Quantitation of 35S Promoter in Maize DNA Extracts from Genetically Modified Organisms Using Real-Time Polymerase Chain Reaction, Part 2: Interlaboratory Study

The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism® 7700 (Applied Biosystems, Foster City, CA) or Light Cycler® (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about ±50%. These data were fitted to a power model (r2 = 0.96). Thanks to this model, it is possible to propose an estimation of uncertainty of the QRT-PCR quantitation step and an uncertainty budget depending on the analytical conditions.

P2525Relationship of Charlson Comorbidity Index with adverse events in elderly patients with Acute Coronary Syndromes: an analysis from LONGEVO-SCA Registry

Background

Elderly patients with Acute Coronary Syndromes (ACS) are under-represented in clinical trials and they have higher risk of new due their comorbidities. Charlson Comorbidity Index (CCI) is an established tool for evaluating the burden of comorbidity status and a high score of CCI is related with an increased risk of death.

Purpose

The aim of this study was to analyze the relationship of CCI in adverse outcomes at short-term follow-up in elderly patients admitted by an ACS.

Methods

The prospective multicenter LONGEVO-SCA included unselected elderly patients (≥80 years old) hospitalized after non-STACS. In this substudy, we analyze the influence of comorbidities, comparing the relationship between quartiles of CCI and adverse events at 6 months follow-up of CCI.

Results

We analyzed 520 patients (mean age 84.4±3.6 years; 320 (61.5%) male). 196 (37.6%) were classified into Q1, 105 (20.2%) into Q2, 93 (17.9%) into Q3 and 126 (24.2%) into Q4. No differences were observed in treatment at discharge across different quartiles for aspirin (p=0.648), beta-blockers (p=0.908) or statins (p=0.756). We observed a significant increase for all-cause mortality [9 (4.8%) vs 10 (10.2%) vs 11 (12.0%) vs 32 (26.0%); p<0.001] and readmissions [36 (18.4%) vs 21 (20%) vs 33 (35.5%) vs 48 (38.1%); p<0.001] respectively from Q1 to Q4. After Cox multivariate regression analysis, CCI was independently associated with mortality or readmissions [HR 1.15, 95% CI (1.06–1.26); p=0.001] and patients into high quartile had 6-fold risk of mortality [HR 6.19, 95% CI (2.95–12.99); p<0.001]. Kaplan Meier analysis showed that patients in the highest quartiles had significantly worse prognosis during the follow-up with high risk of all-cause mortality and readmissions (both p<0.001).

Event Free Survival according Charlson

Conclusions

In LONGEVO-SCA registry, we validated for the first time CCI as an independent factor related with adverse events. Patients into high quartiles of CCI had significantly worse prognosis during the follow-up and elderly patients into Q4 had 6-fold risk of mortality compared to Q1 patients.

P2530Frailty assessment in atrial fibrillation patients with acute coronary syndromes: a subanalysis from LONGEVO-SCA registry

Background

Different studies have observed a significant correlation between frailty, morbidity and mortality in elderly patients with cardiovascular diseases.Several scores have been developed to assess frailty in elderly patients. The FRAIL scale is a bed-side and easy tool that evaluates 5 items: fatigue, resistance, ambulation, concomitant diseases and weight loss. However, the evaluation of frailty status in AF patients with ACS is scarce.

Purpose

The aim of this study was to analyze the management of elderly patients with AF and ACS and the predictive value of frailty for adverse events.

Methods

The prospective multicentre LONGEVO-SCA enrolled unselected elderly patients hospitalized after non-STACS. In this substudy, we divided patients according to rhythm status (AF or sinus rhythm [SR]) and to frail status. We validated the predictive performance of FRAIL scores for adverse events at 6 months follow-up.

Results

We analyzed 531 patients (mean age 84.4±3.6 years; 322 (60.6%) male). 128 (24.1%) had AF diagnosis and 145 (27.3%) patients were frail. Frail AF patients had higher risk of global mortality [HR 2.61, (95% CI 1.28–5.31; p=0.008)], readmissions [HR 2.28, (95% CI 1.37–3.80); p=0.002)] and the composite endpoint [HR 2.28, (95% CI 1.44–3.60); p<0.001)] compared with non-frail SR patients. After multivariate adjustment, Frail score [HR 1.41; 95% CI (1.02–1.97); p=0.040] was independently associated with mortality. Kaplan Meier analysis showed that frail AF patients had significantly worse prognosis during the follow-up with high risk of global mortality (log rank p=0.024) and readmission (log rank p<0.001) followed closely by those frail SR patients.

