Chave analítica para determinação de dez variedades de cana-de-açúcar (Saccharum spp.)

Utilizando dados obtidos sobre a atividade de isoenzinias de esterase e peroxidase, o teor de proteína total solúvel e o nível de sólidos solúveis (sacarose, grau Brix, bem como parâmetros organográficos de colmo e folhas já publicados), foi possível elaborar uma chave analítica para determinação de 10 variedades de cana-de-açúcar (Saccharum spp.): NA 56-79, IAC 52-150, IAC 64-257, SP 70-1143, SP 71-3146, SP 71-3149. SP 71-1406. SP 71-6163, SP 71-6168 e SP 71-799.Using the data on organographic and biochemical parameter (isoenzymes, total soluble protein and Brix values) characterization, it was possible to establish mi analytical key to taxonomicaly classify the following sugarcane (Saccharum spp.) varieties: NA 56-79, IAC 52-150, IAC 64-257, SP 70-1143, SP 71-3146, SP 71-3149, SP 71-1406, SP 71-6163, SP 71-6168 and SP 71-799

Efeito da temperatura na germinação de sementes de vigna, feijoeiro e soja

This experiment was carried out to study the effects of the temperatures of 14, 21 and 28°C on germination of three cultivars of Vigna unguiculata, Phaseolus vulgaris and Glycine max. The seeds where germinated on Petri dishes provided with cotton and filter paper, maintained in incubator with high humidity. The Petri dishes were maintained under controlled temperature conditions. Higher germination was observed at 21°C in relation to temperatures of 14 and 28°C, for Vigna, bean and soybean cultivars. Best germination were showed by 'Carioca' and 'Goiano Precoce' beans,followed by 'Rosinha' bean, 'EPACE 1' Vigna and 'Davis' soybean at 21°C. Vigna cultivars adapted to high temperatures presented problems for germination at 14°C. Normaly velocity of hypocotyl emergence was lower tham velocity of radicle emergence.Estudou-se em condições controladas, o efeito das temperaturas de 14, 21 e 28°C na germinação de três cultivares de Vigna unguiculata, Phaseolus vulgaris e Glycine max. As sementes foram acondicionadas em placas de Petri com algodão e papel de filtro , mantidos sob alta umidade. Maior germinação foi observada a 21°C em relação as temperaturas de 14 e 28°C, para os cultivares de vigna, feijoeiro e soja. Melhor germinação foi apresentada pelos cultivares de feijoeiro Carioca e Goiano Precoce, seguidos pelo feijoeiro 'Rosinha' , vigna ' EPACE 1' e soja 'Davis' a 21ºC. Os cultivares de vigna, adaptados a altas temperaturas, apresentaram problemas na germinação a 14ºC. Normalmente a velocidade de emergência do hipocólito revelou-se inferior a velocidade de emergência da radícula

DETERMINAÇÃO COMPLEXOMÉTRICA DOS ÍONS ZINCO COM DITIZONA NO SISTEMA DE SOLVENTES ÁGUA-ETANOL-CLOROFÓRMIO

Elementos traço vêm despertando grande interesse quanto a sua determinação devido ao seu aspecto de essencialidade ou toxicidade para os seres vivos. Diferentes setores da sociedade utilizam a análise de elementos traço na elucidação de problemas, por exemplo, a criminalística, a toxicologia, o meio ambiente, a medicina do trabalho e os estudos de nutrição. O zinco é considerado um elemento com aspectos essencial e tóxico, desta forma, torna-se justificável sua determinação e desenvolvimento de métodos para tanto.Propõe-se neste trabalho o emprego de soluções fase única que proporcione o meio de reação e formação do complexo de zinco com ditizona e sua determinação espectrofotométrica no sistema água-etanol-clorofórmioem λ = 517nm. O estudo revelou que é possível determinar zinco em diversas amostras, desde que os valores estejam numa faixa linear de 2,0 a 6,0 mg L-1. A curva analítica para a determinação de zinco(II) apresenta-se caracterizada porΔAbs = 0,0673 CZn+2 + 0,0015 (R2 =0,9997) com LD= 0,002 mg L-1 e LQ=0,058 mg L-1 de zinco(II) na porção aquosa da fase única.

Highly potent anti-leishmanial derivatives of hederagenin, a triperpenoid from Sapindus saponaria L.

Leishmaniasis is a neglected tropical disease (NTDs), endemic in 88 countries that affect more than 12 million people. Current drugs are limited due to their toxicity, development of biological resistance, length of treatment and high cost. Thus, the search for new effective and less toxic treatments is an urgent need. In this study, we report the synthesis of 3 new amide derivatives of hederagenin (22–24) with yields between 70% and 90%, along with 57 other derivatives of hederagenin (1–21, 25–60) carrying different groups at C-28 previously reported by our group, and the results of their in vitro ability to inhibit the growth of Leishmania infantum. Some derivatives (3, 4, 44, 49 and 52), showed activity at micromolar level and low toxicity against BGM and HepG2 cells. Moreover, the ability of hederagenin derivatives 3 (IC50 = 9.7 μM), 4 (12 μM), 44 (11 μM) and 49 (2 μM), to prevent proliferation of intracellular amastigote forms of L. infantum and their higher selectivity index and low toxicity compared to commercial positive drug control of choice (potassium antimonyl tartrate trihydrate) (IC50 = 80 μM, SI = 0.1), make these compounds promising candidates for the treatment of leishmaniasis

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta