bluuebunny/crossref_metadata_2025 huggingface dataset:
Resilience as the Mediating Factor in the Relationship Between Sleep Disturbance and Post-stroke Depression of Stroke Patients in China: A Structural Equation Modeling Analysis
Authors: Zhao Lina , Yang Fengzhi , Sznajder Kristin K. , Zou Changqing , Jia Yajing , Yang Xiaoshi
Published: May 2021

Background: Stroke patients may suffer from a variety of symptoms which can result in sleep disturbance and post-stroke depression (PSD). Whereas, resilience can alleviate sleep disturbance and help maintain well-being after stroke.

Objective: The aim of this study is to explore whether resilience plays a mediating role in the relationship between sleep disturbance and PSD of stroke patients in China.

Methods: A cross-sectional study with a multi-stage sampling was carried out in Liaoning Rehabilitation Center and the Third People's Hospital of Chongqing in China from May to September 2019. A total of 353 stroke patients were enrolled in this study. Structural equation model (SEM) was used to test the mediating effect of resilience on the relationship between sleep disturbance and PSD.

Results: The prevalence of PSD of stroke patients was 34.56%. Sleep disturbance contributed most to the variance of PSD and had a significantly positive association with PSD among stroke patients (P < 0.01). Resilience was negatively associated with PSD, and acted as a mediator between sleep disturbance and PSD (a * b = 0.201, BCa 95% CI: 0.156~0.254).

Conclusions: The prevalence of PSD was high among the Chinese stroke patients. Sleep disturbance was highly associated with PSD, resulting in the increased risk of PSD. Furthermore, resilience has a mediating effect on the relationship between sleep disturbance and PSD, and could reduce the negative effect of sleep disturbance on the development of PSD.
Oral Health Care Delivery for Children During COVID-19 Pandemic—A Retrospective Study
Authors: Fux-Noy Avia , Mattar Luna , Shmueli Aviv , Halperson Elinor , Ram Diana , Moskovitz Moti
Published: May 2021

Aim: COVID-19 outbreak and the lockdown period following was a very challenging time for pediatric dentistry. We aimed to find whether the characteristics of dental care provided to children at the Department of Pediatric Dentistry at Hadassah medical center, Jerusalem, Israel, differed between the periods, before COVID-19 outbreak, during the lockdown period and during the period that followed it.

Materials and Methods: We retrospectively reviewed computerized records of patients who visited the pediatric dental clinic at three different periods: pre-lockdown period, lockdown period, and post-lockdown period.

Results: Nine-hundred and forty-nine children were included in the study; most of them were healthy children between 3 and 6 years old. During lockdown, all scheduled appointments except for treatments under general anesthesia and deep sedation were canceled due to the government's restrictions; the frequency of treatments with non-pharmacological behavior management, general anesthesia or deep sedation was higher than in the previous or subsequent periods and the use of inhaled/conscious sedation was significantly lower. During lockdown most of the children were diagnosed with dentoalveolar abscess (32.3%), compared to 14 and 21% at the previous or subsequent periods, respectively (P < 0.001). Treatments combination during lockdown included more extractions, pulpectomies and pulp extirpation and less permanent restorations (P < 0.001). None of the staff members was infected with COVID-19 at the clinic during these periods. We concluded that dentists should be updated about Covid-19 modes of transmission and the recommended infection control measures in dental settings. Effective management protocols can help the dental staff to continue to provide efficient treatment and prevent Covid-19 contamination.
From Village to Globe: A Dynamic Real-Time Map of African Fields Through PlantVillage
Authors: Kehs Annalyse , McCloskey Peter , Chelal John , Morr Derek , Amakove Stellah , Plimo Bismark , Mayieka John , Ntango Gladys , Nyongesa Kelvin , Pamba Lawrence , Jeptoo Melodine , Mugo James , Tsuma Mercyline , Mukami Wincate , Onyango Winnie , Hughes David
Published: May 2021

A major bottleneck to the application of machine learning tools to satellite data of African farms is the lack of high-quality ground truth data. Here we describe a high throughput method using youth in Kenya that results in a cost-effective method for high-quality data in near real-time. This data is presented to the global community, as a public good and is linked to other data sources that will inform our understanding of crop stress, particularly in the context of climate change.
Effect of Sedation on the Neurological Examination of the Patellar and Withdrawal Reflexes in Healthy Dogs
Authors: Horsley Kristen T. , Olby Natasha J. , Mitchell Mark A. , Aulakh Karanvir S. , Gines J. Alberto
Published: May 2021

Introduction: Pain, temperament, fear, and anxiety can prevent safe and accurate evaluation of common neurologic reflexes in dogs. When sedation is used it is unknown how the neurological examination, and specifically patellar and withdrawal reflexes are affected, and, if present, how long any effect might last. The purpose of this study is to investigate the effect of sedation on the evaluation of select common limb spinal reflexes in healthy dogs.

Material and Methods: Fourteen healthy dogs with normal neurologic exams were included. After placing joint landmarks, patellar reflex and pelvic and thoracic limb withdrawal reflexes were tested. Joint angles were measured, obtaining reflex angle endpoints, change in angle, and change in time to reflex completion. These measurements were recorded at different time points: prior to sedation (awake timepoint), 15 and 30 min following administration of standardized sedation protocol of dexmedetomidine and butorphanol, and 15 and 30 min following administration of a standardized reversal agent, atipamazole.

