bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomic Analysis of Multidrug-Resistant Hypervirulent (Hypermucoviscous) Klebsiella pneumoniae Strain Lacking the Hypermucoviscous Regulators (rmpA/rmpA2)
Authors: Altayb Hisham N. , Elbadawi Hana S. , Baothman Othman , Kazmi Imran , Alzahrani Faisal A. , Nadeem Muhammad Shahid , Hosawi Salman , Chaieb Kamel
Published: April 2022

Hypervirulent K. pneumoniae (hvKP) strains possess distinct characteristics such as hypermucoviscosity, unique serotypes, and virulence factors associated with high pathogenicity. To better understand the genomic characteristics and virulence profile of the isolated hvKP strain, genomic data were compared to the genomes of the hypervirulent and typical K. pneumoniae strains. The K. pneumoniae strain was isolated from a patient with a recurrent urinary tract infection, and then the string test was used for the detection of the hypermucoviscosity phenotype. Whole-genome sequencing was conducted using Illumina, and bioinformatics analysis was performed for the prediction of the isolate resistome, virulome, and phylogenetic analysis. The isolate was identified as hypermucoviscous, type 2 (K2) capsular polysaccharide, ST14, and multidrug-resistant (MDR), showing resistance to ciprofloxacin, ceftazidime, cefotaxime, trimethoprim-sulfamethoxazole, cephalexin, and nitrofurantoin. The isolate possessed four antimicrobial resistance plasmids (pKPN3-307_type B, pECW602, pMDR, and p3K157) that carried antimicrobial resistance genes (ARGs) (blaOXA-1,blaCTX-M-15, sul2, APH(3″)-Ib, APH(6)-Id, and AAC(6′)-Ib-cr6). Moreover, two chromosomally mediated ARGs (fosA6 and SHV-28) were identified. Virulome prediction revealed the presence of 19 fimbrial proteins, one aerobactin (iutA) and two salmochelin (iroE and iroN). Four secretion systems (T6SS-I (13), T6SS-II (9), T6SS-III (12), and Sci-I T6SS (1)) were identified. Interestingly, the isolate lacked the known hypermucoviscous regulators (rmpA/rmpA2) but showed the presence of other RcsAB capsule regulators (rcsA and rcsB). This study documented the presence of a rare MDR hvKP with hypermucoviscous regulators and lacking the common capsule regulators, which needs more focus to highlight their epidemiological role.
Editorial for the Special Issue: “Antibiotic Use in Clinical Infection: How to Reinvent Old Molecules and How to Squeeze out New Ones”
Authors: Di Bella Stefano
Published: April 2022

The optimization of a number of strategies is required to overcome the problem of antibiotic resistance [...]
Antimicrobial Resistance Patterns and Clonal Distribution of E. coli, Enterobacter spp. and Acinetobacter spp. Strains Isolated from Two Hospital Wastewater Plants
Authors: Galarde-López Miguel , Velazquez-Meza Maria Elena , Bobadilla-del-Valle Miriam , Cornejo-Juárez Patricia , Carrillo-Quiroz Berta Alicia , Ponce-de-León Alfredo , Sassoé-González Alejandro , Saturno-Hernández Pedro , Alpuche-Aranda Celia Mercedes
Published: April 2022

The objective of this study was to determine the presence and persistence of antimicrobial-resistant enterobacteria and their clonal distribution in hospital wastewater. A descriptive cross-sectional study was carried out in wastewater from two Mexico City tertiary level hospitals. In February and March of 2020, eight wastewater samples were collected and 26 isolates of enterobacteria were recovered, 19 (73.1%) isolates were identified as E. coli, 5 (19.2%) as Acinetobacter spp. and 2 (7.7%) as Enterobacter spp. Antimicrobial susceptibility profiles were performed using the VITEK 2® automated system and bacterial identification was performed by the Matrix-Assisted Laser Desorption/Ionization-Time of Flight mass spectrometry (MALDI-TOF MS®). ESBL genes were detected by polymerase chain reaction (PCR) and clonal distributions of isolates were determined by pulsed-field gel electrophoresis (PFGE). E. coli susceptibility to different classes of antimicrobials was analyzed and resistance was mainly detected as ESBLs and fluoroquinolones. One E. coli strain was resistant to doripenem, ertapenem, imipenem and meropenem. The analysis by PCR showed the presence of specific β-lactamases resistance genes (blaKPC, blaCTX-M). The PFGE separated the E. coli isolates into 19 different patterns (A–R). PFGE results of Acinetobacter spp. showed the presence of a majority clone A. Surveillance of antimicrobial resistance through hospital wastewater is an important tool for early detection of clonal clusters of clinically important bacteria with potential for dissemination.
Ceftazidime–Avibactam in Combination with Imipenem as Salvage Therapy for ST11 KPC-33-Producing Klebsiella pneumoniae
Authors: Ding Li , Shen Siquan , Han Renru , Yin Dandan , Guo Yan , Hu Fupin
Published: April 2022

