RESUMO
We present 15 high-mass X-ray binary (HMXB) candidates in the disk of M31 for which we are able to infer compact object type, spectral type of the donor star, and age using multiwavelength observations from NuSTAR, Chandra, and the Hubble Space Telescope. The hard X-ray colors and luminosities from NuSTAR permit the tentative classification of accreting X-ray binary systems by compact object type, distinguishing black hole from neutron star systems. We find hard-state black holes, pulsars, and non-magnetized neutron stars associated with optical point-source counterparts with similar frequency. We also find nine non-magnetized neutron stars coincident with globular clusters and an equal number of pulsars with and without point-source optical counterparts. We perform spectral energy distribution (SED) fitting for the most likely optical counterparts to the HMXB candidates, finding seven likely high-mass stars and one possible red helium-burning star. The remaining seven HMXB optical counterparts have poor SED fits, so their companion stars remain unclassified. Using published star formation histories, we find that the majority of HMXB candidates-X-ray sources with UV-bright point-source optical counterpart candidates-are found in regions with star formation bursts less than 50 Myr ago, and three are associated with young stellar ages (<10Myr). This is consistent with similar studies of HMXB populations in the Magellanic Clouds, M33, NGC 300, and NGC 2403.
RESUMO
We examined the suppression of virus expression by cleaveage of the HIV-1 RNA gene using a mammalian tRNA 3' processing endoribonuclease and an External Guide Sequence Oligozyme (EGS) in vivo. We constructed an EGS expression vector that used the tRNA(met) promoter as an expression cassette for EGS. The EGS expression vector was targeted to the upstream region of gag, region. The EGS expression vector was co-transfected into COS cells with the HIV-1 gene plasmid vector. As compared with the EGS non-expressing cells and the EGS expressing cells, the EGS expressing cells with the targeted gag start codon had a clearly decreased amount of the HIV-1 gag p24 protein. The EGS expressing cells with the targeted gag start codon showed effective suppression of HIV-1 gene expression. Thus, these studies describe novel gene targeting agents for the inhibition of gene expression and antiviral activity.
Assuntos
Endorribonucleases/farmacologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , HIV-1/efeitos dos fármacos , HIV-1/genética , Oligonucleotídeos Antissenso/farmacologia , Animais , Células COS , Endorribonucleases/genética , Regulação Viral da Expressão Gênica/genética , Proteína do Núcleo p24 do HIV/biossíntese , Proteína do Núcleo p24 do HIV/genética , HIV-1/metabolismo , Oligonucleotídeos Antissenso/genética , Regiões Promotoras Genéticas , RNA de Transferência de Metionina/genética , RNA Viral/genética , RNA Viral/metabolismoAssuntos
Antraz , Adulto , Antraz/diagnóstico , Antraz/tratamento farmacológico , Surtos de Doenças , Humanos , Japão , Masculino , Pessoa de Meia-IdadeRESUMO
We examined the suppression of virus expression by cleavage of the HIV-1 RNA gene using a mammalian tRNA 3' processing endoribonuclease and an External Guide Sequence Oligozyme (EGS) in vivo. We constructed an EGS expression vector that used the tRNA(met) promoter as an expression cassette for EGS. The EGS expression vector was targeted to the upstream region of gag, region. The EGS expression vector was co-transfected into COS cells with the HIV-1 gene plasmid vector. As compared with the EGS non-expressing cells and the EGS expressing cells, the EGS expressing cells with the targeted gag start codon had a clearly decreased amount of the HIV-1 gag p24 protein. The EGS expressing cells with the targeted gag start codon showed effective suppression of HIV-1 gene expression. Thus, these studies describe novel gene targeting agents for the inhibition of gene expression and antiviral activity.