Fabrication and characterization of high-performance forward-osmosis membrane by introducing manganese oxide incited graphene quantum dots.

Forward osmosis (FO) is the futuristic membrane desalination technology as it transcends the disadvantages of other pressure-driven techniques. But, there still remain critical challenges like fabrication of highly permeable membrane with ideal structures maintaining high rejection rates that need to be addressed for implementation as a practical technology. In this work, novel thin-film composite (TFC) membranes were fabricated by means of incorporating manganese oxide (MnO2) incited graphene quantum dots (GQDs) nanocomposite into a cellulose acetate (CA) suspension followed by phase inversion (PI) for enhanced FO performance. The surface morphology and chemical structure of fabricated membranes were studied using various characterization techniques like XRD, FT-IR, SEM-EDS, Mapping, AFM, and TGA. The structural parameters, water flux, reverse salt flux and salt rejection was estimated on the basis of data obtained from four varying initial draw solution concentrations. At high nanocomposites stacking, the hydrophilicity of the casting blend increase, and subsequently, the PI exchange rate additionally increases, which brings about noticeable difference in the surface morphology. The membrane with 0.5 wt% nanocomposite exhibited superior FO separation performance with osmotic water flux of 18.89, 34.49, 41.76 and 42.34 in L.m-2.h-1 with variable concentrations of NaCl salt solution (0.25M, 0.5M, 1M, and 2M), respectively. Also, the porosity of the membrane was increased to 47.23% with 96.87% salt rejection. The results indicate that the hydrophilicity of the nanocomposite drives them to the interface among CA and water during PI process leading to solid hydrogen bonding to achieve high water permeability.

Treatment of textile industry wastewater by using high-performance forward osmosis membrane tailored with alpha-manganese dioxide nanoparticles for fertigation.

Forward osmosis (FO) technology has been acknowledged as an energy-efficient cutting-edge water treatment innovation; however, the inefficient performance of polymer-based membranes remains a tailback in the practical utilization of FO. A significant issue in FO is membrane fouling, which negatively influences the flux efficiency, working expenses and membrane life expectancy. Membranes having high water flux and minimum reverse solute flux at low operating pressures are the ideal membranes for this process. This study reports a thin-film nanocomposite (TFNC) membrane for the treatment of textile industry wastewater utilizing fertilizer as draw solution fabricated via the phase inversion process. The chemical structure and morphology of the synthesized manganese oxide (MnO2) incorporated membrane were studied by various characterization techniques like X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy, contact angle and gravimetry. The outcomes demonstrated that the nanoparticles were bonded to cellulose acetate polymer via covalent bonds and showed very hydrophilic membrane surface, along with an increased osmotic water flux of 52.5 L.m2.h-1 and reverse salt flux of 10.9 g.m2.h-1, when deionized wastewater and potassium chloride were used as the feed solution and the draw solution, respectively. In this manner, incorporating manganese oxide into the FO membrane may introduce its extraordinary possible application for the production of diluted fertilizer solution with balanced nutrients.

Congenital syphilis presenting as fulminant early-onset sepsis.

Congenital syphilis (CS) is a rare entity and one of the most well-known congenital infections. A case of early CS presenting with fulminant sepsis is reported. A high index of suspicion is needed by the clinician to diagnose and treat this potentially life-threatening disease.

Differential effects of nitric oxide synthase inhibitors on anxiety in unstressed and stressed mice.

Effects of selective nitric oxide synthase (NOS) inhibitors, 7-nitroindazole (7-NI), a selective inhibitor of neuronal nitric oxide synthase (nNOS) and aminoguanidine (AG), a selective inhibitor of inducible nitric oxide synthase (iNOS) on anxiety in unstressed and stressed mice were investigated using elevated plus maze (EPM) test and light-dark test (LDT). 7-NI (20 and 40 mg/kg, ip) produced anti-anxiety effect in unstressed mice but not in stressed mice. AG (50 and 100 mg/kg, ip) produced anxiolytic effect in stressed mice and failed to produce the similar effect in unstressed mice. Nitrite levels were increased in stressed mice, but not in unstressed mice, exposed to EPM and LDT for 5 min. Increased nitrite levels in stressed mice were attenuated by AG, but not by 7-NI. The effects of AG were enhanced by pyrrolidine-dithio-carbamate (PDTC), an inhibitor of NF-kappaB induction, in stressed mice. The results suggest the possible role of inducible nitric oxide synthase in stress-induced anxiogenesis as compared to unstressed mice, where neuronal form of NOS may plays predominant role.