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1.
Neurol Clin Pract ; 14(2): e200260, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38585442

RESUMO

Background and Objectives: Among health care providers (HCPs), neurologists have one of the highest rates of burnout in the United States, compromising the quality and accessibility of patient care. Patients with refractory epilepsy are especially challenging to treat. This study aims to understand the burnout level in neurologists treating patients with refractory epilepsy and identify key contributing factors. Methods: US board-certified pediatric/adult neurologists who devote ≥50% of their time to clinical practice and treat ≥10 unique patients with refractory epilepsy annually were invited to take a noninterventional quantitative survey, designed to capture key elements of the HCP's background, burnout level, current practice, burden domains, and satisfaction with current antiseizure medications (ASMs). Burnout in 3 domains (emotional exhaustion, depersonalization, and personal accomplishment) was assessed by the validated Maslach Burnout Inventory-Human Services Survey. Results: From March 11, 2022, to April 10, 2022, a total of 138 neurology-specialist HCPs participated in the survey, divided between adult epileptologists (n = 44), adult neurologists (n = 41), pediatric epileptologists (n = 36), and pediatric neurologists (n = 17). Of participating HCPs, 61% experienced at least some burnout (≥1 of 3 burnout domains categorized as high), and 4% experienced high burnout (3 of 3 burnout domains categorized as high). High burnout levels were driven by high pediatric and inpatient caseloads and unexpected pediatric patient reluctance to transition to adult care. HCPs with high burnout had a higher yearly caseload of patients with refractory epilepsy. Most HCPs (approximately 90%) indicated that patients with refractory epilepsy were more difficult to manage than those with nonrefractory epilepsy. The proportion of HCPs satisfied or extremely satisfied with ASMs was lower for patients with refractory epilepsy (20%) than that for patients with nonrefractory epilepsy (73%). Dissatisfaction was mostly due to workload and latency of the insurance approval process, out-of-pocket costs, and poor efficacy, safety, and tolerability. For 32% of HCPs, stopping practicing or moving to another practice within 5 years was probable or very probable. Discussion: Some burnout is common among HCPs who treat patients with refractory epilepsy. However, management of refractory epilepsy is challenging, and satisfaction with available ASMs is low. Thus, addressing these contributing factors may help to alleviate HCP burnout.

2.
Radiol Phys Technol ; 17(2): 476-487, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38652208

RESUMO

The objective of this study was to investigate patient radiation doses by a dose audit of three common interventional cardiology (IC) procedures: coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) and CA-PTCA procedures performed in IC centres in the Uttarakhand state of India, for the establishment of local diagnostic reference levels (DRLs) and the estimation of average effective dose (Eav) for these procedures. For each procedure, the values of kerma-area product (PKA), reference air kerma (Ka,r), fluoroscopy time (FT) and the number of cine images were recorded from 1233 CA, 458 PTCA and 736 CA-PTCA procedures performed over a 12-month period at 13 IC centres of the state. From the recorded dose data, 0.6%, 1.53% and 7.9% patients were identified to have exceeded the PKA trigger level of 500 Gy cm2 for possible skin injury for CA, PTCA and CA-PTCA procedures, respectively. The 3rd quartile of the distribution of the recorded PKA values for each type of procedure was calculated to estimate local DRL values. The estimated values of DRLs and Eav were 37, 153 and 224 Gy cm2, and 6.72, 23.97 and 34.79 mSv for CA, PTCA and CA-PTCA procedures, respectively. For about 77% of the surveyed centres, the recorded patient doses were in agreement with the international standards. The local DRLs proposed in this study may be used to achieve patient dose optimization during IC procedures and the obtained patient dose data may also be archived into national dose database for the establishment of national DRLs.


Assuntos
Doses de Radiação , Humanos , Índia , Masculino , Feminino , Angiografia Coronária , Pessoa de Meia-Idade , Fluoroscopia , Cardiologia , Idoso , Auditoria Médica , Níveis de Referência de Diagnóstico , Adulto
3.
Cureus ; 16(1): c154, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38260107

RESUMO

[This corrects the article DOI: 10.7759/cureus.48684.].

