bluuebunny/crossref_metadata_2025 huggingface dataset:
Inspection Optimization Justification for PWR Main Steam and Feedwater Nozzles Using Probabilistic Fracture Mechanics
Authors: Lohse C. , Shim D. J. , Somasundaram D. , Grizzi R. , Stevens G. L. , Cinson T.
Published: November 2019

Pressurized water reactor (PWR) steam generator (SG) main steam and feedwater nozzles are classified as ASME Code, Section XI, Class 2, Category C-B, pressure retaining welds in pressure vessels. Current ASME Code requirements specify that the nozzle-to-shell welds (Item No. C2.21 & C2.32) and nozzle inner radius sections (Item C2.22) are to be examined very 10 years. An evaluation was performed to establish a technical basis for optimized inspection frequencies for these items. The work included a review of inspection history and results, a survey of components in the PWR fleet (which included both U.S. and overseas plants), selection of representative main steam and feedwater nozzle configurations and operating transients for stress analysis, evaluation of potential degradation mechanisms, and flaw tolerance evaluations consisting of probabilistic and deterministic fracture mechanics analyses. The results of multiple inspection scenarios and sensitivity studies were compared to the U.S. Nuclear Regulatory Commission (NRC) safety goal of 10−6 failures per year.
Does the Biaxial Loading Affect the Apparent Fracture Toughness (Kc)?
Authors: Chen Chentong , Xiao Hanbin , Chao Yuh J. , Lam Poh-Sang
Published: November 2019

From linear elastic fracture mechanics (LEFM), it is well accepted that only the singular stress near the crack tip contributes to the fracture event through the crack tip stress intensity factor K. In the biaxial loading, the stress component that adds to the T-stress at the crack tip, affects only the second term in the Williams’ series solution around the crack tip. Therefore, it is generally believed that biaxial load does not change the apparent fracture toughness or the critical stress intensity factor (Kc). This paper revisited several specimen geometries under biaxial loading with finite element method. The sources of discrepancy between the theory and the test data were identified. It was found that the ideal biaxial loading would not be achieved for typical fracture specimens with finite geometry. Comparison to available test data shows that, while the biaxial load could affect the apparent fracture toughness, the contribution is relatively small.
A Novel Approach to Account for Weld Residual Stresses in Pressure Vessel Flaw Assessments
Authors: Brust F. W. , Hill L. , Wilkowski G. , Hioe Y. , Bagnoli K.
Published: November 2019

A periodic inspection of a reactor pressure vessel in refinery was scheduled. Prior to that inspection, criteria need to be established to determine what flaw indication would be tolerable so that the vessel can safely be put back in to service in a timely manner, or in the worst case, identify what flaw indication would create a very strong case for repair or replacement criteria for the vessel. A flaw tolerance criterion that can be applied to the refinery inspection process was developed for numerous potential flaw locations in this vessel. The finite element alternating method was used to determine the appropriate fracture parameters to assist in this flaw assessment procedure. These computational efforts involved examining the fracture response of the system in preparation for planned inspections.

Stress intensity factors were evaluated for a total of ten (10) cracks inserted into the refinery pressure vessel at several locations and crack orientations. Most of the cracks had depth to thickness ratios of 0.25 and a half width 3 times this depth. The crack sizes are chosen based on the assumed maximum initial flaw sizes expected to be found from NDI. The stress intensity factor for residual stress loading was conservatively estimated by placing a unit tensile pressure on the crack face for all 10 cracks. The approximation of crack face pressure loading to simulate residual stress is also shown to be accurate. Therefore, one can estimate the contribution to stress intensity factor by multiplying the residual stress value of K by the estimated residual stress ratio. The final estimate of crack driving force for a crack, KI, is obtained by adding the contributions of the pressure loading with the residual stress contribution. Internal pressure loading of this vessel is the only significant source of loading in this vessel.
An Optimized Start-Up Mode of Tower Solar Turbines With Heat Transfer Coefficient Model Based on Experiment Data
Authors: Xiaoxiao Li , Gang Chen , Peng Wang
Published: November 2019

Lifetime assessment of steam turbine components has become more and more important for the past years. Tower solar turbines experience a greater number of start-ups than those operating in base-load plants and high levels of thermal stress occurs during fast start-up, which both have a significant impact on lifetime. To achieve the fastest start-up time without reducing the lifetime of solar turbine it is essential to fully understand the thermal behavior of the turbine components during start-up. A series of experiments have been carried on a combined cycle steam turbine. The operation mode and inlet parameters of experiment unit are similar to tower solar turbine, so the new thermal model of heat transfer coefficient based on these experiment data can be used for the start-up research of tower solar turbine. A Finite Element (FE) turbine model is created and analyzed with the new thermal model in many start-up cases such as warm start, hot start to seek for an optimized start-up mode.
Fractography Study of the Mixed Mode Fatigue Crack Growth Process in Pressure Vessel P355NL1 Steel
Authors: Lesiuk Grzegorz , Correia Jose A. F. O. , Smolnicki Michał , Błażejewski Wojciech , El Amine Ben Seghier Mohamed , Jesus Abilio , Calcada R. A. B.
Published: November 2019

