Vapour-liquid equilibrium relationship between toluene and mixed surfactants.

Micellar partitioning of volatile organic compounds (VOCs) in surfactant solutions and its effects on vapour-liquid equilibrium is fundamental to the overall design and implementation ofsurfactant-enhanced remediation. Knowledge of the vapour-liquid equilibrium partitioning coefficients for VOCs, especially in contaminated soils and groundwater in which they exist, is required. Headspace experiments were performed to quantify the effect of three mixed surfactants, cetyltrimethyl ammonium bromide (CTMAB) with tetrabutylammonium bromide (TBAB), sodium dodecyl sulphate (SDS) with Triton X-405 (TX405), and CTMAB with Triton X-100 (TX100), on the apparent Henry's constants (Hc) of toluene at temperatures ranging from 25 degrees C to 40 degrees C. The Hc values were significantly reduced in the presence of all three mixed surfactants at concentrations above their critical micelle concentrations (CMC). Mixed micellar partitioning, showing effects on the vapour-liquid equilibrium of toluene, was primarily responsible for the significant reduction of Hc in their mixed systems. The mixed surfactants CTMAB-TX100 had the greatest effect on Hc above the CMC, followed by SDS-TX405, then CTMAB-TBAB. Mixed systems of CTMAB-TX100 decreased Hc at concentrations significantly lower than the SDS-TX405 and CTMAB-TBAB concentrations, because of to the lower CMC of CTMAB-TX100. Vapour-liquid equilibrium data were also tested against the model (Hc = H/(1 + K(X - CMC)) that described the partitioning of VOCs in vapour-water-micelle phases. The correlation of Hc with mixed surfactant concentrations (X) and CMC can be utilized as an effective tool to predict the Hc by mixed surfactants.

Decellularized scaffold-based poly(ethylene glycol) biomimetic vascular patches modified with polyelectrolyte multilayer of heparin and chitosan: preparation and vascular tissue engineering applications in a porcine model.

Mechanical property mismatch between vascular patches and native blood vessels can result in post-operation failure; therefore, vascular patches that mimic the biomechanical properties of native blood vessels must be developed. In this study, we constructed a biomimetic vascular patch by coating a poly(ethylene glycol) (PEG) film onto a decellularized scaffold (DCS) and modifying its surface with a heparin-chitosan polyelectrolyte multilayer (PEM). The PEM-modified PEG/DCS vascular patches exhibited comparable mechanical characteristics with native blood vessels. They effectively resisted platelet adhesion, reduced the hemolysis rate, increased the clotting time in vitro, and favoured the adhesion and growth of endothelial progenitor cells. In addition, the modified patches maintained long-term patency (5 months) of the treated arteries in vivo. Because of the synergistic effect of heparin and chitosan in PEM, the vascular patches may be able to manage medical complications. Thus, the PEM-modified PEG/DCS vascular patches may have promising applications in the repair of damaged or diseased blood vessels.

[Gene transfer system mediated by PEI-cholesterol lipopolymer with lipid microbubbles].

The properties of polyethyleneimine-cholesterol cationic lipopolymer (PEI-Chol) as gene carries and its gene transfer efficiency in vitro with lipid microbubbles were presented in this paper. PEI-Chol lipopolymer was synthesized by linking cholesterol chloroformate to the amino groups of branched poly(ethyleneimine) (PEI) of 1 800. The structure and molecular weight of PEI-Chol were confirmed by IR, 1H NMR and MADI-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry), respectively. The average molecular weight of PEI-Chol was approximately 2 000. The gene delivery system of bubble/PEI-Chol/DNA was constructed by mixed PEI-Chol/pDNA (N/P 10:1) complexes with lipid microbubbles (2-8 microm) which were prepared by DPPC, DSPE-PEG2000 and perfluoropropane with the reverse phase evaporation technique. pEGFP-Cl (enhanced green fluorescent protein) was used as report gene to investigate the DNA condensing ability of PEI-Chol lipopolymer by agarose gel electrophoresis. And their cytotoxicity and in vitro transfer efficiency of different complexes were compared with each other in A549 and MCF-7. The results indicated PEI-Chol lipopolymer can condense plasmid DNA when N/P ratio upto 4, PEI-Chol complexes and bubble/PEI-Chol/DNA complexes were nontoxic to A549 and MCF-7 when formulated at the N/P ratio of 10/1 as determined by MTT assay. This bubble/PEI-Chol/DNA delivery system provided good transfer efficiency with other desirable characteristics such as against-precipitation of plasma proteins. In conclusion, bubble/PEI-Chol/DNA complex is a novel non-viral gene delivery system.

