9,378 research outputs found
SMA observations of C2H in High-Mass Star Forming Regions
CH is a representative hydrocarbon that is abundant and ubiquitous in the
interstellar medium (ISM). To study its chemical properties, we present
Submillimeter Array (SMA) observations of the CH and HCN
transitions and the 1.1 mm continuum emission toward four OB
cluster-forming regions, AFGL 490, ON 1, W33 Main, and G10.6-0.4, which cover a
bolometric luminosity range of 10--10 . We found that
on large scales, the CH emission traces the dense molecular envelope.
However, for all observed sources, the peaks of CH emission are offset by
several times times 10 AU from the peaks of 1.1 mm continuum emission,
where the most luminous stars are located. By comparing the distribution and
profiles of CH hyperfine lines and the 1.1 mm continuum emission, we find
that the CH column density (and abundance) around the 1.1 mm continuum
peaks is lower than those in the ambient gas envelope. Chemical models suggest
that CH might be transformed to other species owing to increased
temperature and density; thus, its reduced abundance could be the signpost of
the heated molecular gas in the 10 AU vicinity around the embedded
high-mass stars. Our results support such theoretical prediction for centrally
embedded -- OB star-forming cores, while future
higher-resolution observations are required to examine the CH
transformation around the localized sites of high-mass star formation.Comment: 10 pages, 6 figures. ApJ accepted. Comments welcom
Cofilin Activation in Peripheral CD4 T Cells of HIV-1 Infected Patients: A Pilot Study
Cofilin is an actin-depolymerizing factor that regulates actin dynamics critical for T cell migration and T cell activation. In unstimulated resting CD4 T cells, cofilin exists largely as a phosphorylated inactive form. Previously, we demonstrated that during HIV-1 infection of resting CD4 T cells, the viral envelope-CXCR4 signaling activates cofilin to overcome the static cortical actin restriction. In this pilot study, we have extended this in vitro observation and examined cofilin phosphorylation in resting CD4 T cells purified from the peripheral blood of HIV-1-infected patients. Here, we report that the resting T cells from infected patients carry significantly higher levels of active cofilin, suggesting that these resting cells have been primed in vivo in cofilin activity to facilitate HIV-1 infection. HIV-1-mediated aberrant activation of cofilin may also lead to abnormalities in T cell migration and activation that could contribute to viral pathogenesis.Department of Defense (National Defense Science and Engineering Fellowship); National Institute of Allergy and Infectious Diseases (AI069981
Comparison of capecitabine and tegafur/gimeracil/oteracil (S-1) in the treatment of advanced breast carcinoma in the elderly
Purpose: To analyse and compare the clinical effects and safety of capecitabine and tegafur/gimeracil/oteracil (S-1) in the treatment of advanced breast carcinoma.Methods: Eighty-four metastatic breast cancer elderly patients for whom first or second-line treatment had failed, were selected from among those admitted to the oncology ward of Binjiang People’s Hospital, China between January 2014 and June 2015. They were randomly divided into S-1 group (n =41) and capecitabine group (n = 41) and received varying doses of those drugs according to body surface area. Clinical effects, progression-free survival, and incidence of adverse reactions were compared for the two groups following treatment.Results: Disease control rate (CR) in S-1 group was 55.6 %, much higher than 35.1 % observed for capecitabine group (p < 0.05). The disease control rate for the S-1 group was 93.7 %, also much higher than the 70.6 % found in capecitabine group. Survival analysis showed that the median survival times of the two groups did not differ significantly (p > 0.05). Furthermore, some adverse reactions such as myelosuppression and lack of strength, did not differ significantly between the two groups (p > 0.05), whereas others, including leukopenia, nausea and vomiting and hand-foot syndrome were more serious and frequent in capecitabine group than in S-1 group (p < 0.05).Conclusion: Monotherapy with S-1 is more effective than that with capecitabine. Adverse reactions are minimal for both drugs.Keywords: Breast carcinoma, Capecitabine, S-1, Adverse reactions, Myelosuppression, Leukopenia, Hand-foot syndrom
AZI23'UTR Is a New SLC6A3 Downregulator Associated with an Epistatic Protection Against Substance Use Disorders
Regulated activity of SLC6A3, which encodes the human dopamine transporter (DAT), contributes to diseases such as substance abuse disorders (SUDs); however, the exact transcription mechanism remains poorly understood. Here, we used a common genetic variant of the gene, intron 1 DNP1B sequence, as bait to screen and clone a new transcriptional activity, AZI23'UTR, for SLC6A3. AZI23'UTR is a 3' untranslated region (3'UTR) of the human 5-Azacytidine Induced 2 gene (AZI2) but appeared to be transcribed independently of AZI2. Found to be present in both human cell nuclei and dopamine neurons, this RNA was shown to downregulate promoter activity through a variant-dependent mechanism in vitro. Both reduced RNA density ratio of AZI23'UTR/AZI2 and increased DAT mRNA levels were found in ethanol-naive alcohol-preferring rats. Secondary analysis of dbGaP GWAS datasets (Genome-Wide Association Studies based on the database of Genotypes and Phenotypes) revealed significant interactions between regions upstream of AZI23'UTR and SLC6A3 in SUDs. Jointly, our data suggest that AZI23'UTR confers variant-dependent transcriptional regulation of SLC6A3, a potential risk factor for SUDs
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