258 research outputs found
Experimental realization of a relativistic fluxon ratchet
We report the observation of the ratchet effect for a relativistic flux
quantum trapped in an annular Josephson junction embedded in an inhomogeneous
magnetic field. In such a solid state system mechanical quantities are
proportional to electrical quantities, so that the ratchet effect represents
the realization of a relativistic-flux-quantum-based diode. Mean static voltage
response, equivalent to directed fluxon motion, is experimentally demonstrated
in such a diode for deterministic current forcing both in the overdamped and in
the underdamped dynamical regime. In the underdamped regime, the recently
predicted phenomenon of current reversal is also recovered in our fluxon
ratchet.Comment: 4 pages, 6 figures. To appear in PHYSICA
Chlamydophila pecorum in fetuses of mediterranean buffalo (bubalus bubalis) bred in Italy
In order to study the role played by the different species of Chlamydophila in causing abortions in Mediterranean buffalo, the Authors examined 164 fetuses from 80 different buffalo herds in Southern Italy. Three fetuses, came from two different herds, were positive. Our study confirms the pathogenic role of C. pecorum in buffalo, not only as a cause of neuropathology in calves but as an infectious abortive agent
Whispering Vortices
Experiments indicating the excitation of whispering gallery type
electromagnetic modes by a vortex moving in an annular Josephson junction are
reported. At relativistic velocities the Josephson vortex interacts with the
modes of the superconducting stripline resonator giving rise to novel
resonances on the current-voltage characteristic of the junction. The
experimental data are in good agreement with analysis and numerical
calculations based on the two-dimensional sine--Gordon model.Comment: 5 pages, 5 figures, text shortened to fit 4 pages, correction of
typo
Experimental investigation of flux motion in exponentially shaped Josephson junctions
We report experimental and numerical analysis of expontentially shaped long
Josephson junctions with lateral current injection. Quasi-linear flux flow
branches are observed in the current-voltage characteristic of the junctions in
the absence of magnetic field. A strongly asymmetric response to an applied
magnetic field is also exhibited by the junctions. Experimental data are found
in agreement with numerical predictions and demonstrate the existence of a
geometry-induced potential experienced by the flux quanta in nonuniform width
junctions.Comment: 16 pg, 8 figures, Submitted in PRB March
Multiple endocrine neoplasias type 2B and RET proto-oncogene
Multiple Endocrine Neoplasia type 2B (MEN 2B) is an autosomal dominant complex oncologic neurocristopathy including medullary thyroid carcinoma, pheochromocytoma, gastrointestinal disorders, marphanoid face, and mucosal multiple ganglioneuromas. Medullary thyroid carcinoma is the major cause of mortality in MEN 2B syndrome, and it often appears during the first years of life. RET proto-oncogene germline activating mutations are causative for MEN 2B. The 95% of MEN 2B patients are associated with a point mutation in exon 16 (M918/T). A second point mutation at codon 883 has been found in 2%-3% of MEN 2B cases. RET proto-oncogene is also involved in different neoplastic and not neoplastic neurocristopathies. Other RET mutations cause MEN 2A syndrome, familial medullary thyroid carcinoma, or Hirschsprung's disease. RET gene expression is also involved in Neuroblastoma. The main diagnosis standards are the acetylcholinesterase study of rectal mucosa and the molecular analysis of RET. In our protocol the rectal biopsy is, therefore, the first approach. RET mutation detection offers the possibility to diagnose MEN 2B predisposition at a pre-clinical stage in familial cases, and to perform an early total prophylactic thyroidectomy. The surgical treatment of MEN 2B is total thyroidectomy with cervical limphadenectomy of the central compartment of the neck. When possible, this intervention should be performed with prophylactic aim before 1 year of age in patients with molecular genetic diagnosis. Recent advances into the mechanisms of RET proto-oncogene signaling and pathways of RET signal transduction in the development of MEN 2 and MTC will allow new treatment possibilities
High anorectal malformation in a five-month-old boy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Anorectal malformation, one of the most common congenital defects, may present with a wide spectrum of defects. Almost all male patients present within first few days of life.</p> <p>Case presentation</p> <p>A five-month-old baby boy of Indian origin and nationality presented with anal atresia and associated rectourethral prostatic fistula. The anatomy of the malformation and our patient's good condition permitted a primary definitive repair of the anomaly. A brief review of the relevant literature is included.</p> <p>Conclusion</p> <p>Delayed presentation of a patient with high anorectal malformation is rare. The appropriate treatment can be rewarding.</p
Characterization of circulating miRNA signature in water buffaloes (Bubalus bubalis) during Brucella abortus infection and evaluation as potential biomarkers for non-invasive diagnosis in vaginal fluid
Brucellosis is an infectious disease caused by bacteria from the Brucella genus that can be transmitted to humans through contact with infected animals or contaminated animal products. Brucellosis also causes financial losses in animal production. Ruminants are highly susceptible to brucellosis, and the causative agent water buffaloes (Bubalus bubalis) is Brucella abortus. Circulating microRNAs (miRNAs) are cropping up as promising biomarkers for several infectious diseases. The goals of this study were to characterize the serum miRNA signature associated with brucellosis in water buffaloes and investigate the miRNAs' potential use as biomarkers in vaginal fluids. Next Generation Sequencing was used to assess miRNA expression profiles in Brucella-positive and Brucella-negative blood sera; dysregulated miRNAs in blood serum and vaginal fluids were validated using RT-qPCR. ROC curves were generated to evaluate the diagnostic value of miRNAs for Brucella. GO and KEGG pathway enrichment analyses were exploited to investigate the biological functions of dysregulated miRNAs. The results showed that 20 miRNAs were modulated, of which, 12 were upregulated and 8 were downregulated. These findings were corroborated by RT-qPCR, and ROC curves indicated that the miRNAs can serve as potential biomarkers for Brucella. GO and KEGG pathway analyses pointed out that some of these miRNAs are related to immune response and apoptosis. These results provided an overview of miRNA expression profiles and highlighted potential biomarkers for Brucella infection in water buffaloes. We also demonstrated the potential of vaginal fluids in studies involving microRNA detection. Further functional and mechanistic studies of these miRNAs may improve our understanding of the biological processes involved in Brucella infection and host immune response
Resection of primary tumor in stage 4S neuroblastoma: a second study by the Italian Neuroblastoma Group
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