253 research outputs found

    Big fish, big pond? The joint effect of formal and informal core-periphery positions on the generation of incremental innovations

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    In this paper, we apply a core/periphery framework to an intraorganizational context to study the interplay between formal and informal core/periphery structures. Specifically, we consider how core positions occupied by inventors in the corporate research and development division of a large multinational high-tech company affect their ability to generate incremental innovations. We theorize and empirically observe that formal and informal core positions have positive and independent effects on the generation of incremental innovations. These effects have a multiplicative impact on innovative productivity when inventors who are core in the informal knowledge-sharing network are also affiliated with a core organizational unit. We also observe, however, that the positive effect of being located at the core of both the informal and formal structures is negatively moderated by individuals’ distribution of knowledge ties when these reach outside the core of their informal knowledge-sharing network

    Social Cohesion, Structural Holes, and a Tale of Two Measures

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    EMBARGOED - author can archive pre-print or post-print on any open access repository after 12 months from publication. Publication date is May 2013 so embargoed until May 2014.This is an author’s accepted manuscript (deposited at arXiv arXiv:1211.0719v2 [physics.soc-ph] ), which was subsequently published in Journal of Statistical Physics May 2013, Volume 151, Issue 3-4, pp 745-764. The final publication is available at link.springer.com http://link.springer.com/article/10.1007/s10955-013-0722-

    Poorly differentiated neuroendocrine larynx carcinoma: Clinical features and mirnas signature—a new goal for early diagnosis and therapy?

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    Laryngeal neuroendocrine carcinomas (LNECs) are rare and highly heterogeneous malignancies presenting a wide range of pathological and clinical manifestations. Herein, we retrospectively characterize ten patients diagnosticated with LNEC, five of which were defined as well‐moderately differentiated neuroendocrine carcinomas, and five that were defined as poorly differentiated neuroendocrine carcinomas, according to the latest WHO classification. Clinical features were analyzed and compared between the two subgroups together with a microRNA study which evidenced a peculiar signature likely related to poorly differentiated larynx neuroendocrine carcinomas. These findings may offer new useful insights for clinicians to improve diagnosis efficiency, therapy response, and patients’ outcome for this aggressive neoplasm

    First-Trimester Follistatin-Like-3 Levels in Pregnancies Complicated by Subsequent Gestational Diabetes Mellitus

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    Objective: To determine whether maternal levels of follistatin-like-3 (FSTL3), an inhibitor of activin and myostatin involved in glucose homeostasis, are altered in the first trimester of pregnancies complicated by subsequent gestational diabetes mellitus (GDM). Research Design and Methods: This was a nested case-control study of subjects enrolled in a prospective cohort of pregnant women with and without GDM (\geq2 abnormal values on a 100-g glucose tolerance test at ~28 weeks of gestation). We measured FSTL3 levels in serum collected during the first trimester of pregnancy. Logistic regression analyses were used to determine the risk of GDM. Results: Women who developed GDM (n = 37) had lower first-trimester serum levels of FSTL3 compared with women who did not (n = 127) (median 10,789 [interquartile range 7,013-18,939] vs. 30,670 [18,370-55,484] pg/ml, P < 0.001). When subjects were divided into tertiles based on FSTL3 levels, women with the lowest levels demonstrated a marked increase in risk for developing GDM in univariate (odds ratio 11.2 [95% CI 3.6-35.3]) and multivariate (14.0 [4.1-47.9]) analyses. There was a significant negative correlation between first-trimester FSTL3 levels and ~28-week nonfasting glucose levels (r = -0.30, P < 0.001). Conclusions: First-trimester FSTL3 levels are associated with glucose intolerance and GDM later in pregnancy

    Cefuroxime Pharmacokinetics in Pediatric Cardiovascular Surgery Patients Undergoing Cardiopulmonary Bypass

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    Objectives The objective of this study was to determine the pharmacokinetics of cefuroxime in children undergoing cardiopulmonary bypass (CPB) for cardiovascular surgery. Design A prospective study. Setting A tertiary pediatric teaching hospital. Participants Infants and children undergoing CPB were enrolled in the study. Intervention An initial dose (mean, 24.2 ± 1.6 mg/kg) of cefuroxime was administered before surgical incision, and a second dose (mean, 14.4 ± 7.9 mg/kg) was administered in the CPB prime solution. Serial blood samples were obtained before, during, and after the CPB process. Samples were shipped on dry ice to the analytic laboratory and concentrations determined by a validated high-performance liquid chromatography method. A 2-compartment pharmacokinetic model was fitted to the data using maximum a priori–Bayesian estimation, with weight as a covariate. Monte Carlo simulations of a single-dose (25 mg/kg pre-CPB) approach and a 2-dose (25 mg/kg pre- and 12.5-mg/kg prime solution dose) approach were performed. Measurements and Main Results Fifteen subjects (9 males/6 females) were enrolled in the study, with median (range) age and weight of 11 (3-34) months and 9.5 (4.5-15.4) kg, respectively. The median (range) duration of CPB was 136 (71-243) minutes. Median and range cefuroxime pharmacokinetic parameters were as follows: maximum concentration (Cmax) dose, 1: 328 (150-512) μg/mL; systemic clearance, 0.050 (0.041-0.058) L/h/kg; steady-state volume of distribution, 0.213 (0.081-0.423) L/kg; volume of distribution in the central compartment, 0.081 (0.046-0.162) L/kg; and elimination half-life, 3.76 (1.03-6.81) hours. The median 8-hour post–dose-simulated cefuroxime concentrations were 26.5 and 16.0 mg/L for the 2-dose and single-dose regimens, respectively. Conclusion Manufacturers recommend that pediatric doses of cefuroxime (25-50 mg/kg) can be used in infants and children undergoing CPB to maintain adequate serum concentrations for surgical-site infection prophylaxis. A second intraoperative dose, administered through the CPB circuit, provides no additional prophylactic advantage

    Paclitaxel, vinorelbine and 5-fluorouracil in breast cancer patients pretreated with adjuvant anthracyclines

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    We investigated the activity and toxicity of a combination of vinorelbine (VNB), paclitaxel (PTX) and 5-fluorouracil (5-FU) continuous infusion administered as first-line chemotherapy in metastatic breast cancer patients pretreated with adjuvant anthracyclines. A total of 61 patients received a regimen consisting of VNB 25 mg m−2 on days 1 and 15, PTX 60 mg m−2 on days 1, 8 and 15 and continuous infusion of 5-FU at 200 mg m−2 every day. Cycles were repeated every 28 days. Disease response was evaluated by both RECIST and World Health Organization (WHO) criteria. Objective responses were recorded in 39 of 61 patients (64.0%) assessed by WHO and in 36 of 50 patients (72.0%) assessable by RECIST criteria. Complete remission occurred in 15 (24.6%) and 14 patients (28.0%), respectively. The median time to progression and overall survival of entire population was 10.6 and 27.3 months, respectively, and median duration of complete response was 14.8 months. The dose-limiting toxicity was myelosuppression (leucopenia grade 3/4 in 52.5% of patients). Grade 3/4 nonhaematologic toxicities included mucositis/diarrhoea in 13.1%, skin in 3.3% and cardiac in 1.6% of patients. Grade 2/3 neurotoxicity was observed in five patients (7.2%). The VNB, PTX and 5-FU continuous infusion combination regimen was active and manageable. Complete responses were frequent and durable
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