bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Mycoplasma Activity of Bacilotetrins C–E, Cyclic Lipodepsipeptides from the Marine-Derived Bacillus subtilis and Structure Revision of Bacilotetrins A and B
Authors: Lee Hwa-Sun , Shin Hee Jae
Published: September 2021

Mycoplasma hyorhinis most commonly causes polyserositis and arthritis in swine and is a common contaminant during the cell culture in the laboratory. In our continuing research for diverse bioactive compounds from Bacillus subtilis 109GGC020, we discovered uncommon cyclic lipotetrapeptides showing inhibitory activities against M. hyorhinis with similar structures to previously reported bacilotetrins A and B. Bacilotetrins C–E (1–3), new cyclic lipodepsipeptides, were isolated from the EtOAc extract obtained from the fermentation of marine-derived Bacillus subtilis isolated from a marine sponge sample collected from the Gageo reef, Republic of Korea. The structures of 1–3, consisting of three leucine residues, one glutamic acid, and a β-hydroxy fatty acid, were elucidated by detailed analysis of 1D, 2D NMR, and HR-ESIMS data. The absolute configurations of the amino acids and β-hydroxy fatty acid were established by advanced Marfey’s method and Mosher’s method, respectively. The localization of L- and D-amino acids within the compounds was determined by retention time comparison of each purchased dipeptide standard to the partial hydrolysate products using LC-MS. Compounds 1–3 exhibited anti-mycoplasma activity, with an MIC value of 31 μg/mL, twofold stronger than that of the positive control, BioMycoX®. Detailed analysis and comparison of the spectroscopic data between bacilotetrins A (4) and B (5) and 1–3 led us to revise the structures of 4 and 5.
Efficacy of Chondroprotective Food Supplements Based on Collagen Hydrolysate and Compounds Isolated from Marine Organisms
Authors: Eckert Thomas , Jährling-Butkus Mahena , Louton Helen , Burg-Roderfeld Monika , Zhang Ruiyan , Zhang Ning , Hesse Karsten , Petridis Athanasios K. , Kožár Tibor , Steinmeyer Jürgen , Schauer Roland , Engelhard Peter , Kozarova Anna , Hudson John W. , Siebert Hans-Christian
Published: September 2021

Osteoarthritis belongs to the most common joint diseases in humans and animals and shows increased incidence in older patients. The bioactivities of collagen hydrolysates, sulfated glucosamine and a special fatty acid enriched dog-food were tested in a dog patient study of 52 dogs as potential therapeutic treatment options in early osteoarthritis. Biophysical, biochemical, cell biological and molecular modeling methods support that these well-defined substances may act as effective nutraceuticals. Importantly, the applied collagen hydrolysates as well as sulfated glucosamine residues from marine organisms were strongly supported by both an animal model and molecular modeling of intermolecular interactions. Molecular modeling of predicted interaction dynamics was evaluated for the receptor proteins MMP-3 and ADAMTS-5. These proteins play a prominent role in the maintenance of cartilage health as well as innate and adapted immunity. Nutraceutical data were generated in a veterinary clinical study focusing on mobility and agility. Specifically, key clinical parameter (MMP-3 and TIMP-1) were obtained from blood probes of German shepherd dogs with early osteoarthritis symptoms fed with collagen hydrolysates. Collagen hydrolysate, a chondroprotective food supplement was examined by high resolution NMR experiments. Molecular modeling simulations were used to further characterize the interaction potency of collagen fragments and glucosamines with protein receptor structures. Potential beneficial effects of collagen hydrolysates, sulfated glycans (i.e., sulfated glucosamine from crabs and mussels) and lipids, especially, eicosapentaenoic acid (extracted from fish oil) on biochemical and physiological processes are discussed here in the context of human and veterinary medicine.
Muscle Regeneration and Function in Sports: A Focus on Vitamin D
Authors: Iolascon Giovanni , Moretti Antimo , Paoletta Marco , Liguori Sara , Di Munno Ombretta
Published: September 2021

Muscle is one of the main targets for the biological effects of vitamin D. This hormone modulates several functions of skeletal muscles, from development to tissue repair after injury, through genomic and non-genomic mechanisms. Vitamin D deficiency and supplementation seem to significantly affect muscle strength in different populations, including athletes, although optimal serum 25(OH)D3 level for sport performance has not been defined so far. Additionally, vitamin D deficiency results in myopathy characterized by fast-twitch fiber atrophy, fatty infiltration, and fibrosis. However, less is known about regenerative effects of vitamin D supplementation after sport-related muscle injuries. Vitamin D receptor (VDR) is particularly expressed in the embryonic mesoderm during intrauterine life and in satellite cells at all stages of life for recovery of the skeletal muscle after injury. Vitamin D supplementation enhances muscle differentiation, growth, and regeneration by increasing the expression of myogenic factors in satellite cells. The objective of this narrative review is to describe the role of vitamin D in sport-related muscle injury and tissue regeneration.
Ionic Liquid in Phosphoric Acid-Doped Polybenzimidazole (PA-PBI) as Electrolyte Membranes for PEM Fuel Cells: A Review
Authors: Seng Leong Kok , Masdar Mohd Shahbudin , Shyuan Loh Kee
Published: September 2021