Event Free Survival according Frailty

Conclusions

In the LONGEVO-SCA registry, frail AF patients have 2-fold risk of adverse events compared to non-frail SR patients. Frailty status was an independent condition associated with high risk of adverse events at 6 months of follow-up.

P1752Impact of frailty addition in ischemic and bleeding risk scores in elderly patients with Atrial Fibrillation and Acute Coronary Syndrome: a subanalysis from LONGEVO-SCA registry

Background

The prevalence of Atrial Fibrillation (AF) and Acute Coronary Syndrome (ACS) increases with age. Frail older adults are at high risk of multiple adverse events during admission and short term mortality. FRAIL score is an easy tool that evaluates: fatigue, resistance, ambulation, concomitant diseases and weight loss.

Purpose

The aim of this study was to validate FRAIL score in AF elderly patients with ACS related to adverse events and the impact of its addition in clinical scores.

Methods

The prospective multicenter LONGEVO-SCA enrolled unselected elderly patients hospitalized after non-STACS. We analyzed the predictive performance of FRAIL score in AF subgroup for adverse events (primary endpoint mortality or readmission) and the impact of frailty addition in ischaemic and bleeding scores.

Results

We analyzed 531 patients. 128 (24.1%) of them have AF (main age 84.6±3.7 years; 78 (61%) male) and 27.3% were frail (defined by FRAIL score ≥3). Frail AF patients had more prevalent comorbidities and received less evidence-based ACS therapies at discharge as oral anticoagulation (66% vs 60%; p<0.001) or statins 96.3% vs 82.6%; p<0.001). We analyzed the predictive performance of FRAIL score to adverse events and observed a modest predictive performance for mortality (c-statistic 0.648; 95% CI [0.605–0.690]; p<0.001), readmissions (c-statistic 0.600; 95% CI [0.557–0.642]; p<0.001) and for composite endpoint (c-statistic 0.620; 95% CI [0.577–0.663]; p<0.001). We compared the addition of FRAIL score to the original risk scores and observed a significant improvement for the primary endpoint with the addition to CHA2DS2-Vasc score (p=0.009), GRACE (p<0.001) and CRUSADE scores (p<0.001). (Table)

C-indexes for mortality or readmissions C-index 95% CI p p* Z* CHA2DS2-VASc score 0.619 0.576 to 0.662 <0.001 0.009 2.586 CHA2DS2-VASc score + FRAIL 0.641 0.598 to 0.683 <0.001 HAS-BLED score 0.649 0.606 to 0.691 <0.001 0.445 0.764 HAS-BLED score + FRAIL 0.634 0.590 to 0.675 <0.001 GRACE score 0.599 0.554 to 0.644 0.006 0.001 3.930 GRACE score + FRAIL 0.602 0.556 to 0.646 <0.001 CRUSADE score 0.660 0.613 to 0.705 0.051 0.001 3.287 CRUSADE score + FRAIL 0.664 0.617 to 0.709 <0.001 CI: Confidence interval. *For c-index comparison. p: P value.

Conclusions

This is the first validation of the FRAIL score in AF patients under ACS with a modest predictive performance to adverse events. The addition of frailty to clinical scores improved the predictive performance to adverse events in AF patients.

Dextromethorphan Analgesia in a Human Experimental Model of Hyperalgesia

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Central pain sensitization is often refractory to drug treatment. Dextromethorphan, an N-methyl-d-aspartate receptor antagonist, is antihyperalgesic in preclinical pain models. The hypothesis is that dextromethorphan is also antihyperalgesic in humans.

Methods

This randomized, double-blind, placebo-controlled, crossover study explores the antihyperalgesic effect of single and repeated 30-mg dose of oral dextromethorphan in 20 volunteers, using the freeze-injury pain model. This model leads to development of primary and secondary hyperalgesia, which develops away from the site of injury and is associated with central sensitization and activation of N-methyl-d-aspartate receptor in the spinal cord. The primary outcome was antihyperalgesia calculated with the area under the curve of the percentage change in mechanical pain threshold (electronic von Frey) on the area of secondary hyperalgesia. The secondary outcomes were mechanical pain threshold on the area of primary hyperalgesia and cognitive (reaction time) effect.

