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1.
Front Plant Sci ; 15: 1391348, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952849

RESUMO

Introduction: Arsenate, a metalloid, acting as an analog to phosphate, has a tendency to accumulate more readily in plant species, leading to adverse effects. Methods: In the current study, sunflower seedlings were exposed to 25, 50 and 100 ppm of the arsenic. Results: Likewise, a notable reduction (p<0.05) was observed in the relative growth rate (RGR) by 4-folds and net assimilation rate (NAR) by 75% of Helianthus annuus when subjected to arsenic (As) stress. Nevertheless, the presence of Staphylococcus arlettae, a plant growth-promoting rhizobacterium with As tolerance, yielded an escalation in the growth of H. annuus within As-contaminated media. S. arlettae facilitated the conversion of As into a form accessible to plants, thereby, increasing its uptake and subsequent accumulation in plant tissues. S. arlettae encouraged the enzymatic antioxidant systems (Superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT)) and non-enzymatic antioxidants (flavonoids, phenolics, and glutathione) in H. annuus seedlings following substantial As accumulation. The strain also induced the host plant to produce osmolytes like proline and sugars, mitigating water loss and maintaining cellular osmotic balance under As-induced stress. S. arlettae rectified imbalances in lignin content, reduced high malonaldehyde (MDA) levels, and minimized electrolyte leakage, thus counteracting the toxic impacts of the metal. Conclusion: The strain exhibited the capability to concurrently encourage plant growth and remediate Ascontaminated growth media through 2-folds rate of biotransformation and bio-mobilization.

2.
Heliyon ; 10(12): e33078, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38988560

RESUMO

The issue of arsenic (As) contamination in the environment has become a critical concern, impacting both human health and ecological equilibrium. Addressing this challenge requires a comprehensive strategy encompassing water treatment technologies, regulatory measures for industrial effluents, and the implementation of sustainable agricultural practices. In this study, diverse strategies were explored to enhance As accumulation in the presence of Acinetobacter bouvetii while safeguarding the host from the toxic effects of arsenate exposure. The sunflower seedlings associated with A. bouvetii demonstrated a favorable relative growth rate (RGR) and net assimilation rate (NAR) even less than 100 ppm of As stress. Remarkably, the NAR and RGR of A. bouvetii-associated seedlings outperformed those of control seedlings cultivated without A. bouvetii in As-free conditions. Additionally, a markedly greater buildup of bio-transformed As was observed in A. bouvetii-associated seedlings (P = 0.05). An intriguing observation was the normal levels of reactive oxygen species (ROS) in A. bouvetii-associated seedlings, along with elevated activities of key enzymatic antioxidants like catalases (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), and peroxidases (POD), along with non-enzymatic antioxidants (phenols and flavonoids). This coordinated antioxidant defense system likely contributed to the improved survival and growth of the host plant species amidst As stress. A. bouvetii not only augmented the growth of the host plants but also facilitated the uptake of bio-transformed As in the contaminated medium. The rhizobacterium's modulation of various biochemical and physiological parameters indicates its role in ensuring the better survival and progression of the host plants under As stress.

3.
Drugs Context ; 132024.
Artigo em Inglês | MEDLINE | ID: mdl-38989131

RESUMO

Background: Epilepsy is a persistent tendency to experience epileptic seizures and can lead to various neurobiological disorders, with an elevated risk of premature mortality. This study evaluates the efficacy of brivaracetam adjuvant therapy in patients with epilepsy. Methods: A prospective observational multicentre study that was conducted in Pakistan from March to September 2022, by using a non-probability convenience sampling technique. The population consisted of 543 individuals with a diagnosis of epilepsy for whom adjunctive brivaracetam (Brivera; manufactured by Helix Pharma Pvt Ltd., Sindh, Pakistan) was recommended by the treating physician. The research sample was drawn from various private neurology clinics of Karachi, Lahore, Rawalpindi, Islamabad and Peshawar. Data originating from routine patient visits, and assessments at three study time points, were recorded in the study case report form. Results: Across 18 clinical sites, 543 individuals participated, with a mean age of 32.9 years. The most prescribed dosages were 50 mg BD, followed by 100 mg BD. Notably, brivaracetam combined with divalproex sodium was the most prevalent treatment, followed by brivaracetam with levetiracetam. At both the 14th and 90th day assessments, a significant reduction in seizure frequency was observed, with 63.1% of individuals showing a favourable response by day 90. Treatment-naive individuals exhibited higher rates of seizure freedom and response compared with treatment-resistant individuals. Conclusions: The study demonstrates the effectiveness of brivaracetam combination therapy in epilepsy management, with notable reductions in seizure frequency and favourable clinical responses observed, particularly in treatment-naive individuals.

