Low Tc Research Articles

Magnetic and Magnetocaloric Properties of Nano- and Polycrystalline Manganites La(0.7-x)EuxBa0.3MnO3.

Here, we report synthesis and investigations of bulk and nano-sized La(0.7-x)EuxBa0.3MnO3 (x ≤ 0.4) compounds. The study presents a comparison between the structural and magnetic properties of the nano- and polycrystalline manganites La(0.7-x)EuxBa0.3MnO3, which are potential magnetocaloric materials to be used in domestic magnetic refrigeration close to room temperature. The parent compound, La0.7Ba0.3MnO3, has Curie temperature TC = 340 K. The magnetocaloric effect is at its maximum around TC. To reduce this temperature below 300 K, we partially replaced the La ions with Eu ions. A solid-state reaction was used to prepare bulk polycrystalline materials, and a sol-gel method was used for the nanoparticles. X-ray diffraction was used for the structural characterization of the compounds. Transmission electron spectroscopy (TEM) evidenced nanoparticle sizes in the range of 40-80 nm. Iodometry and inductively coupled plasma optical emission spectrometry (ICP-OES) was used to investigate the oxygen content of the studied compounds. Critical exponents were calculated for all samples, with bulk samples being governed by tricritical mean field model and nanocrystalline samples governed by the 3D Heisenberg model. The bulk sample with x = 0.05 shows room temperature phase transition TC = 297 K, which decreases with increasing x for the other samples. All nano-sized compounds show lower TC values compared to the same bulk samples. The magnetocaloric effect in bulk samples revealed a greater magnetic entropy change in a relatively narrow temperature range, while nanoparticles show lower values, but in a temperature range several times larger. The relative cooling power for bulk and nano-sized samples exhibit approximately equal values for the same substitution level, and this fact can substantially contribute to applications in magnetic refrigeration near room temperature. By combining the magnetic properties of the nano- and polycrystalline manganites, better magnetocaloric materials can be obtained.

The role of rare earth elements in tailorable thermal and magnetocaloric properties of RE-Co-Al (RE = Gd, Tb, and Dy) metallic glasses

RE55Co17.5Al27.5 (RE = Gd, Tb, and Dy) metallic glass (MG) rods with critical diameters of 8 mm were successfully fabricated by the copper-mold suction casting method. With the replacement of Gd by Tb and Dy, the thermal stability is improved, while the Curie temperature (Tc) decreases, which is attributed to the strong f-d hybridization and weak magnetic exchange interaction between Co and Tb/Dy. The reversed trend of the glass transition temperatures Tg and Tc was further discussed based on around 33 RE-based MGs for the competition between the dominant thermal effect and magnetic exchange interaction. Dy55Co17.5Al27.5 with a relatively strong dynamic behavior and wide supercooled liquid region of 66 K performs a high cooling efficiency in the hydrogen liquefaction temperature range ascribed to its low Tc below 50 K and rapid response to the applied magnetic field due to the large 4f electron number and low G-factor.

Neuromotor deficits and altered physiological responses to repeated exertional heat stroke exposures in mice.

Exertional heat stroke (EHS) is a life-threatening illness that can lead to negative health outcomes. Using a "severe" preclinical mouse model of EHS, we tested the hypotheses that one EHS exposure results in altered susceptibility to a subsequent EHS and reduced neuromotor performance. Female C57BL/6 mice underwent two protocols, 2 wk apart, either an EHS trial (EHS) or a sham exercise control trial (EXC). For EHS, mice ran in a forced running wheel at 37.5°C/40% relative humidity until loss of consciousness, followed by a slow cooling protocol (2 h recovery at 37.5°C). EXC mice exercised equally but in ∼22°C. Mice were randomized into three groups: 1) EXC-EXC (two consecutive EXC, n = 6, 2) EHS-EXC (EHS followed by EXC, n = 5), and 3) EHS-EHS (repeated EHS, n = 9). Mice underwent noninvasive neuromotor and behavioral tests during recovery and isolated soleus force measurements at the end of recovery. At the first EHS, mice reached average peak core temperatures (Tc,max) of 42.4°C, (46% mortality). On the second EHS, average Tc,max was reduced by ∼0.7°C (P < 0.05; mortality 18%). After the first EHS, both EHS-EX and EHS-EHS showed significant reductions in maximum strength (24 h and 1 wk post). After the second EHS, strength, horizontal rotation, hindlimb tone, suspended hindlimb splay, trunk curl, and provoked biting continued to decline in the EHS-EHS group. In conclusion, exposure to a second EHS after 2 wk leads to increased exercise times in the heat, symptom limitation at a lower Tc,max, and greater deficits in neuromotor and behavioral function during recovery.

