bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/fibrinogen/bredigite nanofibrous membranes and their integration with osteoblasts for guided bone regeneration
Authors: Kouhi Monireh , Jayarama Reddy Venugopal , Fathi Mohammadhossein , Shamanian Morteza , Valipouri Afsaneh , Ramakrishna Seeram
Published: January 2019

Guided bone regeneration (GBR) has been established to be an effective method for the repair of defective tissues, which is based on isolating bone defects with a barrier membrane for faster tissue reconstruction. The aim of the present study is to develop poly (hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV)/fibrinogen (FG)/bredigite (BR) membranes with applicability in GBR. BR nanoparticles were synthesized through a sol–gel method and characterized using transmission electron microscopy and X‐ray diffractometer. PHBV, PHBV/FG, and PHBV/FG/BR membranes were fabricated using electrospinning and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle, pore size, thermogravimetric analysis and tensile strength. The electrospun PHBV, PHBV/FG, and PHBV/FG/BR nanofibers were successfully obtained with the mean diameter ranging 240–410 nm. The results showed that Young's modulus and ultimate strength of the PHBV membrane reduced upon blending with FG and increased by further incorporation of BR nanoparticles, Moreover hydrophilicity of the PHBV membrane improved on addition of FG and BR. The in vitro degradation assay demonstrated that incorporation of FG and BR into PHBV matrix increased its hydrolytic degradation. Cell‐membrane interactions were studied by culturing human fetal osteoblast cells on the fabricated membrane. According to the obtained results, osteoblasts seeded on PHBV/FG/BR displayed higher cell adhesion and proliferation compared to PHBV and PHBV/FG membrane. Furthermore, alkaline phosphatase activity and alizarin red‐s staining indicated enhanced osteogenic differentiation and mineralization of cells on PHBV/FG/BR membranes. The results demonstrated that developed electrospun PHBV/FG/BR nanofibrous mats have desired potential as a barrier membrane for guided bone tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1154–1165, 2019.
HOX transcript antisense RNA is elevated in gastric carcinogenesis and regulated by the NF‐κB pathway
Authors: Zhang Zhun , Fan Bingbing , Liu Fengyan , Song Ning , Peng Yanping , Ma Wenzheng , Ma Rongtao , Dong Tianyi , Liu Shili
Published: January 2019

The expression pattern of HOX transcript antisense RNA (HOTAIR) in the progression of gastric cancer and the regulation of its expression are still unclear. In the current study, HOTAIR expressions in gastric tissues collected from patients with superficial gastritis, atrophic gastritis, atypical hyperplasia, and gastric cancer as well as normal controls was quantitatively examined. The results showed that the expression of HOTAIR was higher in gastric cancer than in normal tissues, but reached the highest level in atrophic gastritis, suggesting that HOTAIR may be involved in the molecular process of nonresolving inflammation. Then tumor necrosis factor‐α‐induced protein‐8 like‐2 (TIPE2), a known gene associated with nonresolving inflammation, was overexpressed and the results showed that the promotion in TIPE2 expression triggered HOTAIR reduction, this result was further verified by microarray analysis and TIPE2 knockout mice. Subsequently, the data obtained from HOTAIR knockdown experiment showed that it significantly enhanced colony forming capability and inhibited p27 expression in AGS cells. Furthermore, deletion constructs and luciferase‐based activity assays indicated that the −475 to −443bp region of HOTAIR promoter contained a crucial regulatory element. Transcription factor prediction with software TRANSFAC revealed that nuclear factor‐κB signaling protein p65 had a binding site in this region and might have roles in HOTAIR expression. The binding of phosphor‐p65 to HOTAIR promoter was verified by chromatin immunoprecipitation, and succeeding experiment results demonstrated that p65 reduction by p65 small interfering RNA and TIPE2 overexpression also decreased HOTAIR expression. Conclusively, our results suggest that HOTAIR was associated with nonresolving inflammation, and its expression is regulated by p65.
Effectiveness of different irrigation systems in the presence of intracanal‐separated file
Authors: Seven Naimenur , Cora Sabri
Published: January 2019

The aim of this study was to evaluate conventional syringe irrigation and three different irrigant activation techniques' effectiveness for smear layer removal in the absence and presence of intracanal‐separated file (SF) fragment. Mandibular anterior teeth (160 total) with single canal were used and each root canal preparation was finished with the ProTaper Universal F1. The samples were randomly divided into eight equal groups with n = 20 in each group. The Protaper Universal F3 file was used to simulate intracanal file separation in four groups. To remove the smear layer, final irrigation for each group was performed with conventional syringe irrigation (CSI), EndoActivator, Vibringe, and passive ultrasonic irrigation (PUI). The roots were divided into two longitudinal parts and evaluated with scanning electron microscopy, and two observers scored smear layers at 1, 2, and 3 mm away from the minor foramen. The data were analyzed using the Kruskal–Wallis and Mann–Whitney U tests (p < .05). PUI significantly removed the smear layer better at all levels than other nonseparated file groups (p < .05). In the presence of intracanal SF, PUI had the most efficiency loss. Sonic techniques and CSI revealed statistically better smear layer removal efficiency than PUI at 3 mm level in the presence of SF (p < .05). The intragroup score analysis at all levels revealed that there were less smear layers at 3 mm than at 1 mm in all SF groups (p < .001). As a conclusion, sonic/ultrasonic methods did not yield better irrigant by‐passing than CSI in the presence of intracanal SF.
Differentiation between glioblastoma, brain metastasis and subtypes using radiomics analysis
Authors: Artzi Moran , Bressler Idan , Ben Bashat Dafna
Published: January 2019

Background

Differentiation between glioblastoma and brain metastasis is highly important due to differing medical treatment strategies. While MRI is the modality of choice for the assessment of patients with brain tumors, differentiation between glioblastoma and solitary brain metastasis may be challenging due to their similar appearance on MRI.

