bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge-Based Approach for the Perception Enhancement of a Vehicle
Authors: Khezaz Abderraouf , Hina Manolo Dulva , Guan Hongyu , Ramdane-Cherif Amar
Published: November 2021

An autonomous vehicle relies on sensors in order to perceive its surroundings. However, there are multiple causes that would hinder a sensor’s proper functioning, such as bad weather or lighting conditions. Studies have shown that rainfall and fog lead to a reduced visibility, which is one of the main causes of accidents. This work proposes the use of a drone in order to enhance the vehicle’s perception, making use of both embedded sensors and its advantageous 3D positioning. The environment perception and vehicle/Unmanned Aerial Vehicle (UAV) interactions are managed by a knowledge base in the form of an ontology, and logical rules are used in order to detect and infer the environmental context and UAV management. The model was tested and validated in a simulation made on Unity.
Goal-Setting among Biology Undergraduates during a Free-Choice Learning Experience at a Regional Zoo
Authors: Heim Ashley B. , Holt Emily A.
Published: November 2021

Free-choice learning occurs when individuals have autonomy in what and how they learn, and often takes place in informal settings such as zoos. To describe goal-setting and -achievement of biology undergraduates at a regional zoo, we primarily asked: (1) What types of learning goals do students set for themselves for a trip to the zoo?; and (2) What activities do students intend to engage in on a zoo trip? Participating students completed the first portion of a goal-setting assessment prior to entering the zoo, which asked students to develop learning and activity goals for themselves. At the conclusion of the zoo trip, students completed the second portion of this survey, which asked whether students achieved their goals, and if not, why. We found that most students devised learning goals related to gaining knowledge and identified passive interactions with animals as activities they hoped to engage in during their trip.
Understanding the Impacts of Financial Flows in the Landscape
Authors: Louman Bas , Shames Seth , Pamerneckyte Gabija , Owusu Ansah Mercy , Koesoetjahjo Irene , Nghi Tran Huu , Kusters Koen
Published: November 2021

Donors and non-governmental organizations are showing increased interest in integrated landscape initiatives (ILIs), where landscape stakeholders work together to achieve common goals related to development, climate change and conservation. In order to support the work of ILIs, we developed a novel methodology with which stakeholders—organized in multi-stakeholder partnerships—can assess how financial flows in the landscape are impacting their common goals and to identify funding gaps. Piloting the methodology in three landscapes in Indonesia, Ghana and Vietnam, we found that there were trade-offs between ensuring broad stakeholder participation in the assessments (to capture different perspectives) and the level of technical and quantifiable detail that could be acquired. The methodology effectively contributed to a common understanding among landscape-level stakeholders and triggered discussions on methods in which financial flows can be adapted to reduce their negative impacts or increase their positive impacts. It also functioned as a basis for the development of joint action plans and to initiate collaborations with the providers of financial flows that have potential to contribute to common landscape objectives. In addition to promoting common understanding and providing a basis for the development of action plans, we conclude that implementing the methodology also helped with strengthening the landscape partnerships themselves.
Does Farmland Scale Management Promote Rural Collective Action? An Empirical Study of Canal Irrigation Systems in China
Authors: Zang Liangzhen , Wang Yahua , Su Yiqing
Published: November 2021

Farmland scale management represents an inevitable trend toward global modern agriculture. In the new development context, the key to solving the tough problem of the insufficient supply of rural public goods is to effectively improve the enthusiasm of farming households to participate in rural collective action in countries with a small arable area per capita, such as India, China and countries in Eastern Europe. This paper adopts the Institutional Analysis and Development (IAD) framework in the context of a land system with Chinese characteristics, and uses sample data of 3663 rural households in 17 provinces to study the impact of farmland scale and various relevant systems on farming households’ participation in rural collective action. We found that the advantages of collective action, such as reduced production costs, enhanced risk resistance and improved production efficiency, can offset the disadvantages incurred by free-riding behavior, and the expansion of farmland scale can significantly facilitate rural collective action. Additionally, as the farmland scale expands, stable farmland tenure and reasonable farmland tenure transfer can help to optimize the allocation of arable land resources, increase investment, and reduce free-riding behavior, thus effectively stimulating farming households to actively participate in collective action. However, since socialized agricultural services lead to the separation of the suppliers and the users of rural public goods, the expansion of farmland scale shows a negative effect. Therefore, in the context of the continuous migration of the rural population to cities, a stable farmland tenure adjustment mechanism should be established, while the balance between farmland tenure transfer and socialized agricultural services, in pushing forward rural collective action, should be emphasized, so as to ensure the effective supply of rural public goods in propelling farmland scale management. Especially in promoting the development of socialized agricultural services, more attention should be paid to specifying the responsibilities and obligations of the main provider of commercialized services in the supply of rural public goods.
Generation and Characterization of the Drosophila melanogaster paralytic Gene Knock-Out as a Model for Dravet Syndrome
Authors: Tapia Andrea , Giachello Carlo N. , Palomino-Schätzlein Martina , Baines Richard A. , Galindo Máximo Ibo
Published: November 2021

