Search

Once doped away from their parent Mott insulating state, the hole-doped cuprates enter into many varied and exotic phases. The onset temperature of each phase is then plotted versus p-the number of doped holes per copper atom - to form a representative phase diagram. Apart from differences in the absolute temperature scales among the various families, the resultant phase diagrams are strikingly similar. In particular, the p values corresponding to optimal doping (popt ~ 0.16) and to the end of the pseudogap phase (p* ~ 0.19-0.20) are essentially the same for all cuprate families bar one: the single-layer Bi-based cuprate Bi2+z-yPbySr2-x-zLaxCuO6+d (Bi2201). This anomaly arises partly due to the complex stoichiometry of this material and also to the different p values inferred from disparate (e.g., bulk or surface) measurements performed on samples with comparable superconducting transition temperatures Tc. Here, by combining measurements of the in-plane resistivity in zero and high magnetic fields with angle-resolved photoemission spectroscopy studies in the superconducting and normal state, we argue that the phase diagram of Bi2201 may in fact be similar to that realized in other families. This study therefore brings Bi2201 into the fold and supports the notion of universality of popt and p* in all hole-doped cuprates.

EuTe4 is a newly-discovered van der Waals material exhibiting a novel charge-density wave (CDW) with a large thermal hysteresis in the resistivity and CDW gap. In this work, we systematically study the electronic structure and transport properties of EuTe4 using high-resolution angle-resolved photoemission spectroscopy (ARPES), magnetoresistance measurements, and scanning tunneling microscopy (STM). We observe a CDW gap of about 200 meV at low temperatures that persists up to 400 K, suggesting that the CDW transition occurs at a much higher temperature. We observe a large thermal hysteretic behavior of the ARPES intensity near the Fermi level, consistent with the resistivity measurement. The hysteresis in the resistivity measurement does not change under a magnetic field up to 7 T, excluding the thermal magnetic hysteresis mechanism. Instead, the surface topography measured with STM shows surface domains with different CDW trimerization directions, which may be important for the thermal hysteretic behavior of EuTe4. Interestingly, we observe a large negative magnetoresistance at low temperatures that can be associated with the canting of magnetically ordered Eu spins. Our work shed light on the understanding of magnetic, transport, and electronic properties of EuTe4.

Introduction The remnant cholesterol (RC) promotes atherosclerotic cardiovascular disease. However, the prognostic impact of elevated RC levels in patients with non-ST-elevation acute coronary syndrome have not been established in the current population. Then, our objetive is investigated the effect of RC in terms of long-term mortality in patients admitted for NSTACS Methods This is an observational study in which we included all patients discharged from cardiology for ACS in two centers from 2003 to 2018. Patients were classified by low RC values Results We included 5685 patients diagnosed with ACS, with a mean age of 66.50 (SD ±13.20) years, 27.1% female. The baseline, during admission and discharge characteristics are shown in table (1 and 2). During follow-up (median 56 months, IQR 21–79 months) there was an increased risk of all-cause mortality in patients with higher levels os RC unadjusted and adjusted for several factors (age, sex, GRACE, early coronariography, hypertension, treatment at discharge), HR (1.003, CI 1.000–1.005, p 0.003). Similar results were observed for cardiovascular mortality (HR 1.003, CI 1.000–1.006, p 0.003), and MACE (HR 1.002, CI 1.000–1.003, p 0.002) Conclusion RC could have prognostic impact in the long-term follow up in patients with NSTACS, even after adjusting for risk factors and evidence-based treatments. There results should be taken under consideration for the treatment and management of NSTACS patients. Funding Acknowledgement Type of funding sources: None.

