bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Temperature CO Oxidation over CuO-CeO2/Fe2O3 Catalyst: Effect of KMnO4 Modification
Authors: Feng Lu , Xing Xiangdong , Du Yueli , Shen Zhenghua , Zhang Hui , Yang Liu , Lv Ming
Published: January 2023

In this paper, the effect of KMnO4 modification on the performance of CO oxidation over a CuCeOx/Fe2O3 catalyst in industrial flue gas was studied. X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction by H2 (H2-TPR), Fourier transform infrared spectroscope (FTIR), and Raman spectra were employed to reveal the relationship between the structural properties and the performance of the catalyst. The results show that the catalytic activity could be increased by KMnO4 modification. CuCeOx/Fe2O3 modified with 0.07 mol/L KMnO4 exhibited high activity, with a CO conversion of 78.2% at 160 °C. The modification of KMnO4 reduced the grain size and promoted the uniform dispersion of active particles. In addition, the number of oxygen-containing functional groups increased, which could anchor metal particles and provide active oxygen species for CO oxidation.
Influence of the Grain-Flow Orientation after Hot Forging Process Evaluated through Rotational Flexing Fatigue Test
Authors: Suris Jaques Araripe , Yurgel Charles Chemale , Alves de Sousa Ricardo
Published: January 2023

The hot forging process brings significant advantages in terms of improved mechanical properties of the part compared with other processes, such as casting or machining. The metal flow in the forging process leads to texture modifications and can be macroscopically visualized by the so-called grain-flow orientation (GFO). This study showed the effect of GFO on fatigue life by using a rotational flexing fatigue test. The tests that were performed using SAE 1045H steel material, at rolling and transverse directions, showed the influence of GFO on the specimens’ mechanical properties compared with the reference samples taken from the machined rolled bar. The experimental results showed that the forged samples with the GFO in the main deformation direction presented a higher fatigue life than the other tested configurations.
Acknowledgment to the Reviewers of Meteorology in 2022
Authors:   Meteorology Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review [...]
Transceiver Optimization for mmWave Line-of-Sight MIMO Systems Using Hybrid Arrays
Authors: Deng Junwen , Li Hang , Zhang Jian Andrew , Huang Xiaojing , Cheng Zhiqun
Published: January 2023

The performance of millimeter wave (mmWave) line-of-sight multiple input multiple output (LOS MIMO) systems using hybrid arrays of planar subarrays was studied. We characterized the achievable maximum spatial multiplexing gain for such LOS MIMO systems by the measures of spectral efficiency and effective degree of freedom (EDoF). By proposing a joint plane-wave and spherical-wave-based general 3D channel model, we derived the optimal design parameters in the analog domain, i.e., the optimal subarray separation products, and analyzed their sensitivity on the system performance. We also gave analytical eigenvalue expressions of the equivalent LOS MIMO channel matrix, which are applicable to the case of a non-optimal design, as well as the upper and lower bounds of the EDoF for system performance evaluation. A piecewise uniform quantization codebook was further designed for quantizing phase shifter values in practical applications. The numerical and simulation results show that planar subarrays are superior to traditional arrays in terms of spectral efficiency and EDoF in Ricean fading channels because they are more robust to the change in the communication distance and the deviation from the optimal design. The use of hybrid arrays of planar subarrays effectively removes the limitation of mmWave LOS MIMO systems using traditional arrays, through which, the conventional Rayleigh distance criterion has to be satisfied to achieve the optimal performance.
Blood Cell Separation Using Polypropylene-Based Microfluidic Devices Based on Deterministic Lateral Displacement
Authors: Matsuura Koji , Takata Koji
Published: January 2023

Mammalian blood cell separation methods contribute to improving the diagnosis and treatment of animal and human diseases. Microfluidic deterministic lateral displacement (DLD) devices can sort cells based on their particle diameter. We developed microfluidic DLD devices with poly(propylene)-based resin and used them to separate bovine and human red blood cells (RBCs) and white blood cells (WBCs) without electric devices. To determine the critical cut-off diameter (Dc) of these devices, we used immunobeads with a diameter of 1–20 μm. The Dc values of the microfluidic DLD devices for the immunobeads in the experiments were similar to the calculated Dc values (8–10 μm). Results from bovine blood cell separation experiments suggest that lymphocytes and neutrophils can be separated from diluted, whole blood. Human RBCs were occasionally observed in the left outlet where larger particles with diameters closer to the Dc value were collected. Based on the Dc values, human neutrophils were sorted to the left outlet, whereas lymphocytes were observed in both outlets. Although microfluidic channel optimization is required for the concentration of sorted cells, the microfluidic DLD device prepared with a poly(propylene)-based resin has the potential for clinical use.
A Phase Canceling Technique to Improve SAW Duplexer Isolation
Authors: Tao Jianbin , Tang Zhengjie , Zou Yali , Wang Bin , Li Jiawei , Liu Yuhao , Wu Tao
Published: January 2023

