Preparation and Interfacial Properties of Hydroxyl-Containing Polyimide Fibers.

Developing polyimide (PI) fibers with excellent interfacial adhesion and high mechanical properties for the PI fiber-reinforced polymer matrix composites (PFRPs) industry has been challenging. In this work, 4,4'-diamino-(1,1'-biphenyl)-3,3'-diol (HAB) diamine was introduced into the rigid molecular chains, and the high-performance PI fibers, presenting an interfacial shear strength (IFSS) value of 46.33 MPa, tensile strength of 2.

Abnormalities of Peripheral Lymphocyte Subsets in Rheumatoid Arthritis Patients Complicated with Osteoporosis.

Introduction: Osteoporosis (OP) is one of the major comorbidities of rheumatoid arthritis (RA). Recent studies have shown that immune cells modulate bone health and regulate bone remodeling. However, the alterations of lymphocyte subsets in RA patients with OP are unclear.

Fabrication of polyimide/graphene nanosheet composite fibers microwave-assisted imidization strategy.

Here, a rapid and efficient strategy was introduced to prepare polyimide/graphene nanosheet (PI/GN) composite fibers by microwave-assisted imidization. The mechanical properties of the PI/GNs (1 wt%) fibers treated by microwave-assisted imidization were apparently improved with the tensile strength of 1.12 GPa at 350 °C, which was approximately 1.

Low-Dose Interleukin-2 Altered Gut Microbiota and Ameliorated Collagen-Induced Arthritis.

Purpose: Low-dose interleukin-2 (ld-IL-2) has been shown to regulate the balance between effector T and regulatory T (Treg) cells and has been used in several clinical trials to treat autoimmune diseases including rheumatoid arthritis (RA). In this study, we investigated the effects of ld-IL-2 on collagen-induced arthritis (CIA) in mice.

Methods: Arthritis severity in CIA mice was measured using the arthritis index (AI), radiographs, and hematoxylin and eosin staining.

Revealing the High-Modulus Mechanism of Polyimide Films Prepared with 3,4'-ODA.

To prepare PIs (polyimides) with desirable thermal and mechanical properties is highly demanded due to their widespread applications in flexible optoelectronic devices and printed circuit boards. Here, the PI films of BPDA/4,4'-ODA, BPDA/3,4'-ODA, PMDA/4,4'-ODA, PMDA/3,4'-ODA systems were prepared, and it was found that the PIs with 3,4'-ODA always exhibit a high modulus compared with the PIs with 4,4'-ODA. To disclose the mechanism of high-modulus PI films with 3,4'-ODA, amorphous PI models and uniaxial drawing PI models were established and calculated based on MD simulation.

Decreased numbers and sex-based differences of circulating regulatory T cells in patients with seropositive undifferentiated arthritis.

Aims: CD4 T cells play crucial roles as both mediators and regulators of the pathogenesis of rheumatoid arthritis (RA). However, the characteristics of CD4 T cell subpopulations in the earliest stage of RA development remain unclear. Hence, we determined the proportions and absolute counts of circulating CD4 T cell subsets in patients with seropositive undifferentiated arthritis (SUA), the early and preclinical stage of RA.

Characteristics and reference ranges of CD4T cell subpopulations among healthy adult Han Chinese in Shanxi Province, North China.

Background: Immunophenotyping of blood lymphocytes is an essential tool to evaluate the immune function of patients with immunodeficiency or autoimmunity. Predominately identified CD4T cell subsets, Th1, Th2, Th17, as well as regulatory T (Treg) cells, play crucial roles in several immunological and pathological conditions. Considering the variations in cell counts among populations and ethnicities, specific CD4T cell subset reference values need to be locally established to enable meaningful comparisons and accurate data interpretation in clinical and research settings.

T-Follicular Regulatory Cells: Potential Therapeutic Targets in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an incurable aggressive chronic inflammatory joint disease with a worldwide prevalence. High levels of autoantibodies and chronic inflammation may be involved in the pathology. Notably, T follicular regulatory (Tfr) cells are critical mediators of T follicular helper (Tfh) cell generation and antibody production in the germinal center (GC) reaction.

The design of a multifunctional separator regulating the lithium ion flux for advanced lithium-ion batteries.

