bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomedical Applications of Electromagnetic Detection: A Brief Review
Authors: Huang Pu , Xu Lijun , Xie Yuedong
Published: July 2021

This paper presents a review on the biomedical applications of electromagnetic detection in recent years. First of all, the thermal, non-thermal, and cumulative thermal effects of electromagnetic field on organism and their biological mechanisms are introduced. According to the electromagnetic biological theory, the main parameters affecting electromagnetic biological effects are frequency and intensity. This review subsequently makes a brief review about the related biomedical application of electromagnetic detection and biosensors using frequency as a clue, such as health monitoring, food preservation, and disease treatment. In addition, electromagnetic detection in combination with machine learning (ML) technology has been used in clinical diagnosis because of its powerful feature extraction capabilities. Therefore, the relevant research involving the application of ML technology to electromagnetic medical images are summarized. Finally, the future development to electromagnetic detection for biomedical applications are presented.
Performance Comparison of Flow-Through Optofluidic Biosensor Designs
Authors: Wright Joel , Amin Md , Schmidt Holger , Hawkins Aaron
Published: July 2021

Optofluidic flow-through biosensors are being developed for single particle detection, particularly as a tool for pathogen diagnosis. The sensitivity of the biosensor chip depends on design parameters, illumination format (side vs. top), and flow configuration (parabolic, two- and three-dimensional hydrodynamic focused (2DHF and 3DHF)). We study the signal differences between various combinations of these design aspects. Our model is validated against a sample of physical devices. We find that side-illumination with 3DHF produces the strongest and consistent signal, but parabolic flow devices process a sample volume more quickly. Practical matters of optical alignment are also discussed, which may affect design choice.
Applications of CRISPR-Cas9 as an Advanced Genome Editing System in Life Sciences
Authors: Tavakoli Kamand , Pour-Aboughadareh Alireza , Kianersi Farzad , Poczai Peter , Etminan Alireza , Shooshtari Lia
Published: July 2021

Targeted nucleases are powerful genomic tools to precisely change the target genome of living cells, controlling functional genes with high exactness. The clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) genome editing system has been identified as one of the most useful biological tools in genetic engineering that is taken from adaptive immune strategies for bacteria. In recent years, this system has made significant progress and it has been widely used in genome editing to create gene knock-ins, knock-outs, and point mutations. This paper summarizes the application of this system in various biological sciences, including medicine, plant science, and animal breeding.
Contextual Acquisition of Concrete and Abstract Words: Behavioural and Electrophysiological Evidence
Authors: Mkrtychian Nadezhda , Gnedykh Daria , Blagovechtchenski Evgeny , Tsvetova Diana , Kostromina Svetlana , Shtyrov Yury
Published: July 2021

Abstract and concrete words differ in their cognitive and neuronal underpinnings, but the exact mechanisms underlying these distinctions are unclear. We investigated differences between these two semantic types by analysing brain responses to newly learnt words with fully controlled psycholinguistic properties. Experimental participants learned 20 novel abstract and concrete words in the context of short stories. After the learning session, event-related potentials (ERPs) to newly learned items were recorded, and acquisition outcomes were assessed behaviourally in a range of lexical and semantic tasks. Behavioural results showed better performance on newly learnt abstract words in lexical tasks, whereas semantic assessments showed a tendency for higher accuracy for concrete words. ERPs to novel abstract and concrete concepts differed early on, ~150 ms after the word onset. Moreover, differences between novel words and control untrained pseudowords were observed earlier for concrete (~150 ms) than for abstract (~200 ms) words. Distributed source analysis indicated bilateral temporo-parietal activation underpinning newly established memory traces, suggesting a crucial role of Wernicke’s area and its right-hemispheric homologue in word acquisition. In sum, we report behavioural and neurophysiological processing differences between concrete and abstract words evident immediately after their controlled acquisition, confirming distinct neurocognitive mechanisms underpinning these types of semantics.
Modified Tumor Budding as a Better Predictor of Lymph Node Metastasis in Early Gastric Cancer: Possible Real-World Applications
Authors: Yim Kwangil , Jang Won Mo , Lee Sung Hak
Published: July 2021

Endoscopic resection (ER) is a minimally invasive treatment for early gastric cancer (EGC) with a low risk of lymph node metastasis (LNM). Recently, tumor budding (TB) has emerged as a potential predictor of LNM in EGC. We assessed the clinical significance of modified TB (mTB) that excludes the signet ring cell component and compared several TB assessment methods. Two hundred and eighty-nine patients with EGC at Uijeongbu St. Mary’s Hospital from 2010 to 2021 were enrolled. In univariate analysis, age, size, depth of invasion, tumor type, histologic type, Lauren classification, lymphatic invasion, venous invasion, poorly differentiated carcinoma (“not otherwise specified” predominant), and TB were significantly associated with LNM. Multivariate regression analysis showed that mTB (difference area under the curve [dAUC] = 0.085 and 0.087) was superior to TB (dAUC = 0.054 and 0.057) in predicting LNM. In addition, total TB counts on representative slide sections (dAUC = 0.087 and 0.057) in assessing TB and mTB and the ITBCC method (dAUC = 0.085) in mTB were superior to the presence or absence method (dAUC = 0.042 and 0.029). The mTB significantly increases LNM prediction ability, which can provide important information for patients with EGC.
Valproic Acid and Breast Cancer: State of the Art in 2021
Authors: Wawruszak Anna , Halasa Marta , Okon Estera , Kukula-Koch Wirginia , Stepulak Andrzej
Published: July 2021

