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1.
Nature ; 608(7923): 558-562, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35948632

RESUMO

The productivity of rainforests growing on highly weathered tropical soils is expected to be limited by phosphorus availability1. Yet, controlled fertilization experiments have been unable to demonstrate a dominant role for phosphorus in controlling tropical forest net primary productivity. Recent syntheses have demonstrated that responses to nitrogen addition are as large as to phosphorus2, and adaptations to low phosphorus availability appear to enable net primary productivity to be maintained across major soil phosphorus gradients3. Thus, the extent to which phosphorus availability limits tropical forest productivity is highly uncertain. The majority of the Amazonia, however, is characterized by soils that are more depleted in phosphorus than those in which most tropical fertilization experiments have taken place2. Thus, we established a phosphorus, nitrogen and base cation addition experiment in an old growth Amazon rainforest, with a low soil phosphorus content that is representative of approximately 60% of the Amazon basin. Here we show that net primary productivity increased exclusively with phosphorus addition. After 2 years, strong responses were observed in fine root (+29%) and canopy productivity (+19%), but not stem growth. The direct evidence of phosphorus limitation of net primary productivity suggests that phosphorus availability may restrict Amazon forest responses to CO2 fertilization4, with major implications for future carbon sequestration and forest resilience to climate change.


Assuntos
Mudança Climática , Fósforo , Floresta Úmida , Solo , Árvores , Clima Tropical , Aclimatação , Dióxido de Carbono/metabolismo , Dióxido de Carbono/farmacologia , Sequestro de Carbono , Cátions/metabolismo , Cátions/farmacologia , Mudança Climática/estatística & dados numéricos , Modelos Biológicos , Nitrogênio/metabolismo , Nitrogênio/farmacologia , Fósforo/metabolismo , Fósforo/farmacologia , Solo/química , Árvores/efeitos dos fármacos , Árvores/metabolismo , Incerteza
2.
Langmuir ; 40(11): 5776-5784, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38456666

RESUMO

Deposition of molybdenum disulfide (MoS2) coatings using physical vapor deposition (PVD) and mechanical burnishing has been widely assessed for solid lubricants in space applications but still suffers from line-of-sight constraints on complex geometries. Here, we highlight one of the first demonstrations of electrodeposited MoxSyOz and MoxSyOz/Ni thin-film coatings from aqueous solutions of ammonium tetrathiomolybdate for solid lubricant applications and their remarkable ability to provide low coefficients of friction and high wear resistance. Characterization of the coating morphology shows amorphous microstructures with a high oxygen content and cracking upon drying. Even so, electrodeposited MoxSyOz can achieve low steady-state coefficients of friction (µ ∼ 0.05-0.06) and wear rates (2.6 × 10-7 mm3/(N m)) approaching those of physical vapor deposited coatings (2.3 × 10-7 mm3/(N m)). Additionally, we show that adding dopants such as nickel increased the wear rate (7.5 × 10-7 mm3/(N m)) and initial coefficient of friction (µi = 0.23) due to compositional modifications such as dramatic sub-stoichiometry (S/Mo ∼ 1) and expression of a NiOx surface layer, although doping did reduce the degree of cracking upon drying.

3.
J Chem Inf Model ; 63(14): 4433-4446, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37395685

RESUMO

Most processes at the water-membrane interface often involve protonation events in proteins or peptides that trigger important biological functions and events. This is the working principle behind the pHLIP peptide technology. A key titrating aspartate (Asp14 in wt) is required to protonate to induce the insertion process, increase its thermodynamic stability when membrane-embedded, and trigger the peptide's overall clinical functionality. At the core of pHLIP properties, the aspartate pKa and protonation are a consequence of the residue side chain sensing the changing surrounding environment. In this work, we characterized how the microenvironment of the key aspartate residue (Asp13 in the investigated pHLIP variants) can be modulated by a simple point mutation of a cationic residue (ArgX) at distinct sequence positions (R10, R14, R15, and R17). We carried out a multidisciplinary study using pHRE simulations and experimental measurements. Fluorescence and circular dichroism measurements were carried out to establish the stability of pHLIP variants in state III and establish the kinetics of the insertion and exit of the peptide from the membrane. We estimated the contribution of the arginine to the local electrostatic microenvironment, which promotes or hinders other electrostatic players from coexisting in the Asp interaction shell. Our data indicate that the stability and kinetics of the peptide insertion and exit from the membrane are altered when Arg is topologically available for a direct salt-bridge formation with Asp13. Hence, the position of arginine contributes to fine-tuning the pH responses of pHLIP peptides, which finds wide applications in clinics.