Spectrum resources are becoming increasingly crowded, and the isolation interval between different systems is getting smaller and smaller. This puts forward higher requirements for the duplexer. The duplexer is an important part of the radio frequency front end, and the isolation requirement is becoming higher. This paper presents a phase canceling circuit to improve the performance of the duplexer to meet the requirement of the communication system for isolation. A phase canceling circuit is an effective method to enhance the isolation through use of a surface acoustic wave (SAW) on-chip circuit. It contains a duplexer and a branch. The branch is designed for diminishing the leakage signal of the duplexer. Compared with the leakage signal, the branch consists of two attenuators and a phase shifter to generate a signal which has equal extent and reverse phase. As a result, this method is capable of increasing the isolation of band 5 by 12 dB in the downlink frequency. Meanwhile, it neither affects other factors, such as insertion loss or return loss, nor increases the size of the chip. The phase canceling circuit is expected to promote the quality of duplexer to satisfy the strict requirements in 4G and 5G systems.
Acknowledgment to the Reviewers of Microbiology Research in 2022
Authors:   Microbiology Research Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review [...]
Pentafluoropropionic Anhydride Derivatization and GC-MS Analysis of Histamine, Agmatine, Putrescine, and Spermidine: Effects of Solvents and Starting Column Temperature
Authors: Tsikas Dimitrios , Beckmann Bibiana , Baskal Svetlana , Brunner Gorig
Published: January 2023

Gas chromatography–mass spectrometry (GC-MS) is useful for the quantitative determination of the polyamines spermidine (SPD) and putrescine (PUT) and of the biogenic amine agmatine (AGM) in biological samples after derivatization. This GC-MS method involves a two-step extraction with n-butanol and hydrochloric acid, derivatization with pentafluoropropionic anhydride (PFPA) in ethyl acetate, and extraction of the pentafluoropropionic (PFP) derivatives by toluene of SPD, PUT, and AGM. We wanted to extend this GC-MS method for the biogenic amine histamine (HA), but we faced serious problems that did not allow reliable quantitative analysis of HA. In the present work, we addressed this issue and investigated the derivatization of HA and the effects of toluene and ethyl acetate, two commonly used water-insoluble organic solvents in GC-MS, and oven temperature program. Derivatization of unlabelled HA (d0-HA) and deuterium-labelled HA (d4-HA) with PFPA in ethyl acetate (PFPA-EA, 1:4, v/v; 30 min, 65 °C) resulted in the formation of d0-HA-(PFP)2 and d4-HA-(PFP)2 derivatives. d4-HA and 13C4-SPD were used as internal standards for the amines after standardization. Considerable quantitative effects of toluene and ethyl acetate were observed. The starting GC column temperature was also found to influence considerably the GC-MS analysis of HA. Our study shows the simultaneous quantitative analysis of HA as HA-(PFP)2, AGM as AGM-(PFP)3, PUT as PUT-(PFP)2, and SPD as SPD-(PFP)3 derivatives requires the use of ethyl acetate for their extraction and injection into the GC-MS apparatus and a starting GC column temperature of 40 °C instead of 70 °C. The PFP derivatives of HA, AGM, PUT, and SPD were found to be stable in ethyl acetate for several hours at room temperature. Analytically satisfactory linearity, precision, and accuracy were observed for HA, AGM, PUT, and SPD in biologically relevant ranges (0 to 700 pmol). The limits of detection of AGM, PUT, and SPD were about two times lower in ethyl acetate compared to toluene (range, 1–22 fmol). The limits of detection were 1670 fmol for d0-HA and 557 fmol for d4-HA. Despite the improvements achieved in the study for HA, its analysis by GC-MS as a PFP derivative is challenging and less efficient than that of PUT, AGM, and SPD.
Biological Assessment of Stevioside and Sucralose as Sucrose Substitutes for Diabetics on STZ-Induced Diabetes in Rats
Authors: Barakat Hassan , Al-Roug Khaled , Algonaiman Raya , Althwab Sami A. , Alfheeaid Hani A. , Alhomaid Raghad M. , Almujaydil Mona S. , Bushnaq Taqwa , Ebeid Tarek A.
Published: January 2023

Numerous food organizations have identified excessive calorie consumption and accompanying ailments as significant health risks associated with high sugar consumption. Administering stevioside (ST), sucralose (SU), and the two synergically (SU+ST) affected normal rats’ weight gain. In the current study, SU showed the highest undesired effect. Indeed, administering the three treatments to diabetic rats (DR) did not improve the rats’ weight gain. Although, insulin injection synergically with the treatments improved the weight gain, as recorded after three weeks. The best-improving rate was observed in the ST group. After the administration of ST and ST+SU to the DR, the blood glucose level (GL) was positively affected, with SU having no effects on reducing the GL. A considerable reduction in serum insulin (SIL) was noted in the DR+SU group. On the contrary, ST did not negatively affect the SIL, rather an improvement was recorded. In addition, giving SU did not significantly affect the ALT level in the DR or normal rats (NR). A significant improvement in total bilirubin (TBILI) was observed when insulin was injected with ST or SU in DR groups. Further, triglycerides (TG) after administering ST, SU, or ST+SU to NR had no significant difference compared to the control group (NR). Although, the three treatments markedly but not significantly lowered TG in the DR. For total cholesterol (CHO), both DR and NR had no significant effect after the three treatments. No histopathological alterations were recorded in the NR group. Diffuse and severe atrophy of the islands of Langerhans due to depletion of their cells and mild papillary hyperplasia of the pancreatic ducts were represented by a slightly folded ductal basement membrane and newly formed ductules in STZ-DR. Simultaneous atrophy and absence of the cells of islands of Langerhans besides ductal hyperplasia were evident in DR+SU. Hyperplastic ductal epithelium and atrophic Langerhans cells were seen in DR+SU+In. Degeneration and mild atrophy were observed in the islands of Langerhans structures. There was essentially no noticeable change after utilizing ST. A slight shrinkage of the Langerhans’ islets was detected in DR+ST. In DR+ST+In, no histopathological alterations in the islands of Langerhans were recorded. Congestion in the stromal blood vessels associated with degenerative and necrotic changes in the cells of the islands of Langerhans in DR+SU+ST was observed. In NR+SU, congestion of the blood vessels associated with mild atrophy in the islands of Langerhans and dilatation in stromal blood vessels was noticed. In conclusion, ST is safe, and SU should be taken cautiously, such as mixing with ST and/or taken at a very low concentration to avoid its drastic effect on the human body.
Polyaromatic Group Embedded Cd(II)-Coordination Polymers for Microwave-Assisted Solvent-Free Strecker-Type Cyanation of Acetals
Authors: Karmakar Anirban , Paul Anup , Guedes da Silva Maria Fátima C. , Pombeiro Armando J. L.
Published: January 2023