Valproic acid (2-propylpentanoic acid, VPA) is a short-chain fatty acid, a member of the group of histone deacetylase inhibitors (HDIs). VPA has been successfully used in the treatment of epilepsy, bipolar disorders, and schizophrenia for over 50 years. Numerous in vitro and in vivo pre-clinical studies suggest that this well-known anticonvulsant drug significantly inhibits cancer cell proliferation by modulating multiple signaling pathways. Breast cancer (BC) is the most common malignancy affecting women worldwide. Despite significant progress in the treatment of BC, serious adverse effects, high toxicity to normal cells, and the occurrence of multi-drug resistance (MDR) still limit the effective therapy of BC patients. Thus, new agents which improve the effectiveness of currently used methods, decrease the emergence of MDR, and increase disease-free survival are highly needed. This review focuses on in vitro and in vivo experimental data on VPA, applied individually or in combination with other anti-cancer agents, in the treatment of different histological subtypes of BC.
Hedgehog/GLI Signaling Pathway: Transduction, Regulation, and Implications for Disease
Authors: Sigafoos Ashley N. , Paradise Brooke D. , Fernandez-Zapico Martin E.
Published: July 2021

The Hh/GLI signaling pathway was originally discovered in Drosophila as a major regulator of segment patterning in development. This pathway consists of a series of ligands (Shh, Ihh, and Dhh), transmembrane receptors (Ptch1 and Ptch2), transcription factors (GLI1–3), and signaling regulators (SMO, HHIP, SUFU, PKA, CK1, GSK3β, etc.) that work in concert to repress (Ptch1, Ptch2, SUFU, PKA, CK1, GSK3β) or activate (Shh, Ihh, Dhh, SMO, GLI1–3) the signaling cascade. Not long after the initial discovery, dysregulation of the Hh/GLI signaling pathway was implicated in human disease. Activation of this signaling pathway is observed in many types of cancer, including basal cell carcinoma, medulloblastoma, colorectal, prostate, pancreatic, and many more. Most often, the activation of the Hh/GLI pathway in cancer occurs through a ligand-independent mechanism. However, in benign disease, this activation is mostly ligand-dependent. The upstream signaling component of the receptor complex, SMO, is bypassed, and the GLI family of transcription factors can be activated regardless of ligand binding. Additional mechanisms of pathway activation exist whereby the entirety of the downstream signaling pathway is bypassed, and PTCH1 promotes cell cycle progression and prevents caspase-mediated apoptosis. Throughout this review, we summarize each component of the signaling cascade, non-canonical modes of pathway activation, and the implications in human disease, including cancer.
Mild and Efficient Tunable Brønsted Acidic Ionic Liquid Catalyzed O-Acetylation and O-Trimethylsilylation with Trimethylsilyl Acetate (TMSOAc) and Hexamethyldisilazane (HMDS)
Authors: Pantawane Amit Ravindra , Thul Mayur , Lin Yi-Jyun , Lin Michelle , Lin Wesley , Julakanti Satyanarayana Reddy , Wu Hsin-Ru , Luo Shun-Yuan
Published: July 2021

This report discloses a mild and efficient O-acetylation using easily accessible TMSOAc as a novel acetyl reagent and O-trimethylsilylation using HMDS for various alcohols catalyzed by tunable Brønsted acidic ionic liquids (TBAILs). Imidazolium-based TBAILs were prepared by a two-step atom-economic reaction and acidities measured by using UV-visible spectroscopy. Both protections for alcohols were accomplished at room temperature with good to excellent yields, while the products and TBAILs were separated by simple work-up for O-silylation and column chromatography for O-acetylation. Notably, with the simple post-process, TBAILs catalyst in this solvent free method easily recovered and recycled several times without significant degradation.
In Vitro Cell Toxicity and Intracellular Uptake of Doxorubicin Exposed as a Solution or Liposomes: Implications for Treatment of Hepatocellular Carcinoma
Authors: Kullenberg Fredrik , Degerstedt Oliver , Calitz Carlemi , Pavlović Nataša , Balgoma David , Gråsjö Johan , Sjögren Erik , Hedeland Mikael , Heindryckx Femke , Lennernäs Hans
Published: July 2021

Cytostatic effects of doxorubicin in clinically applied doses are often inadequate and limited by systemic toxicity. The main objective of this in vitro study was to determine the anti-tumoral effect (IC50) and intracellular accumulation of free and liposomal doxorubicin (DOX) in four human cancer cell lines (HepG2, Huh7, SNU449 and MCF7). The results of this study showed a correlation between longer DOX exposure time and lower IC50 values, which can be attributed to an increased cellular uptake and intracellular exposure of DOX, ultimately leading to cell death. We found that the total intracellular concentrations of DOX were a median value of 230 times higher than the exposure concentrations after exposure to free DOX. The intracellular uptake of DOX from solution was at least 10 times higher than from liposomal formulation. A physiologically based pharmacokinetic model was developed to translate these novel quantitative findings to a clinical context and to simulate clinically relevant drug concentration–time curves. This showed that a liver tumor resembling the liver cancer cell line SNU449, the most resistant cell line in this study, would not reach therapeutic exposure at a standard clinical parenteral dose of doxorubicin (50 mg/m2), which is serious limitation for this drug. This study emphasizes the importance of in-vitro to in-vivo translations in the assessment of clinical consequence of experimental findings.
Contribution of Adventitia-Derived Stem and Progenitor Cells to New Vessel Formation in Tumors
Authors: Upcin Berin , Henke Erik , Kleefeldt Florian , Hoffmann Helene , Rosenwald Andreas , Irmak-Sav Ster , Aktas Huseyin Bertal , Rückschloß Uwe , Ergün Süleyman
Published: July 2021

