Cystic fibrosis: a label-free detection approach based on thermally modulated electrochemical impedance spectroscopy.

Cystic fibrosis is one of the most common genetically inherited diseases in northern Europe, with the DF508 mutation being the most common, and among the Caucasian population being responsible for almost 70% of cases. In this work, we report on the use of thermally modulated electrochemical impedance spectroscopy for the discrimination of the DF508 mutation from the wild-type sequence. DNA probes (15 and 21 bases long) were immobilised on the surface of gold electrodes and the variation of the charge-transfer resistance was monitored as a function of hybridisation.

Beam shaping using Gaussian beam modes.

A beam shaping method is presented where a diffractive optical element (DOE) is designed by optimizing the complex mode coefficient weights of a set of Gaussian beam modes. This method is compared with the more standard unidirectional approach. Differential evolution is used for the optimization in both the unidirectional and Gaussian beam mode optimization methods.

Amperometric immunosensor for carcinoembryonic antigen in colon cancer samples based on monolayers of dendritic bipodal scaffolds.

Detection of proteins that signal the presence or recurrence of cancer is a powerful therapeutic tool for effective early diagnosis and treatment. Carcinoembryonic antigen (CEA) has been extensively studied as a tumor marker in clinical diagnosis. We report on the development of an amperometric biosensor for the detection of CEA based on the immobilization of anti-CEA monoclonal antibody on a novel class of bipodal thiolated self-assembled monolayers containing reactive N-hydroxysuccinimide (NHS) ester end groups.

Triad of trichomegaly, alopecia and male-pattern hair growth during treatment with erlotinib in non-small-cell lung cancer.

Introduction: Description of the cutaneous side effects of erlotinib.

Materials: Report with images of a single case.

Methods: Case report and review of the literature.

Proposed epidemiological case definition for serious skin infection in children.

Aim: Researching the rising incidence of serious skin infections in children is limited by the lack of a consistent and valid case definition. We aimed to develop and evaluate a good quality case definition, for use in future research and surveillance of these infections.

Methods: We tested the validity of the existing case definition, and then of 11 proposed alternative definitions, by assessing their screening performance when applied to a population of paediatric skin infection cases identified by a chart review of 4 years of admissions to a New Zealand hospital.

Women with protective orders report failure to remove firearms from their abusive partners: results from an exploratory study.

Aims: The purpose of this study was to describe the perceptions of women who sought court protection orders for domestic violence (PODV) about actions to implement laws intended to disarm their abusers.

Methods: We identified female victims of intimate partner violence (IPV) in New York and Los Angeles primarily through family courts and records of police calls for domestic violence. Of these, 782 were surveyed and asked about their experiences seeking PODV from courts, judges ordering the removal of firearms from defendants, and if firearms were actually surrendered or confiscated.

Intimate partner violence: development of a brief risk assessment for the emergency department.

Objectives: Women assaulted by intimate partners are frequently patients in emergency departments (EDs). Many victims and health care providers fail to take into account the potential risks of repeat partner violence. The objective of this study was to use data from a larger study of domestic violence risk assessment methods to develop a brief assessment for acute care settings to identify victims at highest risk for suffering severe injury or potentially lethal assault by an intimate partner or former partner.

Methylene blue as an electrochemical indicator for DF508 cystic fibrosis mutation detection.

Cystic fibrosis is one of the most common life-shortening, childhood-onset inherited diseases. Among the 1,000 known cystic fibrosis-related mutations, DF508 is the most common, with a frequency varying between 50% and 70% according to geographical areas and population typology. In this work, we report the use of methylene blue as an electrochemical reporting agent in the discrimination of synthetic PCR analogue of the DF508 cystic fibrosis mutation (Mut) from the wild type (Wt).

Microfluorimeter with disposable polymer chip for detection of coeliac disease toxic gliadin.

Coeliac disease is an inflammatory disease of the upper small intestine and results from gluten ingestion in genetically susceptible individuals, and is the only life-long nutrient-induced enteropathy. The only treatment is a strict gluten-free diet and the longer the individual fails to adhere to this diet, the greater the chance of developing malnutrition and other complications. The existence of reliable gluten free food is crucial to the well-being of the population.

Curvature-tuned preparation of nanoliposomes.

Numerous methods have been reported for the preparation of liposomes, many of which, in addition to requiring time-consuming preparative steps and the use of organic solvents, result in heterogeneous liposome populations of incontrollable size. Taking into consideration the phenomenon of spontaneous vesiculation and the theory of curvature, here we present an extremely rapid and simple, solvent-free method for the preparation of monodisperse solutions of highly stable small unilamellar vesicles using both charged and zwitterionic lipids mixed with lyso-palmitoylphosphatidylcholine, exploiting a combination of a rapid pH change followed by a defined period of equilibration. Various experimental parameters and their interactions were evaluated in terms of their effect on resulting liposome size and shape, as well as on liposome stability and size distribution, with transmission electron microscope imaging being used to visualize the formed liposomes, and photon correlation spectroscopy to obtain statistical data on mean diameter and monodispersity of the liposome population.

Perceiving emotion in crowds: the role of dynamic body postures on the perception of emotion in crowded scenes.

Although the perception of emotion in individuals is an important social skill, very little is known about how emotion is determined from a crowd of individuals. We investigated the perception of emotion in scenes of crowds populated by dynamic characters each expressing an emotion. Facial expressions were masked in these characters and emotion was conveyed using body motion and posture only.

Electrochemcial characterisation and hybridisation efficiency of co-assembled monolayers of PEGylated ssDNA and mercaptohexanol on planar gold electrodes.

