462 research outputs found

    WEIZZ: Automatic grey-box fuzzing for structured binary formats

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    Fuzzing technologies have evolved at a fast pace in recent years, revealing bugs in programs with ever increasing depth and speed. Applications working with complex formats are however more difficult to take on, as inputs need to meet certain format-specific characteristics to get through the initial parsing stage and reach deeper behaviors of the program. Unlike prior proposals based on manually written format specifications, we propose a technique to automatically generate and mutate inputs for unknown chunk-based binary formats. We identify dependencies between input bytes and comparison instructions, and use them to assign tags that characterize the processing logic of the program. Tags become the building block for structure-aware mutations involving chunks and fields of the input. Our technique can perform comparably to structure-aware fuzzing proposals that require human assistance. Our prototype implementation WEIZZ revealed 16 unknown bugs in widely used programs

    SHELF-LIFE OF HALAL FRESH SLICED BEEF AND MINCED MEAT

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    Microbiological and chemical-physical characterization of Halal beef fresh and minced meat, vacuum-packaged and stored at +2°C and +8°C, were examined, at 0, 7, 14 and 21 days, to evaluate the shelf-life. Lactic Acid Bacteria and Coliforms were higher in samples stored at +8 °C, particularly in minced meat. Pseudomonas were the most prevalent flora in all the products, and the contamination level, above 4 log10 cfu/g, were reached at 7 days in all the samples and was maintained during the study. The shelf-life can be extended reducing the storage temperature (< +2°C), and improving the packaging conditions

    All-optical trapping and acceleration of heavy particles

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    A scheme for fast, compact, and controllable acceleration of heavy particles in vacuum is proposed, in which two counterpropagating lasers with variable frequencies drive a beat-wave structure with variable phase velocity, thus allowing for trapping and acceleration of heavy particles, such as ions or muons. Fine control over the energy distribution and the total charge of the beam is obtained via tuning of the frequency variation. The acceleration scheme is described with a one-dimensional theory, providing the general conditions for trapping and scaling laws for the relevant features of the particle beam. Two-dimensional, electromagnetic particle-in-cell simulations confirm the validity and the robustness of the physical mechanism.Comment: 10 pages, 3 figures, to appear in New Journal of Physic

    Statistical kinetic treatment of relativistic binary collisions

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    In particle-based algorithms, the effect of binary collisions is commonly described in a statistical way, using Monte Carlo techniques. It is shown that, in the relativistic regime, stringent constraints should be considered on the sampling of particle pairs for collision, which are critical to ensure physically meaningful results, and that nonrelativistic sampling criteria (e.g., uniform random pairing) yield qualitatively wrong results, including equilibrium distributions that differ from the theoretical J\"uttner distribution. A general procedure for relativistically consistent algorithms is provided, and verified with three-dimensional Monte Carlo simulations, thus opening the way to the numerical exploration of the statistical properties of collisional relativistic systems.Comment: Accepted for publication as a Rapid Communication in Phys. Rev.

    CyberKnife(® )radiosurgery in the treatment of complex skull base tumors: analysis of treatment planning parameters

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    BACKGROUND: Tumors of the skull base pose unique challenges to radiosurgical treatment because of their irregular shapes, proximity to critical structures and variable tumor volumes. In this study, we investigate whether acceptable treatment plans with excellent conformity and homogeneity can be generated for complex skull base tumors using the Cyberknife(® )radiosurgical system. METHODS: At Georgetown University Hospital from March 2002 through May 2005, the CyberKnife(® )was used to treat 80 patients with 82 base of skull lesions. Tumors were classified as simple or complex based on their proximity to adjacent critical structures. All planning and treatments were performed by the same radiosurgery team with the goal of minimizing dosage to adjacent critical structures and maximizing target coverage. Treatments were fractionated to allow for safer delivery of radiation to both large tumors and tumors in close proximity to critical structures. RESULTS: The CyberKnife(® )treatment planning system was capable of generating highly conformal and homogeneous plans for complex skull base tumors. The treatment planning parameters did not significantly vary between spherical and non-spherical target volumes. The treatment parameters obtained from the plans of the complex base of skull group, including new conformity index, homogeneity index and percentage tumor coverage, were not significantly different from those of the simple group. CONCLUSION: Our data indicate that CyberKnife(® )treatment plans with excellent homogeneity, conformity and percent target coverage can be obtained for complex skull base tumors. Longer follow-up will be required to determine the safety and efficacy of fractionated treatment of these lesions with this radiosurgical system

    Plasmatic and urinary glycosaminoglycans characterization in mucopolysaccharidosis II Patient treated with enzyme-replacement therapy with Idursulfase

