Polyethylene Glycol Research Articles

Induction of somatic embryogenesis and cryopreservation of Abies pinsapo Boiss.

Abies pinsapo is an endangered species, endemic to southern Spain. Somatic embryogenesis and cryopreservation constitute important biotechnological tools, which can be used in order to improve the management and conservation of threatened species. The objective of this work was to develop somatic embryogenesis and cryopreservation protocols for A. pinsapo. Somatic embryogenesis was induced from mature zygotic embryos of A. pinsapo cultured on solid MS medium with macroelements at half-strength and supplemented with 20 g L-1 sucrose and 5 mg L-1 6-benzylaminopurine (BA). Embryogenic cultures successfully proliferated on solid medium with the same formulation supplemented with 20 g L-1 sucrose, 500 mg L-1 L-glutamine, 1 g L-1 casein hydrolysate and 1 mg L-1 BA. Different preconditioning and cryoprotective treatments were tested in order to optimize cryopreservation of embryogenic tissues by using the slow-cooling technique. Embryogenic cultures at their exponential growth phase, i.e. 12-14 days after the last subculture, were used as cryopreservation explants. The best results were achieved after sucrose preculture and cryoprotecion with PGD I (mixture of polyethylene glycol, glucose and DMSO I), with 100% of explants resuming somatic embryogenesis after thawing. Following fluorescein diacetate (FDA) staining, more intense and abundant green fluorescence could be observed in these samples, compared to those subjected to other preconditioning and cryoprotective treatments, thus evincing a higher proportion of viable cells after freezing in liquid nitrogen. Cold hardening did not improve cryotolerance. In fact, incubation at 5 °C for two weeks appeared to affect explants response, delaying tissue regrowth after cryopreservation. This is the first time in which somatic embryogenesis and cryopreservation have been reported in Spanish fir. The results obtained allow to establish the bases for the integration of these techniques into in situ and ex situ conservation strategies.

Mechanisms Involved in Cell Wall Remodeling in Etiolated Rice Shoots Grown Under Osmotic Stress

Osmotic stress impacts the cell wall properties in plants. This study aimed to elucidate the mechanisms involved in cell wall remodeling in etiolated (dark-grown) rice (Oryza sativa L.) shoots grown under polyethylene glycol (PEG)-induced osmotic stress conditions. Shoot growth was inhibited by 70% by the treatment with 60 mM PEG for 2 days. However, when the stressed seedlings were transferred to a solution without PEG, their shoot growth rate increased significantly. A measurement of the cell wall mechanical properties revealed that the cell walls of the stressed shoots became looser and more extensible than those of unstressed shoots. Among the cell wall constituents, the amounts of cellwall-bound phenolic acids, such as ferulic acid (FA), p-coumaric acid (p-CA), and diferulic acid (DFA), per shoot and per unit of matrix polysaccharide content were significantly reduced in the stressed shoots compared to those in the unstressed shoots. Concerning the formation of cellwall-bound phenolic acids, the activity of cellwall-bound peroxidase (CW-PRX) per unit of cell wall content, which is responsible for the coupling reaction of FA to produce DFA, was 3.5 times higher in stressed shoots than in unstressed shoots, while the activity was reduced by 20% on a shoot basis in stressed shoots compared to that in unstressed shoots. The expression levels of the major class III peroxidase genes in stressed shoots were either comparable to or slightly lower than those in unstressed shoots. Conversely, the phenylalanine ammonia-lyase (PAL) activity, which contributes to the biosynthesis of FA and p-CA, was reduced by 55% and 30% on a shoot and unit-of-protein-content basis, respectively, in stressed shoots compared to that in unstressed shoots. The expression levels of abundantly expressed PAL genes decreased by 14–46% under osmotic stress. Moreover, the gene expression levels of specific BAHD acyltransferases, which are responsible for the addition of FA and p-CA to form ester-linked moieties on cell wall constituents, decreased by 15–33% under osmotic stress. These results suggest that the downregulation of the expression of specific PAL and BAHD acyltransferase genes in osmotically stressed rice shoots is responsible for a reduction in the formation of cellwall-bound phenolic acid monomers. This, in turn, may result in a decrease in the levels of DFAs. The reduction in the formation of DFA-mediated cross-linking structures within the cell wall may contribute to an increase in the mechanical extensibility of the cell wall. The remodeling of cell walls in an extensible and loosened state could assist in maintaining the growth capacity of etiolated rice shoots grown under osmotic stress and contribute to rapid growth recovery following the alleviation of osmotic stress.

