolution reveals novel interfaces responsible for assembly and anti–HIV-1 activity.
Rapid and near-complete dissolution of wood lignin at ≤80°C by a recyclable acid hydrotrope
Authors: Chen Liheng , Dou Jinze , Ma Qianli , Li Ning , Wu Ruchun , Bian Huiyang , Yelle Daniel J. , Vuorinen Tapani , Fu Shiyu , Pan Xuejun , Zhu Junyong (J.Y.)
Published: September 2017

We report a near-complete dissolution of wood lignin at less than 80°C for 20 min using an easily recyclable hydrotrope.
Real-time probing of granular dynamics with magnetic resonance
Authors: Penn Alexander , Tsuji Takuya , Brunner David O. , Boyce Christopher M. , Pruessmann Klaas P. , Müller Christoph R.
Published: September 2017

Real-time MRI of granular dynamics enabled by a joint optimization of imaging hardware, pulse sequences, and sample properties.
KIR2DS2 recognizes conserved peptides derived from viral helicases in the context of HLA-C
Authors: Naiyer Mohammed M. , Cassidy Sorcha A. , Magri Andrea , Cowton Vanessa , Chen Kevin , Mansour Salah , Kranidioti Hariklia , Mbiribindi Berenice , Rettman Pauline , Harris Scott , Fanning Liam J. , Mulder Arend , Claas Franz H. J. , Davidson Andrew D. , Patel Arvind H. , Purbhoo Marco A. , Khakoo Salim I.
Published: September 2017

KIR2DS2, an activating natural killer cell receptor, recognizes conserved peptides derived from the RNA helicases of pathogenic flaviviruses.
Potential of Rice Stubble as a Reservoir of Bradyrhizobial Inoculum in Rice-Legume Crop Rotation
Authors: Piromyou Pongdet , Greetatorn Teerana , Teamtisong Kamonluck , Tittabutr Panlada , Boonkerd Nantakorn , Teaumroong Neung
Published: September 2017

Bradyrhizobium
encompasses a variety of bacteria that can live in symbiotic and endophytic associations with leguminous and nonleguminous plants, such as rice. Therefore, it can be expected that rice endophytic bradyrhizobia can be applied in the rice-legume crop rotation system. Some endophytic bradyrhizobial strains were isolated from rice (
Oryza sativa
L.) tissues. The rice biomass could be enhanced when supplementing bradyrhizobial strain inoculation with KNO
3
, NH
4
NO
3
, or urea, especially in
Bradyrhizobium
sp. strain SUTN9-2. In contrast, the strains which suppressed rice growth were photosynthetic bradyrhizobia and were found to produce nitric oxide (NO) in the rice root. The expression of genes involved in NO production was conducted using a quantitative reverse transcription-PCR (qRT-PCR) technique. The
nirK
gene expression level in
Bradyrhizobium
sp. strain SUT-PR48 with nitrate was higher than that of the
norB
gene. In contrast, the inoculation of SUTN9-2 resulted in a lower expression of the
nirK
gene than that of the
norB
gene. These results suggest that SUT-PR48 may accumulate NO more than SUTN9-2 does. Furthermore, the
nifH
expression of SUTN9-2 was induced in treatment without nitrogen supplementation in an endophytic association with rice. The indole-3-acetic acid (IAA) and 1-amino-cyclopropane-1-carboxylic acid (ACC) deaminase produced
in planta
by SUTN9-2 were also detected. Enumeration of rice endophytic bradyrhizobia from rice tissues revealed that SUTN9-2 persisted in rice tissues until rice-harvesting season. The mung bean (
Vigna radiata
) can be nodulated after rice stubbles were decomposed. Therefore, it is possible that rice stubbles can be used as an inoculum in the rice-legume crop rotation system under both low- and high-organic-matter soil conditions.