4.
Environ Sci Technol ; 58(6): 2750-2761, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38294931

RESUMO

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a charcoal-like ConAC-rich material. ConAC was also produced during laboratory oxidations of pine, maple, and brown-rotted oak woods, as well as algae, corn root, and tree bark. Back-of-the-envelope calculations suggest that biomass oxidation could be producing massive non-pyrogenic ConAC fluxes to terrestrial and aquatic environments. These estimates (e.g., 163-182 Tg-ConAC/year to soils) are much higher than the estimated pyrogenic "BC" fluxes (e.g., 128 Tg-ConAC/year to soils) implying that environmental ConAC is primarily non-pyrogenic. This novel perspective suggests that wildfire research trajectories should shift to assessing non-pyrogenic ConAC sources and fluxes, developing new methods for quantifying true BC, and establishing a new view of ConAC as an intermediate species in the biogeochemical processing of biomass during soil humification, aquatic photochemistry, microbial degradation, or mineral-organic matter interactions. We also advise against using BC or pyrogenic carbon (pyC) terminologies for ConAC measured in environmental matrices, unless a pyrogenic source can be confidently assigned.


Assuntos
Carbono , Incêndios , Biomassa , Carvão Vegetal , Fuligem/análise , Solo
5.
Cureus ; 15(11): e48684, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38090409

RESUMO

BACKGROUND AND OBJECTIVE: Despite modern healthcare infrastructure, there is a paucity of information about the clinical research framework supporting healthcare in the United Arab Emirates (UAE). Therefore, this study aimed to assess research performance productivity, and the clinical research framework, complementing medical residency, at the nation's hub for clinical research. METHODS: A cross-sectional retrospective review of records from the research database of the institution was conducted to assess productivity, and framework development, and data analyzed. RESULTS:  The migration of global healthcare providers, and the pharmaceutical industry offices, the adoption of the International Conference on Harmonization (ICH) guidelines, and electronic medical records established a research culture. Following the development of the governance framework, a total of 1,328 research projects were submitted to the ethics committee until 2023. Approximately 63% of the total studies were of minimal risk, followed by industry-sponsored clinical trials (4.9%, 58/1,163), and prospective interventional studies (3.5%, 39/1,163). Almost half (48.3%, 28/58) of the total industry-sponsored clinical trials were phase II and phase III. The number of peer-reviewed indexed publications, a measure of research productivity, indicated that the periods between 2011 and 2015, 2016 and 2020, and 2021 and 2023 witnessed a 3.8-, 9.3-, and 7.9-fold increase compared to the baseline period (1995-2005). The implementation of the Focus on International Research Strategy, Teaching, Evaluation, and Mentoring (FIRSTEM) strategy, to accommodate mandatory research activity requirements for residents by the physician licensing boards, observed substantial increases in output. The number of international peer-reviewed indexed publications/resident projects doubled from 10.8% (2010-2015) to 24% (2016-2020) and reached 40.1% in 2023. CONCLUSION: This is the first research governance model established in the UAE, a country with an increasing prevalence of diabetes, and cardiovascular and genetic diseases. The model indicates that the medical trainees differentiate the best research evidence in making decisions about the clinical care of patients. The study outcomes may potentially be useful for other countries in developing a clinical research framework.

6.
Plant Signal Behav ; 18(1): 2290336, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38050377

RESUMO

Sustainable agriculture faces major challenges under abiotic stress conditions owing to extensive application of chemical fertilizers which pollute water, soil and atmosphere. Biostimulants (BSs), comprising of naturally derived complex mixtures of uncharacterized biomolecules, pure biochemicals and nanomaterials, enhance nutrient use efficiency (NUE) and trigger crop's natural defense mechanisms. While it is difficult to specify the metabolic effects of uncharacterized natural mixtures (seaweed extract, protein hydrolyzates, etc.), exogenous application of pure biochemicals and nanomaterials offers an edge as BSs since their physiological roles and mechanisms of action are decipherable. Foliar application or seed treatment of some amino acids, polyamines and biopolymers (chitosan, lipochitin oligosaccharides and thuricin 17) enable plants to overcome drought and salinity stress via activation of mechanisms for reactive oxygen species (ROS) scavenging, osmolyte regulation and chlorophyll accumulation. Interaction of nitric oxide (NO) with some vitamins and melatonin exhibits potential significance as BSs for mitigating stress by ROS scavenging and maintenance of intracellular ionic balance and membrane integrity. Near future is likely to see wide applications of nanoparticles (NPs) and nanomaterials (NMs) as BSs in view of their biphasic mode of action (bio-physical activation of membrane receptors followed by gradual release of BS into the plant cells).