Effect of hydrogen content on superconductivity in La–H compounds

Finding room-temperature superconductors is one of the most important subjects in scientific search. Due to its hydrogen clathrate structures, LaH10 has become one of the widely known room-temperature superconductors under pressure. So exploring the role of hydrogen content would help understanding the mechanism of superconductivity in the hydrides. Here, we explore the evolution of hydrogen content in lanthanum hydrides based on the first-principles calculations. We found new lanthanum hydrides at pressures, such as Cmcm-LaH. The electronic properties and electron–phonon coupling have been studied and found that Fm3¯m-LaH obtained an unexpected low Tc of ∼ 0.001 K. The superconductive mechanism has been studied in LaHx (x = 0, 1, 2, 3, 8, 10), where LaH0 means elemental lanthanum. We found that low content of hydrogen depresses the electron–phonon interaction in La–H compounds before H–H bonds formed. But with the increases of H content, the strong electron–phonon coupling of H atoms would help the compounds obtain high Tc. This result would explain the lanthanum hydrides with lower H content obtain weaker electron–phonon coupling and could not became potential high-temperature superconductors.

Influence of annealing temperature and isostatic pressure on microstructure and superconducting properties of isotopic Mg11B2 wires fabricated by internal Mg diffusion method

Here, we report superconducting Mg11B2 wires made by using the internal Mg diffusion technique with isotopic amorphous nano boron (11B) as the precursor material. We show the influence of annealing temperature and isostatic pressure of 0.1 MPa and 1.1 GPa on Mg diffusion into 11B layer, microstructure of superconducting filament, critical current density (Jc) at 20 K and 25 K, critical temperature (Tc) and irreversible magnetic induction (Birr) in mono (single-core) - and multi-filament Mg11B2 wires. Our research shows that thermal treatment at 700 °C and 0.1 MPa for 60 min yields a superconducting phase with low Tc, Birr and Jc in single-core Mg11B2 wire. A higher annealing temperature (740 °C and 0.1 MPa for 60 min) significantly accelerates the diffusion of Mg into the 11B layer and increases the Tc, Birr and Jc. However, the distribution of Mg in 11B layer is very heterogeneous (places with high and low Mg concentration). This leads to heterogeneity in the superconducting material and inhomogeneous Tc, Birr and Jc. Further studies showed that higher annealing temperatures at 770 °C and 800 °C significantly accelerates the diffusion of Mg into the 11B layer and leads to the increase of Tc, Birr and Jc in single-core Mg11B2 wire. In single-core wire annealing treatment under isostatic pressure of 1.1 GPa for 60 min at temperature of 800 °C it causes Mg penetrates into the 11B layer very heterogeneously and large amount of 11B remains unreacted. However, the same heat treatment at 800 °C and 1.1 GPa for 60 min in multi-filament wires leads to a complete Mg synthesis reaction with the 11B layer. This leads to increase Birr and Jc. This work shows that the formation and accumulation of pinning centers is essential to further increase Jc in Mg11B2 wires.

(Student Award, 1st Place, Invited) Rapid Nanometer Scale Patterning Using New High-Sensitivity, Dry-Develop Resists

A family of high-resolution, photo-thermal resists based on low ceiling temperature copolymers has been developed and used in a nanometer scale, direct-write thermal patterning tool. The polymer resists are composed of cyclic, low ceiling temperature (Tc) poly(aldehydes). Tc is the thermodynamic temperature which separates polymer from monomer. The Tc of the polymers is below room temperature making the polymer meta-stable at room temperature. The resists very rapidly and cleanly decompose into monomer only when triggered during patterning because the mechanism of depolymerization is suppressed. Cleaving a single bond in the polymer chain initiates the spontaneous and complete depolymerization of the polymer. The use of these low Tc polymers in thermal scanning probe lithography to resolve nanometer size features will be described. Laser ablation of the same polymers has been demonstrated in thermal scanning probe tools allowing for the rapid removal of large areas of the resist adding speed to the hot-tip thermal patterning capability. A particular advantage of the laser assisted thermal scanning probe patterning tools is the ability to form three-dimensional features both by hot-tip patterning and laser ablation.

