bluuebunny/crossref_metadata_2025 huggingface dataset:
A Multiple and Multi-Level Substructure Method for the Dynamics of Complex Structures
Authors: Wang Binbin , Liu Jingze , Cao Zhifu , Zhang Dahai , Jiang Dong
Published: June 2021

Based on the fixed interface component mode synthesis, a multiple and multi-level substructure method for the modeling of complex structures is proposed in this paper. Firstly, the residual structure is selected according to the structural characteristics of the assembled complex structure. Secondly, according to the assembly relationship, the parts assembled with the residual structure are divided into a group of substructures, which are named the first-level substructure, the parts assembled with the first-level substructure are divided into a second-level substructure, and consequently the multi-level substructure model is established. Next, the substructures are dynamically condensed and assembled on the boundary of the residual structure. Finally, the substructure system matrix, which is replicated from the matrix of repeated physical geometry, is obtained by preserving the main modes and the constrained modes and the system matrix of the last level of the substructure is assembled to the upper level of the substructure, one level up, until it is assembled in the residual structure. In this paper, an assembly structure with three panels and a gear box is adopted to verify the method by simulation and a rotor is used to experimentally verify the method. The results show that the proposed multiple and multi-level substructure modeling method is not unique to the selection of residual structures, and different classification methods do not affect the calculation accuracy. The selection of 50% external nodes can further improve the analysis efficiency while ensuring the calculation accuracy.
SA-SVM-Based Locomotion Pattern Recognition for Exoskeleton Robot
Authors: Yin Zeyu , Zheng Jianbin , Huang Liping , Gao Yifan , Peng Huihui , Yin Linghan
Published: June 2021

An exoskeleton robot is a kind of wearable mechanical instrument designed according to the shape and function of the human body. The main purpose of its design and manufacture is to enhance human strength, assist human walking and to help patients recover. The walking state of the exoskeleton robot should be highly consistent with the state of the human, so the accurate locomotion pattern recognition is the premise of the flexible control of the exoskeleton robot. In this paper, a simulated annealing (SA) algorithm-based support vector machine model is proposed for the recognition of different locomotion patterns. In order to improve the overall performance of the support vector machine (SVM), the simulated annealing algorithm is adopted to obtain the optimal parameters of support vector machine. The pressure signal measured by the force sensing resistors integrated on the sole of the shoe is fused with the position and pose information measured by the inertial measurement units attached to the thigh, shank and foot, which are used as the input information of the support vector machine. The max-relevance and min-redundancy algorithm was selected for feature extraction based on the window size of 300 ms and the sampling frequency of 100 Hz. Since the signals come from different types of sensors, normalization is required to scale the input signals to the interval (0,1). In order to prevent the classifier from overfitting, five layers of cross validation are used to train the support vector machine classifier. The support vector machine model was obtained offline in MATLAB. The finite state machine is used to limit the state transition and improve the recognition accuracy. Experiments on different locomotion patterns show that the accuracy of the algorithm is 97.47% ± 1.16%. The SA-SVM method can be extended to industrial robots and rehabilitation robots.
Erlanger Glaucoma Registry: Effect of a Long-Term Therapy with Statins and Acetyl Salicylic Acid on Glaucoma Conversion and Progression
Authors: Thiermeier Nina , Lämmer Robert , Mardin Christian , Hohberger Bettina
Published: June 2021

Purpose: Drugs with cardiovascular protective properties (statins, acetylsalicylic acid (ASS)) were assumed to have positive effects on patients suffering from glaucoma disease. The present retrospective study aimed to investigate the influence of statins, ASS or a combination of both on the glaucoma conversion and progression rate in glaucoma suspects and glaucoma patients with a 20-year follow-up period. Methods: A retrospective analysis of 199 eyes of 120 patients (63 male, 57 female) of the Erlanger Glaucoma Registry (EGR; ClinicalTrials.gov Identifier: NCT00494923; ISSN 2191-5008, CS-2011) was performed considering systemic therapy with statins, ASS or a combination of both: 107 eyes with ocular hypertension (OHT) and 92 eyes with pre-perimetric primary open-angle glaucoma (pre-POAG). All patients received an ophthalmological examination including morphometric and functional glaucoma diagnostics. Glaucoma conversion was defined as the conversion of OHT to pre-POAG. Glaucoma progression was defined as confirmed visual field loss. Data were shown as percentages. Statistical analysis was performed by Chi-Quadrat tests. Results: 1. Glaucoma conversion/progression was observed in 46.7% of the subjects, additionally in combination with hypercholesterinemia in 76.8%. 2. Statins: 27.3% of eyes under systemic statin therapy showed a conversion/progression. Patients taking statins ≥ 10 years yielded a reduced conversion/progression rate (p = 0.028, non-significant after Bonferroni–Holm). 3. ASS: 34.7% of eyes under systemic ASS therapy showed a conversion/progression. A significantly lower conversion/progression rate was observed after ASS therapy ≥ 12 years (p = 0.017, significant after Bonferroni–Holm). 4. ASS and statins: 25.0% of eyes under combined therapy showed a conversion/progression. A significantly reduced conversion/progression rate was reached after 8 years of combined therapy (p = 0.049, non-significant after Bonferroni–Holm). Conclusions: Patients with ocular hypertension and early glaucoma seem to benefit from adjuvant cardiovascular protective therapy. However, the benefits and disadvantages of treatment with statins and/or ASS should be kept in mind. Thus, a thorough risk–benefit evaluation has to be performed for each patient individually to avoid unwanted side effects.
A Case of COVID-19-Related Thrombocytopenia and Leukopenia in an Adolescent with Mild Symptoms
Authors: Kossiva Lydia , Thirios Athanasios , Panagouli Eleni , Panos Alexandros , Lampidi Stavroula , Bacopoulou Flora , Tsolia Maria , Tsitsika Artemis
Published: June 2021

