Leaf structure of curaua in different intensities of photosynthetically active radiation

O objetivo deste trabalho foi caracterizar a anatomia foliar de Ananas comosus var. erectifolius e comparar as características anatômicas de suas fibras foliares, quando submetidas a dois índices de radiação fotossinteticamente ativa (54 e 100%). Para a análise das estruturas anatômicas, especialmente as fibras, foram utilizadas técnicas de dissociação da epiderme foliar, contagem do número de estômatos por milímetro quadrado, cortes histológicos e microscopia eletrônica de varredura no material botânico fixado. A epiderme estava revestida por cutícula espessa e bem desenvolvida nas folhas nos dois índices de radiação. Nas folhas a 100% de radiação fotossinteticamente ativa, foi observado aumento de espessura nas regiões apical e basal. Foram observadas diferenças no número de camadas e altura do parênquima paliçádico e na quantidade de feixes fibrosos relativas aos índices de radiação. A quantidade de feixes fibrosos foi maior na condição de 54% do que em 100% de radiação fotossinteticamente ativa.The aim of this work was to characterize the leaf anatomy of Ananas comosus var. erectifolius and to compare the anatomical characterists of its leaf fibres, when submitted to two levels of photosynthetically active radiation (54 and 100%). For the analysis of the anatomical structures, specially the fibres, the settled botanical material was submitted to techniques of dissociation of the foliar epidermis, microscopic number of stomata per square millimeter, cuts and scanning electron microscopy. The epidermis was coated for thick cuticle and developed well in leaves in the two intensity indexes of radiation. For leaves at 100% PAR a fast increase of thickness was observed in the apical and basal regions. Regarding the radiation levels, differences were observed in the number of layers, the height of palisade parenchyma, and in the amount of fibre beams. The amount of fibre beams was bigger at 54% than at 100% PAR

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Caracterização estrutural e farmacognóstica dos órgãos vegetativos aéreos de três espécies de piper l. (piperaceae): parâmetros de autenticidade e de grau de pureza para o controle de qualidade

The purpose this study was to establish authenticity and purity degree parameters for the quality control of Piper arboreum Aubl. var. arboreum, P. callosum Ruiz & Pav. and P. tuberculatum Jacq leaves and stem, plant species of large ethno-medicinal usage, currently being traded as traditional phytotherapeutic products, and with chemical and pharmacological potential to become phytomedicines. Fertile samples of the three Piper species were collected in Belém and Manaus states. The samples were processed and analyzed according to standard methods for light and scanning electron microscopies, histochemistry, energy-dispersive X-ray spectroscopic microanalyses, inductively coupled plasma optical emission spectrometry, and physicochemical determinations, such as moisture, pH, loss on drying, and total, sulphated and acid-insoluble ash. Size, shape, color, texture, fracture surface and transection characteristics, and leaf venation patterns are macroscopic morpho-diagnostic characters to identify the herbal drugs of the studied Piper species when they are not ground or powdered. Leaf callosus emergences in P. callosum and leaf and stem glandular emergences in P. tuberculatum are key-characters to identify the whole herbal drugs of both species. Since medicinal plants and herbal drugs do not differ anatomically, the following characters for the studied Piper species can be used for microscopic morpho-diagnosis purposes of both types raw plant materials: crystal macropatterns; epicuticular wax and cuticular flanges patterns; type and position of the collenchyma; arrangement pattern of the vascular bundles of the petiole; shape in transection of the midrib, leaf margin, petiole, and stem. In addition to these characters are: the occurrence of fibers immediately beneath the epidermis, and arrangement pattern of the vascular bundles in the midrib as well as starch grain morphology in P. callosum; the types of cuticular ornamentation and non-glandular trichomes, arrangement pattern of the stem vascular bundles, and type of hilum of the starch grains in P. arboreum var. arboreum and P. tuberculatum. Acid lipids, essential oils, mixture of essentials and resins, steroids, tannins, and flavonoids are common metabolic compounds for the three Piper species. Terpenoids with carbonyl group and alkaloids were identified only in P. arboreum var. arboreum and P. tuberculatum, respectively. Oleoresins were detected in P. callosum and P. tuberculatum. The moisture, volatile, and total, sulphated and acid-insoluble ash values of the herbals drugs of these species are within the permissible limits. In general, these values were higher in the leaf herbal drugs than in the stem herbal drugs. The metal levels analyzed (aluminum, cadmium, cobalt, chromium, copper, manganese, molybdenum, nickel, lead, tin, vanadium, mercury and arsenic) in the herbal drugs of the studied Piper species are below the toxic levels for human health. The highest metal levels were of aluminum, copper, manganese and vanadium. The structural and pharmacognostical characteristics reported herein for first time for Piper arboreum var. arboreum, P. callosum, and P. tuberculatum should be used as safe parameters of authenticity and purity degree for the quality control of the raw plant materials (i.e. medicinal plants and herbal drugs) of these species.O objetivo deste estudo foi estabelecer parâmetros de autenticidade e de grau de pureza para o controle de qualidade das folhas e do caule de Piper arboreum Aubl. var. arboreum, P. callosum Ruiz & Pav. e P. tuberculatum Jacq., espécies vegetais de ampla utilização etnomedicinal, comercializadas como produtos tradicionais fitoterápicos e com potencial químico e farmacológico para tornarem-se fitomedicamentos. Para tanto, amostras de indivíduos férteis das três espécies foram coletadas em Manaus e Belém, processadas e analisadas segundo protocolos padrões para microscopias de luz e eletrônica de varredura, histoquímica, microanálises de Raios-X por dispersão de energia, espectrometria de emissão ótica com plasma indutivamente acoplado e determinações físico-químicas de umidade, perda por dessecação, pH e cinzas totais, sulfatadas e ácido-insolúveis. Aspectos como dimensões, forma, cor, sabor, textura, características da superfície de fratura e da secção transversal e padrões de venação foliar são caracteres morfodiagnósticos macroscópicos para as drogas vegetais íntegras das espécies de Piper estudadas. Emergências calosas foliares em P. callosum, assim como emergências glandulares foliares e caulinares em P. tuberculatum são caracteres-chave à identificação macroscópica das drogas vegetais dessas espécies. Os macropadrões cristalinos, os padrões de cera epicuticular e de flanges cuticulares, o tipo e posição do colênquima, o padrão de organização dos feixes vasculares peciolares e a forma em secção transversal da nervura central, margem foliar, pecíolo e caule são caracteres morfodiagnósticos microscópicos tanto para as plantas medicinais como para as drogas vegetais das três espécies, pois ambas as matérias-primas vegetais não diferiram anatomicamente. A esses caracteres somam-se a presença de fibras subjacentes à epiderme e o padrão de organização dos feixes vasculares na nervura central, bem como a morfologia dos grãos de amido em P. callosum; os tipos de ornamentação cuticular e de tricomas tectores, o padrão de organização dos feixes vasculares caulinares e o tipo de hilo dos grãos de amido em P. arboreum var. arboreum e P. tuberculatum. Lipídios ácidos, óleos essenciais, mistura de essências e resinas, esteroides, taninos e flavonoides são comuns às três espécies. Terpenoides com grupo carbonila e alcaloides foram identificados apenas em P. arboreum var. arboreum e P. tuberculatum respectivamente. Óleos-resina foram detectados em P. callosum e P. tuberculatum. Os valores dos teores de umidade e voláteis e de cinzais totais, sulfatadas e ácido-insolúveis das drogas vegetais das espécies estudadas estão dentro dos limites permitidos e, geralmente, foram maiores nas drogas vegetais foliares que nas caulinares. As concentrações dos metais analisados (alumínio, cádmio, cobalto, cromo, cobre, manganês, molibdênio, níquel, chumbo, titânio, vanádio, mercúrio e arsênio) nas drogas vegetais das três espécies estão abaixo dos níveis considerados tóxicos à saúde humana. Dentre esses metais, alumínio, cobre, manganês e vanádio tiveram as maiores concentrações. O presente estudo relatou pela primeira vez as características estruturais e farmacognósticas dos órgãos vegetativos aéreos de Piper arboreum var. arboreum, P. callosum e P. tuberculatum, que devem ser utilizadas como parâmetros seguros de autenticidade e de grau de pureza para o controle de qualidade das matérias-primas vegetais, planta medicinal e droga vegetal, dessas espécies

