149 research outputs found

    Using digital watermarking to enhance security in wireless medical image transmission

    Get PDF
    This is the published version of the article. Copyright 2010 Mary Ann Liebert Inc.During the last few years, wireless networks have been increasingly used both inside hospitals and in patients’ homes to transmit medical information. In general, wireless networks suffer from decreased security. However, digital watermarking can be used to secure medical information. In this study, we focused on combining wireless transmission and digital watermarking technologies to better secure the transmission of medical images within and outside the hospital. Methods: We utilized an integrated system comprising the wireless network and the digital watermarking module to conduct a series of tests. Results: The test results were evaluated by medical consultants. They concluded that the images suffered no visible quality degradation and maintained their diagnostic integrity. Discussion: The proposed integrated system presented reasonable stability, and its performance was comparable to that of a fixed network. This system can enhance security during the transmission of medical images through a wireless channel.The General Secretariat for Research and Technology of the Hellenic Ministry of Development and the British Council

    Biosensor development for the analysis of food quality

    Get PDF
    This thesis describes the development and evaluation of a number of biosensors for food applications. The first part of this thesis deals with the development of Surface Plasmon Resonance (SPR) biosensor systems, coupled with Polymerase Chain Reaction (PCR) for the detection of GMO related amplified nucleic acids in foodstuffs. The first SPR Biosensor described, used streptavidin-biotin linkage chemistry to attach a P35S nucleic acid probe on dextran-coated SPR transducer chips. Methodologies were developed for both the PCR stage and post-PCR sample preparation for the sensitive, rapid and cost-effective detection of GMO-specific amplified DNA sequences. The final embodiment of the method was an asymmetric PCR amplification system with a simple sample processing step (0.3 M NaOH for 30 min in 20 % v/v formamide). The developed PCR-SPR system was successfully applied to the screening of samples of GMO origin. The second SPR biosensor reported herein, is based on a SPR chip immobilised single-stranded thiolated DNA. The thiolated probe exhibited a hybridisation capacity of 95 RU (Resonance Units) for 100 nM of complementary DNA target and a detection limit of 5 nM. The potential of the current probe system for the detection of symmetrically amplified DNA sequences of short length was subsequently confirmed. The second part of this thesis involved preliminary studies into the development of simple, disposable screen-printed electrodes for the electrochemical determination of glucose and L-amino acids in horticultural products. The dynamic range of the developed biosensors was up to 10 mM for glucose and up to 1 mM for L-leucine determination. The developed glucose biosensor exhibited encouraging analytical performance in fresh fruit samples. However, the L-amino acid oxidase electrodes consistently underestimated the amino acid content of the fruit samples. The latter observation was found to be primarily due to inhibitory components in the matrix.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Effects of long-term immobilisation on endomysium of the soleus muscle in humans

    Get PDF
    Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-tofibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness

    Post partum anxiety and depression in peri-urban communities of Karachi, Pakistan: a quasi-experimental study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Postpartum anxiety and depression is a major public health concern because of its adverse effects on the cognitive and social development of the infant. Globally postpartum depression has been widely investigated but as anxiety is a more prominent feature of postpartum depression we assessed the prevalence of anxiety and depression and their associated factors in post partum women.</p> <p>Methods</p> <p>A quasi-experimental study investigating the impact of postpartum anxiety and depression on child growth and development was conducted in two peri-urban, multiethnic, communities of Karachi, a mega city of Pakistan. A house to house questionnaire based survey was done by trained field workers; 420 consenting pregnant women were identified and data for socio-demographic, home environment and family relationship variables was collected between 36 weeks of pregnancy and within 10 days of childbirth. Mother's levels of anxiety and depression were assessed after one month, two months, six months and twelve months of childbirth; this was two step process: initially an indigenous, validated screening instrument Aga Khan University Anxiety and Depression Scale was used and diagnostic confirmation was done through a psychologist's interview based on DSM IV criteria. Women found to be anxious and depressed at least once out of four assessments were considered for the computation of overall prevalence of postpartum anxiety and depression as well as its risk factors. However, point prevalence's of postpartum anxiety and depression were also reported at each assessment time. Two sixty seven women could be followed for one year. Data was analyzed using SPSS. Chi-square test, simple and multiple logistic regression were used to see the association of different factors.</p> <p>Results</p> <p>The overall prevalence of postpartum anxiety and depression was found to be 28.8 percent. Domestic violence, difficulty in breast feeding at birth and unplanned current pregnancy were found to be significantly associated with postpartum anxiety and depression.</p> <p>Conclusion</p> <p>Domestic violence and not having the right to plan pregnancy are related to the patriarchal culture and lack of empowerment of women. The association with difficulties in breast feeding needs to be further explored in future studies</p