A 22-year-old man, after a hematopoietic stem cell transplant, suffered long-term pneumonia caused by blaKPC-2-positive K. pneumoniae and blaKPC-33-positive K. pneumoniae alternately and finally achieved pathogenic clearance and improvement of clinical infectious conditions after using ceftazidime–avibactam in combination with imipenem as salvage therapy. This case provides a reference for treating infection caused by K. pneumoniae with a KPC variant in countries lacking new antimicrobial agents.
Rhamnolipid Nano-Micelles versus Alcohol-Based Hand Sanitizer: A Comparative Study for Antibacterial Activity against Hospital-Acquired Infections and Toxicity Concerns
Authors: Abo-zeid Yasmin , Bakkar Marwa Reda , Elkhouly Gehad E. , Raya Nermeen R. , Zaafar Dalia
Published: April 2022

Hospital-acquired infections (HAIs) are considered to be a major global healthcare challenge, in large part because of the development of microbial resistance to currently approved antimicrobial drugs. HAIs are frequently preventable through infection prevention and control measures, with hand hygiene as a key activity. Improving hand hygiene was reported to reduce the transmission of healthcare-associated pathogens and HAIs. Alcohol-based hand sanitizers are commonly used due to their rapid action and broad spectrum of microbicidal activity, offering protection against bacteria and viruses. However, their frequent administration has been reported to be associated with many side effects, such as skin sensitivity, skin drying, and cracks, which promote further skin infections. Thus, there is an essential need to find alternative approaches to hand sanitation. Rhamnolipids are glycolipids produced by Pseudomonas aeruginosa, and were shown to have broad antimicrobial activity as biosurfactants. We have previously demonstrated the antimicrobial activity of rhamnolipid nano-micelles against selected drug-resistant Gram-negative (Salmonella Montevideo and Salmonella Typhimurium) and Gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae). To the best of our knowledge, the antimicrobial activity of rhamnolipid nano-micelles in comparison to alcohol-based hand sanitizers against microorganisms commonly causing HAIs in Egypt—such as Acinetobacter baumannii and Staphylococcus aureus—has not yet been studied. In the present work, a comparative study of the antibacterial activity of rhamnolipid nano-micelles versus alcohol-based hand sanitizers was performed, and their safety profiles were also assessed. It was demonstrated that rhamnolipid nano-micelles had a comparable antibacterial activity to alcohol-based hand sanitizer, with a better safety profile, i.e., rhamnolipid nano-micelles are unlikely to cause any harmful effects on the skin. Thus, rhamnolipid nano-micelles could be recommended to replace alcohol-based hand sanitizers; however, they must still be tested by healthcare workers in healthcare settings to ascertain their antimicrobial activity and safety.
Dietary Tryptophan Supplementation Improves Antioxidant Status and Alleviates Inflammation, Endoplasmic Reticulum Stress, Apoptosis, and Pyroptosis in the Intestine of Piglets after Lipopolysaccharide Challenge
Authors: Liu Guangmang , Tao Jingyuan , Lu Jiajia , Jia Gang , Zhao Hua , Chen Xiaoling , Tian Gang , Cai Jingyi , Zhang Ruinan , Wang Jing
Published: April 2022

Tryptophan can alleviate stress and improve intestinal health, but the precise mechanism has not been fully elucidated. This study aimed to examine the effects of tryptophan supplementation on antioxidant status, inflammation, endoplasmic reticulum (ER) stress, apoptosis, and pyroptosis signaling pathway in the intestine of piglets after Escherichia coli lipopolysaccharide (LPS) challenge. Thirty-two weaning piglets were allotted to four treatments including: non-challenged control, LPS-challenged control, LPS + 0.2% tryptophan and LPS + 0.4% tryptophan. On day 35 of feeding, piglets were injected intraperitoneally with 100 μg/kg of body weight LPS or saline. Among the LPS-challenged pigs, tryptophan supplementation improved intestinal morphology as indicated by greater villus height, villus area and smaller crypt depth, and antioxidant status, and decreased the mRNA expression and concentration of proinflammatory cytokines. Moreover, tryptophan downregulated the expression of ER stress (ER oxidoreductase-1α, ER oxidoreductase-1β, glucose-regulated protein-78, activating transcription factor 6, C/EBP homologous protein), apoptosis (B-cell lymphoma-2, BCL2-associated X protein, caspase 3), and pyroptosis signaling pathway (nucleotide-binding oligomerization domain-like receptor protein 3, caspase 1, gasdermin-D, apoptosis-associated speck-like protein containing a CARD). Collectively, tryptophan supplementation can contribute to gut health by improving antioxidant status and alleviating inflammation, ER stress, apoptosis, and pyroptosis in the intestine of piglets after lipopolysaccharide challenge.
New Progress in the Molecular Regulations and Therapeutic Applications in Cardiac Oxidative Damage Caused by Pressure Overload
Authors: Shi Xiaomeng , Dorsey Arin , Qiu Hongyu
Published: April 2022