Since the beginning of the COVID-19 pandemic, there have been numerous reports and reviews on the complications caused by the disease, analyzing the acute and chronic consequences. The main symptoms of SARS-CoV-2 are dry cough, fever, and fatigue. COVID-19 appears to affect all systems, including renal, cardiovascular, circulatory, and respiratory systems, causing chronic obstructive pulmonary disease. We report on a 14-year-old male adolescent, who presented with thrombocytopenia (platelet count 92 × 109 /L) and leukopenia (white blood count 4.2 × 103 /μL) that was observed two months ago. Ten days before the first blood test, a viral infection with nasal congestion and runny nose was reported, without other accompanying symptoms. Viral antibodies screening revealed positivity for all the three specific COVID-19 antibodies. Further haematological evaluation with bone marrow aspiration revealed non-specific dysplastic features of the red cell and megakaryocyte progenitors. Although haematological alterations due to COVID-19 infection are available from adult patients’ reports, the effect of COVID-19 infection in the pediatric population is underestimated and this is the first case with such haematological involvement. Noteworthy, in the current case, the impact of the COVID-19 infection was not related to the severity of the disease, as the symptoms were mild. In similar cases, bone marrow aspiration would not be performed as a part of routine work-up. Thus, it is important when evaluating pediatric patients with COVID-19 infection to search and report those alterations in order to better understand the impact and the spectrum of clinical manifestations of the specific viral infection in children and adolescents.
District-Heating-Grid Simulation in Python: DiGriPy
Authors: Vorspel Lena , Bücker Jens
Published: June 2021

DiGriPy is a newly developed Python tool for the simulation of district heating networks published as open-source software in GitHub and offered as a Python package on PyPI. It enables the user to easily build a network model, run large-scale demand time series, and automatically compare different temperature-control conditions. In this paper, implementation details and usage instructions are given. Tests showing the results of different scenarios are presented and interpreted.
The Use of Monologue Speaking Tasks to Improve First-Year Students’ English-Speaking Skills
Authors: Karpovich Irina , Sheredekina Oksana , Krepkaia Tatyana , Voronova Larisa
Published: June 2021

A significant number of studies are devoted to the psychological and social adaptation of students to the educational process at university. This research contributes to the solution of the problem of first-year students’ academic performance in the framework of studying a foreign language by working with monologue speaking tasks. The study offers an analysis of the improvement of academic performance in this particular type of language activity. The study took place at Peter the Great Saint Petersburg Polytechnic University, Russia, and involved 274 first-year students enrolled in undergraduate programs. Mixed qualitative and quantitative methods were applied to collect and analyse data for the study. The research included the qualitative content analysis of monologue speaking tasks. Results of the study make it possible to conclude that the use of monologue speaking tasks paired with peer interaction and peer assessment can improve first-year students’ English-speaking skills.
Development of a Simple Robotic Driver System (SimRoDS) to Test Fuel Economy of Hybrid Electric and Plug-In Hybrid Electric Vehicles Using Fuzzy-PI Control
Authors: Hwang Kyunghun , Park Joonghoo , Kim Heejung , Kuc Tea-Yong , Lim Sejoon
Published: June 2021

Over the past decade, new models of hybrid electric vehicles have been released worldwide, and the fuel efficiency of said vehicles has increased by more than 5%. To further improve fuel efficiency, vehicle manufacturers have made efforts to design modules (e.g., engines, motors, transmissions, and batteries) with the highest efficiency possible. To do so, the fuel economy test process, which is conducted primarily using a chassis dynamometer, must produce reliable and accurate results. To accurately analyze the fuel efficiency improvement rate of each module, it is necessary to reduce the test deviation. When the test conducted by human drivers, the test deviation is somewhat large. When the test is conducted by a physical robot driver, the test deviation is improved; however, these robots are expensive and time-consuming to install and take up considerable amount of space in the driver’s seat. To compensate for these shortcomings, we propose a simple, structured robot system that manipulates electrical signals without using mechanical link structures. The controller of this robot driver uses the widely used PI controller. Although PI controllers are simple and perform well, since the dynamics of each test vehicle is different (e.g., acceleration response), the PI controller has a disadvantage in that it cannot determine the optimal PI gain value for each vehicles. In this work, the fuzzy control theorem is applied to overcome this disadvantage. By using fuzzy control to deduce the optimal value of the PI gain, we confirmed that our proposed system is available to conduct tests on vehicles with different dynamics.
Relationship between Everyday Discrimination and Substance Use among Adolescents in Northern Chile
Authors: Caqueo-Urízar Alejandra , Urzúa Alfonso , Mena-Chamorro Patricio , Flores Jerome , Irarrázaval Matías , Graniffo Ellen , Williams David R.
Published: June 2021