4.
Pharmaceuticals (Basel) ; 17(6)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38931372

RESUMO

Diabetes mellitus is a heterogeneous metabolic disorder that poses significant health and economic challenges across the globe. Polysaccharides, found abundantly in edible plants, hold promise for managing diabetes by reducing blood glucose levels (BGL) and insulin resistance. However, most of these polysaccharides cannot be digested or absorbed directly by the human body. Here we report the production of antidiabetic oligosaccharides from cress seed mucilage polysaccharides using yeast fermentation. The water-soluble polysaccharides extracted from cress seed mucilage were precipitated using 75% ethanol and fermented with Pichia pastoris for different time intervals. The digested saccharides were fractionated through gel permeation chromatography using a Bio Gel P-10 column. Structural analysis of the oligosaccharide fractions revealed the presence of galacturonic acid, rhamnose, glucuronic acid, glucose and arabinose. Oligosaccharide fractions exhibited the potential to inhibit α-amylase and α-glucosidase enzymes in a dose-dependent manner in vitro. The fraction DF73 exhibited strong inhibitory activity against α-amylase with IC50 values of 38.2 ± 1.12 µg/mL, compared to the positive control, acarbose, having an IC50 value of 29.18 ± 1.76 µg/mL. Similarly, DF72 and DF73 showed the highest inhibition of α-glucosidase, with IC50 values of 9.26 ± 2.68 and 50.47 ± 5.18 µg/mL, respectively. In in vivo assays in streptozotocin (STZ)-induced diabetic mice, these oligosaccharides significantly reduced BGL and improved lipid profiles compared to the reference drug metformin. Histopathological observations of mouse livers indicated the cytoprotective effects of these sugars. Taken together, our results suggest that oligosaccharides produced through microbial digestion of polysaccharides extracted from cress seed mucilage have the potential to reduce blood glucose levels, possibly through inhibition of carbohydrate-digesting enzymes and regulation of the various signaling pathways.

5.
PLoS One ; 19(6): e0303890, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38843255

RESUMO

Anomaly detection in time series data is essential for fraud detection and intrusion monitoring applications. However, it poses challenges due to data complexity and high dimensionality. Industrial applications struggle to process high-dimensional, complex data streams in real time despite existing solutions. This study introduces deep ensemble models to improve traditional time series analysis and anomaly detection methods. Recurrent Neural Networks (RNNs) and Long Short-Term Memory (LSTM) networks effectively handle variable-length sequences and capture long-term relationships. Convolutional Neural Networks (CNNs) are also investigated, especially for univariate or multivariate time series forecasting. The Transformer, an architecture based on Artificial Neural Networks (ANN), has demonstrated promising results in various applications, including time series prediction and anomaly detection. Graph Neural Networks (GNNs) identify time series anomalies by capturing temporal connections and interdependencies between periods, leveraging the underlying graph structure of time series data. A novel feature selection approach is proposed to address challenges posed by high-dimensional data, improving anomaly detection by selecting different or more critical features from the data. This approach outperforms previous techniques in several aspects. Overall, this research introduces state-of-the-art algorithms for anomaly detection in time series data, offering advancements in real-time processing and decision-making across various industrial sectors.


Assuntos
Redes Neurais de Computação , Algoritmos , Análise Multivariada , Aprendizado Profundo , Fatores de Tempo
6.
Front Plant Sci ; 15: 1353352, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38689842

