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ACS Omega Nov 2022The 7-nitro-2'-phenyl-5',6',7',7a'-tetrahydrospiro[indeno[1,2-]quinoxaline-11,3'-pyrrolizine]-1',1'(2')-dicarbonitrile (SIQPI),...
The 7-nitro-2'-phenyl-5',6',7',7a'-tetrahydrospiro[indeno[1,2-]quinoxaline-11,3'-pyrrolizine]-1',1'(2')-dicarbonitrile (SIQPI), 2'-(4-cyanophenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-]quinoxaline-11,3'-pyrrolizine]-1',1'(2') dicarbonitrile (SIQPII), and 2'-(4-methoxyphenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-]quinoxaline-11,3'-pyrrolizine]-1',1'(2')-dicarbonitrile (SIQPIII) were used to photocatalyze quinonoid phenolphthalein (QHIn) in aq-ACN-EtOH (mixed solvent) with NaCl and KCl electrolytes. SIQPI, II, and III spiroindenoquinoxaline pyrrolidines (SIQPs) as spiroheterocyclic photocatalysts alone could not reduce QHIn, but with the addition of electrolytes they are reduced via π cationic interactions (PCI). SIQPI, II, and III with NaCl reduced QHIn in 120, 28, and 50 min, unlike in 138, 58, and 63 min with KCl in mixed solvent. SIQPI, II, and III alone have reduced methylene blue (MB) in 120, 45, and 70 min, unlike in 110, 27, and 55 min with graphene oxide (GO), whereas with NaCl and KCl hey are reduced in 82, 36, and 44 min and 89, 43, and 50 min, respectively. SIQPs with GO had reduced MB in less time than the SIQPs alone, and SIQPs with NaCl had reduced QHIn in a shorter time than KCl. The electrolytes have cocatalyzed a reduction of dyes under sunlight (SL). The electrolytes have reduced a quinonoid structure (QS) and dyes by generating negative and positive ( and ) holes in a shorter time. SIQPII and magnetic nanoparticles (MNPs) of 58 nm with NaCl photocatalyzed the QHIn in 2880 min. The SIQPs also reduced methyl orange (MO) and brilliant blue R (BBR) at variable temperature () and pH range, whereas SIQPs have developed a molecular organic framework (MOF) with transition-metal salts (NiCl, CrO, KMnO, CuSO, and MnCl) on photocatalysis.
PubMed: 36385858
DOI: 10.1021/acsomega.2c05103 -
Polymers Feb 2024Aluminum butylmethylphosphinate AiBMP as a flame retardant and phenolphthalein as a synergistic agent were applied in a thermoplastic polyester elastomer (TPEE)) in the...
Aluminum butylmethylphosphinate AiBMP as a flame retardant and phenolphthalein as a synergistic agent were applied in a thermoplastic polyester elastomer (TPEE)) in the current study. The thermal properties, flame retardancy, crystallization and mechanical properties of TPEE/AiMBP with or without phenolphthalein were investigated using various characterizations, including the limiting oxygen index (LOI), vertical burning test (UL 94), thermogravimetric analysis TG, differential scanning calorimetry, microcombustion calorimeter (MCC), scanning electron microscopy (SEM), and mechanical tests. The results revealed that AiBMP alone is an efficient flame retardant of TPEE. Adding 15 wt.% AiBMP increases the LOI value of TPEE from 20% to 36%. The formula TPEE-15 AiBMP passed the UL 94 V-0 rating with no dripping occurring. The MCC test shows that AiBMP depresses the heat release of TPEE. In comparison with pure TPEE, the heat release rate at peak temperature and the heat release capacity of TPEE-15AiBMP are reduced by 46.1% and 55.5%, respectively. With the phenolphthalein added, the formula TPEE/13AiBMP/2Ph shows a higher char yield at high temperatures (>600 °C), and the char layer is stronger and more condensed than TPEE-15AiBMP.The tensile strength and elongation at break values of TPEE-13AiBMP-2Ph are increased by 29.63% and 4.8% in comparison with TPEE-15AiBMP. The SEM morphology of the fracture surface of the sample shows that phenolphthalein acts as a plasticizer to improve the dispersion of AiBMP within the matrix. The good char charming ability of phenolphthalein itself and improved dispersion of AiBMP make the TPEE composites achieve both satisfying flame retardancy and high mechanical properties.
PubMed: 38399930
DOI: 10.3390/polym16040552 -
ACS Sensors Aug 2021This study introduces a spinning and fully integrated paper-based microdevice that can perform multiple functions, including DNA extraction, amplification, and...