Substance use is a public health problem that affects the normal physical, neurological, and psychological development of adolescents. Apparently, discrimination is an important variable for explaining the initiation and continued use of alcohol and marijuana. Since most research focused on discrimination based on factors, such as race, ethnicity, sexual orientation, or gender faced by minority groups, studies on discrimination faced by the general population remain scarce. This cross-sectional study described the relationship between everyday discrimination and alcohol and marijuana use-related behaviors among Chilean adolescents. It included 2330 students between 12 and 20 years of age from educational establishments in the city of Arica. To evaluate substance use, specifically alcohol and marijuana, the Child and Adolescent Evaluation System (SENA) was used. The Everyday Discrimination scale was used to evaluate discrimination. Age and everyday discrimination can predict up to 11% of the variance in substance use. Reducing the incidence of everyday discrimination may help reduce heavy alcohol and marijuana consumption among adolescents.
Double-Negative T-Cell Reaction in a Case of Listeria Meningitis
Authors: Ullah Asad , Patterson G. , Mattox Samantha , Cotter Thomas , Patel Nikhil , Savage Natasha
Published: June 2021

Gamma delta T-cells are commonly found in response to Listeria monocytogenes infection in mice, whereas this same immunological response has only been reported a few times in vivo in humans. Moreover, gamma delta T-cell response in cerebral spinal fluid samples in conjunction with Listeria meningitis has never been described in medical literature to date. Thus, we describe a 64-year-old male who presented with altered mental status, fever, and neck stiffness. After lumbar puncture revealed elevated glucose, protein, lactate dehydrogenase, and white blood cell count, further cytologic analysis was indicated. The CSF showed a markedly hypercellular sample with a lymphocytic pleocytosis, including some enlarged forms with irregular nuclear contours, and rare macrophage containing intracytoplasmic bacteria. Lymphocyte immunophenotyping was performed via flow cytometric analysis, which ultimately revealed a prominent CD4/CD8 negative T-cell population, suggestive of a gamma delta T-cell population. Thus, an initial suspicion of malignancy was considered but was ruled out due to the absence of mass lesion on imaging and overall features including heterogenous lymphocyte morphology. Shortly after, gram stain and cultures were obtained revealing Listeria monocytogenes. Unfortunately, the patient rapidly succumbed to disease following the diagnosis of Listeria meningitis. Studies suggest that gamma delta T-cells are activated by the protein components of Listeria and thus have been found to be an important mediator of resistance to Listeria infection. Studies have also discovered that the level of activation for these T-cells appears to be tissue specific and dose dependent, with most cases occurring within visceral organs. Hence, we herein present the first case of gamma delta T-cell activation due to Listeria monocytogenes within the cerebral spinal fluid of a human patient.
Cross-Platform Comparative Study of Public Concern on Social Media during the COVID-19 Pandemic: An Empirical Study Based on Twitter and Weibo
Authors: Deng Wen , Yang Yi
Published: June 2021

The COVID-19 pandemic has created a global health crisis that has affected economies and societies worldwide. During these times of uncertainty and crisis, people have turned to social media platforms as communication tools and primary information sources. Online discourse is conducted under the influence of many different factors, such as background, culture, politics, etc. However, parallel comparative research studies conducted in different countries to identify similarities and differences in online discourse are still scarce. In this study, we combine the crisis lifecycle and opinion leader concepts and use data mining and a set of predefined search terms (coronavirus and COVID-19) to investigate discourse on Twitter (101,271 tweets) and Sina Weibo (92,037 posts). Then, we use a topic modeling technique, Latent Dirichlet Allocation (LDA), to identify the most common issues posted by users and temporal analysis to research the issue’s trend. Social Network Analysis (SNA) allows us to discover the opinion leader on the two different platforms. Finally, we find that online discourse reflects the crisis lifecycle according to the stage of COVID-19 in China and the US. Regarding the status of the COVID-19 pandemic, users of Twitter tend to pay more attention to the economic situation while users of Weibo pay more attention to public health. The issues focused on in online discourse have a strong relationship with the development of the crisis in different countries. Additionally, on the Twitter platform many political actors act as opinion leaders, while on the Weibo platform official media and government accounts control the release of information.
The Relation between Functional Performance, Falls and Previous Falls Among Participants in the Otago Programme: A Secondary Data Analysis
Authors: Company-Sancho María Consuelo , Alonso-Poncelas Emma , Rich-Ruiz Manuel , Cidoncha-Moreno María Ángeles , Gonzalez-Pisano Ana , Abad-Corpa Eva ,   on behalf of Otago Project Working Group
Published: June 2021

