bluuebunny/crossref_metadata_2025 huggingface dataset:
Logistic Regression Based on Individual-Level Predictors and Aggregate-Level Responses
Authors: Xu Zheng
Published: February 2023

We propose estimation methods to conduct logistic regression based on individual-level predictors and aggregate-level responses. We derive the likelihood of logistic models in this situation and proposed estimators with different optimization methods. Simulation studies have been conducted to evaluate and compare the performance of the different estimators. A real data-based study has been conducted to illustrate the use of our estimators and compare the different estimators.
Student Experience, Satisfaction and Commitment in Blended Learning: A Structural Equation Modelling Approach
Authors: Batista-Toledo Santiago , Gavilan Diana
Published: February 2023

The COVID-19 pandemic led to higher education institutions adopting alternative teaching models to continue their work while complying with health measures. Specifically, in Spain, once the lockdown period was over, universities adopted the blended learning (BL) model, which allowed for a partial return to the classroom. The BL model meant a completely new approach for students that impacted their learning experience. Using structural equation modelling (SEM), this paper explores in-depth students’ experience with BL—social–behavioural, cognitive–affective, sensory and formative—and tests the impact of BL on students’ satisfaction and their commitment to learning. Data were collected from a sample of 467 undergraduate students at Complutense University of Madrid (Spain) who filled out a self-administered questionnaire. The model proposed shows fit indices above the recommended thresholds, indicating an adequate model fit. Results suggest a positive influence of the different dimensions of BL experience on satisfaction. In addition, satisfaction with BL had a positive impact on students’ affective commitment. Going by these results, the students’ experience with BL has been positive, increasing their willingness to study. Finally, the implications of these results for higher educational institutions are discussed and future research lines suggested.
Effect of Antiviral Therapy for HCV Treatment in the Presence of Hepatocyte Growth Factor
Authors: Sharma Santosh Kumar , Chatterjee Amar Nath , Ahmad Bashir
Published: February 2023

The effect of antiviral therapy during Hepatitis C Virus (HCV) infection is the focus of this study. HCV infection destroys healthy hepatocyte cells in the human liver, causing cirrhosis and hepatocellular carcinoma. We introduce a cell-population model representing the long-term dynamics of HCV infection in response to antiviral drug therapies. The proliferation of existing cells can create hepatocyte cells in the system. Such models are based on the dynamics of susceptible hepatocytes, infected hepatocytes and HCV with interactive dynamics, which can give a complete understanding of the host dynamics of the system in the presence of antiviral drug therapy. Infection-free equilibrium and endemic equilibrium are two equilibrium states in the absence of drugs. The existence and stability conditions for both systems are presented. We also construct an optimal control system to find the optimal control strategy. Numerical results show that the effects of the proliferation rate and infection rate are critical for the changes in the dynamics of the model. The impact of different weight factors on the optimal control problem is analysed through numerical simulation.
Algebraic Characterizations of Relationships between Different Linear Matrix Functions
Authors: Tian Yongge , Yuan Ruixia
Published: February 2023

Let f(X1,X2,…,Xk) be a matrix function over the field of complex numbers, where X1,X2,…,Xk are a family of matrices with variable entries. The purpose of this paper is to propose and investigate the relationships between certain linear matrix functions that regularly appear in matrix theory and its applications. We shall derive a series of meaningful, necessary, and sufficient conditions for the collections of values of two given matrix functions to be equal through the cogent use of some highly selective formulas and facts regarding ranks, ranges, and generalized inverses of block matrix operations. As applications, we discuss some concrete topics concerning the algebraic connections between general solutions of a given linear matrix equation and its reduced equations.
Bayesian Variable Selection in Generalized Extreme Value Regression: Modeling Annual Maximum Temperature
Authors: Castillo-Mateo Jorge , Asín Jesús , Cebrián Ana C. , Mateo-Lázaro Jesús , Abaurrea Jesús
Published: February 2023

In many applications, interest focuses on assessing relationships between covariates and the extremes of the distribution of a continuous response. For example, in climate studies, a usual approach to assess climate change has been based on the analysis of annual maximum data. Using the generalized extreme value (GEV) distribution, we can model trends in the annual maximum temperature using the high number of available atmospheric covariates. However, there is typically uncertainty in which of the many candidate covariates should be included. Bayesian methods for variable selection are very useful to identify important covariates. However, such methods are currently very limited for moderately high dimensional variable selection in GEV regression. We propose a Bayesian method for variable selection based on a stochastic search variable selection (SSVS) algorithm proposed for posterior computation. The method is applied to the selection of atmospheric covariates in annual maximum temperature series in three Spanish stations.
5G Multi-Slices Bi-Level Resource Allocation by Reinforcement Learning
Authors: Yu Zhipeng , Gu Fangqing , Liu Hailin , Lai Yutao
Published: February 2023