Differing Prevalence and Correlates of Metabolic Syndromes Between Chlorpromazine and Clozapine: A 10-year Retrospective Study of a Male Chinese Cohort.

Antipsychotics are known to be associated with metabolic syndromes (MetS). Chlorpromazine (CPZ) and Clozapine (CLZ) are currently the most commonly used antipsychotics in low-income districts of China. However, potential differences in the long-term effects of CPZ and CLZ on MetS in schizophrenia inpatients are not well understood. Here, we aimed to identify any MetS profile differences between long-term schizophrenia patients who were prescribed either CPZ or CLZ at a primary psychiatric hospital. We recruited a total of 204 male schizophrenia patients who received either CPZ or CLZ. We measured their weight, height, body mass index (BMI), waist circumference (WC), diastolic blood pressure (DBP), and systolic blood pressure (SBP), as well as their biochemical indicators, including fasting blood glucose (FBS), triglycerides (TG), cholesterol (TC), high-density lipoprotein cholesterol (HDL-c) and low-density lipoprotein cholesterol (LDL-c). The MetS prevalence in the CPZ and CLZ groups was 31% and 37.5%, respectively. The CLZ group had significantly higher DBP levels and a higher incidence of dyslipidemia (HDL-c) but lower HDL-c and TC levels than the CPZ group. We also determined that smoking history, BMI, and duration of hospitalisation were risk factors for the development of MetS. Moreover, we found that CPZ and CLZ were correlated with the same risk for developing MetS and that BMI was a vital risk factor of MetS for both the CPZ and CLZ groups. Long-term CPZ and CLZ prescriptions were associated with similar profiles for developing MetS of schizophrenia patients.

Electron-phonon interaction and point contact enhanced superconductivity in trigonal PtBi2

PtBi2 is a Weyl semimetal, which demonstrates superconductivity with low critical temperature Tc ∼ 0.6 K in the bulk. Here, we report our study of electron-phonon interaction (EPI) in trigonal PtBi2 by the Yanson point- contact (PC) spectroscopy and present the observation of PC enhanced superconductivity. We show that the Yanson’s PC spectra display a broad maximum around 15 meV, indicating, apparently, EPI mechanism of Cooper pairing in PtBi2. Moreover, we discovered a substantial increase of Tc up to ∼ 3.5 K in PCs. The observed Tc is suf­ficiently higher than the bulk value, as well as detected at hydrostatic pressure. We calculated the phonon density of states and Eliashberg EPI function in PtBi2 within the framework of the density functional theory. A comparison of experimental data with theoretical calculations showed acceptable agreement. The theoretical Tc is 3.5 K, which corresponds to the experimental value.

High-Temperature Ferromagnetism in a Two-Dimensional Semiconductor with a Rectangular Spin Lattice

Atomically thin two-dimensional (2D) ferromagnetic (FM) semiconductors with a high Curie temperature (TC) are essential and highly desired for nanoscale spintronic devices. However, the recently discovered 2D FM semiconductors show rather low TC (≤45 K), which limits their practical application. An important reason for the low TC is the lack of effective spin interactions. Here, we reveal that increasing the number of effective spin interactions by constructing a rectangular spin–lattice can significantly improve the TC of FM semiconductors. Based on this mechanism, we design a rectangular lattice of the CrO2 monolayer (denoted as R-CrO2) by performing global structural optimizations. The first-principles calculations show that the R-CrO2 is energetically more stable than the previously reported H- and T-CrO2. As expected, the R-CrO2 monolayer is an intrinsic FM semiconductor with TC up to ∼370 K, which is more than twice that of the T-CrO2 monolayer (∼150 K). This is because the R-CrO2 monolayer possesses four effective spin interactions between adjacent Cr sites, more than that of the T-CrO2 monolayer (3). These findings give rise to a new and efficient design principle for realizing high-temperature 2D FM semiconductors.

