36 research outputs found

    Non-Hermitian SUSY Hydrogen-like Hamiltonians with real spectra

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    It is shown that the radial part of the Hydrogen Hamiltonian factorizes as the product of two not mutually adjoint first order differential operators plus a complex constant epsilon. The 1-susy approach is used to construct non-hermitian Hamiltonians with hydrogen spectra. Other non-hermitian Hamiltonians are shown to admit an extra `complex energy' at epsilon. New self-adjoint hydrogen-like Hamiltonians are also derived by using a 2-susy transformation with complex conjugate pairs epsilon, (c.c) epsilon.Comment: LaTeX2e file, 13 pages, 6 EPS figures. New references added. The present is a reorganized and simplified versio

    Quadratic pseudosupersymmetry in two-level systems

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    Using the intertwining relation we construct a pseudosuperpartner for a (non-Hermitian) Dirac-like Hamiltonian describing a two-level system interacting in the rotating wave approximation with the electric component of an electromagnetic field. The two pseudosuperpartners and pseudosupersymmetry generators close a quadratic pseudosuperalgebra. A class of time dependent electric fields for which the equation of motion for a two level system placed in this field can be solved exactly is obtained. New interesting phenomenon is observed. There exists such a time-dependent detuning of the field frequency from the resonance value that the probability to populate the excited level ceases to oscillate and becomes a monotonically growing function of time tending to 3/4. It is shown that near this fixed excitation regime the probability exhibits two kinds of oscillations. The oscillations with a small amplitude and a frequency close to the Rabi frequency (fast oscillations) take place at the background of the ones with a big amplitude and a small frequency (slow oscillations). During the period of slow oscillations the minimal value of the probability to populate the excited level may exceed 1/2 suggesting for an ensemble of such two-level atoms the possibility to acquire the inverse population and exhibit lasing properties.Comment: 5 figure

    Association of kidney fibrosis with urinary peptides: a path towards non-invasive liquid biopsies?

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    Chronic kidney disease (CKD) is a prevalent cause of morbidity and mortality worldwide. A hallmark of CKD progression is renal fibrosis characterized by excessive accumulation of extracellular matrix (ECM) proteins. In this study, we aimed to investigate the correlation of the urinary proteome classifier CKD273 and individual urinary peptides with the degree of fibrosis. In total, 42 kidney biopsies and urine samples were examined. The percentage of fibrosis per total tissue area was assessed in Masson trichrome stained kidney tissues. The urinary proteome was analysed by capillary electrophoresis coupled to mass spectrometry. CKD273 displayed a significant and positive correlation with the degree of fibrosis (Rho = 0.430, P = 0.0044), while the routinely used parameters (glomerular filtration rate, urine albumin-to-creatinine ratio and urine protein-to-creatinine ratio) did not (Rho = -0.222; -0.137; -0.070 and P = 0.16; 0.39; 0.66, respectively). We identified seven fibrosis-associated peptides displaying a significant and negative correlation with the degree of fibrosis. All peptides were collagen fragments, suggesting that these may be causally related to the observed accumulation of ECM in the kidneys. CKD273 and specific peptides are significantly associated with kidney fibrosis; such an association could not be detected by other biomarkers for CKD. These non-invasive fibrosis-related biomarkers can potentially be implemented in future trials

    Nonlinear Supersymmetric Quantum Mechanics: concepts and realizations

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    Nonlinear SUSY approach to preparation of quantum systems with pre-planned spectral properties is reviewed. Possible multidimensional extensions of Nonlinear SUSY are described. The full classification of ladder-reducible and irreducible chains of SUSY algebras in one-dimensional QM is given. Emergence of hidden symmetries and spectrum generating algebras is elucidated in the context of Nonlinear SUSY in one- and two-dimensional QM.Comment: 75 pages, Minor corrections, Version published in Journal of Physics

    Osteoprotegerin in Exosome-Like Vesicles from Human Cultured Tubular Cells and Urine

