bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the gen locus involved in β‐1,6‐oligosaccharide utilization by Enterococcus faecalis
Authors: Grand Maxime , Aubourg Marion , Pikis Andreas , Thompson John , Deutscher Josef , Hartke Axel , Sauvageot Nicolas 
Published: September 2019

SummaryThe bicistronic genBA operon (formerly named celBA) of the opportunistic pathogen Enterococcus faecalis, encodes a 6‐phospho‐β‐glucosidase (GenA) and a phosphotransferase system permease EIIC (GenB). It resembles the cel operon of Streptococcus pyogenes, which is implicated in the metabolism of cellobiose. However, genBA mutants grew normally on cellobiose, but not (genA) or only slowly (genB) on gentiobiose and amygdalin. The two glucosides were also found to be the main inducers of the operon, confirming that the encoded proteins are involved in the utilization of β‐1,6‐ rather than β‐1,4‐linked oligosaccharides. Expression of the genBA operon is regulated by the transcriptional activator GenR, which is encoded by the gene upstream from genB. Thermal shift analysis showed that it binds gentiobiose‐6′‐P with a Kd of 0.04 mM and with lower affinity also other phospho‐sugars. The GenR/gentiobiose‐6′‐P complex binds to the promoter region upstream from genB. The genBA promoter region contains a cre box and gel‐shift experiments demonstrated that the operon is under negative control of the global carbon catabolite regulator CcpA. We also show that the orphan EIIC (GenB) protein needs the EIIA component of the putative OG1RF_10750‐OG1RF_10755 operon situated elsewhere on the chromosome to form a functional PTS transporter.
Two new species of Gloniopsis (Hysteriales, Ascomycota) from clinical specimens: Morphological and molecular characterisation
Authors: Valenzuela‐Lopez Nicomedes , Magaña‐Dueñas Viridiana , Cano‐Lira José F. , Wiederhold Nathan , Guarro Josep , Stchigel Alberto M. 
Published: September 2019

SummaryBackgroundThe coelomycetes comprise a wide range of fungal species distributed in at least three different classes of the phylum Ascomycota. These are morphologically characterised by producing their conidia inside of fruiting bodies called pycnidia or acervuli, and only a reduced number of species are able to cause human infections. However, their identification in the clinical laboratory is often difficult, due to their few morphological features or because they remain sterile.Materials and MethodsIn the present study, three isolates of coelomycetes of clinical origin were phenotypically and molecularly studied, by sequencing the D1‐D2 fragment of the 28S nuclear ribosomal RNA (nrRNA) (LSU), the internal transcribed spacer region (ITS1‐5.8S‐ITS2) and a fragment of the translation elongation factor 1‐alpha (tef1) genes.Results and ConclusionsAs result of the molecular analysis, the isolates were identified as belonging to the genus Gloniopsis (order Hysteriales, Dothideomycetes) but without the characteristics of any of the species described so far. Therefore, we propose the new species Gloniopsis percutanea and Gloniopsis pneumoniae. Furthermore, this study revealed that some isolates from clinical specimens identified previously as Rhytidhysteron spp. were misidentified, and considering the few studies in the order Hysteriales and the scarce number of sequences of phylogenetic markers, future revisions of this order should be performed to clarify their taxonomy and obtain a better identification from isolates involved in human mycoses.
Coagulative function assessed preoperatively via the clot formation and lysis assay as a prognostic factor for blood loss in adolescents undergoing posterior spinal fusion for idiopathic scoliosis
Authors: Fernandez Allison M. , Neustadt Jeffrey B. , Hahn Gregory V. , Nguyen Anh Thy H. , Amankwah Ernest K. , Goldenberg Neil A. 
Published: September 2019