RESUMO

Among tropical fruit trees, coconut holds significant edible and economic importance. The natural growth of coconuts faces a challenge in the form of low temperatures, which is a crucial factor among adverse environmental stresses impacting their geographical distribution. Hence, it is essential to enhance our comprehension of the molecular mechanisms through which cold stress influences various coconut varieties. We employed analyses of leaf growth morphology and physiological traits to examine how coconuts respond to low temperatures over 2-hour, 8-hour, 2-day, and 7-day intervals. Additionally, we performed transcriptome and metabolome analyses to identify the molecular and physiological shifts in two coconut varieties displaying distinct sensitivities to the cold stress. As the length of cold stress extended, there was a prominent escalation within the soluble protein (SP), proline (Pro) concentrations, the activity of peroxidase (POD) and superoxide dismutase (SOD) in the leaves. Contrariwise, the activity of glutathione peroxidase (GSH) underwent a substantial reduction during this period. The widespread analysis of metabolome and transcriptome disclosed a nexus of genes and metabolites intricately cold stress were chiefly involved in pathways centered around amino acid, flavonoid, carbohydrate and lipid metabolism. We perceived several stress-responsive metabolites, such as flavonoids, carbohydrates, lipids, and amino acids, which unveiled considerably, lower in the genotype subtle to cold stress. Furthermore, we uncovered pivotal genes in the amino acid biosynthesis, antioxidant system and flavonoid biosynthesis pathway that presented down-regulation in coconut varieties sensitive to cold stress. This study broadly enriches our contemporary perception of the molecular machinery that contributes to altering levels of cold stress tolerance amid coconut genotypes. It also unlocks several unique prospects for exploration in the areas of breeding or engineering, aiming to identifying tolerant and/or sensitive coconut varieties encompassing multi-omics layers in response to cold stress conditions.

7.
Sensors (Basel) ; 24(9)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38732932

RESUMO

In this paper, a 3D conformal meta-lens designed for manipulating electromagnetic beams via height-to-phase control is proposed. The structure consists of a 40 × 20 array of tunable unit cells fabricated using 3D printing, enabling full 360° phase compensation. A novel automatic synthesizing method (ASM) with an integrated optimization process based on genetic algorithm (GA) is adopted here to create the meta-lens. Simulation using CST Microwave Studio and MATLAB reveals the antenna's beam deflection capability by adjusting phase compensations for each unit cell. Various beam scanning techniques are demonstrated, including single-beam, dual-beam generation, and orbital angular momentum (OAM) beam deflection at different angles of 0°, 10°, 15°, 25°, 30°, and 45°. A 3D-printed prototype of the dual-beam feature has been fabricated and measured for validation purposes, with good agreement between both simulation and measurement results, with small discrepancies due to 3D printing's low resolution and fabrication errors. This meta-lens shows promise for low-cost, high-gain beam deflection in mm-wave wireless communication systems, especially for sensing applications, with potential for wider 2D beam scanning and independent beam deflection enhancements.

9.
Front Chem ; 12: 1374739, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38601886

RESUMO

The iron-based biomass-supported catalyst has been used for Fischer-Tropsch synthesis (FTS). However, there is no study regarding the life cycle assessment (LCA) of biomass-supported iron catalysts published in the literature. This study discusses a biomass-supported iron catalyst's LCA for the conversion of syngas into a liquid fuel product. The waste biomass is one of the source of activated carbon (AC), and it has been used as a support for the catalyst. The FTS reactions are carried out in the fixed-bed reactor at low or high temperatures. The use of promoters in the preparation of catalysts usually enhances C5+ production. In this study, the collection of precise data from on-site laboratory conditions is of utmost importance to ensure the credibility and validity of the study's outcomes. The environmental impact assessment modeling was carried out using the OpenLCA 1.10.3 software. The LCA results reveals that the synthesis process of iron-based biomass supported catalyst yields a total impact score in terms of global warming potential (GWP) of 1.235E + 01 kg CO2 equivalent. Within this process, the AC stage contributes 52% to the overall GWP, while the preparation stage for the catalyst precursor contributes 48%. The comprehensive evaluation of the iron-based biomass supported catalyst's impact score in terms of human toxicity reveals a total score of 1.98E-02 kg 1,4-dichlorobenzene (1,4-DB) equivalent.

10.
Front Plant Sci ; 15: 1364945, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628364

RESUMO

Introduction: Fresh Aareca nut fruit for fresh fruit chewing commonly found in green or dark green hues. Despite its economic significance, there is currently insufficient research on the study of color and luster of areca. And the areca nut fruits after bagging showed obvious color change from green to tender yellow. In the study, we tried to explain this interesting variation in exocarp color. Methods: Fruits were bagged (with a double-layered black interior and yellow exterior) 45 days after pollination and subsequently harvested 120 days after pollination. In this study, we examined the the chlorophyll and carotenoid content of pericarp exocarp, integrated transcriptomics and metabolomics to study the effects of bagging on the carotenoid pathway at the molecular level. Results: It was found that the chlorophyll and carotenoid content of bagged areca nut (YP) exocarp was significantly reduced. A total of 21 differentially expressed metabolites (DEMs) and 1784 differentially expressed genes (DEGs) were screened by transcriptomics and metabolomics. Three key genes in the carotenoid biosynthesis pathway as candidate genes for qPCR validation by co-analysis, which suggested their role in the regulation of pathways related to crtB, crtZ and CYP707A. Discussion: We described that light intensity may appear as a main factor influencing the noted shift from green to yellow and the ensuing reduction in carotenoid content after bagging.

