Antimicrobial activity of the essential oils from the leaves and stems of Amomum rubidum Lamxay & N. S. Lý / Actividad antimicrobiana de los aceites esenciales de las hojas y tallos de Amomum rubidum Lamxay & N. S. Lý

This paper described the chemical compositions and antimicrobial activity of the essential oils from the leaves and stem of Amomum rubidumLamxay & N. S. Lý, collected from Bidoup Nui Ba National Park, Lam Dong, Vietnam. The essential oils were obtained by hydrodisitllation method while antimicrobial activity was evaluetd by microdilution broth susceptibility assay. The main constituents of the leaf essential oil were identified as 1,8-cineole (37.7%), δ-3-carene (19.5%) and limonene (16.3%) while δ-3-carene (21.9%), limonene (17.8%) and ß-phellandrene (14.6%) dominated in the stem essentialoil. The leaf and stem essential oils displayed stronger inhibition of Pseudomonas aeruginosa with MIC of 25 µg/mLand 50 µg/mL respectively. The stem essential oil was active against Candida albicans (MIC, 50 µg/mL) while both essential oils inhibited the growth of Fusarium oxysporum (MIC 50 µg/mL). This is the first report on chemical constituents and antimicrobial activity of the essential oils of A. rubidum.

Este artículo describe la composición química y la actividad antimicrobiana de aceites esenciales de las hojas y el tallo de Amomum rubidum Lamxay & N. S. Lý recolectados del Parque Nacional Bidoup Nui Ba, Lam Dong, Vietnam. Los aceites esenciales se obtuvieron mediante el método de hidrodisitilación, mientras que la actividad antimicrobiana se evaluó mediante un ensayo de susceptibilidad de caldo de microdilución. Los principales componentes del aceite esencial de la hoja se identificaron como 1,8-cineol (37,7%), δ-3-careno (19,5%) y limoneno (16,3%), mientras que δ-3-careno (21,9%), limoneno (17,8 %) y ß-felandreno (14,6%) dominaron en el aceite esencial del tallo. Los aceites esenciales de hoja y tallo mostraron una inhibición más fuerte de Pseudomonas aeruginosa con un MIC de 25 µg/mL y 50 µg/mL, respectivamente. El aceite esencial del tallo fue activo contra Candida albicans (MIC, 50 µg/mL) mientras que ambos aceites esenciales inhibieron el crecimiento de Fusarium oxysporum (MIC 50 µg/mL). Este es el primer informe sobre los componentes químicos y la actividad antimicrobiana de los aceites esenciales de A. rubidum.

Spontaneous enanti-omorphism in poly-phased alkaline salts of tris-(oxalato)ferrate(III): crystal structure of cubic NaRb5[Fe(C2O4)3]2.

We show here that the phenomenon of spontaneous resolution of enanti-omers occurs during the crystallization of the sodium and rubidium double salts of the transition metal complex tris-(oxalato)ferrate(III), namely sodium penta-rubidium bis-[tris-(oxalato)ferrate(III)], NaRb5[Fe(C2O4)3]2. One enanti-omer of the salt crystallizes in the cubic space group P4332 with Z = 4 and a Flack absolute structure parameter x = -0.01 (1) and its chiral counterpart in the space group P4132 with x = -0.00 (1). All metal ions are at crystallographic special positions: the iron(III) ion is on a threefold axis, coordinated by three oxalate dianions in a propeller-like conformation. One of the two independent rubidium ions is on a twofold axis in an eightfold coordination with neighbouring oxalate oxygen atoms, and the other one on a threefold axis in a sixfold RbO6 coordination. The sodium ion is at a site of D3 point group symmetry in a trigonal-anti-prismatic NaO6 coordination.

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

OBJECTIVES: Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (82RbPET) MPI. Thus, this study aimed to evaluate agreement between 82RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. METHODS: Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. RESULTS: There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). CONCLUSIONS: There was a significant agreement between dipyridamole stress 320-CT MPI and 82RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. KEY POINTS: • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Foliar application of microbial and plant based biostimulants increases growth and potassium uptake in almond (Prunus dulcis [Mill.] D. A. Webb).

