bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioengineering Technology in Context of COVID-19 Pandemic: Potential Roles and Applications
Authors: Bahl Shashi , Iyengar Karthikeyan P , Bagha Ashok Kumar , Jaly Ibrahim , Jain Vijay , Vaishya Raju
Published: January 2021

Bioengineering (BE) technology has significant influence on the healthcare environment. This has grown steadily particularly since the medical practice has become more technology based. We have tried to assess the impact of bioengineering in tackling the COVID-19 pandemic. The use of bioengineering principles in healthcare has been evaluated. The practical implications of these technologies in fighting the current global health pandemic have been presented. There has been a shared drive worldwide to harness the advancements of bioengineering to combat COVID-19. These efforts have ranged from small groups of volunteers to large scale research and mass production. Together the engineering and medical fields have worked to address areas of critical need including the production and delivery of personal protective equipment, ventilators as well as the creation of a viable vaccine. The fight against COVID-19 has helped highlight the work and contributions of so many professionals in the bioengineering fields who are working tirelessly to help our health services cope. Their innovation and ingenuity are paving the way to successfully beat this virus. We must continue to support these fields as we evolve our health systems to deal with the challenges of healthcare in the future.
The Electrostatic Features of Dengue Virus Capsid Assembly
Authors: Lopez-Hernandez Alan E , Xie Yixin , Guo Wenhan , Li Lin
Published: January 2021

Dengue virus causes serious diseases and deaths in the world. Understanding the fundamental mechanisms of dengue virus is highly demanded to develop treatments for dengue virus caused diseases. Here, we present a computational work which focused on the stability of dengue viral capsid. The interactions among E proteins on the dengue viral capsid were studied using several computational approaches. It was found that the electrostatic distribution on a single E protein monomer is highly inhomogeneous, which makes an E protein strongly binding with another E protein. This is the reason why all the E proteins form homodimers as the basic units on the whole dengue viral capsids. The pKa calculations of E proteins demonstrated that the folding energy of an E protein is low and stable in the range of pH 6–10, which is different from many other proteins that are stable at certain pH. The pH dependence of binding energy of E protein homodimer shows that the binding energy is low and independent from pH when the pH is also in the range of 6–10. This finding implies that the dengue virus can survive in a wide range of pH, which can explain why the dengue virus is so widely distributed in the world and spreads fast.
Accommodation of India–Asia convergence via strike-slip faulting and block rotation in the Qilian Shan fold–thrust belt, northern margin of the Tibetan Plateau
Authors: Cheng Feng , Zuza Andrew V. , Haproff Peter J. , Wu Chen , Neudorf Christina , Chang Hong , Li Xiangzhong , Li Bing
Published: January 2021

Existing models of intracontinental deformation have focused on plate-like rigid body motion v. viscous-flow-like distributed deformation. To elucidate how plate convergence is accommodated by intracontinental strike-slip faulting and block rotation within a fold–thrust belt, we examine the Cenozoic structural framework of the central Qilian Shan of northeastern Tibet, where the NW-striking, right-slip Elashan and Riyueshan faults terminate at the WNW-striking, left-slip Haiyuan and Kunlun faults. Field- and satellite-based observations of discrete right-slip fault segments, releasing bends, horsetail termination splays and off-fault normal faulting suggest that the right-slip faults accommodate block rotation and distributed west–east crustal stretching between the Haiyuan and Kunlun faults. Luminescence dating of offset terrace risers along the Riyueshan fault yields a Quaternary slip rate of
c.
1.1 mm a
−1
, which is similar to previous estimates. By integrating our results with regional deformation constraints, we propose that the pattern of Cenozoic deformation in northeastern Tibet is compatible with west–east crustal stretching/lateral displacement, non-rigid off-fault deformation and broad clockwise rotation and bookshelf faulting, which together accommodate NE–SW India–Asia convergence. In this model, the faults represent strain localization that approximates continuum deformation during regional clockwise lithospheric flow against the rigid Eurasian continent.

Supplementary material:
Luminescence dating procedures and protocols is available at
https://doi.org/10.17605/OSF.IO/CR9MN

Thematic collection:
This article is part of the Fold-and-thrust belts and associated basins collection available at:
https://www.lyellcollection.org/cc/fold-and-thrust-belts
Engaging Young Learners through Online Teaching
Authors: Saffold Felicia
Published: January 2021

This article explored the transformation of an early childhood center from face-to-face instruction to online learning and examined how principles of effective online instruction design were related to community building, interactivity, and online presence. The case study is from an early head start institution in Milwaukee, Wisconsin. After creating an online program over the summer of 2020, teachers share their perspectives of teaching online with young learners. Results suggest benefits of technology integration in early learning classrooms.
Reactive Nitrogen Cycling in the Atmosphere and Ocean
Authors: Altieri Katye E. , Fawcett Sarah E. , Hastings Meredith G.
Published: January 2021

