bluuebunny/crossref_metadata_2025 huggingface dataset:
Phacoemulsification versus Phacoemulsification/Trabeculectomy for the Treatment of Primary Open-Angle Glaucoma Coexistent with Cataract: A Comparative Study
Authors: Kaliardas Athanasios , Chatziralli Irini , Katsanos Andreas , Kitsos George
Published: February 2023

Background: The purpose of this study was to evaluate the clinical outcomes in patients with primary open-angle glaucoma (POAG) and coexistent cataract treated with phacoemulsification cataract surgery, either alone or in combination with trabeculectomy. Methods: Participants in this retrospective study were 52 patients diagnosed with previously controlled POAG and coexistent cataract, who underwent either uneventful phacoemulsification cataract surgery (Group I, n = 27) or combined uneventful phacoemulsification cataract surgery and trabeculectomy (Group II, n = 25), with at least a 24-month postoperative follow-up. We recorded the changes in intraocular pressure (IOP) and in the need of anti-glaucoma medications before and after surgical procedures. Results: There was a statistically significant decrease in IOP at postoperative day 7 in both groups (p < 0.001), which remained until the end of the 24-month follow-up. At month 24, the two groups did not differ significantly in terms of IOP (14.3 ± 1.4 vs. 13.1 ± 1.2 for Group I and Group II, respectively; p = 0.447). In addition, there was a statistically significant decrease in the number of anti-glaucoma medications needed at postoperative day 7 in both groups (p < 0.001 for both groups compared to baseline). At month 24, patients in both groups needed about one additional anti-glaucoma medication to control their IOP. Of note, during the first month after surgery, 20% of patients in Group II needed 0.1 mL 5-FU injections to the bleb, although antimetabolites were not used in the primary surgery. Conclusions: Both surgical interventions, namely phacoemulsification cataract surgery alone and phacoemulsification/trabeculectomy, were found to be effective in the management of POAG with coexistent cataract, presenting a significant decrease in IOP and in the need of anti-glaucoma medications postoperatively at a long-term follow-up period of 24 months.
Preparation of Polyacrylonitrile-Based Immobilized Copper-Ion Affinity Membranes for Protein Adsorption
Authors: Yang Yin-Jie , Chang Hou-Chien , Wang Min-Ying , Suen Shing-Yi
Published: February 2023

A polyacrylonitrile (PAN)-based immobilized metal-ion affinity membrane (IMAM) was prepared with a high capacity for protein adsorption. PAN was selected as the substrate due to its excellent thermal and chemical stability. The cyano groups on the PAN membrane were substituted with carboxyl groups, followed by reactions with ethylenediamine (EDA) and ethylene glycol diglycidyl ether (EGDGE) to produce the terminal epoxy groups. The chelating agent iminodiacetic acid (IDA) was then bound to the modified PAN membrane and further chelated with copper ions. The immobilized copper ion amount of membrane was analyzed to obtain the optimal reaction conditions, which were 60 °C/3 h for EDA coupling and 60 °C/4 h for EGDGE grafting. Furthermore, under the use of minor IDA and copper ion concentrations, the immobilized copper ion capacity of the IMAM was 4.8 μmol/cm2 (253.4 µmol/mL, or 1.47 μmol/mg). At a neutral pH, the cationic lysozyme exhibited a large adsorption capacity with the IMAM (1.96 μmol/mL), which was most likely multilayer binding, whereas the adsorption capacity for bovine serum albumin (BSA) and histidine-tagged green fluorescent protein (GFP-His6) was 0.053 μmol/mL and 0.135 μmol/mL, respectively, with a monolayer adsorption arrangement. The protein desorption efficiency was greater than 95%, implying that the prepared IMAM could be reused for protein adsorption.
An Economical Composite Membrane with High Ion Selectivity for Vanadium Flow Batteries
Authors: Zhang Yue , Zhang Denghua , Luan Chao , Zhang Yifan , Yu Wenjie , Liu Jianguo , Yan Chuanwei
Published: February 2023

The ion exchange membrane of the Nafion series widely used in vanadium flow batteries (VFBs) is characterized by its high cost and high vanadium permeability, which limit the further commercialization of VFBs. Herein, a thin composite membrane enabled by a low-cost microporous polyethylene (PE) substrate and perfluorosulfonic acid (PFSA) resin is proposed to reduce the cost of the membrane. Meanwhile, the rigid PE substrate limits the swelling of the composite membrane, which effectively reduces the penetration of vanadium ions and improves the ion selectivity of the composite membrane. Benefiting from such a rational design, a VFB assembled with the PE/PFSA composite membrane exhibited a higher coulombic efficiency (CE ≈ 96.8%) compared with commercial Nafion212 at 200 mA cm−2. Significantly, the energy efficiency maintained stability within 200 cycles with a slow decay rate. In practical terms, the thin PE/PFSA composite membrane with low cost and high ion selectivity can make an ideal membrane candidate in VFBs.
Comparative Energetics of Various Membrane Distillation Configurations and Guidelines for Design and Operation
Authors: Islam Md Rashedul , Lin Bosong , Yu Yue , Chen Chau-Chyun , Malmali Mahdi
Published: February 2023

