773 research outputs found

    Distributed Edge Connectivity in Sublinear Time

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    We present the first sublinear-time algorithm for a distributed message-passing network sto compute its edge connectivity λ\lambda exactly in the CONGEST model, as long as there are no parallel edges. Our algorithm takes O~(n1−1/353D1/353+n1−1/706)\tilde O(n^{1-1/353}D^{1/353}+n^{1-1/706}) time to compute λ\lambda and a cut of cardinality λ\lambda with high probability, where nn and DD are the number of nodes and the diameter of the network, respectively, and O~\tilde O hides polylogarithmic factors. This running time is sublinear in nn (i.e. O~(n1−ϵ)\tilde O(n^{1-\epsilon})) whenever DD is. Previous sublinear-time distributed algorithms can solve this problem either (i) exactly only when λ=O(n1/8−ϵ)\lambda=O(n^{1/8-\epsilon}) [Thurimella PODC'95; Pritchard, Thurimella, ACM Trans. Algorithms'11; Nanongkai, Su, DISC'14] or (ii) approximately [Ghaffari, Kuhn, DISC'13; Nanongkai, Su, DISC'14]. To achieve this we develop and combine several new techniques. First, we design the first distributed algorithm that can compute a kk-edge connectivity certificate for any k=O(n1−ϵ)k=O(n^{1-\epsilon}) in time O~(nk+D)\tilde O(\sqrt{nk}+D). Second, we show that by combining the recent distributed expander decomposition technique of [Chang, Pettie, Zhang, SODA'19] with techniques from the sequential deterministic edge connectivity algorithm of [Kawarabayashi, Thorup, STOC'15], we can decompose the network into a sublinear number of clusters with small average diameter and without any mincut separating a cluster (except the `trivial' ones). Finally, by extending the tree packing technique from [Karger STOC'96], we can find the minimum cut in time proportional to the number of components. As a byproduct of this technique, we obtain an O~(n)\tilde O(n)-time algorithm for computing exact minimum cut for weighted graphs.Comment: Accepted at 51st ACM Symposium on Theory of Computing (STOC 2019

    A Decisive Role of [18F] Fdg PET/CT for Diagnosis of Neoplastic Vascular Thrombosis: Report of A Case

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    The combined use of PET scan with CT and fluorodeoxyglucose ([18F]FDG) can modify, in selected oncologic patients, the clinical management and care. We report here the case of a 63-year old female who showed increase serum level of CEA 3 years following left colectomy for cancer. Ultrasound and CT (computed tomography) of the abdomen showed a single lesion in the segment II of the liver with portal thrombosis. [18F] FDG PET/CT revealed two lesions (the first area was histologically proven to be a colorectal carcinoma metastasis, the second one corresponded to the portal thrombosis). No antithrombotic drugs were administered and patient underwent chemotherapy for 4 courses (eloxatin plus 5-fluorouracil anf leucovorin). Liver resection was performed 2 weeks after the end of chemotherapy, and intraoperative ultrasound revealed a normal portal flow

    Cancer treatment-induced oral mucositis

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    Oral mucositis is one of the main complications in non-surgical cancer treatments. It represents the major dose-limiting toxicity for some chemotherapeutic agents, for radiotherapy of the head and neck region and for some radiochemotherapy combined treatments. Many reviews and clinical studies have been published in order to define the best clinical protocol for prophylaxis or treatment of mucositis, but a consensus has not yet been obtained. This paper represents an updated review of prophylaxis and treatment of antineoplastic-therapy-related mucositis using a MEDLINE search up to May 2006, in which more than 260 clinical studies have been found. They have been divided according to antineoplastic therapy (chemotherapy, radiotherapy, chemo-radiotherapy, high-dose chemotherapy). The prophylactic or therapeutic use of the analysed agents, the number of enrolled patients and the study design (randomized or not) were also specified for most studies. Accurate pre-treatment assessment of oral cavity hygiene, frequent review of symptoms during treatment, use of traditional mouthwashes to obtain mechanical cleaning of the oral cavity and administration of some agents like benzydamine, imidazole antibiotics, tryazolic antimycotics, povidone iodine, keratinocyte growth factor and vitamin E seem to reduce the intensity of mucositis. Physical approaches like cryotherapy, low energy Helium-Neon laser or the use of modern radiotherapy techniques with the exclusion of the oral cavity from radiation fields have been shown to be efficacious in preventing mucositis onset. Nevertheless a consensus protocol of prophylaxis and treatment of oral mucositis has not yet been obtained

    L19-IL2 immunocytokine in combination with the anti-syndecan-1 46F2SIP antibody format: A new targeted treatment approach in an ovarian carcinoma model

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    Epithelial ovarian cancer (EOC) is the fifth most common cancer affecting the female population. At present, different targeted treatment approaches may improve currently employed therapies leading either to the delay of tumor recurrence or to disease stabilization. In this study we show that syndecan-1 (SDC1) and tumor angiogenic-associated B-fibronectin isoform (B-FN) are involved in EOC progression and we describe the prominent role of SDC1 in the vasculogenic mimicry (VM) process. We also investigate a possible employment of L19-IL2, an immunocytokine specific for B-FN, and anti-SDC1 46F2SIP (small immuno protein) antibody in combination therapy in a human ovarian carcinoma model. A tumor growth reduction of 78% was obtained in the 46F2SIP/L19-IL2-treated group compared to the control group. We observed that combined treatment was effective in modulation of epithelial-mesenchymal transition (EMT) markers, loss of stemness properties of tumor cells, and in alleviating hypoxia. These effects correlated with reduction of VM structures in tumors from treated mice. Interestingly, the improved pericyte coverage in vascular structures suggested that combined therapy could be efficacious in induction of vessel normalization. These data could pave the way for a possible use of L19-IL2 combined with 46F2SIP antibody as a novel therapeutic strategy in EOC

    RENO, a European Postmarket Surveillance Registry, confirms effectiveness of coronary brachytheraypy in routine clinical practice.

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    Purpose: To assess, by a European registry trial, the clinical event rate in patients with discrete stenotic lesions of coronary arteries (de novo or restenotic) in single or multiple vessels (native or bypass grafts) treated with -radiation. Methods and Materials: Between April 1999 and September 2000, 1098 consecutive patients treated in 46 centers in Europe and the Middle East with the Novoste Beta-Cath System were included in Registry Novoste (RENO). Results: Six-month follow-up data were obtained for 1085 patients. Of 1174 target lesions, 94.1% were located in native vessels and 5.9% in a bypass graft; 17.7% were de novo lesions, 4.1% were restenotic, and 77.7% were in-stent restenotic lesions. Intravascular brachytherapy was technically successful in 95.9% of lesions. Multisegmental irradiation, using a manual pullback stepping maneuver to treat longer lesions, was used in 16.3% of the procedures. The in-hospital rate of major adverse cardiac events was 1.8%. At 6 months, the rate was 18.7%. Angiographic follow-up was available for 70.4% of the patients. Nonocclusive restenosis was seen in 18.8% and total occlusion in 5.7% of patients. A combined end point for late (30–180 days) definitive or suspected target vessel closure was reached in 5.4%, but with only 2% of clinical events. Multivariate analysis was performed for major adverse cardiac events and late thrombosis. Conclusion: Data obtained from the multicenter RENO registry study, derived from a large cohort of unselected consecutive patients, suggest that the good results of recent randomized controlled clinical trials can be replicated in routine clinical practice. © 2003 Elsevier Science Inc
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