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    Urinary exosomes have been proposed as potential diagnostic tools. TNF superfamily cytokines and receptors may be present in exosomes and are expressed by proximal tubular cells. We have now studied the expression of selected TNF superfamily proteins in exosome-like vesicles from cultured human proximal tubular cells and human urine and have identified additional proteins in these vesicles by LC-MS/MS proteomics. Human proximal tubular cells constitutively released exosome-like vesicles that did not contain the TNF superfamily cytokines TRAIL or TWEAK. However, exosome-like vesicles contained osteoprotegerin (OPG), a TNF receptor superfamily protein, as assessed by Western blot, ELISA or selected reaction monitoring by nLC-(QQQ)MS/MS. Twenty-one additional proteins were identified in tubular cell exosomelike vesicles, including one (vitamin D binding protein) that had not been previously reported in exosome-like vesicles. Twelve were extracellular matrix proteins, including the basement membrane proteins type IV collagen, nidogen-1, agrin and fibulin-1. Urine from chronic kidney disease patients contained a higher amount of exosomal protein and exosomal OPG than urine from healthy volunteers. Specifically OPG was increased in autosomal dominant polycystic kidney disease urinary exosome-like vesicles and expressed by cystic epithelium in vivo. In conclusion, OPG is present in exosome-like vesicles secreted by proximal tubular epithelial cells and isolated from Chronic Kidney Disease urine.This work was supported by grants from the Instituto de Salud Carlos III (ISCIIIRETIC REDINREN RD06/0016, RD12/0021, PI11/01854, PI10/00072 PI09/ 00641 and PS09/00447); Comunidad de Madrid (Fibroteam S2010/BMD-2321, S2010/BMD-2378); Sociedad Española de NefrologÍa; European Network (HEALTH F2-2008-200647); DIALOK European project LSHB-CT-2007-036644; Fundacion Lilly and IRSIN/FRIAT to JE; Programa Intensificación Actividad Investigadora (ISCIII/ Agencia Laín-Entralgo/CM) to AO; Instituto de Salud Carlos III (FIS PI11/01401, CP09/00229); and Fundación Conchita Rábago de Jiménez DÍaz to GAL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

    RICORS2040 : The need for collaborative research in chronic kidney disease

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    Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

    Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

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    Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

    Osteoporosis management in hematologic stem cell transplant recipients: Executive summary

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    Background: Treatment advances have reduced the adverse events associated with hematopoietic stem cell transplant (HSCT) and led to an increased number of transplants performed. HSCT patients are living longer with concerns on long-term outcomes. Bone fragility and fracture are at the forefront for long-term morbidities post-HSCT. Results: In HSCT recipients, evidence has accumulated to support recommendations for more extensive monitoring of bone fragility and more appropriate administration of osteoporosis pharmacotherapies for patients at high risk of bone loss and/or fracture. Conclusion: This executive summary reports and summarizes the main recommendations published previously, including bone assessment, dietary and lifestyle recommendations and osteoporosis medication

    Bone management in hematologic stem cell transplant recipients

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    Autologous and allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for patients with some malignant and non-malignant hematological diseases. Advances in transplantation techniques and supportive care measures have substantially increased the number of long-term HSCT survivors. This has led to an increasing patient population suffering from the late effects of HSCT, of which, bone loss and its consequent fragility fractures lead to substantial morbidity. Altered bone health, with consequent fragility fractures, and chronic graft-versus-host disease (GVHD) are factors affecting long-term quality of life after HSCT. Hypogonadism, HSCT preparative regimens, nutritional factors, and glucocorticoids all contribute to accelerated bone loss and increased fracture risk. Management strategies should include bone mineral density examination, evaluation of clinical risk factors, and general dietary and physical activity measures. Evidence has accumulated permitting recommendations for more attentiveness to evaluation and monitoring of bone health, with appropriate application of osteoporosis pharmacotherapies to patients at increased risk of bone loss and fracture

    Osteoporosis management in hematologic stem cell transplant recipients: Executive summary

    No full text
    Background: Treatment advances have reduced the adverse events associated with hematopoietic stem cell transplant (HSCT) and led to an increased number of transplants performed. HSCT patients are living longer with concerns on long-term outcomes. Bone fragility and fracture are at the forefront for long-term morbidities post-HSCT. Results: In HSCT recipients, evidence has accumulated to support recommendations for more extensive monitoring of bone fragility and more appropriate administration of osteoporosis pharmacotherapies for patients at high risk of bone loss and/or fracture. Conclusion: This executive summary reports and summarizes the main recommendations published previously, including bone assessment, dietary and lifestyle recommendations and osteoporosis medication
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