AbstractBackgroundPosterior spinal fusion for adolescent idiopathic scoliosis is a complex surgery often associated with clinically significant blood loss leading to perioperative blood transfusion. Knowledge of risk factors for blood loss and transfusion stems mostly from retrospective studies.AimWe sought to prospectively investigate putative prognostic factors for intraoperative blood loss and perioperative blood transfusion in adolescent idiopathic scoliosis patients undergoing posterior spine fusion, including clinical characteristics, surgical factors, and preoperative assessment of overall coagulative and fibrinolytic functions in plasma using the clot formation and lysis (CloFAL) assay.MethodsFollowing Internal Review Board approval, adolescents 10 to <21 years old with idiopathic scoliosis undergoing posterior spine fusion were enrolled preoperatively in a single‐institutional prospective cohort and biobanking study. Clinical data were collected on patient characteristics, surgical approach, perioperative management, intraoperative estimated blood loss, and blood transfusion through hospital discharge. Coagulative and fibrinolytic functions in plasma were measured on preoperative samples by CloFAL assay (Coagulation Index and modified Fibrinolytic Index). Univariate linear regression and multivariable linear regression were performed to identify predictors of weight‐indexed intraoperative estimated blood loss EBL (EBL/kg).ResultsThe final study population included 74 patients. Median age was 14.8 years (SD = 2.2). After adjustment for other putative prognostic factors via multivariable linear regression, coagulative function as determined preoperatively by CloFAL Coagulation Index was an independent predictor of intraoperative (EBL)/kg. Specifically, each 10% increase in CloFAL CI was associated with 3% decrease in the geometric mean of EBL/kg (OR 0.97, 95%CI 0.94‐0.99, P = .01).ConclusionIn adolescents undergoing posterior spinal fusion for idiopathic scoliosis, increased coagulative function measured preoperatively using the CloFAL assay is independently associated with decreased intraoperative blood loss. Future studies should expand upon these investigations of plasma coagulative and fibrinolytic capacities in combination with clinical factors, to guide precise preventive strategies against blood loss and blood transfusion in this patient population.
Pediatric intestinal transplantation: Analysis of the intestinal transplant registry
Authors: Raghu Vikram K. , Beaumont Jennifer L. , Everly Matthew J. , Venick Robert S. , Lacaille Florence , Mazariegos George V. 
Published: September 2019

AbstractThe ITR serves as an international database for centers around the world to contribute to current knowledge about intestinal transplant outcomes. Led by the IRTA and managed by the Terasaki Research Institute, the ITR collects data annually and uses these data to generate reports that guide management strategies and policy statements. The aim of this manuscript was to analyze outcomes specific to pediatric intestinal transplantation. Outcome data for children transplanted from 1985 to 2017 were analyzed and predictive factors assessed. A total of 2010 children received 2080 intestine containing allografts during this period. Overall, 1‐year and 5‐year patient and graft survival were 72.7%/66.1% and 57.2/48.8%, respectively. One‐year conditional survival was most strongly associated with being a first‐time transplant recipient and liver‐inclusive grafts. Patient survival was most strongly associated with elective status of transplantation as compared with hospitalized status. Enteral autonomy following transplantation has continued to improve by era with colonic inclusion demonstrating additional incremental improvement in enteral autonomy and freedom from intravenous fluid. While PTLD and technical complications contribute less to graft loss than in earlier eras, rejection remains the largest contributor to long‐term graft loss. Re‐transplantation is linked with significantly worse conditional graft survival, and sepsis remains the largest contributor to patient death. Newer data elements are focusing on impact of donor variables, donor and recipient tissue typing, and impact of the development of de novo antibodies.
Optimal Fluctuation Regulation Method in Low-Speed Digital Piston Pump
Authors: Yu Licheng , Shi Guanglin 
Published: September 2019

AbstractIn digital displacement pump (DDP), the states of valves are nonlinear correlation with the instantaneous flow rate and flow fluctuation. For low-speed working condition, the digital valve has potential to switch several times to improve flow fluctuation. So, the relationship between the valve states and the flow rate is decoded, and a novel optimal fluctuation regulation (OFR) method including OFR-strict (OFR-S) and OFR-relaxation (OFR-R) is designed in this paper. The periodicity and the symmetry of OFR methods are proved and an optimal solution in the predefined minimum characteristic interval (MCI) is realized. Compared to the traditional sequential, partial, and pulse width modulation (PWM) methods, OFR-S has the minimum flow fluctuation, while OFR-R is preferred in low-speed ratio to reduce the digital valve switching frequency. At last, the effects of valve delay and oil compressibility are analyzed. As a theoretical precise optimal solution, OFR method demonstrates its ability in handling nonlinear problems in MCI. And it definitely will be a good base for the nonlinear controller design in the future.
Cicada-inspired self-cleaning superhydrophobic surfaces
Authors: Oh Junho , Yin Sabrina , Dana Catherine E. , Hong Sungmin , Roman Jessica K. , Jo Kyoo Dong , Chavan Shreyas , Cropek Don , Alleyne Marianne , Miljkovic Nenad 
Published: September 2019

