Super-resolution and apodization with discrete adaptive optics.

High-resolution imaging is of great importance in various fields. The use of pupil phase-only filters (PPF) exceeds the diffraction limit of the imaging system in a simple way. When dealing with distorted wavefronts, however, PPF require that aberrations be compensated for. In this paper, we introduce a novel technique consisting of the use of discrete adaptive optics with PPFs so that the compensating device implements the PPF at the same time. Analysis of the theory for point spread function reshaping using PPFs has enabled us to develop a new approach to characterizing apodizing filters. A validation experiment has been carried out, the first of its kind to our knowledge, in which a number of PPFs were combined with two levels of compensation. Our experimental results are discussed.

Blazar spectral variability as explained by a twisted inhomogeneous jet.

Blazars are active galactic nuclei, which are powerful sources of radiation whose central engine is located in the core of the host galaxy. Blazar emission is dominated by non-thermal radiation from a jet that moves relativistically towards us, and therefore undergoes Doppler beaming. This beaming causes flux enhancement and contraction of the variability timescales, so that most blazars appear as luminous sources characterized by noticeable and fast changes in brightness at all frequencies. The mechanism that produces this unpredictable variability is under debate, but proposed mechanisms include injection, acceleration and cooling of particles, with possible intervention of shock waves or turbulence. Changes in the viewing angle of the observed emitting knots or jet regions have also been suggested as an explanation of flaring events and can also explain specific properties of blazar emission, such as intra-day variability, quasi-periodicity and the delay of radio flux variations relative to optical changes. Such a geometric interpretation, however, is not universally accepted because alternative explanations based on changes in physical conditions-such as the size and speed of the emitting zone, the magnetic field, the number of emitting particles and their energy distribution-can explain snapshots of the spectral behaviour of blazars in many cases. Here we report the results of optical-to-radio-wavelength monitoring of the blazar CTA 102 and show that the observed long-term trends of the flux and spectral variability are best explained by an inhomogeneous, curved jet that undergoes changes in orientation over time. We propose that magnetohydrodynamic instabilities or rotation of the twisted jet cause different jet regions to change their orientation and hence their relative Doppler factors. In particular, the extreme optical outburst of 2016-2017 (brightness increase of six magnitudes) occurred when the corresponding emitting region had a small viewing angle. The agreement between observations and theoretical predictions can be seen as further validation of the relativistic beaming theory.

Identification of new variants and candidate genes in women with familial premature ovarian insufficiency using whole-exome sequencing.

PURPOSE: To identify candidate variants in genes possibly associated with premature ovarian insufficiency (POI). METHODS: Fourteen women, from 7 families, affected by idiopathic POI were included. Additionally, 98 oocyte donors of the same ethnicity were enrolled as a control group. Whole-exome sequencing (WES) was performed in 14 women with POI to identify possibly pathogenic variants in genes potentially associated with the ovarian function. The candidate genes selected in POI patients were analysed within the exome results of oocyte donors. RESULTS: After the variant filtering in the WES analysis of 7 POI families, 23 possibly damaging genetic variants were identified in 22 genes related to POI or linked to ovarian physiology. All variants were heterozygous and five of the seven families carried two or more variants in different genes. We have described genes that have never been associated to POI pathology; however, they are involved in important biological processes for ovarian function. In the 98 oocyte donors of the control group, we found no potentially pathogenic variants among the 22 candidate genes. CONCLUSION: WES has previously shown as an efficient tool to identify causative genes for ovarian failure. Although some studies have focused on it, and many genes are identified, this study proposes new candidate genes and variants, having potentially moderate/strong functional effects, associated with POI, and argues for a polygenic etiology of POI in some cases.

Genetic inhibition of flowering differs between juvenile and adult Citrus trees.