Increasing world energy demand and the rapid depletion of fossil fuels has initiated explorations for sustainable and green energy sources. High-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) are viewed as promising materials in fuel cell technology due to several advantages, namely improved kinetic of both electrodes, higher tolerance for carbon monoxide (CO) and low crossover and wastage. Recent technology developments showed phosphoric acid-doped polybenzimidazole (PA-PBI) membranes most suitable for the production of polymer electrolyte membrane fuel cells (PEMFCs). However, drawbacks caused by leaching and condensation on the phosphate groups hindered the application of the PA-PBI membranes. By phosphate anion adsorption on Pt catalyst layers, a higher volume of liquid phosphoric acid on the electrolyte–electrode interface and within the electrodes inhibits or even stops gas movement and impedes electron reactions as the phosphoric acid level grows. Therefore, doping techniques have been extensively explored, and recently ionic liquids (ILs) were introduced as new doping materials to prepare the PA-PBI membranes. Hence, this paper provides a review on the use of ionic liquid material in PA-PBI membranes for HT-PEMFC applications. The effect of the ionic liquid preparation technique on PA-PBI membranes will be highlighted and discussed on the basis of its characterization and performance in HT-PEMFC applications.
Hydrogen Separation Performance of UiO-66-NH2 Membranes Grown via Liquid-Phase Epitaxy Layer-by-Layer Deposition and One-Pot Synthesis
Authors: Micero Alessandro , Hashem Tawheed , Gliemann Hartmut , Léon Aline
Published: September 2021

The quality assurance of hydrogen fuel for mobile applications is assessed by the guidelines and directives given in the European and international standards. However, the presence of impurities in the hydrogen fuel, in particular nitrogen, water, and oxygen, is experienced in several refueling stations. Within this work, metal-organic framework (MOF)-based membranes are investigated as a fine-purification stage of the hydrogen fuel. Three H2/N2 concentrations have been used to analyze the separation factor of UiO-66-NH2 membranes prepared using the layer-by-layer (LBL) and the one-pot (OP) synthesis methods. It is shown that the separation factor for an equimolar ratio is 14.4% higher for the LBL sample compared to the OP membrane, suggesting a higher orientation and continuity of the LBL surface-supported metal-organic framework (SURMOF). Using an equimolar ratio of H2/N2, it is shown that selective separation of hydrogen over nitrogen occurs with a separation factor of 3.02 and 2.64 for the SURMOF and MOF membrane, respectively. To the best of our knowledge, this is the highest reported performance for a single-phase UiO-66-NH2 membrane. For higher hydrogen concentrations, the separation factor decreases due to reduced interactions between pore walls and N2 molecules.
Quantitative Examination of the Inclusion and the Rotated Bending Fatigue Behavior of SAE52100
Authors: An Xueliang , Shi Zhiyue , Xu Haifeng , Wang Cunyu , Wang Yuhui , Cao Wenquan , Yu Jinku
Published: September 2021

This study investigated the effect of maximum inclusion on the life of SAE52100 bearing steel processed by two different melting routes, vacuum induction melting plus electroslag remelting (VIM + ESR), and basic oxygen furnace plus ladle furnace plus vacuum degassing process (BOF + LF + RH) by the metallographic method, Aspex explorer, and rotated bending fatigue test. The rotated bending method was applied to examine the maximum inclusion size in a satisfactory manner, whereas both the metallographic method and Aspex explorer underestimated the result. Regardless of the characterization methods, the results show that the total number of inclusions in VIM + ESR melted steel is significantly higher than that in BOF + LF + RH processed steel, but the maximum inclusion size of VIM + ESR melted steel is significantly smaller than that of the BOF + LF + RH degassed steel. The distribution of the maximum inclusion size could be well fitted by the inverse Weibull distribution and could be well applied to reveal the different inclusion size distribution based on the data examined by the rotated bending fatigue method. Finally, a new equation was proposed to establish the relationship among the loading stress amplitude, rotated bending fatigue number, and the maximum inclusion size.
Transitory Ultrasonic Absorption in “Domain Engineered” Structures of 10 M Ni-Mn-Ga Martensite
Authors: Kustov Sergey , Saren Andrey , D’Agosto Bruno , Sapozhnikov Konstantin , Nikolaev Vladimir , Ullakko Kari
Published: September 2021

In this work we create in 10 M Ni-Mn-Ga martensitic samples special martensitic variant structures consisting of only three twins separated by two a/c twin boundaries: Type I and Type II, with relatively low and very high mobility, respectively. The “domain engineered” structure thus created allows us to investigate the dynamics of a single highly mobile a/c twin boundary (TB). We show that temperature variations between 290 and 173 K in our samples induce an intense transitory internal friction at ultrasonic frequencies ca. 100 kHz, peaking around 215 K. A comparison is made of the data for the “domain engineered” sample with the behaviour of reference samples without a/c TB. Reference samples have two different orientations of a/b twins providing zero and maximum shear stresses in a/b twinning planes. We argue, first, that the transitory internal friction, registered at rather high ultrasonic frequencies, has magnetic origin. It is related with the rearrangement of magnetic domain structure due to the motion of a/c twin boundary induced by thermal stresses. This internal friction term can be coined “magnetic transitory internal friction”. Magnetic transitory internal friction is a new category, linking the classes of transitory and magnetomechanical internal friction. Second, the structure of a/b twins is strongly non-equilibrium over a broad temperature range. As a consequence, the Young’s modulus values of the samples with maximum shear stress in a/b twinning planes can take any value between ca. 15 and 35 GPa, depending on the prehistory of the sample.
The Evolution of the Nugget Zone for Dissimilar AA6061/AA7075 Joints Fabricated via Multiple-Pass Friction Stir Welding
Authors: Chen Yu , Cai Zhihui , Ding Hua , Zhang Fenghe
Published: September 2021

AA6061 and AA7075 aluminum alloys were successfully joined by using single-pass and multiple-pass friction stir welding techniques after which the effects on the nugget zone evolution from a second overlapping pass and its welding direction, were investigated. In comparison to single-pass friction stir welding, the application of a second overlapping pass prolonged the dynamic recrystallization time, and the grains of the nugget zone became finer with increased high angle grain boundaries. Moreover, reversing the welding direction of the second overlapping pass enhanced the vertical flow of materials, increasing the strain of the friction stir welding in the nugget zone. As a result, the efficiency of the grain refinement and mixture of dissimilar materials during the second overlapping pass were significantly elevated. The tensile strength of the nugget zone was improved after the second overlapping pass due to both the grain refinement and mechanical interlocking of the AA6061/AA7075 alloys. The nugget zone, which was fabricated via the multiple-pass friction stir welding technique using an opposite welding direction, exhibited a 23% increase in yield strength as compared to the sample using the single-pass friction stir welding technique.
Computational Failure Analysis under Overloading
Authors: Boljanović Slobodanka , Carpinteri Andrea
Published: September 2021

The aim of this research work is to shed more light on performance-based design through a computational framework that assesses the residual strength of damaged plate-type configurations under overloading. Novel expressions are generated to analyze the power of crack-like stress raisers coupled with retardation effects. Analytical outcomes show that careful consideration of the overload location and crack size can be quite effective in improving safety design and failure mode estimation.
Effect of ECAP Die Angle on Mechanical Properties and Biocompatibility of SS316L
Authors: Awang Sh’ri Dayangku Noorfazidah , Zahari Zahiruddeen Salam , Yamamoto Akiko
Published: September 2021

In this study, ultrafine grain (UFG) SS316L was produced using an equal channel angular pressing (ECAP) process at two different die angles namely 120° and 126°. The effect of different die angles on mechanical, corrosion, and surface properties were thoroughly investigated. Furthermore, the subsequent effect on the cytotoxicity of SS316L was investigated. The microstructure observation shows ECAP processing has produced an elongated, finer grain size at 120° than 126°. The ECAP processing also increases the hardness of SS316L. There is no change in wettability and surface roughness observed. However, the ectrochemical measurement reveals that ECAP processing improves the corrosion resistance of SS316L. The cytocompatibility of ECAPed SS316L was evaluated by both a direct and an extract methods, finding the contribution of grain refinement by ECAP processing.
FE Analysis of Laser Shock Peening on STS304 and the Effect of Static Damping on the Solution
Authors: Kim Ryoonhan , Suh Jeong , Shin Dongsig , Lee Kwang-Hyeon , Bae Seung-Hoon , Cho Dae-Won , Yi Won-Geun
Published: September 2021

Laser shock peening creates compressive residual stress on the surface of the material, reducing stress corrosion cracking and increasing fatigue life. FE simulation of laser shock peening is an effective way to determine the mechanical effects on the material. In conventional FE simulations of laser shock peening, explicit analysis is used while pressure loads are applied and switched into implicit analysis to dissipate kinetic energy. In this study, static damping was adopted to dissipate kinetic energy without conversion into implicit analysis. Simulation of a single laser shock and multiple shocks was performed, and deformation and minimum principal stress were compared to evaluate the static damping effect. The history of the internal and kinetic energy were analyzed to compare the stabilization time depending on the damping value. Laser shock peening experiments were also performed on stainless steel 304 material. The residual stress of the specimen was measured by the hole drilling method and it was compared to the FE simulation result. The residual stress from the experiment and the simulation results showed similar distributions in the depth direction. Anisotropic residual stress distribution due to the laser path was observed in both results.
Effect of Bimodal Grain Structure on the Microstructural and Mechanical Evolution of Al-Mg/CNTs Composite
Authors: Sadeghi Behzad , Cavaliere Pasquale
Published: September 2021

The Al-Mg alloy structure reinforced with carbon nanotubes was evaluated after the composites production through a modified flake metallurgy technique followed by hot extrusion. The obtained bimodal microstructure of the matrix allowed to identify the microstructural mechanisms leading to high strength; uniform elongation and strain hardening ability of the produced composites. The presence of Mg transformed the native Al2O3 layer into spinel MgAl2O4 nano-phases dispersed both inside CG and UFGs and on the interfaces, improving the interfacial bonding of Al-Al as well as Al-CNT. The effect of the reinforcing phases percentages on the dislocations mechanisms evolution was evaluated through stress relaxation tests leading to the underlying of the effect of reinforcing phases on the modification of the interphase influence zone
Coexisting Multiple Martensites in Ni57−xMn21+xGa22 Ferromagnetic Shape Memory Alloys: Crystal Structure and Phase Transition
Authors: Huang Lian , Cong Daoyong , Wang Mingguang , Wang Yandong
Published: September 2021

A comprehensive study of the crystal structure and phase transition as a function of temperature and composition in Ni57−xMn21+xGa22 (x = 0, 2, 4, 5.5, 7, 8) (at. %) magnetic shape memory alloys was performed by a temperature-dependent synchrotron X-ray diffraction technique and transmission electron microscopy. A phase diagram of this Ni57−xMn21+xGa22 alloy system was constructed. The transition between coexisting multiple martensites with monoclinic and tetragonal structures during cooling was observed in the Ni51.5Mn26.5Ga22 (x = 5.5) alloy, and it was found that 5M + 7M multiple martensites coexist from 300 K to 160 K and that 5M + 7M + NM multiple martensites coexist between 150 K and 100 K. The magnetic-field-induced transformation from 7M martensite to NM martensite at 140 K where 5M + 7M + NM multiple martensites coexist before applying the magnetic field was observed by in situ neutron diffraction experiments. The present study is instructive for understanding the phase transition between coexisting multiple martensites under external fields and may shed light on the design of novel functional properties based on such phase transitions.
Recent Advancements in AI-Enabled Smart Electronics Packaging for Structural Health Monitoring
Authors: Sharma Vinamra Bhushan , Tewari Saurabh , Biswas Susham , Lohani Bharat , Dwivedi Umakant Dhar , Dwivedi Deepak , Sharma Ashutosh , Jung Jae Pil
Published: September 2021

Real-time health monitoring of civil infrastructures is performed to maintain their structural integrity, sustainability, and serviceability for a longer time. With smart electronics and packaging technology, large amounts of complex monitoring data are generated, requiring sophisticated artificial intelligence (AI) techniques for their processing. With the advancement of technology, more complex AI models have been applied, from simple models to sophisticated deep learning (DL) models, for structural health monitoring (SHM). In this article, a comprehensive review is performed, primarily on the applications of AI models for SHM to maintain the sustainability of diverse civil infrastructures. Three smart data capturing methods of SHM, namely, camera-based, smartphone-based, and unmanned aerial vehicle (UAV)-based methods, are also discussed, having made the utilization of intelligent paradigms easier. UAV is found to be the most promising smart data acquisition technology, whereas convolution neural networks are the most impressive DL model reported for SHM. Furthermore, current challenges and future perspectives of AI-based SHM systems are also described separately. Moreover, the Internet of Things (IoT) and smart city concepts are explained to elaborate on the contributions of intelligent SHM systems. The integration of SHM with IoT and cloud-based computing is leading us towards the evolution of future smart cities.
Metabolomics, Microbiota, and In Vivo and In Vitro Biomarkers in Type 2 Severe Asthma: A Perspective Review
Authors: Caruso Cristiano , Colantuono Stefania , Nicoletti Alberto , Arasi Stefania , Firinu Davide , Gasbarrini Antonio , Coppola Angelo , Di Michele Loreta
Published: September 2021

Precision medicine refers to the tailoring of therapeutic strategies to the individual characteristics of each patient; thus, it could be a new approach for the management of severe asthma that considers individual variability in genes, environmental exposure, and lifestyle. Precision medicine would also assist physicians in choosing the right treatment, the best timing of administration, consequently trying to maximize drug efficacy, and, possibly, reducing adverse events. Metabolomics is the systematic study of low molecular weight (bio)chemicals in a given biological system and offers a powerful approach to biomarker discovery and elucidating disease mechanisms. In this point of view, metabolomics could play a key role in targeting precision medicine.
Identification of Possible Salivary Metabolic Biomarkers and Altered Metabolic Pathways in South American Patients Diagnosed with Oral Squamous Cell Carcinoma
Authors: de Sá Alves Mariana , de Sá Rodrigues Nayara , Bandeira Celso Muller , Chagas José Francisco Sales , Pascoal Maria Beatriz Nogueira , Nepomuceno Gabrielle Luana Jimenez Teodoro , da Silva Martinho Herculano , Alves Mônica Ghislaine Oliveira , Mendes Maria Anita , Dias Meriellen , Alves Levy Anderson César , Almeida Janete Dias
Published: September 2021

Oral squamous cell carcinoma (OSCC) represents 90% of oral malignant neoplasms. The search for specific biomarkers for OSCC is a very active field of research contributing to establishing early diagnostic methods and unraveling underlying pathogenic mechanisms. In this work we investigated the salivary metabolites and the metabolic pathways of OSCC aiming find possible biomarkers. Salivary metabolites samples from 27 OSCC patients and 41 control individuals were compared through a gas chromatography coupled to a mass spectrometer (GC-MS) technique. Our results allowed identification of pathways of the malate-aspartate shuttle, the beta-alanine metabolism, and the Warburg effect. The possible salivary biomarkers were identified using the area under receiver-operating curve (AUC) criterion. Twenty-four metabolites were identified with AUC > 0.8. Using the threshold of AUC = 0.9 we find malic acid, maltose, protocatechuic acid, lactose, 2-ketoadipic, and catechol metabolites expressed. We notice that this is the first report of salivary metabolome in South American oral cancer patients, to the best of our knowledge. Our findings regarding these metabolic changes are important in discovering salivary biomarkers of OSCC patients. However, additional work needs to be performed considering larger populations to validate our results.
Flow Direction-Dependent Elastic Instability in a Symmetry-Breaking Microchannel
Authors: Zhang Wu , Wang Zihuang , Zhang Meng , Lin Jiahan , Chen Weiqian , Hu Yuhong , Li Shuzhou
Published: September 2021

This paper reports flow direction-dependent elastic instability in a symmetry-breaking microchannel. The microchannel consisted of a square chamber and a nozzle structure. A viscoelastic polyacrylamide solution was used for the instability demonstration. The instability was realized as the viscoelastic flow became asymmetric and unsteady in the microchannel when the flow exceeded a critical Weissenberg number. The critical Weissenberg number was found to be different for the forward-directed flow and the backward-directed flow in the microchannel.
A 3D-Printed Fin Ray Effect Inspired Soft Robotic Gripper with Force Feedback
Authors: Yang Yang , Jin Kaixiang , Zhu Honghui , Song Gongfei , Lu Haojian , Kang Long
Published: September 2021

Soft robotic grippers are able to carry out many tasks that traditional rigid-bodied grippers cannot perform but often have many limitations in terms of control and feedback. In this study, a Fin Ray effect inspired soft robotic gripper is proposed with its whole body directly 3D printed using soft material without the need of assembly. As a result, the soft gripper has a light weight, simple structure, is enabled with high compliance and conformability, and is able to grasp objects with arbitrary geometry. A force sensor is embedded in the inner side of the gripper, which allows the contact force required to grip the object to be measured in order to guarantee successful grasping and to provide the most suitable gripping force. In addition, it enables control and data monitoring of the gripper’s operating state at all times. Characterization and grasping demonstration of the gripper are given in the Experiment section. Results show that the gripper can be used in a wide range of scenarios and applications, such as the service robot and food industry.
Comparison between Bosch and STiGer Processes for Deep Silicon Etching
Authors: Tillocher Thomas , Nos Jack , Antoun Gaëlle , Lefaucheux Philippe , Boufnichel Mohamed , Dussart Rémi
Published: September 2021

The cryogenic process is well known to etch high aspect ratio features in silicon with smooth sidewalls. A time-multiplexed cryogenic process, called STiGer, was developed in 2006 and patented. Like the Bosch process, it consists in repeating cycles composed of an isotropic etching step followed by a passivation step. If the etching step is similar for both processes, the passivation step is a SiF4/O2 plasma that efficiently deposits a SiOxFy layer on the sidewalls only if the substrate is cooled at cryogenic temperature. In this paper, it is shown that the STiGer process can achieve profiles and performances equivalent to the Bosch process. However, since sidewall passivation is achieved with polymer free plasma chemistry, less frequent chamber cleaning is necessary, which contributes to increase the throughput.
Microfluidic Single-Cell Proteomics Assay Chip: Lung Cancer Cell Line Case Study
Authors: Jung Yugyung , Son Minkook , Nam Yu Ri , Choi Jongchan , Heath James R. , Yang Sung
Published: September 2021

Cancer is a dynamic disease involving constant changes. With these changes, cancer cells become heterogeneous, resulting in varying sensitivity to chemotherapy. The heterogeneity of cancer cells plays a key role in chemotherapy resistance and cancer recurrence. Therefore, for effective treatment, cancer cells need to be analyzed at the single-cell level by monitoring various proteins and investigating their heterogeneity. We propose a microfluidic chip for a single-cell proteomics assay that is capable of analyzing complex cellular signaling systems to reveal the heterogeneity of cancer cells. The single-cell assay chip comprises (i) microchambers (n = 1376) for manipulating single cancer cells, (ii) micropumps for rapid single-cell lysis, and (iii) barcode immunosensors for detecting nine different secretory and intracellular proteins to reveal the correlation among cancer-related proteins. Using this chip, the single-cell proteomics of a lung cancer cell line, which may be easily masked in bulk analysis, were evaluated. By comparing changes in the level of protein secretion and heterogeneity in response to combinations of four anti-cancer drugs, this study suggests a new method for selecting the best combination of anti-cancer drugs. Subsequent preclinical and clinical trials should enable this platform to become applicable for patient-customized therapies.
Computational Simulations in Advanced Microfluidic Devices: A Review
Authors: Carvalho Violeta , Rodrigues Raquel O. , Lima Rui A. , Teixeira Senhorinha
Published: September 2021

Numerical simulations have revolutionized research in several engineering areas by contributing to the understanding and improvement of several processes, being biomedical engineering one of them. Due to their potential, computational tools have gained visibility and have been increasingly used by several research groups as a supporting tool for the development of preclinical platforms as they allow studying, in a more detailed and faster way, phenomena that are difficult to study experimentally due to the complexity of biological processes present in these models—namely, heat transfer, shear stresses, diffusion processes, velocity fields, etc. There are several contributions already in the literature, and significant advances have been made in this field of research. This review provides the most recent progress in numerical studies on advanced microfluidic devices, such as organ-on-a-chip (OoC) devices, and how these studies can be helpful in enhancing our insight into the physical processes involved and in developing more effective OoC platforms. In general, it has been noticed that in some cases, the numerical studies performed have limitations that need to be improved, and in the majority of the studies, it is extremely difficult to replicate the data due to the lack of detail around the simulations carried out.
Challenges in Determining the Role of Microbiome Evolution in Barrett’s Esophagus and Progression to Esophageal Adenocarcinoma
Authors: Guccione Caitlin , Yadlapati Rena , Shah Shailja , Knight Rob , Curtius Kit
Published: September 2021

Esophageal adenocarcinoma (EAC) claims the lives of half of patients within the first year of diagnosis, and its incidence has rapidly increased since the 1970s despite extensive research into etiological factors. The changes in the microbiome within the distal esophagus in modern populations may help explain the growth in cases that other common EAC risk factors together cannot fully explain. The precursor to EAC is Barrett’s esophagus (BE), a metaplasia adapted to a reflux-mediated microenvironment that can be challenging to diagnose in patients who do not undergo endoscopic screening. Non-invasive procedures to detect microbial communities in saliva, oral swabs and brushings from the distal esophagus allow us to characterize taxonomic differences in bacterial population abundances within patients with BE versus controls, and may provide an alternative means of BE detection. Unique microbial communities have been identified across healthy esophagus, BE, and various stages of progression to EAC, but studies determining dynamic changes in these communities, including migration from proximal stomach and oral cavity niches, and their potential causal role in cancer formation are lacking. Helicobacter pylori is negatively associated with EAC, and the absence of this species has been implicated in the evolution of chromosomal instability, a main driver of EAC, but joint analyses of microbiome and host genomes are needed. Acknowledging technical challenges, future studies on the prediction of microbial dynamics and evolution within BE and the progression to EAC will require larger esophageal microbiome datasets, improved bioinformatics pipelines, and specialized mathematical models for analysis.
The Nasopharyngeal, Ruminal, and Vaginal Microbiota and the Core Taxa Shared across These Microbiomes in Virgin Yearling Heifers Exposed to Divergent In Utero Nutrition during Their First Trimester of Gestation and in Pregnant Beef Heifers in Response to Mineral Supplementation
Authors: Amat Samat , Holman Devin B. , Schmidt Kaycie , Menezes Ana Clara B. , Baumgaertner Friederike , Winders Thomas , Kirsch James D. , Liu Tingting , Schwinghamer Timothy D. , Sedivec Kevin K. , Dahlen Carl R.
Published: September 2021

In the present study, we evaluated whether the nasopharyngeal, ruminal, and vaginal microbiota would diverge (1) in virgin yearling beef heifers (9 months old) due to the maternal restricted gain during the first trimester of gestation; and (2) in pregnant beef heifers in response to the vitamin and mineral (VTM) supplementation during the first 6 months of pregnancy. As a secondary objective, using the microbiota data obtained from these two cohorts of beef heifers managed at the same location and sampled at the same time, we performed a holistic assessment of the microbial ecology residing within the respiratory, gastrointestinal, and reproductive tract of cattle. Our 16S rRNA gene sequencing results revealed that both α and β-diversity of the nasopharyngeal, ruminal and vaginal microbiota did not differ between virgin heifers raised from dams exposed to either a low gain (targeted average daily gain of 0.28 kg/d, n = 22) or a moderate gain treatment (0.79 kg/d, n = 23) during the first 84 days of gestation. Only in the vaginal microbiota were there relatively abundant genera that were affected by maternal rate of gain during early gestation. Whilst there was no significant difference in community structure and diversity in any of the three microbiota between pregnant heifers received no VTM (n = 15) and VTM supplemented (n = 17) diets, the VTM supplementation resulted in subtle compositional alterations in the nasopharyngeal and ruminal microbiota. Although the nasopharyngeal, ruminal, and vaginal microbiota were clearly distinct, a total of 41 OTUs, including methanogenic archaea, were identified as core taxa shared across the respiratory, gastrointestinal, and reproductive tracts of both virgin and pregnant heifers.
Genome Evolution of Filamentous Cyanobacterium Nostoc Species: From Facultative Symbiosis to Free Living
Authors: Huo Da , Li Hua , Cai Fangfang , Guo Xiaoyu , Qiao Zhiyi , Wang Weibo , Yu Gongliang , Li Renhui
Published: September 2021

In contrast to obligate bacteria, facultative symbiotic bacteria are mainly characterized by genome enlargement. However, the underlying relationship of this feature with adaptations to various habitats remains unclear. In this study, we used the global genome data of Nostoc strains, including 10 novel genomes sequenced in this study and 26 genomes available from public databases, and analyzed their evolutionary history. The evolutionary boundary of the real clade of Nostoc species was identified and was found to be consistent with the results of polyphasic taxonomy. The initial ancestral species of Nostoc was demonstrated to be consistent with a facultative symbiotic population. Further analyses revealed that Nostoc strains tended to shift from facultative symbiosis to a free-living one, along with an increase in genome sizes during the dispersal of each exterior branch. Intracellular symbiosis was proved to be essentially related to Nostoc evolution, and the adaptation of its members to free-living environments was coupled with a large preference for gene acquisition involved in gene repair and recombination. These findings provided unique evidence of genomic mechanisms by which homologous microbes adapt to distinct life manners and external environments.
Bloodstream Infections in Hospitalized Patients with COVID-19: A Systematic Review and Meta-Analysis
Authors: Ippolito Mariachiara , Simone Barbara , Filisina Carlotta , Catalanotto Francesca Romana , Catalisano Giulia , Marino Claudia , Misseri Giovanni , Giarratano Antonino , Cortegiani Andrea
Published: September 2021

Background: Little is known about the occurrence of bloodstream infections in hospitalized patients with COVID-19 and the related clinical consequences. The aim of this systematic review and meta-analysis was to estimate the pooled occurrence of BSIs among hospitalized patients with COVID-19 and mortality of this patient population. Methods: A systematic search was performed on PubMed, EMBASE, and Web of Science from inception to 19 April 2021. The primary outcome was the occurrence of BSIs among hospitalized patients with COVID-19. The secondary outcome was mortality at the longest available follow-up. Results: Forty-six studies met the inclusion criteria, with a total of 42,694 patients evaluated. The estimated occurrence of BSIs was 7.3% (95% CI 4.7–1.1%) among hospitalized patients with COVID-19, with a mortality rate of 41% (95% CI 30%–52.8%). The subgroup analysis conducted on patients admitted to ICU provided an estimated occurrence of 29.6% (95% CI 21.7%–38.8%). A higher occurrence of BSI was observed in patients with COVID-19, in comparison with patients without COVID-19 (OR 2.77; 95% CI 1.53–5.02; p < 0.001). Conclusions: Our analysis estimated the occurrence of BSIs among hospitalized patients with COVID-19 at around 7%. A four-times higher occurrence was estimated among patients admitted to ICU.
Effect of Ca2+ Replacement with Cu2+ Ions in Brushite on the Phase Composition and Crystal Structure
Authors: Alshaaer Mazen , Al-Kafawein Juma’a , Afify Ahmed S. , Hamad Nagat , Saffarini Ghassan , Issa Khalil
Published: September 2021

The gradual replacement of Ca2+ with Cu2+ ions in brushite (CaHPO4·2H2O) has been extensively studied and discussed. The approach adopted in this work has not been systematically explored in previous studies. This novel approach may prove beneficial for the production of Ca1−xCuxHPO4·nH2O materials with desired properties suitable for medical applications. Solutions of sodium dihydrogen orthophosphate dihydrate, NaH2PO4·2H2O, calcium nitrate tetrahydrate, Ca(NO3)2·4H2O, copper nitrate trihydrate, Cu(NO3)2·3H2O, ammonium hydroxide solution, and diluted HCl were used for the preparation of these materials. At low Cu/Ca molar ratios (up to 0.25) in the starting solution, biphasic phosphate minerals were formed: brushite and sampleite. When the Cu/Ca molar ratio increases gradually from 0.67 to 1.5, sampleite-like mineral precipitates. Powdered XRD (X-ray diffraction), thermogravimetric (TG) analysis, and SEM (scanning electron microscopy) techniques were employed for the study of the microstructure of the produced materials for different degrees of Ca replacement with Mg. It is found that the Cu/Ca ratio in the starting solution can be adjusted to obtain materials with tailored composition. Thus, a new method of sampleite-like synthesis as a rare mineral is introduced in this study. Both phosphate minerals brushite and sampleite-like minerals are attractive as precursors of bioceramics and biocements. The search for such products that may decrease the possibility of post prosthetic or implant infection can be crucial in preventing devastating post-surgical complications.
Archean Zircons with Omphacite Inclusions from Eclogites of the Belomorian Province, Fennoscandian Shield: The First Finding
Authors: Volodichev Oleg I. , Maksimov Oleg A. , Kuzenko Tatiana I. , Slabunov Alexander I.
Published: September 2021

Early Precambrian retrogressed eclogites are abundant in the central and northern parts of the Belomorian Province of the Fennoscandian Shield (Gridino + Keret and Salma + Kuru-Vaara study areas, respectively). Older and younger eclogites are recognized and their Archean and Paleoproterozoic ages are argued. Archean eclogites are intensely retrogressed and occur in amphibolite boudins in the tonalite-trondhjemite-granodiorite (TTG) gneiss matrix of the Archean Gridino eclogite-bearing mélange. Less retrogressed Paleoproterozoic eclogites form patches in mafic dikes and some amphibolite boudins; their Paleoproterozoic age is supported by U-Pb/SIMS data on zircons depleted in heavy rare earth elements (REE) with omphacite, garnet, and kyanite inclusions, and Sm-Nd and Lu-Hf mineral isochrons. Archean eclogites contain Archean heavy rare-earth elements (REE)-depleted zircons with garnet and zoisite inclusions and Archean garnets. No omphacite inclusions were found in these zircons, and this fact was considered as evidence against the existence of Archean eclogites. This study reports on the first finding of omphacite (23–25% Jd) inclusions in 2.68 Ga metamorphic zircons from eclogites from the Gridino eclogite-bearing mélange. The zircons are poorly enriched in heavy REE and display a weak negative Eu-anomaly but a poor positive Ce-anomaly typical of eclogitic zircons. Thus, zircons with these decisive features provide evidence for an Archean eclogite-facies metamorphism.
Chemical Evaluation, Antioxidant, Antiproliferative, Anti-Inflammatory and Antibacterial Activities of Organic Extract and Semi-Purified Fractions of the Adriatic Sea Fan, Eunicella cavolini
Authors: Matulja Dario , Grbčić Petra , Bojanić Krunoslav , Topić-Popović Natalija , Čož-Rakovac Rozelindra , Laclef Sylvain , Šmuc Tomislav , Jović Ozren , Marković Dean , Pavelić Sandra Kraljević
Published: September 2021

Due to sedentary lifestyle and harsh environmental conditions, gorgonian coral extracts are recognized as a rich source of novel compounds with various biological activities, of interest to the pharmaceutical and cosmetic industries. The presented study aimed to perform chemical screening of organic extracts and semi-purified fractions obtained from the common Adriatic gorgonian, sea fan, Eunicella cavolini (Koch, 1887) and explore its abilities to exert different biological effects in vitro. Qualitative chemical evaluation revealed the presence of several classes of secondary metabolites extended with mass spectrometry analysis and tentative dereplication by using Global Natural Product Social Molecular Networking online platform (GNPS). Furthermore, fractions F4 and F3 showed the highest phenolic (3.28 ± 0.04 mg GAE/g sample) and carotene (23.11 ± 2.48 mg β-CA/g sample) content, respectively. The fraction F3 inhibited 50% of DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and ABTS (2,2′-azino-bis (3-ethylbenzthiazolin-6-yl) sulfonic acid) radicals at the concentrations of 767.09 ± 11.57 and 157.16 ± 10.83 µg/mL, respectively. The highest anti-inflammatory potential was exhibited by F2 (IC50 = 198.70 ± 28.77 µg/mL) regarding the inhibition of albumin denaturation and F1 (IC50 = 254.49 ± 49.17 µg/mL) in terms of soybean lipoxygenase inhibition. In addition, the most pronounced antiproliferative effects were observed for all samples (IC50 ranging from 0.82 ± 0.14–231.18 ± 46.13 µg/mL) against several carcinoma cell lines, but also towards non-transformed human fibroblasts pointing to a generally cytotoxic effect. In addition, the antibacterial activity was tested by broth microdilution assay against three human pathogenic bacteria: Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The latter was the most affected by fractions F2 and F3. Finally, further purification, isolation and characterization of pure compounds from the most active fractions are under investigation.
Pursuing High-Resolution Structures of Nicotinic Acetylcholine Receptors: Lessons Learned from Five Decades
Authors: Delgado-Vélez Manuel , Quesada Orestes , Villalobos-Santos Juan C. , Maldonado-Hernández Rafael , Asmar-Rovira Guillermo , Stevens Raymond C. , Lasalde-Dominicci José Antonio
Published: September 2021

Since their discovery, nicotinic acetylcholine receptors (nAChRs) have been extensively studied to understand their function, as well as the consequence of alterations leading to disease states. Importantly, these receptors represent pharmacological targets to treat a number of neurological and neurodegenerative disorders. Nevertheless, their therapeutic value has been limited by the absence of high-resolution structures that allow for the design of more specific and effective drugs. This article offers a comprehensive review of five decades of research pursuing high-resolution structures of nAChRs. We provide a historical perspective, from initial structural studies to the most recent X-ray and cryogenic electron microscopy (Cryo-EM) nAChR structures. We also discuss the most relevant structural features that emerged from these studies, as well as perspectives in the field.
Development and Validation of QuEChERS Followed by UHPLC-ToF-MS Method for Determination of Multi-Mycotoxins in Pistachio Nuts
Authors: Mateus Ana Rita Soares , Barros Sílvia , Pena Angelina , Silva Ana Sanches
Published: September 2021

Pistachios are one of the types of tree nut fruits with the highest mycotoxin contamination, especially of aflatoxins, worldwide. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method that was followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC–ToF-MS) for the determination of mycotoxins in pistachios. Different approaches to dispersive solid phase extraction as a clean-up method for high lipid matrices were evaluated. For this, classic sorbents such as C18 (octadecyl-modified silica) and PSA (primary secondary amine), and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide), were used. The QuEChERS method, followed by Z-Sep d-SPE clean-up, provided the best analytical performance for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2) in pistachios. The method was validated in terms of linearity, sensitivity, repeatability, interday precision and recovery; it achieved good results according to criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to real samples and the results show that pistachios that are available in Portuguese markets are safe from mycotoxins that are of concern to human health.
Gelatin Reinforced with CNCs as Nanocomposite Matrix for Trichoderma harzianum KUEN 1585 Spores in Seed Coatings
Authors: Dogaru Bianca-Ioana , Stoleru Vasile , Mihalache Gabriela , Yonsel Sems , Popescu Maria-Cristina
Published: September 2021

Increasing interest on sustainable agriculture has led to the development of new materials which can be used as seed coating agents. In this study, a new material was developed based on gelatin film reinforced with cellulose nanocrystals (CNC) which was further used as nanocomposite matrix for Trichoderma harzianum KUEN 1585 spores. The nanocomposite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), showing the formation of new hydrogen bonds between the components with a good compatibility between them. Measurements of water contact angles and tests of water vapor sorption and swelling degree revealed an improvement in the water vapor absorption properties of the films as a result of their reinforcement with CNC. Furthermore, by adding the Trichoderma harzianum KUEN 1585 spp. in the seed coating material, the germination percentage, speed of germination and roots length of the corn seeds improved. The polymeric coating did not inhibit the growth of T. harzianum KUEN 1585, with this material being a good candidate in modern agriculture.