Abstract
Water-based heat transfer surfaces in HVAC&R (Heating, Ventilation, Air Conditioning and Refrigeration) systems have biofouling or microbial growth which might not only impose adverse effects to public health but also deteriorate the heat transfer performance of surfaces. In nature, a living creature is surviving while being exposed to formidable condition such as bacteria and fungi. Cicada wing has known to have multi-functional wings exhibiting nonwetting, and anti-microbial due to nanoscale pillars and biochemicals to achieve non-wetting characteristics. We conducted experiments on cicada wings and cicada-inspired engineered superhydrophobic samples to show that droplets jumping from superhydrophobic wings could carry away individual particles (~100 µm) or cluster of particles. This study was investigated on self-cleaning mechanism using jumping droplet condensation and elucidate further antifouling characteristics of non-wetting heat transfer surfaces.
Nonaxisymmetric Study of Tip Leakage Flow in a Centrifugal Compressor With a Volute During Stall Process
Authors: Yang Ce , Su Botai , Fu Li , Zhang Hang 
Published: September 2019

Abstract
Tip leakage flow (TLF) patterns, which affect compressor performance, are closely related to compressor stability. To date, minimal attention has been given to circumferential nonuniformity of the TLF in a centrifugal compressor with a nonaxisymmetric volute structure. In this study, the circumferential difference of the TLF in a centrifugal compressor with a volute during the stall process is analyzed. The circumferential nonuniformity of tip leakage vortex (TLV) trajectories, loading distribution near the tip, and distance between the TLV core and the leading edge (LE) of splitter blades were also investigated. It is shown that in the circumferential direction, there are two peaks associated with the angle (α) between the TLV trajectory of the seven main blades and the axial direction. As the stall process progresses, the blade whose LE is affected by the high static pressure band (PP) induced by the volute tongue (VT) loses its work capacity first and the α difference between this blade and the other blades increases. In addition, the tip loading and TLF velocity of the blade whose LE is affected by the high static pressure band induced by the VT are at a minimum, and the flow loss in the tip clearance is higher. There is a phenomenon of the TLV breakdown. When the blade trailing edge (TE) is located in the low static pressure region, TLV streamlines appear as a significant turn at the breakdown point. However, the TLV streamlines at other circumferential positions do not exhibit this phenomenon.
A Friction–Wear Correlation for Four-Ball Extreme Pressure Lubrication
Authors: Chan Chung-Hung , Lim Wen Huei , Yeong Shoot Kian , Kow Kien Woh , Ho Yong Kuen 
Published: September 2019

AbstractA first-ever friction–wear model for four-ball extreme pressure (EP) lubrication is developed in this work based on 12 oil samples comprising minerals, esters, and other formulated lubricants. The model considers the rate of entropy generation and dissipation within the lubricated tribosystem to describe the interaction between the friction and the wear behaviors at extreme pressure conditions. The model can be used to calculate the probability to pass or fail at a specific load to estimate the weld point of a lubricant. The calculated probability exhibited a similar trend as a load-wear index from the ASTM D2783 EP test method. Besides, the model is able to estimate the EP performance of an unknown lubricant based on the model parameter, namely the dissipative coefficient. This parameter describes the proportionality between the friction and the wear phenomena from the perspective of thermodynamic analysis. This work provides useful tools to better understand the fundamentals of EP lubrication and to characterize the lubricants without overly relying on tribotest machines.
In Situ Identification of Natural Frequency Branches in Gyroscopic Systems via Autoresonance and Phase-Locked Loop
Authors: Davis Solomon , Tresser Shachar , Ariel Netanel , Ferdinskoif Alex , Bucher Izhak 
Published: September 2019