BACKGROUND AND AIMS: In woody species, the juvenile period maintains the axillary meristems in a vegetative stage, unable to flower, for several years. However, in adult trees, some 1-year-old meristems flower whereas others remain vegetative to ensure a polycarpic growth habit. Both types of trees, therefore, have non-flowering meristems, and we hypothesize that the molecular mechanism regulating flower inhibition in juvenile trees is different from that in adult trees. METHODS: In adult Citrus trees, the main endogenous factor inhibiting flower induction is the growing fruit. Thus, we studied the expression of the main flowering time, identity and patterning genes of trees with heavy fruit load (not-flowering adult trees) compared to that of 6-month-old trees (not-flowering juvenile trees). Adult trees without fruits (flowering trees) were used as a control. Second, we studied the expression of the same genes in the meristems of 6-month, and 1-, 3-, 5- and 7-year-old juvenile trees compared to 10-year-old flowering trees. KEY RESULTS: The axillary meristems of juvenile trees are unable to transcribe flowering time and patterning genes during the period of induction, although they are able to transcribe the FLOWERING LOCUS T citrus orthologue (CiFT2) in leaves. By contrast, meristems of not-flowering adult trees are able to transcribe the flowering network genes but fail to achieve the transcription threshold required to flower, due to CiFT2 repression by the fruit. Juvenile meristems progressively achieve gene expression, with age-dependent differences from 6 months to 7 years, FD-like and CsLFY being the last genes to be expressed. CONCLUSIONS: During the juvenile period the mechanism inhibiting flowering is determined in the immature bud, so that it progressively acquires flowering ability at the gene expression level of the flowering time programme, whereas in the adult tree it is determined in the leaf, where repression of CiFT2 gene expression occurs.

Rationally designed haptens for highly sensitive monoclonal antibody-based immunoanalysis of fenhexamid.

Immunochemical methods have been consolidated during the last few years as complementary analytical strategies for chemical contaminant and residue determination. However, generation of suitable immunoreagents for small organic molecules demands adequate hapten design. In this study, fenhexamid was considered as a model compound and novel haptens were designed and synthesized in order to evaluate the influence of the linker tethering site on antibody binding properties and immunoassay parameters. Haptens were conceived with the spacer arm at different positions, while the more antigenic aromatic moiety was kept free. The synthesis of these functionalized compounds was accomplished by total construction of the molecule through several steps. This strategy afforded very high-affinity monoclonal antibodies specific of fenhexamid, with IC50 values around or below 0.1 nM. Using these novel immunoreagents, a direct competitive enzyme-linked immunosorbent assay with a remarkably low limit of detection (4 ng L-1) was developed for the determination of fenhexamid residues. The selected immunoassay was investigated in terms of trueness, precision, repeatability, and robustness. The QuEChERS extraction methodology was applied to fortified samples and recoveries between 83% and 113%, with relative standard deviations below 20%, were observed. Moreover, contaminated and blind spiked samples were measured by the developed immunoassay and by ultra-performance liquid chromatography coupled to tandem mass spectrometry, showing statistically comparable results.

Phytoextraction of heavy metals from a multiply contaminated dredged sediment by chicory (Cichorium intybus L.) and castor bean (Ricinus communis L.) enhanced with EDTA, NTA, and citric acid application.

The remediation of contaminated dredged sediments is necessary to eliminate the risk towards human beings or the environment when there is disposal on land. A greenhouse experiment was carried out to evaluate the chemically assisted phytoextraction to clean up dredged sediment contaminated with Cr, Cu, Pb, and Zn. The ability of castor bean and chicory to absorb, translocate, and accumulate metals from sediment to root and shoot was evaluated by applying EDTA (5 mM), NTA (5 mM), and citric acid (60 mM) to sediment, before the harvest. Citric acid 60 mM was the most effective treatment in increasing Cr, Cu, and Pb in castor bean and chicory shoot. Chicory could accumulate 1730 mg Cr kg-1 in shoot, and had greater values than one for the bioaccumulation and translocation factors when citric acid was added to the sediment. But, the Cr percentages removed per harvest of chicory were 0.05% and were lower for Cu, Pb, and Zn due to low biomass obtained. Citric acid-assisted phytoextraction with chicory can be a promising short time solution to reduce Cr concentration in sediment and reach the Cr level guide for industrial land use only if suitable agronomic practices could be implemented to increase crop yield.

