Dynamics of multisystem inflammatory syndrome in children associated to COVID-19 in Chile: Epidemiologic trends during pandemic, before and after children vaccination.

BACKGROUND: Multisystem inflammatory syndrome associated to Covid-19 (MIS-C) is one of the most severe outcomes of SARS-CoV-2 in children. Covid-19 vaccines were successfully implemented in Chile for the pediatric population since 2021, using both mRNA and inactivated platforms. Effectiveness against MIS-C has been reported for mRNA vaccines. The aim of this study was to describe the epidemiologic trend of MIS-C in Chile during Covid-19 pandemic, both before and after the availability of vaccination for children. MATERIALS AND METHODS: Analytic study of MIS-C cases from April 2020 to December 2022. Epidemiological data, SARS-CoV-2 variants and vaccination uptake information were obtained from the Epidemiology Department-Ministry of Health, Institute of Public Health and the National Immunization Program, respectively. RESULTS: 496 cases of MIS-C were reported, 58 % males. Median age was 5 years and most frequent age-cohorts were 6-11 and 0-2 years old with a 33 % each. After the introduction of the Covid-19 vaccine, most cases occurred in children aged 0-2 years. Incidence rates were 3.8, 5.4 and 1.7 per 100,000 inhabitants in 2020, 2021 and 2022, respectively. 97 % of cases (481) occurred in unvaccinated subjects. On those previously vaccinated (15), all but one case occurred in children receiving the inactivated vaccine. No association among circulating variants and incidence was observed. Incidence rate reduction (IRR) comparison between 2020 and 2021-2022 periods was 0.72 (CI 95 % 0.65-0.81, p < 0.05) overall; 0.86 for 0-2 years (CI 95 %:0.71-1; p = 0.12); 0.88 for 3-5 years (CI 95 %:0.69-1.11; p = 0.28); 0.61 for 6-11 years (CI 95 %: 0.50-0.75; p < 0.05); and 0.64 for 12-17 years (CI 95 %:0.47-0.89; p < 0.05), consistent with vaccination uptake during the studied period: 63 % for 3-5 years, 91 % for 6-11 years, and 99 % for 12-17 years. CONCLUSIONS: A decline of MIS-C incidence and a shift to younger, unvaccinated population overtime was observed. IRR decreased in age-cohorts which achieved high vaccination rates.

Feather's Composition of South Polar Skua (Stercorarius maccormicki) Using WDXRF.

This study investigated the feathers' composition of South polar skua (Stercorarius maccormicki) using WDXRF, evaluating the concentration of essential and non-essential elements in the feathers, and dividing it into rachis and barb parts. We collected South polar skuas feathers from Hennequin Point, King George Island, South Shetland, Antarctic Peninsula in January of 2013. Our results show that 18 elements were observed in the composition of the feathers, with a different concentration between the rachis and barbs, qualitatively and quantitatively. Only 3 elements observed were classified as non-essentials but still mostly elements do not have a function described in the literature to the feathers. According to our knowledge, this is the first study that uses this technique to evaluate the concentration of different elements in the feathers. The findings of this study highlight the use of alternative techniques to biomonitoring elements in the ecosystem and bring baseline information for future studies.

Assessing the trophic ecology and migration on the exposure of cape petrels and Wilson's storm petrels from Antarctica to perfluoroalkylated substances, trace and major elements.

Chemical pollution is a global concern as contaminants are transported and reach even the remote regions of Antarctica. Seabirds serve as important sentinels of pollution due to their high trophic position and wide distribution. This study examines the influence of migration and trophic ecology on the exposure of two Antarctic seabirds, Wilson's storm petrel (Oceanites oceanicus - Ooc), and Cape petrel (Daption capense - Dca), to chemical elements and perfluoroalkyl substances (PFAS). Our methodology involved assessing the concentration of these pollutants in feather samples obtained from carcasses, offering a practical means for monitoring contamination. Trace and major element concentrations were comparable in both species, suggesting that migratory patterns have a minimal impact on exposure levels. However, Ooc had higher concentration of PFAS compared to Dca (mean, ng g-1dry weight, PFOA: Ooc:0.710, Dca:0.170; PFTrDA: Ooc:0.550, Dca:0.360, and PFTeDA: Ooc:1.01, Dca:0.190), indicating that migration to the more polluted Northern Hemisphere significantly affects PFAS exposure. Furthermore, while no strong associations were found between either trace elements or PFAS and the three stable isotopes (δ13C, δ15N, and δ34S), a negative association was observed between PFUnDA and δ15N, hinting at potential biodilution. The research concludes that the migratory patterns of these seabird species affect their PFAS exposure, underscoring the critical need for further exploration and understanding of these relationships to better inform conservation strategies.

