95 research outputs found

    Analysis of Some Downhole Acceleration Records from Central De Abasto Oficinas Site at Mexico City

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    The surface and downhole accelerations records of “Central de Abasto Oficinas (CAO)” array at Mexico City, have been analyzed to determine the soil stiffness as a function of shear strain amplitude. The 09/10/95 seismic event (NS component) has been used for this purpose. The shear stress-strain histories have been evaluated directly from the field downhole acceleration records, employing a technique of system identification, and used to obtain the variation of shear modulus with shear strain amplitude. A shear-beam model, calibrated by the identified properties, is found to represent the site dynamic response characteristics. The results have been compared with values obtained in previous investigations from field and laboratory tests

    Socio-economic factors do also matter: comments on the article "can climatic factors explain the differences in COVID-19 incidence and severity across the SPANISH regions?: an ecological study"

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    Phosri et al., commented on our previous study about the influence of climate variables at the beginning of the SARS-CoV-2 pandemic in Spain. They showed the impact of the association of gross domestic product (GDP) with the cumulative COVID-19 incidence per 105 inhabitants in our country and the rise of several methodologic issues. Here we discussed the main advantages and disadvantages of ecological studies and we advocate to test the hypothesis created in this type of studies using individual-level research designs

    Can climatic factors explain the differences in COVID-19 incidence and severity across the Spanish regions?: An ecological study

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    Background: Environmental factors play a central role in seasonal epidemics. SARS-CoV-2 infection in Spain has shown a heterogeneous geographical pattern This study aimed to assess the influence of several climatic factors on the infectivity of SARS-CoV-2 and the severity of COVID-19 among the Spanish Autonomous Communities (AA.CC.). Methods: Data on coronavirus infectivity and severity of COVID-19 disease, as well as the climatic variables were obtained from official sources (Ministry of Health and Spanish Meteorological Agency, respectively). To assess the possible influence of climate on the development of the disease, data on ultraviolet radiation (UVR) were collected during the months before the start of the pandemic. To analyze its influence on the infectivity of SARS-CoV-2, data on UVR, temperature, and humidity were obtained from the months of highest contagiousness to the peak of the pandemic. Results: From October 2019 to January 2020, mean UVR was significantly related not only to SARS-CoV-2 infection (cumulative incidence -previous 14 days- × 105 habitants, rho = - 0.0,666; p = 0.009), but also with COVID-19 severity, assessed as hospital admissions (rho = - 0.626; p = 0.017) and ICU admissions (rho = - 0.565; p = 0.035). Besides, temperature (February: rho = - 0.832; p < 0.001 and March: rho = - 0.904; p < 0.001), was the main climatic factor responsible for the infectivity of the coronavirus and directly contributed to a different spread of SARS-CoV-2 across the Spanish regions. Conclusions: Climatic factors may partially explain the differences in COVID-19 incidence and severity across the different Spanish regions. The knowledge of these factors could help to develop preventive and public health actions against upcoming outbreaks of the disease

    Measurement of anti-DFS70 antibodies in patients with ANA-associated autoimmune rheumatic diseases suspicion is cost-effective

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    The presence of antinuclear antibodies (ANA) is associated with a wide range of ANA-associated autoimmune rheumatic diseases (AARD). The most commonly method used for the detection of ANA is indirect immunofluorescence (IIF) on HEp-2 cells. This method is very sensitive but unspecific. As a consequence, ANA testing on HEp-2 substrates outside a proper clinical specialist framework may lead to inappropriate referrals to tertiary care specialists and, worst case inappropriate and potentially toxic therapy for the patient. Among ANA, isolated anti-DFS70 antibodies represent a potentially important biomarker that can be clinically used to discriminate AARD from non-AARD patients in ANA IIF positive individuals. Therefore, their presence may avoid unnecessary follow-up testing and referrals. In our study, we investigated if the implementation of a new ANA workup algorithm allowing for the identification of anti- DFS70 antibodies is cost-effective through the reduction of both unnecessary follow-up testing and outpatient clinic visits generated by the clinical suspicion of a potential AARD. None of the 181 patients included with a positive monospecific anti-DFS70 antibody result developed SARD during the follow-up period of 10 years. The reduction in number of tests after ANA and anti-DFS70 positive results was significant for anti-ENA (230 vs. 114 tests; p\0.001) and anti-dsDNA antibodies (448 vs. 114 tests; p\0.001). In addition, the outpatient clinic visits decreased by 70 % (p\0.001). In total, the adoption of the new algorithm including anti-DFS70 antibody testing resulted in a cost saving of 60869.53 € for this pilot study. In conclusion, the use of anti-DFS70 antibodies was clearly cost-efficient in our setting

    Accurate EMC engineering on realistic platforms using an integral equation domain decomposition approach