Blocking tumor vascularization has not yet come to fruition to the extent it was hoped for, as angiogenesis inhibitors have shown only partial success in the clinic. We hypothesized that under-appreciated vascular wall-resident stem and progenitor cells (VW-SPCs) might be involved in tumor vascularization and influence effectiveness of anti-angiogenic therapy. Indeed, in patient samples, we observed that vascular adventitia-resident CD34+ VW-SPCs are recruited to tumors in situ from co-opted vessels. To elucidate this in detail, we established an ex vivo model using concomitant embedding of multi-cellular tumor spheroids (MCTS) and mouse aortic rings (ARs) into collagen gels, similar to the so-called aortic ring assay (ARA). Moreover, ARA was modified by removing the ARs’ adventitia that harbors VW-SPCs. Thus, this model enabled distinguishing the contribution of VW-SPCs from that of mature endothelial cells (ECs) to new vessel formation. Our results show that the formation of capillary-like sprouts is considerably delayed, and their number and network formation were significantly reduced by removing the adventitia. Substituting iPSC-derived neural spheroids for MCTS resulted in distinct sprouting patterns that were also strongly influenced by the presence or absence of VW-SPCs, also underlying the involvement of these cells in non-pathological vascularization. Our data suggest that more comprehensive approaches are needed in order to block all of the mechanisms contributing to tumor vascularization.
UV-A Treatment of ZrO2 Thin Films Fabricated by Environmental Friendlier Water-Based Solution Processing: Structural and Optical Studies
Authors: Bashir Aneeqa , Farooq Mehwish , Malik Abdul , Naseem Shahzad , Bhatti Arshad Saleem
Published: July 2021

An environmentally friendlier solution processing has been introduced to fabricate zirconium oxide (ZrO2) films on quartz substrates, using spin coating of simple water-based solution. The films cured with UV-A = 330 nm for different times (40, 80, 120 min) were investigated for structural and optical properties and compared with thermally annealed film (at 350 °C). XRD and Raman spectroscopy showed amorphous structure in all the samples with no significant phase transformation with UV-A exposure. AFM microscopy showed smooth and crack free films with surface roughness ≤2 nm that reduced with UV-A exposure. Ultraviolet-visible (UV–Vis) spectroscopy demonstrated optical transmittance ≥88% and energy band gap variations as 4.52–4.70 eV. Optical constants were found from spectroscopic ellipsometry (SE). The refractive index (n) values, measured at 470 nm increased from 1.73 to 2.74 as the UV-A exposure prolonged indicating densification and decreasing porosity of the films. The extinction coefficient k decreased from 0.32 to 0.19 indicating reduced optical losses in the films under the UV-A exposure. The photoluminescence (PL) spectra exhibited more pronounced UV emissions which grew intense with UV-A exposure thereby improving the film quality. It is concluded that UV-A irradiation can significantly enhance the optical properties of ZrO2 films with minimal changes induced in the structure as compared to thermally treated film. Moreover, the present work indicates that water-based solution processing has the potential to produce high-quality ZrO2 films for low cost and environmental friendlier technologies. The work also highlights the use of UV-A radiations as an alternate to high temperature thermal annealing for improved quality.
The Effect of Match between High Power Impulse and Bias Voltage: TiN Coating Deposited by High Power Impulse Magnetron Sputtering
Authors: Chang Chi-Lung , Lin Ching-Yen , Yang Fu-Chi , Tang Jian-Fu
Published: July 2021

Practical experience in the use of high power impulse magnetron sputtering (HiPIMS) technology has revealed that output bias current depends on the total energy output of the cathodes, which means that bias voltage settings do not necessarily match the actual output. In this study, we investigated the effects of bias current and voltage on the characteristics of titanium nitride thin films produced using high impulse magnetron sputtering. The bias current and voltage values were adjusted by varying the supplied cathode power and substrate bias under DC and pulsed-DC output models. Our results revealed that pulse delay (PD) and feed forward (FF) settings can be used to control bias current and voltage. Increasing the bias current from 0.56 to 0.84 was shown to alter the preferred orientation from (111) to (220), increase the deposition rate, and lead to a corresponding increase in film thickness. The surface morphology of all titanium nitride samples exhibited tapered planes attributable to the low bias current and voltage (−30 V). The maximum hardness values were as follows: DC mode (23 GPa) and pulsed-DC mode (19 GPa). The lower hardness values of pulsed-DC samples can be attributed to residual stress, preferred orientation, and surface morphology. The surface of the samples was shown to be hydrophobic, with contact angles of >100°.
N-Doped Carbon Quantum Dots as Fluorescent Bioimaging Agents
Authors: Ou Shih-Fu , Zheng Ya-Yun , Lee Sin-Jen , Chen Shyi-Tien , Wu Chien-Hui , Hsieh Chien-Te , Juang Ruey-Shin , Peng Pei-Zhen , Hsueh Yi-Huang
Published: July 2021

