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1.
BACKGROUND: Granular cell tumor was first described by Abrikossoff in 1926. It is rare and usually presents as a benign solitary lesion. Multifocal and malignant forms are known to occur. METHODS: This presentation illustrates an additional case of granular cell tumor. Clinical and histological features to distinguish malignant and benign forms are presented. RESULTS: Tumor can develop years after therapy for the primary lesion. Treatment recommendations are presented. CONCLUSIONS: Patients diagnosed with granular cell tumor require close follow-up. Radiographic evaluation for the presence of metastatic disease is necessary if a malignant variant is suspected.  相似文献   
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Ventriculo-peritoneal shunts (VPS) are the most frequent operative procedures used to treat hydrocephalic children. Abdominal complications of VPS are now a rare event; however, their frequency varies from 5% to 47% according to reports. Anything that causes an obstruction or impediment of the VP derivation system will lead to intracranial hypertension, which requires immediate surgery. From 1985 to 1995 at the Division of Pediatric Surgery of the Federico II University of Naples, ten laparoscopies were performed in ten children with VPS complications. Cerebrospinal fluid pseudocysts were found in four infants. There was one case of abdominal wall perforation by the tip of the catheter at the umbilical level, two bowel obstructions, and one catheter was lost in the abdominal cavity. Finally, two children had malfunctioning of the peritoneal limb of the catheter. The laparoscopic technique was curative in all ten cases, thus avoiding a conventional laparotomy and the consequent risk of adhesions, which could cause further complications.  相似文献   
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The recent availability of reliable schemes for physically unclonable constants (PUC) opens interesting possibilities in the field of security. In this paper, we explore the possibility of using PUCs to embed in a chip random permutations to be used, for example, as building blocks in cryptographic constructions such as sponge functions, substitution–permutation networks, and so on. We show that the most difficult part is the generation of random integers using as the only randomness source the bit-string produced by the PUC. In order to solve the integer generation problem, we propose a partial rejection method that allows the designer to trade-off between entropy and efficiency. The results show that the proposed schemes can be implemented with reasonable complexity.  相似文献   
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The single-objective optimization of structures, whose parameters are assigned as fuzzy numbers or fuzzy relations, is presented in this paper as a particular case of the random set theory and evidence theory approach to uncertainty. Some basic concepts concerning these theories are reviewed and the relationships among interval analysis, convex modeling, possibility theory and probability theory are pointed out. In this context a frequentistic view of fuzzy sets makes sense and it is possible to calculate bounds on the probability that the solution satisfies the constraints. Some special but useful cases illustrate in detail the meaning of the approach proposed and its links with a recent formulation conceived within the context of convex modeling. Some theorems allow a very efficient computational procedure to be set up in many real design situations. Two numerical examples illustrate the model presented.  相似文献   
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We propose an alternative approach to generate languages by means of P systems: building up an appropriate representation for a string by means of a corresponding membrane structure and then generating the string by visiting the membrane structure according to a well-specified strategy. To this aim, we consider P systems with active membranes, allowing membrane creation or division or duplication and dissolution, where the output of a computation may be obtained either by visiting the tree associated with the membrane structure, or by following the traces of a specific object, called traveller, or sending out the objects. For each of these approaches, we provide characterizations of recursively enumerable languages based on P systems that use different sets of operations for modifying the membrane structure. Francesco Bernardini: He started his Ph.D. at the University of Sheffield in December 2002 after having previously got a master degree in Computer Science from the University of Pisa in Italy. His research is dedicated to the study of theoretical aspects of membrane computing (P systems) and discrete models of biological systems based on P systems. Marian Gheorghe, Ph.D.: His main research interests are in computational models and their applications to software modelling and testing, formal specifications of agent based systems, software engineering. He was investigating computational power of various generative devices (regular, context-free, fully initial; grammar systems; L-systems and variants). He is currently interested in natural computing (membrane calculus) and biological modelling.  相似文献   
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The present study investigated the processing of painful electrical stimuli in patients with unilateral frontal or parietal lobe damage and matched control subjects. Patients with frontal lesions showed increased pain thresholds when the stimuli were administered contralateral to the lesion. While the peak-to-peak amplitudes of the N150/P250 components of the somatosensory potentials increased linearly with stimulus intensity in the control subjects, the responses in the frontal group did not change significantly between stimulation at pain and tolerance threshold. There was no evidence for altered pain processing in patients with parietal lobe lesions. The findings of the present study support the hypothesis of an involvement of the frontal cortex in pain perception in humans.  相似文献   
9.
We previously described the first reference map for the proteome of one strain of serogroup A Neisseria meningitidis (MenA), a major cause of epidemic meningitis in humans. As a preliminary finding, in that work we noted that 2‐DE protein maps of closely related MenA isolates from different epidemics spreads could be easily compared to detect minor differences and that 2‐DE phenotypes attributable to the well‐known epidemiological marker tbpB agreed with the genoclouds model of MenA epidemiological variation during pandemic waves. We explored here the possibility that an extended comparative study of 2‐DE maps of isolates representative of the nine genoclouds described by Achtman and collaborators could be used to discriminate between strains otherwise undistinguishable. We showed the example of 14 proteins with different 2‐DE spot patterns in different genoclouds that could be considered as putative tracers for alike‐strains discrimination. We introduce the novel concept that comparative proteomics can be useful in identifying new epidemiological markers for N. meningitidis.  相似文献   
10.
The 5S ribosomal RNA is a very suitable target for easy, rapid and inexpensive fish species identification due to its structure, consisting of a conserved region followed by a species-specific noncoding region called ‘nontranscribed spacer’. We have exploited this species-specificity in length and sequence to discriminate among fish species which can be subjected to substitution in the fish markets. After sequencing and alignment of the corresponding portions of the 5S rRNAs of different fish species, we have designed the primer pairs necessary for PCR amplification on the DNA traits which most diverged and a primer pair on conserved regions. Our results have shown the feasibility, simplicity and reliability of the proposed approach for the detection of mislabelling or fraudulent substitution of fish species.  相似文献   
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