Chronic pressure overload is a key risk factor for mortality due to its subsequent development of heart failure, in which the underlying molecular mechanisms remain vastly undetermined. In this review, we updated the latest advancements for investigating the role and relevant mechanisms of oxidative stress involved in the pathogenesis of pressure-overload-induced cardiomyopathy and cardiac dysfunction, focusing on significant biological sources of reactive oxygen species (free radical) production, antioxidant defenses, and their association with the cardiac metabolic remodeling in the stressed heart. We also summarize the newly developed preclinical therapeutic approaches in animal models for pressure-overload-induced myocardial damage. This review aims to enhance the current understanding of the mechanisms of chronic hypertensive heart failure and potentially improve the development of better therapeutic strategies for the associated diseases.
Clinical and Preclinical Studies of Fermented Foods and Their Effects on Alzheimer’s Disease
Authors: Kumar Muganti Rajah , Azizi Nor Farahin , Yeap Swee Keong , Abdullah Janna Ong , Khalid Melati , Omar Abdul Rahman , Osman Mohd. Azuraidi , Leow Adam Thean Chor , Mortadza Sharifah Alawieyah Syed , Alitheen Noorjahan Banu
Published: April 2022

The focus on managing Alzheimer’s disease (AD) is shifting towards prevention through lifestyle modification instead of treatments since the currently available treatment options are only capable of providing symptomatic relief marginally and result in various side effects. Numerous studies have reported that the intake of fermented foods resulted in the successful management of AD. Food fermentation is a biochemical process where the microorganisms metabolize the constituents of raw food materials, giving vastly different organoleptic properties and additional nutritional value, and improved biosafety effects in the final products. The consumption of fermented foods is associated with a wide array of nutraceutical benefits, including anti-oxidative, anti-inflammatory, neuroprotective, anti-apoptotic, anti-cancer, anti-fungal, anti-bacterial, immunomodulatory, and hypocholesterolemic properties. Due to their promising health benefits, fermented food products have a great prospect for commercialization in the food industry. This paper reviews the memory and cognitive enhancement and neuroprotective potential of fermented food products on AD, the recently commercialized fermented food products in the health and food industries, and their limitations. The literature reviewed here demonstrates a growing demand for fermented food products as alternative therapeutic options for the prevention and management of AD.
Essential Oils, Phytoncides, Aromachology, and Aromatherapy—A Review
Authors: Thangaleela Subramanian , Sivamaruthi Bhagavathi Sundaram , Kesika Periyanaina , Bharathi Muruganantham , Kunaviktikul Wipada , Klunklin Areewan , Chanthapoon Chatnithit , Chaiyasut Chaiyavat
Published: April 2022

Chemical compounds from plants have been used as a medicinal source for various diseases. Aromachology is a unique field that studies the olfactory effects after inhaling aromatic compounds. Aromatherapy is a complementary treatment methodology involving the use of essential oils containing phytoncides and other volatile organic compounds for various physical and mental illnesses. Phytoncides possess an inherent medicinal property. Their health benefits range from treating stress, immunosuppression, blood pressure, respiratory diseases, anxiety, and pain to anti-microbial, anti-larvicidal, anti-septic, anti-cancer effects, etc. Recent advancements in aromatherapy include forest bathing or forest therapy. The inhalation of phytoncide-rich forest air has been proven to reduce stress-induced immunosuppression, normalize immune function and neuroendocrine hormone levels, and, thus, restore physiological and psychological health. The intricate mechanisms related to how aroma converts into olfactory signals and how the olfactory signals relieve physical and mental illness still pose enormous questions and are the subject of ongoing research. Aromatherapy using the aroma of essential oils/phytoncides could be more innovative and attractive to patients. Moreover, with fewer side effects, this field might be recognized as a new field of complementary medicine in alleviating some forms of physical and mental distress. Essential oils are important assets in aromatherapy, cosmetics, and food preservatives. The use of essential oils as an aromatherapeutic agent is widespread. Detailed reports on the effects of EOs in aromatherapy and their pharmacological effects are required to uncover its complete biological mechanism. This review is about the evolution of research related to phytoncides containing EOs in treating various ailments and provides comprehensive details from complementary medicine.
Effect of Wing Membrane Material on the Aerodynamic Performance of Flexible Flapping Wing
Authors: Lang Xinyu , Song Bifeng , Yang Wenqing , Yang Xiaojun
Published: April 2022

Flexible deformation of the insect wing has been proven to be beneficial to lift generation and power consumption. There is great potential for shared research between natural insects and bio-inspired Flapping wing Micro Aerial Vehicles (FWMAVs) for performance enhancement. However, the aerodynamic characteristics and deformation process of the flexible flapping wing, especially influenced by wing membrane material, are still lacking in-depth understanding. In this study, the flexible flapping wings with different membrane materials have been experimentally investigated. Power input and lift force were measured to evaluate the influence of membrane material. The rotation angles at different wing sections were extracted to analyze the deformation process. It was found that wings with higher elastic modulus membrane could generate more lift but at the cost of more power. A lower elastic modulus means the wing is more flexible and shows an advantage in power loading. Twisting deformation is more obvious for the wing with higher flexibility. Additionally, flexibility is also beneficial to attenuate the rotation angle fluctuation, which in turn enhances the aerodynamic efficiency. The research in this paper is helpful to further understand the aerodynamic characteristics of flexible flapping wing and to design bio-inspired FWMAVs with higher performance.
X-Transformer: A Machine Translation Model Enhanced by the Self-Attention Mechanism
Authors: Liu Huey-Ing , Chen Wei-Lin
Published: April 2022

