bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning Conceptual Modeling Design Through the Classutopia Serious Game
Authors: Marín Beatriz , Larenas Felipe , Giachetti Giovanni
Published: January 2019

One of the more complex topics to teach to Software Engineering students is the conceptual modeling design, which has several concepts that students must learn in order to specify the structural, behavioral and interaction views of software systems. Learning the design of class diagrams is of paramount importance since these diagrams are used to guide concrete development tasks such as programming and testing, and, consequently, to avoid defective software products. Applying novel teaching/learning techniques in this topic may help students to reduce the defects that are committed at the moment of designing a class diagram. One interesting technique is the use of serious games, since they provide learning environments free of risks and pressure for students, allowing the students to know the topics that they must learn in a funny way. Serious games have been widely used in programming courses. We aim to investigate the feasibility to replicate this experience for conceptual modeling of class diagrams at Software Engineering courses. In this paper, we present a role-playing game especially focused on the class diagram, which is called Classutopia. This serious game provides modeling challenges, comprehension and correction of diagrams with different complexity levels for learning conceptual modeling design.
SmartClean: Smart City Street Cleanliness System Using Multi-Level Assessment Model — Research Notes
Authors: Li Wenrui , Bhushan Bharat , Gao Jerry , Zhang Pengcheng
Published: January 2019

Advancements in mobile, cloud computing and other techniques have made the world even smaller and connected like never before. It has become a challenge and an opportunity for cities to leverage these growing technologies to solve real city administration problems. Cities are in the transformation to become state-of-the-art smart cities using these technologies. This paper is about the automation of street cleanliness assessment in near real-time. It answers the question of how can we assess the status of streets in a more efficient and effective way. To address the problem, this paper proposes a multi-level assessment system on how the cleanliness status of streets is collected using mobile stations. They are connected via city network, analyzed in the cloud and presented to city administrators online or on mobile. The real case studies show the usability and feasibility of our system. This also gives opportunities for city residents to participate and contribute to making the city a better place.
The geometry of k-free hyperbolic 3-manifolds
Authors: Guzman R. K. , Shalen P. B.
Published: January 2019

We investigate the geometry of closed, orientable, hyperbolic 3-manifolds whose fundamental groups are [Formula: see text]-free for a given integer [Formula: see text]. We show that any such manifold [Formula: see text] contains a point [Formula: see text] with the following property: If [Formula: see text] is the set of maximal cyclic subgroups of [Formula: see text] that contain non-trivial elements represented by loops of [Formula: see text], then for every subset [Formula: see text], we have rank [Formula: see text]. This generalizes to all [Formula: see text] results proved in [J. W. Anderson, R. D. Canary, M. Culler and P. B. Shalen, Free Kleinian groups and volumes of hyperbolic 3-manifolds, J. Differential Geom. 43 (1996) 738–782; M. Culler and P. B. Shalen, 4-free groups and hyperbolic geometry, J. Topol. 5 (2012) 81–136], which have been used to relate the volume of a hyperbolic manifold to its topological properties, and it strictly improves on the result obtained in [R. K. Guzman, Hyperbolic 3-manifolds with [Formula: see text]-free fundamental group, Topology Appl. 173 (2014) 142–156] for [Formula: see text]. The proof avoids the use of results about ranks of joins and intersections in free groups that were used in [M. Culler and P. B. Shalen, 4-free groups and hyperbolic geometry, J. Topol. 5 (2012) 81–136; R. K. Guzman, Hyperbolic 3-manifolds with [Formula: see text]-free fundamental group, Topology Appl. 173 (2014) 142–156].
Characterizing the luminescent properties of upconversion nanoparticles in single and densely packed state
Authors: Chen Xiaohu , Gui Zhengyu , Liang Yong , Jin Xin , Li Simin , Zhao Pengjiu , Yu Zhangsen , Wu Aiguo , Liu Shoupeng , Li Hui
Published: January 2019

Luminescent properties of Er[Formula: see text]- and Yb[Formula: see text]- co-doped CaF2 upconversion nanoparticles (UCNPs) were investigated in single particle and densely-packed states with a custom-built microscope. The single UCNPs exhibit linear dependency of luminescent intensity on excitation power while the densely-packed UCNPs exhibit a 2-order power law-dependency indicating a two-photon absorption process. Time-domain luminescence intensity measurements were performed and the curves were fitted to excitation[Formula: see text]emission rate functions based on a simplified three-state model. The results indicate that the intermediates in single particles are much less and saturated in a short time, and there are strong couplings of the ground states and intermediate states between neighboring UCNPs in densely packed UCNPs.
LIQUIDITY AS AN ASSET PRICING FACTOR IN THE UK
Authors: ARTIKIS PANAYIOTIS G.
Published: January 2019

This study examines whether there is a strong relationship between stock liquidity, which proxies for the implicit cost of trading shares, and future stock returns in an asset-pricing context in the UK stock market. The time period, 1994–2016, includes the most recent global financial crisis that drained liquidity from financial markets worldwide. Four different measures of stock liquidity are employed; the empirical findings indicate that liquidity is a systematic pricing factor and explains a significant portion of the variation in stock returns, even after the inclusion of the other traditional risk factors. The results are robust to both forms of liquidity, either as a residual effect or in its original form as a separate risk factor. Finally, for the first time quantile regression is applied, showing that the liquidity risk factor (LIQ) absorbs a significant portion of the information content of the size and value factors, while remaining independent of the momentum factor.
Affine Formation Algorithms and Implementation Based on Triple-Integrator Dynamics
Authors: Onuoha Okechi , Tnunay Hilton , Li Zhenhong , Ding Zhengtao
Published: January 2019