This quantitative-qualitative research study investigated the extent of integration of values in the science and mathematics education in the elementary and secondary level. It also determined what scientific values were mostly prevalent in the science and mathematics classrooms. Four hundred science and mathematics teachers both from elementary and secondary levels, from big and small schools, either from private or public schools were taken as the respondents of the study. A researcher-made questionnaire on values integration on science and mathematics teaching was used to gather the data. Results revealed that most of the science and mathematics teachers highly integrated values in their teaching. However, when they were categorized into certain variables, science teachers highly integrated values as compared to mathematics teachers. Moreover, teachers who were teaching 20 years and below dedicatedly integrated values in the classroom highly than those who were already more than 20 years in the service. The same results can be noted in terms of educational qualification, that those masters and doctorate degree holders highly integrated values than those bachelor’s degree holders. When grouped into type of school and school level, all science and mathematics teachers highly integrate values in their teaching. In the interview conducted, the learners were described as digital learners, impatient and most of them were not intellectually honest. The teachers further attested that the learners be given the chance and opportunity to change their attitudes. During the focus-group discussion, the science and mathematics teachers emphasized that the integration of values among learners during the teaching-learning process was much affected by the behavior of the learners. Factors affecting the extent of integration depended largely on the quality of learners being enrolled, and the kind of attitude of learners. In such, it can be construed that the availability of materials in the classroom during the experiment can be a factor in the integration of values for patience and intellectual honesty were intervened. Thus, science and mathematics teachers were challenged to be more resourceful in handling science and mathematics subjects of attaining holistic literacy among learners

Objectives The objective of our work is to evaluate the prognostic benefit of an early invasive strategy in patients with high-risk NSTACS according to the recommendations of the 2020 clinical practice guidelines during long-term follow-up. Methods This retrospective observational study included 6454 consecutive NSTEACS patients. We analyze the effects of early coronary angiography (140 and (b) patients with “established NSTEMI” (non ST-segment elevation myocardial infarction defined by an increase in troponins) or dynamic ST-T-segment changes with a GRACE risk score Results From 2003 to 2017, 6454 patients with “new high-risk NSTEACS” were admitted, and 6031 (93.45%) of these underwent coronary angiography. After inverse probability of treatment weighting, the long-term cumulative probability of being free of all-cause mortality, cardiovascular mortality and MACE differed significantly due to an early coronary interven- tion in patients with NSTEACS and GRACE >140 [HR 0.62 (IC 95% 0.57–0.67), HR 0.62 (IC 95% 0.56–0.68), HR 0.57 (IC 95% 0.53–0.61), respectively]. In patients with NSTEACS and GRACE Conclusions An early invasive management is associated with reduced all-cause mortality, cardiovascular mortality and MACE in NSTEACS with high GRACE risk score. However, this benefit is less evident in the subgroup of patients with a GRACE score Funding Acknowledgement Type of funding sources: None.

Introduction and objectives Cardiogenic shock is a condition caused by reduced cardiac output and hypotension, resulting in end-organ damage and multiorgan failure. Although prognosis has been improved in recent years, this state is still associated with high morbidity and mortality. The aim of our study was to perform a predictive model for in-hospital mortality that allows stratifying the risk of death in patients with cardiogenic shock. Methods This is a retrospective analysis from a prospective registry, that included 135 patients from one Spanish Universitary Hospital between 2011 and 2020. Multivariate analysis was performed among those variables with significant association with short-term outcome of univariate analysis with a p-value 0.1 in the multivariable analysis were excluded of the final model. Our method was assessed using the area under the ROC-curve (AUC). Goodness of fit was tested using Hosmer-Lemeshow statistic test. Finally, we performed a risk score using the pondered weight of the coefficients of a simplified model created after categorizing the continuous quantitative variables included in the final model, giving a maximum of 16 points and creating three categories of risk. Results The in-hospital mortality rate was 41.5%, the average of age was 74.2 years, 35.6% were females and acute coronary syndrome (ACS) was the main cause of shock (60.7%). Mitral regurgitation (moderate-severe), age, ACS etiology, NT-proBNP, blood hemoglobin and lactate at admission were included in the final model. Risk-adjustment model had good accuracy in predicting in-hospital mortality (AUC 0.85; 95% CI 0,78–0,90) and the goodness of fit test was p-value>0.10. According to the risk score made with the simplified model, these patients were stratified into three categories: low (scores 0–6), intermediate (scores 7–10), and high (scores 11–16) risk with observed mortality of 12.9%, 49.1% and 87.5% respectively (p Conclusions Our predictive model using six variables, shows good discernment for in-hospital mortality and the risk score has identified three groups with significant differences in prognosis. This model could help in guiding treatments and clinical decision-making, so it needs external validation and to be compared with other models already published. Funding Acknowledgement Type of funding sources: None. ROC curveRisk Score

