Search

Extremely metal-poor (EMPs, [Fe/H] < −3.0) and carbon-enhanced EMP (CE-EMP, [Fe/H] < −3.0 and [C/Fe]>  + 1.0) stars are crucial for understanding the chemical evolution and early formation of the galaxies. Current research on EMP stars is limited by small samples, and ultraviolet (UV) band spectra are lacking. The China Space Station Telescope (CSST) will provide high-quality, low-resolution spectra across wavelengths from near-ultraviolet to near-infrared, with a limiting magnitude of about 21 mag. These will help in identifying EMPs and CE-EMP candidates in the distant Milky Way and nearby galaxies. The present study first uses the simulated CSST spectra to quantitatively evaluate the contribution of UV band spectra in predicting [Fe/H], [α/Fe], and [C/Fe]. The results indicate that UV band spectra reduce the mean absolute error by 0.04, 0.04, and 0.03, respectively, with a σ of 0.02, 0.03, and 0.04, respectively. Further spectral analysis reveals that the EMP stars show unique spectral-line features in the UV band, with significant differences compared to stars of higher metallicity, which could help in identifying EMP stars. Additionally, we tested the impact of UV band spectra on identifying EMP and CE-EMP stars at different noise levels and find that models including UV band spectra improve the identification of EMP and CE-EMP stars in terms of accuracy, recall, and F1 score. At low signal-to-noise ratio (S/N), the model including the UV band achieves a recall of 0.94, significantly higher than the model without the UV band (Recall = 0.48), doubling the capability to identify EMP stars. As the S/N increases, the inclusion of the UV band maintains high recall. This suggests that UV spectra in future large surveys could reduce the risk of missing potentially interesting stellar candidates, ensuring a more comprehensive identification of all possible EMP and CE-EMP star candidates. [ABSTRACT FROM AUTHOR]

Background and Aim: Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common chronic liver diseases worldwide, characterized by the presence of lipid droplets. Rab18 is an important lipid droplet protein; however, its effects and mechanisms of action on NAFLD remain unclear. Methods: Free fatty acid‐stimulated AML‐12 cells and high‐fat diet (HFD)‐fed mice were used as NAFLD models. Lentiviruses overexpressing Rab18 (Rab18‐OE) or knockdown (Rab18‐KD) were used to generate stable cell lines for genetic analysis. Blood serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, glucose, and leptin were measured using a biochemical autoanalyzer. Hematoxylin and eosin staining was performed to detect pathological damage to the liver. Lipid accumulation in the cells was assessed by Oil Red O staining. Target expression was measured using qPCR, western blotting, and immunocytochemistry. Results: Rab18 mRNA and protein expression levels increased in free fatty acid‐stimulated AML‐12 cells and the livers of HFD‐fed mice. Rab18‐OE increased lipid accumulation in vitro, which was attenuated by Rab18‐KD. In vivo, Rab18‐OE augmented liver pathological damage, serum alanine aminotransferase/aspartate aminotransferase activity, and triglyceride, total cholesterol, and low‐density lipoprotein levels, whereas Rab18‐KD decreased these indicators. Rab18‐KD also downregulated blood glucose levels in HFD‐fed mice. Mechanistically, Rab18‐OE and Rab18‐KD regulated the mRNA and protein expression levels of perilipin 2 (PLIN2) and peroxisome proliferator‐activated receptor gamma (PPARγ) in vitro and in vivo, respectively. Immunocytochemistry revealed that Rab18 colocalized with PLIN2 and PPARγ in AML‐12 cells. Conclusion: Rab18 expression was elevated in vitro and in vivo in the NAFLD mouse model. Rab18 regulates PLIN2 and PPARγ expression to exaggerate liver injury and lipid accumulation in patients with NAFLD. Thus, Rab18 may be a crucial protein in this disease and a potential therapeutic target. [ABSTRACT FROM AUTHOR]

For high PPI LCD products, PS size has an increasing influence on the opening rate. This paper proposes a high precision PS technology to maximize the opening rate. [ABSTRACT FROM AUTHOR]

Background: Anti-tumor necrosis factor (TNF) monoclonal antibodies, especially infliximab (IFX) and adalimumab (ADA), are considered the first-line treatment for active Crohn's disease (CD). However, the predictive role of therapeutic drug monitoring (TDM) of serum anti-TNF in monitoring the treatment of inflammatory bowel disease (IBD) remains controversial. Objectives: To explore the correlation between serum anti-TNF levels and early endoscopic response in active CD using a TDM-based nomogram. Design: Cross-sectional study. Methods: The simplified endoscopic activity score for CD (SES-CD), Crohn's disease activity index (CDAI), laboratory parameters, and the serum trough levels of IFX and ADA were assessed. Results: The trough levels of IFX or ADA were significantly higher in patients with endoscopic response compared to non-responders in the development cohort (p < 0.001). The IFX and ADA levels showed a weak but significantly negative correlation with SES-CD (p < 0.001), CDAI (p < 0.001), and C-reactive protein (CRP) (p < 0.001) at week 14 post-IFX therapy in the development cohort. Furthermore, the receiver operating characteristic curve revealed that an optimal level of IFX (4.80 μg/mL) and ADA (8.80 μg/mL) exhibited the best performance in predicting endoscopic response. Concomitantly, we developed a novel nomogram prediction model based on the results of multivariate logistic regression analysis, which consisted of CRP, albumin (Alb), and anti-TNF trough levels at week 14. The nomogram showed significant discrimination and calibration for both IFX and ADA in the development cohort and performed well in the external validation cohort. Conclusion: This study demonstrates a robust association between serum concentrations of IFX, ADA, Alb, and CRP and primary endoscopic response in active CD patients. Importantly, the TDM- and laboratory marker-based nomogram may be used to evaluate the primary endoscopic response to anti-TNF therapy, especially for optimizing treatment strategies and switching therapy in CD patients. Plain language summary: Therapeutic drug monitoring-based nomogram predicts primary endoscopic response in Crohn's disease The present study established a therapeutic drug monitoring-based nomogram, which exhibits an exceptional predictive value, remarkable accuracy, and discrimination. This algorithmic nomogram holds the potential to enhance clinicians' comprehension of the underlying mechanisms contributing to individual patients' failure in achieving expected efficacy. Such approach is crucial for optimizing therapy options and facilitating biologic switching in refractory Crohn's disease. [ABSTRACT FROM AUTHOR]