The use of biostimulants has become a common practice in agriculture. However, there is little peer-reviewed research on this topic. In this study we tested, under controlled and replicated conditions, the effect of one biostimulant derived from seaweed extraction (Bio-1) and another biostimulant derived from microbial fermentation (Bio-2). This experiment utilized 2-years-old almond plants over two growing seasons in a randomized complete design with a full 2 × 4 factorial structure with two soil potassium treatments (125 µg g(-1) of K vs. 5 µg g(-1)) and four foliar treatments (No spray, Foliar-K, Bio-1, Bio-2). Rubidium was utilized as a surrogate for short-term potassium uptake and plant growth, nutrient concentration, and final plant biomass were evaluated. There was a substantial positive effect of both biostimulant treatments on total shoot leaf area, and significant increases in shoot length and biomass under adequate soil potassium supply with a positive effect of Bio-1 only under low K supply. Rubidium uptake was increased by Bio-1 application an effect that was greater under the low soil K treatment. Though significant beneficial effects of the biostimulants used on plant growth were observed, it is not possible to determine the mode of action of these materials. The results presented here illustrate the promise and complexity of research involving biostimulants.

Studies on mineral nutrition of the coffee plant (Coffea arabica L. cv. Catuaí Vermelho): LXIV. Remobilization and re-utilization of nitrogen and potassium by normal and deficient plants

Remobilization and re-utilization of 15N and 85Rb labelled nitrogen and potassium reserves for new growth and fruit formation was studied under greenhouse conditions using both normal and deficient young coffee plants. It was found that K reserves are used in higher proportion than is stored N by fruits and other organs. The export of N by organs of residence in the normal plants obeyed the following proportions of the total: leaves 47%-58%, branches and flower buds 21%-27%, roots 21%-32%. The corresponding figures in the case of deficient plants were: leaves 49%-65%, branches and flower buds 21%-27%, roots 14%-25%. Re-utilization of K took place in the following proportions in the normal plants: leaves 54%-64%, branches and flower buds 20%-21%, roots 30%-41%. In K deficient plants the figures were: leaves 62%-79%, branches and flower buds 1.2%-4.4%, roots 20%-33%. In tissues formed after the initiation of flowering buds, the demand for N is met by reserves as follows: normal plants: fruits 20.6%-24.8%, leaves 15.6%-19.4%, twigs 19%-20.5%; deficient plants: fruits 43.5%-48.5%, leaves 48.1%-51.9%, twigs 46%-53%. The K needs for new tissues are met in the order: normal plants: fruits 40%-45.8%, leaves 27%-37.6%, twigs 26%-33.1%; deficient plants: fruits 65.7%-81.5%, leaves 52.6%-68.4%, twigs 62%-86.1%. Fruits represent the main sink for both N and K. Re-utilization of both elements is higher in the case of deficient plants.

A remobilização do N (15N) e do K (85Rb) de reserva e seu uso pelas diferentes partes do cafeeiro (Coffea arabica cv. Catuaí Vermelho) no período reprodutivo, particularmente pelos frutos, foram estudados sob condições normais e de carência de N ou K. O K de reserva, comparado ao N de reserva, é utilizado em maior proporção pelos frutos e demais órgãos do cafeeiro. A exportação do N pelos órgãos de reserva foi a seguinte: plantas normais - folhas (47%-58%); ramos + gemas florais (20%-21%); raízes (21%-32%). Plantas deficientes - folhas (49%-65%); ramos + gemas florais (21%-27%); raízes (14%-25%). A remobilização do K de reserva ocorreu na seguinte proporção: plantas normais - folhas (54%-64%); ramos + gemas florais (20%-21%); raízes (30%-41%). Plantas deficientes - folhas (62%-79%); ramos + gemas florais (1,2%-4,4%); raízes (20%-33%). Em tecidos lançados após a iniciação da gema floral, a demanda por N é coberta pelas reservas do cafeeiro com o seguinte porcentual: plantas normais - frutos (20,6%-24,8%), folhas (15,6%-19,4%), ramos (19,0%-20,5%); plantas deficientes: frutos (43,5%-48,5%); folhas (48,1%-51,9%); ramos (46,0%-53,0%). Para o K em plantas normais: frutos (40,0%-45,8%), folhas (27,0%-37,6%), ramos (26%-33,1%); plantas deficientes: frutos (65,7%-81,5%); folhas (52,6%-68,4%); ramos (62,0%-86,1%).