Mercury exposure in Antarctic seabirds: Assessing the influence of trophic position and migration patterns.

Although naturally present in the environment, mercury (Hg) input is significantly amplified by anthropogenic activities on a global scale, leading to a growing concern about the recent increase in Hg levels observed in Antarctica. This study investigated total mercury (THg) concentrations in feathers and eggs of resident and migratory Antarctic seabirds. Stable isotope data (δ15N, δ13C, and δ34S) were employed to ascertain the key factors influencing the exposure of these species to Hg. We gathered feathers and eggs from three resident species - Adélie, Gentoo, and Chinstrap penguins, as well as five migratory species - Snowy Sheathbill, Antarctic Tern, Southern Giant Petrel, Kelp Gull, and South Polar Skua. These samples were collected from Admiralty Bay, King George Island, in the Antarctica Peninsula. For all species, THg concentrations were higher in feathers (mean ± SD: 2267 ± 2480 ng g-1 dw) than in eggs (906 ± 1461 ng g-1 dw). Species occupying higher trophic positions, such as the Southern Giant Petrel (5667 ± 1500 ng g-1 dw) and South Polar Skua (4216 ± 1101 ng. g-1 dw), exhibited higher THg levels in their feathers than those at lower positions, like Antarctic Tern (1254 ± 400 ng g-1 dw) and Chinstrap Penguin (910 ± 364 ng g-1 dw). The δ15N values, which serve as a proxy for the trophic position, significantly correlated with THg concentrations. These findings reveal that trophic position influences THg concentrations in Antarctic seabirds. Migration did not appear to significantly affect the exposure of seabirds to THg, contrary to initial expectations. This research highlights the importance of evaluating the impacts of THg contamination on the Antarctic ecosystem by considering a variety of species. This multi-species approach offers critical insights into the factors that may potentially influence the exposure of these species to contaminants.

Trace elements in migratory species arriving to Antarctica according to their migration range.

The levels of eighteen trace elements (TEs) were evaluated in association with stable isotopes (δ15N, δ34S, and δ13C) in feathers and eggs of five migratory species breeding on the Antarctic Peninsula to test the factors that influence their exposure to contaminants. The feathers of seabirds migrating to the Northern Hemisphere (South polar skua) have concentrations (mean ± SD, µg. g-1) of Li (1.71 ± 2.08) and Mg (1169.5 ± 366.8) one order of magnitude higher than southern migrants, such as Snowy sheathbill Li (0.01 ± 0.005) and Mg (499.6 ± 111.9). Feathers had significantly higher concentrations for 11 of a total of 18 metals measured compared to eggs. South polar skua have higher concentrations of all TEs in eggs compared to antarctic tern. Therefore, the present study showed that migration and trophic ecology (δ15N, δ13C, and δ34S) influence Fe, Mn, Cu, and Se concentrations in feathers of Antarctic seabirds. The concentrations of Cu, Mn, Rb, Zn, Pb, Cd, Cr are higher than previously reported, which may be due to increased local and global human activities.

Electroanatomical mapping improves procedural outcomes of cryoballoon pulmonary vein isolation (the Achieve Plus study).