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    This article investigates the efficiency, accuracy and versatility of a surface integral equation (SIE) multisolver scheme to address very complex and large-scale radiation problems including multiple scale features, in the context of realistic electromagnetic compatibility (EMC)/electromagnetic interference (EMI) studies. The tear-and-interconnect domain decomposition (DD) method is applied to properly decompose the problem into multiple subdomains attending to their material, geometrical, and scale properties, while different materials and arbitrarily shaped connections between them can be combined by using the so-called multiregion vector basis functions. The SIE-DD approach has been widely reported in the literature, mainly applied to scattering problems or small radiation problems. Complementarily, in this article, the focus is placed on realistic radiation problems, involving tens of antennas and sensors and including multiscale ingredients and multiple materials. Such kind of problems are very demanding in terms of both convergence and computational resources. Throughout two realistic case studies, the proposed SIE-DD approach is shown to be a powerful electromagnetic modeling tool to provide the accurate and fast solution which is indispensable to rigorously accomplish real-life EMC/EMI studies.Agencia Estatal de Investigación | Ref. TEC2017-85376-C2-1-RAgencia Estatal de Investigación | Ref. TEC2017-85376-C2-2-

    Serological evolution in women with positive antiphospholipid antibodies

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    Objectives To explore the clinical and serological course of fertile women with positive antiphospholipid (aPL), and the factors and therapeutic implications associated with aPL negativization. Methods Retrospective study including 105 women with a positive aPL serology between 1995 and 2013 attending the obstetric autoimmune pathology clinic of a tertiary facility. Patients were classified into the following 3 groups: patients with primary antiphospholipid syndrome (pAPS, 49), patients with a positive serology for aPL, not meeting clinical criteria (42), and patients with systemic lupus erythematosus and a positive aPL serology (14). They were also classified according to the serological aPL evolution: persistently negative aPL, transiently positive serology, and persistently positive serology according to established criteria. Results After a mean follow-up of 114.4 ± 37.2 months, 59% of patients had persistently negative antibodies, while 25.7% of patients presented persistently positive aPL serology. Multivariate analysis confirmed that smoking (OR = 4; 95% CI: 1.45?11.08; p = 0.008) was an independent risk factor for positive persistence. Persistent positivity as well as a higher antibody load was associated with higher risk for further pregnancy morbidity. In 29 patients, with persistently negative serology who were asymptomatic, treatment with low-dose aspirin was discontinued. No clinical events related to APS were reported after treatment withdrawal, during the 40.95 months of follow-up. Conclusions A significant proportion of fertile women with aPL antibodies became negative during follow-up. Tobacco use and the number of positive antibodies are associated with persistently positive serology. Patients with persistently positive aPL serology suffer more obstetric complications. Treatment withdrawal might be safe in selected patients

    Peripheral B-cell subset distribution in primary antiphospholipid syndrome

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    Background: B-cell differentiation and B-cell tolerance checkpoints may be different in antiphospholipid syndrome (APS) from systemic lupus erythematosus (SLE) and can help to understand differences between them. Our aim was to define alterations of B-cell subsets in patients with primary APS (pAPS) and to compare them with SLE patients and healthy controls (HC). Methods: Cross-sectional study including three study groups: 37 patients with pAPS, 11 SLE patients, and 21 age- and gender-matched HC. We determined the frequencies of different B-cell subsets in peripheral blood naïve and memory compartments. In addition, we measured serum B cell-activating factor (BAFF) levels and circulating pro-inflammatory cytokines, such as IL-6, by commercial ELISA and CBA, respectively. Results: Patients with pAPS showed a lower percentage of immature and naïve B cells than patients with SLE (p = 0.013 and p = 0.010, respectively) and a higher percentage of non-switched memory B cells than patients with SLE (p = 0.001). No differences either in the percentage of switched memory cells or plasma cells were found among the different groups. Serum BAFF levels were higher in SLE patients than in healthy controls and pAPS patients (p = 0.001 and p = 0.017, respectively). A significant increase in the serum BAFF levels was also observed in pAPS patients compared to HC (p = 0.047). Circulating IL-6 levels were higher in SLE and pAPS patients than HC (p = 0.036 and p = 0.048, respectively). A positive correlation was found between serum BAFF and IL-6 levels in patients with SLE but not in pAPS (p = 0.011). Conclusions: Our characterization of peripheral blood B-cell phenotypes in pAPS demonstrates different frequencies of circulating B cells at different stages of differentiation. These differences in the naïve B-cell repertoire could explain the higher number and variety of autoantibodies in SLE patients in comparison to pAPS patients, especially in those with obstetric complications

    Risk Factors for the Development of the Disease in Antiphospholipid Antibodies Carriers: A Long-term Follow-up Study

