133 research outputs found
Discovering a Light Higgs Boson with Light
We evaluate the prospects for detecting a non-standard light Higgs boson with
a significant branching ratio to two photons, in Run II of the Fermilab
Tevatron. We derive the reach for several channels: inclusive,
jet and jets. We present the expected Run II limits on
the branching ratio of as a function of the Higgs mass, for
the case of ``bosonic'', as well as ``topcolor'' Higgs bosons.Comment: 11 pages, LaTeX, 7 figures, 4 tables, uses aipproc2.sty, contributed
to the Physics at Run II Workshop, analysis redone with optimized cuts and
improved background estimate, references adde
Searching for a light Fermiophobic Higgs Boson at the Tevatron
We propose new production mechanisms for light fermiophobic Higgs bosons
() with suppressed couplings to vector bosons () at the Fermilab
Tevatron. These mechanisms (e.g. ) are complementary to the
conventional process , which suffers from a strong suppression of
in realistic models with a . The new mechanisms extend the
coverage at the Tevatron Run II to the larger region, and offer the
possibility of observing new event topologies with up to 4 photons.Comment: 15 pages, including 5 eps-figure
The CP-conserving two-Higgs-doublet model: the approach to the decoupling limit
A CP-even neutral Higgs boson with Standard-Model-like couplings may be the
lightest scalar of a two-Higgs-doublet model. We study the decoupling limit of
the most general CP-conserving two-Higgs-doublet model, where the mass of the
lightest Higgs scalar is significantly smaller than the masses of the other
Higgs bosons of the model. In this case, the properties of the lightest Higgs
boson are nearly indistinguishable from those of the Standard Model Higgs
boson. The first non-trivial corrections to Higgs couplings in the approach to
the decoupling limit are also evaluated. The importance of detecting such
deviations in precision Higgs measurements at future colliders is emphasized.
We also clarify the case in which a neutral Higgs boson can possess
Standard-Model-like couplings in a regime where the decoupling limit does not
apply. The two-Higgs-doublet sector of the minimal supersymmetric model
illustrates many of the above features.Comment: 54 pages, 2 tables, revtex4 format, some new material added
(including elegant forms for the three-Higgs and four-Higgs couplings) and
typographical errors fixe
A phase II trial of preoperative chemotherapy with epirubicin, cisplatin and capecitabine for patients with localised gastro-oesophageal junctional adenocarcinoma
Preoperative cisplatin/fluorouracil is used for the treatment of localised oesophageal carcinoma. This phase II study aimed to assess the efficacy and safety of administering preoperative epirubicin/cisplatin/capecitabine (ECX). Patients with stage II or III oesophageal/gastro-oesophageal junctional adenocarcinoma from one institution received 4 cycles of ECX (epirubicin 50 mg m−2 day 1, cisplatin 60 mg m−2 day 1, capecitabine 625 mg m−2 b.i.d. daily) followed by surgery. The primary end point was the pathological complete response (pCR) rate based on a Simon two-stage design. Secondary end points included overall and progression-free survival (OS/PFS). Thirty-four patients were recruited: median age 60 years (range 41–81), 91% male, 97% PS 0/1, 80% T3, 68% N1. Thirty-one patients completed four ECX cycles. Grade 3/4 toxicities ⩾5% included neutropenia (62%), hand–foot syndrome (15%) and nausea/vomiting (9%). Thirteen out of 28 (46%) evaluable patients responded to chemotherapy by EUS (⩾30% reduction in maximal tumour thickness). Twenty-six out of 34 (76%) patients underwent resection (R0=73%, R1=27%). Post-operatively, two patients died within 60 days of surgery. The pCR rate was 5.9% (95% CI 0–14%) in the intent-to-treat population. According to the statistical design, this prompted early study termination. However, with a median follow-up of 34 months the median OS and 1- and 2-year survival rates were 17 months, 67 and 39% respectively. Median PFS was 13 months. Of the 14 relapsed patients, 10 presented with distant metastases. Preoperative ECX is feasible and well tolerated. Although associated with a low pCR rate, survival with ECX was comparable with published studies suggesting that pCR may not correlate with satisfactory outcome from preoperative chemotherapy for localised oesophageal adenocarcinoma
Differences in the histological findings, phenotypic marker expressions and genetic alterations between adenocarcinoma of the gastric cardia and distal stomach