BACKGROUND: Validation of pulmonary vein (PV) isolation (PVI) using only the Achieve catheter following cryoballoon ablation (CBA) is imperfect since pulmonary vein potentials (PVP) can be recorded in only 50-85% of the veins and residual PVP are found in up to 4.3-7.6% of the isolated veins in remapping studies. OBJECTIVE: To study if addition of electroanatomical mapping to Achieve catheter-guided CBA is superior for PVI. METHODS: One hundred patients were randomized between Achieve catheter-guided CBA (control group; N = 50) and Achieve catheter-guided CBA with additional EnSite voltage maps performed pre- and post-CBA (Achieve Plus group; N = 50). Confirmation of PVI was done by circular mapping catheter (CMC) and EnSite mapping by a second blinded operator. RESULTS: Despite apparent PVI in all PVs after CBA, incomplete PVI was present in 0 out of 50 patients (0%) and 0 out of 204 PVs in the Achieve Plus group versus 6 patients out of 50 (12%; P = 0.012) and 6 out of 203 PVs (3%; P = 0.013) in the control group. All 6 non-isolated PVs could be successfully isolated by additional cryoapplications. Procedure time was longer in the Achieve Plus group (75.76 ± 21.65 vs 66.06 ± 16.83 min; P = 0.014) with equal fluoroscopy times (14.85 ± 6.41 vs 14.33 ± 8.55; P = 0.732). CONCLUSION: The addition of electroanatomical EnSite mapping to the Achieve catheter improves the PVI rate of CBA and could be considered for future use. Design and Results of the Achieve Plus study. The Achieve Plus study shows that the addition of electro-anatomical EnSite mapping to the Achieve catheter improves PVI rate of CBA and could be considered for future use. See text for further explanation. ABBREVIATIONS: CBA: cryoballoon ablation; PVI: pulmonary vein isolation.

Similar programmed death ligand 1 (PD-L1) expression profile in patients with mild COPD and lung cancer.

Programmed Death Ligand 1 (PD-L1) is crucial in regulating the immunological tolerance in non-small cell lung cancer (NSCLC). Alveolar macrophage (AM)-derived PD-L1 binds to its receptor, PD-1, on surveilling lymphocytes, leading to lymphocyte exhaustion. Increased PD-L1 expression is associated with cigarette smoke (CS)-exposure. However, the PD-L1 role in CS-associated lung diseases associated with NSCLC, such as chronic obstructive pulmonary disease (COPD), is still unclear. In two different cohorts of ever smokers with COPD or NSCLC, and ever and never smoker controls, we evaluated PD-L1 expression: (1) via cutting-edge digital spatial proteomic and transcriptomic profiling (Geomx) of formalin-fixed paraffin-embedded (FFPE) lung tissue sections (n = 19); and (2) via triple immunofluorescence staining of bronchoalveolar lavage (BAL) AMs (n = 83). PD-L1 mRNA expression was also quantified in BAL AMs exposed to CS extract. PD-L1 expression was increased in the bronchiolar wall, parenchyma, and vascular wall from mild-moderate (GOLD 1-2) COPD patients compared to severe-very severe (GOLD 3-4) COPD patients and controls. Within all the COPD patients, PD-L1 protein expression was associated with upregulation of genes involved in tumor progression and downregulation of oncosuppressive genes, and strongly directly correlated with the FEV1% predicted, indicating higher PD-L1 expression in the milder vs. more severe COPD stages. In bronchioles, PD-L1 levels were strongly directly correlated with the number of functionally active AMs. In BAL, we confirmed that AMs from patients with both GOLD 1-2 COPD and NSCLC had the highest and similar, PD-L1 expression levels versus all the other groups, independently from active cigarette smoking. Intriguingly, AMs from patients with more severe COPD had reduced AM PD-L1 expression compared to patients with mild COPD. Acute CS extract stimulation increased PD-L1 mRNA expression only in never-and not in ever-smoker AMs. Lungs from patients with mild COPD and NSCLC are characterized by a similar strong PD-L1 expression signature in bronchioles and functionally active AMs compared to patients with severe COPD and controls. Active smoking does not affect PD-L1 levels. These observations represent a new resource in understanding the innate immune mechanisms underlying the link between COPD and lung cancer onset and progression and pave the way to future studies focused on the mechanisms by which CS promotes tumorigenesis and COPD.

