Baryon Acoustic Oscillations from Integrated Neutral Gas Observations: an instrument to observe the 21cm hydrogen line in the redshift range 0.13 < z < 0.45 - status update.

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ∼ δ =-15 ^{\circ} ∘ , mapping \sim ∼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Grande Federal University (Brazil). Telescope subsystems have already been fabricated and tested, and the dish and structure fabrication are expected to start in late 2020, as well as the road and terrain preparation.

Technetium-99m labeled antisense oligonucleotide-noninvasive tumor imaging in mice

The 15-mer oligonucleotide sequence was synthesized, aminolinked (sense and antisense phosphodiester) and conjugated with S-Acetyl-NHS-MAG3 by a N-hydroxy-succinimide derivative. The purified MAG3-DNA was radiolabeled with 99mTc by transchelation from sodium tartrate and free 99mTc was separated by gel filtration. The radiolabeled antisense and sense probes were injected intravenously in mammary tumor-bearing KM mice(1×106 cells,6 days post inoculation).Biodistribution was studied and the mice were imaged.Essentially complete conjugation was achieved by reverse-phase Sep-Pak C18 chromatography analysis.The MAG3-DNA was labeled with 99mTc at room temperature and neutral pH, with a mean labeling efficiency of 80.11 percent (s.d=2.96 percent , N=4). After labeling, the stability of the DNA in saline or serum was retained as determined by reverse-phase Sep-Pak C18 chromatography analysis, except a shift at 30 min in serum incubation which might suggest a short time serum protein binding. The labeled antisense DNA still remained the ability to hybridize with its complementary DNA. The pharmacodynamics of 99mTc labeled c-myc probes (antisense and sense) in mammary tumor-bearing KM mice did not change with the time postinjection. The highest accumulation of label was in the liver first, with the kidney and small bowel next. The injected activity localized in the lesion as early as 30min and reached a saturation value at 4hr. The accumulation of radioactivity in the tumor was lower at all time points in animals receiving the blocking oligonucleotides or sense probes. All images obtained with 99mTc-MAG3-c-myc antisense probes showed specific accumulation of radioactivity at the site of tumor. Radiolabel rapidly accumulates at the site of tumor and remains associated with the site even though circulation levels of radioactivity have greatly diminished. The tumor was readily evident since 45min and reached the highest tumor-to-muscle ratio at 4hr. The quite encouraging result was obtained at 20hr to 22hr when the background activity was diminished sufficiently. Positive imaging was not obtained in case of control group (in which non-conjugated, non-labeled antisense oligonucleotides were administered 2hr before the radiolabeled antisense probes were injected) and of sense group. Conclusion The 99mTc labeled antisense probe may provide a sensible and specific tool for noninvasive imaging of c-myc oncogene mRNA for a variety of malignant tumors at an earlier stage