The budget of reactive nitrogen (Nr; oxidized and reduced inorganic and organic forms of nitrogen) has at least doubled since the preindustrial era due to human activities. Excess Nr causes significant detrimental effects on many terrestrial and aquatic ecosystems; less is known about the impact on the open ocean. Nr deposition may already rival biological N2fixation quantitatively and will likely continue to rise. However, it is unclear how much of the Nr currently deposited to the ocean is external in origin. Understanding the importance of ocean Nr emissions versus external Nr deposition is key to quantifying the influence of deposition on ocean biogeochemistry and climate. This article reviews our understanding of the impacts of Nr deposition on the open ocean and the emissions of Nr from the ocean, placing particular emphasis on stable isotopes as a tool to investigate the surface ocean–lower atmosphere Nr cycle and its variations over time. ▪  The ocean has a dynamic exchange of reactive nitrogen with the atmosphere and is not just a passive recipient of nitrogen pollution from land. ▪  Tracing anthropogenic nitrogen deposition to the ocean is a challenge due to overlapping geochemical signatures with other nitrogen inputs. ▪  However, studies suggest an imprint of external (anthropogenic) nitrogen deposition in the Mediterranean Sea and North Pacific Ocean. ▪  Climate change will impact nitrogen emissions from the ocean through warming, acidification, stratification, and changes in food webs.
Metformin impairs homing ability and efficacy of mesenchymal stem cells for cardiac repair in streptozotocin-induced diabetic cardiomyopathy in rats
Authors: Ammar Hania Ibrahim , Shamseldeen Asmaa Mohammed , Shoukry Heba Samy , Ashour Hend , Kamar Samaa Samir , Rashed Laila Ahmed , Fadel Mostafa , Srivastava Abhay , Dhingra Sanjiv
Published: January 2021

Metformin treatment reduces the efficacy of mesenchymal stem cell therapy for cardiac repair during diabetic cardiomyopathy. Stem cell therapy in diabetics may be more effective in combination with AMPK inhibitors.
Paraquat herbicide diminishes chemoreflex sensitivity, induces cardiac autonomic imbalance and impair cardiac function in rats
Authors: Pereyra Katherin V. , Schwarz Karla G. , Andrade David C. , Toledo Camilo , Rios-Gallardo Angélica , Díaz-Jara Esteban , Bastías Sussy S. , Ortiz Fernando C. , Ortolani Domiziana , Del Rio Rodrigo
Published: January 2021

Paraquat herbicide is still employed in agricultural practices in several countries. Here, we showed for the first time that 1 mo paraquat administration results in cardiac adverse remodeling, blunts ventilatory chemoreflex drive, and promotes irregular breathing at rest in previously healthy rats. In addition, paraquat exposure induced cardiac autonomic imbalance and cardiac electrophysiology alterations. Lastly, cardiac diastolic dysfunction was overt in rats following 1 mo of paraquat treatment.
Cellular signaling cross-talk between different cardiac cell populations: an insight into the role of exosomes in the heart diseases and therapy
Authors: Nguyen Binh Yen , Azam Tayyiba , Wang Xin
Published: January 2021

Exosomes are a subgroup of extracellular bilayer membrane nanovesicles that are enriched in a variety of bioactive lipids, receptors, transcription factors, surface proteins, DNA, and noncoding RNAs. They have been well recognized to play essential roles in mediating intercellular signaling by delivering bioactive molecules from host cells to regulate the physiological processes of recipient cells. In the context of heart diseases, accumulating studies have indicated that exosome-carried cellular proteins and noncoding RNA derived from different types of cardiac cells, including cardiomyocytes, fibroblasts, endothelial cells, immune cells, adipocytes, and resident stem cells, have pivotal roles in cardiac remodeling under disease conditions such as cardiac hypertrophy, diabetic cardiomyopathy, and myocardial infarction. In addition, exosomal contents derived from stem cells have been shown to be beneficial for regenerative potential of the heart. In this review, we discuss current understanding of the role of exosomes in cardiac communication, with a focus on cardiovascular pathophysiology and perspectives for their potential uses as cardiac therapies.
Improving the Thermal Aging Resistance of γ‐Vulcanized Polybutadiene Rubber (BR)/Nature Rubber (NR) Blends with Sulfur Added
Authors: Mao Zongyuan , Wang Wenzhao , Mao Gang
Published: January 2021

In this paper, sulfur was added into polybutadiene rubber/nature rubber (BR/NR) blends for improving the resistance of thermal aging. BR/NR blends with sulfur were vulcanized by 60Co γ radiation with different irradiation doses. Afterwards, the specimens underwent thermal aging by using air oven, the non‐aged specimens without such process. It was found that the crosslink degree of BR/NR blends increased with the increase in the irradiation dose, according to the results of gel and molecular weight between crosslinks (Mc). Furthermore, the crosslink degree of BR/NR blends increased after thermal aging. This made the mechanical properties and initial degradation temperature (IDT) of aged BR/NR blends improve. Sulfur could improve thermal resistance of γ‐irradiated BR/NR blends. Finally, the possible mechanism of improved crosslink degree in aged BR/NR blends was illuminated in the paper.
Bipolar Soft Sets: Relations between Them and Ordinary Points and Their Applications
Authors: Al-shami Tareq M.
Published: January 2021

Bipolar soft set is formulated by two soft sets; one of them provides us the positive information and the other provides us the negative information. The philosophy of bipolarity is that human judgment is based on two sides, positive and negative, and we choose the one which is stronger. In this paper, we introduce novel belong and nonbelong relations between a bipolar soft set and an ordinary point. These relations are considered as one of the unique characteristics of bipolar soft sets which are somewhat expression of the degrees of membership and nonmembership of an element. We discuss essential properties and derive the sufficient conditions of some equivalence of these relations. We also define the concept of soft mappings between two classes of bipolar soft sets and study the behaviors of an ordinary point under these soft mappings with respect to all relations introduced herein. Then, we apply bipolar soft sets to build an optimal choice application. We give an algorithm of this application and show the method for implementing this algorithm by an illustrative example. In conclusion, it can be noted that the relations defined herein give another viewpoint to explore the concepts of bipolar soft topology, in particular, soft separation axioms and soft covers.
The Mixed Liu Estimator in Stochastic Restricted Linear Measurement Error Model
Authors: Wu Jibo
Published: January 2021