Purpose

To differentiate between glioblastoma and brain metastasis subtypes using radiomics analysis based on conventional post‐contrast T1‐weighted (T1W) MRI.

Study Type

Retrospective.

Subjects

Data were acquired from 439 patients: 212 patients with glioblastoma and 227 patients with brain metastasis (breast, lung, and others).

Field Strength/Sequence

Post‐contrast 3D T1W gradient echo images, acquired with 1.5 and 3.0 T MR systems.

Assessment

Analysis included image preprocessing, segmentation of tumor area, and features extraction including: patients' clinical information, tumor location, first‐ and second‐order statistical, morphological, wavelet features, and bag‐of‐features. Following dimension reduction, classification was performed using various machine‐learning algorithms including support‐vector machine (SVM), k‐nearest neighbor, decision trees, and ensemble classifiers.

Statistical Tests

For classification, the data were divided into training (80%) and testing datasets (20%). Following optimization of the classifiers, mean sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were calculated.

Results

For the testing dataset, the best results for differentiation of glioblastoma from brain metastasis were obtained using the SVM classifier with mean accuracy = 0.85, sensitivity = 0.86, specificity = 0.85, and AUC = 0.96. The best classification results between glioblastoma and brain metastasis subtypes were obtained using SVM classifier with mean accuracy = 0.85, 0.89, 0.75, 0.90; sensitivity = 1.00, 0.60, 0.57, 0.11; specificity = 0.76, 0.92, 0.87, 0.99; and AUC = 0.98, 0.81, 0.83, 0.57 for the glioblastoma, breast, lung, and other brain metastases, respectively.

Data Conclusion

Differentiation between glioblastoma and brain metastasis showed a high success rate based on postcontrast T1W MRI. Classification between glioblastoma and brain metastasis subtypes may require additional MR sequences with other tissue contrasts.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2019;50:519–528.
Are BRCA1 and BRCA2 gene mutation patients underscreened for pancreatic adenocarcinoma?
Authors: Roch Alexandra M. , Schneider Justine , Carr Rosalie A. , Lancaster William P. , House Michael G. , Zyromski Nicholas J. , Nakeeb Attila , Schmidt C. Max , Ceppa Eugene P.
Published: January 2019

Background

Breast cancer (BRCA) mutations account for the highest proportion of hereditary causes of pancreatic ductal adenocarcinoma (PDAC). Screening is currently recommended only for patients with one first‐degree relative or two family members with PDAC. We hypothesized that screening all BRCA1/2 patients would identify a higher rate of pancreatic abnormalities.

Methods

All BRCA1/2 patients at a single academic center were retrospectively reviewed (2005‐2015). Pancreatic abnormalities were defined on cross‐sectional imaging as pancreatic neoplasm (cystic/solid) or main‐duct dilation.

Results

Two hundred and four patients were identified with BRCA mutations. Forty‐seven (40%) had abdominal imaging (20 computerized tomography and 27 magnetic resonance imaging). Twenty‐one percent had pancreatic abnormalities (PDAC [n = 2] and intraductal papillary mucinous neoplasm [IPMN; n = 8]). The prevalence of pancreatic abnormalities and IPMN was higher in BRCA2 patients than in the general population (21% vs 8% and 17% vs 1%; P = 0.0007 and P < 0.0001, respectively), with no influence of family history. Similarly, BRCA1 patients had an increased prevalence of IPMN (8.3% vs 1%; P < 0.0001).

Conclusions

In this series, 4% and 17% of BRCA2 patients developed PDAC and IPMN, respectively. Eight percent of BRCA1 patients developed IPMN. Under current recommended screening, 60% of BRCA1/2 patients had incompletely pancreatic assessment. With no influence of family history, this study suggests all BRCA1/2 patients should undergo a high‐risk screening protocol that will identify a higher rate of precancerous pancreatic neoplasms amenable to curative resection.
Kinetics of Ag300 nanoclusters formation: The catalytically effective nucleus via a steady‐state approach
Authors: Kytsya Andriy , Bazylyak Liliya , Simon Paul , Zelenina Iryna , Antonyshyn Iryna
Published: January 2019

The kinetics of formation of silver nanoparticles consisting of nearly 300 metal atoms is investigated, which were prepared by reduction of silver nitrate with hydrazine in ethylene glycol at 25°C without any stabilizer other than the glycol solvent. The resulting sigmoidal kinetic curves are analyzed by using the 1997 Finke–Watzky two‐step mechanism of slow continuous nucleation with subsequent fast autocatalytic surface growth. The kinetics of homogeneous nucleation of metal nanoparticles was analyzed using the assumption about the stepwise adjunction of precursor and the quasi steady‐state approximation. The equations were proposed to calculate the concentration of the formed metal nanoparticles and their mean size from the experimentally determined values of the Finke–Watzky rate constants. It is shown that a stepwise nucleation process can be described in the terms of the catalytically effective nucleus concept and that the number of atoms in the catalytically effective nucleus can be estimated.
Enhancing soil physical quality and cotton yields through diversification of agricultural practices in central Brazil
Authors: Anghinoni Guilherme , Tormena Cássio Antonio , Lal Rattan , Zancanaro Leandro , Kappes Claudinei
Published: January 2019