12.
Heliyon ; 10(3): e25385, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38356584

RESUMO

The aim of this study was to prepare poly-N-isopropylmethacrylamide-co-acrylic acid-acrylamide [p-(NIPMAM-co-AA-AAm)] via precipitation polymerization in an aqueous medium. Rhodium nanoparticles were formed in the microgel network by an in-situ reduction technique with the addition of sodium borohydride as a reducing agent. Pure p-(NIPMAM-co-AA-AAm) and hybrid microgels [Rh-(p-NIPMAM-co-AA-AAm)] microgels were examined by using UV-Visible, FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), DLS (Dynamic Light Scattering) and XRD (X-Ray Diffraction) techniques. The catalytic activities of the hybrid microgel [Rh-(p-NIPMAM-co-AA-AAm)] for the degradation of azo dyes such as alizarin yellow (AY), congo red (CR), and methyl orange (MO) were compared and the mechanism of the catalytic action by this system was examined. Various parameters including the catalyst amount and dye concentration influenced the catalytic decomposition of azo dyes. In order to maximize the reaction conditions for the dye's quick and efficient decomposition, the reaction process was monitored by spectroscopic analysis. The rate constants for reductive degradation of azo dyes were measured under various conditions. When kapp values were compared for dyes, it was found that [Rh-(p-NIPMAM-co-AA-AAm)] hybrid microgels showed superior activity for the degradation of MO dyes compared to the reductive degradation of CR and AY.

13.
Food Chem (Oxf) ; 8: 100190, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38259870

RESUMO

Sugar and fatty acid content are among the important factors that contribute to the intensity of flavor in aromatic coconut. Gaining a comprehensive understanding of the sugar and fatty acid metabolites in the flesh of aromatic coconuts, along with identifying the key synthetic genes, is of significant importance for improving the development of desirable character traits in these coconuts. However, the related conjoint analysis of metabolic targets and molecular synthesis mechanisms has not been carried out in aromatic coconut until now. UPLC-MS/MS combined with RNA-Seq were performed in aromatic coconut (AC) and non-aromatic coconut (NAC) meat at 7, 9 and 11 months. The results showed that D-fructose in AC coconut meat was 3.48, 2.56 and 3.45 fold higher than that in NAC coconut meat. Similarly, D-glucose in AC coconut meat was 2.48, 2.25 and 3.91 fold higher than that in NAC coconut meat. The NAC coconut meat showed a 1.22-fold rise in the content of lauric acid compared to the AC coconut meat when it reached 11 months of age. Myristic acid content in NAC coconut meat was 1.47, 1.44 and 1.13 fold higher than that in AC coconut meat. The palmitic acid content in NAC coconut meat was 1.62 and 1.34 fold higher than that in AC coconut meat. The genes SPS, GAE, GALE, GLCAK, UGE, UGDH, FBP, GMLS, PFK, GPI, RHM, ACC, FabF, FatA, FabG, and FabI exhibited a negative correlation with D-fructose (r = -0.81) and D-glucose (r = -0.99) contents, while showing a positive correlation (r = 0.85-0.96) with lauric acid and myristic acid. Furthermore, GALE, GLCAK, FBP, GMLS, and ACC displayed a positive correlation (r = 0.83-0.94) with palmitic acid content. The sugar/organic acid ratio exhibited a positive correlation with SPS, GAE, UGE, FabF, FabZ and FabI.

14.
Heliyon ; 10(1): e23988, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38230248

RESUMO

Alternative fuel opportunities can satisfy energy security and reduce carbon emissions. In this regard, the hydrogen fuel is derived from the source of environmental pollutants like sewage and algae wastewater through hydrothermal gasification technique using a KOH catalyst with varied gasification process parameters of duration and temperature of 6-30 min and 500-800 °C. The novelty of the work is to identify the optimum gasification process parameter for obtaining the maximum hydrogen yield using a KOH catalyst as an alternative fuel for agricultural engine applications. Influences of gasification processing time and temperature on H2 selectivity, Carbon gasification efficiency (CE), Lower heating value (LHV), Hydrogen yield potential (HYP), and gasification efficiency (GE) were studied. Its results showed that the gasifier operated at 800 °C for 30 min, offering maximum hydrogen yield (26 mol/kg) and gasification efficiency (58 %). The synthesized H2 was an alternative fuel blended with diesel fuel/TiO2 nanoparticles. It was experimentally studied using an internal combustion engine. Influences of H2 on engine performance, like brake-specific fuel consumption, brake thermal efficiency and emission performances, were measured and compared with diesel fuel. The results showed that DH20T has the least (420g/kWh) brake-specific fuel consumption (BSFC) and superior brake thermal efficiency of about 25.2 %. The emission results revealed that the DH20T blend showed the NOX value increased by almost 10.97 % compared to diesel fuel, whereas the CO, UHC, and smoke values reduced by roughly 31.25, 28.34, and 42.35 %. The optimum fuel blend (DH20T) result is recommended for agricultural engine applications.