IMPORTANCE
This study shows that some rice endophytic bradyrhizobia could produce IAA and ACC deaminase and have a nitrogen fixation ability during symbiosis inside rice tissues. These characteristics may play an important role in rice growth promotion by endophytic bradyrhizobia. However, the NO-producing strains should be of concern due to a possible deleterious effect of NO on rice growth. In addition, this study reports the application of endophytic bradyrhizobia in rice stubbles, and the rice stubbles were used directly as an inoculum for a leguminous plant (mung bean). The degradation of rice stubbles leads to an increased number of SUTN9-2 in the soil and may result in increased mung bean nodulation. Therefore, the persistence of endophytic bradyrhizobia in rice tissues can be developed to use rice stubbles as an inoculum for mung bean in a rice-legume crop rotation system.
Succinate Transport Is Not Essential for Symbiotic Nitrogen Fixation by Sinorhizobium meliloti or Rhizobium leguminosarum
Authors: Mitsch Michael J. , diCenzo George C. , Cowie Alison , Finan Turlough M.
Published: September 2017

Symbiotic nitrogen fixation (SNF) is an energetically expensive process performed by bacteria during endosymbiotic relationships with plants. The bacteria require the plant to provide a carbon source for the generation of reductant to power SNF. While C
4
-dicarboxylates (succinate, fumarate, and malate) appear to be the primary, if not sole, carbon source provided to the bacteria, the contribution of each C
4
-dicarboxylate is not known. We address this issue using genetic and systems-level analyses. Expression of a malate-specific transporter (MaeP) in
Sinorhizobium meliloti
Rm1021
dct
mutants unable to transport C
4
-dicarboxylates resulted in malate import rates of up to 30% that of the wild type. This was sufficient to support SNF with
Medicago sativa
, with acetylene reduction rates of up to 50% those of plants inoculated with wild-type
S. meliloti
.
Rhizobium leguminosarum
bv. viciae 3841
dct
mutants unable to transport C
4
-dicarboxylates but expressing the
maeP
transporter had strong symbiotic properties, with
Pisum sativum
plants inoculated with these strains appearing similar to plants inoculated with wild-type
R. leguminosarum
. This was despite malate transport rates by the mutant bacteroids being 10% those of the wild type. An RNA-sequencing analysis of the combined
P. sativum
-
R. leguminosarum
nodule transcriptome was performed to identify systems-level adaptations in response to the inability of the bacteria to import succinate or fumarate. Few transcriptional changes, with no obvious pattern, were detected. Overall, these data illustrated that succinate and fumarate are not essential for SNF and that, at least in specific symbioses,
l
-malate is likely the primary C
4
-dicarboxylate provided to the bacterium.

IMPORTANCE
Symbiotic nitrogen fixation (SNF) is an economically and ecologically important biological process that allows plants to grow in nitrogen-poor soils without the need to apply nitrogen-based fertilizers. Much research has been dedicated to this topic to understand this process and to eventually manipulate it for agricultural gains. The work presented in this article provides new insights into the metabolic integration of the plant and bacterial partners. It is shown that malate is the only carbon source that needs to be available to the bacterium to support SNF and that, at least in some symbioses, malate, and not other C
4
-dicarboxylates, is likely the primary carbon provided to the bacterium. This work extends our knowledge of the minimal metabolic capabilities the bacterium requires to successfully perform SNF and may be useful in further studies aiming to optimize this process through synthetic biology approaches. The work describes an engineering approach to investigate a metabolic process that occurs between a eukaryotic host and its prokaryotic endosymbiont.
CmeABC Multidrug Efflux Pump Contributes to Antibiotic Resistance and Promotes Campylobacter jejuni Survival and Multiplication in Acanthamoeba polyphaga
Authors: Vieira Ana , Ramesh Amritha , Seddon Alan M. , Karlyshev Andrey V.
Published: September 2017

Campylobacter jejuni
is a foodborne pathogen that is recognized as the leading cause of human bacterial gastroenteritis. The widespread use of antibiotics in medicine and in animal husbandry has led to an increased incidence of antibiotic resistance in
Campylobacter
. In addition to a role in multidrug resistance (MDR), the
Campylobacter
CmeABC resistance-nodulation-division (RND)-type efflux pump may be involved in virulence. As a vehicle for pathogenic microorganisms, the protozoan
Acanthamoeba
is a good model for investigations of bacterial survival in the environment and the molecular mechanisms of pathogenicity. The interaction between
C. jejuni
81-176 and
Acanthamoeba polyphaga
was investigated in this study by using a modified gentamicin protection assay. In addition, a possible role for the CmeABC MDR pump in this interaction was explored. Here we report that this MDR pump is beneficial for the intracellular survival and multiplication of
C. jejuni
in
A. polyphaga
but is dispensable for biofilm formation and motility.