The aim of the paper is to present a fatigue crack growth analysis thru a fractography study of different crack paths obtained in different operating conditions of the pressure vessel P355NL1 steel. All experiments were performed on CTS (Compact Tension Shear) specimens under the mixed mode (I+II) loading conditions. These stress states aim to reflect simple biaxiality stress states in a pressurized cylinder. In the experiments, different operating conditions were considered. Two different kinetic fatigue fracture diagrams were proposed for mixed mode fatigue crack growth rate estimation. The obtained results suggested a fact that energy approach describes synonymously the kinetics of fatigue crack growth under mixed mode loading conditions with respect to the mean stress effect – R-ratio. Finally, the fractography analysis sugessted that the fatigue fracture surface topography changes with the mixity level.
Implementing B31J-2017 SIF and Flexibility Factor Changes for B31 Piping Systems
Authors: Paulin Anthony W. , Carpenter Lorna , Becht Charles
Published: November 2019

This paper discusses when new SIF and k-Factors from ASME B31J-2017 should be used for operating and new piping systems. Screening guidelines are provided to help plant owners know when current operating facilities may be subject to through-wall leaks as they approach given life milestones. The paper also shows when these same guidelines can be used in new system designs to require the use of more applicable SIF data, of qualified vendor lists and additional inspections.
Domain adaptation for ultrasound tongue contour extraction using transfer learning: A deep learning approach
Authors: Hamed Mozaffari M. , Lee Won-Sook
Published: November 2019

Automatic and precise delineating of the tongue surface in real-time frames is a challenging task because of the noisy nature of ultrasound images and rapid changes of the tongue. Deep convolutional neural networks have been shown to be successful in medical image analysis tasks such as tongue contour extraction. However, they are typically weak for the same task on different domains. Domain adaptation is an alternative solution for this difficulty by transferring and fine-tuning models on different datasets. In this study, the problem of transfer learning for tongue contour extraction was investigated on different ultrasound datasets.
HIV-1 Accessory Protein Vpr Interacts with REAF/RPRD2 To Mitigate Its Antiviral Activity
Authors: Gibbons Joseph M. , Marno Kelly M. , Pike Rebecca , Lee Wing-yiu Jason , Jones Christopher E. , Ogunkolade Babatunji W. , Pardieu Claire , Bryan Alexander , Fu Rebecca Menhua , Warnes Gary , Rowley Paul A. , Sloan Richard D. , McKnight Áine
Published: November 2019

For at least 30 years, it has been known that HIV-1 Vpr, a protein carried in the virion, is important for efficient infection of primary macrophages. Vpr is also a determinant of the pathogenic effects of HIV-1in vivo. A number of cellular proteins that interact with Vpr have been identified. So far, it has not been possible to associate these proteins with altered viral replication in macrophages or to explain why Vpr is carried in the virus particle. Here, we show that Vpr mitigates the antiviral effects of REAF, a protein highly expressed in primary macrophages and one that inhibits virus replication during reverse transcription. REAF is degraded by Vpr within 30 min of virus entry in a manner dependent on the nuclear localization of Vpr and its interaction with the cell’s protein degradation machinery.
Evolution and Global Transmission of a Multidrug-Resistant, Community-Associated Methicillin-Resistant Staphylococcus aureus Lineage from the Indian Subcontinent
Authors: Steinig Eike J. , Duchene Sebastian , Robinson D. Ashley , Monecke Stefan , Yokoyama Maho , Laabei Maisem , Slickers Peter , Andersson Patiyan , Williamson Deborah , Kearns Angela , Goering Richard V. , Dickson Elizabeth , Ehricht Ralf , Ip Margaret , O’Sullivan Matthew V. N. , Coombs Geoffrey W. , Petersen Andreas , Brennan Grainne , Shore Anna C. , Coleman David C. , Pantosti Annalisa , de Lencastre Herminia , Westh Henrik , Kobayashi Nobumichi , Heffernan Helen , Strommenger Birgit , Layer Franziska , Weber Stefan , Aamot Hege Vangstein , Skakni Leila , Peacock Sharon J. , Sarovich Derek , Harris Simon , Parkhill Julian , Massey Ruth C. , Holden Mathew T. G. , Bentley Stephen D. , Tong Steven Y. C.
Published: November 2019

The Bengal Bay clone (ST772) is a community-associated and multidrug-resistantStaphylococcus aureuslineage first isolated from Bangladesh and India in 2004. In this study, we showed that the Bengal Bay clone emerged from a virulent progenitor circulating on the Indian subcontinent. Its subsequent global transmission was associated with travel or family contact in the region. ST772 progressively acquired specific resistance elements at limited cost to its fitness and continues to be exported globally, resulting in small-scale community and health care outbreaks. The Bengal Bay clone therefore combines the virulence potential and epidemiology of community-associated clones with the multidrug resistance of health care-associatedS. aureuslineages. This study demonstrates the importance of whole-genome sequencing for the surveillance of highly antibiotic-resistant pathogens, which may emerge in the community setting of regions with poor antibiotic stewardship and rapidly spread into hospitals and communities across the world.
Measles Virus Ribonucleoprotein Complexes Rapidly Spread across Well-Differentiated Primary Human Airway Epithelial Cells along F-Actin Rings
Authors: Singh Brajesh K. , Pfaller Christian K. , Cattaneo Roberto , Sinn Patrick L.
Published: November 2019