Assuntos
Nanoestruturas , Espécies Reativas de Oxigênio , Agricultura , Estresse Fisiológico , Plantas
7.
Nat Commun ; 14(1): 5748, 2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37717035

RESUMO

Constraining the controlling factors of fault rupture is fundamentally important. Fluids influence earthquake locations and magnitudes, although the exact pathways through the lithosphere are not well-known. Ocean transform faults are ideal for studying faults and fluid pathways given their relative simplicity. We analyse seismicity recorded by the Passive Imaging of the Lithosphere-Asthenosphere Boundary (PI-LAB) experiment, centred around the Chain Fracture Zone. We find earthquakes beneath morphological transpressional features occur deeper than the brittle-ductile transition predicted by simple thermal models, but elsewhere occur shallower. These features are characterised by multiple parallel fault segments and step overs, higher proportions of smaller events, gaps in large historical earthquakes, and seismic velocity structures consistent with hydrothermal alteration. Therefore, broader fault damage zones preferentially facilitate fluid transport. This cools the mantle and reduces the potential for large earthquakes at localized barriers that divide the transform into shorter asperity regions, limiting earthquake magnitudes on the transform.

8.
Cureus ; 15(8): e43355, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37700973

RESUMO

Background and objective The negligible side effects of paracetamol along with its ease of availability have catapulted paracetamol to be a widely used medication in emergency room management to reduce pain and subsequent elevations in blood pressure (BP). Our study aimed to address the challenges in informed clinical decision-making in the emergency room following paracetamol intravenous infusion. Methods This was a retrospective cross-sectional study involving the extraction of data from electronic medical records of patients who received intravenous paracetamol infusion between January 2022 and May 2022. Demographic information and BP-related data were collected for analysis. Results We initially considered a total of 162 patient records, with 132 of them eventually meeting the inclusion criteria. Among patients receiving paracetamol infusion for 15 minutes or less, 34% showed a drop of 1-5 mmHg in systolic BP (SBP), while 26% experienced a drop of 6-10 mmHg. However, infusion time longer than 16 minutes did not significantly reduce SBP. Diastolic BP (DBP) was not significantly affected by the duration of the paracetamol infusion. Analysis of the drop in SBP revealed no significant associations with age, gender, or ethnicity. Mean arterial pressure (MAP) was not significantly affected by the duration of paracetamol infusion. Conclusion Our findings suggest that intravenous paracetamol infusion does not significantly lower BP in adults in the emergency room, except for infusions of shorter durations. However, various factors, including infusion rate, patient characteristics, and concomitant medications, may influence BP measurements. The study emphasizes the need for establishing standardized criteria and conducting further research to assess intravenous paracetamol's hemodynamic effects accurately.

9.
Sci Adv ; 9(39): eadi2698, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37774034

RESUMO

Models of magmatic systems suggest that the architecture of crustal magma bodies plays an important role in where volcanic eruptions occur, but detailed field observations are needed to evaluate them. We present ultrahigh-resolution reflection images of magma bodies beneath a region of multiple eruptions along the East Pacific Rise derived from three-dimensional seismic surveying. The observations reveal magma bodies with elongate ridges and troughs vertically aligned with seafloor eruptive fissures that we interpret as remnant dike root zones where repeat dikes nucleate. We document a triangular feeder zone to the axially centered magma body from the off-axis source for a newly forming seamount of the Lamont chain and infer bottom-up eruption triggering due to recharge from this deeper source. The findings indicate that magma bodies are sculpted by both processes of magma recharge from below and magma extraction to the surface, leaving a morphological imprint that contributes to localization of dike nucleation and eruption sites at the East Pacific Rise.