Results: For patellar reflex, the stifle end angle increased from 91.5 to 108.55 degrees (p < 0.0001) 15 min following sedation, and remained increased at 104.5 degrees (p < 0.0001) 30 min following sedation. Stifle change in angle increased from 9.6 to 24.4 degrees (p < 0.0001) 15 min following sedation, and remained increased at 20.85 degrees (p < 0.0001) and 11 degrees (p = 0.012) at 30 min sedation and 15 min reversal. Tarsal joint in pelvic withdrawal and elbow in thoracic withdrawal reflexes did not differ in at any timepoint of sedation or reversal when compared with the awake timepoint, for end angle or change in angle. The increases in end angle and change in angle for patellar reflex generated a change in time for patellar reflex from 0.12 s (awake) to 0.129 s (15 min sedation) which was statistically significant (p = 0.041). Change in time did not differ for pelvic withdrawal or thoracic withdrawal.

Discussion/Conclusions: Reflexes were elicited in all dogs under sedation. Sedation does not affect the evaluation of the withdrawal reflex on any limb but improves the visualization of the patellar reflex in this group of neurologically normal dogs.
Educational Level, but Not Income or Area Deprivation, is Related to Macrovascular Disease: Results From Two Population-Based Cohorts in Germany
Authors: Ptushkina Violetta , Seidel-Jacobs Esther , Maier Werner , Schipf Sabine , Völzke Henry , Markus Marcello Ricardo Paulista , Nauck Matthias , Meisinger Christa , Peters Annette , Herder Christian , Schwettmann Lars , Dörr Marcus , Felix Stephan B. , Roden Michael , Rathmann Wolfgang
Published: May 2021

Objectives: An inverse relationship between education and cardiovascular risk has been described, however, the combined association of education, income, and neighborhood socioeconomic status with macrovascular disease is less clear. The aim of this study was to evaluate the association of educational level, equivalent household income and area deprivation with macrovascular disease in Germany.

Methods: Cross-sectional data from two representative German population-based studies, SHIP-TREND (n = 3,731) and KORA-F4 (n = 2,870), were analyzed. Multivariable logistic regression models were applied to estimate odds ratios and 95% confidence intervals for the association between socioeconomic determinants and macrovascular disease (defined as self-reported myocardial infarction or stroke).

Results: The study showed a higher odds of prevalent macrovascular disease in men with low and middle educational level compared to men with high education. Area deprivation and equivalent income were not related to myocardial infarction or stroke in any of the models.

Conclusion: Educational level, but not income or area deprivation, is significantly related to the macrovascular disease in men. Effective prevention of macrovascular disease should therefore start with investing in individual education.
Bariery nauki. Szkic o epistemologicznych granicach ludzkiego poznania
Authors: Mider Daniel
Published: May 2021

The article is devoted to the analysis of factors that prevent or limit the development of broadly understood science. The following types of limitations have been distinguished: psychosocial, biological, political, resource barriers and the final nature of science. Biological barriers lie in human sensory endowment. Psychosocial barriers are determined by the conditions of the functioning of human societies. Resource barriers are constraints on economic and energy reserves. The problem of the scope of science is understood as the finite scope of the mysteries of science itself – the fact of a limited number of possible discoveries.
Poselski immunitet formalny w dyskusjach parlamentarnych (na przykładzie Druku nr 433/VI kad.)
Authors: Buczkowski Łukasz
Published: May 2021

The construct of parliamentary formal immunity has so far been the subject of five bills amending the Constitution of the Republic of Poland, provoking discussion on the desirability of maintaining the immunity in the Polish political system. The purpose of this study is to present the basic hypotheses of the changes proposed in this area and to analyze the arguments raised for and against the continued validity of Art. 105 section 3 of the Polish Constitution in its current wording. To illustrate the course of parliamentary work on limiting the protection of the MPs, a representative example, accumulating classic elements of discussions on the legitimacy of changes in the formal approach to parliamentary immunity, was used as a study of the legislative process accompanying print No. 433/VI cad.
Prolegomena do politologii jakościowej
Authors: Marciniak Ewa Maria
Published: May 2021

The topic of this article is methodological pluralism in political science, as a result of widening the scope of political science research. The objective is to reflect on qualitative research and to critically analyze its purpose and rules in political science. This article conceptualized the idea of qualitative political science.
Badanie wyborcze realizowane w dniu wyborów prezydenckich w 2010 roku jako przykład badania realizowanego w miejscu publicznym
Authors: Kuźma Konrad Krystian
Published: May 2021

As part of the article, the author presents the advantages and disadvantages of research solutions used during the presidential election in 2010. The decision to choose these elections as an example was dictated, on the one hand, by the fact that the survey on the day of the election was carried out by three companies, and on the other hand, by the fact that different research techniques were used. Moreover, the conducted research is well documented both in the journalism and in the report of Professor Domański’s team, and by the author himself, who analyzed this problem in terms of the selection of an appropriate research technique earlier.
Biological Properties of Bee Bread Collected from Apiaries Located across Greece
Authors: Didaras Nikos Asoutis , Kafantaris Ioannis , Dimitriou Tilemachos G. , Mitsagga Chrysanthi , Karatasou Katerina , Giavasis Ioannis , Stagos Dimitris , Amoutzias Grigoris D. , Hatjina Fani , Mossialos Dimitris
Published: May 2021

