Search Results (30)

With the rapid progression of global industrialization and urbanization, heavy metal contamination has emerged as a major global threat, especially cadmium pollution. Consequently, optimizing remediation measures has become a pivotal means to solve cadmium contamination. Compared to traditional physical and chemical remediation methods, microbial remediation has great potential in addressing cadmium pollution. In this study, a novel bacterial strain, Chryseobacterium sp. HGX-24, exhibiting high cadmium resistance was successfully isolated and screened from cadmium-contaminated environments. A preliminary discussion of the response mechanisms of this strain under cadmium stress is provided. Additionally, preliminarily explored the synergistic remediation of microbial-plant in cadmium-contaminated soil. Under conditions of high cadmium concentration, cadmium ions were effectively adsorbed by strain HGX-24 through extracellular polymers and functional groups on the cell wall surface, including −COOH, −CONH−, −NH, −OH, and >C=O. Extracellular proteins and polysaccharides were secreted by strain HGX-24 to regulate the adverse effects of heavy-metal cadmium ions on bacterial growth. Furthermore, the expression of genes such as antioxidant defense and ROS scavenging (katG, fabG, ybjT), Fe-S cluster assembly (sufB, sufD), sulfur metabolism (cysAU), amino acid metabolism (hisA, cysD, aspC), phenylacetic acid catabolism (paaC), and ribosomal proteins (rplC, rpsC, rpsL, rplA, rplY, rpmC) was regulated, affecting the synthesis and metabolism of membrane transporters (ABC transporters and efflux RND transporters), antioxidant enzymes (SOD, COT, POD), Fe-S clusters, thioredoxin family proteins, and ribosomal proteins, thereby enhancing resistance to cadmium toxicity. Moreover, strain HGX-24 was found to regulate the activities of redox enzymes in Zea mays L., thereby alleviating oxidative stress and reducing the negative feedback effects of reactive oxygen species in Z. mays. Full article

Memristor-based neuromorphic computing offers a promising pathway for efficient in-memory processing. However, the scalability and reliability of such systems are severely compromised by parasitic resistances (including line and input resistances) in crossbar arrays, which cause significant IR-drop during vector–matrix multiplication (VMM). Existing research often suffers from high computational latency or relies on the precise extraction of parasitic parameters, which is impractical and computationally expensive for large-scale integration. To overcome these limitations, we propose a Parameter-Agnostic Adaptive Compensation (PAAC) method based on a distributed linear approximation model. By analyzing the circuit characteristics, we conquered the challenge of coupling between parasitic effects and output current, deriving a simplified linear relationship that requires no prior knowledge of specific resistance values. The PAAC method involves only a single-step pre-calibration experiment to determine a global compensation factor, achieving an ultra-low computational complexity during inference. We validated the method using a comprehensive two-stage strategy: board-level hardware experiments confirmed its feasibility by reducing current distortion from 71% to 2%, while extensive large-scale HSPICE simulations verified its scalability, restoring classification accuracy from 89% to 95%. This work provides a robust, low-overhead solution that eliminates the dependency on precise parameter modeling, facilitating the realization of large-scale, high-precision neuromorphic hardware. Full article

Introduction: This study aims to predict mortality using chest radiographs obtained on the first day of intensive care admission, thereby contributing to better planning of doctors’ treatment strategies and more efficient use of limited resources through early and accurate predictions. Methods: We retrospectively analyzed 510 ICU patients. After data augmentation, a total of 3019 chest radiographs were used for model training and validation, while an independent, non-augmented test set of 100 patients (100 images) was reserved for final evaluation. Seventy-four (74) radiomic features were extracted from the images and analyzed using machine learning algorithms. Model performances were evaluated using the area under the ROC curve (AUC), sensitivity, and specificity metrics. Results: A total of 3019 data samples were included in the study. Through feature selection methods, the initial 74 features were gradually reduced to 10. The Subspace KNN algorithm demonstrated the highest prediction accuracy, achieving AUC 0.88, sensitivity 0.80, and specificity 0.87. Conclusions: Machine learning algorithms such as Subspace KNN and features obtained from PAAC radiographs, such as GLCM Contrast, Kurtosis, Cobb angle, Haralick, Bilateral Infiltrates, Cardiomegaly, Skewness, Unilateral Effusion, Median Intensity, and Intensity Range, are promising tools for mortality prediction in patients hospitalized in the internal medicine intensive care unit. These tools can be integrated into clinical decision support systems to provide benefits in patient management. Full article