Machine translation has received significant attention in the field of natural language processing not only because of its challenges but also due to the translation needs that arise in the daily life of modern people. In this study, we design a new machine translation model named X-Transformer, which refines the original Transformer model regarding three aspects. First, the model parameter of the encoder is compressed. Second, the encoder structure is modified by adopting two layers of the self-attention mechanism consecutively and reducing the point-wise feed forward layer to help the model understand the semantic structure of sentences precisely. Third, we streamline the decoder model size, while maintaining the accuracy. Through experiments, we demonstrate that having a large number of decoder layers not only affects the performance of the translation model but also increases the inference time. The X-Transformer reaches the state-of-the-art result of 46.63 and 55.63 points in the BiLingual Evaluation Understudy (BLEU) metric of the World Machine Translation (WMT), from 2014, using the English–German and English–French translation corpora, thus outperforming the Transformer model with 19 and 18 BLEU points, respectively. The X-Transformer significantly reduces the training time to only 1/3 times that of the Transformer. In addition, the heat maps of the X-Transformer reach token-level precision (i.e., token-to-token attention), while the Transformer model remains at the sentence level (i.e., token-to-sentence attention).
Identification of the Critical Enablers for Perishable Food Supply Chain Using Deterministic Assessment Models
Authors: Karanam Malleswari , Krishnanand Lanka , Manupati Vijaya Kumar , Antosz Katarzyna , Machado Jose
Published: April 2022

Today’s perishable food supply chains must be resilient to handle volatile demands, environmental restrictions, and disruptions in order to meet customers’ requirements. The enablers of the perishable food supply chain have not yet been explored. In this paper, a bibliometric systematic literature review has been conducted to identify the articles related to the perishable food supply chain. Next, with these identified articles, a map is created with bibliographic data using Vosviewer network visualization software, and then the enablers were identified by conducting keyword co-occurrence analysis. Later, a total interpretive structural modeling (TISM) is employed to analyze the interrelationships among enablers and then determine each enabler’s hierarchies, further representing them in a diagraph. Finally, the identified enablers are classified using cross-impact matrix multiplication applied to classification (MICMAC) analysis, and the graph is plotted. The results obtained from the deterministic assessment model provide the critical enablers for the perishable food supply chain. The obtained critical enablers and their hierarchies provide valuable insights for researchers in the context of perishable food supply chain for further study.
Optimization of the Battery Pack Heat Dissipation Structure of a Battery-Type Loader
Authors: Yi Shengxian , Yang Zhongjiong , Cheng Yu , Xie Huangxin
Published: April 2022

The development of a battery-type loader is an important research direction in the field of industrial mining equipment. In the energy system, the battery will inevitably encounter the problem of heat dissipation when using high-power electricity. In this study, we took the power battery pack of a 3 m3 battery-type underground loader as the research object. The influence of single factors, such as the position of the air outlet of the battery pack, the size of the air outlet, the width of the separator, and the reverse plate, on the heat dissipation characteristics of the battery pack were studied. Then, a prediction model between the structural parameters and temperature was established using a radial basis function (RBF) neural network. This prediction model was then used as an adaptation evaluation model for global optimization through the multiobjective particle swarm optimization (PSO) algorithm, using which the optimal combination of structural parameters was obtained. The maximum temperature of the battery pack after optimization was reduced by 22%, compared to that before optimization, and the average temperature was reduced by 12.5%. Overall, the heat dissipation effect significantly improved. The optimization results indicate that the method proposed in this paper is feasible for use in optimizing battery heat dissipation systems in electric vehicles, thus providing a reference for research related to battery pack heat dissipation.
Hydro-Mechanically Coupled Numerical Modelling on Vibratory Open-Ended Pile Driving in Saturated Sand
Authors: Wei Jiabin , Wang Weidong , Wu Jiangbin
Published: April 2022

Vibratory pile diving with resonance-free technique is an advanced construction approach that can play an important part in underground engineering. This paper aims to propose a numerical model for this construction approach, which commonly involves soils below the groundwater table. Such simulations are still challenging tasks as dynamic analyses considering hydro-mechanical interactions are very complicated. Several simulations have been performed by constructing a user-defined element in the finite element code ABAQUS or developing an inhouse finite-element program for this issue. These simulations have some limitations and pay less attention to open-ended piles. This paper presents a way to simulate the vibratory open-ended pile driving in saturated sand using the finite difference code FLAC3D. The model computation efficiency is increased around 67 times by the density scaling method and this method has little effect on the numerical stability. The proposed model can generally replicate the pore pressure results of a model test. The maximum excess pore pressures are predicted with a percent error of 2–22%, and these maximums occur near the pile toe. The excess pore pressure of an observation point slowly decreases after the pile toe passes the point. This work could provide an efficient and effective method for simulating vibratory open-ended pile driving in saturated sand.
Neuromorphic Neural Engineering Framework-Inspired Online Continuous Learning with Analog Circuitry
Authors: Hazan Avi , Ezra Tsur Elishai
Published: April 2022