Graphene quantum dots, carbon nanomaterials with excellent fluorescence characteristics, are advantageous for use in biological systems owing to their small size, non-toxicity, and biocompatibility. We used the hydrothermal method to prepare functional N-doped carbon quantum dots (N-CQDs) from 1,3,6-trinitropyrene and analyzed their ability to fluorescently stain various bacteria. Our results showed that N-CQDs stain the cell septa and membrane of the Gram-negative bacteria Escherichia coli, Salmonellaenteritidis, and Vibrio parahaemolyticus and the Gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. The optimal concentration of N-CQDs was approximately 500 ppm for Gram-negative bacteria and 1000 ppm for Gram-positive bacteria, and the exposure times varied with bacteria. N-Doped carbon quantum dots have better light stability and higher photobleaching resistance than the commercially available FM4-64. When excited at two different wavelengths, N-CQDs can emit light of both red and green wavelengths, making them ideal for bioimaging. They can also specifically stain Gram-positive and Gram-negative bacterial cell membranes. We developed an inexpensive, relatively easy, and bio-friendly method to synthesize an N-CQD composite. Additionally, they can serve as a universal bacterial membrane-staining dye, with better photobleaching resistance than commercial dyes.
Bridgman Growth and Physical Properties Anisotropy of CeF3 Single Crystals
Authors: Karimov Denis N. , Lisovenko Dmitry S. , Ivanova Anna G. , Grebenev Vadim V. , Popov Pavel A. , Sizova Natalya L.
Published: July 2021

Bulk c-oriented CeF3 single crystals (sp. gr. P3¯c1) were grown successfully by the vertical Bridgman technique in a fluorinating atmosphere. A description of the crystal growth procedure and the solution of the difficulties during the growth process are presented in detail. The anisotropy of the mechanical, thermal and electrophysical properties were studied for the first time. The maximum values of the thermal conductivity coefficient (α = 2.51 ± 0.12 W·m−1·K−1) and the ionic conductivity (σdc = 2.7 × 10−6 S/cm) at room temperature are observed in the [0001] direction for the CeF3 crystals. The Vickers (HV) and Berkovich (HB) microhardnesses for the (0001), (101¯0) and (112¯0) crystallographic planes were investigated. The HB values were higher than the HV ones and decreased from 3.8 to 2.9 GPa with an increase in the load in the range of 0.5–0.98 N for the hardest (0001) plane. The {112¯0}, {101¯0} and {0001} cleavage planes were observed during the indentation process of the CeF3 crystals. The variability of Young’s, the shear modules and Poisson’s ratio were analyzed. A significant correlation between the shapes of the Vickers indentation patterns with Young’s modulus anisotropy was found. The relationship between the anisotropy of the studied properties and the features of the CeF3 trigonal crystal structure is discussed.
Qualitative Data Clustering to Detect Outliers
Authors: Nowak-Brzezińska Agnieszka , Łazarz Weronika
Published: July 2021

Detecting outliers is a widely studied problem in many disciplines, including statistics, data mining, and machine learning. All anomaly detection activities are aimed at identifying cases of unusual behavior compared to most observations. There are many methods to deal with this issue, which are applicable depending on the size of the data set, the way it is stored, and the type of attributes and their values. Most of them focus on traditional datasets with a large number of quantitative attributes. The multitude of solutions related to detecting outliers in quantitative sets, a large and still has a small number of research solutions is a problem detecting outliers in data containing only qualitative variables. This article was designed to compare three different categorical data clustering algorithms: K-modes algorithm taken from MacQueen’s K-means algorithm and the STIRR and ROCK algorithms. The comparison concerned the method of dividing the set into clusters and, in particular, the outliers detected by algorithms. During the research, the authors analyzed the clusters detected by the indicated algorithms, using several datasets that differ in terms of the number of objects and variables. They have conducted experiments on the parameters of the algorithms. The presented study made it possible to check whether the algorithms similarly detect outliers in the data and how much they depend on individual parameters and parameters of the set, such as the number of variables, tuples, and categories of a qualitative variable.
Voltage Variations and Their Reduction in a Rural Low-Voltage Network with PV Sources of Energy
Authors: Szultka Agata , Szultka Seweryn , Czapp Stanislaw , Zajczyk Ryszard
Published: July 2021

Renewable sources of energy (RES), especially photovoltaic (PV) micro-sources, are very popular in many countries. This way of clean power production is applied on a wide scale in Poland as well. The Polish legal regulations and tariffs specify that every prosumer in a low-voltage network may feed this network with a power not higher than the maximum declared consumed power. In power networks with RES, the voltage level changes significantly along the power line and depends on the actually generated as well as consumed power by particular prosumers. There are cases that prosumers connected to this line cannot produce and inject the full permissible power from PV sources due to the level of a voltage higher than the technically acceptable value. In consequence, it leads to the lack of profitability of investments in installations with PV sources. In this paper, voltage variations in a real rural low-voltage network with PV micro-sources are described. The possible two general solutions of voltage levels improvement are discussed—increase in the cross-sectional area of the bare conductors in the existing overhead line as well as the replacement of the overhead line with a cable line. The recommended solution for the analyzed network, giving the best reduction of voltage variations and acceptable cost, is underlined. Such a recommendation can also be utilized in other rural networks.
Analysis and Implementation of a Frequency Control DC–DC Converter for Light Electric Vehicle Applications
Authors: Lin Bor-Ren
Published: July 2021