Polyurethane/polyurethane nanoparticle-modified expanded poly(tetrafluoroethylene) vascular patches promote endothelialization.

Expanded poly(tetrafluoroethylene) (ePTFE) has been widely used as a vascular graft material due to the fact that it is durable, porous, flexible, and inert. However, ePTFE grafts easily induce thrombosis, calcification and neointimal hyperplasia in small-diameter (<6 mm) graft bypass surgeries and thus cause surgical failure. Therefore, it is necessary to improve the in vitro and in vivo performances of ePTFE grafts. In this work, we first prepared a polyurethane/polyurethane nanoparticles (PU/PU-NPs) composite film by a simple cosedimentation method. Compared with the pure PU film, the blood compatibility and the cell compatibility of the PU/PU-NPs composite film were significantly improved. Then, we constructed a PU/PU-NPs/ePTFE vascular patch (PPVP) by coating PU and PU-NPs onto the surface of an ePTFE graft. PU-NP modification endowed the ePTFE graft with the nanopatterned surface similar to the luminal surface of a blood vessel. PU NPs and the structural likeness of the surface synergistically optimized the overall performance, and thus improved the blood and cell compatibilities, effectively inhibited platelet adhesion, enhanced cell attachment and proliferation, and facilitated the formation of endothelial tissue-endothelialization. The abdominal artery patched with PPVP was not blocked and the endothelialization was achieved 30 days after the implantation. All the results taken together indicate that PPVP may be a promising alternative for a vascular patch. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2131-2140, 2018.

A PC-PU nanoparticle/PU/decellularized scaffold composite vascular patch: Synergistically optimized overall performance promotes endothelialization.

Composite vascular patches have gained increasingly attention due to the limited availability of autologous patches (vascular graft materials made from the blood vessels of the same recipient), the lack of growth capability of nonautologous patches (vascular graft materials made from the blood vessels of a different donor) and the disadvantages of synthetic patches. In this study, we report a highly biocompatible phosphatidylcholine-polyurethane nanoparticle/polyurethane/decellularized scaffold composite vascular patch (PCVP). It was fabricated by a facile method - cosedimentation. Its in vitro blood and cell compatibility including hemolysis, plasma recalcification time, coagulation time, platelet adhesion and cytotoxicity was evaluated. The surface modified with phosphatidylcholine-polyurethane (PC-PU) nanoparticles exhibited the improved anticoagulation activity. The in vivo performance of the PCVP was investigated in a mouse model. The nanopatterned surface that resembled the concave-convex structure of the luminal surface of native blood vessels enhanced cell attachment, proliferation, migration and differentiation. The decellularized scaffold had the mechanical property similar to that of the targeted blood vessels, which could withstand in vivo dynamic blood pressure. The overall performance of the PCVP was synergistically optimized by each layer of the multilayer design. The patched artery remained patent and the formation of endothelial tissue - endothelialization was achieved 30days after the in vivo implantation in a mouse model.

Efficacy of splint therapy for the management of temporomandibular disorders: a meta-analysis.

Temporomandibular disorders (TMD) are a group of clinical problems affecting temporomandibular joint (TMJ), myofascial muscles and other related structures. Splint therapy is the most commonly used approach to treatment of TMD, but its effectiveness is remains unclear. We therefore conducted a meta-analysis to evaluate the effectiveness of splint therapy for TMD in adults. The electronic databases PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched for reports published up to March 31, 2016. Thirteen eligible studies involving 538 patients were identified. The results indicated that splint therapy increased maximal mouth opening (MMO) for patients with a MMO <45mm and reduced pain intensity measured using the visual analogue scale (VAS) for patients with TMD without specific description (TMDSD). Splint therapy also reduced the frequency of painful episodes for patients with TMJ clicking. No publication bias was observed, as determined with Egger's test for all outcomes. On the basis of this evidence, we recommend the use of splints for the treatment and control of TMD in adults.

A retrospective study of temporomandibular joint ankylosis secondary to surgical treatment of mandibular condylar fractures.

