Seasonal variation of particulate matter in the ambient conditions of Khanspur, Pakistan

Concentrations of particulate matter tend to vary with shifting seasons. Levels of particulate matter were monitored during the summer and winter season in Khanspur, a high altitude tourist resort in Pakistan. A DustTrak DRX (Model 8533, TSI Inc.) and Kestrel 4500 Pocket Weather Tracker (Nielsen- Kellerman) were installed at selected site in Khanspur and run for 24 hours. During summer the 24- hour average concentrations of PM1, PM2.5, PM4, PM10 and PMTotal were 96 ± 26.42, 106± 29.02, 118± 33.3, 163± 52.5 and 209 ± 79.5 μg/m3 while these were considerably lower during the winter season for the same size fractions (62 ± 48.6, 63± 49.3, 63 ± 49.5, 65.33 ± 50.06 and 66.96 ± 50.78μg/m3). A one way ANOVA was applied on the obtained data and it was concluded that seasons have a substantial impact upon PM concentrations. Moreover, this study provides evidence that seasonal variation of particulate matter is influenced by meteorological parameters

Newtonian flow inside carbon nanotube with permeable boundary taking into account van der Waals forces

Here, water flow inside large radii semi-infinite carbon nanotubes is investigated. Permeable wall taking into account the molecular interactions between water and a nanotube, and the slip boundary condition will be considered. Furthermore, interactions among molecules are approximated by the continuum approximation. Incompressible and Newtonian fluid is assumed, and the Navier-Stokes equations, after certain assumptions, transformations and derivations, can be reduced into two first integral equations. In conjunction with the asymptotic expansion technique, we are able to derive the radial and axial velocities analytically, capturing the effect of the water leakage, where both mild and exceptionally large leakages will be considered. The radial velocity obeys the prescribed boundary condition at the (im)permeable wall. Through the mean of the radial forces, the sufficiently large leakages will enhance the radial velocity at the center of the tube. On the other hand, unlike the classical laminar flow, the axial velocity attains its maximum at the wall due to the coupling effect with the radial forces as water is being pushed into the proximity of the inner wall. In addition, the axial velocity and the flux with the consideration of the suck-in forces, induced by the tubes’ entry turn out to be one order higher than that without the suck-in forces. All the aforementioned considerations might partially resolve the mysteriously high water penetration through nanotubes. Axial velocity also drops with the tube’s length when the water leakage is permitted and the suck-in forces will ease the decline rate of the axial velocity. The present mathematical framework can be directly employed into the water flow inside other porous nano-materials, where large water leakage is permitted and therefore are of huge practical impact on ultra-filtration and environmental protection

Rescue of the MERTK phagocytic defect in a human iPSC disease model using translational read-through inducing drugs

Inherited retinal dystrophies are an important cause of blindness, for which currently there are no effective treatments. In order to study this heterogeneous group of diseases, adequate disease models are required in order to better understand pathology and to test potential therapies. Induced pluripotent stem cells offer a new way to recapitulate patient specific diseases in vitro, providing an almost limitless amount of material to study. We used fibroblast-derived induced pluripotent stem cells to generate retinal pigment epithelium (RPE) from an individual suffering from retinitis pigmentosa associated with biallelic variants in MERTK. MERTK has an essential role in phagocytosis, one of the major functions of the RPE. The MERTK deficiency in this individual results from a nonsense variant and so the MERTK-RPE cells were subsequently treated with two translational readthrough inducing drugs (G418 & PTC124) to investigate potential restoration of expression of the affected gene and production of a full-length protein. The data show that PTC124 was able to reinstate phagocytosis of labeled photoreceptor outer segments at a reduced, but significant level. These findings represent a confirmation of the usefulness of iPSC derived disease specific models in investigating the pathogenesis and screening potential treatments for these rare blinding disorders

High-performance solution-based CdS-conjugated hybrid polymer solar cells

In this study, hybrid BHJ - bulk heterojunction polymer solar cells were fabricated by incorporating CdS quantum dots (QDs) in a blend of P3HT (donor) and PCBM (acceptor) using dichlorobenzene and chlorobenzene as solvents. CdS QDs at various ratios were mixed in a fixed amount of the P3HT and PCBM blend. The prepared samples have been characterized by a variety of techniques such as I-V and EQE measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultraviolet-visible (UV-vis) spectroscopy. The mixing of QDs in the polymer blends improved the PCE - power conversion efficiency of the solar cells under standard light conditions. The improved PCE from 2.95 to 4.41% is mostly due to the increase in the fill factor (FF) and short-circuit current (J(sc)) of the devices with an optimum amount of CdS in the P3HT:PCBM blend. The increase in J(sc) possibly originated from the formation of a percolation network of CdS. The conjugation of QDs has increased the absorption of the active layers in the visible region. These results well matched as reported, conjugation of CdS in the perovskite active layer increased the absorption and PCE of the devices relative to those of the perovskite films. This increment in parameters is attributed to the decrease in charge recombinations that improved the performance of the doped device