10.
Cureus ; 15(7): e42543, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37637583

RESUMO

Introduction Pre-eclampsia is a pregnancy-specific hypertensive disorder and is one of the leading causes of maternal and infant morbidity and mortality in India and worldwide. Evidence of the association between various risk factors and pre-eclampsia is scarce in developing countries. As pre-eclampsia remains a leading cause of maternal mortality and morbidity, focusing on the causes and risk factors of pre-eclampsia during antenatal surveillance would prevent maternal deaths and reduce the maternal mortality rate. Our study aimed to determine the risk factors of pre-eclampsia. Materials and methods An unmatched case-control study was conducted at Veer Surendra Sai Institute of Medical Sciences and Research (VIMSAR), Burla, Odisha, taking 100 cases of pre-eclampsia and 100 controls without pre-eclampsia from January 2021 to January 2023. The study population included patients admitted to the Obstetrics & Gynecology labor room. Study participants were selected randomly from the labor room thrice weekly. Data were collected using a predesigned pre-tested questionnaire and case report format. Data were analyzed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States). Appropriate statistical tests (Odds ratio, proportions, Chi-square test) were applied, and the final interpretation was made. Results Family history of hypertension (AOR = 4.2), history of chronic hypertension (AOR = 13.7), and AB blood group (AOR = 3.6) were found to be significant risk factors for pre-eclampsia. No significant association was found between pre-eclampsia and factors such as mother's age, caste, mother's education, type of family, socioeconomic status, education and occupation of husband, family history of diabetes mellitus, parity, history of abortion, and anemia. Conclusion Risk factors identified in the present study can be used to identify women at risk of pre-eclampsia during antenatal check-ups to minimize the complications of pre-eclampsia in both the mother and the fetus.

11.
J Cardiol Cases ; 28(2): 62-63, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37521579

RESUMO

Para mitral annular ring leakage can occur following ring dehiscence after mitral annuloplasty. Percutaneous device closure of para-annular ring leakage can be performed successfully to treat such regurgitations with good transesophageal echocardiography guidance and patient selection. While para valvular device closure has been described in the medical literature, there have been few anecdotal reports published on para ring leak device closures. In this case, we highlight our experience from the successful closure of a para mitral annular ring closure with an AVP III device. The patient had a para annular ring regurgitation post coronary artery bypass grafting with mitral ring annuloplasty presenting with hemolytic anemia and acute renal failure, successfully treated by percutaneous device closure. Learning objective: This report describes the safety and effectiveness of a transcatheter para ring leak closure with an AVP III device. We applied the principles of device closure of paravalvular leak from our experience and related data from literature for this case and describe various hardware and techniques used for a successful closure of a para mitral ring leak.

12.
Indian J Nephrol ; 33(2): 119-124, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37234443

RESUMO

Introduction: The clinical practice guidelines for peritoneal access state that no particular peritoneal dialysis catheter (PDC) type has been proven superior to another. We present our experience with the use of different PDC tip designs. Method: The study is a retrospective, real-world, observational, outcome analysis correlating the PDC tip design (straight vs. coiled-tip) and technique survival. The primary outcome was technique survival, and the secondary outcome included catheter migration and infectious complications. Result: A total of 50 PDC (28 coiled-tip and 22 straight-tip) were implanted between March 2017 and April 2019 by using a guided percutaneous approach. The 1-month and 1-year technique survival in the coiled-tip PDC was 96.4% and 92.8%, respectively. Of the two coiled-tip catheters lost, one was a consequence of the patient having undergone live related kidney transplantation. The corresponding 1-month and 1-year technique survival with straight-tip PDC was 86.4% and 77.3%, respectively. When compared to straight-tip PDC, the use of coiled-tip PDC was associated with fewer early migration (3.6% vs. 31.8%; odds ratio (OR): 12.6; 95% confidence interval (CI): 1.41-112.39; P = 0.02) and a trend toward favorable 1-year technique survival (P = 0.07; numbers needed to treat = 11). Therapy-related complications noted in the study included peri-catheter leak and PD peritonitis. The PD peritonitis rate in the coiled-tip and straight-tip group was 0.14 and 0.11 events per patient year, respectively. Conclusion: The use of coiled-tip PDC, when placed using a guided percutaneous approach, reduces early catheter migration and shows a trend toward favorable long-term technique survival.

