bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac Reverse Remodeling in Ischemic Heart Disease with Novel Therapies for Heart Failure with Reduced Ejection Fraction
Authors: Leancă Sabina Andreea , Afrăsânie Irina , Crișu Daniela , Matei Iulian Theodor , Duca Ștefania Teodora , Costache Alexandru Dan , Onofrei Viviana , Tudorancea Ionuţ , Mitu Ovidiu , Bădescu Minerva Codruța , Șerban Lăcrămioara Ionela , Costache Irina Iuliana
Published: April 2023

Despite the improvements in the treatment of coronary artery disease (CAD) and acute myocardial infarction (MI) over the past 20 years, ischemic heart disease (IHD) continues to be the most common cause of heart failure (HF). In clinical trials, over 70% of patients diagnosed with HF had IHD as the underlying cause. Furthermore, IHD predicts a worse outcome for patients with HF, leading to a substantial increase in late morbidity, mortality, and healthcare costs. In recent years, new pharmacological therapies have emerged for the treatment of HF, such as sodium-glucose cotransporter-2 inhibitors, angiotensin receptor-neprilysin inhibitors, selective cardiac myosin activators, and oral soluble guanylate cyclase stimulators, demonstrating clear or potential benefits in patients with HF with reduced ejection fraction. Interventional strategies such as cardiac resynchronization therapy, cardiac contractility modulation, or baroreflex activation therapy might provide additional therapeutic benefits by improving symptoms and promoting reverse remodeling. Furthermore, cardiac regenerative therapies such as stem cell transplantation could become a new therapeutic resource in the management of HF. By analyzing the existing data from the literature, this review aims to evaluate the impact of new HF therapies in patients with IHD in order to gain further insight into the best form of therapeutic management for this large proportion of HF patients.
Sleep and Core Body Temperature Alterations Induced by Space Radiation in Rats
Authors: Sanford Larry D. , Adkins Austin M. , Boden Alea F. , Gotthold Justin D. , Harris Ryan D. , Shuboni-Mulligan Dorela , Wellman Laurie L. , Britten Richard A.
Published: April 2023

Sleep problems in astronauts can arise from mission demands and stress and can impact both their health and ability to accomplish mission objectives. In addition to mission-related physical and psychological stressors, the long durations of the proposed Mars missions will expose astronauts to space radiation (SR), which has a significant impact on the brain and may also alter sleep and physiological functions. Therefore, in this study, we assessed sleep, EEG spectra, activity, and core body temperature (CBT) in rats exposed to SR and compared them to age-matched nonirradiated rats. Male outbred Wistar rats (8–9 months old at the time of the study) received SR (15 cGy GCRsim, n = 15) or served as age- and time-matched controls (CTRL, n = 15) without irradiation. At least 90 days after SR and 3 weeks prior to recording, all rats were implanted with telemetry transmitters for recording EEG, activity, and CBT. Sleep, EEG spectra (delta, 0.5–4 Hz; theta, 4–8 Hz; alpha, 8–12 Hz; sigma, 12–16 Hz; beta, 16–24 Hz), activity, and CBT were examined during light and dark periods and during waking and sleeping states. When compared to the CTRLs, SR produced significant reductions in the amounts of dark period total sleep time, total nonrapid eye movement sleep (NREM), and total rapid eye movement sleep (REM), with significant decreases in light and dark period NREM deltas and dark period REM thetas as well as increases in alpha and sigma in NREM and REM during either light or dark periods. The SR animals showed modest increases in some measures of activity. CBT was significantly reduced during waking and sleeping in the light period. These data demonstrate that SR alone can produce alterations to sleep and temperature control that could have consequences for astronauts and their ability to meet mission demands.
2-(2,7-Bis(pyridin-3-ylethynyl)fluoren-9-ylidene)malononitrile
Authors: Podda Enrico , Arca Massimiliano , Pintus Anna , Meloni Francesca , Lippolis Vito , Ferino Giulio , Orton James B. , Coles Simon J. , Aragoni Maria Carla
Published: April 2023

The 2-(2,7-bis(pyridin-3-ylethynyl)fluoren-9-ylidene)malononitrile (1) was synthesized by reaction of 2,7-bis(pyridin-3-ylethynyl)fluoren-9-one with malononitrile in DMSO solution. The structural characterization of 1 by SC-XRD analysis was accompanied by elemental analysis, FT-IR, NMR, and MS measurements.
Influence of Measurement Uncertainty in the Determination of Selected Rock Parameters—A Realistic Approach
Authors: Voit Klaus , Zeman Oliver , Gappmaier Peter , Wriessnig Karin , Adamcova Renata
Published: April 2023

To determine and compare the measurement uncertainty of different geological-geotechnical testing methods, numerous test locations were selected in a hard rock quarry. Measurements were carried out along two vertical measurement lines perpendicular to the mining levels of an existing exploration. Along these lines, the rock quality basically varies due to weathering (decreasing influence with increasing distance from the original ground surface), but also due to the influence of the geological-tectonic conditions on site. The mining conditions (blasting) are identical over the considered area. The rock quality was examined as follows: as field tests, the rock compressive strength was determined by means of point load test and rebound hammer, as laboratory method the Los Angeles test (standard laboratory test for the determination of the mechanical rock quality) was used to identify the impact abrasion resistance. The statistical evaluation and comparison of the results allowed conclusions to be drawn about the contribution of the individual test methods to the measurement uncertainty whereas, in practice, a priori information can be applied complementarily. It shows that the influence on the combined measurement uncertainty u of the different methods due to the geological variability in horizontal direction reaches values between 17 and 32%, whereby the rebound hammer method shows the highest values. However, the highest influences on the measurement uncertainties are a result of the vertical direction due to weathering phenomena with percentages of 55 to 70%. For the point load test, the vertical direction shows the highest significance with an influence of approximately 70%. This leads to the conclusion that a higher weathering degree of the rock mass shows an increasing effect on the measurement uncertainty which needs to be considered using a priori information in measurements.
Gaussian Model of Anti-Radar Properties for Coatings Based on Carbonyl Iron Powder
Authors: Przybył Wojciech , Mazurczuk Robert , Kalinowski Artur , Bogdanowicz Krzysztof A.
Published: April 2023