Dravet syndrome is a severe rare epileptic disease caused by mutations in the SCN1A gene coding for the Nav1.1 protein, a voltage-gated sodium channel alpha subunit. We have made a knock-out of the paralytic gene, the single Drosophila melanogaster gene encoding this type of protein, by homologous recombination. These flies showed a heat-induced seizing phenotype, and sudden death in long term seizures. In addition to seizures, neuromuscular alterations were observed in climbing, flight, and walking tests. Moreover, they also manifested some cognitive alterations, such as anxiety and problems in learning. Electrophysiological analyses from larval motor neurons showed a decrease in cell capacitance and membrane excitability, while persistent sodium current increased. To detect alterations in metabolism, we performed an NMR metabolomic profiling of heads, which revealed higher levels in some amino acids, succinate, and lactate; and also an increase in the abundance of GABA, which is the main neurotransmitter implicated in Dravet syndrome. All these changes in the paralytic knock-out flies indicate that this is a good model for epilepsy and specifically for Dravet syndrome. This model could be a new tool to understand the pathophysiology of the disease and to find biomarkers, genetic modifiers and new treatments.
UVC LED and Conducting Yarn-Based Heater for a Smart Germicidal Face Mask to Protect against Airborne Viruses
Authors: Pattanaik Priyabrata , Holderbaum William , Khandual Asimananda , Tripathy Hara Prasada
Published: November 2021

“Wear a mask. Save lives” is the slogan of WHO and all the government agencies over the world to the public. One of the most adopted prevention measures that can limit the spread of the airborne virus in the form of respiratory viral diseases, including the new strain of COVID-19, is wearing a proper mask. If the mask surface is heated to 65 to 70 °C, it could help potentially diminish any viruses or bacteria accumulated. The FAR-Ultraviolet -C (FAR-UV-C) dose for the influenza limit to 254 nm light is ~3 mJ/cm2/hour exposure is not harmful to the human skin and eyes. Here, we propose an intelligent mask served by FAR-UV-C and conducting a yarn-based heater that could potentially be activated in a controlled manner to kill the virus. The effective irradiation intensity for skin application would be under 0.1 µW/cm2. The exposure risk of UV-C is technically prevented by fabricating multi-layered fabrics with multiple functionalities. Along with experimental validation on bacterial filtration efficiency (BFE), tinker cad simulation for circuit design, and comsol multiphysics for temperature profile study, we probed Moisture Management Test (MMT) in addition with cytotoxicity risk by MTT Assay for survivability to ensure safer application potential. This novel proposed design with the germicidal combination of heating and FAR-UV-C models, described here, is promising in retaliating and combating any airborne viruses.
Preparation of BiOCl/Bi2WO6 Photocatalyst for Efficient Fixation on Cotton Fabric: Applications in UV Shielding and Self-Cleaning Performances
Authors: Chen Jiayi , Wang Kuang , Tian Jialong , Yu Wenhui , Chen Yujie , Li Na , Qi Zhenming , Wang Chunxia
Published: November 2021

In this work, a visible-light-driven BiOCl/Bi2WO6 photocatalyst was obtained via a facile hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), ultraviolet/visible light diffuse reflection spectroscopy (UV/Vis), and photocurrent (PC). BiOCl/Bi2WO6 was modified with (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride to obtain the cationized BiOCl/Bi2WO6. Cotton fabric was pretreated with sodium hydroxide (NaOH) and sodium chloroacetate solution to obtain carboxymethylated cotton fabric, which was further reacted with cationized BiOCl/Bi2WO6 to achieve finished cotton fabric. The cotton fabrics were characterized by Fourier-transform infrared spectroscopy (FT-IR), XRD, SEM, and EDS. The photocatalytic activity of the BiOCl/Bi2WO6 photocatalyst and cotton fabrics was assessed by photocatalytic degradation of MB (methylene blue) solution under simulated visible light. The self-cleaning property of cotton fabrics was evaluated by removing MB solution and red-wine stains. Results revealed that the coated cotton fabrics exhibited appreciable photocatalytic and self-cleaning performance. In addition, anti-UV studies showed that the finished cotton fabrics had remarkable UV blocking properties in the UVA and UVB regions. Therefore, the finished cotton fabric with BiOCl/Bi2WO6 can provide a framework for the development of multifunctional textiles.
In Situ Monitoring of Powder Bed Fusion Homogeneity in Electron Beam Melting
Authors: Grasso Marco
Published: November 2021

Increasing attention has been devoted in recent years to in situ sensing and monitoring of the electron beam melting process, ranging from seminal methods based on infrared imaging to novel methods based on backscattered electron detection. However, the range of available in situ monitoring capabilities and solutions is still quite limited compared to the wide number of studies and industrial toolkits in laser-based additive manufacturing processes. Some methods that are already industrially available in laser powder bed fusion systems, such as in situ detection of recoating errors, have not yet been investigated and tested in electron beam melting. Motivated by the attempt to fill this gap, we present a novel in situ monitoring methodology that can be easily implemented in industrial electron beam melting machines. The method is aimed at identifying local inhomogeneity and irregularities in the powder bed by means of layerwise image acquisition and processing, with no external illumination source apart from the light emitted by the hot material underneath the currently recoated layer. The results show that the proposed approach is suitable to detect powder bed anomalies, while also highlighting the link between the severity of in situ detected errors and the severity of resulting defects in the additively manufactured part.
Concrete Compressive Strength by Means of Ultrasonic Pulse Velocity and Moduli of Elasticity
Authors: Bolborea Bogdan , Baera Cornelia , Dan Sorin , Gruin Aurelian , Burduhos-Nergis Dumitru-Doru , Vasile Vasilica
Published: November 2021