A PAAc-PVI(4:1)@MWCNT hybrid was synthesized for the selective electrochemical detection of serotonin. Multi-walled carbon nanotubes (MWCNT) enhanced electrode conductivity, while the hydrophilic polymer Poly(Acrylic Acid-co-Vinyl imidazole) (PAAc-PVI) facilitated serotonin recognition. At pH 7.4, the carboxyl (-COO⁻) groups in PAAc-PVI interacted with the amine (-NH₃⁺) groups of serotonin, enabling oxidation and electron transfer for signal detection. Additionally, π-π interactions between vinylimidazole and MWCNT improved dispersion and stability. The hybrid materials enhanced electron transfer efficiency, increasing sensitivity and reliability. Structural and electrochemical properties were characterized using FT-IR, HR-TEM, TGA, Raman spectroscopy, impedance analysis, and differential pulse voltammetry (DPV). Serotonin detection using the fabricated electrode demonstrated high selectivity (LOD 0.077 μM and LOQ 0.26 μM), reproducibility (%RSD 1X PBS condition (4.63%) and human serum condition (4.81%)), and quantitative capability (dynamic range 1.2 μM to 10.07 μM) without interference (potential shift from +0.40 V to −0.15 V) from blood-based substances, confirming its potential for electrochemical biosensing applications. Full article

Poly(dimethyl siloxane) (PDMS) is one of the most widely used materials in the biomedical field. Despite its numerous advantages, its hydrophobic character promotes bacterial adhesion and biofilm formation. For breast implants, biocompatibility is challenged due to the biofilm formed around the implant that can degenerate to severe capsular contracture over time. Thus, the laboratory has set up strategies to prevent bacterial contamination by grafting covalently hydrophilic bioactive polymers on the surface of implants. In this study, poly(methacrylic acid) (PMAc) and poly(acrylic acid) (PAAc) were chosen as non-toxic and biocompatible bioactive polymers known for reducing bacteria adhesion. These polymers are also good candidates to lend reactivity on the surface for further functionalization. X-ray photoelectron Spectroscopy (XPS) and Fourier-Transform Infrared spectroscopy (FTIR) analysis have highlighted the covalent grafting of these polymers. Apparent water contact angle measurements have shown the change in hydrophilicity on the surface, and a colorimetric assay allowed us to assess the grafting rate of PMAc and PAAc. Tensile strength assays were performed to ensure that the functionalization process does not significantly alter the material’s mechanical properties. Analyses of the surface aspect and roughness by Scanning Electron Microscope (SEM) and optical profilometer allow us to formulate hypotheses to approach the understanding of the behavior of the polymer once grafted. Full article

To avoid risk, spacecraft docking technologies can transport batches of different astronauts or cargoes to a space station. Before now, spacecraft-docking multicarrier/multidrug delivery systems have not been reported on. Herein, inspired by spacecraft docking technology, a novel system including two different docking units, one made of polyamide (PAAM) and on of polyacrylic acid (PAAC), grafted respectively onto polyethersulfone (PES) microcapsules, is designed, based on intermolecular hydrogen bonds in aqueous solution. VB12 and vancomycin hydrochloride were chosen as the release drugs. The release results show that the docking system is perfect, and has a good responsiveness to temperature when the grafting ratio of PES-g-PAAM and PES-g-PAAC is close to 1:1. Below 25 °C, this system exhibited an “off” effect because the polymer chains on the microcapsule’s surface produced intermolecular hydrogen bonds. Above 25 °C, when the hydrogen bonds were broken, the microcapsules separated from each other, and the system exhibited an “on” state. The results provide valuable guidance for improving the feasibility of multicarrier/multidrug delivery systems. Full article