In this work, two new 1D Cd(II) coordination polymers (CPs), [Cd(L1)(NMF)2]n (1) and [Cd(L2)(DMF)(H2O)2]n·n(H2O) (2), have been synthesized, characterized and employed as catalysts for the microwave-assisted solvent-free Strecker-type cyanation of different acetals. Solvothermal reaction between the pro-ligand, 5-{(pyren-1-ylmethyl)amino}isophthalic acid (H2L1) or 5-{(anthracen-9-ylmethyl)amino}isophthalic acid (H2L2), and Cd(NO3)2.6H2O in the presence of NMF or DMF:THF solvent, produces the coordination polymer 1 or 2, respectively. These frameworks were characterized by single-crystal and powder X-ray diffraction analyses, ATR-FTIR, elemental and thermogravimetry analysis. Their structural analysis revealed that both CPs show one-dimensional structures, but CP 1 has a 1D double chain type structure whereas CP 2 is a simple one-dimensional network. In CP 1, the dinuclear {Cd2(COO)4} unit acts as a secondary building unit (SBU) and the assembly of dinuclear SBUs with deprotonated ligand (L12−) led to the formation of a 1D double chain framework. In contrast, no SBU was observed in CP 2. To test the catalytic effectiveness of these 1D compounds, the solvent-free Strecker-type cyanation reactions of different acetals in presence of trimethylsilyl cyanide (TMSCN) was studied with CPs 1 and 2 as heterogenous catalysts. CP 1 displays a higher activity (yield 95%) compared to CP 2 (yield 84%) after the same reaction time. This is accounted for by the strong hydrogen bonding packing network in CP 2 that hampers the accessibility of the metal centers, and the presence of the dinuclear Cd(II) SBU in CP 1 which can promote the catalytic process in comparison with the mononuclear Cd(II) center in CP 2. Moreover, the recyclability and heterogeneity of both CPs were tested, demonstrating that they can be recyclable for at least for four cycles without losing their structural integrity and catalytic activity.
Ag–NHC Complexes in the π-Activation of Alkynes
Authors: Yang Shiyi , Zhou Tongliang , Yu Xiang , Szostak Michal
Published: January 2023

Silver–NHC (NHC = N-heterocyclic carbene) complexes play a special role in the field of transition-metal complexes due to (1) their prominent biological activity, and (2) their critical role as transfer reagents for the synthesis of metal-NHC complexes by transmetalation. However, the application of silver–NHCs in catalysis is underdeveloped, particularly when compared to their group 11 counterparts, gold–NHCs (Au–NHC) and copper–NHCs (Cu–NHC). In this Special Issue on Featured Reviews in Organometallic Chemistry, we present a comprehensive overview of the application of silver–NHC complexes in the p-activation of alkynes. The functionalization of alkynes is one of the most important processes in chemistry, and it is at the bedrock of organic synthesis. Recent studies show the significant promise of silver–NHC complexes as unique and highly selective catalysts in this class of reactions. The review covers p-activation reactions catalyzed by Ag–NHCs since 2005 (the first example of p-activation in catalysis by Ag–NHCs) through December 2022. The review focuses on the structure of NHC ligands and p-functionalization methods, covering the following broadly defined topics: (1) intramolecular cyclizations; (2) CO2 fixation; and (3) hydrofunctionalization reactions. By discussing the role of Ag–NHC complexes in the p-functionalization of alkynes, the reader is provided with an overview of this important area of research and the role of Ag–NHCs to promote reactions that are beyond other group 11 metal–NHC complexes.
Control of Explosive Chemical Reactions by Optical Excitations: Defect-Induced Decomposition of Trinitrotoluene at Metal Oxide Surfaces
Authors: Tsyshevsky Roman V. , Rashkeev Sergey N. , Kuklja Maija M.
Published: January 2023

