Pyrolysis of Polyacrylonitrile/Technical Hydrolytic Lignin Composites

One important problem is utilization of technical hydrolytic lignin (the waste formed in paper-and-pulp and hydrolysis industry). For a practical implementation, the essential task of transforming insoluble hydrolytic lignin into low molecular weight products with high degree of functionalization should be performed. In prospect, these products can serve as raw materials for synthesis of various organic compounds demanded in chemical industry. Among other things, activation and fragmentation of hydrolytic lignin yields low molecular weight compounds which may be used for modifying synthetic polymers (polymer-analogous transformations). In the present work, the search for the optimal solvents (activators) for technical hydrolytic lignin (THL) has been conducted; the dimethyl sulfoxide/water binary mixture proved to be the best solvent. Methods of thermal analysis (thermogravimetric analysis, TGA; differential thermal analysis, DTA; differential scanning calorimetry, DSC; thermal volumetric analysis, TVA) combined with pyrolysis-gas chromatography/mass spectrometry (GC-MS) were used to determine the grades of technical hydrolytic lignin most suitable for activation and fragmentation. The necessary conditions for thermal treatment of lignin samples and concentrations of initial compounds (lignin and polyacrylonitrile, PAN) in the binary solvent mixture (dimethyl sulfoxide/water) facilitating maximum THL fragmentation and its successful interaction with PAN were found. When using the dimethylsulfoxide-water binary mixture (70:30 mass ratio) as a solvent, homogeneous forming solution of initial components (THL-PAN) was prepared. With the use of syringe method, form-stable fibers with a maximum lignin content of 80% and strength of about 50 MPa were obtained. Analytical pyrolysis of composites (products of THL-PAN interaction in the binary solvent) allowed us to suggest a mechanism for THL fragmentation involving the binary solvent

PSYCHOLOGICAL CHARACTERISTICS OF PERSONALITY ORIENTATION IN PUPILS, STUDYING AT HOME

In the article the problems of psychological peculiarities of the personality orientation of the pupils, who study at home. The methods and results for investigating the relationship between the orientation of the personality, motivation and self-regulation are presented. The opportunities of using the obtained results in practice are outlined

Adipose- and Bone Marrow-Derived Mesenchymal Stem Cells Prolong Graft Survival in Vascularized Composite Allotransplantation

BACKGROUND Strategies aiming at minimization or elimination of systemic immunosuppression are key immediate goals for clinical expansion of vascularized composite allotransplantation (VCA). We compared the in vitro and in vivo immunomodulatory efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and bone marrow (BM)-derived MSCs in a rat VCA model. METHODS Both cell types were tested in vitro for suppressor function using mixed lymphocyte reactivity assays. AD-MSCs or BM-MSCs were administered intravenously (1 × 10 or 5 × 10 cells/animal) to Lewis rat recipients of mismatched Brown Norway hindlimb transplants. Short course tacrolimus (FK-506) monotherapy was withdrawn at postoperative day 21. In vivo regulatory T-cell induction, peripheral blood chimerism, and microchimerism in lymphatic organs were analyzed. RESULTS AD-MSCs and BM-MSCs exhibited strong dose-dependent suppressor function in vitro, which was significantly more pronounced for AD cells. In vivo, all animals revealed peripheral multi-lineage chimerism at four weeks (P 120 day) allograft survival in 47% of the animals, which correlated with durable microchimerism in BM and spleen. CONCLUSIONS AD-MSCs and BM-MSCs exert immunomodulatory effects that prolong survival of immunogenic skin-bearing VCA grafts with short course (21 day) tacrolimus induction therapy. The in vivo findings in terms of allograft survival did not reflect superior immunomodulatory characteristics of AD-MSCs found in vitro

IGF-1 and chondroitinase ABC augment nerve regeneration after vascularized composite limb allotransplantation

Impaired nerve regeneration and inadequate recovery of motor and sensory function following peripheral nerve repair remain the most significant hurdles to optimal functional and quality of life outcomes in vascularized tissue allotransplantation (VCA). Neurotherapeutics such as Insulin-like Growth Factor-1 (IGF-1) and chondroitinase ABC (CH) have shown promise in augmenting or accelerating nerve regeneration in experimental models and may have potential in VCA. The aim of this study was to evaluate the efficacy of low dose IGF-1, CH or their combination (IGF-1+CH) on nerve regeneration following VCA. We used an allogeneic rat hind limb VCA model maintained on low-dose FK506 (tacrolimus) therapy to prevent rejection. Experimental animals received neurotherapeutics administered intra-operatively as multiple intraneural injections. The IGF-1 and IGF-1+CH groups received daily IGF-1 (intramuscular and intraneural injections). Histomorphometry and immunohistochemistry were used to evaluate outcomes at five weeks. Overall, compared to controls, all experimental groups showed improvements in nerve and muscle (gastrocnemius) histomorphometry. The IGF-1 group demonstrated superior distal regeneration as confirmed by Schwann cell (SC) immunohistochemistry as well as some degree of extrafascicular regeneration. IGF-1 and CH effectively promote nerve regeneration after VCA as confirmed by histomorphometric and immunohistochemical outcomes

Experimental Groups, Dosing, Administration, Frequency of Treatment.

<p>Experimental Groups, Dosing, Administration, Frequency of Treatment.</p

Immunohistochemical staining of the distal nerve.

<p>Regeneration marker—GAP43 (green), immature non-myelinating Schwann cells (SCs)—GFAP (red), pre-myelinating SCs—Oct6 (red), committed non-myelinating and myelinating SCs—S100 (red), myelinating SCs—Krox20 (green) are shown. Comparison of expression to that in naïve nerves is indicated in the white boxes. The name of antigen is shown in each column, identification for naive sample and groups is shown in rows: (A row) naive; (B) control; (C) IGF-1; (D) CH; (E) IGF-1+Ch. Magnification 60x, scale 10 μm.</p

Neurofilament M (NF-M) (axonal marker, green) and myelin (SC marker, red) expression.

<p>The images were cropped from images in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156149#pone.0156149.g004" target="_blank">Fig 4</a>. Scale 100 μm. Images: (A) negative control; (B) naive nerve; (C) control nerve; (D) CH; (E) IGF-1; (F) IGF-1+CH.</p

Quantitative representation of differentiation and proliferation markers.

<p>Histograms show product of staining of differentiation markers/commited Schwann cells: (A) Krox20, (B) S100; proliferation markers/immature Schwann cells: (C) GFAP, (D) Oct-6; nerve regeneration: (E) GAP43; axonal growth/myelination: (F) NF-M, (G) myelin.</p