Connshing syndrome (CoSh) (adrenal-related synchronous aldosterone (A) and cortisol (C) excess) represents a distinct entity among PA (primary hyperaldosteronisms) named by W. Arlt et al. in 2017, but the condition has been studied for more than 4 decades. Within the last few years, this is one of the most dynamic topics in hormonally active adrenal lesions due to massive advances in steroids metabolomics, molecular genetics from CYP11B1/B2 immunostaining to genes constellations, as well as newly designated pathological categories according to the 2022 WHO classification. In gross, PA causes 4–10% of all high blood pressure (HBP) cases, and 20% of resistant HBP; subclinical Cushing syndrome (SCS) is identified in one-third of adrenal incidentalomas (AI), while CoSh accounts for 20–30% to 77% of PA subjects, depending on the tests used to confirm autonomous C secretion (ACS). The clinical picture overlaps with PA, hypercortisolemia being mild. ACS is suspected in PA if a more severe glucose and cardiovascular profile is identified, or there are larger tumours, ACS being an independent factor risk for kidney damage, and probably also for depression/anxiety and osteoporotic fractures. It seems that one-third of the PA-ACS group harbours mutations of C-related lines like PRKACA and GNAS. A novel approach means we should perform CYP11B2/CYP11B1 immunostaining; sometimes negative aldosteronoma for CYP11B1 is surrounded by micronodules or cell clusters with positive CYP11B1 to sustain the C excess. Pitfalls of hormonal assessments in CoSh include the index of suspicion (check for ACS in PA patients) and the interpretation of A/C ratio during adrenal venous sample. Laparoscopic adrenalectomy is the treatment of choice. Post-operative clinical remission rate is lower in CoSh than PA. The risk of clinically manifested adrenal insufficiency is low, but a synthetic ACTH stimulating testing might help to avoid unnecessary exposure to glucocorticoids therapy. Finally, postponing the choice of surgery may impair the outcome, having noted that long-term therapy with mineralocorticoids receptors antagonists might not act against excessive amounts of C. Awareness of CoSh improves management and overall prognosis. Full article

Sustainable tourism is a main priority of European Union policies, with the aim of mitigating the potential harmful consequences of this sector on a given territory. The main research goal of this article is to better understand the impact of the public investments financed via EU Cohesion Policy in the tourism sector in the Portuguese Algarve NUT2. This paper focuses on the Portuguese Operational Programme for Sustainability and Efficient Use of Resources (POSEUR 20142020), which was an operational programme of a Portuguese framework to implement EU Cohesion Policy funds in Portugal between 2014 and 2020, and was specifically focused on supporting sustainable development processes. The sustainability performance of POSEUR in the Algarve was evaluated in five different dimensions of analysis: (1) low-emissions economy, (2) adaptation to climate change, (3) risk prevention and management, (4) environmental protection, and (5) resource efficiency. The results showed that POSEUR had a low impact in almost all dimensions in the Algarve, apart from the adaptation to climate change dimension, which exhibits a high impact score, mostly due to the support given for carrying out the Plans for Adaptation to Climate Change (PAAC). Full article

In this study, nanofibers of poly (acrylic acid) (PAAc), polyacrylamide (PAAm) and poly (vinyl alcohol) (PVOH) were prepared using the electrospinning technique. Based on the Taguchi DOE (design of experiment) method, the effects of electrospinning parameters, i.e., needle tip to collector distance, polymer solution concentration, applied voltage, polymer solution feed rate and polymer type, on the diameter and morphology of polymer nanofibers were evaluated. Analyses of the experiments for the diameters of the polymer nanofibers showed that the type of polymer was the most significant factor. The optimal combination to obtain the smallest diameters with minimum deviations for electrospun polymer nanofibers was also determined. For this purpose, the appropriate factor levels were determined as follows: polymer PAAm, applied voltage 10 kV, delivery rate 0.1 mL/h, needle tip to collector distance 10 cm, and polymer solution concentration 8%, to obtain the thinnest nanofibers. This combination was further validated by conducting a confirmation experiment, and the average diameter of the polymer nanofibers was found to be close to the optimal conditions estimated by the Taguchi DOE method. Full article