This paper presents novel affine formation algorithms and implementations in different scenarios for the coordination of multi-agent systems with triple-integrator agent dynamics for both sampled-data and continuous-time settings. The agents in affine maneuver control are to be capable of producing required geometric shapes and simultaneously accomplishing desired maneuvers such as shearing, rotation, translation and scaling. From existing work, these tasks can be accomplished for systems whose agent dynamics are described using double-integrators and the agents communicate continuously in time. In some practical situations, however, the inter-agent communication may be limited to periodic intervals of time. Furthermore, a wide range of systems is governed by complex dynamics described with higher-orders. This paper presents two novel algorithms based on triple-integrator agent dynamics. Four implementation cases comprising of two scenarios each studied in both continuous-time and sampled-data cases are considered. Under the proposed algorithms, the collection of agents are capable of tracking time-varying targets which are affine transforms of the reference formation, if the leaders have knowledge of the required formation maneuvers. Detailed implementation results are presented to demonstrate the efficacy of the proposed algorithms.
GeoHumanities 2018 workshop report
Authors: Martins Bruno , Murrieta-Flores Patricia
Published: January 2019

This article reports on the 2nd ACM SIGSPATIAL Workshop on Geospatial Humanities, held in conjunction with the 26th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems. The article outlines the objectives of the workshop, and briefly describes the technical program.
Botsourcing's impact on society
Authors: Vedder Richard , Guynes Stephen , Parrish James
Published: January 2019

Botsourcing has been defined as "the use of robots or robotic technology to replace human workers". Over the past 10-15 years there has been an explosion in the capabilities of both robots and computing systems in general. These advances allow robots and other computer systems to assist humans in their work, as well as replace them in some instances. In this paper the authors will use the term botsourcing, and consider it as the augmentation or replacement of human workers by robots or other computing systems. This paper will discuss the nature and appeal of botsourcing, as well as its positive and negative impact on society.
On the detection of applications in co-resident virtual machines via a memory deduplication side-channel
Authors: Lindemann Jens , Fischer Mathias
Published: January 2019

Nowadays, hosting services of multiple customers on the same hardware via virtualiation techniques is very common. Memory deduplication allows to save physical memory by merging identical memory pages of multiple Virtual Machines (VMs) running on the same host. However, this mechanism can leak information on memory pages to other. In this paper, we propose a timing-based side-channel to identify software versions running in co-resident VMs. The attack tests whether pages that are unique to a specific software version are present in co-resident VMs. We evaluate the attack in a setting without background load and in a more realistic setting with significant background load on the host memory. Our results indicate that, with few repetitions of our attack, we can precisely identify software versions within reasonable time frames and nearly independent of the background load. Finally, we discuss potential coun-termeasures against the presented side-channel attack.
Knockdown of PHF5A Inhibits Migration and Invasion of HCC Cells via Downregulating NF-κB Signaling
Authors: Yang Qing , Zhang Jianwen , Xu Shilei , Jia Changchang , Meng Wei , Tang Hui , Zhang Xiaomei , Zhang Yi , Fu Binsheng
Published: January 2019

Background. Inflammation is the major risk factor for the progression of hepatocellular carcinoma (HCC), and the nuclear factor-κB (NF-κB) signaling plays the central role in the inflammation process. However, the activated mechanism of NF-κB signaling in HCC is unclear. Methods. The expression of PHF5A is examined by qPCR, western blotting, and immunohistochemistry (IHC) assay. The potential of PHF5A (PHD-finger domain protein 5a) for migration and invasion is examined by wound healing and Transwell assay. Luciferase reporter assay, western blotting, and qPCR were applied to explore the mechanism by which PHF5A is involved in progression of HCC. Results. PHF5A was significantly upregulated in HCC tissues and cells. Downregulation of PHF5A inhibits the migration and invasion of HCC cells. Further study demonstrated that PHF5A is implicated in HCC progression through NF-κB signaling. In addition, blocking the NF-κB signaling can weaken the stimulatory effect of PHF5A on migration and invasion of HCC cells. Conclusion. PHF5A expression is upregulated in HCC tissues, and depletion of PHF5A inhibits the migration and invasion of HCC cells. Further experiments demonstrated that PHF5A is implicated in NF-κB signaling and knockdown of PHF5A downregulates the activity of NF-κB pathway to inhibit the tumor progression. The above results provide the evidence that PHF5A plays an indispensable role in progressive effect of NF-κB pathway in HCC and may be a novel therapeutic target of HCC.
Delay‐Range‐Dependent Robust Constrained Model Predictive Control for Industrial Processes with Uncertainties and Unknown Disturbances
Authors: Shi Huiyuan , Li Ping , Wang Limin , Su Chengli , Yu Jingxian , Cao Jiangtao
Published: January 2019

