bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesenchymal Stem Cells for Liver Regeneration in Liver Failure: From Experimental Models to Clinical Trials
Authors: de Miguel Maria P. , Prieto I. , Moratilla A. , Arias J. , Aller M. A.
Published: May 2019

The liver centralizes the systemic metabolism and thus controls and modulates the functions of the central and peripheral nervous systems, the immune system, and the endocrine system. In addition, the liver intervenes between the splanchnic and systemic venous circulation, determining an abdominal portal circulatory system. The liver displays a powerful regenerative potential that rebuilds the parenchyma after an injury. This regenerative mission is mainly carried out by resident liver cells. However, in many cases this regenerative capacity is insufficient and organ failure occurs. In normal livers, if the size of the liver is at least 30% of the original volume, hepatectomy can be performed safely. In cirrhotic livers, the threshold is 50% based on current practice and available data. Typically, portal vein embolization of the part of the liver that is going to be resected is employed to allow liver regeneration in two-stage liver resection after portal vein occlusion (PVO). However, hepatic resection often cannot be performed due to advanced disease progression or because it is not indicated in patients with cirrhosis. In such cases, liver transplantation is the only treatment possibility, and the need for transplantation is the common outcome of progressive liver disease. It is the only effective treatment and has high survival rates of 83% after the first year. However, donated organs are becoming less available, and mortality and the waiting lists have increased, leading to the initiation of living donor liver transplantations. This type of transplant has overall complications of 38%. In order to improve the treatment of hepatic injury, much research has been devoted to stem cells, in particular mesenchymal stem cells (MSCs), to promote liver regeneration. In this review, we will focus on the advances made using MSCs in animal models, human patients, ongoing clinical trials, and new strategies using 3D organoids.
Modal Analysis for a Rod‐Fastened Rotor considering Contact Effect Based on Double Fractal Model
Authors: Liu Yang , Yuan Qi , Li Pu , Zhu Guangyu
Published: May 2019

The rod‐fastened rotor is the core component of the gas turbine. It comprises several discs and tie rods. The flexural stiffness of the contact interface is the key factor for rotordynamic analysis. The contact interfaces of the discs are usually manufactured by grinding. The measured contour curve of the contact interfaces of an experimental rod‐fastened rotor is analyzed by the structural function method, which shows that the contact interfaces can be well described by the double fractal model with fractal dimensions D1 and D2 and the fractal roughness parameters G1 and G2. The Hertz model is used to analyze the contact of the single asperity on the contact interface. On this basis, the flexural stiffness of the contact interface considering the pretightening force and the bending moment is derived. Modal frequencies of the experimental rod‐fastened rotor under different pretightening forces and the bending moment (caused by gravity) are obtained by three‐dimensional finite element analysis and experimental modal tests. It is observed that the modal frequencies increase with the nominal pressure of the contact interface, and the experimental results are consistent with the calculated results.
Complications of Intrathecal Chemotherapy in Adults: Single-Institution Experience in 109 Consecutive Patients
Authors: Byrnes Diana M. , Vargas Fernando , Dermarkarian Christopher , Kahn Ryan , Kwon Deukwoo , Hurley Judith , Schatz Jonathan H.
Published: May 2019

Acute lymphoblastic leukemia and other aggressive lymphoid malignancies like Burkitt leukemia/lymphoma have high incidence of central nervous system (CNS) involvement. Various solid tumors, most notably breast cancer, can also metastasize into the CNS as a late stage complication causing devastating effects. Intrathecal (IT) chemotherapy consisting of methotrexate, cytarabine, or the two in combination is frequently used for the prophylaxis and treatment of CNS metastasis. Because of the high toxicity of these chemotherapeutic agents, however, their side effect profiles are potentially catastrophic. The incidence of neurotoxicity secondary to IT chemotherapy is well defined in the pediatric literature but is poorly reported in adults. Here, we investigated the incidence of neurologic and nonneurologic side effects secondary to IT chemotherapy in 109 consecutive adult patients over a two-year time period at hospitals associated with our institution. Of 355 IT chemotherapy treatments received by these patients, 11 (3.10%) resulted in paresthesias or paralysis, which we defined as significant neurologic events in our analysis. We also examined minor events that arose after IT chemotherapy, including back pain, headache, fever, vomiting, and asthenia. At least one of these occurred after 30.70% of IT chemotherapy doses. Clinicians involved in the care of patients receiving IT chemotherapy should be aware of these findings and consider treatment options lower rate of neurotoxicity such as high-dose systemic methotrexate.
A Case of Incomplete Removal of Horseshoe Kidney by Laparoscopic Nephrectomy in an Adult Leading to Urinary Leak: An Eye Opener
Authors: Venkat Ramanan S. , Velmurugan P. , Bhaskar Prakash A. R. , Arora Anuj , Karri LeelaKrishna
Published: May 2019

Horseshoe kidney is a common congenital fusion anomaly of the kidneys. It poses a challenge to surgeon because of its very variable anatomy in terms of location and lie, fusion, pelvicalyceal system, and the renal vessels. Here we describe a case of laparoscopic nephrectomy in a horseshoe kidney complicated by incomplete removal because of not realizing the lower and medial extent of pelvicalyceal system across midline to the contralateral side leading to persistent urine leak. The relevant anatomy and the necessary precautions to prevent such complication have been discussed.
Timolol 0.1% in Glaucomatous Patients: Efficacy, Tolerance, and Quality of Life
Authors: Negri Letizia , Ferreras Antonio , Iester Michele
Published: May 2019

