On the non-abelian superalgebra spanned by the conserved quantities of N=1 supersymmetric Korteweg-de Vries equation

We obtain an infinite sequence of bosonic non-local conserved quantities for the N=1 supersymmetric Korteweg-de Vries equation. It is generated from a bosonic non-local conserved quantity of Super Gardner equation. In distinction to the already known one with odd parity and dimension 1/2, it has even parity and dimension 1. It fits exactly in the supersymmetric cohomology in the space of conserved quantities that we also introduce here. Using results from this cohomology we obtain the Poisson bracket of several non-local conserved quantities, including the already known odd ones and the new even ones. The algebra closes in terms of polynomials of local and non-local conserved quantities. We prove that the bosonic non-local conserved quantities cannot be expressed as functions of the already known local and non-local conserved quantities of Super KdV equation.Comment: To be published in: Physics Letters A. 16 page

New Integrable Models from Fusion

Integrable multistate or multiflavor/color models were recently introduced. They are generalizations of models corresponding to the defining representations of the U_q(sl(m)) quantum algebras. Here I show that a similar generalization is possible for all higher dimensional representations. The R-matrices and the Hamiltonians of these models are constructed by fusion. The sl(2) case is treated in some detail and the spin-0 and spin-1 matrices are obtained in explicit forms. This provides in particular a generalization of the Fateev-Zamolodchikov Hamiltonian.Comment: 11 pages, Latex. v2: statement concerning symmetries qualified, 3 minor misprints corrected. J. Phys. A (1999) in pres

Bethe ansatz for the SU(4) extension of the Hubbard Model

We apply the nested algebraic Bethe ansatz method to solve the eigenvalue problem for the SU(4) extension of the Hubbard model. The Hamiltonian is equivalent to the SU(4) graded permutation operator. The graded Yang-Baxter equation and the graded Quantum Inverse Scattering Method are used to obtain the eigenvalue of the SU(4) extension of the Hubbard model.Comment: Latex file, 12 page

Fermionisation of the Spin-S Uimin-Lai-Sutherland Model: Generalisation of Supersymmetric t-J Model to Spin-S

The spin-1 Uimin-Lai-Sutherland (ULS) isotropic chain model is expressed in terms of fermions and the equivalence of the fermionic representation to the supersymmetric t-J model is established directly at the level of Hamiltonians.The spin-S ULS model is fermionized and the Hamiltonian of the corresponding generalisation of the t-J model is written down.Comment: 16 page

N=2 local and N=4 nonlocal reductions of supersymmetric KP hierarchy in N=2 superspace

A N=4 supersymmetric matrix KP hierarchy is proposed and a wide class of its reductions which are characterized by a finite number of fields are described. This class includes the one-dimensional reduction of the two-dimensional N=(2|2) superconformal Toda lattice hierarchy possessing the N=4 supersymmetry -- the N=4 Toda chain hierarchy -- which may be relevant in the construction of supersymmetric matrix models. The Lax pair representations of the bosonic and fermionic flows, corresponding local and nonlocal Hamiltonians, finite and infinite discrete symmetries, the first two Hamiltonian structures and the recursion operator connecting all evolution equations and the Hamiltonian structures of the N=4 Toda chain hierarchy are constructed in explicit form. Its secondary reduction to the N=2 supersymmetric alpha=-2 KdV hierarchy is discussed.Comment: 26 pages, LaTeX, a few misprints correcte

Impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field

We report on the observation and experimental studies of impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field. The terahertz electroluminescence is observed in a wide range of doping levels (at noncompensated donor density from 4.5×10[sup 16] to 3.4×10[sup 18] cm[sup −3]). Spectra of terahertz luminescence and photoconductivity are studied by means of Fourier transform spectrometry. Distinctive features of the spectra can be assigned to intracenter electron transitions between excited and ground states of silicon and oxygen donors and to hot electron transitions to the donor states.Peer reviewe

Value of team approach combined with clinical pathway for diabetic foot problems: a clinical evaluation