Developing non-destructive methods (NDT) that can deliver faster and more accurate results is an objective pursued by many researchers. The purpose of this paper is to present a new approach in predicting the concrete compressive strength through means of ultrasonic testing for non-destructive determination of the dynamic and static modulus of elasticity. For this study, the dynamic Poisson’s coefficient was assigned values provided by technical literature. Using ultra-sonic pulse velocity (UPV) the apparent density and the dynamic modulus of elasticity were determined. The viability of the theoretical approach proposed by Salman, used for the air-dry density determination (predicted density), was experimentally confirmed (measured density). The calculated accuracy of the Salman method ranged between 98 and 99% for all the four groups of specimens used in the study. Furthermore, the static modulus of elasticity was deducted through a linear relationship between the two moduli of elasticity. Finally, the concrete compressive strength was mathematically determined by using the previously mentioned parameters. The accuracy of the proposed method for concrete compressive strength assessment ranged between 92 and 94%. The precision was established with respect to the destructive testing of concrete cores. For this research, the experimental part was performed on concrete cores extracted from different elements of different structures and divided into four distinct groups. The high rate of accuracy in predicting the concrete compressive strength, provided by this study, exceeds 90% with respect to the reference, and makes this method suitable for further investigations related to both the optimization of the procedure and = the domain of applicability (in terms of structural aspects and concrete mix design, environmental conditions, etc.).
Straw/Spring Teeth Interaction Analysis of Baler Picker in Smart Agriculture via an ADAMS-DEM Coupled Simulation Method
Authors: Wang Qingqing , Bai Ziwen , Li Zhiqiang , Xie Dongbo , Chen Liqing , Wang Hai
Published: November 2021

In this paper, a new coupling simulation method is proposed for baler picker using automatic dynamic analysis of mechanical systems (ADAMS) and discrete element method (DEM). Field tests are carried out to verify the accuracy of the simulation model. By using the coupling method, not only was it obtained that the forward velocity (FV) and the ground clearance of spring teeth (GCST) are positively correlated with the pick-up loss rate (PLR), but also that the blockage of the picker mainly occurs in the straw pushing area, and an optimization plan is proposed. Through the analysis of the acting force (AF) between the roller and the track groove, we speculate that the structure of the track groove in a certain area is defective. The coupling method and optimization scheme proposed in this paper can provide a reference for the optimal design of the picker.
Theoretical Disquisition on the Static and Dynamic Characteristics of an Adaptive Stepped Hydrostatic Thrust Bearing with a Displacement Compensator
Authors: Kodnyanko Vladimir , Kurzakov Andrey , Grigorieva Olga , Brungardt Maxim , Belyakova Svetlana , Gogol Ludmila , Surovtsev Alexey , Strok Lilia
Published: November 2021

Stepped hydrostatic thrust bearings used in metal-cutting machines are characterized by high load capacity and damping, which ensure the stable operation of structures. However, in comparison with throttle thrust bearings, they have a high compliance. It is preferable that, in addition to the main bearing function, a modern hydrostatic bearing has the ability to provide low (including negative) compliance for the implementation of an adaptive function in order to actively compensate for the deformation of the machine resilient system, thereby increasing the accuracy of metalworking. This paper considers the design of a stepped hydrostatic thrust bearing, which, in order to reduce the compliance to negative values, features a technical improvement consisting of the use of an active displacement compensator on an elastic suspension. In this paper, the results of mathematical modeling and theoretical research of stationary and non-stationary modes of operation of the adaptive thrust bearing are presented. The possibility of a significant reduction in the static compliance of the structure, including the negative compliance values, is shown. It was found that negative compliance is provided in a wide range of loads, which can be up to 80% of the range of permissible bearing loads. The study of the dynamic characteristics showed that with a targeted selection of parameters that ensure optimal performance, the adaptive thrust bearing is able to operate stably in the entire range of permissible loads. It has been established that an adaptive stepped hydrostatic thrust bearing with a displacement compensator has a high stability margin, sufficient to ensure its operability when implementing the adaptive function.
Modeling and Verifying the CKB Blockchain Consensus Protocol
Authors: Sun Meng , Lu Yuteng , Feng Yichun , Zhang Qi , Liu Shaoying
Published: November 2021

The Nervos CKB (Common Knowledge Base) is a public permissionless blockchain designed for the Nervos ecosystem. The CKB consensus protocol is the key protocol of the Nervos CKB, which improves the limit of the consensus’s performance for Bitcoin. In this paper, we developed the formal model of the CKB consensus protocol using timed automata. Based on the model, we formally verified various important properties of the Nervos CKB to provide a sufficient trustworthiness assurance. Especially, the security of the Nervos CKB against the selfish mining attacks to the protocol was investigated.
Exploring Latent Topics and Research Trends in Mathematics Teachers’ Knowledge Using Topic Modeling: A Systematic Review
Authors: Hwang Sunghwan , Cho Eunhye
Published: November 2021

