515 research outputs found

    FINITE ELEMENT ANALYSIS FOR OPTIMIZING ANTENNA FOR MICROWAVE COAGULATION THERAPY

    Get PDF
    Microwave coagulation therapy (MCT) is emerging as an attractive modality for thermal therapy of soft tissues targeted in short periods of time, making it particularly suitable for ablation of hepatic and other tumors. In this field of microwave coagulation therapy, the use of minimally invasive antenna is recognized as a very promising technique for the treatment of small tumors because a very thin antenna can be easily inserted inside the body and precisely localized using the advanced 3D imaging techniques and surgical robots. The authors investigated the microwave coaxial antenna operating at 2.45 GHz by varying the slots size for the removal of liver tumor. The analysis was done using 2D finite element modeling. By several optimization steps the antenna is simulated and optimized by comparing the values of specific absorption rate (SAR), mesh statistics and temperature distributions in tissue generated by the antenna with the variations of dimensions of slot from 1 mm to 1.7 mm

    Mood instability : significance, definition and measurement

    Get PDF
    Mood instability is common, and an important feature of several psychiatric disorders. We discuss the definition and measurement of mood instability, and review its prevalence, characteristics, neurobiological correlates and clinical implications. We suggest that mood instability has underappreciated transdiagnostic potential as an investigational and therapeutic target

    Affective Instability, Childhood Trauma and Major Affective Disorders

    Get PDF
    BACKGROUND: Affective instability (AI), childhood trauma, and mental illness are linked, but evidence in affective disorders is limited, despite both AI and childhood trauma being associated with poorer outcomes. Aims were to compare AI levels in bipolar disorder I (BPI) and II (BPII), and major depressive disorder recurrent (MDDR), and to examine the association of AI and childhood trauma within each diagnostic group. METHODS: AI, measured using the Affective Lability Scale (ALS), was compared between people with DSM-IV BPI (n=923), BPII (n=363) and MDDR (n=207) accounting for confounders and current mood. Regression modelling was used to examine the association between AI and childhood traumas in each diagnostic group. RESULTS: ALS scores in descending order were BPII, BPI, MDDR, and differences between groups were significant (p<0.05). Within the BPI group any childhood abuse (p=0.021), childhood physical abuse (p=0.003) and the death of a close friend in childhood (p=0.002) were significantly associated with higher ALS score but no association was found between childhood trauma and AI in BPII and MDDR. LIMITATIONS: The ALS is a self-report scale and is subject to retrospective recall bias. CONCLUSIONS: AI is an important dimension in bipolar disorder independent of current mood state. There is a strong link between childhood traumatic events and AI levels in BPI and this may be one way in which exposure and disorder are linked. Clinical interventions targeting AI in people who have suffered significant childhood trauma could potentially change the clinical course of bipolar disorder

    Polymorphisms of MTHFR and MTR genes are not related to susceptibility to childhood ALL in north India

    No full text
    Background:Acute lymphoblastic leukemia (ALL) is the most worldwide common type of childhood cancer. Methylenetetrahydrofolate reductase (MTHFR) and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) participate in folate pathways and are known as critical factors for DNA integrity as well as DNA hypomethylation. The aim of this work is to investigate frequency of MTHFR (677C→T and 1298A→C) and MTR (2756A→G) polymorphisms and their interaction with respect to possible effect on risk of childhood ALL among North Indian population. Procedure: A case control study from has been conducted on bone marrow and peripheral blood samples from 125 ALL patients and 100 sex-age matched healthy controls using PCR-RFLP method. Results: No statistically significant differences were observed for different genotypes between patients and controls (p>0.05). Significant difference for the risk of ALL in individuals having genotype of MTHFR 677TT (OR=0.61, 95% CI=0.21–1.77) and MTHFR 1298CC (OR=0.56, 95% CI=0.18–1.68) was not observed. The correlation of SNP of MTR gene and risk of ALL was not observed, too. Conclusions: The differences in distribution of possible combined genotypes of MTHFR (677C→T, 1298A→C) and MTR (2756A→G) between ALL patients and controls were statistically insignificant

    Global prevalence of, and risk factors for, uninvestigated dyspepsia: a meta-analysis

    Get PDF
    OBJECTIVES: Many cross-sectional surveys have reported the prevalence of uninvestigated dyspepsia, but there has been no recent systematic review of data from all studies to determine its global prevalence and risk factors. DESIGN: MEDLINE, EMBASE and EMBASE Classic were searched (until January 2014) to identify population-based studies that reported the prevalence of uninvestigated dyspepsia in adults (≥15 years old); dyspepsia was defined using symptom-based criteria or questionnaires. The prevalence of dyspepsia was extracted for all studies and according to the criteria used to define it. Pooled prevalence, according to study location and certain other characteristics, ORs and 95% CIs were calculated. RESULTS: Of the 306 citations evaluated, 103 reported the prevalence of uninvestigated dyspepsia in 100 separate study populations, containing 312 415 subjects. Overall pooled prevalence in all studies was 20.8% (95% CI 17.8% to 23.9%). The prevalence varied according to country (from 1.8% to 57.0%) and criteria used to define dyspepsia. The greatest prevalence values were found when a broad definition of dyspepsia (29.5%; 95% CI 25.3% to 33.8%) or upper abdominal or epigastric pain or discomfort (20.4%; 95% CI 16.3% to 24.8%) were used. The prevalence was higher in women (OR 1.24; 95% CI 1.13 to 1.36), smokers (OR 1.25; 95% CI 1.12 to 1.40), non-steroidal anti-inflammatory drug (NSAID) users (OR 1.59; 95% CI 1.27 to 1.99) and Helicobacter pylori-positive individuals (OR 1.18; 95% CI 1.04 to 1.33). CONCLUSIONS: The overall pooled prevalence of uninvestigated dyspepsia was 21%, but varied among countries and according to the criteria used to define its presence. Prevalence is significantly higher in women, smokers, NSAID users and H. pylori-positive individuals, although these associations were modest

