8,500 research outputs found

    A standardized comparison of peri-operative complications after minimally invasive esophagectomy: Ivor Lewis versus McKeown.

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    BACKGROUND: While our institutional approach to esophageal resection for cancer has traditionally favored a minimally invasive (MI) 3-hole, McKeown esophagectomy (MIE 3-hole) during the last five years several factors has determined a shift in our practice with an increasing number of minimally invasive Ivor Lewis (MIE IL) resections being performed. We compared peri-operative outcomes of the two procedures, hypothesizing that MIE IL would be less morbid in the peri-operative setting compared to MIE 3-hole. METHODS: Our institution\u27s IRB-approved esophageal database was queried to identify all patients who underwent totally MI esophagectomy (MIE IL vs. MIE 3-hole) from June 2011 to May 2016. Patient demographics, preoperative and peri-operative data, as well as post-operative complications were compared between the two groups. Post-operative complications were analyzed using the Clavien-Dindo classification system. RESULTS: There were 110 patients who underwent totally MI esophagectomy (MIE IL n = 49 [45%], MIE 3-hole n = 61 [55%]). The majority of patients were men (n = 91, 83%) with a median age of 62.5 (range 31-83). Preoperative risk stratifiers such as ECOG score, ASA, and Charlson Comorbidity Index were not significantly different between groups. Anastomotic leak rate was 2.0% in the MIE IL group compared to 6.6% in the MIE 3-hole group (p = 0.379). The rate of serious (Clavien-Dindo 3, 4, or 5) post-operative complications was significantly less in the MIE IL group (34.7 vs. 59.0%, p = 0.013). Serious pulmonary complications were not significantly different (16.3 vs. 26.2%, p = 0.251) between the two groups. CONCLUSIONS: In this cohort, totally MIE IL showed significantly less severe peri-operative morbidity than MIE 3-hole, but similar rates of serious pulmonary complications and anastomotic leaks. These findings confirm the safety of minimally invasive Ivor Lewis esophagectomies for esophageal cancer when oncologically and clinically appropriate. Minimally invasive McKeown esophagectomy remains a satisfactory and appropriate option when clinically indicated

    Increased Yield of ttbb at Hadron Colliders in Low-Energy Supersymmetry

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    Light bottom squarks and gluinos have been invoked to explain the b quark pair production excess at the Tevatron. We investigate the associated production of ttbb at hadron colliders in this scenario, and find that the rates for this process are enhanced over the Standard Model prediction. If light gluinos exist, it may be possible to detect them at the Tevatron, and they could easily be observed at the LHC.Comment: 5p, references added, version accepted to PR

    Does diabetes mellitus influence pathologic complete response and tumor downstaging after neoadjuvant chemoradiation for esophageal and gastroesophageal cancer? A two-institution report.

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    BACKGROUND: Esophageal carcinoma is an aggressive disease that is often treated with neoadjuvant therapy followed by surgical resection. Diabetes mellitus (DM) has been associated with reduced efficacy of chemoradiation (CRT) in other gastrointestinal cancers. The goal of this study was to determine if DM affects response to neoadjuvant CRT in the management of gastroesophageal carcinoma. METHODS: We retrospectively reviewed the esophageal cancer patient databases and subsequently analyzed those patients who received neoadjuvant CRT followed by surgical resection at two institutions, Thomas Jefferson University (TJUH) and Fox Chase Cancer Center (FCCC). Comparative analyses of rates of pathologic complete response rate (pCR) and pathologic downstaging in DM patients versus non-DM patients was performed. RESULTS: Two hundred sixty patients were included in the study; 36 patients had DM and 224 were non-diabetics. The average age of the patients was 61 years (range 24-84 years). The overall pCR was 26%. The pCR rate was 19% and 27% for patients with DM and without DM, respectively (P = 0.31). Pathologic downstaging occurred in 39% of study patients, including of 33% of DM patients and 40% of non-DM patients (P = 0.42). CONCLUSIONS: Although the current analysis does not demonstrate a significant reduction in pCR rates or pathologic downstaging in patients with DM, the observed trend suggests that a potential difference may be observed with a larger patient population. Further studies are warranted to evaluate the influence of DM on the effectiveness of neoadjuvant CRT in esophageal cancer

    Dialogue Act Modeling for Automatic Tagging and Recognition of Conversational Speech

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    We describe a statistical approach for modeling dialogue acts in conversational speech, i.e., speech-act-like units such as Statement, Question, Backchannel, Agreement, Disagreement, and Apology. Our model detects and predicts dialogue acts based on lexical, collocational, and prosodic cues, as well as on the discourse coherence of the dialogue act sequence. The dialogue model is based on treating the discourse structure of a conversation as a hidden Markov model and the individual dialogue acts as observations emanating from the model states. Constraints on the likely sequence of dialogue acts are modeled via a dialogue act n-gram. The statistical dialogue grammar is combined with word n-grams, decision trees, and neural networks modeling the idiosyncratic lexical and prosodic manifestations of each dialogue act. We develop a probabilistic integration of speech recognition with dialogue modeling, to improve both speech recognition and dialogue act classification accuracy. Models are trained and evaluated using a large hand-labeled database of 1,155 conversations from the Switchboard corpus of spontaneous human-to-human telephone speech. We achieved good dialogue act labeling accuracy (65% based on errorful, automatically recognized words and prosody, and 71% based on word transcripts, compared to a chance baseline accuracy of 35% and human accuracy of 84%) and a small reduction in word recognition error.Comment: 35 pages, 5 figures. Changes in copy editing (note title spelling changed