Mathematics teachers’ knowledge is considered one of the most critical factors in instruction and student achievement. As such, various studies have focused on mathematics teachers’ knowledge. Despite the expansion of the field, however, a systematic review was rarely implemented. Therefore, this study aimed to identify major research topics and trends on mathematics teachers’ knowledge by analyzing abstracts of 3485 scholarly articles published from 1987 to 2021. Using a text-mining technique, 11 underlying topics were found in the articles. The topics were classified based on their relationships and the following four groups were identified: “assessment”, “teachers’ knowledge for teaching”, “students’ knowledge and understanding”, and “teachers’ professional learning”. Over time, the analysis of research trends showed that professional development is the most popular topic, followed by pedagogical content knowledge and students’ mathematical understanding. Moreover, the popularity of these topics has not changed considerably over time. This study provides implications based on these results.
A Space-Time Fully Decoupled Wavelet Integral Collocation Method with High-Order Accuracy for a Class of Nonlinear Wave Equations
Authors: Weng Jiong , Liu Xiaojing , Zhou Youhe , Wang Jizeng
Published: November 2021

A space-time fully decoupled wavelet integral collocation method (WICM) with high-order accuracy is proposed for the solution of a class of nonlinear wave equations. With this method, wave equations with various nonlinearities are first transformed into a system of ordinary differential equations (ODEs) with respect to the highest-order spatial derivative values at spatial nodes, in which all the matrices in the resulting nonlinear ODEs are constants over time. As a result, these matrices generated in the spatial discretization do not need to be updated in the time integration, such that a fully decoupling between spatial and temporal discretization can be achieved. A linear multi-step method based on the same wavelet approximation used in the spatial discretization is then employed to solve such a semi-discretization system. By numerically solving several widely considered benchmark problems, including the Klein/sine–Gordon equation and the generalized Benjamin–Bona–Mahony–Burgers equation, we demonstrate that the proposed wavelet algorithm possesses much better accuracy and a faster convergence rate than many existing numerical methods. Most interestingly, the space-associated convergence rate of the present WICM is always about order 6 for different equations with various nonlinearities, which is in the same order with direct approximation of a function in terms of the proposed wavelet approximation scheme. This fact implies that the accuracy of the proposed method is almost independent of the equation order and nonlinearity.
The Lymphatic System in Breast Cancer: Anatomical and Molecular Approaches
Authors: Natale Gianfranco , Stouthandel Michael E. J. , Van Hoof Tom , Bocci Guido
Published: November 2021

Breast cancer is one of the most important causes of premature mortality among women and it is one of the most frequently diagnosed tumours worldwide. For this reason, routine screening for prevention and early diagnosis is important for the quality of life of patients. Breast cancer cells can enter blood and lymphatic capillaries, then metastasizing to the regional lymph nodes in the axilla and to both visceral and non-visceral sites. Rather than at the primary site, they seem to enter the systemic circulation mainly through the sentinel lymph node and the biopsy of this indicator can influence the axillary dissection during the surgical approach to the pathology. Furthermore, secondary lymphoedema is another important issue for women following breast cancer surgical treatment or radiotherapy. Considering these fundamental aspects, the present article aims to describe new methodological approaches to assess the anatomy of the lymphatic network in the axillary region, as well as the molecular and physiological control of lymphatic vessel function, in order to understand how the lymphatic system contributes to breast cancer disease. Due to their clinical implications, the understanding of the molecular mechanisms governing lymph node metastasis in breast cancer are also examined. Beyond the investigation of breast lymphatic networks and lymphatic molecular mechanisms, the discovery of new effective anti-lymphangiogenic drugs for future clinical settings appears essential to support any future development in the treatment of breast cancer.
The Use of NaOH Solutions for Fouling Control in a Membrane Bioreactor: A Feasibility Study
Authors: Tomczak Wirginia , Grubecki Ireneusz , Gryta Marek
Published: November 2021

Nowadays, the microbial production of 1,3-propanediol (1,3-PD) is recognized as preferable to the chemical synthesis. However, finding a technological approach allowing the production of 1,3-PD in the membrane bioreactor (MBR) is a great challenge. In the present study, a ceramic ultrafiltration (UF) membrane (8 kDa) for treatment of 1,3-PD broths was used. It has been demonstrated that the membrane used provides the stable permeate flux that is necessary to ensure the stability of the fermentation process in MBR technology. It was noticed that the broth pH has a significant impact on both the final 1,3-PD concentration and permeate flux. Moreover, the feasibility of using NaOH for fouling control in the MBR was evaluated. It has been shown that 1% NaOH solution is effective in restoring the initial membrane performance. To the best of our knowledge, this study is the first to shed light onto the possibility of reducing the amount of the alkaline solutions generated during the MBR operation. Indeed, it has been found that 1% NaOH solution can be successfully used several times for both membrane cleaning and to stabilize the broth pH. Finally, based on the results obtained, the technological conceptions of the MBR technology were designed.
Advances and Applications of Hollow Fiber Nanofiltration Membranes: A Review
Authors: Sewerin Tim , Elshof Maria G. , Matencio Sonia , Boerrigter Marcel , Yu Jimmy , de Grooth Joris
Published: November 2021