A class-selective immunoassay for simultaneous analysis of anilinopyrimidine fungicides using a rationally designed hapten.

The development of multianalyte immunoassays constitutes a main research issue in the field of bioanalytical techniques. In the present study, class-specific antibodies against the three members of the anilinopyrimidine family of fungicides (pyrimethanil, cyprodinil and mepanipyrim) were raised by using a bioconjugate of a rationally designed hapten [5-(6-methyl-2-(phenylamino)pyrimidin-4-yl)pentanoic acid]. Highly sensitive immunoassays were developed for the generic determination of these compounds, using the competitive enzyme-linked immunosorbent assay (ELISA). Particularly, a direct antibody-coated competitive ELISA afforded identical sensitivity for the three anilinopyrimidines, with IC50 values of 0.26, 0.27 and 0.25 µg L-1 for pyrimethanil, cyprodinil and mepanipyrim, respectively. This immunoassay was fully characterized and applied to the multianalyte determination of anilinopyrimidine fungicides in white and red wines, with a limit of quantification of 1 µg L-1, average recoveries from 93.1 to 114.4%, and relative standard deviations lower than 20%. Commercial wine samples were analyzed and those containing detectable anilinopyrimide residues were verified by a reference chromatographic technique.

Investigating biogeographic boundaries of the Sunda shelf: A phylogenetic analysis of two island populations of Macaca fascicularis.

OBJECTIVES: Cyclical submergence and re-emergence of the Sunda Shelf throughout the Pleistocene served as a dynamic biogeographic landscape, across which long-tailed macaques (Macaca fascicularis) have migrated and evolved. Here, we tested the integrity of the previously reported continental-insular haplotype divide reported among Y and mitochondrial DNA lineages across multiple studies. MATERIALS AND METHODS: The continental-insular haplotype divide was tested by heavily sampling wild macaques from two important biogeographic regions within Sundaland: (1) Singapore, the southernmost tip of continental Asia and (2) Bali, Indonesia, the southeastern edge of the Indonesian archipelago, immediately west of Wallace's line. Y DNA was haplotyped for samples from Bali, deep within the Indonesian archipelago. Mitochondrial D-loop from both islands was analyzed against existing data using Maximum Likelihood and Bayesian approaches. RESULTS: We uncovered both "continental" and "insular" Y DNA haplotypes in Bali. Between Singapore and Bali we found 52 unique mitochondrial haplotypes, none of which had been previously described. Phylogenetic analyses confirmed a major haplogroup division within Singapore and identified five new Singapore subclades and two primary subclades in Bali. DISCUSSION: While we confirmed the continental-insular divide among mtDNA haplotypes, maintenance of both Y DNA haplotypes on Bali, deep within the Indonesian archipelago calls into question the mechanism by which Y DNA diversity has been maintained. It also suggests the continental-insular designation is less appropriate for Y DNA, leading us to propose geographically neutral Y haplotype designations.

Human dental pulp cells response to mineral trioxide aggregate (MTA) and MTA Plus: cytotoxicity and gene expression analysis.