Brazil plays an important role in the global agricultural production, making Brazilian productive land use and management a critical issue. This study tested the hypothesis that soil physical quality (SPQ) of the Cerrado biome in central Brazil depends on appropriate crop rotation and tillage practices in cotton (Gossypium hyrsutum [L.])‐based cropping systems and is critical to achieve optimal cotton yields (COT). SPQ of an Oxisol was accessed for layers of 0.0–0.1, 0.1–0.2, and 0.2–0.4 m under conventional tillage (CT) and no‐tillage (NT) systems, in different farming systems, such as cotton monoculture, crop succession, and crop rotation in central Brazil. Variables studied were soil bulk density, total porosity, air permeability, pore continuity index, water content at field capacity, relative saturation at field capacity, the least limiting water range (LLWR), and COT. Soil sampling was performed in 2014, and COT was obtained in the 2013 and 2014 cropping seasons. Conservationist practices, such as crop diversity and absence of soil tillage, improved water availability, enlarged the LLWR, and indicated that brachiaria cultivation positively influences the SPQ, whereas continuous soil tillage and less crop diversity adversely affected SPQ. COT was positively influenced by SPQ aspects regarding the increased water access in the 0.2–0.4 m layer of NT and in the 0.0–0.1 m of CT management. Differences in SPQ, as indicated by the LLWR, were reflected in differences in COT, as well as in soil air permeability in the CT treatments for the 2014 cropping season. Other SPQ variables had no relation to COT.
An experimental study on the physical and mechanical properties of B4C/PI/AA6061 hybrid composites with various concentrations
Authors: Fu Xuelong , Ji Zhengbo , Lin Wei , Liu Wei , Lin Yuebin , Zhou Zhongwang
Published: January 2019

The effects of boron carbide (B4C) concentrations on the physical properties and interfacial adhesion of hybrid composites were systematically investigated. B4C/polyimide (PI) resin blends were composed of PI resin and B4C particles at weight ratios of 90:10, 80:20, 70:30, 60:40, and 50:50. The effects of alkoxysilane coupling agent KH550 on the chemical structures of B4C particles were performed using Fourier transform infrared Spectroscopy. The testing results illustrated that, the addition of alkoxysilane coupling agent was conducive to improve the interfacial adhesion between PI resin and B4C particles, while the peak at 2,932.12 cm−1 was emerged which corresponded to the C‐H anti‐symmetric stretching vibration peak of ‐CH2 group. Single‐lap‐shear strength of the specimens was firstly increased and then decreased with the increasing of B4C content, while the maximum value appeared at 30 wt% of B4C particles. Lap‐shear strength of the specimens with precoated primer layer was 12.2 MPa, which was 6.09% higher than that without primer layer. It was also corroborated that physical crosslinking reaction between B4C particles and PI resin was formed, which can effectively prevent the formation of crack and fracture in the adhesive layer under the action of tensile stress. POLYM. COMPOS., 40:3140–3148, 2019. © 2019 Society of Plastics Engineers
Facile Assembly of Polyaniline/Graphene Oxide Composite Hydrogels as Adsorbent for Cr(VI) Removal
Authors: Han Xiao , Liu Yulan , Xiong Lijun , Huang Huabo , Zhang Qiao , Li Liang , Yu Xianghua , Wei Lai
Published: January 2019

A facile method for the assembly of polyaniline/graphene oxide (PANi/GO) composite hydrogel has been successfully demonstrated by in‐situ polymerization of aniline in the presence of phytic acid with the aid of GO. During the polymerization of aniline, the 2D GO nanosheets can regulate the aggregation state of polymer and prompt the formation of the hydrogel. The chemical structure, morphology and mechanical property are investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy and compressive stress–strain measurements, et al. Pani/GO composite hydrogel with high surface area and 3D porous nanostructures exhibits higher adsorption capability for Cr(VI) in compared with PANi hydrogel. Pseudo‐second‐order and Langmuir isotherm models are effectively employed to describe the adsorption behaviors of PANi/GO composite hydrogel. Furthermore, the regeneration experiments indicate that the as‐prepared composite hydrogel can remain 73.5% of the original removal capability after five adsorption–desorption cycles. It is expected that the PANi/GO composite hydrogel can be an effective candidate for the removal of Cr(VI) due to the synergistic effects between PANi and GO within the hydrogel network. POLYM. COMPOS., 40:E1777–E1785, 2019. © 2019 Society of Plastics Engineers
Quantitative analysis of phenolic metabolites in Copaifera langsdorffii leaves from plants of different geographic origins cultivated under the same environmental conditions
Authors: Motta Erick V.S. , Sampaio Bruno L. , Costa Juliana C. , Teixeira Simone P. , Bastos Jairo K.
Published: January 2019

Introduction

Galloylquinic acid derivatives and flavonoids are the main phenolic metabolites found in Copaifera langsdorffii leaves (Leguminosae, Detarioideae), a medicinal plant with potential therapeutic application in the treatment of kidney stones. The factors that affect metabolite production in this plant species are not well understood but may include environmental and genetic factors.