Hollow fiber nanofiltration (NF) membranes have gained increased attention in recent years, partly driven by the availability of alternatives to polyamide-based dense separation layers. Moreover, the global market for NF has been growing steadily in recent years and is expected to grow even faster. Compared to the traditional spiral-wound configuration, the hollow fiber geometry provides advantages such as low fouling tendencies and effective hydraulic cleaning possibilities. The alternatives to polyamide layers are typically chemically more stable and thus allow operation and cleaning at more extreme conditions. Therefore, these new NF membranes are of interest for use in a variety of applications. In this review, we provide an overview of the applications and emerging opportunities for these membranes. Next to municipal wastewater and drinking water processes, we have put special focus on industrial applications where hollow fiber NF membranes are employed under more strenuous conditions or used to recover specific resources or solutes.
Islet Biology and Metabolism
Authors: Yau Belinda , Kebede Melkam A.
Published: November 2021

This Special Issue, Islet Biology and Metabolism, was intended as a collection of studies highlighting the importance of the pancreatic islet—in both form and function—to our growing understanding of metabolic physiology and disease [...]
Central and Peripheral Oxygen Distribution in Two Different Modes of Interval Training
Authors: Ksoll Korbinian Sebastian Hermann , Mühlberger Alexander , Stöcker Fabian
Published: November 2021

In high-intensity interval training the interval duration can be adjusted to optimize training results in oxygen uptake, cardiac output, and local oxygen supply. This study aimed to compare these variables in two interval trainings (long intervals HIIT3m: 3 min work, 3 min active rest vs. short intervals HIIT30s: 30 s work, 30 s active rest) at the same overall work rate and training duration. 24 participants accomplished both protocols, (work: 80% power output at VO2peak, relief: 85% power output at gas exchange threshold) in randomized order. Spirometry, impedance cardiography, and near-infrared spectroscopy were used to analyze the physiological stress of the cardiopulmonary system and muscle tissue. Although times above gas exchange threshold were shorter in HIIT3m (HIIT3m 1669.9 ± 310.9 s vs. HIIT30s 1769.5 ± 189.0 s, p = 0.034), both protocols evoked similar average fractional utilization of VO2peak (HIIT3m 65.23 ± 4.68% VO2peak vs. HIIT30s 64.39 ± 6.78% VO2peak, p = 0.261). However, HIIT3m resulted in higher cardiovascular responses during the loaded phases (VO2p < 0.001, cardiac output p < 0.001). Local hemodynamics were not different between both protocols. Average physiological responses were not different in both protocols owning to incomplete rests in HIIT30s and large response amplitudes in HIIT3m. Despite lower acute cardiovascular stress in HIIT30s, short submaximal intervals may also trigger microvascular and metabolic adaptions similar to HIIT3m. Therefore, the adaption of interval duration is an important tool to adjust the goals of interval training to the needs of the athlete or patient.
Feature-Based Molecular Networking—An Exciting Tool to Spot Species of the Genus Cortinarius with Hidden Photosensitizers
Authors: Hammerle Fabian , Quirós-Guerrero Luis , Rutz Adriano , Wolfender Jean-Luc , Schöbel Harald , Peintner Ursula , Siewert Bianka
Published: November 2021

Fungi have developed a wide array of defense strategies to overcome mechanical injuries and pathogen infections. Recently, photoactivity has been discovered by showing that pigments isolated from Cortinarius uliginosus produce singlet oxygen under irradiation. To test if this phenomenon is limited to dermocyboid Cortinarii, six colourful Cortinarius species belonging to different classical subgenera (i.e., Dermocybe, Leprocybe, Myxacium, Phlegmacium, and Telamonia) were investigated. Fungal extracts were explored by the combination of in vitro photobiological methods, UHPLC coupled to high-resolution tandem mass spectrometry (UHPLC-HRMS2), feature-based molecular networking (FBMN), and metabolite dereplication techniques. The fungi C. rubrophyllus (Dermocybe) and C. xanthophyllus (Phlegmacium) exhibited promising photobiological activity in a low concentration range (1–7 µg/mL). Using UHPLC-HRMS2-based metabolomic tools, the underlying photoactive principle was investigated. Several monomeric and dimeric anthraquinones were annotated as compounds responsible for the photoactivity. Furthermore, the results showed that light-induced activity is not restricted to a single subgenus, but rather is a trait of Cortinarius species of different phylogenetic lineages and is linked to the presence of fungal anthraquinones. This study highlights the genus Cortinarius as a promising source for novel photopharmaceuticals. Additionally, we showed that putative dereplication of natural photosensitizers can be done by FBMN.
Studying Corrosion Using Miniaturized Particle Attached Working Electrodes and the Nafion Membrane
Authors: Son Jiyoung , Buck Edgar C. , Riechers Shawn L. , Tripathi Shalini , Strange Lyndi E. , Engelhard Mark H. , Yu Xiao-Ying
Published: November 2021