In order to realize emission-free solutions and clean transportation alternatives, this paper presents a new DC converter with pulse frequency control for a battery charger in electric vehicles (EVs) or light electric vehicles (LEVs). The circuit configuration includes a resonant tank on the high-voltage side and two variable winding sets on the output side to achieve wide output voltage operation for a universal LEV battery charger. The input terminal of the presented converter is a from DC microgrid with voltage levels of 380, 760, or 1500 V for house, industry plant, or DC transportation vehicle demands, respectively. To reduce voltage stresses on active devices, a cascade circuit structure with less voltage rating on power semiconductors is used on the primary side. Two resonant capacitors were selected on the resonant tank, not only to achieve the two input voltage balance problem but also to realize the resonant operation to control load voltage. By using the variable switching frequency approach to regulate load voltage, active switches are turned on with soft switching operation to improve converter efficiency. In order to achieve wide output voltage capability for universal battery charger demands such as scooters, electric motorbikes, Li-ion e-trikes, golf carts, luxury golf cars, and quad applications, two variable winding sets were selected to have a wide voltage output (50~160 V). Finally, experiments with a 1 kW rated prototype were demonstrated to validate the performance and benefits of presented converter.
Managing SARS-CoV-2 Testing in Schools with an Artificial Intelligence Model and Application Developed by Simulation Data
Authors: Valtchev Svetozar Zarko , Asgary Ali , Chen Michael , Cronemberger Felippe A. , Najafabadi Mahdi M. , Cojocaru Monica Gabriela , Wu Jianhong
Published: July 2021

Research on SARS-CoV-2 and its social implications have become a major focus to interdisciplinary teams worldwide. As interest in more direct solutions, such as mass testing and vaccination grows, several studies appear to be dedicated to the operationalization of those solutions, leveraging both traditional and new methodologies, and, increasingly, the combination of both. This research examines the challenges anticipated for preventative testing of SARS-CoV-2 in schools and proposes an artificial intelligence (AI)-powered agent-based model crafted specifically for school scenarios. This research shows that in the absence of real data, simulation-based data can be used to develop an artificial intelligence model for the application of rapid assessment of school testing policies.
Quantum-Driven Energy-Efficiency Optimization for Next-Generation Communications Systems
Authors: Chien Su Fong , Lim Heng Siong , Kourtis Michail Alexandros , Ni Qiang , Zappone Alessio , Zarakovitis Charilaos C.
Published: July 2021

The advent of deep-learning technology promises major leaps forward in addressing the ever-enduring problems of wireless resource control and optimization, and improving key network performances, such as energy efficiency, spectral efficiency, transmission latency, etc. Therefore, a common understanding for quantum deep-learning algorithms is that they exploit advantages of quantum hardware, enabling massive optimization speed ups, which cannot be achieved by using classical computer hardware. In this respect, this paper investigates the possibility of resolving the energy efficiency problem in wireless communications by developing a quantum neural network (QNN) algorithm of deep-learning that can be tested on a classical computer setting by using any popular numerical simulation tool, such as Python. The computed results show that our QNN algorithm can be indeed trainable and that it can lead to solution convergence during the training phase. We also show that the proposed QNN algorithm exhibits slightly faster convergence speed than its classical ANN counterpart, which was considered in our previous work. Finally, we conclude that our solution can accurately resolve the energy efficiency problem and that it can be extended to optimize other communications problems, such as the global optimal power control problem, with promising trainability and generalization ability.
Acoustic Properties of Larch Bark Panels
Authors: Tudor Eugenia , Kristak Lubos , Barbu Marius , Gergeľ Tomáš , Němec Miroslav , Kain Günther , Réh Roman
Published: July 2021

The potential of tree bark, a by-product of the woodworking industry, has been studied for more than seven decades. Bark, as a sustainable raw material, can replace wood or other resources in numerous applications in construction. In this study, the acoustic properties of bark-based panels were analyzed. The roles of the particle size (4–11 mm and 10–30 mm), particle orientation (parallel and perpendicular) and density (350–700 kg/m3) of samples with 30 mm and 60 mm thicknesses were studied at frequencies ranging from 50 to 6400 Hz. Bark-based boards with fine-grained particles have been shown to be better in terms of sound absorption coefficient values compared with coarse-grained particles. Bark composites mixed with popcorn bonded with UF did not return the expected results, and it is not possible to recommend this solution. The best density of bark boards to obtain the best sound absorption coefficients is about 350 kg/m3. These lightweight panels achieved better sound-absorbing properties (especially at lower frequencies) at higher thicknesses. The noise reduction coefficient of 0.5 obtained a sample with fine particles with a parallel orientation and a density of around 360 kg/m3.
Spatial Relationships between Pockmarks and Sub-Seabed Gas in Fjordic Settings: Evidence from Loch Linnhe, West Scotland
Authors: Audsley Allan , Bradwell Tom , Howe John , Baxter John
Published: July 2021

Sub-seabed gas is commonly associated with seabed depressions known as pockmarks—the main venting sites for hydrocarbon gases to enter the water column. Sub-seabed gas accumulations are characterized by acoustically turbid or opaque zones in seismic reflection profiles, taking the form of gas blankets, curtains or plumes. How the migration of sub-seabed gas relates to the origin and distribution of pockmarks in nearshore and fjordic settings is not well understood. Using marine geophysical data from Loch Linnhe, a Scottish fjord, we show that shallow sub-seabed gas occurs predominantly within glaciomarine facies either as widespread blankets in basins or as isolated pockets. We use geospatial ‘hot-spot’ analysis conducted in ArcGIS to identify clusters of pockmarks and acoustic (sub-seabed) profile interpretation to identify the depth to gas front across the fjord. By combining these analyses, we find that the gas below most pockmarks in Loch Linnhe is between 1.4 m and 20 m deep. We anticipate that this work will help to understand the fate and mobility of sedimentary carbon in fjordic (marine) settings and advise offshore industry on the potential hazards posed by pockmarked seafloor regions even in nearshore settings.
Temporal and Spatial Evolution Analysis of Earthquake Events in California and Nevada Based on Spatial Statistics
Authors: Shan Weifeng , Wang Zhihao , Teng Yuntian , Wang Maofa
Published: July 2021