Glaucoma is a progressive, chronic optic neuropathy characterized by a typical visual field defects. Four main classes of topical medication are actually available on the market: beta-blockers, prostaglandins, alpha2-agonists, and topical carbonic anhydrase inhibitor to treat intraocular pressure (IOP). The aim of this review is to outline the efficacy of timolol and to evaluate the impact of this treatment on patients’ quality of life. Among beta-blockers, timolol is most used at three different concentrations: 0.1%, 0.25%, and 0.5%. While the first one is a gel, the other two products are solution. Timolol has few topical side effects, while it has some important systemic side effects on the cardiac and respiratory systems. The balance between efficacy and safety is always the main aspect to care patients. Because of the less efficacy of timolol 0.1% solution, the possibility to use carbomers as vehicle in the gel drops helped timolol 0.1 to be used in clinics, extending the time contact between the active ingredient and the surface of the cornea. Using preservative-free timolol 0.1 for treatment, IOP was at the same level of the other beta-blockers at higher concentration, but it was better tolerated. Preservative-free treatment improved the quality of life reducing dry-eye like symptoms; furthermore, the presence of an artificial tear in the medication bottle could help adherence. The once daily dosing improves compliance.
Association of Single-Nucleotide Polymorphism REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 with Primary Lung Cancer Susceptibility: A Case-Control Study in a Chinese Population
Authors: Shen Qi , Wang Wen-xiang , Xu Qiu-ping , Xiong Wen-min , Liu Zhi-qiang , Hu Zhi-jian , Cai Lin , He Fei
Published: May 2019

The purpose of the current study is to explore the contribution of single-nucleotide polymorphisms (SNPs) of REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 to the risk of lung cancer. A questionnaire survey was used to obtain basic information of the included subjects. A case control study was performed in 1121 patients and 1121 controls. All subjects were subjected to blood sampling for genomic DNA extraction and genotyping of the cancer stem cell-associated gene SNPs, including REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 by real-time PCR. The association with the risk of primary lung cancer and interaction with environmental factors were assessed using unconditional logistic regression for the odds ratios and corresponding 95% confidence intervals. The genotype frequency distribution of OCT4 rs13409 loci was statistically significant, but there was no significant difference in the rest of the loci between lung cancer patients and healthy controls. The OCT4 gene was also related with lung cancer susceptibility in the genetic model after adjusting for lung cancer-related factors. Despite the presence of the dominant or recessive model, the four loci polymorphisms were associated with pollution near the place of residence, house type, worse ventilation situation, smoking, passive smoking, cooking oil fumes (COF), and family history of cancer, which increased the risk of lung cancer. Nonmarried status, 18.5≤BMI, COF, smoking, passive smoking, family history of cancer, and history of lung disease were independent risk factors of lung cancer susceptibility. Additionally, college degree or above, no pollution near the place of residence, protective genotype 1 or 2, and well ventilation can reduce the occurrence of lung cancer. There is an interaction between the four loci and environmental factors, and OCT4 rs13409 is a risk factor of primary lung cancer.
The Incremental Cost of Delivering PrEP as a Bridge to ART for HIV Serodiscordant Couples in Public HIV Care Clinics in Kenya
Authors: Irungu Elizabeth M. , Sharma Monisha , Maronga Christopher , Mugo Nelly , Ngure Kenneth , Celum Connie , Barnabas Ruanne V. , Baeten Jared , Heffron Renee
Published: May 2019

Background. In 2016, the Kenyan Ministry of Health (MOH) released guidelines that recommend preexposure prophylaxis (PrEP) for persons with substantial ongoing HIV risk, including those in HIV serodiscordant partnerships. Estimates of the costs of delivering PrEP within Kenyan public health facilities are needed for planning for PrEP scale up. Methods. We estimated the incremental annual costs of providing PrEP to HIV uninfected partners as a time-limited “bridge” until the infected partner is virally suppressed on ART within HIV serodiscordant couples as part of routine clinic care in Thika, Kenya. Costs were collected from the Partners Demonstration Project, a prospective evaluation of integrated delivery of preexposure prophylaxis (PrEP) and antiretroviral therapy (ART) to high-risk HIV serodiscordant couples. We conducted time and motion studies to distinguish between activities related to research, routine clinical care, and PrEP delivery. Costs (2015 US dollars) were collected from the MOH perspective and divided into staff, transportation, equipment, supplies, buildings and overhead, and start-up. Results. PrEP related activities conducted during the screening, enrollment, and follow-up visits took an average of 13 minutes, 51 minutes, and 12 minutes, respectively. Assuming a staff structure of 3 counselors, 1 nurse, and 2 clinicians, we estimate that 3,178 couples can be screened, 1,444 couples offered PrEP and ART, and 6,138 couples followed up annually in an average HIV care clinic. Using costs incurred by the MOH for personnel, drug, and laboratory tests, we estimate that the incremental cost of offering PrEP to HIV uninfected partners within existing ART programs is $86.79 per couple per year. Personnel and PrEP medication made up the largest portion of the costs. We estimate that the total cost to Ministry of Health of delivering integrated PrEP and ART program in public health facilities is $250.19 per HIV serodiscordant couple per year. Conclusions. Time-limited provision of PrEP to the HIV uninfected partner within HIV serodiscordant couples can be an affordable delivery model implemented in HIV care programs in Kenya and similar settings. These costs can be used for budgetary planning and cost effectiveness analyses.
Energy-Efficient Hybrid Precoding Scheme Based on Antenna Selection Technology in Massive Multiple-Input Multiple-Output Systems
Authors: Ding Jian Jun , Jiang Jing
Published: May 2019