Factors that influence trace element levels in blood and feathers of Pygoscelis penguins from South Shetland Islands, Antarctica.

Contaminant levels are lower in Antarctica than elsewhere in the world because of its low anthropogenic activities. However, the northern region of the Antarctic Peninsula, is close to South America and experiences the greatest anthropogenic pressure in Antarctica. Here, we investigated, in two Antarctic Peninsula islands, intra and interspecific factors that influence the concentrations of 17 trace elements (TEs) in blood and feathers of three penguin species breeding sympatrically in relation to their trophic ecology assessed via a stable isotopic approach (C, N and S). Geographical location, foraging zone (δ13C and δ34S) and diet influences the interspecific difference, and sex and maturity stage diet influence the intraspecific difference of Pygoscelis penguins. Penguins from Livingston showed higher values (mean, ng. g-1, dry weight - dw) of Zn (103), Mn (0.3), and Fe (95) than those from King George Island (Zn: 80, Mn: 1.9, and Fe: 11). Gender-related differences were observed, as males showed significantly higher values (mean, ng. g-1, dw) of Rb (3.4) and δ15N in blood of gentoo, and Ca (1344) in Adélie feathers. Chicks of gentoo and Adélie presented higher Zn, Mg, Ca, and Sr and lower 13C values in blood than adults. The highest concentrations (mean, ng. g-1, dw) of Cd (0.2) and Cu (26), and the lowest δ15N values were found in chinstrap. Geographical, intraspecific (i.e., ontogenetic and gender-related) and interspecific differences in feeding seemed to have influenced TE and stable isotope values in these animals. The TE bioaccumulation by penguins may have also been influenced by natural enrichment in environmental levels of these elements, which seems to be the case for Fe, Zn, and Mn. However, the high level of some of the TEs (Mn, Cd, and Cr) may reflect the increase of local and global human activities.

Surgical Outcomes in a Lung Cancer-Screening Program Using Low Dose Computed Tomography.

OBJECTIVE: Lung cancer (LC) is the leading cause of death from cancer worldwide. More than 27,000 LCs are diagnosed annually in Spain, and most are unresectable. Early detection and treatment reduce LC mortality. This study describes surgical outcomes in a longstanding LC screening cohort in Spain. METHODS: We conducted a retrospective study of surgical outcomes in a LC screening (LCS) program using low dose computed tomography (LDCT) since the year 2000. A descriptive analysis of clinical and radiological parameters, presence or absence of a preoperative diagnosis, pathological staging, morbidity, mortality, and survival was performed. RESULTS: Ninety-seven (2.5%) LC were diagnosed in 3825 screened. Twenty individuals with LC had no surgery due to advanced stage or small cell histology. Eighty-seven surgical procedures were carried out for suspected or biopsy proven LC, detected by LDCT. Most operated patients were male (57[85%]) aged 64±9.1 years. Nine patients underwent a second operation for a metachronous primary lung cancer. Mean tumor size was 15.2±7.6mm. Eight nodules were benign (9.2%). Lobectomy was performed in 56 cases (83.6%). Adenocarcinoma (n=39; 58.2%) was the most frequent histological type followed by squamous cell carcinoma (n=17; 25.4%). Fifty-nine (88%) tumors were in Stage I. Thirteen patients (15.4%) had 16 complications. The estimated survival rates at 5 and 10 years for stage I were 93% (95% CI: 79%-98%) and 83% (95% CI: 65%-92%), respectively. CONCLUSION: Lung cancer screening was associated with excellent surgical outcomes with 5 and 10-year survival rates exceeding 90 and 80%, respectively.

Protein succination as a potential surrogate biomarker of airway obstruction. The ilervas project.