Fall prevention is a key priority in healthcare policies. Multicomponent exercises reduce the risk of falls. The purpose of this study is to describe the relationship between functional performance and falls after following the Otago multicomponent exercise programme and previous falls. A prospective multi-centre intervention study was performed on 498 patients aged over 65 in primary care, with or without a history of previous falls. Sociodemographic, anthropometric and functionality data were collected. The primary outcome was the occurrence of falls; functional performance was measured using the Tinetti, Short Physical Performance Battery and Timed Up and Go tests. Among the patients, 29.7% referred to previous falls. There was a statistically significant (p < 0.001) increase in falls at 6 months (10.1%) and at 12 months (7.6%) among participants with previous falls in the baseline assessment compared to those without. In addition, the existence of previous falls could be considered a risk factor at 6 and 12 months (OR =2.37, p = 0.002, and OR = 1.76, p = 0.046, respectively). With regard to balance and gait, differences between the groups were observed at 6 months in the Tinetti score (p < 0.001) and in the baseline assessment Timed Up and Go score (p < 0.044). Multicomponent exercises improve the fall rate, balance and gait in older people, although this improvement is less in people with previous falls. Earlier intervention and tailoring of exercises in patients with previous falls could help improve outcomes.
Integrating Network Centrality and Node-Place Model to Evaluate and Classify Station Areas in Shanghai
Authors: Dou Mingxuan , Wang Yandong , Dong Shihai
Published: June 2021

Transit-oriented development (TOD) is generally understood as an effective urban design model for encouraging the use of public transportation. Inspired by TOD, the node-place (NP) model was developed to investigate the relationship between transport stations and land use. However, existing studies construct the NP model based on the statistical attributes, while the importance of travel characteristics is ignored, which arguably cannot capture the complete picture of the stations. In this study, we aim to integrate the NP model and travel characteristics with systematic insights derived from network theory to classify stations. A node-place-network (NPN) model is developed by considering three aspects: land use, transportation, and travel network. Moreover, the carrying pressure is proposed to quantify the transport service pressure of the station. Taking Shanghai as a case study, our results show that the travel network affects the station classification and highlights the imbalance between the built environment and travel characteristics.
Monitoring the Spatiotemporal Trajectory of Urban Area Hotspots Using the SVM Regression Method Based on NPP-VIIRS Imagery
Authors: Ruan Yuling , Zou Yanhong , Chen Minghui , Shen Jingya
Published: June 2021

Urban area hotspots are considered to be an ideal proxy for spatial heterogeneity of human activity, which is vulnerable to urban expansion. Nighttime light (NTL) images have been extensively employed in monitoring current urbanization dynamics. However, the existing studies related to NTL images mainly concern detection of urban areas, leaving inner spatial differences in urban NTL luminosity poorly explored. In this study, we propose an innovative approach to explore the spatiotemporal trajectory of urban area hotspots using monthly Visible Infrared Imaging Radiometer Suite (VIIRS) NTL images. Firstly, multi-temporal VIIRS NTL intensity was decomposed by time-series analysis to obtain annual stable components after data preprocessing. Secondly, the support vector machine (SVM) regression model was utilized to identify urban area hotspots. In order to ensure the model accuracy, the grid search and cross-validation method was integrated to achieve the optimized model parameters. Finally, we analyzed the spatiotemporal migration trajectory of urban area hotspots by the center of gravity method (i.e., shift distance and angle of urban area hotspot centroid). The results indicate that our method successfully captured urban area hotspots with a regression coefficient over 0.8. Meanwhile, the findings give an intuitive understanding of coupling interaction between urban area hotspots and socioeconomic indicators. This study provides important insights for further decision-making regarding sustainable urban planning.
A Signaling View into the Inflammatory Tumor Microenvironment
Authors: Pereira Joana F. S. , Jordan Peter , Matos Paulo
Published: June 2021

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.
The Role of Non-Gaussian Models of Diffusion Weighted MRI in Hepatocellular Carcinoma: A Systematic Review
Authors: Tramontano Liberatore , Cavaliere Carlo , Salvatore Marco , Brancato Valentina
Published: June 2021

