27 research outputs found

    Resource Competition on Integral Polymatroids

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    We study competitive resource allocation problems in which players distribute their demands integrally on a set of resources subject to player-specific submodular capacity constraints. Each player has to pay for each unit of demand a cost that is a nondecreasing and convex function of the total allocation of that resource. This general model of resource allocation generalizes both singleton congestion games with integer-splittable demands and matroid congestion games with player-specific costs. As our main result, we show that in such general resource allocation problems a pure Nash equilibrium is guaranteed to exist by giving a pseudo-polynomial algorithm computing a pure Nash equilibrium.Comment: 17 page

    Could X-ray microbeams inhibit angioplasty-induced restenosis in the rat carotid artery?

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    Background: Parallel, thin (<100 μm) planes of synchrotron-generated X rays, have been shown to spare normal tissues and preferentially damage tumors in animal models. The aim of the present study was to assess the effect of such microbeams directed unidirectionally on angioplasted rat carotid arteries. Methods and materials: Three groups of Sprague-Dawley rats were studied: (a) rats with normal, untreated arteries, (b) rats treated by balloon angioplasty, but not irradiated, and (c) rats treated with balloon angioplasty and exposed to single fraction, unidirectional, parallel, microbeams an hour after angioplasty. The microbeam array, 15 mm wide×7.6 mm high, consisting of 27-μm-wide beam slices, spaced 200 μm center-to-center laterally traversed the damaged artery. The in-depth in-beam dose was 150 Gy, the "valley" dose (dose midway between microbeams resulting mainly from X-ray scattering) was 4.5 Gy on average, and the "integrated" (averaged) dose was 26 Gy. Results: Microbeam irradiation, as given in the present study, was tolerated, but was insufficient to significantly suppress the neointimal hyperplasia. Discussion: The microbeam dose used is considered low. Dose escalation would be necessary to reach conclusive results regarding the X-ray microbeam efficacy to control restenosis. © 2004 Elsevier Inc. All rights reserved

    Operative treatment of athletic pubalgia in competitive athletes: A retrospective study

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    BACKGROUND: Athletic pubalgia is an obscure sport injury, presenting mainly with groin pain during twisting movements. The present 15 year study reports outcomes, intraoperative findings and complications of the endoscopic surgical treatment in competitive athletes. METHODS: All competitive athletes, from 2004 to 2018, suffering from athletic pubalgia, treated with laparoscopic Total Extra-Peritoneal technique, at the Department of General, Laparoscopic, Oncologic and Robotic Surgery of the Athens Medical Center were included in this retrospective cohort. Postoperative pain, complications, return to previous training routine and patients’ satisfaction were evaluated. RESULTS: A total of 130 patients (115; 88.5% males and 15; 11.5% females) with a mean age of 26.7±7.5 years were evaluated. Preoperatively, mean numeric scale pain was found to be 7.7±1.7. Three days postoperatively, the mean numeric pain scale was 3.4±1.5, showing 55.8% decrease. The mean time for return to sports activity was found to be 6.27±3.02 weeks. Regarding complications, six patients (4.6%) had slight numbness at the groin area during the first 6 postoperative months and one patient (0.8%) suffered from a postoperative hematoma. No recurrence was observed. At the final follow-up (mean 76.58±46.5 months), a total of 97 (74.7%) patients were very satisfied, 31 (23.8%) satisfied and two (1.5%) not satisfied with the outcome. CONCLUSIONS: Laparoscopic operative treatment in competitive athletes suffering from athletic pubalgia seems to offer rapid recovery, rapid return to sports, as well as very low complications rate and no recurrence. © 2020 EDIZIONI MINERVA MEDIC

    7q Deletion/12q Duplication Is the Possible Cause of an Alobar Holoprosencephaly Case