IMPORTANCE
The endosymbiotic relationship between amoebae and microbial pathogens may contribute to persistence and spreading of the latter in the environment, which has significant implications for human health. In this study, we found that
Campylobacter jejuni
was able to survive and to multiply inside
Acanthamoeba polyphaga
; since these microorganisms can coexist in the same environment (e.g., on poultry farms), the latter may increase the risk of infection with
Campylobacter
. Our data suggest that, in addition to its role in antibiotic resistance, the CmeABC MDR efflux pump plays a role in bacterial survival within amoebae. Furthermore, we demonstrated synergistic effects of the CmeABC MDR efflux pump and TetO on bacterial resistance to tetracycline. Due to its role in both the antibiotic resistance and the virulence of
C. jejuni
, the CmeABC MDR efflux pump could be considered a good target for the development of antibacterial drugs against this pathogen.
The Fungal Tree of Life: from Molecular Systematics to Genome-Scale Phylogenies
Authors: Spatafora Joseph W. , Aime M. Catherine , Grigoriev Igor V. , Martin Francis , Stajich Jason E. , Blackwell Meredith
Published: September 2017

The kingdom Fungi is one of the more diverse clades of eukaryotes in terrestrial ecosystems, where they provide numerous ecological services ranging from decomposition of organic matter and nutrient cycling to beneficial and antagonistic associations with plants and animals. The evolutionary relationships of the kingdom have represented some of the more recalcitrant problems in systematics and phylogenetics. The advent of molecular phylogenetics, and more recently phylogenomics, has greatly advanced our understanding of the patterns and processes associated with fungal evolution, however. In this article, we review the major phyla, subphyla, and classes of the kingdom Fungi and provide brief summaries of ecologies, morphologies, and exemplar taxa. We also provide examples of how molecular phylogenetics and evolutionary genomics have advanced our understanding of fungal evolution within each of the phyla and some of the major classes. In the current classification we recognize 8 phyla, 12 subphyla, and 46 classes within the kingdom. The ancestor of fungi is inferred to be zoosporic, and zoosporic fungi comprise three lineages that are paraphyletic to the remainder of fungi. Fungi historically classified as zygomycetes do not form a monophyletic group and are paraphyletic to Ascomycota and Basidiomycota. Ascomycota and Basidiomycota are each monophyletic and collectively form the subkingdom Dikarya.
Incidence of retinopathy of prematurity (ROP) and ROP treatment in Switzerland 2006–2015: a population-based analysis
Authors: Gerull Roland , Brauer Viviane , Bassler Dirk , Laubscher Bernard , Pfister Riccardo E , Nelle Mathias , Müller Béatrice , Gerth-Kahlert Christina , Adams Mark
Published: September 2017

Background

Retinopathy of prematurity (ROP) is a severe complication of preterm birth and can lead to severe visual impairment or even blindness if untreated. The incidence of ROP requiring treatment is increasing in some developed countries in conjunction with higher survival rates at the lower end of gestational age (GA).

Material and methods

The incidence of ROP and severe ROP (sROP) requiring treatment in Switzerland was analysed using the SwissNeoNet registry. We conducted a retrospective cohort analysis of very preterm infants with a GA below 32 weeks who were born between 2006 and 2015 in Switzerland. Patient characteristics were stratified according to GA.

