761 research outputs found

    Оптимізація макрологістичних мереж

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    We report on a Laser source, emitting in the mid-IR spectral range. A mode-locked Nd: YVO Laser is used as a pump Laser, followed by two nonlinear frequency conversion steps (OPG, DFG). The broad-band output beam is tunable between 9 ?m and 13 ?m, with average powers up to 10 mW. Further extension of the tuning range is possible

    Fixed-angle plates in patella fractures - a pilot cadaver study

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    <p>Abstract</p> <p>Objective</p> <p>Modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring are currently the fixation of choice for patellar fractures. Failure of fixation, migration of the wires, postoperative pain and resulting revision surgery, however, are not uncommon. After preliminary biomechanical testing of a new fixed-angle plate system especially designed for fixation of patella fractures the aim of this study was to evaluate the surgical and anatomical feasibility of implanting such a plate-device at the human patella.</p> <p>Methods</p> <p>In six fresh unfixed female cadavers without history of previous fractures around the knee (average age 88.8 years) a bilateral fixed-angle plate fixation of the patella was carried out after previous placement of a transverse central osteotomy. Operative time, intra-operative problems, degree of retropatellar arthritis (following Outerbridge), quality of reduction and existence of any intraarticular screw placement have been raised. In addition, lateral and anteroposterior radiographs of all specimens were made.</p> <p>Results</p> <p>Due to the high average age of 88.8 years no patella showed an unimpaired retropatellar articular surface and all were severely osteoporotic, which made a secure fixation of the reduction forceps during surgery difficult. The operation time averaged 49 minutes (range: 36-65). Although in postoperative X-rays the fracture gap between the fragments was still visible, the analysis of the retropatellar surface showed no residual articular step or dehiscence > 0.5 mm. Also in a total of 24 inserted screws not one intraarticular malposition was found. No intraoperative complications were noticed.</p> <p>Conclusions</p> <p>Osteosynthesis of a medial third patella fracture with a bilateral fixed-angle plate-device is surgically and anatomically feasible without difficulties. Further studies have to depict whether the bilateral fixed-angle plate-osteosynthesis of the patella displays advantages over the established operative procedures.</p

    A new non-isidiate Leptogium species with transverse septate ascospores from Southeastern Brazil

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    Abstract A non-isidiate Leptogium species with transverse septate ascospores is described as new. The species was collected in Serra da Mantiqueira and initially identified as L. megapotamicum, but the study of the type specimen demonstrated differences in the tissues of the apothecia, which supported the observed morphological variations of the thalli and apothecia found by our descriptive protocol

    Multi-minicore Disease

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    Multi-minicore Disease (MmD) is a recessively inherited neuromuscular disorder characterized by multiple cores on muscle biopsy and clinical features of a congenital myopathy. Prevalence is unknown. Marked clinical variability corresponds to genetic heterogeneity: the most instantly recognizable classic phenotype characterized by spinal rigidity, early scoliosis and respiratory impairment is due to recessive mutations in the selenoprotein N (SEPN1) gene, whereas recessive mutations in the skeletal muscle ryanodine receptor (RYR1) gene have been associated with a wider range of clinical features comprising external ophthalmoplegia, distal weakness and wasting or predominant hip girdle involvement resembling central core disease (CCD). In the latter forms, there may also be a histopathologic continuum with CCD due to dominant RYR1 mutations, reflecting the common genetic background. Pathogenetic mechanisms of RYR1-related MmD are currently not well understood, but likely to involve altered excitability and/or changes in calcium homeoestasis; calcium-binding motifs within the selenoprotein N protein also suggest a possible role in calcium handling. The diagnosis of MmD is based on the presence of suggestive clinical features and multiple cores on muscle biopsy; muscle MRI may aid genetic testing as patterns of selective muscle involvement are distinct depending on the genetic background. Mutational analysis of the RYR1 or the SEPN1 gene may provide genetic confirmation of the diagnosis. Management is mainly supportive and has to address the risk of marked respiratory impairment in SEPN1-related MmD and the possibility of malignant hyperthermia susceptibility in RYR1-related forms. In the majority of patients, weakness is static or only slowly progressive, with the degree of respiratory impairment being the most important prognostic factor

    Reduced H3K27me3 Expression Is Common in Nodular Melanomas of Childhood Associated With Congenital Melanocytic Nevi But Not in Proliferative Nodules

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    The formation of a nodule within a congenital melanocytic nevus (CMN) raises concerns about possible melanoma. Most new nodular growths that develop during childhood, however, are benign proliferative nodules (PN); melanoma is very rare. The distinction of melanoma from PN can at times be difficult clinically and histopathologically, requiring ancillary molecular tests for diagnosis. While the application of molecular methods has revealed new insights into the mutational and genomic landscape of childhood melanomas, little is known about epigenetic events that may drive the growth of a melanoma or PN in a CMN. In this study we compared the expression of H3K27me3, a key regulator in chromatin remodelling-controlled transcription, in PNs and pediatric nodular melanomas arising within medium-sized to large CMN by immunohistochemistry (IHC). Significant loss of H3K27me3 expression was seen in four of five melanomas, but not in any of the 20 PNs. This observation suggests that epigenetic events likely play a role in the pathogenesis of melanoma developing in the dermis or subcutis of CMN. Furthermore, assessing for H3K27me3 expression by IHC may be diagnostically useful for problematic cases