Formulation and Evaluation of Polymeric Spherical Agglomerates-Based Porous Orodispersible Tablets of Cilnidipine

Background/Objectives: Cilnidipine (CIL) is a calcium channel blocker that exhibits low bioavailability (~13%) due to poor aqueous solubility and extensive pre-systemic gut wall metabolism. The current study aimed to enhance the oral bioavailability of CIL by formulation of polymeric spherical agglomerates (CILSAs)-based orodispersible tablets (ODTs). Methods: Eight different batches of CILSAs were prepared by a crystallo-co-agglomeration technique using different proportions of hydrophilic polymers like hydroxy propyl methyl cellulose E50, polyvinyl pyrrolidone K30, or polyethylene glycol (PEG) 6000 as carriers. Fourier transform infrared spectroscopy (FTIR) of CILSAs proved the chemical integrity of CIL in SAs, while scanning electron microscopy revealed the spherical shape of CILSAs. Results: Differential scanning calorimetry and powder X-ray diffraction studies confirmed that CIL was rendered more amorphous in CILSAs. CILSAs displayed good flow behavior, high percentage yield, and high drug loads. The batch F4 composed of PEG 6000 emerged as the optimized batch as it displayed high percentage dissolution efficiency (57.01 ± 0.01%), which was significantly greater (p < 0.001) compared to CIL (26.27 ± 0.06%). The optimized formulation of CILSAs was directly compressed into ODTs that were rendered porous by vacuum drying. The optimized formulation of porous ODTs (T3) displayed low friability (0.28 ± 0.03%), short disintegration time (6.26 ± 0.29 s), and quicker dissolution (94.16 ± 1.41% in 60 min) as compared to marketed tablet Cildipin® 10 mg (85 ± 2.3%). Conclusions: Thus, porous ODTs of CILSAs can rapidly release the drug, bypass gut metabolism, enhance oral bioavailability, and improve CIL's therapeutic effectiveness for angina and hypertension.

Novel protocol for isolation and transient transformation of Rhodes grass (Chloris gayana) protoplasts

Abstract Rhodes grass (Chloris gayana) is a warm-season C4 grass currently grown as a forage in some tropical regions, with anticipated future application in areas affected by climate change. However, there are few resources available for this grass, with few genomic resources and only one established transformation system, thus limiting the application of biotechnology methods for its improvement. Protoplast transformation can be used as a time- and resource-efficient way to examine gene pathways and functions of transcriptional elements via proteomics and transcriptomics, and to validate gene constructs. The aim of this work was therefore to establish the first Rhodes grass leaf mesophyll protoplast isolation and transient transformation protocol. A range of protoplast isolation factors were examined, including enzyme quantity and vacuum infiltration time. Up to 4.13 × 106 protoplasts were isolated per gram of fresh weight with an average 94.8% viability from an overnight digestion protocol with 4% (w/v) cellulase R10, 0.8% (w/v) Macerozyme R10, and no vacuum infiltration. Transformation conditions were optimized via Taguchi’s orthogonal array, which compared combinations of three levels each of green fluorescent protein (GFP) plasmid DNA quantity, polyethylene glycol (PEG) concentration, and transformation time. A transient transformation efficiency of up to 27.88% was observed by GFP expression. DNA quantity was identified to be the only factor from those tested effecting transformation efficiency (p < 0.001) in a linear way. Work here represents the first report for Rhodes grass protoplast isolation and transformation, which could facilitate genome editing and transcriptome and proteome studies.