A delay‐range‐dependent robust constrained model predictive control is proposed for discrete‐time system with uncertainties and unknown disturbances. The dynamic characteristic of the discrete‐time system is established as a new extended state space model in which state variables and output tracking error are integrated and regulated independently. It is used as the design of control law of system, which cannot only guarantee the convergence and tracking performance but also offer more degrees of freedom for designed controller. Unlike the traditional robust model predictive control (RMPC), the novel, less conservative, and more simplified delay‐range‐dependent stable conditions are derived by linear matrix inequality (LMI) theory and some relaxed technologies, which make use of the information of the upper and lower bounds of the time‐varying delay. Meanwhile, the H∞ performance index is introduced in the RMPC controller design, which can reject any unknown bounded disturbances. As a result, the design controller has better abilities of both tracking and disturbance rejection. The control results on the liquid level of tank system show that the proposed control method is effective and feasible.
Rapid Production of Human VEGF-A following Intradermal Injection of Modified VEGF-A mRNA Demonstrated by Cutaneous Microdialysis in the Rabbit and Pig In Vivo
Authors: Pehrsson Susanne , Hölttä Mikko , Linhardt Gunilla , Danielson Regina Fritsche , Carlsson Leif
Published: January 2019

Chemically modified mRNA is a novel, highly efficient, biocompatible modality for therapeutic protein expression that may overcome the challenges and safety concerns with current gene therapy strategies. We explored the efficiency of intradermally injected modified VEGF-A165 mRNA (VEGF-A mRNA) formulated in a biocompatible citrate/saline buffer to locally produce human VEGF-A165 protein. Rabbits (n=4) and minipigs (n=3) were implanted with subcutaneous microdialysis probes close to the injection sites and interstitial-fluid samples and skin biopsies were analysed for production of VEGF-A protein over time for up to 8 hours. Three to 4 hours after the intradermal injection of VEGF-A mRNA, detectable levels of human VEGF-A protein were seen in the microdialysis eluates in both species. In the pig, the VEGF-A concentrations increased dose-dependently reaching a maximum 6 hours after dosing (62.7±28.4, 357.6±240.6, and 746.3±210.2 pg/mL following injection of 24, 120, and 600 μg VEGF-A mRNA, respectively). Likewise, in tissue biopsies harvested at study end (8 hours after VEGF-A mRNA injection), the content of VEGF-A protein increased dose-dependently. In contrast, VEGF-A protein was not detected in eluates originating from sites injected with citrate/saline vehicle. It is concluded that intradermal injection of VEGF-A mRNA is associated with a rapid and local production of VEGF-A protein. Considering the pro-angiogenic effect of VEGF-A, VEGF-A mRNA may hold promise for regenerative treatment of patients with diabetic wounds and ischemic cardiovascular disease.
Giant Gastroschisis with Complete Liver Herniation: A Case Report of Two Patients
Authors: Svetanoff Wendy Jo , Zendejas Benjamin , Demehri Farokh R. , Cuenca Alex , Nath Bharath , Smithers C. Jason
Published: January 2019

Introduction. There are no reported survivors of gastroschisis with complete liver herniation. We describe a case report of two patients, one of whom survived. Case #1. The patient was born with gastroschisis and herniation of the entire liver. Along with silo placement, the abdominal fascia was attached to an external traction system for growth. Complete closure was achieved at 5 months. Due to pulmonary hypoplasia, high-frequency ventilation was required. The patient is doing well, on a home ventilator wean, at 20 months. Case #2. The patient was born prematurely with gastroschisis, total liver herniation, and a defect extending to the pericardium. A silo was attached to the fascia to provide growth of the abdominal cavity. The patient developed respiratory failure, diffuse anasarca, and renal failure. She died at 38 days of life. Discussion. We report the first survivor of gastroschisis with complete liver herniation, contrasting it with a death of a similar case. The associated pulmonary hypoplasia may require long-term ventilation, the inflammatory response can lead to anasarca, and renal injury can occur from acute-on-chronic compartment syndrome. Conclusion. External fascial traction systems can help induce growth of the abdominal wall, allowing closure of the challenging abdomen. While critical care management is complex, survival is possible.
Preparation of Pore-Size Controllable Activated Carbon from Rice Husk Using Dual Activating Agent and Its Application in Supercapacitor
Authors: Le Van Khu , Luong Thi Thu Thuy
Published: January 2019

Activated carbons prepared from rice husk by chemical activation with dual activation agents, KOH and NaOH, have been studied and characterized by BET, SEM, EDX, FTIR, Boehm titration, Raman, and TGA. It was found that the KOH/NaOH impregnation ratio plays an important role on textural properties of AC. At the same amount of total alkali hydroxide, the KOH/NaOH ratio higher than 1.33 resulted in larger specific surface area (2990∼3043 m2·g−1), microporous surface area (2747∼2831 m2·g−1), and higher micropore volume (1.4250∼1.4316 cm3·g−1). The as-prepared samples exist in the form of spherical-shaped particles with the size ranging from 20 to 60 nm and contain numerous surface functional groups. The as-prepared activated carbons were then assessed as an electrode material of supercapacitor operating in the 0.5 M K2SO4 electrolyte in potential windows of −1.0∼0.0 V. The highest capacitance obtained was 205 F·g−1 at the scan rate of 2 mV·s−1 and 225 F·g−1 at a current density of 0.2 A·g−1. At the scan rate as high as 50 mV·s−1, all the as-prepared activated carbons in this study have the specific capacitance greater than 100 F·g−1.
Controlling Noncommunicable Diseases in Transitional Economies: Mental Illness in Suicide Attempters in Singapore—An Exploratory Analysis
Authors: Choo Carol C. , Chew Peter K. H. , Ho Roger C.
Published: January 2019

