RESUMO
Cucurbiturils (CBs), barrel-shaped macrocyclic molecules, are capable of self-assembling at the surface of nanomaterials in their native state, via their carbonyl-ringed portals. However, the symmetrical two-portal structure typically leads to aggregated nanomaterials. We demonstrate that fluorescent quantum dot (QD) aggregates linked with CBs can be broken-up, retaining CBs adsorbed at their surface, via inclusion of guests in the CB cavity. Simultaneously, the QD surface is modified by a functional tail on the guest, thus the high affinity host-guest binding (logKa > 9) enables a non-covalent, click-like modification of the nanoparticles in aqueous solution. We achieved excellent modification efficiency in several functional QD conjugates as protein labels. Inclusion of weaker-binding guests (logKa = 4-6) enables subsequent displacement with stronger binders, realising modular switchable surface chemistries. Our general "hook-and-eye" approach to host-guest chemistry at nanomaterial interfaces will lead to divergent routes for nano-architectures with rich functionalities for theranostics and photonics in aqueous systems.
RESUMO
The maturation of spirit in wooden casks is key to the production of whisky, a hugely popular and valuable product, with the transfer and reaction of molecules from the wooden cask with the alcoholic spirit imparting color and flavor. However, time in the cask adds significant cost to the final product, requiring expensive barrels and decades of careful storage. Thus, many producers are concerned with what "age" means in terms of the chemistry and flavor profiles of whisky. We demonstrate here a colorimetric test for spirit "agedness" based on the formation of gold nanoparticles (NPs) by whisky. Gold salts were reduced by barrel-aged spirit and produce colored gold NPs with distinct optical properties. Information from an extinction profile, such as peak position, growth rate, or profile shape, was analyzed, and our assay output was correlated with measurements of the whisky sample makeup, assays for key functional groups, and spiking experiments to explore the mechanism in more detail. We conclude that age is not just a number, that the chemical fingerprint of key flavor compounds is a useful marker for determining whisky "age", and that our simple reduction assay could assist in defining the aged character of a whisky and become a useful future tool on the warehouse floor.
RESUMO
AIMS: Studies have established a link between vasovagal syncope (VVS) and anxiety, depression, and functional impairment. This study examines the prevalence of psychological problems in patients with VVS and whether non-responders are psychologically different from those whose symptoms respond to conservative treatment. METHODS AND RESULTS: Subjects with tilt-confirmed VVS completed the hospital anxiety and depression scale (HADS) (measures current levels of anxiety and depression) and the syncope functional status questionnaire (SFSQ) (syncope-specific quality-of-life measure) and participated in a semi-structured interview to ascertain potential triggers, thought content, and coping strategies. In this study, 41 subjects participated. There was no difference in gender and age duration of symptoms between responders (n=21) and non-responders (n=20). Non-responders were significantly more anxious (P=0.003) and depressed (P=0.003) and had a higher level of state (P=0.008) and trait (P=0.004) anxiety than responders. Non-responders reported more fear/worry (P=0.02), a significantly higher degree of impairment owing to syncope (P=0.01), and a greater number of perceived triggers (P=0.039); on average, participants reported eight negative thoughts about the consequences of VVS, with particular emphasis on threats of physical harm or death. Non-responders had higher levels of avoidance/protection coping and rumination. CONCLUSION: This study has confirmed that patients with VVS have a significant degree of psychological distress, which is worthy of consideration in its own right, out with management purely aimed at reducing syncopal or pre-syncopal symptoms. Further, this distress may actually influence the natural history of what is a chronic relapsing condition and may in fact be more relevant to the patient than the number of syncopal episodes that they are experiencing.
Assuntos
Ansiedade/etiologia , Fludrocortisona/uso terapêutico , Midodrina/uso terapêutico , Síncope Vasovagal/tratamento farmacológico , Síncope Vasovagal/psicologia , Vasoconstritores/uso terapêutico , Adaptação Psicológica/efeitos dos fármacos , Adaptação Psicológica/fisiologia , Adulto , Idoso , Ansiedade/fisiopatologia , Ansiedade/psicologia , Estudos Transversais , Depressão/etiologia , Depressão/fisiopatologia , Depressão/psicologia , Medo/fisiologia , Medo/psicologia , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Estresse Psicológico , Inquéritos e Questionários , Síncope Vasovagal/fisiopatologia , Teste da Mesa InclinadaRESUMO
We describe training in CBT techniques for 20 palliative care practitioners delivered as 12 days' equivalent teaching plus skills-building supervision over a six month period. Audiotapes of trainees' interactions with patients during their usual work were rated using a specially devised 'Cognitive First Aid' rating scale (CFARS). The CFARS was highly internally consistent (Cronbach's Alpha 0.93) and inter-rater reliability was high. Trainees showed significant gain in CBT skills competency over six months (p=0.001). After initial training, half the trainees were randomised to discontinue supervision; their measured CBT skill dropped as did their self-reported confidence when reassessed six months later, whereas those who continued in supervision gained further skill and maintained confidence (p=0.007). Palliative care practitioners can be trained in CBT skills by a simple and brief training course and supportive, skills-building supervision. These skills are compatible with national guidelines on delivery of psychological support to patients at all stages of cancer. Supervision is necessary to ensure maintenance of skills and confidence to use them.