Effects of Sericea Lespedeza Supplementation on Steers Grazing Wild-Type Endophyte-Infected Tall Fescue

Condensed tannins (CTs) in certain leguminous forages can mitigate toxic alkaloid absorption linked to fescue toxicosis due to their high affinity towards various steroidal and protein-like alkaloids. However, their use as feed supplements remains underexplored. This study evaluated the impact of CT-rich sericea lespedeza (Lespedeza cuneata) pellets on the post-ingestive effects of fescue toxicosis. Twelve steers on wild-type endophyte-infected tall fescue pastures received either sericea lespedeza pellets (LES) or LES with polyethylene glycol (LPEG; negative control) for 12 weeks over three consecutive summers. Body weight, hair coat scores, temperatures (rectal and extremity), cortisol levels, and caudal artery lumen area were measured every four weeks. Steers fed LES showed trends toward higher ADG (p = 0.0999) and reduced hair retention (p = 0.0547) compared to those fed LPEG. Steers on LES also showed hotter tail skin temperatures (p = 0.0053) and cooler rectal temperatures (p < 0.0001) compared to those fed LPEG. LES-fed steers had a 21% larger caudal artery lumen area (p < 0.01), suggesting reduced vasoconstriction. Additionally, LES-fed steers tended to have lower hair cortisol (p = 0.0746), indicating reduced chronic stress. These results suggest that supplementation with CTs may alleviate the post-ingestive effects of fescue toxicosis, potentially by improving blood flow and reducing stress. However, further research is needed to determine whether CTs directly reduce alkaloid absorption, as well as to validate the long-term efficacy of CT supplementation.

Nanoconfinement-Driven Energy-Efficient CO2 Capture and Release at High Pressures on a Unique Large-Pore Mesoporous Carbon.

Although microporous carbons can perform well for CO2 separations under high pressure conditions, their energy-demanding regeneration may render them a less attractive material option. Here, we developed a large-pore mesoporous carbon with pore sizes centered around 20-30 nm using a templated technical lignin. During the soft-templating process, unique cylindrical supramolecular assemblies form from the copolymer template. This peculiar nanostructuring takes place due to the presence of polyethylene glycol (PEG) segments on both the Pluronic® template and the PEG-grafted lignin derivative (glycol lignin). A large increase in CO2 uptake occurs on the resulting large-pore mesoporous carbon at 270 K close to the saturation pressure (3.2 MPa), owing to capillary condensation. This phenomenon enables a CO2/CH4 selectivity(SCO2/CH4,mol/mol) of 3.7 at 270 K and 3.1 MPa absolute pressure, and a swift pressure swing regeneration process with desorbed CO2 per unit pressure far outperforming a benchmark activated carbon (i.e., notably rapid decrease in the amount of adsorbed CO2 with decreasing pressure). We propose large-pore mesoporous carbons as a novel family of CO2 capture adsorbents, based on the phase-transition behavior shift of CO2 in the nanoconfined environment. This novel material concept may open new horizons for physisorptive CO2 separations with energy-efficient regeneration options.

Assembly of Genetically Engineered Ionizable Protein Nanocage-based Nanozymes for Intracellular Superoxide Scavenging

Nanozymes play a pivotal role in mitigating excessive oxidative stress, however, determining their specific enzyme-mimicking activities for intracellular free radical scavenging is challenging due to endo-lysosomal entrapment. In this study, we employ a genetic engineering strategy to generate ionizable ferritin nanocages (iFTn), enabling their escape from endo-lysosomes and entry into the cytoplasm. Specifically, ionizable repeated Histidine-Histidine-Glutamic acid (9H2E) sequences are genetically incorporated into the outer surface of human heavy chain FTn, followed by the assembly of various chain-like nanostructures via a two-armed polyethylene glycol (PEG). Utilizing endosome-escaping ability, we design iFTn-based tetrameric cascade nanozymes with high superoxide dismutase- and catalase-mimicking activities. The in vivo protective effects of these ionizable cascade nanozymes against cardiac oxidative injury are demonstrated in female mouse models of cardiac ischemia-reperfusion (IR). RNA-sequencing analysis highlight the crucial role of these nanozymes in modulating superoxide anions-, hydrogen peroxide- and mitochondrial functions-relevant genes in IR injured cardiac tissue. These genetically engineered ionizable protein nanocarriers provide opportunities for developing ionizable drug delivery systems.

