Thieno[3,2-]thiophene for the Construction of Far-Red Molecular Rotor Hemicyanines as High-Affinity DNA Aptamer Fluorogenic Reporters.

The construction of far-red fluorescent molecular rotors (FMRs) is an imperative task for developing nucleic acid stains that have superior compatibility with cellular systems and complex matrices. A typical strategy relies on the methine extension of asymmetric cyanines, which unfortunately fails to produce sensitive rotor character. To break free from this paradigm, we have synthesized far-red hemicyanines using a dimethylamino thieno[3,2-]thiophene donor.

Ferroelectric hydrogels from amino acids and oleic acid.

Ferroelectric bio-based materials with a high water content (≈90 wt %) were not previously developed. Here, we develop hydrogels containing ≈90 wt % water, amino acids (lysine and arginine) and oleic acid. The NH and CH groups of lysine hydrogen bond water, as shown by attenuated total reflectance-Fourier transform infrared spectroscopy, yielding electrically conductive solutions.

Sensitive electrochemical detection of methimazole based on a unique copper and exfoliated graphene oxide nanocomposite.

Herein, we report the creation of a novel sensitive electrochemical sensing platform based on a copper and exfoliated graphene oxide (Cu-eGO) nanocomposite using a facile synthesis technique, which simultaneously removes the sodium ions that result from the exfoliation process to generate eGO from graphite. This novel Cu-eGO nanocomposite was characterized via SEM, EDX, Raman and XPS. The Cu-eGO/GCE exhibited much greater activity for the electrochemical oxidation of methimazole than the eGO/GCE or bare GCE.

Mechanical Exfoliation of Expanded Graphite to Graphene-Based Materials and Modification with Palladium Nanoparticles for Hydrogen Storage.

Hydrogen is a promising green fuel carrier that can replace fossil fuels; however, its storage is still a challenge. Carbon-based materials with metal catalysts have recently been the focus of research for solid-state hydrogen storage due to their efficacy and low cost. Here, we report on the exfoliation of expanded graphite (EG) through high shear mixing and probe tip sonication methods to form graphene-based nanomaterial ShEG and sEG, respectively.

Spatially Resolved Optical Spectroscopic Measurements with Simultaneous Photoelectrochemical Mapping Using Scanning Electrochemical Probe Microscopy.

A deep understanding of the properties of semiconductor films at the micro-/nanoscale level is fundamental toward designing effective photoelectrocatalysts. Here, we integrated spatially resolved optical spectroscopy (SR-OS) with scanning photoelectrochemical microscopy (SPECM) to collect UV/vis spectra and quantify photocurrents of localized sites on a nanostructured BiVO thin film. Direct measurement of absorbance allowed for the determination of band gap energy at each location.

Experimental and computational studies of photoelectrochemical degradation of atrazine by modified nanoporous titanium dioxide.

The presence of herbicides like Atrazine (ATZ) in groundwater from non-target runoff of the agriculture industry becomes a big concern due to its potential negative impacts on the environment and human health. The use of advanced oxidative processes (AOP) to remove harmful contaminants has been shown to be effective for wastewater treatment. Herein, we report on an advanced photoelectrochemical (PEC) approach based on electrochemically modified nanoporous TiO electrode for efficient degradation of ATZ.

Unraveling the Chemosensing Mechanism by the 7-(Diethylamino)coumarin-hemicyanine Hybrid: A Ratiometric Fluorescent Probe for Hydrogen Peroxide.

The hemicyanine hybrid containing the 7-(diethylamino)coumarin (ACou) donor attached to the cationic indolenium (Ind) acceptor through a vinyl linkage (ACou-Ind) represents a classic ratiometric fluorescent probe for detecting nucleophilic analytes, such as cyanide and reactive sulfur species (RSS), through addition reactions that disrupt dye conjugation to turn off red internal charge transfer (ICT) fluorescence and turn on blue coumarin emission. The chemosensing mechanism for RSS detection by ACou-Ind suggested in the literature has now been revised. Our studies demonstrate that thiolates react with ACou-Ind through conjugate addition to afford C4-SR adducts that lack coumarin fluorescence due to photoinduced electron transfer quenching by the electron-rich enamine intermediate.

Methods for Enhanced Fluorescence Detection of Proteins by using Entrapped Gold Nanoparticles in Membranes.

Measuring protein levels from biofluids can provide important insight into human health and disease during various physiological and pathological conditions. In many situations, sensitive methods are required for protein quantification because at the early stages of many diseases, proteins in biofluids are present at very low concentrations. Here, a new and simple method is presented in the form of Basic and Alternative Protocols for an immunoassay performed on a nitrocellulose membrane, followed by the addition of gold nanoparticles prior to measuring fluorescence with a microscope.

Entrapping gold nanoparticles in membranes for simple-to-use enhanced fluorescence detection of proteins.

Quantifying proteins under different physiological and pathological conditions can give important insights into human health and disease, since proteins are the functional components of cells. In order to be able to use protein expression levels to diagnose diseases, sensitive protein quantification techniques are required, because some proteins can be present in low concentrations in biofluids at early stages of a disease. Here, a novel and simple-to-implement signal enhancement method for fluorescence-based protein detection is presented, in which an immunoassay was conducted on a nitrocellulose membrane, and a solution of gold nanoparticles was then pipetted onto the membrane before signal acquisition with a fluorescence microscope.

Highly boosted gas diffusion for enhanced electrocatalytic reduction of N to NH on 3D hollow Co-MoS nanostructures.