Assuntos
Ácido Aspártico , Bicamadas Lipídicas , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Peptídeos/química , Concentração de Íons de Hidrogênio
4.
Postgrad Med J ; 99(1168): 56-62, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-36828395

RESUMO

PURPOSE: This work aims to describe patients hospitalized in internal medicine wards in terms of nutrition and sarcopenia. It also seeks to evaluate short- and long-term mortality related to malnutrition and sarcopenia. METHODS: This cross-sectional study collected data on consecutive patients admitted to a single center's internal medicine ward. Patients were recruited in May and October 2021. Malnutrition was determined by the Mini-Nutritional Assessment-Short Form (MNA-SF) and sarcopenia by the Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls questionnaire (SARC-F scale) and handgrip strength test. Patients who were hospitalized for >48 hours were excluded. RESULTS: The sample included 619 patients with a mean ± SD age of 76.0 ± 14.8 years of which 50.6% were women. Patients were classified into three groups based on malnutrition: group 1 (MNA-SF 12-14 points) (no risk) included 158 patients, group 2 (MNA-SF 8-12 points) (high risk) included 233 patients, and group 3 (MNA-SF 0-7 points) (malnourished) included 228 patients. Malnourished patients had more dysphagia, significantly lower protein and albumin levels, and significantly higher inflammatory marker levels and pressure ulcers. In-hospital mortality was significantly higher in groups 2 and 3 (p < .00001). The worst outcome (mortality and readmissions or mortality) was more common among malnourished patients (p = .0001). Inflammation, comorbidity, and sarcopenia were most closely associated with negative outcomes. CONCLUSION: Malnutrition upon admission is associated with worse short- and long-term outcomes in internal medicine inpatients. Sarcopenia, multimorbidity, and inflammation-measured by albumin, C-reactive protein, or their ratios-are key risk factors. Early identification of malnutrition and sarcopenia through active screening is important in caring for internal medicine patients.


Assuntos
Desnutrição , Sarcopenia , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Masculino , Sarcopenia/epidemiologia , Pacientes Internados , Força da Mão , Estudos Transversais , Desnutrição/epidemiologia , Desnutrição/diagnóstico , Estado Nutricional , Avaliação Nutricional , Proteína C-Reativa , Inflamação , Avaliação Geriátrica
5.
J Exp Bot ; 73(3): 939-952, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-34545938

RESUMO

Addressing the intraspecific variability of functional traits helps understand how climate change might influence the distribution of organismal traits across environments, but this is notably understudied in the Amazon, especially for plant hydraulic traits commonly used to project drought responses. We quantified the intraspecific trait variability of leaf mass per area, wood density, and xylem embolism resistance for two dominant central Amazonian tree species, along gradients of water and light availability, while accounting for tree age and height. Intraspecific variability in hydraulic traits was high, with within-species variability comparable to the whole-community variation. Hydraulic trait variation was modulated mostly by the hydrological environment, with higher embolism resistance of trees growing on deep-water-table plateaus compared with shallow-water-table valleys. Intraspecific variability of leaf mass per area and wood density was mostly modulated by intrinsic factors and light. The different environmental and intrinsic drivers of variation among and within individuals lead to an uncoupled coordination among carbon acquisition/conservation and water-use traits. Our findings suggest multivariate ecological strategies driving tropical tree distributions even within species, and reflect differential within-population sensitivities along environmental gradients. Therefore, intraspecific trait variability must be considered for accurate predictions of the responses of tropical forests to climate change.