We developed a new approach to attach particles onto a conductive layer as a working electrode (WE) in a microfluidic electrochemical cell with three electrodes. Nafion, an efficient proton transfer molecule, is used to form a thin protection layer to secure particle electrodes. Spin coating is used to develop a thin and even layer of Nafion membrane. The effects of Nafion (5 wt% 20 wt%) and spinning rates were evaluated using multiple sets of replicates. The electrochemical performance of various devices was demonstrated. Additionally, the electrochemical performance of the devices is used to select and optimize fabrication conditions. The results show that a higher spinning rate and a lower Nafion concentration (5 wt%) induce a better performance, using cerium oxide (CeO2) particles as a testing model. The WE surfaces were characterized using atomic force microscopy (AFM), scanning electron microscopy-focused ion beam (SEM-FIB), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and X-ray photoelectron spectroscopy (XPS). The comparison between the pristine and corroded WE surfaces shows that Nafion is redistributed after potential is applied. Our results verify that Nafion membrane offers a reliable means to secure particles onto electrodes. Furthermore, the electrochemical performance is reliable and reproducible. Thus, this approach provides a new way to study more complex and challenging particles, such as uranium oxide, in the future.
Wavelet Frequency Separation Attention Network for Chest X-ray Image Super-Resolution
Authors: Yu Yue , She Kun , Liu Jinhua
Published: November 2021

Medical imaging is widely used in medical diagnosis. The low-resolution image caused by high hardware cost and poor imaging technology leads to the loss of relevant features and even fine texture. Obtaining high-quality medical images plays an important role in disease diagnosis. A surge of deep learning approaches has recently demonstrated high-quality reconstruction for medical image super-resolution. In this work, we propose a light-weight wavelet frequency separation attention network for medical image super-resolution (WFSAN). WFSAN is designed with separated-path for wavelet sub-bands to predict the wavelet coefficients, considering that image data characteristics are different in the wavelet domain and spatial domain. In addition, different activation functions are selected to fit the coefficients. Inputs comprise approximate sub-bands and detail sub-bands of low-resolution wavelet coefficients. In the separated-path network, detail sub-bands, which have more sparsity, are trained to enhance high frequency information. An attention extension ghost block is designed to generate the features more efficiently. All results obtained from fusing layers are contracted to reconstruct the approximate and detail wavelet coefficients of the high-resolution image. In the end, the super-resolution results are generated by inverse wavelet transform. Experimental results show that WFSAN has competitive performance against state-of-the-art lightweight medical imaging methods in terms of quality and quantitative metrics.
Evanescent Field Controllable MZ Sensor via Femtosecond Laser Processing and Mechanic Polishing
Authors: Zhang Zong-Da , Duan Yan-Zhao , Guo Qi , Gao Si , Gao Bing-Rong
Published: November 2021

Recently, optical sensors interacting with evanescent fields and the external environment around waveguides have attracted extensive attention. In the process of light propagation in the waveguide, the depth of the evanescent field is closely related to the accuracy of the optical sensor, and adjusting the depth of the evanescent field to obtain higher accuracy has become the primary challenge in fabricating on-chip optical sensors. In this study, the waveguide structure of a Mach–Zehnder interferometer was written directly in Corning Eagle 2000 borosilicate glass by a femtosecond laser, and the sensing window was exposed out of the bulk material by mechanical polishing. The refractive index detection device based on the proposed on-chip Mach–Zehnder interferometer has the advantages of small volume, light weight, and good stability. Its sensitivity can reach 206 nm/RIU or 337 dB/RIU, and the theoretical maximum measurement range is 1–1.508. Therefore, it can measure the refractive index quickly and accurately in extreme or complex environments, and has excellent application prospects.
Colorimetric Sensing with Gold Nanoparticles on Electrowetting-Based Digital Microfluidics
Authors: Gu Zhen , Luo Jing-Jing , Ding Le-Wei , Yan Bing-Yong , Zhou Jia-Le , Wang Jun-Gang , Wang Hui-Feng , Kong Cong
Published: November 2021

Digital microfluidic (DMF) has been a unique tool for manipulating micro-droplets with high flexibility and accuracy. To extend the application of DMF for automatic and in-site detection, it is promising to introduce colorimetric sensing based on gold nanoparticles (AuNPs), which have advantages including high sensitivity, label-free, biocompatibility, and easy surface modification. However, there is still a lack of studies for investigating the movement and stability of AuNPs for in-site detection on the electrowetting-based digital microfluidics. Herein, to demonstrate the ability of DMF for colorimetric sensing with AuNPs, we investigated the electrowetting property of the AuNPs droplets on the hydrophobic interface of the DMF chip and examined the stability of the AuNPs on DMF as well as the influence of evaporation to the colorimetric sensing. As a result, we found that the electrowetting of AuNPs fits to a modified Young–Lippmann equation, which suggests that a higher voltage is required to actuate AuNPs droplets compared with actuating water droplets. Moreover, the stability of AuNPs was maintained during the processing of electrowetting. We also proved that the evaporation of droplets has a limited influence on the detections that last several minutes. Finally, a model experiment for the detection of Hg2+ was carried out with similar results to the detections in bulk solution. The proposed method can be further extended to a wide range of AuNPs-based detection for label-free, automatic, and low-cost detection of small molecules, biomarkers, and metal ions.
Synthesis and Characteristics of Double-Shell Mesoporous Hollow Silica Nanomaterials to Improve CO2 Adsorption Performance
Authors: Lee Jong-tak , Bae Jae-Young
Published: November 2021

