Aptamer-Based Tumor-Targeted Diagnosis and Drug Delivery.

Early cancer identification is crucial for providing patients with safe and timely therapy. Highly dependable and adaptive technologies will be required to detect the presence of biological markers for cancer at very low levels in the early stages of tumor formation. These techniques have been shown to be beneficial in encouraging patients to develop early intervention plans, which could lead to an increase in the overall survival rate of cancer patients. Targeted drug delivery (TDD) using aptamer is promising due to its favorable properties. Aptamer is suitable for superior TDD system candidates due to its desirable properties including a high binding affinity and specificity, a low immunogenicity, and a chemical composition that can be simply changed.Due to these properties, aptamer-based TDD application has limited drug side effect along with organ damages. The development of aptasensor has been promising in TDD for cancer cell treatment. There are biomarkers and expressed molecules during cancer cell development; however, only few are addressed in aptamer detection study of those molecules. Its great potential of attachment of binding to specific target molecule made aptamer a reliable recognition element. Because of their unique physical, chemical, and biological features, aptamers have a lot of potential in cancer precision medicine.In this review, we summarized aptamer technology and its application in cancer. This includes advantages properties of aptamer technology over other molecules were thoroughly discussed. In addition, we have also elaborated the application of aptamer as a direct therapeutic function and as a targeted drug delivery molecule (aptasensor) in cancer cells with several examples in preclinical and clinical trials.

Froth flotation beneficiation and physiochemical characterization of coal from Achibo-Sombo-Dabaso area, southwestern Ethiopia.

This study was carried out with one of the physiochemical techniques of coal sample beneficiation using froth flotation technique for upgrading the quality of Achibo-Sombo-Dabaso coal, southwestern Ethiopia. The investigations aimed to beneficiate high impure Ethiopian coal and to minimize its impurities present, so that it can replace the imported coal and the environmental pollution generated during combustion is reduced. The proximate and ultimate characterization studies show that the raw coal samples contain 11.81-20.27% moisture, 22.47-36.58% ash, 22.74-34.85% volatile matter, 23.85-38.31% fixed carbon, 1.22-1.44% nitrogen, 0.57-1.9% sulfur with 3243.59-5295.34 kcal/kg calorific value. Froth flotation experiments were carried out on the raw coal samples at varying parameters of collector dosages (0.0095 kg/ton, 0.0283 kg/ton, 0.0472 kg/ton, 0.0661 kg/ton and 0.085 kg/ton of diesel oil), frother dosages (0.0922 kg/ton, 0.1845 kg/ton, 0.2767 kg/ton, 0.3689 kg/ton and 0.4611 kg/ton of n-octanol) and particle size (500-250, 250-125, 125-63 µm). The experimental results for the treated coal samples are 8.12-14.02% moisture, 7.49-13.62% ash, 21.92-30.64% volatile matter, 44.47-55.87% fixed carbon, 0.52-0.92% nitrogen, 0.25-0.41% sulfur content with 5243.40-6531.46 kcal/kg of calorific value. The results of this study indicate that the treated coal samples are relative with high calorific value, fixed carbon and low ash content compared to the raw samples. The coal samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) to understand the flotation and size distribution of coal. Therefore, the froth flotation technique at parameters of collector dosages (0.0472 kg/ton of diesel oil), frother dosages (0.3689 kg/ton of n-octanol) and particle size (125-63 µm) is effective to increase the calorific value above 5000 kcal/kg and increment carbon content of Achibo-Sombo-Dabaso coal that suitable as an energy source in cement and steel industries.

Inverted (p-i-n) perovskite solar cells using a low temperature processed TiO x interlayer.

In this article, we present the improvement in device performance and stability as well as reduction in hysteresis of inverted mixed-cation-mixed-halide perovskite solar cells (PSCs) using a low temperature, solution processed titanium oxide (TiO x ) interlayer between [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) and an Al electrode. Upon applying a TiO x interlayer, device resistance was reduced compared to that of the control devices, which results in improved rectification of the characteristic current density-voltage (J-V) curve and improved overall performance of the device. PSCs with the TiO x interlayer show an open-circuit voltage (V oc) of around 1.1 V, current density (J sc) of around 21 mA cm-2, fill factor (FF) of around 72% and enhanced power conversion efficiency (PCE) of 16% under AM1.5 solar spectrum. Moreover, devices with the TiO x interlayer show improved stability compared to devices without the TiO x interlayer. This finding reveals the dual role of the TiO x interlayer in improving device performance and stability.

Flexible high power-per-weight perovskite solar cells with chromium oxide-metal contacts for improved stability in air.

Photovoltaic technology requires light-absorbing materials that are highly efficient, lightweight, low cost and stable during operation. Organolead halide perovskites constitute a highly promising class of materials, but suffer limited stability under ambient conditions without heavy and costly encapsulation. Here, we report ultrathin (3 µm), highly flexible perovskite solar cells with stabilized 12% efficiency and a power-per-weight as high as 23 W g(-1). To facilitate air-stable operation, we introduce a chromium oxide-chromium interlayer that effectively protects the metal top contacts from reactions with the perovskite. The use of a transparent polymer electrode treated with dimethylsulphoxide as the bottom layer allows the deposition-from solution at low temperature-of pinhole-free perovskite films at high yield on arbitrary substrates, including thin plastic foils. These ultra-lightweight solar cells are successfully used to power aviation models. Potential future applications include unmanned aerial vehicles-from airplanes to quadcopters and weather balloons-for environmental and industrial monitoring, rescue and emergency response, and tactical security applications.

Inverted bulk-heterojunction solar cell with cross-linked hole-blocking layer.

We have developed a hole-blocking layer for bulk-heterojunction solar cells based on cross-linked polyethylenimine (PEI). We tested five different ether-based cross-linkers and found that all of them give comparable solar cell efficiencies. The initial idea that a cross-linked layer is more solvent resistant compared to a pristine PEI layer could not be confirmed. With and without cross-linking, the PEI layer sticks very well to the surface of the indium-tin-oxide electrode and cannot be removed by solvents used to process PEI or common organic semiconductors. The cross-linked PEI hole-blocking layer functions for multiple donor-acceptor blends. We found that using cross-linkers improves the reproducibility of the device fabrication process.