Neuromorphic hardware designs realize neural principles in electronics to provide high-performing, energy-efficient frameworks for machine learning. Here, we propose a neuromorphic analog design for continuous real-time learning. Our hardware design realizes the underlying principles of the neural engineering framework (NEF). NEF brings forth a theoretical framework for the representation and transformation of mathematical constructs with spiking neurons, thus providing efficient means for neuromorphic machine learning and the design of intricate dynamical systems. Our analog circuit design implements the neuromorphic prescribed error sensitivity (PES) learning rule with OZ neurons. OZ is an analog implementation of a spiking neuron, which was shown to have complete correspondence with NEF across firing rates, encoding vectors, and intercepts. We demonstrate PES-based neuromorphic representation of mathematical constructs with varying neuron configurations, the transformation of mathematical constructs, and the construction of a dynamical system with the design of an inducible leaky oscillator. We further designed a circuit emulator, allowing the evaluation of our electrical designs on a large scale. We used the circuit emulator in conjunction with a robot simulator to demonstrate adaptive learning-based control of a robotic arm with six degrees of freedom.
Blockchain-Based Reference Architecture for Automated, Transparent, and Notarized Attestation of Compliance Adaptations
Authors: Weber Thorsten , Buchkremer Rüdiger
Published: April 2022

With cloud computing, organizations must comply with applicable laws, policies, and best practices. Companies typically rely on cloud service providers to implement and adopt regulations. This consulting phase is often time-consuming, costly, and not transparent. Organizations must trust the third party’s implementation and associated documentation processes. To resolve this dilemma, we present a blockchain-based reference architecture for the automated, transparent, and notarized attestation of such compliance adaptations. Before proposing a solution, our approach is to understand the underlying research context. We conduct a machine-learning-supported systematic literature review to create a knowledge base. A reference architecture, including a prototype for configuring intrusion-detection systems, is developed using design science research. A mixed-methods-based approach is used for the evaluation of the proposed architecture. A quantitative survey is then used to show that the user experience of the developed prototype can be rated as positive, with an average value of 0.7. Finally, two focus group discussions are used to analyze the presented prototype qualitatively. As a result, we demonstrate how to actively support secure and trustworthy communication between a cloud service provider and an organization applying blockchain configurations.
Advanced Equipment Development and Clinical Application in Neurorehabilitation for Spinal Cord Injury: Historical Perspectives and Future Directions
Authors: Kasukawa Yuji , Shimada Yoichi , Kudo Daisuke , Saito Kimio , Kimura Ryota , Chida Satoaki , Hatakeyama Kazutoshi , Miyakoshi Naohisa
Published: April 2022

Partial to complete paralysis following spinal cord injury (SCI) causes deterioration in health and has severe effects on the ability to perform activities of daily living. Following the discovery of neural plasticity, neurorehabilitation therapies have emerged that aim to reconstruct the motor circuit of the damaged spinal cord. Functional electrical stimulation (FES) has been incorporated into devices that reconstruct purposeful motions in the upper and lower limbs, the most recent of which do not require percutaneous electrode placement surgery and thus enable early rehabilitation after injury. FES-based devices have shown promising results for improving upper limb movement, including gripping and finger function, and for lower limb function such as the ability to stand and walk. FES has also been employed in hybrid cycling and rowing to increase total body fitness. Training using rehabilitation robots is advantageous in terms of consistency of quality and quantity of movements and is particularly applicable to walking training. Initiation of motor reconstruction at the early stage following SCI is likely to advance rapidly in the future, with the combined use of technologies such as regenerative medicine, brain machine interfaces, and rehabilitation robots with FES showing great promise.
Analysis of the Seismic Properties for Engineering Purposes of the Shallow Subsurface: Two Case Studies from Italy and Croatia
Authors: Da Col Federico , Accaino Flavio , Böhm Gualtiero , Meneghini Fabio
Published: April 2022

We present two case studies of the application of seismic surveys to estimate the elastic properties of soil and rock in the shallow subsurface. The two sites present very different geological characteristics. The first test site is a town on the Croatian coast, not far from the city of Split, built on hard rock, where we acquired three seismic lines. The second site is located in the outskirts of the city of Ferrara, in Italy, in an alluvial plain, where two lines were acquired. In both sites, for detailed characterization, we acquired surface-, compressional- and shear-waves, further distinguishing the latter between horizontally (SH) and vertically (SV) polarized wavefields. We processed the data by performing a Multichannel Analysis of Surface Waves to compute a preliminary one-dimensional shear wave velocity profile. Then, we performed first-break tomography to compute P-, SH- and SV-velocity profiles. Such unusual acquisition allowed us to compute not only basic engineering parameters such as the equivalent shear-wave velocity of the first 30 m of subsurface (VS30) from the SH profiles but also other useful parameters such as the VP/VS and estimate the anisotropy of the medium thanks to the VSV/VSH. Given the level of detail of the results and their engineering value, we conclude that the method of investigation we applied in the two test sites is a valuable tool for characterizing the shallow subsurface.
Single-Shot Compressed Imaging via Random Phase Modulation
Authors: Zhang Cheng , Zhang Ru , Zhu Yuanyuan , Yang Hairong , Shen Chuan , Wei Sui
Published: April 2022