Assuntos
Árvores , Xilema , Secas , Florestas , Folhas de Planta/fisiologia , Árvores/fisiologia , Água , Xilema/fisiologia
6.
J Intensive Care Med ; 37(12): 1606-1613, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35642279

RESUMO

Objective: There exists controversy about the pathophysiology and lung mechanics of COVID-19 associated acute respiratory distress syndrome (ARDS), because some report severe hypoxemia with preserved respiratory system mechanics, contrasting with "classic" ARDS. We performed a detailed hourly analysis of the characteristics and time course of lung mechanics and biochemical analysis of patients requiring invasive mechanical ventilation (IMV) for COVID-19-associated ARDS, comparing survivors and non-survivors. Methods: Retrospective analysis of the data stored in the ICU information system of patients admitted in our hospital ICU that required IMV due to confirmed SARS-CoV-2 pneumonia between March 5th and April 30th, 2020. We compare respiratory system mechanics and gas exchange during the first ten days of IMV, discriminating volume and pressure controlled modes, between ICU survivors and non-survivors. Results: 140 patients were included, analyzing 11 138 respiratory mechanics recordings. Global mortality was 38.6%. Multivariate analysis showed that age (OR 1.092, 95% (CI 1.014-1.176)) and need of renal replacement therapies (OR 10.15, (95% CI 1.58-65.11)) were associated with higher mortality. Previous use of Angiotensin Converting Enzyme inhibitor (ACEI)/angiotensin-receptor blockers (ARBs) also seemed to show an increased mortality (OR 4.612, (95% CI 1.19-17.84)) although this significance was lost when stratifying by age. Respiratory variables start to diverge significantly between survivors and non-survivors after the 96 to 120 hours (hs) from mechanical ventilation initiation, particularly respiratory system compliance. In non survivors, mechanical power at 24 and 96 hs was higher regardless ventilatory mode. Conclusions: In patients admitted for SARS-CoV-2 pneumonia and requiring mechanical ventilation, non survivors have different respiratory system mechanics than survivors in the first 10 days of ICU admission. We propose a checkpoint at 96-120 hs to assess patients improvement or worsening in order to consider escalating to extracorporeal therapies.


Assuntos
COVID-19 , Pneumonia , Síndrome do Desconforto Respiratório , Adulto , Humanos , COVID-19/terapia , Respiração Artificial , SARS-CoV-2 , Estado Terminal/terapia , Estudos Retrospectivos , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina
7.
PLoS Genet ; 15(3): e1007873, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30889179

RESUMO

Autosomal recessive retinal degenerative diseases cause visual impairment and blindness in both humans and dogs. Currently, no standard treatment is available, but pioneering gene therapy-based canine models have been instrumental for clinical trials in humans. To study a novel form of retinal degeneration in Labrador retriever dogs with clinical signs indicating cone and rod degeneration, we used whole-genome sequencing of an affected sib-pair and their unaffected parents. A frameshift insertion in the ATP binding cassette subfamily A member 4 (ABCA4) gene (c.4176insC), leading to a premature stop codon in exon 28 (p.F1393Lfs*1395), was identified. In contrast to unaffected dogs, no full-length ABCA4 protein was detected in the retina of an affected dog. The ABCA4 gene encodes a membrane transporter protein localized in the outer segments of rod and cone photoreceptors. In humans, the ABCA4 gene is associated with Stargardt disease (STGD), an autosomal recessive retinal degeneration leading to central visual impairment. A hallmark of STGD is the accumulation of lipofuscin deposits in the retinal pigment epithelium (RPE). The discovery of a canine homozygous ABCA4 loss-of-function mutation may advance the development of dog as a large animal model for human STGD.