The article presents the Gaussian model of the electromagnetic radiation attenuation properties of two resin systems containing 75% or 80% of a carbonyl iron load as an absorber in the 4–18 GHz range. For the attenuation values obtained in the laboratory, mathematical fitting was performed in the range of 4–40 GHz to visualize the full curve characteristics. The simulated curves fitted up to a 0.998 R2 value of the experimental results. The in depth analysis of the simulated spectra allowed a thorough evaluation of the influence of the type of resin, absorber load, and layer thickness on reflection loss parameters such as the maximum attenuation, peak position, half-height width, and base slope of the peak. The simulated results were convergent with the literature findings, allowing a much deeper analysis. This confirmed that the suggested Gaussian model could provide additional information, useful in terms of comparative analyses of datasets.
The Role of GaN in the Heterostructure WS2/GaN for SERS Applications
Authors: Ko Tsung-Shine , Lin En-Ting , Ho Yen-Teng , Deng Chen-An
Published: April 2023

In the application of WS2 as a surface–enhanced Raman scattering (SERS) substrate, enhancing the charge transfer (CT) opportunity between WS2 and analyte is an important issue for SERS efficiency. In this study, we deposited few-layer WS2 (2–3 layers) on GaN and sapphire substrates with different bandgap characteristics to form heterojunctions using a chemical vapor deposition. Compared with sapphire, we found that using GaN as a substrate for WS2 can effectively enhance the SERS signal, with an enhancement factor of 6.45 × 104 and a limit of detection of 5 × 10−6 M for probe molecule Rhodamine 6G according to SERS measurement. Analysis of Raman, Raman mapping, atomic force microscopy, and SERS mechanism revealed that The SERS efficiency increased despite the lower quality of the WS2 films on GaN compared to those on sapphire, as a result of the increased number of transition pathways present in the interface between WS2 and GaN. These carrier transition pathways could increase the opportunity for CT, thus enhancing the SERS signal. The WS2/GaN heterostructure proposed in this study can serve as a reference for enhancing SERS efficiency.
Lead Zirconate Titanate Transducers Embedded in Composite Laminates: The Influence of the Integration Method on Ultrasound Transduction
Authors: Kergosien Nina , Gavérina Ludovic , Ribay Guillemette , Saffar Florence , Beauchêne Pierre , Mesnil Olivier , Bareille Olivier
Published: April 2023

In the context of an embedded structural health monitoring (SHM) system, two methods of transducer integration into the core of a laminate carbon fiber-reinforced polymer (CFRP) are tested: cut-out and between two plies. This study focuses on the effect of integration methods on Lamb wave generation. For this purpose, plates with an embedded lead zirconate titanate (PZT) transducer are cured in an autoclave. The embedded PZT insulation, integrity, and ability to generate Lamb waves are checked with electromechanical impedance, X-rays, and laser Doppler vibrometry (LDV) measurements. Lamb wave dispersion curves are computed by LDV using two-dimensional fast Fourier transform (Bi-FFT) to study the quasi-antisymmetric mode (qA0) excitability in generation with the embedded PZT in the frequency range of 30 to 200 kHz. The embedded PZT is able to generate Lamb waves, which validate the integration procedure. The first minimum frequency of the embedded PZT shifts to lower frequencies and its amplitude is reduced compared to a surface-mounted PZT.
Degree of Impurity and Carbon Contents in the Grain Size of Mg-Al Magnesium Alloys
Authors: Jung Sung-Su , Park Yong-Ho , Lee Young-Cheol
Published: April 2023

In this study, the tendency of having different grain structures depending on the impurity levels in AZ91 alloys was investigated. Two types of AZ91 alloys were analyzed: commercial-purity AZ91 and high-purity AZ91. The average grain size of the commercial-purity AZ91 alloy and high-purity AZ91 is 320 µm and 90 µm, respectively. Thermal analysis revealed negligible undercooling in the high-purity AZ91 alloy, while undercooling of 1.3 °C was observed in the commercial-purity AZ91 alloy. A CS analyzer was employed to precisely analyze the carbon composition of both alloys. The carbon content of the high-purity AZ91 alloy was found to be 197 ppm, while the commercial-purity AZ91 alloy contained 104 ppm, indicating a difference of approximately 2 times. The higher carbon content in the high-purity AZ91 alloy is believed to be due to the use of high-purity pure Mg in its production (the carbon content of high-purity pure Mg is 251 ppm). To simulate the vacuum distillation process commonly used in the production of high-purity Mg ingots, experiments were conducted to investigate the reaction of carbon with oxygen to produce CO and CO2. XPS analysis and simulation results for activities confirmed the formation of CO and CO2 during the vacuum distillation process. It could be speculated that the carbon sources in the high-purity Mg ingot provide Al-C particles, which act as nucleants for Mg grains in the high-purity AZ91 alloy. Thus, it can be considered the main reason that high-purity AZ91 alloys have a finer grain structure than that of commercial-purity AZ91 alloys.
Band Gaps and Optical Properties of RENiO3 upon Strain: Combining First-Principles Calculations and Machine Learning
Authors: Tang Xuchang , Luo Zhaokai , Cui Yuanyuan
Published: April 2023