AIM: To investigate the cytotoxicity, osteogenic bioactivity and mRNA expression of osteogenic markers of bone morphogenetic protein 2 (BMP-2), osteocalcin (OC) and alkaline phosphatase (ALP) induced by the extracts of set MTA Plus (MTA P) (Avalon Biomed Inc. Bradenton, FL, USA) in comparison with MTA (Angelus, Londrina, PR, Brazil) on human dental pulp cells (hDPCs). METHODOLOGY: Cell viability was assessed by mitochondrial dehydrogenase enzymatic (MTT) assay, and the mechanism of cell death was evaluated by flow cytometry. Bioactivity was evaluated by alkaline phosphatase (ALP) assay and detection of calcium deposits with alizarin red staining (ARS). The gene expression of BMP-2, OC and ALP was quantified with real-time PCR. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: MTA and MTA P were not cytotoxic and did not induce apoptosis. MTA P had significant higher ALP activity in relation to MTA and the control (P < 0.05). MTA had a significantly higher percentage of mineralized area than MTA P (P < 0.05). The expression of BMP2 and OC mRNA was significantly higher in cells exposed to MTA than MTA P after 1 day (P < 0.05). At day 3, the mRNA expression of ALP was significantly higher in MTA P compared with MTA (P < 0.05). CONCLUSIONS: MTA and MTA Plus were noncytotoxic, increased mineralization processes in vitro and induced the expression of osteogenic markers.

Electromyographic activity of the jaw muscles and mandibular kinematics in young adults with theoretically ideal dental occlusion: Reference values.

BACKGROUND: A necessary step to use neuromuscular analysis as diagnostic tool is to establish normal reference values for the physiological range in a healthy population. Surface electromyographic (sEMG) activity of the jaw muscles and mandibular kinematics were measured in young adults with theoretically ideal dental occlusion to determine normal reference values during different tasks. Differences between the sexes were evaluated. MATERIAL AND METHODS: Forty young adults (20 men, 20 women; mean age 22.8 ± 3.9 years) with theoretically ideal dental occlusion were selected using very restrictive criteria. sEMG activity of the anterior temporalis (AT), posterior temporalis, masseter (MA), and suprahyoid muscles were evaluated in the rest position and during swallowing, mastication, and clenching. Mandibular kinematics in the rest position and during maximum excursions were assessed. Asymmetry, activity, and torque indices and MA/AT ratios were calculated. RESULTS: For all muscles, sEMG values were 1.01-3.57 µV at rest, 3.50-10.85 µV during swallowing, and 41.04-86.59 µV during mastication. During clenching, values were 230.08-243.55 µV for the AT and MA muscles. Mean total asymmetry, activity, and torque indices at rest were 20.34 %, -15.04 %, and 19.02 %, respectively; during clenching, these values were 6.14 %, -2.62 %, and 4.46 %. MA/AT ratios were near 1. Kinematic measurements during lateral excursion, protrusive and maximum opening were 7.54, 8.44, and 37.38 mm respectively; lateral mandibular shift was 1.41 mm; free way and lateral displacement at rest were 1.40 and 0.26 mm. Right MA activity during mastication and clenching was higher in men than women. CONCLUSIONS: Reference values for sEMG activity and mandibular kinematics were determined. Some muscular asymmetry and torque were observed.

Characterization of Surgical Procedures in the Spanish Mohs Surgery Registry (REGESMOHS) for 2013-2015. / Descripción de las intervenciones quirúrgicas recogidas en el registro español de cirugía de Mohs (REGESMOHS) (2013-2015).

