47 research outputs found

    A supramolecular helix that disregards chirality

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    The functions of complex crystalline systems derived from supramolecular biological and non-biological assemblies typically emerge from homochiral programmed primary structures via first principles involving secondary, tertiary and quaternary structures. In contrast, heterochiral and racemic compounds yield disordered crystals, amorphous solids or liquids. Here, we report the self-assembly of perylene bisimide derivatives in a supramolecular helix that in turn self-organizes in columnar hexagonal crystalline domains regardless of the enantiomeric purity of the perylene bisimide. We show that both homochiral and racemic perylene bisimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecular level, self-organize to form single-handed helical assemblies with identical single-crystal-like order. We propose that this high crystalline order is generated via a cogwheel mechanism that disregards the chirality of the self-assembling building blocks. We anticipate that this mechanism will facilitate access to previously inaccessible complex crystalline systems from racemic and homochiral building blocks

    Effectiveness of interventions to improve cancer treatment and follow‐up care in socially disadvantaged groups

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    To identify and characterize the interventions that aimed to improve cancer treatment and follow-up care in socially disadvantaged groups. To summarize the state of the art for clinicians and researchers. We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were randomized controlled trials and quasi-experimental studies with a control group (usual care or enhanced usual care) conducted in Organization for Economic Co-operation and Development (OECD) member countries and published until 2016. Thirty-one interventions were identified, the majority of which were conducted in the United States in patients with breast cancer. Most interventions aimed to decrease social inequalities based on ethnicity/race and/or socioeconomic level, with fewer interventions targeting inequalities based on geographical area. The most frequently assessed outcomes were quality of life (n = 20) and psychosocial factors (n = 20), followed by treatment adherence or satisfaction (n = 12,), knowledge (n = 11), pain management (n = 10), and lifestyle habits (n = 3). The impact of interventions designed to improve cancer treatment and follow-up care in socially disadvantages groups is multifactorial. Multicomponent-intervention approaches and cultural adaptations are common, and their effectiveness should be evaluated in the populations of interest. More interventions are needed from outside the Unite States and in patients with cancers other than breast cancer, targeting gender or geographical inequalities and addressing key outcomes such as treatment adherence or symptom management
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