Introduction and objectives There is insufficient data regarding risk scores validation in patients with diabetes mellitus and non-ST elevation acute coronary syndrome (NSTEACS). We performed a diabetes mellitus-specific analysis of cardiovascular outcomes after NSTEACS using a large contemporary cohort of patients from two tertiary hospitals. Methods This work is a retrospective analysis from a prospective registry, that included 7415 consecutive NSTEACS patients from two Spanish Universitary Hospitals between the years 2003 and 2017. We tested the predictive power of the GRACE and PRECISE DAPT score, calculating the area under the ROC curve among with and without diabetes mellitus patients. Results Among the study participants, 2124 patients (28.0%) were diabetic. The median follow up was 54,3 months (IQR 24.7–80.0 months). Diabetic patients were more women (30.5% vs 25.7%) and older (70.0±10.8 vs 65.3±13.2 years old); they had higher GRACE (146±36 vs 137±36), PRECISE DAPT (15±7 vs 18±9) and CRUSADE (17±14 vs 30±18) at admission. Early invasive coronary angiography (≤24 hours after admission) was performed more frequently in non-diabetic. We tested the predictive power of the GRACE and PRECISE DAPT risk scores among diabetic and non-diabetic. PRECISE DAPT risk score showed a good predictive power for all-cause mortality, cardiovascular mortality and MACE in diabetic admitted with NSTEACS, without differences compared to non diabetic. Conclusions PRECISE DAPT risk score has an appropriate predictive power in diabetic patients admitted with NSTEACS compared to non diabetic NSTEACS. However, GRACE would be predictive worse in non diabetic during long term follow up in a large contemporary registry. Funding Acknowledgement Type of funding sources: None.

Angle-resolved photoemission spectroscopy (ARPES) is a powerful method for measuring the electronic band structure of solids. Diamond Light Source is planning to build a multibend-achromat (MBA) synchrotron – Diamond-II - which will provide an almost diffraction-limited photon source in the vacuum-ultraviolet photon energy range. The improved emittance and higher coherence of MBA synchrotrons means that samples with features smaller than 1 µm can be readily studied using ARPES, provided the beamline is designed to take full advantage of the new photon source. We have developed an analytical method for optimising the optical design of a future Nano-ARPES beamline for Diamond-II. Our method enables one to explore large regions of parameter space for a beamline design in an unbiased and systematic way, with minimal requirements on computing power. We believe that the analytical method presented here will be a useful tool for synchrotron beamline designers, as it allows many beamline characteristics to be simulated quickly while working within any practical limitations.

Introduction Ischaemic stroke (IS) risk after acute coronary syndrome is increasing. The aim of our study was to evaluate the stroke rate in a multicentre study and to determine the prediction ability of the PRECISE DAPT score, added to the prediction power of the GRACE score, already demonstrated. Methods This was a retrospective study, carried out in two centres with 5916 patients, with ACS discharged between 2011 and 2017 (median 66±13 years, 27.7% women). The primary endpoint was the occurrence of ischaemic stroke and its risk during follow up (median 5.5, IQR 2.6–7.0). Results A multivariable logistic regression analysis was made, where GRACE (HR 1.01, IC 95% 1.00–1.02) and PRECISE DAPT score (HR 1.03, IC 95% 1.01–1.05) were both an independent predictor of ischaemic stroke after ACS, in a model adjusted by age and AF, which was found to be the independent factor with highest risk (HR 1.67, IC 95% 1.09–2.55). Conclusions GRACE and PRECISE DAPT scores are ischaemic stroke predictors used during follow-up for patients after acute coronary syndrome. We should use both of them not only trying to predict ischaemic/haemorrhagic risk respectively but also as ischaemic stroke predictors. Figure 1. AUC Curves Funding Acknowledgement Type of funding source: None

Objective This study sought to analyse the association of early coronary intervention with poor outcomes in patients ≥75 years with NSTEMI. Methods This retrospective observational study included 7811 NSTEMI patients between the years 2005 and 2017; 2451 were older than 75 years old. We compared baseline characteristics according to GRACE risk score. Results We found that 1486 patients (60.6%) underwent early invasive coronary intervention. The long-term all-cause mortality, cardiovascular mortality and MACE differed significantly according to early coronary intervention (HR 0.67, 95% CI: 0.59–0.76; HR 0.64, 95% CI: 0.54–0.74; and HR 0.70, 95% CI: 0.63–0.78, respectively). Conclusion In elderly high-risk NSTEMI patients, early revascularization was associated with reduced all-cause and cardiovascular mortality and MACE. Funding Acknowledgement Type of funding source: None

