Development and characterization of polymeric hollow fiber membrane with high CO2 separation performance

In this study, we prepared the polyimide based hollow fiber membrane with High CO2 permeance property. In other to prepare high permeable gas separation membrane, we synthesized novel polyimide material using 6FDA, Durene and PEG monomers. And then general property of the polyimide membrane is characterized using flat sheet type of membrane. The membranes were prepared under various controlled conditions such as retention time and concentration of the polymer. And then the hollow fiber membrane is also prepared and then characterized for confirmation of their potential. The Ionic liquid mainchain polymer is also developed to investigate the gas permeability and potential for utilization to coating materials of hollow fiber membrane. Polyimide with pendant ionic liquid (Im-PpC) membrane showed the high α(CO2/N2) value and the main chain polymer prepared by UV crosslinking with PEG & ILMP crosslinker also showed high α(CO2/N2). Please click Additional Files below to see the full abstract

Synthesis and characterization of PEEK containing imidazole moiety and effect of functional groups

Anion exchange membrane fuel cells (AEMFCs) are considered as one of the alternative power generation systems due to their high efficiency. Anion exchange membrane (AEM) is a key component in fuel cells for the transfer of anion which is effect to the performance of the fuel cell system. \Therefore, it needs to have high chemical, mechanical, and thermal stabilities, as well as excellent electrochemical properties. For these reasons, various types of novel polymeric materials have been developed for the anion exchange membrane fuel cells. Especially, hydrocarbon based polymer materials such as poly(arylene ether sulfone), poly(ether ether ketone)(PEEK), polybenzimidazole (PBI) have been fabricated for use as electrolytes in fuel cell systems. Also, a number of preparation methods have been developed to enhance the performance of fuel cell membranes. In this study, we modified the monomer by chemical modification reaction and we synthesized the PEEK based polymer with different amination degree. Also we compared the chemical stability of the PEEK based membrane with different functional groups such as ammonium and imidazolium. Finally, the effect of the contents of the anion exchange groups in the PEEK based polymer was evaluated in terms of morphology, water behavior, mechanical properties, chemical stability and ion conductivity. Please click Additional Files below to see the full abstract

Acute kidney injury in patients with acute-on-chronic liver failure: clinical significance and management

Acute-on-chronic-liver failure (ACLF) refers to a phenomenon in which patients with chronic liver disease develop multiple organ failure due to acute exacerbation of underlying liver disease. More than 10 definitions of ACLF are extant around the world, and there is lack of consensus on whether extrahepatic organ failure is a main component or a consequence of ACLF. Asian and European consortiums have their own definitions of ACLF. The Asian Pacific Association for the Study of the Liver ACLF Research Consortium does not consider kidney failure as a diagnostic criterion for ACLF. Meanwhile, the European Association for the Study of the Liver Chronic Liver Failure and the North American Consortium for the Study of End-stage Liver Disease do consider kidney failure as an important factor in diagnosing and assessing the severity of ACLF. When kidney failure occurs in ACLF patients, treatment varies depending on the presence and stage of acute kidney injury (AKI). In general, the diagnosis of AKI in cirrhotic patients is based on the International Club of Ascites criteria: an increase of 0.3 mg/dL or more within 48 hours or a serum creatinine increase of 50% or more within one week. This study underscores the importance of kidney failure or AKI in patients with ACLF by reviewing its pathophysiology, prevention methods, and treatment approaches

Lacrimal Silicone Intubation for Anatomically Successful but Functionally Failed External Dacryocystorhinostomy

PURPOSE: To investigate the efficacy of lacrimal silicone intubation for the management of epiphora in patients who have previously undergone anatomically successful dacryocystorhinostomy (DCR). METHODS: The authors recruited 13 patients (4 male, 9 female) who had persistent epiphora after an anatomically successful primary external DCR and conducted lacrimal silicone intubation through the dacryocystorhinostomy site. RESULTS: Mean patient age was 54.2 years (range 42-80) and mean follow-up was 13.8 months (range 6-30). Epiphora was resolved in all 13 patients following silicone intubation. Spontaneous tube extrusion occurred in three patients, but a new one was easily reintubated. CONCLUSIONS: Lacrimal silicone intubation is a simple safe and effective procedure for patients with epiphora even after anatomically successful DCR

Effects of a Tumor Necrosis Factor-α Antagonist on Experimentally Induced Rhinosinusitis