    Prevalence of diaphragmatic muscle weakness and dyspnoea in Graves' disease and their reversibility with carbimazole therapy

    Get PDF
    Objectives: Dyspnoea is a common complaint among patients with thyrotoxicosis. However, its causative mechanisms have not been identified. We assessed the role of thoracic diaphragmatic muscle weakness in dyspnoea among patients with active Graves' disease. Methods: Twenty-seven patients (19 female, 8 male) with active Graves' disease were assessed for the clinical severity of dyspnoea, functional (pressure generating capacity) and anatomical aspects (thickness and excursion) of the diaphragm at presentation. The severity of dyspnoea was assessed using a visual analogue scale (VAS) and the 6 min walk test. Lung function tests, diaphragmatic strength (sniff oesophageal pressure, SniffPoeso), maximum inspiratory and expiratory pressures, diaphragmatic thickness and movements on real time ultrasonography were evaluated during normal and deep respiration. Twenty of the 27 patients were reassessed after achieving euthyroidism with carbimazole therapy at a mean interval of 5&#177;2 months. Results: Reevaluation after carbimazole therapy revealed a significant reduction in dyspnoea on the VAS (59&#177;26 to 23&#177;13%). Patients covered a similar distance during the 6 min walk before and after euthyroidism. Significant improvement was observed in the vital capacity (2.57&#177;0.62 to 2.94&#177;0.60 l), forced expiratory volume in the first second (2.21&#177;0.49 to 2.45&#177;0.47 l), total lung capacity (3.57&#177;1.19 to 4.1&#177;1.12 l), diaphragmatic movement during deep respiration (5.5&#177;1.0 to 6.6&#177;1.1 cm) and SniffPoeso (68.7&#177;23 to 93.1&#177;25.2 cmH2O). There was no significant change in the distance walked in 6 min, tidal volume, lung diffusion capacity and diaphragmatic thickness. There was no significant correlation between the net change in dyspnoea score and net change in lung function tests, diaphragmatic movement and SniffPoeso. Conclusions: Significant functional weakness of diaphragm muscle is present in patients with active Graves' disease. This weakness is more marked during a maximal respiratory manoeuvre, indicating a diminished diaphragmatic reserve which could be the cause of dyspnoea observed on exertion among patients with thyrotoxicosis

    Maturation-Dependent Response of the Piglet Brain to Scaled Cortical Impact

    Get PDF
    Object. The goal of this study was to investigate the relationship between maturational stage and the brain\u27s response to mechanical trauma in a gyrencephalic model of focal brain injury. Age-dependent differences in injury response might explain certain unique clinical syndromes seen in infants and young children and would determine whether specific therapies might be particularly effective or even counterproductive at different ages. Methods. To deliver proportionally identical injury inputs to animals of different ages, the authors have developed a piglet model of focal contusion injury by using specific volumes of rapid cortical displacement that are precisely scaled to changes in size and dimensions of the growing brain. Using this model, the histological response to a scaled focal cortical impact was compared at 7 days after injury in piglets that were 5 days, 1 month, and 4 months of age at the time of trauma. Despite comparable injury inputs and stable physiological parameters, the percentage of hemisphere injured differed significantly among ages, with the youngest animals sustaining the smallest lesions (0.8%, 8.4%, and 21.5%, for 5-day-, 1-month-, and 4-month-old animals, respectively, p = 0.0018). Conclusions. These results demonstrate that, for this particular focal injury type and severity, vulnerability to mechanical trauma increases progressively during maturation. Because of its developmental and morphological similarity to the human brain, the piglet brain provides distinct advantages in modeling age-specific responses to mechanical trauma. Differences in pathways leading to cell death or repair may be relevant to designing therapies appropriate for patients of different ages

    A systematic review of the neurobiological underpinnings of borderline personality disorder (BPD) in childhood and adolescence

    Get PDF
    Contemporary theories for the aetiology of borderline personality disorder (BPD) take a lifespan approach asserting that inborn biological predisposition is potentiated across development by environmental risk factors. In this review, we present and critically evaluate evidence on the neurobiology of BPD in childhood and adolescence, compare this evidence to the adult literature, and contextualise within a neurodevelopmental framework. A systematic review was conducted to identify studies examining the neurobiological (i.e. genetic, structural neuroimaging, neurophysiological, and neuropsychological) correlates of BPD symptoms in children and adolescents aged 19 years or under. We identified, quality assessed, and narratively summarised 34 studies published between 1980 and June 2016. Similar to findings in adult populations, twin studies indicated moderate to high levels of heritability of BPD, and there was some evidence for gene-environment interactions. Also consistent with adult reports is that some adolescents with BPD demonstrated structural (grey and white matter) alterations in frontolimbic regions and neuropsychological abnormalities (i.e. reduced executive function and disturbances in social cognition). These findings suggest that neurobiological abnormalities observed in adult BPD may not solely be the consequence of chronic morbidity or prolonged medication use. They also provide tentative support for neurodevelopmental theories of BPD by demonstrating that neurobiological markers may be observed from childhood onwards and interact with environmental factors to increase risk of BPD in young populations. Prospective studies with a range of repeated measures are now required to elucidate the temporal unfurling of neurobiological features and further delineate the complex pathways to BPD

    GAS TURBINE COMPRESSOR INLET AIR FILTERS PERFORMANCE COMPARISON

    Get PDF
    Case Studie
    corecore