Background The Longitudinal Strain (LS) pattern in cardiac amyloidosis (CA) typically spares the apex of the heart, and this is a sensitive and specific finding that can be used to distinguish AC from other causes of left ventricular (LV) hypertrophy. Purpose To assess the clinical profitability of the LV deformation echocardiographic criteria derived from LS described as suggestive of CA, in patients with severe symptomatic aortic stenosis (AS) without amyloidosis referred for TAVI. Methods Within AMY-TAVI study (NCT03984877). Prior to TAVI implantation, conventional echocardiographic parameters were analyzed, along with LV deformation parameters and strain phenotype using Speckle-Tracking Echocardiography. Strain derived Indices accepted for CA screening were calculated: RELAPS: relative apical LS (average apical LS/sum of the average basal and mid LS); SAB: septal apical to base ratio (apical septal LS/basal septal LS); EFSR: ejection fraction strain ratio (LVEF/GLS). After implant, technetium pyrophosphate99 scintigraphy and proteinogram were performed to diagnose or exclude CA, and those patients in which CA was excluded were selected. Results 109 patients were consecutively included. The mean age was 81±6 yo, 58% were women. The mean aortic valve area (AVA) was 0.7±0.1 cm2 and the mean LVEF was 57.8±15%. Strain analysis could only be performed in 92 patients. Of these, 39 (42%) presented a LV strain pattern with relative apical sparing of LS respect to basal and middle segments (RELAPS>1 pattern); 82 patients (89%) SAB was >2.1; and 39 (42%) showed EFSR >4.1. The RELAPS>1 pattern was significantly associated with greater severity of AS based on AVA (0.7 cm2 in RELAPS 1, p=0.041), maximum velocity (4,4 vs 4,7 m/s, p=0.018), maximum aortic valve gradient (81 vs 91 mmHg, p=0.021) and medium gradient (49 vs 56 mmHg, p=0.020); higher degree of LV hypertrophic remodeling (Maximum wall thickness 14,3 vs 16,1 mm, p=0,003; Relative wall thickness 0,5 vs 0,6 mm, p=0,008); LV mass index: 168 vs 192 gr/m2, p=0,005; LV end-diastolic volume 112 vs 91 ml, p=0,005), and significantly lower myocardial contraction fraction (0,22 vs. 0,18, p=0,001). Conclusions In our series, patients with severe symtomatic AS without CA referred for TAVI frequently present a strain phenotype with relative apical preservation and a LVEF/GLS ratio similar to those described in CA. Our results suggest that the classic patterns of CA are common in patients with severe AS, in absence of said pathology, which limits its use for CA screening in these patients. Polar map patterns according to RELAPS Funding Acknowledgement Type of funding source: None

We report high-resolution angle-resolved photoemission measurements on single crystals of Pt_{2}HgSe_{3} grown by high-pressure synthesis. Our data reveal a gapped Dirac nodal line whose (001) projection separates the surface Brillouin zone in topological and trivial areas. In the nontrivial k-space range, we find surface states with multiple saddle points in the dispersion, resulting in two van Hove singularities in the surface density of states. Based on density-functional theory calculations, we identify these surface states as signatures of a topological crystalline state, which coexists with a weak topological phase.

