152 research outputs found

    Archaeological Geophysical Prospection in Peatland Environments: case studies and suggestions for future practice

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    Peatland environments, in contrast to ‘dry-land’ sites, preserve organic material, including anthropogenic objects, because they are anaerobic, and are therefore of great importance to archaeology. Peat also preserves macro- and micro- paleoenvironmental evidence and is the primary resource for understanding past climates and ecology. Archaeological sites often lie within or at the base of wet, deep, homogenous peat rendering them invisible to surface observers. As a result, they most often c..

    Aspectos patológicos de miopatias em frangos de corte.

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    As alterações patológicas que ocorrem no músculo das aves são denominadas de miopatias. A primeira miopatia descrita foi a necrose do músculo peitoral profundo em perus e frangos, que podia ser reproduzida com estímulo para batimento de asas (1). Posteriormente foi identificada a alteração conhecida como ?white striping?, caracterizada por estrias brancas de gordura na superfície do músculo peitoral superficial. Mais recentemente foram observados novos quadros como o ?wooden breast - peito madeira? (2). Podem ocorrer também alterações na coloração ou tonalidade da carne de aves devido à queda brusca e acentuada do pH muscular, levando à condição conhecida como carne PSE (pale, soft and exudative) - carne pálida, mole e exudativa - ou quando por depleção de glicogênio no músculo ocorre a carne DFD (dark, firm and dry) - carne dura, firme e seca. O presente trabalho objetiva determinar se as condições observadas nas carcaças têm relação com causas microbianas e/ou infecciosas e avaliar se estas condições apresentam riscos para a saúde do consumidor

    Synthesis of localized 2D-layers of silicon nanoparticles embedded in a SiO2 layer by a stencil-masked ultra-low energy ion implantation process

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    We propose an original approach called “stencil-masked ion implantation process” to perform a spatially localized synthesis of a limited number of Si nanoparticles (nps) within a thin SiO2 layer. This process consists in implanting silicon ions at ultra-low energy through a stencil mask containing a periodic array of opened windows (from 50 nm to 2 um). After the stencil removal, a thermal annealing is used to synthesize small and spherical embedded nps. AFM observations show that the stencil windows are perfectly transferred into the substrate without any clogging or blurring effect. The samples exhibit a 3 nm localized swelling of the regions rich in Si nps. Moreover, photoluminescence (PL) spectroscopy shows that due to the quantum confinement only the implanted regions containing the Si nps are emitting light

    The Type and the Position of HNF1A Mutation Modulate Age at Diagnosis of Diabetes in Patients with Maturity-Onset Diabetes of the Young (MODY)-3

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    OBJECTIVE—The clinical expression of maturity-onset diabetes of the young (MODY)-3 is highly variable. This may be due to environmental and/or genetic factors, including molecular characteristics of the hepatocyte nuclear factor 1-α (HNF1A) gene mutation. RESEARCH DESIGN AND METHODS—We analyzed the mutations identified in 356 unrelated MODY3 patients, including 118 novel mutations, and searched for correlations between the genotype and age at diagnosis of diabetes. RESULTS—Missense mutations prevailed in the dimerization and DNA-binding domains (74%), while truncating mutations were predominant in the transactivation domain (62%). The majority (83%) of the mutations were located in exons 1- 6, thus affecting the three HNF1A isoforms. Age at diagnosis of diabetes was lower in patients with truncating mutations than in those with missense mutations (18 vs. 22 years, P = 0.005). Missense mutations affecting the dimerization/DNA-binding domains were associated with a lower age at diagnosis than those affecting the transactivation domain (20 vs. 30 years, P = 10−4). Patients with missense mutations affecting the three isoforms were younger at diagnosis than those with missense mutations involving one or two isoforms (P = 0.03). CONCLUSIONS—These data show that part of the variability of the clinical expression in MODY3 patients may be explained by the type and the location of HNF1A mutations. These findings should be considered in studies for the search of additional modifier genetic factors

    Intra-operative spectroscopic assessment of surgical margins during breast conserving surgery

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    Background: In over 20% of breast conserving operations, postoperative pathological assessment of the excised tissue reveals positive margins, requiring additional surgery. Current techniques for intra-operative assessment of tumor margins are insufficient in accuracy or resolution to reliably detect small tumors. There is a distinct need for a fast technique to accurately identify tumors smaller than 1 mm2 in large tissue surfaces within 30 min. Methods: Multi-modal spectral histopathology (MSH), a multimodal imaging technique combining tissue auto-fluorescence and Raman spectroscopy was used to detect microscopic residual tumor at the surface of the excised breast tissue. New algorithms were developed to optimally utilize auto-fluorescence images to guide Raman measurements and achieve the required detection accuracy over large tissue surfaces (up to 4 × 6.5 cm2). Algorithms were trained on 91 breast tissue samples from 65 patients. Results: Independent tests on 121 samples from 107 patients - including 51 fresh, whole excision specimens - detected breast carcinoma on the tissue surface with 95% sensitivity and 82% specificity. One surface of each uncut excision specimen was measured in 12–24 min. The combination of high spatial-resolution auto-fluorescence with specific diagnosis by Raman spectroscopy allows reliable detection even for invasive carcinoma or ductal carcinoma in situ smaller than 1 mm2. Conclusions: This study provides evidence that this multimodal approach could provide an objective tool for intra-operative assessment of breast conserving surgery margins, reducing the risk for unnecessary second operations

    Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

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    We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts
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