Assuntos
Membro 4 da Subfamília A de Transportadores de Cassetes de Ligação de ATP/genética , Doenças do Cão/genética , Degeneração Macular/congênito , Mutação , Membro 4 da Subfamília A de Transportadores de Cassetes de Ligação de ATP/química , Membro 4 da Subfamília A de Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Códon sem Sentido , Modelos Animais de Doenças , Doenças do Cão/metabolismo , Doenças do Cão/patologia , Cães , Feminino , Genes Recessivos , Homozigoto , Humanos , Lipofuscina/metabolismo , Degeneração Macular/genética , Degeneração Macular/metabolismo , Degeneração Macular/veterinária , Masculino , Microscopia de Fluorescência , Modelos Moleculares , Mutagênese Insercional , Linhagem , Conformação Proteica , Retina/metabolismo , Retina/patologia , Doença de Stargardt , Sequenciamento Completo do Genoma
8.
Strahlenther Onkol ; 197(11): 1010-1020, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34230996

RESUMO

PURPOSE: To evaluate the efficacy and safety of lung low-dose radiation therapy (LD-RT) for pneumonia in patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: Inclusion criteria comprised patients with COVID-19-related moderate-severe pneumonia warranting hospitalization with supplemental O2 and not candidates for admission to the intensive care unit because of comorbidities or general status. All patients received single lung dose of 0.5 Gy. Respiratory and systemic inflammatory parameters were evaluated before irradiation, at 24 h and 1 week after LD-RT. Primary endpoint was increased in the ratio of arterial oxygen partial pressure (PaO2) or the pulse oximetry saturation (SpO2) to fractional inspired oxygen (FiO2) ratio of at least 20% at 24 h with respect to the preirradiation value. RESULTS: Between June and November 2020, 36 patients with COVID-19 pneumonia and a mean age of 84 years were enrolled. Seventeen were women and 19 were men and all of them had comorbidities. All patients had bilateral pulmonary infiltrates on chest X­ray. All patients received dexamethasone treatment. Mean SpO2 pretreatment value was 94.28% and the SpO2/FiO2 ratio varied from 255 mm Hg to 283 mm Hg at 24 h and to 381 mm Hg at 1 week, respectively. In those who survived (23/36, 64%), a significant improvement was observed in the percentage of lung involvement in the CT scan at 1 week after LD-RT. No adverse effects related to radiation treatment have been reported. CONCLUSIONS: LD-RT appears to be a feasible and safe option in a population with COVID-19 bilateral interstitial pneumonia in the presence of significant comorbidities.


Assuntos
COVID-19/radioterapia , Radioterapia Conformacional/métodos , SARS-CoV-2 , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/uso terapêutico , Proteína C-Reativa/análise , COVID-19/diagnóstico por imagem , COVID-19/mortalidade , COVID-19/terapia , Causas de Morte , Terapia Combinada , Comorbidade , Dexametasona/uso terapêutico , Feminino , Ferritinas/sangue , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Mortalidade Hospitalar , Humanos , Interleucina-6/sangue , L-Lactato Desidrogenase/sangue , Pulmão/diagnóstico por imagem , Pulmão/efeitos da radiação , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/radioterapia , Doenças Pulmonares Intersticiais/terapia , Masculino , Oxigênio/sangue , Oxigênio/uso terapêutico , Oxigenoterapia , Pressão Parcial , Estudos Prospectivos , Dosagem Radioterapêutica , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X , Resultado do Tratamento
9.
BMC Infect Dis ; 21(1): 16, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407206

