364 research outputs found

    Extracting causal rules from spatio-temporal data

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-23374-1_2This paper is concerned with the problem of detecting causality in spatiotemporal data. In contrast to most previous work on causality, we adopt a logical rather than a probabilistic approach. By defining the logical form of the desired causal rules, the algorithm developed in this paper searches for instances of rules of that form that explain as fully as possible the observations found in a data set. Experiments with synthetic data, where the underlying causal rules are known, show that in many cases the algorithm is able to retrieve close approximations to the rules that generated the data. However, experiments with real data concerning the movement of fish in a large Australian river system reveal significant practical limitations, primarily as a consequence of the coarse granularity of such movement data. In response, instead of focusing on strict causation (where an environmental event initiates a movement event), further experiments focused on perpetuation (where environmental conditions are the drivers of ongoing processes of movement). After retasking to search for a different logical form of rules compatible with perpetuation, our algorithm was able to identify perpetuation rules that explain a significant proportion of the fish movements. For example, approximately one fifth of the detected long-range movements of fish over a period of six years were accounted for by 26 rules taking account of variations in water-level alone.EPSRCAustralian Research Council (ARC) under the Discovery Projects Schem

    Mean-Field Effects on the Phosphorescence of Dinuclear Re(I) Complex Polymorphs

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    A computational study rationalizes the different phosphorescence colors of two highly emitting crystal polymorphs of a dinuclear Re(I) complex, [Re2(μ-Cl)2(CO)6(μ-4,5-(Me3Si)2pyridazine)]. The electrostatic interactions between the charge distributions on neighboring molecules inside the crystal are responsible for the different stabilization of the emitting triplet state because of the different molecular packing. These self-consistent effects play a major role in the phosphorescence of crystals made of polar and polarizable molecular units, offering a powerful handle to tune the luminescence wavelength in the solid state through supramolecular engineering

    SURGERY IN PATIENTS WITH TESTICULAR MALIGNANT GERM CELL TUMORS: COMPLIANCE TO SURGICAL GUIDELINES AND RESULTS IN THE ITALIAN COOPERATIVE STUDY

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    Purpose: Surgery represents a main and often the only treatment in patients with testicular Malignant Germ Cell Tumors (MGCT). We analyzed the compliance to surgical guidelines and the results in a series of patients with testicular MGCT -/+ retroperitoneal node involvement, without distant metastases. Method: 42 patients, observed in 15 Centers were enrolled in the Italian Cooperative Study on MGCT (January2004–December2010). 14/42 were younger than 2 y. of age, 28/42 between 13–18 y. Treatment was delivered according to COG-Staging-System: St.I patients (complete excision with inguinal orchifunicolectomy+decrease of markers, +hemiscrotectomy if scrotal involvement) did not receive further treatment; St.II patients (scrotal involvement after hemiscrotectomy and/or retroperitoneal node (RPN) enlargement:2 cm) had RPN Dissection if residuals were suspected after PEBx3or4. Results: St.I: 26 patients. 3/26 had a scrotal approach due to suspected testicular torsion: 1/3 underwent hemiscrotectomy, 2 did not receive further therapy after decrease of alphaFP, due to patient’s or physician’s decision respectively. 3/26 were successfully treated for RPN relapse, occurred at 3,6,9 months after adequate surgery (2 adolescents, 1 infant). St.II: in 4 patients CTwas delivered due to slight enlargement of RPN (+persistent alphaFP in 1). St.III: 12 patients received CT and RPND (bilateral in 1). Histology was negative in 11/12. All patients are alive without disease, 39 in 1stCR, 3 in 2ndCR (f.u 9–86 m.:med.48). 1 St.1 patient suffered from postoperative scrotal hematoma. Among patients younger than 2 y, 10/14 had a pure YST, 12/14 had St.I disease; among those between 13–18 y, 27/28 had a mixed histology, 14/28 were St.II or St.III. In 3 adolescents a testicular prosthesis was positioned during primary operation. Conclusion: Outcome was excellent. Regional relapses, observed only in St.I patients, were cured. Surgical guidelines were followed in 40/42 cases. Scrotal approach did not worsen the outcome of patients who did not receive further treatment

    Chemotherapy-related damage to ovarian reserve in childhood cancer survivors : interpreting the evidence

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    Chemotherapy during childhood damages ovarian reserve and can affect future fertility. However, recent large epidemiological studies showed that the detrimental impact on fertility is less severe if women seek for pregnancy at a younger age. To explain this observation, we hypothesize that the detrimental effects of previous chemotherapy on the ovarian reserve may be attenuated in young adults for two main reasons. Firstly, recent evidence showed that the amount of ovarian reserve is not a critical factor for effective natural conceptions. Provided that the residual ovarian reserve allows regular ovulatory cycles, the chances of pregnancy are similar in women with intact or reduced ovarian reserve. Secondly, ovarian reserve depletion appears to be a phenomenon that is inversely related to the residual ovarian reserve rather than to age. From a mathematical perspective, this kind of regulation intrinsically attenuates the effects of an early loss of a significant amount of primordial follicles. In conclusion, the detrimental effects of chemotherapy on natural fertility may be less severe if women with a history of chemotherapy during childhood seek for pregnancy early. This information should be part of the counseling