Compressed sensing (CS) provides an innovative framework for signal sampling, which enables accurate recovery of the sparse or compressible signal from a small set of linear measurements far fewer than the Nyquist rate in traditional signal processing. In compressed sensing, random modulation plays a key role, which can spread out the signal information more or less evenly across all locations. There are many modulation techniques, such as amplitude modulation, frequency modulation, phase modulation, spectrum modulation, and so on. Among these modulation techniques, phase modulation is vital due to the efficiency and convenience of modulation. In this paper, we review both the theoretical and application of compressed sensing and several compressed imaging systems using random phase modulation. First, we review the fundamentals of compressed sensing, dividing it into three parts: sparse representation, incoherent measurement, and nonlinear reconstruction algorithm. We then show how phase modulation can be applied to compressed sensing and compressed imaging, where the presentation can be divided into six main parts, corresponding to different aspects of phase modulation applied in compressed sensing or compressed imaging: (1) Fundamentals of compressed sensing. (2) Principles of phase modulation. (3) Single-shot compressed imaging with spatial-domain single random phase mask (CI-SSRPM). (4) Single-shot compressed imaging with a random convolution using a double random phase mask (CI-DRPM). (5) Single-shot compressed imaging with Fourier-domain single random phase mask (CI-FSRPM). (6) Single-shot compressed imaging with double random phase encoding (CI-DRPE).
Impact of Seat Inclination and Misalignment on Airborne Pollutant Transport in a Single-Aisle Aircraft Cabin
Authors: Zhang Tengfei (Tim) , Fan Mingqi , Liu Sumei
Published: April 2022

Airborne pollutant transport in an aircraft cabin is greatly affected by the created airflow. The seat layout can impact the flow and thus the pollutant transport. Most studies have adopted symmetric upright seats for simplicity. The influence of seat inclination and seat misalignment on airflow and pollutant transport is still unclear. This investigation adopted a validated computational fluid dynamics (CFD) method to study the airflow and airborne pollutant distribution in a single-aisle cabin with seven rows of seats. The pollutant was assumed to be released from a passenger seated in the middle of three adjacent seats. A total of five different seat layouts were considered, including all of the upright seats, the inclination of three adjacent seats, the inclination of all of the seats in half a cabin, the inclination of all of the seats in a whole cabin, and the misalignment seat rows across the aisle. The flows in both the cross and longitudinal sections were compared. The pollutant concentrations in the respiratory zone of the passengers in different seats were adopted to evaluate the cross-contamination. The results revealed that the symmetric seat layout aids to circumscribe the released pollutant in a small region and reduces the cross-contamination either by maintaining the upright seats or inclining all of the seats. Contrarily, any inclination of seats or a misalignment of seat rows should be avoided during the pandemic since an asymmetric seat layout would generate asymmetric flow and strengthen the spreading of pollutants.
Comparative Analysis of SCMOC and Models Rainstorm Forecasting Performance in Qinling Mountains and Their Surrounding Areas
Authors: Pan Liujie , Zhang Hongfang , Liu Jing , Gao Xingxing , Qi Chunjuan
Published: April 2022

Taking CMPA (CMA Multi-source Merged Precipitation Analysis System) analysis data as a reference, the research analyzes the forecast performance of ECMWF, CMA-Meso, and SCMOC (National Meteorological Center grid precipitation forecast guidance product) in 74 rainstorm cases in 2020 and 2021 in Qinling Mountains and their surrounding areas by using the dichotomy classical verification score comprehensive diagram and the object-oriented MODE spatial verification method, based on the circulation classification in rainstorm weather. The research conclusions are as follows: (1) based on the high- and low-altitude circulation situation and focused on the direct impact system, rainstorms in the Qinling Mountains and their surrounding areas can be divided into five patterns. (2) Point-to-point verification shows that SCMOC has obvious advantages in rainstorm forecast, but the disadvantage is that the Bias is relatively high. CMA-Meso has advantages in RST (weak weather system) decentralized rainstorm forecast. (3) MODE verification shows that the number of ECMWF and SCMOC independent objects is significantly lower than that of observation, the forecast area of regional rainstorm objects of SCMOC is significantly larger, the SCMOC scattered rainstorm objects are missed, and the number of independent precipitation objects of CMA-Meso is higher than that of the other two precipitation products. (4) The forecast object area and intensity of SCMOC and observation match best in the XFC (westerly trough) circulation situation, while ECMWF has the best results for the forecast of FGXFC (subtropical high westerly trough) rainstorms.
Understanding the Sources of Ambient Fine Particulate Matter (PM2.5) in Jeddah, Saudi Arabia
Authors: Nayebare Shedrack R. , Aburizaiza Omar S. , Siddique Azhar , Hussain Mirza M. , Zeb Jahan , Khatib Fida , Carpenter David O. , Blake Donald R. , Khwaja Haider A.
Published: April 2022