Results

9.3% and 1.8% of very preterm infants in Switzerland developed ROP of any stage and sROP, respectively. The incidence of ROP treatment was 1.2%. Patients with 24 and 25 weeks GA had the highest proportion of ROP treatment at 14.5% and 7.3%, respectively, whereas the proportion of treated infants at or above a GA of 29 weeks was 0.06%. Similarly, the risk of sROP declined strongly with increasing GA. During the observation period of 10 years, the incidence of ROP treatment ranged between 0.8% and 2.0%. Incidences of sROP or ROP treatment did not increase over time.

Conclusion

The incidence of ROP treatment in Switzerland is low and was stable over the analysed period. The low incidence of sROP in patients with a GA of 29 weeks or more leaves room for a redefinition of ROP screening criteria.
Rare case of primary leiomyosarcoma of sigmoid mesocolon
Authors: Ilias Aizat Sabri , Yaacob Huzairi , Wan Zain Wan Zainira , Zakaria Andee Dzulkarnaen
Published: September 2017

We experienced a rare case of primary leiomyosarcoma of sigmoid mesentery. A 45-year-old woman was presented to us with left iliac fossa mass and discomfort for 4-month duration. CT scan of abdomen and pelvis revealed a huge mass 14 cm×14 cm×16 cm occupying left iliac fossa mimicked having a large left ovarian carcinoma. She was subsequently planned for elective total abdominal hysterectomy and bilateral salpingo-oophorectomy by gynaecology team. During laparotomy, a huge mass was revealed arising from sigmoid mesentery invaded to the left lower ureter. Curative resection was done and pathological findings show the tumour being leiomyosarcoma with immunohistochemistry tests on caldesmon, desmin, smooth muscle actin and CD34 reagent all positive. Clinicopathological and literature review of this rare primary leiomyosarcoma of mesocolon was discussed in our case presentation
Successful twice interrupted therapy of HCV infection in patients with cirrhosis with hepatocellular carcinoma before and after liver transplantation
Authors: Szymanek-Pasternak Anna , Rostkowska Karolina , Simon Krzysztof
Published: September 2017

We are presenting the case study of the patient diagnosed at the age of 37 with liver cirrhosis due to genotype 1b hepatitis C virus infection. At the age of 46, he was diagnosed with hepatocellular carcinoma with subsequent resection of the tumour in May 2015. In December 2015, the treatment was started with ombitasvir, paritaprevir/ritonavir and dasabuvir (3D) with ribavirin (RBV) 1000 mg per day. After 24 days of this treatment, the patient received a deceased donor liver transplantation, followed by 18-day interruption of 3D therapy. Due to the anaemia, RBV dose was reduced to 600 mg per day for the rest of the treatment. At the 11th week of 3D+RBV treatment, there was another 8-day long discontinuation of therapy due to the postoperative wound infection. In total, the patient received 24 weeks of 3D+RBV treatment, achieving sustained virological response at week 24 post-treatment.
Combined caesarean with splenectomy in pregnancy with portal hypertension: defining plausibility
Authors: Pol Manjunath Maruti , Chawla Latika Uniyal , Rathore Yashwant Singh , Goel Ritesh
Published: September 2017

24-year-old woman at 28 weeks gestation was referred from peripheral hospital with diagnosis of pregnancy with portal hypertension. She had received multiple transfusion for pancytopaenia in the past and had undergone endoscopic sclerotherapy for oesophageal varices. Initially, she was admitted in our hospital at 28 weeks gestation for blood transfusion and was evaluated by multispecialty team of doctors. She was advised splenectomy for transfusion-dependent pancytopaenia secondary to hypersplenism in non-cirrhotic portal hypertension. She was readmitted at 36 weeks gestation. A decision for caesarean was taken owing to failed induction of labour at 38 weeks gestation. She underwent combined caesarean with splenectomy. Mother and child had an uneventful postoperative recovery and were discharged on ninth postoperative day. Preconceptional counselling, treatment of oesophageal varices and multispecialty approach was paramount in the management. Combined caesarean with splenectomy is feasible and cost-effective treatment associated with improved quality of life. Prospective clinical trials are essential to prove safety and efficacy of treatment.
Reproductive, maternal, neonatal and child health in conflict: a case study on Syria using Countdown indicators
Authors: DeJong Jocelyn , Ghattas Hala , Bashour Hyam , Mourtada Rima , Akik Chaza , Reese-Masterson Amelia
Published: September 2017

Introduction

Women and children account for a disproportionate morbidity burden among conflict-affected populations, and yet they are not included in global accountability frameworks for women’s and children’s health. We use Countdown to 2015 (Millennium Development Goals) health indicators to provide an up-to-date review and analysis of the best available data on Syrian refugees in Jordan, Lebanon and Turkey and internally displaced within Syria and explore data challenges in this conflict setting.