Hybrid precoding is a promising technology for massive multiple-input multiple-output (MIMO) systems. It can reduce the number of radio frequency (RF) chains. However, the power consumption is still very high owing to the large-scale antenna array. In this paper, we propose an energy-efficient precoding scheme based on antenna selection technology. The precoding scheme greatly increases the energy efficiency (EE) of the system. In the first step, we derive an exact closed-form expression of EE. Meanwhile, we further study the relationship between the number of transmit antennas and EE on the basis of the exact closed-form expression of EE. We prove that there exists an optimal value. When the number of transmit antennas equals to the value, the EE of the system can reach the maximum by a proper hybrid precoding scheme. Then, we propose an antenna selection algorithm to select antennas from the transmit antennas. And the number of selected antennas equals to the optimal value. Subsequently, we design the analog precoder based on a codebook to maximize the equivalent channel gain. At last, we further improve the EE by baseband digital precoding. The precoding algorithm we proposed offers a compromise between spectral efficiency (SE) and EE in millimeter wave (mmWave) massive MIMO systems. Finally, simulation results validate our theoretical analysis and show that a substantial EE gain can be obtained over the precoding scheme we proposed without large performance loss.
GSK-3β at the Intersection of Neuronal Plasticity and Neurodegeneration
Authors: Jaworski Tomasz , Banach-Kasper Ewa , Gralec Katarzyna
Published: May 2019

In neurons, Glycogen Synthase Kinase-3β (GSK-3β) has been shown to regulate various critical processes underlying structural and functional synaptic plasticity. Mouse models with neuron-selective expression or deletion of GSK-3β present behavioral and cognitive abnormalities, positioning this protein kinase as a key signaling molecule in normal brain functioning. Furthermore, mouse models with defective GSK-3β activity display distinct structural and behavioral abnormalities, which model some aspects of different neurological and neuropsychiatric disorders. Equalizing GSK-3β activity in these mouse models by genetic or pharmacological interventions is able to rescue some of these abnormalities. Thus, GSK-3β is a relevant therapeutic target for the treatment of many brain disorders. Here, we provide an overview of how GSK-3β is regulated in physiological synaptic plasticity and how aberrant GSK-3β activity contributes to the development of dysfunctional synaptic plasticity in neuropsychiatric and neurodegenerative disorders.
Reuse of Zeolite By-Products Derived from Petroleum Refining for Sustainable Roads
Authors: Sol-Sánchez M. , Moreno-Navarro F. , Rubio-Gámez M. C. , Pérez-Mena V. , Cabanillas P.
Published: May 2019

The reduction in consumption of natural resources (fuel, gas, etc.) and contaminant emissions (CO2, CO, NOx, etc.) during the production of asphalt mixtures has become one of the main challenges in road engineering. Warm mix asphalts (WMAs) have been developed in order to achieve this objective while ensuring the mechanical performance and durability of traditional hot mix asphalts (HMAs). However, these materials are commonly manufactured using additives or products whose production could reduce both their environmental benefits and cost effectiveness. This paper presents a research study that aims to analyse the reuse of zeolite wastes derived from petroleum refining in the production of warm mix asphalts. For this purpose, two different types of zeolite wastes were analysed as additives for the manufacture of two warm mix asphalts, whose mechanical performance was compared with conventional WMA and hot mix asphalt. The results indicate that zeolite wastes with a lower particles size presented higher capacity to absorb water, while its dosage at 0.3% allows for producing warm mix asphalts at temperatures around 145°C, with comparable workability and densification to conventional HMA at 165°C without reducing its bearing capacity, fatigue life, and resistance to water action and plastic deformation.
An Incremental Version of L-MVU for the Feature Extraction of MI-EEG
Authors: Li Mingai , Xi Hongwei , Zhu Xiaoqing
Published: May 2019