As the centralized unit (CU)—distributed unit (DU) separation in the fifth generation mobile network (5G), the multi-slice and multi-scenario, can be better applied in wireless communication. The development of the 5G network to vertical industries makes its resource allocation also have an obvious hierarchical structure. In this paper, we propose a bi-level resource allocation model. The up-level objective in this model refers to the profit of the 5G operator through the base station allocating resources to slices. The lower-level objective in this model refers to the slices allocating the resource to its users fairly. The resource allocation problem is a complex optimization problem with mixed-discrete variables, so whether a resource allocation algorithm can quickly and accurately give the resource allocation scheme is the key to its practical application. According to the characteristics of the problem, we select the multi-agent twin delayed deep deterministic policy gradient (MATD3) to solve the upper slice resource allocation and the discrete and continuous twin delayed deep deterministic policy gradient (DCTD3) to solve the lower user resource allocation. It is crucial to accurately characterize the state, environment, and reward of reinforcement learning for solving practical problems. Thus, we provide an effective definition of the environment, state, action, and reward of MATD3 and DCTD3 for solving the bi-level resource allocation problem. We conduct some simulation experiments and compare it with the multi-agent deep deterministic policy gradient (MADDPG) algorithm and nested bi-level evolutionary algorithm (NBLEA). The experimental results show that the proposed algorithm can quickly provide a better resource allocation scheme.
Recent Development in Novel Lithium-Sulfur Nanofiber Separators: A Review of the Latest Fabrication and Performance Optimizations
Authors: Kim Andrew , Dash Jatis Kumar , Patel Rajkumar
Published: February 2023

Lithium-Sulfur batteries (LSBs) are one of the most promising next-generation batteries to replace Li-ion batteries that power everything from small portable devices to large electric vehicles. LSBs boast a nearly five times higher theoretical capacity than Li-ion batteries due to sulfur’s high theoretical capacity, and LSBs use abundant sulfur instead of rare metals as their cathodes. In order to make LSBs commercially viable, an LSB’s separator must permit fast Li-ion diffusion while suppressing the migration of soluble lithium polysulfides (LiPSs). Polyolefin separators (commonly used in Li-ion batteries) fail to block LiPSs, have low thermal stability, poor mechanical strength, and weak electrolyte affinity. Novel nanofiber (NF) separators address the aforementioned shortcomings of polyolefin separators with intrinsically superior properties. Moreover, NF separators can easily be produced in large volumes, fine-tuned via facile electrospinning techniques, and modified with various additives. This review discusses the design principles and performance of LSBs with exemplary NF separators. The benefits of using various polymers and the effects of different polymer modifications are analyzed. We also discuss the conversion of polymer NFs into carbon NFs (CNFs) and their effects on rate capability and thermal stability. Finally, common and promising modifiers for NF separators, including carbon, metal oxide, and metal-organic framework (MOF), are examined. We highlight the underlying properties of the composite NF separators that enhance the capacity, cyclability, and resilience of LSBs.
Efficacy of Soft-Rot Disease Biocontrol Agents in the Inhibition of Production Field Pathogen Isolates
Authors: Cigna Jérémy , Robic Kévin , Dewaegeneire Pauline , Hélias Valérie , Beury Amélie , Faure Denis
Published: February 2023

The Dickeya and Pectobacterium bacterial species cause blackleg and soft-rot diseases on potato plants and tubers. Prophylactic actions are essential to conserve a high quality of seed potato tubers. Biocontrol approaches are emerging, but we need to know how efficient biocontrol agents are when facing the natural diversity of pathogens. In this work, we sampled 16 production fields, which were excluded from the seed tuber certification scheme, as well as seven experimental parcels, which were planted with seed tubers from those production fields. We collected and characterized 669 Dickeya and Pectobacterium isolates, all characterized using nucleotide sequence of the gapA gene. This deep sampling effort highlighted eleven Dickeya and Pectobacterium species, including four dominant species namely D. solani, D. dianthicola, P. atrosepticum and P. parmentieri. Variations in the relative abundance of pathogens revealed different diversity patterns at a field or parcel level. The Dickeya-enriched patterns were maintained in parcels planted with rejected seed tubers, suggesting a vertical transmission of the pathogen consortium. Then, we retained 41 isolates representing the observed species diversity of pathogens and we tested each of them against six biocontrol agents. From this work, we confirmed the importance of prophylactic actions to discard contaminated seed tubers. We also identified a couple of biocontrol agents of the Pseudomonas genus that were efficient against a wide range of pathogen species.
The Effect of High-Pressure Processing on the Survival of Non-O157 Shiga Toxin-Producing Escherichia coli in Steak Tartare: The Good- or Best-Case Scenario?
Authors: Kameník Josef , Dušková Marta , Dorotíková Kateřina , Hušáková Markéta , Ježek František
Published: February 2023

Samples of steak tartare were artificially contaminated with a cocktail of Shiga toxin-producing Escherichia coli (STEC) O91, O146, O153, and O156 to the level of 3 log and 6 log CFU/g. Immediately after vacuum packing, high-pressure processing (HPP) was performed at 400 or 600 MPa/5 min. Some of the samples not treated with HPP were cooked under conditions of 55 °C for 1, 3, or 6 h. HPP of 400 MPa/5 min resulted in a 1–2 log reduction in the STEC count. In contrast, HPP of 600 MPa/5 min led to the elimination of STEC even when inoculated to 6 log CFU/g. Nevertheless, sub-lethally damaged cells were resuscitated after enrichment, and STEC was observed in all samples regardless of the pressure used. STEC was not detected in the samples cooked in a 55 °C water bath for 6 h, even after enrichment. Unfortunately, the temperature of 55 °C negatively affected the texture of the steak tartare. Further experiments are necessary to find an optimal treatment for steak tartare to assure its food safety while preserving the character and quality of this attractive product.
Biosynthesis of Metal and Metal Oxide Nanoparticles Using Microbial Cultures: Mechanisms, Antimicrobial Activity and Applications to Cultural Heritage
Authors: Carrapiço António , Martins Maria Rosário , Caldeira Ana Teresa , Mirão José , Dias Luís
Published: February 2023