Interfaces formed by high energy density materials and metal oxides present intriguing new opportunities for a large set of novel applications that depend on the control of the energy release and initiation of explosive chemical reactions. We studied the role of structural defects at a MgO surface in the modification of electronic and optical properties of the energetic material TNT (2-methyl-1,3,5-trinitrobenzene, also known as trinitrotoluene, C7H5N3O6) deposited at the surface. Using density functional theory (DFT)-based solid-state periodic calculations with hybrid density functionals, we show how the control of chemical explosive reactions can be achieved by tuning the electronic structure of energetic compound at an interface with oxides. The presence of defects at the oxide surface, such as steps, kinks, corners, and oxygen vacancies, significantly affects interfacial properties and modifies electronic spectra and charge transfer dynamics between the oxide surface and adsorbed energetic material. As a result, the electronic and optical properties of trinitrotoluene, mixed with an inorganic material (thus forming a composite), can be manipulated with high precision by interactions between TNT and the inorganic material at composite interfaces, namely, by charge transfer and band alignment. Also, the electron charge transfer between TNT and MgO surface reduces the decomposition barriers of the energetic material. In particular, it is shown that surface structural defects are critically important in the photodecomposition processes. These results open new possibilities for the rather precise control over the decomposition initiation mechanisms in energetic materials by optical excitations.
Acknowledgment to the Reviewers of MTI in 2022
Authors:   MTI Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review Multimodal Technologies and Interaction (MTI) was able to uphold its high standards for published papers due to the outstanding efforts of our reviewers [...]
A Self-Healing PVA-Linked Phytic Acid Hydrogel-Based Electrolyte for High-Performance Flexible Supercapacitors
Authors: Zhao Jing , Lu Yuanqi , Liu Yuhua , Liu Lanxin , Yin Jinling , Sun Baozhi , Wang Guiling , Zhang Yongquan
Published: January 2023

Flexible supercapacitors can be ideal flexible power sources for wearable electronics due to their ultra-high power density and high cycle life. In daily applications, wearable devices will inevitably cause damage or short circuit during bending, stretching, and compression. Therefore, it is necessary to develop proper energy storage devices to meet the requirements of various wearable electronic devices. Herein, Poly(vinyl alcohol) linked various content of phytic acid (PVA-PAx) hydrogels are synthesized with high transparency and high toughness by a one-step freeze-thaw method. The effects of different raw material ratios and agents on the ionic conductivity and mechanical properties of the hydrogel electrolyte are investigated. The PVA-PA21% with 2 M H2SO4 solution (PVA-PA21%-2 M H2SO4) shows a high ionic conductivity of 62.75 mS cm−1. Based on this, flexible supercapacitors fabricated with PVA-PA21%-2 M H2SO4 hydrogel present a high specific capacitance at 1 A g−1 after bending at 90° (64.8 F g−1) and for 30 times (67.3 F g−1), respectively. Moreover, the device shows energy densities of 13.5 Wh kg−1 and 14.0 Wh kg−1 at a power density of 300 W kg−1 after bending at 90° and for 30 times during 10,000 cycles. It provides inspiration for the design and development of electrolytes for related energy electrochemical devices.
Ongoing Treatment with a Spore-Based Probiotic Containing Five Strains of Bacillus Improves Outcomes of Mild COVID-19
Authors: Catinean Adrian , Sida Anamaria , Silvestru Celina , Balan Gheorghe G.
Published: January 2023

Spore-based Bacillus probiotic treatment improves intestinal health. The intestinal microbiota influences both the innate and adaptive immune responses. As such, the influence of ongoing spore-based probiotic treatment (five probiotic strains of Bacillus) on the clinical outcomes of mild COVID-19 was evaluated in this retrospective, observational study. Demographics, medical history, probiotic use, and COVID-19 symptom information were collected. The study included 120 patients with a PCR-confirmed SARS-CoV-2 infection and mild COVID-19 symptoms. The probiotic group (n = 60) comprised patients with ongoing probiotic treatment (≥1 month); the control group comprised patients not taking probiotics (n = 60). The primary outcome was time to symptom resolution; secondary outcomes included time to fever resolution and presence of digestive symptoms. The probiotic group had a significantly shorter time to symptom resolution (mean (95% confidence interval) days: control group, 8.48 (6.56, 10.05); probiotic group, 6.63 (5.56; 6.63); p = 0.003) and resolution of fever (control group, 2.67 (1.58, 3.61); probiotic group, 1.48 (1.21, 2.03); p < 0.001). More patients in the probiotic group (n = 53) than in the control group (n = 34) did not have digestive symptoms (p < 0.001). Among adults with mild COVID-19, participants receiving ongoing probiotic treatment had a shorter clinical course, and fewer had digestive symptoms compared with those not taking probiotics.
A Randomized Trial on Resveratrol Supplement Affecting Lipid Profile and Other Metabolic Markers in Subjects with Dyslipidemia
Authors: Zhou Yuqing , Zeng Yupeng , Pan Zhijun , Jin Yufeng , Li Qing , Pang Juan , Wang Xin , Chen Yu , Yang Yan , Ling Wenhua
Published: January 2023