Soluble Covalent Organic Frameworks as Efficient Lithiophilic Modulator for High‐Performance Lithium Metal Batteries

Lithium metal batteries (LMBs) are regarded as the potential alternative of lithium‐ion batteries due to their ultrahigh theoretical specific capacity (3860 mAh g‐1). However, severe instability and safety problems caused by the dendrite growth and inevitable side reactions have hindered the commercialization of LMBs. To solve them, in this contribution, a design strategy of soluble lithiophilic covalent organic frameworks (COFs) is proposed. By introducing polyethylene glycol as the side chains, two COFs (CityU‐28 and CityU‐29) not only become soluble for the facile spin‐coating technique, but also can facilitate the lithium‐ion migration in batteries. Furthermore, when coated on the lithium anode of LMB, both COFs can act as artificial solid electrolyte interphase to prevent dendrite growth thus enabling the long‐term stability of the cells. Notably, the symmetric CityU‐29@Li cell can work for more than 5000 h at a current density of 2 mA cm‐2 and an areal capacity of 1 mAh cm‐2. A remarkable capacity retention of 78.9% after 1500 cycles and a Coulombic efficiency of about 99.9% at 1.0 C can also be realized in CityU‐29@Li||LiFePO4 full cell. This work could provide a universal design strategy for soluble COFs and enlighten their application in diverse scenarios, especially energy‐related fields.

Soluble Covalent Organic Frameworks as Efficient Lithiophilic Modulator for High-Performance Lithium Metal Batteries.

Lithium metal batteries (LMBs) are regarded as the potential alternative of lithium-ion batteries due to their ultrahigh theoretical specific capacity (3860 mAh g-1). However, severe instability and safety problems caused by the dendrite growth and inevitable side reactions have hindered the commercialization of LMBs. To solve them, in this contribution, a design strategy of soluble lithiophilic covalent organic frameworks (COFs) is proposed. By introducing polyethylene glycol as the side chains, two COFs (CityU-28 and CityU-29) not only become soluble for the facile spin-coating technique, but also can facilitate the lithium-ion migration in batteries. Furthermore, when coated on the lithium anode of LMB, both COFs can act as artificial solid electrolyte interphase to prevent dendrite growth thus enabling the long-term stability of the cells. Notably, the symmetric CityU-29@Li cell can work for more than 5000 h at a current density of 2 mA cm-2 and an areal capacity of 1 mAh cm-2. A remarkable capacity retention of 78.9% after 1500 cycles and a Coulombic efficiency of about 99.9% at 1.0 C can also be realized in CityU-29@Li||LiFePO4 full cell. This work could provide a universal design strategy for soluble COFs and enlighten their application in diverse scenarios, especially energy-related fields.

Fabrication of AFM-Compatible Hydrogel Probe to Achieve Hydration Superlubrication in Salt Solutions.

Hydrogels demonstrate effective lubricating properties, but the underlying mechanisms at the nanoscale remain elucidated. In this study, a novel strategy is proposed by fabricating the hydrogel probes compatible with atomic force microscopy (AFM) to establish a superlubrication system based on the hydration interactions. The probe is made of polyethylene glycol diacrylate (PEGDA)-based hydrogel microspheres, which can achieve an extremely low friction coefficient of 0.0014 when sliding on the mica surface in NaCl solution. The friction coefficients in salt solutions sequence μ(NaCl) <0.01 < μ(KCl) < μ(LiCl), which contradicts the sequence based on the ion hydration capacity (K+ < Na+ < Li+), suggesting that the hydrogel-based lubrication systems are governed by the interplay between ion hydration lubrication and ions-polymer interactions simultaneously. The observed superlubrication in NaCl solution is ascribed to the superior hydration capacity of Na+ ions, which forms a stable and smooth hydration layer within the contact zone. This work provides new avenues for AFM-based hydrogel studies, and also significantly advances the comprehension of hydrogel lubrication mechanisms at the nanoscale.

