ULTRA-LOCAL TEMPERATURE MAPPING WITH AN INTRINSIC THERMOCOUPLE

Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920)International audienceWe report on a set-up derived from an Electrostatic Force Microscope (EFM) allowing us to probe temperature with a high spatial resolution. The system uses the well-known Seebeck effect through an intrinsic thermocouple made from an EFM conducting tip put in contact with a conducting sample. The contact radius between tip and sample is currently estimated to be in the 50 to 100 nm range depending on the elastic or the plastic deformation. The contact area can be assimilated to the electrical and thermal contact areas. In those conditions, the issue of heat conduction in air is solved. The thermal measurement is related to the Seebeck junction effect : it will therefore not be sensitive to buried materials or impurities

Temperature Measurement of Microsystems by Scanning Thermal Microscopy

Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920)International audienceSurface temperature measurements were performed with a Scanning Thermal Microscope. We aim at proving an eventual sub-micrometric resolution of this metrology when using a wollaston wire probe of micrometric size. A dedicated CMOS device was designed with arrays of lines 0.35mm in size with 0.8 mm and 10mm periods. Integrated Circuits with or without a passivition layer were tested. To enhance sensitivity, the IC heat source was excited with an AC current. We show that the passivation layer spreads heat so that the lines are not distinguishable. Removing this layer allows us to distinguish the lines in the case of the 10mm period

A new role for complement C3: regulation of antigen processing through an inhibitory activity.

International audienceIncreasing evidence underlines the involvement of complement component C3 in the establishment of acquired immunity which appears to play a complex role and to act at different levels. As antigen proteolysis by antigen presenting cells is a key event in the control of antigen presentation efficiency, and consequently in the quality of the immune response, we investigated whether C3 could modulate this step. Our results demonstrate for the first time that C3 can interfere with antigen proteolysis: (i) proteolysis of tetanus toxin (TT) by the lysosomal fraction from a human monocytic cell line (U937) is impaired in the presence of C3, (ii) this effect is C3-specific and involves the C3c fragment of the protein, (iii) C3c is effective even after disulfide disruption, but none of its three constitutive peptides is individually accountable for this inhibitory effect and (iv) the target-protease(s) exhibit(s) a serine-protease activity. The physiological relevance of our results is demonstrated by experiments showing a subcellular colocalisation of TT and C3 after their uptake by U937 and the reduction of TT proteolysis once internalised together with C3. These results highlight a novel role for C3 that broadens its capacity to modulate acquired immune response

Front Aging Neurosci

We studied the influence of emotions on autobiographical memory (AbM) in patients with Alzheimer's disease (AD), characteristically triggering atrophy in the hippocampus and the amygdala, two crucial structures sustaining memory and emotional processing. Our first aim was to analyze the influence of emotion on AbM in AD patients, on both the proportion and the specificity of emotional memories. Additionally, we sought to determine the relationship of emotional AbM to amygdalar-hippocampal volumes. Eighteen prodromal to mild AD patients and 18 age-matched healthy controls were included. We obtained 30 autobiographical memories per participant using the modified Crovitz test (MCT). Analyses were performed on global scores, rates and specificity scores of the emotional vs. neutral categories of memories. Amygdalar-hippocampal volumes were extracted from 3D T1-weighted MRI scans and tested for correlations with behavioral data. Overall, AD patients displayed a deficit in emotional AbMs as they elicited less emotional memories than the controls, however, the specificity of those memories was preserved. The deficit likely implied retrieval or storage as it was extended in time and without reminiscence bump effect. Global scores and rates of emotional memories, but not the specificity scores, were correlated to right amygdalar and hippocampal volumes, indicating that atrophy in these structures has a central role in the deficit observed. Conversely, emotional memories were more specific than neutral memories in both groups, reflecting an enhancement effect of emotion that could be supported by other brain regions that are spared during the early stages of the disease

Neural correlates of visual hallucinations in dementia with Lewy bodies.