Ghapani and Babdi [1] proposed a mixed Liu estimator in linear measurement error model with stochastic linear restrictions. In this article, we propose an alternative mixed Liu estimator in the linear measurement error model with stochastic linear restrictions. The performance of the new mixed Liu estimator over the mixed estimator, Liu estimator, and mixed Liu estimator proposed by Ghapani and Babdi [1] are discussed in the sense of mean squared error matrix. Finally, a simulation study is given to show the performance of these estimators.
Effect of Cognitive Function on Balance and Posture Control after Stroke
Authors: Yu Hui-xian , Wang Zhao-xia , Liu Chang-bin , Dai Pei , Lan Yue , Xu Guang-qing
Published: January 2021

Hemiplegic gait is the most common sequela of stroke. Patients with hemiplegic gait are at a risk of falling because of poor balance. The theory of cognitive-motor networks paved the way for a new field of research. However, the mechanism of the relationship of cognition with gait or posture control networks is unclear because of the dynamic characteristics of walking and changing postures. To explore differences in the balance function and fall risk between patients with and without cognitive impairment after stroke, we utilized the Berg balance scale, Timed “Up and Go” test, and 10 m walking test. Patients were divided into two groups: the observation group (16 patients, female 6 and male 10), comprising patients with cognitive impairment after stroke, and the control group (16 patients, female 7 and male 9), comprising patients without cognitive impairment after stroke. We found that patients with cognitive impairment had worse balance function and a higher risk of falls. They needed a longer time to turn around or sit down. Our findings indicated that posture control in turning around and sitting down required more cognitive resources in daily life.
A Hybrid Whale Optimization with Seagull Algorithm for Global Optimization Problems
Authors: Che Yanhui , He Dengxu
Published: January 2021

Seagull optimization algorithm (SOA) inspired by the migration and attack behavior of seagulls in nature is used to solve the global optimization problem. However, like other well-known metaheuristic algorithms, SOA has low computational accuracy and premature convergence. Therefore, in the current work, these problems are solved by proposing the modified version of SOA. This paper proposes a novel hybrid algorithm, called whale optimization with seagull algorithm (WSOA), for solving global optimization problems. The main reason is that the spiral attack prey of seagulls is very similar to the predation behavior of whale bubble net, and the WOA has strong global search ability. Therefore, firstly, this paper combines WOA’s contraction surrounding mechanism with SOA’s spiral attack behavior to improve the calculation accuracy of SOA. Secondly, the levy flight strategy is introduced into the search formula of SOA, which can effectively avoid premature convergence of algorithms and balance exploration and exploitation among algorithms more effectively. In order to evaluate the effectiveness of solving global optimization problems, 25 benchmark test functions are tested, and WSOA is compared with seven famous metaheuristic algorithms. Statistical analysis and results comparison show that WSOA has obvious advantages compared with other algorithms. Finally, four engineering examples are tested with the proposed algorithm, and the effectiveness and feasibility of WSOA are verified.
Correlations between Geometric Properties and Permeability of 2D Fracture Networks
Authors: Wang Xiaolin , Yu Liyuan , Yang Hanqing
Published: January 2021

The equivalent permeability of fractured rock masses plays an important role in understanding the fluid flow and solute transport properties in underground engineering, yet the effective predictive models have not been proposed. This study established mathematical expressions to link permeability of 2D fracture networks to the geometric properties of fractured rock masses, including number density of fracture lines, total length of fractures per square meter, and fractal dimensions of fracture network structures and intersections. The results show that the equivalent permeability has power law relationships with the geometric properties of fracture networks. The fractal dimensions that can be easily obtained from an engineering site can be used to predict the permeability of a rock fracture network. When the fractal dimensions of fracture network structures and intersections exceed the critical values, the effect of randomness of fracture locations is negligible. The equivalent permeability of a fracture network increases with the increment of fracture density and/or fractal dimensions proportionally.
Joint Motion Control for Lower Limb Rehabilitation Based on Iterative Learning Control (ILC) Algorithm
Authors: Guan Wei , Zhou Lan , Cao YouShen
Published: January 2021

At present, the motion control algorithms of lower limb exoskeleton robots have errors in tracking the desired trajectory of human hip and knee joints, which leads to poor follow‐up performance of the human‐machine system. Therefore, an iterative learning control algorithm is proposed to track the desired trajectory of human hip and knee joints. In this paper, the experimental platform of lower limb exoskeleton rehabilitation robot is built, and the control system software and hardware design and robot prototype function test are carried out. On this basis, a series of experiments are carried out to verify the rationality of the robot structure and the feasibility of the control method. Firstly, the dynamic model of the lower limb exoskeleton robot is established based on the structure analysis of the human lower limb; secondly, the servo control model of the lower limb exoskeleton robot is established based on the iterative learning control algorithm; finally, the exponential gain closed‐loop system is designed by using MATLAB software. The relationship between convergence speed and spectral radius is analyzed, and the expected trajectory of hip joint and knee joint is obtained. The simulation results show that the algorithm can effectively improve the gait tracking accuracy of the lower limb exoskeleton robot and improve the follow‐up performance of the human‐machine system.
Development and Application of Model Test System for Reconstruction and Expansion of Existing Shallow Single‐Hole Tunnel into Twin‐Arch Tunnel
Authors: Jia Yanling , Ouyang Aohui , Wang Siyu , Liang Xing , Wang Bin , Liu Chang , Ye Fei
Published: January 2021