Due to the nonlinear and high-dimensional characteristics of motor imagery electroencephalography (MI-EEG), it can be challenging to get high online accuracy. As a nonlinear dimension reduction method, landmark maximum variance unfolding (L-MVU) can completely retain the nonlinear features of MI-EEG. However, L-MVU still requires considerable computation costs for out-of-sample data. An incremental version of L-MVU (denoted as IL-MVU) is proposed in this paper. The low-dimensional representation of the training data is generated by L-MVU. For each out-of-sample data, its nearest neighbors will be found in the high-dimensional training samples and the corresponding reconstruction weight matrix be calculated to generate its low-dimensional representation as well. IL-MVU is further combined with the dual-tree complex wavelet transform (DTCWT), which develops a hybrid feature extraction method (named as IL-MD). IL-MVU is applied to extract the nonlinear features of the specific subband signals, which are reconstructed by DTCWT and have the obvious event-related synchronization/event-related desynchronization phenomenon. The average energy features of α and β waves are calculated simultaneously. The two types of features are fused and are evaluated by a linear discriminant analysis classifier. Based on the two public datasets with 12 subjects, extensive experiments were conducted. The average recognition accuracies of 10-fold cross-validation are 92.50% on Dataset 3b and 88.13% on Dataset 2b, and they gain at least 1.43% and 3.45% improvement, respectively, compared to existing methods. The experimental results show that IL-MD can extract more accurate features with relatively lower consumption cost, and it also has better feature visualization and self-adaptive characteristics to subjects. The t-test results and Kappa values suggest the proposed feature extraction method reaches statistical significance and has high consistency in classification.
Diagnostic Value of Salivary Markers in Neuropsychiatric Disorders
Authors: Kułak-Bejda Agnieszka , Waszkiewicz Napoleon , Bejda Grzegorz , Zalewska Anna , Maciejczyk Mateusz
Published: May 2019

A growing interest in the usability of saliva has been observed recently. Using saliva as a diagnostic material is possible because it contains a varied range of composites, organic and inorganic like proteins, carbohydrates, and lipids, which are secreted into saliva. Moreover, this applies to drugs and their metabolites. Saliva collection is noninvasive, and self-collection is possible. There is a lack of risk of injuries related to injection with needle, and it is generally safe. Human saliva has been successfully used, for example, in the diagnosis of many systemic diseases like cancers, autoimmunological diseases, infectious diseases (HIV, hepatitis, and malaria), and endocrinological diseases, as well as diseases of the gastrointestinal tract. Also, it is used in toxicological diagnostics, drug monitoring, and forensic medicine. The usefulness of saliva as a biological marker has also been extended to psychiatry. The specificity of mental illness and patients limits or prevents cooperation and diagnosis. In many cases, the use of saliva as a marker seems to be the most sensible choice.
Functional Metagenomics Characterization of an Anaerobic Saltwater Bioreactor
Authors: Derilus D. , Forestil A. , Fortuné J. , Polyanska O. , Louime C. , Gervais G. , Massey S. E.
Published: May 2019

Methanogens are restricted to a few genera of Archaea, however they have great importance in the carbon cycle, impacting climactic considerations, and also find a role in renewable energy in the form of biogas. Here, we examine the microbial contribution to the production of methane in a sargassum fed anaerobic saltwater bioreactor, which are poorly characterized compared to fresh water bioreactors, using a comprehensive functional metagenomics approach. Despite abundant production of methane, we detected a low proportion of Archaea in the system using 16S rRNA community profile analyses. We address the low representation using an additional 16S rRNA analysis of shotgun data and a consideration of CO2:CH4production. Using a novel network alignment and tree building approach, we measured similarity between the meta-metabolic capabilities of different anaerobic microbial communities. The saltwater bioreactor samples clustered together, validating the approach and providing a method of determining meta-metabolic similarity between microbial communities, with a range of potential applications. We also introduce a number of additional approaches for examining and interpreting meta-metabolic network topology. The low abundance of methanogens appears as a common property of such anaerobic systems and likely reflects the relatively poor energetics of methanogens, while examination of key enzymes confirms that hydrogen producing bacteria are the major fermentative guild. Our results indicate that the use of readily available seawater and marine macroalgae is a promising approach to the production of biogas as a source of renewable energy.
Visual Object Tracking in RGB‐D Data via Genetic Feature Learning
Authors: Jiang Ming-xin , Luo Xian-xian , Hai Tao , Wang Hai-yan , Yang Song , Abdalla Ahmed N.
Published: May 2019

Visual object tracking is a fundamental component in many computer vision applications. Extracting robust features of object is one of the most important steps in tracking. As trackers, only formulated on RGB data, are usually affected by occlusions, appearance, or illumination variations, we propose a novel RGB‐D tracking method based on genetic feature learning in this paper. Our approach addresses feature learning as an optimization problem. As owning the advantage of parallel computing, genetic algorithm (GA) has fast speed of convergence and excellent global optimization performance. At the same time, unlike handcrafted feature and deep learning methods, GA can be employed to solve the problem of feature representation without prior knowledge, and it has no use for a large number of parameters to be learned. The candidate solution in RGB or depth modality is represented as an encoding of an image in GA, and genetic feature is learned through population initialization, fitness evaluation, selection, crossover, and mutation. The proposed RGB‐D tracker is evaluated on popular benchmark dataset, and experimental results indicate that our method achieves higher accuracy and faster tracking speed.
Biomarkers for Alzheimer’s Disease in Saliva: A Systematic Review
Authors: Gleerup Helena Sophia , Hasselbalch Steen Gregers , Simonsen Anja Hviid
Published: May 2019

