bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of microbially influenced corrosion on carbon steel in a simulated water injection system
Authors: Zhong Huiyun , Shi Zhiming , Jiang Guangming , Song Yarong , Yuan Zhiguo 
Published: April 2019

AbstractMicrobially influenced corrosion (MIC) on internal pipeline surfaces has become a severe problem during the water injection process in secondary oil recovery. The formation of a biofilm, normally dominated by sulfate‐reducing bacteria (SRB), is believed to be the critical step of the MIC process. A continuously fed biofilm simulating the water injection process was operated to investigate the influence of biofilm development on MIC behavior in the early phase of corrosion development. The development of the corrosion product film and biofilm was monitored for 5 months with electrochemical impedance spectroscopy, linear polarization resistance, scanning electron microscopy, 3D optical profiling, and direct weight measurement. MIC development was found to comprise three phases: initialization, transition, and stabilization. The initialization phase involved the formation of the corrosion product layer and the initial attachment of the sessile microbes on metal surface. In the transition phase, the MIC process gradually shifted from charge‐transfer‐controlled reaction to diffusion‐controlled reaction. The stabilization phase featured mature and compact biofilm on the metal surface, and the general corrosion rate (CR) decreased due to the diffusional effect, while the pitting CR was enhanced at a lower carbon source level, which supported the mechanism of direct electron uptake from the metal surface by SRB.
Characterization of corrosion morphologies from deteriorated underground cast iron water pipes
Authors: Deo Ravin N. , Rathnayaka Suranji , Zhang Chunshun , Fu Guoyang Y. , Shannon Benjamin , Wong Leslie , Kodikara Jayantha K. 
Published: April 2019

AbstractFollowing the completion of the Advanced Condition Assessment and Pipe Failure Prediction project in Australia, it has emerged that cast iron pipes normally experience corrosion damages extending over the large spatial area that resemble a patch, and structural failures are commonly associated with these patches. In this study, we defined a corrosion patch as a cluster of individual defects within or less than the one‐wall‐thickness distance of each other and conducted a morphometric study on patches from several deteriorated cast iron pipes. It was found that the size parameters, viz., the patch length, width, area, and volume potentially attain steady‐state progression over long‐term deterioration and are consistent with current understanding in underground corrosion. The rectangularity, convex deficiency, and solidity shape parameters were found to be related to each other and could be described by power‐law functions. Moreover, the analysis of two‐dimensional (D2D) and three dimensional (D3D) fractal dimension parameters revealed that they serve as useful proxies for different patch properties. In particular, the D3D revealed linear trends with the patch aspect ratio and an ability to delineate between failed and in‐service pipes. It is expected that the results from this study will serve as important baseline information for future works aiming to generate and implement realistic corrosion patches for pipe structural integrity analysis.
Impact of Plasticizer Addition on Molecular Properties of Polybutadiene Rubber and its Manifestations to Glass Transition Temperature
Authors: Sharma Pragati , Roy Sudip , Karimi‐Varzaneh Hossein Ali 
Published: April 2019

AbstractEffect of blending low and high Tg polymer on the structural, spatial, and temporal properties of the polybutadiene rubber are investigated using molecular dynamics simulations. It is elucidated that smaller chain length counterpart of polybutadiene (5mer‐OB) acts as plasticizer for the polybutadiene rubber matrix (32mer‐PB). Observed flexibility at macroscopic level by plasticizer addition is corroborated at the molecular level in the form of lower conformational rigidity and faster diffusion of polybutadiene chains in the mixtures. It is inferred that plasticizers decreases Tg of the matrix, due to cooperative influence of decreased chain packing and rigidity. Opposite effect is observed in mixtures with high Tg polymer, polystyrene. Tg of the mixtures showed substantial dependence on the type, concentration, chain length as well as miscibility of plasticizers in the matrix. However, the effect of increasing chain length is more pronounced but counter‐controlled by the spatially heterogeneous distribution of the plasticizer. Clustering of polystyrene chains induced significant dynamic heterogeneity in the homogeneous polybutadiene matrix, which apparently lead to reduced plasticization effect. Addition of plasticizers in rubber induce discernible changes in the structural and dynamic properties of the rubber matrix, which manifest as the variation in glass transition and explains the real‐life activity of plasticizers.
Fibroblasts Impact Goblet Cell Responses to Lactic Acid Bacteria After Exposure to Inflammatory Cytokines and Mucus Disruptors
Authors: Ren Chengcheng , Dokter‐Fokkens Jelleke , Figueroa Lozano Susana , Zhang Qiuxiang , de Haan Bart J. , Zhang Hao , Faas Marijke M. , de Vos Paul 
Published: April 2019

