Designed Monomers and Polymers最新文献

[This corrects the article DOI: 10.1163/138577210X12634696333433.][This corrects the article DOI: 10.1163/138577211X577178.].

Introduction: This trial investigated whether a Facebook smoking cessation intervention culturally tailored to young sexual and gender minority (SGM) smokers (versus non-tailored) would increase smoking abstinence.

Methods: Participants were 165 SGM young adult US smokers (age 18-25) recruited from Facebook in April 2018 and randomized to an SGM-tailored (POP; N = 84) or non-tailored (TSP-SGM; N = 81) intervention. Interventions delivered weekly live counseling sessions and 90 daily Facebook posts to participants in Facebook groups. Primary analyses compared POP and TSP-SGM on biochemically verified smoking abstinence (yes/no; primary outcome), self-reported 7-day point prevalence abstinence (yes/no), reduction in cigarettes per week by 50+% from baseline (yes/no), making a quit attempt during treatment (yes/no), and stage of change (precontemplation/contemplation vs. preparation/action). Supplemental analyses compared POP to two historical control groups.

Results: POP participants were more likely than TSP-SGM participants to report smoking abstinence at 3 (23.8% vs. 12.3%; OR = 2.50; p = .03) and 6 months (34.5% vs. 12.3%; OR = 4.06; p < .001) and reduction in smoking at 3 months (52.4% vs. 39.5%; OR = 2.11; p = .03). Biochemically verified smoking abstinence did not significantly differ between POP and TSP-SGM at 3 (OR = 2.00; p = .33) or 6 months (OR = 3.12; p = .08), potentially due to challenges with remote biochemical verification. In supplemental analyses, POP participants were more likely to report abstinence at 3 (OR = 6.82, p = .01) and 6 (OR = 2.75, p = .03) months and reduced smoking at 3 months (OR = 2.72, p = .01) than participants who received a referral to Smokefree.gov.

Conclusions: This pilot study provides preliminary support for the effectiveness of a Facebook smoking cessation intervention tailored to SGM young adults.

Implications: SGM individuals have disproportionately high smoking prevalence. It is unclear whether smoking cessation interventions culturally tailored to the SGM community are more effective than non-tailored interventions. This pilot trial found preliminary evidence that an SGM-tailored Facebook smoking cessation intervention increased reported abstinence from smoking, compared to a non-tailored intervention.

Trial registration: NCT03259360.

A completely metal-free and environmentally friendly strategy is demonstrated for the preparation of graft copolymers by combining photoinduced Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP). Polymerizations are simultaneously realized in a one-pot manner. For this purpose, bare vinyl monomers, vinyl monomers with hydroxyl functional groups, and lactone monomers were simultaneously polymerized under visible light using specific catalysts. While vinyl monomers construct the main chain, the lactone monomers were polymerized from the hydroxyl functions present at the side chain. Spectral and chromatographic analyses prove that the utilized strategy is successful in the preparation of graft copolymers controlled molecular weights and narrow distributions.

Silver-based nanoparticles and biomaterials have extensive biomedical applications owing to their unique antimicrobial properties. Thus, green and facile synthesis of such materials is highly desirable. This study reports an antibacterial hydrogel based on polyvinyl alcohol/sodium alginate network with the incorporation of silver nanoparticles (AgNPs), which is greenly synthesized by reductive metabolites obtained from the leaves of green tea. The 'flower-shape' AgNPs were acquired, it formed a mono-disperse system with a distinct uniform interparticle separation. The average size of AgNPs varied from 129.5 to 243.6 nm, which could be regulated by using different volumes of the green tea extract. Zeta potentials of the AgNPs were from -39.3 mV to -20.3 mV, indicating the moderate stability of the particles in water. In the next stage, the antibacterial polyvinyl alcohol/sodium alginate hydrogels were fabricated by incorporating prepared AgNPs. Scanning Electron Microscopy (SEM) images showed that the porous structure was obtained, and Energy Dispersive X-Ray (EDX) analysis confirmed that the AgNPs were uniformly dispersed in the polymer network. The hydrogels exhibited superior water absorption properties, which were characterized by a high swelling ratio (500-900%) and fast equilibrium. The hydrogels also exhibited good antimicrobial activity in assays with Gram-positive bacteria Escherichia coli and Gram-negative bacteria Staphylococcus aureus. To sum up, a process for the green preparation of antibacterial hydrogels based on AgNPs derived from tea leaves as a conveniently available cheap local agricultural product was established.

1'-(2-Acryloxyethyl)-3,3'-dimethyl-6-nitrospiro[2 H-1-benzopyran-2,2'-indoline] (SPA) was synthesized and grafted onto a water-soluble carboxymethyl chitin (CMCH) macromolecule to prepare a photochromic copolymer (CMCH-g-SPA). The structure of CMCH-g-SPA was characterized by Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, X-ray diffraction (XRD) analysis, water-solubility evaluation, and UV-vis spectroscopy. XRD patterns of CMCH-g-SPA revealed that grafting copolymerization disrupts the CMCH semicrystalline structure, thus improving water solubility. UV-vis spectroscopy results supported the negative photochromic behavior of the merocyanine (MC) form of CMCH-g-SPA (CMCH-g-MCA) present in a water solution of the target copolymer. In addition to high solvent polarity, the intermolecular and intramolecular electrostatic attraction between the indolenine cation and the COO^- anion were found to be influencing factors, which stabilize these MC form of spiropyran groups grafted onto CMCH. In a water solution, visible light bleaching was completed over a short period (8 minutes) under artificial visible light irradiation and the thermal coloration reaction, whose rate constant at 25 °C was 4.64 × 10^-4 s^-1, which fit the first-order reaction equation. After ten photochromic cycles in water solution, the relative absorption intensity of CMCH-g-MCA decreased by 7.92%.