Resveratrol is a polyphenol with a well-established beneficial effect on dyslipidemia and hyperuricemia in preclinical experiments. Nonetheless, its efficacy and dose–response relationship in clinical trials remains unclear. This study examined whether resveratrol supplement improves the serum lipid profile and other metabolic markers in a dose-response manner in individuals with dyslipidemia. A total of 168 subjects were randomly assigned to placebo (n = 43) and resveratrol treatment groups of 100 mg/d (n = 41), 300 mg/d (n = 43), and 600 mg/d (n = 41). Anthropometric and biochemical parameters were analyzed at baseline and 4 and 8 weeks. Resveratrol supplementation for 8 weeks did not significantly change the lipid profile compared with the placebo. However, a significant decrease of serum uric acid was observed at 8 weeks in 300 mg/d (−23.60 ± 61.53 μmol/L, p < 0.05) and 600 mg/d resveratrol groups (−24.37 ± 64.24 μmol/L, p < 0.01) compared to placebo (8.19 ± 44.60 μmol/L). Furthermore, xanthine oxidase (XO) activity decreased significantly in the 600 mg/d resveratrol group (−0.09 ± 0.29 U/mL, p < 0.05) compared with placebo (0.03 ± 0.20 U/mL) after 8 weeks. The reduction of uric acid and XO activity exhibited a dose–response relationship (p for trend, <0.05). Furthermore, a marked correlation was found between the changes in uric acid and XO activity in the resveratrol groups (r = 0.254, p < 0.01). Resveratrol (10 μmol/L) treatment to HepG2 cells significantly reduced the uric acid levels and intracellular XO activity. Nevertheless, we failed to detect significant differences in glucose, insulin, or oxidative stress biomarkers between the resveratrol groups and placebo. In conclusion, resveratrol supplementation for 8 weeks had no significant effect on lipid profile but decreased uric acid in a dose-response manner, possibly due to XO inhibition in subjects with dyslipidemia. The trial was registered on ClinicalTrials.gov (NCT04886297).
Exploring the Value of Real-Time Medication Adherence Monitoring: A Qualitative Study
Authors: Faisal Sadaf , Ivo Jessica , Abu Fadaleh Sarah , Patel Tejal
Published: January 2023

Smart adherence products enable the monitoring of medication intake in real-time. However, the value of real-time medication intake monitoring to different stakeholders such as patients, their caregivers, clinicians, and insurers is not elucidated. The aim of this study was to explore the value different stakeholders place on the availability of smart adherence products and access to real-time medication intake data. A qualitative study design using semi-structured one-on-one virtual interviews was utilized. Schwartz’s theory of values provided the foundation for the interview questions, data were analyzed using Braun and Clark’s thematic analysis framework, and findings were mapped back to the constructs of Schwartz’s theory of values. A total of 31 interviews with patients, caregivers, healthcare providers, and representatives of private or public insurance providers were conducted. Three themes and ten subthemes were identified. Themes included perceptions of integrating smart medication adherence technologies and real-time monitoring, technology adoption factors and data management. Stakeholders place different values based on the motivators and goals that can drive product use for daily medication management. Stakeholders valued the availability of real-time medication taking data that allow clinicians to make timely data-driven recommendations to their patients that may improve medication management for patients and reduce the caregiver burden.
Fiber Optic All-Polarization Weak Magnetic Field Sensor Based on Sagnac Interferometer
Authors: Liang Cui , Zhang Zhihang , Zhang Dengwei , Huang Tengchao , Che Shuangliang
Published: January 2023

A novel fiber-optic magnetic field sensor, based on a Sagnac structure, is proposed with the approach of polarization interference detection. The sensor takes advantage of common path interference, combining with a high magnetic field sensitivity sensing unit, composed of magneto-optical crystal, and magnetic field concentrators, to achieve high resolution, high stability, and large dynamic measurement of DC magnetic field signals. In this paper, the theoretical model is established and the related theory is derived in detail. The key technologies in the system are thoroughly investigated and verified. Experimental research on the proposed system is demonstrated and the results show that a DC magnetic field resolution of 5.6 nT and a dynamic range of larger than 70 dB is achieved. Furthermore, the linearity of the system is greater than 99.8% and the instability is less than 0.5%.
Acknowledgment to the Reviewers of Physics in 2022
Authors:   Physics Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review [...]
MtCLE08, MtCLE16, and MtCLE18 Transcription Patterns and Their Possible Functions in the Embryogenic Calli of Medicago truncatula
Authors: Kudriashov Andrei A. , Zlydneva Natalia S. , Efremova Elena P. , Tvorogova Varvara E. , Lutova Ludmila A.
Published: January 2023

CLE peptides are well-known hormonal regulators of plant development, but their role in somatic embryogenesis remains undetermined. CLE genes are often regulated by WOX transcription factors and, in their turn, regulate the expression level of WOX genes. In this study, we used in vitro cultivation, as well as qPCR and transcriptomic analysis, to find CLE peptides which could regulate the MtWOX9-1 gene, stimulating somatic embryogenesis in Medicago truncatula. Three CLE peptides were found which could probably be such regulators, but none of them was found to influence MtWOX9-1 expression in the embryogenic calli. Nevertheless, overexpression of one of CLE genes under study, MtCLE16, decreased somatic embryogenesis intensity. Additionally, overexpression of MtCLE08 was found to suppress expression of MtWOX13a, a supposed antagonist of somatic embryo development. Our findings can be helpful for the search for new regeneration regulators which could be used for plant transformation.
DDM1-Mediated TE Silencing in Plants
Authors: Akinmusola Ruth Y. , Wilkins Catherine-Axa , Doughty James
Published: January 2023