Results

Single 30-mg results are reported. Antihyperalgesia (% · min) is significantly higher on the area of secondary hyperalgesia with dextromethorphan than placebo (median [interquartile range]: 3,029 [746; 6,195] vs. 710 [–3,248; 4,439], P = 0.009, Hedge’s g = 0.8, 95% CI [0.1; 1.4]). On primary hyperalgesia area, mechanical pain threshold 2 h after drug intake is significantly higher with dextromethorphan (P = 0.011, Hedge’s g = 0.63, 95% CI [0.01; 1.25]). No difference in antinociception is observed after thermal painful stimuli on healthy skin between groups. Reaction time (ms) is shorter with placebo than with dextromethorphan (median [interquartile range]: 21.6 [–37.4; 0.1] vs. –1.2 [–24.3; 15.4], P = 0.015, Hedge’s g = 0.75, 95% CI [0.12; 1.39]). Nonserious adverse events occurrence (15%, 3 of 20 volunteers) was similar in both groups.

Conclusions

This study shows that low-dose (30-mg) dextromethorphan is antihyperalgesic in humans on the areas of primary and secondary hyperalgesia and reverses peripheral and central neuronal sensitization. Because dextromethorphan had no intrinsic antinociceptive effect in acute pain on healthy skin, N-methyl-d-aspartate receptor may need to be sensitized by pain for dextromethorphan to be effective.

First Measurement of the Total Neutron Cross Section on Argon between 100 and 800 MeV

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst)  b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

6th vital sign app: Testing validity and reliability for measuring gait speed

BACKGROUND

Gait speed tests are useful predictors of different health outcomes in people. These tests can be administered by the convenience of one's smartphone.

RESEARCH QUESTION

Is the 6th Vital Sign app valid and reliable for measuring gait speed?

METHODS

The study used a prospective test-retest design. Fifteen college subjects were asked to walk at their normal pace for 2 min. Each subject performed two trials. Speed was recorded by the 6th Vital Sign app, Brower timing gates, and by hand-measurement of distance walked divided by the 2 min. Criterion validity was assessed by paired t-tests, Cohen's D effect sizes, and Pearson correlation tests. Inter-trial reliability within each device was assessed with Pearson correlation tests.

RESULTS

Speed measured by the app was significantly lower than speed measured by gates (p = 0.004) and by hand-measurement (p = 0.009). The difference between gates and hand-measurement was not significant (p = 0.684). The speed measured by gates and hand-measurement were very highly correlated (r = 0.974), but speed measured by app was only moderately correlated with gates (r = 0.370) and hand-measurement (r = 0.365). The inter-trial reliability was fairly high with correlations r = 0.916, 0.944, and 0.941 when speed was measured by the app, gates, and hand-measurement, respectively.

SIGNIFICANCE

The app tended to underestimate speed when compared to gate and hand-measurements. Therefore, we conclude that the 6^th Vital Sign app is not valid for use for clinical diagnosis or prognosis.

FACEHBI: A Prospective Study of Risk Factors, Biomarkers and Cognition in a Cohort of Individuals with Subjective Cognitive Decline. Study Rationale and Research Protocols

BACKGROUND

Long-term longitudinal studies with multimodal biomarkers are needed to delve into the knowledge of preclinical AD. Subjective cognitive decline has been proposed as a risk factor for the development of cognitive impairment. Thus, including individuals with SCD in observational studies may be a cost-effective strategy to increase the prevalence of preclinical AD in the sample.

OBJECTIVES

To describe the rationale, research protocols and baseline characteristics of participants in the Fundació ACE Healthy Brain Initiative (FACEHBI).

DESIGN

FACEHBI is a clinical trial (EudraCT: 2014-000798-38) embedded within a long-term observational study of individuals with SCD.

SETTING

Participants have been recruited at the memory clinic of Fundació ACE (Barcelona) from two different sources: patients referred by a general practitioner and individuals from an Open House Initiative.

PARTICIPANTS

200 individuals diagnosed with SCD with a strictly normal performance in a comprehensive neuropsychological battery.

MEASUREMENTS

Individuals will undergo an extensive neuropsychological protocol, risk factor assessment and a set of multimodal biomarkers including florbetaben PET, structural and functional MRI, diffusion tensor imaging, determination of amyloid species in plasma and neurophthalmologic assessment with optical coherence tomography.

RESULTS

Two hundred individuals have been recruited in 15 months. Mean age was 65.9 years; mean MMSE was 29.2 with a mean of 14.8 years of education.