RESUMO

BACKGROUND: Epidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted, and in particular in Mozambique. The aim of this study was to detect and characterize extended-spectrum ß-lactamase (ESBL) - and plasmid-mediated AmpC (pAmpC)-producing clinical strains of Escherichia coli at Maputo Central Hospital (MCH), a 1000-bed reference hospital in Maputo, Mozambique. METHODS: A total of 230 clinical isolates of E. coli from urine (n = 199) and blood cultures (n = 31) were collected at MCH during August-November 2015. Antimicrobial susceptibility testing was performed by the disc diffusion method and interpreted according to EUCAST guidelines. Isolates with reduced susceptibility to 3rd generation cephalosporins were examined further; phenotypically for an ESBL-/AmpC-phenotype by combined disc methods and genetically for ESBL- and pAmpC-encoding genes by PCR and partial amplicon sequencing as well as genetic relatedness by ERIC-PCR. RESULTS: A total of 75 isolates with reduced susceptibility to cefotaxime and/or ceftazidime (n = 75) from urine (n = 58/199; 29%) and blood (n = 17/31; 55%) were detected. All 75 isolates were phenotypically ESBL-positive and 25/75 (33%) of those also expressed an AmpC-phenotype. ESBL-PCR and amplicon sequencing revealed a majority of blaCTX-M (n = 58/75; 77%) dominated by blaCTX-M-15. All AmpC-phenotype positive isolates (n = 25/75; 33%) scored positive for one or more pAmpC-genes dominated by blaMOX/FOX. Multidrug resistance (resistance ≥ three antibiotic classes) was observed in all the 75 ESBL-positive isolates dominated by resistance to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin. ERIC-PCR revealed genetic diversity among strains with minor clusters indicating intra-hospital spread. CONCLUSION: We have observed a high prevalence of MDR pAmpC- and/or ESBL-producing clinical E. coli isolates with FOX/MOX and CTX-Ms as the major ß-lactamase types, respectively. ERIC-PCR analyses revealed genetic diversity and some clusters indicating within-hospital spread. The overall findings strongly support the urgent need for accurate and rapid diagnostic services to guide antibiotic treatment and improved infection control measures.


Assuntos
Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Cefotaxima/uso terapêutico , Ceftazidima/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Plasmídeos/metabolismo , beta-Lactamases/genética , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/microbiologia , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/urina , Humanos , Testes de Sensibilidade Microbiana , Moçambique/epidemiologia , Fenótipo , Prevalência
10.
Echocardiography ; 38(9): 1673-1677, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34510529

RESUMO

We present the case of a 46-year-old patient with hypothyroidism secondary to Hashimoto's thyroiditis who was admitted with decompensation in the form of myxedema. A 2-D echocardiogram shows a septal asymmetric hypertrophy, with low-voltage QRS complex in the ECG and a bull's-eye map of longitudinal strain with preserved apical strain with reduction of mid and basal strain that results in "cherry on the top" pattern, similar to the most frequent phenocopy of hypertrophic cardiomyopathy, as is the cardiac amyloidosis, and that, unlike this pathology, reverted after the patient reached the euthyroid state.


Assuntos
Amiloidose , Cardiomiopatias , Cardiomiopatia Hipertrófica , Hipotireoidismo , Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/diagnóstico , Ecocardiografia , Eletrocardiografia , Humanos , Hipotireoidismo/complicações , Pessoa de Meia-Idade
11.
BMC Bioinformatics ; 21(1): 102, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32164527

RESUMO

BACKGROUND: All-Food-Sequencing (AFS) is an untargeted metagenomic sequencing method that allows for the detection and quantification of food ingredients including animals, plants, and microbiota. While this approach avoids some of the shortcomings of targeted PCR-based methods, it requires the comparison of sequence reads to large collections of reference genomes. The steadily increasing amount of available reference genomes establishes the need for efficient big data approaches. RESULTS: We introduce an alignment-free k-mer based method for detection and quantification of species composition in food and other complex biological matters. It is orders-of-magnitude faster than our previous alignment-based AFS pipeline. In comparison to the established tools CLARK, Kraken2, and Kraken2+Bracken it is superior in terms of false-positive rate and quantification accuracy. Furthermore, the usage of an efficient database partitioning scheme allows for the processing of massive collections of reference genomes with reduced memory requirements on a workstation (AFS-MetaCache) or on a Spark-based compute cluster (MetaCacheSpark). CONCLUSIONS: We present a fast yet accurate screening method for whole genome shotgun sequencing-based biosurveillance applications such as food testing. By relying on a big data approach it can scale efficiently towards large-scale collections of complex eukaryotic and bacterial reference genomes. AFS-MetaCache and MetaCacheSpark are suitable tools for broad-scale metagenomic screening applications. They are available at https://muellan.github.io/metacache/afs.html (C++ version for a workstation) and https://github.com/jmabuin/MetaCacheSpark (Spark version for big data clusters).