Cu-loaded C3N4-MgO nanorods for promising antibacterial and dye degradation

Photocatalytic and magnetic stability of two-dimensional nanomaterials is enhanced by metal doping, which is an environmentally friendly technique used in various industries. There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Similarliy, the whole world is facing water crisis and a possible cost-effective solution is photocatalysis. In this study, an economical and convenient co-precipitation method was adopted to synthesize copper (Cu) loaded graphitic carbon nitride (g-C3N4) and magnesium oxide (MgO) composites. Various concentrations (2.5, 5, 7.5, and 10%) of Cu were doped into a fixed amount of g-C3N4/MgO nanostructures for efficient photocatalytic and antimicrobial activities. Results showed that 2.5% Cu loaded samples exhibited best possible results for the photocatalytic activity and 10% loaded Cu nanocomposites displayed enhanced antimicrobial performance. Improved crystallinity and increase in crystal size upon doping were confirmed with X-ray differaction (XRD) analysis, which was corroborated with Selected Area Electron Diffraction (SAED) results. Fourier-transform infrared spectroscopy (FTIR) revealed that MgO spectra consisted of stretching vibrations of Mg-O bond and other functional groups with minor changes in the vibrational modes upon doping. An high resolution transmission electron microscope (HRTEM) fitted with Gatan (R) digital software indicated hexagonal phase formation in as-prepared samples and nanorods upon doping, with confirmed d-spacing values. The UV-visible spectroscopy (UV-Vis) analysis exhibited a slight redshift in absorption intensity leading to decreased bandgap (Eg) for Cu-loaded g-C3N4/MgO. Photoluminescence (PL) spectra were acquired to investigate the recombination of electron-hole pairs. X-ray photoelectron spectroscopy (XPS) was employed to evaluate the elemental and surface composition with binding energy alterations of Cu-loaded g-C3N4/MgO nanorods. The thermal stability and behavior of synthesized samples were investigated by differential scanning calorimetry thermoanalytical (DSC) analysis. Photocatalytic activity (PCA) of as-prepared samples were evaluated against methylene blue and ciprofloxacin (MB&CF) dye in acidic, neutral and basic medium. Furthermore, the efficient antimicrobial potential was evaluated against Escherichia Coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria

Cu-loaded C3N4-MgO nanorods for promising antibacterial and dye degradation

Photocatalytic and magnetic stability of two-dimensional nanomaterials is enhanced by metal doping, which is an environmentally friendly technique used in various industries. There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Similarliy, the whole world is facing water crisis and a possible cost-effective solution is photocatalysis. In this study, an economical and convenient co-precipitation method was adopted to synthesize copper (Cu) loaded graphitic carbon nitride (g-C3N4) and magnesium oxide (MgO) composites. Various concentrations (2.5, 5, 7.5, and 10%) of Cu were doped into a fixed amount of g-C3N4/MgO nanostructures for efficient photocatalytic and antimicrobial activities. Results showed that 2.5% Cu loaded samples exhibited best possible results for the photocatalytic activity and 10% loaded Cu nanocomposites displayed enhanced antimicrobial performance. Improved crystallinity and increase in crystal size upon doping were confirmed with X-ray differaction (XRD) analysis, which was corroborated with Selected Area Electron Diffraction (SAED) results. Fourier-transform infrared spectroscopy (FTIR) revealed that MgO spectra consisted of stretching vibrations of Mg-O bond and other functional groups with minor changes in the vibrational modes upon doping. An high resolution transmission electron microscope (HRTEM) fitted with Gatan (R) digital software indicated hexagonal phase formation in as-prepared samples and nanorods upon doping, with confirmed d-spacing values. The UV-visible spectroscopy (UV-Vis) analysis exhibited a slight redshift in absorption intensity leading to decreased bandgap (Eg) for Cu-loaded g-C3N4/MgO. Photoluminescence (PL) spectra were acquired to investigate the recombination of electron-hole pairs. X-ray photoelectron spectroscopy (XPS) was employed to evaluate the elemental and surface composition with binding energy alterations of Cu-loaded g-C3N4/MgO nanorods. The thermal stability and behavior of synthesized samples were investigated by differential scanning calorimetry thermoanalytical (DSC) analysis. Photocatalytic activity (PCA) of as-prepared samples were evaluated against methylene blue and ciprofloxacin (MB&CF) dye in acidic, neutral and basic medium. Furthermore, the efficient antimicrobial potential was evaluated against Escherichia Coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria

Boron for tissue regeneration-it’s loading into chitosan/collagen hydrogels and testing on chorioallantoic membrane to study the effect on angiogenesis

In the current study, boric acid loaded chitosan (CS) and collagen-based hydrogels were prepared. Hydrogels with four different boric acid concentrations were prepared; control hydrogel (without boric acid), and a hydrogel having boric acid 50 mg (B50), 250 mg boric acid (B250) and 500 mg boric acid (B500). Internal morphology of hydrogel was determined by performing scanning electron microscopy (SEM). Internal linkages of functional groups were confirmed by Fourier transform infrared spectroscopy (FT-IR). The pro-angiogenic potential of these materials was explored in chorioallantoic membrane (CAM) assay and 50 mg boric acid (B50) based hydrogel showed comparatively higher angiogenesis