Enantioselective Dearomatization of Indoles by an Azoalkene-Enabled (3+2) Reaction: Access to Pyrroloindolines.

The enantioselective dearomatization of indoles by an organocatalytic (3+2) reaction has been established. The reaction makes use of simple indole derivatives as substrates, and employs azoalkenes reaction partners. A wide range of pyrroloindolines containing an all-carbon quaternary stereogenic center were readily prepared in high yields and with excellent enantioselectivities.

Protein-level mutant p53 reporters identify druggable rare precancerous clones in noncancerous tissues.

Detecting and targeting precancerous cells in noncancerous tissues is a major challenge for cancer prevention. Massive stabilization of mutant p53 (mutp53) proteins is a cancer-specific event that could potentially mark precancerous cells, yet in vivo protein-level mutp53 reporters are lacking. Here we developed two transgenic protein-level mutp53 reporters, p53R172H-Akaluc and p53-mCherry, that faithfully mimic the dynamics and function of mutp53 proteins in vivo. Using these reporters, we identified and traced rare precancerous clones in deep noncancerous tissues in various cancer models. In classic mutp53-driven thymic lymphoma models, we found that precancerous clones exhibit broad chromosome number variations, upregulate precancerous stage-specific genes such as Ybx3 and enhance amino acid transport and metabolism. Inhibiting amino acid transporters downstream of Ybx3 at the early but not late stage effectively suppresses tumorigenesis and prolongs survival. Together, these protein-level mutp53 reporters reveal undercharacterized features and vulnerabilities of precancerous cells during early tumorigenesis, paving the way for precision cancer prevention.

The effects of media and peers on negative body image among Chinese college students: a chained indirect influence model of appearance comparison and internalization of the thin ideal.

BACKGROUND: Negative body image is a common psychological phenomenon among Chinese college students meriting investigation. Peers and the media are important factors that negatively influence body image. This study explored the mechanisms of media and peers promoting negative body image among Chinese college students. METHOD: Data from 407 college students (173 men and 234 women) were collected using the Revised Social and Cultural Attitude Questionnaire of Appearance, Appearance Comparison Scale, Peer Impact Scale, and Negative Body Image Scale. RESULTS: Correlational analysis results demonstrated that media attention was not significantly correlated with negative body image. All other variables were significantly positively correlated. Path analysis results indicated that the direct effect of media attention on negative body image was not significant, while the direct effect of peer impact was significant. In addition, appearance comparison and internalization of the thin ideal acted as a chained indirect effect between negative body image, media attention, and peer impact. CONCLUSIONS: The research revealed that focusing on perfect bodies displayed in the media did not produce a negative body image. However, focusing on the media and peer conversations regarding the body caused the participants to compare appearances and internalize ideal body shape standards, leading to negative self-evaluations.

Adolescents' peers and media have far-reaching influence. This study explored their impact on the body image of Chinese college students. A questionnaire survey was distributed to 461 Chinese college students. The results showed that peers directly affected body image, while media attention did not. Media attention and peer impact further increased students' negative body image evaluations through the indirect effects of appearance comparison and internalization of the thin ideal.

Catalytic Asymmetric Formal [3+2] Cycloaddition of Azoalkenes with 3-Vinylindoles: Synthesis of 2,3-Dihydropyrroles.

Chiral phosphoric acid-catalyzed highly enantioselective formal [3 + 2] cycloaddition reaction of azoalkenes with 3-vinylindoles has been established. Under mild conditions, the projected cycloaddition proceeded smoothly, affording a variety of 2,3-dihydropyrroles in high yields and excellent enantioselectivities, and also in a diastereospecific manner. As opposed to the common 4-atom synthons in the previous literature reports, azoalkenes served as 3-atom synthons. Besides, the observed selectivity was supported by primary theoretical calculation. The unique chemistry of azoalkenes disclosed herein will empower asymmetric synthesis of nitrogen-containing ring structural motifs in a broader context.

[Major ion chemistry of surface water in the Xilin River Basin and the possible controls].

Under the increasing pressure of water shortage and steppe degradation, information on the hydrological cycle in the steppe region in Inner Mongolia is urgently needed. Major ions are widely used to identify the hydrological processes in a river basin. Based on the analysis results of 239 river water samples collected in 13 sections along the Xilin River system during 2006 to 2008, combined with data from groundwater and precipitation samples collected in the same period and the meteorological and hydrological data in the Xilin River Basin, hydrochemical characteristics and the chemistry of major ions of the Xilin River water have been studied by means of Piper triangle plots and Gibbs diagrams. The results showed that: (1) the total dissolved solid (TDS) in river water mainly ranged between 136.7 mg x L(-1) and 376.5 mg x L(-1), and (2) it had an increasing trend along the river flow path. (3) The major cations and anions of river water were Ca2+ and HCO3-, respectively, and the chemical type of the river water varied from HCO3- -Ca2+ in the headwater area to HCO(3-)-Ca2+ Mg2+ in the lower part. (4) The variation in the concentration of major irons in surface water was not significant at the temporal scale. Usually, the concentration values of major irons were much higher in May than those in other months during the runoff season, while the values were a bit lower in 2007 than those in 2006 and 2008. Except for SO4(2-), the concentrations of other ions such as Ca2+, Na+, Mg2+, K+, Cl- and HCO3- showed a upward trend along the river flow path. Comparing major ion concentrations of the river water with those of local groundwater and precipitation, the concentration in river water was between those of precipitation and groundwater but was much closer to the concentration of groundwater. This indicated that the surface water was recharged by a mixture of precipitation and groundwater, and groundwater showed a larger impact. The Gibbs plot revealed that the chemical compositions of the river water were mainly affected by rock weathering in the drainage area.