BACKGROUND: Airway obstruction (AO) is associated with hypoxemia, systemic inflammation and oxidative stress. These conditions can favor the formation of Advanced Glycation End-products (AGEs) and induce mitochondrial stress. The latter can alter metabolite intermediates in the Krebs cycle leading to the formation of the cysteine-fumarate adduct S-(2-succino) cysteine (2SC) in proteins (protein succination). Protein succination has not been described in airways diseases. RESEARCH QUESTION: To assess differences in levels of AGEs and 2SC between patients with AO and normal spirometry. STUDY DESIGN: and Methods: In this case-control study, we investigated 35 moderate to severe AO patients and 31 subjects with normal spirometry, matched for age, gender, body mass index (BMI), tobacco history, prediabetes and adherence to Mediterranean diet. Plasma 2SC and AGEs concentrations were measured by GS/MS, and AGEs in skin were determined measuring autofluorescence (SAF). Multivariate logistic regression models explored the association between AGEs in the skin, 2SC and the presence of AO. RESULTS: The population was predominantly middle-age (mean of 58.7 years-old), overweight (median of BMI 26.7 kg/m2) and male subjects (69.7%). Patients with AO showed higher values of SAF (p = 0.04) and 2SC (p = 0.047). No differences were observed for plasma AGEs. SAF and 2SC were significantly associated with the presence of AO after adjusting for age, gender, smoking history, BMI and Mediterranean diet score (p = 0.041 and p = 0.038, respectively). INTERPRETATION: Skin AGEs and 2SC are increased in patients with moderate to severe AO and independently associated with its presence. Further studies should confirm these findings and explore their potential role as a biomarker for the disease.

Prospecting bacterial consortia from a geothermal site for metals biotransformation.

Biomats that flourished in a fumarole located on the geothermal site Los Azufres (Mexico) were used as inocula to select aerobic and sulfate-reducing bacteria consortia for studying their capacity to reduce hexavalent chromium [Cr(VI)], aiming to use these consortia in biotransformation technologies. The sample site is characterized by slightly warm (nearly 27 [Formula: see text]C), acid (pH 3) and about hypoxic (1.8 mg L[Formula: see text] of dissolved oxygen) conditions. Four culture systems (2 aerobic and 2 anaerobic) were investigated, including their enzymatic activity, capacity to produce biofilms, and an analysis of the total bacterial populations. For the anaerobic condition (using sulfate and sulfur as electron acceptors), four pH values (from 2 to 8) and four carbon sources (pyruvate, glycerol, Na-lactate and Na-acetate) were probed. Significant biological Cr(VI) removal was observed for all the pH values probed, particularly during the first 12 h, being more effective at the most acid conditions. At a pH value of 4 and using pyruvate as carbon source, 100 mg L[Formula: see text] of Cr(VI) were completely depleted in less than 12 h, while the use of Na-lactate was less effective but still reasonable. These results indicate that sulfate-reducing bacteria consortia from geothermal sites like the one studied here are capable of biotransforming Cr(VI) and have the potential to provide metal bioremediation technologies.

Random number generation by coherent detection of quantum phase noise.

In 2010 Qi et al. [Opt. Lett.35(3), 312 (2010)] demonstrated a random number generator based on the drift of the phase of a laser due to spontaneous emission, The out-of-the-lab implementation of this scheme presents two main drawbacks: it requires a long and highly unbalanced interferometer to generate a random phase with uniform probability distribution, or alternatively, a shorter and slightly unbalanced interferometer that notwithstanding requires active stabilization and does not generate a uniform probability distribution without randomness extraction. Here we demonstrate that making use of the random nature of the phase difference between two independent laser sources and two coherent detectors we can overcome these limitations. The two main advantages of the system demonstrated are: i) it generates a probability distribution of quantum origin which is intrinsically uniform and thus in principle needs no randomness extraction for obtaining a uniform distribution, and ii) the phase is measured with telecom equipment routinely used for high capacity coherent optical communications. The speed of random bit generation is determined by the photodetector bandwidth and the linewidth of the lasers. As a by-product of our method, we have obtained images of how phase noise develops with time in a laser. This provides a highly visual alternative way of measuring the coherence time of a laser.

Occurrence of halogenated natural products in highly consumed fish from polluted and unpolluted tropical bays in SE Brazil.