Rare earth nickel-based perovskite oxides (RENiO3) have been widely studied over recent decades because of their unique properties. In the synthesis of RENiO3 thin films, a lattice mismatch frequently exists between the substrates and the thin films, which may affect the optical properties of RENiO3. In this paper, the first-principles calculations were employed to study the electronic and optical properties of RENiO3 under strain. The results showed that with the increase in tensile strength, the band gap generally shows a widening trend. For optical properties, the absorption coefficients increase with the enhancement of photon energies in the far-infrared range. The compressive strain increases the light absorption, while the tensile strain suppresses it. For the reflectivity spectrum in the far-infrared range, a minimum reflectivity displays around the photon energy of 0.3 eV. The tensile strain enhances the reflectivity in the range of 0.05–0.3 eV, whereas it decreases it when the photon energies are larger than 0.3 eV. Furthermore, machine learning algorithms were applied and found that the planar epitaxial strain, electronegativity, volume of supercells, and rare earth element ion radius play key roles in the band gaps. Photon energy, electronegativity, band gap, the ionic radius of the rare earth element, and the tolerance factor are key parameters significantly influencing the optical properties.
An Improvement of Mechanical Properties of Two Kinds of Silicone Resins Containing Ladder Segments by Chemical Modification with Trimethylborate
Authors: Kalinin Alexei V. , Zuev Vjacheslav V.
Published: April 2023

We suggest a new method for postsynthesis modification of silicones containing silanol groups. It was found that trimethylborate is an effective catalyst for dehydrative condensation of silanol groups with the formation of ladder-like blocks. The utility of this approach was demonstrated on postsynthesis modification of poly-(block poly(dimethylsiloxane)-block ladder-like poly(phenylsiloxane)) and poly-(block poly((3,3′,3″-trifluoropropyl-methyl)siloxane)-block ladder-like poly(phenylsiloxane) with a combination of linear and ladder-like blocks having silanol groups. The postsynthesis modification leads to a 75% increase in tensile strength and 116% elongation on break in comparison with the starting polymer.
Gradient V-Shaped and N-Shaped Seismic Metamaterials
Authors: Su Yu-Chi , Wang Sheng-Shiang
Published: April 2023

Seismic metamaterials provide an innovative alternative in earthquake engineering by reducing the hazards from seismic waves without modifying the existing structures. Although many seismic metamaterials have been proposed, a design for a broad bandgap at low frequencies is still in demand. In this study, two novel seismic metamaterials, V- and N-shaped designs, are proposed. We found that by adding a line to the letter V, turning the V-shaped design into an N-shaped design, the bandgap can be broadened. Both the V- and N-shaped designs are arranged in a gradient pattern to combine the bandgaps from metamaterials with different heights. Using only concrete as the base material for the design makes the proposed seismic metamaterial cost effective. Finite element transient analysis and band structures are in good agreement, validating the accuracy of the numerical simulations. Surface waves are effectively attenuated over a broad range of low frequencies using the gradient V- and N-shaped seismic metamaterials.
Evolution of Microstructure, Mechanical Properties, and Corrosion Resistance of Mg–2.2Gd–2.2Zn–0.2Ca (wt%) Alloy by Extrusion at Various Temperatures
Authors: Zengin Hüseyin , Ari Soner , Turan Muhammet Emre , Hassel Achim Walter
Published: April 2023

The current investigation involved casting the Mg–2.2Gd–2.2Zn–0.2Ca (wt%) alloy (GZX220) through permanent mold casting, followed by homogenization at 400 °C for 24 h and extrusion at 250 °C, 300 °C, 350 °C, and 400 °C. Microstructure investigations revealed that α-Mg, Mg–Gd, and Mg–Gd–Zn intermetallic phases were present in the as-cast alloy. Following the homogenization treatment, a majority of these intermetallic particles underwent partial dissolution into the matrix phase. α-Mg grains exhibited a considerable refinement by extrusion due to dynamic recrystallization (DRX). At low extrusion temperatures, higher basal texture intensities were observed. The mechanical properties were remarkably enhanced after the extrusion process. However, a consistent decline in strength was observed with the rise in extrusion temperature. The corrosion performance of the as-cast GZX220 alloy was reduced by homogenization because of the lack of corrosion barrier effect of secondary phases. A significant enhancement of corrosion resistance was achieved by the extrusion process.
Transient Elastography as the First-Line Assessment of Liver Fibrosis and Its Correlation with Serum Markers
Authors: Uzlova Nikola , Mnozil Stridova Katerina , Merta Dusan , Rychlik Ivan , Frankova Sona
Published: April 2023