ScopeMucus produced by goblet cells contributes to gut barrier function. Lactic acid bacteria (LAB) have been shown to impact mucus production. It is not completely known whether mucus production is influenced by the abundantly present fibroblasts in the intestine.Methods and resultsThe influence of fibroblasts on mucus‐related genes including mucin‐2 (MUC2), trefoil factor 3 (TFF3), resistin‐like molecule β (RETNLB), carbohydrate sulfotransferase 5 (CHST5), and galactose‐3‐O‐sulfotransferase 2 (GAL3ST2) is examined after co‐culture of LS174T‐goblet cells and CCD‐18Co colonic fibroblasts in the presence and absence of LAB‐strains known to impact mucus function. This is also tested after exposure to TNF‐α, IL‐13, or the mucin synthesis inhibitor tunicamycin (Tm). Effects of fibroblasts are treatment duration‐ and bacterial species‐dependent under homeostatic conditions. During TNF‐α challenge, fibroblasts reverse Lactobacillus (L.) rhamnosus CCFM237‐elicited declined TFF3 expression. After IL‐13 exposure, L. rhamnosus CCFM237 and L. fermentum CCFM787 attenuate enhanced TFF3 and RETNLB expression, respectively, only in the presence of fibroblasts. LAB has no effects on Tm‐induced decreased expression of goblet cell‐related genes regardless of the presence of fibroblasts.ConclusionIt is demonstrated that goblet cell–fibroblast crosstalk impacts mucus synthesis and influences the effects of LAB on goblet cell‐related genes. Effects are LAB‐species and stressor dependent.
Numerical modeling of adiabatic heat generation during rock fracture under dynamic loading
Authors: Saksala Timo 
Published: April 2019

SummaryThis paper considers adiabatic heat generation during rock fracture under dynamic loading. To this end, a thermo‐viscoplastic constitutive model for rock based on Mohr‐Coulomb and Rankine criteria augmented with the adiabatic heat equation is developed. Young's modulus and the compressive and tensile strengths are taken as the temperature‐dependent parameters. A numerical solution algorithm based on the Newton‐Raphson iteration and the cutting plane algorithm at the material point level is presented. Furthermore, there is a description of an explicit staggered scheme for solving the heat conduction at the specimen level in rock material. Then, the model is applied in 2D and 3D numerical simulations of compression and tension tests on a rock‐like material with compressive and tensile strengths of 120 and 10 MPa, respectively. The simulations predict that the temperature rise because of adiabatic heat generation during rock fracture is in the order of a few degrees centigrade, even at a strain rate of 100 s−1. In conclusion, the effect of including heat conduction is shown to be insignificant because of the short duration of dynamic loading processes.
Dietary heat‐killed Lactobacillus brevis SBC8803 (SBL88™) improves hippocampus‐dependent memory performance and adult hippocampal neurogenesis
Authors: Ishikawa Rie , Fukushima Hotaka , Nakakita Yasukazu , Kado Hisao , Kida Satoshi 
Published: April 2019