    Probing the Inner Disk Emission of the Herbig Ae Stars HD 163296 and HD 190073

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    The physical processes occurring within the inner few astronomical units of proto-planetary disks surrounding Herbig Ae stars are crucial to setting the environment in which the outer planet-forming disk evolves and put critical constraints on the processes of accretion and planet migration. We present the most complete published sample of high angular resolution H- and K-band observations of the stars HD 163296 and HD 190073, including 30 previously unpublished nights of observations of the former and 45 nights of the latter with the CHARA long-baseline interferometer, in addition to archival VLTI data. We confirm previous observations suggesting significant near-infrared emission originates within the putative dust evaporation front of HD 163296 and show this is the case for HD 190073 as well. The H- and K-band sizes are the same within (3±3)%(3 \pm 3)\% for HD 163296 and within (6±10)%(6 \pm 10)\% for HD 190073. The radial surface brightness profiles for both disks are remarkably Gaussian-like with little or no sign of the sharp edge expected for a dust evaporation front. Coupled with spectral energy distribution analysis, our direct measurements of the stellar flux component at H and K bands suggest that HD 190073 is much younger (<400 kyr) and more massive (~5.6 M_\odot) than previously thought, mainly as a consequence of the new Gaia distance (891 pc).Comment: 19 pages, 6 figure

    Creation and evolution of magnetic helicity

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    Projecting a non-Abelian SU(2) vacuum gauge field - a pure gauge constructed from the group element U - onto a fixed (electromagnetic) direction in isospace gives rise to a nontrivial magnetic field, with nonvanishing magnetic helicity, which coincides with the winding number of U. Although the helicity is not conserved under Maxwell (vacuum) evolution, it retains one-half its initial value at infinite time.Comment: Clarifying remarks and references added; 12 pages, 1 figure using BoxedEPSF, REVTeX macros; submitted to Phys Rev D; email to [email protected]

    Does Intraoperative Radiation Therapy Improve Local Tumor Control in Patients Undergoing Pancreaticoduodenectomy for Pancreatic Adenocarcinoma? A Propensity Score Analysis

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    Background: Locoregional recurrence (LRR) is an important factor after pancreaticoduodenectomy (PD) for pancreatic cancer. IORT administered to the resection bed may improve local tumor control. Methods: We performed a retrospective analysis of patients who underwent PD at Thomas Jefferson University Hospital (TJUH) between 1995 and 2005 to identify patients who underwent resection with and without intraoperative radiation therapy (IORT). Data collected included age, gender, complications, margin status, stage, survival, and recurrence. Unadjusted analyses of the IORT and non-IORT groups were performed using Fisher’s chi-square method for discrete variables and Wilcoxon Rank Sum test for continuous variables. To account for biases in patient selection for IORT, a propensity score was calculated for each patient and adjusted statistical analyses were performed for survival and recurrence outcomes. Results: Between January 1995 and November 2005, 122 patients underwent PD for perimpullary tumors, including 99 pancreatic cancers. Of this group, 37 patients were treated with IORT, and there was adequate follow-up information for a group of 46 patients who underwent PD without IORT. The IORT group contained a higher percentage of Stage IIB or higher tumors (65%) than in the non-IORT group (39.1%), though differences in stage did not reach significance (p = 0.16). There was a non-significant decrease in the rate of LRR in patients who had IORT (39% non-IORT vs. 23% IORT, p = 0.19). The median survival time of patients who received IORT was 19.2 months, which was not significantly different than patients managed without IORT, 21.0 months (p=0.78). In the propensity analyses, IORT did not significantly influence survival or recurrence after PD. Conclusions: IORT can be safely added to management approaches for resectable pancreatic cancer, with acceptable morbidity and mortality. IORT did not improve loco-regional control and did not alter survival for patients with resected pancreatic cancer. IORT is an optional component of adjuvant chemoradiation for pancreatic cancer. In the future, IORT may be combined with novel therapeutic agents in the setting of a clinical trial in order to attempt to improve outcomes for patients with pancreatic cancer. Annals of Surgical Oncology, Volume 16, Edition 8, August, 2009, pages 2116-22, “Does intraoperative radiation therapy improve local tumor control in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma? A propensity score analysis”. Authors: Showalter TN, Rao AS, Anné PR, Rosato FE, Rosato EL, Andrel J, Hyslop T, Xu X, Berger AC

    Electrically Driven Light Emission from Individual CdSe Nanowires

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    We report electroluminescence (EL) measurements carried out on three-terminal devices incorporating individual n-type CdSe nanowires. Simultaneous optical and electrical measurements reveal that EL occurs near the contact between the nanowire and a positively biased electrode or drain. The surface potential profile, obtained by using Kelvin probe microscopy, shows an abrupt potential drop near the position of the EL spot, while the band profile obtained from scanning photocurrent microscopy indicates the existence of an n-type Schottky barrier at the interface. These observations indicate that light emission occurs through a hole leakage or an inelastic scattering induced by the rapid potential drop at the nanowire-electrode interface.Comment: 12 pages, 4 figure
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