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Polymers May 2021Polyetheretherketone (PEEK)/polyethersulfone (PES) blends are initially not miscible, except when the blends are prepared by solvent mixing. We propose a route to...
Polyetheretherketone (PEEK)/polyethersulfone (PES) blends are initially not miscible, except when the blends are prepared by solvent mixing. We propose a route to elaborate PEEK/PES blends with partial miscibility by melt mixing at 375 °C with phenolphthalein. The miscibility of blends has been examined using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMTA). When adding phenolphthalein to PEEK/PES blends, the glass transitions are shifted inward as an indication of miscibility. We suggest that phenolphthalein acts as a compatibilizer by creating cardo side groups on PEEK and PES chains by nucleophilic substitution in the melted state, although this condensation reaction was reported only in the solvent until now. In addition, phenolphthalein acts as a plasticizer for PES by decreasing its glass transition. As a consequence, the PEEK phase is softened which favors the crystallization as the increase of crystalline rate. Due to aromatic moieties in phenolphthalein, the storage modulus of blends in the glassy region is kept identical to pure PEEK. The morphological analysis by SEM pictures displays nano- to microsized PES spherical domains in the PEEK matrix with improved PEEK/PES interfacial adhesion.
PubMed: 34062773
DOI: 10.3390/polym13091466 -
Vaccine Jan 2023Amid the COVID-19 pandemic, the scientific community has been understandably eager to combat misinformation about issues such as vaccine safety. In highly polarized...
Amid the COVID-19 pandemic, the scientific community has been understandably eager to combat misinformation about issues such as vaccine safety. In highly polarized information environments, however, even well-intentioned messages have the potential to produce adverse effects. In this study, we connect different disciplinary strands of social science to derive and experimentally test the novel hypothesis that although particular efforts to debunk misinformation about mRNA vaccines will reduce relevant misperceptions about that technology, these correctives will harm attitudes toward other types of vaccines. We refer to this as the "collateral damage hypothesis." Our study specifically examines a corrective message stating that "mRNA vaccines do not contain live virus," and our results offer some support for our hypothesis, with the corrective triggering increased societal risk perceptions of live vaccines. We also find that the effect is, predictably, most evident among those whose vaccine acceptance is low. Building on the theoretical grounding we outline, we test a "damage control" adjustment to the corrective message and present evidence supporting that it mitigates the collateral damage.
Topics: Humans; Pandemics; COVID-19; Dioctyl Sulfosuccinic Acid; Drug-Related Side Effects and Adverse Reactions; Phenolphthalein; mRNA Vaccines; Communication
PubMed: 36682880
DOI: 10.1016/j.vaccine.2022.12.045 -
Journal of Nuclear Medicine : Official... Mar 2015We report the design, testing, and in vivo application of pH-sensitive contrast agents designed specifically for Cerenkov imaging. Radioisotopes used for PET emit...
UNLABELLED
We report the design, testing, and in vivo application of pH-sensitive contrast agents designed specifically for Cerenkov imaging. Radioisotopes used for PET emit photons via Cerenkov radiation. The multispectral emission of Cerenkov radiation allows for selective bandwidth quenching, in which a band of photons is quenched by absorption by a functional dye. Under acidic conditions, (18)F-labeled derivatives emit the full spectrum of Cerenkov light. Under basic conditions, the dyes change color and a wavelength-dependent quenching of Cerenkov emission is observed.
METHODS
Mono- and di-(18)F-labeled derivatives of phenolsulfonphthalein (phenol red) and meta-cresolsulfonphthalein (cresol purple) were synthesized by electrophilic fluorination. Cerenkov emission was measured at different wavelengths as a function of pH in vitro. Intramolecular response was measured in fluorinated probes and intermolecular quenching by mixing phenolphthalein with (18)F-FDG. Monofluorocresol purple (MFCP) was tested in mice treated with acetazolamide to cause urinary alkalinization, and Cerenkov images were compared with PET images.
