Accessible biometrics: a frustrated total internal reflection approach to imaging fingerprints

Fingerprints are widely used as a means of identifying persons of interest because of the highly individual nature of the spatial distribution and types of features (or minuta) found on the surface of a finger. This individuality has led to their wide application in the comparison of fingerprints found at crime scenes with those taken from known offenders and suspects in custody. However, despite recent advances in machine vision technology and image processing techniques, fingerprint evidence is still widely being collected using outdated practices involving ink and paper – a process that can be both time consuming and expensive. Reduction of forensic service budgets increasingly requires that evidence be gathered and processed more rapidly and efficiently. However, many of the existing digital fingerprint acquisition devices have proven too expensive to roll out on a large scale. As a result new, low-cost imaging technologies are required to increase the quality and throughput of the processing of fingerprint evidence. Here we describe an inexpensive approach to digital fingerprint acquisition that is based upon frustrated total internal reflection imaging. The quality and resolution of the images produced are shown to be as good as those currently acquired using ink and paper based methods. The same imaging technique is also shown to be capable of imaging powdered fingerprints that have been lifted from a crime scene using adhesive tape or gel lifters

An electrochemical investigation on polyvinylidene fluoride-based gel polymer electrolytes

Many types of polymer electrolytes have been developed and characterized in the past few years. Recently special attention has been focussed on the development of gel polymer electrolytes consisting of host polymers such as PAN, PVC, PVP, PVS, PMMA, PEGDA and PVdF etc., as they may find unique applications in consumer electronic and electric vehicle products. In the present study, gel polymer electrolytes have been prepared using the solvent casting technique in the presence of PVdF-1015 (SOLEF), EC1PC as a plasticizer, and LiBF salt. The influence of the amount of polymer, 4 plasticizer and LiBF on the gel electrolytes has been studied using XRD, DSC, AC impedance and charge–discharge 4 studies

An electrochemical investigation on polyvinylidene fluoride-based gel polymer electrolytes

Many types of polymer electrolytes have been developed and characterized in the past few years. Recently special attention has been focussed on the development of gel polymer electrolytes consisting of host polymers such as PAN, PVC, PVP, PVS, PMMA, PEGDA and PVdF etc., as they may find unique applications in consumer electronic and electric vehicle products. In the present study, gel polymer electrolytes have been prepared using the solvent casting technique in the presence of PVdF-1015 (SOLEF), EC1PC as a plasticizer, and LiBF salt. The influence of the amount of polymer, 4 plasticizer and LiBF on the gel electrolytes has been studied using XRD, DSC, AC impedance and charge–discharge 4 studies

Selective correlation of interferon-γ, tumour necrosis factor-α and granulocyte–macrophage colony-stimulating factor with immunoglobulin G1 and immunoglobulin G3 subclass antibody in leprosy

Dysregulation of both B- and T-cell responses is observed in leprosy. Immunoglobulin G1 (IgG1) and IgG3 antibody subclasses are selectively elevated towards the lepromatous or disseminated form of the disease accompanied by a depression of T-cell responses. T-cell and macrophage cytokines influence antibody class switching, differentiation and proliferation of B cells. To understand the dynamic nature of the immune response in leprosy, we examined the relationship between circulating Mycobacterium leprae-specific antibodies and secreted cytokines [interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-5, IL-10, IL-6, tumour necrosis factor-α (TNF-α) and granulocyte–macrophage colony-stimulating factor (GM-CSF)] in leprosy patients (19 lepromatous patients; 25 tuberculoid patients) and their exposed household contacts (HC=14) in response to M. leprae antigens. Paired comparison revealed a highly significant negative correlation between IFN-γ and IgG (P=0·016), IgG1 (P<0·001) and IgG3 (P=0·007) antibodies. No significant relationship was observed with other T-cell cytokines (IL-2, IL-5 and IL-10). These results strongly suggest that IFN-γ may play a role in down-regulating antigen-specific IgG1 and IgG3 antibodies. Among the macrophage cytokines, TNF-α and GM-CSF which have not been shown to play a role in B-cell activation were positively associated with IgG1 (TNF-α, P=0·0005; GM-CSF, P=0·001) and IgG3 (TNF-α, P=0·001; GM-CSF, P=0·021) antibodies. Since macrophages have high-affinity Fc receptors for IgG1 and IgG3, it is possible that antigen uptake via these receptors may influence cytokine expression of TNF-α, a key modulator of disease pathogenesis in mycobacterial diseases. We are currently investigating the role of Fc receptors on activated macrophages, in expression of pro-inflammatory cytokines in mycobacterial diseases