Folding and Functionalizing DNA Origami: A Versatile Approach Using a Reactive Polyamine.

DNA nanotechnology is a powerful synthetic approach to crafting diverse nanostructures through self-assembly. Chemical decoration of such nanostructures is often required to tailor their properties for specific applications. In this Letter, we introduce a pioneering method to direct the assembly and enable the functionalization of DNA nanostructures using an azide-bearing functional polyamine. We first demonstrate the successful polyamine-assisted folding of a scaffolded DNA origami nanostructure equipped with reactive azide groups. Leveraging this reactivity, we next showcase the decoration of the DNA origami via strain-promoted azide-alkyne cycloaddition with dibenzocyclooctyne-containing functional molecules. Specifically, we incorporate a fluorophore (Cy5), polyethylene glycol (PEG), and a hydrophobic phosphatidylethanolamine (PE) tag to tailor the properties of our DNA origami nanostructures. Our approach is expected to streamline and reduce the cost of chemical customization of intricate DNA nanostructures, paving the way for enhanced versatility and applicability.

One-Step Synthesis of Carboxylated Polyethylene Glycol-Modified Polystyrene Microspheres and Their Application in the Luminescent Oxygen Channel Immunoassay.

As one of the key diagnostic methods for detecting biomarkers and antigen-antibody interactions, the luminescent oxygen channel immunoassay (LOCI) has been widely applied in bioanalysis and other fields. In the context of LOCI, the performance of the prepared donor polystyrene (PS) microspheres significantly impacts the detection signal values. In this study, an attempt was made to synthesize PS microspheres via one-step polymerization of styrene with an amphiphilic monomer (PEOOH), followed by swelling the silicon phthalocyanine photosensitizer into the PS microspheres, resulting in the functionalization of the PS microspheres with polyethylene glycol segments. The chemical stability and water solubility of polyethylene glycol (PEG) make it a versatile surface modification material while also inhibiting nonspecific protein adsorption. Results indicated that with increasing PEOOH content, the nonspecific protein adsorption of the resulting PS microspheres reduced, with the adsorption ability for BSA decreasing from 26.8 to 1.3 mg/g, approximately decreasing by 95.2%. Furthermore, the results demonstrated that PS microspheres prepared with 6% PEOOH exhibited a maximum signal-to-noise ratio (S/N) (approximately 28.7), nearly 14 times higher than PS microspheres without PEOOH (approximately 2.1). The analytical performance of the system for detecting staphylococcal enterotoxin B (SEB) revealed a detection limit of 0.1 ng/mL and a linear concentration range of 0.1 to 50 ng/mL for the donor PS microspheres (6% PEOOH). The synthesized donor PS microspheres exhibit a uniform particle size and stable signals, making them effective LOCI microcarriers. These properties facilitate a deeper understanding of molecular interactions and signal transduction mechanisms within biological systems.

Poly(curcumin-co-poly(ethylene glycol)) films provide neuroprotection following reactive oxygen species insult in vitro

Objective.Curcumin is an antioxidant and anti-inflammatory molecule that may provide neuroprotection following central nervous system injury. However, curcumin is hydrophobic, limiting its ability to be loaded and then released from biomaterials for neural applications. We previously developed polymers containing curcumin, and these polymers may be applied to neuronal devices or to neural injury to promote neuroprotection. Thus, our objective was to evaluate two curcumin polymers as potential neuroprotective materials for neural applications.Approach.For each curcumin polymer, we created three polymer solutions by varying the weight percentage of curcumin polymer in solvent. These solutions were subsequently coated onto glass coverslips, and the thickness of the polymer was assessed using profilometry. Polymer degradation and dissolution was assessed using brightfield microscopy, scanning electron microscopy, and gel permeation chromatography. The ability of the polymers to protect cortical neurons from free radical insult was assessed using anin vitrocortical culture model.Main results.The P50 curcumin polymer (containing greater poly(ethylene glycol) content than the P75 polymer), eroded readily in solution, with erosion dependent on the weight percentage of polymer in solvent. Unlike the P50 polymer, the P75 polymer did not undergo erosion. Since the P50 polymer underwent erosion, we expected that the P50 polymer would more readily protect cortical neurons from free radical insult. Unexpectedly, even though P75 films did not erode, P75 polymers protected neurons from free radical insult, suggesting that erosion is not necessary for these polymers to enable neuroprotection.Significance.This study is significant as it provides a framework to evaluate polymers for future neural applications. Additionally, we observed that some curcumin polymers do not require dissolution to enable neuroprotection. Future work will assess the ability of these materials to enable neuroprotection withinin vivomodels of neural injury.