Assuntos
Big Data , Análise de Alimentos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Sequenciamento Completo do Genoma/métodos , Biovigilância , Genoma Bacteriano , Metagenoma , Microbiota/genética , Software
12.
Plant Cell Environ ; 43(10): 2380-2393, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32643169

RESUMO

The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability. We analysed data on maximum photosynthetic capacity (Jmax , Vcmax ), leaf respiration (Rleaf ), leaf mass per area (LMA), leaf thickness and leaf nitrogen and phosphorus concentrations from 66 small trees across 12 common genera at the world's longest running tropical rainfall exclusion experiment and compared responses to those from 61 surviving canopy trees. Small trees increased Jmax , Vcmax , Rleaf and LMA (71, 29, 32, 15% respectively) in response to the drought treatment, but leaf thickness and leaf nutrient concentrations did not change. Small trees were significantly more responsive than large canopy trees to the drought treatment, suggesting greater phenotypic plasticity and resilience to prolonged drought, although differences among taxa were observed. Our results highlight that small tropical trees have greater capacity to respond to ecosystem level changes and have the potential to regenerate resilient forests following future droughts.


Assuntos
Carbono/metabolismo , Árvores/metabolismo , Desidratação , Secas , Florestas , Fotossíntese , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Transpiração Vegetal , Árvores/fisiologia , Clima Tropical
13.
Echocardiography ; 37(2): 293-301, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31957094

RESUMO

BACKGROUND: Fabry disease (FD) is a rare X-linked storage disorder caused by deficiency of the lysosomal enzyme α-galactosidase A, and it typically causes multiorgan dysfunction. The main cause of death is heart disease resulting from left ventricular (LV) diastolic dysfunction, LV systolic dysfunction, severe LV hypertrophy (LVH), and sudden death. In several cardiac disorders, LV systolic dysfunction and ventricular arrhythmias are associated with mechanical dispersion (MD). MD has until now not been studied in patients with FD. OBJECTIVE: To investigate the prevalence of MD in patients with FD. METHODS: Complete echocardiographic data and speckle tracking echocardiographic data were collected. MD is an index of inter-segmental discoordination of contraction and is defined as the standard deviation (SD) of the time-to-peak longitudinal negative strain in 17 LV segments with a value >49 milliseconds. Patients with FD were divided into the following 2 groups: group I (patients with FD but no LVH, n = 64) and group II (patients with FD and LVH, n = 25). These groups were compared with a group of healthy subjects (group III, n = 50). Parametric variables were expressed as mean ± SD, and nonparametric variables were expressed as median and inter-quartile range. A P value <.05 was considered significant. RESULTS: A total of 113 patients with FD were included in this study. Of these, 24 (21%) were excluded because of poor imaging quality or presence of comorbidities, and the final study population consisted of 89 patients (mean age of 33.5 ± 14.5 years, 64% female). Group II patients were older than group I patients (46 ± 13 years vs 27 ± 11 years, P < .0001). There was no difference in LV ejection fraction between the 3 groups. There was also no difference in MD between groups I and III (32.4 ms [26-39] vs 32 ms [26-39]). In group II, the MD in 19 patients (76%) was 56 ms (39-80). CONCLUSIONS: To the best of our knowledge, this is the first study to assess the prevalence of MD in patients with FD. MD was observed in 76% of patients with FD and LVH. The use of MD in strain echocardiography may be beneficial in the assessment of patients with FD who develop heart failure.