In this study, we developed a tunnel excavation model test system to investigate the deformation and mechanical response of the surrounding rocks and tunnel structure during the reconstruction and expansion of an existing shallow single‐hole tunnel into a twin‐arch tunnel. A model test was conducted to study the variation in the ground surface settlement characteristics, surrounding rock pressure, and internal stresses of the supporting structure and midwall during the construction process. The influence of the excavation distance on displacements and structural stress between the faces of the left and right tunnels was analysed using numerical software. A comparison between the model test results and the monitoring and measurement construction results revealed a fairly consistent ground surface settlement, indicating that the system is stable and reliable and can be widely applied to laboratory model test research on tunnel excavation. Results show that the excavation of the first tunnel had a significant effect on the stability of the surrounding rock within the distance of a single‐tunnel span behind the tunnel face. When the excavation distance between the two tunnels exceeded twice the length of the single‐tunnel span, its effect on the stresses and deformation of the reconstructed twin‐arch tunnel was negligible.
Experimental Study on Seepage Anisotropy of a Hexagonal Columnar Jointed Rock Mass
Authors: He Yanxin , Zhu Zhende , Lu Wenbin , Tian Yuan , Xie Xinghua , Wang Sijing
Published: January 2021

Many columnar jointed rock masses (basalt) are present at the Baihetan hydropower dam site, and their seepage characteristics have a significant impact on the project’s safety and stability. In this study, model samples consisting of material similar to the columnar jointed rock mass with different inclination angles (0°–90°) were prepared and laboratory triaxial seepage tests were performed to study the seepage characteristics of the columnar jointed rock mass under maximum axial principal stress. The experimental results showed that the similar material model samples of columnar jointed rock mass showed obvious seepage anisotropy. The nonlinear seepage characteristics were well described by the Forchheimer and Izbash equations, and the fitting coefficients of the two equations were in good correspondence. The curves describing the relationship between the inherent permeability and the stress of the samples with different dip angles were U‐shaped and L‐shaped, and a one‐variable cubic equation well described the relationship. The 45° angle specimen had the highest sensitivity to the maximum principal stress, and its final permeability increased by 144.25% compared with the initial permeability. The research results can provide theoretical support for the stability evaluation of the Baihetan hydropower station.
New Models for Home Health Care under Uncertainty with Consideration of the Coordinated Development of Economy and Environment
Authors: Cui Yan , Zhang Lijun , Gao Qiuye , Li Bohao , Hou Yumei
Published: January 2021

With the aggravation of population aging, home health care (HHC) services are paid more and more attention by the elderly. Previous studies aim at improving service quality and reducing cost, ignoring the coordinated and sustainable development of the economy and environment. From the perspective of sustainable development, this paper first establishes a linear optimization (LO) model considering transportation, time, and carbon emission costs. However, the uncertainty of service demand is a very difficult problem for HHC research. Most of the previous studies only consider the deterministic model, which has difficulty dealing with the uncertain situation. Therefore, a robust optimization (RO) model is proposed to resist uncertain disturbances by introducing a robust uncertain set response. The experimental results show that the increase of low‐carbon transition cost only increases the total cost of the LO model but has a significant positive impact on the RO model. With the increase of uncertainty, the robust model will pay the cost of robustness, but it can obtain a higher service level (93.20% to 93.38%). In addition, when the carbon tax increases, the total transportation cost does not increase but decreases, thus obtaining environmental benefits. When the carbon tax increases by 25%, the average total cost of using the RO model is reduced by 8.274%. The research results of this paper can provide enlightenment and reference for the low‐carbon transformation of HHC enterprises.
Predictors of Acute Postsurgical Pain following Gastrointestinal Surgery: A Prospective Cohort Study
Authors: Liu Qing-Ren , Ji Mu-Huo , Dai Yu-Chen , Sun Xing-Bing , Zhou Cheng-Mao , Qiu Xiao-Dong , Yang Jian-Jun
Published: January 2021

Background. Several predictors have been shown to be independently associated with chronic postsurgical pain for gastrointestinal surgery, but few studies have investigated the factors associated with acute postsurgical pain (APSP). The aim of this study was to identify the predictors of APSP intensity and severity through investigating demographic, psychological, and clinical variables. Methods. We performed a prospective cohort study of 282 patients undergoing gastrointestinal surgery to analyze the predictors of APSP. Psychological questionnaires were assessed 1 day before surgery. Meanwhile, demographic characteristics and perioperative data were collected. The primary outcomes are APSP intensity assessed by numeric rating scale (NRS) and APSP severity defined as a clinically meaningful pain when NRS ≥4. The predictors for APSP intensity and severity were determined using multiple linear regression and multivariate logistic regression, respectively. Results. 112 patients (39.7%) reported a clinically meaningful pain during the first 24 hours postoperatively. Oral morphine milligram equivalent (MME) consumption (β 0.05, 95% CI 0.03–0.07,