Urban air pollution is rapidly becoming a major environmental problem of public concern in several developing countries of the world. Jeddah, the second-largest city in Saudi Arabia, is subject to high air pollution that has severe implications for the health of the exposed population. Fine particulate matter (PM2.5) samples were collected for 24 h daily, during a 1-year campaign from 2013 to 2014. This study presents a detailed investigation of PM2.5 mass, chemical composition, and sources covering all four seasons of the year. Samples were analyzed for black carbon (BC), trace elements (TEs), and water-soluble ionic species (IS). The chemical compositions were statistically examined, and the temporal and seasonal patterns were characterized using descriptive analysis, correlation matrices, and elemental enrichment factor (EF). Source apportionment and source locations were performed on PM2.5 samples using the positive matrix factorization (PMF) model, elemental enrichment factor, and air-mass back trajectory analysis. The 24-h mean PM2.5 and BC concentrations ranged from 33.9 ± 9.1–58.8 ± 25 µg/m3 and 1.8 ± 0.4–2.4 ± 0.6 µg/m3, respectively. Atmospheric PM2.5 concentrations were well above the 24-h WHO guideline of 15 µg/m3, with overall results showing significant temporal and seasonal variability. EF defined two broad categories of TEs: anthropogenic (Ni, V, Cu, Zn, Cl, Pb, S, Lu, and Br), and earth-crust derived (Al, Si, Mg, K, Ca, Ti, Cr, Mn, Fe, and Sr). The five identified factors resulting from PMF were (1) fossil-fuels/oil combustion (45.3%), (2) vehicular emissions (19.1%), (3) soil/dust resuspension (15.6%), (4) industrial mixed dust (13.5%), and (5) sea-spray (6.5%). This study highlights the importance of focusing control strategies, not only on reducing PM concentration but also on the reduction of components of the PM as well, to effectively protect human health and the environment.
Multi-Source Remote Sensing Data for Lake Change Detection in Xinjiang, China
Authors: Liu Yuting , Ye Zhaoxia , Jia Qiaoyun , Mamat Aynur , Guan Hanxiao
Published: April 2022

Lake water resources in arid areas play an important role in regional resource and environmental management. Therefore, to master the dynamic changes in lake water resources in arid areas, the laser altimetry satellite and land resource satellite were used to interpret the changes in water level and the areas of alpine lakes and non-alpine lakes. The dynamic changes in the lake and their relationship with glacial meltwater, precipitation, and runoff of the lake basin were analyzed using the unary linear regression equation, the ratio of glacier area to lake area (G–L ratio), and the ratio of lake basin area to lake area (supply coefficient). The results were as follows: the changes in alpine lakes were closely related to the supply coefficient (basin/lake area ratio) but weakly related to the G–L ratio (glacier/lake area ratio). In addition, the spatial pattern of lake change was consistent with that of climate change. There was a strong correlation between the lake, precipitation, and temperature during the snowmelt period. Thus, it can be seen that the changes in the lake were caused by precipitation, glacial melt, snowmelt, and other multi-factors. Therefore, this study on the changes in water resources in different types of lakes and their influencing factors provides data support for water resources managers to evaluate the health and sustainable utilization of the ecological environment.
Proposed Conceptual Framework to Design Artificial Reefs Based on Particular Ecosystem Ecology Traits
Authors: Carral Luis , Lamas María Isabel , Cartelle Barros Juan José , López Iván , Carballo Rodrigo
Published: April 2022

Overfishing and pollution have led to marine habitat degradation, and as a result, marine fisheries are now in decline. Consequently, there is a real need to enhance marine ecosystems while halting the decline of fish stocks and boosting artisanal fishing. Under these circumstances, artificial reefs (ARs) have emerged as a promising option. Nevertheless, their performance is traditionally assessed years after installation, through experimental and field observations. It is now necessary to adopt an alternative approach, adapting the design of artificial reefs to the specific characteristics of the ecosystem to be enhanced. In this way, it will be possible to determine the potential positive impacts of ARs before their installation. This paper presents a general and integrated conceptual framework to assist in the design of AR units by adopting an ecosystem ecology (EE) perspective. It consists of three main parts. In the first one, starting from an initial geometry, EE principles are used to include modifications with the aim of improving autotrophic resource pathways (additional substrata and increased nutrient circulation) and leading to a habitat enhancement (more shelter for individuals). The second part of the framework is a new dimensionless index that allows the user to select the best AR unit design from different alternatives. The potential impacts on the ecosystem in terms of energy, nutrient cycling and shelter are considered for such a purpose. Finally, a general hydrodynamic methodology to study the stability of the selected AR unit design, considering the effect of high waves under severe storms, is proposed. The framework is applied through a case study for Galician estuaries.
Proteomics Analysis in Japanese Medaka Oryzias latipes Exposed to Humic Acid Revealed Suppression of Innate Immunity and Coagulation Proteins
Authors: Yurchenko Victoria V. , Morozov Alexey A. , Kiriukhin Bogdan A.
Published: April 2022

Humic acids (HA), one of the major components of dissolved organic matter, can interfere with different metabolic pathways in aquatic animals, causing various biological effects. This study aimed to provide a molecular basis for HA-related responses in fish by analyzing changes in the blood plasma proteome following short-term exposure to environmentally relevant HA concentrations using the Japanese medaka Oryzias latipes Hd-rR strain as a model organism. Proteomics data were obtained by high-performance liquid chromatography with tandem mass spectrometry analysis employing a label-free quantification approach. HA caused dysregulation of proteins involved in various biological processes, including protein folding, signaling, transport, metabolism, regulation, immune response, and coagulation. The majority of the differentially abundant proteins were down-regulated, including those involved in humoral immunity and coagulation. HA caused the decrease of the complement cascade and membrane attack complex proteins abundance, as well as proteins participating in activation and regulation of secondary hemostasis. The most pronounced suppression was observed at the highest tested HA concentration.
GTP-Dependent Regulation of CTP Synthase: Evolving Insights into Allosteric Activation and NH3 Translocation
Authors: Bearne Stephen L. , Guo Chen-Jun , Liu Ji-Long
Published: April 2022

