525 resultados para 361.1


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A5/1 is a shift register based stream cipher which provides privacy for the GSM system. In this paper, we analyse the loading of the secret key and IV during the initialisation process of A5/1. We demonstrate the existence of weak key-IV pairs in the A5/1 cipher due to this loading process; these weak key-IV pairs may generate one, two or three registers containing all-zero values, which may lead in turn to weak keystream sequences. In the case where two or three registers contain only zeros, we describe a distinguisher which leads to a complete decryption of the affected messages.

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A 3-year longitudinal study Transforming Children’s Mathematical and Scientific Development integrates, through data modelling, a pedagogical approach focused on mathematical patterns and structural relationships with learning in science. As part of this study, a purposive sample of 21 highly able Grade 1 students was engaged in an innovative data modelling program. In the majority of students, representational development was observed. Their complex graphs depicting categorical and continuous data revealed a high level of structure and enabled identification of structural features critical to this development.

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Endothelin-1 (ET-1) is a potent vasoactive peptide and a hypoxia-inducible angiogenic growth factor associated with the development and growth of solid tumours. This study evaluated the expression of big endothelin-1 (big ET-1), a stable precursor of ET-1, and ET-1 in non-small cell lung cancer (NSCLC). Big ET-1 expression was evaluated in paraffin-embedded tissue sections from 10 NSCLC tumours using immunohistochemistry and in situ hybridisation. The production of big ET-1 and ET-1 was studied in six established NSCLC cell lines. The plasma concentrations of big ET-1 were measured in 30 patients with proven NSCLC prior to chemotherapy by means of a sandwich enzyme-linked immunoassay and compared to levels in 20 normal controls. Big ET-1 immunostaining was detected in the cancer cells of all tumours studied. Using in situ hybridisation, tumour cell big ET-1 mRNA expression was demonstrated in all samples. All six NSCLC cell lines expressed ET-1, with big ET-1 being detected in three. The median big ET-1 plasma level in patients with NSCLC was 5.4 pg/mL (range 0-22.7 pg/mL) and was significantly elevated compared to median big ET-1 plasma levels in controls, 2.1 pg/mL (1.2-13.4 pg/mL) (p=0.0001). Furthermore, patients with plasma big ET-1 levels above the normal range (upper tertile) had a worse outcome (p=0.01). In conclusion, big ET-1/ET-1 is expressed by resected NSCLC specimens and tumour cell lines. Plasma big ET-1 levels are elevated in NSCLC patients compared to controls with levels >7.8 pg/mL being associated with a worse outcome. The development of selective ET-1 antagonists such as Atrasentan indicates that ET-1 may be a therapeutic target in NSCLC. © 2004 Wichtig Editore.

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Purpose: The purpose of this study was to identify retrospectively the predictors of implant survival when the flapless protocol was used in two private dental practices. Materials and Methods: The collected data were initially computer searched to identify the patients; later, a hand search of patient records was carried out to identify all flapless implants consecutively inserted over the last 10 years. The demographic information gathered on statistical predictors included age, sex, periodontal and peri-implantitis status, smoking, details of implants inserted, implant locations, placement time after extraction, use of simultaneous guided hard and soft tissue regeneration procedures, loading protocols, type of prosthesis, and treatment outcomes (implant survival and complications). Excluded were any implants that required flaps or simultaneous guided hard and soft tissue regeneration procedures, and implants narrower than 3.25 mm. Results: A total of 1,241 implants had been placed in 472 patients. Life table analysis indicated cumulative 5-year and 10-year implant survival rates of 97.9% and 96.5%, respectively. Most of the failed implants occurred in the posterior maxilla (54%) in type 4 bone (74.0%), and 55.0% of failed implants had been placed in smokers. Conclusion: Flapless dental implant surgery can yield an implant survival rate comparable to that reported in other studies using traditional flap techniques.