CONCLUSIONS

FACEHBI is a long-term study of cognition, biomarkers and lifestyle that has been designed upon an innovative symptom-based approach using SCD as target population. It will shed light on the pathophysiology of preclinical AD and the role of SCD as a risk marker for the development of cognitive impairment.

Zum genetischen Risiko nach hochdosierter Radiojodtherapie unter Berücksichtigung der Gonadendosis

Ziel der vorliegenden Arbeit ist die Abschätzung des genetischen Risikos nach hochdosierter Radiojodtherapie unter besonderer Berücksichtigung der individuell erreichten Gonadendosis. Methode: Mittels eines Erhebungsbogens wurden die Daten von insgesamt 364 Patientinnen und Patienten mit einem differenzierten Schilddrüsenkarzinom im gebärbzw. zeugungsfähigen Alter bezüglich ihrer Nachkommen ausgewertet. 45 Patienten (41 Frauen und vier Männer) aus dieser Gruppe hatten insgesamt 56 Kinder. Der Verlauf von Schwangerschaft, Geburt und Kindesentwicklung wurde erfaßt. Ergebnisse: Im Rahmen der Therapie und Nachsorge waren insgesamt zwischen 4,144 und 35,15 GBq I-131 verabreicht worden; die individuell auf der Grundlage des MIRD-Modells errechnete Gonadendosis lag zwischen 0,2 und 2,2 Sv (im Mittel 0,51 Sv). Der Abstand zwischen der letzten I-131 Applikation und einer Geburt betrug mindestens 9 Monate und höchstens 14 Jahre. Bezüglich Schwangerschaftsverlauf und Geburt wurden zwei Frühaborte, eine Extrauteringravidität und eine Plazentainsuffizienz mit nachfolgender Frühgeburt ermittelt. In einem Fall trat eine chromosomale Translokation 7/14 als genetischer Defekt auf, die zur Interruptio führte. Die Entwicklung der ausgetragenen Kinder verlief bis auf das Auftreten einer Neurodermitis in zwei Fällen, multipler Allergien in einem anderen Fall und eines frühzeitigen Fontanellenverschlusses bei einem Kind unauffällig. Schlußfolgerung: Unter der Annahme einer Verdoppelung der Häufigkeit spontaner Mutationen bei einer erzielten Gonadendosis von 1 Sv erhöht sich das Risiko irgendeiner angeborenen Erkrankung bei unseren Patienten im Mittel rechnerisch um rund 13%; tatsächlich lag der Anteil genetischer Defekte in unserem Kollektiv mit 1,8% (1/57) im Bereich des natürlichen Risikos. Unter Berücksichtigung der Literatur ließ sich damit bisher bei insgesamt 408 Kindern keine Zunahme genetisch bedingter Erkrankungen oder angeborener Anomalien feststellen.

[Pediatric Morbidity of a Native American Village in French Guiana (2009-2016)]

The situation of the Amerindian village of Camopi in French Guiana is particular because of its geographical isolation and its socio-cultural environment. Does this unique context affect the morbidity of the children? This study describes the morbidity of children aged 0-5 years in Camopi. The study population included all the children living in Camopi, born between 01/01/2009 and 31/12/2013. Sociodemographic and medical data were collected from Child Health Record until 05/01/2016, with a maximum of five years. 149 children were included and received 5916 consultations during the period of study. ENT and upper respiratory diseases were the most frequent diseases that were followed by digestive disorders. Lower respiratory conditions were the leading cause of hospitalization. Tropical diseases were rare. Antibiotics were delivered in 32.5% of the consultations. The vaccination coverage exceeded 95% for BCG, DTP, HBVand yellow fever, remove than that of MMR which was little lower (89.9%) and only 4 children were vaccinated against pneumococcus. Despite the Amazonian context, the morbidity of Camopi's children mainly includes classic disorders. Traumas seem uncommon but can be violent. Facilitating access to rapid diagnostic tests, setting up protocols, and training staff could reduce the prescription of antibiotics.