The ability of viral particles to directly spread cell to cell within the airways without particle release is considered to be highly advantageous to many respiratory viruses. Our previous studies in well-differentiated, primary human airway epithelial cells suggest that measles virus (MeV) spreads cell to cell by eliciting the formation of intercellular membrane pores. Based on a newly generated ribonucleoprotein complex (RNP) “tracker” virus, we document by live-cell microscopy that MeV RNPs move along F-actin rings before entering a new cell. Thus, rather than diffusing through the cytoplasm of a newly infected columnar cell, RNPs take advantage of the cytoskeletal infrastructure to rapidly spread laterally across the human airway epithelium. This results in rapid horizontal spread through the epithelium that does not require particle release.
CD71
+
Erythroid Cells Exacerbate HIV-1 Susceptibility, Mediate
trans
-Infection, and Harbor Infective Viral Particles
Authors: Namdar Afshin , Dunsmore Garett , Shahbaz Shima , Koleva Petya , Xu Lai , Jovel Juan , Houston Stan , Elahi Shokrollah
Published: November 2019

Immature red blood cells (erythroid precursors or CD71
+
erythroid cells) have a wide range of immunomodulatory properties. In this study, we found that these erythroid precursors are abundant in the human cord blood/placental tissues, in the blood of HIV-infected and anemic individuals. We observed that these cells exacerbate HIV-1 replication/infection in target cells and even make HIV target cells more permissible to HIV infection. In addition, we found that HIV gets a free ride by binding on the surface of these cells and thus can travel to different parts of the body. In agreement, we noticed a positive correlation between the plasma viral load and the frequency of these cells in HIV patients. More importantly, we observed that infective HIV particles reside inside these erythroid precursors but not mature red blood cells. Therefore, these cells by harboring HIV can play an important role in HIV pathogenesis.
Granulomatous infective spondylitis in a patient presenting with progressive difficulty in walking: the differential between tuberculosis and brucellosis
Authors: Papachristodoulou Eleni , Kakoullis Loukas , Louppides Stylianos , Panos George
Published: November 2019

We report a case of infectious spondylitis in a 52-year-old woman who presented with progressive difficulty in walking. The patient had a 2-month long history of neurological symptoms, which progressed rapidly to paraplegia, following her admission. Imaging studies demonstrated the presence of vertebral lesions as well as additional tissue with inflammatory elements in the spinal canal, which caused a mass effect. In combination with the presence of increased cells and protein in the cerebrospinal fluid (CSF), the differential was steered towards causes of infectious spondylitis, primarily tuberculosis. However, brucellosis was also considered, as it is endemic in our area. Prompt surgical decompression produced biopsy samples, which confirmed the presence of granulomatous inflammation. The patient was started on an empiric regimen covering both for tuberculosis and brucellosis, and gradually regained full mobility in her lower limbs. The differential of infectious spondylitis is discussed, with an emphasis on the differentiation between tuberculosis and brucellosis.
Assessing small airway disease in GLI versus NHANES III based spirometry using area under the expiratory flow-volume curve
Authors: Ioachimescu Octavian C , Stoller James K
Published: November 2019

Background

Spirometry interpretation is influenced by the predictive equations defining lower limit of normal (LLN), while ‘distal’ expiratory flows such as forced expiratory flow at 50% FVC (FEF50) are important functional parameters for diagnosing small airway disease (SAD). Area under expiratory flow-volume curve (AEX) or its approximations have been proposed as supplemental spirometric assessment tools. We compare here the performance of AEX in differentiating between normal, obstruction, restriction, mixed defects and SAD, as defined by Global Lung Initiative (GLI) or National Health and Nutrition Examination Survey (NHANES) III reference values, and using various predictive equations for FEF50.

Methods

We analysed 15 308 spirometry-lung volume tests. Using GLI versus NHANES III LLNs, and diagnosing SAD by the eight most common equation sets for forced expiratory flow at 50% of vital capacity lower limits of normal (FEF50 LLN), we assessed the degree of diagnostic concordance and the ability of AEX to differentiate between various definition-dependent patterns.

Results

Concordance rates between NHANES III and GLI-based classifications were 93.7%, 78.6%, 86.8%, 88.0%, 93.8% and 98.8% in those without, with mild, moderate, moderately severe, severe and very severe obstruction, respectively (agreement coefficient 0.81 (0.80–0.82)). The prevalence of SAD was 0.6%–6.9% of the cohort, depending on the definition used. The AEX differentiated well between normal, obstruction, restriction, mixed pattern and SAD, as defined by most equations.

