Comparative study on myelotoxic and antineoplastic action of Synadenium umbellatum, Vitis vinifera and Resveratrol

Cancer is one of the pathologies that most challenge medicine, not only because of the complexity of its development, but also because of the difficulty of treatment that is not always effective. Due to the significant toxicity and adverse effects profile presented by the main chemotherapeutic agents used to treat neoplasm, there is a constant interest in the search for new drugs that may be a more effective alternative. Therefore, the search for new compounds of plant origin becomes an interesting tool for the discovery of drugs with antitumor activity. Synadenium umbellatum is a plant native to tropical Africa known as “cola-nota”, “hazel”, “cancerous”, “miraculous”, among others. The plant is used by the Brazilian population as having anti-inflammatory, analgesic, antineoplastic properties, among others. However, the literature is lacking on reports of the toxicity of Synadenium umbellatum macerate. Resveratrol is a polyphenolic compound found in different plant species, mainly in grape species (Vitis) and their seeds. Vitis vinifera is a species of grape easily found in several regions, also containing a high concentrations of phenolic compounds, including resveratrol in its fruits, leaves and seeds. Therefore, this study was aimed to evaluate the myelotoxicity of macerate, extract and resveratrol and their antitumor activity in Balb/c mice with Ehrlich tumor. The hematological evaluation was obtained by flow cytometry and the tumors were measured using a pachymeter and the tumor masses by means of weighing. No statistically significant difference was observed between results from the control group and the treatment groups. It was concluded that macerate, crude extract and resveratrol did not demonstrate a myelotoxic effect and did not cause a decrease in tumor mass1928086sem informaçã

Variação do teor de nitrogênio em ramos produtivos de caquizeiro.

O objetivo deste trabalho foi avaliar a resposta do caquizeiro (Diospyros kaki L.) à adubação nitrogenada. O experimento foi conduzido em um pomar comercial no município de Faxinal, Estado do Paraná, nas coordenadas geográfcas S 23º 57' 35", W51º 13' 34", altitude de 999 metros. A cultivar estudada foi "Giombo". Utilizou-se de 9 tratamentos, sendo uma testemunha sem aplicação de nitrogênio (N), e os demais resultante das épocas de aplicação de N (Maturação fisiológica dos frutos, início de poda, final de florescimento e em 15-12-06), combinadas com duas doses de N (80 e 160 kg/ha). O delineamento experimental foi o de blocos casualizados e 4 repetições. A parcela experimental foi constituída de 3 plantas, sendo a planta central usada para avaliação. A cada quarenta e cinco dias após o início da adubação, foram retirados aleatoriamente de cada tratamento oito ramos produtivos em diferentes pontos da planta. Na folha, os tratamentos IP e MF apresentaram os maiores teores de N na primavera e no verão, e uma diminuição significativa na fase final do ciclo antes da senescência e queda. Na folha e no ramo, todos os tratamentos resultaram em teor de N semelhante no final do ciclo. A época de aplicação, início de poda, foi a época que demonstrou menor variação de N, independentemente da dose

Debris disk size distributions: steady state collisional evolution with P-R drag and other loss processes

We present a new scheme for determining the shape of the size distribution, and its evolution, for collisional cascades of planetesimals undergoing destructive collisions and loss processes like Poynting-Robertson drag. The scheme treats the steady state portion of the cascade by equating mass loss and gain in each size bin; the smallest particles are expected to reach steady state on their collision timescale, while larger particles retain their primordial distribution. For collision-dominated disks, steady state means that mass loss rates in logarithmic size bins are independent of size. This prescription reproduces the expected two phase size distribution, with ripples above the blow-out size, and above the transition to gravity-dominated planetesimal strength. The scheme also reproduces the expected evolution of disk mass, and of dust mass, but is computationally much faster than evolving distributions forward in time. For low-mass disks, P-R drag causes a turnover at small sizes to a size distribution that is set by the redistribution function (the mass distribution of fragments produced in collisions). Thus information about the redistribution function may be recovered by measuring the size distribution of particles undergoing loss by P-R drag, such as that traced by particles accreted onto Earth. Although cross-sectional area drops with 1/age^2 in the PR-dominated regime, dust mass falls as 1/age^2.8, underlining the importance of understanding which particle sizes contribute to an observation when considering how disk detectability evolves. Other loss processes are readily incorporated; we also discuss generalised power law loss rates, dynamical depletion, realistic radiation forces and stellar wind drag.Comment: Accepted for publication by Celestial Mechanics and Dynamical Astronomy (special issue on EXOPLANETS

The ESA Hera Mission: Detailed Characterization of the DART Impact Outcome and of the Binary Asteroid (65803) Didymos

Hera is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October. It will rendezvous in late 2026 December with the binary asteroid (65803) Didymos and in particular its moon, Dimorphos, which will be impacted by NASA’s DART spacecraft on 2022 September 26 as the first asteroid deflection test. The main goals of Hera are the detailed characterization of the physical properties of Didymos and Dimorphos and of the crater made by the DART mission, as well as measurement of the momentum transfer efficiency resulting from DART’s impact. The data from the Hera spacecraft and its two CubeSats will also provide significant insights into asteroid science and the evolutionary history of our solar system. Hera will perform the first rendezvous with a binary asteroid and provide new measurements, such as radar sounding of an asteroid interior, which will allow models in planetary science to be tested. Hera will thus provide a crucial element in the global effort to avert future asteroid impacts at the same time as providing world-leading science

Evidence for multi-fragmentation and mass shedding of boulders on rubble-pile binary asteroid system (65803) Didymos.