This paper presents a comparative performance study of single-stage desalination processes with major configurations of membrane distillation (MD) modules. MD modules covered in this study are (a) direct contact MD (DCMD), (b) vacuum MD (VMD), (c) sweeping gas MD (SGMD), and (d) air gap MD (AGMD). MD-based desalination processes are simulated with rigorous theoretical MD models supported by molecular thermodynamic property models for the accurate calculation of performance metrics. The performance metrics considered in MD systems are permeate flux and energy efficiency, i.e., gained output ratio (GOR). A general criterion is established to determine the critical length of these four MDs (at fixed width) for the feasible operation of desalination in a wide range of feed salinities. The length of DCMD and VMD is restricted by the feed salinity and permeate flux, respectively, while relatively large AGMD and SGMD are allowed. The sensitivity of GOR flux with respect to permeate conditions is investigated for different MD configurations. AGMD outperforms other configurations in terms of energy efficiency, while VMD reveals the highest permeate production. With larger MD modules, utilization of thermal energy supplied by the hot feed for evaporation is in the order of VMD > AGMD > SGMD > DCMD. Simulation results highlight that energy efficiency of the overall desalination process relies on the efficient recovery of spent for evaporation, suggesting potential improvement in energy efficiency for VMD-based desalination.
The Effect of Cholesterol in SOPC Lipid Bilayers at Low Temperatures
Authors: Ivanova Nikoleta , Chamati Hassan
Published: February 2023

We study the behavior of lipid bilayers composed of SOPC (1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine) with different concentrations of cholesterol, ranging from 10 mol% to 50 mol% at 273 K. To this end, we carry out extensive atomistic molecular dynamic simulations with the aid of the Slipid force field aiming at computing basic bilayer parameters, as well as thermodynamic properties and structural characteristics. The obtained results are compared to available relevant experimental data and the outcome of atomistic simulations performed on bilayers composed of analogous phospholipids. Our results show a good quantitative, as well as qualitative, agreement with the main trends associated with the concentration increase in cholesterol. Moreover, it comes out that a change in the behavior of the bilayer is brought about at a concentration of about 30 mol% cholesterol. At this very concentration, some of the bilayer properties are found to exhibit a saturation and a significant long-range ordering of the lipid molecules in the membrane shows up.
Zero-Material Cost Production of Soil-Coated Fabrics with Underwater Superoleophobicity for Antifouling Oil/Water Separation
Authors: Li Maohui , Li Fangfang , Zhen Cheng , Fu Panpan , Yang Shaolin , Lu Youjun
Published: February 2023

Soil-coated fabrics were fabricated by scrape-coating of soil slurry onto cotton fabrics. The raw materials, soil, and cotton fabrics were, respectively, obtained from farmland and waste bed sheets, making the method a zero-material cost way to produce superwetting membrane. The superhydrophilic/underwater superoleophobic soil-coated fabrics exhibit high efficiency (>99%), ultra-high flux (~45,000 L m−2 h−1), and excellent antifouling behavior for separating water from various oils driven by gravity. The simple fabrication and superior performance suggest that the soil-coated fabric could be a promising candidate as a filtration membrane for practical applications in industrial oily wastewater and oil spill treatments.
FAPbBr3 Perovskite Nanocrystals Embedded in Poly(L–lactic acid) Nanofibrous Membranes for Enhanced Air and Water Stability
Authors: Tabassum Madeeha , Zia Qasim , Li Jiashen , Khawar Muhammad Tauseef , Aslam Sameen , Su Lei
Published: February 2023

Formamidinium lead bromide (FAPbBr3) nanocrystals have emerged as a powerful platform for optoelectronic applications due to their pure green photoluminescence (PL). However, their low colloidal stability under storage and operation reduces the potential use of FAPbBr3 perovskite nanocrystals (PeNCs) in various applications. In this study, we prepared the poly(L–lactic acid) (PLLA) nanofibrous membrane embedded with FAPbBr3 perovskite nanocrystals by electrospinning the perovskite and PLLA precursor solution. This is a simple and low-cost technique for the direct confinement of nano-sized functional materials in the continuous polymer nanofibres. PLLA as a polymer matrix provided a high surface framework to fully encapsulate the perovskite NCs. In addition, we found that FAPbBr3 PeNCs crystallize spontaneously inside the PLLA nanofibre. The resultant PLLA-FAPbBr3 nanofibrous membranes were stable and remained in the water for about 45 days without any evident decomposition. The results of this research support the idea of new possibilities for the production of air-stable FAPbBr3 PeNCs by forming a composite with PLLA polymer. The authors believe this study is a new milestone in the development of highly stable metal halide perovskite-based nanofibres, which allow for potential use in lasers, waveguides, and flexible energy harvesters.
The Performance of Microfiltration Process for Purifying Lactic Acid in the Fermented Broth of Kitchen Waste
Authors: Guo Yan , Li Chenglong , Zhao Hongjun , Gao Ming , Wang Qunhui
Published: February 2023

Fermentation broth is plentiful with lactic acid, an important chemical applied in many fields, such as food processing, the chemical industry, and cosmetics. However, the purification of the lactic acid from the broth is still troublesome, when considering the economy. This study first investigated the purification performance of microfiltration (MF) membrane technology for a fermentation broth from kitchen waste. The effect of operation pressure, broth pH, and membrane flushing mode on the membrane filtration performance were investigated. In addition, the change in filtration performance over the increase in cycle time was also investigated. The results showed that under the optimum pressure of 100 KPa, pH of 6.0, and a backflushing mode with deionized water for 3 min, the best performance was achieved, with chroma removal, turbidity removal, protein removal and total sugar removal efficiencies of 60, 92.8, 57.64 and 32.93%, respectively. The results indicated that the MF process could be a desirable broth purification process to some extent, and it is promising in actual application. The MF process combined with other post-purification processes will form the ideal process system, which should be explored in future research.
Bio-Concentration and Influence of Environmental Factors on Accumulation of Heavy Metals in Edible Autumn Morel (Morchella galilaea) of Low Elevation
Authors: Badshah Hussain , Nisa Surat Un , Ali Mohammad Ajmal , Alwahibi Mona S. , Kamal Asif , Kaleem Muhammad , Khan Anwarzeb , Khan Shujaul Mulk , Mumtaz Abdul Samad
Published: February 2023

Morels (Morchella spp.) are wild edible mushrooms and are globally known for their high nutritional value. The current study aims at probing the heavy metal content in early emerging autumn-type Morchella galilaea that occurs exclusively in the irrigated plains of Charsadda, Pakistan. The identification of samples was conducted through morphology and internal transcribed spacer sequence (ITS) data. Atomic absorption spectrophotometer was employed to analyze the soil and M. galilaea samples for heavy metals including Mn, Ni, Pb, Zn, and Cu. The heavy metal content in soil samples was within the permissible limits of SEPA China and WHO, USA with few exceptions. The hymenophore (H) and fruiting bodies (FB) were also analyzed revealing these metals within the permissible limits set by WHO and SEPA. Further analysis indicated that heavy metal concentration in the fruiting body (FB) was higher compared to those in the hymenophore (H). The toxicological assessment revealed that the transfer factor (TF) was less than 1 with a significant difference (p < 0.05) among samples. The daily intake of metals and health risk index values for all samples were <1. Hence, the daily intake of M. galilaea harvested from the wild has no toxicological hazards to human health, especially in the heavy metal concentration.
Effect of Graphite Morphology on the Thermomechanical Performance of Compacted Graphite Iron
Authors: Cao Minghua , Baxevanakis Konstantinos P. , Silberschmidt Vadim V.
Published: February 2023

Compacted graphite iron (CGI) has gained significant attention in automotive industry applications thanks to its superior thermomechanical properties and competitive price. Its main fracture mechanism at the microscale—interfacial damage and debonding between graphite inclusions and a metallic matrix—can happen under high-temperature service conditions as a result of a mismatch in the coefficients of thermal expansion between the two phases of CGI. Macroscopic fracture in cast iron components can be initiated by interfacial damage at the microscale under thermomechanical load. This phenomenon was investigated in various composites but still lacks information for CGI, with its complex morphology of graphite inclusions. This research focuses on the effect of this morphology on the thermomechanical performance of CGI under high temperatures. A set of three-dimensional finite-element models was created, with a unit cell containing a single graphite inclusion embedded in a cubic domain of the metallic matrix. Elastoplastic behaviour was assumed for both phases in numerical simulations. The effect of graphite morphology on the thermomechanical performance of CGI was investigated for pure thermal loading, focusing on a high-temperature response of its constituents. The results can provide a deeper understanding of the correlation between graphite morphology and CGI fracture mechanisms under high temperatures.
Strength Characteristics of a Heat-Resistant Metal-Matrix Composite Inconel 625–5%NiTi–TiB2 Alloy Fabricated by Direct Laser Deposition under Shock-Wave Loading
Authors: Razorenov Sergey , Garkushin Gennady , Savinykh Andrey , Promakhov Vladimir , Matveev Alexey , Klimova-Korsmik Olga , Vorozhtsov Alexander
Published: February 2023

The Hugoniot elastic limit and spall strength were measured for a heat-resistant metal-matrix composite Inconel 625–5%NiTi–TiB2 alloy additive manufactured (AM) by direct laser deposition. The strength characteristics of the alloy were obtained from the analysis of the complete wave profiles recorded with a VISAR laser Doppler velocimeter during shock-wave loading of the samples. The samples were loaded using a PP50 pneumatic gun or ad hoc explosive devices along and across the material deposition direction in order to determine the strength anisotropy of the AM alloy under study. The maximum shock compression pressure was ~7 GPa, and the strain rate under tension before spalling varied in the range of 105–106 s–1. Kinetic dependencies of elastic/plastic transition and critical fracture stresses vs. loading conditions were plotted. It was shown that the Hugoniot elastic limit of the alloy under study decreases as the shock wave travels into the sample, while the spall strength increases as the material’s strain rate increases at the moment of spall fracture. A comparison of the strength characteristics of the Inconel 625–NiTi–TiB2 composite alloy with the original Inconel 625 alloy has shown that an addition of 5% of powder based on NiTi-TiB2 leads to a decrease in its elastic limit and critical fracture stresses upon spalling by more than 10%. The alloy under study demonstrates anisotropy of strength properties relative to the material deposition direction.
Process Design for Manufacturing Fiber-Reinforced Plastic Helical Gears Using a Rapid Heating and Cooling System
Authors: Lee Cheol Hwan , Kang Yong Ki , Kim Dong Kyu , Kim Sang Hyeon , Moon Young Hoon
Published: February 2023

In this study, a lightweight fiber-reinforced plastic (FRP) helical gear was fabricated to investigate the potential application of FRP in automobile parts that require high loads and reduced noise. High-performance aramid FRP processed using the wet-laid method was used in the tooth region, and SCR420 steel was used in the inner hub region. A hot-forming system that combines rapid induction heating and water channel cooling methods was developed to reduce the cycle time. The cooling water flow conditions were analyzed to precisely control the mold temperature. Additionally, a rotating extraction system was developed to mitigate the extraction difficulty owing to the helix angle to the extraction direction. Using the innovative hot-forming system developed in this study, a helical gear without any process-induced defects was fabricated with a significantly reduced cycle time. The performance of the gear was successfully estimated using gear durability, torsional strength, and motion noise tests. The use of FRP materials offers significant potential to realize lightweight components; however, certain challenges related to their properties that may limit their application must be addressed on a case-by-case basis.
Mediterranean Lavenders from Section Stoechas: An Undervalued Source of Secondary Metabolites with Pharmacological Potential
Authors: Domingues Joana , Delgado Fernanda , Gonçalves José Carlos , Zuzarte Mónica , Duarte Ana Paula
Published: February 2023

Globally, climate change and wildfires are disrupting natural ecosystems, thus setting several endemic species at risk. The genus Lavandula is widely present in the Mediterranean region and its species, namely, those included in the section Stoechas, are valuable resources of active compounds with several biological assets. Since ancient times lavenders have been used in traditional medicine and for domestic purposes. These species are melliferous, decorative, and essential oil-producing plants with a high economic interest in the pharmaceutical, flavor, fragrance, and food industries. The essential oils of Lavandula section Stoechas are characterized by high amounts of 1,8-cineole, camphor, fenchone, and specifically for L. stoechas subsp. luisieri one of the major compounds is trans-α-necrodyl acetate. On the other hand, the diversity of non-volatile components like phenolic compounds, such as phenolic acids and flavonoids, make these species an important source of phytochemicals with pharmacological interest. Rosmarinic, caffeic, and salvianolic B acids are the major phenolic acids, and luteolin and eriodictyol-O-glucuronide are the main reported flavonoids. However, the concentration of these secondary metabolites is strongly affected by the plant’s phenological phase and varies in Lavandula sp. from different areas of origin. Indeed, lavender extracts have shown promising antioxidant, antimicrobial, anti-inflammatory, and anticancer properties as well as several other beneficial actions with potential for commercial applications. Despite several studies on the bioactive potential of lavenders from the section Stoechas, a systematized and updated review of their chemical profile is lacking. Therefore, we carried out the present review that gathers relevant information on the different types of secondary metabolites found in these species as well as their bioactive potential.
Diagnostic, Prognostic and Mechanistic Biomarkers of COVID-19 Identified by Mass Spectrometric Metabolomics
Authors: Bourgin Mélanie , Durand Sylvère , Kroemer Guido
Published: February 2023

A number of studies have assessed the impact of SARS-CoV-2 infection and COVID-19 severity on the metabolome of exhaled air, saliva, plasma, and urine to identify diagnostic and prognostic biomarkers. In spite of the richness of the literature, there is no consensus about the utility of metabolomic analyses for the management of COVID-19, calling for a critical assessment of the literature. We identified mass spectrometric metabolomic studies on specimens from SARS-CoV2-infected patients and subjected them to a cross-study comparison. We compared the clinical design, technical aspects, and statistical analyses of published studies with the purpose to identify the most relevant biomarkers. Several among the metabolites that are under- or overrepresented in the plasma from patients with COVID-19 may directly contribute to excessive inflammatory reactions and deficient immune control of SARS-CoV2, hence unraveling important mechanistic connections between whole-body metabolism and the course of the disease. Altogether, it appears that mass spectrometric approaches have a high potential for biomarker discovery, especially if they are subjected to methodological standardization.
A Successful Bisphosphonates Monotherapy in Spinal Form of Paediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO)—Case Report
Authors: Opala Aleksandra , Hofman Jagoda , Hutny Michał , Wylazlowska Aleksandra , Matusik Paweł
Published: February 2023

Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious inflammatory disorder resulting from the multifocal bone and bone marrow lesions with periodic relapses and remissions and with an uncertain prognosis. Treatment options in CRMO are based on expert opinion and relatively small groups of patients. A nine-year-old female patient with no significant past medical history presented with compression fractures and multifocal bone lesions in the thoracic and lumbar spine, as shown in imaging (CT, MRI). Densitometry revealed a diffuse decrease in bone density. Based on the patient’s clinical image and above examinations, the other possible aetiologies—infectious (including tuberculosis), neoplasms, Langerhans cell histiocytosis—were ruled out, which led to eventual final diagnosis—CRMO. The patient was successfully treated with pamidronate infusion initiated in cycles over three consecutive days every 3 months. In addition to clinical improvement, there was a significant remission of inflammation and bone structure healing assessed by MRI after four treatment cycles. Intravenous bisphosphonates usage seems to be a good therapeutic option in CRMO paediatric patients with spinal localization of the lesions complicated by compressive fractures. However, more data, based on larger patient populations, are needed to provide a detailed paediatric CRMO treatment algorithm.
Metabolic Profile of Whole Unstimulated Saliva in Patients with Sjögren’s Syndrome
Authors: Setti Giacomo , Righi Valeria , Mucci Adele , Panari Lucia , Bernardelli Giuditta , Tarentini Elisabetta , Gambini Anna , Consolo Ugo , Generali Luigi , Magnoni Cristina , Meleti Marco , Sandri Gilda , Bellini Pierantonio
Published: February 2023

Primary Sjögren’s Syndrome (pSS) is a multi-system autoimmune disease that involves the exocrine glands. Lymphocytes infiltrate the gland tissue, leading to anatomical modification and hypofunction. Even if the prognosis of pSS is favorable, quality of life is typically reduced due to the diverse manifestations of the disease. The aim of this study is to compare the salivary metabolomes of pSS with healthy controls (HCs). Seven cases were selected from a cohort of pSS patients, and six age- and sex-matched HCs were recruited from a cohort of volunteers. Whole unstimulated saliva was collected for NMR analysis. Our metabolomic analysis focused on 360 ms total echo 1D 1H NMR CPMG spectra. Metabolites detected with CPMG NMR spectra were assigned through 2D NMR spectra (COSY, TOCSY, and HSQC). About 50 metabolites were detected and assigned. Unsupervised exploratory PCA returned partial clustering, and PLS-DA improved the separation between pSS and HCs, highlighting a pool of metabolites distinctly describing each group. Despite the limited number of samples, the presented preliminary data are promising. PLS-DA indicated well-defined group separation, suggesting that the application of 1H-NMR metabolomics is suitable for the study of pSS.
Understanding the Seasonal Effect of Metabolite Production in Terminalia catappa L. Leaves through a Concatenated MS- and NMR-Based Metabolomics Approach
Authors: Zanatta Ana C. , Vieira Natália Carolina , Dantas-Medeiros Renato , Vilegas Wagner , Edrada-Ebel RuAngelie
Published: February 2023

Terminalia catappa L. (Combretaceae) is a medicinal plant that is part of the Brazilian biodiversity; this plant is popularly used for the treatment of a wide range of diseases. To better understand the chemical composition of T. catappa in different seasons, we conducted a thorough study using LC-MS and NMR data analysis techniques. The study helped obtain a chemical profile of the plant ethanolic extracts in different seasons of the year (spring, summer, autumn, and winter). The dereplication of LC-HRMS data allowed the annotation of 90 compounds in the extracts of T. catappa (hydrolyzable tannins, ellagic acid derivatives, and glycosylated flavonoids). Triterpenes and C-glycosyl flavones were the compounds that significantly contributed to differences observed between T. catappa plant samples harvested in autumn/winter and spring, respectively. The variations observed in the compound composition of the plant leaves may be related to processes induced by environmental stress and leaf development. Data fusion applied in the metabolomic profiling study allowed us to identify metabolites with greater confidence, and provided a better understanding regarding the production of specialized metabolites in T. catappa leaves under different environmental conditions, which may be useful to establish appropriate quality criteria for the standardization of this medicinal plant.
Identification and Analysis of Antimicrobial Activities from a Model Moss Ceratodon purpureus
Authors: Dague Ashley L. , Valeeva Lia R. , McCann Natalie M. , Sharipova Margarita R. , Valentovic Monica A. , Bogomolnaya Lydia M. , Shakirov Eugene V.
Published: February 2023

The emergence of bacterial drug resistance is often viewed as the next great health crisis of our time. While more antimicrobial agents are urgently needed, very few new antibiotics are currently in the production pipeline. Here, we aim to identify and characterize novel antimicrobial natural products from a model dioicous moss, Ceratodon purpureus. We collected secreted moss exudate fractions from two C. purpureus strains, male R40 and female GG1. Exudates from the female C. purpureus strain GG1 did not exhibit inhibitory activity against any tested bacteria. However, exudates from the male moss strain R40 exhibited strong inhibitory properties against several species of Gram-positive bacteria, including Staphylococcus aureus and Enterococcus faecium, though they did not inhibit the growth of Gram-negative bacteria. Antibacterial activity levels in C. purpureus R40 exudates significantly increased over four weeks of moss cultivation in liquid culture. Size fractionation experiments indicated that the secreted bioactive compounds have a relatively low molecular weight of less than 1 kDa. Additionally, the R40 exudate compounds are thermostable and not sensitive to proteinase K treatment. Overall, our results suggest that the bioactive compounds present in C. purpureus R40 exudates can potentially add new options for treating infections caused by antibiotic-resistant Gram-positive bacteria.
Application of Polymethylpentene, an Oxygen Permeable Thermoplastic, for Long-Term on-a-Chip Cell Culture and Organ-on-a-Chip Devices
Authors: Sønstevold Linda , Czerkies Maciej , Escobedo-Cousin Enrique , Blonski Slawomir , Vereshchagina Elizaveta
Published: February 2023

The applicability of a gas-permeable, thermoplastic material polymethylpentene (PMP) was investigated, experimentally and analytically, for organ-on-a-chip (OoC) and long-term on-a-chip cell cultivation applications. Using a sealed culture chamber device fitted with oxygen sensors, we tested and compared PMP to commonly used glass and polydimethylsiloxane (PDMS). We show that PMP and PDMS have comparable performance for oxygen supply during 4 days culture of epithelial (A549) cells with oxygen concentration stabilizing at 16%, compared with glass control where it decreases to 3%. For the first time, transmission light images of cells growing on PMP were obtained, demonstrating that the optical properties of PMP are suitable for non-fluorescent, live cell imaging. Following the combined transmission light imaging and calcein-AM staining, cell adherence, proliferation, morphology, and viability of A549 cells were shown to be similar on PMP and glass coated with poly-L-lysine. In contrast to PDMS, we demonstrate that a film of PMP as thin as 0.125 mm is compatible with high-resolution confocal microscopy due to its excellent optical properties and mechanical stiffness. PMP was also found to be fully compatible with device sterilization, cell fixation, cell permeabilization and fluorescent staining. We envision this material to extend the range of possible microfluidic applications beyond the current state-of-the-art, due to its beneficial physical properties and suitability for prototyping by different methods. The integrated device and measurement methodology demonstrated in this work are transferrable to other cell-based studies and life-sciences applications.
Research on the Cutting Force and Serrated Chips in Ultra-Precision Micro-Grooving of SLM Ti6Al4V Alloy
Authors: Zheng Zhongpeng , Guo Jiajing , Gao Ruilin , Jin Xin
Published: February 2023