Conclusions

If the SAD diagnosis is established by using mean FEF50 LLNor a set number of predictive equations, AEX is able to differentiate well between various spirometric patterns. Using the most common predictive equations (NHANES III and GLI), the diagnostic concordance for functional type and obstruction severity is high.
Growth differentiation factor 11 attenuates liver fibrosis via expansion of liver progenitor cells
Authors: Dai Zhen , Song Guangqi , Balakrishnan Asha , Yang Taihua , Yuan Qinggong , Möbus Selina , Weiss Anna-Carina , Bentler Martin , Zhu Jimin , Jiang Xuemei , Shen Xizhong , Bantel Heike , Jaeckel Elmar , Kispert Andreas , Vogel Arndt , Saborowski Anna , Büning Hildegard , Manns Michael , Cantz Tobias , Ott Michael , Sharma Amar Deep
Published: November 2019

Objective

Liver fibrosis and cirrhosis resulting from chronic liver injury represent a major healthcare burden worldwide. Growth differentiation factor (GDF) 11 has been recently investigated for its role in rejuvenation of ageing organs, but its role in chronic liver diseases has remained unknown. Here, we investigated the expression and function of GDF11 in liver fibrosis, a common feature of most chronic liver diseases.

Design

We analysed the expression of GDF11 in patients with liver fibrosis, in a mouse model of liver fibrosis and in hepatic stellate cells (HSCs) as well as in other liver cell types. The functional relevance of GDF11 in toxin-induced and cholestasis-induced mouse models of liver fibrosis was examined by in vivo modulation ofGdf11expression using adeno-associated virus (AAV) vectors. The effect of GDF11 on leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5)+ liver progenitor cells was studied in mouse and human liver organoid culture. Furthermore, in vivo depletion of LGR5+ cells was induced by injecting AAV vectors expressing diptheria toxin A under the transcriptional control ofLgr5promoter.

Results

We showed that the expression of GDF11 is upregulated in patients with liver fibrosis and in experimentally induced murine liver fibrosis models. Furthermore, we found that therapeutic application of GDF11 mounts a protective response against fibrosis by increasing the number of LGR5+ progenitor cells in the liver.

Conclusion

Collectively, our findings uncover a protective role of GDF11 during liver fibrosis and suggest a potential application of GDF11 for the treatment of chronic liver disease.
Optimal link rewiring strategy for transport efficiency on scale-free networks with limited bandwidth
Authors: Zhang Yongqiang , Li Yaming , Zhou Yi , Ma Jinlong
Published: November 2019

The network topology structure has great impact on its traffic capacity. Most of the biological and technological networks have been proved to exhibit scale-free feature. In real networks, the hub links, which usually bear large traffic loads, have restricted transport efficiency of the complex networks. In this paper, we focus on the bandwidth congestion and propose a rewiring link strategy to optimize traffic dynamics on scale-free networks. Two link rewiring strategies are compared and the simulation results on scale-free networks show that our strategy has more advantages, which makes the degree distribution of the network more uniform, reducing the average path length of different nodes, balancing the resources of the network and increasing the traffic capacity of the network. This work will be beneficial for designing network topology and optimizing network performances.
Shannon information entropy for a one-dimensional ionic crystal
Authors: González Gabriel , Salgado-Blanco Daniel
Published: November 2019

In this work, we present the information theoretic lengths given by Shannon and Fisher for the lowest-lying stationary state of a one-dimensional ionic crystal modeled by [Formula: see text] equally spaced attractive and repulsive Dirac delta potentials. The entropic uncertainty relations related to position and momentum spaces are studied as a function of the number of ions and the distance between them. Our results show that the stability of the ionic crystal depends on the number of ions and distance between them. In particular, we show that the position Shannon entropy is always positive and increases as the lattice constant between ions grows, in contrast with the momentum Shannon entropy which decreases and becomes negative beyond a particular lattice constant value.
The first-order optical potential evaluation for the elastic scattering of neutron on the bound system using the impulse approximation method
Authors: Abusini M.
Published: November 2019

The method of impulse approximation is used to check the validity of the first-order optical potential for the elastic scattering problem of the neutron on the bound system, namely, [Formula: see text] and [Formula: see text]at incident neutron energies of 155 and 225[Formula: see text]MeV. The optical potential is derived as the first-order term within the spectator expansion of a nonrelativistic multiple scattering terms using the Lippmann–Schwinger equation. The Modern realistic two-body potential ArgonneV18 in the momentum space was used as input in the Lippmann–Schwinger equation. The obtained results for the elastic differential cross-sections are in a good agreement with the experimental data taken from EXFOR Database for all studied targets at neutron energy above 200[Formula: see text]MeV. As the neutron energy decreases down to approximately 155[Formula: see text]MeV, the discrepancies with experimental data appear, which is in accordance with the impulse approximation formalism.
Modeling Slab Track for Vehicle –Track-Coupled Dynamics Analysis Using Spline Function Method
Authors: Yang Jianjin , Zhu Shengyang , Zhai Wanming
Published: November 2019