Superconductivity of disordered NbN films deposited on magnesium oxide and oxidized silicon substrates

This study investigates the evolution of superconducting properties as a function of disorder in epitaxial and polycrystalline niobium nitride (NbN) thin films grown on MgO and SiO2/Si substrates, respectively. By reducing the film thickness from 100 to 4 nm, the effective disorder in these two sets of films encompasses a large range, with the Ioffe–Regel parameter in the range of 5.7–9.3 and 1.5–3.0, respectively. Moreover, the density of states at the Fermi level [N(0)] of epitaxial NbN films decreases from 1.91 × 1028 to 1.46 × 1028 states eV−1m−3 with the superconducting transition temperature (Tc ) ranging from 16.0 to 11.8 K. In contrast, the N(0) of polycrystalline NbN films decreases from 2.18 × 1028 to 1.80 × 1028 states eV−1m−3 with Tc ranging from 14.9 to 2.56 K. The experimental results reveal that the Tc of NbN films with different thicknesses is mainly controlled by N(0), and the greater Coulomb pseudopotential (μ*) in the polycrystalline films leads to lower Tc and larger resistivity. The changes in N(0) and μ* should collectively account for the reduction of Tc with disorder in NbN thin films.

Formation of zircon-type DyCrO4 and its magnetic properties

The formation mechanism of hydrolytic sol-gel synthesized DyCrO4 with a complexing agent in acidic and basic mediums is thoroughly studied. The role of complexing agents and pH on phase formation temperature is also intensively investigated. The formation temperature for DyCrO4 is ∼500 °C in the absence and presence of complexing agents such as oxalic acid and ethylenediaminetetraacetic acid (EDTA) at pH 10. When critic acid is used, the DyCrO4 forms with Cr2O3 impurity. The crystallite size in the presence of a complexing agent in the basic medium is ∼55 nm which is small as compared to only ammonia solution. The various reaction modes lead to tetragonal zircon-type DyCrO4 at ∼500 °C, transforming into orthorhombic perovskite DyCrO3 at 800 °C. The magnetization curve shows the ferromagnetic behavior of DyCrO4 below transition temperature Tc ∼21 K. This low Tc makes nanocrystalline DyCrO4 a potential material for cryogenic applications.

Arctium lappa leaves based on network pharmacology and experimental validation attenuate atherosclerosis by targeting the AMPK-mediated PPARG/LXRα pathway

Arctium lappa (A. lappa) leaves are widely used in various traditional Chinese herbal formulae to ameliorate atherosclerosis (AS) and its complications such as stroke; however, there is no literature reporting the anti-atherosclerotic effect and mechanism of A. lappa leaves thus far. In the present study, we used network pharmacology and molecular docking approaches to examine the protective effect and potential mechanism of A. lappa leaves against AS in vivo and in vitro. From the network pharmacology, PPARG, HMGCR and SREBF2 were identified as the core targets of A. lappa leaves against AS. Further enrichment analyses of GO and KEGG pathways suggested that A. lappa leaves might play an anti-AS role by regulating metabolic processes and PPAR signalling pathways. The results of molecular docking experiment revealed that the major components of A. lappa leaves interacted with cholesterol efflux-regulating core proteins (PPARG, LXRα, ABCA1, and ABCG1), AMPK and SIRT1. Both in vivo and in vitro experimental results demonstrated that treatment with A. lappa leaves significantly lowered TC and LDL-C, increased HDL-C, and reduced cholesterol accumulation in the liver and aorta of the AS rat model and the foam cell model. Importantly, both in vivo and in vitro experimental results demonstrated that A. lappa leaves regulate the activity of the PPARG/LXRα signalling and AMPK/SIRT1 signalling pathways. Moreover, after treatment with the AMPK inhibitor Compound C in vitro, the improvement induced by A. lappa leaves was significantly reversed. In conclusion, A. lappa leaves attenuated AS-induced cholesterol accumulation by targeting the AMPK-mediated PPARG/LXRα pathway and promoting cholesterol efflux.

Alterations of liver enzymes and lipid profile in response to exhaustive eccentric exercise: vitamin D supplementation trial in overweight females with non-alcoholic fatty liver disease