Assuntos
Doença de Fabry , Disfunção Ventricular Esquerda , Adulto , Ecocardiografia , Doença de Fabry/complicações , Doença de Fabry/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Função Ventricular Esquerda , Adulto Jovem
14.
Echocardiography ; 37(8): 1205-1212, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32686870

RESUMO

INTRODUCTION: Chagas disease (ChD) is one of the main parasitic diseases in Latin-America. Its heart involvement is the most important cause of death. The aim of this study is to evaluate if Doppler Tissue Imaging (DTI) may have a predictive value for later events in subjects with chronic ChD. METHODS: we analyses DTI variables of 543 patients with chronic ChD for the evaluation of predicting factors of events. Major adverse cardiovascular events (MACE) were considered as stroke, heart failure resistant to treatment, sustained ventricular tachycardia, implantable cardioverter-defibrillator, sudden death, and cardiovascular death. The following findings were also included in total evens: heart failure, bradycardia, ventricular arrhythmia, new conduction system abnormalities, and new echocardiographic abnormalities. Multivariate analysis with logistic regression was used in order to assess the Doppler and DTI parameters predicting events. Variables with a P-value ≤ .5 in the univariate analysis were included in the multivariate analysis. RESULTS: In patients with chronic ChD, the analysis of DTI parameters showed that S' wave and E' wave of the lateral wall of the left ventricle were significant predictors of MACE (OR: 0.83; 95% CI: 0.71-0.96; P-value: .015 and OR: 0.80; 95% CI: 0.66-0.98; P-value: .031, respectively). CONCLUSIONS: This study found that patients with chronic ChD who had events showed significantly lower parameters in the DTI. What is more, this study showed that even lower DTI parameters are significant predictors of events.


Assuntos
Doença de Chagas , Insuficiência Cardíaca , Doença de Chagas/complicações , Doença de Chagas/diagnóstico por imagem , Ecocardiografia , Ventrículos do Coração , Humanos , Ultrassonografia Doppler
15.
Proc Natl Acad Sci U S A ; 114(51): E10937-E10946, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29196525

RESUMO

Our ability to understand and predict the response of ecosystems to a changing environment depends on quantifying vegetation functional diversity. However, representing this diversity at the global scale is challenging. Typically, in Earth system models, characterization of plant diversity has been limited to grouping related species into plant functional types (PFTs), with all trait variation in a PFT collapsed into a single mean value that is applied globally. Using the largest global plant trait database and state of the art Bayesian modeling, we created fine-grained global maps of plant trait distributions that can be applied to Earth system models. Focusing on a set of plant traits closely coupled to photosynthesis and foliar respiration-specific leaf area (SLA) and dry mass-based concentrations of leaf nitrogen ([Formula: see text]) and phosphorus ([Formula: see text]), we characterize how traits vary within and among over 50,000 [Formula: see text]-km cells across the entire vegetated land surface. We do this in several ways-without defining the PFT of each grid cell and using 4 or 14 PFTs; each model's predictions are evaluated against out-of-sample data. This endeavor advances prior trait mapping by generating global maps that preserve variability across scales by using modern Bayesian spatial statistical modeling in combination with a database over three times larger than that in previous analyses. Our maps reveal that the most diverse grid cells possess trait variability close to the range of global PFT means.


Assuntos
Ecossistema , Plantas , Característica Quantitativa Herdável , Meio Ambiente , Geografia , Modelos Estatísticos , Dispersão Vegetal , Análise Espacial
16.
Ecol Lett ; 22(3): 506-517, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30609108

RESUMO

Earth system models (ESMs) use photosynthetic capacity, indexed by the maximum Rubisco carboxylation rate (Vcmax ), to simulate carbon assimilation and typically rely on empirical estimates, including an assumed dependence on leaf nitrogen determined from soil fertility. In contrast, new theory, based on biochemical coordination and co-optimization of carboxylation and water costs for photosynthesis, suggests that optimal Vcmax can be predicted from climate alone, irrespective of soil fertility. Here, we develop this theory and find it captures 64% of observed variability in a global, field-measured Vcmax dataset for C3 plants. Soil fertility indices explained substantially less variation (32%). These results indicate that environmentally regulated biophysical constraints and light availability are the first-order drivers of global photosynthetic capacity. Through acclimation and adaptation, plants efficiently utilize resources at the leaf level, thus maximizing potential resource use for growth and reproduction. Our theory offers a robust strategy for dynamically predicting photosynthetic capacity in ESMs.