Selective laser melting (SLM) has significant advantages in the near net shape manufacturing of metal parts with complex geometries. However, SLM parts usually have problems such as poor surface quality and low dimensional accuracy, which require post-processing. This paper focuses on the research around the influence of ultra-precision micro-grooving the SLM Ti6Al4V alloy on the cutting force and serrated chips. The influence of the processing parameters on the cutting force and surface processing quality was analyzed in detail, and the cutting simulation model of the SLM Ti6Al4V alloy was established. The formation process of the serrated chip was successfully simulated, and the experiments verified the reliability of the established model. The research results show that the dynamic cutting force and surface processing quality are mainly related to the depth of cut, and the two trends are consistent. It is also shown that the serrated chip begins on the free surface of the workpiece and propagates deeply in the shear zone, forming a shear band, and its serrated nodules move upward and forward to form periodic serrated chips.
Recent Progress in Solution Processed Aluminum and co-Doped ZnO for Transparent Conductive Oxide Applications
Authors: Singh Mandeep , Scotognella Francesco
Published: February 2023

With the continuous growth in the optoelectronic industry, the demand for novel and highly efficient materials is also growing. Specifically, the demand for the key component of several optoelectronic devices, i.e., transparent conducting oxides (TCOs), is receiving significant attention. The major reason behind this is the dependence of the current technology on only one material—indium tin oxide (ITO). Even though ITO still remains a highly efficient material, its high cost and the worldwide scarcity of indium creates an urgency for finding an alternative. In this regard, doped zinc oxide (ZnO), in particular, solution-processed aluminum doped ZnO (AZO), is emerging as a leading candidate to replace ITO due to its high abundant and exceptional physical/chemical properties. In this mini review, recent progress in the development of solution-processed AZO is presented. Beside the systematic review of the literature, the solution processable approaches used to synthesize AZO and the effect of aluminum doping content on the functional properties of AZO are also discussed. Moreover, the co-doping strategy (doping of aluminum with other elements) used to further improve the properties of AZO is also discussed and reviewed in this article.
Research on Vibration Energy Harvester Based on Two-Dimensional Acoustic Black Hole
Authors: Yang Chunlai , Yuan Yikai , Wang Hai , Tang Ye , Gui Jingsong
Published: February 2023

The wave energy focus effect of an acoustic black hole (ABH) is used for broadband vibration energy harvesting and boosts the harvested power. A vibration energy harvester based on two-dimensional ABH is proposed in this study, which consists of a rectangle plate with 2-D ABH and PZT film attached. The structure of ABH was designed and analyzed based on numerical simulation. The optimal parameters of the ABH were obtained, such as the power index, truncation thickness, cross-sectional length, and round table diameter, which were 3, 0.4 mm, 40 mm, and 24 mm, respectively. The quadratic velocity of the plate surface with ABH is up to 22.33 times that of a flat plate, and PZT film adheres to the corresponding positions of the ABH structure and plate structure, respectively. In the same condition, the average output power of a PZT with an ABH structure is higher than that of a flat plate under the same excitation-vibration condition.
Research on Lower Limb Step Speed Recognition Method Based on Electromyography
Authors: Zhang Peng , Wu Pengcheng , Wang Wendong
Published: February 2023

Wearable exoskeletons play an important role in people’s lives, such as helping stroke and amputation patients to carry out rehabilitation training and so on. How to make the exoskeleton accurately judge the human action intention is the basic requirement to ensure that it can complete the corresponding task. Traditional exoskeleton control signals include pressure values, joint angles and acceleration values, which can only reflect the current motion information of the human lower limbs and cannot be used to predict motion. The electromyography (EMG) signal always occurs before a certain movement; it can be used to predict the target’s gait speed and movement as the input signal. In this study, the generalization ability of a BP neural network and the timing property of a hidden Markov chain are used to properly fuse the two, and are finally used in the research of this paper. Experiments show that, using the same training samples, the recognition accuracy of the three-layer BP neural network is only 91%, while the recognition accuracy of the fusion discriminant model proposed in this paper can reach 95.1%. The results show that the fusion of BP neural network and hidden Markov chain has a strong solving ability for the task of wearable exoskeleton recognition of target step speed.
Spatial Trajectory Tracking of Wall-Climbing Robot on Cylindrical Tank Surface Using Backstepping Sliding-Mode Control
Authors: Xue Jiameng , Chen Jingyu , Stancu Alexsandru , Wang Xingsong , Li Jie
Published: February 2023

Wall-climbing robots have been well-developed for storage tank inspection. This work presents a backstepping sliding-mode control (BSMC) strategy for the spatial trajectory tracking control of a wall-climbing robot, which is specially designed to inspect inside and outside of cylindrical storage tanks. The inspection robot is designed with four magnetic wheels, which are driven by two DC motors. In order to achieve an accurate spatial position of the robot, a multisensor-data-fusion positioning method is developed. The new control method is proposed with kinematics based on a cylindrical coordinate system as the robot is moving on a cylindrical surface. The main purpose is to promote a smooth and stable tracking performance during inspection tasks, under the consideration of the robot’s kinematic constraints and the magnetic restrictions of the adhesion system. The simulation results indicate that the proposed sliding mode controller can quickly correct the errors and global asymptotic stability is achieved. The prototype experimental results further validate the advancement of the proposed method; the wall-climbing robot can track both longitudinal and horizontal spatial trajectories stably with high precision.
Design of a Compact Quad-Channel Microstrip Diplexer for L and S Band Applications
Authors: Roshani Sobhan , Yahya Salah I. , Mezaal Yaqeen Sabah , Chaudhary Muhammad Akmal , Al-Hilali Aqeel A. , Mojirleilani Afshin , Roshani Saeed
Published: February 2023

In this paper, two novel dual-band bandpass filters (BPFs) and a compact quad-channel diplexer working at 1.7/3.3 GHz and 1.9/3.6 GHz are proposed. In the proposed diplexer design, triangular loop resonators and rectangular loop resonators are used together to reduce the circuit size and improve diplexer performances. Insertion loss (IL) and return loss (RL) of the proposed diplexer are better than 0.8 dB and 21 dB, respectively, at these four operating frequencies. Output ports isolation parameter is better than 30 dB. With the achieved specifications, the proposed diplexer can be used in L and S band applications.
Low-Density sEMG-Based Pattern Recognition of Unrelated Movements Rejection for Wrist Joint Rehabilitation
Authors: Bu Dongdong , Guo Shuxiang , Guo Jin , Li He , Wang Hanze
Published: February 2023

sEMG-based pattern recognition commonly assumes a limited number of target categories, and the classifiers often predict each target category depending on probability. In wrist rehabilitation training, the patients may make movements that do not belong to the target category unconsciously. However, most pattern recognition methods can only identify limited patterns and are prone to be disturbed by abnormal movement, especially for wrist joint movements. To address the above the problem, a sEMG-based rejection method for unrelated movements is proposed to identify wrist joint unrelated movements using center loss. In this paper, the sEMG signal collected by the Myo armband is used as the input of the sEMG control method. First, the sEMG signal is processed by sliding signal window and image coding. Then, the CNN with center loss and softmax loss is used to describe the spatial information from the sEMG image to extract discriminative features and target movement recognition. Finally, the deep spatial information is used to train the AE to reject unrelated movements based on the reconstruction loss. The results show that the proposed method can realize the target movements recognition and reject unrelated movements with an F-score of 93.4% and a rejection accuracy of 95% when the recall is 0.9, which reveals the effectiveness of the proposed method.
Preparation, Characterization, and Application of AlN/ScAlN Composite Thin Films
Authors: Nian Laixia , Qu Yuanhang , Gu Xiyu , Luo Tiancheng , Xie Ying , Wei Min , Cai Yao , Liu Yan , Sun Chengliang
Published: February 2023

Piezoelectric aluminum nitride (AlN) thin film, as a commonly used material for high-frequency acoustic resonators, has been a research hotspot in the RF field. Doping Sc elements in AlN is one of most effective methods to improve the piezoelectricity of the material. In this work, the first principal calculation and Mori–Tanaka model are used to obtain the piezoelectric constants of AlN, ScAlN, and AlN/ScAlN composites. Then, five types of AlN/ScAlN thin films are prepared on 8 inch silicon substrates. The crystal quality, roughness, and stress distribution are measured to characterize the film quality. The results show that composite film can effectively solve the problem of abnormal grains and reduce the roughness. Finally, a lamb wave resonator with an AlN/Sc0.2Al0.8N composite working at 2.33 GHz is fabricated. The effective electromechanical coupling coefficient Keff2 is calculated to be 6.19%, which has the potential to design high-frequency broadband filters.
Promotion of Peanut (Arachis hypogaea L.) Growth by Plant Growth-Promoting Microorganisms
Authors: Frezarin Edvan Teciano , Santos Carlos Henrique Barbosa , Sales Luziane Ramos , dos Santos Roberta Mendes , de Carvalho Lucas Amoroso Lopes , Rigobelo Everlon Cid
Published: February 2023

