Deep Learning Image Analysis of Nanoplasmonic Sensors: Toward Medical Breath Monitoring.

Sensing biomarkers in exhaled breath offers a potentially portable, cost-effective, and noninvasive strategy for disease diagnosis screening and monitoring, while high sensitivity, wide sensing range, and target specificity are critical challenges. We demonstrate a deep learning-assisted plasmonic sensing platform that can detect and quantify gas-phase biomarkers in breath-related backgrounds of varying complexity. The sensing interface consisted of Au/SiO nanopillars covered with a 15 nm metal-organic framework.

Conformational Changes of Immobilized Polythymine due to External Stressors Studied with Temperature-Controlled Electrochemical Microdevices.

Conformational changes of single-stranded DNA (ssDNA) play an important role in a DNA strand's ability to bind to target ligands. A variety of factors can influence conformation, including temperature, ionic strength, pH, buffer cation valency, strand length, and sequence. To better understand the effects of these factors on immobilized DNA structures, we employ temperature-controlled electrochemical microsensors to study the effects of salt concentration and temperature variation on the conformation and motion of polythymine (polyT) strands of varying lengths (10, 20, 50 nucleotides).

Miniaturized nanohole array based plasmonic sensor for the detection of acetone and ethanol with insights into the kinetics of adsorptive plasmonic sensing.

The present work demonstrates development of a miniaturized plasmonic platform comprised of a Au nanohole array (NHA) on a Si/Si3N4 substrate. Plasmonic responses of the NHA platform, which is coated with Cu-benzenetricarboxylate metal organic framework (MOF), are found to be promising even towards 500 nmol mol-1 (ppb) of acetone or ethanol vapors at room temperature. The sensing characteristics are further investigated by varying the operating temperature (296 K to 318 K) of the sensor and the concentrations of vapors (500 nmol mol-1 to 320 μmol mol-1).

UV-assisted room-temperature chemiresistive NO sensor based on TiO thin film.

TiO thin film based, chemiresistive sensors for NO gas which operate at room temperature under ultraviolet (UV) illumination have been demonstrated in this work. The rf-sputter deposited and post-annealed TiO thin films have been characterized by atomic force microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction to obtain surface morphology, chemical state, and crystal structure, respectively. UV-vis absorption spectroscopy and Tauc plots show the optical properties of the TiO films.

Mechanisms of criticality in environmental adhesion loss.

Moisture attack on adhesive joints is a long-standing scientific and engineering problem. A particularly interesting observation is that when the moisture level in certain systems exceeds a critical concentration, the bonded joint shows a dramatic loss of strength. The joint interface plays a dominant role in this phenomenon; however, why a critical concentration of moisture exists and what role is played by the properties of the bulk adhesive have not been adequately addressed.

Dithiol-based modification of poly(dopamine): enabling protein resistance via short-chain ethylene oxide oligomers.

We present a facile strategy to modify poly(dopamine) (PDA)-coated substrates. Using thiol-terminated short chain ethylene oxide oligomers (OEG) under aqueous conditions, we explore the creation of a model surface exhibiting resistance to nonspecific protein absorption (RPA) by engineering the surface properties of a PDA adlayer. Surprisingly, dithiol-terminated OEG molecules demonstrated significantly greater coverage on PDA surfaces than analogous monothiol molecules.

A generalized strategy for immobilizing uniformly oriented membrane proteins at solid interfaces.

We have developed a method based on self-assembly of thiols on Au substrates to immobilize membrane proteins at interfaces. Using water soluble nitrilotriacetic acid (NTA)-terminated oligo(ethylene glycol) thiols, a histidine-tagged G protein-coupled membrane receptor (GPCR) was captured in a defined orientation with little nonspecific binding.

Characterization of composition C4 explosives using time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy.

The application of surface analytical techniques such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) is explored as a means of differentiating between composition C4 plastic explosives (C-4). Three different C-4 samples including U.S.

Azacytidine induces cell cycle arrest and suppression of neuroendocrine markers in carcinoids.

Neuroendocrine tumors (NETs) hypersecrete neuropeptides that cause debilitating symptoms of carcinoid syndrome, including cardiac abnormalities. Surgical resection is the only potentially curative treatment for NETs; however, 90% of NE cancer patients are not candidates for surgery due to extensive hepatic sites involved with NETs. Recently, DNA methyltransferase inhibitors (DNMTI) such as azacytidine (AzaC) have shown efficacy in clinical treatments of hematological malignancies, but effects on NETs are not well-studied.

Elastic, adhesive, and charge transport properties of a metal-molecule-metal junction: the role of molecular orientation, order, and coverage.

The elastic, adhesive, and charge transport properties of a metal-molecule-metal junction were studied via conducting-probe atomic force microscopy (AFM) and correlated with molecular structure by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The junctions consisted of Co-Cr-coated AFM tips in contact with methyl-terminated alkanethiols (CH(3)(CH(2))(n-1)SH, denoted by C(n), where n is the number of carbons in the molecular chain) on Au substrates. AFM contact data were analyzed with the Derjaguin-Muller-Toporov contact model, modified by a first-order elastic perturbation method to account for substrate effects, and a parabolic tunneling model, appropriate for a metal-insulator-metal junction in which the thickness of the insulator is comparable to the Fermi wavelength of the conducting electrons.

On the origins of sudden adhesion loss at a critical relative humidity: examination of bulk and interfacial contributions.

The origins for abrupt adhesion loss at a critical relative humidity (RH) for polymeric adhesives bonded to inorganic surfaces have been explored using a model poly(methyl methacrylate) (PMMA) film on glass. The interfacial and bulk water concentrations within the polymer film as a function of D 2O partial pressure were quantified using neutron reflectivity. Adhesion strength of these PMMA/SiO 2 interfaces under the same conditions was quantified using a shaft loaded blister test.