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    Holoprosencephaly (HPE) spectrum disorder is the most common congenital malformation of the human brain with absence of or incomplete midline cleavage. Its cause is heterogenic, making genetic counseling a challenge. In this case report, a pregnancy affected by alobar HPE is described. Using aCGH, an 8.9-Mb deletion at 7q36.1q36.3 together with a 4.9-Mb duplication at 12q24.32q24.33 is assumed to be the possible reason for this alobar HPE case. It is discussed that disruption of key elements of the developing brain, taking environmental factors into account, contributes to the HPE spectrum. The use of aCGH for invasive prenatal testing is starting to become the standard technique, providing accurate information about the cause of congenital diseases for couples receiving genetic counseling. © 2017 S. Karger AG, Basel

    Robotic resection of a giant retroperitoneal leiomyosarcoma: A case report

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    The management of abdominal leiomyosarcoma is challenging. Surgical excision is considered the only effective treatment; however, this is associated with considerable morbidity. Robotic surgery has emerged during the past decades and has enhanced the general surgery armamentarium, allowing surgeons to carry out demanding operations in a safe manner. The surgical resection of retroperitoneal leiomyosarcoma (RPLM) can be associated with significant morbidity, which is primarily due to the origin or the close proximity of the tumor with important vascular structures, including the inferior vena cava and tributaries, the duodenum and the ureter. The present case describes the first case of robotic resection of RPLM in a high-volume robotic center. In the present case, a large RPLM was safely removed with respect to oncological principles with the use of the Da Vinci platform. © 2019, Spandidos Publications. All rights reserved

    7q Deletion/12q Duplication Is the Possible Cause of an Alobar Holoprosencephaly Case

    No full text
    Holoprosencephaly (HPE) spectrum disorder is the most common congenital malformation of the human brain with absence of or incomplete midline cleavage. Its cause is heterogenic, making genetic counseling a challenge. In this case report, a pregnancy affected by alobar HPE is described. Using aCGH, an 8.9-Mb deletion at 7q36.1q36.3 together with a 4.9-Mb duplication at 12q24.32q24.33 is assumed to be the possible reason for this alobar HPE case. It is discussed that disruption of key elements of the developing brain, taking environmental factors into account, contributes to the HPE spectrum. The use of aCGH for invasive prenatal testing is starting to become the standard technique, providing accurate information about the cause of congenital diseases for couples receiving genetic counseling. © 2017 S. Karger AG, Basel

    Acute radiation impacts contractility of guinea-pig bladder strips affecting mucosal-detrusor interactions

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    Radiation-induced bladder toxicity is associated with radiation therapy for pelvic malignancies, arising from unavoidable irradiation of neighbouring normal bladder tissue. This study aimed to investigate the acute impact of ionizing radiation on the contractility of bladder strips and identify the radiation-sensitivity of the mucosa vs the detrusor. Guinea-pig bladder strips (intact or mucosa-free) received ex vivo sham or 20Gy irradiation and were studied with in vitro myography, electrical field stimulation and Ca2+-fluorescence imaging. Frequency-dependent, neurogenic contractions in intact strips were reduced by irradiation across the force-frequency graph. The radiation-difference persisted in atropine (1μM); subsequent addition of PPADs (100μM) blocked the radiation effect at higher stimulation frequencies and decreased the force-frequency plot. Conversely, neurogenic contractions in mucosa-free strips were radiation-insensitive. Radiation did not affect agonist-evoked contractions (1μM carbachol, 5mM ATP) in intact or mucosa-free strips. Interestingly, agonist-evoked contractions were larger in irradiated mucosa-free strips vs irradiated intact strips suggesting that radiation may have unmasked an inhibitory mucosal element. Spontaneous activity was larger in control intact vs mucosa-free preparations; this difference was absent in irradiated strips. Spontaneous Ca2+-transients in smooth muscle cells within tissue preparations were reduced by radiation. Radiation affected neurogenic and agonist-evoked bladder contractions and also reduced Ca2+-signalling events in smooth muscle cells when the mucosal layer was present. Radiation eliminated a positive modulatory effect on spontaneous activity by the mucosa layer. Overall, the findings suggest that radiation impairs contractility via mucosal regulatory mechanisms independent of the development of radiation cystitis
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