AbstractAimsLactobacillus species are used widely as various food and supplements to improve health. Previous studies have shown that heat‐killed Lactobacillus brevis SBC8803 induces serotonin release from intestinal cells and affects sleep rhythm and the autonomic nervous system. However, the effect of SBC8803 on cognitive function remains unknown. Here, we examined the effects of dietary heat‐killed SBC8803 on hippocampus‐dependent memory and adult hippocampal neurogenesis.MethodsHippocampus‐dependent memory performance was assessed in mice fed heat‐killed SBC8803 using social recognition and contextual fear conditioning tasks. Adult hippocampal neurogenesis was evaluated before, during, and after feeding heat‐killed SBC8803 by measuring the number of 5‐bromo‐2‐deoxyuridine (BrdU)‐positive cells following systemic injections of BrdU using immunohistochemistry.ResultsMice fed a heat‐killed SBC8803 diet showed an improvement of hippocampus‐dependent social recognition and contextual fear memories and enhanced adult hippocampal neurogenesis by increasing the survival, but not proliferation, of newborn neurons.ConclusionDietary heat‐killed SBC8803 functions as memory and neurogenesis enhancers.
Stochastic model predictive control for tracking linear systems
Authors: D' Jorge Agustina , Santoro Bruno F. , Anderson Alejandro , González Alejandro H. , Ferramosca Antonio 
Published: April 2019

SummaryThis note presents a stochastic formulation of the model predictive control for tracking (MPCT), based on the results of the work of Lorenzen et al. The proposed controller ensures constraints satisfaction in probability, and maintains the main features of the MPCT, that are feasibility for any changing setpoints and enlarged domain of attraction, even larger than the one delivered by Lorenzen et al, thanks to the use of artificial references and relaxed terminal constraints. The asymptotic stability (in probability) of the minimal robust positively invariant set centered on the desired setpoint is guaranteed. Simulations on a DC‐DC converter show the benefits and the properties of the proposal.
Enrichment and distribution of counterions in spherical polyelectrolyte brushes probed by SAXS
Authors: Ye Zhishuang , Li Li , Zhao Fang , Tian Yuchuan , Wang Yunwei , Yang Qingsong , Dai Liheng , Guo Xuhong 
Published: April 2019

ABSTRACTThe spatial correlation of counterions [Li+, Na+, Rb+, Cs+, NH4+, (CH3)4N+] with spherical polyelectrolyte brushes (SPBs), which consist of a PS core and chemically grafted PSS chains, was comprehensively studied through a combination of SAXS, DLS, and Zeta potential. Results show that the SAXS intensity profiles of the brush appears to be “insensitive” to the concentration of Na+. By contrast, introducing salt ions with a density lower than sodium [NH4+, (CH3)4N+ and Li+] into the brush layer will cause a decrease in the scattering intensity while introducing those with a higher density than sodium (Rb+ and Cs+) will cause the opposite result. As verified by the combined results of SAXS, DLS, and Zeta potential, the collapse of the brush and the enrichment of the counterions in the brush layer occur simultaneously. It was further demonstrated that the concentration of counterions enriched in the innermost layer of the brush shell can be enhanced up to hundreds of times compared with the bulk concentration, and the counterion distribution in SPB shell follows a radial attenuation distribution. SAXS is confirmed to be powerful in probing the enrichment and distribution of counterions within SPB. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 738–747
Less direct patient care delivered by medical trainees by the end of a hematology‐oncology ward rotation: Association with empathy and related factors
Authors: McFarland Daniel C. 
Published: April 2019

AbstractObjectiveThe education of trainee physicians in hematology‐oncology is challenged by inherent stressors of hematology‐oncology. Clinical work load, death and dying, and the known phenomenon of empathy decline during clinical education affect trainees. Time spent with patients or direct patient care time (DPCT) is influenced by many factors, which ultimately affect medical education. Therefore, DPCT may decrease by the end training on a busy hematology‐oncology ward rotation.MethodsInternal medicine interns and residents (n = 64) rotating on a hematology‐oncology ward rotation were consecutively selected to participate. Questionnaires containing Likert scale questions assessing time spent with patients before and after the rotation, empathy/resilience/distress measurements (Interpersonal Reactivity Index [IRI], Connors‐Davidson Resilience Scale [CD‐RISC], and Impact of Events Scale‐Revised [IES‐R], respectively), and demographic and situational information were collected at the beginning and end of the rotationResultsDPCT decreased from over 10 to 15 minutes per patient to slightly over 1 to 5 minutes with over half of the trainees spending less than 1 minute per patient per day (P < .001, Cohen's d = 1.05). Empathy scores decreased 2.01 points from 58.9 to 56.8 (P = .018, Cohen's d = 0.33) during the rotation. DPCT decrease was associated mistreatment (P < .001) and lack of support (P = .001) while endorsing external issues (P = .002) and longer rotation time predicted for greater DPCT accounting for 67% of DPCT variance on multivariate analysis.ConclusionMedical trainees in oncology who feel a lack of social/familial support and feel mistreated by mentors/superiors spend significantly less time with patients. Educational initiatives should replicate and utilize these associations to enhance patient‐centric care in oncology.
Atmospheric pressure air plasma treatment to improve the 3D printing of polyoxymethylene
Authors: Muro‐Fraguas Ignacio , Sainz‐García Elisa , Pernía‐Espinoza Alpha , Alba‐Elías Fernando 
Published: April 2019