Shape memory property of hybrid polyurethane with polyols having different chain length and POSS-DGEBA

POSS-DGEBA was synthesized by the ring opening reaction of the epoxy group of bisphenol A diglycidyl ether (DGEBA) with the amine group of aminopropyl isobutyl polyhedral oligomeric silsesquioxane (NH2-POSS). POSS-DGEBA was incorporated to PU as the chain extender for improving thermal stability and the shape memory behavior in hybrid polyurethane. PU prepolymer was prepared by the reaction of MDI with polyols having different chain length which are poly(ethylene glycol) or poly(tetramethylene ether) glycol. The hybrid polyurethanes (HPU-PEG and HPU-PTMG) with different contents of POSS-DGEBA were fabricated by using PU prepolymer, a chain extender, and different mole ratios of POSS-DGEBA.

Performance Evaluation of PρT-SAFT, PρT-PC-SAFT, PC-SAFT, and CPA Equations of State for Predicting Density, Thermal Expansion Coefficient, Isothermal Compressibility, Isobaric Heat Capacity, Speed of Sound, and Saturated Vapor Pressure of Three Pure Ethylene Glycols and Their Mixtures

Ethylene glycols are a group of versatile industrial solvents with broad applications across various sectors. Accurate thermodynamic modeling of these compounds is essential for enhancing their utilization and optimizing industrial processes. Among the advanced models available, the Statistical Associating Fluid Theory (SAFT) type equation of state (EoS) stands out for its effectiveness in capturing the thermodynamic behavior of complex fluids. This study employs the PρT-SAFT, PρT-PC-SAFT, PC-SAFT, and CPA EoSs to model pure monoethylene glycol (MEG), diethylene glycol (DEG), triethylene glycol (TEG), and their mixtures. Furthermore, the predictive capabilities of these models are critically evaluated for polyethylene glycol 400 (PEG 400). The performance of the PρT-SAFT, PρT-PC-SAFT, PC-SAFT, and CPA EoSs was evaluated for predicting key thermodynamic properties, including density, thermal expansion coefficient, isothermal compressibility, isobaric heat capacity, speed of sound, and saturated vapor pressure, for pure MEG, DEG, TEG, and PEG 400. Among the models, the PρT-SAFT demonstrated superior accuracy in modeling their properties. Subsequently, the volumetric properties and vapor–liquid equilibrium data of binary mixtures of MEG, DEG, and TEG were predicted using the same EoSs, without incorporating any binary interaction parameters. Under these conditions, the PρT-SAFT achieved the highest accuracy. Furthermore, predictions of the volumetric properties for the ternary mixture of MEG, DEG, and TEG also indicated that the PρT-SAFT outperformed the other models. The overall average absolute deviation percentages for the PρT-SAFT, PρT-PC-SAFT, PC-SAFT, and CPA EoSs across all examined thermodynamic properties and systems were 7.0, 8.2, 22.2, and 30.2, respectively, confirming the robustness of the PρT-SAFT.

Enhanced Anticancer Efficiency of Curcumin Co-Loaded Lawsone Solid Lipid Nanoparticles Against MCF-7 Breast Cancer Cell Lines: Optimization by Statistical JMP Software-Based Experimental Approach.