Objective

To quantify the variation in metabolite production over a 12‐month period for 10 groups of C. langsdorffii cultivated under the same environmental conditions.

Methods

Copaifera langsdorffii seeds were collected from 10 different regions in southeast, Brazil and grown in the same field. HPLC‐UV was used to quantify nine galloylquinic acid derivatives and two flavonoids in leaf samples from mature trees. Climate data for humidity, radiation, precipitation and temperature were provided by the National Institute of Meteorology, Brazil. Multivariate analyses were performed to correlate chemical and environmental variables.

Results

The overall effect of environmental factors on the production of phenolic metabolites was uniform among C. langsdorffii groups. Chemical variation between groups was present, but small, and probably due to differences in their genetics and physiology. Seasonal changes influenced the production of the major phenolic metabolites, with increases in temperature and radiation levels favouring metabolite production.

Conclusion

When C. langsdorffii trees are cultivated in the same environment, the production of the major secondary metabolites found in their leaves is very similar quantitatively, varying based on geographic location of original population and seasonal changes. This favours the standardisation of plant raw material for the production of a phytomedicine.
Synthesis and biological activity of analogs of the antifungal antibiotic UK‐2A. II. Impact of modifications to the macrocycle benzyl position
Authors: Owen W John , Meyer Kevin G , Meyer Stacy T , Li Fangzheng , Slanec Thomas J , Wang Nick X , Yao Chenglin
Published: January 2019

BACKGROUND

UK‐2A is an antifungal antibiotic produced by Streptomyces sp. 517‐02. Derivatization of its picolinamide OH to form the isobutyryl acetal led to the discovery of fenpicoxamid (InatreqTM active), which is currently under development as a fungicide by Dow AgroSciences LLC. This paper documents efforts to achieve additional efficacy enhancements through semi‐synthetic modification of the benzyl substituent of the UK‐2A macrocycle.

RESULTS

Of 34 analogs prepared, the most active had mitochondrial electron transport IC50 values 1.5‐ to 3.7‐fold higher than UK‐2A (IC50 0.86 nM). The cyclohexyl analog (38, IC50 1.23 nM) was the most intrinsically active derivative, and inhibited in vitro growth of Zymoseptoria tritici (EC50 2.8 ppb) and Leptosphaeria nodorum (EC50 6.2 ppb) more strongly than UK‐2A (EC50 5.3 and 11.3 ppb for Z. tritici and L. nodorum, respectively). Heterocyclic ring systems and polar linker functionalities resulted in substantial activity loss. Several analogs (20, 22, 23, 24, 36 and 38) translated Z. tritici in vitro growth inhibition activity to in planta disease control more effectively than did UK‐2A, with log D being a key factor in this regard.

CONCLUSIONS

UK‐2A is amenable to further modification at the benzyl position on the macrocycle, which provides opportunities for manipulation of physical properties while retaining strong intrinsic and antifungal activity. © 2019 Society of Chemical Industry
The Methodological Approach of the Long-Term Study
Authors: Paus-Hasebrink Ingrid , Kulterer Jasmin , Sinner Philip
Published: January 2019

This chapter outlines our study’s specific methodological approach as derived from its theoretical foundation. We deal with the questions of collecting, processing and analysing data from a qualitative longitudinal study over 12 years from 2005 to 2017 but also with questions of recruitment and panel maintenance, as well as ethical issues. This chapter, therefore, focuses on the ways in which the methodological design was revised and judiciously complemented, in order to grasp the complexity of the topic. Following the logic of triangulation, we developed and implemented a rich design, where all the components draw on, complement, and monitor each other in the processes of data collection and analysis. This means that we have to discuss the importance of transparency and comprehensibility in terms of intersubjectivity, paying special attention to the qualitative and longitudinal character of the study.
Generalized Gibbs Ensemble of 2d CFTs at large central charge in the thermodynamic limit
Authors: Dymarsky Anatoly , Pavlenko Kirill
Published: January 2019

Abstract

We discuss partition function of 2d CFTs decorated by higher qKdV charges in the thermodynamic limit when the size of the spatial circle goes to infinity. In this limit the saddle point approximation is exact and at infinite central charge generalized partition function can be calculated explicitly. We show that leading 1/c corrections to free energy can be reformulated as a sum over Young tableaux which we calculate for the first two qKdV charges. Next, we compare generalized ensemble with the “eigenstate ensemble” that consists of a single primary state. At infinite central charge the ensembles match at the level of expectation values of local operators for any values of qKdV fugacities. When the central charge is large but finite, for any values of the fugacities the aforementioned ensembles are distinguishable.
Topological strings, strips and quivers
Authors: Panfil Miłosz , Sułkowski Piotr
Published: January 2019

