Patterning multiplex protein microarrays in a single microfluidic channel

The development of versatile biofunctional surfaces is a fundamental prerequisite in designing Lab on a Chip (LOC) devices for applications in biosensing interfaces and microbioreactors. The current paper presents a rapid combinatorial approach to create multiplex protein patterns in a single microfluidic channel. This approach consists of coupling microcontact printing with microfluidic patterning, where microcontact printing is employed for silanization using (3-Aminopropyl) triethoxysilane (APTES), followed by microfluidic patterning of multiple antibodies. As a result, the biomolecules of choice could be covalently attached to the microchannel surface, thus creating a durable and highly resistant functional interface. Moreover, the experimental procedure was designed to create a microfluidic platform that maintains functionality at high flow rates. The functionalized surfaces were characterized using X-ray photoelectron spectroscopy (XPS) and monitored with fluorescence microscopy at each step of functionalization. To illustrate the possibility of patterning multiple biomolecules along the cross section of a single microfluidic channel, microarrays of five different primary antibodies were patterned onto a single channel and their functionality was evaluated accordingly through a multiplex immunoassay using secondary antibodies specific to each patterned primary antibody. The resulting patterns remained stable at shear stresses of up to 50 dyn/cm(2). The overall findings suggest that the developed multiplex functional interface on a single channel can successfully lead to highly resistant multiplex functional surfaces for high throughput biological assays.     

Single section,octave bandwidth,high‐power combiner in the UHF band

In this work, a planar broadband high‐power combiner in the ultra‐high‐frequency band (UHF) is presented. The proposed broadband combiner is a modified version of the conventional Wilkinson power combiner. The isolation resistor of 100 Ω in the conventional Wilkinson combiner is replaced by two 50 Ω terminating resistors. Two overlay couplers transform the terminating resistors to a floating resistor between the input branches. Terminating resistors are preferred to a floating resistor because of higher power handling and lower parasitics. Even‐ and odd‐mode method is employed for the analysis. The design goal is 20 dB isolation and ports return loss in an octave bandwidth. To verify the design concept, a high‐power combiner in the frequency range of 470 to 860 MHz used for digital video broadcasting‐terrestrial (DVB‐T) applications is designed and constructed. Full‐wave simulations are compared with measurements. The fabricated power combiner handles 400 W output power. Analytical formulations presented in this work are not restricted to UHF band and can be used to design an octave bandwidth combiner in other frequency bands.     

Artificial neural networks application to predict the ultimate tensile strength of X70 pipeline steels

The paper presents some results of the research connected with the development of new approach based on the artificial neural network (ANN) of predicting the ultimate tensile strength of the API X70 steels after thermomechanical treatment. The independent variables in the model are chemical compositions (carbon equivalent), based upon the International Institute of Welding equation (CE_IIW), the carbon equivalent, based upon the chemical portion of the Ito-Bessyo carbon equivalent equation (CE_Pcm), the sum of the niobium, vanadium and titanium concentrations (VTiNb), the sum of the niobium and vanadium concentrations (NbV), the sum of the chromium, molybdenum, nickel and copper concentrations (CrMoNiCu), Charpy impact energy at ?10 °C (CVN) and yield strength at 0.005 offset (YS). For purpose of constructing these models, 104 different data were gathered from the experimental results. The data used in the ANN model is arranged in a format of seven input parameters that cover the chemical compositions, yield stress and Charpy impact energy, and output parameter which is ultimate tensile strength. In this model, the training, validation and testing results in the ANN have shown strong potential for prediction of relations between chemical compositions and mechanical properties of API X70 steels.     

Lubricant‐Infused PET Grafts with Built‐In Biofunctional Nanoprobes Attenuate Thrombin Generation and Promote Targeted Binding of Cells

New surface coatings that enhance hemocompatibility and biofunctionality of synthetic vascular grafts such as expanded poly(tetrafluoroethylene) (ePTFE) and poly(ethylene terephthalate) (PET) are urgently needed. Lubricant‐infused surfaces prevent nontargeted adhesion and enhance the biocompatibility of blood‐contacting surfaces. However, limited success has been made in incorporating biofunctionality onto these surfaces and generating biofunctional lubricant‐infused coatings that both prevent nonspecific adhesion and enhance targeted binding of biomolecules remains a challenge. Here, a new generation of fluorosilanized lubricant‐infused PET surfaces with built‐in biofunctional nanoprobes is reported. These surfaces are synthesized by starting with a self‐assembled monolayer of fluorosilane that is partially etched using plasma modification technique, thereby creating a hydroxyl‐terminated fluorosilanized PET surface. Simultaneously, silanized nanoprobes are produced by amino‐silanizing anti‐CD34 antibody in solution and directly coupling the anti‐CD34‐aminosilane nanoprobes onto the hydroxyl terminated, fluorosilanized PET surface. The PET surfaces are then lubricated, creating fluorosilanized biofunctional lubricant‐infused PET substrates. Compared with unmodified PET surfaces, the designed biofunctional lubricant‐infused PET surfaces significantly attenuate thrombin generation and blood clot formation and promote targeted binding of endothelial cells from human whole blood.     

