74 research outputs found

    Dormência vegetativa da nogueira-pecã – Uma revisão

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    Pecan is a fruit tree that needs low temperatures in the winter, so that it can induce and overcome dormancy and reestablish a new cycle of productive development. Through this review, the producer will be able to have reliable information on the climatic requirement of the crop, in order to support his decision making on management practices that reduce the damage caused by these phenomena and serve to optimize the production system, improving his profits. In view of this, it becomes propitious to provide information about the crop with a focus on the cold demand required to overcome the dormancy of pecan cultivars. It was possible to verify the divergence between the authors in relation to the need for cold for pecan and the need for more tests about the products used to induce sprouting in pecan.A nogueira-pecã é uma frutífera que necessita de baixas temperaturas no período hibernal para que possa induzir e superar a dormência, restabelecendo assim um novo ciclo de desenvolvimento produtivo. Através desta revisão, o produtor poderá ter informações confiáveis da exigência climática da cultura, a fim de respaldar sua tomada de decisão sobre práticas de gestão que reduzam os danos causados por esses fenômenos e sirvam para otimizar o sistema de produção, melhorando seus lucros. Em vista disso, torna-se propício adaptar informações sobre a cultura com foco na exigência em frio hibernal necessária para a superação da dormência dos cultivares de nogueira-pecã. Pôde-se constatar a divergência entre os autores em relação à necessidade de frio para a nogueira-pecã, bem como a necessidade de mais trabalhos no que se refere aos produtos utilizados para induzir a brotação na nogueira-pecã

    Chips de papa, la fritura en vacío y beneficios para la salud = Potatoes chips, vacuum frying and health profits

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    Existe una tendencia del mercado al consumo de alimentos más saludables que ha motivado a la industria alimentaria a innovar en tecnologías. La fritura en vacío es una tecnología alternativa a la fritura tradicional que preserva las propiedades sensoriales del snack frito y mejora la calidad nutricional. El objetivo del trabajo fue estudiar los beneficios nutricionales y para la salud y las características organolépticas de chips de papa elaborados por fritura en vacío en relación a los elaborados por fritura tradicional y diferenciarlos de los actualmente presentes en el mercado uruguayo. Los chips elaborados por fritura en vacío presentaron un 61% menos de materia grasa y 90% menos de acrilamida que los chips elaborados por fritura tradicional. Sensorialmente fueron muy bien evaluados en todos los atributos menos en la percepción de intensidad de sabor salado

    Mixing and matching siderophore clusters: structure and biosynthesis of serratiochelins from Serratia sp. v4

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    Studying the evolutionary history underlying the remarkable structures and biological activities of natural products has been complicated by not knowing the functions they have evolved to fulfill. Siderophores - soluble, low molecular weight compounds - have an easily understood and measured function: acquiring iron from the environment. Bacteria engage in a fierce competition for acquiring iron, which rewards the production of siderophores that bind iron tightly and cannot be used or pirated by competitors. The structures and biosyntheses of 'odd' siderophores can reveal the evolutionary strategy that led to their creation. Here, we here report a new Serratia strain that produces serratiochelin and an analog of serratiochelin. A genetic approach located the serratiochelin gene cluster, and targeted mutations in several genes implicated in serratiochelin biosynthesis were generated. Bioinformatic analyses and mutagenesis results demonstrate that genes from two well known siderophore clusters, the Escherichia coli enterobactin cluster and the Vibrio cholerae vibriobactin cluster, were shuffled to produce a new siderophore biosynthetic pathway. These results highlight how modular siderophore gene clusters can be mixed and matched during evolution to generate structural diversity in siderophores.This work was supported by the National Institutes of Health (Grants GM82137 to R.K., and AI057159 and GM086258 to J.C.). M.R.S. acknowledges support from the NIH Pathway to Independence Award (Grant 1K99 GM098299-01). S.C. and M.J.V. acknowledge support from the Portuguese Foundation for Science and Technology (PhD Grant SFRH/BD/38298/2007 to S.C.; Project PTDC/EBB-EBI/104263/2008 to M.J.V.)

    Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

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    BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction

    Outcomes of Mechanical Thrombectomy for Patients With Stroke Presenting With Low Alberta Stroke Program Early Computed Tomography Score in the Early and Extended Window

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    Importance: Limited data are available about the outcomes of mechanical thrombectomy (MT) for real-world patients with stroke presenting with a large core infarct. Objective: To investigate the safety and effectiveness of MT for patients with large vessel occlusion and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of 2 to 5. Design, setting, and participants: This retrospective cohort study used data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combines the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia. The study included 2345 patients presenting with an occlusion in the internal carotid artery or M1 segment of the middle cerebral artery from January 1, 2016, to December 31, 2020. Patients were followed up for 90 days after intervention. The ASPECTS is a 10-point scoring system based on the extent of early ischemic changes on the baseline noncontrasted computed tomography scan, with a score of 10 indicating normal and a score of 0 indicating ischemic changes in all of the regions included in the score. Exposure: All patients underwent MT in one of the included centers. Main outcomes and measures: A multivariable regression model was used to assess factors associated with a favorable 90-day outcome (modified Rankin Scale score of 0-2), including interaction terms between an ASPECTS of 2 to 5 and receiving MT in the extended window (6-24 hours from symptom onset). Results: A total of 2345 patients who underwent MT were included (1175 women [50.1%]; median age, 72 years [IQR, 60-80 years]; 2132 patients [90.9%] had an ASPECTS of ≥6, and 213 patients [9.1%] had an ASPECTS of 2-5). At 90 days, 47 of the 213 patients (22.1%) with an ASPECTS of 2 to 5 had a modified Rankin Scale score of 0 to 2 (25.6% [45 of 176] of patients who underwent successful recanalization [modified Thrombolysis in Cerebral Ischemia score ≥2B] vs 5.4% [2 of 37] of patients who underwent unsuccessful recanalization; P = .007). Having a low ASPECTS (odds ratio, 0.60; 95% CI, 0.38-0.85; P = .002) and presenting in the extended window (odds ratio, 0.69; 95% CI, 0.55-0.88; P = .001) were associated with worse 90-day outcome after controlling for potential confounders, without significant interaction between these 2 factors (P = .64). Conclusions and relevance: In this cohort study, more than 1 in 5 patients presenting with an ASPECTS of 2 to 5 achieved 90-day functional independence after MT. A favorable outcome was nearly 5 times more likely for patients with low ASPECTS who had successful recanalization. The association of a low ASPECTS with 90-day outcomes did not differ for patients presenting in the early vs extended MT window