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    The natural history of antiphospholipid antibodies (aPL) carriers is not well-established. The objectives of the present study were (a) to study the probability of developing clinical criteria of antiphospholipid syndrome (APS), (b) to identify potential risk factors for developing thrombosis and/or obstetric complications, (c) to study the association between the antibody profile and development of APS, and (d) to determine the efficacy of primary prophylaxis. We retrospectively analyzed 138 subjects with positive aPL who did not fulfill clinical criteria for APS. The mean follow-up time was 138 ± 63.0 months. Thirteen patients (9.4%) developed thrombosis after an average period of 73.0 ± 48.0 months. Independent risk factors for thrombosis were smoking, hypertension, thrombocytopenia, and triple aPL positivity. Low-dose acetyl salicylic acid did not prevent thrombotic events. A total of 28 obstetric complications were detected in 92 pregnancies. During the follow-up, only two women developed obstetric APS. Prophylactic treatment in pregnant women was associated with a better outcome in the prevention of early abortions. The thrombosis rate in patients with positive aPL who do not meet diagnostic criteria for APS is 0.82/100 patients-year. Smoking, hypertension, thrombocytopenia, and the aPL profile are independent risk factors for the development of thrombosis in aPL carriers. Although the incidence of obstetric complications in this population is high (31.6%), only a few of them meet APS criteria. In these women, prophylactic treatment might be effective in preventing early abortions

    Hypercalcemia in patients with rheumatoid arthritis: a retrospective study

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    Objetivo: Investigar la prevalencia de hipercalcemia en pacientes con artritis reumatoide (AR) y analizar las características clínicas y las causas de la hipercalcemia. Material y métodos: Estudio retrospectivo de revisión basado en casos que incluyó 500 pacientes con AR. Se identificaron los pacientes con niveles de calcio aumentados en al menos dos ocasiones. Resultados: La hipercalcemia estuvo presente en 24 de los 500 pacientes con AR (4,8%). La edad osciló entre 50 y 80 años, con una media de 68±10 años. La duración media de la enfermedad fue de 10±7 años. De los pacientes con hipercalcemia, 22 eran mujeres postmenopáusicas (92%) y solo dos eran hombres (8%). El hiperparatiroidismo se encontró en 9 pacientes de la serie; solo un paciente tenía una hipercalcemia maligna debido a un mieloma múltiple, y un caso fue consecuencia de una intoxicación por vitamina D. En un paciente la hipercalcemia parecía relacionada con el síndrome calcio-alcalino. En el resto de pacientes, la hipercalcemia fue idiopática (8/24) o el estudio fue incompleto (4/24). No se encontró una relación evidente entre la actividad de la enfermedad y la aparición de hipercalcemia. Conclusión: Al igual que sucede en la población general, el hiperparatiroidismo primario es la causa más común de hipercalcemia en pacientes con AR. En algunos pacientes no se identificaron otros trastornos causantes de hipercalcemia, lo que plantea la posibilidad de una relación causal entre la AR y la hipercalcemia.Objetive: To investigate the prevalence of hypercalcemia in patients with rheumatoid arthritis (RA) and analyze the clinical features and causes of hypercalcemia. Material and methods: Retrospective case?based review study that included 500 patients with RA. Patients with increased calcium levels on at least two occasions were identified. Results: Hypercalcemia was present in 24 of the 500 RA patients (4.8%). The age ranged between 50 and 80 years, with a mean of 68±10 years. The mean duration of the disease was 10±7 years. Of the patients with hypercalcemia, 22 were postmenopausal women (92%) and only two were men (8%). Hyperparathyroidism was found in 9 patients in the series; only one patient had malignant hypercalcemia due to multiple myeloma, and one case was a consequence of vitamin D intoxication. In one patient, hypercalcemia appeared to be related to calcium?alkali syndrome. In the remaining patients, hypercalcemia was idiopathic (8/24) or the study was incomplete (4/24). No obvious relationship was found between disease activity and the appearance of hypercalcemia. Conclusion: As in the general population, primary hyperparathyroidism is the most common cause of hypercalcemia in patients with RA. In some patients, no other disorders causing hypercalcemia were identified, raising the possibility of a causal relationship between RA and hypercalcemia

    Integrating plasmonic supercrystals in microfluidics for ultrasensitive, label-free, and selective surface-enhanced raman spectroscopy detection

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    Surface-enhanced Raman spectroscopy (SERS) microfluidic chips for label-free and ultrasensitive detection are fabricated by integrating a plasmonic supercrystal within microfluidic channels. This plasmonic platform allows the uniform infiltration of the analytes within the supercrystal, reaching the so-called hot spots. Moreover, state-of-the-art simulations performed using large-scale supercrystal models demonstrate that the excellent SERS response is due to the hierarchical nanoparticle organization, the interparticle separation (IPS), and the presence of supercrystal defects. Proof-of-concept experiments confirm the outstanding performance of the microfluidic chips for the ultradetection of (bio)molecules with no metal affinity. In fact, a limit of detection (LOD) as low as 10–19 M was reached for crystal violet. The SERS microfluidic chips show excellent sensitivity in the direct analysis of pyocyanin secreted by Pseudomonas aeruginosa grown in a liquid culture medium. Finally, the further integration of a silica-based column in the plasmonic microchip provides charge-selective SERS capabilities as demonstrated for a mixture of positively and negatively charged molecules.Agencia Estatal de Investigación | Ref. TEC2017-85376-C2-1-RAgencia Estatal de Investigación | Ref. TEC2017-85376-C2-2-RXunta de Galicia | Ref. GRC ED431C 2016−486 048Gobierno de Extremadura | Ref. IB18073Agencia Estatal de Investigación | Ref. IJCI-2016-2910
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