Resummation of Yukawa enhanced and subleading Sudakov logarithms in longitudinal gauge boson and Higgs production

Future colliders will probe the electroweak theory at energies much larger than the gauge boson masses. Large double (DL) and single (SL) logarithmic virtual electroweak Sudakov corrections lead to significant effects for observable cross sections. Recently, leading and subleading universal corrections for external fermions and transverse gauge boson lines were resummed by employing the infrared evolution equation method. The results were confirmed at the DL level by explicit two loop calculations with the physical Standard Model (SM) fields. Also for longitudinal degrees of freedom the approach was utilized for DL-corrections via the Goldstone boson equivalence theorem. In all cases, the electroweak Sudakov logarithms exponentiate. In this paper we extend the same approach to both Yukawa enhanced as well as subleading Sudakov corrections to longitudinal gauge boson and Higgs production. We use virtual contributions to splitting functions of the appropriate Goldstone bosons in the high energy regime and find that all universal subleading terms exponentiate. The approach is verified by employing a non-Abelian version of Gribov's factorization theorem and by explicit comparison with existing one loop calculations. As a side result, we obtain also all top-Yukawa enhanced subleading logarithms for chiral fermion production at high energies to all orders. In all cases, the size of the subleading contributions at the two loop level is non-negligible in the context of precision measurements at future linear colliders.Comment: 32 pages, 7 figures, uses LaTeX2

On the Resummation of Large QCD Logarithms in Higgs -> 2 Photons Decay

We study the strong corrections to the Higgs coupling to two photons. This coupling is the dominant mechanism for Higgs production in photon-photon collisions. In addition, the two photon decay mode of the Higgs is an important and relatively background free channel of relevance at the LHC and the Tevatron. We develop a method for the resummation of large QCD corrections in the form of Sudakov-like logarithms of the type \alpha_s^n\ln^{2n}(m/m_H) and \alpha_s^n\ln^{2n-1}(m/m_H) (where m is the light quark mass) which can contribute to this process in certain models (for example, the MSSM for large tan \beta) up to next-to-leading-logarithmic (NLL) accuracy. The NLL correction is moderate, the substantial part of which comes from terms not related to running coupling effects.Comment: 13 pages, LaTeX, 5 Postscript Figures, version published in Phys. Rev.

Endoscopic palliation of oesophageal cancer: results of a prospective comparison of Nd:YAG laser and ethanol injection

To evaluate the effectiveness of intratumoral alcohol injection compared with Nd:YAG laser in the treatment of unresectable fungating cancers of the oesophagus

Improving results of esophageal stenting: a study on 160 consecutive unselected patients

Esophageal stenting is a valuable treatment in the management of malignant dysphagia. Recently, self-expanding stents have proved effective in reducing morbidity and mortality. The aim of this study was to evaluate the early and late results of esophageal stenting in a series of 160 consecutive unselected patients with unresectable esophageal and cardial carcinoma treated between November 1992 and December 1996

Endoscopic laser ablation of nondysplastic Barrett's epithelium: is it worthwhile?