Cytidine-5′-triphosphate (CTP) synthase (CTPS) is the class I glutamine-dependent amidotransferase (GAT) that catalyzes the last step in the de novo biosynthesis of CTP. Glutamine hydrolysis is catalyzed in the GAT domain and the liberated ammonia is transferred via an intramolecular tunnel to the synthase domain where the ATP-dependent amination of UTP occurs to form CTP. CTPS is unique among the glutamine-dependent amidotransferases, requiring an allosteric effector (GTP) to activate the GAT domain for efficient glutamine hydrolysis. Recently, the first cryo-electron microscopy structure of Drosophila CTPS was solved with bound ATP, UTP, and, notably, GTP, as well as the covalent adduct with 6-diazo-5-oxo-l-norleucine. This structural information, along with the numerous site-directed mutagenesis, kinetics, and structural studies conducted over the past 50 years, provide more detailed insights into the elaborate conformational changes that accompany GTP binding at the GAT domain and their contribution to catalysis. Interactions between GTP and the L2 loop, the L4 loop from an adjacent protomer, the L11 lid, and the L13 loop (or unique flexible “wing” region), induce conformational changes that promote the hydrolysis of glutamine at the GAT domain; however, direct experimental evidence on the specific mechanism by which these conformational changes facilitate catalysis at the GAT domain is still lacking. Significantly, the conformational changes induced by GTP binding also affect the assembly and maintenance of the NH3 tunnel. Hence, in addition to promoting glutamine hydrolysis, the allosteric effector plays an important role in coordinating the reactions catalyzed by the GAT and synthase domains of CTPS.
Hyperthermia Enhances Efficacy of Chemotherapeutic Agents in Pancreatic Cancer Cell Lines
Authors: Maurici Costanza E. , Colenbier Robin , Wylleman Britta , Brancato Luigi , van Zwol Eke , Van den Bossche Johan , Timmermans Jean-Pierre , Giovannetti Elisa , Mori da Cunha Marina G. M. C. , Bogers Johannes
Published: April 2022

Chemotherapy (CT) is the standard care for advanced pancreatic ductal adenocarcinoma (PDAC); however, with limited efficacy. Hyperthermia (HT) treatment has been suggested as a sensitizer to improve outcomes. However, the direct effect of the HT and CT combination is not fully understood. Therefore, we aim to assess the direct cytotoxic effect of HT in PDAC cells as monotherapy or in combination with chemotherapeutics. Different temperatures (37-, 40.5-, 41-, and 41.5 °C) and durations (6-, 12-, and 24 h) were tested in PDAC cell lines (BxPC-3, Capan-1, Capan-2, PANC-1, and MIA-PaCa-2). Different concentrations of gemcitabine, 5-fluorouracil, and cisplatin were also tested in these conditions. The impact on cell metabolic activity was determined by an MTS assay. Enhancement of chemosensitivity was assessed by a reduction in half-maximal inhibitory concentration (IC50). HT and chemotherapeutics interactions were classified as antagonistic, additive, or synergistic using the combination index. HT inhibited cell proliferation in a cell type, temperature, and duration-dependent manner. The induction of apoptosis was seen after 6 h of HT treatment, eventually followed by secondary necrosis. The HT and CT combination led to an IC50 reduction of the tested CT. At 12 h of HT, this effect was between 25 to 90% and reached a 95% reduction at 24 h. The additive or synergistic effect was demonstrated in all cell lines and chemotherapeutics, although, again, this depended on cell type, duration, and temperature. HT is cytotoxic and enhances the therapeutic effectiveness of gemcitabine, 5-fluorouracil, and cisplatin on PDAC cells. This result was further confirmed by the decrease in the expression of RRM2, TS, and ERCC1 in BxPC-3 and Capan-2 cells. These observations warrant further study in specific subsets of PDAC patients to improve their clinical outcomes.
Oncogenomic Changes in Pancreatic Cancer and Their Detection in Stool
Authors: Sammallahti Heidelinde , Sarhadi Virinder Kaur , Kokkola Arto , Ghanbari Reza , Rezasoltani Sama , Asadzadeh Aghdaei Hamid , Puolakkainen Pauli , Knuutila Sakari
Published: April 2022

Pancreatic cancer (PC) is an aggressive malignancy with a dismal prognosis. To improve patient survival, the development of screening methods for early diagnosis is pivotal. Oncogenomic alterations present in tumor tissue are a suitable target for non-invasive screening efforts, as they can be detected in tumor-derived cells, cell-free nucleic acids, and extracellular vesicles, which are present in several body fluids. Since stool is an easily accessible source, which enables convenient and cost-effective sampling, it could be utilized for the screening of these traces. Herein, we explore the various oncogenomic changes that have been detected in PC tissue, such as chromosomal aberrations, mutations in driver genes, epigenetic alterations, and differentially expressed non-coding RNA. In addition, we briefly look into the role of altered gut microbiota in PC and their possible associations with oncogenomic changes. We also review the findings of genomic alterations in stool of PC patients, and the potentials and challenges of their future use for the development of stool screening tools, including the possible combination of genomic and microbiota markers.