Brazil is an important peanut producer, but despite its high production, there still needs to be an inoculant for the peanut crop. In addition, the use of microorganisms that promote plant growth (PGPM) is not common, and this crop is highly dependent on chemical fertilizers. An excellent alternative to reduce the use of fertilizers and chemical inputs in peanut crops while reducing the production cost and environmental impact is the use of PGPM. The objective of this study was to evaluate the effects of Azospirillum brasilense, Bacillus subtilis, Bradyrhizobium japonicum, and Trichoderma harzianum as single inoculants and co-inoculants on the growth promotion and productivity of peanuts in greenhouse and field conditions. In the greenhouse, the experiment was conducted with 12 treatments with six repetitions. In the field conditions, the experiment was conducted with five treatments with four repetitions. Both experiments were conducted in randomized blocks. In general, all the microorganisms evaluated in the present study promoted increases in root dry mass, shoot dry mass, phosphorus concentrations, and plant height in the greenhouse and under field conditions compared with the control. Interestingly, the mixtures of microorganisms inoculated in peanut plants did not promote greater plant growth and development compared with inoculations of the microorganisms separately. Specifically, in the field, the highest productivity was found for the inoculation of B. japonicum alone. The PGPM evaluated in the present study for peanut crops generally promoted some increases in productivity in greenhouse and field conditions.
Microcystin-Detoxifying Recombinant Saccharomyces cerevisiae Expressing the mlrA Gene from Sphingosinicella microcystinivorans B9
Authors: Silva Fernando de Godoi , Lopes Daiane Dias , Hector Ronald E. , Nascimento Maikon Thiago do , Miguel Tatiana de Ávila , Kuroda Emília Kiyomi , Nóbrega Gisele Maria de Andrade de , Harada Ken-Ichi , Hirooka Elisa Yoko
Published: February 2023

Contamination of water by microcystins is a global problem. These potent hepatotoxins demand constant monitoring and control methods in potable water. Promising approaches to reduce contamination risks have focused on natural microcystin biodegradation led by enzymes encoded by the mlrABCD genes. The first enzyme of this system (mlrA) linearizes microcystin structure, reducing toxicity and stability. Heterologous expression of mlrA in different microorganisms may enhance its production and activity, promote additional knowledge on the enzyme, and support feasible applications. In this context, we intended to express the mlrA gene from Sphingosinicella microcystinivorans B9 in an industrial Saccharomyces cerevisiae strain as an innovative biological alternative to degrade microcystins. The mlrA gene was codon-optimized for expression in yeast, and either expressed from a plasmid or through chromosomal integration at the URA3 locus. Recombinant and wild yeasts were cultivated in medium contaminated with microcystins, and the toxin content was analyzed during growth. Whereas no difference in microcystins content was observed in cultivation with the chromosomally integrated strain, the yeast strain hosting the mlrA expression plasmid reduced 83% of toxins within 120 h of cultivation. Our results show microcystinase A expressed by industrial yeast strains as a viable option for practical applications in water treatment.
Distinct Effects of Chemical Toxicity and Radioactivity on Metabolic Heat of Cultured Cells Revealed by “Isotope-Editing”
Authors: Oertel Jana , Sachs Susanne , Flemming Katrin , Obeid Muhammad Hassan , Fahmy Karim
Published: February 2023

Studying the toxicity of chemical compounds using isothermal microcalorimetry (IMC), which monitors the metabolic heat from living microorganisms, is a rapidly expanding field. The unprecedented sensitivity of IMC is particularly attractive for studies at low levels of stressors, where lethality-based data are inadequate. We have revealed via IMC the effect of low dose rates from radioactive β−-decay on bacterial metabolism. The low dose rate regime (<400 µGyh−1) is typical of radioactively contaminated environmental sites, where chemical toxicity and radioactivity-mediated effects coexist without a predominance or specific characteristic of either of them. We found that IMC allows distinguishing the two sources of metabolic interference on the basis of “isotope-editing” and advanced thermogram analyses. The stable and radioactive europium isotopes 153Eu and 152Eu, respectively, were employed in monitoring Lactococcus lactis cultures via IMC. β−-emission (electrons) was found to increase initial culture growth by increased nutrient uptake efficiency, which compensates for a reduced maximal cell division rate. Direct adsorption of the radionuclide to the biomass, revealed by mass spectrometry, is critical for both the initial stress response and the “dilution” of radioactivity-mediated damage at later culture stages, which are dominated by the chemical toxicity of Eu.
Microcystin-LR, a Cyanobacterial Toxin, Induces Changes in the Organization of Membrane Compartments in Arabidopsis
Authors: Juhász Gabriella Petra , Kéki Sándor , Dékány-Adamoczky Anita , Freytag Csongor , Vasas Gábor , Máthé Csaba , Garda Tamás
Published: February 2023

To evaluate the effects of the cyanobacterial toxin microcystin-LR (MCY-LR, a protein phosphatase inhibitor) and diquat (DQ, an oxidative stress inducer) on the organization of tonoplast, the effect of MCY-LR on plastid stromule formation and on mitochondria was investigated in wild-type Arabidopsis. Tonoplast was also studied in PP2A catalytic (c3c4) and regulatory subunit mutants (fass-5 and fass-15). These novel studies were performed by CLSM microscopy. MCY-LR is produced during cyanobacterial blooms. The organization of tonoplast of PP2A mutants of Arabidopsis is much more sensitive to MCY-LR and DQ treatments than that of wild type. In c3c4, fass-5 and fass-15, control and treated plants showed increased vacuole fragmentation that was the strongest when the fass-5 mutant was treated with MCY-LR. It is assumed that both PP2A/C and B” subunits play an important role in normal formation and function of the tonoplast. In wild-type plants, MCY-LR affects mitochondria. Under the influence of MCY-LR, small, round-shaped mitochondria appeared, while long/fused mitochondria were typical in control plants. Presumably, MCY-LR either inhibits the fusion of mitochondria or induces fission. Consequently, PP2A also plays an important role in the fusion of mitochondria. MCY-LR also increased the frequency of stromules appearing on chloroplasts after 1 h treatments. Along the stromules, signals can be transported between plastids and endoplasmic reticulum. It is probable that they promote a faster response to stress.