This study introduces a spinning and fully integrated paper-based microdevice that can perform multiple functions, including DNA extraction, amplification, and colorimetric detection, for monitoring two major vancomycin-resistant (VREs), which carry the A and B genes. The spinning microdevice is composed of a stationary part and a spinning part. The square-shaped stationary part has two zones: the lysis and reaction zones. The spinning part, which has a spin wheel-like shape, was inserted perpendicularly into the stationary part so that its two semicircles remained on the upper and lower parts. Sodium hydroxide-treated glass microfiber filter discs, inserted in the upper semicircle, were soaked in the lysis chambers by folding them toward the lysis zone to capture DNA in the lysis chambers. The captured DNA was transferred to the reaction chambers by folding the discs toward the reaction chambers. Water was added to the sodium hydroxide-treated glass microfiber filter discs to elute purified DNA into the reaction chambers. The upper semicircle was then unfolded, and the reaction chambers were sealed for subsequent loop-mediated isothermal amplification (LAMP) for 45 min. After the reaction, the spinning part was spun in the lysis zone direction to bring the lower semicircle, inserted with phenolphthalein-treated glass microfiber filter discs, toward the upper part of the stationary part. By folding it toward the reaction chambers, the lower semicircle came into contact with them and the phenolphthalein-treated glass microfiber filter discs were soaked in the reaction chambers and expressed color after 30 s. Based on the pH change during the LAMP reaction, the phenolphthalein-treated discs remained pink in the absence of target DNA, while those in contact with the positive samples turned colorless. A sensitive detection with a VRE limit of detection of 10 CFU/mL for tap water spiked with VRE carrying the A gene was achieved using this microdevice. Both VREs, carrying A and B genes, were successfully identified from tap water and contaminated equipment surfaces within 75 min. The introduced microdevice demonstrated a rapid, accurate, and sensitive performance for the environmental assessment of VRE contamination in resource-limited regions.
Topics: Molecular Diagnostic Techniques; Nucleic Acid Amplification Techniques; Vancomycin; Vancomycin-Resistant Enterococci
PubMed: 34292707
DOI: 10.1021/acssensors.1c00639 -
Small (Weinheim An Der Bergstrasse,... Jan 2019One of the basic operations in microfluidic systems for biological and chemical applications is the rapid mixing of different fluids. However, flow profiles in...
One of the basic operations in microfluidic systems for biological and chemical applications is the rapid mixing of different fluids. However, flow profiles in microfluidic systems are laminar, which means molecular diffusion is the only mixing effect. Therefore, mixing structures are crucial to enable more efficient mixing in shorter times. Since traditional microfabrication methods remain laborious and expensive, 3D printing has emerged as a potential alternative for the fabrication of microfluidic devices. In this work, five different passive micromixers known from literature are redesigned in comparable dimensions and manufactured using high-definition MultiJet 3D printing. Their mixing performance is evaluated experimentally, using sodium hydroxide and phenolphthalein solutions, and numerically via computational fluid dynamics. Both experimental and numerical analysis results show that HC and Tesla-like mixers achieve complete mixing after 0.99 s and 0.78 s, respectively, at the highest flow rate (Reynolds number (Re) = 37.04). In comparison, Caterpillar mixers exhibit a lower mixing rate with complete mixing after 1.46 s and 1.9 s. Furthermore, the HC mixer achieves very good mixing performances over all flow rates (Re = 3.7 to 37.04), while other mixers show improved mixing only at higher flow rates.
PubMed: 30548194
DOI: 10.1002/smll.201804326 -
Carbohydrate Polymers Mar 2020A simple method was proposed for preparing the dialdehyde-β-cyclodextrin (DA-β-CD) cross-linked carboxymethyl chitosan (CMCS) hydrogels for drug delivery. DA-β-CD was...
A simple method was proposed for preparing the dialdehyde-β-cyclodextrin (DA-β-CD) cross-linked carboxymethyl chitosan (CMCS) hydrogels for drug delivery. DA-β-CD was yielded from the sodium periodate oxidation of β-CD. Phenolphthalein (PhP) was adopted as a model drug to study the drug loading and releasing properties of the obtained hydrogels. The results show that the ability of the hydrogel to load drug is affected by the aldehyde content of DA-β-CD. The inclusion constant of DA-β-CD toward PhP is lower than that of the original β-CD and decreased with the rising of the aldehyde content. An increased cross-linking degree between DA-β-CD and CMCS slows the PhP release to some extent. In comparison with glyoxal/CMCS, DA-β-CD/CMCS presents better PhP release properties. Only 19.2 % of PhP loaded in glyoxal/CMCS was released within 24 h. Half of PhP loaded in DA-β-CD/CMCS was released in 2 h and about 90 % was released within 12 h.