    Association of Noncontrast Computed Tomography and Perfusion Modalities With Outcomes in Patients Undergoing Late-Window Stroke Thrombectomy

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    Importance: There is substantial controversy with regards to the adequacy and use of noncontrast head computed tomography (NCCT) for late-window acute ischemic stroke in selecting candidates for mechanical thrombectomy. Objective: To assess clinical outcomes of patients with acute ischemic stroke presenting in the late window who underwent mechanical thrombectomy stratified by NCCT admission in comparison with selection by CT perfusion (CTP) and diffusion-weighted imaging (DWI). Design, setting, and participants: In this multicenter retrospective cohort study, prospectively maintained Stroke Thrombectomy and Aneurysm (STAR) database was used by selecting patients within the late window of acute ischemic stroke and emergent large vessel occlusion from 2013 to 2021. Patients were selected by NCCT, CTP, and DWI. Admission Alberta Stroke Program Early CT Score (ASPECTS) as well as confounding variables were adjusted. Follow-up duration was 90 days. Data were analyzed from November 2021 to March 2022. Exposures: Selection by NCCT, CTP, or DWI. Main outcomes and measures: Primary outcome was functional independence (modified Rankin scale 0-2) at 90 days. Results: Among 3356 patients, 733 underwent late-window mechanical thrombectomy. The median (IQR) age was 69 (58-80) years, 392 (53.5%) were female, and 449 (65.1%) were White. A total of 419 were selected with NCCT, 280 with CTP, and 34 with DWI. Mean (IQR) admission ASPECTS were comparable among groups (NCCT, 8 [7-9]; CTP, 8 [7-9]; DWI 8, [7-9]; P = .37). There was no difference in the 90-day rate of functional independence (aOR, 1.00; 95% CI, 0.59-1.71; P = .99) after adjusting for confounders. Symptomatic intracerebral hemorrhage (NCCT, 34 [8.6%]; CTP, 37 [13.5%]; DWI, 3 [9.1%]; P = .12) and mortality (NCCT, 78 [27.4%]; CTP, 38 [21.1%]; DWI, 7 [29.2%]; P = .29) were similar among groups. Conclusions and relevance: In this cohort study, comparable outcomes were observed in patients in the late window irrespective of neuroimaging selection criteria. Admission NCCT scan may triage emergent large vessel occlusion in the late window

    Efeitos de fontes de pólen na qualidade de castanhas produzidas por cultivares de noz-pecã Kiowa e Barton

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    Selection of pecan cultivars and their pollinizers is essential to reach maximum potential of production. Synchrony of blooming periods of cultivars may not be enough to ensure nut quality because of the xenia effect. This study aimed at evaluating effects of different pollinizers on dimensions and yields of fruit borne by cultivars Kiowa and Barton. Both cultivars were submitted to six treatments. Kiowa: no pollination, free pollination, self-pollination and pollination controlled by pollen from cultivars Cape Fear, Pawnee and Desirable. Barton: no pollination, free pollination, self-pollination and pollination controlled by pollen from cultivars Melhorada, Jackson and Success. Self-pollination decreased dimensions and yields of fruit and kernels. Pollen from different cultivars was found to exhibit positive and negative xenia effect on fruit characteristics. The largest fruit and the highest yield of kernels were reached when ‘Kiowa’ was pollinized with ‘Desirable’ and ‘Barton’ was pollinized with ‘Success’.A seleção de cultivares de noz-pecã e seus polinizadores é essencial para atingir o máximo potencial de produção. A sincronia dos períodos de floração das cultivares pode não ser suficiente para garantir a qualidade da castanha devido ao efeito xenia. O objetivo deste trabalho foi avaliar os efeitos de diferentes polinizadores nas dimensões e produtividade dos frutos das cultivares Kiowa e Barton. Ambas as cultivares foram submetidas a seis tratamentos. Kiowa: sem polinização, polinização livre, autopolinização e polinização controlada por pólen das cultivares Cape Fear, Pawnee e Desmable. Barton: sem polinização, polinização livre, autopolinização e polinização controlada por pólen das cultivares Melhorada, Jackson e Success. A autopolinização diminuiu as dimensões e a produção de frutos e grãos. Pólen de diferentes cultivares exibiu efeito xenia positivo e negativo sobre as características dos frutos. O maior fruto e a maior produção de grãos foram alcançados quando 'Kiowa' foi polinizado com 'Desejável' e 'Barton' foi polinizado com 'Sucesso'.                &nbsp
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