Methods

We searched Medline, PubMed, Scopus, Popline and Index Medicus for WHO Eastern Mediterranean Region Office and relevant development/humanitarian databases in all languages from January 2011 until December 2015. We met in person or emailed relevant key stakeholders in Lebanon, Jordan, Syria and Turkey to obtain any unpublished or missing data. We convened a meeting of experts working with these populations to discuss the results.

Results

The following trends were found based on available data for these populations as compared with preconflict Syria. Birth registration in Syria and in host neighbouring countries decreased and was very low in Lebanon. In Syria, the infant mortality rate and under-five mortality rate increased, and coverage of antenatal care (one visit with a skilled attendant), skilled birth attendance and vaccination (except for DTP3 vaccine) declined. The number of Syrian refugee women attending more than four antenatal care visits was low in Lebanon and in non-camp settings in Jordan. Few data were available on these indicators among the internally displaced. In conflict settings such as that of Syria, coverage rates of interventions are often unknown or difficult to ascertain because of measurement challenges in accessing conflict-affected populations or to the inability to determine relevant denominators in this dynamic setting.

Conclusion

Research, monitoring and evaluation in humanitarian settings could better inform public health interventions if findings were more widely shared, methodologies were more explicit and globally agreed definitions and indicators were used consistently.
Did the right to health get across the line? Examining the United Nations resolution on the Sustainable Development Goals
Authors: Brolan Claire E , Te Vannarath , Floden Nadia , Hill Peter S , Forman Lisa
Published: September 2017

Since the new global health and development goal, Sustainable Development Goal (SDG) 3, and its nine targets and four means of implementation were introduced to the world through a United Nations (UN) General Assembly resolution in September 2015, right to health practitioners have queried whether this goal mirrors the content of the human right to health in international law. This study examines the text of the UN SDG resolution,Transforming our world: the 2030 Agenda for Sustainable Development, from a right to health minimalist and right to health maximalist analytic perspective. When reviewing the UN SDG resolution’s text, a right to health minimalist questions whether the content of the right to health is at leastimplicitlyincluded in this document, specifically focusing on SDG 3 and its metrics framework. A right to health maximalist, on the other hand, queries whether the content of the right to health isexplicitlyincluded. This study finds that whether the right to health is contained in the UN SDG resolution, and the SDG metrics therein, ultimately depends on the individual analyst’s subjective persuasion in relation to right to health minimalism or maximalism. We conclude that the UN General Assembly’s lack of cogency on the right to health’s position in the UN SDG resolution will continue to blur if not divest human rights’ (and specifically the right to health’s) integral relationship to high-level development planning, implementation and SDG monitoring and evaluation efforts.
Cutaneous angiosarcoma: a current update
Authors: Shustef Elina , Kazlouskaya Viktoryia , Prieto Victor G , Ivan Doina , Aung Phyu P
Published: September 2017

Cutaneous angiosarcoma (cAS) is a rare malignant neoplasm with variable clinical presentation. Although a distinct vascular tumour, cAS shares many overlapping histopathological features with other vasoformative and epithelioid tumours or ‘mimickers’. cAS shows aggressive behaviour and carries a grave prognosis, thus early diagnosis is of paramount importance to achieve the best possible outcomes. Recently, several genetic studies were conducted leading to the identification of novel molecular targets in the treatment of cAS. Herein, we present a comprehensive review of cAS with discussion of its clinical, histopathological and molecular aspects, the differential diagnosis, as well as current therapies including ongoing clinical trials.