Topics: Chitosan; Cross-Linking Reagents; Drug Delivery Systems; Drug Liberation; Glyoxal; Humans; Hydrogels; beta-Cyclodextrins
PubMed: 31888806
DOI: 10.1016/j.carbpol.2019.115678 -
Chemosphere Oct 2023The occurrence and removal rate of 52 typical pharmaceuticals and personal care products (PPCPs) were investigated in a wastewater treatment plant in Beijing, China....
The occurrence and removal rate of 52 typical pharmaceuticals and personal care products (PPCPs) were investigated in a wastewater treatment plant in Beijing, China. Thirty-three PPCPs were found in the influent, with caffeine (CF, 11387.0 ng L) being the most abundant, followed by N,N-diethyl-meta-toluamide (DEET, 9568.4 ng L), metoprolol (MTP, 930.2 ng L), and diclofenac (DF, 710.3 ng L). After treatment processes, the cumulative concentration of PPCPs decreased from 2.54 × 10 ng L to 1.44 × 10 ng L, with the overall removal efficiency (RE) of 94.3%. Different treatment processes showed varying contributions in removing PPCPs. PPCPs were efficiently removed in sedimentation, anoxic, and ultraviolet units. For individual compounds, a great variation in RE (52.1-100%) was observed. Twenty-two PPCPs were removed by more than 90%. The highly detected PPCPs in the influent were almost completely removed. Aerated grit chamber removed nearly 50% of fluoroquinolone (FQs) and more than 60% of sulfonamides. Most PPCPs showed low or negative removals during anaerobic treatment, except for CF which was eliminated by 64.9%. Anoxic treatment demonstrated positive removals for most PPCPs, with the exceptions of DF, MTP, bisoprolol, carbamazepine (CBZ), and sibutramine. DEET and bezafibrate were efficiently removed during the secondary sedimentation. Denitrification biological filter and membrane filtration also showed positive effect on most PPCPs removals. The remaining compounds were oxidized by 16-100% in ozonation. DF, sulpiride, ofloxacin (OFL), trimethoprim, and phenolphthalein were not amenable to ultraviolet. After the treatment, the residue OFL, CBZ, and CF in receiving water were identified to pose high risk to aquatic organisms. Considering the complex mixtures emitted into the environment, therapeutic groups psychotropics, stimulant, and FQs were classified as high risk. These findings provide valuable insights into adopting appropriate measures for more efficient PPCPs removals, and emphasize the importance of continued monitoring specific PPCPs and mixtures thereof to safeguard the ecosystem.
Topics: Beijing; DEET; Ecosystem; Water Pollutants, Chemical; Cosmetics; China; Water Purification; Pharmaceutical Preparations; Environmental Monitoring; Waste Disposal, Fluid
PubMed: 37495050
DOI: 10.1016/j.chemosphere.2023.139644 -
Materials (Basel, Switzerland) Jul 2021In light of the scientific research, the corrosion of concrete structures is one of the main problems that may reduce their durability due to the negative impact of the...
In light of the scientific research, the corrosion of concrete structures is one of the main problems that may reduce their durability due to the negative impact of the natural environment. The paper analyzes the influence of the type of component on the selected properties of lightweight concrete subjected to the influence of aggressive liquids. Four concrete mixes were prepared with a granular aggregate made of foamed glass (GEGA) and aggregate made of sintered fly ash (GAA) with the use of a mineral additive: silica fly ash. The prepared lightweight concrete after one year was exposed for 60 days to the following environments: strong acid-HCl, 1% and 2% concentration, weak acid-CHCOOH, 1% and 2% concentration, and an aqueous salt solution of NaSO, 1% and 2% concentration. Then, the compressive strength was tested, and the microstructure analysis of the ready-made lightweight concrete (LWC) was performed. The degree of penetration of aggressive solutions into the cracks of the samples was assessed by means of applying 1% phenolphthalein solution. Changes in the weight of lightweight concrete samples after the test period were estimated. The obtained test results indicate that the decrease in the durability of lightweight concrete can be classified as a long-term process. Concrete with GEGA and GAA showed high resistance to aggressive environments. Moreover, the environment containing chlorides turned out to be the most aggressive, while the environment containing sulfates proved to be the least aggressive. The higher the concentration of the destructive factor was, the faster the corrosion process went. This has been proven by measuring the pH using phenolphthalein and carrying out microscopic examination. Concretes containing aggregates made of foamed glass and sintered fly ash are suitable for use both in traditional construction and in facilities exposed to an aggressive environment (e.g., in the chemical industry and at gas stations).
PubMed: 34361376
DOI: 10.3390/ma14154185 -
Journal of Pharmaceutical and... May 2016One hundred and sixty food supplements (FS) marketed for weight loss and mainly purchased on the Internet were analyzed. All the FS were claimed as 100% natural...