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Objectives: Superficial bladder cancer (SBC) presents a difficult clinical dilemma at diagnosis as only a small subgroup of patients will subsequently develop invasive disease. Study of cancer biology has found that angiogenesis is central to growth and spread. This study examines the relationship between the angiogenic inhibitory factor Thrombospondin-1 (TSP-1) at initial presentation and subsequent progression of SBC. Methods: Using immunohistochemistry, 220 cases of SBC were examined for pattern and extent of expression of TSP-1 at initial presentation. Results: TSP-1 was detected in perivascular tissue, at the epithelial-stromal junction, in the stroma and in tumour cells and reduced perivascular TSP-1 staining at presentation was an independent predictive factor for the subsequent development of muscle invasive or metastatic disease. Conclusion: This adds further weight to the theory that TSP-1 plays a major part in the biology of bladder cancer possibly through the control of angiogenesis. © 2002 Elsevier Science B.V. All rights reserved.

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Natural single-crystal specimens of althausite from Brazil, with general formula Mg2(PO4)(OH,F,O) were investigated by Raman and infrared spectroscopy. The mineral occurs as a secondary product in granitic pegmatites. The Raman spectrum of althausite is characterized by bands at 1020, 1033 and 1044 cm-1, assigned to ν1 symmetric stretching modes of the HOPO33- and PO43- units. Raman bands at around 1067, 1083 and 1138 cm-1 are attributed to both the HOP and PO antisymmetric stretching vibrations. The set of Raman bands observed at 575, 589 and 606 cm-1 are assigned to the ν4 out of plane bending modes of the PO4 and H2PO4 units. Raman bands at 439, 461, 475 and 503 cm-1 are attributed to the ν2 PO4 and H2PO4 bending modes. Strong Raman bands observed at 312, 346 cm-1 with shoulder bands at 361, 381 and 398 cm-1 are assigned to MgO stretching vibrations. No bands which are attributable to water were found. Vibrational spectroscopy enables aspects of the molecular structure of althausite to be assessed.

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Purpose: To identify a 15-KDa novel hypoxia-induced secreted protein in head and neck squamous cell carcinomas (HNSCC) and to determine its role in malignant progression. Methods: We used surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and tandem MS to identify a novel hypoxia-induced secreted protein in FaDu cells. We used immunoblots, real-time polymerase chain reaction (PCR), and enzyme-linked immunoabsorbent assay to confirm the hypoxic induction of this secreted protein as galectin-1 in cell lines and xenografts. We stained tumor tissues from 101 HNSCC patients for galectin-1, CA IX (carbonic anhydrase IX, a hypoxia marker) and CDS (a T-cell marker). Expression of these markers was correlated to each other and to treatment outcomes. Results: SELDI-TOF studies yielded a hypoxia-induced peak at 15 kDa that proved to be galectin-1 by MS analysis. Immunoblots and PCR studies confirmed increased galectin-1 expression by hypoxia in several cancer cell lines. Plasma levels of galectin-1 were higher in tumor-bearing severe combined immunodeficiency (SCID) mice breathing 10% O 2 compared with mice breathing room air. In HNSCC patients, there was a significant correlation between galectin-1 and CA IX staining (P = .01) and a strong inverse correlation between galectin-1 and CDS staining (P = .01). Expression of galectin-1 and CDS were significant predictors for overall survival on multivariate analysis. Conclusion: Galectin-1 is a novel hypoxia-regulated protein and a prognostic marker in HNSCC. This study presents a new mechanism on how hypoxia can affect the malignant progression and therapeutic response of solid tumors by regulating the secretion of proteins that modulate immune privilege. © 2005 by American Society of Clinical Oncology.