Background. The histopathological changes of Alzheimer’s disease (AD) are detectable decades prior to its clinical expression. However, there is a need for an early, inexpensive, noninvasive diagnostic biomarker to detect specific Alzheimer pathology. Recently developed neuroimaging biomarkers show promising results, but these methods are expensive and cause radiation. Furthermore, the analysis of cerebrospinal fluid (CSF) biomarkers requires an invasive lumbar puncture. Saliva is an easily obtained body fluid, and a stable saliva biomarker would therefore be a promising candidate for a future method for diagnosing AD. The purpose of this systematic review was to investigate studies of biomarkers in saliva samples for the diagnosis of AD. Methods. The included articles were identified through a literature search in PubMed and Google Scholar for all articles until November 1st, 2018, and furthermore, all reference lists of included articles were reviewed by hand. We included articles written in English investigating saliva from patients with AD and a control group. Results. A total of 65 studies were identified, whereof 16 studies met the inclusion criteria and were included in the systematic review. A plethora of different biomarkers were investigated, and ten out of the sixteen studies showed a statistical significance in biomarkers between patients with AD and healthy, elderly controls, among these biomarkers for specific AD pathology (amyloid beta 1-42 (Aβ42) and tau). Conclusion. Aβ42 and tau seem to be worthy candidates for future salivary biomarkers for AD, but other biomarkers such as lactoferrin and selected metabolites also have potential. More studies must be carried out with larger sample sizes and a standardization of the sampling and processing method. Factors such as diurnal variation, AD patients’ decreased ability of oral self-care, and salivary flowrates must be taken into consideration.
A Geometric Model to Determine Patient-Specific Cup Anteversion Based on Pelvic Motion in Total Hip Arthroplasty
Authors: Sutter E. Grant , Wellman Samuel S. , Bolognesi Michael P. , Seyler Thorsten M.
Published: May 2019

Introduction. Cup position is critical to stability in total hip arthroplasty and is affected by pelvis motion during positions of daily life. The purpose of this study was to explicitly define the relationship between sagittal pelvic motion and resultant cup functional anteversion and create a tool to guide the surgeon to a patient-specific intra-operative anteversion. Materials and Methods. 10,560 combinations of inclination, anteversion, and pelvic tilt were generated using a geometric model. Resultant functional anteversion was calculated for each iteration and variables were correlated. An electronic mobile tool was created that compares inputted patient-specific values to population-based averages to determine pelvic positions and dynamics that may lead to instability. Results. A third-degree polynomial equation was used to describe the relationship between variables. The freely downloadable mobile tool uses input from pre-operative plain radiographic measurements to provide the surgeon a quantitative correction to intra-operative cup anteversion based on differences in functional anteversion compared to population-based averages. Conclusion. This study provides a geometric relationship between planned cup position, pelvic position and motion, and the resultant functional anteversion. This mathematical model was applied to an electronic tool that seeks to determine an individualized intra-operative cup anteversion based on measured patient-specific pelvic dynamics.
Mechanical Properties of the Hard Sandstone Fracture Surface under Hydrochemical Corrosion
Authors: Xia Bin-wei , Xu Ming-xiang , Pan Chao
Published: May 2019

To realize a quantitative expression of change laws of the fracture surface shear strength with hydrochemical damage and to obtain optimal weakening effect of solution on the fracture surface strength, hard roof sandstone specimens containing hydraulic fracture surfaces from the Tashan Coal Mine located in Datong were subjected to a shear test after corrosion using solutions at different concentrations. The relational expression between shear strength and porosity of the fracture surface was established, and new damage parameters were introduced to describe the evolution laws of the shear strength of sandstone specimens with change in test conditions. Results were as follows. (1) Under sealed hydrochemical environment, corrosion effect on sandstone strengthened, and porosity and roughness gradually increased with increasing solution concentration and soaking time. (2) At a solution concentration of 3%-10%, shear strength and roughness of the fracture surface initially increased and then decreased. Hydrochemical solution concentration and action time were important factors that caused strength attenuation of the fracture surface. (3) When the solution concentration was greater than 3%, the roughness of the fracture surface increased with corrosion time, but its strength showed the tendency to stabilize. The shear strength of the fracture surface increased with shear displacement at a concentration of 5%. The study results can provide a new idea for strong strata pressure control through ground hydrofracturing hard roof.
UAV-Based Gigapixel Panoramic Image Acquisition Planning with Ray Casting-Based Overlap Constraints
Authors: Zhang Shuhang , Liu Chun , Zhou Yuan
Published: May 2019

Panoramic imaging is information-rich, low-cost, and effective. In panoramic image acquisition, unmanned aerial vehicles (UAVs) have a natural advantage that owes to their flexibility and relatively large observation ranges. Using a panoramic gimbal and a single camera may be the most common means of capturing gigapixel panoramas. In order to manage the constraints of UAV power and facilitate the use of a variety of camera lenses, an effective and flexible method for planning UAV gigapixel panorama acquisitions is required. To address this need, a panoramic image acquisition planning method is proposed in this paper. The method defines image overlaps via a ray casting procedure and then generates an acquisition plan according to the constraints of horizontal and vertical overlap thresholds. This method ensures the completeness of the panorama by maintaining the overlap between adjacent images. Two experiments, including simulated and field cases, were performed to evaluate the proposed method through comparisons with an existing panorama acquisition plan. Results showed that the proposed method can capture complete panoramas with fewer images.
Sulfonic Containing Polymer Bead Synthesized through Inverse Suspension Polymerization and Its Characteristics for Esterification Catalyst
Authors: Shan Cengliang , Wang Ye , Nie Jun , He Yong
Published: May 2019