AbstractThe methods described allow one to directly measure the individual branches of the Campbell diagram of a physical gyroscopic system at any rotation speed. Typically, such data are acquired by exciting the vibration modes through naturally occurring unbalance forces. During run-up, these forces expose some of the Campbell diagram, but mainly the forward whirling branches, leaving the backward whirling branches mostly hidden. Furthermore, good modal frequency data are only acquired at critical speeds. The methods proposed here allow one to excite either a forward or backward whirling mode at any rotation speed in a precisely controlled manner, greatly improving the quality of an acquired Campbell diagram. The technique employs an external excitation device that automatically produces oscillating forces at a chosen modal frequency. Control is based on the autoresonance feedback algorithm, which can excite a mechanical system at resonance effectively. It will also be shown that with two actuators and two sensors, one can choose which bending mode to excite at resonance in either the forward or backward whirling direction. As the rotation speed is then gradually increased, one can measure the speed dependence of the resonance frequency. Furthermore, when combining autoresonance with a phase-locked loop, one can acquire very clean measurements by removing most of the noise generated by the unbalance and other sources. The technique is demonstrated analytically, numerically, and experimentally.
Efficiency Assessment of an Evacuated U-Tube Solar Collector Using Silver Nanofluid
Authors: Kaya Hüseyin , Eltugral Nurettin , Kurukavak Ali , Arslan Kamil 
Published: September 2019

Abstract
A water-based silver nanofluid (Ag/PW) was prepared from gelatin-stabilized silver nanoparticles (Ag NPs) of about 15 nm and further used as a working fluid in an evacuated U-tube solar collector (EUSC) to investigate the variation in the collector efficiency. An Ag/PW nanofluid having 0.035 wt% was prepared and demonstrated a good promise of colloidal stability when dispersed in pure water. Collector efficiency measurements were carried out at outdoor conditions with four different mass flow rate values (0.063, 0.051, 0.033, and 0.02 kg/s). Results showed that Ag/PW have superior heat transfer properties than that of pure water as the base fluid. It was found that the efficiency of the collector was directly proportional to the mass flow rate of the working fluid until an optimum value was attained. Experimental results show that the highest collector efficiency was 72.2% at 0.051 kg/s mass flow rate, which is 21.3% higher than that of the pure water.
On the Liftoff of Diffusion Flame: An Experimental and Analytical Study
Authors: Akbarzadeh Mohsen , Birouk Madjid 
Published: September 2019

Abstract
The effect of lip thickness of fuel nozzle on the liftoff of an attached diffusion methane flame with and without a coflow was experimentally and analytically investigated. Three fuel nozzles made of a long pipe with the same internal diameter but different nozzle lip thickness were tested. The co-airflow was also varied to assess its impact on the liftoff of jet diffusion flame. The results showed that the effect of fuel nozzle lip thickness on the liftoff of a free jet flame (i.e., no coflow) is marginal. However, the presence of a weak to moderate coflow (0.05 m/s &lt; Uco &lt; 0.3 m/s) reduced the liftoff velocity of an attached flame. The reduction rate of the liftoff velocity with co-airflow was found to be more significant for the fuel nozzle with the smaller lip thickness. At a relatively higher coflow (Uco &gt; ∼0.3 m/s), a more pronounced drop in the liftoff velocity with coflow was observed. Flow field characteristics obtained using PIV measurements showed that the coflow stream experienced a transition to the turbulent regime for Uco &gt; ∼0.3 m/s range which is believed to cause the inception of the flame liftoff to occur. A model for predicting the liftoff velocity of an attached flame in the presence of a coflow was developed based on the stoichiometric mixture velocity equation. This model showed good agreement with the present experimental data. However, although it can predict successfully the observed trends in the literature, further experiments are required to generalize it.
Quantifying and Qualifying Alloys Based on Level of Homogenization: A U-10Mo Alloy Case Study
Authors: Wang Chao , Xu Zhijie , Fagan Deborah , Field David P. , Lavender Curt , Joshi Vineet V. 
Published: September 2019