Introduction Women have been less represented in every NSTEMI clinical trial. Moreover, it has been observed that this group of patients have usually received less revascularization and evidence based treatment, therefore presenting with a greater long and short-term mortality. Purpose The purpose of our study is to analyze the presence of differences in baseline characteristics, management and outcome of women with NSTEMI during the last decade. Methods and results Retrospective study including 861 women admitted for NSTEMI between 2003 and 2015 in our center. We divided 2 groups according to hospitalization period (2003–2008 and 2009–2015) with a medium follow up of 4.5±2.9 years. Baseline characteristics and treatment at discharge are described on table 1. We noticed a greater use of statins and ACEI/ARB on the second period as well as a greater percentage of patients receiving early revascularization. It is remarkable on women a non-significant reduction of heart failure hospitalization at follow up (6.8% vs 4.5%; p=0.091), neither differences on 30-day mortality (1.3% vs 0,4%) or 1-year mortality (7.1% vs 5.8%). However, long-term mortality for the second group is reduced (HR 0.69; CI 95% 0.52–0.89), even after performing a multivariate analysis (HR 0.64; CI 95% 0.48–0.85). Characteristic Population (n=861) 2003–2008 (n=395) 2009–2015 (n=466) p-value Age (years) 73±12 73±12 72±12 0.316 Hypertension 629 (73.1%) 285 (72.2%) 344 (73.8%) 0.318 Hypercholesterolemia 414 (48.1%) 190 (48.1%) 224 (48.1%) 0.523 Killip class 0.292 I 664 (77.1%) 299 (75.7%) 365 (78.3%) II 143 (16.6%) 74 (18.7%) 69 (14.8%) III 47 (5.5%) 20 (5.1%) 27 (5.8%) IV 4 (0.5%) 2 (0.5%) 2 (0.4) GRACE score 129±32 130±37 128±33 0.897 Early PCI 249 (29.3%) 76 (19.2%) 173 (38.0%) Conclusions In recent years, early interventionist management and greater use of evidence-based therapies have been observed in women with NSTEMI. This has been associated with a lesser long-term mortality, although short-term events have remained the same.

The new European Society of Cardiology guideline for ST-segment elevation myocardial infarction recommends that left and right bundle branch block should be considered equal for recommending urgent angiography in patients with suspected myocardial infarction. This consideration is not taken into account in the management of patients with coronary syndrome without ST elevation (NSTEMI). We evaluate the evolution of patients with acute coronary syndrome and long-term bundle branch block. Patients and methods We included 8771 patients admitted to two tertiary hospitals between 2003 and 2017 with an acute coronary syndrome, 5673 NSTEMI (64.3%) and 3098 STEMI (35.7%). All patients had an ECG recorded immediately upon admission. Patients were classified as having right bundle branch block (RBBB), left bundle branch block (LBBB). Long-term follow-up was performed (median 55 months) to assess mortality. Results A total of 8771 patients were included with a mean age of 66.1 years, 72.5% males, 4.1% (362) with LBBB and 5% (440) with RBBB. Patients with BBB were older, with more previous history of myocardial infarction and coronary revascularization and higher prevalence of cardiovascular risk factors. Medical treatment was similar but they were less often submitted to angioplasty. During the acute phase, patients with RBBB and LBBB presented a higher rate of heart failure than those without branch block (4.8% vs 9.1% vs 3.5%, p=0.0001); higher mortality (8.4% vs 10.5% vs 3.0%, p=0.0001); higher stroke rate (2.5% vs 1.4% vs 0.8%, p=0.001); higher rate of renal failure (8.2% vs 9.7% vs 3.9%, p=0.0001) and higher rate of reinfarction (3.0% vs 4.1% vs 1.7%, p=0.001). Patients who had a RBBB or an LBBB had a worse prognosis throughout the follow-up. Heart failure was present in 17.7% of the group with RBBB, 29.6% of LBBB and 11% in the group without branch block (p=0.0001). Mortality during follow-up was 31% in RBBB, 40.6% in LBBB and 18.7% without branch block (p=0.0001). In multivariate analysis of Cox, both RBBB (HR 1.55, 95% CI 1.23–1.98, p=0.0001) and LBBB (HR 1.48, 95% CI 1.22–1.53, p=0.001) were an independent predictors of all-cause mortality (adjustment for GRACE score, gender, treatment with betablockers, angiotensin conversor enzym inhibitors, statin and coronary revascularization). Cox regression model multivariate Conclusions The presence of RBBB or LBBB in the ECG of patients with an ACS is associated with a worse prognosis both during the hospital phase and in the long term. In addition, both bundle branch blocks are independent predictors of long-term mortality in patients with ACS.

