1,941 research outputs found

    Notes on the Verlinde formula in non-rational conformal field theories

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    We review and extend evidence for the validity of a generalized Verlinde formula in particular non-rational conformal field theories. We identify a subset of representations of the chiral algebra in non-rational conformal field theories that give rise to an analogue of the relation between modular S-matrices and fusion coefficients in rational conformal field theories. To that end we review and extend the Cardy-type brane calculations in bosonic and supersymmetric Liouville theory (and its duals) as well as in the hyperbolic three-plane H3+. We analyze the three-point functions of Liouville theory and of H3+ in detail to directly identify the fusion coefficients from the operator product expansion.Comment: 29 pages, 6 figures, v2: minor corrections, PRD versio

    Physeal Distraction for Joint Preservation in Malignant Metaphyseal Bone Tumors in Children

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    Background: Physeal distraction facilitates metaphyseal bone tumor resection in children and preserves the adjacent joint. The technique was first described by Cañadell. Tumor resection procedures allowing limb-sparing reconstruction have been used increasingly in recent years without compromising oncologic principles. Questions/purposes: We report our results with Cañadell's technique by assessing tumor control, functional outcome, and complications. Methods: Six consecutive children with primary malignant metaphyseal bone tumors underwent physeal distraction as a part of tumor resection. Tumor location was the distal femur in four patients, the proximal humerus in one patient, and the proximal tibia in one patient. The functional outcome was evaluated after a minimum of 18months (median, 62months; range, 18-136months) using the Musculoskeletal Tumor Society (MSTS) score and the Toronto Extremity Salvage Score (TESS). Results: At latest followup, five patients were alive and disease-free and one had died from metastatic disease. All tumor resections resulted in local control; there were no local recurrencies. The mean MSTS score was 79% (range, 53%-97%) and corresponding mean TESS was 83% (range, 71%-92%). In one case, postoperative infection required amputation of the proximal lower leg. All physeal distractions were successful except for one patient in whom distraction resulted in rupturing into the tumor. This situation was salvaged by transepiphyseal resection. Conclusions: We consider Cañadell's technique a useful tool in the armamentarium to treat children with malignant tumors that are in close proximity to an open physis. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidenc

    A point mutation in the hair cell nicotinic cholinergic receptor prolongs cochlear inhibition and enhances noise protection

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    The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9â€ČT of knockin mice with a threonine for leucine change (L9â€ČT) at position 9â€Č of the second transmembrane domain of the α9 nicotinic cholinergic subunit, rendering α9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9â€ČT allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9â€ČT mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the α9α10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9L9â€ČT/L9â€ČT mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter α9α10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma.Fil: Taranda, Julian. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; Argentina. Tufts University School of Medicine; Estados UnidosFil: Maison, StĂ©phane F.. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Ballestero, Jimena Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Katz, Eleonora. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Savino, Jessica. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Vetter, Douglas E.. Tufts University School of Medicine; Estados UnidosFil: Boulter, Jim. University of California at Los Angeles; Estados UnidosFil: Liberman, M. Charles. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Fuchs, Paul A.. The Johns Hopkins University School of Medicine; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de FarmacologĂ­a; Argentin

    Prospective Study of Bowel Movement, Laxative Use, and Risk of Colorectal Cancer among Women

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    The authors prospectively examined the association between bowel movement frequency, laxative use, and the risk of colorectal cancer in 84, 577 women of the Nurses' Health Study living in the United States, 36-61 years of age and free of cancer in 1982. Between 1984 and 1996, 611 incident cases of colorectal cancer were documented. After controlling for age, body mass index, fiber intake, postmenopausal status and hormone use, physical activity, and use of laxatives, the relative risks associated with having bowel movements every third day or less, compared with those with bowel movements once daily, were 0.94 (95% confidence interval (Cl): 0.69, 1.28) for colorectal cancer, 0.88 (95% Cl: 0.62, 1.26) for colon cancer, and 1.18 (95% Cl: 0.63, 2.20) for rectal cancer. Compared with women who never used laxatives, the multivariate relative risks associated with weekly to daily laxative use were 1.00 (95% Cl: 0.72, 1.40) for colorectal cancer, 1.09 (95% Cl: 0.76, 1.57) for colon cancer, and 0.68 (95% Cl: 0.29, 1.57) for rectal cancer. These findings do not support an association between infrequent bowel movement, laxative use, and risk of colorectal cancer and indicate that simple questions directed at bowel movement frequency are unlikely to enhance our ability to predict colorectal cancer risk. Am J Epidemiol2000; 151: 958-6

    KEYNOTE-859: a Phase III study of pembrolizumab plus chemotherapy in gastric/gastroesophageal junction adenocarcinoma

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    Adenocarcinoma; Gastroesophageal junction cancer; PembrolizumabAdenocarcinoma; CĂĄncer de la uniĂłn gastroesofĂĄgica; PembrolizumabAdenocarcinoma; CĂ ncer de la uniĂł gastroesofĂ gica; PembrolizumabCurrent guidelines recommend two-drug cytotoxic chemotherapy with a fluoropyrimidine (fluorouracil or capecitabine) and a platinum-based agent (oxaliplatin or cisplatin) as first-line treatment for advanced gastric cancer. Pembrolizumab monotherapy has demonstrated durable antitumor activity in patients with advanced programmed death ligand 1-positive (combined positive score ≄1) gastric/gastroesophageal junction adenocarcinoma. Accumulating evidence indicates that combining pembrolizumab with standard-of-care chemotherapy for the treatment of advanced or metastatic cancer improves clinical outcomes. We describe the rationale for and the design of the randomized, double-blind, placebo-controlled, Phase III KEYNOTE-859 study, which is investigating pembrolizumab in combination with chemotherapy as first-line treatment for patients with human epidermal growth factor receptor 2-negative advanced unresectable or metastatic gastric/gastroesophageal junction adenocarcinoma. The planned sample size is 1542 patients, and the primary end point is overall survival
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