BackgroundEccentric exhaustive exercise (EEE) training has been known as a promising training modality to enhance performance and stimulate adaptation in healthy individuals or patients that might also cause abnormal liver enzymes and lipid profiles. Vitamin D (Vit D) supplementation is believed to improve the condition of Non-Alcoholic Fatty Liver Disease (NAFLD) patients. However, there is limited evidence on the effect of Vit D supplementation on the EEE-induced alterations. This study aimed to investigate the effect of short-term supplementation of Vit D on the liver enzymes and lipid profile alterations following EEE in overweight women with NAFLD.MethodsIn this clinical trial, 22 overweight women with NAFLD were randomly divided into experimental and control (n = 11 in each). The experimental group consumed 2000 IU of Vit D per day for six weeks; the control group consumed a lactose placebo daily with the same color, shape, and warmth percentage. Two treadmill EEE sessions were performed before and after the six-week Vit D supplementation. Blood was taken from the antecubital vein to measure the liver enzymes, lipid profile, and Vit D at four stages: Pre 1(before the first EEE session), Post 1(after the first EEE session), Pre 2 (before the second EEE session), and Post 2 (after the second EEE session).ResultsThe results indicate that Vit D supplementation significantly reduced Bodyweight (BW; P = 0.047), Body Mass Index (BMI; P = 0.044), Body Fat Percentage (BFP; P = 0.001), and Waist Hip Ratio (WHR; P = 0.001) in the experimental group. Additionally, the results showed increased liver enzymes (ALT, AST, and GGT) and lipid profile (TC, TG, and LDL) following EEE. While the HDL levels decreased significantly after EEE. Compared with control, the results of the independent t-test showed significantly lower ALT (P = 0.001; P = 0.001), AST (P = 0.001; P = 0.001), and GGT (P = 0.001; P = 0.001); while significantly higher Vit D (P = 0.001, P = 0.001) in the experimental in both Pre 2 and Post 2; receptively. Also, significantly lower TC (P = 0.001; P = 0.001), TG (P = 0.048; P = 0.001), and LDL (P = 0.001; P = 0.001); while significantly higher HDL (P = 0.001, P = 0.001) were observed in the experimental group compared to the control in both Pre 2 and Post 2; receptively.ConclusionsVit D supplementation reduces the liver enzymes and improves lipid profile alterations following EEE in overweight women with NAFLD. Thus, Vit D supplementation can be considered a functional supplement to improve the EEE-induced alteration.Trial registration: The trial was in the Iranian Clinical Trial Registration Center under the (IRCT20201130049538N1) on 05/07/2021.

Lipid and Haematologic Profiling of Regular Blood Donors Revealed Health Benefits.

BackgroundBlood banks have been suffering a shortage of blood worldwide due to limited donations. By and large, it is widely believed that blood donation has multiple health benefits. However, there are limited studies that support it. As a result, assessing the biochemical profiles of the regular blood donors is indispensable to evaluating an individual’s risk for chronic inflammation.ObjectiveWe strived to compare lipid and haematological profiles of the regular and first-time blood donors in the National Blood Bank Service of Ethiopia.Materials and MethodsA comparative cross-sectional study, involving 104 blood samples (52 each of regular and first-time donors), was designed to analyze lipid and haematological profiles and anthropometric parameters were measured. Data were analyzed using SPSS version 25, Chi-square (χ2) was used to compare the relationship between categorical variables and an independent Student’s t-test was used to compare the mean of the two groups. A p-value <0.05 was considered statistically significant.ResultsRegular blood donors had lower mean TC (144.3 ± 28 mg/dL), TG (159.3 ± 88.2 mg/dL), LDL-c (75.9 ± 25.9 mg/dL) than the first-time blood donors with values of TC (158.1 ± 38.94 mg/dL), TG (163.9 ± 82.7 mg/dL), LDL-c (93.1 ± 31.5 mg/dL), respectively. The ratio of LDL-c/HDL-c and TC/HDL-c was found to be lower in regular blood donors when compared to the first-time donors (P < 0.05). Even though the level of HDL-c was higher (39.8 ± 8.8 mg/dL) in regular blood donors compared to first-time blood donors (36.8 ± 7.7 mg/dL), it was not statistically significant. The mean of some haematologic parameters like a platelet, RDW, lymphocyte, and MCH was significantly lower in regular blood donors than in first-time blood donors. BMI and WHR in regular donors were less than the first-time donors, albeit statistically insignificant.ConclusionInterestingly, blood donation has a significant health benefit by lowering TC, TG and LDL-c, which have the potential risk of developing chronic inflammation.