    Effects of long‐term immobilisation on endomysium of the soleus muscle in humans

    Get PDF
    New findings: What is the central question of this study? While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest? What is the main finding and its importance? Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness. Abstract: Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-to-fibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness

    Quantum technologies in diamond enabled by laser processing

    Get PDF
    Integrated photonic circuits promise to be foundational for applications in quantum information and sensing technologies, through their ability to confine and manipulate light. A key role in such technologies may be played by spin-active quantum emitters, which can be used to store quantum information or as sensitive probes of the local environment. A leading candidate is the negatively charged nitrogen vacancy (NV−) diamond color center, whose ground spin state can be optically read out, exhibiting long (≈1 ms) coherence times at room temperature. These properties have driven research toward the integration of photonic circuits in the bulk of diamond with the development of techniques allowing fabrication of optical waveguides. In particular, femtosecond laser writing has emerged as a powerful technique, capable of writing light guiding structures with 3D configurations as well as creating NV complexes. In this Perspective, the physical mechanisms behind laser fabrication in diamond will be reviewed. The properties of waveguides, single- and ensemble-NV centers, will be analyzed, together with the possibility to combine such structures in integrated photonic devices, which can find direct application in quantum information and sensing

    Transcription Factor SP4 Is a Susceptibility Gene for Bipolar Disorder

    Get PDF
    The Sp4 transcription factor plays a critical role for both development and function of mouse hippocampus. Reduced expression of the mouse Sp4 gene results in a variety of behavioral abnormalities relevant to human psychiatric disorders. The human SP4 gene is therefore examined for its association with both bipolar disorder and schizophrenia in European Caucasian and Chinese populations respectively. Out of ten SNPs selected from human SP4 genomic locus, four displayed significant association with bipolar disorder in European Caucasian families (rs12668354, p = 0.022; rs12673091, p = 0.0005; rs3735440, p = 0.019; rs11974306, p = 0.018). To replicate the genetic association, the same set of SNPs was examined in a Chinese bipolar case control sample. Four SNPs displayed significant association (rs40245, p = 0.009; rs12673091, p = 0.002; rs1018954, p = 0.001; rs3735440, p = 0.029), and two of them (rs12673091, rs3735440) were shared with positive SNPs from European Caucasian families. Considering the genetic overlap between bipolar disorder and schizophrenia, we extended our studies in Chinese trios families for schizophrenia. The SNP7 (rs12673091, p = 0.012) also displayed a significant association. The SNP7 (rs12673091) was therefore significantly associated in all three samples, and shared the same susceptibility allele (A) across all three samples. On the other hand, we found a gene dosage effect for mouse Sp4 gene in the modulation of sensorimotor gating, a putative endophenotype for both schizophrenia and bipolar disorder. The deficient sensorimotor gating in Sp4 hypomorphic mice was partially reversed by the administration of dopamine D2 antagonist or mood stabilizers. Both human genetic and mouse pharmacogenetic studies support Sp4 gene as a susceptibility gene for bipolar disorder or schizophrenia. The studies on the role of Sp4 gene in hippocampal development may provide novel insights for the contribution of hippocampal abnormalities in these psychiatric disorders
    corecore