EXAFS study of nickel exchanged into zeolite Y

EXAFS and near edge spectroscopy were used to monitor changes i n Ni coordination as a function of treatment conditions after aqueous exchange into zeolite Y. Our results suggest that after calcination and dehydration under the conditions of this study, major site occupancy for Ni appears to be in the tri-coordinate exchange sites , and not i n the hexagonal prisms as suggested by previous x-ray diffraction results

Homocysteine in cerebrovascular disease: An independent risk factor for subcortical vascular encephalopathy

Hyperhomocysteinemia is a risk factor for obstructive large-vessel disease. Here, we studied plasma concentrations of homocysteine and vitamins in patients suffering from subcortical vascular encephalopathy (SVE), a cerebral small-vessel disease leading to dementia. These results were compared to the homocysteine and vitamin plasma concentrations from patients with cerebral large vessel disease and healthy control subjects. Plasma concentrations of homocysteine, vascular risk factors and vitamin status (B-6, B-12, folate) were determined in 82 patients with subcortical vascular encephalopathy, in 144 patients with cerebral large-vessel disease and in 102 control subjects. Patients with SVE, but not those with cerebral large-vessel disease, exhibited pathologically increased homocysteine concentrations in comparison with control subjects without cerebrovascular disease. Patients with SVE also showed lower vitamin B6 values in comparison to subjects without cerebrovascular disease. Logistic regression analysis showed that homocysteine is associated with the highest risk for SVE (odds ratio 5.7; CI 2.5-12.9) in comparison to other vascular risk factors such as hypertension, age and smoking. These observations indicate that hyperhomocysteinemia is a strong independent risk factor for SVE

Buffer Strip Design, Establishment, and Maintenance

This publication discusses how to design, plant, and maintain a multi-species buffer strip, which is an important part of river ecosystems.https://lib.dr.iastate.edu/extension_ag_pubs/1213/thumbnail.jp

Developing a contemporary community clinic for patients with heart failure with preserved ejection fraction within the current National Health Service model

INTRODUCTION: The diagnostic and therapeutic arsenal for heart failure with preserved ejection (HFpEF) has expanded. With novel therapies (eg, sodium-glucose co-transporter 2 inhibitors) and firmer recommendations to optimise non-cardiac comorbidities, it is unclear if outpatient HFpEF models can adequately deliver this. We; therefore, evaluated the efficacy of an existing dedicated HFpEF clinic to find innovative ways to design a more comprehensive model tailored to the modern era of HFpEF. METHODS: A single-centre retrospective analysis of 202 HFpEF outpatients was performed over 12 months before the COVID-19 pandemic. Baseline characteristics, clinic activities (eg, medication changes, lifestyle modifications, management of comorbidities) and follow-up arrangements were compared between a HFpEF and general cardiology clinic to assess their impact on mortality and morbidity at 6 and 12 months. RESULTS: Between the two clinic groups, the sample population was evenly matched with a typical HFpEF profile (mean age 79±9.6 years, 55% female and a high prevalence of cardiometabolic comorbidities). While follow-up practices were similar, the HFpEF clinic delivered significantly more interventions on lifestyle changes, blood pressure and heart rate control (p60% of hospitalisation, including causes of recurrent admissions. CONCLUSION: This study suggests that existing general and emerging dedicated HFpEF clinics may not be adequate in addressing the multifaceted aspects of HFpEF as clinic activities concentrated primarily on cardiological measures. Although the small cohort and short follow-up period are important limitations, this study reminds clinicians that HFpEF patients are more at risk of non-cardiac than HF-related events. We have therefore proposed a pragmatic framework that can comprehensively deliver the modern guideline-directed recommendations and management of non-cardiac comorbidities through a multidisciplinary approach

Performance of the Syva Direct Fluorescent Antibody Assay for Chlamydia in a Low-Prevalence Population

Chlamydia trachomatis is the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence of C. trachomatis

Diagnostic accuracy of contrast-enhanced FDG-PET/CT in primary staging of cutaneous malignant melanoma

Purpose: To evaluate the diagnostic accuracy of contrast-enhanced FDG-PET/CT (ce-PET/CT), PET-only, and CT-only in patients with newly diagnosed and resected cutaneous malignant melanoma. Methods: A final group of 56 patients (mean age 62years, range 23-86years; 29 women, 27 men) were staged with ce-PET/CT after resection of the primary tumour. Histopathology as well as clinical follow-up (mean 780days, range 102-1,390 days) served as the standards of reference. Differences between the staging modalities were tested for statistical significance with McNemar's test. Results: All imaging procedures provided low sensitivities in the detection of lymph nodes (sensitivity N-stage: PET/CT and PET-only 38.5%; CT-only 23.1%) and distant metastases (sensitivity M-stage: PET/CT 41.7%, PET-only 33.3%, CT-only 25.0%) in initial staging after resection of the primary tumour. No statistically significant differences were detected between the imaging procedures (p > 0.05). PET/CT resulted in an alteration in further treatment in two patients compared to PET-only and in four patients compared to CT-only. Conclusion: All imaging modalities had a low sensitivity on initial staging of patients with malignant melanoma. Thus, close patient follow-up must be considered mandator

Avalanche of stimulated forward scattering in high harmonic generation

© 2016 [Optical Society of America]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.Optical amplifiers in all ranges of the electromagnetic spectrum exhibit an essential characteristic, namely the input signal during the propagation in the amplifier medium is multiplied by the avalanche effect of the stimulated emission to produce exponential growth. We perform a theoretical study motivated and supported by experimental data on a He gas amplifier driven by intense 30-fs-long laser pulses and seeded with attosecond pulse trains generated in a separated Ne gas jet. We demonstrate that the strong-field theory in the frame of high harmonic generation fully supports the appearance of the avalanche effect in the amplification of extreme ultraviolet attosecond pulse trains. We theoretically separate and identify different physical processes taking part in the interaction and we demonstrate that X-ray parametric amplification dominates over others. In particular, we identify strong-field mediated intrapulse X-ray parametric processes as decisive for amplification at the single-atom level. We confirm that the amplification takes place at photon energies where the amplifier is seeded and when the seed pulses are perfectly synchronized with the driving strong field in the amplifier. Furthermore, propagation effects, phase matching and seed synchronization can be exploited to tune the amplified spectral range within the seed bandwidth.Peer ReviewedPostprint (author's final draft

A large aperture reflective wave-plate for high-intensity short-pulse laser experiments

We report on a reflective wave-plate system utilizing phase-shifting mirrors (PSM) for a continuous variation of elliptical polarization without changing the beam position and direction. The scalability of multilayer optics to large apertures and the suitability for high-intensity broad-bandwidth laser beams make reflective wave-plates an ideal tool for experiments on relativistic laser-plasma interaction. Our measurements confirm the preservation of the pulse duration and spectrum when a 30-fs Ti:Sapphire laser beam passes the system