The present study highlighted enhancing the therapeutic effectiveness of curcumin (CUR) co-loaded lawsone (LS) through a solid lipid nanoparticles (SLNs)-based delivery system. The cetyl palmitate (CP), polyethylene glycol 400 (PEG), and probe sonication time (PS) were considered as independent variables whereas particle size and % entrapment efficiency (EE) were selected as dependent variables. The CUR-LS-SLN was developed by hot emulsification followed by probe sonication. A 23 factorial design was utilized in formulation development using JMP software version 17. Notably, the particle size and %EE of all the formulations were about 500 nm and greater than 75%, respectively. The zeta potential value was found to be -46.8 mV. From leverage plots significant and sensitive factors on particle size and %EE were identified. Contour plots led to the identification of an optimized formula whereby maintaining CP at 100 mg, PEG 400 at 6 mL, and PS at 10 min the desired particle size and %EE was achieved. TEM studies indicated the spherical shape of the particles. MTT assays of Michigan Cancer Foundation-7 (MCF-7) cells showed enhanced efficacy and greater cell inhibition of CUR-LS-SLN and combining both drugs using nanocarriers gave superior inhibition as compared with using either of the drugs evident from IC50 values of 3.7, 9.4, and 2.5 μM, respectively, for CUR, LS, and CUR-LS-SLN. The cells in the combination mostly had irregular cell walls and cell shrinkage was noted and greater cell reduction was also seen. It was found that the enhanced cytotoxicity effect of MCF-7 cells on the developed formulation was attributed to the drug's synergistic actions, more efficient nanocarrier internalizations, and sustained drug release from the formulation. Stability studies indicated that the optimized SLN was stable for 6 months.

Real-world effectiveness and safety of 1L polyethylene glycol and ascorbic acid for bowel preparation in patients aged 80 years or over

Background and study aim: Clinical trials and real-world studies show a 1L polyethene glycol and ascorbic acid solution (1L PEG-ASC) to be an effective and safe bowel preparation for colonoscopy in the general population. Here, the effectiveness and safety of 1L PEG-ASC were evaluated in patients aged 80 years or over in a real-world setting. Patients and methods: A post-hoc analysis of an observational, multicentre, retrospective study assessed the effectiveness and safety of 1L PEG-ASC on out-patients aged ≥80 years old undergoing a colonoscopy at 8 centres in Spain and Portugal. Cleansing quality was assessed using the Boston Bowel Preparation Scale, with overall scores ≥6 and all segmental scores ≥2 considered adequate colon cleansing, and overall scores ≥8 or 3 in the right colon considered high-quality cleansing. The caecal intubation rate, withdrawal time, polyp and adenoma detection rates, and adverse events (AEs) were also monitored. Results: Data were analysed from 423 patients aged ≥80 years; mean age 83.5 (±3.2) years and 49.2% males. The adequate colon cleansing success rate was 88.9%, with high-quality cleansing of the overall and right colon achieved in 54.1% and 46.1% of the patients, respectively. Colonoscopy was complete in 94.1% of cases, and the adenoma detection rate was 51.3%. At least one AE was experienced by 4.5% of participants, the most frequent being mild dehydration (2.8%) and nausea (1.2%). Conclusions: This post-hoc analysis confirms 1L PEG-ASC to be an effective and safe bowel cleansing preparation for patients aged 80 years or over in a real-world setting.

Insight into the rheological performance of plasticized-cement paste containing a tailored comb-shaped polycarboxylate superplasticizers: molecular architecture and functionalizing