The clinical value of endoscopic ablation of nondysplastic Barrett's epithelium is controversial. It has been stated that ablation, combined with acid suppression or antireflux surgery, may reduce the risk of adenocarcinoma, thereby obviating the need for endoscopic surveillance in these patients. Eighteen symptomatic patients were enrolled in a prospective study of Nd:YAG laser ablation of Barrett's esophagus followed by treatment with proton pump inhibitors or antireflux surgery. All patients had intestinal metaplasia and no associated dysplasia or carcinoma. Laser treatment was performed with noncontact fibers and a power output of 60 watts. The mean number of treatment sessions was three (range 1 to 5), and the mean energy delivered during each session was 2800 joules (range 600 to 4800 joules). All patients were given a standard dose of omeprazole (40 mg/day) throughout the study period. In two patients a mild distal esophageal stricture occurred and required a single dilatation. Macroscopic and histologic eradication of the specialized columnar epithelium was documented in 8 of 12 patients with tongues of Barrett's metaplasia, in one of four patients with circumferential Barrett's metaplasia, and in two of two patients with short-segment Barrett's esophagus. In five patients (28%) only a partial ablation could be achieved despite repeated laser treatment. Two patients (11%), one with tongues and the other with circumferential Barrett's metaplasia, were considered nonresponders. Adenocarcinoma undermining regenerated squamous epithelium was found, 6 months after eradication, in one patient who underwent esophagogastric resection. Twelve patients agreed to undergo antireflux surgery. Over a mean follow-up period of 14 months (range 4 to 32 months), two patients presented with recurrent Barrett's metaplasia: one at 8 months after successful Nissen fundoplication and the other after 1 year of continuous omeprazole treatment. Progression of Barrett's metaplasia was found in two other patients receiving pharmacologic therapy in whom a partial response to laser treatment had been obtained. In conclusion, Nd:YAG laser therapy of nondysplastic Barrett's esophagus, performed in conjunction with omeprazole treatment and followed by antireflux surgery, allows a partial regression of specialized columnar epithelium in most patients. However, this is a time-consuming procedure that produced only temporary eradication, did not prove effective in reducing cancer risk, and did not obviate the need for endoscopic surveillance

Phenolic compounds in red Chicorium intybus vegetable

Polyphenols are biologically active compounds widely distributed in the plant kingdom and so present in plant-derived foods and intrinsic components of human diets. Polyphenols have been shown to possess a range of biological activities, that are consistent with them contributing to the protection afforded by a diet rich in fruit and vegetables against degenerative diseases, inflammatory process, and aging, and modulating the immunity system. Cichorium intybus with its different varieties is a genus rich in polpyphenols; in fact, it is known to contain a number of hydroxycinnamic acid derivatives and flavonoids, with anthocyanins characterizing the var. silvestre, but the qualitative evaluation of polyphenolic fraction of red chicories, commonly used as food, is far to be completed. As the degree of hydroxylation of polyphenols is important in determining the biological activity and the degree and type of glycosylation are important in determining the ability of these compounds to be adsorbed in humans, the aim of this work was to investigate red chicory variety largely consumed in Italian diet, characterizing the different isomeric forms of polyphenols. The investigation was carried out using HPLC-DAD-ESI-MSn. The obtained results indicated the presence of a variety of phenolic acids in their different isomeric forms, flavonols (kaempferol and quercetin derivatives), and anthocyanidins glycosilated with one or more sugar moieties

Assessment of an lc-ms method for plasma quantification of the new immunosuppressant fk778 through comparison with hplc-uv

FK778 is a new immunosuppressive agent, derived from the leflunomide-active metabolite A77 1726. It inhibits de novo pyrimidine nucleotide synthesis showing efficacy in the prevention and treatment of rejection in experimental transplant models. The aim of this work was to develop an HPLC-MS method to measure FK778 in plasma for pharmacokinetic studies. The equipment used for mass evaluation was an HLPC coupled to an ion trap analyzer through an electrospray source. After precipitation of plasma proteins with acetonitrile, the supernatant was injected onto an analytical RP-C18 column. Chromatographic separation was performed under isocratic conditions, using a mobile phase consisting of ammonium acetate buffer and acetonitrile (55:45. vol/vol). MS detection was performed in the negative ionization mode by monitoring the molecular ion of FK778 (m/z 307) and IS (m/z 269), using selected ion monitoring for both. However, we observed peaks corresponding to dimers, trimers, and tetramers of FK778 (m/z 637, m/z 945, m/z 1274). The HPLC-MS method was applied to pharmacokinetics in animal models showing comparable results to those obtained by an HPLC-UV assay at 290 nm. Good agreement was observed in the plasma FK778 concentration versus time curves. The rapid preparation of samples and the short run-time make this method attractive for use in clinical practic