Substâncias ergásticas foliares de espécies amazônicas de Oenocarpus Mart. (Arecaceae): caracterização histoquímica e ultra-estrutural Leaf ergastic substances of Amazonian species of Oenocarpus Mart. (Arecaceae): histochemical and ultrastructural characterization

O presente estudo teve por objetivo diagnosticar e caracterizar as substâncias ergásticas foliares de Oenocarpus bacaba Mart., O. distichus Mart., O. mapora H. Karst. e O. minor Mart. através de microscopias óptica e eletrônica de varredura, análises histoquímicas e microanálises físicas. Secções transversais e longitudinais, assim como maceração foram realizadas em material botânico fixado. As análises histoquímicas foram empregadas em material botânico in natura, seguindo-se protocolos específicos para mucilagem, amido e sílica. Microanálises físicas foram feitas com Energy Dispersive Spectroscopy (EDS) detector. Nas espécies estudadas de Oenocarpus Mart., as substâncias ergásticas foliares correspondem a mucilagem amorfa; grãos de amido poliédricos do tipo simples e sílica opalina sob a forma de corpos elípticos e esféricos-globosos de superfície espiculada, ambos com elevado teor de dióxido de silício. As observações microscópicas, os testes histoquímicos e as microanálises físicas permitiram diagnosticar, caracterizar e elucidar a estrutura e ultra-estrutura das substâncias ergásticas ocorrentes nas folhas dos táxons analisados de Oenocarpus Mart.The purpose of this study was to diagnose and characterize the leaf ergastic substance of Oenocarpus bacaba Mart., O. distichus Mart., O. mapora H. Karst. and O. minor Mart. by light and scanning electron microscopy, histochemical analyses and physical microanalyses. Transverse and longitudinal sections as well as maceration were made in fixed botanical material. The histochemical analyses were made in non-fixed botanical material, using specific tests for mucilage, starch and silica. An Energy Dispersive Spectroscopy (EDS) detector was used for the physical microanalyses. In the Oenocarpus Mart. species studied, the leaf ergastic substances corresponded to amorphous mucilage, simple-type polyhedrical starch grain and opaline silica in the shape of elliptical and spherical, globular of pointed surface bodies, both with silicon dioxide in the correct concentration. The microscopic observations, histochemical analyses and physical microanalyses permitted us to diagnose, characterize and elucidate the structure and ultrastructure of the ergastic substances occurring in the leaves of the analyzed Oenocarpus Mart. taxa