50 research outputs found
DNAGPT: A Generalized Pre-trained Tool for Versatile DNA Sequence Analysis Tasks
Pre-trained large language models demonstrate potential in extracting
information from DNA sequences, yet adapting to a variety of tasks and data
modalities remains a challenge. To address this, we propose DNAGPT, a
generalized DNA pre-training model trained on over 200 billion base pairs from
all mammals. By enhancing the classic GPT model with a binary classification
task (DNA sequence order), a numerical regression task (guanine-cytosine
content prediction), and a comprehensive token language, DNAGPT can handle
versatile DNA analysis tasks while processing both sequence and numerical data.
Our evaluation of genomic signal and region recognition, mRNA abundance
regression, and artificial genomes generation tasks demonstrates DNAGPT's
superior performance compared to existing models designed for specific
downstream tasks, benefiting from pre-training using the newly designed model
structure
Association between gut microbiota and hepatocellular carcinoma from 2011 to 2022: Bibliometric analysis and global trends
BackgroundHepatocellular carcinoma (HCC) is a primary malignant tumor responsible for approximately 90% of all liver cancers in humans, making it one of the leading public health problems worldwide. The gut microbiota is a complex microbial ecosystem that can influence tumor formation, metastasis, and resistance to treatment. Therefore, understanding the potential mechanisms of gut microbiota pathogenesis is critical for the prevention and treatment of HCC.Materials and methodsA search was conducted in the Web of Science Core Collection (WoSCC) database for English literature studies on the relationship between gut microbiota and HCC from 2011 to 2022. Bibliometric analysis tools such as VOSviewer, CiteSpace, and R Studio were used to analyze global trends and research hotspots in this field.ResultsA total of 739 eligible publications, comprising of 383 articles and 356 reviews, were analyzed. Over the past 11 years, there has been a rapid increase in the annual number of publications and average citation levels, especially in the last five years. The majority of published articles on this topic originated from China (n=257, 34.78%), followed by the United States of America (n=203, 27.47%), and Italy (n=85, 11.50%). American scholars demonstrated high productivity, prominence, and academic environment influence in the research of this subject. Furthermore, the University of California, San Diego published the most papers (n=24) and had the highest average citation value (value=152.17) in the study of the relationship between gut microbiota and HCC. Schnabl B from the USA and Ohtani N from Japan were the authors with the highest number of publications and average citation value, respectively.ConclusionIn recent years, research on the gut microbiotaâs role in HCC has made rapid progress. Through a review of published literature, it has been found that the gut microbiota is crucial in the pathogenesis of HCC and in oncotherapy
CRAFTS for Fast Radio Bursts : extending the dispersion-fluence relation with new FRBs detected by FAST
We report three new FRBs discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST), namely FRB 181017.J0036+11, FRB 181118, and FRB 181130, through the Commensal Radio Astronomy FAST Survey (CRAFTS). Together with FRB 181123, which was reported earlier, all four FAST-discovered FRBs share the same characteristics of low fluence (1000 pc cm(-3)), consistent with the anticorrelation between DM and fluence of the entire FRB population. FRB 181118 and FRB 181130 exhibit band-limited features. FRB 181130 is prominently scattered (tau(s) 8 ms) at 1.25 GHz. FRB 181017.J0036+11 has full-bandwidth emission with a fluence of 0.042 Jy ms, which is one of the faintest FRB sources detected so far. CRAFTS has started to build a new sample of FRBs that fills the region for more distant and fainter FRBs in the fluence-DME diagram, previously out of reach of other surveys. The implied all-sky event rate of FRBs is 1.24(-0.90)(+1.94) x 5 sky(-1) day(-1) at the 95% confidence interval above 0.0146 Jy ms. We also demonstrate here that the probability density function of CRAFTS FRB detections is sensitive to the assumed intrinsic FRB luminosity function and cosmological evolution, which may be further constrained with more discoveries
CRAFTS for Fast Radio Bursts Extending the dispersion-fluence relation with new FRBs detected by FAST
We report three new FRBs discovered by the Five-hundred-meter Aperture
Spherical radio Telescope (FAST), namely FRB 181017.J0036+11, FRB 181118 and
FRB 181130, through the Commensal Radio Astronomy FAST Survey (CRAFTS).
