DJ-1,
a 20.7 kDa protein, is overexpressed in people who have bladder
cancer (BC). Its elevated concentration in urine allows it to serve
as a marker for BC. However, no biosensor for the detection of DJ-1
has been demonstrated. Here, we describe a virus bioresistor (VBR) capable of detecting DJ-1 in urine at a concentration
of 10 pM in 1 min. The VBR consists of a pair of
millimeter-scale gold electrodes that measure the electrical impedance
of an ultrathin (≈ 150–200 nm), two-layer polymeric
channel. The top layer of this channel (90–105 nm in thickness)
consists of an electrodeposited virus-PEDOT (PEDOT is poly(3,4-ethylenedioxythiophene))
composite containing embedded M13 virus particles that are engineered
to recognize and bind to the target protein of interest, DJ-1. The
bottom layer consists of spin-coated PEDOT–PSS (poly(styrenesulfonate)).
Together, these two layers constitute a current divider. We demonstrate
here that reducing the thickness of the bottom PEDOT–PSS layer
increases its resistance and concentrates the resistance drop of the
channel in the top virus-PEDOT layer, thereby increasing the sensitivity
of the VBR and enabling the detection of DJ-1. Large
signal amplitudes coupled with the inherent simplicity of the VBR sensor design result in high signal-to-noise (S/N > 100) and excellent sensor-to-sensor
reproducibility characterized by coefficients of variation in the
range of 3–7% across the DJ-1 binding curve down to a concentration
of 30 pM, near the 10 pM limit of detection (LOD), encompassing four
orders of magnitude in concentration.
Mechano-activated chemistry is a powerful tool for remodeling of synthetic polymeric materials, however, few reactions are currently available. Here we show that using piezochemical reduction of a Cu -based pre-catalyst, a step-growth polymerization occurs via the copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction to form a linear polytriazole. Furthermore, we show that a linear polymer can be crosslinked mechanochemically using the same chemistry to form a solid organogel. We envision that this chemistry can be used to harness mechanical energy for constructive purposes in polymeric materials.
This study assesses the water quality of the Upper Santa Cruz Watershed in southern Arizona in terms of fecal coliform and Escherichia coli (E. coli) bacteria concentrations discharged as treated effluent and from nonpoint sources into the Santa Cruz River and surrounding tributaries. The objectives were to (1) assess the water quality in the Upper Santa Cruz Watershed in terms of fecal coliform and E. coli by comparing the available data to the water quality criteria established by Arizona, (2) to provide insights into fecal indicator bacteria (FIB) response to the hydrology of the watershed and (3) to identify if point sources or nonpoint sources are the major contributors of FIB in the stream. Assessment of the available wastewater treatment plant treated effluent data and in-stream sampling data indicate that water quality criteria for E. coli and fecal coliform in recreational waters are exceeded at all locations of the Santa Cruz River. For the wastewater discharge, 13%-15% of sample concentrations exceeded the 800 colony forming units (cfu) per 100 mL sample maximum for fecal coliform and 29% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli; while for the in-stream grab samples, 16%-34% of sample concentrations exceeded the 800 cfu/100 mL sample maximum for fecal coliforms and 34%-75% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli. Elevated fecal coliform and E. coli concentrations were positively correlated with periods of increased streamflow from rainfall. FIB concentrations observed in-stream are significantly greater (p-value < 0.0002) than wastewater treatment plants effluent concentrations; therefore, water quality managers should focus on nonpoint
OPEN ACCESSWater 2013, 5 244 sources to reduce overall fecal indicator loads. Findings indicate that fecal coliform and E. coli concentrations are highly variable, especially along urban streams and generally increase with streamflow and precipitation events. Occurrences of peaks in FIB concentrations during baseflow conditions indicate that further assessment of ecological factors such as interaction with sediment, regrowth, and source tracking are important to watershed management.
OBJECTIVES:
The prevalence of psychiatric disease in patients with eosinophilic esophagitis (EoE) is not fully characterized. We aimed to determine the prevalence of psychiatric disease and centrally acting medication use in a cohort of children and adults with EoE and evaluated whether psychiatric disease affects the EoE clinical presentation.
METHODS:
We conducted a retrospective study of newly diagnosed cases with EoE at the University of North Carolina from 2002 to 2018. Psychiatric comorbidities and relevant treatments were extracted from the medical records. The demographic and clinical features of patients with EoE with and without psychiatric diagnoses, and those with and without psychiatric medication use, were compared.
RESULTS:
Of 883 patients (mean age 26.6 years, 68% men, 79% white), 241 (28%) had a psychiatric comorbidity. The most common diagnosis was anxiety (23%) followed by depression (17%); 28% of patients were treated pharmacologically. There were 45 patients (5%) treated pharmacologically without a psychiatric diagnosis for chronic pain syndromes, insomnia, and/or epilepsy. Cases with EoE with a psychiatric diagnosis were more likely to be women, white, and 18 years or older and to have a longer symptom duration before diagnosis.
DICUSSION:
Psychiatric comorbidities were common in EoE, seen in a third of adults and more than 1 in 7 children, and with similar proportions receiving a prescription medication. These illnesses affected the EoE presentation because psychiatric comorbidities were more likely in older, female, and white patients with a longer duration of symptoms preceding diagnosis.
The COVID-19 pandemic has resulted in over two million deaths worldwide. Despite efforts to fight the virus, the disease continues to overwhelm hospitals with severely ill patients.
A polymer-based electrode capable of specific detection of human serum albumin, and its glycated derivatives, is described. The sensor is constructed from a glass microscope slide coated with a synthesized, polythiophene film bearing a protected, iminodiacetic acid motif. The electrode surface is then further elaborated to a functional biosensor through deprotection of the iminodiacetic acid, followed by metal-affinity immobilization of a specific and high-affinity, albumin ligand. Albumin was then quantified in buffer and synthetic urine via electrochemical impedance spectroscopy. Glycated albumin was next bound to a boronic acid-modified, singlecysteine dihydrofolate reductase variant to quantify glycation ratios by square-wave voltammetry. The platform offers high sensitivity, specificity, and reproducibility in an inexpensive arrangement. The detection limits exceed the requirements for intermediate-term glycemic control monitoring in diabetes patients at 5 and 1 nM for albumin and its glycated forms, respectively.
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