Natural compounds from the metabolism of marine organisms have been detected at high concentrations in environmental samples which are not the producers of these compounds. These natural substances are known as halogenated natural products (HNPs). HNPs are possibly toxic halogenated compounds analogous to POPs that may bioaccumulate and biomagnify along the food web and pose a further risk to human and environmental health. The present study analyzed the occurrence of HNPs in the edible muscle of the three most consumed commercial fish species in the state of Rio de Janeiro: sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri) and mullet (Mugil liza) from the highly polluted Guanabara Bay (GB) and the less polluted Ilha Grande Bay (IGB). The analytical steps included Soxhlet extraction, clean-up step and injection in a gas chromatography system coupled to a mass spectrometer operated in the electron-capture negative ion mode (GC/ECNI-MS). The compounds 2,4,6-TBP, 2,4,6-TBA, MHC-1, Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 were found in the analyzed fish from both studied areas. Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 showed the highest concentrations in samples. Q1 concentrations in the sardines from IGB were higher than the sardines from GB (p < 0.05) and higher than the other IGB species (p < 0.05). The differences found among the species may be related to their characteristic habitat and diet. It is noteworthy that most of these compounds do not have any toxicological reference value. Moreover, the HNPs are being detected in species of low trophic level and since this study has worked only with commercial species, these fish may be considered as a source for human exposure to these natural compounds.

Gas exchange and breathing pattern in women with postmenopausal bone fragility.

BACKGROUND: Little is known about the relationship between bone fragility and respiratory function. We hypothesized that women with osteoporosis or osteopenia, without cardio-pulmonary disease, have perturbations in the pattern of breathing and gas exchange. METHODS: In 44 women with bone fragility (BF, T score: < -1), and 20 anthropomorphically-matched control women (T score > -1) we compared pulmonary function tests, central respiratory drive (mouth occlusion pressure or P 0.1), pattern of breathing using optoelectronic plethysmograph and arterial blood gases at rest. RESULTS: Static pulmonary function was similar in BF subjects and controls. However, the arterial blood gas measurements differed significantly. The arterial pH was significantly higher in BF subjects than in controls (P < 0.001). The partial pressure of carbon dioxide (PaCO2) and oxygen (PaO2) in arterial blood were significantly lower in BF subjects than controls (P < 0.001 and P = 0.009, respectively). The BF subjects had a shorter inspiratory fraction compared with controls (P = 0.036). Moreover, T-scores were significantly inversely correlated with the alveolar-arterial gradient of oxygen (r = -0.5; P = 0.0003) and the arterial pH (r = -0.4; P = 0.002), and positively correlated with arterial PaO2 (r = 0.3; P = 0.01) and PaCO2 (r = 0.4; P = 0.002) among all subjects. CONCLUSION: In the absence of known cardio-pulmonary disease, BF is associated with statistically significant perturbations in gas exchange and alterations in the pattern of breathing including shortening of the inspiratory time.

Statistical data for the tensile properties of natural fibre composites.

This article features a large statistical database on the tensile properties of natural fibre reinforced composite laminates. The data presented here corresponds to a comprehensive experimental testing program of several composite systems including: different material constituents (epoxy and vinyl ester resins; flax, jute and carbon fibres), different fibre configurations (short-fibre mats, unidirectional, and plain, twill and satin woven fabrics) and different fibre orientations (0°, 90°, and [0,90] angle plies). For each material, ~50 specimens were tested under uniaxial tensile loading. Here, we provide the complete set of stress-strain curves together with the statistical distributions of their calculated elastic modulus, strength and failure strain. The data is also provided as support material for the research article: "The mechanical properties of natural fibre composite laminates: A statistical study" [1].

Efficacy and safety of withholding antimicrobial treatment in children with cancer, fever and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial.