To improve the adsorption performance of carbon dioxide, which is considered the main culprit of greenhouse gases, the specific surface area and high pore volume of the adsorbing material should be considered. For a porous material, the performance of carbon dioxide adsorption is determined by the amine groups supporting capacity; the larger the pore volume, the greater the capacity to support the amine groups. In this study, a double-shell mesoporous hollow silica nanomaterial with excellent pore volume and therefore increased amine support capacity was synthesized. A core–shell structure capable of having a hollow shape was synthesized using polystyrene as a core material, and a double-shell mesoporous shape was synthesized by sequentially using two types of surfactants. The synthesized material was subjected to a sintering process of 600 degrees, and the N2 sorption analysis confirmed a specific surface area of 690 m2/g and a pore volume of 1.012 cm3/g. Thereafter, the amine compound was impregnated into the silica nanomaterial, and then, a carbon dioxide adsorption experiment was conducted, which confirmed that compared to the mesoporous hollow silica nanomaterial synthesized as a single shell, the adsorption performance was improved by about 1.36 times.
Bacterial Morphotypes as Important Trait for Uropathogenic E. coli Diagnostic; a Virulence-Phenotype-Phylogeny Study
Authors: Ballesteros-Monrreal Manuel G. , Arenas-Hernández Margarita M. P. , Barrios-Villa Edwin , Juarez Josue , Álvarez-Ainza Maritza Lizeth , Taboada Pablo , De la Rosa-López Rafael , Bolado-Martínez Enrique , Valencia Dora
Published: November 2021

Urinary tract infections (UTIs) belong to the most common pathologies in Mexico and are mainly caused by Uropathogenic Escherichia coli (UPEC). UPEC possesses a wide diversity of virulence factors that allow it to carry out its pathogenesis mechanism in the urinary tract (UT). The development of morphotypes in UT represents an important feature of UPEC because it is associated with complications in diagnosis of UTI. The aim of this study was to determine the presence of bacterial morphotypes, virulence genes, virulence phenotypes, antibiotic resistant, and phylogenetic groups in clinical isolates of UPEC obtained from women in Sonora, Mexico. Forty UPEC isolates were obtained, and urine morphotypes were observed in 65% of the urine samples from where E. coli was isolated. Phylogenetic group B2 was the most prevalent. The most frequent virulence genes were fimH (100%), fliCD (90%), and sfaD/focC (72%). Biofilm formation (100%) and motility (98%) were the most prevalent phenotypes. Clinical isolates showed high resistance to aminoglycosides and β-lactams antibiotics. These data suggest that the search for morphotypes in urine sediment must be incorporated in the urinalysis procedure and also that clinical isolates of UPEC in this study can cause upper, lower, and recurrent UTI.
Assessment of Oral Microbiome Changes in Healthy and COVID-19-Affected Pregnant Women: A Narrative Review
Authors: Butera Andrea , Maiorani Carolina , Morandini Annalaura , Simonini Manuela , Colnaghi Arianna , Morittu Stefania , Barbieri Stefania , Ricci Maria , Guerrisi Gaetano , Piloni Daniela , Cimarossa Roberta , Fusaro Barbara , Sinesi Antonia , Bruni Ambra , Scribante Andrea
Published: November 2021

During pregnancy, there are several metabolic changes and an alteration in the composition of microorganisms that inhabit the oral cavity, with an increase in pathogenic bacteria that promote the onset of gingival diseases. This review is based on research in reference to the PICO model (Problem/Intervention/Comparison/Outcome), related to changes in the oral microbiome of pregnant women and possible oral consequences in patients with COVID-19. The results showed a growth of some pathogenic bacteria in pregnant women, including Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum, and the selective growth of the Prevotella intermedia, Porphyromonas gingivalis and Tannerella species, probably due to the fact that these bacteria use progesterone as a source of nutrition. These same bacteria are implicated in the development of periodontal disease. Periodontal pockets have bidirectional interactions between the oral cavity and the systemic circulatory system through the peripheral gingival blood vessels. The affinity of the SARS-CoV-2 virus to specific membrane receptors is now clear, and could involve the internal and external epithelial lining or the fibroblasts of the periodontal ligament. According to the results of the present review, the control of oral microbiome changes during pregnancy would be welcomed. The use of probiotics could help clinicians manage pregnant patients, reducing inflammatory indexes. Future studies should focus not only on changes in the level of the oral microbiome in pregnancy or the correlation between periodontal disease and COVID-19, but also on oral changes induced by both clinical situations.
Bacterial Communities in the Embryo of Maize Landraces: Relation with Susceptibility to Fusarium Ear Rot
Authors: Passera Alessandro , Follador Alessia , Morandi Stefano , Miotti Niccolò , Ghidoli Martina , Venturini Giovanni , Quaglino Fabio , Brasca Milena , Casati Paola , Pilu Roberto , Bulgarelli Davide
Published: November 2021