15.
Int J Biol Macromol ; 253(Pt 3): 126885, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37709213

RESUMO

In this research paper, a novel process was developed for reactive printing of cotton fabric, with the objective of producing a high-quality printed fabric that is sustainable, eco-friendly, and low-cost which will ultimately reduce the impact of climate change. The study incorporated substituted tamarind polysaccharide (STP) obtained from agricultural waste, trichloro-ethanoic acid (TCEA), and polyethylene glycol (PEG-400) in the reactive printing paste. Tamarind starch was extracted from the seeds having 72 % yield, and substitution was performed to use it as a thickener in the printing paste. The conventional printing system was formulated with sodium alginate, urea, and sodium bicarbonate at dose levels of 2 %, 15 %, and 2.5 %, respectively, while the modified recipe was formulated with STP and TCEA at 5 % and 3 % dose levels, respectively along with varying doses of PEG-400 (0 %, 1 %, and 2 %) in novel prints. Various factors such as shade comparison, penetration, staining on the white ground, washing, rubbing, light and perspiration fastness, sharpness of edges, and fabric hardness were evaluated for all the recipes. The study demonstrated that the optimal outcomes were obtained with a 2 % PEG-400 dose level. This study represents a significant contribution to sustainable textile production, as tamarind agriculture waste was used as a raw material, which is an environmentally friendly alternative of sodium alginate that reduces the wastewater load. Additionally, PEG-400 was utilized as a nitrogen-free solubilizing moisture management substitution of urea for printing, while TCEA dissociated at high temperature to make alkaline pH during curing of the printed fabric to replace sodium bicarbonate. This research is a novel contribution to the printing industry, as these three constituents have not been previously used together other than this research group, in the history of reactive printing.


Assuntos
Mudança Climática , Bicarbonato de Sódio , Alginatos , Agricultura , Ureia
16.
Sci Rep ; 13(1): 14728, 2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37679372

RESUMO

This work presents the simple synthesis of a green and novel Palladium based magnetic nanocatalyst with effective catalytic properties and reusability. These heterogeneous catalysts were prepared by the anchoring of Pd(0) on the surface of ZrFe2O4 MNPs coated with a di-substituted adenine (Ade) compound as a green linker. The as-synthesized ZrFe2O4@SiO2@Ade-Pd MNPs were methodically characterized over different physicochemical measures like VSM, EDX, Map, SEM, TEM, ICP, and FT-IR analysis. The catalytic activity of ZrFe2O4@SiO2@Ade-Pd was carefully examined for the room-temperature Carbon-Carbon coupling reaction in acetonitrile as a solvent. It is worth noting that the synthesized solid catalyst can be easily recovered with a bar magnet and reused for five cycles without decrease of catalytic activity.

17.
Methods Protoc ; 6(5)2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37736958

RESUMO

Procuring high-grade RNA from mature coconut tissues is a tricky and labor-intensive process due to the intricate scaffold of polysaccharides, polyphenols, lipids, and proteins that form firm complexes with nucleic acids. However, we have effectively developed a novel method for the first time, letting the retrieval of high-grade RNA from the roots, endosperm, and mesocarp of mature coconut trees take place. In this method, we exploited dichloromethane as a replacement to phenol/chloroform for RNA recovery from mature coconut tissues. The amount of high-grade RNA acquired from the roots of mature coconut trees was 120.7 µg/g, with an A260/280 ratio of 1.95. Similarly, the mature coconut mesocarp yielded 134.6 µg/g FW of quality RNA with A260/280 ratio of 1.98, whereas the mature coconut endosperm produced 120.4 µg/g FW of quality RNA with A260/280 ratio of 2.01. Furthermore, the RNA isolation using the dichloromethane method exhibited excellent performance in downstream experiments, particularly in RT-PCR for cDNA production and amplification. On the contrary, the RNA plant kit, TRIZOL, and Cetyl Trimethyl Ammonium Bromide (CTAB) methods were unsuccessful in isolating substantial quantities of RNA with exceptional purities from the mentioned coconut tissues. In view of these findings, we conclude that the newly developed method will be pivotal in effectively extracting RNA with high purity from mature coconut tissues.