Nanoparticles (1 to 100 nm) have unique physical and chemical properties, which makes them suitable for application in a vast range of scientific and technological fields. In particular, metal nanoparticle (MNPs) research has been showing promising antimicrobial activities, paving the way for new applications. However, despite some research into their antimicrobial potential, the antimicrobial mechanisms are still not well determined. Nanoparticles’ biosynthesis, using plant extracts or microorganisms, has shown promising results as green alternatives to chemical synthesis; however, the knowledge regarding the mechanisms behind it is neither abundant nor consensual. In this review, findings from studies on the antimicrobial and biosynthesis mechanisms of MNPs were compiled and evidence-based mechanisms proposed. The first revealed the importance of enzymatic disturbance by internalized metal ions, while the second illustrated the role of reducing and negatively charged molecules. Additionally, the main results from recent studies (2018–2022) on the biosynthesis of MNPs using microorganisms were summarized and analyzed, evidencing a prevalence of research on silver nanoparticles synthesized using bacteria aiming toward testing their antimicrobial potential. Finally, a synopsis of studies on MNPs applied to cultural heritage materials showed potential for their future use in preservation.
Host Immune Responses to Surface S-Layer Proteins (SLPs) of Clostridioides difficile
Authors: Chandra Harish , Kovall Rhett A. , Yadav Jagjit S. , Sun Xingmin
Published: February 2023

Clostridioides difficile, a nosocomial pathogen, is an emerging gut pathobiont causing antibiotic-associated diarrhea. C. difficile infection involves gut colonization and disruption of the gut epithelial barrier, leading to the induction of inflammatory/immune responses. The expression of two major exotoxins, TcdA and TcdB is the major cause of C. difficile pathogenicity. Attachment of bacterial abundant cell wall proteins or surface S-layer proteins (SLPs) such as SlpA with host epithelial cells is critical for virulence. In addition to being toxins, these surface components have been shown to be highly immunogenic. Recent studies indicate that C. difficile SLPs play important roles in the adhesion of the bacteria to the intestinal epithelial cells, disruption of tight junctions, and modulation of the immune response of the host cells. These proteins might serve as new targets for vaccines and new therapeutic agents. This review summarizes our current understanding of the immunological role of SLPs in inducing host immunity and their use in the development of vaccines and novel therapeutics to combat C. difficile infection.
Metabolic Profiling and Potential Taste Biomarkers of Two Rambutans during Maturation
Authors: Deng Hao , Wu Guang , Guo Li , Hu Fuchu , Zhou Liying , Xu Bin , Yin Qingchun , Chen Zhe
Published: February 2023

The metabolite-caused taste variation during rambutan maturation is unknown due to a lack of systematic investigation of all components. In this study, three growing stages, including unripe (S1), half-ripe (S2), and full-ripe (S3) BY2 and BY7 rambutans were compared and profiled by UPLC–MS/MS-based widely targeted metabolomics analysis. We demonstrated that the sugar-acid ratios of two rambutans were greatly improved between the S2 and S3 stages. A total of 821 metabolites were identified, including 232, 205, 204, and 12 differential metabolites (DMs) in BY2-S1 vs. BY2-S2, BY2-S2 vs. BY2-S3, BY7-S1 vs. BY7-S2, and BY7-S2 vs. BY7-S3, respectively. A correlation analysis showed that gamma-aminobutyric acid (GABA) could be the sugar-acid ratio biomarker of BY2 rambutan. Methionine (Met), alanine (Ala), and S-methyl-L-cysteine (SMC) could be total amino acid biomarkers of BY2 and BY7 rambutans. In addition, UPLC-MS/MS-based quantitative verification of the above biomarkers exhibited the same variations as metabolomics analysis. This study not only provides useful nutritive information on rambutans but also valuable metabolic data for rambutan breeding strategies.
Hydrogenase and Nitrogenase: Key Catalysts in Biohydrogen Production
Authors: Xuan Jinsong , He Lingling , Wen Wen , Feng Yingang
Published: February 2023

Hydrogen with high energy content is considered to be a promising alternative clean energy source. Biohydrogen production through microbes provides a renewable and immense hydrogen supply by utilizing raw materials such as inexhaustible natural sunlight, water, and even organic waste, which is supposed to solve the two problems of “energy supply and environment protection” at the same time. Hydrogenases and nitrogenases are two classes of key enzymes involved in biohydrogen production and can be applied under different biological conditions. Both the research on enzymatic catalytic mechanisms and the innovations of enzymatic techniques are important and necessary for the application of biohydrogen production. In this review, we introduce the enzymatic structures related to biohydrogen production, summarize recent enzymatic and genetic engineering works to enhance hydrogen production, and describe the chemical efforts of novel synthetic artificial enzymes inspired by the two biocatalysts. Continual studies on the two types of enzymes in the future will further improve the efficiency of biohydrogen production and contribute to the economic feasibility of biohydrogen as an energy source.
In Vitro Evaluation of Antiprotozoal Properties, Cytotoxicity Effect and Anticancer Activity of New Essential-Oil Based Phytoncide Mixtures
Authors: Iwiński Hubert , Różański Henryk , Pachura Natalia , Wojciechowska Aleksandra , Gębarowski Tomasz , Szumny Antoni
Published: February 2023