Bee bread is the only fermented product of the beehive. It constitutes the main source of proteins, lipids, vitamins, and macro- and microelements in honeybee nutrition and it exerts antioxidant and antimicrobial properties, though research on these aspects has been limited so far. In this study 18 samples of Greek bee bread, two of which were monofloral, were collected during different seasons from diverse locations such as Crete and Mount Athos and were tested for their bioactivity. Samples were analyzed for their antibacterial properties, antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC). The antimicrobial activity of each sample was tested against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella typhimurium. Our data demonstrate that all samples exert inhibitory and most of them bactericidal activity against at least two pathogens. Furthermore, all samples exert significant antioxidant activity, where the monofloral Castanea Sativa sample demonstrated superior antioxidant activity. Nevertheless, the antioxidant and antimicrobial activity were not strongly correlated. Furthermore, machine learning methods demonstrated that the palynological composition of the samples is a good predictor of their TPC and ABTS activity. This is the first study that focuses on the biological properties of Greek bee bread and demonstrates that bee bread can be considered a functional food and a possible source of novel antimicrobial compounds.
Antioxidant or Apoptosis Inhibitor Supplementation in Culture Media Improves Post-Thaw Recovery of Murine Spermatogonial Stem Cells
Authors: Jung Sang-Eun , Oh Hui-Jo , Ahn Jin-Seop , Kim Yong-Hee , Kim Bang-Jin , Ryu Buom-Yong
Published: May 2021

We postulated that supplementation of antioxidant or apoptosis inhibitor in post-thaw culture media of spermatogonial stem cells (SSCs) alleviates reactive oxygen species (ROS) generation and apoptosis. Our aim was to develop an effective culture media for improving post-thaw recovery of SSCs. To determine the efficacy of supplementation with hypotaurine (HTU), α-tocopherol (α-TCP), and Z-DEVD-FMK (ZDF), we assessed the relative proliferation rate and SSC functional activity and performed a ROS generation assay, apoptosis assay, and western blotting for determination of the Bax/Bcl-xL ratio, as well as immunocytochemistry and real-time quantitative polymerase chain reaction (RT-qPCR) for SSC characterization. The relative proliferation rates with HTU 400 μM (133.7 ± 3.2%), α-TCP 400 μM (158.9 ± 3.6%), and ZDF 200 μM (133.1 ± 7.6%) supplementation were higher than that in the DMSO control (100 ± 3.6%). ROS generation was reduced with α-TCP 400 μM (0.8-fold) supplementation in comparison with the control (1.0-fold). Early apoptosis and Bax/Bcl-xL were lower with α-TCP 400 μM (2.4 ± 0.4% and 0.5-fold) and ZDF 200 μM (1.8 ± 0.4% and 0.3-fold) supplementation in comparison with the control (5.3 ± 1.4% and 1.0-fold) with normal characterization and functional activity. Supplementation of post-thaw culture media with α-TCP 400 μM and ZDF 200 μM improved post-thaw recovery of frozen SSCs via protection from ROS generation and apoptosis after cryo-thawing.
CNN Training Using 3D Virtual Models for Assisted Assembly with Mixed Reality and Collaborative Robots
Authors: Židek Kamil , Piteľ Ján , Balog Michal , Hošovský Alexander , Hladký Vratislav , Lazorík Peter , Iakovets Angelina , Demčák Jakub
Published: May 2021

The assisted assembly of customized products supported by collaborative robots combined with mixed reality devices is the current trend in the Industry 4.0 concept. This article introduces an experimental work cell with the implementation of the assisted assembly process for customized cam switches as a case study. The research is aimed to design a methodology for this complex task with full digitalization and transformation data to digital twin models from all vision systems. Recognition of position and orientation of assembled parts during manual assembly are marked and checked by convolutional neural network (CNN) model. Training of CNN was based on a new approach using virtual training samples with single shot detection and instance segmentation. The trained CNN model was transferred to an embedded artificial processing unit with a high-resolution camera sensor. The embedded device redistributes data with parts detected position and orientation into mixed reality devices and collaborative robot. This approach to assisted assembly using mixed reality, collaborative robot, vision systems, and CNN models can significantly decrease assembly and training time in real production.
An Adapted Model of Cognitive Digital Twins for Building Lifecycle Management
Authors: Yitmen Ibrahim , Alizadehsalehi Sepehr , Akıner İlknur , Akıner Muhammed Ernur
Published: May 2021

In the digital transformation era in the Architecture, Engineering, and Construction (AEC) industry, Cognitive Digital Twins (CDT) are introduced as part of the next level of process automation and control towards Construction 4.0. CDT incorporates cognitive abilities to detect complex and unpredictable actions and reason about dynamic process optimization strategies to support decision-making in building lifecycle management (BLM). Nevertheless, there is a lack of understanding of the real impact of CDT integration, Machine Learning (ML), Cyber-Physical Systems (CPS), Big Data, Artificial Intelligence (AI), and Internet of Things (IoT), all connected to self-learning hybrid models with proactive cognitive capabilities for different phases of the building asset lifecycle. This study investigates the applicability, interoperability, and integrability of an adapted model of CDT for BLM to identify and close this gap. Surveys of industry experts were performed focusing on life cycle-centric applicability, interoperability, and the CDT model’s integration in practice besides decision support capabilities and AEC industry insights. The evaluation of the adapted model of CDT model support approaching the development of CDT for process optimization and decision-making purposes, as well as integrability enablers confirms progression towards Construction 4.0.
Retrospective Modeling of a Large Paleo-Landslide Related to Deglaciation in the Sierra de Urbión, Cordillera Ibérica, Spain
Authors: Sanz de Ojeda Pablo , Sanz Pérez Eugenio , Galindo Rubén , Sanz Riaguas Cesar
Published: May 2021