Abstract

We find a direct relation between quiver representation theory and open topological string theory on a class of toric Calabi-Yau manifolds without compact four-cycles, also referred to as strip geometries. We show that various quantities that characterize open topological string theory on these manifolds, such as partition functions, Gromov-Witten invariants, or open BPS invariants, can be expressed in terms of characteristics of the moduli space of representations of the corresponding quiver. This has various deep consequences; in particular, expressing open BPS invariants in terms of motivic Donaldson-Thomas invariants, immediately proves integrality of the former ones. Taking advantage of the relation to quivers we also derive explicit expressions for classical open BPS invariants for an arbitrary strip geometry, which lead to a large set of number theoretic integrality statements. Furthermore, for a specific framing, open topological string partition functions for strip geometries take form of generalizedq-hypergeometric functions, which leads to a novel representation of these functions in terms of quantum dilogarithms and integral invariants. We also study quantum curves and A-polynomials associated to quivers, various limits thereof, and their specializations relevant for strip geometries. The relation between toric manifolds and quivers can be regarded as a generalization of the knots-quivers correspondence to more general Calabi-Yau geometries.
Comprehensive Application of Graphene: Emphasis on Biomedical Concerns
Authors: Syama S. , Mohanan P. V.
Published: January 2019

Graphene, sp2 hybridized carbon framework of one atom thickness, is reputed as the strongest material to date. It has marked its impact in manifold applications including electronics, sensors, composites, and catalysis. Current state-of-the-art graphene research revolves around its biomedical applications. The two-dimensional (2D) planar structure of graphene provides a large surface area for loading drugs/biomolecules and the possibility of conjugating fluorescent dyes for bioimaging. The high near-infrared absorbance makes graphene ideal for photothermal therapy. Henceforth, graphene turns out to be a reliable multifunctional material for use in diagnosis and treatment. It exhibits antibacterial property by directly interacting with the cell membrane. Potential application of graphene as a scaffold for the attachment and proliferation of stem cells and neuronal cells is captivating in a tissue regeneration scenario. Fabrication of 2D graphene into a 3D structure is made possible with the help of 3D printing, a revolutionary technology having promising applications in tissue and organ engineering. However, apart from its advantageous application scope, use of graphene raises toxicity concerns. Several reports have confirmed the potential toxicity of graphene and its derivatives, and the inconsistency may be due to the lack of standardized consensus protocols. The present review focuses on the hidden facts of graphene and its biomedical application, with special emphasis on drug delivery, biosensing, bioimaging, antibacterial, tissue engineering, and 3D printing applications.
The Choice of Norms in Courtroom Adjudication in Vietnam: In Search of Legitimacy in a Socialist Regulatory Context
Authors: TRAN Thi Quang Hong
Published: January 2019

Notwithstanding its defining feature of normative pluralism, the socialist state of Vietnam basically adopts a legal centralist approach to regulation. The judiciary is arguably the most illustrative of this approach, since it is the main forum where legal centralism encounters normative pluralism. Our research examines the choice of norms in judicial adjudication in Vietnam to check the effectiveness of its legal centralist approach. It finds that, despite lacking institutional support, judges managed to apply customary norms at their discretion against the state’s emphasis on top-down legal rules. A legitimacy-based analysis explains this phenomenon. It points out that judges conceptualized their legitimacy under the influence of both legal and extra-legal rules, thus making it apart from the legality. Judges attempt to bridge the gap between legitimacy and legality enabled de factor normative pluralism. In looking at the influence of customary norms over judicial adjudication, the article aims to make both theoretical and practical contributions. Theoretically, it enriches the scholarship of normative pluralism by showing how legitimacy-building keeps normative pluralism effective, irrespective of the dominating legal centralism. Practically, it proffers insightful implications for the ongoing court reforms in Vietnam based upon the findings.
Dynamics of heavy and buoyant underwater pendulums
Authors: Mathai Varghese , Loeffen Laura A. W. M. , Chan Timothy T. K. , Wildeman Sander
Published: January 2019

The humble pendulum is often invoked as the archetype of a simple, gravity driven, oscillator. Under ideal circumstances, the oscillation frequency of the pendulum is independent of its mass and swing amplitude. However, in most real-world situations, the dynamics of pendulums is not quite so simple, particularly with additional interactions between the pendulum and a surrounding fluid. Here we extend the realm of pendulum studies to include large amplitude oscillations of heavy and buoyant pendulums in a fluid. We performed experiments with massive and hollow cylindrical pendulums in water, and constructed a simple model that takes the buoyancy, added mass, fluid (nonlinear) drag and bearing friction into account. To first order, the model predicts the oscillation frequencies, peak decelerations and damping rate well. An interesting effect of the nonlinear drag captured well by the model is that, for heavy pendulums, the damping time shows a non-monotonic dependence on pendulum mass, reaching a minimum when the pendulum mass density is nearly twice that of the fluid. Small deviations from the model’s predictions are seen, particularly in the second and subsequent maxima of oscillations. Using time-resolved particle image velocimetry (TR-PIV), we reveal that these deviations likely arise due to the disturbed flow created by the pendulum at earlier times. The mean wake velocity obtained from PIV is used to model an extra drag term due to incoming wake flow. The revised model significantly improves the predictions for the second and subsequent oscillations.
Absolute and convective instabilities in electrohydrodynamic flow subjected to a Poiseuille flow: a linear analysis
Authors: Li Fang , Wang Bo-Fu , Wan Zhen-Hua , Wu Jian , Zhang Mengqi
Published: January 2019

