Gradients from GOCE reveal gravity changes before Pisagua Mw = 8.2 and Iquique Mw = 7.7 large megathrust earthquakes

Considerable improvements in the measurement of the Earth gravity field from GOCE satellite mission have provided global gravity field models with homogeneous coverage, high precision and good spatial resolution. In particular, the vertical gravity gradient (Tzz), in comparison to the classic Bouguer anomaly, defines more accurately superficial mass heterogeneities. Moreover, the correction of these satellitederived data from the effect of Earth topographic masses by means of new techniques taking into account the Earth curvature, improves results in regional analyses. In a recent work we found a correlation between Tzz and slip distribution for the 2010 Maule Mw= 8.8 earthquake. In the present work, we derive the vertical gravity gradient from the last GOCE only model, corrected by the topographic effect and also by the sediments on depocenters of the offshore region at the PerueChile margin, in order to study a spatial relationship between different lobes of the gravity derived signal and the seismic sources of large megathrust earthquakes. In particular, we analyze this relation for the slip models of the 1996 Mw = 7.7 Nazca, 2001 Mw = 8.4 Arequipa, 2007 Mw = 8.0 Pisco events and for the slip models of the 2014 Mw = 8.2 Pisagua and Mw = 7.7 Iquique earthquakes from Schurr et al. (2014), including the previously analyzed 2010 Mw = 8.8 Maule event. Then we find a good correlation between vertical gravity gradients and main rupture zones, correlation that becomes even stronger as the event magnitude increases. Besides this, a gravity fall in the gravity gradient was noticed over the area of the main slip patches at least for the two years before 2014 Mw = 8.2 Pisagua and Mw = 7.7 Iquique earthquakes. Additionally, we found temporal variations of the gravity field after 2010 Mw = 8.8 Maule event, related to the main patches of the slip distribution, and coseismic deformation. Therefore, we analyzed vertical gravity gradient field variations as an indirect measure of the variable seismic coupling finding a potential relationship between Tzz and the seismic b-value. These relationships exemplify the strong potential of the satellite only derived models as a predictive tool to determine potential seismic energy released in a subduction segment, determining the potential size of a potential rupture zone, and in particular internal slip distribution that allows inferring coseismic displacement field at surface

Gadolinium-enhanced cardiovascular magnetic resonance: administered dose in relationship to united states food and drug administration (FDA) guidelines

<p>Abstract</p> <p>Purpose</p> <p>Myocardial late gadolinium enhancement was originally validated using higher than label-recommended doses of gadolinium chelate. The objective of this study was to evaluate available evidence for various gadolinium dosing regimens used for CMR. The relationship of gadolinium dose warnings (due to nephrogenic systemic fibrosis) announced in 2008 to gadolinium dosing regimens was also examined.</p> <p>Methods</p> <p>We conducted a meta-analysis of peer reviewed publications from January, 2004 to December, 2010. Major subject search headings (MeSh) terms from the National Library of Medicine's PubMed were: contrast media, gadolinium, heart, magnetic resonance imaging; searches were limited to human studies with abstracts published in English. Case reports, review articles, editorials, MRA related papers and all reports that did not indicate gadolinium type or weight-based dose were excluded. For all included references, full text was available to determine the total administered gadolinium dose on a per kg basis. Average and median dose values were weighted by the number of subjects in each study.</p> <p>Results</p> <p>399 publications were identified in PubMed; 233 studies matched the inclusion criteria, encompassing 19,934 patients with mean age 54.2 ± 11.4 (range 9.3 to 76 years). 34 trials were related to perfusion testing and 199 to myocardial late gadolinium enhancement. In 2004, the weighted-median and weighted-mean contrast dose were 0.15 and 0.16 ± 0.06 mmol/kg, respectively. Median contrast doses for 2005-2010 were: 0.2 mmol/kg for all years, respectively. Mean contrast doses for the years 2005-2010 were: 0.19 ± 0.03, 0.18 ± 0.04, 0.18 ± 0.10, 0.18 ± 0.03, 0.18 ± 0.04 and 0.18 ± 0.04 mmol/kg, respectively (p for trend, NS). Gadopentetate dimeglumine was the most frequent gadolinium type [114 (48.9%) studies]. No change in mean gadolinium dose was present before, versus after the Food and Drug Administration (FDA) black box warning (p > 0.05). Three multi-center dose ranging trials have been published for cardiac MRI applications.</p> <p>Conclusion</p> <p>CMR studies in the peer-reviewed published literature routinely use higher gadolinium doses than regulatory agencies indicated in the package leaflet. Clinical trials should be supported to determine the appropriate doses of gadolinium for CMR studies.</p

Estimativa do potencial erosivo das chuvas em municípios no entorno a Flona Tapajós, Amazônia.