RESULTS
Fluorinated pH indicators were produced with radiochemical yields of 4%-11% at greater than 90% purity. Selective Cerenkov quenching was observed intramolecularly with difluorophenol red or monofluorocresol purple and intermolecularly in phenolphthalein (18)F-FDG mixtures. The probes were selectively quenched in the bandwidth closest to the indicator's absorption maximum (λmax) at pHs above the indicator pKa (the negative logarithm of the acid dissociation constant). Addition of acid or base to the probes resulted in reversible switching from unquenched to quenched emission. In vivo, the bladders of acetazolamide-treated mice exhibited a wavelength-dependent quenching in Cerenkov emission, with the greatest reduction occurring near the λmax. Ratiometric imaging at 2 wavelengths showed significant decreases in Cerenkov emission at basic pH and allowed the estimation of absolute pH in vivo.
CONCLUSION
We have created contrast agents that selectively quench photons emitted during Cerenkov radiation within a given bandwidth. In the presence of a functional dye, such as a pH indicator, this selective quenching allows for a functional determination of pH in vitro and in vivo. This method can be used to obtain functional information from radiolabeled probes using multimodal imaging. This approach allows for the imaging of nonfluorescent chromophores and is generalizable to any functional dye that absorbs at suitable wavelengths.
Topics: Acetazolamide; Animals; Contrast Media; Disease Models, Animal; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Hydrogen-Ion Concentration; Mice; Models, Chemical; Multimodal Imaging; Optics and Photonics; Phenolphthalein; Phenolsulfonphthalein; Photons; Positron-Emission Tomography; Radioisotopes; Radiopharmaceuticals
PubMed: 25655631
DOI: 10.2967/jnumed.114.146605 -
Membranes Jun 2021A class of phenolphthalein anilide (PA)-based poly(ether sulfone) multiblock copolymers containing pendant quaternary ammonium (QA) and imidazolium (IM) groups were...
Phenolphthalein Anilide Based Poly(Ether Sulfone) Block Copolymers Containing Quaternary Ammonium and Imidazolium Cations: Anion Exchange Membrane Materials for Microbial Fuel Cell.
A class of phenolphthalein anilide (PA)-based poly(ether sulfone) multiblock copolymers containing pendant quaternary ammonium (QA) and imidazolium (IM) groups were synthesized and evaluated as anion exchange membrane (AEM) materials. The AEMs were flexible and mechanically strong with good thermal stability. The ionomeric multiblock copolymer AEMs exhibited well-defined hydrophobic/hydrophilic phase-separated morphology in small-angle X-ray scattering and atomic force microscopy. The distinct nanophase separated membrane morphology in the AEMs resulted in higher conductivity (IECw = 1.3-1.5 mequiv./g, σ(OH) = 30-38 mS/cm at 20 °C), lower water uptake and swelling. Finally, the membranes were compared in terms of microbial fuel cell performances with the commercial cation and anion exchange membranes. The membranes showed a maximum power density of ~310 mW/m (at 0.82 A/m); 1.7 and 2.8 times higher than the Nafion 117 and FAB-PK-130 membranes, respectively. These results demonstrated that the synthesized AEMs were superior to Nafion 117 and FAB-PK-130 membranes.
PubMed: 34203084
DOI: 10.3390/membranes11060454 -
The Journal of General Physiology Sep 1918Minute amounts of photosynthesis in marine plants can be accurately measured by adding a little phenolphthalein to the sea water, and observing changes in the color of...
Minute amounts of photosynthesis in marine plants can be accurately measured by adding a little phenolphthalein to the sea water, and observing changes in the color of the indicator. In the case of fresh water aquatics bicarbonates are added. By this method it is found that Ulva which has been kept in the dark begins photosynthesis as soon as it is exposed to sunlight and that the rate steadily increases until a constant speed is attained. This may be explained by assuming that sunlight decomposes a substance whose products either catalyze photosynthesis or enter directly into the reaction. Quantitative theories are developed in order to account for the facts.
PubMed: 19871720
DOI: 10.1085/jgp.1.1.1 -
ACS Omega Jan 2019β-cyclodextrin (β-CD) forms a host-guest inclusion complex with many organic and amphiphilic compounds found in pharmaceutical, textile, cosmetic, food, and personal...