Background and objectives: Recently, rapid progress has been made in the development of noninvasive methods for liver fibrosis assessment. The study aimed to assess the correlation between LSM and serum fibrosis markers to identify patients with advanced liver fibrosis in daily clinical practice. Methods: Between 2017 and 2019, 89 patients with chronic liver disease of various etiology, 58 males and 31 females, were enrolled in the study and underwent ultrasound examination, vibration-controlled transient elastography (VCTE), AST to Platelet Ratio Index (APRI score), Fibrosis-4 (FIB-4) score, and enhanced liver fibrosis (ELF) test. Results: The diagnoses were as follows: NAFLD (30.3%), HCV (24.3%), HBV (13.1%), ALD (10.1%), other (7.8%). Their median age was 49 (21–79), and their median BMI was 27.5 (18.4–39.5). The median liver stiffness measurement (LSM) was 6.7 kPa (2.9–54.2 kPa), the median of the ELF test was 9.0 (7.3–12.6), and the median APRI was 0.40 (0.13–3.13). Advanced fibrosis assessed by LSM was present in 18/89 (20.2%) patients. The LSM values correlated with the ELF test results (r2 = 0.31, p < 0.0001), with the APRI score (r2 = 0.23, p < 0.0001), the age of the patients (r2 = 0.14, p < 0.001), and with the FIB-4 values (r2 = 0.58, p < 0.0001). The ELF test values correlated with the APRI score (r2 = 0.14, p = 0.001), the age (r2 = 0.38, p < 0.0001), and the FIB-4 (r2 = 0.34, p < 0.0001). By determining the confidence intervals of the linear model, we proved that patients younger than 38.1 years have a 95% probability of absence of advanced liver fibrosis when assessed by VCTE. Conclusions: We identified APRI and FIB-4 as simple tools for screening liver disease in primary care in an unselected population of patients. The results also showed that individuals younger than 38.1 years had a negligible risk of advanced liver fibrosis.
Effects of Supraglottic Airway Devices on Hemodynamic Response and Optic Nerve Sheath Diameter: Proseal LMA, LMA Supreme, and I-gel LMA
Authors: Okyay Rahşan Dilek , Küçükosman Gamze , Köksal Bengü Gülhan , Pişkin Özcan , Ayoğlu Hilal
Published: April 2023

Background and Objectives: Supraglottic airway devices (SADs) are known to be useful in eliminating the drawbacks of laryngoscopy and tracheal intubation, especially ocular pressure and stress responses. The ultrasonographic measurement of optic nerve sheath diameter (ONSD) reflects increases in intracranial pressure (ICP). In our study, we aimed to compare the effects of SADs on hemodynamic response and ONSD. Materials and Methods: Our prospective study included 90 ASA I–II patients over the age of 18 who did not have a history of difficult intubation or ophthalmic pathology. The patients were randomly divided into three groups based on the laryngeal mask airway (LMA) devices used: ProSeal LMA (pLMA, n = 30), LMA Supreme (sLMA, n = 30), and I-gel (n = 30). The bilateral ONSD measurements and hemodynamic data of the patients who underwent standard anesthesia induction and monitoring were recorded before induction (T0) and 1 min (T1), 5 min (T5), and 10 min (T10) after SAD placement. Results: At all measurement times, the hemodynamic responses and ONSD values of the groups were similar. In all three groups, intergroup hemodynamic changes at T0 and T1 were similar and higher than those at other times of measurement (p < 0.001). The ONSD values of all groups increased at T1, and they tended to return to baseline values afterward (p < 0.001). Conclusions: We concluded that all three SADs could be used safely because they preserved both hemodynamic stability and ONSD changes in their placement processes, and they did not cause elevations in ONSD to an extent that would lead to increased ICP.
Effect of Annealing Process on Interface Behavior of Al/Zn Laminated Composites
Authors: Wang Renfu , Duan Yonghua , Peng Mingjun , Shu Baipo , Wang Yiren , Li Mengnie , Li Caiju , Zheng Shanju , Qi Huarong , Jia Ruijiao
Published: April 2023

Laminated metal composites have attracted more attention due to their ultra-high strength, fracture toughness and elongation, full considerations of each component, and coordinated deformation effect between interfaces. Herein, Zn and Al were selected as the component materials to prepare Al/Zn laminated composite plates using hot rolling and low temperature annealing, and studied the influence of the thickness of the diffusion layer at the interface to understand the reason for the strengthening and toughening mechanism. The results show that, with an increase in annealing temperature and time, the grain will recover and recrystallize to grow. A diffusion layer with a certain thickness formed at the interface due to the mutual diffusion of Al and Zn atoms at the interface. As annealing time and temperature increase, the yield and tensile strengths first increased and then decreased. The tensile fracture morphology showeds many deep dimples. In the rolling state, the micro-hardness value at the interface was between Al and Zn.
Effect of Cooling Rate and Remelting Temperature on the Solidification Structure of Al-5Zr Master Alloy
Authors: Li Zhenhua , Zhang Wangming , Fan Siyue , Jiang Qingwei
Published: April 2023

Zr is an important element to improve the heat resistance of aluminum alloys, which is usually added to alloys using the Al-Zr master alloys. The microstructure of Al-Zr master alloys has a significant impact on the properties of Zr-bearing aluminum alloys. In this paper, the microstructure of commercial Al-5Zr master alloys was examined, and the effect of the remelting temperature and cooling rate on the solidification structure of the remelted Al-5Zr master alloys was investigated, aiming to develop a feasible way for quality improvement of Al-5Zr master alloys. The results showed that the microstructure of the remelted Al-5Zr master alloy could be regulated effectively by controlling the remelting temperature and cooling rate. When the remelting temperature was 1320 °C, the primary Al3Zr phase in the remelted Al-5Zr master alloy was mainly precipitated as coarse plate-like or fine long needle-like. Higher cooling rate increased nucleation density and refined microstructure. The average length of the primary Al3Zr phase was 178.2, 87.4, and 61.3 μm when the cooling rate was 4.6, 30.8, and 43.9 °C/s, respectively. Lower remelting temperature was generally conducive to refinement of primary Al3Zr phase. When the remelting temperature was 920 °C, the primary Al3Zr phase in the remelted Al-5Zr master alloy was mainly precipitated as block-like, fine needle-like, and petal-like. When the cooling rate was 4.6 °C, coarse plate-like Al3Zr phase precipitated. With increasing cooling rate to 25.3 °C, the coarse plate-like Al3Zr phase disappeared and the block-like and fine needle-like Al3Zr phase precipitated followed by a large number of fine petal-like Al3Zr phase precipitated after cooling rate to 45.6 °C. The optimized remelting process can improve the microstructure of the commercial Al-5Zr master alloy.
Grain Refinement of Aluminum and Aluminum Alloys by Sc and Zr
Authors: Lei Zhiguo , Wen Shengping , Huang Hui , Wei Wu , Nie Zuoren
Published: April 2023