Development of SQUID based TDEM system and its utilization for field survey at Tumallapalle, Andhra Pradesh, India

This paper describes the development of low Tc SQUID (Superconducting Quantum Interference Device) based TDEM (Time Domain Electro-Magnetic) system for geophysical applications. The SQUID system has been used to perform central loop TDEM sounding measurements near Tumallapalle Uranium mine, Cuddapah (dt), AP, India, where the terrain consists of a thin conducting layer below which low grade Uraniferous Phosphatic Siliceous Dolostone is present. Locating the thin conducting layer which is covered by a thick and highly resistive layer is a challenging task due to the induction of weak eddy currents. In order to enhance the resolution of the target located at larger depth, it is essential to apply larger transmitter moment and use a sensitive receiver. In this work, we combine the use of sensitive SQUID sensor and transmitter loop with larger size to achieve better target resolution. The survey has been performed using transmitter loop sizes of 100 m × 100 m and 400 m × 400 m. In order to compare the performance of the SQUID based TDEM system, the same experiments have also been repeated using induction coil as receiver which has been built for this work. In this article, we describe in detail the results obtained from the central loop TDEM measurements.

The Influence of pH/Salt Concentrations on Tuning Lower Critical Solution Temperature of Poly(NIPAAm-co-DMAA-co-DTBAVA) Multi-Environmentally Terpolymer

New series of thermo-pH multi-responsive terpolymers were fabricated. Cationic acrylate monomer was synthesized and named by [2-((ditert-butylamino)methyl)-4-formyl-6-methoxyphenyl acrylate] and abbreviated as (DTBAVA). 1H NMR and 13C NMR investigated the new compounds and FT IR. The new terpolymers were fabricated by the free radical polymerization of N-isopropylacrylamide NIPAAm, 10 mol% N, N-dimethylacrylamide and 5, 10, and 20 mol% DTBAVA. The investigation process involved the chemical method such as 1H NMR and FT IR; physical methods for the solid terpolymers as glass temperature by DSC, polymer degradation by TGA, and polymer crystallinity via XRD. GPC was performed for molecular weights and dispersity; contact angles for identifying the hydrophilic or hydrophobic terpolymers solutions. The lower critical solution temperatures Tc,s, and cloud points Cp,s of terpolymers were recorded considering the impact of pH solutions and the concentrations of different sodium salts of (SO4−2, Cl−1, and SCN−1) in the Hofmeister series; turbidity measurements were used via UV/vis spectroscopy and micro-DSC. In a new optimization study, we will use these terpolymers in the post-polymerization with biomolecules such as chitosan, protein, and amino acids via Schiff base.

Morphology Modulation in Self-Assembly of Chiral 2-Hydroxy-2-Phenylacetic Acids in Polymeric Diluents

This study focused on the chirality effects that control the lamellar bending sense in self-assembled crystals of chiral 2-hydroxy-2-phenylacetic acids. 2-Hydroxy-2-phenylacetic acid or mandelic acid (MA) was crystallized in the presence of poly(4-vinyl phenol) (PVPh), and its crystalline structures and morphologies were assessed using polarized optical microscopy (POM) and scanning electron microscopy (SEM). MA of two opposite chiral forms (S- and R-) was crystallized with PVPh as the morphology modulator; with adjustment of the PVPh content, the morphology of MA crystals transforms from ring-banded spherulites to highly dendritic spherulites. For MA/PVPh (50/50 wt./wt.) blend and neat MA at same Tc, the dendritic spherulites are packed with single crystals where the lamellae bend at a specific direction varying with Tc and chirality. Contrary to conventional thought, the bending senses of the MA lamellae in the dendritic spherulites are not solely governed by the MA molecular chirality (S or R), but also by Tc. Only at high Tc (&gt;65 °C) is the lamellar bending direction in dendritic spherulites of (S)-MA or (R)-MA blended with PVPh dictated by the chirality, i.e., displaying counterclockwise and clockwise bending direction for (S)-MA/PVPh and (R)-MA/PVPh, respectively. Nevertheless, at low Tc (45 °C), the bending sense of dendritic spherulites displays an opposite direction from those at the higher Tc, which is to say that the chirality alone does not control the lamellar bending direction.

Carbon Stock Potential across Different Land Covers in Tropical Ecosystems of Damota Natural Vegetation, Eastern Ethiopia