Abstract
Homogenization heat treatment is performed to attain uniformity in microstructure which is helpful to achieve the desired workability and microstructure in final products and, eventually, to gain predictive and consistent performance. Fabrication of low-enriched uranium alloys with 10 wt% molybdenum (U-10Mo) fuel plates involves multiple thermomechanical processing steps. It is well known that the molybdenum homogeneity in the final formed product affects the performance in the nuclear reactor. To ensure uniform homogenization, a statistical method is proposed to quantify and characterize the molybdenum concentration variation in U-10Mo fuel plates by analyzing the molybdenum concentration measurement data from scanning electron microscopy energy dispersive spectroscopy line-scan. Statistical tolerance intervals (TI) are employed to determine the qualification of the U-10Mo fuel plate. We formulate an argument for the minimum number of independent samples to define fuel plate qualification if no molybdenum measurement data are available in advance and demonstrate that the given TI requirements can be equivalently reduced to a sample variance criterion in this application. The outcome of the statistical analysis can be used to optimize casting design and eventually increase productivity and reduce fabrication costs. The statistical strategy developed in this paper can be implemented for other applications especially in the field of material manufacturing to assess qualification requirements and monitor and improve the process design.
Frictional Characteristics and Electrical Conductivity of Electrical Sliding Contacts With Circular Grooved Porous Disk Under Lubricated Conditions
Authors: Kaneko Satoru , Taura Hiroo , Taira Masahiro , Luu Van Manh 
Published: September 2019

Abstract
In this study, porous materials were applied to the surface materials of electrical sliding contacts to produce long and stable operations. The proposed sliding contacts consist of a rotating circular grooved porous disk and a stationary rider having a spherical surface. We conducted the experimental analysis from two perspectives. The first perspective was to inspect the effect of the design parameters on the electrical conductivity and the frictional characteristics; this was done by performing tests under various loads applied on the sliding contacts. The second perspective was to investigate the durability and stability of the sliding contacts by using the tests for a long operating time under a constant applied load. Our experimental results proved that the porous disk generated a lower and a more stable contact voltage and frictional force than the conventional nonporous solid disk. This effect is significant when a large curvature radius of grooves is provided on the disk surface. These results are attributable to the reduction of the hydrodynamic fluid force by the porous material and the grooves; the porous material yields lower hydrodynamic pressure due to the seepage of the lubricant oil across the interface between the oil film and the porous matrix and the grooves enhance the reduction of the hydrodynamic effect because of oil leakage to the downstream region. These factors reduce the oil film thickness between the disk and rider and facilitate the metal contact, and thereby a porous grooved disk generates higher electrical conductivity than a conventional solid disk.
Thermal Expansion Induced Neutrality of a Circular and an Annular Elastic Inhomogeneity
Authors: Song K. , Song H. P. , Schiavone P. , Gao C. F. 
Published: September 2019

Abstract
An elastic inhomogeneity is termed neutral if its introduction does not disturb the original stress field in the initially uncut elastic body. Neutrality in this sense is often achieved by appropriate design criteria such as a careful choice of the shape of the inhomogeneity and the properties of the interfacial layer between the inhomogeneity and its surrounding matrix. Unfortunately, mismatched stress and strain fields in the resulting composite structure make it difficult to simultaneously control both the shape of the inhomogeneity and its interfacial properties to achieve the desired neutrality property. We assert that the associated temperature field can be used to adjust the stress and strain fields within the inhomogeneity via thermal expansion, thus allowing us to control the properties of the interfacial layer for a given shape of inhomogeneity. Our theoretical results show that the design of a neutral circular or annular elastic inhomogeneity requires an accompanying internal uniform temperature field when the elastic body is in equi-biaxial tension and an internal temperature field which is quadratic if the body is subjected to uniaxial tension or shear force. More importantly, in contrast to the well-established result in the literature for a purely elastic inhomogeneity, under certain conditions, a neutral elastic inhomogeneity can be designed via thermal expansion despite the assumption of a perfectly bonded interface between the inhomogeneity and the surrounding matrix.