Aims: To evaluate the effectiveness of management of diabetic foot problems (DFP) by the National University Hospital (NUH) Multidisciplinary Diabetic Foot Team combined with a clinical pathway in terms of average length of stay (ALOS), readmission rates, hospitalisation cost per patient, major reamputation rate, and complication rate. Methods: 939 patients admitted to the Department of Orthopaedic Surgery, NUH, for DFP from 2002 (before team formation) to 2007 (after team formation). It consisted of six cohorts of patients – 61 for 2002, 70 for 2003, 148 for 2004, 180 for 2005, 262 for 2006, and 218 for 2007. All patients were managed by the NUH Multidisciplinary Diabetic Foot Team combined with a clinical pathway. Statistical analyses were carried out for five parameters (ALOS, hospitalisation cost per patient, major amputation rate, readmission rate, and complication rate). Results: From 2002 to 2007, the ALOS was significantly reduced from 20.36 days to 12.20 days (p=0.0005). Major amputation rate was significantly reduced from 31.15 to 11.01% (p<0.0005). There was also a significant reduction in complication rate from 19.67 to 7.34% (p=0.005). There were reductions in the hospitalisation cost per patient and readmission rate after formation of the multidisciplinary team but they were not statistically significant. Conclusion: Our evaluation showed that a multidisciplinary team approach combined with the implementation of a clinical pathway in NUH was effective in reducing the ALOS, major amputation rate, and complication rate of DFP

Ten years of a multidisciplinary diabetic foot team approach in Sao Paulo, Brazil

Diabetes mellitus can cause devastating foot problems including loss of protective sensation with subsequent ulcerations and amputations. The natural history and pathophysiology of diabetic foot ulcers is best understood and managed by a multiprofessional team approach. The main factors for prevention and treatment of these devastating diabetic foot conditions are shown, with special attention to education of the patient. This approach decreases the morbidity of the disease, besides its economical and social feasibility

Diabetic foot infections: a team-oriented review of medical and surgical management

As the domestic and international incidence of diabetes and metabolic syndrome continues to rise, health care providers need to continue improving management of the long-term complications of the disease. Emergency department visits and hospital admissions for diabetic foot infections are increasingly commonplace, and a like-minded multidisciplinary team approach is needed to optimize patient care. Early recognition of severe infections, medical stabilization, appropriate antibiotic selection, early surgical intervention, and strategic plans for delayed reconstruction are crucial components of managing diabetic foot infections. The authors review initial medical and surgical management and staged surgical reconstruction of diabetic foot infections in the inpatient setting

Double blind, randomized, placebo controlled clinical trial for the treatment of diabetic foot ulcers, using a nitric oxide releasing patch: PATHON

<p>Abstract</p> <p>Background</p> <p>Diabetes Mellitus constitutes one of the most important public health problems due to its high prevalence and enormous social and economic consequences. Diabetic foot ulcers are one of the chronic complications of diabetes mellitus and constitute the most important cause of non-traumatic amputation of inferior limbs. It is estimated that 15% of the diabetic population will develop an ulcer sometime in their lives. Although novel therapies have been proposed, there is no effective treatment for this pathology. Naturally produced nitric oxide participates in the wound healing process by stimulating the synthesis of collagen, triggering the release of chemotactic cytokines, increasing blood vessels permeability, promoting angiogenic activity, stimulating the release of epidermical growth factors, and by interfering with the bacterial mitochondrial respiratory chain. Topically administered nitric oxide has demonstrated to be effective and safe for the treatment of chronic ulcers secondary to cutaneous leishmaniasis. However, due to their unstable nitric oxide release, the topical donors needed to be applied frequently, diminishing the adherence to the treatment. This difficulty has led to the development of a multilayer polymeric transdermal patch produced by electrospinning technique that guarantees a constant nitric oxide release. The main objective of this study is to evaluate the effectiveness and safety of this novel nitric oxide releasing wound dressing for the treatment of diabetic foot ulcers.</p> <p>Methods and design</p> <p>A double-blind, placebo-controlled clinical trial, including 100 diabetic patients was designed. At the time of enrollment, a complete medical evaluation and laboratory tests will be performed, and those patients who meet the inclusion criteria randomly assigned to one of two groups. Over the course of 90 days group 1 will receive active patches and group 2 placebo patches. The patients will be seen by the research group at least every two weeks until the healing of the ulcer or the end of the treatment. During each visit the healing process of the ulcer, the patient's health status and the presence of adverse events will be assessed. Should the effectiveness of the patches be demonstrated an alternative treatment would then be available to patients.</p> <p>Trial registration</p> <p>NCT00428727.</p