p
<
0.001

), preoperative anxiety (β 0.12, 95% CI 0.08–0.15,

p
<
0.001

), and expected postsurgical pain intensity (β 0.12, 95% CI 0.06–0.18,

p
<
0.001

) were positively associated with APSP intensity. Furthermore, MME consumption (OR 1.15, 95% CI 1.10–1.21,

p
<
0.001

), preoperative anxiety (OR 1.33, 95% CI 1.21–1.46,

p
<
0.001

), and expected postsurgical pain intensity (OR 1.36, 95% CI 1.17–1.57,

p
<
0.001

) were independently associated with APSP severity. Conclusion. These results suggested that the predictors for APSP intensity following gastrointestinal surgery included analgesic consumption, preoperative anxiety, and expected postsurgical pain, which were also the risk factors for APSP severity.
Fixed‐Time Synchronization for Different Dimensional Complex Network Systems with Unknown Parameters via Adaptive Control
Authors: Ji Yude , Gong Yunli , Su Shan , Bai Xiaoxue
Published: January 2021

This article is related to the issue of fixed‐time synchronization of different dimensional complex network systems with unknown parameters. Two suitable adaptive controllers and dynamic parameter estimations are proposed such that the complex network driving and response systems can be synchronized in the settling time. Based on fixed‐time control theory and Lyapunov functional method, novel sufficient conditions are provided to guarantee the synchronization within the fixed times, and the settling times are explicitly evaluated, which are independent of the initial synchronization errors. Finally, a numerical example is given to illustrate the effectiveness of the proposed control algorithms.
Short Circuit Fault Detection against High Thermal Background Using a Two‐Level Scheme Based on DoG Filter
Authors: Li Xin , Li Yonggang , Zhu Hongqiu , Wu Renchao , Zhou Can
Published: January 2021

Short circuit is a key factor which drastically affects the efficiency of metal electrorefining. Infrared image of the intercell busbar region is used to perform short circuit detection. To cope with the high thermal background, a two‐level short circuit detection method is designed. Firstly, with background subtraction, high intensity short circuit electrodes, as well as the background, are removed, and normal working electrodes are preserved. In the second stage, suspicious short circuit areas are sifted out by normal electrode detecting and texture period estimation. Gaussian difference filter (DoG) which is based on the human visual system is improved to match the target gray distribution. A comparative experiment indicates that the proposed orthogonal DoG outperforms the original DoG and top‐hat in the accuracy of normal electrode detection. The two‐level detection method in this paper is applied in a copper electrolysis plant and exhibits superiority in locating short circuits and avoiding miss detection.
Efficacy of Rg1-Oil Adjuvant on Inducing Immune Responses against Bordetella bronchiseptica in Rabbits
Authors: Chenwen Xiao , Quanan Ji , Yee Huang , Yan Liu , Jiaoyu Wang , Qiang Wei , Litao Qiao , Li Nan , Guolian Bao
Published: January 2021

Bordetella bronchiseptica (B. bronchiseptica) is an obligately aerobic, oxidase- and catalase-positive, nonfermentative Gram-negative coccobacillus. This study is aimed at examining the immune effects of Rg1, Rg1 plus oil, and other common adjuvants on inactivated B. bronchiseptica vaccine in rabbits. The mechanism underlying the adjuvant effect of Rg1 plus oil on the vaccine was also explored. Rg1 (100 μg) plus oil significantly improved the immune effect of B. bronchiseptica vaccine at both the humoral and cellular levels. Rg1-oil adjuvant increased the levels of IL-2 and IL-4 in rabbits after immunization. Rg1 (100 μg) plus oil also significantly increased TLR2 expression and downregulated NF-κB in splenocytes. Rg1-oil adjuvant may increase the levels of IL-2 and IL-4 via upregulating TLR2, thereby enhancing the immune effect of B. bronchiseptica vaccine. In conclusion, Rg1 plus oil could be used as a potential vaccine adjuvant for rabbit B. bronchiseptica vaccine.
A Coupling Graphic Pipeline with Normal Mode Model for Rapid Calculation of Underwater Acoustic Field
Authors: Zhuo Jianghao , Wang Ling , Xu Ke , Wan Jianwei
Published: January 2021

Rapid execution is required in operation‐oriented applications in underwater acoustic modelling. In this paper, the GPU graphic pipeline is used to accelerate the calculation of high‐resolution sound field image in the normal mode model of underwater acoustic propagation. The computer times of the proposed graphic pipeline method, the MATLAB code, and the C# code are compared for a stratified shallow water waveguide using the KRAKEN model at different frequencies. The research validates that the graphic pipeline method outperforms the classic CPU‐based methods in terms of execution speed at the frequencies where the eigenvalue equation in normal mode models can be solved.
Wind Tunnel Test on Local Wind Field around the Bridge Tower of a Truss Girder
Authors: Zhang Jingyu , Zhang Mingjin , Huang Bing , Li Yongle , Yu Jiaxin , Jiang Fanying
Published: January 2021

