Low-Temperature Photoluminescence Spectroscopy of Solvent-Free PCBM Single-Crystals

PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) is a highly soluble C60 derivative that is extensively used in organic solar cells, enabling power conversion efficiencies above 10%. Here we report, for the first time to the best of our knowledge, the photoluminescence of high-quality solvent-free PCBM crystals between room temperature and 4 K. Interestingly, the PL spectra of these crystals become increasingly structured as the temperature is lowered, with extremely well-resolved emission lines (and a minimum line width of ∼1.3 meV at 1.73 eV). We are able to account for such a structured emission by means of a vibronic coupling model including Franck–Condon, Jahn–Teller and Herzberg–Teller effects. Although optical transitions are not formally forbidden from the low-lying excited states of PCBM, the high symmetry of the electronically active fullerene core limits the intensity of the 0–0 transition, such that Herzberg–Teller transitions which borrow intensity from higher-lying states represent a large part of the observed spectrum. Our simulations suggest that the emissive state of PCBM can be considered as a mixture of the T1g and Hg excited states of C60 and hence that the Hg state plays a larger role in the relaxed excited state of PCBM than in that of C60

Increased luminescence efficiency by synergistic exploitation of lipo/hydrophilic co-solvency and supramolecular design

We use steady-state and time-resolved photoluminescence (PL) spectroscopy to investigate the luminescent properties of a sulfonated poly(diphenylenevinylene) lithium salt (PDV.Li) in water/propanol solutions at different concentrations, with a view to assessing its aggregation behavior. In particular, we compare results from uninsulated PDV.Li and cyclodextrin-threaded PDV.Li polyrotaxane (PDV.Li⊂β-CD). We find that addition of 1-propanol (≥20 weight%) leads to a significant blue-shift (of ∼0.20 eV) of the PL spectra, that we assign to suppressed interchain aggregation in PDV.Li solutions, with a concomitant fourfold increase in the fluorescence quantum efficiency (i.e. from 14 to 60%). Surprisingly, a moderate concentration of propanol increases further the luminescence efficiency even for PDV.Li⊂β-CD, whose supramolecular encapsulation already provides a shield against aggregation. Indeed, addition of propanol reduces the solvent polarity, and therefore helps solubilizing these materials that are still largely aromatic in nature. Interestingly, however, both uninsulated PDV.Li and polyrotaxane solutions exhibit signs of aggregation at high propanol fraction (>70%) with a distinctively weaker coupling than that of interchain states in PDV.Li at high water concentration and in pure water in particular. While we ascribe such behavior to a poor solvation of the polar moieties, we also report a different strength of aggregation for PDV.Li and PDV.Li⊂β-CD that can be attributed to the presence of the cyclodextrin rings. In PDV.Li⊂β-CD hydrogen bonding between the cyclodextrin rings may lead to closer packing between the polymer chains. We therefore suggest that a content of propanol between 30 and 70% provides a good balance of hydrophobic and hydrophilic interactions both for PDV.Li and PDV.Li⊂β-CD

Exercise levels and preferences in cancer patients: A cross-sectional study

Background: Despite the benefits related to physical exercise, large numbers of cancer patients are not sufficiently active. Methods: To investigate exercise levels and preferences in cancer patients, a cross-sectional study was conducted on a random sample of 392 cancer outpatients who anonymously completed a questionnaire investigating general and medical characteristics, and expressed willingness to participate in exercise programs. Current exercise levels were estimated with the Leisure Score Index (LSI). Results: Most patients (93%) were insufficiently active but 80% declared an interest in exercise programs. Patients preferred oncologist-instructed programs and specified particular exercise needs. Multivariate logistic regression showed that willingness to exercise was associated with education (OR: 1.87; 95% CI: 1.15–3.04 beyond age 14 years vs. up to 14 years) and current physical activity (OR: 1.92; 95% CI: 1.92–3.63 for sweat-inducing activity >2 times/week vs. <1 time/week). Patients given chemotherapy were less inclined to exercise (OR: 0.45; 95% CI: 0.23–0.86) than those who did not. LSI was lower if cancer stage was advanced (β:-0.36; 95% CI: −0.75 to −0.02) than if it was in remission. High LSI was also associated with longer education, lower BMI, and longer time after diagnosis. Conclusion: Cancer patients are insufficiently active but are willing to participate in personalized exercise programs. Information from this survey may help in designing personalized interventions so these patients will achieve sufficient exercise

NUP98-fusion transcripts characterize different biological entities within acute myeloid leukemia: A report from the AIEOP-AML group.

In the last years, collaborative studies have joined to link the degree of genetic heterogeneity of acute myeloid leukemia (AML) to clinical outcome,1, 2 allowing risk stratification before therapy and guiding post-induction treatment of children with AML. So far, still half of these patients, whose disease is usually characterized by a grim prognosis, lack a known biomarker offering opportunities of targeted treatment

Exercise prehabilitation in lung cancer: Getting stronger to recover faster

Despite several recent advances, lung cancer surgery is still associated with potentially severe postoperative complications. It has been suggested that preoperative exercise training could render patients with borderline functional parameters eligible for surgery, improve perioperative outcomes and that these benefits might reduce healthcare costs. Nevertheless, given the substantial heterogeneity of the available studies, no specific guidelines for preoperative exercise training have been released so far. This narrative review aims to provide an overview of the potential benefits of exercise training in the preoperative period as a central intervention for lung cancer patients. In detail, the effects of exercise (with different regimens) were evaluated in terms of physical functions, patients' eligibility for curative surgery, postoperative complications and length of stay, with an exploratory focus on healthcare costs and long-term outcomes. Furthermore, a feasible approach for every-day clinical practice is proposed in order to increase the expected benefit deriving from a more extensive and methodical application of prehabilitation exercise, ideally in the context of a comprehensive approach to lung cancer patients, including nutritional and psychological support

The long non-coding RNA CDK6-AS1 overexpression impacts on acute myeloid leukemia differentiation and mitochondrial dynamics

Patients with acute myeloid leukemia (AML) carrying high-risk genetic lesions or high residual disease levels after therapy are particularly exposed to the risk of relapse. Here, we identified the long non-coding RNA CDK6-AS1 able to cluster an AML subgroup with peculiar gene signatures linked to hematopoietic cell differentiation and mitochondrial dynamics. CDK6-AS1 silencing triggered hematopoietic commitment in healthy CD34+ cells, whereas in AML cells the pathological undifferentiated state was rescued. This latter phenomenon derived from RUNX1 transcriptional control, responsible for the stemness of hematopoietic precursors and for the block of differentiation in AML. By CDK6-AS1 silencing in vitro, AML mitochondrial mass decreased with augmented pharmacological sensitivity to mitochondria-targeting drugs. In vivo, the combination of tigecycline and cytarabine reduced leukemia progression in the AML-PDX model with high CDK6-AS1 levels, supporting the concept of a mitochondrial vulnerability. Together, these findings uncover CDK6-AS1 as crucial in myeloid differentiation and mitochondrial mass regulation