Rare earth elements and transition elements are widely used in aluminum alloys, magnesium alloys and copper alloys due to their unique microalloying effects. With regard to in-depth research on the grain refinement characteristics of rare earth elements and transition elements, the combination of grain refinement and microalloying in the master alloys has a great impact on the theories and technical research of refinement, and the broadening of the application field of master alloys. This paper first summarizes the grain refinement mechanisms and analyzes the effects of rare earth elements and transition elements on the grain refinement of aluminum and aluminum alloys, and summarizes the elements suitable for the preparation of Al-M master alloys and their refinement mechanism.
Fabrication of Nanoporous Gold via an Improved Solid-Phase Method for Non-Enzymatic Detection of Aniline
Authors: Wan Qihang , Li Jun , Liu Zhang , Han Lu , Huang Siyi , Wang Zumin
Published: April 2023

In this paper, nanoporous gold (NPG) thin films with superior catalytic performance were prepared on glassy carbon electrodes (GCE) by optimizing the process parameters and adopting an improved solid-phase reaction method. The morphology and structures of NPG films were comprehensively investigated and the structural defects on continuous NPG ligaments were observed. The NPG films demonstrated higher sensitivity and a lower detection limit during the amperometric sensing of aniline than NPGs made using conventional techniques. The results of multiple electrochemical tests demonstrated that the NPG/GCE electrodes possess high stability and good reproducibility. The prepared NPG film is a favorable material that can be superior in aniline electrochemical detection and can also be applied in other electrochemical sensing reactions.
Influence of Pre-Milling on the Mn Solid Solubility in the Al-Mn-Cu Alloy during Mechanical Alloying
Authors: Yakovtseva Olga A. , Emelina Nadezhda B. , Mochugovskiy Andrey G. , Tabachkova Nataliya Yu. , Prosviryakov Alexey S. , Mikhaylovskaya Anastasia V.
Published: April 2023

Increasing the strength of Al-based alloys is an important issue of physical metallurgy and industrial processing. Severe plastic deformation and related extension of solid solubility during mechanical alloying provide an opportunity for significant strengthening due to grain refinement, solid solution, and precipitation strengthening mechanisms. During mechanical alloying, an anomalous increase in the solid-state solubility of alloying elements occurs. The present study focuses on the investigation of the pre-milling treatment to the microstructure, phase composition, and solubility in Al-7.7 Mn-3.5 Cu (wt%) alloy processed by a high-energy ball milling of Al-14.3 Mn-6.5 Cu (wt%) master alloy diluted with Al powder. During milling, the mean granular size decreased to ~5 µm, and a strong grain refinement occurred. According to our TEM and XRD data, ball milling provided a mean grain size of 13–14 nm and a microhardness of 490–540 HV. The lattice parameter of the Al-based solid solution decreased with an increase in the milling time to 7.5–10 h, which suggested the dissolution of the alloying elements, and the lattice parameter increased at a higher milling time of 12.5–40 h, which suggested the decomposition of the solid solution. The XRD data revealed the dissolution of the Al6Mn and Al20Cu2Mn3 solidification-originated phases with a further precipitation of the Al6Mn dispersoids. Pre-milling of the master alloy entailed a significant decrease in the minimal lattice parameter value from 0.4029 nm to 0.4023 nm due to an increase in the Mn solute content from 6.2 wt% (3.3 at%) to 7.5 wt % (4.0 at%) in the studied alloy during high-energy ball milling.
Effects of Cr Addition on the Precipitation and Properties of Cryo-Rolled CuNiSi Alloys
Authors: Wang Wei , Chen Zongning , Guo Enyu , Zhang Siruo , Kang Huijun , Wang Tongmin
Published: April 2023

CuNiSi alloys are widely used for lead frames and connectors due to the combination of high strength and high electrical conductivity. In this work, the microstructures, properties and precipitation behaviors of cryo-rolled CuNiSi alloys with different Cr additions were investigated. The results show that the microstructures of cryo-rolled CuNiSi alloys are mainly composed of nano-sized deformation twins. During aging, discontinuous precipitation gradually takes the place of continuous precipitation with the onset of recrystallization. The addition of chromium reacts to form Cr3Si particles and facilitates the formation of lamellar structures in the cryo-rolled states of CuNiSi alloys. Moreover, both the recrystallization and the discontinuous precipitation of cryo-rolled CuNiSi alloys are hindered by the addition of Cr elements. As a result, the mechanical strength of cryo-rolled CuNiSi alloys after aging can be maintained. The best combination of properties obtained in the CuNiSi-0.15Cr alloy is 761 MPa, 6.1% and 48.4% IACS in ultimate strength, elongation and electrical conductivity, respectively.
Lipid Differences and Related Metabolism Present on the Hand Skin Surface of Different-Aged Asiatic Females—An Untargeted Metabolomics Study
Authors: Chen Tian , Wang Juan , Mao Zhenxing
Published: April 2023

