377 research outputs found
A Unified Algebraic Approach to Classical Yang-Baxter Equation
In this paper, the different operator forms of classical Yang-Baxter equation
are given in the tensor expression through a unified algebraic method. It is
closely related to left-symmetric algebras which play an important role in many
fields in mathematics and mathematical physics. By studying the relations
between left-symmetric algebras and classical Yang-Baxter equation, we can
construct left-symmetric algebras from certain classical r-matrices and
conversely, there is a natural classical r-matrix constructed from a
left-symmetric algebra which corresponds to a parak\"ahler structure in
geometry. Moreover, the former in a special case gives an algebraic
interpretation of the ``left-symmetry'' as a Lie bracket ``left-twisted'' by a
classical r-matrix.Comment: To appear in Journal of Physics A: Mathematical and Theoretica
Chemoprevention of lung cancer—from biology to clinical reality
Lung cancer is the commonest cause of cancer death in developed countries and throughout the world. Cigarette smoking is the main risk factor for lung cancer and ex-smokers today comprise ∼50% of all new lung cancer cases. Chemoprevention builds on the concepts of field of cancerization and multistep carcinogenesis and can be defined as the use of natural or chemical compounds to prevent, inhibit or reverse the process of carcinogenesis. So far, chemoprevention studies in lung cancer have failed to reduce lung cancer mortality. New developments in biotechnology have made it possible to define more accurately high-risk populations, make earlier diagnosis possible, and allow more specific targeted therapies to be developed. Both the development and validation of biomarkers, for the selection of high-risk study populations and for response evaluation in chemoprevention studies, are important for the faster turnover of studies evaluating new agents. This article reviews the current status and describes the perspectives for new approaches in the chemoprevention of lung cance
Combining gemcitabine, oxaliplatin and capecitabine (GEMOXEL) for patients with advanced pancreatic carcinoma (APC): a phase I/II trial
Background: Gemcitabine remains the mainstay of palliative treatment of advanced pancreatic carcinoma (APC). Adding capecitabine or a platinum derivative each significantly prolonged survival in recent meta-analyses. The purpose of this study was to determine dose, safety and preliminary efficacy of a first-line regimen combining all three classes of active cytotoxic drugs in APC. Patients and methods: Chemotherapy-naive patients with locally advanced or metastatic, histologically proven adenocarcinoma of the pancreas were treated with a 21-day regimen of gemcitabine [1000 mg/m2 day (d) 1, d8], escalating doses of oxaliplatin (80-130 mg/m2 d1) and capecitabine (650-800 mg/m2 b.i.d. d1-d14). The recommended dose (RD), determined in the phase I part of the study by interpatient dose escalation in cohorts of three to six patients, was further studied in a two-stage phase II part with the primary end point of response rate by RECIST criteria. Results: Forty-five patients were treated with a total of 203 treatment cycles. Thrombocytopenia and diarrhea were the toxic effects limiting the dose to an RD of gemcitabine 1000 mg/m2 d1, d8; oxaliplatin 130 mg/m2 d1 and capecitabine 650 mg/m2 b.i.d. d1-14. Central independent radiological review showed partial remissions in 41% [95% confidence interval (CI) 26% to 56%] of patients and disease stabilization in 37% (95% CI 22% to 52%) of patients. Conclusion: This triple combination is feasible and, by far, met the predefined efficacy criteria warranting further investigation
Neoadjuvant chemoradiotherapy with or without panitumumab in patients with wild-type KRAS, locally advanced rectal cancer (LARC): a randomized, multicenter, phase II trial SAKK 41/07
Background We conducted a randomized, phase II, multicenter study to evaluate the anti-epidermal growth factor receptor (EGFR) mAb panitumumab (P) in combination with chemoradiotherapy (CRT) with standard-dose capecitabine as neoadjuvant treatment for wild-type KRAS locally advanced rectal cancer (LARC). Patients and methods Patients with wild-type KRAS, T3-4 and/or N+ LARC were randomly assigned to receive CRT with or without P (6 mg/kg). The primary end-point was pathological near-complete or complete tumor response (pNC/CR), defined as grade 3 (pNCR) or 4 (pCR) histological regression by Dworak classification (DC). Results Forty of 68 patients were randomly assigned to P + CRT and 28 to CRT. pNC/CR was achieved in 21 patients (53%) treated with P + CRT [95% confidence interval (CI) 36%-69%] versus 9 patients (32%) treated with CRT alone (95% CI: 16%-52%). pCR was achieved in 4 (10%) and 5 (18%) patients, and pNCR in 17 (43%) and 4 (14%) patients. In immunohistochemical analysis, most DC 3 cells were not apoptotic. The most common grade ≥3 toxic effects in the P + CRT/CRT arm were diarrhea (10%/6%) and anastomotic leakage (15%/4%). Conclusions The addition of panitumumab to neoadjuvant CRT in patients with KRAS wild-type LARC resulted in a high pNC/CR rate, mostly grade 3 DC. The results of both treatment arms exceeded prespecified thresholds. The addition of panitumumab increased toxicit
Bevacizumab continuation versus no continuation after first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer: a randomized phase III non-inferiority trial (SAKK 41/06)
In this trial, stopping bevacizumab after completion of induction chemotherapy was associated with a shorter time to progression, but no statistically significant difference in overall survival compared with the bevacizumab continuation strategy. Non-inferiority could not be demonstrated. Treatment costs are substantially higher for continuous bevacizumab treatmen