NTRODUCTION: The aim of this study was to investigate the association between visual hallucinations in dementia with Lewy bodies (DLB) and brain perfusion using single-photon emission computed tomography. METHODS: We retrospectively included 66 patients with DLB, 36 of whom were having visual hallucinations (DLB-hallu) and 30 of whom were not (DLB-c). We assessed visual hallucination severity on a 3-point scale of increasing severity: illusions, simple visual hallucinations and complex visual hallucinations. We performed voxel-level comparisons between the two groups and assessed correlations between perfusion and visual hallucinations severity. RESULTS: We found a significant decrease in perfusion in the left anterior cingulate cortex, the left orbitofrontal cortex and the left cuneus in the DLB-hallu group compared with the DLB-c group. We also found a significant correlation between decreased bilateral anterior cingulate cortex, left orbitofrontal cortex, right parahippocampal gyrus, right inferior temporal cortex and left cuneus perfusion with the severity of hallucinations. CONCLUSIONS: Visual hallucinations seem to be associated with the impairment of anterior and posterior regions (secondary visual areas, orbitofrontal cortex and anterior cingulate cortex) involved in a top-down and bottom-up mechanism, respectively. Furthermore, involvement of the bilateral anterior cingulate cortex and right parahippocampal gyrus seems to lead to more complex hallucinations.journal article20152015 02 17importe

A community-integrated home based depression intervention for older African Americans: descripton of the Beat the Blues randomized trial and intervention costs

ABSTRACT: BACKGROUND: Primary care is the principle setting for depression treatment; yet many older African Americans in the United States fail to report depressive symptoms or receive the recommended standard of care. Older African Americans are at high risk for depression due to elevated rates of chronic illness, disability and socioeconomic distress. There is an urgent need to develop and test new depression treatments that resonate with minority populations that are hard-to-reach and underserved and to evaluate their cost and cost-effectiveness. METHODS/DESIGN: Beat the Blues (BTB) is a single-blind parallel randomized trial to assess efficacy of a non-pharmacological intervention to reduce depressive symptoms and improve quality of life in 208 African Americans 55+ years old. It involves a collaboration with a senior center whose care management staff screen for depressive symptoms (telephone or in-person) using the Patient Health Questionnaire (PHQ-9). Individuals screened positive (PHQ-9 ≥ 5) on two separate occasions over 2 weeks are referred to local mental health resources and BTB. Interested and eligible participants who consent receive a baseline home interview and then are randomly assigned to receive BTB immediately or 4 months later (wait-list control). All participants are interviewed at 4 (main study endpoint) and 8 months at home by assessors masked to study assignment. Licensed senior center social workers trained in BTB meet with participants at home for up to 10 sessions over 4 months to assess care needs, make referrals/linkages, provide depression education, instruct in stress reduction techniques, and use behavioral activation to identify goals and steps to achieve them. Key outcomes include reduced depressive symptoms (primary), reduced anxiety and functional disability, improved quality of life, and enhanced depression knowledge and behavioral activation (secondary). Fidelity is enhanced through procedure manuals and staff training and monitored by face-to-face supervision and review of taped sessions. Cost and cost effectiveness is being evaluated. DISCUSSION: BTB is designed to bridge gaps in mental health service access and treatments for older African Americans. Treatment components are tailored to specific care needs, depression knowledge, preference for stress reduction techniques, and personal activity goals. Total costs are $584.64/4 months; or$146.16 per participant/per month. TRIAL REGISTRATION: ClinicalTrials.gov #NCT00511680

Differences in patient outcomes and chronic care management of oral anticoagulant therapy: an explorative study

Contains fulltext : 96817.pdf (publisher's version ) (Open Access)BACKGROUND: The oral anticoagulant therapy - provided to prevent thrombosis - is known to be associated with substantial avoidable hospitalization. Improving the quality of the oral anticoagulant therapy could avoid drug related hospitalizations. Therefore, this study compared the patient outcomes between Dutch anticoagulant clinic (AC) regions taking the variation in chronic care management into account in order to explore whether chronic care management elements could improve the quality of oral anticoagulant therapy. METHODS: Two data sources were combined. The first source was a questionnaire that was send to all ACs in the Netherlands in 2008 (response = 100%) to identify the application of chronic care management elements in the AC regions. The Chronic Care Model of Wagner was used to make the concept of chronic care management operational. The second source was the report of the Dutch National Network of ACs which contains patient outcomes of the ACs. RESULTS: Patient outcomes achieved by the ACs were good, yet differences existed; for instance the percentage of patients in the appropriate therapeutic ranges varied from 67 to 87% between AC regions. Moreover, differences existed in the use of chronic care management elements of the chronic care model, for example 12% of the ACs had multidisciplinary meetings and 58% of the ACs had formal agreements with at least one hospital within their region. Patient outcomes were significantly associated with patient orientation and the number of specialized nurses versus doctors (p-values < 0.05). Furthermore, the overall extent to which chronic care management elements were applied was positively associated with patient outcomes (p-values < 0.05). CONCLUSIONS: Substantial differences in the patient outcomes as well as chronic care management of oral anticoagulant therapy existed. Since our results showed a positive association between overall application of chronic care management and patient outcomes, additional research is needed to fully understand the working mechanism of chronic care management