New SDW phases in quasi-one-dimensional systems dimerized in the transverse direction

The spin density wave instabilities in the quasi-one-dimensional metal (TMTSF)_2ClO_4 are studied in the framework a matrix random phase approximation for intra-band and inter-band order parameters. Depending on the anion ordering potential V which measures the lattice doubling in the transverse direction, two different instabilities are possible. The SDW_0 state at low values of V is antiferromagnetic in b direction and has the critical temperature that decreases rapidly with V. The degenerated states SDW_(+-), stable at higher values of V, are superpositions of two magnetic orders, each one on its subfamily of chains. As V increases the ratio between two components of SDW_(+-) tends to zero and the critical temperature increases asymptotically towards that of SDW instability for a system having perfect nesting and no anion order. At intermediate V the metallic state can persist down to T=0.Comment: Submitted to Europhysics Letter

Magnetic oscillations and field induced spin density waves in (TMTSF)_2ClO_4

We report an analysis of the effects of magnetic field on a quasi-one-dimensional band of interacting electrons with a transverse dimerizing potential. One-particle problem in bond-antibond representation is solved exactly. The resulting propagator is used to calculate the spin-density-wave (SDW) response of the interacting system within the matrix RPA for the SDW susceptibility. We predict the magnetic field induced transition of the first order between interband SDW_0 and intraband SDW_(+-) phases. We reproduce the rapid oscillations with a period of 260 Tesla and the overal profile of the TMTSF_2ClO_4 phase diagram.Comment: 6 pages, 3 figure

Pauli and orbital effects of magnetic field on charge density waves

Taking into account both Pauli and orbital effects of external magnetic field we compute the mean field phase diagram for charge density waves in quasi-one-dimensional electronic systems. The magnetic field can cause transitions to CDW states with two types of the shifts of wave vector from its zero-field value. It can also stabilize the field-induced charge density wave. Furthermore, the critical temperature shows peaks at a new kind of magic angles.Comment: 3 pages, 1 figure include

Colloidal stability of tannins: astringency, wine tasting and beyond

Tannin-tannin and tannin-protein interactions in water-ethanol solvent mixtures are studied in the context of red wine tasting. While tannin self-aggregation is relevant for visual aspect of wine tasting (limpidity and related colloidal phenomena), tannin affinities for salivary proline-rich proteins is fundamental for a wide spectrum of organoleptic properties related to astringency. Tannin-tannin interactions are analyzed in water-ethanol wine-like solvents and the precipitation map is constructed for a typical grape tannin. The interaction between tannins and human salivary proline-rich proteins (PRP) are investigated in the framework of the shell model for micellization, known for describing tannin-induced aggregation of beta-casein. Tannin-assisted micellization and compaction of proteins observed by SAXS are described quantitatively and discussed in the case of astringency

U-J Synergy Effect for the High Tc Superconductors

Using renormalization group and exact diagonalization of small clusters we investigate the ground state phase diagram of a two-dimensional extended Hubbard model with nearest-neighbor exchange interaction J, in addition to the local Coulomb repulsion U. The main instabilities are antiferromagnetism close to half-filling and d-wave superconductivity in the doped system. Our results suggest that the combined action of J and U interactions provide a remarkably efficient mechanism to enhance both d-wave superconducting and antiferromagnetic correlations.Comment: Final version, to appear in PR

Effects of non-magnetic impurities on spin-fluctuations induced superconductivity

We study the effects of non-magnetic impurities on the phase diagram of a system of interacting electrons with a flat Fermi surface. The one-loop Wilsonian renormalization group flow of the angle dependent diffusion function $D(\theta_1,\theta_2,\theta_3)$ and interaction $U(\theta_1,\theta_2,\theta_3)$ determines the critical temperature and the nature of the low temperature state. As the imperfect nesting increases the critical temperature decreases and the low temperature phase changes from the spin-density wave (SDW) to the d-wave superconductivity (dSC) and finally, for bad nesting, to the random antiferromagnetic state (RAF). Both SDW and dSC phases are affected by disorder. The pair breaking depends on the imperfect nesting and is the most efficient when the critical temperature for superconductivity is maximal.Comment: 4 pages, 4 figures. Submitted to PR

Long-term low-dose ketoconazole treatment in bilateral macronodular adrenal hyperplasia