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Hanford Site Hazardous waste determination report for transuranic debris waste streams NPFPDL1A, NPFPDL1B, NPFPDL1C and NPFPDL1D
This Hazardous Waste Determination Report is intended to satisfy the terms of a Memorandum of Agreement (Agreement signed on June 16, 1999) between the U.S. Department of Energy and the New Mexico Environment Department. The Agreement pertains to the exchange of information before a final decision is made on the Waste Isolation Pilot Plant application for a permit under the ''New Mexico Hazardous Waste Act''. The Agreement will terminate upon the effective date of a final ''New Mexico Hazardous Waste Act'' permit for the Waste Isolation Pilot Plant. In keeping with the principles and terms of the Agreement, this report describes the waste stream data and information compilation process, and the physical and chemical analyses that the U.S. Department of Energy has performed on selected containers of transuranic debris waste to confirm that the waste is nonhazardous (non-mixed). This also summarizes the testing and analytical results that support the conclusion that the selected transuranic debris waste is not hazardous and thus, not subject to regulation under the ''Resource Conservation and Recovery Act'' or the ''New Mexico Hazardous Waste Act''. This report will be submitted to the New Mexico Environment Department no later than 45 days before the first shipment of waste from the Hanford Site to the Waste Isolation Pilot Plant, unless the parties mutually agree in writing to a shorter time. The 52 containers of transuranic debris waste addressed in this report were generated, packaged, and placed into storage between 1995 and 1997. Based on reviews of administrative documents, operating procedures, waste records, generator certifications, and personnel interviews, this transuranic debris waste was determined to be nonhazardous. This determination is supported by the data derived from nondestructive examination, confirmatory visual examination, and the results of container headspace gas sampling and analysis. Therefore, it is concluded that this transuranic debris waste, which consists of 52 containers from waste streams NPFPDLIA, NPFPDLIB, NPFPDLIC, and NPFPDLID, is not hazardous waste, and no hazardous waste numbers specified in Title 40 Code of Federal Regulations, Part 261, have been assigned. Accordingly, the 52 containers of transuranic debris waste addressed in this report meet the requirements for transuranic waste as defined by the Department of Energy Waste Acceptance Criteria for the Waste Isolation Pilot Plant. The 52 containers are acceptable for disposal at the Waste Isolation Pilot Plant as nonhazardous transuranic waste
Combination of bevacizumab and 2-weekly pegylated liposomal doxorubicin as first-line therapy for locally recurrent or metastatic breast cancer. A multicenter, single-arm phase II trial (SAKK 24/06)
Background: Pegylated liposomal doxorubicin (PLD) and bevacizumab are active agents in the treatment of metastatic breast cancer (MBC). We carried out a multicenter, single-arm phase II trial to evaluate the toxicity and efficacy of PLD and bevacizumab as first-line treatment in MBC patients. Methods: Bevacizumab (10 mg/kg) and PLD (20 mg/m2) were infused on days 1 and 15 of a 4-week cycle for a maximum of six cycles. Thereafter, bevacizumab monotherapy was continued at the same dose until progression or toxicity. The primary objective was safety and tolerability, and the secondary objective was to evaluate efficacy of the combination. Results: Thirty-nine of 43 patients were assessable for the primary end point. Eighteen of 39 patients (46%, 95% confidence interval 30% to 63%) had a grade 3 toxicity. Sixteen (41%) had grade 3 palmar-plantar erythrodysesthesia, one had grade 3 mucositis, and one severe cardiotoxicity. Secondary end point of overall response rate among 43 assessable patients was 21%. Conclusions: In this nonrandomized single-arm trial, the combination of bimonthly PLD and bevacizumab in locally recurrent and MBC patients demonstrated higher than anticipated toxicity while exhibiting only modest activity. Based on these results, we would not consider this combination for further investigation in this settin
Emergence and Evolution of Cooperation Under Resource Pressure
We study the influence that resource availability has on cooperation in the context of hunter-gatherer
societies. This paper proposes a model based on archaeological and ethnographic research on resource
stress episodes, which exposes three different cooperative regimes according to the relationship
between resource availability in the environment and population size. The most interesting regime
represents moderate survival stress in which individuals coordinate in an evolutionary way to increase
the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival.
Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share
the part of the resource that is not strictly necessary for survival, thereby collectively lowering the
chances of starving. Our findings shed further light on the emergence and evolution of cooperation in
hunter-gatherer societies.Spanish Ministry of Science and Innovation Project CSD2010-00034
(SimulPast CONSOLIDER-INGENIO 2010) and HAR2009-06996; from the Argentine National Scientific
and Technical Research Council (CONICET): Project PIP-0706; from the Wenner-Gren Foundation for
Anthropological Research: Project GR7846; and from the project H2020 FET OPEN RIA IBSEN/66272
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