This cross-sectional study aimed to investigate differences in skin surface lipids (SSL) and explore related metabolic pathways among females of different ages in Henan Province. Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to determine the lipid composition of the skin surface of 58 female volunteers who were divided into three age groups. Statistical analysis was performed using Progenesis QI, Ezinfo, and MetaboAnalyst. Multivariate and enrichment analysis were used to identify the different SSL among the groups. A total of 530 lipid entities were identified and classified into eight classes. Among these, 63 lipids were significantly different between the groups. Lower levels of glycerolipids (GLs) and sphingolipids (SPs) were observed in the middle-aged group, while higher levels of GLs were found in the elder group. GLs belonged to the largest and statistically significant enrichment of lipid metabolic pathways, and the lipid individuals enriched to the sphingoid bases metabolism were the most and statistically significant. These findings suggest that there are differences in hand SSL among females of different ages, which may be related to GLs and sphingoid bases metabolism.
Optical Characterization of ALD-Coated Nanoporous Alumina Structures: Effect of Sample Geometry or Coated Layer Material
Authors: Cuevas Ana Laura , Vega Víctor , Domínguez Antonia , González Ana Silvia , Prida Víctor M. , Benavente Juana
Published: April 2023

Optical characterization of nanoporous alumina-based structures (NPA-bSs), obtained by ALD deposition of a thin conformal SiO2 layer on two alumina nanosupports with different geometrical parameters (pore size and interpore distance), was performed by two noninvasive and nondestructive techniques such as spectroscopic ellipsometry (SE) and photoluminescence (Ph) spectra. SE measurements allow us to estimate the refraction index and extinction coefficient for the studied samples and their dependence with wavelength for the 250–1700 nm interval, showing the effect of sample geometry and cover-layer material (SiO2, TiO2, or Fe2O3), which significantly affect the oscillatory character of both parameters, as well as changes associated with the light incidence angle, which are attributed to surface impurities and inhomogeneity. Photoluminescence curves exhibit a similar shape independently of sample pore-size/porosity, but they seem to affect intensity values. This analysis shows the potential application of these NPA-bSs platforms to nanophotonics, optical sensing, or biosensing.
Automatic Piecewise Extreme Learning Machine-Based Model for S-Parameters of RF Power Amplifier
Authors: Wang Lulu , Zhou Shaohua , Fang Wenrao , Huang Wenhua , Yang Zhiqiang , Fu Chao , Liu Changkun
Published: April 2023

This paper presents an automatic piecewise (Auto-PW) extreme learning machine (ELM) method for S-parameters modeling radio-frequency (RF) power amplifiers (PAs). A strategy based on splitting regions at the changing points of concave-convex characteristics is proposed, where each region adopts a piecewise ELM model. The verification is carried out with S-parameters measured on a 2.2–6.5 GHz complementary metal oxide semiconductor (CMOS) PA. Compared to the long-short term memory (LSTM), support vector regression (SVR), and conventional ELM modeling methods, the proposed method performs excellently. For example, the modeling speed is two orders of magnitude faster than SVR and LSTM, and the modeling accuracy is more than one order of magnitude higher than ELM.
Ore Mineralogy and Typomorphism of Native Gold of the Spokoininsky Cluster of the Aldan–Stanovoy Gold Province
Authors: Kondratieva Larisa A. , Anisimova Galina S. , Kardashevskaia Veronika N.
Published: April 2023

The ore mineralogy of a new promising target of the Aldan–Stanovoy gold province—the Spokoininsky cluster—is considered. Gold mineralization is represented by a volumetric, nonlinear type, unconventional for the region; it is related to elements of fold structures and reverse fault in the enclosing metamorphic basement rocks. Vein-disseminated sulfide–(pyrite)–quartz ores build up deposit-like bodies in beresites from gneisses and granite gneisses and are associated with Mesozoic igneous rocks of subalkaline formations. Mineralization is characterized by polysulfide (Fe-Cu-Pb); gold–bismuth (Au-Bi) and gold–silver–telluride (Au-Ag-Te) mineral types. Different mineral types have their own typomorphic minerals and typochemistry (fineness and impurities) of native gold. The widespread distribution of telluride mineralization and its great importance in the formation of gold mineralization on the Aldan shield is confirmed. The distribution area of bismuth (including tellurium–bismuth) mineralization in the southern part of the Aldan shield, in the zone of influence of the Stanovoy deep fault, has been identified.
Mesoporous Drug Delivery System: From Physical Properties of Drug in Solid State to Controlled Release
Authors: Wang Yanan , Li Fang , Xin Junbo , Xu Jia , Yu Guanghua , Shi Qin
Published: April 2023

Mesoporous materials, which exhibit great potential in the control of polymorphs and delivery of poorly water-soluble drugs, have obtained considerable attention in the field of pharmaceutical science. The physical properties and release behaviors of amorphous or crystalline drugs may be affected by formulating them into mesoporous drug delivery systems. In the past few decades, an increasing amount of papers have been written about mesoporous drug delivery systems, which play a crucial role in improving the properties of drugs. Herein, mesoporous drug delivery systems are comprehensively reviewed in terms of their physicochemical characteristics, control of polymorphic forms, physical stability, in vitro performance, and in vivo performance. Moreover, the challenges and strategies of developing robust mesoporous drug delivery systems are also discussed.
The Challenging Treatment of Cisplatin-Resistant Tumors: State of the Art and Future Perspectives
Authors: Coffetti Giulia , Moraschi Martina , Facchetti Giorgio , Rimoldi Isabella
Published: April 2023