In this paper, novel microgels containing nano-SiO₂ were prepared by in situ copolymerization using nano-SiO₂ particles as a reinforcing agent, nanosilica functional monomer (silane-modified nano-SiO₂) as a structure and morphology director, acrylamide (AAm) as a monomer, acrylic acid (AAc) as a comonomer, potassium persulfate (KPS) as a polymerization initiator, and N,N′-methylene bis (acrylamide) (MBA) as a crosslinker. In addition, a conventional copolymeric hydrogel based on poly (acrylamide/acrylic acid) was synthesized by solution polymerization. The microgel samples, hydrogel and nanoparticles were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). A FESEM micrograph of copolymeric hydrogel showed the high porosity and 3D interconnected microstructure. Furthermore, FESEM results demonstrated that when nano-SiO₂ particles were used in the AAm/AAc copolymerization process, the microstructure and morphology of product changed from porous hydrogel to a nanocomposite microgel with cauliflower-like morphology. According to FESEM images, the copolymerization of AAm and AAc monomers with a nanosilica functional monomer or polymerizable nanosilica particle as a seed led to a microgel with core–shell structure and morphology. These results demonstrated that the polymerizable vinyl group on nano-SiO₂ particles have controlled the copolymerization and the product morphology. FTIR analysis showed that the copolymeric chains of polyacrylamide (PAAm) and poly (acrylic acid) (PAAc) were chemically bonded to the surfaces of the nano-SiO₂ particles and silane-modified nano-SiO₂. The particulate character of microgel samples and the existence of long distance among aggregations of particles led to rapid swelling and increasing of porosity and therefore increasing of degree of swelling. Full article

A diblock copolymer (P(VBTAC/NaSS)₁₇-b-PAPTAC₅₀; P(VS)₁₇A₅₀) composed of amphoteric random copolymer, poly(vinylbenzyl trimethylammonium chloride-co-sodium p-styrensunfonate) (P(VBTAC/NaSS); P(VS)) and cationic poly(3-(acrylamidopropyl) trimethylammonium chloride) (PAPTAC; A) block, and poly(acrylic acid) (PAAc₄₉) were prepared via a reversible addition−fragmentation chain transfer radical polymerization. Scrips V, S, and A represent VBTAC, NaSS, and PAPTAC blocks, respectively. Water-soluble polyion complex (PIC) vesicles were formed by mixing P(VS)₁₇A₅₀ and PAAc₄₉ in water under basic conditions through electrostatic interactions between the cationic PAPTAC block and PAA_c49 with the deprotonated pendant carboxylate anions. The PIC vesicle collapsed under an acidic medium because the pendant carboxylate anions in PAAc₄₉ were protonated to delete the anionic charges. The PIC vesicle comprises an ionic PAPTAC/PAAc membrane coated with amphoteric random copolymer P(VS)₁₇ shells. The PIC vesicle showed upper critical solution temperature (UCST) behavior in aqueous solutions because of the P(VS)₁₇ shells. The pH- and thermo-responsive behavior of the PIC vesicle were studied using ¹H NMR, static and dynamic light scattering, and percent transmittance measurements. When the ratio of the oppositely charged polymers in PAPTAC/PAAc was equal, the size and light scattering intensity of the PIC vesicle reached maximum values. The hydrophilic guest molecules can be encapsulated into the PIC vesicle at the base medium and released under acidic conditions. It is expected that the PIC vesicles will be applied as a smart drug delivery system. Full article

Infectious diseases are one of the core biological complications for public health. It is important to recognize the pathogen-specific mechanisms to improve our understanding of infectious diseases. Differentiations between bacterial- and viral-targeted human proteins are important for improving both prognosis and treatment for the patient. Here, we introduce machine learning-based classifiers to discriminate between the two groups of human proteins. We used the sequence, network, and gene ontology features of human proteins. Among different classifiers and features, the deep neural network (DNN) classifier with amino acid composition (AAC), dipeptide composition (DC), and pseudo-amino acid composition (PAAC) (445 features) achieved the best area under the curve (AUC) value (0.939), F1-score (94.9%), and Matthews correlation coefficient (MCC) value (0.81). We found that each of the selected top 100 of the bacteria- and virus-targeted human proteins from a candidate pool of 1618 and 3916 proteins, respectively, were part of distinct enriched biological processes and pathways. Our proposed method will help to differentiate between the bacterial and viral infections based on the targeted human proteins on a global scale. Furthermore, identification of the crucial pathogen targets in the human proteome would help us to better understand the pathogen-specific infection strategies and develop novel therapeutics. Full article