The importance of Diffusion Weighted Imaging (DWI) in hepatocellular carcinoma (HCC) has been widely handled in the literature. Due to the mono-exponential model limitations, several studies recently investigated the role of non-Gaussian DWI models in HCC. However, their results are variable and inconsistent. Therefore, the aim of this systematic review is to summarize current knowledge on non-Gaussian DWI techniques in HCC. A systematic search of the literature, including PubMed, Google Scholar, MEDLINE, and ScienceDirect databases, was performed to identify original articles since 2010 that evaluated the role of non-Gaussian DWI models for HCC diagnosis, grading, response to treatment, and prognosis. Studies were grouped and summarized according to the non-Gaussian DWI models investigated. We focused on the most used non-Gaussian DWI models (Intravoxel Incoherent Motion (IVIM), Diffusion Kurtosis Imaging (DKI), and Stretched Exponential—SE). The quality of included studies was evaluated by using QUADAS-2 and QUIPS tools. Forty-three articles were included, with IVIM and DKI being the most investigated models. Although the role of non-Gaussian DWI models in clinical settings has not fully been established, our findings showed that their parameters may potentially play a role in HCC. Further studies are required to identify a standardized DWI acquisition protocol for HCC diagnosis, grading, response to treatment, and prognosis.
Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Withdrawal Is Associated with Higher Mortality in Hospitalized Patients with COVID-19
Authors: Roy-Vallejo Emilia , Sánchez Purificación Aquilino , Torres Peña José , Sánchez Moreno Beatriz , Arnalich Francisco , García Blanco María , López Miranda José , Romero-Cabrera Juan , Herrero Gil Carmen , Bascunana José , Rubio-Rivas Manuel , Pintos Otero Sara , Martínez Sempere Verónica , Ballano Rodríguez-Solís Jesús , Gil Sánchez Ricardo , Luque del Pino Jairo , González Noya Amara , Navas-Alcántara María , Cortés Rodríguez Begoña , Alcalá José , Suárez-Lombraña Ana , Andrés Soler Jorge , Gómez-Huelgas Ricardo , Casas-Rojo José , Millán Núñez-Cortés Jesús ,   on behalf of the SEMI-COVID-19 Network
Published: June 2021

Our main aim was to describe the effect on the severity of ACEI (angiotensin-converting enzyme inhibitor) and ARB (angiotensin II receptor blocker) during COVID-19 hospitalization. A retrospective, observational, multicenter study evaluating hospitalized patients with COVID-19 treated with ACEI/ARB. The primary endpoint was the incidence of the composite outcome of prognosis (IMV (invasive mechanical ventilation), NIMV (non-invasive mechanical ventilation), ICU admission (intensive care unit), and/or all-cause mortality). We evaluated both outcomes in patients whose treatment with ACEI/ARB was continued or withdrawn. Between February and June 2020, 11,205 patients were included, mean age 67 years (SD = 16.3) and 43.1% female; 2162 patients received ACEI/ARB treatment. ACEI/ARB treatment showed lower all-cause mortality (p < 0.0001). Hypertensive patients in the ACEI/ARB group had better results in IMV, ICU admission, and the composite outcome of prognosis (p < 0.0001 for all). No differences were found in the incidence of major adverse cardiovascular events. Patients previously treated with ACEI/ARB continuing treatment during hospitalization had a lower incidence of the composite outcome of prognosis than those whose treatment was withdrawn (RR 0.67, 95%CI 0.63–0.76). ARB was associated with better survival than ACEI (HR 0.77, 95%CI 0.62–0.96). ACEI/ARB treatment during COVID-19 hospitalization was associated with protection on mortality. The benefits were greater in hypertensive, those who continued treatment, and those taking ARB.
COVID-19 and Delayed Cerebral Ischemia—More in Common Than First Meets the Eye
Authors: Bhogal Pervinder , Makalanda Levansri , Hassan Ameer E. , Fiorella Dave , Andersson Tommy , Ahmad Muhammad , Bäzner Hansjörg , Jaffer Ounali , Henkes Hans
Published: June 2021

Since the arrival of the global COVID-19 pandemic scientists around the world have been working to understand the pathological mechanisms resulting from infection. There has gradually been an understanding that COVID-19 triggers a widespread endotheliopathy and that this can result in a widespread thrombosis and in particular a microthrombosis. The mechanisms involved in the microthrombosis are not confined to infection and there is evidence that patients with aneurysmal sub-arachnoid haemorrhage (SAH) also suffer from an endotheliopathy and microthrombosis. In this article we attempt to shed light on similarities in the underlying processes involved in both diseases and suggest potential treatment options.
Prostate Cancer Dormancy and Reactivation in Bone Marrow
Authors: Singh Deepak K. , Patel Vaibhav G. , Oh William K. , Aguirre-Ghiso Julio A.
Published: June 2021

Prostate cancer has a variable clinical course, ranging from curable local disease to lethal metastatic spread. Eradicating metastatic cells is a unique challenge that is rarely met with the available therapies. Thus, targeting prostate cancer cells in earlier disease states is a crucial window of opportunity. Interestingly, cancer cells migrate from their primary site during pre-cancerous and malignant phases to seed secondary organs. These cells, known as disseminated cancer cells (DCCs), may remain dormant for months or decades before activating to form metastases. Bone marrow, a dormancy-permissive site, is the major organ for housed DCCs and eventual metastases in prostate cancer. The dynamic interplay between DCCs and the primary tumor microenvironment (TME), as well as that between DCCs and the secondary organ niche, controls the conversion between states of dormancy and activation. Here, we discuss recent discoveries that have improved our understanding of dormancy signaling and the role of the TME in modulating the epigenetic reprogramming of DCCs. We offer potential strategies to target DCCs in prostate cancer.
Adapting the Pore Size of Individual, 3D-Printed CPC Scaffolds in Maxillofacial Surgery
Authors: Muallah David , Sembdner Philipp , Holtzhausen Stefan , Meissner Heike , Hutsky André , Ellmann Daniel , Assmann Antje , Schulz Matthias C. , Lauer Günter , Kroschwald Lysann M.
Published: June 2021

