122 research outputs found
In vitro leishmanicidal, antibacterial and antitumour potential of anhydrocochlioquinone A obtained from the fungus Cochliobolus sp
The bioassay-guided fractionation of the ethyl acetate extract of the fungus Cochliobolus sp. highlighted leishmanicidal activity and allowed for anhydrocochlioquinone A (ANDC-A) isolation. MS, 1D and 2D NMR spectra of this compound were in agreement with those published in the literature. ANDC-A exhibited leishmanicidal activity with EC50value of 22.4 \uc2\ub5g/mL (44 \uce\ubcM) and, when submitted to the microdilution assay against Gram-positive and Gram-negative bacteria, showed a minimal inhibitory concentration against Staphylococcus aureus ATCC 25295 of 128 \uce\ubcg/mL (248.7 \uce\ubcM). It was also active against five human cancer cell lines, showing IC50values from 5.4 to 20.3 \uce\ubcM. ANDC-A demonstrated a differential selectivity for HL-60 (SI 5.5) and THP-1 (SI 4.3) cell lines in comparison with Vero cells and was more selective than cisplatin and doxorubicin against MCF-7 cell line in comparison with human peripheral blood mononuclear cells. ANDC-A was able to eradicate clonogenic tumour cells at concentrations of 20 and 50 \uce\ubcM and induced apoptosis in all tumour cell lines at 20 \uce\ubcM. These results suggest that ANDC-A might be used as a biochemical tool in the study of tumour cells biochemistry as well as an anticancer agent with durable effects on tumours
PHIBSS2: survey design and z=0.5-0.8 results Molecular gas reservoirs during the winding-down of star formation
Following the success of the Plateau de Bure high-z Blue Sequence Survey (PHIBSS), we present the PHIBSS2 legacy program, a survey of the molecular gas properties of star-forming galaxies on and around the star-formation main sequence (MS) at different redshifts using IRAMâs NOrthern Extended Millimeter Array (NOEMA). This survey significantly extends the existing sample of star-forming galaxies with CO molecular gas measurements, probing the peak epoch of star formation (zâ=â1â
ââ
1.6) as well as its building-up (zâ=â2â
ââ
3) and winding-down (zâ=â0.5â
ââ
0.8) phases. The targets are drawn from the well-studied GOODS, COSMOS, and AEGIS cosmological deep fields and uniformly sample the MS in the stellar mass (Mâ) â star formation rate (SFR) plane with log(Mâ/Mâ) = 10â
ââ
11.8 and SFRâ=â3.5â
ââ
500âMââyrâ1 without morphological selection, thus providing a statistically meaningful census of star-forming galaxies at different epochs. We describe the survey strategy and sample selection before focusing on the results obtained at redshift zâ=â0.5â
ââ
0.8, where we report 60 CO(2-1) detections out of 61 targets. We determine molecular gas masses between 2â
Ăâ
109 and 5â
Ăâ
1010âMâ and separately obtain disc sizes and bulge-to-total (B/T) luminosity ratios from HST I-band images. The median molecular gas-to-stellar mass ratio ÎŒgas⌠= 0.28 ± 0.04, gas fraction fgas⌠= 0.22 ± 0.02, and depletion time as well as their dependence with stellar mass and offset from the MS follow published scaling relations for a much larger sample of galaxies spanning a significantly wider range of redshifts, the cosmic evolution of the SFR being mainly driven by that of the molecular gas fraction. The galaxy-averaged molecular KennicuttâSchmidt (KS) relation between molecular gas and SFR surface densities is strikingly linear, pointing towards similar star formation timescales within galaxies at any given epoch. In terms of morphology, the molecular gas content, the SFR, the disc stellar mass, and the disc molecular gas fraction do not seem to correlate with B/T and the stellar surface density, which suggests an ongoing supply of fresh molecular gas to compensate for the build-up of the bulge. Our measurements do not yield any significant variation of the depletion time with B/T and hence no strong evidence for morphological quenching within the scatter of the MS
De pivete a funqueiro: genealogia de uma alteridade
Com base na teoria das representaçÔes sociais de Moscovici e a partir de contextualizaçÔes do fenĂŽmeno dos arrastĂ”es, esse texto se propĂ”e a discutir elementos que respondam Ă s questĂ”es: por que discursos criminalizantes, que afirmam a periculosidade do funkeiro, se fizeram tĂŁo presentes desde o inĂcio da dĂ©cada de noventa no Rio de Janeiro? Como esses discursos, que apontam para uma determinada construção social do funkeiro, interferiram na relação do funk com a sociedade? A discussĂŁo passa pela compreensĂŁo dos dispositivos criados na sociedade carioca daquele perĂodo para a solução de problemas com os quais ela se via confrontada. Trata-se de tentar compreender como, em certo momento, o funkeiro ganha um perfil amplamente difundido como problema que requer um tipo de intervenção especĂfica
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