β-cyclodextrin (β-CD) forms a host-guest inclusion complex with many organic and amphiphilic compounds found in pharmaceutical, textile, cosmetic, food, and personal care systems. Therefore, grafting of β-CD onto a cellulose nanocrystal (CNC) offers a possible strategy to use functionalized CNC to complex with surface-active molecules. We have successfully grafted β-CD onto CNCs in a stepwise manner using cyanuric chloride as the linker. The structure of β-CD-grafted CNC (CNC-CD) was characterized by UV-vis and Fourier-transform infrared spectroscopy, and the grafting ratio of β-CD was determined by the phenolphthalein inclusion protocol. Ionic surfactants induced the aggregation of CNC-CDs by forming inclusion complexes with β-CDs on the surface of CNC. The interactions of amphiphilic compounds with CNC-CD were examined by surface tensiometry, conductometric and potentiometric titration, and isothermal titration calorimetry. Mechanisms describing the complex formation between surfactants and CNC-CD were proposed, where an improved understanding of CD interactions with surfactants and lipids would enable better strategies for drug encapsulation and delivery with CDs.
PubMed: 31459458
DOI: 10.1021/acsomega.8b02534 -
RSC Advances Nov 2022Tracing carbonation in cementitious slurries is very necessary, as it helps to accurately design the durability of infrastructure and achieve carbon neutrality. In this...
Tracing carbonation in cementitious slurries is very necessary, as it helps to accurately design the durability of infrastructure and achieve carbon neutrality. In this study, anthocyanins extracted from fresh or stale () flowers on campus were prepared, and their capability as substitute of phenolphthalein, to trace carbonation in cementitious materials was studied. Anthocyanin extracted from stale petal had undergone significant deterioration, while that extracted from fresh petal could be cryo-preserved effectively for at least one year. Combining pH, chemical and porosity analysis, the reliability of the novel anthocyanin indicator in tracing carbonation was verified. With the increase of discoloration pH, the carbonation depth read from anthocyanin contained partial carbonated zone, thus was larger than those read from phenolphthalein. Moreover, the varied evolving pattern on the spatial distribution of local saturation degree in cementitious slurries during carbonation was studied, based on which factors affecting the broadness of partial carbonated zone were offered, and circumstances under which anthocyanin would be more accurate than phenolphthalein were offered. For conditions where a broad partial carbonated zone is presented or a condition where higher standard on human safety is required, the new-developed indicator is more competitive over phenolphthalein.
PubMed: 36425711
DOI: 10.1039/d2ra04980e -
Frontiers in Microbiology 2022The aim of this study was to investigate the effects of subsp VHProbi YB11 (YB11) on attenuating sucralfate-induced constipation in BALB/c mice. The strain of YB11...
INTRODUCTION
The aim of this study was to investigate the effects of subsp VHProbi YB11 (YB11) on attenuating sucralfate-induced constipation in BALB/c mice. The strain of YB11 exhibited favorable tolerance of simulated gastrointestinal (GI) juice. Only 0.42 Log value declined when the live cells of YB11 were co-incubated with simulated GI juice. Meanwhile, this strain also displayed perfect ability to adhere the intestinal epithelium Caco-2 cells with adhesion index of 18.5. 24 of female mice were randomized into four groups.
METHODS
The normal group (NOR) was fed with a normal diet, whereas the placebo group (PLA), positive group (POS), and probiotic group (PRO) were fed with sucralfate to induce constipation. After first successfully establishing the constipation model, groups NOR and PLA received the oral administration of saline solutions. Meanwhile, the POS and PRO groups were orally administered phenolphthalein and YB11 suspensions, respectively. Several indices, including fecal water content, GI transit time, short-chain fatty acids (SCFAs), intestinal neuropeptides level, and histopathology of colonic tissues, were investigated.
RESULTS AND DISCUSSION
Compared with PLA, YB11 had a positive effect in increasing the fecal water content and intestinal peristalsis. Some positive trends, including the acetic and total acids level of fecal samples, and the colonic tissue histopathology, were also observed. Furthermore, YB11 had an ability to upregulate the levels of gut excitatory neuropeptides including motilin, gastrin, and substance P, whereas it downregulated the levels of inhibitory neuropeptides including endothelin-1, somatostatin, and vasoactive intestinal peptide. We conclude that the strain YB11 has a positive impact on improving gastrointestinal mobility and reducing the severity of constipation.