Through a study of glacial geomorphology and retrospective modeling of the stability of the slopes, it has been possible to reconstruct and know the mechanism of the formation of a large landslide induced by the retreat of the glacier corresponding to the Picos de Urbión (Coordillera Ibérica, Spain) during the last glacial cycle. It is a rotational landslide of 150 Mm3 that involved a layer of lutites and clays of the Cameros Basin that outcropped on one of the slopes of the valley, and whose initial geometry was modified by the over-excavation of the glacier tongue, which reached 140 m in height. The breakage occurred when the support of the ice tongue was partially removed. The structural layout and high water table also contributed to the landslide. It is the first time that landslides associated with the deglaciations of the last glacial cycle have been retrospectively modeled, which may be of interest when applied to geomorphological sciences.
Control Strategy for Direct Teaching of Non-Mechanical Remote Center Motion of Surgical Assistant Robot with Force/Torque Sensor
Authors: Kim Minhyo , Zhang Youqiang , Jin Sangrok
Published: May 2021

This paper presents a control strategy that secures both precision and manipulation sensitivity of remote center motion with direct teaching for a surgical assistant robot. Remote center motion is an essential function of conventional laparoscopic surgery, and the most intuitive way a surgeon manipulates a robot is through direct teaching. The surgical assistant robot must maintain the position of the insertion port in three-dimensional space during the four-degree-of-freedom motions such as pan, tilt, spin, and forward/backward. In addition, the robot should move smoothly when controlling it with the hands during the surgery. In this study, a six-degree-of-freedom collaborative robot performs the cone-shaped trajectory with pan and tilt motion of an end-effector keeping the position of the remote center. Instead of the bulky mechanically constrained remote center motion mechanism, a conventional collaborative robot is used to mimic the wrist movement of a scrub nurse. A force/torque sensor that is attached between the robot and end-effector estimates the surgeon’s intention. A direct teaching control strategy based on position control is applied to guarantee precise remote center position maintenance performance. A motion generation algorithm is designed to generate motion by utilizing a force/torque sensor value. The parameters of the motion generation algorithm are optimized so that the robot can be operated with uniform sensitivity in all directions. The precision of remote center motion and the torque required for direct teaching are analyzed through pan and tilt motion experiments.
Constructing 3D Underwater Sensor Networks without Sensing Holes Utilizing Heterogeneous Underwater Robots
Authors: Kim Jonghoek
Published: May 2021

This article handles building underwater sensor networks autonomously using multiple surface ships. For building underwater sensor networks in 3D workspace with many obstacles, this article considers surface ships dropping underwater robots into the underwater workspace. We assume that every robot is heterogeneous, such that each robot can have a distinct sensing range while moving with a distinct speed. The proposed strategy works by moving a single robot at a time to spread out the underwater networks until the 3D cluttered workspace is fully covered by sensors of the robots, such that no sensing hole remains. As far as we know, this article is novel in enabling multiple heterogeneous robots to build underwater sensor networks in a 3D cluttered environment, while satisfying the following conditions: (1) Remove all sensing holes. (2) Network connectivity is maintained. (3) Localize all underwater robots. In addition, we address how to handle the case where a robot is broken, and we discuss how to estimate the number of robots required, considering the case where an obstacle inside the workspace is not known a priori. Utilizing MATLAB simulations, we demonstrate the effectiveness of the proposed network construction methods.
Vibration-Based Fingerprint Algorithm for Structural Health Monitoring of Wind Turbine Blades
Authors: Loss Theresa , Bergmann Alexander
Published: May 2021

Monitoring the structural health of wind turbine blades is essential to increase energy capture and operational safety of turbines, and therewith enhance competitiveness of wind energy. With the current trends of designing blades ever longer, detailed knowledge of the vibrational characteristics at any point along the blade is desirable. In our approach, we monitor vibrations during operation of the turbine by wirelessly measuring accelerations on the outside of the blades. We propose an algorithm to extract so-called vibration-based fingerprints from those measurements, i.e., dominant vibrations such as eigenfrequencies and narrow-band noise. These fingerprints can then be used for subsequent analysis and visualisation, e.g., for comparing fingerprints across several sensor positions and for identifying vibrations as global or local properties. In this study, data were collected by sensors on two test turbines and fingerprints were successfully extracted for vibrations with both low and high operational variability. An analysis of sensors on the same blade indicates that fingerprints deviate for positions at large radial distance or at different blade sides and, hence, an evaluation with larger datasets of sensors at different positions is promising. In addition, the results show that distributed measurements on the blades are needed to gain a detailed understanding of blade vibrations and thereby reduce loads, increase energy harvesting and improve future blade design. In doing so, our method provides a tool for analysing vibrations with relation to environmental and operational variability in a comprehensive manner.
Investigation of Nanogrids for Improved Navy Installation Energy Resilience
Authors: Kain Alissa , Van Bossuyt Douglas L. , Pollman Anthony
Published: May 2021