Background Elderly patients are usually under-represented in randomized controlled trials, therefore there is less data providing prognostic information for this particular group. NSTEMI clinical practice guidelines indicate that older patients should receive the same therapeutic strategy than younger patients. Methods Observational retrospective study including 8771 patients admitted for acute coronary syndrome in two tertiary referral hospitals between 2003 and 2017: 5673 NSTEMI (64.3%) and 3098 STEMI (35.7%). 999 patients presenting with NSTEMI and aged over 75 years were selected and divided into 3 groups: aged 75–80, aged 80–89 and aged over 90. Cox proportional hazard regression analysis was performed in order to determine independent predictors of mortality. Mortality and survival were represented by Kaplan-Meier curves and log rank test was conducted to assess significant differences in survival between groups. Median follow-up period was 48 months. Results A significant association between female sex and elder age was observed, also a higher prevalence of hyperlipemia and diabetes. In acute phase, no significant differences were found in between congestive heart failure onset, myocardial re-infarction, acute renal failure, stroke or in-hospital mortality amongst the 3 groups. However, at follow-up period, higher mortality in elder groups was documented. After performing a multivariate analysis, age was identified as an independent predictor of mortality at follow-up (90 years: HR 1.93 CI 95% 1.27–2.93, p=0.002) as well as GRACE score (HR 1.06, CI 95% 1.02–1.09, p=0.002), CRUSADE score (HR 1.01 CI 95% 1.01–1.02, p=0.0001) and treatment with digoxine (HR 1.38 CI 95% 0.95–2.0, p=0.08). On the other side, beta-blockers (HR 0.71 CI 95% 0.59–0.86, p=0.0001) and complete coronary revascularization (HR 0.48 CI 95% 0.37–0.64, p=0.0001) were found to be protective factors. Conclusions In very elderly patients presenting with NSTEMI, prognostic predictors of mild-term mortality are similar to those present in younger patients. Recommendations of clinical practice guidelines, such as beta-blockers' treatment and coronary revascularization, should also be applied in elderly patients.

The discovery in 2008 of the iron-based superconducting pnictide and chalcogenide compounds has provided an entirely new family of materials for studying the crucial interplay between superconductivity and magnetism in unconventional superconductors. The alkali-metal-intercalated iron selenide (A x Fe2−y Se2, A = alkali metal) superconductors are of particular interest owing to their relatively high transition temperatures over 30 K and the co-existence of the superconducting state with antiferromagnetic ordering. Intrinsic phase separation on the mesoscopic scale is known to occur in 'single crystals' of these compounds, adding to the complexity of interpretation of bulk property measurements. In this study, we investigate the local electronic structure and chemistry of Rb x Fe2−y Se2 crystals using scanning microscopy techniques. Nano-focussed angle-resolved photoemission spectroscopy has enabled the band structure of the minority superconducting phase and the non-superconducting matrix to be measured independently and linked to the surface chemistry from the same regions using core level spectroscopy. Valence band mapping reveals the characteristic microstructure of these crystals, but does not have sufficient spatial resolution to enable the precise morphology of the superconducting phase to be elucidated. Cryogenic magnetic force microscopy has shown that the superconducting phase has a fine-scale stripey morphology that was not resolved in the scanning photoemission spectroscopy experiment. The correlation of these findings with previous microstructural studies, bulk measurements and first-principles density functional theory calculations paves the way for understanding the intriguing electronic and magnetic properties of these compounds.

This two-phase action research examined the profile and knowledge level of Grade III pupils about their knowledge on the distinct local vocabularies in order to formulate enrichment or intervention, to address any deficiency or lack of, and to assess whether such enrichment programs are effective for authentic, localized implementation of the MTB-MLE. The research instruments used in the first phase included survey and vocabulary assessment test. The researchers initially employed descriptive statistics to interpret the result. Majority of the respondents have established residency in Lopez, Quezon for at least four years. All of the pupils speak Tagalog only at home. The first phase of the research revealed that the pupils of Lopez West Elementary School Bldg. 1 performed satisfactorily in the language test. Most of them found that the most difficult words are generally content words. The initial results of this study serve as baseline information implying that the pupils’ level of understanding of the Lopezeños words needs enhancement and/or reinforcements; hence, there is an urgent need to implement the 2nd cycle of this action research. The second phase once implemented seeks to evaluate the effectiveness of the intervention and/or enrichment activities that may guide language teachers in the conduct of classroom-based, culturally sensitive, contextualized language instruction.