The sulfonic containing polymer bead was synthesized using sodium p-styrenesulfonate (SSS) and N,N′-methylenebisacrylamide (MBA) through inverse suspension polymerization and evaluated as catalyst for esterification of of n-octanol and acrylic acid. The influence of some principal factors, such as combination dispersant, crosslink agent content, posttreatment methods, and porogen types, was investigated in detail. The results showed that the morphology and characteristics of polymer beads were controllable. The polymer beads with 20wt% crosslink agent showed the best catalysis ability achieving almost 96% esterification conversion at the first time and 80% after 5 cycles.
Risk Factors for Prolonged Length of Stay of Older Patients in an Academic Emergency Department: A Retrospective Cohort Study
Authors: Sir Özcan , Hesselink Gijs , Van Den Bogaert Mara , Akkermans Reinier P. , Schoon Yvonne
Published: May 2019

Emergency departments (EDs) are challenged with a growing population of older patients. These patients are at risk for a prolonged length of stay (LOS) at the ED and face more complications and poorer clinical outcomes. We aimed to identify risk factors for a prolonged LOS of older patients at the ED. For this retrospective clinical database study, we analyzed medical records of 2000 patients ≥70 years old presenting at the ED of a large level I trauma center in the Netherlands. LOS above the 75th percentile of LOS at our ED, 293 minutes, was considered prolonged. After bivariate analysis, we identified associations between LOS and patient, organizational, and clinical factors. Associations with a p < 0.05 were inserted in multivariable logistic regression models. We analyzed 1048 men (52%) and 952 women (48%) with a mean age of 78 ± 6.2 years. Risk factors for prolonged LOS of older patients at the ED were follows: higher number (more than one) of consultations (OR [odds ratio] 2.4, CI [confidence interval] 2.0-2.91), or diagnostic interventions (OR 1.5, CI 1.4-1.7); presenting complaints of a neurological (OR 2.2, CI 1.0-4.5) or internal medicine focus (OR 2.6, CI 1.4-4.6); patients with an altered consciousness (OR 3.3, CI 1.6-6.6); treatment by physicians of the departments of surgery (OR 3.4, CI 2.2-5.2), internal medicine (OR 2.6, CI 1.9-3.7), or pulmonology (OR 2.2, CI 1.4-3.6); and urgency category of ≥ U1. Awareness of factors associated with prolonged LOS of older patients presenting at the ED is essential. Physicians should recognize and take these factors into account, in order to improve clinical outcomes of the (strongly increasing) population of older patients at the ED.
Evaluation of Geomembrane Effect Based on Mobilized Shear Stress due to Localized Sinking
Authors: Lu Weihua , Zhang Yongxing , Liu Weizheng , Liu Cheng , Wang Haibo
Published: May 2019

Installing geosynthetic reinforcement at the bottom of the embankment will provide positive support for subgrade stability and settlement control, if there is a void or a weak foundation. In routine design work, the geomembrane effect must be well estimated and the tensile strain should be precisely predicted. Conventional analytical methods often adopt the limit state method to calculate the overlying load on the deflected geosynthetic. However, this assumption does not necessarily apply to all conditions, especially when the foundation soil can provide certain resistance. In this study, a semiempirical prediction method for evaluating the geomembrane effect of the basal reinforcement was proposed, and an iterative solution for calculating tensile strains of a deflected geosynthetic was deduced. In derivation, a virtual inclined slip surface and interaction between the geosynthetic and soil were quantitatively evaluated by coupling the arching effect and the geomembrane effect. Moreover, the development of shear stress along the slip surface can be considered, as well as different segments of the basal reinforcement. Then, the proposed method was validated by two large‐scale experiments. Comparison of the results of this method with measurements and results of other analytical models confirmed that this analytical method can take good care of the varying process of the localized sinking, regarding the overlying loads on the geosynthetic and the subsequent tensile strains.
Determination of Parameters of the Discrete Element Bond Model for Asphalt Mixture Based on Splitting Test
Authors: Shan Jingsong , Du Yang , Fan Dahai , Guo Laiyao
Published: May 2019