    BCOR Overexpression Is a Highly Sensitive Marker in Round Cell Sarcomas With BCOR Genetic Abnormalities

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    open10With the advent of next-generation sequencing, an increasing number of novel gene fusions and other abnormalities have emerged recently in the spectrum of EWSR1-negative small blue round cell tumors (SBRCTs). In this regard, a subset of SBRCTs harboring either BCOR gene fusions (BCOR-CCNB3, BCOR-MAML3), BCOR internal tandem duplications (ITD), or YWHAE-NUTM2B share a transcriptional signature including high BCOR mRNA expression, as well as similar histologic features. Furthermore, other tumors such as clear cell sarcoma of kidney (CCSK) and primitive myxoid mesenchymal tumor of infancy also demonstrate BCOR ITDs and high BCOR gene expression. The molecular diagnosis of these various BCOR genetic alterations requires an elaborate methodology including custom BAC fluorescence in situ hybridization (FISH) probes and reverse transcription polymerase chain reaction assays. As these tumors show high level of BCOR overexpression regardless of the genetic mechanism involved, either conventional gene fusion or ITD, we sought to investigate the performance of an anti-BCOR monoclonal antibody clone C-10 (sc-514576) as an immunohistochemical marker for sarcomas with BCOR gene abnormalities. Thus we assessed the BCOR expression in a pathologically and genetically well-characterized cohort of 25 SBRCTs, spanning various BCOR-related fusions and ITDs and YWHAE-NUTM2B fusion. In addition, we included related pathologic entities such as 8 CCSKs and other sarcomas with BCOR gene fusions. As a control group we included 20 SBRCTs with various (non-BCOR) genetic abnormalities, 10 fusion-negative SBRCTs, 74 synovial sarcomas, 29 rhabdomyosarcomas, and other sarcoma types. In addition, we evaluated the same study group for SATB2 immunoreactivity, as these tumors also showed SATB2 mRNA upregulation. All SBRCTs with BCOR-MAML3 and BCOR-CCNB3 fusions, as well as most with BCOR ITD (93%), and all CCSKs showed strong and diffuse nuclear BCOR immunoreactivity. Furthermore, all SBRCTs with YWHAE-NUTM2B also were positive. SATB2 stain was also positive in tumors with YWHAE-NUTM2B, BCOR-MAML3, BCOR ITD (75%), BCOR-CCNB3 (71%), and a subset of CCSKs (33%). In conclusion, BCOR immunohistochemical stain is a highly sensitive marker for SBRCTs and CCSKs with BCOR abnormalities and YWHAE-rearrangements and can be used as a useful diagnostic marker in these various molecular subsets. SATB2 immunoreactivity is also present in the majority of this group of tumors.openKao, Yc; Sung, Ys; Zhang, L; Jungbluth, Aa; Huang, Sc; Argani, P; Agaram, Np; Zin, A; Alaggio, R; Antonescu, CrKao, Yc; Sung, Ys; Zhang, L; Jungbluth, Aa; Huang, Sc; Argani, P; Agaram, Np; Zin, A; Alaggio, Rita; Antonescu, C

    Probabilistic Super-Resolution of Solar Magnetograms: Generating Many Explanations and Measuring Uncertainties

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    Machine learning techniques have been successfully applied to super-resolution tasks on natural images where visually pleasing results are sufficient. However in many scientific domains this is not adequate and estimations of errors and uncertainties are crucial. To address this issue we propose a Bayesian framework that decomposes uncertainties into epistemic and aleatoric uncertainties. We test the validity of our approach by super-resolving images of the Sun's magnetic field and by generating maps measuring the range of possible high resolution explanations compatible with a given low resolution magnetogram

    Single-Frame Super-Resolution of Solar Magnetograms: Investigating Physics-Based Metrics \& Losses

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    Breakthroughs in our understanding of physical phenomena have traditionally followed improvements in instrumentation. Studies of the magnetic field of the Sun, and its influence on the solar dynamo and space weather events, have benefited from improvements in resolution and measurement frequency of new instruments. However, in order to fully understand the solar cycle, high-quality data across time-scales longer than the typical lifespan of a solar instrument are required. At the moment, discrepancies between measurement surveys prevent the combined use of all available data. In this work, we show that machine learning can help bridge the gap between measurement surveys by learning to \textbf{super-resolve} low-resolution magnetic field images and \textbf{translate} between characteristics of contemporary instruments in orbit. We also introduce the notion of physics-based metrics and losses for super-resolution to preserve underlying physics and constrain the solution space of possible super-resolution outputs
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