5,170 research outputs found
Strong supernovae bounds on ALPs from quantum loops
We show that in theories of axionlike particles (ALPs) coupled to electrons
at tree-level, the one-loop effective coupling to photons is process dependent:
the effective coupling relevant for decay processes,
, differs significantly from the coupling appearing
in the phenomenologically important Primakoff process,
. We show that this has important implications for
the physics of massive ALPs in hot and dense environments, such as supernovae.
We derive, as a consequence, new limits on the ALP-electron coupling,
, from SN 1987A by accounting for all relevant production
processes, including one-loop processes, and considering bounds from excess
cooling as well as the absence of an associated gamma-ray burst from ALP
decays. Our limits are among the strongest to date for ALP masses in the range
. Moreover, we also show how
cosmological bounds on the ALP-photon coupling translate into new, strong
limits on at one loop. Our analysis emphasises that large
hierarchies between ALP effective couplings are difficult to realise once
quantum loops are taken into account.Comment: 36 pages, 10 figures. Changes in v2: gravitational redshift taken
into account, small corrections. This is an author-created, un-copyedited
version of an article published in JCAP. IOP Publishing Ltd is not
responsible for any errors or omissions in this version of the manuscript or
any version derived from i
Synthesis, photochemical and in vitro cytotoxic evaluation of benzoselenazole-based aminosquaraines
Squaraine dyes have recently attracted interest as potential second generation photosensitizers for photodynamic
therapy. Several cationic aminosquaraine dyes bearing benzoselenazole terminal nuclei were
synthezised and their cytotoxic activity was tested against four different human tumor cell lines – breast
(MCF-7), non-small cell lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas – and
against a non-tumor porcine liver primary cell line (PLP2), both in the absence of light and under
irradiation. All dyes, which displayed strong absorption within the phototherapeutic window, were found
to exhibit photodynamic activity and were shown to be, in most cases, more cytotoxic, both in the dark
and upon irradiation, than their benzothiazole analogues.The authors are grateful to the Foundation for Science and
Technology (FCT, Portugal) and the FEDER for CIMO (UID/
AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial
support.info:eu-repo/semantics/publishedVersio
Epidemiological situation of bovine brucellosis in the State of Santa Catarina, Brazil
Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado de Santa Catarina. O Estado foi estratificado em cinco circuitos produtores. Em cada circuito produtor foram amostradas aleatoriamente cerca de 300 propriedades e, dentro dessas, foi escolhido, de forma aleatória, um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total foram amostrados 7801 animais, provenientes de 1586 propriedades. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal foi reagente às duas provas sorológicas. As prevalências de focos e de animais infectados no Estado foram de 0,32% [0,10-0,69%] e 0,06% [0,0-0,17%], respectivamente. A prevalência de focos nos circuitos pecuários foram: circuito 1, 0,33% [0,0-0,99%]; circuito 2, 0,33% [0,0-1,0%]; circuito 3, 0,25% [0,0-0,75%]; circuito 4, 0,66% [0,08-1,84%] e circuito 5, 0,33% [0,0-1,0%]. _____________________________________________________________________________________________________ ABSTRACTA study to characterize the brucellosis epidemiological situation in the State of Santa Catarina was carried out. The State was divided into five regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 7,801 serum samples from 1,586 herds were collected. In each herd, it was applied an epidemiological questionnaire regarding herd features and also husbandry and sanitary practices that could be associated with risk of infection. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal Test (RBT), and all RBT-positive sera re-tested by the 2-mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalences of infected herds and animals in Santa Catarina State were, respectively: 0.32% [0.10-0.69%] and 0.06% [0.0-0.17%]. The prevalence of infected herds in the regions were: region 1, 0.33% [0.0-0.99%]; region 2, 0.33% [0.0-1.0%]; region 3, 0.25% [0.0-0.75%]; region 4, 0.66% [0.08-1.84%]; and region 5, 0.33% [0.0-1.00%]
Insights on the extraction performance of Alkanediols and Glycerol: ssing Juglans regia L. Leaves as a source of bioactive compounds
Glycerol and alkanediols are being studied as alternative solvents to extract phytochemicals
from plant material, often as hydrogen bond donors in deep eutectic solvents (DESs). Many of those
alcohols are liquid at room temperature, yet studies of their use as extraction solvents are scarce.
In this work, glycerol and a series of alkanediols (1,2-ethanediol, 1,2-propanediol, 1,3-propanediol,
1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, and 1,2-hexanediol) were studied for the extraction
of phenolic compounds from Juglans regia L. leaves, a rich source of this class of bioactive compounds.
The extraction yield was quantified, and the bioactivity of both extracts and pure solvents was
evaluated by measuring the anti-inflammatory and cytotoxic activities. The solvents showing the best
combined results were 1,2 and 1,3-propanediol, as their extracts presented a high amount of phenolic
compounds, close to the results of ethanol, and similar cytotoxicity against cervical carcinoma cells,
with no impact on non-tumor porcine liver cells in the studied concentration range. On the other hand,
none of the extracts (and solvents) presented anti-inflammatory activity. Overall, the results obtained
in this work contribute to the study of alternative solvents that could potentially be used also as
formulation media, highlighting the importance of walnut leaves as a source of bioactive compounds.This work was developed within the scope of the CIMO-Mountain Research Center UIDB/00690/2020
and CICECO-Aveiro Institute of Materials UIDB/50011/2020 & UIDP/50011/2020 projects, both financed by
national funds through the Portuguese Foundation for Science and Technology (FCT)/MCTES, as well as
POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by ERDF, through POCI-COMPETE2020 and FCT.
The authors also thank the national funding from FCT, P.I., through the individual scientific employment
program-contract for L. Barros and R. C. Calhelha and V. Vieira’s grant (SFRH/BD/108487/2015). Support was
also provided by project AllNat—POCI-01-0145-FEDER-030463 (PTDC/EQU-EPQ/30463/2017), funded by FEDER
funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI), and by
national funds through the Foundation for Science and Technology (FCT/MCTES).info:eu-repo/semantics/publishedVersio
Aminosquaraines as potential photodynamic agents: Synthesis and evaluation of in vitro cytotoxicity
© 2017 Elsevier Ltd The synthesis of several aminosquaraine cationic dyes displaying strong absorption within the so-called phototherapeutic window (650–850 nm) is described. Their cytotoxicity, under dark and illuminated conditions, was tested against several human tumor cell lines (breast, lung, cervical and hepatocellular carcinomas) and non-tumor porcine liver primary cells. All compounds showed to inhibit the growth of the tumor cells upon irradiation more than in the absence of light, in more or less extension, clearly exhibiting photodynamic activity. The photosensitizing ability against some cell lines, together with the low toxicity for the non-tumor primary PLP2 cells displayed by some of the compounds synthetized, turns them into potential candidates as photosensitizers for PDT.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER for CIMO (UID/AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support.info:eu-repo/semantics/publishedVersio
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