    Renal cell carcinoma in children: A clinicopathologic study

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    Purpose: To identify the prognostic factors, treatment, and outcome of children affected by renal cell carcinoma (RCC). Patients and Methods: The series included 41 patients (18 males and 23 females) with a median age of 124 months observed at the 11 Italian Association for Pediatric Hematology and Oncology centers from January 1973 to January 2001. Clinical data, surgical notes, pathologic findings, and summaries of therapy were taken from the charts. Results: Seven (17%) of the 41 patients had a papillary histology, and 34 (82.4%) had nonpapillary histology. Eighteen patients (43.9%) had stage I, one patient (2.4%) had stage II, two patients (4.8%) had stage IIIA, 10 patients (24.3%) had stage IIIB, and nine patients (21.9%) had stage IV disease. One patient had a bilateral involvement at diagnosis. Seven patients experienced disease recurrence. Lung and liver were the most common distant lesions and usually were fatal. In this study, the major factor influencing the prognosis was the stage. Event-free survival at 20 years was 53.5% for all patients. Overall survival at 20 years was 54.9% for all patients. Conclusion: RCC is a rare disease in children and adolescents. This neoplasm has a different clinical presentation in children compared with adults but the same outcome. In our experience, patients with localized disease could be cured by nephrectomy alone. Prospective studies in a larger number of patients are needed to confirm radiation therapy and biologic response modifiers as effective adjunct therapy in RCC stage III. The alternative therapy seems warranted in patients with advanced disease. © 2003 by American Society of Clinical Oncology

    Improvement of imiquimod solubilization and skin retention via tpgs micelles: Exploiting the co-solubilizing effect of oleic acid

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    Imiquimod (IMQ) is an immunostimulant drug approved for the topical treatment of actinic keratosis, external genital-perianal warts as well as superficial basal cell carcinoma that is used off-label for the treatment of different forms of skin cancers, including some malignant melanocytic proliferations such as lentigo maligna, atypical nevi and other in situ melanoma-related diseases. Imiquimod skin delivery has proven to be a real challenge due to its very low water-solubility and reduced skin penetration capacity. The aim of the work was to improve the drug solubility and skin retention using micelles of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), a water-soluble derivative of vitamin E, co-encapsulating various lipophilic compounds with the potential ability to improve imiquimod affinity for the micellar core, and thus its loading into the nanocarrier. The formulations were characterized in terms of particle size, zeta potential and stability over time and micelles performance on the skin was evaluated through the quantification of imiquimod retention in the skin layers and the visualization of a micelle-loaded fluorescent dye by two-photon microscopy. The results showed that imiquimod solubility strictly depends on the nature and concentration of the co-encapsulated compounds. The micellar formulation based on TPGS and oleic acid was identified as the most interesting in terms of both drug solubility (which was increased from few µg/mL to 1154.01 ± 112.78 µg/mL) and micellar stability (which was evaluated up to 6 months from micelles preparation). The delivery efficiency after the application of this formulation alone or incorporated in hydrogels showed to be 42-and 25-folds higher than the one of the commercial creams

    Assessing an ontology for the representation of clinical protocols in decision support systems

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    In order to assess the expressiveness of the CompGuide ontology for Clinical Practice Guidelines, a study was conducted with fourteen students of the Integrated Masters in Biomedical Engineering from the University of Minho in Portugal to whom it was proposed the representation of multiple guidelines according to the ontology. They were then asked to evaluate the ontology through a questionnaire and written reports. Although the results seem promising, there is the need for significant improvements mainly in: the representation of medication prescriptions, the tasks used to retrieve information from the patient, the diversity of actions offered by the ontology, the expressiveness of conditions regarding the state of a patient, and temporal constraints.FCT - Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/publishedVersio

    Mature and Immature Teratoma: A Report From the Second Italian Pediatric Study

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    Background. Teratomas demonstrate a benign clinical behavior, however they may recur with malignant components or as teratoma, and in a small group of patients prognosis could be fatal. After the ®rst Italian study, we collected cases of teratoma, alongside the protocol for malignant germ cell tumors. Procedure. Patients with teratoma were collected from 2004 to 2014. Teratomas were classi®ed according to the WHO classi®cations, as mature and immature. Patients with pathological aFP and/or bHCG, and those with a malignant germ cell component were not included. Results. The study enrolled 219 patients (150 mature, 69 immature teratomas) with a median age at diagnosis of 42 months. The primary sites involved were: 118 gonadal and 101 extragonadal teratomas. Two females with ovarian teratoma had a positive family history. Complete and incomplete surgeries were performed in 85% and 9% of cases. Seventeen events occurred: six females had a second metachronous tumor (5 contralateral ovarian teratoma, 1 adrenal neuroblastoma) and 11 teratomas relapsed/progressed (3 mature, 8 immature teratomas). Two patients died, one of progressive immature teratoma and one of surgical complications. At a median follow up of 68 months, the event-free, relapse-free, and overall survival rates were 90.6%, 94.3%, 98.6%, respectively. Conclusions. Teratomas show a good prognosis, especially the mature ones: surgery and follow-up remain the standard approach. Incomplete surgery in immature teratoma is the group at greatest risk of relapse. Bilateral ovarian tumors are a possibility, and the rare family predisposition to ovarian mature teratoma warrants further analyses
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