The research was carried out in Damota kebele, in the Oromia regional state of Ethiopia, to examine the carbon sequestration potentials under three land covers (i.e., farmland (FL); bushland (BL), and woodland (WL)). In the three land covers, 60 squares of 20 m × 20 m, 5 m × 5 m, and 1 m × 1 m with six horizontal transect lines were employed to gather data on tree, shrub, herbaceous, and soil, respectively. To estimate organic carbon percentage, soil parameters were collected from three soil profiles (i.e., 0–10 cm, 10–20 cm, and 20–30 cm). The results showed that MA had significantly higher above-ground carbon (AGC) with 67.9 ± 11.4 Mg ha−1, whereas BL had significantly higher below-ground carbon (BGC) stocks with 16.32 ± 5.5 Mg ha−1, compared to other gradients. However, FL had the lowest AGC (53.2 ± 4.5 Mg ha−1) and BGC (8.04 ± 2.9 Mg ha−1). FL exhibited a significantly higher SOC value than the other two land covers followed by WL. The BL had the lowest SOC value. SOC across the three soil profiles follows a reduction trend from topsoil depth to lower soil depth with significant variation. WL had relatively higher TC than the other gradients. But FL had the lowest TC stock. Due to a high amount of human and animal interference in FL, weak security, and law enforcement measures, it has low TC. In conclusion, FL should embrace the better ecological, policy, and socioeconomic considerations than the other land covers.

Analyzing Corin-BNP-NEP Protein Pathway Revealing Differential Mechanisms in AF-Related Ischemic Stroke and No AF-Related Ischemic Stroke.

BackgroundThe incidence of atrial fibrillation (AF)-related stroke increases with aging. Natriuretic peptides (NPs) family, including Corin-B type natriuretic peptide (BNP)-neprilysin (NEP) protein levels increased with age and are risk markers of cardiovascular and cerebrovascular diseases, such as AF and cardioembolic stroke. Aging is also linked to epigenetics, specifically DNA methylation. However, only a few studies have investigated the effect of DNA methylation on the NP system. Thus, the present study aimed to investigate whether the Corin-BNP-NEP protein pathway is involved in the pathogenesis of AF-stroke and CpG methylation in the promoter region of the Corin protein gene has an effect on AF-related ischemic stroke.MethodsA total of 82 patients hospitalized with acute ischemic strokes were enrolled in this study. The differences in clinical information were compared between the AF-stroke (n = 37) and no AF-stroke groups (n = 45). Plasma-soluble Corin and NEP were detected using an ELISA kit. CpG methylation in the promoter region of the gene was assessed by a next-generation sequencing-based bisulfite sequencing polymerase chain reaction (BSP).Results(1) Patients in AF-stroke were older, had higher initial NIHSS score, 90-day mRs, higher D2-dimer, INR, and APTT, and low TG, TC, and HbA1c (all p < 0.05). (2) Serum levels of Corin and BNP in the AF-stroke group were significantly higher than that in the no AF-stroke group (p < 0.05). No significant difference was detected in the serum levels of NEP between the two groups. (3) The levels of CpG methylation in the promoter region of the Corin protein gene in the AF-stroke group was significantly lower than that in the no AF-stroke group (p < 0.05). The CpG sites with maximal methylation differences between the two groups were CORIN:678, CORIN:682, CORIN:694, and CORIN:700.ConclusionThe current findings raise the possibility that the Corin–BNP–NEP protein pathway may be involved in the pathogenesis of AF-related ischemic stroke. Deficient CpG methylation in the promoter region of the Corin protein gene is associated with AF-related ischemic stroke.

Symmetrical SnO2/W-doped VO2/SnO2 sandwich structures with high luminous transmittance, excellent solar modulation ability and low phase transition temperature

Until now, it is still a challenging task to obtain VO2-based smart windows with high luminous transmittance (Tlum), satisfactory solar modulation ability (ΔTsol) and low phase transition temperature (Tc) close to room temperature. In this work, symmetrical SnO2(d nm)/W doped VO2 (W-VO2, 60 nm)/SnO2(d nm) (d = 0, 90, 150, 230, 260, 330) multilayer films were proposed and deposited on quartz glass substrates by pulsed laser deposition. The bottom SnO2 layer acted as buffer to improve the crystallinity of VO2, while the top SnO2 layer served as antireflection layer to enhance the optical properties. When SnO2 layer reached a certain thickness, the crystallinity of W-VO2 interlayer was significantly improved, and therefore the optical properties of the obtained tri-layer films were greatly increased. In comparison with the W-VO2 monolayer film, Tlum and ΔTsol of the tri-layer film with d = 260 nm increased from 45.0% to 54.4% and from 2.6% to 10.7%, respectively, while maintaining a low Tc of 39.0 °C. Interestingly, the prepared SnO2/W-VO2/SnO2 tri-layer films showed lively golden yellow or iridescent colors. The results provide a possibility for the design of VO2-based smart windows with low phase transition temperature and excellent thermochromic properties.