One hundred and sixty food supplements (FS) marketed for weight loss and mainly purchased on the Internet were analyzed. All the FS were claimed as 100% natural containing only natural compounds, plant extracts and/or vitamins and the presence of an active pharmaceutical ingredient (API) was never mentioned. (1)H NMR spectroscopy was used for detecting the presence of adulterants and for their identification and quantification. Mass spectrometry was used as a complementary method for supporting their identification. Among the 164 samples considered because capsules from 5 different blisters of the same FS were analyzed, 56% were tainted with six API. Forty three contained sibutramine as single adulterant (26%), 9 phenolphthalein (6%) and 23 a mixture of these API (14%) that were both withdrawn from the market several years ago because of toxicity concerns. Sildenafil was found in 12 samples, either as a single adulterant (n=5) or in combination with sibutramine (n=3), phenolphthalein (n=3) and both sibutramine and phenolphthalein (n=1). Fluoxetine was present in 4 formulations, alone (n=3) or in combination with sibutramine and orlistat (n=1). At last, lorcaserine was detected in one FS. The content of sibutramine per dosage unit was comprised between 0.1 and 22 mg and that of phenolphthalein between 0.05 and 56 mg. The study also highlights poor manufacturing practices as evidenced for instance by the variability of API in capsules from different blisters of the same box. This paper demonstrates the need for more effective quality control of weight loss FS and the efficiency of (1)H NMR spectroscopy for the detection of tainted FS.
Topics: Dietary Supplements; Herbal Medicine; Mass Spectrometry; Proton Magnetic Resonance Spectroscopy
PubMed: 26928212
DOI: 10.1016/j.jpba.2016.02.022 -
The Journal of Chemical Physics Oct 2019Electron attachment to the 3-benzelidenephthalide and phenolphthalein molecules and decay channels of their molecular anions were investigated by means of dissociative...
Electron attachment to the 3-benzelidenephthalide and phenolphthalein molecules and decay channels of their molecular anions were investigated by means of dissociative electron attachment spectroscopy and electron transmission spectroscopy. Interpretations of these experimental data were supported with UV-spectroscopy and density functional theory calculations. The average electron detachment times for the long-lived molecular anions of 3-benzelidenephthalide and phenolphthalein were measured to be 150 µs at 120 °C and 560 µs at 190 °C, respectively. The long-lived molecular anions of phenolphthalein are ascribed to an isomer formed by ring opening. The present results suggest that, opposite to phenolphthalein, polymeric materials based on 3-benzylidenephthalide cannot be switched to a high conductive state due to different mechanisms of stabilization of their long-lived molecular anions.
PubMed: 31594321
DOI: 10.1063/1.5119777 -
Talanta May 2022A high-throughput method for the determination of ethanol in vodka and cachaça using 96-well-plate digital images was proposed and validated. The standard method...
A high-throughput method for the determination of ethanol in vodka and cachaça using 96-well-plate digital images was proposed and validated. The standard method consists of beverage distillation, measuring its density using a pycnometer, and converting it into ethanol content. It is simple, but it is time-consuming and susceptive to error. The proposed method exploits the suppression of phenolphthalein ionization by ethanol in an alkaline solution and the fading of the pink solution was converted into ethanol content. It consists in mixing 1 mL of sample with 0.1 mL of an alkaline phenolphthalein solution. 96-well-plate images were acquired using a desktop scanner. Red, green, and blue (RGB) values from the 96 wells were automatically extracted using ReadPlate (ImageJ plugin). Then, RGB values were exported to a spreadsheet that converted these values into analytical signals and calculated the ethanol content in beverages. The ethanol content of cachaças and vodkas was 33-45% (v/v) and it was also the linear range of the proposed method. The method's precision was evaluated using relative standard deviation (RSD). Five cachaças and three vodkas were analyzed. Each beverage was analyzed six times on the same day (intra-day repeatability) and three consecutive days (inter-day repeatability) by three different analysts (inter-analyst repeatability). The intra-day repeatability average was 1.7% (1.2-2.2% range), the intra-day repeatability average was 2.6% (1.9-3.5% range), and the inter-analyst repeatability average was 4% (2.6-6.2% range). Accuracy was evaluated by comparing the proposed method with the standard method using a percent error and a paired t-test. The average percent error was 1.9%, in the paired t-test, the p-value average value was 0.25. The proposed method can analyze 12 samples in 30 min, whereas the standard method spends around 1 h on each sample. Thus, the proposed method provides high-throughput compared with the standard method.
Topics: Alcoholic Beverages; Beverages; Ethanol
PubMed: 35085992
DOI: 10.1016/j.talanta.2022.123229