Military bases perform important national security missions. In order to perform these missions, specific electrical energy loads must have continuous, uninterrupted power even during terrorist attacks, adversary action, natural disasters, and other threats of specific interest to the military. While many global military bases have established microgrids that can maintain base operations and power critical loads during grid disconnect events where outside power is unavailable, many potential threats can cause microgrids to fail and shed critical loads. Nanogrids are of specific interest because they have the potential to protect individual critical loads in the event of microgrid failure. We present a systems engineering methodology that analyzes potential nanogrid configurations to understand which configurations may improve energy resilience and by how much for critical loads from a national security perspective. This then allows targeted deployment of nanogrids within existing microgrid infrastructures. A case study of a small military base with an existing microgrid is presented to demonstrate the potential of the methodology to help base energy managers understand which options are preferable and justify implementing nanogrids to improve energy resilience.
Inertial Parameter Identification in Robotics: A Survey
Authors: Leboutet Quentin , Roux Julien , Janot Alexandre , Guadarrama-Olvera Julio Rogelio , Cheng Gordon
Published: May 2021

This work aims at reviewing, analyzing and comparing a range of state-of-the-art approaches to inertial parameter identification in the context of robotics. We introduce “BIRDy (Benchmark for Identification of Robot Dynamics)”, an open-source Matlab toolbox, allowing a systematic and formal performance assessment of the considered identification algorithms on either simulated or real serial robot manipulators. Seventeen of the most widely used approaches found in the scientific literature are implemented and compared to each other, namely: the Inverse Dynamic Identification Model with Ordinary, Weighted, Iteratively Reweighted and Total Least-Squares (IDIM-OLS, -WLS, -IRLS, -TLS); the Instrumental Variables method (IDIM-IV), the Maximum Likelihood (ML) method; the Direct and Inverse Dynamic Identification Model approach (DIDIM); the Closed-Loop Output Error (CLOE) method; the Closed-Loop Input Error (CLIE) method; the Direct Dynamic Identification Model with Nonlinear Kalman Filtering (DDIM-NKF), the Adaline Neural Network (AdaNN), the Hopfield-Tank Recurrent Neural Network (HTRNN) and eventually a set of Physically Consistent (PC-) methods allowing the enforcement of parameter physicality using Semi-Definite Programming, namely the PC-IDIM-OLS, -WLS, -IRLS, PC-IDIM-IV, and PC-DIDIM. BIRDy is robot-agnostic and features a complete inertial parameter identification pipeline, from the generation of symbolic kinematic and dynamic models to the identification process itself. This includes functionalities for excitation trajectory computation as well as the collection and pre-processing of experiment data. In this work, the proposed methods are first evaluated in simulation, following a Monte Carlo scheme on models of the 6-DoF TX40 and RV2SQ industrial manipulators, before being tested on the real robot platforms. The robustness, precision, computational efficiency and context of application the different methods are investigated and discussed.
Characterization of Geometry and Surface Texture of AlSi10Mg Laser Powder Bed Fusion Channels Using X-ray Computed Tomography
Authors: Klingaa Christopher G. , Zanini Filippo , Mohanty Sankhya , Carmignato Simone , Hattel Jesper H.
Published: May 2021

Channels manufactured by laser powder bed fusion have an inherent process-induced dross formation and surface texture that require proper characterization for design and process optimization. This work undertakes surface texture characterization of AlSi10Mg channels of nominal diameter sizes ranging from 1 mm to 9 mm using X-ray computed tomography. Profile parameters, including Pa, Pz, and Pq, were found to be interchangeable for qualitative characterization of surface texture variation. Psk, Pvv, and the fractal dimension could identify the presence of extreme dross and sintered particles on the measured profiles. A method for predicting the equivalent diameter of the unobstructed cross-sectional area (Deq) was presented and its reduction was found to follow a logarithmic trend, as a function of channel length. An empirical model Pa (β, D), as a function of local angular position (β) and channel diameter (D), was demonstrated on a perfect channel geometry, resulting in well-predicted roughness and internal geometry.
Surface Functionalization of PLGA Nanoparticles to Increase Transport across the BBB for Alzheimer’s Disease
Authors: Del Amo Laura , Cano Amanda , Ettcheto Miren , Souto Eliana B. , Espina Marta , Camins Antoni , García Maria Luísa , Sánchez-López Elena
Published: May 2021

Alzheimer’s disease (AD) is a chronic neurodegenerative disorder that accounts for about 60% of all diagnosed cases of dementia worldwide. Although there are currently several drugs marketed for its treatment, none are capable of slowing down or stopping the progression of AD. The role of the blood-brain barrier (BBB) plays a key role in the design of a successful treatment for this neurodegenerative disease. Nanosized particles have been proposed as suitable drug delivery systems to overcome BBB with the purpose of increasing bioavailability of drugs in the brain. Biodegradable poly (lactic-co-glycolic acid) nanoparticles (PLGA-NPs) have been particularly regarded as promising drug delivery systems as they can be surface-tailored with functionalized molecules for site-specific targeting. In this review, a thorough discussion about the most recent functionalization strategies based on PLGA-NPs for AD and their mechanisms of action is provided, together with a description of AD pathogenesis and the role of the BBB in brain targeting.
Thermal Characteristics Study of the Bump Foil Thrust Gas Bearing
Authors: Liu Xiaomin , Li Changlin , Du Jianjun , Nan Guodong
Published: May 2021