Epigenetic modifications are indispensable for regulating gene bodies and TE silencing. DECREASE IN DNA METHYLATION 1 (DDM1) is a chromatin remodeller involved in histone modifications and DNA methylation. Apart from maintaining the epigenome, DDM1 also maintains key plant traits such as flowering time and heterosis. The role of DDM1 in epigenetic regulation is best characterised in plants, especially arabidopsis, rice, maize and tomato. The epigenetic changes induced by DDM1 establish the stable inheritance of many plant traits for at least eight generations, yet DDM1 does not methylate protein-coding genes. The DDM1 TE silencing mechanism is distinct and has evolved independently of other silencing pathways. Unlike the RNA-directed DNA Methylation (RdDM) pathway, DDM1 does not depend on siRNAs to enforce the heterochromatic state of TEs. Here, we review DDM1 TE silencing activity in the RdDM and non-RdDM contexts. The DDM1 TE silencing machinery is strongly associated with the histone linker H1 and histone H2A.W. While the linker histone H1 excludes the RdDM factors from methylating the heterochromatin, the histone H2A.W variant prevents TE mobility. The DDM1-H2A.W strategy alone silences nearly all the mobile TEs in the arabidopsis genome. Thus, the DDM1-directed TE silencing essentially preserves heterochromatic features and abolishes mobile threats to genome stability.
Influence of Seed-Covering Layers on Caper Seed Germination
Authors: Foschi María Laura , Juan Mariano , Pascual Bernardo , Pascual-Seva Nuria
Published: January 2023

Caper is a perennial shrub that is widespread in the Mediterranean Basin. Although the fruits contain many seeds, they germinate slowly and with very low percentages, due to their nondeep physiological dormancy. The influence of the testa and endosperm, as well as the effect of applying gibberellic acid (GA3) solutions on seed germination to release its dormancy, are reported in this study. The mechanical resistance exerted by the testa and endosperm against radicle protrusion in mature caper seeds was measured. The best germination results were obtained with seeds devoid of testa wetted with water and with intact seeds wetted with a 500 mg L−1 GA3 solution, without statistical differences between them. The GA3 addition triggers an increase in both the content of endogenous gibberellins (GA) and the GA/abscisic acid ratio, increasing germination. Its germination consists of two temporally separated events: testa cracking and endosperm piercing. Testa cracking begins in the hilum-micropillar area; it involves a signal from the embryo, which GA can replace, possibly by increasing the growth potential of the embryo. After testa cracking, the radicle emerges through a hole in the micropylar endosperm. The puncture force necessary to pierce the micropylar endosperm decreased drastically during the first day of imbibition, remaining practically constant until testa cracking, decreasing afterwards, regardless of the addition or not of gibberellins.
Strengthening Polylactic Acid by Salification: Surface Characterization Study
Authors: Schlosser Jessica , Keller Michael , Fouladi Kamran , Eslami Babak
Published: January 2023

Polylactic acid (PLA) is one of the market’s most commonly used biodegradable polymers, with diverse applications in additive manufacturing, specifically fused deposition modeling (FDM) 3D printing. The use of PLA in complex and sophisticated FDM applications is continually growing. However, the increased range of applications requires a better understanding of the material properties of this polymer. For example, recent studies have shown that PLA has the potential to be used in artificial heart valves. Still, the durability and longevity of this material in such a harsh environment are unknown, as heart valve failures have been attributed to salification. Additionally, there is a gap in the field for in situ material characterization of PLA surfaces during stiffening. The present study aims to benchmark different dynamic atomic force microscopy (AFM) techniques available to study the salification phenomenon of PLA at micro-scales using different PLA thin films with various salt concentrations (i.e., 10%, 15%, and 20% of sodium chloride (NaCl)). The measurements are conducted by tapping mode AFM, bimodal AFM, the force spectroscopy technique, and energy quantity analysis. These measurements showed a stiffening phenomenon occurring as the salt solution is increased, but the change was not equally sensitive to material property differences. Tapping mode AFM provided accurate topographical information, while the associated phase images were not considered reliable. On the other hand, bimodal AFM was shown to be capable of providing the topographical information and material compositional mapping through the higher eigenmode’s phase channel. The dissipated power energy quantities indicated that how the polymers become less dissipative as salt concentration increases can be measured. Lastly, it was shown that force spectroscopy is the most sensitive technique in detecting the differences in properties. The comparison of these techniques can provide a helpful guideline for studying the material properties of PLA polymers at micro- and nano-scales that can prove beneficial in various fields.
Post-Polymerization Modification of Fluoropolymers via UV Irradiation in the Presence of a Photoacid Generator
Authors: Nika Anastasia , Gkioka Christina , Machairioti Fotini , Bilalis Panayiotis , Xu Jiaxi , Gajos Katarzyna , Awsiuk Kamil , Petrou Panagiota , Chatzichristidi Margarita
Published: January 2023

Fluorinated polymers have unique wettability and protein adsorption properties. The site-specific alteration of these properties could expand their application to different research areas. In this work, a fluorinated homopolymer and two of its copolymers with 4-vinylbenzyl glycidyl ether (VBGE) are synthesized by free radical polymerization. The produced polymers are then used to develop resist formulations by the addition of a photoacid generator. Films of these formulations are exposed to ultraviolet radiation through a binary mask and heated to create the pattern. It is found that the water contact angle values of the exposed films areas are reduced compared to those of the unexposed ones, with the exception of pentafluorophenyl methacrylate (PFMA) homopolymer film. This is attributed to the reaction of the epoxy groups creating x-links and producing hydroxyl groups and the cleavage of the pentafluorophenyl group from the ester group leading to carboxylic acid groups. Both modifications on the exposed areas are verified by FTIR spectroscopy and ToF-SIMS analysis. In addition, the biomolecules adsorption ability of the exposed area is increasing 10–15 times compared to the unexposed one for the PFMA homopolymer and the PFMA/VBGE 1:1 copolymer. Thus, the proposed polymers and patterning procedure could find application to spatially directed immobilization of biomolecules and/or cells onto a surface for both biosensing and tissue engineering purposes.
Processive Pathways to Metastability in Block Copolymer Thin Films
Authors: Hendeniya Nayanathara , Hillery Kaitlyn , Chang Boyce S.
Published: January 2023