Adenocarcinoma of the gastric cardia (C-Ca) is possibly a specific subtype of gastric carcinoma. The purpose of this study was to clarify the differences in the clinicopathological characteristics between C-Ca and adenocarcinoma of the distal stomach (D-Ca), and also the differences in the expressions of gastric and intestinal phenotypic markers and genetic alterations between the two. The clinicopathological findings in 72 cases with C-Ca were examined and compared with those in 170 cases with D-Ca. The phenotypic marker expressions examined were those of human gastric mucin (HGM), MUC6, MUC2 and CD10. Furthermore, the presence of mutations in the APC, K-ras and p53 genes and the microsatellite instability status of the tumour were also determined. C-Ca was associated with a significantly higher incidence of differentiated-type tumours and lymphatic vessel invasion (LVI) as compared with D-Ca (72.2 vs 48.2%, P=0.0006 and 72.2 vs 55.3%, P=0.0232, respectively). Oesophageal invasion by the tumour beyond the oesophago-gastric junction (OGJ) was found in 56.9% of cases with C-Ca; LVI in the area of oesophageal invasion was demonstrated in 61% of these cases. Also, LVI was found more frequently in cases of C-Ca with oesophageal invasion than in those without oesophageal invasion (82.9 vs 58.1%, P=0.0197). The incidence of undifferentiated-type tumours was significantly higher in cases with advanced-stage C-Ca than in those with early-stage C-Ca (5 vs 36.5%, P=0.0076). A significantly greater frequency of HGM expression in early-stage C-Ca and significantly lower frequency of MUC2 expression in advanced-stage C-Ca was observed as compared with the corresponding values in cases of D-Ca (78.9 vs 52.2%, P=0.0402 and 51.5 vs 84.6%, P=0.0247, respectively). Mutation of the APC gene was found in only one of all cases of C-Ca, and the frequency of mutation of the APC gene was significantly lower in cases of C-Ca than in those of D-Ca (2.4 vs 20.0%, P=0.0108). The observations in this study suggest that C-Ca is a more aggressive tumour than D-Ca. The differences in biological behavior between C-Ca and D-Ca may result from the different histological findings in the wall of the OGJ and the different genetic pathways involved in the carcinogenesis
Some technique-dependent patterns of collateral flow during cerebral angiography
During selective transfemoral catheter cerebral angiography, anastomoses between external carotid branches and the vertebral artery, between the vertebral and deep or ascending cervical arteries, and between the middle meningeal and ophthalmic arteries can be demonstrated fairly frequently in patients with no known vascular abnormalities. One can occasionally show bidirectional filling of these anastomoses depending on the vessel injected. Visualization of these anastomoses occurs to a variable degree and is sometimes entirely technique-dependent, reflecting a transient increase in the intraluminal pressure during the injection of contrast medium.-Thus, demonstration of extracranial collateral arterial flow during cerebral angiography should not necessarily be interpreted as an abnormal phenomenon, such as may be seen with arterial occlusive disease, vascular malformation, or a very vascular tumor. Au cours de l'angiographie cérébrale parcathétérismes sélectifs par voie fémorale, peuvent apparaître des anastomoses entre des branches carotidiennes externes et l'artère vertébrale, entre l'artère vertébrale et les artères cérébrales profondes ou ascendantes et entre l'artère méningée moyenne et l'artère ophtalmique. Occasionnellement, on peut mettre en évidence un remplissage bidirectionnel de ces anastomoses, en rapport avec le vaisseau injecté. La visualisation de ces anastomoses se produit de facon variable dépend parfois entièrement de la technique, reflétant une augmentation transitoire de la pression dans l'artère durant l'injection du produit de contraste. Par conséquent, l'observation d'une circulation artérielle collatérale extracrânienne pendant une angiographie cérébrale ne représente pas nécéssairement un phénomène anormal tel qu'on le rencontre dans les troubles artériels occlusifs, dans les malformations vasculaires et dans les tumeurs vascularisées. Während der selektiven transfemoralen Katheter-Angiographie können sich Anastomosen zwischen Externa-Gefäßen und der A. vertebralis, zwischen der A. vertebralis und tiefen oder aufsteigenden cervicalen Arterien und zwischen der A. meningica media und der A. ophthalmica darstellen. Diese Befunde finden sich auch bei Patienten, bei denen keine Gef:aßanomalien vorliegen. Gelegentlich wird ein bidirektionaler Kontrastmitteldurchfluß durch diese Anastomosen nachgewiesen, dabei ist die Kontrastmittelfüllung von der Lokalisation der Kontrastmittelinjektion abhängig. Es zeigt sich also, daß diese unterschiedlichen Durchströmungen technisch bedingt werden können und nicht immer als abnormales Phänomen gedeutet werden können.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46671/1/234_2004_Article_BF00341594.pd
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Manufacture of die casting dies by hot isostatic pressing. CRADA final report
The reason for this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Doehler-Jarvis was to investigate the manufacture die-casting dies with internal water-cooling lines by hot-isostatic pressing (HIPing) of H13 tool steel powder. The use of HIPing will allow the near-net-shape manufacture of dies and the strategic placement of water-cooling lines during manufacture. The production of near-net-shape dies by HIPing involves the generation of HIPing diagrams, the design of the can that can be used for HIPing a die with complex details, strategic placement of water-cooling lines in the die, computer modeling to predict movement of the water lines during HIPing, and the development of strategies for placing water lines in the appropriate locations. The results presented include a literature review, particle analysis and characterization of H13 tool steel powder, and modeling of the HIPing process
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