This study deals with developing efficient comb-shaped polycarboxylate superplasticizers (PCs) with different molecular architectures as sustainable additives for mortar and concrete processing. The PC synthesis involved polycondensation of methacrylic acid (MAA) and methoxy polyethylene glycol (MPEG) with different molecular weights (750, 1000, and 2000 Da), followed by free-radical copolymerization of MAA, 2-acrylamide-2-methylpropane sulfonic acid (AMPS), hydroxyethyl methacrylate, acrylamide, and the attained MPEG-grafted macromonomer. Successful copolymerization and grafting were approved by employing H NMR, FTIR, and GPC. The performance of PCs was evaluated for their dispersing ability in cement paste (water/cement: 0.30, PC content: 0.25 wt.%) through the slump retention, fluidity, apparent viscosity monitoring, and rheological behavior of cement pastes via the Herschel–Bulkley model using shear stress versus shear rate diagrams to calculate the yield stress. It was found that the grafted and ungrafted copolymers based on MAA-AMPS (with mass ratio of MAA:AMPS of 50:50 wt%) display greater workability due to the higher negative charge density and better adsorption on cement particles owing to sulfonate (−SO3 −) and CONH2 groups. So, slump values of 300 mm and 400 mm were attained by ungrafted and MPEG750-grafted MAA-AMPS copolymers, respectively. Furthermore, the findings demonstrated that longer MPEG side chains higher than 750 Da greatly weaken the dispersing ability due to the lower steric hindrance repulsive forces, lower electrostatic interactions, and more chain-folding. Moreover, the incorporation of 0.25 wt.% by weight of cement of MPEG750-grafted MAA-AMPS copolymer in cement pastes reduced the yield stress over than 90%. Consequently, the know-how for tailoring effective MPEG-grafted superplasticizers with great slump retention (400 mm), low viscosity (lower than 0.1 Pa·s at a shear rate: 10 s−1), and low yield stress (2.22 e−14 Pa), compared to industrial ones, was achieved. Accordingly, this attempt provides a beneficial insight into developing high-performance water-reducing superplasticizers, as a promising candidate for advanced greener cement-based materials.

Effect of polyethylene glycol on rheological, thermo‐mechanical, and tribological behavior of epoxy

AbstractOver the past few years, polyethylene glycol (PEG) has been recognized as an effective blend to enhance the mechanical properties of brittle epoxy. However, the literature contains limited systematic studies evaluating PEG's role in improving epoxy performance. Therefore, a systematic approach was employed in the present study to assess the impact of varying weight percentages of PEG on the viscosity, thermo‐mechanical, and tribological properties of epoxy. Adding 10 wt% PEG (PEG‐10) in epoxy is identified as the threshold limit. With PEG‐10, the viscosity significantly decreased by approximately 78%, while fracture toughness, tensile strength, tensile modulus, and failure strain improved by 59.5%, 38.5%, 37.8%, and 54%, respectively, compared to neat epoxy. Additionally, the wear rate was significantly reduced by 92% compared to neat epoxy, though thermo‐mechanical and flexural properties were slightly compromised. Furthermore, the failure mechanisms of the tensile fracture surfaces and wear tracks of epoxy–PEG blends were examined to understand PEG's role more comprehensively.Highlights A Significant drop in the viscosity of epoxy resin is achieved with the help of PEG‐400. PEG‐400 is mixed with epoxy resin to improve its fracture toughness and tensile properties. A 92% reduction is observed in the wear rate when PEG‐400 is mixed with epoxy resin at 10 wt%.

Theoretical and experimental investigation on the dispersion mechanisms of surfactants on CeO2 particles

The dispersion mechanisms of ionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant polyethylene glycol (PEG), and inorganic dispersant sodium hexametaphosphate (SHMP) on CeO2 particles were investigated. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations were employed to analyze the properties of surfactant molecules and their interaction mechanisms with CeO2 surface. The results of these calculations and simulations were verified through experiments. The experimental results showed that the dispersion of CeO2 particles initially decreased at 0.02 wt % SDS concentration, subsequently improved, and reached its optimum at 0.2 wt%. The dispersion effect enhanced with increasing PEG concentration, peaking at 0.05 wt%, but deteriorated with further increases. Adding a small amount of SHMP significantly improved dispersion, with the best results at 0.2 wt % SHMP concentration. The dispersion mechanisms of the three surfactants for CeO2 particles are as follows: SDS molecules can be adsorbed vertically on the CeO2 surface and not only increase the absolute value of the zeta potential of CeO2 particles, but also play a role in steric hindrance. PEG molecules, which do not ionize in water, can be adsorbed on the CeO2 surface to improve the dispersion of CeO2 particles through a steric hindrance effect. The SHMP molecule tends to hydrolyze into [HPO4]2- ions and can be adsorbed on the CeO2 surface stably, significantly increasing the absolute value of the zeta potential of CeO2 particles. The findings of this study contribute to a better understanding of the dispersion mechanisms of CeO2 particles by different surfactants.