AbstractPolyoxymethylene (POM), an excellent engineering material, shows drawbacks as a three‐dimensional (3D) printing material: (a) difficulties in the adhesion of the first‐printed layer and (b) thermal contractions during printing. In this study, an atmospheric pressure air plasma treatment is applied on a polycarbonate (PC)‐printing base. The effect of the plasma treatment parameters is studied. Chemical and morphological tests are conducted. Results shows that, in general, as the plasma exposure rises, so does the degree of oxidation of the PC surface and the adhesion of POM. However, care must be taken as thermal residual stresses may reduce adhesion. Finally, an increase in adhesion of up to 45% is achieved.
Phytobiome metabolism: beneficial soil microbes steer crop plants' secondary metabolism
Authors: Korenblum Elisa , Aharoni Asaph 
Published: April 2019

AbstractCrops are negatively affected by abiotic and biotic stresses, however, plant‐microbe cooperation allows prompt buffering of these environmental changes. Microorganisms exhibit an extensive metabolic capability to assist plants in reducing these burdens. Interestingly, beneficial microbes may also trigger, at the host side, a sequence of events from signal perception to metabolic responses leading to stress tolerance or protection against biotic threats. Although plants are well known for their vast chemical diversity, plant‐microbial interactions often stimulate the production of a rich and different repertoire of metabolites in plants. The targeted microbial‐plant interactions reprogramming plant metabolism represent potential means to foster various pest managements. However, the molecular mechanisms of microbial modulation of plant metabolic plasticity are still poorly understood. Here, we review an increasing amount of reports providing evidence for alterations to plant metabolism caused by beneficial microbial colonization. In addition, we highlight the vital importance of these metabolic reprograms for plants under stress erratic conditions. © 2019 Society of Chemical Industry
Fully numerical Hartree‐Fock and density functional calculations. II. Diatomic molecules
Authors: Lehtola Susi 
Published: April 2019

AbstractWe present the implementation of a variational finite element solver in the HelFEM program for benchmark calculations on diatomic systems. A basis set of the form is used, where (μ, ν, φ) are transformed prolate spheroidal coordinates,
B
n(μ) are finite element shape functions, and are spherical harmonics. The basis set allows for an arbitrary level of accuracy in calculations on diatomic molecules, which can be performed at present with either nonrelativistic Hartree‐Fock (HF) or density functional (DF) theory. Hundreds of DFs at the local spin density approximation (LDA), generalized gradient approximation (GGA), and the meta‐GGA level can be used through an interface with the Libxc library; meta‐GGA and hybrid DFs are not available in other fully numerical diatomic program packages. Finite electric fields are also supported in HelFEM, enabling access to electric properties. We introduce a powerful tool for adaptively choosing the basis set by using the core Hamiltonian as a proxy for its completeness. HelFEM and the novel basis set procedure are demonstrated by reproducing the restricted open‐shell HF limit energies of 68 diatomic molecules from the first to the fourth period with excellent agreement with literature values, despite requiring orders of magnitude fewer parameters for the wave function. Then, the electric properties of the BH and N2 molecules under finite field are studied, again yielding excellent agreement with previous HF limit values for energies, dipole moments, and dipole polarizabilities, again with much more compact wave functions than what were needed for the literature references. Finally, HF, LDA, GGA, and meta‐GGA calculations of the atomization energy of N2 are performed, demonstrating the superb accuracy of the present approach.
Fully numerical Hartree‐Fock and density functional calculations. I. Atoms
Authors: Lehtola Susi 
Published: April 2019

