OBJECTIVE To determine the diagnostic value of fetal ST-segment analysis (STAN) in predicting neonatal acidosis. METHODS The STAN S21 was used to monitor singleton fetuses in labor with abnormal FHR. Physicians later reviewed tracings to identify any ST events dictating intervention. Outcome measures were umbilical artery pH< or =7.15 and pH< or =7.05 at birth. The sensitivity, specificity, P...

System A and N amino acid transporters are key effectors of movement of amino acids across the plasma membrane of mammalian cells. These Na+-dependent transporters of the SLC38 gene family are highly sensitive to changes in pH within the physiological range, with transport markedly depressed at pH 7.0. We have investigated the possible role of histidine residues in the transporter proteins in d...

A pH-sensitive RuO&#8322; electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO&#8322; working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO&#8322; pH-sensitive working electrode and a SiO&#8322;-PVB junction-modified RuO&...

In this work, automatic pH changing system on lab-on-paper devices for enzyme-linked immunosorbent (ELISA) has been developed in order to improve their sensitivity and make the technique much more applicable to real samples. The most widely used enzyme in immunoassay are alkaline phosphatase (ALP) and peroxidase. ALP-conjugated secondary detection with BCIP/NBT substrate provides high sensitivi...

A series of luminescent transition metal complexes using the pH-sensitive ligand 5-carboxy-1,10-phenanthroline has been synthesized and characterized. The complexes, based on Ru(II) and Re(I), show monotonic changes in both luminescent intensity and lifetime with pH values over the range 2 < pH < 9. The impact of various structural features on both the range of pH sensitivity and dynamic respon...

Fe2O3-Bi2O3-B2O3 (FeBiB) glasses were developed as novel pH responsive hydrophobic glasses. The influence of the glass composition on the pH sensitivity of FeBiB glasses was investigated. The pH sensitivity drastically decreased with decreasing B2O3 content. A moderate amount of Fe2O3 and a small amount of B2O3 respectively produces bulk electronic conduction and a pH response on glass surfaces...

pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP) magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for...

TRPM2 is a Ca(2+)-permeable nonselective cation channel that plays important roles in oxidative stress-mediated cell death and inflammation processes. However, how TRPM2 is regulated under physiological and pathological conditions is not fully understood. Here, we report that both intracellular and extracellular protons block TRPM2 by inhibiting channel gating. We demonstrate that external prot...

Overcoming the nonspecific cellular uptake of cell-penetrating peptides (CPPs) is a major hurdle in their clinical application. Using pH as the activation switch, histidine-glutamic acid (HE) dipeptide repeats were fused to CPPs to trigger the membrane-penetrating activity at mildly acidic pH environments (i.e., pH 6.5 or below) while masking the internalization at neutral pH (i.e., pH 7.0 or a...