Protozoa, in both humans and animals, are one of the leading causes of disease. International programmes introduced in many countries have helped reduce the incidence of disease. However, it has recently become increasingly difficult to achieve the goals set for the coming years. One of the main reasons for this, as with other pathogenic organisms, such as bacteria and fungi, is the increasing resistance to current methods of treating and preventing infection. Therefore, new therapies with high efficacy are needed. In the present study, the novel mixtures of essential oils (EOs), clove, garlic, Ceylon cinnamon, and rosemary with organic acids (acetic, propionic, lactic) and metal ions (Cu, Mn, Zn) were tested against five selected model protozoa (Euglena gracilis, Gregarina blattarum, Amoeba proteus, Paramecium caudatum, Pentatrichomonas hominis). The cytotoxicity and potential anticancer activity of the obtained combinations were tested on the human fibroblasts (NHDF) and human cancer cell lines (A549, MCF7, LoVo, HT29). All of the mixtures showed very good antiprotozoal properties. The most efficient were the combination of clove and rosemary essential oils, mixtures of acids, and Mn ions. The LD50 values were in the range of 0.001–0.006% and the LD100 values were 0.002–0.008%. All of the tested mixtures did not show cytotoxicity against normal cells, but did show growth inhibition against cancer cell lines. The most cytotoxic against cancer cells were combinations with cinnamon essential oil. Nevertheless, the proposed combinations containing essential oils, organic acids, and metal ions have high antiprotozoal activity, with low toxicity to healthy human cells.
The Multifaceted MEP Pathway: Towards New Therapeutic Perspectives
Authors: Allamand Alizée , Piechowiak Teresa , Lièvremont Didier , Rohmer Michel , Grosdemange-Billiard Catherine
Published: February 2023

Isoprenoids, a diverse class of natural products, are present in all living organisms. Their two universal building blocks are synthesized via two independent pathways: the mevalonate pathway and the 2-C-methyl-ᴅ-erythritol 4-phosphate (MEP) pathway. The presence of the latter in pathogenic bacteria and its absence in humans make all its enzymes suitable targets for the development of novel antibacterial drugs. (E)-4-Hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), the last intermediate of this pathway, is a natural ligand for the human Vγ9Vδ2 T cells and the most potent natural phosphoantigen known to date. Moreover, 5-hydroxypentane-2,3-dione, a metabolite produced by Escherichia coli 1-deoxy-ᴅ-xylulose 5-phosphate synthase (DXS), the first enzyme of the MEP pathway, structurally resembles (S)-4,5-dihydroxy-2,3-pentanedione, a signal molecule implied in bacterial cell communication. In this review, we shed light on the diversity of potential uses of the MEP pathway in antibacterial therapies, starting with an overview of the antibacterials developed for each of its enzymes. Then, we provide insight into HMBPP, its synthetic analogs, and their prodrugs. Finally, we discuss the potential contribution of the MEP pathway to quorum sensing mechanisms. The MEP pathway, providing simultaneously antibacterial drug targets and potent immunostimulants, coupled with its potential role in bacterial cell–cell communication, opens new therapeutic perspectives.
Do Fungicides Affect Alkaloid Production in Catharanthus roseus (L.) G. Don. Seedlings?
Authors: Purnama Purin Candra , Hernandez Leonardo Castellanos , Verpoorte Robert
Published: February 2023

The presence of endophytes in plants is undeniable, but how significant their involvement is in the host plant biosynthetic pathways is still unclear. The results reported from fungicide treatments in plants varied. Fungicide treatment in Taxus was found to decrease the taxol content. In Ipomoea asarifolia, Pronto Plus and Folicur treatments coincided with the disappearance of ergot alkaloids from the plant. In Narcissus pseudonarcissus cv. Carlton, a mixture of fungicide applications decreased the alkaloids concentration and altered the carbohydrate metabolism. Jacobaea plants treated with Folicur reduced the pyrrolizidine alkaloids content. There have not been any studies into the involvement of endophytic fungi on alkaloids production of Catharanthus roseus until now. Though there is a report on the isolation of the endophytic fungi, Fusarium oxysporum from C. roseus, which was reported to produce vinblastine and vincristine in vitro. To detect possible collaborations between these two different organisms, fungicides were applied to suppress the endophytic fungi in seedlings and then measure the metabolomes by 1HNMR and HPLC analysis. The results indicate that endophytic fungi were not directly involved in alkaloids biosynthesis. Treatment with fungicides influenced both the primary and secondary metabolism of C. roseus. The systemic fungicides Pronto Plus and Folicur caused an increase in loganin and secologanin levels. In contrast, control samples had higher level of catharanthine and vindoline. This means that fungicide treatments cause changes in plant secondary metabolism.
Heteroaromatic Diazirines Are Essential Building Blocks for Material and Medicinal Chemistry
Authors: Murai Yuta , Hashimoto Makoto
Published: February 2023