The aerodynamic performance of vehicles on a bridge deck depends on the local wind field, especially in a region near a bridge tower. This study was carried out on a large‐scale (1: 20.4) truss girder, and wind tunnel tests were performed to determine how the wind fields were affected by the bridge tower in the presence of different wind barriers. The wind barrier parameters significantly affect the wind field. Wind barriers should be sufficiently high to provide a wide protection range and have relatively small porosities to reduce the wind speed. The opening form of the wind barrier should also be considered, where a circular‐holed form reduces the wind speed and turbulence more than a horizontal‐slatted form. The wind field is affected by structures and bridge towers on the deck. A turning point in the wind speed occurs at a measurement point near the bridge tower, and this point gradually moves upward towards lanes on the leeward side of the bridge. The equivalent wind speed is significantly reduced over a four‐meter height range because of shadowing from the bridge tower and the wind barrier.
Fabrication and Characterization of the Core‐Shell Structure of Poly(3‐Hydroxybutyrate‐4‐Hydroxybutyrate) Nanofiber Scaffolds
Authors: Guo Wentai , Yang Zifeng , Qin Xiusen , Wei Yingqi , Li Chuangkun , Huang Rongkang , Zhou Chen , Wang Huaiming , Jin Lin , Wang Hui
Published: January 2021

Tissue engineering scaffolds with nanofibrous structures provide positive support for cell proliferation and differentiation in biomedical fields. These scaffolds are widely used for defective tissue repair and drug delivery. However, the degradation performance and mechanical properties of scaffolds are often unsatisfactory. Here, we successfully prepared a novel poly(3‐hydroxybutyrate‐4‐hydroxybutyrate)/polypyrrole (P34HB‐PPy) core‐shell nanofiber structure scaffold with electrospinning and in situ surface polymerization technology. The obtained composite scaffold showed good mechanical properties, hydrophilicity, and thermal stability based on the universal material testing machine, contact angle measuring system, thermogravimetric analyzer, and other methods. The results of the in vitro bone marrow‐derived mesenchymal stem cells (BMSCs) culture showed that the P34HB‐PPy composite scaffold effectively mimicked the extracellular matrix (ECM) and exhibited good cell retention and proliferative capacity. More importantly, P34HB is a controllable degradable polyester material, and its degradation product 3‐hydroxybutyric acid (3‐HB) is an energy metabolite that can promote cell growth and proliferation. These results strongly support the application potential of P34HB‐PPy composite scaffolds in biomedical fields, such as tissue engineering and soft tissue repair.
Layered Synchronization and Identification of Uncertain Delayed Hierarchical Networks
Authors: Chai Yuan , Zhang Hudong
Published: January 2021

This paper investigates the layered synchronization and identification of uncertain delayed hierarchical networks, featured by highlights in three aspects: first, the presentation of a multilayered delayed network model, which can be regarded as a 3D stereochemical structure in compliance with the ever-developing trend of hierarchical network modeling structure; second, the design of a multi-identification scheme combined with uncertain delayed hierarchical networks, which matches the unknown and hierarchical properties of the proposed networks; and third, the construction of a layered control method of Lyapunov function, which synthesizes the factors of the unknown, time delay and hierarchy. Based on these points, the laws of layered synchronization between drive hierarchical networks (DHNs) and response hierarchical networks (RHNs) are derived, the dual identification criteria for monitoring topological structures and identifying system parameters, respectively, are provided, and the hierarchical multiformity of the proposed method is validated through abundant numerical simulations in the end.
Design of a New Catheter Operating System for the Surgical Robot
Authors: Ma Xu , Zhou Jinpeng , Zhang Xu , Qi Yang , Huang Xiaochen
Published: January 2021

In interventional surgery, the manual operation of the catheter is not accurate. It is necessary to operate the catheter skillfully and effectively to protect the surgeon from radiation injury. The purpose of this paper is to design a new robot catheter operating system, which can help surgeons to complete the operation with high mechanical precision. On the basis of the original mechanical structure—real catheter, the operation information of the main end operator is collected. After the information is collected, the control algorithm of the system is improved, and the BP neural network is combined with the traditional PID controller to adjust the PID control parameters more effectively and intelligently so that the motor can reflect the output of the controller better and faster. The feasibility and superiority of the BP neural network PID controller are verified by simulation experiments.
Selective ERBB2 and BCL2 Inhibition Is Synergistic for Mitochondrial-Mediated Apoptosis in MDS and AML Cells
Authors: Kam Angel Y.F. , Piryani Sadhna O. , Lee Chang-Lung , Rizzieri David A. , Spector Neil L. , Sarantopoulos Stefanie , Doan Phuong L.
Published: January 2021

The ERBB2 proto-oncogene is associated with an aggressive phenotype in breast cancer. Its role in hematologic malignancies is incompletely defined, in part because ERBB2 is not readily detected on the surface of cancer cells. We demonstrate that truncated ERBB2, which lacks the extracellular domain, is overexpressed on primary CD34+ myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) cells compared with healthy hematopoietic cells. This overexpression of ERBB2 is associated with aberrant, oncogenic signaling with autophosphorylation of multiple tyrosine sites. Like in breast cancers, ERBB2 can exist as truncated isoforms p95ERBB2 and p110ERBB2 in MDS and AML. Neutralization of ERBB2 signaling with ERBB2 tyrosine kinase inhibitors (i.e., lapatinib, afatinib, and neratinib) increases apoptotic cell death and reduces human engraftment of MDS cells in mice at 21 weeks posttransplantation. Inhibition of ERBB2 modulates the expression of multiple pro- and anti-apoptotic mitochondrial proteins, including B-cell lymphoma 2 (BCL2). Dual blockade with ERBB2 and BCL2 inhibitors triggers additional reductions of BCL2 phosphorylation and myeloid cell leukemia-1 (MCL1) expression compared with single drug treatment. Dual therapy was synergistic at all tested doses, with a dose reduction index of up to 29 for lapatinib + venetoclax compared with venetoclax alone. Notably, these agents operated together and shifted cancer cells to a pro-apoptotic phenotype, resulting in increased mitochondrial cytochrome c release and activated caspase-3-mediated cell death.