RESULTS FROM A NEW METHOD TO ASSESS THE OCCUPATIONAL LENS DOSE IN INTERVENTIONAL RADIOLOGY

Interventional radiology procedures have always been of particular concern because of the potential high dose to the workers. Special attention has recently been given to the lens dose: in 2011 the ICRP issued the recommendation 'Statement on Tissue Reactions' where a new limit of 20 mSv in a year, averaged over defined periods of 5 years, is given. Due to the impossibility of measuring the dose directly on the eye, there is not still a general consensus on a standardized methodology to assess the lens dose, which should be at the same time reliable, robust and simple to implement in practice. The procedure described here aims to assess the lens dose using the Hp(0.07) equivalent dose measured with a dosimeter worn at chest level above the lead apron, through a correlation with the total KAP per procedure and considering the type of the protection tools used during each procedure: glasses (with lateral shields), ceiling screen, both or neither of them and the frequency of their use.

Rh nanoparticles from thiolate dimers: selective and reusable hydrogenation catalysts in ionic liquids

Thiolate-capped RhNPs in imidazolium-based ionic liquids were synthesized from [Rh(μ-SR)(COD)]₂ dimmers under H₂ pressure without external addition of ligand stabilizers, preserving thiolate integrity on the nanoparticle surface. This nanoparticulated systems showed a remarkable selectivity that led to their application in the one pot reductive N-alkylation to produce amines.

[The importance of the thickness of the bone in osteocartilaginous autografts of the rabbit knee]

This experimental study is complementary to the clinical series of cartilaginous autografts in the knee for medial condylar necrosis. The aim was to determine the viability of the articular cartilage in a series of grafts with variable thickness of the underlying spongy bone.The study was done on 36 adult rabbits and the cartilage was studied by biochemical, histochemical and ultrastructural methods. The results are conclusive. The earliest abnormal signs in the first few weeks affect the thinnest grafts of 4 mm whereas the 12 mm thickness grafts hardly show any lesions.It is therefore possible to use large autogenic grafts for osteocartilaginous defects provided the proportion between the area of the articular surface and the underlying spongy bone of the graft is at least 1/4. Under these circumstances, cartilaginous deterioration will be avoided and reduce long term degeneration.

Comparison of 12-month anatomic and functional results between Z6 femtosecond laser-assisted and manual trephination in deep anterior lamellar keratoplasty for advanced keratoconus

The management of severe keratoconus requires corneal transplantation, for which the gold standard is deep anterior lamellar keratoplasty (DALK), preserving the healthy Descemet's membrane and endothelium. The safety and reproducibility of corneal cuts have been improved by the evolution of femtosecond lasers in refractive surgery, and femtosecond laser in DALK would seem to provide the same advantages over the manual method. In our retrospective study, we compare functional and anatomical results of femtosecond-assisted DALK versus manual trephination DALK in patients with keratoconus in stage 4 of the Krumeich classification. It is a retrospective study including all patients with stage 4 keratoconus who underwent femtosecond laser-assisted DALK between November 2012 and November 2015 in Nantes university medical center. We compared those patients to a group of patients who underwent manual DALK in the same period, paired by age and maximal keratometry. We assessed visual acuity, pachymetry, endothelial cell density (specular microscopy), and keratometry before surgery and at 4, 8 and 12 months of follow-up. Laser settings and intraoperative complications were recorded. Nineteen patients underwent surgery by femtosecond-assisted DALK, 6 women and 12 men with average age 30.2±10.8 years at transplantation. They were paired with a group of 17 patients who underwent manual DALK in order to compare results. Before surgery, mean visual acuity in the femtosecond group was 0.90 logMAR versus 0.89 logMAR in the manual group, showing no statistically significant difference (P=0.96). Both groups were similar in terms of preoperative age, mean keratometry, pachymetry and endothelial cell density. Average visual acuity post-surgery was 0.27; 0.26; and 0.14 logMAR for femtosecond DALK versus 0.27; 0.17 et 0.25 for manual DALK at 4, 8 and 12 months follow-up respectively, showing no statistically significant difference. After surgery, at 4, 8 and 12 months, mean pachymetry was similar in both groups, and average endothelial cell density was 2390 cells/mm² for femto DALK versus 2531 cells/mm² for manual DALK at 12 months of follow-up, showing no statistically significant difference (P=0.5726). The rate of Descemet's membrane microperforations during the procedure was low and similar for both groups. Our study allows for a 12-month follow-up, with assessment of visual recovery, anatomic result and endothelial safety in a series of 19 femtosecond laser-assisted DALK with no statistical significant difference versus the manual trephination group. Femtosecond laser allows for increased reproducibility of the DALK procedure without reducing adverse effects during surgery. Femtosecond laser seems to improve the technique of the DALK procedure, and future developments could improve the reproducibility of DALK even further. A medical economics study would be necessary to determine the cost-effectiveness of femtosecond laser-assisted DALK.