This paper presents a new approach for modeling the slab tracks by using the spline function to derive an element that is capable of describing the vertical motions of the entire slab. The accuracy and advantages of the method are verified through comparison with the finite element method (FEM) by the frequency response analysis for the CRTS-III slab track system. With this, a three-dimensional train–slab track-coupled dynamic (TSTCD) model is developed and solved by a hybrid explicit–implicit time integration method. Finally, the characteristics and feasibility of the developed TSTCD model are demonstrated through two typical case studies together with the comparison made for verifications. The results indicate that the proposed method provides an alternative approach for modeling the slabs, by simplifying the modeling process and decreasing the computational time without losing accuracy, with respect to the FEM. Besides, the modes of the slab appear many dips and peaks above the first resonant frequency, leading to complicated frequency responses of the CRTS-III slab. Moreover, the developed TSTCD model is not only feasible, but also capable of describing the slab vibrations at medium-high frequencies.
Review of methods to improve the performance of linear array-based photoacoustic tomography
Authors: Wang Yuehang , Zhan Ye , Tiao Melinda , Xia Jun
Published: November 2019

As a hybrid imaging modality that combines optical excitation with acoustic detection, photoacoustic tomography (PAT) has become one of the fastest growing biomedical imaging modalities. Among various types of transducer arrays used in a PAT system configuration, the linear array is the most commonly utilized due to its convenience and low-cost. Although linear array-based PAT has been quickly developed within the recent decade, there are still two major challenges that impair the overall performance of the PAT imaging system. The first challenge is that the three-dimensional (3D) imaging capability of a linear array is limited due to its poor elevational resolution. The other challenge is that the geometrical shape of the linear array constrains light illumination. To date, substantial efforts have been made to address the aforementioned challenges. This review will present current technologies for improving the elevation resolution and light delivery of linear array-based PAT systems.
Investigation of optical reflectance from different animal vertebra along the fixation trajectory of pedicle screw in frequency domain
Authors: Liu Yangyang , Zhang Huan , Tong Ying , Qian Zhiyu , Li Weitao
Published: November 2019

Accurate placement of pedicle screw (PS) is crucial in spinal surgery. Developing new real-time intra-operative monitoring and navigation methods is an important direction of clinical application research. In this paper, we studied the spectrum along the fixation trajectory of PS in frequency domain to tackle the accuracy problem. Fresh porcine vertebrae, bovine vertebrae and ovine vertebrae were measured with the near-infrared spectrum (NIR) device to obtain the reflected spectrum from the vertebrae. Along the fixation trajectory of PS, average energy from different groups was calculated and used for identifying different tissues and compared to achieve the optimal recognition factor. Compared with the time domain approach, the frequency domain method could divide the spectra measured at different tissue points into different groups more stably and accurately, which could serve as a new method to assist the PS insertion. The results gained from this study are significant to the development of hi-tech medical instruments with independent intellectual property rights.
Memristive Crossbar Mapping for Neuromorphic Computing Systems on 3D IC
Authors: Xu Qi , Geng Hao , Chen Song , Yu Bei , Wu Feng
Published: November 2019

In recent years, neuromorphic computing systems based on memristive crossbar have provided a promising solution to enable acceleration of neural networks. However, most of the neural networks used in realistic applications are often sparse. If such sparse neural network is directly implemented on a single memristive crossbar, then it would result in inefficient hardware realizations. In this work, we propose E3D-FNC, an enhanced three-dimesnional (3D) floorplanning framework for neuromorphic computing systems, in which the neuron clustering and the layer assignment are considered interactively. First, in each iteration, hierarchical clustering partitions neurons into a set of clusters under the guidance of the proposed distance metric. The optimal number of clusters is determined by L-method. Then matrix re-ordering is proposed to re-arrange the columns of the weight matrix in each cluster. As a result, the reordered connection matrix can be easily mapped into a set of crossbars with high utilizations. Next, since the clustering results will in turn affect the floorplan, we perform the floorplanning of neurons and crossbars again. All the proposed methodologies are embedded in an iterative framework to improve the quality of NCS design. Finally, a 3D floorplan of neuromorphic computing systems is generated. Experimental results show that E3D-FNC can achieve highly hardware-efficient designs compared to the state of the art.
Analog/RF Post-silicon Tuning via Bayesian Optimization
Authors: Pan Renjian , Tao Jun , Su Yangfeng , Zhou Dian , Zeng Xuan , Li Xin
Published: November 2019

Tunable analog/RF circuit has emerged as a promising technique to address the significant performance uncertainties caused by process variations. To optimize these tunable circuits after fabrication, most existing post-silicon programming methods are developed by using real-valued performance metrics. However, when measuring a performance of interest on silicon, it is often substantially more expensive to obtain a real-valued measurement than a binary testing outcome (i.e., pass or fail). In this article, we propose a Gaussian Process Classification model to capture the binary performance metrics of tunable analog/RF circuits. Based on these models, post-silicon programming is cast into an optimization problem that can be solved by a novel Bayesian optimization algorithm. Moreover, measurement noises are further incorporated into our proposed post-silicon programming to produce a robust circuit. Two circuit examples demonstrate that the proposed approach can efficiently program tunable circuits with binary performance metrics while other conventional methods are not applicable.
Moderate alcohol intake promotes pancreatic ductal adenocarcinoma development in mice expressing oncogenic Kras
Authors: Asahina Kinji , Balog Steven , Hwang Edward , Moon Eugene , Wan Emily , Skrypek Kaitlin , Chen Yibu , Fernandez Jay , Romo Janet , Yang Qihong , Lai Keane , French Samuel W. , Tsukamoto Hidekazu
Published: November 2019

