We report fabrication and characterization of a new hydrogel-based microsensor for wireless chemical monitoring. The basic device structure is a high-sensitivity capacitive pressure sensor coupled to a stimuli-sensitive hydrogel that is confined between a stiff porous membrane and a thin glass diaphragm. As small molecules pass through the porous membrane, the hydrogel swells and deflects the d...

The effect of environmental variation on the susceptibility of Neisseria gonorrhoeae to pyocin produced by Pseudomonas aeruginosa was examined. Susceptibility to at least one pyocin was demonstrated in strains of N. gonorrhoeae (99%), N. meningitidis (35%), and N. lactamica (47%). The degree of sensitivity to pyocin displayed by N. gonorrhoeae was affected by varying the pH of the growth enviro...

We reported recently that regulation by intracellular pH (pH(i)) of the murine Cl-/HCO(3)(-) exchanger AE2 requires amino acid residues 310-347 of the polypeptide's NH(2)-terminal cytoplasmic domain. We have now identified individual amino acid residues within this region whose integrity is required for regulation of AE2 by pH. 36Cl- efflux from AE2-expressing Xenopus oocytes was monitored duri...

Fabrication and characterization of U-shaped fiber optic pH probes utilizing evanescent field absorption spectroscopy and dye doped solgel immobilization technology are presented. The U-shaped probe is used to increase the evanescent field in the film and hence its interaction with the dyes present in the film. The influences of bending radius of the probe and the numerical aperture of the fibe...

Pressure-damaged Escherichia coli O157 cells were more acid sensitive than native cells and were impaired in pH homeostasis. However differences in acid sensitivity were not related to differences in cytoplasmic pH (pH(i)). Cellular beta-galactosidase was more acid labile in damaged cells. Sensitization to acid may thus involve loss of protective or repair functions.

BACKGROUND Pulmonary hypertension (PH) is a serious complication to interstitial lung disease (ILD) and has a poor prognosis. PH is often diagnosed by screening with echocardiography followed by right heart catheterisation. A previous study has shown that a value of NT-pro-brain natriuretic peptide (NT-proBNP) <95 ng/l could be used to rule out PH in patients with ILD. AIM To evaluate this ru...

We report a systematic investigation about the mechanism of pH sensing using SnO2 nanobelt field effect transistors (FETs). The FETs, based on single SnO2 nanobelts, are channel-limited and with proper contact passivation; the pH sensing was conducted with sodium phosphate solutions through integrated microfluidics. The responses of the FET channel conductance to pH were measured at different g...

Polyelectrolyte complexes (PECs) are self-assembling nano-sized constructs that offer several advantages over traditional nanoparticle carriers including controllable size, biodegradability, biocompatibility, and lack of toxicity, making them particularly appealing as tools for drug delivery. Here, we discuss potential application of PECs for drug delivery to the slightly acidic tumor microenvi...

Several kinds of biodegradable hydrogels were prepared via in situ photopolymerization of Pluronic F127/poly(ε-caprolactone) macromer and acrylic acid (AA) comonomer in aqueous medium. The swelling kinetics measurements showed that the resultant hydrogels exhibited both thermoand pH-sensitive behaviors, and that this stimuli-responsiveness underwent a fast reversible process. With increasing pH...

This study fabricated novel multifunctional pH-sensitive nanoparticles loaded into microbubbles (PNP-MB) with the combined advantages of two excellent drug delivery vehicles, namely, pH-sensitive nanoparticles and microbubbles. As an antitumor drug, resveratrol (RES) was loaded into acetylated β-cyclodextrin nanoparticles (RES-PNP). The drug-loaded nanoparticles were then encapsulated into the ...