Background. Mental illness is a pertinent risk factor related to suicide. However, research indicates there might be underdiagnosis of mental illness in Asian suicide attempters; this phenomenon is concerning. This study explored prediction of diagnosis of mental illness in suicide attempters in Singapore using available variables. Methods. Three years of medical records related to suicide attempters (N = 462) who were admitted to the emergency department of a large teaching hospital in Singapore were subjected to analysis. Of the sample, 25% were diagnosed with mental illness; 70.6% were females and 29.4% were males; 62.6% were Chinese, 15.4% Malays, and 16.0% Indians. Their age ranged from 12 to 86 (M = 29.37, SD = 12.89). All available variables were subjected to regression analyses. Findings. The full model was significant in predicting cases with and without diagnosis of mental illness and accurately classified 79% of suicide attempters with diagnosis of mental illness. Conclusions. The findings were discussed in regard to clinical implications in diagnosis and primary prevention.
A Concession Equilibrium Solution Method without Weighted Aggregation Operators for Multiattribute Group Decision-Making Problems
Authors: Jiang Min , Shen Rui , Meng Zhiqing
Published: January 2019

This paper introduces a concession equilibrium solution without weighted aggregation operators to multiattribute group decision-making problems (in short MGDMPs). It is of practical significance for all decision-makers to find an optimal solution to MGDMPs or to sort out all candidate solutions to MGDMPs. It is proved that under certain conditions the optimal concession equilibrium solution does exist, and on this important result the optimal concession equilibrium solution is obtained by solving a single objective optimization problem. Moreover, the optimal concession equilibrium solution is equivalent to the robust optimal solution with the group weight aggregation under the worst weight condition. Finally, it is proved that the concession equilibrium solution is equivalent to a complete order, i.e. all candidate alternatives can be sorted by concession equilibrium solution. By defining the triangular fuzzy numbers of target concession value, the optimal concession equilibrium solution or the order of the alternative solutions can be obtained in the range of objective concession ambiguity. Numerical experiment shows that the solution can balance the evaluations of multiattribute group decision makers. This paper provides a new approach to solving multiattribute group decision-making problems.
Genus-Wide Comparative Genomics Analysis ofNeisseriato Identify New Genes Associated with Pathogenicity and Niche Adaptation ofNeisseriaPathogens
Authors: Lu Qun-Feng , Cao De-Min , Su Li-Li , Li Song-Bo , Ye Guang-Bin , Zhu Xiao-Ying , Wang Ju-Ping
Published: January 2019

N. gonorrhoeaeandN. meningitidis, the only two human pathogens ofNeisseria, are closely related species. But the niches they survived in and their pathogenic characteristics are distinctly different. However, the genetic basis of these differences has not yet been fully elucidated. In this study, comparative genomics analysis was performed based on 15N. gonorrhoeae, 75N. meningitidis, and 7 nonpathogenicNeisseriagenomes. Core-pangenome analysis found 1111 conserved gene families among them, and each of these species groups had opening pangenome. We found that 452, 78, and 319 gene families were unique inN. gonorrhoeae,N. meningitidis, and both of them, respectively. Those unique gene families were regarded as candidates that related to their pathogenicity and niche adaptation. The relationships among them have been partly verified by functional annotation analysis. But at least one-third genes for each gene set have not found the certain functional information. Simple sequence repeat (SSR), the basis of gene phase variation, was found abundant in the membrane or related genes of each unique gene set, which may facilitate their adaptation to variable host environments. Protein-protein interaction (PPI) analysis found at least five distinct PPI clusters inN. gonorrhoeaeand four inN. meningitides, and 167 and 52 proteins with unknown function were contained within them, respectively.
Inside-Out 3D Reversible Ion-Triggered Shape-Morphing Hydrogels
Authors: Du X. , Cui H. , Zhao Q. , Wang J. , Chen H. , Wang Y.
Published: January 2019

Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro- and nanostructures within cell walls, resulting in different swelling behaviors. Recent efforts have been dedicated to mimicking the behaviors that nature has perfected over billions of years. We present a robust strategy for preparing 3D periodically patterned single-component sodium alginate hydrogel sheets cross-linked with Ca2+ ions, which can reversibly deform and be retained into various desirable inside-out shapes as triggered by biocompatible ions (Na+/Ca2+). By changing the orientations of the patterned microchannels or triggering with Na+/Ca2+ ions, various 3D twisting, tubular, and plant-inspired architectures can be facilely programmed. Not only can the transformation recover their initial shapes reversibly, but also it can keep the designated shapes without continuous stimuli. These inside-out 3D reversible ion-triggered hydrogel transformations shall inspire more attractive applications in tissue engineering, biomedical devices, and soft robotics fields.
Caecal Epiploic Appendagitis Masquerading Clinically as an Acute Appendicitis: A Case Report and Brief Literature Review
Authors: Ejaz Tallat , Saad Eltaib , Nabil Andik , Slattery James
Published: January 2019