INTRODUCTION: The Spanish Mohs Surgery Registry is used to collect data on the use and outcomes of Mohs micrographic surgery (MMS) in Spain. The aim of this study was to describe perioperative and intraoperative data recorded for MMS procedures performed between July 2013 (when the registry started) and January 2016. MATERIAL AND METHODS: Prospective cohort study of data from 18 hospitals. The data collected included type of anesthesia, surgical technique, hospital admission, number of Mohs stages, management of preoperative risk factors, additional treatments, previous treatments, type of tumor, operating time, and complications. RESULTS: Data were available for 1796 operations. The most common tumor treated by MMS was basal cell carcinoma (85.96%), followed by squamous cell carcinoma (6.18%), lentigo maligna (2.81%), and dermatofibrosarcoma protuberans (1.97%). Primary tumors accounted for 66.9% of all tumors operated on; 19.2% of tumors were recurrent and 13.9% were persistent. The most common previous treatment was surgical. MMS was mostly performed under local anesthesia (86.7% of cases) and as an outpatient procedure (71.8%). The frozen section technique was used in 89.5% of cases. One stage was needed to achieve tumor-free margins in 56.45% of patients; 2 stages were required in 32.1% of patients, 3 in 7.1%%, 4 in 2.7%, and 5 or more in 1.8%. The defect was reconstructed by the dermatologist in 98% of patients and the most common technique was flap closure (47.2%). Intraoperative complications were recorded for just 1.62% of patients and the median (interquartile range) duration of surgery was 75 (60-100) minutes. CONCLUSION: The characteristics of the patients and tumors treated by MMS are similar to those reported for similar studies in other geographic areas. Lentigo maligna and dermatofibrosarcoma protuberans accounted for a higher proportion of cases in our series, and repair of the surgical defect by a dermatologist was also more common. Operating times in MMS are not much longer than those reported for other procedures and the rate of intraoperative complications is very low.

Role of primary care in the follow-up of patients with obstructive sleep apnoea undergoing CPAP treatment: a randomised controlled trial.

OBJECTIVE: To evaluate whether follow-up of patients with obstructive sleep apnoea (OSA) undergoing CPAP treatment could be performed in primary care (PC) settings. DESIGN: Non-inferiority, randomised, prospective controlled study. SETTINGS: Sleep unit (SU) at the University Hospital and in 8 PC units in Lleida, Spain. PARTICIPANTS: Patients with OSA were randomised to be followed up at the SU or PC units over a 6-month period. MAIN OUTCOMES MEASURED: The primary outcome was CPAP compliance at 6 months. The secondary outcomes were Epworth Sleep Scale (ESS) score, EuroQoL, patient satisfaction, body mass index (BMI), blood pressure and cost-effectiveness. RESULTS: We included 101 patients in PC ((mean±SD) apnoea-hypopnoea index (AHI) 50.8±22.9/h, age 56.2±11 years, 74% male) and 109 in the SU (AHI 51.4±24.4/h, age 55.8±11 years, 77% male)). The CPAP compliance was (mean (95% CI) 4.94 (4.47 to 5.5) vs 5.23 (4.79 to 5.66) h, p=0.18) in PC and SU groups, respectively. In the SU group, there were greater improvements in ESS scores (mean change 1.79, 95% CI +0.05 to +3.53, p=0.04) and patient satisfaction (-1.49, 95% CI -2.22 to -0.76); there was a significant mean difference in BMI between the groups (0.57, 95% CI +0.01 to +1.13, p=0.04). In the PC setting, there was a cost saving of 60%, with similar effectiveness, as well as a decrease in systolic blood pressure (-5.32; 95% CI -10.91 to +0.28, p=0.06). CONCLUSIONS: For patients with OSA, treatment provided in a PC setting did not result in worse CPAP compliance compared with a specialist model and was shown to be a cost-effective alternative. TRIAL REGISTRATION NUMBER: Clinical Trials NCT01918449.

Does breathing type influence electromyographic activity of obligatory and accessory respiratory muscles?