O objetivo deste trabalho foi estimar o potencial erosivo das chuvas em municípios no entorno da Floresta Nacional do Tapajós, no estado do Pará para avaliar anos com maior ameaça a erosão dos solos. Foram utilizados dados de precipitação pluvial disponibilizados por órgãos de monitoramento meteorológico na região. Para garantir as avaliações de uma série longa de dados fez-se o cálculo do fator (R) considerando-se o maior período (1972 a 2012) em Belterra, período intermediário (1979 a 2009) em Santarém e na série homogênea, entre 1983 a 2002. Os dados evidenciaram que nos três municípios a distribuição anual do potencial erosivo das chuvas tem comportamentos semelhantes, sendo em Rurópolis as maiores flutuações. O ano de 1995 foi o que apresentou maior erosividade das chuvas anuais, no período de maior pluviosidade com 14.328,3 MJ mm ha-1 ano -1 em Santarém, 14.620,2 MJ mm ha-1 ano -1 em Belterra e 15.251,3 MJ mm ha-1 ano -1 em Ruropolis. Chuvas anuais com menores valores foram estimados em 1992, com 5.543,4 MJ mm ha-1ano-1 (Santarém), 5.830,9 MJ mm ha-1 ano-1 (Belterra) e 7.710,5 MJ mm ha-1ano-1 (Ruroplois). Esses dados evidenciam que as áreas cultivadas com grãos ou pastagens mal manejadas mais próximas ao município de Rurópolis são mais vulneráveis à erosão hídrica em relação a Belterra e Santarém. Práticas conservacionais devem ser adotadas para manter a capacidade produtiva dos solos nessa região

Liver transplant after SARS-CoV-2 infection: A systematic review

Background: The Coronavirus&nbsp;19 (COVID-19) pandemic has dramatically impacted liver organ transplantation. The American Society of Transplantation recommends a minimum of&nbsp;28&nbsp;days after symptom resolution for organ donation. However, the exact time for transplantation for recipients is unknown. Considering that mortality on the waiting list for patients with MELD&nbsp;&gt;25 or fulminant hepatitis is higher than that of COVID-19, the best time for surgery after SARS-CoV-2 infection remains undetermined. This study aims to expand the current knowledge regarding the Liver Transplantation (LT) time for patients after COVID-19 and to provide transplant physicians with essential decision-making tools to manage these critically ill patients during the pandemic. Methods: Systematic review of patients who underwent liver transplantation after diagnosis of COVID-19. The MEDLINE, PubMed, Cochrane, Lilacs, Embase, and Scielo databases were searched until June&nbsp;20, 2021. The MESH terms used were “COVID-19” and “Liver transplantation”. Results: 558&nbsp;articles were found; of these&nbsp;13&nbsp;articles and a total of&nbsp;18&nbsp;cases of COVID-19 prior to liver transplantation were reported. The mean age was&nbsp;38.7±14.6, with male prevalence. Most had mild symptoms of COVID. Five patients have specific treatment for COVID-19 with convalescent plasm or remdesivir/oseltamivir, just one patient received hydroxychloroquine, and 12&nbsp;patients received only symptomatic treatment. The median time between COVID-19 to LT was&nbsp;19&nbsp;days (13.5‒44.5). Deceased donor liver transplantation accounted for&nbsp;61% of cases, while living donor transplantation was&nbsp;39%. Conclusion: Despite the concerns regarding the postoperative evolution, the mortality of patients with high MELD or fulminant hepatitis transplanted shortly after COVID-19 diagnosis does not seem to be higher. (PROSPERO, registration number&nbsp;=&nbsp;CRD42021261790

The westward lithospheric drift, its role on the subduction and transform zones surrounding Americas. Andean to cordilleran orogenic types cyclicity

We investigate the effect of the westerly rotation of the lithosphere on the active margins that surround the Americas and find good correlations between the inferred easterly-directed mantle counterflow and the main structural grain and kinematics of the Andes and Sandwich arc slabs. In the Andes, the subduction zone is shallow and with low dip, because the mantle flow sustains the slab; the subduction hinge converges relative to the upper plate and generates an uplifting doubly verging orogen. The Sandwich Arc is generated by a westerly-directed SAM (South American) plate subduction where the eastward mantle flow is steepening and retreating the subduction zone. In this context, the slab hinge is retreating relative to the upper plate, generating the backarc basin and a low bathymetry single-verging accretionary prism. In Central America, the Caribbean plate presents a more complex scenario: a) To the East, the Antilles Arc is generated by westerly directed subduction of the SAM plate, where the eastward mantle flow is steepening and retreating the subduction zone. b) To the West, the Middle America Trench and Arc are generated by the easterly-directed subduction of the Cocos plate, where the shallow subduction caused by eastward mantle flow in its northern segment gradually steepens to the southern segment as it is infered by the preexisting westerly-directed subduction of the Caribbean Plateau. In the frame of the westerly lithospheric flow, the subduction of a divergent active ridge plays the role of introducing a change in the oceanic/continental plate's convergence angle, such as in NAM (North American) plate with the collision with the Pacific/Farallon active ridge in the Neogene (Cordilleran orogenic type scenario). The easterly mantle drift sustains strong plate coupling along NAM, showing at Juan de Fuca easterly subducting microplate that the subduction hinge advances relative to the upper plate. This lower/upper plate convergence coupling also applies along strike to the neighbor continental strike slip fault systems where subduction was terminated (San Andreas and Queen Charlotte). The lower/upper plate convergence coupling enables the capture of the continental plate ribbons of Baja California and Yakutat terrane by the Pacific oceanic plate, transporting them along the strike slip fault systems as para-autochthonous terranes. This Cordilleran orogenic type scenario, is also recorded in SAM following the collision with the Aluk/Farallon active ridge in the Paleogene, segmenting SAM margin into the eastwardly subducting Tupac Amaru microplate intercalated between the proto-Liquiñe-Ofqui and Atacama strike slip fault systems, where subduction was terminated and para-autochthonous terranes transported. In the Neogene, the convergence of Nazca plate with respect to SAM reinstalls subduction and the present Andean orogenic type scenario

