An early transition to magnetic supercriticality in star formation

Magnetic fields have an important role in the evolution of interstellar medium and star formation^1,2. As the only direct probe of interstellar field strength, credible Zeeman measurements remain sparse owing to the lack of suitable Zeeman probes, particularly for cold, molecular gas³. Here we report the detection of a magnetic field of +3.8 ± 0.3 microgauss through the H I narrow self-absorption (HINSA)^4,5 towards L1544^6,7—a well-studied prototypical prestellar core in an early transition between starless and protostellar phases^8–10 characterized by a high central number density¹¹ and a low central temperature¹². A combined analysis of the Zeeman measurements of quasar H I absorption, H I emission, OH emission and HINSA reveals a coherent magnetic field from the atomic cold neutral medium (CNM) to the molecular envelope. The molecular envelope traced by the HINSA is found to be magnetically supercritical, with a field strength comparable to that of the surrounding diffuse, magnetically subcritical CNM despite a large increase in density. The reduction of the magnetic flux relative to the mass, which is necessary for star formation, thus seems to have already happened during the transition from the diffuse CNM to the molecular gas traced by the HINSA. This is earlier than envisioned in the classical picture where magnetically supercritical cores capable of collapsing into stars form out of magnetically subcritical envelopes^13,14.

An analysis of Zeeman measurements reveals that the reduction of magnetic flux relative to mass, which is necessary for star formation, seems to have occurred earlier than previously thought.

AIB1 regulates the ovarian cancer cell cycle through TUG1

OBJECTIVE

To explore the mechanism of amplified in breast cancer 1 (AIB1) to promote ovarian cancer progress.

MATERIALS AND METHODS

Cor correlation analysis was performed to obtain the top 100 lncRNAs that were positively correlated with AIB1. The relationship of taurine upregulated gene 1 (TUG1) and clinicopathological characteristics. Moreover, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) were performed to predict the biological process where TUG1 may be involved in. At last, Cell Counting Kit-8 (CCK-8), colon formation and flow cytometry were conducted to explore the biological process that TUG1 may influence. Meanwhile, Western blot was performed to explore the mechanism of TUG1.

RESULTS

In this study, it was found that P73 antisense RNA 1T (TP73-AS1), LINC00654 and TUG1 had the tumor-promoting effect in the top 100 lncRNAs that were positively correlated with AIB1. The expression level of TUG1 was significantly decreased after intervention of AIB1. Then, the clinical data were analyzed and the results showed that TUG1 was related to the tumor residue, tumor staging, tumor grade and lymph node metastasis. Moreover, the bioinformatics analysis revealed that TUG1 was mainly involved in the regulation of cell cycle. After intervention in TUG1, it was found that the cell proliferation capacity was significantly decreased, and the cell cycle was arrested in G1 phase. Finally, Western blot revealed that the expressions of G1 phase-related proteins were significantly changed. This study indicated that AIB1 regulates the cycle of ovarian cancer cells through TUG1.

CONCLUSIONS

This study proved that AIB1 can regulate the cell cycle through regulating TUG1.

Dysbaric osteonecrosis by X-ray and CT scan in Chinese divers

OBJECTIVE

To compare the results of X-ray and CT scan for dysbaric osteonecrosis in Chinese divers.

METHODS

Both shoulders, hips and knees of 66 asymptomatic divers with diving duration of more than one year were examined by X-ray and CT scan.

RESULTS

The most frequent locations of dysbaric osteonecrosis were the upper femurs, followed by the upper humerus, lower femurs and upper tibias, and the most frequent radiographic lesions were calcification spots and cystic changes. Of the lesions detected, 38% (27/71) and 42% (95/229) werejuxta-articular of the femoral and humeral heads by X-ray and CT respectively. The detection rates of dysbaric necrosis (juxta- and/or other lesions) of X-ray and CT scan were 42.4% (95% confidence interval: 30.5%-54.3%) and 81.8% (95% CI: 72.4%-91.2%) respectively (p<0.05). If CT scan was used as the gold standard, the sensitivity of X-ray was 100% and the specificity was 31.6%.

CONCLUSION

CT scan showed a higher detection rate of dysbaric necrosis than X-ray. We recommend that CT scan be used for early diagnosis of dysbaric osteonecrosis.