A discrete element method (DEM) has widely been used to simulate asphalt mixture characteristics, and DEM models can consider the effect of aggregate gradation and interaction between particles. However, proper selection of model parameters is crucial to obtain convincing results from DEM‐based simulations. This paper presents a method to appropriately determine the mechanical parameters to be used in DEM‐based simulation of asphalt concrete mixture. Splitting test specimens are prepared by using asphalt mixture, and the splitting test results are compared with simulation results from two‐dimensional (2D) DEM and three‐dimensional (3D) DEM. Basing on the DEM results, the effects of contact model parameters on the simulation results are analyzed. The slope of the load‐displacement curve at the beginning stage is mainly affected by the stiffness parameters, and the peak load is mainly determined by using the value of the bond strength. The laboratory splitting test of AC‐20 and AC‐13 specimens were performed at different temperatures, namely, −10°C, 0°C, 10°C, and 20°C, and the load‐displacement relationships were plotted. According to the real load‐displacement curve’s slope at the beginning stage and peak load applied, the range of DEM bond model parameters is determined. On the basis of DEM results of the splitting test, the relationships between simulation load‐displacement curve’s characteristics and bond model parameters are fitted. The values of the parameters of the DEM contact bond model at different temperatures are obtained depending on the actual load‐displacement curve’s initial slope and peak load. Lastly the DEM and laboratory test results are compared, which illustrates that the parallel bond model can well simulate the behavior of asphalt mixture.
An Opposition-Based Evolutionary Algorithm for Many-Objective Optimization with Adaptive Clustering Mechanism
Authors: Wang Wan Liang , Li Weikun , Wang Yu Le
Published: May 2019

Balancing convergence and diversity has become a key point especially in many-objective optimization where the large numbers of objectives pose many challenges to the evolutionary algorithms. In this paper, an opposition-based evolutionary algorithm with the adaptive clustering mechanism is proposed for solving the complex optimization problem. In particular, opposition-based learning is integrated in the proposed algorithm to initialize the solution, and the nondominated sorting scheme with a new adaptive clustering mechanism is adopted in the environmental selection phase to ensure both convergence and diversity. The proposed method is compared with other nine evolutionary algorithms on a number of test problems with up to fifteen objectives, which verify the best performance of the proposed algorithm. Also, the algorithm is applied to a variety of multiobjective engineering optimization problems. The experimental results have shown the competitiveness and effectiveness of our proposed algorithm in solving challenging real-world problems.
Estimating the Tensile Strength of Ultrahigh-Performance Fiber-Reinforced Concrete Beams
Authors: Yang In-Hwan , Joh Changbin , Bui The Quang
Published: May 2019

The tensile behavior of ultrahigh-performance fiber-reinforced concrete (UHPFRC) depends on the dispersion and orientation of steel fibers within the concrete matrix. The uneven dispersion of randomly oriented steel fibers in concrete may cause differences in the tensile behavior between material testing specimens and beams. Therefore, in this study, the tensile behavior was investigated by fitting the analysis result of the moment-curvature curve to the experimental result of a UHPFRC beam. To this end, three UHPFRC mixtures with different compressive strengths were fabricated to test the material properties and flexural behavior of UHPFRC beams. Both a single type of steel fiber and a combination of steel fiber types were used with volume fractions of 1.0% and 1.5%, respectively, in the three mixtures. Based on the design recommendations, the material properties of UHPFRC were modeled. The results ultimately show that by fitting the analysis results to the experimental results of the moment-curvature curves, the tensile strength of UHPFRC beams can be reasonably estimated.
Visible Light-Active CdS/TiO2 Hybrid Nanoparticles Immobilized on Polyacrylonitrile Membranes for the Photodegradation of Dyes in Water
Authors: Nyamukamba Pardon , Moloto Makwena Justice , Mungondori Henry
Published: May 2019

Reusable photocatalytic polyacrylonitrile membrane-supported cadmium sulphide/titanium dioxide hybrid nanoparticles (CdS/TiO2-PAN) were prepared using a dry-wet phase inversion technique. Scanning electron microscopy (SEM) analysis revealed that the photocatalytic membranes had a porous sublayer, a compact top layer, and that, some of the nanoparticles were not encapsulated by the membranes. The average crystallite sizes of the CdS, TiO2, and CdS/TiO2 hybrid nanoparticles were 3.41 nm, 10.47 nm, and 12.17 nm, respectively. The combination of CdS and TiO2 nanoparticles led to a red shift (band gap; ca. 2.6 eV) of the absorption band and extended the optical absorption spectrum into the visible region relative to TiO2. The photocatalytic activity of CdS/TiO2-PAN membranes was explored in the degradation of methylene blue dye under visible light irradiation, and the results revealed that the best photocatalytic performance was achieved by 0.1 g CdS/TiO2-PAN photocatalytic membrane with 5% loading of the CdS/TiO2 hybrid nanoparticles, which degraded 66.29% of methylene blue in 210 minutes at 25°C and pH 8.5. It was found that the optimum loading of nanoparticles in the membranes was 0.1 g. All the photocatalytic membranes showed an insignificant decrease in the photocatalytic activity when used repeatedly. According to literature, CdS/TiO2-PAN photocatalytic membranes have not been prepared before for the purpose of treating simulated wastewater.
Rapid-Response and Highly Sensitive Boronate Derivative-Based Fluorescence Probe for Detecting H2O2 in Living Cells
Authors: Selvaraj Muthusamy , Rajalakshmi Kanagaraj , Nam Yun-Sik , Lee Yeonhee , Kim Byoung Chan , Pai Sung Jin , Han Sang Soo , Lee Kang-Bong
Published: May 2019