Craniomandibular electromyographic (EMG) studies frequently include several parameters, e.g. resting, chewing and tooth-clenching. EMG activity during these parameters has been recorded in the elevator muscles, but little is known about the respiratory muscles. The aim of this study was to compare EMG activity in obligatory and accessory respiratory muscles between subjects with different breathing types. Forty male subjects were classified according to their breathing type into two groups of 20 each: costo-diaphragmatic breathing type and upper costal breathing type. Bipolar surface electrodes were placed on the sternocleidomastoid, diaphragm, external intercostal and latissimus dorsi muscles. EMG activity was recorded during the following tasks: (i) normal quiet breathing, (ii) maximal voluntary clenching in intercuspal position, (iii) natural rate chewing until swallowing threshold, (iv) short-time chewing. Diaphragm EMG activity was significantly higher in the upper costal breathing type than in the costo-diaphragmatic breathing type in all tasks (P < 0·05). External intercostal EMG activity was significantly higher in the upper costal breathing type than in the costo-diaphragmatic breathing type in tasks 3 and 4 (P < 0·05). Sternocleidomastoid and latissimus dorsi EMG activity did not show significant differences between breathing types in the tasks studied (P > 0·05). The significantly higher EMG activity observed in subjects with upper costal breathing than in the costo-diaphragmatic breathing type suggests that there could be differences in motor unit recruitment strategies depending on the breathing type. This may be an expression of the adaptive capability of muscle chains in subjects who clinically have a different thoraco-abdominal expansion during inspiration at rest.

Effect of three types of flexibility training on active and passive hip range of motion.

AIM: The aim of this study was to measure the effect of 3 types of flexibility training, hold-relax (HR, N.=9), active isolated stretching (AIS, N.=9) and passive static stretching (PSS, N.=11) on passive and active range of motion of hip flexion after 9 weeks of flexibility training. METHODS: The subjects were physical education college students (14 men and 15 women) whose ages ranged between 20 and 24 years (age mean 21.79, SD: 2.45). A multigroup pre- post-test design with three experimental groups was used. The range of movement was measured by digitalization of pre-test and post-test images. RESULTS: Significant differences were found among the pre- and post-test for the three groups (P<0.05) on passive range of motion of the hip flexion, although there were no significant post-test differences between experimental groups. However, on the active range of motion of hip flexion there was only significant improvement among the pre-test and post-tests for PSS group (P<0.05). CONCLUSION: The results suggest that PSS is the best option for the improvement of both active and passive range of motion.

Ameloblastic carcinoma of the mandible: A case report.

Ameloblastic carcinoma (AC) is a rare, primary epithelial odontogenic malignant neoplasm. It is the malignant counterpart of ameloblastoma. It comprises 1% of all cysts and tumours occurring in the jaws, arising from tissues associated with odontogenic epithelium. The objective of the present study was to describe a clinical case of a 63-year-old male with an enlargement in the mandible on the left side. Panoramic radiography revealed a radiolucent area with poorly defined borders, and an incisional biopsy was performed for the histopathological study using immunomarkers such as SOX2 and Ki-67. Ki-67 is considered a marker of cell proliferation, and SOX2 reportedly participates in the development of the ameloblastic epithelium lineage and is associated with a more aggressive clinical course. A final histopathological diagnosis of AC was given. Unfortunately, the patient died one week before surgical resection (the surgical treatment of choice for AC).

Improvement of the optical, photocatalytic and antibacterial properties of ZnO semiconductor nanoparticles using different pepper aqueous extracts.

Peppers are fruits that grow on plants of the genus Capsicum and are popular for their use in gastronomy as a condiment and for their anti-inflammatory and anti-cancer properties due to their phytocompounds such as flavonoids, polyphenols, or alkaloids. Semiconductor zinc oxide (ZnO) nanoparticles (NPs) were synthesized using a green approach employing natural aqueous extracts of several varieties of peppers (jalapeño, morita, and ghost). The obtained NPs were characterized by different techniques, and their photocatalytic and antibacterial activity was studied. The signal at 620 cm-1 in the FTIR spectra belonging to the Zn-O bond, the appearance of the main peaks of a hexagonal wurtzite structure in the XRD pattern, and the characteristic signals in the UV-Vis spectra confirm the correct formation of ZnO NPs. The photocatalytic activity was analyzed against Methylene Blue (MB), Rhodamine B (RB), and Methyl Orange (MO) under UV and sunlight. All syntheses were able to degrade more than 93% of the pollutants under UV light. Antibacterial assays were performed against gram-positive and gram-negative bacteria. All syntheses exhibited antibacterial activity against all bacteria and maximum growth inhibition against Bacillus subtilis. The prominent results demonstrate that natural aqueous extracts obtained from peppers can be used to synthesize ZnO NPs with photocatalytic and biomedical applications.