Studying the temporal and spatial evolution trends in earthquakes in an area is beneficial for determining the earthquake risk of the area so that local governments can make the correct decisions for disaster prevention and reduction. In this paper, we propose a new method for analyzing the temporal and spatial evolution trends in earthquakes based on earthquakes of magnitude 3.0 or above from 1980 to 2019 in California and Nevada. The experiment’s results show that (1) the frequency of earthquake events of magnitude 4.5 or above present a relatively regular change trend of decreasing–rising in this area; (2) by using the weighted average center method to analyze the spatial concentration of earthquake events of magnitude 3.0 or above in this region, we find that the weighted average center of the earthquake events in this area shows a conch-type movement law, where it moves closer to the center from all sides; (3) the direction of the spatial distribution of earthquake events in this area shows a NW–SE pattern when the standard deviational ellipse (SDE) method is used, which is basically consistent with the direction of the San Andreas Fault Zone across the north and south of California; and (4) the spatial distribution pattern of the earthquake events in this region is found to be clustered using the global spatial autocorrelation analysis method. This study provides a new perspective for the exploration of the temporal and spatial evolution trends in earthquakes and understanding the earthquake risk in an area.
Impact of Nesting Socotra Cormorants on Terrestrial Invertebrate Communities
Authors: Al Shehhi Hiba , Muzaffar Sabir Bin
Published: July 2021

Seabirds and some inland waterbirds nest in densely aggregated colonies. Nesting activities for a duration of months could lead to large quantities of guano deposition that affects the soil chemistry, flora and fauna. We assessed the effects of nesting Socotra Cormorants on soil invertebrates on Siniya Island, United Arab Emirates. Artificial substrate traps were set in nesting and non-nesting areas to sample invertebrates both before and after nesting had occurred. Diversity of soil invertebrate taxa decreased significantly in nesting areas compared to non-nesting areas after the commencement of nesting. This indicated that nesting activities had a negative effect on diversity. Among selected taxa, isopods and spiders decreased significantly in response to nesting activities. In contrast, ants were likely affected by habitat while beetles did not change significantly in response to nesting activities, suggesting that their numbers probably fluctuated in relation to seasonality. Ticks increased significantly but only in non-nesting areas. Thus, the impact of nesting varied between taxa depending on life history and seasonality. Our observations reflect the dynamic nature of invertebrate abundance that is affected by seasonality and the hyper-abundance of nesting seabirds.
Finding the Appropriate Therapeutic Strategy in Patients with Neuroendocrine Tumors of the Pancreas: Guideline Recommendations Meet the Clinical Reality
Authors: Krug Sebastian , Damm Marko , Garbe Jakob , König Senta , Schmitz Rosa Lynn , Michl Patrick , Schrader Jörg , Rinke Anja
Published: July 2021

The systemic treatment of patients with pancreatic neuroendocrine tumors is based on placebo-controlled trials and long-established chemotherapy approaches. In addition, peptide receptor radionuclide therapy (PRRT) was approved as a parallel approach for pancreatic neuroendocrine tumors (NET), in addition to small bowel NET, after the NETTER-1 trial. The current ESMO and NCCN guidelines attempted to describe treatment algorithms for pancreatic NET based on the current data. In our survey, we recorded therapy decisions for the first- until the third-line of therapy in German-speaking countries (Germany, Austria, and Switzerland) using fictional case reports and discussed these in the context of the current ESMO guidelines. Compared with the recommendations of the guidelines, PRRT was used more frequently and earlier. In patients with NET G1/G2 Ki-67 < 10%, the therapy algorithm consisting of somatostatin analogs (SSA)-PRRT-targeted therapy is a relevant approach. In clinical situations where chemotherapy is primarily used (remission pressure, Ki-67 > 10%), second-line PRRT was found acceptance and was often considered prior to targeted therapies. Despite the lack of prospective controlled trials, our study demonstrated the pivotal impact of PRRT. Therefore, further studies should compare PRRT with chemotherapy in pancreatic NETs in different clinical settings in first- and second-line approaches.
Serum Visfatin Levels in Nonalcoholic Fatty Liver Disease and Liver Fibrosis: Systematic Review and Meta-Analysis
Authors: Ismaiel Abdulrahman , Leucuta Daniel-Corneliu , Popa Stefan-Lucian , Dumitrascu Dan L.
Published: July 2021