This prospective, randomized, and controlled study examined the effects of tumor necrosis factor soluble receptor type I (sTNFRI, a TNF-α antagonist) on experimentally induced rhinosinusitis in rats. The experimental groups received an instillation of lipopolysaccharide (LPS) plus an intramuscular injection of amoxicillin/clavulanate (antibiotic group), an instillation of sTNFRI (sTNFRI group), an instillation of sTNFRI and an injection of amoxicillin/clavulanate (sTNFRI/antibiotic group), or no additional treatment (LPS group). Histopathological changes were determined using hematoxylin-eosin and periodic acid-Schiff (PAS) staining. Leakage of exudate was determined using fluorescence microscopy. Vascular permeability was measured using the Evans blue dye technique. Expression of MUC5AC was measured using reverse transcriptase PCR. The sTNFRI, antibiotic, and sTNFRI/antibiotic groups had significantly less capillary permeability, mucosal edema, PAS staining, and expression of MUC5AC than the LPS group. There were no differences in capillary permeability, mucosal edema, PAS staining, and MUC5AC expression between the sTNFRI and sTNFRI/antibiotic groups. The antibiotic group had PAS staining similar to that of the sTNFRI and sTNFRI/antibiotic groups but had a greater increase in capillary permeability, mucosal edema, and MUC5AC expression. This study shows that sTNFRI reduces inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats

Single-walled carbon nanotubes as excitonic optical wires

Although metallic nanostructures are useful for nanoscale optics, all of their key optical properties are determined by their geometry. This makes it difficult to adjust these properties independently, and can restrict applications. Here we use the absolute intensity of Rayleigh scattering to show that single-walled carbon nanotubes can form ideal optical wires. The spatial distribution of the radiation scattered by the nanotubes is determined by their shape, but the intensity and spectrum of the scattered radiation are determined by exciton dynamics, quantum-dot-like optical resonances and other intrinsic properties. Moreover, the nanotubes display a uniform peak optical conductivity of ~8 e^2/h, which we derive using an exciton model, suggesting universal behaviour similar to that observed in nanotube conductance. We further demonstrate a radiative coupling between two distant nanotubes, with potential applications in metamaterials and optical antennas

On-Chip Rayleigh Imaging and Spectroscopy of Carbon Nanotubes

We report a novel on-chip Rayleigh imaging technique using wide-field laser illumination to measure optical scattering from individual single-walled carbon nanotubes (SWNTs) on a solid substrate with high spatial and spectral resolution. This method in conjunction with calibrated AFM measurements accurately measures the resonance energies and diameters for a large number of SWNTs in parallel. We apply this technique for fast mapping of key SWNT parameters, including the electronic-types and chiral indices for individual SWNTs, position and frequency of chirality-changing events, and intertube interactions in both bundled and distant SWNTs

Efficacy and Safety of Autologous Stromal Vascular Fraction in the Treatment of Empty Nose Syndrome

Objectives Regenerative treatment using stem cells may serve as treatment option for empty nose syndrome (ENS), which is caused by the lack of turbinate tissue and deranged nervous system in the nasal cavity. We aimed to assess the efficacy and safety of the autologous stromal vascular fraction (SVF) in the treatment of ENS. Methods In this prospective observational clinical study, we enrolled 10 ENS patients who volunteered to undergo treatment of ENS through the injection of autologous SVF. Data, including demographic data, pre- and postoperative Sino-Nasal Outcome Test-25 (SNOT-25) scores, overall patient satisfaction, and postoperative complications, were prospectively collected. Nasal secretion was assessed using the polyurethane foam absorption method, and the levels of biological markers were analyzed in both ENS group and control group using enzyme-linked immunosorbent assay. The SVF extracted from abdominal fat was diluted and injected into both inferior turbinates. Results Among the 10 initial patients, one was excluded from the study. Subjective satisfaction was rated as “much improved” in two and “no change” in seven. Among the improved patients, the mean preinjection SNOT-25 score was 55.0 and the score at 6 months after injection was 19.5. However, the average SNOT-25 score of nine participants at 6 months after injection (mean±standard deviation, 62.4±35.8) did not differ significantly from the baseline SNOT25 score (70.1±24.7, P>0.05, respectively). Among the various inflammatory markers assessed, the levels of interleukin (IL)-1β, IL-8, and calcitonin gene-related peptide were significantly higher in ENS patients. Compared with preinjection secretion level, the nasal secretions from SVF-treated patients showed decreased expressions of IL-1β and IL-8 after injection. Conclusion Although SVF treatment appears to decrease the inflammatory cytokine levels in the nasal mucosa, a single SVF injection was not effective in terms of symptom improvement and patient satisfaction. Further trials are needed to identify a more practical and useful regenerative treatment modality for patients with ENS