Kras mutations are associated with pancreatic ductal adenocarcinoma (PDAC). Although tobacco smoking, pancreatitis, and obesity are known environmental risk factors for PDAC, the contribution of moderate alcohol intake to PDAC remains elusive. In the present study, we tested whether a combination of risk factors or moderate alcohol intake induces PDAC development in mice. Control Pdx1Cre and Pdx1Cre;LSL- KrasG12D mutant mice were fed a Western alcohol diet containing high levels of cholesterol and saturated fat, 3.5% alcohol, and lipopolysaccharide for 5 mo. In addition, mice were treated with cerulein, for induction of pancreatitis, and nicotine every month. Treatment with all of these risk factors promoted development of advanced pancreatic neoplasia and PDAC in the Pdx1Cre;LSL- KrasG12D mice but not in the control Pdx1Cre mice. Moderate alcohol intake or Western diet feeding also significantly promoted advanced neoplasia and PDAC development in Pdx1Cre;LSL- KrasG12D mice compared with mice fed a regular chow. Alcohol, but not Western diet, increased tumor development in the liver in the Pdx1Cre;LSL- KrasG12D mice, but its origin remained elusive due to leakiness of Pdx1Cre in hepatocytes. RNA-seq analysis revealed that alcohol feeding increases expression of markers for tumors ( Epcam, Krt19, Prom1, Wt1, and Wwtr1), stroma ( Dcn, Fn1, and Tnc), and cytokines ( Tgfb1 and Tnf) and decreases expression of Fgf21 and Il6 in the pancreatic tumor tissues. Immunostaining showed heterogeneous expression of nephronectin, S100 calcium-binding protein A6, and vascular cell adhesion molecule 1 in pancreatic tumors surrounded by podoplanin-positive stromal cells. Our data indicate that moderate alcohol drinking is a risk factor for development of PDAC.

NEW & NOTEWORTHY Heavy alcohol intake has been suspected to be a risk factor of pancreatic ductal adenocarcinoma (PDAC) in humans. However, the contribution of moderate alcohol intake to PDAC development remains elusive. In the present study, we experimentally show that moderate alcohol feeding significantly induces advanced stages of pancreatic intraepithelial neoplasia development and invasive PDAC in Pdx1Cre;LSL- KrasG12D mutant mice. Our data indicate that moderate alcohol drinking is a risk factor for PDAC.
Intra- and intergenerational changes in the cortical DNA methylome in response to therapeutic intermittent hypoxia in mice
Authors: Belmonte Krystal Courtney D. , Harman Jarrod C. , Lanson Nicholas A. , Gidday Jeffrey M.
Published: November 2019

Recent evidence from our laboratory documents functional resilience to retinal ischemic injury in untreated mice derived from parents exposed to repetitive hypoxic conditioning (RHC) before breeding. To begin to understand the epigenetic basis of this intergenerational protection, we used methylated DNA immunoprecipitation and sequencing to identify genes with differentially methylated promoters (DMGPs) in the prefrontal cortex of mice treated directly with the same RHC stimulus (F0-RHC) and in the prefrontal cortex of their untreated F1-generation offspring (F1-*RHC). Subsequent bioinformatic analyses provided key mechanistic insights into how changes in gene expression secondary to promoter hypo- and hypermethylation might afford such protection within and across generations. We found extensive changes in DNA methylation in both generations consistent with the expression of many survival-promoting genes, with twice the number of DMGPs in the cortex of F1*RHC mice relative to their F0 parents that were directly exposed to RHC. In contrast to our hypothesis that similar epigenetic modifications would be realized in the cortices of both F0-RHC and F1-*RHC mice, we instead found relatively few DMGPs common to both generations; in fact, each generation manifested expected injury resilience via distinctly unique gene expression profiles. Whereas in the cortex of F0-RHC mice, predicted protein-protein interactions reflected activation of an anti-ischemic phenotype, networks activated in F1-*RHC cortex comprised networks indicative of a much broader cytoprotective phenotype. Altogether, our results suggest that the intergenerational transfer of an acquired phenotype to offspring does not necessarily require the faithful recapitulation of the conditioning-modified DNA methylome of the parent.
A New System Reliability Optimization Model Based on Swapping Existing Components
Authors: Li Yuxiong , Huang Xianzhen , En Xinong , Ding Pengfei
Published: November 2019

Complex systems contain a large number of components, and in some cases, failure of one or more of these components can cause the entire system to fail. Replacing failed components with other functioning components properly in the original system can be an attractive way for improving system reliability. This paper proposes a new system reliability optimization model to achieve optimal component reliability and the ideal component‐swapping strategy under a certain set of constraints. Furthermore, the survival signature is introduced to more efficient calculation of system reliability under various component‐swapping cases, and an artificial bee colony (ABC) algorithm with local search method for component swapping is applied to solve the optimization problem. Finally, numerical examples are presented to illustrate the optimization process.
Adipose-Derived Mesenchymal Stem Cells Isolated from Patients with Abdominal Aortic Aneurysm Exhibit Senescence Phenomena
Authors: Huang Xiaoran , Zhang Hao , Liang Xiaoting , Hong Yimei , Mao Mengmeng , Han Qian , He Haiwei , Tao Wuyuan , Jiang Guojun , Zhang Yuelin , Li Xin
Published: November 2019