In materials (polymer) science and medicinal chemistry, heteroaromatic derivatives play the role of the central skeleton in development of novel devices and discovery of new drugs. On the other hand, (3-trifluoromethyl)phenyldiazirine (TPD) is a crucial chemical method for understanding biological processes such as ligand–receptor, nucleic acid–protein, lipid–protein, and protein–protein interactions. In particular, use of TPD has increased in recent materials science to create novel electric and polymer devices with comparative ease and reduced costs. Therefore, a combination of heteroaromatics and (3-trifluoromethyl)diazirine is a promising option for creating better materials and elucidating the unknown mechanisms of action of bioactive heteroaromatic compounds. In this review, a comprehensive synthesis of (3-trifluoromethyl)diazirine-substituted heteroaromatics is described.
Mnx+ Substitution to Improve Na3V2(PO4)2F3-Based Electrodes for Sodium-Ion Battery Cathode
Authors: Su Renyuan , Zhu Weikai , Liang Kang , Wei Peng , Li Jianbin , Liu Wenjun , Ren Yurong
Published: February 2023

Na3V2(PO4)2F3 (NVPF) is an extremely promising sodium storage cathode material for sodium-ion batteries because of its stable structure, wide electrochemical window, and excellent electrochemical properties. Nevertheless, the low ionic and electronic conductivity resulting from the insulated PO43− structure limits its further development. In this work, the different valence states of Mnx+ ions (x = 2, 3, 4) doped NVPF were synthesized by the hydrothermal method. A series of tests and characterizations reveals that the doping of Mn ions (Mn2+, Mn3+, Mn4+) changes the crystal structure and also affects the residual carbon content, which further influences the electrochemical properties of NVPF-based materials. The sodiation/desodiation mechanism was also investigated. Among them, the as-prepared NVPF doped with Mn2+ delivers a high reversible discharge capacity (116.2 mAh g−1 at 0.2 C), and the capacity retention of 67.7% after 400 cycles at 1 C was obtained. Such excellent performance and facile modified methods will provide new design ideas for the development of secondary batteries.
ACT001 Relieves NMOSD Symptoms by Reducing Astrocyte Damage with an Autoimmune Antibody
Authors: Li Hongen , Yang Mo , Song Honglu , Sun Mingming , Zhou Huanfen , Fu Junxia , Zhou Di , Bai Wenhao , Chen Biyue , Lai Mengying , Kang Hao , Wei Shihui
Published: February 2023

Neuromyelitis optica spectrum disorder (NMOSD) is a central nervous system inflammatory demyelinating disease, the pathogenesis of which involves autoantibodies targeting the extracellular epitopes of aquaporin-4 on astrocytes. We neutralized the AQP4-IgG from NMOSD patient sera using synthesized AQP4 extracellular epitope peptides and found that the severe cytotoxicity produced by aquaporin-4 immunoglobin (AQP4-IgG) could be blocked by AQP4 extracellular mimotope peptides of Loop A and Loop C in astrocyte protection and animal models. ACT001, a natural compound derivative, has shown anti-tumor activity in various cancers. In our study, the central nervous system anti-inflammatory effect of ACT001 was investigated. The results demonstrated the superior astrocyte protection activity of ACT001 at 10 µM. Furthermore, ACT001 decreases the behavioral score in the mouse NMOSD model, which was not inferior to Methylprednisolone Sodium Succinate, the first-line therapy of NMOSD in clinical practice. In summary, our study showed that astrocytes are protected by specific peptides, or small molecular drugs, which is a new strategy for the treatment of NMOSD. It is possible for ACT001 to be a promising therapy for NMOSD.
Exploring the Relationship between Biosynthetic Gene Clusters and Constitutive Production of Mycosporine-like Amino Acids in Brazilian Cyanobacteria
Authors: Dextro Rafael B. , Delbaje Endrews , Geraldes Vanessa , Pinto Ernani , Long Paul F. , Fiore Marli F.
Published: February 2023

Cyanobacteria are oxygenic phototrophic prokaryotes that have evolved to produce ultraviolet-screening mycosporine-like amino acids (MAAs) to lessen harmful effects from obligatory exposure to solar UV radiation. The cyanobacterial MAA biosynthetic cluster is formed by a gene encoding 2-epi-5-epi-valiolone synthase (EVS) located immediately upstream from an O-methyltransferase (OMT) encoding gene, which together biosynthesize the expected MAA precursor 4-deoxygadusol. Accordingly, these genes are typically absent in non-producers. In this study, the relationship between gene cluster architecture and constitutive production of MAAs was evaluated in cyanobacteria isolated from various Brazilian biomes. Constitutive production of MAAs was only detected in strains where genes formed a co-linear cluster. Expectedly, this production was enhanced upon exposure of the strains to UV irradiance and by using distinct culture media. Constitutive production of MAAs was not detected in all other strains and, unexpectedly, production could not be induced by exposure to UV irradiation or changing growth media. Other photoprotection strategies which might be employed by these MAA non-producing strains are discussed. The evolutionary and ecological significance of gene order conservation warrants closer experimentation, which may provide a first insight into regulatory interactions of genes encoding enzymes for MAA biosynthesis.
Towards Probing Conformational States of Y2 Receptor Using Hyperpolarized 129Xe NMR
Authors: Schmidt Peter , Vogel Alexander , Schwarze Benedikt , Seufert Florian , Licha Kai , Wycisk Virginia , Kilian Wolfgang , Hildebrand Peter W. , Mitschang Lorenz
Published: February 2023

