Colorless and transparent poly(amide imide) nanocomposites containing organically modified hectorite.

Polyamic acid (PAA) was synthesized using the diamine monomer ,'-[2,2'-bis(trifluoromethyl)-4,4'-biphenylene]bis(4-aminobenzamide) and dianhydride monomer 4,4'-oxydiphthalic anhydride. Colorless and transparent poly(amide imide) (CPAI) hybrid films were prepared multi-step thermal imidization of PAA in which various contents of nano-filler were dispersed. The CPAI hybrid films were prepared by dispersing organoclay STN, which was obtained by organically modifying hectorite, in CPAI by solution intercalation with various contents ranging from 1 to 7 wt%.

Comparison of the properties of polyimide nanocomposite films containing functionalized-graphene and organoclay as nanofillers.

Poly(amic acid) (PAA) is prepared by the reaction of dianhydride 4,4'-biphthalic anhydride and diamine bis[4-(3-aminophenoxy)phenyl]sulfone in N,N'-dimethylacetamide. Two types of fillers were dispersed in the as-synthesized PAA via a solution intercalation method; polyimide (PI) hybrid films were synthesized under various heat treatment conditions. Octylamine (C8) was introduced into graphene sheets (C8-GS) and bentonite (C8-BTN), which were then used as nanofillers in the PI hybrid films.

Oral Nanomedicines for siRNA Delivery to Treat Inflammatory Bowel Disease.

RNA interference (RNAi) therapies have significant potential for the treatment of inflammatory bowel diseases (IBD). Although administering small interfering RNA (siRNA) via an oral route is desirable, various hurdles including physicochemical, mucus, and cellular uptake barriers of the gastrointestinal tract (GIT) impede both the delivery of siRNA to the target site and the action of siRNA drugs at the target site. In this review, we first discuss various physicochemical and biological barriers in the GI tract.

Phase transition, thermal stability, and molecular dynamics of organic-inorganic hybrid perovskite [NH(CH)NH]CuCl crystals.

Organic-inorganic hybrid perovskites have various potential applications in fuel cells and solar cells. In this regard, the physicochemical properties of an organic-inorganic [NH(CH)NH]CuCl crystal was conducted. The crystals had a monoclinic structure with space group 2/ and lattice constants = 7.

Comparison of Properties of Colorless and Transparent Polyimide Nanocomposites Containing Chemically Modified Nanofillers: Functionalized-Graphene and Organoclay.

Poly(amic acid) (PAA) was synthesized from dianhydride 4,4-(4,4-isopropylidenediphenoxy)bis(phthalic anhydride) and diamine bis [4-(3-aminophenoxy) phenyl] sulfone. Colorless and transparent polyimide (CPI) hybrid films were synthesized through thermal imidization after dispersing nanofillers using an intercalation method in a PAA solution. C16-GS and C16-MMT, in which hexadecylamine (C16) was substituted on graphene sheet (GS) and montmorillonite (MMT), respectively, were used as nanofillers to reinforce the CPI hybrid films.

Effects of diamine isomers on the properties of colorless and transparent copoly(amide imide)s.

To fully understand the structure-property relationship of aromatic copoly(amide-imide)s (Co-PAIs) and determine which factors lead to chain rigidity, we prepared two series of Co-PAIs. They were synthesized from two types of amine monomers containing - and -isomers and different ratios of 4,4'-(hexafluoroiso-propylidene)diphthalic anhydride (6FDA) and 4,4'-biphthalic anhydride (BPA). -Substituted and -substituted ,'-[2,2'-bis(trifluoromethyl)-4,4'-biphenylene]bis(aminobenzamide) (MPAB) diamine isomers were synthesized from 3- and 4-nitrobenzoyl chloride and 2,2'-bis(trifluoromethyl) benzidine (TFB), respectively.

Effect of Methylene Chain Length on the Thermodynamic Properties, Ferroelastic Properties, and Molecular Dynamics of the Perovskite-type Layer Crystal [NH(CH) NH]MnCl ( = 2, 3, and 4).

The structures and phase transitions of [NH(CH) NH]MnCl ( = 2, 3, and 4) crystals were confirmed through X-ray diffraction and differential scanning calorimetry (DSC) experiments. Thermodynamic properties, ferroelastic properties, and molecular dynamics of three crystals were studied as a function of the number () of CH groups in the alkylene chains. The loss in molecular weight due to a decrease in marked the onset of the partial thermal decomposition.

Colorless and Transparent Polyimide Microporous Film with Excellent Physicochemical Property.

4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) as a dianhydride and bis(3-aminophenyl) sulfone (APS) and bis(3-amino-4-hydroxyphenyl) sulfone (APS-OH) as diamines were used to synthesize two types of poly(amic acid) (PAA). Varying amounts (0-5.0 wt%) of water-soluble poly(vinyl alcohol) (PVA) were mixed with PAA, and the resulting blend was heat-treated at different stages to obtain the colorless and transparent polyimide (CPI) blend films.

Distinct genetic profile with recurrent population-specific missense variants in Korean adult atypical hemolytic uremic syndrome.

Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare thrombotic microangiopathy (TMA), characterized by micro-angiopathic hemolytic anemia, thrombocytopenia, and renal failure. In more than half of cases, genetic defects leading to overactivation of the alternative complement system have been identified. In this study, we investigated genetic defects in Korean adult patients with aHUS.

P3HT-based visible-light organic photodetectors using PEI/PAA multilayers as a p-type buffer layer.

A low leakage current is critical for achieving organic photodetectors (OPDs) with high detectivity. The insertion of buffer layers is an effective approach for reducing the reverse-biased leakage current. In this study, polyelectrolyte multilayers comprising polyethyleneimine (PEI) and polyacrylic acid (PAA) were introduced by a spin-assisted layer-by-layer technique into an OPD as a p-type buffer layer.

Oxygen and Acrylic Acid Plasma Treatment on Titanium Mesh for Improving the Hydroxyapatite Formation.

Customized titanium (Ti) meshes were treated with O2 plasma and acrylic acid plasmapolymerization (PPAAc). The optimum conditions for PPAAc were as follows: 20 W, 15 mTorr, and 5 min. Hydroxyapatite formation increased in Ti meshes treated with O2 and PPAAc compared with that in untreated Ti meshes.

Impaired colony-forming capacity of circulating endothelial progenitor cells in patients with emphysema.

Chronic obstructive pulmonary disease (COPD) is classified into emphysema and chronic bronchitis, which are thought to result from different pathophysiological pathways. Smoking-induced lung parenchymal destruction and inadequate repair are involved in the pathogenesis of emphysema. In addition, decreased expression of vascular endothelial growth factor and increased endothelial cell apoptosis in the lung may participate in emphysema pathogenesis.

Frequency of Pro475Ser polymorphism of ADAMTS13 gene and its association with ADAMTS-13 activity in the Korean population.

Purpose: The in vitro study suggested that proline to serine polymorphism in codon 475 (C1423T) of the A Disintegrin and Metalloprotease with ThromboSpondin type 1 repeats-13 (ADAMTS-13) gene is related to reduced activity of ADAMTS-13. In this study, the frequency of the Pro475Ser polymorphism in Koreans was studied and plasma ADAMTS-13 activity was measured to find out whether this polymorphism contributes to decreased ADAMTS-13 activity in Koreans.

Patients And Methods: The frequency of the C1423T allele of the ADAMTS13 gene was studied along with measuring plasma ADAMTS-13 activity in 250 healthy Korean individuals.