54 research outputs found
Multilingual Pretraining and Instruction Tuning Improve Cross-Lingual Knowledge Alignment, But Only Shallowly
Despite their strong ability to retrieve knowledge in English, current large
language models show imbalance abilities in different languages. Two approaches
are proposed to address this, i.e., multilingual pretraining and multilingual
instruction tuning. However, whether and how do such methods contribute to the
cross-lingual knowledge alignment inside the models is unknown. In this paper,
we propose CLiKA, a systematic framework to assess the cross-lingual knowledge
alignment of LLMs in the Performance, Consistency and Conductivity levels, and
explored the effect of multilingual pretraining and instruction tuning on the
degree of alignment. Results show that: while both multilingual pretraining and
instruction tuning are beneficial for cross-lingual knowledge alignment, the
training strategy needs to be carefully designed. Namely, continued pretraining
improves the alignment of the target language at the cost of other languages,
while mixed pretraining affect other languages less. Also, the overall
cross-lingual knowledge alignment, especially in the conductivity level, is
unsatisfactory for all tested LLMs, and neither multilingual pretraining nor
instruction tuning can substantially improve the cross-lingual knowledge
conductivity
Narrative review of magnetic resonance imaging in quantifying liver iron load
ObjectiveTo summarize the research progress of magnetic resonance imaging (MRI) in quantifying liver iron load.MethodsTo summarize the current status and progress of MRI technology in the quantitative study of liver iron load through reviewing the relevant literature at home and abroad.ResultsDifferent MRI sequence examination techniques have formed a series of non-invasive methods for the examination of liver iron load. These techniques have important clinical significance in the imaging diagnosis of liver iron load. So far, the main MRI methods used to assess liver iron load are: signal intensity measurement method (signal intensity, SI) [signal intensity ratio (SIR) and difference in in-phase and out-of-phase signal intensity], T2/R2 measurement (such as FerriScan technique), ultra-short echo time (UTE) imaging technique, and susceptibility weighted imaging (including conventional susceptibility weighted imaging) (SWI), quantitative susceptibility mapping (QSM), T2*/R2* measurement, Dixon and its derivative techniques.ConclusionMRI has become the first choice for the non-invasive examination of liver iron overload, and it is helpful to improve the early detection of liver injury, liver fibrosis, liver cirrhosis and liver cancer caused by liver iron overload
ATOMS : ALMA Three-millimeter Observations of Massive Star-forming regions - X. Chemical differentiation among the massive cores in G9.62+0.19
Investigating the physical and chemical structure of massive star-forming regions is critical for understanding the formation and early evolution of massive stars. We performed a detailed line survey toward six dense cores, named MM1, MM4, MM6, MM7, MM8, and MM11, in the G9.62+0.19 star-forming region resolved in Atacama Large Millimeter/submillimeter Array (ALMA) band 3 observations. Toward these cores, about 172 transitions have been identified and attributed to 16 species, including organic oxygen-, nitrogen-, and sulphur-bearing molecules and their isotopologues. Four dense cores, MM7, MM8, MM4, and MM11, are line-rich sources. Modelling of these spectral lines reveals that the rotational temperature lies in the range 72-115, 100-163, 102-204, and 84-123 K for MM7, MM8, MM4, and MM11, respectively. The molecular column densities are 1.6 x 10(15) -9.2 x 10(17) cm(-2) toward the four cores. The cores MM8 and MM4 show a chemical difference between oxygenand nitrogen-bearing species, i.e. MM4 is rich in