G protein-coupled receptors can adopt many different conformational states, each of them exhibiting different restraints towards downstream signaling pathways. One promising strategy to identify and quantify this conformational landscape is to introduce a cysteine at a receptor site sensitive to different states and label this cysteine with a probe for detection. Here, the application of NMR of hyperpolarized 129Xe for the detection of the conformational states of human neuropeptide Y2 receptor is introduced. The xenon trapping cage molecule cryptophane-A attached to a cysteine in extracellular loop 2 of the receptor facilitates chemical exchange saturation transfer experiments without and in the presence of native ligand neuropeptide Y. High-quality spectra indicative of structural states of the receptor–cage conjugate were obtained. Specifically, five signals could be assigned to the conjugate in the apo form. After the addition of NPY, one additional signal and subtle modifications in the persisting signals could be detected. The correlation of the spectroscopic signals and structural states was achieved with molecular dynamics simulations, suggesting frequent contact between the xenon trapping cage and the receptor surface but a preferred interaction with the bound ligand.
Valorization of Hemp-Based Packaging Waste with One-Pot Ionic Liquid Technology
Authors: Choi Julius , Rodriguez Alberto , Simmons Blake A. , Gladden John M.
Published: February 2023

The range of applications for industrial hemp has consistently increased in various sectors over the years. For example, hemp hurd can be used as a resource to produce biodegradable packaging materials when incorporated into a fungal mycelium composite, a process that has been commercialized. Although these packaging materials can be composted after usage, they may present an opportunity for valorization in a biorefinery setting. Here, we demonstrate the potential of using this type of discarded packaging composite as a feedstock for biofuel production. A one-pot ionic liquid-based biomass deconstruction and conversion process was implemented, and the results from the packaging material were compared with those obtained from untreated hemp hurd. At a 120 °C reaction temperature, 7.5% ionic liquid loading, and 2 h reaction time, the packaging materials showed a higher lignocellulosic sugar yield and sugar concentrations than hemp hurd. Hydrolysates prepared from packaging materials also promoted production of higher titers (1400 mg/L) of the jet-fuel precursor bisabolene when used to cultivate an engineered strain of the yeast Rhodosporidium toruloides. Box–Behnken experiments revealed that pretreatment parameters affected the hemp hurd and packaging materials differently, evidencing different degrees of recalcitrance. This study demonstrated that a hemp hurd-based packaging material can be valorized a second time once it reaches the end of its primary use by supplying it as a feedstock to produce biofuels.
Ranking Crossing Scenario Complexity for eHMIs Testing: A Virtual Reality Study
Authors: Fratini Elena , Welsh Ruth , Thomas Pete
Published: February 2023

External human–machine interfaces (eHMIs) have the potential to benefit AV–pedestrian interactions. The majority of studies investigating eHMIs have used relatively simple traffic environments, i.e., a single pedestrian crossing in front of a single eHMI on a one-lane straight road. While this approach has proved to be efficient in providing an initial understanding of how pedestrians respond to eHMIs, it over-simplifies interactions which will be substantially more complex in real-life circumstances. A process is illustrated in a small-scale study (N = 10) to rank different crossing scenarios by level of complexity. Traffic scenarios were first developed for varying traffic density, visual complexity of the road scene, road geometry, weather and visibility conditions, and presence of distractions. These factors have been previously shown to increase difficulty and riskiness of the crossing task. The scenarios were then tested in a motion-based, virtual reality environment. Pedestrians’ perceived workload and objective crossing behaviour were measured as indirect indicators of the level of complexity of the crossing scenario. Sense of presence and simulator sickness were also recorded as a measure of the ecological validity of the virtual environment. The results indicated that some crossing scenarios were more taxing for pedestrians than others, such as those with road geometries where traffic approached from multiple directions. Further, the presence scores showed that the virtual environments experienced were found to be realistic. This paper concludes by proposing a “complex” environment to test eHMIs under more challenging crossing circumstances.
Surveillance of Daughter Micronodule Formation Is a Key Factor for Vaccine Evaluation Using Experimental Infection Models of Tuberculosis in Macaques
Authors: Nogueira Isabel , Català Martí , White Andrew D. , Sharpe Sally A , Bechini Jordi , Prats Clara , Vilaplana Cristina , Cardona Pere-Joan
Published: February 2023

Tuberculosis (TB) is still a major worldwide health problem and models using non-human primates (NHP) provide the most relevant approach for vaccine testing. In this study, we analysed CT images collected from cynomolgus and rhesus macaques following exposure to ultra-low dose Mycobacterium tuberculosis (Mtb) aerosols, and monitored them for 16 weeks to evaluate the impact of prior intradermal or inhaled BCG vaccination on the progression of lung disease. All lesions found (2553) were classified according to their size and we subclassified small micronodules (<4.4 mm) as ‘isolated’, or as ‘daughter’, when they were in contact with consolidation (described as lesions ≥ 4.5 mm). Our data link the higher capacity to contain Mtb infection in cynomolgus with the reduced incidence of daughter micronodules, thus avoiding the development of consolidated lesions and their consequent enlargement and evolution to cavitation. In the case of rhesus, intradermal vaccination has a higher capacity to reduce the formation of daughter micronodules. This study supports the ‘Bubble Model’ defined with the C3HBe/FeJ mice and proposes a new method to evaluate outcomes in experimental models of TB in NHP based on CT images, which would fit a future machine learning approach to evaluate new vaccines.
Efficacy of Lanthanum Carbonate and Sevelamer Carbonate as Phosphate Binders in Chronic Kidney Disease—A Comparative Clinical Study
Authors: Nain Parminder , Nayak Narendra , Maj Mary C. , Singh Rohit Kumar , Kaur Jaspreet , Jeong Yujin , Maity Sabyasachi , Nath Reetuparna , Hilgers Robert H. , Nauhria Shreya , Nauhria Samal
Published: February 2023