We present a study of absolute and convective instabilities in electrohydrodynamic flow subjected to a Poiseuille flow (EHD-Poiseuille). The electric field is imposed on two infinite flat plates filled with a non-conducting dielectric fluid with unipolar ion injection. Mathematically, the dispersion relation of the linearised problem is studied based on the asymptotic response of an impulse disturbance imposed on the base EHD-Poiseuille flow. Transverse, longitudinal and oblique rolls are investigated to identify the saddle point satisfying the pinching condition in the corresponding complex wavenumber space. It is found that when the ratio of Coulomb force to viscous force increases, the transverse rolls can transit from convective instability to absolute instability. The ratio of hydrodynamic mobility to electric mobility, which exerts negligible effect on the linear stability criterion when the cross-flow is small, has significant influence on the convective–absolute instability transition, especially when the ratio is small. As we change the value of the mobility ratio, a saddle point shift phenomenon occurs in the case of transverse rolls. The unstable longitudinal rolls are convectively unstable as long as there is a cross-flow, a result which is deduced from a one-mode Galerkin approximation. Longitudinal rolls have a larger growth rate than transverse rolls except for a small cross-flow. Finally, regarding the oblique rolls, a numerical search for the saddle point simultaneously in the complex streamwise and transverse wavenumber spaces always yields an absolute transverse wavenumber of zero, implying that oblique rolls give way to transverse rolls when the flow is unstable.
Incipient bedforms in a bidirectional wind regime
Authors: Gadal Cyril , Narteau Clément , Courrech du Pont Sylvain , Rozier Olivier , Claudin Philippe
Published: January 2019

Most terrestrial sand seas form at ‘horse’ latitudes, where the wind direction exhibits seasonal variation. Here, we extend the two-dimensional linear stability analysis of a flat sand bed associated with a unidirectional wind to the three-dimensional case in order to account for multidirectional wind regimes. Focusing on the simplest case of bidirectional flow regimes, we show that the transition from transverse to oblique or longitudinal patterns is controlled by the transport ratio and the divergence angle between the two flows. Our predictions agree with previous results for dune orientation, and also provide a wider range of possible alignments depending on flow strength, especially when the two winds are perpendicular, at which the transition occurs. This analysis also predicts the selected pattern wavelength, which either decreases close to the transition angle for strong winds, due to a geometric effect, or increases at low winds, when the bed slope affects the transport. This theoretical analysis is complemented by analogous subaqueous experiments, where bedforms are submitted to alternate water flows. For transverse bedforms, the experimental data validate the model at strong flows, providing evidence for the predicted geometric effect, but also for the increase of the wavelength close to the transport threshold. For longitudinal bedforms, a discrepancy is observed, which we interpret as the sign of enhanced nonlinearities induced by the development of slip faces when the flow alternately blows on both sides of the dune.
Pathwise large deviations for the rough Bergomi model
Authors: Jacquier Antoine , Pakkanen Mikko S. , Stone Henry
Published: January 2019

Introduced recently in mathematical finance by Bayer et al. (2016), the rough Bergomi model has proved particularly efficient to calibrate option markets. We investigate some of its probabilistic properties, in particular proving a pathwise large deviations principle for a small-noise version of the model. The exponential function (continuous but superlinear) as well as the drift appearing in the volatility process fall beyond the scope of existing results, and a dedicated analysis is needed.
The nonhomogeneous frog model on ℤ
Authors: Rosenberg Josh
Published: January 2019

We examine a system of interacting random walks with leftward drift on ℤ, which begins with a single active particle at the origin and some distribution of inactive particles on the positive integers. Inactive particles become activated when landed on by other particles, and all particles beginning at the same point possess equal leftward drift. Once activated, the trajectories of distinct particles are independent. This system belongs to a broader class of problems involving interacting random walks on rooted graphs, referred to collectively as the frog model. Additional conditions that we impose on our model include that the number of frogs (i.e. particles) at positive integer points is a sequence of independent random variables which is increasing in terms of the standard stochastic order, and that the sequence of leftward drifts associated with frogs originating at these points is decreasing. Our results include sharp conditions with respect to the sequence of random variables and the sequence of drifts that determine whether the model is transient (meaning the probability infinitely many frogs return to the origin is 0) or nontransient. We consider several, more specific, versions of the model described, and a cleaner, more simplified set of sharp conditions will be established for each case.
Strong maximum principles for fractional Laplacians
Authors: Musina Roberta , Nazarov Alexander I.
Published: January 2019

We give a unified approach to strong maximum principles for a large class of nonlocal operators of order s ∈ (0, 1) that includes the Dirichlet, the Neumann Restricted (or Regional) and the Neumann Semirestricted Laplacians.
Dietary modification for laryngopharyngeal reflux: systematic review
Authors: Min C , Park B , Sim S , Choi H G
Published: January 2019

Objective

This study aimed to determine the relationship between laryngopharyngeal reflux and dietary modification.

Methods

A systematic review was conducted. The data sources for the study were PubMed, Embase, Cochrane Library and Web of Science. Articles were independently extracted by two authors according to inclusion and exclusion criteria. The outcome focus was laryngopharyngeal reflux improvement through diet or dietary behaviour.