In this paper, a thermo-hydrodynamic model of the bump foil thrust gas bearing is developed, which solves the coupled gas film three-dimensional energy equation, non-isothermal Reynolds equation, and the foil deformation equation. The effects of bearing speed, thrust load, and external cooling gas on the bearing temperature field are calculated and analyzed. The test rig of foil thrust gas bearing was built to measure the bearing temperature under different working conditions. Both simulation and experiment results show that there exist temperature gradients on the top foil both in the circumferential and radial directions. The simulation results also shows that the top foil side of the gas film has the highest temperature value in the entire lubrication field, and the position of highest temperature moves radially inward on the thrust plate side as the rotor speed increases. The gas film temperature increases with the increasing rotor speed and bearing static load, and rotor speed has greater effects on the temperature variation. Cooling air flow passing through the bump foil is also considered in the simulations, and the cooling efficiency decreases as the mass of gas flow increases.
Chronic Leg Ulcers: Are Tissue Engineering and Biomaterials Science the Solution?
Authors: Kyriakidis Christos , Lali Ferdinand , Greco Karin Vicente , García-Gareta Elena
Published: May 2021

Chronic leg ulcers (CLUs) are full thickness wounds that usually occur between the ankle and knee, fail to heal after 3 months of standard treatment, or are not entirely healed at 12 months. CLUs present a considerable burden on patients, subjecting them to severe pain and distress, while healthcare systems suffer immense costs and loss of resources. The poor healing outcome of the standard treatment of CLUs generates an urgent clinical need to find effective solutions for these wounds. Tissue Engineering and Biomaterials Science offer exciting prospects for the treatment of CLUs, using a broad range of skin substitutes or scaffolds, and dressings. In this review, we summarize and discuss the various types of scaffolds used clinically in the treatment of CLUs. Their structure and therapeutic effects are described, and for each scaffold type representative examples are discussed, supported by clinical trials. Silver dressings are also reviewed due to their reported benefits in the healing of leg ulcers, as well as recent studies on new dermal scaffolds, reporting on clinical results where available. We conclude by arguing there is a further need for tissue-engineered products specifically designed and bioengineered to treat these wounds and we propose a series of properties that a biomaterial for CLUs should possess, with the intention of focusing efforts on finding an effective treatment.
Multifunctional Injectable Hydrogel Loaded with Cerium-Containing Bioactive Glass Nanoparticles for Diabetic Wound Healing
Authors: Chen Yue-Hua , Rao Zhou-Feng , Liu Yu-Jie , Liu Xiang-Sheng , Liu Yu-Fei , Xu Lan-Ju , Wang Ze-Qi , Guo Jing-Yue , Zhang Lin , Dong Yun-Sheng , Qi Chun-Xiao , Yang Chao , Wang Shu-Fang
Published: May 2021

Diabetic foot wound healing is a major clinical problem due to impaired angiogenesis and bacterial infection. Therefore, an effective regenerative dressing is desiderated with the function of promoting revascularization and anti-bacteria. Herein, a multifunctional injectable composite hydrogel was prepared by incorporation of the cerium-containing bioactive glass (Ce-BG) into Gelatin methacryloyl (GelMA) hydrogel. The Ce-BG was synthesized by combining sol-gel method with template method, which maintained spherical shape, chemical structure and phase constitution of bioactive glass (BG). The Ce-BG/GelMA hydrogels had good cytocompatibility, promoted endothelial cells migration and tube formation by releasing Si ion. In vitro antibacterial tests showed that 5 mol % CeO2-containing bioactive glass/GelMA (5/G) composite hydrogel exhibited excellent antibacterial properties. In vivo study demonstrated that the 5/G hydrogel could significantly improve wound healing in diabetic rats by accelerating the formation of granulation tissue, collagen deposition and angiogenesis. All in all, these results indicate that the 5/G hydrogel could enhance diabetic wound healing. Therefore, the development of multifunctional materials with antibacterial and angiogenic functions is of great significance to promote the repair of diabetic wound healing.
Ultrasonic Synthesis and Biomedical Application of Mn0.5Zn0.5ErxYxFe2−2xO4 Nanoparticles
Authors: Rehman Suriya , Almessiere Munirah A. , A. Al-Suhaimi Ebtesam , Hussain Mehwish , Yousuf Bari Maha , Mehmood Ali Syed , Al-Jameel Suhailah S. , Slimani Yassine , Khan Firdos Alam , Baykal Abdulhadi
Published: May 2021

In the present study, biocompatible manganese nanoparticles have been linked with zinc and iron molecules to prepare different derivatives of Mn0.5Zn0.5ErxYxFe2−2xO4 NPs (x = 0.02, 0.04, 0.06, 0.08, 0.10), using an ultrasonication approach. The structure, surface morphology, and chemical compositions of Mn0.5Zn0.5ErxYxFe2−2xO4 NPs were elucidated by X-ray diffractometer (XRD), High-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), and Energy Dispersive X-Ray Analysis (EDX) techniques. The bioactivity of Mn0.5Zn0.5ErxYxFe2−2xO4 NPs on normal (HEK-293) and (HCT-116) colon cancer cell line was evaluated. The Mn0.5Zn0.5ErxYxFe2−2xO4 NPs treatment post 48 h resulted in a significant reduction in cells (via MTT assay, having an IC50 value between 0.88 µg/mL and 2.40 µg/mL). The specificity of Mn0.5Zn0.5ErxYxFe2−2xO4 NPs were studied by treating them on normal cells line (HEK-293). The results showed that Mn0.5Zn0.5ErxYxFe2−2xO4 NPs did not incur any effect on HEK-293, which suggests that Mn0.5Zn0.5ErxYxFe2−2xO4 NPs selectively targeted the colon cancerous cells. Using Candida albicans, antifungal activity was also studied by evaluating minimum inhibitory/fungicidal concentration (MIC/MFC) and the effect of nanomaterial on the germ tube formation, which exhibited that NPs significantly inhibited the growth and germ tube formation. The obtained results hold the potential to design nanoparticles that lead to efficient bioactivity.
Computational Study on Selective PDE9 Inhibitors on PDE9-Mg/Mg, PDE9-Zn/Mg, and PDE9-Zn/Zn Systems
Authors: Sivakumar Dakshinamurthy , Mudedla Sathishkumar , Jang Seonghun , Kim Hyunjun , Park Hyunjin , Choi Yonwon , Oh Joongyo , Wu Sangwook
Published: May 2021

