It was found that BN/graphene/GCE based sensor exhibited excellent electro-catalytic activity for nicotine oxidation at lower potential of +0.97 V in phosphate buffer solution (PBS, pH 7.0) and the linear response was observed from 1 to 1000 μM. The limit of detection (LOD) was estimated as 0.42 μM. The common interferent compounds such as uric acid (UA), paracetamol (PA), glucose (Glu), melamine (Mel), cysteine (Cys) and dopamine (DA) did not interfere on the sensor selectivity. Furthermore, BN/graphene/GCE exhibited high stability and reproducibility. Finally, BN/graphene/GCE-based sensor was successfully applied to detect nicotine in a tobacco sample with high recovery.Oxidase nanozymes have attracted particular attention in colorimetric immunoassay due to their high activity, stability, and biocompatibility. In this work, the well-dispersed Co(OH)2 nanocages were synthesized by a template-assisted strategy. The prepared Co(OH)2 nanocages exhibited an intrinsic oxidase-like activity, which can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) without the addition of hydrogen peroxide (H2O2). Hence, a simple and sensitive colorimetric immunoassay was established to detect ochratoxin A (OTA). In this immunosensor, the microplates were modified with dopamine as the substrate to capture antigens. Then, the uniform Co(OH)2 nanocages were used as the vehicle to carry the secondary antibody for the recognition of immunoreaction. The sensing system can generate color responses with the OTA concentration in the range from 0.5 ng/L to 5 μg/L, and the detection limit was as low as 0.26 ng/L. Therefore, as a nano-artificial enzyme, Co(OH)2 nanocages may show promising potential in visual detection of the real samples.The fabrication of carbon black/polylactic acid (PLA) electrodes using a 3D printing pen is presented and compared with electrodes obtained by a desktop fused deposition modelling (FDM) 3D printer. The 3D pen was used for the fast production of electrodes in two designs using customized 3D printed parts to act as template and guide the reproducible application of the 3D pen (i) a single working electrode at the bottom of a 3D-printed cylindrical body and (ii) a three-electrode system on a 3D-printed planar substrate. Both devices were electrochemically characterized using the redox probe [Fe(CN)6]3-/4- via cyclic voltammetry, which presented similar performance to an FDM 3D-printed electrode or a commercial screen-printed carbon electrode (SPE) regarding peak-to-peak separation (ΔEp) and current density. The surface treatment of the carbon black/PLA electrodes fabricated by both 3D pen and FDM 3D-printing procedures provided substantial improvement of the electrochemical activity by removing excess of PLA, wha advantage over chemically-modified electrochemical sensors applied for TNT detection.Three-dimensional printing techniques have been widely used in the fabrication of new materials applied to energy, sensing and electronics due to unique advantages, such as fast prototyping, reduced waste generation, and multiple fabrication designs. In this paper, the production of a conductive 3D-printing filament composed of Ni(OH)2 microparticles and graphene within a polylactic acid matrix (Ni-G-PLA) is reported. The nanocomposite was characterized by thermogravimetric, energy-dispersive X-ray spectroscopic, scanning electronic microscopic, Raman spectroscopic and electrochemical techniques. Characteristics such as printability (using fused deposition modelling), electrical conductivity and mechanical stability of the polymer nanocomposite were evaluated before and after 3D printing. MRTX849 Ras inhibitor The novel 3D-printed disposable electrode was applied for selective detection of glucose (enzyme-less sensor) with a detection limit of 2.4 μmol L-1, free from the interference of ascorbic acid, urea and uric acid, compounds typically found in biological samples. The sensor was assembled in a portable electrochemical system that enables fast (160 injection h-1), precise (RSD less then 5%) and selective determination of glucose without the need of enzymes (electrocatalytic properties of the Ni-G-PLA nanocomposite). The obtained results showed that Ni-G-PLA is a promising material for the production of disposable sensors for selective detection of glucose using a simple and low-cost 3D-printer.Failure to appreciate key anatomic features and suboptimal sonographic technique lead to incorrect assessment of the key elements of developmental dysplasia of the hip position, stability, and morphology. In this article, we address common errors, identify sonographic features critical for accurate image interpretation, and address measurement variability.There is a broad spectrum of soft-tissue masses in children that can be challenging to diagnose clinically and on imaging. This article reviews the typical clinical and imaging findings of the most common and relevant benign, intermediate and malignant pediatric soft-tissue tumors in the following categories of the 2013 World Health Organization (WHO) classification adipocytic tumors (lipoma, lipoblastoma, and liposarcoma), fibroblastic/myofibroblastic tumors (nodular fasciitis, myositis ossificans, fibrous hamartoma of infancy, fibromatosis colli, desmoid-type fibromatosis, lipofibromatosis, and infantile fibrosarcoma), pericytic tumors (myofibroma/myofibromatosis), skeletal muscle tumor (rhabdomyosarcoma), nerve sheath tumors (neurofibroma, malignant peripheral nerve sheath tumor), and uncertain differentiation (synovial sarcoma). In general, ultrasound and magnetic resonance imaging are used as first- and second-line imaging modalities, with limited roles for plain radiographs, computed tomography, and fluorodeoxyglucose-positron emission tomography. Many of these tumors have nonspecific imaging findings although there are some key imaging clues that in conjunction with the clinical information allow a specific diagnosis or a narrow differential diagnosis. However, in many instances, histology is required for final diagnosis.Osteoid osteoma (OO) is a benign bone neoplasm consisting of a central prostaglandin-secreting nidus surrounded by a zone of reactive sclerosis. The diagnosis is suspected in children and young adults with longstanding nighttime pain that is relieved by salicylates or nonsteroidal anti-inflammatory drugs. Early studies suggested that computed tomography had a higher sensitivity and specificity in the diagnosis of OO compared to magnetic resonance imaging (MRI). More recent literature suggests MRI done with dynamic postcontrast imaging to be equal to or slightly better at detecting the nidus of OOs, particularly the ones in atypical locations. Being able to evaluate for OO utilizing MRI is important given that the majority of these lesions occur in younger patients, in whom there is greater concern to limit ionizing radiation. Furthermore, patients with atypical OOs often receive an MRI if radiographs are not suggestive of the diagnosis. Therefore, it is important for radiologists to be aware of the imaging features that can help make the diagnosis on MRI.