A new aromatic diacid (II) was synthesized and Characterized by Spectroscopic techniques namely, FT-IR, ¹ H and ¹³ C NMR, etc. A series of aromatic aliphatic polyamides containing phenoxy s-triazine ring with methylene spacer group was synthesized from diacid (II) and various aromatic diamines by using Yamazaki Phosphorylation method. These polyamides were obtained in good yields and characterized by solubility in common organic solvent, inherent viscosity, FT-IR, X-ray diffraction analysis. All of these polyamides were found to be amorphous in morphology as indicated by XRD to posses outstanding solubilities, and to be easily dissolved in amide-type polar aprotic polar solvents. Polyamides with moderate inherent viscosity in the range 0.21 to 0.41 dL/g in N,N,dimethyl formamide solvent (DMF) at 30 ± 0.1° C. The Thermal properties of the polyamides were evaluated by Thermogravimetric analysis and Differential scanning calorimetery. These polymer shows good thermal stability with glass transition temperature (T_g) of 143-223°C and their (T_max) weight loss temperature were around 426-455°C, confirming their good thermal stability. The char yields of these polymers were given their limiting oxygen index LOI 32.3 to 37.5 5% values of polyamides; indicate these polymers also show good flame resistance. The NPs were negatively charged with a zeta potential of -24.2 to -37.9 mV indicating a good colloidal stability against aggregation.

Hyperbranched polymers (HPs), which in terms of structure may be compared to the branching structure of trees, are referred to as tree-like materials, but role of leave in these tree-like polymers is neglected and much attention has only been paid to their branches. In fact, functional groups in these polymers play a vital role the same as the role of leaves in trees. Therefore, in this paper, an attempt has been made to design and synthesize three AB₂ monomers containing extra hydroxyl and nitro groups. The benefits of their presence in the structure of produced hyperbranched polyamides (HPs) are investigated. The polymer structure was characterized by FT-IR and ¹ H NMR. The solubility of synthesized HPs was studied in different protic and aprotic solvents. The thermal stability of the prepared HPs was investigated by thermogravimetric and differential scanning calorimetric analyses. The photoluminescent properties of the HPs were also investigated.

Condensation of isopropyl cyanoacetate and substituted benzoic aldehydes resulted in formation of novel isopropyl esters of 2-cyano-3-phenyl-2-propenoic acid, RPhCH = C(CN)CO₂CH(CH₃)₂ (where R is 2,3,4-trimethoxy, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3-bromo-4,5-dimethoxy, 5-bromo-2,3-dimethoxy, 5-bromo-2,4-dimethoxy, 6-bromo-3,4-dimethoxy, 2-bromo-3-hydroxy-4-methoxy, 4-bromo-2,6-difluoro, 2-chloro-3,4-dimethoxy, 3-chloro-4,5-dimethoxy, 5-chloro-2,3-dimethoxy, 2,3,6-trichloro, 3-chloro-2,6-difluoro, 2,3,4-trifluoro, 2,4,5-trifluoro, 2,4,6-trifluoro, 3,4,5-trifluoro, 2,3,5,6-tetrafluoro, 2,3,4,5,6-pentafluoro). Copolymerization of the esters with vinyl benzene in solution with radical initiation (ABCN) at 70°C led to formation copolymers. The products were characterized by CHN elemental analysis, IR, ¹ H- and ¹³ C-NMR, GPC, DSC, and TGA.

A new series of polyurea derivatives and its nanocomposites were synthesised by the solution polycondensation method through the interaction between 4(2-aminothiazol-4-ylbenzylidene)-4-(tert-butyl) cyclohexanone and diisocyanate compound in pyridine. The PU_1-3 structure was confirmed using Fourier transform-infrared (FTIR) spectroscopy and characterised by solubility, viscometry, gel permeation chromatography (GPC), and X-ray diffraction (XRD) analysis. In addition, PU_1-3 was evaluated by TGA. Polyurea-TiO₂nanocomposites were synthesised using the same technique as that of PU_1-3 by adding TiO₂ as a nanofiller. The thermal properties of PU₂TiO₂a-d were evaluated by TGA. Moreover, the morphological properties of a selected sample were examined by SEM and TEM. In addition, PU_1-3 and PU₂TiO₂a-d were examined for antimicrobial activity against certain bacteria and fungi. The PU_1-3 showed antibacterial activity against some of the tested bacteria and fungi, as did PU₂TiO₂a-d, which increased with the increase in TiO₂ content. Furthermore, molecular docking studies were displayed against all PU_1-3 derivatives against two types of proteins. The results show that the increase in the strength of π-H interactions and H-donors contributed to improved binding of PU2 compared to PU1 andPU_3. The docking of 1KZN against the tested polymers suggests an increase in the docking score of PU_2, then PU₁, and PU₃, which is in agreement with the antibacterial study.

Three azido-terminated poly(ethylene glycol) macromonomers (ATPEGs) were synthesized from poly(ethylene glycol)s (PEGs) and characterized. The extended polytriazole (EPTA) resins were prepared from the macromonomers, azide and alkyne monomers. Toughening effect of PEGs on polytriazole resins was analyzed by means of mechanical, thermal and electronic microscope characterization. The results show that molecular weight and content of ATPEGs have great influence on the thermal and mechanical properties of cured EPTA resins. The impact strength of cured EPTA resins increases with the increase of the amount and molecular weight of ATPEGs. The flexural strength and heat resistance of cured EPTA resins decrease with the increase of addition amount and molecular weight of ATPEGs. High impact EPTA resins were obtained.