The realisation of efficient genosensors relies crucially on the surface chemistry strategy selected for the immobilisation of DNA probes. We report on the performance of surfaces prepared via the direct co-immobilisation of a 20-nucleotide (nt) thiolated single stranded DNA probe (ssDNA) in the presence of the short alkanethiol mercaptohexanol (MCH) at varying ratio. Electrochemical impedance spectroscopy was used for the physical characterisation of the formed monolayers.

Microsystem for isolation of fetal DNA from maternal plasma by preparative size separation.

Background: Routine prenatal diagnosis of chromosomal anomalies is based on invasive procedures, which carry a risk of approximately 1%-2% for loss of pregnancy. An alternative to these inherently invasive techniques is to isolate fetal DNA circulating in the pregnant mother's plasma. Free fetal DNA circulates in maternal plasma primarily as fragments of lengths <500 bp, with a majority being <300 bp.

Design and testing of a packaged microfluidic cell for the multiplexed electrochemical detection of cancer markers.

We present the rapid prototyping of electrochemical sensor arrays integrated to microfluidics towards the fabrication of integrated microsystems prototypes for point-of-care diagnostics. Rapid prototyping of microfluidics was realised by high-precision milling of polycarbonate sheets, which offers flexibility and rapid turnover of the desired designs. On the other hand, the electrochemical sensor arrays were fabricated using standard photolithographic and metal (gold and silver) deposition technology in order to realise three-electrode cells comprising gold counter and working electrodes as well as silver reference electrode.

Spontaneous room temperature elongation of CdS and Ag2S nanorods via oriented attachment.

Spontaneous elongation from nanorod to nanowire in the presence of an amine is reported for nanocrystals of cadmium sulfide and silver sulfide (cation exchanged from CdS). Elongation occurs instantaneously where the final aspect ratio is a controllable multiple of the original nanorod length. Transmission electron microscopy (TEM) analysis reveals the influential factors on the attachment process are the concentration of amine, duration and temperature of the reaction.

Electrochemical immunosensor for detection of celiac disease toxic gliadin in foodstuff.

Celiac disease is a gluten-sensitive enteropathy that affects as much as 1% of the population. Patients with celiac disease should maintain a lifelong gluten-free diet, in order to avoid serious complications and consequences. It is essential to have methods of analysis to reliably control the contents of gluten-free foods, and there is a definitive need for an assay that is easy to use, and can be used on site, to facilitate the rapid testing of incoming raw materials or monitoring for gluten contamination, by industries generating gluten-free foods.

Parity violation constraints using cosmic microwave background polarization spectra from 2006 and 2007 observations by the QUaD polarimeter.

We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 degrees +/-0.

Rapid and efficient method for the size separation of homogeneous fluorescein-encapsulating liposomes.

Liposomes are colloidal structures formed by the self-assembly of lipid molecules in solution into spherical, self-closed structures through their amphiphilic properties. All liposome preparation protocols reported consist of several steps of preparation, homogenization, and purification, which are labor-intensive, arduous, and lengthy to execute. In this work, a new procedure has been developed to reduce the time of the postrehydration sizing of liposomes from multilamellar vesicles, while improving the uniformity of the resulting liposomes produced and achieving high encapsulation efficiencies.

Amperometric immunosensor for detection of celiac disease toxic gliadin based on Fab fragments.

Immunosensor sensitivity is strongly dependent on the density of free active epitopes per surface area, which could be achieved via well-oriented immobilization of antibody fragments as bioreceptor molecules. Here, we report on the development of an electrochemical gliadin immunosensor based on the spontaneous self-assembly of antigliadin Fab fragments (CDC5-Fab) on Au surfaces. The analytical performance of this immunosensor is compared with a similar containing whole CDC5 antibodies previously modified with thiol groups (CDC5-SH) as the recognition element.

Real-time apta-PCR for 20 000-fold improvement in detection limit.

A real-time apta-PCR for the ultrasensitive detection of thrombin is reported, where the thrombin aptamer acts not only as a biomolecular recognition element, but also as a label for amplification via real-time PCR. Aptamers can be easily converted to a reporter agent for detection by real-time PCR, simply via flanking of the aptamer's recognition moiety with primer sequences. The reported technique has the advantage of the ultrasensitivity achievable with immuno-PCR, but without the complications of addition of a DNA label, and is a technique generically applicable to all aptamers.

Label free optical sensor for Avidin based on single gold nanoparticles functionalized with aptamers.

Optical spectroscopy of a single gold nanoparticle, functionalized with an aptamer, is used to sense the specific binding of avidin. Herewith, the field of single noble metal nanoparticle biosensors is extended to the important field of aptamer based assays. The sensitivity of this initial, but not yet optimized apta-nano-sensor is in the range of 20 nM.

Microsystem for field-amplified electrokinetic trapping preconcentration of DNA at poly(ethylene terephthalate) membranes.

In electrokinetic trapping (EKT), the electroosmotic velocity of a buffer solution in one area of a microfluidic device opposes the electrophoretic velocity of the analyte in a second area, resulting in transport of DNA to a location where the electrophoretic and electroosmotic velocities are equal and opposite and DNA concentrates at charged nanochannels. The method does not require an optical plug localization, a considerable advantage as compared to preconcentration techniques previously presented. In the work reported here, the trapping process is preceded by a field-amplification in the sample reservoir to reduce trapping time, as field-amplified EKT is shown to be an effective technique to preconcentrate samples from larger volumes.