OBJECTIVES: To determine efficacy and safety of withholding antimicrobials in children with cancer, fever and neutropenia (FN) with a demonstrated respiratory viral infection. METHODS: Prospective, multicentre, randomized study in children presenting with FN at five hospitals in Santiago, Chile, evaluated at admission for diagnosis of bacterial and viral pathogens including PCR-microarray for 17 respiratory viruses. Children positive for a respiratory virus, negative for a bacterial pathogen and with a favourable evolution after 48 h of antimicrobial therapy were randomized to either maintain or withhold antimicrobials. Primary endpoint was percentage of episodes with uneventful resolution. Secondary endpoints were days of fever/hospitalization, bacterial infection, sepsis, admission to paediatric intensive care unit (PICU) and death. RESULTS: A total of 319 of 951 children with FN episodes recruited between July 2012 and December 2015 had a respiratory virus as a unique identified microorganism, of which 176 were randomized, 92 to maintain antimicrobials and 84 to withdraw. Median duration of antimicrobial use was 7 days (range 7-9 days) versus 3 days (range 3-4 days), with similar frequency of uneventful resolution (89/92 (97%) and 80/84 (95%), respectively, not significant; OR 1.48; 95% CI 0.32-6.83, p 0.61), and similar number of days of fever (2 versus 1), days of hospitalization (6 versus 6) and bacterial infections throughout the episode (2%-1%), with one case of sepsis requiring admission to PICU in the group that maintained antimicrobials, without any deaths. CONCLUSIONS: The reduction of antimicrobials in children with FN and respiratory viral infections, based on clinical and microbiological/molecular diagnostic criteria, should favour the adoption of evidence-based management strategies in this population.

Metal bioaccumulation in consumed marine bivalves in Southeast Brazilian coast.

This work aimed to investigate metal bioaccumulation by mussels (Perna perna) and Lion's Scallop (Nodipecten nodosus) farmed in tropical bays, in order to estimate spatial and temporal variation in the exposure to these elements, as well as human health risk. The concentration of each measured element was considered for this evaluation, using maximum residue level (MRL) in foods established by the Brazilian (ANVISA), American (USFDA) and European Communities (EC) legislations. Values for estimated daily ingestion (EDI) were determined for metals intake through mussel and scallop consumption. These estimates were compared with the reference value of (PTDI) proposed by World Health Organization (WHO). Trace elements concentration was measured on ninety mussels P. perna (tissue) and ninety Lion's Scallop N. nodosus (muscle and gonad) reared in four different tropical areas of the Southeast Brazilian coast, between 2009 and 2010. Zinc (Zn), Iron (Fe), Copper (Cu), Manganese (Mn), Chrome (Cr), Nickel (Ni), Cadmium (Cd) and Lead (Pb) concentrations were measured by flame atomic absorption spectrometry after acid mineralization. Cd and Mn were more efficiently bioaccumulated by scallops than mussels and the opposite was found for Fe, Cu and Ni. Guanabara Bay and Sepetiba Bay were considered the most impacted between ecosystems studied. Higher Cd values in Arraial do Cabo in the other sites studied were associated with upwelling that occurs in the region. Consumption of both species cannot be considered safe, because the Cu and Cr concentrations, in accordance with the limits established by the Brazilian Agency (ANVISA). On the other hand, any EDI value exceeded the corresponding value of the PTDI, proposed by World Health Organization (WHO).

Enhancement of the sensitivity of a temperature sensor based on fiber Bragg gratings via weak value amplification.

We present a proof-of-concept experiment aimed at increasing the sensitivity of Fiber-Bragg-gratings temperature sensors by making use of a weak-value-amplification scheme. The technique requires only linear optics elements for its implementation and appears as a promising method for increasing the sensitivity than state-of the-art sensors can currently provide. The device implemented here is able to generate a shift of the centroid of the spectrum of a pulse of ∼0.035 nm/°C, a nearly fourfold increase in sensitivity over the same fiber-Bragg-grating system interrogated using standard methods.

Nanostep height measurement via spatial mode projection.

We demonstrate an optical scheme for measuring the thickness of thin nanolayers with the use of light beam's spatial modes. The novelty in our scheme is the projection of the beam reflected by the sample onto a properly tailored spatial mode. In the experiment described below, we are able to measure a step height smaller than 10 nm, i.e., one-eightieth (1/80) of the wavelength with a standard error in the picometer scale. Since our scheme enhances the signal-to-noise ratio, which effectively increases the sensitivity of detection, the extension of this technique to the detection of subnanometric layer thicknesses is feasible.