We investigated the incidence of ankylosis of the temporomandibular joint (TMJ) after open operations for fractures of the mandibular condyle, and analysed possible risk factors in a total of 385 patients with 492 condylar fractures who had been operated on in our department from 2001 to 2010. Sixteen patients developed postoperative ankylosis of the TMJ with 26 joints (5%) affected during a follow-up of 6 months-10 years. Of the 492 condylar fractures, the most common ones that were associated with postoperative ankylosis were those of the condylar head (20/248), followed by the condylar neck (6/193). Subcondylar fractures did not cause postoperative ankylosis (0/51). Among the 16 patients with postoperative ankylosis, 13 had associated anterior mandibular fractures. Long-screw (bicortical screw) fixation of fractures of the condylar head seemed to be associated with a lower incidence of postoperative ankylosis than fixation by miniplate and wire or removal of the fractured fragment. The articular discs were damaged in all ankylosed joints, and the remaining fractured fragment was found in 10 ankylosed joints after fractures of the condylar head. The results suggest that fractures of the condylar head are more prone to lead to postoperative ankylosis of the TMJ, and that the possible risk factors seem to include the technique used for fixation and damage to the disc, together with an anterior mandibular fracture with the fractured fragment remaining.

Ameloblastic fibrosarcoma of the mandible: A case report and mini review.

Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic neoplasm of the jaw. AFS is characteristically composed of a benign odontogenic epithelium and a malignant mesenchymal component. The posterior region of the mandible is the predominantly occupied site. In the present report, a new case of AFS in a 22-year-old male that originated from ameloblastic fibroma was described. Histologically, the tumor showed biphasic components: Benign epithelium and a malignant mesenchymal component. Immunochemical findings revealed that the tumor cells were positive for cluster of differentiation (CD) 34, vimentin, Ki-67 and p53, but negative for smooth muscle actin, S-100, CD68 and desmin. The clinical presentation, radiographic appearances and treatment measures were additionally described and reviewed.

Electrospun drug-loaded core-sheath PVP/zein nanofibers for biphasic drug release.

Core-sheath nanofibers prepared using coaxial electrospinning were investigated for providing biphasic drug release profiles. With ketoprofen (KET) as the model drug, polyvinylpyrrolidone and zein as the sheath polymer and core matrix, respectively, the coaxial process could be carried out smoothly and continuously without any clogging of the spinneret. Scanning electron microscopy and transmission electron microscopy observations demonstrated that the nanofibers were linear with homogeneous structure and had a clear core-sheath structure with an average diameter of 730 ± 190 nm, in which the sheath had a thickness of ca. 90 nm. Differential scanning calorimetric and X-ray diffraction analyses verified that all the components in the core-sheath nanofibers were present in an amorphous state. Attenuated total reflectance Fourier transform infrared spectra demonstrated both the sheath and core matrix had good compatibility with KET owing to hydrogen bonding. In vitro dissolution tests showed that the nanofibers could provide an immediate release of 42.3% of the contained KET, followed by a sustained release over 10h of the remaining drug. The present study exhibited a simple and useful approach to systematically design and fabricate nanostructures using coaxial electrospinning for providing biphasic drug release profiles.

[Electrosonographic analysis of sounds emanating from temporomandibular joint without symptom].

OBJECTIVE: To study the characteristic of joint sounds from temporomandibular joint (TMJ) without symptom during mandible movement. METHODS: Joint sounds of 42 asymptomatic TMJ were recorded and analyzed with K6-I system during mandible movement, the waveform, frequency range, peak frequency and amplitude of joint sounds electrosonogram were studied. RESULTS: Joint sounds were recorded in 25 joints of the 42 joints, 4 kinds of joint sounds were found according to the waveform, frequency range, peak frequency and amplitude of the electrosonography. CONCLUSIONS: Joint sounds can be recorded in asymptomatic TMJ during mandible movement, 4 kinds of joints sounds were found according to the electrosonographic characteristics.

[Evaluation of temporomandibular joint function after condylectomy for condylar hyperplasia].

OBJECTIVE: To investigate the temporomandibular joint (TMJ) function of the condylar hyperplasia patients after condylectomy. METHODS: Twelve patients with condylar hyperplasia were included in this study. Before and after condylectomy, they were examined and the Fricton' s Craniomandibular Index (CMI) was calculated to assess the functional disorder of TMJ. RESULTS: (1) The facial asymmetry was improved after condylectomy. The morphological symmetry of the bilateral condyle and ramus was displayed by X-ray examinations. There was new cortex formed on the surface of the operated condyle. (2) The TMJ function was improved in terms of Fricton's DI and CMI, which decreased from 0.131 and 0.066 to 0.042 and 0.021 respectively (P < 0.05). CONCLUSIONS: Condylectomy is an effective method to remedy facial asymmetry and, at the same time, improve the TMJ function of the condylar hyperplasia patients.