In this study, cellulose nanocrystals (CNCs) were produced from pea peels by acid hydrolysis to be used with pectin and acrylic acid (AAc) to form Pectin-PAAc/CNC nanocomposite by γ-irradiation. The structure, morphology, and properties of the nanocomposite were investigated using Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) techniques. The nanocomposite hydrogel was used for the removal of methylene blue dye (MB) from wastewater. The results revealed that the presence of CNCs in the polymeric matrix enhances the swelling and adsorption properties of Pectin-PAAc/CNC. The optimum adsorbate concentration is 70 mg/L. The kinetic experimental data were fit by pseudo-first-order (PFO), pseudo-second-order (PSO), and Avrami (Avr) kinetic models. It was found that the kinetic models fit the adsorption of MB well where the correlation coefficients of all kinetic models are higher than 0.97. The Avr kinetic model has the lowest ∆q_e (normalized standard deviation) value, making it the most suitable one for describing the adsorption kinetics. The adsorption isotherm of MB by Pectin-PAAc follows the Brouers–Sotolongo model while that by Pectin-PAAc/CNC follows the Langmuir isotherm model. The negative values of ∆G confirmed the spontaneous nature of adsorption, and the positive value of ∆H indicated the endothermic nature of the adsorption. Full article

Stimuli-responsive microgels have recently attracted great attention in fundamental research as their soft particles can be deformed and compressed at high packing fractions resulting in singular phase behaviours. Moreover, they are also well suited for a wide variety of applications such as drug delivery, tissue engineering, organ-on-chip devices, microlenses fabrication and cultural heritage. Here, thermoresponsive and pH-sensitive cross-linked microgels, composed of interpenetrating polymer networks of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAAc), are synthesized by a precipitation polymerization method in water and investigated through differential scanning calorimetry in a temperature range across the volume phase transition temperature of PNIPAM microgels. The phase behaviour is studied as a function of heating/cooling rate, concentration, pH and PAAc content. At low concentrations and PAAc contents, the network interpenetration does not affect the transition temperature typical of PNIPAM microgel in agreement with previous studies; on the contrary, we show that it induces a marked decrease at higher concentrations. DSC analysis also reveals an increase of the overall calorimetric enthalpy with increasing concentration and a decrease with increasing PAAc content. These findings are discussed and explained as related to emerging aggregation processes that can be finely controlled by properly changing concentration, PAAc content an pH. A deep analysis of the thermodynamic parameters allows to draw a temperature–concentration state diagram in the investigated concentration range. Full article

Glutamic acid-co-poly(acrylic acid) (GAcPAAc) hydrogels were prepared by the free radical polymerization technique using glutamic acid (GA) as a polymer, acrylic acid (AAc) as a monomer, ethylene glycol dimethylacrylate (EGDMA) as a cross-linker, and ammonium persulfate (APS) as an initiator. Increase in gel fraction was observed with the increasing concentration of glutamic acid, acrylic acid, and ethylene glycol dimethylacrylate. High percent porosity was indicated by developed hydrogels with the increase in the concentration of glutamic acid and acrylic acid, while a decrease was seen with the increasing concentration of EGDMA, respectively. Maximum swelling and drug release was exhibited at high pH 7.4 compared to low pH 1.2 by the newly synthesized hydrogels. Similarly, both swelling and drug release increased with the increasing concentration of glutamic acid and acrylic acid and decreased with the increase in ethylene glycol dimethylacrylate concentration. The drug release was considered as non-Fickian transport and partially controlled by viscoelastic relaxation of hydrogel. In-vivo study revealed that the AUC_0–∞ of fabricated hydrogels significantly increased compared to the drug solution and commercial product Keten. Hence, the results indicated that the developed hydrogels could be used as a suitable carrier for controlled drug delivery. Full article