The association between physical activity and cognition in men with and without HIV infection

OBJECTIVES

HIV-associated neurocognitive disorders are highly prevalent, and physical activity (PA) is a modifiable behaviour that may affect neurocognitive function. Our objective was to determine the association between PA and neurocognitive function and the effect of HIV on this association.

METHODS

PA was assessed in the Multicenter AIDS Cohort Study with the International Physical Activity Questionnaire. A neuropsychological test battery assessed global impairment and domain-specific impairment (executive function, speed of processing, working memory, learning, memory, and motor function) every 2 years. Semiannually, the Symbol Digit Modalities Test and Trail Making Test Parts A and B were performed. Adjusted logistic regression models were used to assess the PA-neurocognitive function association. Using longitudinal data, we also assessed the PA category-decline of neurocognitive function association with multivariate simple regression.

RESULTS

Of 601 men, 44% were HIV-infected. Low, moderate, and high PA was reported in 27%, 25%, and 48% of the HIV-infected men vs. 19%, 32% and 49% of the HIV-uninfected men, respectively. High PA was associated with lower odds of impairment of learning, memory, and motor function [odds ratio (OR) ranging from 0.52 to 0.57; P < 0.05 for all]. The high PA-global impairment association OR was 0.63 [95% confidence interval (CI) 0.39, 1.02]. Among HIV-infected men only, across multiple domains, the high PA-impairment association was even more pronounced (OR from 0.27 to 0.49). Baseline high/moderate PA was not associated with decline of any domain score over time. HIV infection was marginally associated with a higher speed of decline in motor function.

CONCLUSIONS

A protective effect of high PA on impairment in neurocognitive domains was observed cross-sectionally. Longitudinal PA measurements are needed to elucidate the PA-neurocognitive function relationship over time.

A simple and reliable anion-exchange resin method for sulfate extraction and purification suitable for multiple O- and S-isotope measurements

RATIONALE

The O- and S-isotope compositions of sulfates can be used as key tracers of the fate and sink of sulfate in both terrestrial and extra-terrestrial environments. However, their application remains limited in those geological systems where sulfate occurs in low concentrations. Here we present a simple and reliable method to extract, purify and concentrate sulfate from natural samples. The method allows us to take into account the separation of nitrate, which is known to be an issue in O-isotope analysis.

METHODS

The separation and concentration of sulfate from other anions in any aqueous solution are performed within a few hours via anion-exchange resin. The possible O- (δ¹⁸ O and Δ¹⁷ O) and S- (δ³⁴ S, Δ³³ S and Δ³⁶ S) isotope exchanges, fractionations and/or contaminations are for the first time monitored during the whole procedure using initial O- and S-mass-dependent and mass-independent sulfate solutions.

RESULTS

After elution in HCl, pure sulfate is fully retrieved and precipitated into BaSO₄ , which is suitable for O- and S-isotopic measurements using established techniques. The analysis of retrieved barite presents no variation within 2σ uncertainties: ±0.5‰ and ±0.1‰ in O- (δ¹⁸ O, Δ¹⁷ O) and ±0.2‰, ±0.02‰ and ±0.09‰ in S- (δ³⁴ S, Δ³³ S and Δ³⁶ S) isotope ratios, respectively.

CONCLUSIONS

This study shows that the resin method for sulfate extraction and purification, in addition to being cheap, simple and quick, is applicable for the measurements of all O- and S-isotopic ratios in sulfates (including the Δ¹⁷ O, Δ³³ S and Δ³⁶ S values). Therefore, this method can be easily used for a high range of natural samples in which sulfate occurs in low concentration including aerosols, ice cores, sediments, volcanic deposits, (paleo)soils and rainwater, and thus it can be a key to our understanding of the sulfur cycle on Earth. Copyright © 2016 John Wiley & Sons, Ltd.

Two-photon controlled sol–gel condensation for the microfabrication of silica based microstructures. The role of photoacids and photobases

Two-photon excitation of photobases is used to induce pH changes and control the condensation step of the sol–gel process at the focal point of a laser beam in a confocal configuration.

Aminophosphine ligands as a privileged platform for development of antitumoral ruthenium(ii) arene complexes

The potential utility of aminophosphine ligands in both high-throughput testing and rational design of new anticancer metallodrugs.