One of the main problems in chemotherapy using platinum drugs as anticancer agents is the resistance phenomenon. Synthesizing and evaluating valid alternative compounds is challenging. This review focuses on the last two years of progress in the studies of platinum (II)- and platinum (IV)-based anticancer complexes. In particular, the research studies reported herein focus on the capability of some platinum-based anticancer agents to bypass resistance to chemotherapy, which is typical of well-known drugs such as cisplatin. Regarding platinum (II) complexes, this review deals with complexes in trans conformation; complexes containing bioactive ligands, as well as those that are differently charged, all experience a different reaction mechanism compared with cisplatin. Regarding platinum (IV) compounds, the focus was on complexes with biologically active ancillary ligands that exert a synergistic effect with platinum (II)-active complexes upon reduction, or those for which controllable activation can be realized thanks to intracellular stimuli.
Naturally Occurring Chalcones with Aggregation-Induced Emission Enhancement Characteristics
Authors: Budziak-Wieczorek Iwona , Kamiński Daniel , Skrzypek Alicja , Ciołek Anna , Skrzypek Tomasz , Janik-Zabrotowicz Ewa , Arczewska Marta
Published: April 2023

In this paper, the natural chalcones: 2′-hydroxy-4,4′,6′-trimethoxychalcone (HCH), cardamonin (CA), xanthohumol (XN), isobavachalcone (IBC) and licochalcone A (LIC) are studied using spectroscopic techniques such as UV–vis, fluorescence spectroscopy, scanning electron microscopy (SEM) and single-crystal X-ray diffraction (XRD). For the first time, the spectroscopic and structural features of naturally occurring chalcones with varying numbers and positions of hydroxyl groups in rings A and B were investigated to prove the presence of the aggregation-induced emission enhancement (AIEE) effect. The fluorescence studies were carried out in the aggregate form in a solution and in a solid state. As to the results of spectroscopic analyses conducted in the solvent media, the selected mixtures (CH3OH:H2O and CH3OH:ethylene glycol), as well as the fluorescence quantum yield (ϕF) and SEM, confirmed that two of the tested chalcones (CA and HCH) exhibited effective AIEE behaviour. On the other hand, LIC showed a large fluorescence quantum yield and Stokes shift in the polar solvents and in the solid state. Moreover, all studied compounds were tested for their promising antioxidant activities via the utilisation of 1,1- diphenyl-2-picrylhydrazyl as a free-radical scavenging reagent as well as potential anti-neurodegenerative agents via their ability to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Finally, the results demonstrated that licochalcone A, with the most desirable emission properties, showed the most effective antioxidant (DPPH IC50 29%) and neuroprotective properties (AChE IC50 23.41 ± 0.02 μM, BuChE IC50 42.28 ± 0.06 μM). The substitution pattern and the biological assay findings establish some relation between photophysical properties and biological activity that might apply in designing AIEE molecules with the specified characteristics for biological application.
An Ethanol Extract of Perilla frutescens Leaves Suppresses Adrenergic Agonist-Induced Metastatic Ability of Cancer Cells by Inhibiting Src-Mediated EMT
Authors: Jeong Jae-Hoon , Park Hyun-Ji , Chi Gyoo-Yong , Choi Yung-Hyun , Park Shin-Hyung
Published: April 2023

Previous studies have indicated that the adrenergic receptor signaling pathway plays a fundamental role in chronic stress-induced cancer metastasis. In this study, we investigated whether an ethanol extract of Perilla frutescens leaves (EPF) traditionally used to treat stress-related symptoms by moving Qi could regulate the adrenergic agonist-induced metastatic ability of cancer cells. Our results show that adrenergic agonists including norepinephrine (NE), epinephrine (E), and isoproterenol (ISO) increased migration and invasion of MDA-MB-231 human breast cancer cells and Hep3B human hepatocellular carcinoma cells. However, such increases were completely abrogated by EPF treatment. E/NE induced downregulation of E-cadherin and upregulation of N-cadherin, Snail, and Slug. Such effects were clearly reversed by pretreatment with EPF, suggesting that the antimetastatic activity of EPF could be related to epithelial–mesenchymal transition (EMT) regulation. EPF suppressed E/NE-stimulated Src phosphorylation. Inhibition of Src kinase activity with dasatinib completely suppressed the E/NE-induced EMT process. Transfecting MDA-MB-231 cells with constitutively activated Src (SrcY527F) diminished the antimigration effect of EPF. Taken together, our results demonstrate that EPF can suppress the adrenergic agonist-promoted metastatic ability of cancer cells by inhibiting Src-mediated EMT. This study provides basic evidence supporting the probable use of EPF to prevent metastasis in cancer patients, especially those under chronic stress.
Steroids and Fatty Acid Esters from Cyperus sexangularis Leaf and Their Antioxidant, Anti-Inflammatory and Anti-Elastase Properties
Authors: Miya Gugulethu Mathews , Oriola Ayodeji Oluwabunmi , Payne Bianca , Cuyler Marizé , Lall Namrita , Oyedeji Adebola Omowunmi
Published: April 2023