18.
Sci Rep ; 13(1): 13347, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37587167

RESUMO

Presented here is a reactively loaded microstrip transmission line that exhibit an ultra-wide bandgap. The reactive loading is periodically distributed along the transmission line, which is electromagnetically coupled. The reactive load consists of a circular shaped patch which is converted to a metamaterial structure by embedded on it two concentric slit-rings. The patch is connected to the ground plane with a via-hole. The resulting structure exhibits electromagnetic bandgap (EBG) properties. The size and gap between the slit-rings dictate the magnitude of the reactive loading. The structure was first theoretically modelled to gain insight of the characterizing parameters. The equivalent circuit was verified using a full-wave 3D electromagnetic (EM) solver. The measured results show the proposed EBG structure has a highly sharp 3-dB skirt and a very wide bandgap, which is substantially larger than any EBG structure reported to date. The bandgap rejection of the single EBG unit-cell is better than - 30 dB, and the five element EBG unit-cell is better than - 90 dB. The innovation can be used in various applications such as biomedical applications that are requiring sharp roll-off rates and high stopband rejection thus enabling efficient use of the EM spectrum. This can reduce guard band and thereby increase the channel capacity of wireless systems.

19.
Sci Rep ; 13(1): 13246, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582883

RESUMO

This paper described a four-band implantable RF rectifier with simplified circuit complexity. Each RF-rectifier cell is sequentially matched to the four operational frequencies to accomplish the proposed design. The proposed RF rectifier can harvest RF signals at 1.830, 2.100, and white space Wi-Fi bands between 2.38 to 2.68 GHz, respectively. At 2.100 GHz, the proposed RF harvester achieved a maximum (radio frequency direct current) RF-to-DC power conversion efficiency (PCE) of 73.00% and an output DC voltage [Formula: see text] of 1.61 V for an RF power of 2 dBm. The outdoor performance of the rectenna shows a [Formula: see text] of 0.440 V and drives a low-power bq25504-674 evaluation module (EVM) at 1.362 V. The dimension of the RF-rectifier on the FR-4 PCB board is 0.27[Formula: see text] [Formula: see text] 0.29[Formula: see text]. The RF-rectifier demonstrates the capacity to effectively utilize the frequency domain by employing multi-band operation and exhibiting a good impedance bandwidth through a sequential matching technique. Thus, by effectively controlling the rectenna's ambient performance, the proposed design holds the potential for powering a range of low-power biomedical implantable devices. (BIDs).

20.
Plant Physiol Biochem ; 201: 107826, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37331076

RESUMO

A rhizobacterium, Pantoea conspicua, was examined against sunflower seedlings' growth under arsenate stress. Sunflower upon exposure to arsenate resulted in compromised growth that might be due to the accumulation of higher concentrations of arsenate and reactive oxygen species (ROS) in seedlings' tissues. The deposited arsenate led to oxidative damage and electrolyte leakage, making the sunflower seedlings vulnerable to compromise its growth and development. However, inoculation of sunflower seedlings with P. conspicua alleviated arsenate stress in host by initiating a multilayered defence mechanism. In fact, P. conspicua filtered out 75.1% of the arsenate from growth medium that were available to the plant roots in the absence of the said strain. To accomplish such activity, P. conspicua secreted exopolysaccharides as well as altered lignification in host roots. The arsenate (24.9%) that made its way to plant tissues was countered by helping the host seedlings to produce higher levels of indole acetic acid, non enzymatic antioxidants (phenolics and flavonoids) and antioxidant enzymes (catalase, ascorbte peroxidase, peroxidase, superoxide dismutase). As a result, ROS accumulation and electrolyte leakage were brought back to normal levels as observed in control seedlings. Hence, the rhizobacterium associated host seedlings achieved higher net assimilation (127.7%) and relative growth rate (113.5%) under 100 ppm of arsenate stress. The work concluded that P. conspicua alleviated arsenate stress in the host plants by imposing physical barrier as well as improving host seedlings' physiology and biochemistry.


Assuntos
Arseniatos , Helianthus , Helianthus/metabolismo , Espécies Reativas de Oxigênio , Antioxidantes/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Plântula/metabolismo , Raízes de Plantas/metabolismo
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