Over the years chemotherapy failure has been a vital research topic as researchers have been striving to discover reasons behind it. The extensive studies carried out on chemotherapeutic agents confirm that resistance to chemotherapy is a major reason for treatment failure. “Resistance to chemotherapy,” however, is a comprehensive phrase that refers to a variety of different mechanisms in which ATP-binding cassette (ABC) mediated efflux dominates. The ABC is one of the largest gene superfamily of transporters among both eukaryotes and prokaryotes; it represents a variety of genes that code for proteins, which perform countless functions, including drug efflux – a natural process that protects cells from foreign chemicals. Up to date, chemotherapy failure due to ABC drug efflux is an active research topic that continuously provides further evidence on multiple drug resistance (MDR), aiding scientists in tackling and overcoming this issue. This review focuses on drug resistance by ABC efflux transporters in human, viral, parasitic, fungal and bacterial cells and highlights the importance of the MDR permeability glycoprotein being the mutual ABC transporter among all studied organisms. Current developments and future directions to overcome this problem are also discussed.

Satellite-based multi-sensor data coupled with field and microscopic investigations are used to unravel the setting and controls of gold mineralization in the Wadi Beitan–Wadi Rahaba area in the South Eastern Desert of Egypt. The satellite-based multispectral and Synthetic Aperture Radar (SAR) data promoted a vibrant litho-tectonic understanding and abetted in assessing the regional structural control of the scattered gold occurrences in the study area. The herein detailed approach includes band rationing, principal component and independent component analyses, directional filtering, and automated and semi-automated lineament extraction techniques to Landsat 8- Operational Land Imager (OLI), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Phased Array L-band Synthetic Aperture Radar (PALSAR), and Sentinel-1B data. Results of optical and SAR data processed as grayscale raster images of band ratios, Relative Absorption Band Depth (RBD), and (mafic–carbonate–hydrous) mineralogical indices are used to extract the representative pixels (regions of interest). The extracted pixels are then converted to vector shape files and are finally imported into the ArcMap environment. Similarly, manually and automatically extracted lineaments are merged with the band ratios and mineralogical indices vector layers. The data fusion approach used herein reveals no particular spatial association between gold occurrences and certain lithological units, but shows a preferential distribution of gold–quartz veins in zones of chlorite–epidote alteration overlapping with high-density intersections of lineaments. Structural features including en-echelon arrays of quartz veins and intense recrystallization and sub-grain development textures are consistent with vein formation and gold deposition syn-kinematic with the host shear zones. The mineralized, central-shear quartz veins, and the associated strong stretching lineation affirm vein formation amid stress build-up and stress relaxation of an enduring oblique convergence (assigned as Najd-related sinistral transpression; ~640–610 Ma). As the main outcome of this research, we present a priority map with zones defined as high potential targets for undiscovered gold resources.

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Exhumed Paleozoic glacial deposits and landforms of the North Gondwana are reported here for the first time from the South Eastern Desert (SED) of Egypt. Using field observations and remote sensing datasets (Advanced Land Observing Satellite [ALOS], Phased Array L-band Synthetic Aperture Radar [PALSAR] radar, multispectral Landsat TM datasets, and digital elevation models [DEMs]), we mapped the distribution of Paleozoic glacial features (i.e. deposits and landforms) in the SED. Two main glaciogenic facies were identified in three locations in the SED: (1) massive, poorly sorted, matrix supported, boulder-rich diamictites in Wadi El-Naam and Korbiai, and (2) moderately-sorted, occasionally bedded outwash deposits in Betan area. Inspection of radar, DEMs, and Landsat Operational Land Imager (OLI) images revealed previously unrecognized ENE-WSW trending glacial megalineations (MLs) over the peneplained Neoproterozoic basement rocks in the central sections of the SED, whose trends align along their projected extension with those of glacial features (tunnel valleys and striation trends) reported from Saudi Arabia. The glaciogenic features in the SED are believed to be largely eroded during the uplift associated with the Red Sea opening, except for those preserved as basal units beneath the Nubia Sandstone Formation or as remnant isolated deposits within paleo-depressions within the basement complex. The apparent spatial correlation of the SED glacial features with well-defined Late Ordovician deposits in North Africa and in Saudi Arabia, and the reported thermochronometric analyses and fossil records are consistent with a Late Ordovician age for the SED glaciogenic features and support models that call on the continuation of the Late Ordovician (Hirnantian) ice sheet from the Sahara into Arabia through the SED of Egypt.

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