Three dimensional (3D) printing allows additive manufacturing of patient specific scaffolds with varying pore size and geometry. Such porous scaffolds, made of 3D-printable bone-like calcium phosphate cement (CPC), are suitable for bone augmentation due to their benefit for osteogenesis. Their pores allow blood-, bone- and stem cells to migrate, colonize and finally integrate into the adjacent tissue. Furthermore, the pore size affects the scaffold’s stability. Since scaffolds in maxillofacial surgery have to withstand high forces within the jaw, adequate mechanical properties are of high clinical importance. Although many studies have investigated CPC for bone augmentation, the ideal porosity for specific indications has not been defined yet. We investigated 3D printed CPC cubes with increasing pore sizes and different printing orientations regarding cell migration and mechanical properties in comparison to commercially available bone substitutes. Furthermore, by investigating clinical cases, the scaffolds’ designs were adapted to resemble the in vivo conditions as accurately as possible. Our findings suggest that the pore size of CPC scaffolds for bone augmentation in maxillofacial surgery necessarily needs to be adapted to the surgical site. Scaffolds for sites that are not exposed to high forces, such as the sinus floor, should be printed with a pore size of 750 µm to benefit from enhanced cell infiltration. In contrast, for areas exposed to high pressures, such as the lateral mandible, scaffolds should be manufactured with a pore size of 490 µm to guarantee adequate cell migration and in order to withstand the high forces during the chewing process.
Evaluation of the Effect of Surgical Extraction of an Impacted Mandibular Third Molar on the Periodontal Status of the Second Molar—Prospective Study
Authors: Aniko-Włodarczyk Magda , Jaroń Aleksandra , Preuss Olga , Grzywacz Anna , Trybek Grzegorz
Published: June 2021

Dental injury to the second molar (SM) caused by the surgical extraction of the impacted third molar tends to be underestimated. The necessity of assessment of the impact of the removal of the wisdom tooth in the mandible on the second molar arose. The study group (n = 60) was the one with the second molar on the surgical side, and the control group (n = 60) was the one with the tooth on the opposite side of the alveolar arch. Before the surgery, the difficulty level was assessed according to the Pederson scale. The periodontal status of the SM was assessed by probing depth (PD), gingival index (GI), tooth mobility (TM) examination by the percussion method and resonance frequency. Measurements were taken before and after the surgery, 7 days and 8 weeks after the surgery. The study demonstrated the significant impact of the surgical removal of the wisdom tooth on the PD, GI and TM of the SM. The predicted degree of difficulty of the very difficult surgery had an influence on the increase in PD on the distal buccal and lingual surface of the SM, and on the GI in the proximity of the examined tooth. The results of the presented research confirm the necessity of the clinical assessment of the lower SM before and after the surgical removal of the impacted wisdom tooth in the mandible.
Assessing Controversial Desertification Prevention Policies in Ecologically Fragile and Deeply Impoverished Areas: A Case Study of Marginal Parts of the Taklimakan Desert, China
Authors: Liu Shidong , Zhang Jianjun , Zhang Jie , Li Zheng , Geng Yuhuan , Guo Yiqiang
Published: June 2021

Overgrazing plays an important role in the grassland desertification in global drylands. The effectiveness of policies related to grazing directly affects efforts to combat desertification and sustainable rangeland management. However, there remain questions around how the interplay of grassland desertification and poverty affects the implementation of policies. To reveal the effectiveness of the desertification prevention policy that delineates national key ecological function areas (NKEFAs), the main objective was to perform a sustainability assessment and on-site investigation in Northwest China. A parallel index system, which integrates the indices for economic input–output and material supply–demand to represent sustainability, and the indices for interview records from managers and questionnaires from residents to represent the effectiveness of NKEFA policy, was proposed to comprehensively judge the performance of NKEFA policy, and the underlying causes behind undesirable effects were further analyzed. The results indicate that (1) the performance of desertification control policy is related to socioeconomic conditions—a few counties with increased socioeconomic and land resource sustainability (SLS) are peri-urban or resource-rich; (2) the fact that the socioeconomic benefits of the NKEFA policy are not obvious to impoverished farmers greatly reduces their enthusiasm for preventing desertification; and (3) the livelihood needs and defective ecological compensation force residents with underdeveloped comprehensive quality to overdevelop or use grassland resources even though they have received subsidies for conserving grassland. It is concluded that poverty and grassland desertification interact to influence potential policy performance. Our analysis can help decision makers to formulate desertification control policies with multiple goals to achieve sustainable performance in an economy–ecology system.
A Proposal for Streamlining 3D Digital Cadastral Data Lifecycle
Authors: Olfat Hamed , Atazadeh Behnam , Badiee Farshad , Chen Yiqun , Shojaei Davood , Rajabifard Abbas
Published: June 2021