Implications:

These findings warrant study of ERBB2 and BCL2 combination therapy in patients with MDS and AML.
Diet-Dependent Metabolic Regulation of DNA Double-Strand Break Repair in Cancer: More Choices on the Menu
Authors: de Polo Anna , Labbé David P.
Published: January 2021

Despite several epidemiologic and preclinical studies supporting the role of diet in cancer progression, the complexity of the diet–cancer link makes it challenging to deconvolute the underlying mechanisms, which remain scantly elucidated. This review focuses on genomic instability as one of the cancer hallmarks affected by diet-dependent metabolic alterations. We discuss how altered dietary intake of metabolites of the one-carbon metabolism, including methionine, folate, and vitamins B and C, can impact the methylation processes and thereby tumorigenesis. We present the concept that the protumorigenic effect of certain diets, such as the Western diet, is in part due to a diet-induced erosion of the DNA repair capacity caused by altered epigenetic and epitranscriptomic landscapes, while the protective effect of other dietary patterns, such as the Mediterranean diet, can be partly explained by their ability to sustain a proficient DNA repair. In particular, considering that diet-dependent alterations of the one-carbon metabolism can impact the rate of methylation processes, changes in dietary patterns can affect the activity of writers and erasers of histone and RNA methyl marks and consequently impair their role in ensuring a proficient DNA damage repair.
Immunosuppressive Myeloid Cells Induce Nitric Oxide–Dependent DNA Damage and p53 Pathway Activation in CD8+ T Cells
Authors: Cartwright Adam N.R. , Suo Shengbao , Badrinath Soumya , Kumar Sushil , Melms Johannes , Luoma Adrienne , Bagati Archis , Saadatpour Assieh , Izar Benjamin , Yuan Guo-Cheng , Wucherpfennig Kai W.
Published: January 2021

Tumor-infiltrating myeloid-derived suppressor cells (MDSC) are associated with poor survival outcomes in many human cancers. MDSCs inhibit T cell–mediated tumor immunity in part because they strongly inhibit T-cell function. However, whether MDSCs inhibit early or later steps of T-cell activation is not well established. Here we show that MDSCs inhibited proliferation and induced apoptosis of CD8+ T cells even in the presence of dendritic cells (DC) presenting a high-affinity cognate peptide. This inhibitory effect was also observed with delayed addition of MDSCs to cocultures, consistent with functional data showing that T cells expressed multiple early activation markers even in the presence of MDSCs. Single-cell RNA-sequencing analysis of CD8+ T cells demonstrated a p53 transcriptional signature in CD8+ T cells cocultured with MDSCs and DCs. Confocal microscopy showed induction of DNA damage and nuclear accumulation of activated p53 protein in a substantial fraction of these T cells. DNA damage in T cells was dependent on the iNOS enzyme and subsequent nitric oxide release by MDSCs. Small molecule–mediated inhibition of iNOS or inactivation of the Nos2 gene in MDSCs markedly diminished DNA damage in CD8+ T cells. DNA damage in CD8+ T cells was also observed in KPC pancreatic tumors but was reduced in tumors implanted into Nos2-deficient mice compared with wild-type mice. These data demonstrate that MDSCs do not block early steps of T-cell activation but rather induce DNA damage and p53 pathway activation in CD8+ T cells through an iNOS-dependent pathway.
Lessons Learnt during the COVID-19 Pandemic: For Patients with End-Stage Renal Disease, We Should Prioritize Home-Based Treatment and Telemedicine
Authors: Brunori Giuliano , Reboldi Gianpaolo , Aucella Filippo
Published: January 2021

Backgrounds: The recent coronavirus disease 2019 (CO­VID-19) pandemic has placed worldwide health systems and hospitals under pressure, and so are the renal care models. This may be a unique opportunity to promote and expand alternative models of health-care delivery in patients undergoing renal replacement therapies. Summary: Despite the high risk of acquiring communicable diseases when undergoing in-centre treatments, only a small proportion of patients are currently being treated with home therapies. Recent data provided by the Italian Society of Nephrology (SIN), the REIN French Registry and the Wuhan Hemodialysis Quality Control Center clearly show that patients receiving hospital-based treatment have a 3- to 4-fold greater risk of infection, and a subsequent fatality proportion between 21 and 34%. On the other hand, home-based therapy can be managed remotely, there is little or no need for transport to and from the hospital, and it is less expensive. Besides, the digital revolution in health care with the development of virtual care systems can make home dialysis with telehealth a cost-effective solution for both patients and health-care providers. Such a transition would require specific training for physicians and health-care professionals and a functional re-organization of dialysis centres to improve the skills and expertise in caring for patients at home. Conclusion: The need for more widespread home treatment is the main lesson learnt by nephrologists by the COVID-19 pandemic.
Incidence of Thyroid Dysfunction Facing Metabolic Syndrome: A Prospective Comparative Study with 9 Years of Follow-Up
Authors: Mehran Ladan , Amouzegar Atieh , Abdi Hengameh , Delbari Negar , Madreseh Elham , Tohidi Maryam , Mansournia Mohammad Ali , Azizi Fereidoun
Published: January 2021