Herein, we design a controllable approach for preparing multifunctional polybenzimidazole porous membranes with superior fire-resistance, excellent thermo-stability, and high wettability. Specifically, the recyclable imidazole is firstly utilized as the eco-friendly template for micropores formation, which is an interesting finding and has tremendous potential for low-cost industrial production. The unique backbone structure of the as-prepared polybenzimidazole porous membrane endows the separator with superb thermal dimensional stability at 300 °C.

Low-Dose Sirolimus Immunoregulation Therapy in Patients with Active Rheumatoid Arthritis: A 24-Week Follow-Up of the Randomized, Open-Label, Parallel-Controlled Trial.

Background: We have reported previously the insufficient absolute number or functional defects of regulatory T cells (Tregs) in patients with rheumatoid arthritis (RA), challenging conventional unspecific immunosuppressive therapy. Sirolimus, a mTOR inhibitor, is reported to allow growth of functional Tregs; here, we investigated the efficacy of low-dose sirolimus combined with conventional immunosuppressants (sirolimus immunoregulation therapy) for RA treatment with lower side effects and better tolerance.

Methods: In this nonblinded and parallel-group trial, we randomly assigned 62 patients to receive conventional glucocorticoids and immunosuppressants with or without sirolimus at a dosage of 0.

The introduction of benzimidazole and ether moieties into poly(-phenylene terephthalamide): effects on its microstructure, interactions and properties.

Co-poly(-phenylene terephthalamide) (co-PPTA) fibers containing 4,4'-oxidianiline (4,4'-ODA) and 2-(4-aminophenyl)-5-aminobenzimidazole (BIA) in terephthaloyl chloride (TPC) and -phenylene diamine (-PDA) were prepared a wet spinning method, followed by water washing and drawing at a high temperature. With the addition of a new acid-binding agent, imidazole, the solution prepared by low-temperature polycondensation had suitable viscosity for spinning. Herein, the properties of six co-PPTA fibers with different contents of BIA and 4,4'-ODA segments were studied.

IL-17A upregulates P-glycoprotein expression in peripheral blood lymphocytes of patients with rheumatoid arthritis through TAK1.

Objectives: P-glycoprotein (P-gp) mediated drug efflux is the most essential mechanism of multi-drug resistance (MDR) in rheumatoid arthritis (RA). The study was undertaken to clarify the mechanism whereby IL-17 regulate the P-gp efflux function in peripheral blood lymphocytes of patients with RA.

Methods: Lymphocytes from RA patients and healthy individuals were cultured with IL-17A (0, 10, 100 ng/ml), IL-17A+(5Z)-7-Oxozeaenol (TAK1 inhibitor), and IL-17A+PD98059 (ERK inhibitor), respectively.

Sirolimus selectively increases circulating Treg cell numbers and restores the Th17/Treg balance in rheumatoid arthritis patients with low disease activity or in DAS28 remission who previously received conventional disease-modifying anti-rheumatic drugs.

Objectives: Regulatory T (Treg) cells are crucial players in the prevention of autoimmunity. Mechanistic target of rapamycin (mTOR) signalling negatively controls the development and function of Treg cells. The aim of the present study was to evaluate the effects of rapamycin, under the generic name sirolimus, on CD4+CD25+FoxP3+ Treg cells in rheumatoid arthritis (RA) patients with low disease activity or in DAS28 remission.

Preparation of polyimide films microwave-assisted thermal imidization.

A series of polyimide (PI) films based on aromatic heterocyclic monomers of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), -phenylenediamine (p-PDA) and 4,4'-oxydianiline (ODA) were prepared a microwave-assisted thermal imidization and conventional thermal imidization method at different temperatures. The effects of microwave irradiation on the imidization degree, microstructures, mechanical and thermal properties of PI films were investigated. The imidization degree of the PI films treated with microwave-assisted heating reached a relatively high value at 250 °C, which was twice as much as those treated with traditional thermal imidization.

Burden and depression in caregivers of patients with rheumatoid arthritis in China.

Aim: Caregivers of patients with rheumatoid arthritis (RA) often experience a sense of burden and depression. This study aimed to determine the degree of burden and depression on caregivers of RA patients and identify characteristics of both patients and caregivers that may contribute to that distress.

