175 research outputs found

    Race and Educational Leadership

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    The decay of quadrupole-octupole 11^- states in 40^{40}Ca and 140^{140}Ce

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    Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying E1E1 excitations is the coupling of quadrupole and octupole phonons. Purpose: In this work, the γ\gamma-decay behavior of candidates for the (21+31)1(2_1^+\otimes 3_1^-)_{1^-} state in the doubly-magic nucleus 40^{40}Ca and in the heavier and semi-magic nucleus 140^{140}Ce is investigated. Methods: (γ,γ)(\vec{\gamma},\gamma') experiments have been carried out at the High Intensity γ\gamma-ray Source (HIγ{\gamma}S) facility in combination with the high-efficiency γ\gamma-ray spectroscopy setup γ3\gamma^3 consisting of HPGe and LaBr3_3 detectors. The setup enables the acquisition of γ\gamma-γ\gamma coincidence data and, hence, the detection of direct decay paths. Results: In addition to the known ground-state decays, for 40^{40}Ca the decay into the 313^-_1 state was observed, while for 140^{140}Ce the direct decays into the 21+2^+_1 and the 02+0^+_2 state were detected. The experimentally deduced transition strengths and excitation energies are compared to theoretical calculations in the framework of EDF theory plus QPM approach and systematically analyzed for N=82N=82 isotones. In addition, negative parities for two J=1J=1 states in 44^{44}Ca were deduced simultaneously. Conclusions: The experimental findings together with the theoretical calculations support the two-phonon character of the 111^-_1 excitation in the light-to-medium-mass nucleus 40^{40}Ca as well as in the stable even-even N=82N=82 nuclei.Comment: 11 pages, 6 figures, as accepted in Phys. Rev.

    Biliary stenting in patients with pancreatic cancer: results from a population-based cohort study

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    We aimed to describe management of biliary obstruction (BO) in the context of pancreatic cancer within a population-based cohort.We examined management of BO in 1863 patients diagnosed as having pancreatic cancer in 2010/2011. We used descriptive statistics and logistic regression to describe patterns of biliary stent usage, complications and duration of patency, associations between preoperative stenting and surgical outcomes, and between patient factors and management of jaundice.Almost half of the people in the cohort (n = 909) were jaundiced within 12 months of diagnosis. Two-thirds of these had at least 1 stent inserted. Preoperative stenting, mostly with plastic stents, occurred for 72% of patients who experienced jaundice prior to an attempted resection but was not associated with surgical outcomes. Seventy percent of the jaundiced patients who did not have an attempted resection were stented. Metal stents were less frequently replaced within 30 days than plastic (9% vs 42%). Living in a rural area was associated with reduced likelihood of having jaundice managed.Plastic stents were still used frequently, despite guidelines recommending metal in most contexts. Patients living in rural areas were less likely to have BO managed. This work highlights the need to monitor current practice

    Identification of genes and pathways associated with cytotoxic T lymphocyte infiltration of serous ovarian cancer

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    BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are predictors of disease-specific survival (DSS) in ovarian cancer. It is largely unknown what factors contribute to lymphocyte recruitment. Our aim was to evaluate genes and pathways contributing to infiltration of cytotoxic T lymphocytes (CTLs) in advanced-stage serous ovarian cancer. METHODS: For this study global gene expression was compared between low TIL (n=25) and high TIL tumours (n=24). The differences in gene expression were evaluated using parametric T-testing. Selectively enriched biological pathways were identified with gene set enrichment analysis. Prognostic influence was validated in 157 late-stage serous ovarian cancer patients. Using immunohistochemistry, association of selected genes from identified pathways with CTL was validated. RESULTS: The presence of CTL was associated with 320 genes and 23 pathways (P<0.05). In addition, 54 genes and 8 pathways were also associated with DSS in our validation cohort. Immunohistochemical evaluation showed strong correlations between MHC class I and II membrane expression, parts of the antigen processing and presentation pathway, and CTL recruitment. CONCLUSION: Gene expression profiling and pathway analyses are valuable tools to obtain more understanding of tumour characteristics influencing lymphocyte recruitment in advanced-stage serous ovarian cancer. Identified genes and pathways need to be further investigated for suitability as therapeutic targets

    The presence of tumour-associated lymphocytes confers a good prognosis in pancreatic ductal adenocarcinoma: an immunohistochemical study of tissue microarrays

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    Background Tumour-associated lymphocytes (TALs) have been linked with good prognosis in several solid tumours. This study aimed to evaluate the prognostic significance of CD3, CD8 and CD20 positive lymphocytes in pancreatic ductal adenocarcinoma. Methods After histological re-evaluation of the tumours of 81 patients who underwent surgical resection for exclusively pancreatic ductal adenocarcinoma, tissue micro-arrays (TMA) were constructed and immunohistochemistry was performed for CD3, CD8 and CD20. The number of lymphocytes within specific tumour compartments (i.e. stromal and intratumoural) was quantified. X-tile software (Yale School of Medicine, CT, USA) was used to stratify patients into 'high’ and 'low’ for each of the lymphocytes stained and their association with survival. Receiver operating curves (ROC) were constructed to evaluate the association between the TALs, alone and in combination, with clinicopathological features. Results CD3 and CD8 positive lymphocytes were associated with grade of tumour differentiation. The presence of intratumoural CD3 positive cells was associated with improved survival (p = 0.028), and intratumoural and stromal CD3 in combination also correlated with improved survival (p = 0.043). When CD20 positive lymphocyte levels were high, survival improved (p = 0.029) and similar results were seen for CD20 in combination with intratumoural CD3 (p = 0.001) and stromal CD8 (p = 0.013). Conclusions This study has shown a correlation between the presence of TALs and survival in pancreatic ductal adenocarcinoma

    Prognostic impact of peritumoral lymphocyte infiltration in soft tissue sarcomas

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to clarify the prognostic significance of peritumoral lymphocyte infiltration in the capsule of soft tissue sarcomas (STS). Multiple observations in preclinical and clinical studies have shown that the immune system has a role in controlling tumor growth and progression. Prognostic markers in potentially curable STS should guide therapy after surgical resection. The immune status at the time of resection may be important, but the prognostic significance of peritumoral lymphocytes is unknown.</p> <p>Methods</p> <p>Tissue microarrays from 80 patients with STS were constructed from duplicate cores of tissue from the tumor and the peritumoral capsule. Immunohistochemistry was used to evaluate the CD3+, CD4+, CD8+ and CD20+ lymphocytes in the tumor and the peritumoral capsule.</p> <p>Results</p> <p>In univariate analyses, increasing numbers of CD20+ (<it>P </it>= 0.032) peritumoral lymphocytes were associated with a reduced disease free survival (DSS). In multivariate analyses, a high number of CD20+ peritumoral lymphocytes (<it>P </it>= 0.030) in the capsule was an independent negative prognostic factor for DSS. There were no such associations of lymphocyte infiltration in the tumor.</p> <p>Conclusions</p> <p>A high density of CD20+ peritumoral lymphocytes is an independent negative prognostic indicator for patients with STS. Further research is needed to determine whether CD20 cells in the peritumoral capsule of STS may promote tumor invasion in the surrounding tissue and increase the metastatic potential.</p
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