A 46-year-old female presented to our emergency department (ED) with a 2-day history of right lower abdominal pain which was associated with nausea and anorexia. Abdominal examination revealed tenderness in the right iliac fossa (RIF) with rebound tenderness and a localized guarding. Urine dipstick was normal, and the pregnancy test was negative. Her laboratory investigations were significant only for a CRP of 16.6. A presumptive clinical diagnosis of acute appendicitis was suggested based on the given history and relevant physical signs. However, an abdominal computed tomography (CT) scan revealed an epiploic appendagitis of the caecum with a normal-looking appendix. She was managed conservatively and responded well and was discharged after 2 days in good health. Though being a relatively rare case of acute localized right-sided lower abdominal pain, caecal epiploic appendagitis should be considered as one of the differential diagnoses with the final diagnosis reached usually by the radiological findings due to the nonspecific nature of clinical and laboratory features.
DIAPH1 Is Upregulated and Inhibits Cell Apoptosis through ATR/p53/Caspase-3 Signaling Pathway in Laryngeal Squamous Cell Carcinoma
Authors: Yang Jiechao , Zhou Liang , Zhang Yanping , Zheng Juan , Zhou Jian , Wei Zheqiang , Zou Jiaping
Published: January 2019

Cancer bioinformatics has been used to screen possible key cancer genes and pathways. Here, through bioinformatics analysis, we found that high expression of diaphanous related formin 1 (DIAPH1) was associated with poor overall survival in head and neck squamous cell carcinoma and laryngeal squamous cell carcinoma (LSCC). The effect of DIAPH1 in LSCC has not been previously investigated. Therefore, we evaluated the expression, function, and molecular mechanisms of DIAPH1 in LSCC. Immunohistochemistry and western blot analysis confirmed the significant upregulation of DIAPH1 in LSCC. We used DIAPH1 RNA interference to construct two DIAPH1-knockdown LSCC cell lines, AMC-HN-8 and FD-LSC-1, and validated the knockdown efficiency. Flow cytometry data showed that DIAPH1 inhibited apoptosis. Further, western blot analysis revealed that DIAPH1 knockdown increased the protein levels of ATR, p-p53, Bax, and cleaved caspase-3, -8, and -9. Thus, DIAPH1 is upregulated in LSCC and may act as an oncogene by inhibiting apoptosis through the ATR/p53/caspase-3 pathway in LSCC cells.
Influence of Chemical Corrosion on Pore Structure and Mechanical Properties of Sandstone
Authors: Lin Yun , Zhou Keping , Gao Rugao , Li Jielin , Zhang Jian
Published: January 2019

Chemical corrosion plays a significant role in affecting the properties of rock materials. To understand the effects of chemical corrosion on the pore structure and mechanical properties of sandstones, porosity, T2 spectrum distribution, and NMR images of sandstone specimens were measured after every 10 days of immersion in chemical solutions using the nuclear magnetic resonance (NMR) technique. Static uniaxial compressive tests and dynamic compressive tests were conducted using a conventional servo-controlled testing machine and a split Hopkinson pressure bar (SHPB) system for specimens treated with chemical corrosion. The test results showed that after being treated with chemical corrosion, the porosity of a specimen increased, the T2 spectrum distribution would successively shift towards the right, and the distribution of pores tended to become more irregular. Additionally, all of the compressive strength and elastic modulus of sandstone treated with chemical corrosion under static and dynamic loads decreased, and the peak strain increased. The effect order of a chemical solution on the pore structure and mechanical properties of sandstone was H2SO4>NaOH>distilled water, which would be related to the different mechanisms of a water-rock reaction. According to the experimental results, the correlations between the mechanical properties and porosity were established. The results can serve as a reference for research in related fields.
Nonlinear Dynamic Characteristics of Marine Rotor‐Bearing System under Heaving Motion
Authors: Han Yongchao , Li Ming
Published: January 2019

In this paper, the influence of the heaving motion on the nonlinear dynamic behavior of the rotor‐bearing system is considered. First, a mathematic model of the marine rotor‐bearing system is developed on the short bearing theory in the noninertial reference system, in which the heaving motion is taken into account. Then its dynamic characteristics are analyzed based on the numerical integration method, such as the bifurcation diagram, the largest Lyapunov exponents (LLE), the steady‐state response, and the rotor orbit and its Poincaré map. The results indicate that heaving motion has a great effect on the dynamics of the rotor system, which exhibits a period 1 motion at low rotating speed, with the increase of the rotating speed, the phenomena of the quasiperiodic, period 2, and double Hopf bifurcations appear. Its dynamic performance presents a period 1 motion, period 2, quasiperiodic, and chaotic oscillation.
Study on the Permeability of Weakly Cemented Sandstones
Authors: Lyu XianZhou , Zhao Zenghui , Wang Xiaojie , Wang Weiming
Published: January 2019

Fractured rocks are a type of complex media that widely exist in various projects including energy, hydraulic, and underground space engineering, whose permeability properties are a hotspot in current rock mechanics domain. Aiming at investigating the seepage characteristics of the fracture surfaces in different rock strata, uniaxial compressive test and permeability test were performed on single-fracture homogenous and heterogeneous rocks. Specifically, rock’s physical and mechanical parameters were measured in uniaxial tests while the initial width of the single fracture was determined through CT scanning. In combination with test results and the calculation model of the displacement of single-fracture heterogeneous rock under triaxial stress condition, the calculation formula of the permeability coefficient of single-fracture heterogeneous rock was derived. Results show that hydraulic pressure in the fracture can affect the permeability coefficient of the fractured rock. Hydraulic fracturing effect occurred with the increase of hydraulic pressure in the fracture, which then generates slight normal deformations of the rock masses on both two sides of the fracture surface, decreases the contact area in the fracture, and leads to the increases of both fracture width and permeability coefficient. For single-fracture rock, the lithological properties of the rock masses on both two sides of the fracture surface impose significant effects on the permeability coefficient. Under same hydraulic pressure and confining pressure, the permeability coefficient of single-fracture coarse sandstone is greatest, followed by that of single-fracture heterogeneous rock, and finally by single-fracture fine sandstone. Theoretical calculation results agree well with the test results, suggesting that the derived theoretical formula can adequately describe the variation tendencies of permeability coefficient with confining pressure and hydraulic pressure in the fracture.
Experimental Investigation on the Effect of Steel Fibers on the Flexural Behavior and Ductility of High‐Strength Concrete Hollow Beams
Authors: Abbass Ahmmad , Abid Sallal , Özakça Mustafa
Published: January 2019

