Cryosurgery has attracted much attention for the treatment of tumors owing to its clear advantages. However, determining the volume of frozen tissues in real‐time remains a challenge, which greatly lowers the therapeutic efficacy of cryosurgery and hinders its broad application for the treatment of cancers. Herein, we report a freezing‐induced turn‐on strategy for the selective real‐time imaging of frozen cancer cells. As a type of aggregation‐induced emission (AIE) fluorogen, TABD‐Py molecules interact specifically with ice crystals and form aggregates at the ice/water interface. Consequently, bright fluorescent emission appears upon freezing. TABD‐Py molecules are enriched mostly in the cancer cells and exhibit high biocompatibility as well as low cytotoxicity; therefore, a freezing‐induced turn‐on imaging modality for cryosurgery is developed, which will certainly maximize the therapeutic efficacy of cryosurgery in treating tumors.

Insufficient intratumoral penetration and limited stroma distribution of the imaging probes or theranostics can lead to a poor-quality diagnosis or therapeutic resistance. Multicellular tumor spheroids can recapitulate the physiological environment of tumor tissues with the extracellular matrix and is thus a better in vitro tumor model to evaluate the imaging performance and barrier penetration capability of advanced cancer imaging probes. In this Article, we designed and synthesized a series of quinoline-based fluorophores with strong emissions in both solution and solid states. The quinoline core can be constructed via a one-pot iron-catalysis reaction. Optical properties and single crystal structures of these quinoline derivatives were tuned by varying the substitutes at the 6-position of the quinoline core. The twisted intramolecular charge transfer effect can enhance the fluorescent efficiency, resulting in the high quantum yield of TPQ-TPA in both solution (70%) and solid (48%) states (TPQ, triphenylquinoline; TPA, triphenylamine). In addition, TPQ-TPA exhibited a good biocompatibility and can deeply penetrate into 3D tumor spheroids within 12 h. The results indicated that quinoline can be a new fluorescent scaffold, and the employment of quinoline-based probes will provide a new platform for biological applications.

A novel "turn-on" fluorescent bioprobe, 1,2,3,4,5-penta(4-carboxyphenyl)pyrrole sodium salt (PPPNa), with aggregation-enhanced emission characteristics was synthesized for the in situ quantitative detection of Al in serum. It exhibited a high selectivity to Al in both simulated serum and fetal calf serum with no interferences from other metal ions or serum components observed and no isolation required. A weak interaction between PPPNa and serum albumin was found, which caused no interference, but enhanced fluorescence response of PPPNa to Al and improved detection sensitivity. The limit of detection was determined to be 1.50 μmol/L Al in phosphate-buffered saline solution containing 33 μg/mL bovine serum albumin (BSA) and decreased to 0.98 μmol/L as BSA concentration increased to 100 μg/mL. The fluorescence "turn-on" mechanism of the PPPNa probe to detect Al was proposed. A bidentate complex is formed between the carboxy group of PPPNa and Al, causing the photoluminescence (PL) emission enhancement by aggregation. BSA chains further strengthen the stacking compactness of the aggregates of PPPNa and Al and consequently enhance the PL emission of PPPNa by further promoting the restriction of intramolecular rotation of the phenyl ring. Its application to the in situ Al was successfully demonstrated with HeLa cells and NIH 3T3 cells. The low cytotoxicity and highly selective response of PPPNa to Al endow its great potentials to in vivo detecting and imaging of Al as well as an absorbent of Al.

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Background: Bullying tends to peak during adolescence, and it is an important risk factor of self-harm and suicide. However, research on the specific effect of different sub-types of bullying is limited.Objective: The purpose of this study is to examine the associations between four common forms of bullying (verbal, physical, relational, and cyber) and self-harm, suicidal ideation (SI), and suicide attempts (SA).Method: This was a cross-sectional study of a sample including 4,241 Chinese students (55.8% boys) aged 11 to 18 years. Bullying involvement, self-harm, SI, and SA were measured via The Juvenile Campus Violence Questionnaire (JCVQ). The association was examined through multinomial logistic regression analysis, adjusted for demographic characteristics and psychological distress.Results: Bullying victimization and perpetration were reported by 18.0 and 10.7% of participants. The prevalence of self-harm, SI, and SA were 11.8, 11.8, and 7.1%, respectively. Relational bullying victimization and perpetration were significantly associated with SI only, SI plus self-harm, and SA. Physical bullying victimization and perpetration were risk factors of self-harm only and SA. Verbal victimization was significantly associated with SI only. Cyber perpetration was a risk factor of SA.Conclusions: The findings highlight the different effects of sub-types of bullying on self-harm and suicidal risk. Anti-bullying intervention and suicide prevention efforts should be prior to adolescents who are involved in physical and relational bullying.

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Aims The associations between suicidal behaviours and childhood maltreatment (CM), as well as Internet addiction (IA) have been extensively examined. However, few studies pay attention to different types of CM and all stages of suicidality, including suicidal ideation (SI), suicidal plans (SP) and suicidal attempts (SA). Moreover, little is known regarding the mediation of IA on the relationship between CM and suicidal behaviours. The study aims to explore the direct effect of CM and IA on three stages of suicidal behaviours, and the indirect effect of CM on suicidality via IA. Methods A total of 16 130 high-school students aged 12–18 were recruited using a stratified cluster sampling strategy across five representative provinces in China. Relevant information was collected by a self-administered anonymous questionnaire. Multinomial logistic regression analysis and structural equation model were used to examine the associations. Results During the last year, 16.0% of participants reported suicidal behaviours. Specifically, 7.9% reported SI only, 4.6% reported SP but no SA, and 3.5% reported SA. The prevalence of neglect, physical abuse and IA in moderate to severe were 28.9, 19.9 and 33.1%, respectively. After controlling for demographic characteristics and confounding factors, such as loneliness, psychological resilience, and social support, moderate and severe neglect, physical abuse and IA were associated with an increased risk of SI, SP and SA (p < 0.01). The total effect of neglect and physical abuse on suicidal behaviours were 0.152 and 0.172, respectively (p < 0.001). The mediation proportion of IA on the association between neglect and suicidal behaviours, as well as physical abuse and suicidal behaviours were 22.4 and 18.0%, respectively. Conclusions CM and IA are independently associated with suicidal behaviours among Chinese adolescents. Moreover, IA plays a mediating role on the relationship between CM and suicidality. Targeted interventions for adolescents’ suicidal behaviours should focus on those who have experience of CM and IA.