Cyperus sexangularis (CS) is a plant in the sedges family (Cyperaceae) that grows abundantly in swampy areas. The leaf sheath of plants in the Cyperus genus are mostly used domestically for mat making, while they are implicated for skin treatment in traditional medicine. The plant was investigated for its phytochemical contents as well as its antioxidant, anti-inflammatory and anti-elastase properties. The n-hexane and dichloromethane leaf extracts were chromatographed on a silica gel column to afford compounds 1–6. The compounds were characterized by nuclear magnetic resonance spectroscopy and mass spectrometry. The inhibitory effect of each compound against 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and ferric ion radicals were determined by standard in vitro antioxidant methods. The in vitro anti-inflammatory response was measured using egg albumin denaturation (EAD) assay, while the anti-elastase activity of each compound in human keratinocyte (HaCaT) cells was also monitored. The compounds were characterized as three steroidal derivatives, stigmasterol (1), 17-(1-methyl-allyl)-hexadecahydro-cyclopenta[a]phenanthrene (2) and β-sitosterol (3), dodecanoic acid (4) and two fatty acid esters, ethyl nonadecanoate (5) and ethyl stearate (6). Stigmasterol (1) exhibited the best biological properties, with IC50 of 38.18 ± 2.30 µg/mL against DPPH, 68.56 ± 4.03 µg/mL against NO and 303.58 ± 10.33 µAAE/mg against Fe3+. At 6.25 µg/mL, stigmasterol inhibited EAD by 50%. This activity was lower when compared to diclofenac (standard), which demonstrated 75% inhibition of the protein at the same concentration. Compounds 1, 3, 4 and 5 showed comparable anti-elastase activity with an IC50 ≥ 50 µg/mL, whereas the activity of ursolic acid (standard) was double fold with an IC50 of 24.80 ± 2.60 µg/mL when compared to each of the compounds. In conclusion, this study has identified three steroids (1–3), one fatty acid (4), and two fatty acid esters (5 and 6) in C. sexangularis leaf for the first time. The compounds showed considerable antioxidant, anti-inflammatory and anti-elastase properties. Thus, the findings may serve as a justification for the folkloric use of the plant as a local skin ingredient. It may also serve to validate the biological role of steroids and fatty acid compounds in cosmeceutical formulations.
High-Dose Spermidine Supplementation Does Not Increase Spermidine Levels in Blood Plasma and Saliva of Healthy Adults: A Randomized Placebo-Controlled Pharmacokinetic and Metabolomic Study
Authors: Senekowitsch Stefan , Wietkamp Eliza , Grimm Michael , Schmelter Franziska , Schick Philipp , Kordowski Anna , Sina Christian , Otzen Hans , Weitschies Werner , Smollich Martin
Published: April 2023

(1) Background: Spermidine is a biogenic polyamine that plays a crucial role in mammalian metabolism. As spermidine levels decline with age, spermidine supplementation is suggested to prevent or delay age-related diseases. However, valid pharmacokinetic data regarding spermidine remains lacking. Therefore, for the first time, the present study investigated the pharmacokinetics of oral spermidine supplementation. (2) Methods: This study was designed as a randomized, placebo-controlled, triple-blinded, two-armed crossover trial with two 5-day intervention phases separated by a washout phase of 9 days. In 12 healthy volunteers, 15 mg/d of spermidine was administered orally, and blood and saliva samples were taken. Spermidine, spermine, and putrescine were quantified by liquid chromatography–mass spectrometry (LC–MS/MS). The plasma metabolome was investigated using nuclear magnetic resonance (NMR) metabolomics. (3) Results: Compared with a placebo, spermidine supplementation significantly increased spermine levels in the plasma, but it did not affect spermidine or putrescine levels. No effect on salivary polyamine concentrations was observed. (4) Conclusions: This study’s results suggest that dietary spermidine is presystemically converted into spermine, which then enters systemic circulation. Presumably, the in vitro and clinical effects of spermidine are at least in part attributable to its metabolite, spermine. It is rather unlikely that spermidine supplements with doses <15 mg/d exert any short-term effects.
The Relationship between the Dietary Inflammatory Index (DII) and Metabolic Syndrome (MetS) in Middle-Aged and Elderly Individuals in the United States
Authors: Zhao Qilong , Tan Xinyue , Su Zhenni , Manzi Habasi Patrick , Su Li , Tang Zhenchuang , Zhang Ying
Published: April 2023

(1) Background: With the aging demographic shift in society, there is a growing number of middle-aged and elderly individuals affected by metabolic syndrome (MetS), a risk factor contributing to all causes of mortality. Inflammation plays a crucial role in the development of MetS. This study aims to examine the correlation between MetS and pro-inflammatory diets in middle-aged and elderly individuals, utilizing the Dietary Inflammation Index (DII) as a measure. (2) Methods: Data were extracted from the 2007–2016 National Health and Nutrition Examination Survey (NHANES) database for individuals who were 45 years of age or older. The DII was determined for each participant through 24-h dietary recall interviews. The relationship between DII and MetS was assessed using binary logistic regression analysis, and the association between DII and MetS-related indicators was further explored through generalized linear model (GLM) and quantile regression analysis. (3) Results: A total of 3843 middle-aged and elderly individuals were included in the study. After controlling for confounding factors, the highest quartile of DII was associated with a higher risk of MetS (ORQ4:Q1 = 1.339; 95% CI: 1.013, 1.769; p for trend = 0.018). The top DII quartile also increased the risk of reduced HDL-C (ORQ4:Q1 = 1.499; 95% CI: 1.005, 2.234; p for trend = 0.048) and raised FG (ORQ4:Q1 = 1.432; 95% CI: 1.095, 1.873; p for trend = 0.010) compared to the lowest DII quartile. The levels of DII were found to be positively correlated with BMI (β = 0.258, p = 0.001), FPG (β = 0.019, p = 0.049), TG (β = 2.043, p = 0.013), waistline (β = 0.580, p = 0.002), and negatively correlated with HDL-C (β = −0.672, p = 0.003). (4) Conclusions: In middle-aged and elderly individuals in the United States, a high DII score has been linked to the presence of MetS, low HDL-C, and hyperglycemia. Therefore, dietary recommendations for the middle-aged and elderly should focus on reducing the DII by choosing foods rich in antioxidants, dietary fiber, and unsaturated fatty acids.