An analytical methodology based on an on-line sample enrichment of water samples by means of an imprinted polymer, and the separation of benzimidazole compounds within a C(18) column by ion-pair reversed-phase liquid chromatography, has been developed. The molecularly imprinted polymer has been synthesized by precipitation polymerization using thiabendazole as template molecule, methacrylic acid as functional monomer, and divinylbenzene as cross-linker. Initial experiments carried out by solid-phase extraction on cartridges demonstrated a clear imprint effect for thiabendazole, as well as the ability of the imprinted polymer to selectively rebind several benzimidazole compounds. The developed methodology has been applied to the quantification of thiabendazole, carbendazim, and benomyl in river, tap, and well water samples within a single analytical run at concentration levels below the legislated maximum concentration levels. In this sense, detection limits of 2.3-5.7 ng.L(-1) have been obtained for the analysis of benzimidazole fungicides in different water matrices. Recoveries obtained for the determination of benzimidazole fungicides in spiked samples ranged from 87% to 95%, with RSD below 5% in all cases.

An analytical methodology based on a molecularly imprinted solid-phase extraction (MISPE) procedure was developed for the determination of several triazines (atrazine, simazine, desethylatrazine (DEA), desisopropylatrazine (DIA), and propazine) in vegetable samples. A methacrylic acid-based imprinted polymer was prepared by precipitation polymerisation using propazine as template and toluene as porogen. After removal of the template by Soxhlet extraction, the optimum loading, washing, and elution conditions for MISPE of the selected triazines were established. The optimised MISPE procedure was applied to the extraction of the selected triazines in pea, potato, and corn sample extracts and a high degree of clean-up was obtained. However, some remaining interferences, non-specifically and strongly bound to the polymeric matrix, appeared in the chromatogram, preventing quantification of DIA in potatoes and DIA, DEA, and propazine in corn samples. Thus, a new clean-up protocol based on the use of a non-imprinted polymer for removal of these interferences prior to the MISPE step was developed. By following the new two-step MISPE procedure, the matrix compounds were almost completely removed, allowing the determination of all the triazines selected at concentration levels below the established maximum residue limits, making the developed procedure suitable for monitoring these analytes in vegetable samples. Sin financiación 1.715 JCR (2003) Q2, 27/67 Chemistry, analytical; Q3, 30/51 Biochemical research methods UEM

In the present work, an HPLC-UV method was set-up to allow the simultaneous quantification of the reduced- GSH, oxidised-GSSG and nitroso-GSNO glutathione species. Chromatographic separation was achieved on YMC ODS-A C18 column (150 × 4.6 mm, 5 μm), coupled to a Guard-c precolumn (YMC-Pack, 10 × 1-4,0 mm). The eluted compounds were detected at 215 nm by UV-detector, by keeping the column oven at room temperature while the auto-sampler temperature was maintained at 4°C. A fractional factorial design has been applied for the optimization of the mobile phase resulting in baseline separated peaks within 6 minutes. In-house validation was evaluated by linearity, limits of detection (LODs), limits of quantification (LOQs), reproducibility, repeatability and recovery. The detection and quantification limits obtained for standard solutions were below 0.2 μM and 0.6 μM, respectively (RSD values below 2%). The developed method was applied to the measurement of GSH, GSSG and GSNO in human pulmonary cells (A549) exposed to limonene, limonene oxide solubilized into the culture medium and to NO2 as gas phase. Results show an increase in GSH levels, without significant changes in GSSG, when cells were exposed to limonene oxide, while cells exposed to NO2 resulted in a significant increase of GSNO amount. Detection limits were of 1 μM for the glutathione species measured in A549 cells, with RSD values below 2.5%. In conclusion, the present HPLC-UV method can be readily used to measure in a rapid, simultaneous and accurate way the status of GSH, GSSG and GSNO in human cells, their simultaneous quantification helping to better predict the potential impact of chemicals on human health.

Mn-doped amorphous TiO 2 photocatalyst powders containing 0.1% and 1% Mn (w/w) were tested for oxidation of NO under indoor-like illumination conditions. Only the catalyst containing 0.1% Mn was able to degrade NO efficiently upon irradiation with the indoor-like source (visible light), whereas the one containing 1% Mn was active under solar-like irradiation. Preliminary results from addition of the 0.1% Mn–TiO 2 photocatalyst to calcareous filler commonly used in the formulation of building products demonstrate its ability, in this form too, to degrade NO at concentration levels typically found in indoor environments.