Results

Of the 372 studies identified, 7 met our inclusion criteria. In these seven studies, laryngopharyngeal reflux symptoms improved following dietary modifications. However, the studies did not present the independent effect of each dietary factor on laryngopharyngeal reflux. Moreover, only one of the seven studies had a randomised controlled study design.

Conclusion

The reference studies of dietary modification for laryngopharyngeal reflux patients are not sufficient to provide recommendations.
A Hero of the Two Koreas: Yi Sun-shin Dramatized in North and South
Authors: Cho Seong-kwan , Hong Jae-beom
Published: January 2019

Yi Sun-shin (1545–98), an admiral of the Joseon dynasty, is a Korean national hero who is admired by both North and South Korea regardless of political ideology. Yet between 1960 and 1970 North and South Korea presented Yi from different perspectives in accordance with their own political interests. In South Korea, Yi was portrayed as a solitary hero who sacrificed himself to save the country despite the blame and entrapment he suffered as a result. Alongside, North Korea presented Yi as an ideal leader with the warmth of a father figure who embraced the people's aspirations to fight against their Japanese enemies. In this article, Seong-kwan Cho and Jae-beom Hong discuss these representations of Yi and survey North Korean theatre of the 1960s, which is rarely examined in theatre scholarship outside the Korean peninsula. Seong-kwan Cho (first author) lectures in the Korean Department of Konkuk University, and published in NTQ136 on South Korean theatre censorship. Jae-beom Hong (corresponding author) is a Professor in the same Department. The pair have recently been researching North Korean realist theatre, and this article is their third on the subject. This paper was supported by Konkuk University in 2016.
Geological Controls on Fluid Flow and Gas Hydrate Pingo Development on the Barents Sea Margin
Authors: Waage M. , Portnov A. , Serov P. , Bünz S. , Waghorn K. A. , Vadakkepuliyambatta S. , Mienert J. , Andreassen K.
Published: January 2019

In 2014, the discovery of seafloor mounds leaking methane gas into the water column in the northwestern Barents Sea became the first to document the existence of nonpermafrost‐related gas hydrate pingos (GHPs) on the Eurasian Arctic shelf. The discovered site is given attention because the gas hydrates occur close to the upper limit of the gas hydrate stability, thus may be vulnerable to climatic forcing. In addition, this site lies on the regional Hornsund Fault Zone marking a transition between the oceanic and continental crust. The Hornsund Fault Zone is known to coincide with an extensive seafloor gas seepage area; however, until now lack of seismic data prevented connecting deep structural elements to shallow seepages. Here we use high‐resolution P‐Cable 3‐D seismic data to study the subsurface architecture of GHPs and underlying glacial and preglacial deposits. The data show gas hydrates, authigenic carbonates, and free gas within the GHPs on top of gas chimneys piercing a thin section of low‐permeability glacial sediments. The chimneys connect to faults within the underlying tilted and folded fluid and gas‐hydrate‐bearing sedimentary rocks. Correlation of our data with regional 2‐D seismic surveys shows a spatial connection between the shallow subsurface fluid flow system and the deep‐seated regional fault zone. We suggest that fault‐controlled Paleocene hydrocarbon reservoirs inject methane into the low‐permeability glacial deposits and near‐seabed sediments, forming the GHPs. This conceptual model explains the existence of climate‐sensitive gas hydrate inventories and extensive seabed methane release observed along the Svalbard‐Barents Sea margin.
Contribution of Recycling of Surface Precipitation to Landfalling Tropical Cyclone Rainfall: A Modeling Study for Typhoon Utor (2013)
Authors: Liu Lu , Xu Jing , Wang Yuqing , Duan Yihong
Published: January 2019

Surface evaporation is an important factor in the hydrological cycle. It is unknown however how much the recycling of surface precipitation contributes to rainfall in a landfalling tropical cyclone. In this study, ensemble simulations were performed using the Weather Research and Forecasting model to quantify the contribution of re‐evaporation of surface precipitation to rainfall in Typhoon Utor (2013) during and after its landfall over South China. Two sets of ensemble simulations were conducted, one with all default model settings (CTRL) and the other with the surface precipitation rate in the land surface model being set to zero within a radius of 500 km from the storm center so that the re‐evaporation of surface precipitation was removed. Results show that the re‐evaporation of surface precipitation contributed about 15–20% to the total rainfall in the inner core within a 100‐km radius from the storm center after landfall. It is found that the removal of surface precipitation in the land surface model reduced soil moisture and thus surface latent heat flux, which led to a slightly weaker storm, thus the weaker boundary layer inflow and reduced inward moisture transport into the inner‐core region of the storm. The results demonstrate that the reduced surface evaporation and inward moisture transport contributed about 30–40 and 60–70%, respectively, to the decrease in precipitation in the inner‐core region in the experiment with the re‐evaporation of surface precipitation removed.
Climatic Condition and Synoptic Regimes of Two Intense Snowfall Events in Eastern China and Implications for Climate Variability
Authors: Sun Bo , Wang Huijun , Zhou Botao
Published: January 2019