In this study, an experimental work was directed toward comparing the flexural behavior of solid and hollow steel fiber‐reinforced concrete beams. For this purpose, eight square cross‐sectional beam specimens, four solid and four hollow, were prepared. One concrete mixture with four different steel fiber contents of 0, 0.5, 1.0, and 1.5% were used. The side length of the central square hole was 80 mm, whereas the cross‐sectional side length was 150 mm. All beams were tested under four‐point monotonic loading until failure. In addition to the solid and hollow beams, cylinders were cast to evaluate the compressive strength, splitting tensile strength, and modulus of elasticity, whereas prisms were used to conduct the fracture test. The test results showed that all fibrous beams failed in flexure, whereas those without fiber exhibited flexural‐shear failure. In general, the flexural behavior of fibrous‐beams was superior to that of beams without fiber. The hollow beams with fiber contents of 0, 0.5, and 1.0% were observed to withstand lower loads at cracking, yielding, and peak stages compared with their corresponding solid beams; this was not the case for the 1.5% fiber hollow beam, which exhibited a higher peak load than its corresponding solid beam. Although all eight beams exhibited ductility indices higher than 3.7, hollow beams exhibited better ductility than solid beams, showing higher ductility index values.
Facility Layout Planning with SHELL and Fuzzy AHP Method Based on Human Reliability for Operating Theatre
Authors: Lin QingLian , Wang Duojin
Published: January 2019

A well-design facility layout planning refers to the reduction of the operation cost in the manufacturing and service industry. This work consists of reliability analysis of facility layout for an operating theatre; it aims at proposing a new evaluation approach, which integrated the fuzzy analytic hierarchy process and human reliability tool, for optimization of facility layout design with safety and human factors in an operating theatre. Firstly, the systematic layout planning is used to design the layout schemes on the basis of field investigations. Then, the criteria system is proposed based on human reliability analysis from four perspectives: software, hardware, environment, and liveware. Finally, the fuzzy analytic hierarchy process, a fuzzy extension of the multicriteria decision-making technique analytic hierarchy process, is used to compare these layout schemes based on the criteria system. The results that are obtained reveal interesting properties of facility layout planning in hospitals. It reveals that decision in selecting a suitable layout must meet not only the strategies and goals of the system but also meet the safety, security, and reliability of the system.
Image Encryption with Double Spiral Scans and Chaotic Maps
Authors: Tang Zhenjun , Yang Ye , Xu Shijie , Yu Chunqiang , Zhang Xianquan
Published: January 2019

Image encryption is a useful technique of image content protection. In this paper, we propose a novel image encryption algorithm by jointly exploiting random overlapping block partition, double spiral scans, Henon chaotic map, and Lü chaotic map. Specifically, the input image is first divided into overlapping blocks and pixels of every block are scrambled via double spiral scans. During spiral scans, the start-point is randomly selected under the control of Henon chaotic map. Next, image content based secret keys are generated and used to control the Lü chaotic map for calculating a secret matrix with the same size of input image. Finally, the encrypted image is obtained by calculating XOR operation between the corresponding elements of the scrambled image and the secret matrix. Experimental result shows that the proposed algorithm has good encrypted results and outperforms some popular encryption algorithms.
Antioxidant Supplementation in Renal Replacement Therapy Patients: Is There Evidence?
Authors: Liakopoulos Vassilios , Roumeliotis Stefanos , Bozikas Andreas , Eleftheriadis Theodoros , Dounousi Evangelia
Published: January 2019

The disruption of balance between production of reactive oxygen species and antioxidant systems in favor of the oxidants is termed oxidative stress (OS). To counteract the damaging effects of prooxidant free radicals, all aerobic organisms have antioxidant defense mechanisms that are aimed at neutralizing the circulating oxidants and repair the resulting injuries. Antioxidants are either endogenous (the natural defense mechanisms produced by the human body) or exogenous, found in supplements and foods. OS is present at the early stages of chronic kidney disease, augments progressively with renal function deterioration, and is further exacerbated by renal replacement therapy. End-stage renal disease patients, on hemodialysis (HD) or peritoneal dialysis (PD), suffer from accelerated OS, which has been associated with increased risk for mortality and cardiovascular disease. During HD sessions, the bioincompatibility of dialyzers and dialysate trigger activation of white blood cells and formation of free radicals, while a significant loss of antioxidants is also present. In PD, the bioincompatibility of solutions, including high osmolality, elevated lactate levels, low pH, and accumulation of advanced glycation end-products trigger formation of prooxidants, while there is significant loss of vitamins in the ultrafiltrate. A number of exogenous antioxidants have been suggested to ameliorate OS in dialysis patients. Vitamins B, C, D, and E, coenzyme Q10, L-carnitine, a-lipoic acid, curcumin, green tea, flavonoids, polyphenols, omega-3 polyunsaturated fatty acids, statins, trace elements, and N-acetylcysteine have been studied as exogenous antioxidant supplements in both PD and HD patients.
Timeout for Contrast: Using Physician Behavior Modification to Reduce Contrast in the Catheterization Laboratory
Authors: Singh Robby , Zughaib Marcel
Published: January 2019