COVID-19 in solid organ transplantation patients: A systematic review

Coronavirus disease (COVID-19) rapidly progresses to severe acute respiratory syndrome. This review aimed at collating available data on COVID-19 infection in solid organ transplantation (SOT) patients. We performed a systematic review of SOT patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The MEDLINE and PubMed databases were electronically searched and updated until April 20, 2020. The MeSH terms used were ‘‘COVID-19’’ AND ‘‘Transplant.’’ Thirty-nine COVID-19 cases were reported among SOT patients. The median interval for developing SARS-CoV-2 infection was 4 years since transplantation, and the fatality rate was 25.64% (10/39). Sixteen cases were described in liver transplant (LT) patients, and the median interval since transplantation was 5 years. The fatality rate among LT patients was 37.5% (6/16), with death occurring more than 3 years after LT. The youngest patient who died was 59 years old; there were no deaths among children. Twenty-three cases were described in kidney transplant (KT) patients. The median interval since transplantation was 4 years, and the fatality rate was 17.4% (4/23). The youngest patient who died was 71 years old. Among all transplant patients, COVID-19 had the highest fatality rate in patients older than 60 years : LT, 62.5% vs 12.5% (p=0.006); KT 44.44% vs 0 (p=0.039); and SOT, 52.94% vs 4.54% (p=0.001). This study presents a novel description of COVID-19 in abdominal SOT recipients. Furthermore, we alert medical professionals to the higher fatality risk in patients older than 60 years. (PROSPERO, registration number= CRD42020181299

The diagnosis of hypertrophic cardiomyopathy by cardiovascular magnetic resonance

Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease

Liver biopsy may facilitate pancreatic graft evaluation: Positive association between liver steatosis and pancreatic graft adipose infiltration

OBJECTIVES: The number of pancreatic transplants has decreased in recent years. Pancreatic grafts have been underutilized compared to other solid grafts. One cause of discard is the macroscopic appearance of the pancreas, especially the presence of fatty infiltration. The current research is aimed at understanding any graft-related association between fatty tissue infiltration of the pancreas and liver steatosis. METHODS: From August 2013 to August 2014, a prospective cross-sectional clinical study using data from 54 multiple deceased donor organs was performed. RESULTS: Micro- and macroscopic liver steatosis were significantly correlated with the donor body mass index ([BMI]; p=0.029 and p=0.006, respectively). Positive gamma associations between pancreatic and liver macroscopic and microscopic findings (0.98; confidence interval [CI]: 0.95-1 and 0.52; CI 0.04-1, respectively) were observed. Furthermore, comparisons of liver microscopy findings showed significant differences between severe versus absent (

Trabeculated (non-compacted) and compact myocardium in adults: the multi-ethnic study of atherosclerosis

BACKGROUND: A high degree of non-compacted (trabeculated) myocardium in relationship to compact myocardium (T/M ratio >2.3) has been associated with a diagnosis of left ventricular non-compaction (LVNC). The purpose of this study was to determine the normal range of the T/M ratio in a large population-based study and to examine the relationship to demographic and clinical parameters. METHODS AND RESULTS: The thickness of trabeculation and the compact myocardium were measured in eight LV regions on long axis cardiac magnetic resonance (CMR) steady-state free precession cine images in 1000 participants (551 women; 68.1±8.9 years) of the Multi-Ethnic Study of Atherosclerosis cohort. Of 323 participants without cardiac disease or hypertension and with all regions evaluable 140 (43%) had a T/M ratio >2.3 in at least one region; in 20/323 (6%), T/M>2.3 was present in more than two regions. Multivariable linear regression model revealed no association of age, gender, ethnicity, height and weight with maximum T/M ratio in participants without cardiac disease or hypertension (p>0.05). In the entire cohort (n=1000) LVEF (β=−0.02/%; p=0.015), LVEDV (β=0.01/ml; p=<0.0001) and LVESV (β=0.01/ml; p<0.001) were associated with maximum T/M ratio in adjusted models while there was no association with hypertension or myocardial infarction (p>0.05). At the apical level T/M ratios were significantly lower when obtained on short- compared to long-axis images (p=0.017). CONCLUSIONS: A ratio of trabeculated to compact myocardium of more than 2.3 is common in a large population based cohort. These results suggest reevaluation of the current CMR criteria for LVNC may be necessary