Mesenchymal stem cells (MSCs) have shown beneficial effects in the treatment of abdominal aortic aneurysm (AAA). Nonetheless, the biological properties of adipose-derived MSCs (ASCs) from patients with AAA (AAA-ASCs) remain unclear. This study is aimed at investigating the properties of cell phenotype and function of AAA-ASCs compared with ASCs from age-matched healthy donors (H-ASCs). H-ASCs and AAA-ASCs were studied for cell phenotype, differentiation capacity, senescence, and mitochondrial and autophagic functions. Cellular senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. Mitochondrial morphology was determined by MitoTracker staining. Despite the similar surface markers of AAA-ASCs and H-ASCs, AAA-ASCs exhibited altered multidifferentiation potential. Compared with H-ASCs, AAA-ASCs displayed enhanced senescence manifested by increased SA-β-gal activity and decreased proliferation and migration ability. Furthermore, AAA-ASCs showed increased mitochondrial fusion, reactive oxygen species (ROS) production, and decreased mitochondrial membrane potential. In addition, AAA-ASCs exhibited decreased autophagy level, upregulation of IL-6 and TNF-α secretion, and downregulation of IL-10 secretion compared with H-ASCs. Nonetheless, treatment of AAA-ASCs with rapamycin (an autophagy activator) dramatically reduced secretion of IL-6 and TNF-α and enhanced secretion of IL-10. In conclusion, our study showed that AAA-ASCs exhibit senescence phenomena and decreased cell function. Understanding the specific alterations in AAA-ASCs will help explore novel strategies to restore cell function for AAA treatment.
The Incidence of Malaria Parasites in Screened Donor Blood for Transfusion
Authors: Antwi-Baffour Samuel , Kyeremeh Ransford , Amoako Atta Poku , Annison Lawrence , Tetteh John Ocquaye-Mensah , Seidu Mahmood Abdulai
Published: November 2019

Malaria is a protozoan parasitic infection of humans resulting from one or more of the five species of the genus Plasmodium and its burden across the world particularly in the tropics is well known. Blood transfusion on the other hand is a necessary intervention in saving lives. However, it can lead to transfusion transmitted infections including malaria if the blood was donated by an infected person. It is therefore important that the blood from donors in malaria prone environment be examined thoroughly for malaria parasites. The objective of this study was to investigate the incidence of malaria parasites in donor blood. A total of 1,500 samples from donors were examined using microscopy, rapid diagnostic test (RDT), and molecular method for malaria parasites. Malaria parasites were detected in forty-eight (48), 49 and 47 of the blood samples using microscopy, RDT, and molecular method respectively. This gave an average prevalence of 3.2%. All the blood groups examined had some malaria positivity except blood group O and A negative. In all the positive samples, the trophozoites of Plasmodium falciparum were detected. There was no association between blood group type and prevalence of the malaria parasites. There was also no association between age and prevalence of malaria parasite. The results attest to the potential risk of blood transfusion transmitted malaria and thus pose a great risk to blood recipients, especially the malaria vulnerable groups of children and pregnant women. Even though the prevalence in this study was not high enough, together with other results from elsewhere, it can be said that the screening of donated blood or donors for malaria parasites is necessary so that measures will be put in place not to transfuse patients at risk.
Subacute Testicular Toxicity to Cadmium Exposure Intraperitoneally and Orally
Authors: Mouro Viviane G. S. , Martins Ana L. P. , Silva Janaina , Menezes Tatiana P. , Gomes Marcos L. M. , Oliveira Juraci A. , Melo Fabiana C. S. A. , Matta Sérgio L. P.
Published: November 2019

The toxic effects of cadmium (Cd) on reproductive parameters are widely described in the literature. Experimental models often make use of the intraperitoneal route (i.p.), although human intoxication occurs preferentially by the oral route and can be continuous. However, little is known about the effect of Cd administration routes on the testicular structure. Thus, this study investigated the testicular impact of Cd exposure comparing bothi.p.and oral routes, both single dose (SD), in addition to the oral route in fractional doses (FD). Swiss adult male mice received CdCl21.5 mg/kgi.p., 30 mg/kg oral SD, and 4.28 mg/kg oral FD for 7 consecutive days. The Cd bioaccumulation was observed in all routes, mainly in the oral FD route. The concentrations of testicular Ca and Cu decreased in all animals exposed to Cd, while Zn and Mn decreased only in thei.p.route. Testicular SOD activity was reduced in both routes of oral administration, while CAT increased in thei.p.route, and GST increased in all animals exposed to Cd. Changes in the tubular parameters and cell viability were observed in both routes of Cd administration but were more intense in the oral route, mainly in the FD. Serum testosterone concentration was reduced in both routes of oral administration. Tubular damage, such as the vacuolization of the seminiferous epithelium, germ cell detachment, and seminiferous tubule degeneration, occurred in all groups exposed to Cd. Therefore, the oral Cd administration presented greater potential to promote testicular damage, mainly when the metal was given in a fractionated way.
Synchronization in Tempered Fractional Complex Networks via Auxiliary System Approach
Authors: Ma Weiyuan , Li Changpin , Deng Jingwei
Published: November 2019