Locally adapted maize accessions (landraces) represent an untapped resource of nutritional and resistance traits for breeding, including the shaping of distinct microbiota. Our study focused on five different maize landraces and a reference commercial hybrid, showing different susceptibility to fusarium ear rot, and whether this trait could be related to particular compositions of the bacterial microbiota in the embryo, using different approaches. Our cultivation-independent approach utilized the metabarcoding of a portion of the 16S rRNA gene to study bacterial populations in these samples. Multivariate statistical analyses indicated that the microbiota of the embryos of the accessions grouped in two different clusters: one comprising three landraces and the hybrid, one including the remaining two landraces, which showed a lower susceptibility to fusarium ear rot in field. The main discriminant between these clusters was the frequency of Firmicutes, higher in the second cluster, and this abundance was confirmed by quantification through digital PCR. The cultivation-dependent approach allowed the isolation of 70 bacterial strains, mostly Firmicutes. In vivo assays allowed the identification of five candidate biocontrol strains against fusarium ear rot. Our data revealed novel insights into the role of the maize embryo microbiota and set the stage for further studies aimed at integrating this knowledge into plant breeding programs.
Geology and Geochemistry of Selected Gold Deposits in the Ailaoshan Metallogenic Belt, China: Origin of Ore-Forming Fluids
Authors: Li Yang , Wang Denghong , Wang Chenghui , Sun Yan , Pu-chi MIMA
Published: November 2021

The formation of the Ailaoshan metallogenic belt was the result of: the Neoproterozoic super mantle plume, the Indosinian and South China blocks in the Late Triassic after the Paleo-Tethys Ocean closure, and Oligocene-Eocene continental-scale shearing related to the India-Eurasia collision. It is one of the most important Cenozoic gold ore province in the world. In this paper, the geological characteristics, isotopic geochemistry, and geochemical data of ore-forming fluids of four large-scale gold deposits in the Ailaoshan metallogenic belt (Mojiang Jinchang, Zhenyuan Laowangzhai, Yuanyang Daping, and Jinping Chang’an) are comprehensively compared. The features of host-rock alteration, metallogenetic periods and stages, geochronology, fluid inclusion, and C-H-O-S-Pb isotopes of gold deposits are summarized and analyzed. The gold mineralization in the Ailaoshan metallogenic belt occurred mostly in 50–30 Ma, belonging to the Himalayan period. The gold mineralization is closely related to silicification, argillation, carbonation, and pyritization due to the strong mineralization of hydrothermal fluid, the development of alteration products, and the inconspicuous spatial zonation of alteration types. The ore-forming fluid is mainly composed of mantle fluid (magmatic water) and metamorphic fluid (metamorphic water). The ore-forming materials of the Jinchang, Chang’an, and Laowangzhai gold deposits mainly originate the host-rock strata of the mining area, and the carbon is more likely to from marine carbonate. The carbon in the Daping gold deposit from the original magma formed by the partial melting of the mantle. Pb isotopes have characteristics of crustal origin, accompanied by mixing of mantle-derived materials and multisource sulfur mixing, and are strongly homogenized.
Editorial for Special Issue “U-Pb Dating and Chemistry of Zircon in Metamorphic, Magmatic and Sedimentary Rocks”
Authors: Fornelli Annamaria , Micheletti Francesca
Published: November 2021

This Special Issue was conceived with the aim of contributing to disclosure of the applications of U-Pb dating and zircon chemistry for deciphering the growth and the evolution of the continental crust [...]
Replacing Fossil Carbon in the Production of Ferroalloys with a Focus on Bio-Based Carbon: A Review
Authors: Sommerfeld Marcus , Friedrich Bernd
Published: November 2021

The production of ferroalloys and alloys like ferronickel, ferrochromium, ferromanganese, silicomanganese, ferrosilicon and silicon is commonly carried out in submerged arc furnaces. Submerged arc furnaces are also used to upgrade ilmenite by producing pig iron and a titania-rich slag. Metal containing resources are smelted in this furnace type using fossil carbon as a reducing agent, which is responsible for a large amount of direct CO2 emissions in those processes. Instead, renewable bio-based carbon could be a viable direct replacement of fossil carbon currently investigated by research institutions and companies to lower the CO2 footprint of produced alloys. A second option could be the usage of hydrogen. However, hydrogen has the disadvantages that current production facilities relying on solid reducing agents need to be adjusted. Furthermore, hydrogen reduction of ignoble metals like chromium, manganese and silicon is only possible at very low H2O/H2 partial pressure ratios. The present article is a comprehensive review of the research carried out regarding the utilization of bio-based carbon for the processing of the mentioned products. Starting with the potential impact of the ferroalloy industry on greenhouse gas emissions, followed by a general description of bio-based reducing agents and unit operations covered by this review, each following chapter presents current research carried out to produce each metal. Most studies focused on pre-reduction or solid-state reduction except the silicon industry, which instead had a strong focus on smelting up to an industrial-scale and the design of bio-based carbon for submerged arc furnace processes. Those results might be transferable to other submerged arc furnace processes as well and could help to accelerate research to produce other metals. Deviations between the amount of research and scale of tests for the same unit operation but different metal resources were identified and closer cooperation could be helpful to transfer knowledge from one area to another. Life cycle assessment to produce ferronickel and silicon already revealed the potential of bio-based reducing agents in terms of greenhouse gas emissions, but was not carried out for other metals until now.