AbstractAlthough many programs have been published for fully numerical Hartree‐Fock (HF) or density functional (DF) calculations on atoms, we are not aware of any programs that support hybrid DFs, which are popular within the quantum chemistry community due to their better accuracy for many applications, or that can be used to calculate electric properties. Here, we present a variational atomic finite element solver in theHelFEMprogram suite that overcomes these limitations. A basis set of the typeis used, whereBn(r)are finite element shape functions andare spherical harmonics, which allows for an arbitrary level of accuracy.HelFEMsupports nonrelativistic HF and DF calculations even with hybrid functionals, which are not available in other commonly available program packages. Hundreds of functionals at the local spin‐density approximation (LDA), generalized‐gradient approximation (GGA), as well as the meta‐GGA levels of theory are included through an interface with theLibxclibrary. Electric response properties are achievable via finite field calculations. We introduce an alternative grid that yields faster convergence to the complete basis set limit than commonly used alternatives. We also show that high‐order Lagrange interpolating polynomials yield the best convergence, and that excellent agreement with literature HF limit values for electric properties, such as static dipole polarizabilities, can be achieved with the present approach. Dipole moments and dipole polarizabilities at finite field are also reported with the PBE, PBEh, TPSS, and TPSSh functionals. Finally, we show that a recently published Gaussian basis set is able to reproduce absolute HF and DF energies of neutral atoms, cations, as well as anions within a few dozen microhartrees.
Storm effects on nitrogen flux and longitudinal variability in a river–reservoir system
Authors: Keys Tyler A. , Caudill Madeline F. , Scott Durelle T. 
Published: April 2019

AbstractSustainable management of the nitrogen (N) cycle remains a considerable global challenge that has major implications for aquatic ecosystems. Dams play a critical yet often neglected role in addressing this challenge as they increase hydraulic residence time and denitrification potential. However, during storm events when the majority of N loading occurs, less is known about the effects dams have on N fate and transport processes. Here, we examined the flux of N species and phosphorus (P) and longitudinal profiles of nitrate (NO3−) along a sixth‐order river–reservoir system at baseflow and across the falling limb of a multiday, 1‐year storm hydrograph. During the storm event, the reservoir reduced total NO3− flux by 19.1% and P flux by 12.7%. On the contrary, ammonium (NH4+) fluxes were 200% higher downstream of the dam in comparison with fluxes into the reservoir, indicating that there was a substantial net export of NH4+ from the reservoir during the storm event. Longitudinally along the river to reservoir transition, a breakpoint of statistical significance was identified, highlighting the sharp contrast between NO3− concentrations within the river and reservoir. Results suggest that frequent storm events such as the one presented here can greatly alter N removal processes in river–reservoir systems. Overall, this study highlights the need to better understand the role that storm events play in river–reservoir N cycling dynamics.
Indene‐Based Donor‐Acceptor Type Small Molecular Semiconductors for High‐Performance n‐Channel Transistors
Authors: Wei Qibing , Wang Jinlong , Wu Hongzhuo , Qiao Xiaolan , Zhao Baoguo , Li Hongxiang 
Published: April 2019

AbstractIt is a great challenge to design n‐channel donor‐acceptor (D−A) type small molecules because of the lack of strong electron withdrawing acceptor unit. Herein, 3‐(dicyanomethylidene)‐indan‐1‐one (IC) and 1,3‐bis(dicyanomethylidene)‐indene (IDC) based D−A type small molecular organic semiconductors IC–DDTPTI and IDC‐DDTPTI are synthesized and characterized. Both compounds have low‐lying LUMO energy levels, especially for IDC‐DDTPTI with LUMO energy level lower than −4.0 eV. Thin film transistor characteristics show IC–DDTPTI displays ambipolar transistor behavior with balanced hole and electron mobility. The electron mobility is 0.40 cm2 V−1 s−1 and the hole mobility reaches 0.18 cm2 V−1 s−1. IDC‐DDTPTI exhibits unipolar n‐channel character with an electron mobility of 0.027 cm2 V−1 s−1. These results highlight the applications of IC and IDC units in high performance D−A type n‐channel organic semiconductors.