Background: Studies assessing thyroid hormones in metabolic syndrome (MetS) patients are contradictory. Also, the effect of MetS on thyroid function over time is not yet evaluated. This study investigated the prevalence and incidence of thyroid dysfunction (TD) as well as time trends of thyroid hormones in subjects with and without MetS, during a 10-year follow-up in Tehranian adult population. Methods: This is a prospective cohort study conducted in the framework of Tehran Thyroid Study on 5,786 subjects aged ≥20 years: 4,905 eligible participants entered the study after excluding those with corticosteroid or radioactive iodine use, pregnancy, thyrotropin (TSH) <0.1 and >10 mU/L, and missing data. Physical examinations were performed and serum concentrations of TSH, free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), fasting plasma glucose, insulin, and lipid profile were assessed at baseline and 3-year intervals during the follow-up. MetS was defined according to the Joint Interim Statement Definition. Results: At baseline, there were no difference in median serum concentrations of FT4 and TSH between MetS and non-MetS group after adjusting for age, sex, BMI, smoking, and TPOAb positivity. Although there was higher risk of overt (42%) and subclinical hypothyroidism (16%) in MetS compared with non-MetS subjects, no significant difference was observed in adjusted ORs for any TD between 2 groups. There were also no significant differences in time trends of TSH, FT4, TPOAb positivity, and incidence rates of TDs between MetS and non-MetS groups during 10 years, after adjustment for age, sex, BMI, smoking status, and TPOAb positivity. Conclusion: MetS is not associated with thyroid hypofunction considering other important confounders such as age, sex, smoking, BMI, and TPOAb positivity. There is also no difference in the trend of thyroid hormones and incidence of TD between MetS and non-MetS subjects during a 10-year follow-up.
Pediatric Gunshot Wound to Visual Cortex with Retained Bullet: Case Report and Review of the Literature
Authors: Rolle Myron , Duhaime Ann-Christine
Published: January 2021

Introduction: Pediatric gunshot wounds (GSWs) to the head are not well studied in the literature, especially in civilians. With a dearth of case-based and clinically relevant information, pediatric neurosurgeons may be challenged when considering the risks and benefits of removing retained bullet fragments in different intracranial locations. We explore the literature and highlight the key factors in the surgical decision-making case of a 16-year-old girl with GSW to the visual cortex. Case Report: A 16-year-old girl was shot in the head in a parieto-occipital trajectory with the bullet crossing midline, lodging in the occipital lobe into the straight sinus. Her initial Glasgow Coma Scale was 7, and she was urgently stabilized with intracranial pressure monitoring and external ventricular drainage. She underwent craniectomy, debridement, and irrigation and then a reoperation for further debridement and culture 2 weeks later for persistent fevers; cultures remained negative. The retained bullet was not removed. At 18 months post-injury, she had normal speech and motor function, moderate memory dysfunction, and 3-quadrant field loss with retained macular vision. Discussion/Conclusion: Pediatric penetrating GSWs to the head may be challenging to manage since literature is sparse. In this case, the primary focus of management was to maintain normal intracranial pressure, reduce risk of infection, and preserve potentially viable visual cortex. In the civilian context of available antibiotics and serial imaging, it may be possible to manage retained bullets conservatively without delayed complications.
Pesquisa na graduação médica: produção científica de uma unidade curricular obrigatória
Authors: Soares João Marcos Arantes , Rios João Vitor Liboni Guimarães , Maia Juliana Moreira , Rigo Tiago Mello , Araújo Dan Reuter Ferraz de , Camuñas Gabriel Costa
Published: January 2021

Introdução: Em oposição à inserção pontual que ocorre nos projetos de pesquisas desenvolvidos em iniciações científicas, no Curso de Medicina da Universidade Federal de São João Del Rei, as atividades que contemplam a execução de práticas de pesquisa estão concentradas na Prática de Investigação Científica (PIC), uma unidade curricular obrigatória na qual um grupo de alunos deve iniciar um projeto de pesquisa e finalizá-lo passando por todas as etapas de sua construção. Objetivo: Quantificar a produção científica gerada pela unidade curricular obrigatória em prática de pesquisa no curso de Medicina em uma Universidade Federal. Métodos: A coleta de dados foi realizada por entrevistas e análise do currículo Lattes dos docentes do Pic. Para análise estatística, utilizaram-se testes Qui-Quadrado de Fisher entre variáveis quantitativas relacionadas à produção científica da disciplina e informações acadêmicas dos orientadores. Resultados: Foram selecionados 30 docentes que orientaram 47 grupos de pesquisa ao todo, sendo possível identificar como produção científica 19 artigos publicados, 32 apresentações em congresso, 09 iniciações científicas, 01 premiação em congresso, 01 patente e 01 tese de mestrado, totalizando 63 trabalhos. Os resultados apontaram uma produção científica relevante da unidade, que foi influenciada pelo grau acadêmico, participação em programas de pós-graduação e regime de dedicação exclusiva do docente. Conclusão: A inclusão da prática de pesquisa obrigatória no currículo de Medicina durante a graduação pode ser uma estratégia eficiente para gerar produção científica para a universidade.