Search of low-dimensional magnetics on the basis of structural data: spin-1/2 antiferromagnetic zigzag chain compounds In2VO5, beta-Sr(VOAsO4)2,(NH4,K)2VOF4 and alpha-ZnV3O8

A new technique for searching low-dimensional compounds on the basis of structural data is presented. The sign and strength of all magnetic couplings at distances up to 12 A in five predicted new antiferromagnetic zigzag spin-1/2 chain compounds In2VO5, beta-Sr(VOAsO4)2, (NH4)2VOF4, K2VOF4 and alpha-ZnV3O8 were calculated. It was stated that in the compound In2VO5 zigzag spin chains are frustrated, since the ratio (J2/J1) of competing antiferromagnetic (AF) nearest- (J1) and AF next-to-nearest-neighbour (J2) couplings is equal to 1.68 that exceeds the Majumdar-Ghosh point by 1/2. In other compounds the zigzag spin chains are AF magnetically ordered single chains as value of ratios J2/J1 is close to zero. The interchain couplings were analyzed in detail.Comment: 14 pages, 6 figure, 1 table, minor change

Analysis protocols for MRI mapping of the blood oxygenation-sensitive parameters T(2)* and T(2) in the kidney

Renal hypoxia is generally accepted as a key pathophysiologic event in acute kidney injury of various origins and has also been suggested to play a role in the development of chronic kidney disease. Here we describe step-by-step data analysis protocols for MRI monitoring of renal oxygenation in rodents via the deoxyhemoglobin concentration sensitive MR parameters T(2)* and T(2)-a contrast mechanism known as the blood oxygenation level dependent (BOLD) effect.This chapter describes how to use the analysis tools provided by vendors of animal and clinical MR systems, as well as how to develop an analysis software. Aspects covered are: data quality checks, data exclusion, model fitting, fitting algorithm, starting values, effects of multiecho imaging, and result validation.This chapter is based upon work from the PARENCHIMA COST Action, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by two separate chapters describing the basic concept and data analysis

Effectiveness of interspinous implant surgery in patients with intermittent neurogenic claudication: a systematic review and meta-analysis

Item does not contain fulltextINTRODUCTION: Despite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all systematic reviews, randomized clinical trials and prospective cohort series to quantify the effectiveness of IPDs and to evaluate the potential side-effects. METHODS: Data from all studies prospectively describing clinical results based on validated outcome scales and reporting complications of treatment of patients with INC with IPD placement. We searched MEDLINE, EMBASE, Web of Science, Cochrane (CENTRAL), CINAHL, Academic Search Premier, Science Direct up to July 2010. Studies describing patients with INC caused by lumbar stenosis, reporting complication rate and reporting based on validated outcome scores, were eligible. Studies with only instrumented IPD results were excluded. RESULTS: Eleven studies eligible studies were identified. Two independently RCTs and eight prospective cohorts were available. In total 563 patients were treated with IPDs. All studies showed improvement in validated outcome scores after 6 weeks and 1 year. Pooled data based on the Zurich Claudication Questionnaire of the RCTs were more in favor of IPD treatment compared with conservative treatment (pooled estimate 23.2, SD 18.5-27.8). Statistical heterogeneity after pooled data was low (I-squared 0.0, p = 0.930). Overall complication rate was 7%. CONCLUSION: As the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced

The Felix-trial. Double-blind randomization of interspinous implant or bony decompression for treatment of spinal stenosis related intermittent neurogenic claudication

Abstract. Background. Decompressive laminotomy is the standard surgical procedure in the treatment of patients with canal stenosis related intermittent neurogenic claudication. New techniques, such as interspinous process implants, claim a shorter hospital stay, less post-operative pain and equal long-term functional outcome. A comparative (cost-) effectiveness study has not been performed yet. This protocol describes the design of a randomized controlled trial (RCT) on (cost-) effectiveness of the use of interspinous process implants versus conventi

Fast ionic conduction in new oxide materials of the Bi2O3_Ln2O3_TeO2 systems (Ln=La, Sm, Gd, Er)

International audienc

A potential novel mechanism involving connexin 43 gap junction for control of Sertoli cell proliferation by thyroid hormones

There is strong evidence that thyroid hormones through triiodothyronine (T3) regulate Sertoli cell proliferation and differentiation in the neonatal testis. However, the mechanism(s) by which they are able to control Sertoli cell proliferation is unclear. In the present study in vivo approaches (PTU-induced neonatal hypothyroidism known to affect Sertoli cell proliferation) associated with in vitro experiments on a Sertoli cell line were developed to investigate this question.We demonstrated that the inhibitory effect of T3 on Sertoli cell growth, analyzed by evaluating DNA-incorporated [3H] thymidine, was associated with a time and dose-dependent increase in the levels of Cx43, a constitutive protein of gap junctions, known to participate in the control of cell proliferation and the most predominant Cx in the testis. These Cx43 changes were associated with increased gap junction communication measured by gap FRAP. Consistent with these results two specific inhibitors of gap junction coupling, AGA and oleamide, were able to significantly reverse the T3 inhibitory effect on Sertoli cell proliferation. The present data also revealed a nongenomic effect of T3 on Cx43 Sertoli cells that was evidenced by a rapid up-regulation of gap junction plaque number as identified in Cx43-GFP transfected cells exposed to the hormone. This process appears mediated through actin cytoskeleton since incubation of the cells with cytochalasin D totally reversed the T3 stimulatory effect on Cx43-GFP gap junction plaques. Based on these data, we propose a working hypothesis in which Cx43 could be an intermediate target for T3 inhibition of neonatal Sertoli cell proliferation