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In this review we have highlighted a few innovative microfluidic analytical technologies with mobile phone image processing tools for various bio-chemical tests performed using salivary biomarkers. Saliva-based assays for mobile monitoring with a smartphone sensor provide an excellent analytical technique which can be simple to perform. We describe several examples from the literature, utilizing different modalities of analysis, applied to several different applications of mobile health monitoring: cortisol monitoring, infectious disease testing, and drugs of abuse.

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We present a novel microfluidic device for size-based nucleic acid (NA) fractionation using isotachophoresis (ITP) and an ionic spacer. Our rapid-prototyped laser-cut plastic device has easily modifiable channel dimensions, can process up to 10 µL of sample, and contains an in-line extraction reservoir for minimally-disruptive manual collection of size-fractionated NAs. We designed custom buffering reservoirs using 1 mL pipette tips to provide high buffering capacity and prevent bubbles from entering the microfluidic channels. We demonstrated the utility of the device by implementing a proof-of-concept assay in which NAs were preconcentrated (via ITP) and then segregated by size (using the ionic spacer and sieving matrix) to generate two separate fractions, the first comprised of small (<50 nt) NA, and the second comprised of NAs of all sizes. Through this approach, we demonstrated size-based fractionation of both DNA and RNA samples (a mixture of synthetic ssDNA molecules, and a commercially-available RNA molecular weight standard, respectively). Our results indicate that this simple, rapid (≤10 min), and label-free approach is a promising and cost-effective alternative to the commercially-available size-selection kits currently on the market. We discuss the design and features of the device, as well as challenges which must be met in the future in order to further improve its performance and utility.

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Check valves are often essential components in microfluidic devices, enabling automated sample processing for diagnostics at the point of care. However, there is an unmet need for a check valve design that is compatible with rigid thermoplastic devices during all stages of development-from initial prototyping with a laser cutter to final production with injection molding. Here, we present simple designs for a passive, normally closed check valve that is manufactured from commonly available materials with a CO2 laser and readily integrated into prototype and production thermoplastic devices. The check valve consists of a thermoplastic planar spring and a soft elastomeric pad that act together to seal against fluid backflow. The valve's cracking pressure can be tuned by modifying the spring's planar geometry and thickness. Seal integrity is improved with the addition of a raised annular boss beneath the elastomeric pad. To demonstrate the valve's usefulness, we employ these valves to create a finger-operated on-chip reagent reservoir and a finger-actuated pneumatic pump. We also apply this check valve to passively seal a device to enable portable detection of RNA from West Nile virus in a laser-cut device.

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BACKGROUND CONTEXT: The North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Degenerative Lumbar Spondylolisthesis features evidence-based recommendations for diagnosing and treating degenerative lumbar spondylolisthesis. The guideline updates the 2008 guideline on this topic and is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spondylolisthesis as reflected in the highest quality clinical literature available on this subject as of May 2013. The NASS guideline on this topic is the only guideline on degenerative lumbar spondylolisthesis included in the Agency for Healthcare Research and Quality's National Guideline Clearinghouse (NGC). PURPOSE: The purpose of this guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for patients with degenerative lumbar spondylolisthesis. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. STUDY DESIGN: A systematic review of clinical studies relevant to degenerative spondylolisthesis was carried out. METHODS: This NASS spondyolisthesis guideline is the product of the Degenerative Lumbar Spondylolisthesis Work Group of NASS' Evidence-Based Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members used the NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guidelines were submitted to an internal peer review process and ultimately approved by the NASS Board of Directors. Upon publication, the Degenerative Lumbar Spondylolisthesis guideline was accepted into the NGC and will be updated approximately every 5 years. RESULTS: Twenty-seven clinical questions were addressed in this guideline update, including 15 clinical questions from the original guideline and 12 new clinical questions. The respective recommendations were graded by strength of the supporting literature, which was stratified by levels of evidence. Twenty-one new or updated recommendations or consensus statements were issued and 13 recommendations or consensus statements were maintained from the original guideline. CONCLUSIONS: The clinical guideline was created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients with degenerative lumbar spondylolisthesis. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flow chart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/Pages/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx and will remain updated on a timely schedule.

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The conjugation of an uncharged polymer to DNA fragments makes it possible to separate DNA by free-solution electrophoresis. This end-labeled free-solution electrophoresis method has been shown to successfully separate ssDNA with single monomer resolution up to about 110 bases. It is the aim of this paper to investigate in more detail the coupled hydrodynamic and electrophoretic deformation of the ssDNA-label conjugate at fields below 400 V/cm. Our model is an extension of the theoretical approach originally developed by Stigter and Bustamante [Biophys. J. 75, 1197 (1998)] to investigate the problems of a tethered chain stretching in a hydrodynamic flow and of the electrophoretic stretch of a tethered polyelectrolyte. These two separate models are now used together since the charged DNA is "tethered" to the uncharged polymer (and vice versa), and the resulting self-consistent model is used to predict the deformation and the electrophoretic velocity for the hybrid molecule. Our theoretical and experimental results are in good qualitative agreement.

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BACKGROUND: Hyperhidrosis is a common yet poorly understood disease that is often exacerbated by emotional stress. While a psychiatric explanation of causality is frequently offered, there is little evidence to support or reject the view that the condition is primarily an anxiety-based disorder. OBJECTIVES: To quantify objectively the degree of psychopathology in patients with hyperhidrosis. METHODS: Forty-two patients diagnosed as having hyperhidrosis were examined prior to endoscopic sympathectomies. All patients took the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and State-Trait Anxiety Inventory (STAI) before surgery. Results were compared with established norms. RESULTS: The group scored well within established norms on both psychometric measures. On scales measuring anxiety, depression and conversion phenomena, 88% of the MMPI-2 profiles lacked elevations, and 86% of the patients lacked elevations on the STAI State and Trait Anxiety scales. Personality variables were not associated with postsurgical outcome. CONCLUSIONS: Most individuals suffering from essential hyperhidrosis lack overt psychopathology. While some patients subjectively describe symptoms of anxiety, mild depression and social isolation, these complaints appear often to be in reaction to or superimposed upon an organic disease process and not the primary cause of their condition.

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