A pseudo-differential MDAC with a gain-boosting inverter for pipelined ADCs

In this paper, a power-efficient pseudo-differential (PD) multiplying digital-to-analog converter (MDAC) is presented for pipelined analog-to-digital converters (ADCs). The proposed MDAC eliminates the explicit common-mode feedback circuit which is required in fully-differential configurations without any power penalty. Furthermore, a new class-AB gain-boosting inverter is proposed to be used in PD MDAC structures for further power saving. This inverter provides dynamic load current with no significant static power consumption and achieves high DC gain using a new gain-boosting technique. To demonstrate the effectiveness of the proposed circuits, they are utilized in the realization of a 1.5-bit/stage 10 bit 100 MS/s pipelined ADC.     

Dual-Band Antenna Fed with CPW Technology Using Modified Mirrored L-Shaped Conductor-Back Plane

This paper describes a novel configuration of a CPW-fed printed monopole antenna that depicts dual-band operations of WLAN and X-bands. The proposed antenna consists of a simple rectangular-shaped patch as the main radiator, the modified mirrored L-shaped conductor back plane element, and the partial rectangular CPW-ground surface. Dual-band performances can be obtained by embedding and adjusting dimensions of strips on mirrored L-Shaped conductor back plane element. The impedance bandwidth with \(\hbox {s}_{11} < -10\)  dB is about 2.2 GHz (5.05–7.25 GHz) or 36 % for 5 GHz band and 5.2 GHz (7.6–12.8 GHz) or 51 % for X-band. The measured peak gains are about 1.8 dBi at WLAN-band and 4.3 dBi at X-band. The Experimental results indicate that the fabricated antenna with proper dimensions, good radiation characteristics, and reasonable measured gains can be a good candidate for various applications of the future multi-band wireless communication systems and mobile device.     

Optimization of sensitized perovskite solar cells with Zn–Cu–In–Se quantum dots to increase quantum efficiency

Journal of Materials Science: Materials in Electronics - Perovskite solar cells are efficient units in systems with modern renewable energy sources. Increasing the efficiency of solar cells is...     

An Omniphobic Spray Coating Created from Hierarchical Structures Prevents the Contamination of High-Touch Surfaces with Pathogens

Engineered surfaces that repel pathogens are of great interest due to their role in mitigating the spread of infectious diseases. A robust, universal, and scalable omniphobic spray coating with excellent repellency against water, oil, and pathogens is presented. The coating is substrate-independent and relies on hierarchically structured polydimethylsiloxane (PDMS) microparticles, decorated with gold nanoparticles (AuNPs). Wettability studies reveal the relationship between surface texturing of micro- and/or nano-hierarchical structures and the omniphobicity of the coating. Studies of pathogen transfer with bacteria and viruses reveal that an uncoated contaminated glove transfers pathogens to >50 subsequent surfaces, while a coated glove picks up 10⁴ (over 99.99%) less pathogens upon first contact and transfers zero pathogens after the second touch. The developed coating also provides excellent stability under harsh conditions. The remarkable anti-pathogen properties of this surface combined with its ease of implementation, substantiate its use for the prevention of surface-mediated transmission of pathogens.     

Functional Nanomaterials for the Diagnosis of Alzheimer's Disease: Recent Progress and Future Perspectives

Alzheimer's disease (AD) is one of the main causes of dementia worldwide, whereby neuronal death or malfunction leads to cognitive impairment in the elderly population. AD is highly prevalent, with increased projections over the next few decades. Yet current diagnostic methods for AD occur only after the presentation of clinical symptoms. Evidence in the literature points to potential mechanisms of AD induction beginning before clinical symptoms start to present, such as the formation of amyloid beta (Aβ) extracellular plaques and neurofibrillary tangles (NFTs). Biomarkers of AD, including Aβ₄₀, Aβ₄₂, and tau protein, amongst others, show promise for early AD diagnosis. Additional progress is made in the application of biosensing modalities to measure and detect significant changes in these AD biomarkers within patient samples, such as cerebral spinal fluid (CSF) and blood, serum, or plasma. Herein, a comprehensive review of the emerging nano-biomaterial approaches to develop biosensors for AD biomarkers’ detection is provided. Advances, challenges, and potential of electrochemical, optical, and colorimetric biosensors, focusing on nanoparticle-based (metallic, magnetic, quantum dots) and nanostructure-based biomaterials are discussed. Finally, the criteria for incorporating these emerging nano-biomaterials in clinical settings are presented and assessed, as they hold great potential for enhancing early-onset AD diagnostics.