In the famous continuous time random walk (CTRW) model, because of the finite lifetime of biological particles, it is sometimes necessary to temper the power law measure such that the waiting time measure has a convergent first moment. The CTRW model with tempered waiting time measure is the so‐called tempered fractional derivative. In this article, we introduce the tempered fractional derivative into complex networks to describe the finite life span or bounded physical space of nodes. Some properties of the tempered fractional derivative and tempered fractional systems are discussed. Generalized synchronization in two‐layer tempered fractional complex networks via pinning control is addressed based on the auxiliary system approach. The results of the proposed theory are used to derive a sufficient condition for achieving generalized synchronization of tempered fractional networks. Numerical simulations are presented to illustrate the effectiveness of the methods.
Adaptive Navigating Control Based on the Parallel Action-Network ADHDP Method for Unmanned Surface Vessel
Authors: Huang Zhijian , Liu Xinze , Wen Jiayi , Zhang Guichen , Liu Yihua
Published: November 2019

The feedback PID method was mainly used for the navigating control of an unmanned surface vessel (USV). However, when the intelligent control era is coming now, the USV can be navigated more effectively. According to the USV character in its navigating control, this paper presents a parallel action-network ADHDP method. This method connects an adaptive controller parallel to the action network of the ADHDP. The adaptive controller adopts a RBF neural network approximation based on the Lyapunov stability analysis to ensure the system stability. The simulation results show that the parallel action-network ADHDP method has an adaptive control character and can navigate the USV more accurately and rapidly. In addition, this method can also eliminate the overshoot of the ADHDP controller when navigating the USV in various situations. Therefore, the adaptive stability design can greatly improve the navigating control and effectively overcome the ADHDP algorithm limitation. Thus, this adaptive control can be one of the intelligent ADHDP control methods. Furthermore, this method will be a foundation for the development of an intelligent USV controller.
Method and Mathematical Modeling of Formation of Gradually and Homogeneously Oriented Linear Polymers
Authors: Nadareishvili Levan , Bakuradze Roland , Aneli Jimsher , Areshidze Manana , Pavlenishvili Ineza , Sharashidze Liana , Basilaia Giorgi
Published: November 2019

Previously, we developed several technical solutions for the conversion of isotropic polymers into materials of a new type—gradually oriented polymers with a gradient of physical and mechanical properties, thereby materializing for the first time the unused possibilities inherent in the polymeric nature of the substance. The scientific basis of these developments is the concept of a new structural state of linear polymers—a gradually oriented (stretched) state (GOS), the essence of which is set out briefly. An algorithm and a mathematical model for controlling the process of uniaxial, zonal stretching of linear polymers are proposed, which allow the formation of gradually or homogeneously oriented polymers (polymer composites). At the same time, specified values of quantitative parameters are ensured, in particular, the selected profile of distribution of the relative elongation (linear, sinusoidal, etc.) along the length of the gradually oriented polymer sample and the specified constant relative elongation along the length of the homogeneously oriented polymer. Mathematical expressions for calculating the conditions to obtain gradually oriented polymers with given geometric dimensions (length, width) and with a given distribution of relative elongation along the length of the resulting sample were also derived. The description of method and principles of operation of the appropriate device is given. Experimental data illustrating the possibilities of the proposed method and the efficiency of mathematical modeling are presented. The issues of creating functionally graded materials with a gradient of microstructure (gradient of degree of orientation/relative elongation) or chemical composition (volume fraction of functional fillers), respectively, based on thermoplastic polymer/copolymer or polymer composite (containing functional fillers) by method of uniaxial, zonal graded stretching are discussed.
Sibling Relationships, Personality Traits, Emotional, and Behavioral Difficulties in Autism Spectrum Disorders
Authors: Longobardi C. , Prino L. E. , Gastaldi F. G. M. , Jungert T.
Published: November 2019

This study focused on parents’ perceptions of the quality of sibling relationship and its association with some behavioral and emotional characteristics of the typically developing sibling. The participants were parents of children with autism spectrum disorder and typically developing siblings. The sample size was 43. The group comprised 14 fathers (32.6%) and 29 mothers (67.4%) aged 33–53 years (M=43.56; SD = 5.23). The parents completed measures of siblings’ emotional and behavioral difficulties, siblings’ personality, and sibling relationships and their impact on families and siblings. The results showed that behavioral difficulties such as emotional symptoms, conduct problems, hyperactivity/inattention, and peer relationship problems were significantly associated with negative sibling relationships—characterized by rivalry, aggression, avoidance, and teaching behavior toward the brother or sister with an autism spectrum disorder. The implications are that sibling-focused interventions should focus on improving negative sibling relationships to reduce the impact on the difficulties of the typical development of the sibling of both genders and shape the content and delivery framework accordingly. This can be done by providing skills and approaches for enhancing sibling relationships so both parties benefit.