13.
Plant Signal Behav ; 18(1): 2217027, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-37243675

RESUMO

Oil body (OB) mobilization, a crucial event associated with early seedling growth, is delayed in response to salt stress. Previous reports suggest that careful regulation of polyamine (PA) metabolism is essential for salt stress tolerance in plants. Many aspects of PA-mediated regulation of metabolism have been uncovered. However, their role in the process of OB mobilization remains unexplored. Interestingly, the present investigations reveal a possible influence of PA homeostasis on OB mobilization, while implicating complex regulation of oleosin degradation and aquaporin abundance in OB membranes in the process. Application of PA inhibitors resulted in the accumulation of smaller OBs when compared to control (-NaCl) and the salt-stressed counterparts, suggesting a faster rate of mobilization. PA deficit also resulted in reduced retention of some larger oleosins under controlled conditions but enhanced retention of all oleosins under salt stress. Additionally, with respect to aquaporins, a higher abundance of PIP2 under PA deficit both under control and saline conditions, is correlated with a faster mobilization of OBs. Contrarily, TIP1s, and TIP2s remained almost undetectable in response to PA depletion and were differentially regulated by salt stress. The present work, thus, provides novel insights into PA homeostasis-mediated regulation of OB mobilization, oleosin degradation, and aquaporin abundance on OB membranes.


Assuntos
Aquaporinas , Gotículas Lipídicas , Gotículas Lipídicas/metabolismo , Poliaminas/metabolismo , Plântula/metabolismo , Estresse Salino , Aquaporinas/metabolismo , Proteínas de Plantas/metabolismo
14.
Cureus ; 15(4): e37027, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37143628

RESUMO

Background and objective There is a dearth of studies on the knowledge and awareness among mothers on childhood development in the United Arab Emirates (UAE). Maternal knowledge of childhood development is a critical determinant of children's development and behavior. In light of this, we conducted this study to determine the level of maternal knowledge about childhood development. Methodology We employed a cross-sectional study design involving 200 mothers of all ages recruited using stratified random sampling. After obtaining informed consent, the participants were required to complete a questionnaire adapted from the "Ages and Stages" questionnaire, which covered demographics and items on developmental milestones. The questionnaire was validated and checked for reliability by using a focus group. Inferential statistics were used, and the association between the variables was analyzed using the Chi-squared test. Results Our findings indicated that the knowledge among mothers regarding child development is relatively low in the UAE. Two-thirds of the respondents were knowledgeable about gross motor skills (62% of the mothers knew the age at which a child could lift his/her head). Less than half of the mothers were well-informed about fine motor skills such as writing and drawing (44% of the mothers were aware of the age at which a child should be able to scribble on paper). The respondents demonstrated a lack of knowledge regarding children's speech and language skills. Regarding social skills, only 8% of the mothers were aware of the correct age at which a child should start to dress by himself/herself. Conclusion Although mothers in the UAE were knowledgeable about certain aspects of childhood development such as gross motor development, they were less knowledgeable regarding other aspects such as social and language skills. The gaps identified in our study highlight the need to implement effective health education programs so that mothers are better informed to help improve child development outcomes in the community.

15.
Cureus ; 15(4): e37189, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37159760

RESUMO

INTRODUCTION: Population aging is an inevitable demographic reality that is associated with improvements in the health and medical care system. With longevity and declining fertility rates, the population of older persons is growing faster than the general population globally. The elderly population is more prone to various kinds of morbidity due to decreasing immunity and the risk of advancing age. OBJECTIVE: To describe the morbidity pattern of the elderly in an urban area of Burla. MATERIALS AND METHODS:  Community-based cross-sectional study was carried out for one year from 1st July 2021 to 30th June 2022. A total of 385 individuals aged 60 years and above residing in Burla were included in the study. Patient-wise data collection was done by a predesigned, pretested structured questionnaire. The chi-square test for categorical variables at a 95% confidence interval and significance set at 0.05 were used as measures of association in the analysis of factors associated with morbidity. RESULT:  The most common health problem involved was musculoskeletal (68.6%), followed by cardiovascular (57.1%), eye (47.3%), endocrine (25.2%), respiratory (21.3%), digestive (20.5%), skin (16.1%), ear (15.3%), general and unspecified health problems (30.7%), and urological (5.5%) and 4.5% had neurological problems. CONCLUSION:  Elderly population has a high frequency of numerous morbidities, so it is important to educate the elderly population about prevalent age-related health issues as well as preventive care.