Assuntos
Aclimatação , Dióxido de Carbono , Fotossíntese , Adaptação Fisiológica , Nitrogênio , Folhas de Planta , Ribulose-Bifosfato Carboxilase
17.
Nurs Inq ; 26(1): e12260, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30123988

RESUMO

Nursing is possible owing to a series of intricate systemic relations. Building on an established tradition of sociological research, we critically analysed the nursing profession in Chile, with an emphasis on its education system, in the light of social systems theory. The paper's aim was to explore basic characteristics of nursing education as a system, so as to outline its current evolution. Drawing on recent developments in nursing, we applied an empirical framework to identify and discuss functionally differentiated systems that are relevant to nursing and observe communications between them. We found that the dynamics of nursing as a whole develop from communications with closely related systems, including the nursing profession and the education system more broadly. While the discipline (as a system of representations) strives to control the profession (as an applied occupational field), the necessities of practicing nurses imply other forces mediating the making of the profession, a process framed by market dynamics in education and health.


Assuntos
Enfermagem/métodos , Teoria de Sistemas , Chile , Humanos , Pesquisa em Educação em Enfermagem/métodos , Teoria de Enfermagem
18.
Bioinformatics ; 33(18): 2948-2950, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28582480

RESUMO

MOTIVATION: One basic step in many bioinformatics analyses is the multiple sequence alignment. One of the state-of-the-art tools to perform multiple sequence alignment is PASTA (Practical Alignments using SATé and TrAnsitivity). PASTA supports multithreading but it is limited to process datasets on shared memory systems. In this work we introduce PASTASpark, a tool that uses the Big Data engine Apache Spark to boost the performance of the alignment phase of PASTA, which is the most expensive task in terms of time consumption. RESULTS: Speedups up to 10× with respect to single-threaded PASTA were observed, which allows to process an ultra-large dataset of 200 000 sequences within the 24-h limit. AVAILABILITY AND IMPLEMENTATION: PASTASpark is an Open Source tool available at https://github.com/citiususc/pastaspark. CONTACT: josemanuel.abuin@usc.es. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Biologia Computacional/métodos , Alinhamento de Sequência/métodos , Software , Algoritmos
19.
Medicina (B Aires) ; 78(3): 163-170, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-29940542

RESUMO

Congestion in heart failure patients with reduced ejection fraction (HFrEF) is relevant and closely linked to the clinical course. Bedside blood pressure measurement during the Valsalva maneuver (Val) added to clinical examination may improve the assessment of congestion when compared to NT-proBNP levels and left atrial pressure (LAP) estimation by Doppler echocardiography, as surrogate markers of congestion in HFrEF. A clinical examination, LAP and blood tests were performed in 69 HFrEF ambulatory patients with left ventricular ejection fraction ≤ 40% and sinus rhythm. Framingham Heart Failure Score (HFS) was used to evaluate clinical congestion; Val was classified as normal or abnormal, NT-proBNP was classified as low (< 1000 pg/ml) or high (≥ 1000 pg/ml) and the ratio between Doppler early mitral inflow and tissue diastolic velocity was used to estimate LAP and was classified as low (E/e'< 15) or high (E/e' ≥ 15). A total of 69 patients with HFrEF were included; 27 had a HFS ≥ 2 and 13 of them had high NT-proBNP. HFS ≥ 2 had a 62% sensitivity, 70% specificity and a positive likelihood ratio of 2.08 (p=0.01) to detect congestion. When Val was added to clinical examination, the presence of a HFS ≥ 2 and abnormal Val showed a 100% sensitivity, 64% specificity and a positive likelihood ratio of 2.8 (p = 0.0004). Compared with LAP, the presence of HFS = 2 and abnormal Val had 86% sensitivity, 54% specificity and a positive likelihood ratio of 1.86 (p = 0.03). In conclusion, an integrated clinical examination with the addition Valsalva maneuver may improve the assessment of congestion in patients with HFrEF.


Assuntos
Biomarcadores/análise , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico/análise , Fragmentos de Peptídeos/análise , Manobra de Valsalva , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Índice de Gravidade de Doença
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