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10(-1) mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Molecularly imprinted polymers (MIPs) for benzimidazole compounds have been synthesized by precipitation polymerization using thiabendazole (TBZ) as template, methacrylic acid as functional monomer, ethyleneglycol dimethacrylate (EDMA) and divinylbenzene (DVB) as cross-linkers and a mixture of acetonitrile and toluene as porogen. The experiments carried out by molecularly imprinted solid phase extraction (MISPE) in cartridges demonstrated the imprint effect in both imprinted polymers. MIP-DVB enabled a much higher breakthrough volume than MIP-EDMA, and thus was selected for further experiments. The ability of this MIP for the selective recognition of other benzimidazole compounds (albendazole, benomyl, carbendazim, fenbendazole, flubendazole and fuberidazole) was evaluated. The obtained results revealed the high selectivity of the imprinted polymer towards all the selected benzimidazole compounds. An off-line analytical methodology based on a MISPE procedure has been developed for the determination of benzimidazole compounds in tap, river and well water samples at concentration levels below the legislated maximum concentration levels (MCLs) with quantitative recoveries. Additionally, an on-line preconcentration procedure based on the use of a molecularly imprinted polymer as selective stationary phase in HPLC is proposed as a fast screening method for the evaluation of the presence of benzimidazole compounds in water samples. © 2009 Elsevier B.V. All rights reserved.

In this work, the suitability of the combination of molecular imprinting and capillary electrochromatography (MIP-CEC) to be used as powerful tool in environmental or food analysis has been for the first time studied and successfully demonstrated. A molecularly imprinted monolith (MIM) has been synthesised and evaluated as stationary phase for the selective determination of the fungicide thiabendazole (TBZ) in citrus samples by non-aqueous capillary electrochromatography. The influence of the mobile phase composition, the voltage of the power supply and the separation temperature on the recognition of TBZ by the imprinted polymer has been evaluated, and the imprint effect in the MIM was clearly demonstrated. Once optimum recognition conditions were established, other variables affecting mechanical properties and chromatographic performance of MIM were adjusted using computational approach. The high selectivity achieved by the MIP-CEC developed procedure allowed unambiguous detection and quantification of TBZ in citrus samples by direct injection of the crude sample extracts, without any previous clean-up, in less than 6 min. The developed method was properly validated and the calculated detection limits were bellow the established maximum residue limits (MRLs), clearly demonstrating the suitability of the method to be used for the control of the selected fungicide. © 2007 Elsevier B.V. All rights reserved.

A semi-covalent imprinted polymer was prepared by precipitation polymerisation using propazine methacrylate as template molecule, ethylene glycol dimethacrylate as cross-linker and toluene as porogen. After removal of propazine by basic hydrolysis of the covalent bond, the optimum loading, washing and elution conditions for the solid-phase extraction of the selected triazines were established. The binding sites present in the polymeric matrix were characterised by fitting the experimental results of several rebinding studies to the Langmuir–Freundlich isotherm. Subsequently, an analytical methodology based on molecularly imprinted solid-phase extraction (MISPE) was developed for the determination of several triazinic herbicides in soil and vegetable samples. Following this procedure, a good degree of clean-up of the sample extracts was easily achieved, allowing the HPLC-UV determination of selected triazines in complex samples at low concentration levels. Sin financiación 3.554 JCR (2006) Q1, 6/68 Chemistry analitical; Q2, 15/56 Biochemical research methods UEM

In this paper, the Langmuir–Freundlich isotherm (LF) is used to characterise a propazine-imprinted polymer obtained by precipitation polymerisation (MIP-P). Different rebinding studies were carried out allowing to explain the different interactions taking place between the molecularly imprinted polymer and six triazinic herbicides (desisopropylatrazine, desethylatrazine, simazine, atrazine, propazine and prometryn). The LF fitting parameters obtained (total number of binding sites, heterogeneity index and mean binding affinity) were compared to those obtained in a previous work for a propazine-imprinted polymer prepared by bulk polymerisation (MIP-B). From that study, it was concluded that precipitation polymerisation yielded polymers with a more homogeneous binding site distribution and higher affinity constants. Sin financiación 2.176 JCR (2004) Q2, 21/51 Biochemical research methods, 19/70 Chemistry, analytical UEM