(1) Background: Recently, adipokines, including visfatin, have been studied in nonalcoholic fatty liver disease (NAFLD). Several studies evaluated visfatin levels in NAFLD, the presence and severity of hepatic steatosis, liver fibrosis, lobar inflammation, nonalcoholic steatohepatitis (NASH), and gender differences. However, inconclusive results have been reported. Accordingly, we performed a systematic review and meta-analysis, aiming to address these gaps in evidence. (2) Methods: We performed a systematic electronic search on PubMed, EMBASE, and Cochrane Library using predefined keywords. Diagnosis of NAFLD by liver biopsy or imagistic investigations was accepted. Full articles satisfying our inclusion and exclusion criteria were included. NHLBI quality assessment tools were used to evaluate included studies. The principal summary outcome was the mean difference in visfatin levels. (3) Results: There were 21 studies involving 1923 individuals included in our qualitative assessment, while 14 studies were included in the quantitative assessment. No statistical significance was found assessing visfatin levels in NAFLD [3.361 (95% CI −0.175–6.897)], simple steatosis [7.523 (95% CI −16.221–31.267)], hepatic steatosis severity [−0.279 (95% CI −1.843–1.285)], liver fibrosis [4.133 (95% CI −3.176–11.443)], lobar inflammation [0.358 (95% CI −1.470–2.185)], NASH [−2.038 (95% CI −6.839–2.763)], and gender [(95% CI −0.554–0.556)]. (4) Conclusions: In conclusion, visfatin levels are not associated with NAFLD, presence or severity of hepatic steatosis, liver fibrosis, lobar inflammation, NASH, and gender. However, due to the limited methodological quality of the included studies, results should be interpreted with caution.
Upregulated MUC2 Is an Unfavorable Prognostic Indicator for Rectal Cancer Patients Undergoing Preoperative CCRT
Authors: Chou Chia-Lin , Chen Tzu-Ju , Tian Yu-Feng , Chan Ti-Chun , Yeh Cheng-Fa , Li Wan-Shan , Tsai Hsin-Hwa , Li Chien-Feng , Lai Hong-Yue
Published: July 2021

For locally advanced rectal cancer patients, introducing neoadjuvant concurrent chemoradiotherapy (CCRT) before radical resection allows tumor downstaging and increases the rate of anus retention. Since accurate staging before surgery and sensitivity prediction to CCRT remain challenging, a more precise genetic biomarker is urgently needed to enhance the management of such situations. The epithelial mucous barrier can protect the gut lumen, but aberrant mucin synthesis may defend against drug penetration. In this study, we focused on genes related to maintenance of gastrointestinal epithelium (GO: 0030277) and identified mucin 2 (MUC2) as the most significantly upregulated gene correlated with CCRT resistance through a public rectal cancer transcriptome dataset (GSE35452). We retrieved 172 records of rectal cancer patients undergoing CCRT accompanied by radical resection from our biobank. We also assessed the expression level of MUC2 using immunohistochemistry. The results showed that upregulated MUC2 immunoexpression was considerably correlated with the pre-CCRT and post-CCRT positive nodal status (p = 0.001 and p < 0.001), advanced pre-CCRT and post-CCRT tumor status (p = 0.022 and p < 0.001), vascular invasion (p = 0.015), and no or little response to CCRT (p = 0.006). Upregulated MUC2 immunoexpression was adversely prognostic for all three endpoints, disease-specific survival (DSS), local recurrence-free survival (LRFS), and metastasis-free survival (MeFS) (all p < 0.0001), at the univariate level. Moreover, upregulated MUC2 immunoexpression was an independent prognostic factor for worse DSS (p < 0.001), LRFS (p = 0.008), and MeFS (p = 0.003) at the multivariate level. Collectively, these results imply that upregulated MUC2 expression is characterized by a more advanced clinical course and treatment resistance in rectal cancer patients undergoing CCRT, revealing the potential prognostic utility of MUC2 expression.
Occurrence and Persistency of Conduction Disturbances during Transcatheter Aortic Valve Implantation
Authors: Poels Thomas T. , Engels Elien B. , Kats Suzanne , Veenstra Leo , van Ommen Vincent , Vernooy Kevin , Maessen Jos G. , Prinzen Frits W.
Published: July 2021

Background and Objectives: Conduction disturbances such as left bundle branch block (LBBB) and complete atrio-ventricular block (cAVB) are relatively frequent complications following trans-catheter aortic valve implantation (TAVI). We investigated the dynamics of these conduction blocks to further understand luxating factors and predictors for their persistency. Materials and Methods: We prospectively included 157 consecutive patients who underwent a TAVI procedure. Electrocardiograms (ECGs) were obtained at specific time points during the TAVI procedure and at follow-up until at least six months post-procedure. Results: Of the 106 patients with a narrow QRS complex (nQRS) before TAVI, ~70% developed LBBB; 28 (26.4%) being classified as super-transient (ST-LBBB), 20 (18.9%) as transient (T-LBBB) and 24 (22.6%) as persistent (P-LBBB). Risk of LBBB was higher for self-expandable (SE) than for balloon-expandable (BE) prostheses and increased with larger implant depth. During the TAVI procedure conduction disturbances showed a dynamic behavior, as illustrated by alternating kinds of blocks in 18 cases. Most LBBBs developed during balloon aortic valvuloplasty (BAV) and at positioning and deployment of the TAVI prosthesis. The incidence of LBBB was not significantly different between patients who did and did not undergo BAV prior to TAVI implantation (65.3% and 74.2%, respectively (p = 0.494)). Progression to cAVB was most frequent for patients with preexisting conduction abnormalities (5/34) patients) and in patients showing ST-LBBB (6/28). Conclusions: During the TAVI procedure, conduction disturbances showed a dynamic behavior with alternating types of block in 18 cases. After a dynamic period of often alternating types of block, most BBBs are reversible while one third persist. Patients with ST-LBBB are most prone to progressing into cAVB. The observation that the incidence of developing LBBB after TAVI is similar with and without BAV suggests that a subgroup of patients has a substrate to develop LBBB regardless of the procedure.
Investigating the Antibacterial Activity of Polymeric Membranes Fabricated with Aminated Graphene Oxide
Authors: Zahid Muhammad , Akram Saba , Rashid Anum , Rehan Zulfiqar Ahmad , Javed Talha , Shabbir Rubab , Hessien Mahmoud M. , El-Sayed Mahmoud E.
Published: July 2021