PubMed: 36532450
DOI: 10.3389/fmicb.2022.1040371 -
Polymers Aug 2022Over the years, many materials have been used to restore buildings, paintings, ceramics, and mosaic pieces exhibiting different types of dyes and colour hues. Recently,...
Over the years, many materials have been used to restore buildings, paintings, ceramics, and mosaic pieces exhibiting different types of dyes and colour hues. Recently, geopolymers have been used for restoration purposes owing to their high chemical and mechanical resistance. In this work, white metakaolin was used to obtain white geopolymers, cured at 25 and 40 °C, as bulk materials to be coloured with synthetic organic dyes, i.e., bromothymol blue, cresol red, phenolphthalein, and methyl orange. These dyes were added during the fresh paste preparation to obtain dyed geopolymeric solids. Ionic conductivity and pH measurement confirmed the chemical stability of the consolidated materials, while FT-IR analyses were used to follow the geopolymerisation occurrences at different ageing times (from 7 to 56 days). Finally, the colour hues and properties were assessed in the CIELAB colour space before and after immersion in water.
PubMed: 36015635
DOI: 10.3390/polym14163380 -
The Biochemical Journal Jan 19751. Structure-linked latency, a trait for most lysosome hydrolase activities, is customarily ascribed to the permeability-barrier function performed by the...
1. Structure-linked latency, a trait for most lysosome hydrolase activities, is customarily ascribed to the permeability-barrier function performed by the particle-limiting membrane, which shields enzyme sites from externally added substrates. 2. The influence of various substrate concentrations on the reaction rate has been measured for both free (non-latent) and total (completely unmasked by Triton X-100) hydrolase activities in rat liver cell-free preparations. The substrates were: beta-glycerophosphate, phenolphthalein mono-beta-glucuronide. p-nitrophenyl N-acetyl-beta-D-glucosaminide and p-nitrophenyl beta-D-galactopyranoside. The ratio (free activity/total activity) X 100 is called fractional free activity at any given substrate concentration. 3. The fractional free activity of beta-glucuronidase and beta-N-acetylglucosaminidase were clearly independent of substrate concentration, over the range examined, in both homogenates and lysosome-rich fractions. The fractional free activity of acid phosphatase appeared to be either unaffected (homogenate) or even depressed (lysosome-rich fraction) by increasing the beta-glycerophosphate concentration. The fractional free activity of beta-galactosidase consistently showed a non-linear increase with increasing substrate concentration in both homogenates and lysosome-rich fractions. 4. Procedures such as treatment with digitonin, hypo-osmotic shock and acid autolysis, although effective in causing varying degrees of resolution of the latency of lysosome hydrolase activities, were unable to modify appreciably the pattern of dependence or independence of their fractional free activities on substrate concentration, as compared with that exhibited by control preparations. Ouabain did not affect the free beta-N-acetylglucosaminidase activity of liver homogenates at all. 5. Preincubation of control preparations with beta-glycerophosphate or p-nitrophenyl beta-galactoside did not result in any significant stimulation of the free hydrolytic activity toward these substrates. 6. The results consistently support the view that the membrane of "intact" lysosomes is virtually impermeable to all the substrates tested, except for p-nitrophenyl beta-galactoside, for which the evidence is contradictory. Moreover the progressive unmasking of the hydrolase activities produced by these procedures in vitro reflects the increasing proportion of enzyme sites that are fully accessible to their substrates rather than a graded increase in the permeability of the lysosomal membrane.
Topics: Acetylglucosaminidase; Acid Phosphatase; Animals; Binding Sites; Digitonin; Galactosidases; Glucuronidase; Glycerophosphates; Hydrolases; Liver; Lysosomes; Male; Membranes; Nitrophenylgalactosides; Osmosis; Ouabain; Permeability; Polyethylene Glycols; Rats
PubMed: 1041236
DOI: 10.1042/bj1460097