Lignocellulose-based analytical devices: bamboo as an analytical platform for chemical detection.

This article describes the development of lignocellulose-based analytical devices (LADs) for rapid bioanalysis in low-resource settings. LADs are constructed using either a single lignocellulose or a hybrid design consisting of multiple types of lignocellulose. LADs are simple, low-cost, easy to use, provide rapid response, and do not require external instrumentation during operation.

Structural, Mechanistic, and Antigenic Characterization of the Human Astrovirus Capsid.

Unlabelled: Human astroviruses (HAstVs) are nonenveloped, positive-sense, single-stranded RNA viruses that are a leading cause of viral gastroenteritis. HAstV particles display T=3 icosahedral symmetry formed by 180 copies of the capsid protein (CP), which undergoes proteolytic maturation to generate infectious HAstV particles. Little is known about the molecular features that govern HAstV particle assembly, maturation, infectivity, and immunogenicity.

Microneedle electrodes toward an amperometric glucose-sensing smart patch.

Here, efforts toward the development of a microneedle-based glucose sensor or "smart patch" for intradermal glucose sensing are described. Metallic microneedle array electrodes, conducting polymers, and glucose oxidase form the sensor platform. This work represents the first steps toward the development of painless, transdermal-sensing devices for continuous glucose monitoring.

Core-shell hydrogel microcapsules for improved islets encapsulation.

Islets microencapsulation holds great promise to treat type 1 diabetes. Currently used alginate microcapsules often have islets protruding outside capsules, leading to inadequate immuno-protection. A novel design of microcapsules with core-shell structures using a two-fluid co-axial electro-jetting is reported.

Materials for diabetes therapeutics.

This review is focused on the materials and methods used to fabricate closed-loop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and be permeable to small molecules and proteins, such as insulin.

An SFG study of interfacial amino acids at the hydrophilic SiO2 and hydrophobic deuterated polystyrene surfaces.

Sum frequency generation (SFG) vibrational spectroscopy was employed to characterize the interfacial structure of eight individual amino acids--L-phenylalanine, L-leucine, glycine, L-lysine, L-arginine, L-cysteine, L-alanine, and L-proline--in aqueous solution adsorbed at model hydrophilic and hydrophobic surfaces. Specifically, SFG vibrational spectra were obtained for the amino acids at the solid-liquid interface between both hydrophobic d(8)-polystyrene (d(8)-PS) and SiO(2) model surfaces and phosphate buffered saline (PBS) at pH 7.4.

An investigation of the influence of chain length on the interfacial ordering of L-lysine and L-proline and their homopeptides at hydrophobic and hydrophilic interfaces studied by sum frequency generation and quartz crystal microbalance.

Sum frequency generation vibrational spectroscopy (SFG) and quartz crystal microbalance with dissipation monitoring (QCM-D) are employed to study the interfacial structure and adsorbed amount of the amino acids L-lysine and L-proline and their corresponding homopeptides, poly-L-lysine and poly-L-proline, at two liquid-solid interfaces. SFG and QCM-D experiments of these molecules are carried out at the interface between phosphate buffered saline at pH 7.4 (PBS) and the hydrophobic deuterated polystyrene (d8-PS) surface as well as the interface between PBS and hydrophilic fused silica (SiO2).

Infochemistry: encoding information as optical pulses using droplets in a microfluidic device.

This article describes a new procedure for generating and transmitting a message--a sequence of optical pulses--by aligning a mask (an opaque sheet containing transparent "windows") below a microfluidic channel in which flows an opaque continuous fluid containing transparent droplets. The optical mask encodes the message as a unique sequence of windows that can transmit or block light; the flow of transparent droplets in the channel converts this message into a sequence of optical pulses. The properties of the windows on the mask (e.

Sum frequency generation vibrational spectra: the influence of experimental geometry for an absorptive medium or media.

The influence of experimental geometry on infrared total internal reflection surface sum frequency generation (SFG) vibrational spectra at the water/solid interface has been examined. A detailed analysis of the experimental geometry revealed that the enhancement of SFG signal for the "critical angle" can be much weaker than previously thought if the index of refraction of the transmitted or reflected medium is treated as a complex value (i.e.

A new optical parametric amplifier based on lithium thioindate used for sum frequency generation vibrational spectroscopic studies of the amide I mode of an interfacial model peptide.

We describe a new optical parametric amplifier (OPA) that employs lithium thioindate, LiInS2 (LIS), to create tunable infrared light between 1500 cm(-1) and 2000 cm(-1). The OPA based on LIS described within provides intense infrared light with a good beam profile relative to similar OPAs built on silver gallium sulfide, AgGaS2 (AGS), or silver gallium selenide, AgGaSe2 (AGSe). We have used the new LIS OPA to perform surface-specific sum frequency generation (SFG) vibrational spectroscopy of the amide I vibrational mode of a model peptide at the hydrophobic deuterated polystyrene (d8-PS)-phosphate buffered saline interface.

The evolution of model catalytic systems; studies of structure, bonding and dynamics from single crystal metal surfaces to nanoparticles, and from low pressure (<10(-3) Torr) to high pressure (>10(-3) Torr) to liquid interfaces.

The material and pressure gap has been a long standing challenge in the field of heterogeneous catalysis and have transformed surface science and biointerfacial research. In heterogeneous catalysis, the material gap refers to the discontinuity between well-characterized model systems and industrially relevant catalysts. Single crystal metal surfaces have been useful model systems to elucidate the role of surface defects and the mobility of reaction intermediates in catalytic reactivity and selectivity.

Long-range electron transfer through monolayers and bilayers of alkanethiols in electrochemically controlled Hg[bond]neling junctions.

The rates of electron tunneling through monolayers and bilayers of alkanethiols self-assembled in a potentiostatically controlled Hg-Hg junction are reported. An alkanethiolate monolayer is formed in situ on one or both Hg drops via oxidative adsorption at the controlled potential. Subsequently, the Hg drops are brought into contact using micromanipulators.

Using a set-aside to encourage the evaluation of public health service programs.

For over 20 years, the secretary of the Department of Health and Human Services (HHS) has had the authority to use up to 1% of the annual Public Health Service (PHS) appropriations for the evaluation of federal health programs. However, recent changes to the Public Health Service Act put not only a ceiling (1%) but also a floor (0.2%) on the funds that the secretary can set aside for evaluation.

The process of exempt immediate relative immigration to the United States.

"To examine the chain migration issue [in the United States], this article develops and analyzes a new data base that links information on a sample of exempt immediate relative immigrants in Fiscal Year 1985 with information on the characteristics of their petitioners or sponsors. The analysis generally does not indicate that an explosive increase in future chain migration of exempt immediate relative immigrants is likely in the next ten years." Exempt immediate relative immigrants are defined as those who are exempt from numerical limitations because of their relationship with a U.