Effectiveness of a Mobile App to Increase Risk Perception of Tobacco, Alcohol, and Marijuana Use in Mexican High School Students: Quantitative Study.

BACKGROUND: Young people have the highest rate of drug use worldwide. Recent data from Mexico in this population show that the prevalence of illicit drug use doubled between 2011 and 2016 (2.9%-6.2%), with marijuana being the one with the highest increase (2.4%-5.3%), but also point out that alcohol and tobacco use have remained steady or decreased. Mexican adolescents are at high risk for drug use owing to a low perception of risk and the availability of drugs. Adolescence is an ideal period to reduce or prevent risky behaviors using evidence-based strategies. OBJECTIVE: In this study, we aimed to test the short-term effectiveness of a mobile intervention app ("What Happens if you Go Too Far?" ["¿Qué pasa si te pasas?"]) that seeks to increase risk perception of tobacco, alcohol, and marijuana use in a sample of Mexican high school students. METHODS: A nonexperimental evaluation based on pretest-posttest design was used to measure the effectiveness of a preventive intervention using a mobile app, "What Happens If You Go Too Far?" The dimensions analyzed were knowledge of drugs and their effects, life skills, self-esteem, and risk perception. The intervention was conducted on a high school campus with 356 first-year students. RESULTS: The sample included 359 first-year high school students (mean 15, SD 0.588 years; women: 224/359, 62.4% men: 135/359, 37.6%). The intervention increased the overall risk perception of tobacco (χ24=21.6; P<.001) and alcohol use (χ24=15.3; P<.001). There was no significant difference in the perception that it is dangerous to smoke 5 cigarettes, and there was a marginal difference in the perception that it is very dangerous to smoke 1 cigarette or to use alcohol or marijuana. We used a generalized estimating equation method to determine the impact of the variables on risk perception. The results showed that knowledge about smoking increased the risk perception of smoking 1 cigarette (odds ratio [OR] 1.1065, 95% CI 1.013-1.120; P=.01), and that knowledge about marijuana use (OR 1.109, 95% CI 1.138-1.185; P=.002) and self-esteem (OR 1.102, 95% CI 1.007-1.206; P=.04) produced significant increases in the risk perception of consuming 5 cigarettes. Resistance to peer pressure and assertiveness also increased the perceived risk of using tobacco and alcohol. CONCLUSIONS: The intervention has the potential to increase the perception of risk toward drug use in high school students by providing knowledge about the effects and psychosocial risks of drug use and by strengthening life skills that are associated with increased risk perception. The use of mobile technologies in intervention processes may broaden the scope of preventive work for adolescents.

Direct surface plasmon resonance immunosensing of pyraclostrobin residues in untreated fruit juices.

A surface plasmon resonance (SPR) immunoassay for on-line detection of the strobilurin fungicide pyraclostrobin in untreated fruit juices is presented. The analysis of pyraclostrobin residues is accomplished in apple, grape, and cranberry samples by monitoring the recognition events occurring separately in a two-channel home-made SPR biosensor. Covalent coupling of the analyte derivative results in a reversible method, enabling more than 80 measurements on the same sensor surface. Optimization of the immunoassay conditions provides limits of detection as low as 0.16 µg L(-1). The selectivity and reproducibility of the analysis is ensured by studying both non-specific interactions with unrelated compounds and inter-assay coefficients of variation. Excellent recovery ranging from 98 to 103% was achieved by a simple 1:5 dilution of fruit juice with assay buffer before the analysis. The lack of previous cleaning and homogenization procedures reduces the analysis time of a single food sample to only 25 min, including the regeneration cycle.