A novel, functionalized graphene oxide–based cellulose acetate membrane was fabricated using the phase inversion method to improve the membrane characteristics and performance. We studied the effect of aminated graphene oxide (NH2–GO) composite on the CA membrane characteristics and performance in terms of membrane chemistry, hydrophilicity, thermal and mechanical stability, permeation flux, and antibacterial activity. The results of contact angle and water flux indicate the improved hydrophilic behavior of composite membranes in comparison to that of the pure CA membrane. The AGO-3 membrane showed the highest water flux of about 153 Lm−2h−1. The addition of hydrophilic AGO additive in CA membranes enhanced the antibacterial activity of AGO–CA membranes, and the thermal stability of the resulting membrane also improved since it increases the Tg value in comparison to that of a pristine CA membrane. The aminated graphene oxide (NH2–GO) was, therefore, found to be a promising additive for the fabrication of composite membranes with potent applications in wastewater treatment.
Small Residues Inhibit Homo-Dimerization of the Human Carbonic Anhydrase XII Transmembrane Domain
Authors: Cymer Florian , Schneider Dirk
Published: July 2021

Amino acids with small side chains and motifs of small residues in a distance of four are rather abundant in human single-span transmembrane helices. While interaction of such helices appears to be common, the role of the small residues in mediating and/or stabilizing transmembrane helix oligomers remains mostly elusive. Yet, the mere existence of (small)xxx(small) motifs in transmembrane helices is frequently used to model dimeric TM helix structures. The single transmembrane helix of the human carbonic anhydrases XII contains a large number of amino acids with small side chains, and critical involvement of these small amino acids in dimerization of the transmembrane domain has been suggested. Using the GALLEX assay, we show here that the transmembrane domain indeed forms a strong transmembrane helix oligomer within a biological membrane. However, single or multiple mutations of small residue(s) to isoleucine almost always increased, rather than decreased, the interaction propensities. Reduction of helix flexibility and of protein–lipid contacts caused by a reduced lipid accessible surface area likely results in stabilization of helix–helix interactions within the membrane.
Multiphasic Study of Fluid-Dynamics and the Thermal Behavior of a Steel Ladle during Bottom Gas Injection Using the Eulerian Model
Authors: Urióstegui-Hernández Antonio , Garnica-González Pedro , Ramos-Banderas José Ángel , Hernández-Bocanegra Constantin Alberto , Solorio-Díaz Gildardo
Published: July 2021

In this work, the fluid dynamic and thermal behavior of steel was analyzed during argon gas stirring in a 140-t refining ladle. The Eulerian multiphase mathematical model was used in conjunction with the discrete ordinates (DO) thermal radiation model in a steel-slag-argon system. The model was validated by particle image velocimetry (PIV) and the analysis of the opening of the oil layer in a physical scale model. The effect of Al2O3 and Mg-C as a refractory in the walls was studied, and the Ranz-Marshall and Tomiyama models were compared to determine the heat exchange coefficient. The results indicated that there were no significant differences between these heat exchange models; likewise, the radiation heat transfer model adequately simulated the thermal behavior according to plant measurements, finding a thermal homogenization time of the steel of 2.5 min for a gas flow of 0.45 Nm3·min−1. Finally, both types of refractory kept the temperature of the steel within the ranges recommended in the plant; however, the use of Al2O3 had better heat retention, which would favor refining operations.
The Disappearance of Coal Seams Recorded in Associated Gangue Rocks in the SW Part of the Upper Silesian Coal Basin, Poland
Authors: Ciesielczuk Justyna , Fabiańska Monika J. , Misz-Kennan Magdalena , Jura Dominik , Filipiak Paweł , Matuszewska Aniela
Published: July 2021

Coal seams in the Upper Silesian Coal Basin vanish within the Carboniferous Upper Silesian Sandstone Series and below an unconformity marking the Carboniferous top surface. Changes in the geochemical, mineralogical, petrological and palynological characteristics of gangue rocks associated with the vanished seams record what happened. The observed changes could have been caused by (1) coal-seam paleofire, (2) peat combustion, (3) igneous intrusion, (4) metasomatism and/or (5) weathering. Multifaceted research on samples collected at the Jas-Mos mining area, a part of the operating Jastrzębie-Bzie Coal Mine that are representative of different geological settings in the northern and southern parts of the mining area, point to intra-deposit paleofire as the most plausible reason for the disappearance. Biomarkers enabled recognition of differences in heating duration and oxygen access. Coal seams in the south burned quickly with abundant oxygen supply. Seams in the north pyrolyzed for an extended time under conditions of limited oxygen. Though other methods used proved less sensitive, all confirmed low (100–150 °C) paleotemperature heating. Overall, the reason for the local disappearance of the coal seams, making their exploitation difficult and unprofitable, can be assigned to a variety of different processes in a complex overlapping history of variable weathering, heating due to local endogenic fires and, probably, earlier peat combustion.