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    We report the structural characterization of plasmatic and urinary GAGs in a Patient affected by MPS II (Hunter syndrome) before and during the first ten months of enzyme-replacement therapy (ERT). Plasmatic GAGs before ERT were rich in pathological DS consisting of iduronic acid (IdoA) and composed of ~90% \uf044Di4s and trace amounts of disulfated disaccharides. DS was also characterized as the main (~90%) urinary GAG mainly composed of ~90% \uf044Di4s with minor percentages of monosulfated and disulfated disaccharides, in particular \u394Di2,4dis. After 300 days of ERT, plasmatic DS strongly decreased but ~14% of IdoA-rich \uf044Di4s was still detected. Similarly, urinary galactosaminoglycans were mainly composed of 78% \uf044Di4s, ~11% \uf044Di6s and ~4% \uf044Di0s with the persistence of \u394Di2,4dis (~4%). About 40% of IdoA-formed \uf044Di4s were also calculated thus confirming that pathological DS is still present in excreted urinary GAGs during ERT. By considering the % of IdoA, we observed rather similar kinetics of excretion in fluids from the beginning of the treatment. Immediately after the first enzyme infusion, a large amount of abnormal DS is removed from tissues reaching the blood compartment and eliminated via the urine, and this process lasts for about two weeks. After this, the percentage of IdoA-rich material present in biological fluids remains fairly constant over the following nine months of treatment. To date, these are the first data regarding plasmatic and urinary kinetics directly measured on products released by the activity of the recombinant enzyme Idursulfase, iduronate-2-sulfatase, evaluated using specific and sensitive analytical procedures

    Treatment of malignant tumors of the skull base with multi-session radiosurgery

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    <p>Abstract</p> <p>Objective</p> <p>Malignant tumors that involve the skull base pose significant challenges to the clinician because of the proximity of critical neurovascular structures and limited effectiveness of surgical resection without major morbidity. The purpose of this study was to evaluate the efficacy and safety of multi-session radiosurgery in patients with malignancies of the skull base.</p> <p>Methods</p> <p>Clinical and radiographic data for 37 patients treated with image-guided, multi-session radiosurgery between January 2002 and December 2007 were reviewed retrospectively. Lesions were classified according to involvement with the bones of the base of the skull and proximity to the cranial nerves.</p> <p>Results</p> <p>Our cohort consisted of 37 patients. Six patients with follow-up periods less than four weeks were eliminated from statistical consideration, thus leaving the data from 31 patients to be analyzed. The median follow-up was 37 weeks. Ten patients (32%) were alive at the end of the follow-up period. At last follow-up, or the time of death from systemic disease, tumor regression or stable local disease was observed in 23 lesions, representing an overall tumor control rate of 74%. For the remainder of lesions, the median time to progression was 24 weeks. The median progression-free survival was 230 weeks. The median overall survival was 39 weeks. In the absence of tumor progression, there were no cranial nerve, brainstem or vascular complications referable specifically to CyberKnife<sup>® </sup>radiosurgery.</p> <p>Conclusion</p> <p>Our experience suggests that multi-session radiosurgery for the treatment of malignant skull base tumors is comparable to other radiosurgical techniques in progression-free survival, local tumor control, and adverse effects.</p

    Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors

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    In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons

    Transcriptome of male breast cancer matched with germline profiling reveals novel molecular subtypes with possible clinical relevance

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    SIMPLE SUMMARY: Breast cancer in men is a rare disease; however, morbidity and mortality in male breast cancer (MBC) patients is a serious concern. The identification of specific molecular features in MBC is essential for developing more appropriate and targeted therapeutic strategies for MBC patients. In this study, by transcriptome analysis of 63 MBCs characterized for germline mutations in the most relevant BC susceptibility genes, mainly BRCA1/2, we highlighted possible differences in the molecular pathways underlying MBC pathogenesis in relation to germline mutation status. Furthermore, we identified two distinct subgroups of MBCs of clinical relevance, which are characterized by different biological features and prognosis. Overall, our results showed that transcriptome profiling by RNA sequencing is a valuable approach to dissect the molecular heterogeneity of MBC and suggest that the transcriptome matched with germline profiling may lead to the identification of MBC subtypes with possible relevance in the clinical setting, which is a primary step to improve the clinical management of MBC patients. ABSTRACT: Male breast cancer (MBC) is a rare and understudied disease compared with female BC. About 15% of MBCs are associated with germline mutation in BC susceptibility genes, mainly BRCA1/2 and PALB2. Hereditary MBCs are likely to represent a subgroup of tumors with a peculiar phenotype. Here, we performed a whole transcriptome analysis of MBCs characterized for germline mutations in the most relevant BC susceptibility genes in order to identify molecular subtypes with clinical relevance. A series of 63 MBCs, including 16 BRCA2, 6 BRCA1, 2 PALB2, 1 RAD50, and 1 RAD51D germline-mutated cases, was analyzed by RNA-sequencing. Differential expression and hierarchical clustering analyses were performed. Module signatures associated with central biological processes involved in breast cancer pathogenesis were also examined. Different transcriptome profiles for genes mainly involved in the cell cycle, DNA damage, and DNA repair pathways emerged between MBCs with and without germline mutations. Unsupervised clustering analysis revealed two distinct subgroups, one of which was characterized by a higher expression of immune response genes, high scores of gene-expression signatures suggestive of aggressive behavior, and worse overall survival. Our results suggest that transcriptome matched with germline profiling may be a valuable approach for the identification and characterization of MBC subtypes with possible relevance in the clinical setting
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