Asteroids smaller than 10 km are thought to be rubble piles formed from the reaccumulation of fragments produced in the catastrophic disruption of parent bodies. Ground-based observations reveal that some of these asteroids are today binary systems, in which a smaller secondary orbits a larger primary asteroid. However, how these asteroids became binary systems remains unclear. Here, we report the analysis of boulders on the surface of the stony asteroid (65803) Didymos and its moonlet, Dimorphos, from data collected by the NASA DART mission. The size-frequency distribution of boulders larger than 5 m on Dimorphos and larger than 22.8 m on Didymos confirms that both asteroids are piles of fragments produced in the catastrophic disruption of their progenitors. Dimorphos boulders smaller than 5 m have size best-fit by a Weibull distribution, which we attribute to a multi-phase fragmentation process either occurring during coalescence or during surface evolution. The density per km2 of Dimorphos boulders ≥1 m is 2.3x with respect to the one obtained for (101955) Bennu, while it is 3.0x with respect to (162173) Ryugu. Such values increase once Dimorphos boulders ≥5 m are compared with Bennu (3.5x), Ryugu (3.9x) and (25143) Itokawa (5.1x). This is of interest in the context of asteroid studies because it means that contrarily to the single bodies visited so far, binary systems might be affected by subsequential fragmentation processes that largely increase their block density per km2. Direct comparison between the surface distribution and shapes of the boulders on Didymos and Dimorphos suggest that the latter inherited its material from the former. This finding supports the hypothesis that some asteroid binary systems form through the spin up and mass shedding of a fraction of the primary asteroid

Fast boulder fracturing by thermal fatigue detected on stony asteroids.

Spacecraft observations revealed that rocks on carbonaceous asteroids, which constitute the most numerous class by composition, can develop millimeter-to-meter-scale fractures due to thermal stresses. However, signatures of this process on the second-most populous group of asteroids, the S-complex, have been poorly constrained. Here, we report observations of boulders' fractures on Dimorphos, which is the moonlet of the S-complex asteroid (65803) Didymos, the target of NASA's Double Asteroid Redirection Test (DART) planetary defense mission. We show that the size-frequency distribution and orientation of the mapped fractures are consistent with formation through thermal fatigue. The fractures' preferential orientation supports that these have originated in situ on Dimorphos boulders and not on Didymos boulders later transferred to Dimorphos. Based on our model of the fracture propagation, we propose that thermal fatigue on rocks exposed on the surface of S-type asteroids can form shallow, horizontally propagating fractures in much shorter timescales (100 kyr) than in the direction normal to the boulder surface (order of Myrs). The presence of boulder fields affected by thermal fracturing on near-Earth asteroid surfaces may contribute to an enhancement in the ejected mass and momentum from kinetic impactors when deflecting asteroids

Design of analog front-ends for the RD53 demonstrator chip

The RD53 collaboration is developing a large scale pixel front-end chip, which will be a tool to evaluate the performance of 65 nm CMOS technology in view of its application to the readout of the innermost detector layers of ATLAS and CMS at the HL-LHC. Experimental results of the characterization of small prototypes will be discussed in the frame of the design work that is currently leading to the development of the large scale demonstrator chip RD53A to be submitted in early 2017. The paper is focused on the analog processors developed in the framework of the RD53 collaboration, including three time over threshold front-ends, designed by INFN Torino and Pavia, University of Bergamo and LBNL and a zero dead time front-end based on flash ADC designed by a joint collaboration between the Fermilab and INFN. The paper will also discuss the radiation tolerance features of the front-end channels, which were exposed to up to 800 Mrad of total ionizing dose to reproduce the system operation in the actual experiment

The Dimorphos ejecta plume properties revealed by LICIACube

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.This work was supported by the Italian Space Agency (ASI) in the LICIACube project (ASI-INAF agreement AC no. 2019-31-HH.0) and by the DART mission, NASA contract 80MSFC20D0004. M.Z. acknowledges Caltech and the Jet Propulsion Laboratory for granting the University of Bologna a licence to an executable version of MONTE Project Edition software. M.Z. is grateful to D. Lubey, M. Smith, D. Mages, C. Hollenberg and S. Bhaskaran of NASA/JPL for the discussions and suggestions regarding the operational navigation of LICIACube. G.P. acknowledges financial support from the Centre national d’études spatiales (CNES, France). A.C.B. acknowledges funding by the NEO-MAPP project (grant agreement 870377, EC H2020-SPACE-2019) and by the Ministerio de Ciencia Innovación (PGC 2018) RTI2018-099464-B-I00. F.F. acknowledges funding from the Swiss National Science Foundation (SNSF) Ambizione (grant no. 193346). J.-Y.L. acknowledges the support from the NASA DART Participating Scientist Program (grant no. 80NSSC21K1131). S.D.R. and M.J. acknowledge support from the Swiss National Science Foundation (project no. 200021_207359)