Intracellular H2O2 monitoring is important and has driven researchers to pursue advancements for the rapid identification of H2O2, since H2O2 is short-lived in cell lines. An arylboronate derivative has been investigated as a chemospecific fluorescence recognition agent for H2O2. Triphenylimidazoleoxadiazolephenyl (TPIOP) boronate was contrived as a novel candidate for the rapid and sensitive recognition of H2O2. The probe was conjugated using the TPIOP functional group acting as an excellent fluorescent enhancer. The TPIOP group stimulated the polarization of C–B bond due to its extended π-conjugation, which included heteroatoms, and induced the production of rapid signal because of the highly polar C–B bond along with the corresponding boronate unit. While H2O2 reacts with TPIOP boronate, its nucleophilic addition to the boron generates a charged tetrahedral boronate complex, and then the C–B bond migrates toward one of the electrophilic peroxide oxygen atoms. The resulting boronate ester is then hydrolyzed by water into a phenol, which significantly enhances fluorescence through aggregation-induced emission. The TPIOP boronate probe responded to H2O2 rapidly, within 2 min, and exhibited high sensitivity with a limit of detection of 8 nM and a 1000-fold selectivity in the presence of other reactive oxygen species. Therefore, the developed TPIOP boronate chemodosimeter was successfully utilized to visualize and quantify intracellular H2O2 from human breast cancer (MCF-7) cells, as well as gaseous and aqueous H2O2 from environmental samples using Whatman paper strips coated with TPIOP boronate.
Cytokines and the Pathogenesis of Macular Edema in Branch Retinal Vein Occlusion
Authors: Noma Hidetaka , Yasuda Kanako , Shimura Masahiko
Published: May 2019

Branch retinal vein occlusion (BRVO) is a very common retinal vascular problem in patients with lifestyle-related diseases, such as hypertension and arteriosclerosis. In patients with BRVO, development of macular edema is the main cause of visual impairment. BRVO is still a controversial condition in many respects. Over the years, various methods such as laser photocoagulation have been tried to treat macular edema associated with BRVO, but the results were not satisfactory. After vascular endothelial growth factor (VEGF) was found to have an important role in the pathogenesis of macular edema in BRVO patients, treatment of this condition was revolutionized by development of anti-VEGF therapy. Although macular edema improves dramatically following intraocular injection of anti-VEGF agents, repeated recurrence and resistance of edema is a major problem in some BRVO patients. This suggests that factors or cytokines other than VEGF may be associated with inflammation and retinal hypoxia in BRVO and that the pathogenesis of macular edema is complicated. The present review assesses the role of various factors and cytokines in the pathogenesis of macular edema associated with BRVO. We present a mechanism that is not only plausible but should also be useful for developing new therapeutic strategies.
Finding the Intersection of Neuroplasticity, Stroke Recovery, and Learning: Scope and Contributions to Stroke Rehabilitation
Authors: Carey Leeanne , Walsh Alistair , Adikari Achini , Goodin Peter , Alahakoon Damminda , De Silva Daswin , Ong Kok-Leong , Nilsson Michael , Boyd Lara
Published: May 2019

Aim. Neural plastic changes are experience and learning dependent, yet exploiting this knowledge to enhance clinical outcomes after stroke is in its infancy. Our aim was to search the available evidence for the core concepts of neuroplasticity, stroke recovery, and learning; identify links between these concepts; and identify and review the themes that best characterise the intersection of these three concepts. Methods. We developed a novel approach to identify the common research topics among the three areas: neuroplasticity, stroke recovery, and learning. A concept map was created a priori, and separate searches were conducted for each concept. The methodology involved three main phases: data collection and filtering, development of a clinical vocabulary, and the development of an automatic clinical text processing engine to aid the process and identify the unique and common topics. The common themes from the intersection of the three concepts were identified. These were then reviewed, with particular reference to the top 30 articles identified as intersecting these concepts. Results. The search of the three concepts separately yielded 405,636 publications. Publications were filtered to include only human studies, generating 263,751 publications related to the concepts of neuroplasticity (n=6,498), stroke recovery (n=79,060), and learning (n=178,193). A cluster concept map (network graph) was generated from the results; indicating the concept nodes, strength of link between nodes, and the intersection between all three concepts. We identified 23 common themes (topics) and the top 30 articles that best represent the intersecting themes. A time-linked pattern emerged. Discussion and Conclusions. Our novel approach developed for this review allowed the identification of the common themes/topics that intersect the concepts of neuroplasticity, stroke recovery, and learning. These may be synthesised to advance a neuroscience-informed approach to stroke rehabilitation. We also identified gaps in available literature using this approach. These may help guide future targeted research.
Dark Energy in Spherically Symmetric Universe Coupled with Brans-Dicke Scalar Field
Authors: Singh Koijam Manihar , Samanta Gauranga C.
Published: May 2019

The phenomenon of dark energy and its manifestations are studied in a spherically symmetric universe considering the Brans-Dicke scalar tensor theory. In the first model, the dark energy behaves like a phantom type and in such a universe the existence of negative time is validated with an indication that our universe started its evolution before t=0. Dark energy prevalent in this universe is found to be more active at times when other types of energies remain passive. The second model of universe begins with big bang. On the other hand, the dark energy prevalent in the third model is found to be of the quintessence type. Here, it is seen that the dark energy triggers the big bang and after that much of the dark energy reduces to dark matter. One peculiarity in such a model is that the scalar field is prevalent eternally; it never tends to zero.