(1) Background: Hyperphosphatemia is correlated with an increased rate of mortality and morbidity due to cardiovascular diseases in chronic kidney disease (CKD) patients. It can be improved by restricting dietary intake of phosphate and oral phosphate binders, such as lanthanum carbonate and sevelamer carbonate. (2) Objective: To evaluate the clinical efficacy of sevelamer carbonate in comparison to lanthanum carbonate as phosphate binders for the treatment of hyperphosphatemia in CKD patients. (3) Methods: A randomized control comparative clinical study was conducted for one year on 150 CKD patients associated with hyperphosphatemia, divided into two groups, i.e., Group 1 (n = 75) treated with sevelamer carbonate 800 mg thrice daily and Group 2 (n = 75) treated with lanthanum carbonate 500 mg thrice daily. The patients were assessed at the time of enrollment in the study, after three months and after six months from baseline for different parameters, i.e., complete blood count, liver function tests, renal function tests, electrolytes, and serum phosphate level. (4) Results: 150 CKD patients aged 51–60 participated in the study. The mean age of patients was 54 ± 4.6 years, and males (55.71%) were more common than females (44.29%). Hypertension was the common comorbidity in both groups with chronic kidney disease. After six months of treatment, the mean serum phosphate level was significantly decreased from 8.31 ± 0.09 mg/dL to 5.11 ± 0.18 (38%) in Group 1 and from 8.79 ± 0.28 mg/dl to 4.02 ± 0.12 (54%; p < 0.05) in Group 2, respectively. In both groups, no significant difference was found in other parameters such as parathyroid hormone, calcium, uric acid, LFT, RFT, CBC, etc. (5) Conclusion: Lanthanum carbonate is more efficacious in lowering serum phosphate concentrations and effectively managing hyperphosphatemia as compared to sevelamer carbonate.
Robust Pulse-Pumped Quadratic Soliton Assisted by Third-Order Nonlinearity
Authors: Wang Ke , Li Jing , Dai Fan , Wang Mengshuai , Wang Chuanhang , Wang Qiang , Tu Chenghou , Li Yongnan , Wang Huitian
Published: February 2023

The generation of a quadratic soliton in a pulse-pumped microresonator has attracted significant interest in recent years. The strong second-order nonlinearity and high peak power of pumps offer a straightforward way to increase efficiency. In this case, the influence of the third-order nonlinearity effect becomes significant and cannot be ignored. In this paper, we study the quadratic soliton in a degenerate optical parametric oscillator driven synchronously by the pulse pump with third-order nonlinearity. Our simulations verify that the robustness of quadratic soliton generation is enhanced when the system experiences a perturbation from pump power, cavity detuning, and pump pulse width. These results represent a new way of manipulating frequency comb in resonant microphotonic structures.
Pulse Width Control Based on Blumlein Pulse Forming Line and SI-GaAs PCSS
Authors: Wu Meilin , Shi Wei , Ma Cheng , Chen Zhiyuan , Liu Hui
Published: February 2023

In this paper, the output electrical pulse width of semi-insulating gallium arsenide photoconductive semiconductor switch (SI-GaAs PCSS) is controlled by means of Blumlein pulse formation line. Under the condition that the bias voltage is 28 kV and the laser pulse width is 9.5 ns, the electric pulse width obtained by using high-power pulse system transmission is 10 ns and the output voltage is 23 kV. Based on the Blumlein pulse formation line theory, the output pulse width and transient impedance are analyzed. The results show that the holding time of carriers avalanche multiplication can be controlled.
A Study on the Behavior of Cadmium in the Soil Solution–Plant System by the Lysimeter Method Using the 109Cd Radioactive Tracer
Authors: Anisimov Vyacheslav , Anisimova Lydia , Krylenkin Dmitry , Dikarev Dmitry , Sanzharov Andrey , Korneev Yuri N. , Kostyukov Ilya , Kolyagin Yuri G.
Published: February 2023

In soils, cadmium (Cd) and its compounds, originating from industrial activities, differ both in mobility as well as in their ability to permeate the soil solution from naturally occurring cadmium compounds (native Cd). Therefore, the determination of the parameters of cadmium mobility in soils and its accumulation by plants in the soil–soil solution–plant system is very important from both scientific and practical viewpoints. 109Cd was used as a radioactive tracer to study the processes of the transition of Cd into the aqueous phase and its uptake by plants over the course of a vegetative lysimeter experiment. Using sequential extraction according to the Tessier–Förstner procedure and modified BCR schemes, certain patterns were determined in the distribution of Cd/109Cd among their forms in various compounds in the soil, along with the coefficients of the enrichment of native stable Cd with radioactive 109Cd. It was shown that the labile pool of stable Cd compounds (29%) was significantly smaller than that of radioactive 109Cd (69%). The key parameters characterizing the migration capacity of Cd in the soil–soil solution–plant system were determined. It was found that the distribution coefficient of native Cd between the soil and the quasi-equilibrium lysimeter solution exceeded the similar value for the 109Cd radionuclide by 2.2 times, and the concentration coefficients of Cd and 109Cd in the barley roots were 9 times higher than in its vegetative parts. During the experiment, the average removal of Cd (109Cd) from the soil by each barley plant was insignificant: 0.002 (0.004)%. Based on the results of 13C nuclear magnetic resonance (NMR) spectroscopy of a lyophilized sample of the high-molecular-weight dissolved organic matter (HMWDOM) of the soil solution, its components were determined. It transpired that the isolated lyophilized samples of HMWDOM with different molecular weights had an identical structural and functional composition. The selective sorption parameters of the HMWDOM and humic acid (HA) with respect to Cd2+ ions were determined by the isotope dilution method.
Regulatory Effects of Thai Rice By-Product Extracts from Oryza sativa L. cv. Bue Bang 3 CMU and Bue Bang 4 CMU on Melanin Production, Nitric Oxide Secretion, and Steroid 5α-Reductase Inhibition
Authors: Ruksiriwanich Warintorn , Linsaenkart Pichchapa , Khantham Chiranan , Muangsanguan Anurak , Sringarm Korawan , Jantrawut Pensak , Prom-u-thai Chanakan , Jamjod Sansanee , Yamuangmorn Supapohn , Arjin Chaiwat , Rachtanapun Pornchai , Jantanasakulwong Kittisak , Phimolsiripol Yuthana , Barba Francisco J. , Sommano Sarana Rose , Chutoprapat Romchat , Boonpisuttinant Korawinwich
Published: February 2023