oxygen-bearing molecules, while nitrogen-bearing molecules, especially vibrationally excited HC3N lines, are mainly observed in MM8. The distinct initial temperatures at the accretion phase may lead to this N/O differentiation. Through analysing column densities and spatial distributions of O-bearing complex organic molecules (COMB), we found that C2H5OH and CH3OCH3 might have a common precursor, CH3OH. CH3OCHO and CH3OCH3 are likely chemically linked. In addition, the observed variation in HC3N and HC5N emission may indicate their different formation mechanisms in hot and cold regions.Peer reviewe
ATOMS : ALMA Three-millimeter Observations of Massive Star-forming regions - VIII. A search for hot cores by using C2H5CN, CH3OCHO, and CH3OH lines
Hot cores characterized by rich lines of complex organic molecules are considered as ideal sites for investigating the physical and chemical environments of massive star formation. We present a search for hot cores by using typical nitrogen- and oxygen-bearing complex organic molecules (C2H5CN, CH3OCHO, and CH3OH), based on ALMA Three-millimeter Observations of Massive Star-forming regions (ATOMS). The angular resolutions and line sensitivities of the ALMA observations are better than 2 arcsec and 10 mJy beam(-1), respectively. A total of 60 hot cores are identified with 45 being newly detected, in which the complex organic molecules have high gas temperatures (> 100 K) and hot cores have small source sizes (< 0.1 pc). So far, this is the largest sample of hot cores observed with similar angular resolution and spectral coverage. The observations have also shown nitrogen and oxygen differentiation in both line emission and gas distribution in 29 hot cores. Column densities of CH3OH and CH3OCHO increase as rotation temperatures rise. The column density of CH3OCHO correlates tightly with that of CH3OH. The pathways for production of different species are discussed. Based on the spatial position difference between hot cores and ultracompact H ii (UC H ii) regions, we conclude that 24 hot cores are externally heated, while the other hot cores are internally heated. The observations presented here will potentially help establish a hot core template for studying massive star formation and astrochemistry.Peer reviewe
ATOMS : ALMA Three-millimeter Observations of Massive Star-forming regions - XI. From inflow to infall in hub-filament systems
We investigate the presence of hub-filament systems in a large sample of 146 active proto-clusters, using (HCO+)-C-13 J = 1-0 molecular line data obtained from the ATOMS survey. We find that filaments are ubiquitous in proto-clusters, and hub-filament systems are very common from dense core scales (similar to 0.1 pc) to clump/cloud scales (similar to 1-10 pc). The proportion of proto-clusters containing hub-filament systems decreases with increasing dust temperature (T-d) and luminosity-to-mass ratios (L/M) of clumps, indicating that stellar feedback from H ii regions gradually destroys the hub-filament systems as proto-clusters evolve. Clear velocity gradients are seen along the longest filaments with a mean velocity gradient of 8.71 km s(-1) pc(-1) and a median velocity gradient of 5.54 km s(-1) pc(-1). We find that velocity gradients are small for filament lengths larger than similar to 1 pc, probably hinting at the existence of inertial inflows, although we cannot determine whether the latter are driven by large-scale turbulence or large-scale gravitational contraction. In contrast, velocity gradients below similar to 1 pc dramatically increase as filament lengths decrease, indicating that the gravity of the hubs or cores starts to dominate gas infall at small scales. We suggest that self-similar hub-filament systems and filamentary accretion at all scales may play a key role in high-mass star formation.Peer reviewe
Establishment of porcine and human expanded potential stem cells.