Methods: A convenience sample of 195 patients with RA and their caregivers completed a demographic questionnaire, Zarit Care Burden Scale, Center Depression Self Rating Scale, Health Assessment Questionnaire Disability Index, and the Short Form Health Survey.

Polyimide Fibers with High Strength and High Modulus: Preparation, Structures, Properties, and Applications.

High strength and high modulus polyimide (HSHMPI) fibers are a type of novel high-performance organic fiber with an initial modulus higher than 90 GPa and extremely high tensile strength over 2.5 GPa realizing broad applications in the fields of electronic, engineering, aerospace, and atomic energy industries. There are currently two synthetic pathways, i.

Combination of 4-hydroperoxy cyclophosphamide and methotrexate inhibits IL-6/sIL-6R-induced RANKL expression in fibroblast-like synoviocytes via suppression of the JAK2/STAT3 and p38MAPK signaling pathway.

Although conventional combination therapy is effective for most patients with rheumatoid arthritis (RA), many still do not respond to current therapies. Therefore, novel combination regimens that better target cellular processes involved in RA pathogenesis are required. Preliminary studies have demonstrated the beneficial effects of a combination of cyclophosphamide (CTX) and methotrexate (MTX) in models of RA.

High-Performance Liquid Chromatography (HPLC) Quantification of Liposome-Delivered Doxorubicin in Arthritic Joints of Collagen-Induced Arthritis Rats.

BACKGROUND Neoangiogenesis occurring in inflamed articular synovium in early rheumatoid arthritis (RA) is characterized by enhanced vascular permeability that allows nanoparticle agents, including liposomes, to deliver encapsulated drugs to arthritic joints and subsequently improve therapeutic efficacy and reduce adverse effects. However, the targeting distribution of liposomes in arthritic joints during RA has not been quantitatively demonstrated. We performed this study to evaluate the targeting distribution of PEGylated doxorubicin liposomes in the arthritic joints of collagen-induced arthritis (CIA) rats by high-performance liquid chromatography (HPLC).

Consecutive large-scale fabrication of surface-silvered polyimide fibers via an integrated direct ion-exchange self-metallization strategy.

Herein, we report our success on the large-scale online preparation of surface-silver-metallized polyimide (PI) fibers by utilizing silver ammonia complex cation ([Ag(NH3)2](+)) as the silver (Ag) precursor and pyromellitic dianhydride/4,4'-oxidianiline (PMDA/4,4'-ODA)-based polyimide as the matrix via a direct ion-exchange self-metallization process integrated within a consecutive fiber-spinning procedure. The method works by using the online freshly prepared PMDA/4,4'-ODA-based poly(amic acid) (PAA) fibers as the starting material to perform an ion-exchange reaction in aqueous silver(I) solution to load silver(I) into the PAA precursor fibers, followed by a programmed stepwise thermal treatment process to convert PAA to its final imide form with the concomitant silver(I) reduction and the subsequent aggregation, producing the surface-silvered polyimide hybrid fibers. The influence of thermal cycles on the formation of silver nanostructures, and the variation of surface morphologies and fiber properties during the heating process were investigated.

Incorporation of silver nanoparticles into the bulk of the electrospun ultrafine polyimide nanofibers via a direct ion exchange self-metallization process.

This paper reports our works on the preparation of the silver-nanoparticle-incorporated ultrafine polyimide (PI) ultrafine fibers via a direct ion exchange self-metallization technique using silver ammonia complex cation ([Ag(NH(3))(2)](+)) as the silver precursor and pyromellitic dianhydride (PMDA)/4,4'-oxidianiline (4,4'-ODA) polyimide as the matrix. The polyimide precursor, poly(amic acid) (PAA), was synthesized and then electrospun into ultrafine fibers. By thermally treating the silver(I)-doped PAA ultrafine fibers, where the silver(I) ions were loaded through the ion exchange reactions of the carboxylic acid groups of the PAA macromolecules with the [Ag(NH(3))(2)](+) cations in an aqueous solution, ultrafine polyimide fibers embedded with silver nanoparticles with diameters less than 20 nm were successfully fabricated.