A lthough dual-energy CT (DECT) was first conceived in 1976, it has not been used widely for clinical indications (1-11). Recently, the simultaneous acquisition of dual-energy data has been introduced using multidetector CT (MDCT) with two X-ray tubes and rapid peak kilovoltage (kVp) switching (gemstone spectral imaging, GSI) (12-16). Two major advantages of DECT are material decomposition by the almost simultaneous acquisition of two image series with different kVp (80 and 140 kVp) and the elimination of misregistration artifacts. In general, noncontrast (unenhanced) images can be avoided by using the dual-energy mode for body and neurological applications; iodine can be removed from the image, and a virtual non-contrast (water) image can be acquired. The major advantage of 80-kVp compared to 140-kVp images is a higher image contrast (Fig. 1). Hounsfield unit measurements on DECT are not absolute and can change depending on the kVp used for the acquisition (at different keV). Typically, a combination of 80/140 kVp is used for DECT, but for some applications, 100/140 kVp is preferred. In this study, we summarized the clinical applications of DECT in the brain, chest and abdomen and in the cardiovascular and musculoskeletal systems (Table 1). Technique and principlesThe basic principle of dual-energy is the acquisition of 2 datasets from the same anatomic location with different kVp (usually 80 and 140 kVp) (1,2,17,18). In the early days of CT, consecutive single-slice acquisitions with different kVp were performed as a dual-energy technique, but this method suffered from breathing and partial volume artifacts (1, 2). At present, an entire body can be scanned within seconds using the DECT technique, and thus, misregistration artifacts due to breathing are eliminated.Currently, three systems are capable of the nearly simultaneous acquisition of dual-energy data during a single breath hold (12, 14, 15): 64-slice dual-source CT (Definition, Siemens Medical Systems; Erlangen, Germany), 128-slice dual-source CT (Definition Flash, Siemens Medical Systems) and high-definition 64-MDCT (Discovery 750 HD, GE Healthcare; Milwaukee, Wisconsin, USA). In the two systems available from Siemens, the two tubes (tubes A and B) use different kVp (80 and 140 kVp), and in 64-MDCT, the kVp switches from 80 to 140 kVp in less than 0.5 ms. In dual systems, there is concern regarding the susceptibility of the system to cardiac motion due to the time difference (75 or 83 ms) between the tube A and tube B acquisitions of the dual-energy data, but the dual-source CT and 64-MDCT have not been compared to evaluate this issue. The technical specifications of the DECT systems are summarized in Table 2.The images presented in this article were acquired using a 64-slice dual source CT (Definition, Siemens Medical Systems) and a 64-MDCT (Discovery 750HD, GE Healthcare). The DECT data acquired by both systems can be evaluated with a dedicated workstation using dual-energy software that ABSTRACT Although dual-energy CT (DECT) was first conceived in ...

ZnO nanoparticle–based multilayer nanocomposite films were fabricated on cationized woven cotton fabrics via layer-by-layer molecular self-assembly technique. For cationic surface charge, cotton fabrics were pretreated with 2,3-epoxypropyltrimethylammonium chloride (EP3MAC) by pad-batch method. XPS and SEM were used to examine the deposited nano-ZnO multilayer films on the cotton fabrics. The nano-ZnO films deposited on cotton fabrics exhibited excellent antimicrobial activity against Staphylococcus aureus bacteria. The results also showed that the coated fabrics with nano-ZnO multilayer films enhanced the protection of cotton fabrics from UV radiation. Physical tests (tensile strength of weft and warp yarns, air permeability and whiteness values) were performed on the fabrics before and after the treatment with ZnO nanoparticles to evaluate the effect of layer-by-layer (LbL) process on cotton fabrics properties.

A multilayer nanocomposite film composed of anatase TiO(2) nanoparticles was fabricated on cationically modified woven cotton fabrics by the layer-by-layer molecular self-assembly technique. For cationic surface charge, cotton fabrics were pre-treated with 2,3-epoxypropyltrimethylammonium chloride (EP3MAC) by a pad-batch method. Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to verify the presence of deposited nanolayers. Photocatalytic activities of the nanocomposite films were evaluated through the degradation of red wine pollutant. Nano-TiO(2) deposition enhanced the protection of cotton fabrics against UV radiation in comparison with the untreated cotton fabrics. Air permeability and whiteness value analysis was performed on the fabrics before and after the treatment with TiO(2) nanoparticles by the layer-by-layer deposition method. Tensile strength tests of the warp and weft yarns were performed to evaluate the effect of solution pH value changes during the alternate dipping procedures. For the first time the durability of the effect of the self-assembled multilayer films on the cotton fabric functional properties was analyzed after 10 and 20 washing cycles at 40 degrees C for 30 min.

The SARS-CoV-2 virus is a major problem in the world right now. Currently, all the attention of research centers and governments globally are focused on the investigation of vaccination studies and the discovery of small molecules that inhibit the SARS-CoV-2 virus in the treatment of patients. The goal of this study was to locate small molecules to be used against COVID19 instead of favipiravir. Favipiravir analogues were selected as drug candidates from the PubChem web tool. The RNA dependent RNA polymerase (RdRp) protein was selected as the target protein as favipiravir inhibits this protein in the human body. Initially, the inhibition activity of the studied compounds against RdRp of different virus types was investigated. Then, the inhibition properties of selected drug candidates and favipiravir were examined in detail against SARS-CoV-2 RdRp proteins. It was found that 2oxo-1H-pyrazine-3-carboxamide performed better than favipiravir in the results of molecular docking, molecular mechanics Poisson-Boltzmann surface area (MM-PSBA) calculations, and ADME analyses.

Recognizing and evaluating variations in popliteal artery branches is important in terms of vascular surgery approaches and interventional vascular procedures. CTA is an effective screening method to show the vascular frame of lower extremities and variations of popliteal artery. Our study allowed identifying two new branching patterns of the popliteal artery not previously described in the literature.