Medical therapy for Cushing's syndrome due to bilateral macronodular adrenal hyperplasia (BMAH) is generally administered for a limited time before surgery. Aberrant receptors antagonists show inconsistent efficacy in the long run to prevent adrenalectomy. We present a patient with BMAH, treated for 10 years with low doses of ketoconazole to control cortisol secretion. A 48-year-old woman presented with headaches and hypertension. Investigations showed the following: no clinical signs of Cushing's syndrome; enlarged lobulated adrenals; normal creatinine, potassium, and aldosterone; normal urinary aldosterone and metanephrines; elevated urinary free cortisol and steroid metabolites; and suppressed plasma renin activity and ACTH. A screening protocol for aberrant adrenal receptors failed to show any illegitimate hormone dependence. Ketoconazole caused rapid normalisation of cortisol and ACTH that persists over 10 years on treatment, while adrenals show no change in shape or size. Ketoconazole decreases cortisol in patients with Cushing's syndrome, and may prevent adrenal overgrowth. Steroid secretion in BMAH is inefficient as compared with normal adrenals or secreting tumours and can be controlled with low, well-tolerated doses of ketoconazole, as an alternative to surgery. LEARNING POINTS: Enlarged, macronodular adrenals are often incidentally found during the investigation of hypertension in patients harboring BMAH. Although laboratory findings include low ACTH and elevated cortisol, the majority of patients do not display cushingoid features.Bilateral adrenalectomy, followed by life-long steroid replacement, is the usual treatment of this benign condition, and alternative medical therapy is sought. Therapy based on aberrant adrenal receptors gives disappointing results, and inhibitors of steroidogenesis are not always well tolerated.However, ketoconazole at low, well-tolerated doses appeared appropriate to control adrenal steroid secretion indefinitely, while preventing adrenal overgrowth. This treatment probably constitutes the most convenient long-term alternative to surgery

The impact of a multidisciplinary self-care management program on quality of life, self-care, adherence to anti-hypertensive therapy, glycemic control, and renal function in diabetic kidney disease: A Cross-over Study Protocol.

Diabetic kidney disease, a global health issue, remains associated with high morbidity and mortality. Previous research has shown that multidisciplinary management of chronic disease can improve patient outcomes. The effect of multidisciplinary self-care management on quality of life and renal function of patients with diabetic kidney disease has not yet been well established. The aim of this study is to evaluate the impact of a multidisciplinary self-care management program on quality of life, self-care behavior, adherence to anti-hypertensive treatment, glycemic control, and renal function of adults with diabetic kidney disease. A uniform balanced cross-over design is used, with the objective to recruit 40 adult participants with diabetic kidney disease, from public and private out-patient settings in French speaking Switzerland. Participants are randomized in equal number into four study arms. Each participant receives usual care alternating with the multidisciplinary self- care management program. Each treatment period lasts three months and is repeated twice at different time intervals over 12 months depending on the cross-over arm. The multidisciplinary self-care management program is led by an advanced practice nurse and adds nursing and dietary consultations and follow-ups, to the habitual management provided by the general practitioner, the nephrologist and the diabetologist. Data is collected every three months for 12 months. Quality of life is measured using the Audit of Diabetes-Dependent Quality of Life scale, patient self-care behavior is assessed using the Revised Summary of Diabetes Self-Care Activities, and adherence to anti-hypertensive therapy is evaluated using the Medication Events Monitoring System. Blood glucose control is measured by the glycated hemoglobin levels and renal function by serum creatinine, estimated glomerular filtration rate and urinary albumin/creatinine ratio. Data will be analyzed using STATA version 14. The cross-over design will elucidate the responses of individual participant to each treatment, and will allow us to better evaluate the use of such a design in clinical settings and behavioral studies. This study also explores the impact of a theory-based nursing practice and its implementation into a multidisciplinary context. ClinicalTrials.gov identifier: NCT01967901 , registered on the 18th of October 2013

d-wave superconductivity and Pomeranchuk instability in the two-dimensional Hubbard model

We present a systematic stability analysis for the two-dimensional Hubbard model, which is based on a new renormalization group method for interacting Fermi systems. The flow of effective interactions and susceptibilities confirms the expected existence of a d-wave pairing instability driven by antiferromagnetic spin fluctuations. More unexpectedly, we find that strong forward scattering interactions develop which may lead to a Pomeranchuk instability breaking the tetragonal symmetry of the Fermi surface.Comment: 4 pages (RevTeX), 4 eps figure