Background. As the number of procedures using contrast media continues to rise, the ensuing complications place an ever increasing burden on the healthcare system. Contrast-induced nephropathy (CIN) is a common postprocedural complication after cardiac catheterization. Objectives. The purpose of our study was to evaluate the impact of physician behavioral modification on reducing the amount of contrast used during the procedure. Methods. All patients who underwent procedures in the cardiac catheterization laboratory from January 2013 to August 2016 were identified in addition to the total contrast used during the procedure, the type of procedure performed, and the operator performing the procedure. A new addition was made to the preprocedure checklist in September-October 2013 in the form of maximum allowed contrast for the patient. Results. A total of 12,118 cases were identified. Across all procedures, the mean contrast used during the 8 months prior to the intervention was 118 ml per procedure. Mean contrast used per procedure for the first year after the revised timeout was 105 ml, for the second year was 106 ml, and for the third year was 99 ml. Conclusion. A significant reduction in radiocontrast use across all operators and procedures after the introduction of a revised timeout procedure that was seen, which is a change that was sustained over a period of three years. With this straightforward intervention involving physician behavioral modification, patients were exposed to less of the nephrotoxic contrast and were consequently at a lower risk of developing dose-depended CIN and other associated complications.
Screening Five Qi-Tonifying Herbs on M2 Phenotype Macrophages
Authors: Jiang Yi-Xin , Chen Yan , Yang Yue , Chen Xiao-Xia , Zhang Dan-Dan
Published: January 2019

Tumor-associated macrophages (TAMs) with M2 phenotype play an essential role in tumor microenvironment (TME) during the progression and development of numerous cancers and associated with poor prognosis. Thus, regulation of TAMs polarization emerged as a new strategy for tumor immune therapy. According to Traditional Chinese Medicine (TCM) theory, herbs with Qi-tonifying character are involved in improving the defense capacity of immune system. In this study, we screened extracts and ingredients from five Qi-tonifying herbs exhibiting an inhibitory effect on M2 polarization of murine macrophages RAW264.7 induced by IL-4 and IL-13. Among these candidates, total flavonoids from Glycyrrhiza Radix et Rhizoma (TFRG) and ethanol extract of Ginseng Radix et Rhizoma significantly inhibited the expression of Arginase-1 (Arg-1) (above 90% at 100μg/mL), one of the phenotype markers of M2 macrophages. The inhibition of total saponins of Ginseng Radix et Rhizoma, ethanol extract of Cordyceps, ethanol extract of Acanthopanacis senticosi Radix et Rhizoma Seu caulis, and ethanol extract of Astragali Radix reached above 50% at 100μg/mL. The inhibition of ingredients including glabridin, isoliquiritin apioside, lysionotin, cordycepin, astragaloside IV, and calycosin reached above 50% at 50μM. Then, we investigated the molecular mechanisms of TFRG. TFRG abolished the migration of murine breast cancer 4T1 stimulated by the conditioned medium from M2 macrophages (M2-CM). In addition to Arg-1, TFRG also antagonized the IL-4/13-mediated mRNA upregulation of the M2 markers including found in inflammatory zone 1 (FIZZ1), chitinase-3-like protein 3 (YM1), and mannose receptor (CD206) and upregulated the expression of inducible nitric oxide synthase (iNOS), one of the M1 markers. The further exploration showed that TFRG decreased the phosphorylation of STAT6 and increased the expression of miR-155. Our study provides a series of potential immune regulating natural products from five Qi-tonifying herbs on M2 phenotype. For instance, TFRG suppressed M2 polarization of macrophages partly by inactivating STAT6 pathway and enhanced the level of miR-155 to regulate the expressions of M1 and M2 markers.
The First-week Proliferative Response of Peripheral Blood PD-1+CD8+ T Cells Predicts the Response to Anti-PD-1 Therapy in Solid Tumors
Authors: Kim Kyung Hwan , Cho Jinhyun , Ku Bo Mi , Koh Jiae , Sun Jong-Mu , Lee Se-Hoon , Ahn Jin Seok , Cheon Jaekyung , Min Young Joo , Park Su-Hyung , Park Keunchil , Ahn Myung-Ju , Shin Eui-Cheol
Published: January 2019

Purpose:

To investigate blood-based dynamic biomarkers that predict responses to anti–programmed cell death protein 1 (PD-1) therapy in solid tumors.

Experimental Design:

Preplanned biomarker analysis was performed as part of a phase II clinical trial (NCT02607631) in patients with metastatic or refractory thymic epithelial tumors (TETs; n = 31) who received pembrolizumab. The biomarker was further tested in an independent cohort of prospectively recruited patients with metastatic non–small cell lung cancer (NSCLC) who received pembrolizumab or nivolumab (NSCLC cohort 1; n = 33) and validated in an independent cohort of patients with NSCLC (NSCLC cohort 2; n = 46). Peripheral blood samples were obtained immediately before treatment (D0) and 7 days after the first dose (D7) and analyzed using multi-color flow cytometry.

Results:

A higher fold-change in the percentage of Ki-67+ cells among PD-1+CD8+ T cells 7 days after the first dose (Ki-67D7/D0) significantly predicted durable clinical benefit (DCB; P < 0.001) and prolonged progression-free survival (PFS; P = 0.027) in patients with TETs. Ki-67D7/D0 ≥ 2.8 was also associated with better DCB, PFS, and overall survival (OS) in NSCLC cohort 1 (all P < 0.05). Ki-67D7/D0 was subsequently validated in NSCLC cohort 2, and Ki-67D7/D0 ≥ 2.8 significantly predicted better DCB (P = 0.001), PFS (P = 0.002), and OS (P = 0.037). Ki-67D7/D0 had a low correlation with tumor PD-L1 expression and combining both factors did not improve the predictive power of Ki-67D7/D0.

Conclusions:

The proliferative response of peripheral blood PD-1+CD8+ T cells, measured as the fold-change in the percentage of Ki-67+ cells 7 days after treatment (Ki-67D7/D0), may be a useful surrogate biomarker for predicting the response and prognosis to anti-PD-1 therapy in solid tumors.
Continued Endocrine Therapy Is Associated with Improved Survival in Patients with Breast Cancer Brain Metastases
Authors: Bergen Elisabeth S. , Berghoff Anna S. , Medjedovic Mela , Rudas Margaretha , Fitzal Florian , Bago-Horvath Zsuzsanna , Dieckmann Karin , Mader Robert M. , Exner Ruth , Gnant Michael , Zielinski Christoph C. , Steger Guenther G. , Preusser Matthias , Bartsch Rupert
Published: January 2019

Purpose:

Brain metastases (BMs) are a rare but devastating condition in estrogen receptor (ER)–positive metastatic breast cancer (MBC). Although endocrine therapy (ET) is the mainstay of treatment in this disease subtype, only case reports have been published concerning the activity of ET in BMs henceforth. Therefore, we aimed to systematically investigate the impact of ET after diagnosis of BM on outcome and clinical course of disease in patients with ER-positive MBC.

Experimental Design:

Patient characteristics, detailed information about BMs including diagnosis-specific graded prognostic assessment class (DS-GPA), and clinical outcome were obtained by retrospective chart review for all patients treated for ER-positive breast cancer BMs between 1990 and 2017 at an academic care center. Overall survival (OS) was measured as the interval from diagnosis of BM until death or last date of follow-up.

Results:

Overall, 198 patients [female: 195/198 (98.5%); male: 3/198 (1.5%)] with ER-positive breast cancer BMs were available for this analysis. Eighty-eight of 198 patients (44.4%) received ET after diagnosis of BM including aromatase inhibitors (AIs; letrozole, anastrozole, exemestane), tamoxifen, and fulvestrant. Median OS was significantly longer in patients receiving ET after diagnosis of BM compared with patients who did not (15 vs. 4 months, P < 0.001; log-rank test). No significant difference in terms of OS was observed between patients receiving AIs, tamoxifen, or fulvestrant. In patients with concomitant leptomeningeal carcinomatosis (LC), ET prolonged median OS significantly as well (7 vs. 3 months, P = 0.012; log-rank test). In a multivariate analysis including DS-GPA and ET, only treatment with ET after diagnosis of BM (HR, 0.69; 95% confidence interval, 0.48–0.99; P = 0.046) was associated with prognosis (Cox regression model).

Conclusions:

Continuing ET after BM diagnosis was associated with a significantly prolonged OS in this large single-center cohort. No substantial differences between substances were observed. These findings should be validated in a prospective cohort.
Inadvertent Migration of Umbilical Venous Catheters Often Leads to Malposition
Authors: Dubbink-Verheij Gerdina H. , Visser Remco , Tan Ratna N.G.B. , Roest Arno A.W. , Lopriore Enrico , te Pas Arjan B.
Published: January 2019

Background: Migration of umbilical venous catheters (UVCs) has been described anecdotally. Objectives: The aim of this paper was to investigate migration of UVCs using ultrasonography (US). Methods: In a prospective observational study, the position of UVCs was determined using serial US within 24 h, at midweek, and at the end of the week after umbilical catheterization. Migration was recorded in distance and direction. Malposition was defined as a position of the UVC in the heart (right atrium or more distal along the UVC-route), umbilicoportal confluence, or in the umbilical vein. UVC position determined by US was compared with chest X-rays (CXRs) when these were performed for standard care within the same period of 1 h. Results: Migration of UVCs was detected with US in 25/40 infants (63%) in 32 occasions, leading to malposition in 17/25 (68%) infants. UVCs migrated inwards in 18/32 (56%), leading to a position within the heart in 17/18 occasions. Most migrations occurred before Day 3 (21/32 [66%]). When a CXR was taken at the same time as US was performed (30 occasions), the assessment of the catheter-tip position differed in 23% of the occasions. When malposition was detected by US, this was detected on routinely performed CXRs in 11% of the occasions. Conclusions: UVCs often migrate following insertion, often leading to malposition. Awareness for this is needed, and US is a feasible alternative for detecting malposition compared to CXRs and avoids additional radiation. Re-evaluation of the position of UVCs at least once, but within 24 h after placement, is recommended.