This study investigates the climatic condition and synoptic regimes of two intense snowfall events (ISEs) in central eastern China (CEC) during January 2018, focusing on the mechanisms of northerly cold advection and southerly water vapor transport. The northerly cold advections invading CEC were associated with a strengthened Siberian High, which could be partially attributed to an influence of reduced sea ice in the Kara Sea‐Barents Sea during November 2017 to January 2018 on a reduced meridional temperature gradient between the midlatitudinal Eurasia and Arctic regions. The southerly water vapor transport contributing to ISEs was associated with a zonal dipole pattern in the atmosphere, which was characterized by an anomalous anticyclone over the western North Pacific and an anomalous low over the Tibetan Plateau and India. The La Niña condition provided a climatic condition for an anomalous anticyclone persisting over the western North Pacific during January 2018, which was influenced by a strengthened convection over the western tropical Pacific and influenced by the air‐sea interaction over the central‐northern Pacific. The anomalous low over the Tibetan Plateau and India was associated with active eastward propagating synoptic‐scale waves originating from the midlatitudinal North Atlantic. The implication of aforementioned climatic conditions on climate variability was further discussed. Our results suggest that a reduced sea ice in the Kara Sea during the preceding late autumn and a concurrent La Niña‐like condition may contribute to an increased frequency of ISEs in CEC during winter on the interannual time scale.
Panza Receives 2018 International Award
Authors:   AGU
Published: January 2019

Giuliano Francesco Panza received the International Award at the 2018 AGU Fall Meeting Honors Ceremony, held 12 December 2018 in Washington, D. C. The award honors an individual “for making an outstanding contribution to furthering the Earth and space sciences and using science for the benefit of society in developing nations.”
Author Correction: Chemically triggered drug release from an antibody-drug conjugate leads to potent antitumour activity in mice
Authors: Rossin Raffaella , Versteegen Ron M. , Wu Jeremy , Khasanov Alisher , Wessels Hans J. , Steenbergen Erik J. , ten Hoeve Wolter , Janssen Henk M. , van Onzen Arthur H. A. M. , Hudson Peter J. , Robillard Marc S.
Published: January 2019

The original version of this Article omitted the following from the Acknowledgements: ‘This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs, through the Breast Cancer Research Program under Award No. W81XWH-15-1-0692. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense’. This error has now been corrected in the PDF and HTML versions of the Article.
High expression of acidic chitinase and chitin digestibility in the stomach of common marmoset (Callithrix jacchus), an insectivorous nonhuman primate
Authors: Tabata Eri , Kashimura Akinori , Uehara Maiko , Wakita Satoshi , Sakaguchi Masayoshi , Sugahara Yasusato , Yurimoto Terumi , Sasaki Erika , Matoska Vaclav , Bauer Peter O. , Oyama Fumitaka
Published: January 2019

Chitin is a polymer of N-acetyl-D-glucosamine (GlcNAc) and a main constituent of insects’ exoskeleton. Insects are rich in protein with high energy conversion efficiency. Recently, we have reported that acidic chitinases (Chia) act as digestive enzymes in mouse, pig and chicken (omnivorous) but not in dog (carnivorous) and bovine (herbivorous), indicating that feeding behavior affects Chia expression levels, and determines chitin digestibility in the particular animals. Common marmoset (Callithrix jacchus) belongs to New World monkey family and provides a potential bridge between mouse models and human diseases. Common marmoset is an insectivorous nonhuman primate with unknown expression levels and enzymatic functions of the Chia homologue, CHIA. Here, we report that common marmoset highly expresses pepsin-, trypsin- and chymotrypsin-resistant CHIA in the stomach. We show that CHIA is most active at pH 2.0 and degrades chitin and mealworm shells into GlcNAc dimers under gastrointestinal conditions. Although common marmoset and crab-eating monkey (Old World monkey) have two CHIA genes in their genomes, they primarily express one gene in the stomach. Thus, this study is the first to investigate expression levels and enzymatic functions of CHIA in a New World primate, contributing to the understanding of dietary adaptation and digestion in this taxon.
A 14-day repeat dose oral gavage range-finding study of a first-in-class CDI investigational antibiotic, in rats
Authors: Sibley Katherine , Chen Jayson , Koetzner Lee , Mendes Odete , Kimzey Amy , Lansita Janice , Boulos Ramiz A.
Published: January 2019

Drug resistant bacteria are winning the fight over antibiotics with some bacteria not responding to any antibiotics, threatening modern medicine as we know it. The development of new, effective and safe antibiotics is critical for addressing this issue. Ramizol, a first-in-class styrylbenzene based antibiotic, is an investigational drug indicated for Clostridium difficile infections (CDI). The objective of this range-finding study was to evaluate the potential general toxicity (based on toxicological endpoints selected) and toxicokinetics of Ramizol in male and female rats that may arise from repeated exposure via oral gavage over a test period of at least 14 days at doses of 50 mg/kg, 500 mg/kg and 1500 mg/kg. There were no mortalities in this study and no Ramizol-related clinical observations. Additionally, there were no changes in mean body weight, body weight gain, food consumption or food efficiency for male and female rats attributable to Ramizol administration. The observed pharmacokinetic behavior showed the presence of Ramizol in plasma at 24 hours post-dosing combined with increasing AUC(0–24) values during the course of this study in groups administered 1500 mg/kg/day, which suggests that at least some dosing groups will show accumulation of compound during repeated dose studies. These toxicology results have shown Ramizol is well-tolerated at very high concentrations in rats and support the further drug development of Ramizol as a first-in-class antibiotic for the treatment of CDI.