Alopecia and gray hair are common hair abnormalities affecting physical appearance and causing psychological problems. Chemical treatments partially restore hair disorders but have distressing side effects. Bioactive plant compounds constitute promising sources of potential medicinal substances instead of chemical agents, producing high side effects. In this study, we focused on the waste of local rice cultivars: Bue Bang 3 CMU (BB3CMU) and Bue Bang 4 CMU (BB4CMU) from the north of Thailand. The rice bran oil (RBO), defatted rice bran extract (DFRB), and rice husk (H) were determined for in vitro hair revitalization in melanin production, nitric oxide (NO) secretion, and steroid 5α-reductase inhibition. The results indicated that BB4CMU-RBO with high contents of iron, zinc, and free fatty acids showed a comparable induction of melanin production on melanocytes (130.18 ± 9.13% of control) to the standard drug theophylline with no significant difference (p > 0.05). This promising melanin induction could be related to activating the NO secretion pathway, with the NO secretion level at 1.43 ± 0.05 µM. In addition, BB4CMU-RBO illustrated a significant inhibitory effect on both steroid 5α-reductase genes (SRD5A) type 1 and type 2, which relates to its primary source of tocopherols. Hence, rice bran oil from the Thai rice variety BB4CMU could be applied as a promising hair revitalizing candidate, from natural resources, to help promote hair growth and re-pigmentation effects.
Medicinal Plants and Plant-Based Remedies in Grande-Terre: An Ethnopharmacological Approach
Authors: Courric Elisa , Brinvilier David , Couderc Petra , Ponce-Mora Alejandro , Méril-Mamert Vanessa , Sylvestre Muriel , Pelage Jeannie Hélène , Vaillant Jean , Rousteau Alain , Bejarano Eloy , Cebrian-Torrejon Gerardo
Published: February 2023

The island of Grande-Terre is a French overseas region that belongs to the Guadeloupean archipelago, a biodiversity hotspot with unique flora. Herbal medicine is widely used in the island for therapeutical purposes; however, there is a significant knowledge gap in the records relating to medicinal plants and their associated uses. Ethnobotanical survey methodology using quantitative parameters (informant consensus factor, species use value, relative frequency of citation, frequency use of a treatment and plant for an ailment) provided insights into the traditional medicinal use of a given plant. Ninety-six different plant species distributed among 56 families were identified and 523 remedies were documented in the survey. After data filtering, 22 plants species were associated with 182 remedies. The most frequent plant families were Poaceae, Myrtaceae, Cucurbitaceae and Rubiaceae. Aerial parts of these plants were the most common parts of the plant used for the remedies and the most frequent mode of administration was oral ingestion. This study highlights a valuable traditional knowledge of folklore medicine and helps to document and preserve the association of a plant with—and its use frequency for—a given ailment. These findings might be the starting point for the identification of biologically active phytocompounds to fight common health debilities.
Therapeutic Potential of Extracts from Macaranga tanarius (MTE) in Diabetic Nephropathy
Authors: Hsu Yung-Chien , Chang Cheng-Chih , Hsieh Ching-Chuan , Shih Ya-Hsueh , Chang Hsiu-Ching , Lin Chun-Liang
Published: February 2023

Diabetic nephropathy is a complication of diabetes that leads to end-stage kidney disease and is a major health burden worldwide. Prenylflavonoid compounds extracted from Macaranga tanarius (MTE) exhibit anti-inflammation, anti-oxidant, and anti-bacterial properties. However, the effects of these compounds on diabetic nephropathy remain unclear. The effects of MTE on diabetic nephropathy were investigated in vitro by using mouse renal mesangial cells and in vivo by using a db/db knockout mouse model. No overt alteration in proliferation was observed in mouse renal mesangial cells treated with 0–1 μg/mL MTE. Western blot analysis indicated that MTE dose-dependently attenuated the expression of fibronectin, α-smooth muscle actin, and collagen IV. Administration of MTE ameliorated renal albumin loss in db/db mice. Immunohistochemical staining revealed that MTE mitigated diabetes-induced fibronectin and collagen IV expression. Periodic acid–Schiff (PAS) and trichrome staining also showed that administration of MTE reduced the renal fibrosis phenomenon. MTE significantly ameliorated diabetes-induced nephropathy.