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Extrapulmonary small cell and small cell neuroendocrine tumors of unknown primary site are, in general, aggressive neoplasms with a short median survival. Like small cell lung cancer (SCLC), they often are responsive to chemotherapy and radiotherapy. Small cell lung cancer and well differentiated neuroendocrine carcinomas of the gastrointestinal tract and pancreas tend to express somatostatin receptors. These tumors may be localized in patients by scintigraphic imaging using radiolabeled somatostatin analogues. A patient with an anaplastic neuroendocrine small cell tumor arising on a background of multiple endocrine neoplasia type 1 syndrome is reported. The patient had a known large pancreatic gastrinoma and previously treated parathyroid adenopathy. At presentation, there was small cell cancer throughout the liver and skeleton. Imaging with a radiolabeled somatostatin analogue, 111In- pentetreotide (Mallinckrodt Medical B. V., Petten, Holland), revealed all sites of disease detected by routine biochemical and radiologic methods. After six cycles of chemotherapy with doxorubicin, cyclophosphamide, and etoposide, there was almost complete clearance of the metastatic disease. 111In-pentetreotide scintigraphy revealed uptake consistent with small areas of residual disease in the liver, the abdomen (in mesenteric lymph nodes), and posterior thorax (in a rib). The primary gastrinoma present before the onset of the anaplastic small cell cancer showed no evidence of response to the treatment. The patient remained well for 1 year and then relapsed with brain, lung, liver, and skeletal metastases. Despite an initial response to salvage radiotherapy and chemotherapy with carboplatin and dacarbazine, the patient died 6 months later.

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In recent years, it has been recognised that child complainants in the criminal justice system can experience difficulties over and above those of other complainants and that children can experience the court process as extremely traumatising. This can be exacerbated if children are complainants in child sexual offence matters and if they have to give evidence against a family member. This paper has three primary aims. First, it outlines the major factors that contribute to making court processes harrowing for child complainants. Second, it outlines some of the main initiatives that have been introduced to address these factors. Finally, it weighs up the evidence about initiatives designed to assist child complainants and concludes that such initiatives have had only limited practical impact for child complainants in the criminal justice system. The limited impact is attributed to the need to balance the rights of the accused with consideration for the complainant, a failure to translate legislative changes into practice, the impact of judicial discretion and/or a focus on protecting child complainants at the expense of increasing convictions.

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The refereed papers contained in this set of conference proceedings were presented at the 2nd International Conference on Crime, Justice and Social Democracy, hosted by the Crime and Justice Research Centre, Faculty of Law, QUT. The conference attracted an impressive list of internationally distinguished keynote and panel speakers from the United Kingdom, United States, Australia, New Zealand, Canada and this time Latin America, as well as high quality paper submissions.

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This thesis examined the possible role of Y-box binding protein 1 (YBX1) in prostate cancer aggression and spread. Novel roles were uncovered for YBX1 in the regulation of several genes previously implicated in prostate cancer, as well as showing an effect for YBX1 in increasing tumour cell invasion and movement and reciprocal regulation of androgen-regulated gene networks. In addition, it was found that Y-box 1 regulated several other well-known cancer genes implicated in breast and other cancers. The work performed in this thesis has strengthened the foundations for pursuing YBX1 as a possible central target molecule in prostate cancer therapeutics.

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Purpose The aim of this study was to examine the expression and prognostic relevance of thrombospondin-1 (TSP-1) in tumor biopsies taken from a consecutive series of liver resections done at the University Hospitals of Leicester and the Royal Liverpool Hospital. Experimental Design Patients having undergone a liver resection for colorectal liver metastases at our institutions between 1993 and 1999 inclusive were eligible. Inclusion criteria were curative intent, sufficient tumor biopsy, and patient follow-up data. One hundred eighty-two patients were considered in this study. Standard immunohistochemical techniques were used to study the expression of TSP-1 in 5-μm tumor sections from paraffin-embedded tissue blocks. TSP-1 was correlated with survival using the Kaplan-Meier method and log-rank test for univariate analysis and the Cox proportional hazard model for multivariate analysis. Results One hundred eighty-two patients (male, n = 122 and female, n = 60) ages between 25 and 81 years (mean, 61 years) were included. TSP-1 was expressed around blood vessels (n = 45, 25%) or in the stroma (n = 59, 33%). No expression was detected in the remaining tumors. TSP-1 significantly correlated with poor survival on univariate (P = 0.01 for perivascular expression and P = 0.03 for stromal expression) and multivariate analysis (P = 0.01 for perivascular expression). Conclusion TSP-1 is a negatively prognostic factor for survival in resected colorectal liver metastases. © 2005 American Association for Cancer Research.