Transition metal chalcogenide MoS catalysts are highly selective for the electrochemical reduction of dinitrogen (N) to ammonia (NH) in aqueous electrolytes. However, due to the low solubility of N in water, limited N diffusion and mass transport have heavily restricted the yield and the faradaic efficiency (FE). Here, we have demonstrated a highly efficacious assembled gas diffusion cathode with hollow Co-MoS/N@C nanostructures to significantly improve the electrochemical reduction of N to NH.

Graphene-Oxide-Based Electrochemical Sensors for the Sensitive Detection of Pharmaceutical Drug Naproxen.

Here we report on a selective and sensitive graphene-oxide-based electrochemical sensor for the detection of naproxen. The effects of doping and oxygen content of various graphene oxide (GO)-based nanomaterials on their respective electrochemical behaviors were investigated and rationalized. The synthesized GO and GO-based nanomaterials were characterized using a field-emission scanning electron microscope, while the associated amounts of the dopant heteroatoms and oxygen were quantified using x-ray photoelectron spectroscopy.

Sulfur vacancy-rich N-doped MoS nanoflowers for highly boosting electrocatalytic N fixation to NH under ambient conditions.

In this communication, optimized sulfur vacancy-rich nitrogen-doped MoS2 nanoflowers were developed, which served as excellent N2 reduction reaction (NRR) electrocatalysts for the conversion of N2 to NH3 under ambient conditions. Electrochemical results demonstrated that the as-prepared N-doped MoS2 electrode afforded a superior NH3 yield and high faradaic efficiency, which exceeded those of the recently reported MoS2 catalysts. The possible NRR catalytic mechanism and electron transfer pathway were further elucidated via density functional theory calculations.

Seeing baby: women's experience of prenatal ultrasound examination and unexpected fetal diagnosis.

Objective: Although prenatal ultrasound (US) is a common clinical undertaking today, little information is available about women's experience of the procedure from the perspective of women themselves. The objective of this study was to explore women's experience of undergoing a routine prenatal US examination associated with an unexpected fetal diagnosis.

Study Design: Qualitative methods were used to explore the prenatal US experience of 13 women.

Building safer systems by ecological design: using restoration science to develop a medication safety intervention.

Background: Experts call for stronger safety cultures and transparent reporting practices to increase medication safety in today's strained healthcare environments. The field of ecological restoration is concerned with the effective, efficient, and sustainable repair and recovery of ecosystems that have been degraded, damaged, or destroyed. A study was undertaken to determine whether the lessons of restoration science can be adapted to the study of medication safety issues.

Cognitive and language development of healthy preterm infants at 10 years of age.

In this longitudinal study, forty-three Canadian 10-year-olds, 20 born preterm without significant health problems and 23 born at term, were compared. Cognitive development was measured by the Wechsler Intelligence Scale for Children-III. Language development was measured by the Clinical Evaluation of Language Fundamentals-3 (CELF-3) and language used in a 5 minute interview.

Hermeneutic-phenomenology: providing living knowledge for nursing practice.

The phenomenological approach has gained popularity among nurse researchers as an alternative investigative method to those used in the natural sciences. As more nurse scholars and nurse researchers utilize phenomenology as a research approach, it becomes critical to examine the implications this may have for nursing knowledge development and for the utilization of that knowledge in practice. In this paper, an examination of the results of phenomenological inquiry is presented and compared with the types of knowledge considered important for nursing by Carper and White.

The perinatal death of a twin. Karla's story of attaching and detaching.

This article examines the attaching and detaching experience of a mother encountering the perinatal death of a twin. Her experience is related to the relevant theoretical and research literature pertaining to prebirth and postbirth maternal-infant attachment and detachment (grieving). Literature for both single infants and twins is considered.

Accommodating a twin pregnancy: maternal processes.

The object of this study was to develop a theory of the relationship between a mother and her unborn twins using a qualitative grounded theory methodology. Ten women participated in interviews during the last trimester of a twin pregnancy and again during the early postpartum period. Data provided by these women was analysed using the constant comparative method.

Increase of sodium current after pyrethroid insecticides in mouse neuroblastoma cells.

The effects of 4 different pyrethroid insecticides on sodium channel gating in internally perfused, cultured mouse neuroblastoma cells (N1E-115) were studied using the suction pipette, voltage clamp technique. Pyrethroids increased the amplitude of the sodium current, sometimes by more than 200%. Activation of the sodium current occurred at more hyperpolarized potentials than under control conditions.

Temperature- and structure-dependent interaction of pyrethroids with the sodium channels in frog node of Ranvier.

(1) The interaction of a series of pyrethroid insecticides with the Na+ channels in myelinated nerve fibres of the clawed frog, Xenopus laevis, was investigated using the voltage clamp technique. (2) Out of 11 pyrethroids 9 insecticidally active compounds induce a slowly decaying Na+ tail current on termination of a step depolarization, whereas the Na+ current during depolarization was hardly affected. These tail currents are most readily explained by a selective reduction of the rate of closing of the activation gate in a fraction of the Na+ channels that have opened during depolarization.

Frequency response of the lateral-line organ of Xenopus laevis.

The stimulus response relation of the epidermal lateral-line organ of Xenopus laevis was studied by recording activity of single afferent nerve fibres in isolated preparations. Linear frequency response analysis over a frequency range of 0.1--100Hz was performed under steady-state conditions, using small amplitude, sinusoidal water displacements produced by a glass sphere at a short distance from the skin.

Effects of aldrin-transdiol on neuromuscular facilitation and depression.

The effects of aldrin-transdiol, one of the active metabolites of the insecticide dieldrin, on evoked transmitter release, neuromuscular facilitation and neuromuscular depression have been studied in frog sartorius nerve-muscle preparations. Conventional techniques of intracellular recordings were used. Aldrin-transdiol caused a marked increase in end-plate potential amplitude under conditions of low quantal content, i.