16.
Nat Commun ; 14(1): 969, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36813777
17.
Environ Sci Technol ; 57(8): 3104-3113, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36781166

RESUMO

Mining wastes or combustion ash are materials of high carbon sequestration potential but are also known for their toxicity in terms of heavy metal content. To utilize such waste materials for engineered carbon mineralization purposes, there is a need to investigate the fate and mobility of toxic metals. This is a study of the coprecipitation of metals with calcium carbonate for environmental heavy metal mitigation. The study also examines the stability of precipitated phases under environmentally relevant acid conditions. For a wide range of cadmium (Cd) and zinc (Zn) concentrations (10 to 5000 mg/L), induced coprecipitation led to greater than 99% uptake from water. The calcium carbonate phases were found to contain amounts as high as 9.9 wt % (Cd) and 17 wt % (Zn), as determined by novel synchrotron techniques, including X-ray fluorescence element mapping and three-dimensional (3D) nanotransmission X-ray microscopy (TXM). TXM imaging revealed first-of-a-kind observations of chemical gradients and internal nanoporosity within particles. These observations provided new insights into the mechanisms leading to the retention of coprecipitated heavy metals during the dissolution of calcite in acidic (pH 4) solutions. These observations highlight the feasibility of utilizing carbonate coprecipitation as an engineered approach to the durable sequestration of toxic metals.


Assuntos
Metais Pesados , Zinco , Cádmio , Metais Pesados/química , Carbonatos , Carbonato de Cálcio
18.
Nat Commun ; 13(1): 7809, 2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528618

RESUMO

The crustal accretion along mid-ocean ridges is known to be spreading-rate dependent. Along fast-spreading ridges, two-dimensional sheet-like mantle upwelling creates relatively uniform crust. In contrast, the crust formed along slow-spreading ridges shows large along-axis thickness variations with thicker crust at segment centres, which is hypothesised to be due a three-dimensional plume-like mantle upwelling or due to focused melt migration to segment centres. Using wide-angle seismic data acquired from the equatorial Atlantic Ocean, here we show that the crustal thickness is nearly uniform (~5.5 km) across five crustal segments for crust formed at the slow-spreading Mid-Atlantic Ridge with age varying from 8 to 70 Ma. The crustal velocities indicate that this crust is predominantly of magmatic origin. We suggest that this uniform magmatic crustal accretion is due to a two-dimensional sheet-like mantle upwelling facilitated by the long-offset transform faults in the equatorial Atlantic region and the presence of a high concentration of volatiles in the primitive melt in the mantle.

19.
Innovations (Phila) ; 17(5): 452-455, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36317272

RESUMO

An elderly patient with significant aortic regurgitation presented with heart failure. Dilation of the aortic root precluded a transcatheter anatomic site valve implantation, and prohibitive operative risk ruled against surgical implantation. A bail-out transcatheter implantation of the aortic valve in the descending aorta was successfully carried out with satisfactory outcomes.


Assuntos
Insuficiência da Valva Aórtica , Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Idoso , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Estenose da Valva Aórtica/cirurgia , Desenho de Prótese , Fatores de Risco , Resultado do Tratamento , Insuficiência da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia
20.
Nat Geosci ; 15: 741-746, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36246038

RESUMO

Transform faults accommodate the lateral motions between lithospheric plates, producing large earthquakes. Away from active transform boundaries, former oceanic transform faults also form the fracture zones that cover the ocean floor. However, the deep structure of these faults remains enigmatic. Here we present ultra-long offset seismic data from the Romanche transform fault in the equatorial Atlantic Ocean that indicates the presence of a low-velocity anomaly extending down to ~60 km depth below sea level. We performed 3D thermal modelling that suggests the anomaly is likely to be due to extensive serpentinization down to ~16 km depth, overlying a hydrated, shear mylonite zone down to 32 km depth. The water is considered to be sourced from seawater-derived fluids that infiltrate deep into the fault. Below 32 km is interpreted to be a low-temperature, water-induced melting zone that elevates the lithosphere-asthenosphere boundary, causing significant thinning of the lithosphere at the transform fault. The presence of a thinned lithosphere at transform faults could explain observations of volcanism, thickened crust and intra-transform spreading centres at transform faults. It also suggests that migration and mixing of water-induced melt with the high temperature melt may occur beneath the ridge axis.

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