In urban areas, managing the lifecycle of land and property data related to interlocked and intertwined structures and infrastructure services is a grand challenge for cadastral systems. Addressing the physical and legal complexities of vertically stratified ownership arrangements is a major step towards the modernization of cadastral systems. The research problem that this study addresses is the lack of a simplified and effective approach for modelling, storing, visualizing, and querying 3D cadastral data for multi-story buildings. This research primarily leads to the development of an approach based on Building Information Modelling (BIM), as well as state-of-the-art ETL (extract, transform, load), database and visualization technologies for 3D cadastral data lifecycle management in current practices. The proposed steps for recording, preserving, and disseminating 3D cadastral data are crucial in shifting current 2D cadastral systems towards 3D digital information systems. The results showed improvements in data creation, storage, conversion, and communication when upgrading from a 2D to 3D digital cadastre. Therefore, this study confirmed that streamlining the lifecycle of cadastral data using 3D environments would mitigate issues associated with the current fragmented 2D cadastral datasets used in the multi-story developments.
Effects of Dietary Calcium Propionate Supplementation on Hypothalamic Neuropeptide Messenger RNA Expression and Growth Performance in Finishing Rambouillet Lambs
Authors: Cifuentes-Lopez Oswaldo , Lee-Rangel Héctor A. , Mendoza German D. , Delgado-Sanchez Pablo , Guerrero-Gonzalez Luz , Chay-Canul Alfonso , Pinos-Rodriguez Juan Manuel , Flores-Ramírez Rogelio , Roque-Jiménez José Alejandro , Relling Alejandro E.
Published: June 2021

The objective of this experiment was to evaluate the effects of feeding different levels concentrations of dietary calcium propionate (CaPr) on lambs’ growth performance; ruminal fermentation parameters; glucose–insulin concentration; and hypothalamic mRNA expression for neuropeptide Y (NPY), agouti-related peptide (AgRP), and proopiomelanocortin (POMC). Thirty-two individually fed lambs were randomly assigned to four treatments: (1) control diet (0 g/kg of CaPr), (2) low CaPr, (30 g/kg dry matter (DM)), (3) medium CaPr, (35 g/kg DM), and (4) high CaPr (40 g/kg DM). After 42 days of feeding, lambs were slaughtered for collecting samples of the hypothalamus. Data were analyzed as a complete randomized design, and means were separated using linear and quadratic polynomial contrast. Growth performance was not affected (p ≥ 0.11) by dietary CaPr inclusion. The ruminal concentration of total volatile fatty acids (VFA) increased linearly (p = 0.04) as dietary CaPr increased. Likewise, a linear increase in plasma insulin concentration (p = 0.03) as dietary CaPr concentration increased. The relative mRNA expression of NPY exhibited a quadratic effect (p < 0.01), but there were significant differences in the mRNA expression of AgRP and POMC (p ≥ 0.10). Dietary calcium propionate did not improve lamb growth performance in lambs feed with only forage diets. Intake was not correlated with feed intake with mRNA expression of neuropeptides.
Bitcoin and Fiat Currency Interactions: Surprising Results from Asian Giants
Authors: Gunay Samet , Kaskaloglu Kerem , Muhammed Shahnawaz
Published: June 2021

This study examines the interaction of Bitcoin with fiat currencies of three developed (euro, pound sterling and yen) and three emerging (yuan, rupee and ruble) market economies. Empirical investigations are executed through symmetric, asymmetric and non-linear causality tests, and Markov regime-switching regression (MRSR) analysis. Results show that Bitcoin has a causal nexus with Chinese yuan and Indian rupee for price and various return components. The MRSR analysis justifies these findings by demonstrating the presence of interaction in contractionary regimes. Accordingly, it can be stated that when markets display a downward trend, appreciation of the Chinese yuan and Indian rupee positively and strongly affects the value of Bitcoin, possibly due to the market timing. The MRSR analysis also exhibits a transition from a tranquil to a crisis regime in March 2020 because of the pandemic. However, a shorter duration spent in the crisis regime in 2020 indicates the limited and relatively less harmful effect of the pandemic on the cryptocurrency market when compared to the turmoil that occurred in 2018.
Improving the Return Loading Rate Problem in Northwest China Based on the Theory of Constraints
Authors: Huang Wen-Tso , Lu Cheng-Chang , Dang Jr-Fong
Published: June 2021