Together with FRB 181123 that was reported earlier, all four FAST-discovered
FRBs share the same characteristics of low fluence (0.2 Jy ms) and high
dispersion measure (DM, \dmu), consistent with the anti-correlation
between DM and fluence of the entire FRB population. FRB 181118 and FRB 181130
exhibit band-limited features. FRB 181130 is prominently scattered
( ms) at 1.25 GHz. FRB 181017.J0036+11 has full-bandwidth
emission with a fluence of 0.042 Jy ms, which is one of the faintest FRB
sources detected so far. CRAFTS starts to built a new sample of FRBs that fills
the region for more distant and fainter FRBs in the fluence- diagram,
previously out of reach of other surveys. The implied all sky event rate of
FRBs is sky day at the
confidence interval above 0.0146 Jy ms. We also demonstrate here that the
probability density function of CRAFTS FRB detections is sensitive to the
assumed intrinsic FRB luminosity function and cosmological evolution, which may
be further constrained with more discoveries.Comment: 9 Pages, 4 Plots and 1 Table. The Astrophysical Journal Letter
Accepte
Atypical radio pulsations from magnetar SGR 1935+2154
Magnetars are neutron stars with extremely strong magnetic fields, frequently
powering high-energy activity in X-rays. Pulsed radio emission following some
X-ray outbursts have been detected, albeit its physical origin is unclear. It
has long been speculated that the origin of magnetars' radio signals is
different from those from canonical pulsars, although convincing evidence is
still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and
its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was
discovered. Here we report the discovery of X-ray spectral hardening associated
with the emergence of periodic radio pulsations from SGR 1935+2154 and a
detailed analysis of the properties of the radio pulses. The complex radio
pulse morphology, which contains both narrow-band emission and frequency
drifts, has not been seen before in other magnetars, but is similar to those of
repeating FRBs - even though the luminosities are many orders of magnitude
different. The observations suggest that radio emission originates from the
outer magnetosphere of the magnetar, and the surface heating due to the
bombardment of inward-going particles from the radio emission region is
responsible for the observed X-ray spectral hardening.Comment: 47 pages, 11 figure
A repeating fast radio burst associated with a persistent radio source
The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ñ 0.001. The estimated host-galaxy dispersion measure of approximately 903â111+72 parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications
A Fast Radio Burst Discovered in FAST Drift Scan Survey
We report the discovery of a highly dispersed fast radio burst (FRB), FRB 181123, from an analysis of ~1500 hr of drift scan survey data taken using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulse has three distinct emission components, which vary with frequency across our 1.0â1.5 GHz observing band. We measure the peak flux density to be... (See full abstract in article)
Application of new emulsification technology in skin care products in the Clean Beauty era
In the era of Clean Beauty, consumers are more in pursuit of natural products without additives. Through the formula experiment, the emulsification system of natural emulsifiers polyglyceryl-6 stearate, polyglyceryl-6 behenate and glyceryl stearate citrate certified by Ecocert was selected with a reasonable scientific ratio, which is called stearate emulsifiersïŒSTEïŒ emulsification technology. Using this technology, combined with the natural oil squalane, olive oil, shea butter, and macadamia oil, we can significantly improve the moisturizing performance, soothing and other effects of the product, which is in line with the concept of natural green development
Land Use Suitability Assessment in Low-Slope Hilly Regions under the Impact of Urbanization in Yunnan, China
Nowadays, the conflict between land development and land conservation has become increasingly serious in China. The plan called âtown of mountainâ is carried out in many nonplain areas to alleviate the conflict. To avoid geological disasters and ecological risks in those areas, land use suitability assessment is of great importance. In this paper, the fuzzy weight of evidence model is applied into land use suitability assessment in low-slope hilly regions in Yunnan, China. Fuzzy weight of evidences is calculated to determine 9 map layers. Finally, posterior probabilities are modified after synthesizing each map layer, which are used to generate a land use suitability map. The results show that 9.33%, 26.18%, 45.98%, and 18.51% of low-slope hilly regions are separately highly suitable, moderately suitable, marginally suitable, and unsuitable for development. Besides, highly and moderately suitable areas are mainly located in towns with excellent natural and socioeconomic conditions. The largest areas which are marginally suitable for development are most widely distributed. Unsuitable areas are mainly distributed far away from towns and water sources. The findings of the research will promote the rational use and scientific management of the land