Block copolymers (BCPs) self-assemble into intricate nanostructures that enhance a multitude of advanced applications in semiconductor processing, membrane science, nanopatterned coatings, nanocomposites, and battery research. Kinetics and thermodynamics of self-assembly are crucial considerations in controlling the nanostructure of BCP thin films. The equilibrium structure is governed by a molecular architecture and the chemistry of its repeat units. An enormous library of materials has been synthesized and they naturally produce a rich equilibrium phase diagram. Non-equilibrium phases could potentially broaden the structural diversity of BCPs and relax the synthetic burden of creating new molecules. Furthermore, the reliance on synthesis could be complicated by the scalability and the materials compatibility. Non-equilibrium phases in BCPs, however, are less explored, likely due to the challenges in stabilizing the metastable structures. Over the past few decades, a variety of processing techniques were introduced that influence the phase transformation of BCPs to achieve a wide range of morphologies. Nonetheless, there is a knowledge gap on how different processive pathways can induce and control the non-equilibrium phases in BCP thin films. In this review, we focus on different solvent-induced and thermally induced processive pathways, and their potential to control the non-equilibrium phases with regards to their unique aspects and advantages. Furthermore, we elucidate the limitations of these pathways and discuss the potential avenues for future investigations.
Acknowledgment to the Reviewers of Robotics in 2022
Authors:   Robotics Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review [...]
Geophysical and Remote Sensing Assessment of Chad’s Groundwater Resources
Authors: Mohamed Ahmed , Abdelrady Ahmed , Alarifi Saad S. , Othman Abdullah
Published: January 2023

Because of climate change and human activity, North and Central Africa are experiencing a significant water shortage. Recent advancements in earth observation technologies have made widespread groundwater monitoring possible. To examine spatial and temporal mass fluctuations caused by groundwater variations in Chad, gravity solutions from the Gravity Recovery and Climate Experiment (GRACE), climatic model outputs, and precipitation data are integrated. The results are as follows: (1) The investigated region experienced average annual precipitation (AAP) rates of 351.6, 336.22, and 377.8 mm yr−1, throughout the overall investigation period (04/2002–12/2021), Period I (04/2002–12/2011), and Period II (01/2012–12/2021), respectively. (2) Using the three gravity solutions, the average Terrestrial Water Storage Variations (ΔTWS) values are estimated to be +0.26 ± 0.04, +0.006 ± 0.10, and +0.64 ± 0.12 cm yr−1, for the overall study period, periods I, and II, respectively. (3) Throughout the full period, periods I, and II, the groundwater storage fluctuations (ΔGWS) are calculated to be +0.25 ± 0.04, +0.0001 ± 0.099, and +0.62 ± 0.12 cm yr−1, respectively after removing the soil moisture (ΔSMS) and Lake Chad water level trend values. (4) The country receives an average natural recharge rate of +0.32 ± 0.04, +0.068 ± 0.099, and +0.69 ± 0.12 cm yr−1, throughout the whole period, Periods I, and II, respectively. (5) The southern mountainous regions of Erdi, Ennedi, Tibesti, and Darfur are receiving higher rainfall rates that may recharge the northern part of Chad through the stream networks; in addition to the Lake Chad and the higher rainfall over southern Chad might help recharge the central and southern parts of the country. (6) A preferred groundwater flow path from the Kufra (Chad and Libya) to the Dakhla basin (Egypt) appears to be the Pelusium mega shear system, which trends north-east. The findings suggest that GRACE is useful for monitoring changes in groundwater storage and recharge rates across large areas. Our observation-based methodology provides a unique understanding of monthly ground-water patterns at the state level, which is essential for successful interstate resource allocation, future development, and policy initiatives, as well as having broad scientific implications for arid and semiarid countries.
Spectral Characteristics of the Dynamic World Land Cover Classification
Authors: Small Christopher , Sousa Daniel
Published: January 2023