We recently derived mouse expanded potential stem cells (EPSCs) from individual blastomeres by inhibiting the critical molecular pathways that predispose their differentiation. EPSCs had enriched molecular signatures of blastomeres and possessed developmental potency for all embryonic and extra-embryonic cell lineages. Here, we report the derivation of porcine EPSCs, which express key pluripotency genes, are genetically stable, permit genome editing, differentiate to derivatives of the three germ layers in chimeras and produce primordial germ cell-like cells in vitro. Under similar conditions, human embryonic stem cells and induced pluripotent stem cells can be converted, or somatic cells directly reprogrammed, to EPSCs that display the molecular and functional attributes reminiscent of porcine EPSCs. Importantly, trophoblast stem-cell-like cells can be generated from both human and porcine EPSCs. Our pathway-inhibition paradigm thus opens an avenue for generating mammalian pluripotent stem cells, and EPSCs present a unique cellular platform for translational research in biotechnology and regenerative medicine
SENP7 inhibits glioblastoma metastasis and invasion by dissociating SUMO2/3 binding to specific target proteins
The poor surgical efficacy and recurrence of glioblastoma (GBM) are due to its lack of visible infiltrative features. Our bioinformatics study suggests that low expression of small ubiquitin-like modifier (SUMO)-specific protease 7 (SENP7) indicates poor prognosis in GBM
COMPARATIVE STUDY ON THE MEASUREMENT OF LIVER T2* VALUES OF THALASSEMIA PATIENTS AND THE CLINICAL GRADING OF LIVER IRON CONCENTRATION BY DIFFERENT POST-PROCESSING SOFTWARE
Objective: To explore the relationship between the liver T2* values of thalassemia patients measured by Circle Cardiovascular Imaging CVI42 (CVI42), CMRtools / Thalassemia Tools (CMRtools) and Excel spreadsheet (Excel), and the three software's accuracy in clinical grading of liver iron concentration (LIC). Methods: The liver T2* images thalassemia patients were imported into CVI42 and CMRtools to measure the T2* value. And the signal intensity (SI) of the T2* image, measured in the MR scanning equipment, was input into Excel to calculate T2* value. The relationship of the T2* values measured by the above three software were compared. And LIC clinical grading was performed on the three measured T2* value results, and the LIC (LICF) provided by FerriScan was used as the reference standard to compare the accuracy of the three grading results. Results: There was no statistical difference between the T2* values measured by CVI42, CMRtools and Excel (P>0.05), but there was a high degree of consistency between them (P0.05). There is a significant difference between the LIC grading results of Excel and the LICF grading results (P<0.05). Conclusion: The liver T2* values measured by CVI42, CMRtools and Excel are equivalent. However, CVI42 and CMRtools have better diagnostic accuracy for LIC clinical grade, while Excel has worse diagnostic accuracy.
Keywords: THALASSEMIA; lIVER T2 VALUE;
Austalides S-U, New Meroterpenoids from the Sponge-Derived Fungus Aspergillus aureolatus HDN14-107
Three new meroterpenoids, named austalides S-U (1–3), were isolated from the culture of a sponge-derived fungus Aspergillus aureolatus HDN14-107, together with eleven known austalides derivates (4–14). Their structures, including absolute configurations, were assigned on the basis of NMR, MS data, and TDDFT ECD calculations. Compound 1 is the first case of austalides with the terpene ring fused to the chroman ring in trans configuration. Compounds 3 and 5 exhibited activities against influenza virus A (H1N1), with IC50 values of 90 and 99 μM, respectively
Transcriptome Analysis Reveals MAPK/AMPK as a Key Regulator of the Inflammatory Response in PST Detoxification in Mytilus galloprovincialis and Argopecten irradians
Paralytic shellfish toxins (PSTs) are an increasingly important source of pollution. Bivalves, as the main transmission medium, accumulate and metabolize PSTs while protecting themselves from damage. At present, the resistance mechanism of bivalves to PSTs is unclear. In this study, Mytilus galloprovincialis and Argopecten irradians were used as experimental shellfish species for in situ monitoring. We compared the inflammatory-related gene responses of the two shellfish during PSTs exposure by using transcriptomes. The results showed that the accumulation and metabolism rate of PSTs in M. galloprovincialis was five-fold higher than that in A. irradians. The inflammatory balance mechanism of M. galloprovincialis involved the co-regulation of the MAPK-based and AMPK-based anti-inflammatory pathways. A. irradians bore a higher risk of death because it did not have the balance system, and the regulation of apoptosis-related pathways such as the PI3K-AKT signaling pathway were upregulated. Taken together, the regulation of the inflammatory balance coincides with the ability of bivalves to cope with PSTs. Inflammation is an important factor that affects the metabolic pattern of PSTs in bivalves. This study provides new evidence to support the studies on the resistance mechanism of bivalves to PSTs
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