PDE9 inhibitors have been studied to validate their potential to treat diabetes, neurodegenerative disorders, cardiovascular diseases, and erectile dysfunction. In this report, we have selected highly potent previously reported selective PDE9 inhibitors BAY73-6691R, BAY73-6691S, 28r, 28s, 3r, 3s, PF-0447943, PF-4181366, and 4r to elucidate the differences in their interaction patterns in the presence of different metal systems such as Zn/Mg, Mg/Mg, and Zn/Zn. The initial complexes were generated by molecular docking followed by molecular dynamics simulation for 100 ns in triplicate for each system to understand the interactions’ stability. The results were carefully analyzed, focusing on the ligands’ non-bonded interactions with PDE9 in different metal systems.
Fatty Acid-Binding Proteins Aggravate Cerebral Ischemia-Reperfusion Injury in Mice
Authors: Guo Qingyun , Kawahata Ichiro , Degawa Tomohide , Ikeda-Matsuo Yuri , Sun Meiling , Han Feng , Fukunaga Kohji
Published: May 2021

Fatty acid-binding proteins (FABPs) regulate the intracellular dynamics of fatty acids, mediate lipid metabolism and participate in signaling processes. However, the therapeutic efficacy of targeting FABPs as novel therapeutic targets for cerebral ischemia is not well established. Previously, we synthesized a novel FABP inhibitor, i.e., FABP ligand 6 [4-(2-(5-(2-chlorophenyl)-1-(4-isopropylphenyl)-1H-pyrazol-3-yl)-4-fluorophenoxy)butanoic acid] (referred to here as MF6). In this study, we analyzed the ability of MF6 to ameliorate transient middle cerebral artery occlusion (tMCAO) and reperfusion-induced injury in mice. A single MF6 administration (3.0 mg/kg, per os) at 0.5 h post-reperfusion effectively reduced brain infarct volumes and neurological deficits. The protein-expression levels of FABP3, FABP5 and FABP7 in the brain gradually increased after tMCAO. Importantly, MF6 significantly suppressed infarct volumes and the elevation of FABP-expression levels at 12 h post-reperfusion. MF6 also inhibited the promotor activity of FABP5 in human neuroblastoma cells (SH-SY5Y). These data suggest that FABPs elevated infarct volumes after ischemic stroke and that inhibiting FABPs ameliorated the ischemic injury. Moreover, MF6 suppressed the inflammation-associated prostaglandin E2 levels through microsomal prostaglandin E synthase-1 expression in the ischemic hemispheres. Taken together, the results imply that the FABP inhibitor MF6 can potentially serve as a neuroprotective therapeutic for ischemic stroke.
Vancomycin-Loaded Collagen/Hydroxyapatite Layers Electrospun on 3D Printed Titanium Implants Prevent Bone Destruction Associated with S. epidermidis Infection and Enhance Osseointegration
Authors: Suchý Tomáš , Vištejnová Lucie , Šupová Monika , Klein Pavel , Bartoš Martin , Kolinko Yaroslav , Blassová Tereza , Tonar Zbyněk , Pokorný Marek , Sucharda Zbyněk , Žaloudková Margit , Denk František , Ballay Rastislav , Juhás Štefan , Juhásová Jana , Klapková Eva , Horný Lukáš , Sedláček Radek , Grus Tomáš , Čejka Zdeněk , Čejka Zdeněk , Chudějová Kateřina , Hrabák Jaroslav
Published: May 2021

The aim of the study was to develop an orthopedic implant coating in the form of vancomycin-loaded collagen/hydroxyapatite layers (COLHA+V) that combine the ability to prevent bone infection with the ability to promote enhanced osseointegration. The ability to prevent bone infection was investigated employing a rat model that simulated the clinically relevant implant-related introduction of bacterial contamination to the bone during a surgical procedure using a clinical isolate of Staphylococcus epidermidis. The ability to enhance osseointegration was investigated employing a model of a minipig with terminated growth. Six weeks following implantation, the infected rat femurs treated with the implants without vancomycin (COLHA+S. epidermidis) exhibited the obvious destruction of cortical bone as evinced via a cortical bone porosity of up to 20% greater than that of the infected rat femurs treated with the implants containing vancomycin (COLHA+V+S. epidermidis) (3%) and the non-infected rat femurs (COLHA+V) (2%). The alteration of the bone structure of the infected COLHA+S. epidermidis group was further demonstrated by a 3% decrease in the average Ca/P molar ratio of the bone mineral. Finally, the determination of the concentration of vancomycin released into the blood stream indicated a negligible systemic load. Six months following implantation in the pigs, the quantified ratio of new bone indicated an improvement in osseointegration, with a two-fold bone ingrowth on the COLHA (47%) and COLHA+V (52%) compared to the control implants without a COLHA layer (27%). Therefore, it can be concluded that COLHA+V layers are able to significantly prevent the destruction of bone structure related to bacterial infection with a minimal systemic load and, simultaneously, enhance the rate of osseointegration.
Biological Functions of Rat Ultrasonic Vocalizations, Arousal Mechanisms, and Call Initiation
Authors: Brudzynski Stefan M.
Published: May 2021

This review summarizes all reported and suspected functions of ultrasonic vocalizations in infant and adult rats. The review leads to the conclusion that all types of ultrasonic vocalizations subserving all functions are vocal expressions of emotional arousal initiated by the activity of the reticular core of the brainstem. The emotional arousal is dichotomic in nature and is initiated by two opposite-in-function ascending reticular systems that are separate from the cognitive reticular activating system. The mesolimbic cholinergic system initiates the aversive state of anxiety with concomitant emission of 22 kHz calls, while the mesolimbic dopaminergic system initiates the appetitive state of hedonia with concomitant emission of 50 kHz vocalizations. These two mutually exclusive arousal systems prepare the animal for two different behavioral outcomes. The transition from broadband infant isolation calls to the well-structured adult types of vocalizations is explained, and the social importance of adult rat vocal communication is emphasized. The association of 22 kHz and 50 kHz vocalizations with aversive and appetitive states, respectively, was utilized in numerous quantitatively measured preclinical models of physiological, psychological, neurological, neuropsychiatric, and neurodevelopmental investigations. The present review should help in understanding and the interpretation of these models in biomedical research.
Determining Critical Success Factors for Public–Private Partnership Asset-Backed Securitization: A Structural Equation Modeling Approach
Authors: Liu Li , Guo Yubo , Chen Chuan , Martek Igor
Published: May 2021

Public–private partnership (PPP) has been widely applied in China and many developing countries in the recent decade. As new PPP projects gradually enter the operational phase, the issue of refinancing becomes increasingly important. PPP–ABS plays an indispensable role in PPP project refinancing. The factors that promote the success of the emerging PPP–ABS in the China financial market need to be determined. To accomplish two objectives, namely, to identify critical success factors (CSFs) and to explore the relationship between these factors and the success of the PPP asset-backed securitization (PPP–ABS) of this research, methods such as a questionnaire survey and structural equation modeling (SEM) were conducted successively. Four success factors, including underlying asset quality (UAQ), original equity holder credit (OEHC), rationality of security design (RoSD) and maturity of relative institutions (MoRI), were identified in this study. Consequently, nineteen theoretical hypotheses were developed and tested. It is shown in the SEM approach that UAQ and OEHC positively influence the success of PPP–ABS, alongside issuance characteristics (IC) that mediate the relationship between the success of PPP–ABS and UAQ, RoSD and MoRI, respectively. This finding increased knowledge of PPP–ABS and how investors and government can benefit from it.
Etiology of Acute Leukemia: A Review
Authors: Tebbi Cameron K.
Published: May 2021

Acute leukemias constitute some of the most common malignant disorders. Despite significant progress made in the treatment of these disorders, their etiology remains unknown. A large and diverse group of genetic and environmental variables have been proposed. The role of a variety of factors, including pre-existing and acquired genetic mutations, exposure to radiation and various chemicals during preconception, pregnancy and throughout life, have been explored. The effects of inherited genetic variations and disorders, pre-existing diseases, infectious agents, hobbies, occupations, prior treatments, and a host of other factors have been proposed, but none is universally applicable to all cases. Variation in the incidence and prognosis based on the age, sex, race, type of the disease, geographic area of residence and other factors are intriguing but remain unexplained. Advances in genomic profiling, including genome-wide gene expression, DNA copy number and single nucleotide polymorphism (SNP) genotype, may shed some light on the role of genetics in these disparities. Separate two-hit hypotheses for the development of acute myeloblastic and lymphoblastic leukemia have been proposed. The latter combines genetics and infection factors resulting in leukemogenesis. A number of pre- and post-natal environmental conditions and exposure to infections, including a mycovirus infected Aspergillus flavus, have been suggested. The exact nature, timing, sequence of the events and mechanisms resulting in the occurrence of leukemia requires further investigations. This review summarizes some of the above factors in acute lymphoblastic and myeloblastic leukemias and the direction for future research on the etiology of these disorders.
New Insights into the Biological and Clinical Aspects of Merkel Cell Carcinoma
Authors: Koljonen Virve , Lui Weng-Onn , Becker Jürgen C.
Published: May 2021

The Special Issue in Cancers, “The Biological and Clinical Aspects of Merkel Cell Carcinoma”, walks the avid reader through the interesting and sometimes even mysterious facets of Merkel cell carcinoma (MCC), starting at its carcinogenesis to also cover innovative treatment options [...]
Advances and Perspectives in the Treatment of B-Cell Malignancies
Authors: Cuenca Marta , Peperzak Victor
Published: May 2021

B-cell malignancies arise from different stages of B-cell differentiation and constitute a heterogeneous group of cancers including B-cell lymphomas, B-cell leukemias, and plasma cell dyscrasias [...]