The Dynamic World product is a discrete land cover classification of Sentinel 2 reflectance imagery that is global in extent, retrospective to 2015, and updated continuously in near real time. The classifier is trained on a stratified random sample of 20,000 hand-labeled 5 × 5 km Sentinel 2 tiles spanning 14 biomes globally. Since the training data are based on visual interpretation of image composites by both expert and non-expert annotators, without explicit spectral properties specified in the class definitions, the spectral characteristics of the classes are not obvious. The objective of this study is to quantify the physical distinctions among the land cover classes by characterizing the spectral properties of the range of reflectance present within each of the Dynamic World classes over a variety of landscapes. This is achieved by comparing both the eight-class probability feature space (excluding snow) and the maximum probability class assignment (label) distributions to continuous land cover fraction estimates derived from a globally standardized spectral mixture model. Standardized substrate, vegetation, and dark (SVD) endmembers are used to unmix nine Sentinel 2 reflectance tiles from nine spectral diversity hotspots for comparison between the SVD land cover fraction continua and the Dynamic World class probability continua and class assignments. The variance partition for the class probability feature spaces indicates that eight of these nine hotspots are effectively five-dimensional to 95% of variance. Class probability feature spaces of the hotspots all show a tetrahedral form with probability continua spanning multiple classes. Comparison of SVD land cover fraction distributions with maximum probability class assignments (labels) and probability feature space distributions reveal a clear distinction between (1) physically and spectrally heterogeneous biomes characterized by continuous gradations in vegetation density, substrate albedo, and structural shadow fractions, and (2) more homogeneous biomes characterized by closed canopy vegetation (forest) or negligible vegetation cover (e.g., desert, water). Due to the ubiquity of spectrally heterogeneous biomes worldwide, the class probability feature space adds considerable value to the Dynamic World maximum probability class labels by offering users the opportunity to depict inherently gradational heterogeneous landscapes otherwise not generally offered with other discrete thematic classifications.
A Systematic Review on Commercially Available Integrated Systems for Forensic DNA Analysis
Authors: Bruijns Brigitte , Knotter Jaap , Tiggelaar Roald
Published: January 2023

This systematic review describes and discusses three commercially available integrated systems for forensic DNA analysis, i.e., ParaDNA, RapidHIT, and ANDE. A variety of aspects, such as performance, time-to-result, ease-of-use, portability, and costs (per analysis run) of these three (modified) rapid DNA analysis systems, are considered. Despite their advantages and developmental progress, major steps still have to be made before rapid systems can be broadly applied at crime scenes for full DNA profiling. Aspects in particular that need (further) improvement are portability, performance, the possibility to analyze a (wider) variety of (complex) forensic samples, and (cartridge) costs. Moreover, steps forward regarding ease-of-use and time-to-result will benefit the broader use of commercial rapid DNA systems. In fact, it would be a profit if rapid DNA systems could be used for full DNA profile generation as well as indicative analyses that can give direction to forensic investigators which will speed up investigations.
IMF-Based MF and HS Energy Feature Information of F5, and F6 Movement and Motor Imagery EEG Signals in Delta Rhythms Using HHT
Authors: Lin Chin-Feng , Lin Hong-Chang
Published: January 2023

This study aims to extract the energy feature distributions in the form of marginal frequency (MF) and Hilbert spectrum (HS) in the intrinsic mode functions (IMF) domain for actual movement (AM)-based and motor imagery (MI)-based electroencephalogram (EEG) signals using the Hilbert–Huang transformation (HHT) time frequency (TF) analysis method. Accordingly, F5 and F6 EEG signal TF energy feature distributions in delta (0.5–4 Hz) rhythm are explored. We propose IMF-based and residue function (RF)-based MF and HS feature information extraction methods with IMFRFERDD (IMFRF energy refereed distribution density), IMFRFMFERDD (IMFRF MF energy refereed distribution density), and IMFRFHSERDD (IMFRF HS energy refereed distribution density) parameters using HHT with application to AM, MI EEG F5, and F6 signals in delta rhythm. The AM and MI tasks involve simultaneously opening fists and feet, as well as simultaneously closing fists and feet. Eight samples (32 in total) with a time duration of 1000 ms are extracted for analyzing F5AM, F5MI, F6AM, and F6MI EEG signals, which are decomposed into five IMFs and one RF. The maximum average IMFRFERDD values of IMF4 are 3.70, 3.43, 3.65, and 3.69 for F5AM, F5MI, F6 AM, and F6MI, respectively. The maximum average IMFRFMFERDD values of IMF4 in the delta rhythm are 21.50, 20.15, 21.02, and 17.30, for F5AM, F5MI, F6AM, and F6MI, respectively. Additionally, the maximum average IMFRFHSERDD values of IMF4 in delta rhythm are 39,21, 39.14, 36.29, and 33.06 with time intervals of 500–600, 800–900, 800–900, and 500–600 ms, for F5AM, F5MI, F6AM, and F6MI, respectively. The results of this study, advance our understanding of meaningful feature information of F5MM, F5MI, F6MM, and F6MI, enabling the design of MI-based brain-computer interface assistive devices for disabled persons.
Depth-Resolved Elemental Analysis on Moving Electrode Foils with Laser-Induced Breakdown Spectroscopy
Authors: Basler Carl , Kappeler Moritz , Carl Daniel
Published: January 2023

In this study, a new method for the inline measurement of depth profiles on a continuously moving sample with laser-induced breakdown spectroscopy is presented. The ablation profile is generated by ablating the sample with a burst of laser pulses, where the emission spectrum of each laser-induced plasma is analyzed on a spectrometer. A Q-switched Nd:YAG laser at 1064 nm with 10 mJ pulse energy, 6 ns pulse duration and 100 Hz repetition rate was used. The focusing lens for the pulsed laser and a deflection mirror are mounted on a moving stage, which is precisely aligned in height and orientation to the movement of a conveyor belt transporting the sample. The stage speed is actively synchronized to the speed of the moving sample by a wheel encoder to assure that all laser pulses hit the same position at the sample. The feasibility for depth-resolved elemental analysis on moving samples is shown for coatings of electrode foils for lithium-ion batteries. The coating homogeneity was measured at a speed up to 17 m/min. For a 100 μm coating, 10 laser pulses were needed to measure a full depth profile.