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

Effects of silver impurity on the structural, electrical, and optical properties of ZnO nanowires

1, 3, and 5 wt.% silver-doped ZnO (SZO) nanowires (NWs) are grown by hot-walled pulsed laser deposition. After silver-doping process, SZO NWs show some change behaviors, including structural, electrical, and optical properties. In case of structural property, the primary growth plane of SZO NWs is switched from (002) to (103) plane, and the electrical properties of SZO NWs are variously measured to be about 4.26 × 106, 1.34 × 106, and 3.04 × 105 Ω for 1, 3, and 5 SZO NWs, respectively. In other words, the electrical properties of SZO NWs depend on different Ag ratios resulting in controlling the carrier concentration. Finally, the optical properties of SZO NWs are investigated to confirm p-type semiconductor by observing the exciton bound to a neutral acceptor (A0X). Also, Ag presence in ZnO NWs is directly detected by both X-ray photoelectron spectroscopy and energy dispersive spectroscopy. These results imply that Ag doping facilitates the possibility of changing the properties in ZnO NWs by the atomic substitution of Ag with Zn in the lattice

Giant Vascular Eccrine Spiradenoma

Giant vascular eccrine spiradenomas (GVESs) are a rare variant of the eccrine spiradenoma that develops from the sweat gland. It is different from the eccrine spiradenoma in its larger size and greater degree of vascularity. Bleeding and/or ulceration are common clinical features of this tumor, and are the reason why it is often clinically confused with a vascular or malignant tumor. Here, a rare case of GVES without bleeding or ulceration is reported

Effect of Loquat Leaf Extract on Muscle Strength, Muscle Mass, and Muscle Function in Healthy Adults: A Randomized, Double-Blinded, and Placebo-Controlled Trial

Ursolic acid (UA) is the major active component of the loquat leaf extract (LLE) and several previous studies have indicated that UA may have the ability to prevent skeletal muscle atrophy. Therefore, we conducted a randomized, double-blind, and placebo-controlled study to investigate the effects of the LLE on muscle strength, muscle mass, muscle function, and metabolic markers in healthy adults; the safety of the compound was also evaluated. We examined the peak torque/body weight at 60°/s knee extension, handgrip strength, skeletal muscle mass, physical performance, and metabolic parameters at baseline, as well as after 4 and 12 weeks of intervention. Either 500 mg of LLE (50.94 mg of UA) or a placebo was administered to fifty-four healthy adults each day for 12 weeks; no differences in muscle strength, muscle mass, and physical performance were observed between the two groups. However, the right-handgrip strength of female subjects in the LLE group was found to be significantly better than that of subjects in the control group (P=0.047). Further studies are required to determine the optimal dose and duration of LLE supplementation to confirm the first-stage study results for clinical application. ClinicalTrials.gov Identifier is NCT02401113

Comparison of remimazolam–remifentanil and propofol–remifentanil during laparoscopic cholecystectomy

Background Remimazolam is a novel benzodiazepine with fast onset and short half-life. We compared the effects of remimazolam and propofol on recovery profiles for general anesthesia in patients undergoing laparoscopic cholecystectomy. Methods We randomly assigned 108 patients to either a remimazolam (n=54) or propofol (n=54) group. Remimazolam and propofol were used for induction and maintanance of anesthesia. Following anesthesia, we recorded the time until an Aldrete score of 9 was achieved as the primary surrogate marker of complete recovery. The time to reach a Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) score of 2 and the time from the end of anesthesia to eye opening time, recovery time of orientation, time to spontaneous breathing, extubation time, and the time required for analgesics were measured. Heart rate, blood pressure, and bispectral index were assessed before, during, and after pneumoperitoneum. Results We included 101 patients in the analysis. In the remimazolam group, it took longer to reach an Aldrete score of 9 after the drug infusion ended (P = 0.031). There was no difference in the time to reach MOAA/S 2 between the two groups. The time to eye opening, recovery time of orientation, and time required for analgesics were longer and heart rate was higher in the remimazolam group. Neither blood pressure, nor extubation time differed between groups. Conclusions Remimazolam and propofol provided safe induction and maintenance of anesthesia in patients undergoing laparoscopic cholecystectomy. The recovery time from anesthesia was longer than that with propofol. Fewer hemodynamic changes were observed with remimazolam, but further studies are needed

Environmental and dietary exposure of perfluorooctanoic acid and perfluorooctanesulfonic acid in the Nakdong River, Korea

This study performed the first environmental and dietary exposure assessment to explore plant uptake of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from agricultural soil and irrigation water in the Nakdong River delta, South Korea. Annual average concentrations of total PFOA and PFOS ranged from 0.026 to 0.112 µg L−1 (irrigation water), and from 0.818 to 1.364 µg kg−1 (soil), respectively. PFOA and PFOS hotspots were identified downstream of the Nakdong River and were influenced by seasonal climatic variations. The observed average biennial concentration of the sum of PFOA and PFOS decreased in irrigation water, from 0.112 µg L−1 in 2013 to 0.026 µg L−1 in 2015, suggests that the 2013 Persistent Organic Pollutants Control Act may have helped to reduce levels of PFAS at this location. This study calculated some of the highest plant uptake factors reported to date, with values ranging from 0.962 in green onions to < 0.004 in plums. Leafy vegetables and rice are important components of the Korean diet; these groups had the largest contribution to the estimated dietary intake of PFOA and PFOS, which was calculated at 0.449 and 0.140 ng kg −1bw day−1, respectively. This corresponded to 66.4% for PFOA and 7.9% for PFOS of the EFSA reference dose (RfD). The dietary intake of PFOA and PFOS from crops alone did not exceed the RfD. However, when the estimated daily intake (EDI) from other sources such as tap water, meat, fish, dairy, and beverages was included in the exposure risk assessment, both of the EDIs to PFOA and PFOS exceeded the RfDs, indicating that there may be a risk to human health. This study concludes that consumption of crops might, therefore, be a significant and underappreciated pathway for human exposure to PFAS