This paper introduces how to improve the return loading rate problem by integrating the Sub-Tour reversal approach with the method of the Theory of Constraints (TOC). The proposed model generates the initial solution derived by the Sub-Tour reversal approach in phase 1 and then applies TOC to obtain the optimal solution, meeting the goal of improving the return loading rate to more than 50% and then lowering the total transportation distance in phase 2. To see our model capability, this study establishes an original distribution layout to compare the performance of the Sub-Tour reversal approach with our model, based on the simulation data generated by the Monte Carlo simulation. We also conduct the pair t-test to verify our model performance. The results show that our proposed model outperforms the Sub-Tour reversal approach in a significant manner. By utilizing the available data, our model can be easily implemented in the real world and efficiently seeks the optimal solutions.
Dose-Related Aberrant Inhibition of Intracellular Perforin Expression by S1 Subunit of Spike Glycoprotein That Contains Receptor-Binding Domain from SARS-CoV-2
Authors: Huang Chun-Fu , Hsieh Szu-Min , Pan Sung-Ching , Huang Yu-Shang , Chang Shan-Chwen
Published: June 2021

Studies had shown that severe cases of COVID-19 tend to have high viral loads and correlate with functional impairment of cytotoxic lymphocytes, and the features of cytokine storm syndrome are similar to manifestations of severe influenza that have been partially explained by suppressed perforin expression. To test the hypothesis that the spike glycoprotein from SARS-CoV-2 may inhibit the perforin expression, we determined the kinetics of immune responses of CD8+ T cells to low dose (LD) or high dose (HD) of S1 stimulation through an in vitro dendritic cell (DC)-T cell model over seven days of incubation. The cytotoxic activity and intracellular perforin expression of CD8+ T cells induced by HD-S1-presenting DCs were aberrantly lower than those induced by LD-S1-presenting DCs from day three of incubation. Discrepantly, the levels of lymphoproliferation and cytokine (interferon-γ and tumor necrosis factor-α) production induced by HD-S1-presenting DCs were significantly higher than those induced by LD-S1-presenting DCs from day four. The dose-related responses between doses of S1 and intracellular perforin expression showed a significant linear correlation with a negative slope. In conclusion, the S1 subunit may suppress the perforin expression in CD8+ T cells to decrease the cytotoxic capacity to kill spike-presenting cells in a dose-dependent manner; the persistence of antigen presentation may result in an overproduction of interferon-γ and subsequent proinflammatory cytokines. That may help explain the insufficient cytotoxicity against high quantities of viruses or highly replicated strains of SARS-CoV-2 in severe cases of COVID-19.
Imaging of Oral SCC Cells by Raman Micro-Spectroscopy Technique
Authors: Kinoshita Hidetaka , Miyoshi Norio , Ogasawara Toshiyuki
Published: June 2021

We used Raman micro-spectroscopy technique to analyze the molecular changes associated with oral squamous cell carcinoma (SCC) cells in the form of frozen tissue. Previously, Raman micro-spectroscopy technique on human tissue was mainly based on spectral analysis, but we worked on imaging of molecular structure. In this study, we evaluated the distribution of four components at the cell level (about 10 μm) to describe the changes in protein and molecular structures of protein belonging to malignant tissue. We analyzed ten oral SCC samples of five patients without special pretreatments of the use of formaldehyde. We obtained cell level images of the oral SCC cells at various components (peak at 935 cm−1: proline and valine, 1004 cm−1: phenylalanine, 1223 cm−1: nucleic acids, and 1650 cm−1: amide I). These mapping images of SCC cells showed the distribution of nucleic acids in the nuclear areas; meanwhile, proline and valine, phenylalanine, and amide I were detected in the cytoplasm areas of the SCC cells. Furthermore, the peak of amide I in the cancer area shifts to the higher wavenumber side, which indicates the α-helix component may decrease in its relative amounts of protein in the β-sheet or random coil conformation. Imaging of SCC cells with Raman micro-spectroscopy technique indicated that such a new observation of cancer cells is useful for analyzing the detailed distribution of various molecular conformation within SCC cells.
Bioactive Polyphenolic Compounds Showing Strong Antiviral Activities against Severe Acute Respiratory Syndrome Coronavirus 2
Authors: Kandeil Ahmed , Mostafa Ahmed , Kutkat Omnia , Moatasim Yassmin , Al-Karmalawy Ahmed A. , Rashad Adel A. , Kayed Ahmed E. , Kayed Azza E. , El-Shesheny Rabeh , Kayali Ghazi , Ali Mohamed A.
Published: June 2021

Until now, there has been no direct evidence of the effectiveness of repurposed FDA-approved drugs against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections. Although curcumin, hesperidin, and quercetin have broad spectra of pharmacological properties, their antiviral activities against SARS-CoV-2 remain unclear. Our study aimed to assess the in vitro antiviral activities of curcumin, hesperidin, and quercetin against SARS-CoV-2 compared to hydroxychloroquine and determine their mode of action. In Vero E6 cells, these compounds significantly inhibited virus replication, mainly as virucidal agents primarily indicating their potential activity at the early stage of viral infection. To investigate the mechanism of action of the tested compounds, molecular docking studies were carried out against both SARS-CoV-2 spike (S) and main protease (Mpro) receptors. Collectively, the obtained in silico and in vitro findings suggest that the compounds could be promising SARS-CoV-2 Mpro inhibitors. We recommend further preclinical and clinical studies on the studied compounds to find a potential therapeutic targeting COVID-19 in the near future.