Spectroscopic Evaluation of Novel Adenine/Thymine-Conjugated Naphthalenediimides: Preference of Adenine-Adenine over Thymine-Thymine Intermolecular Hydrogen Bonding in Adenine- and Thymine-Functionalized Naphthalenediimides.

The synthesis and spectroscopic characterization of novel nucleobase (adenine/thymine)-conjugated naphthalenediimides (NDIs), namely, NDI-AA, NDI-TT, and NDI-AT have been successfully achieved. NDI-AA, NDI-TT and NDI-AT have similar absorption in the 300-400 nm region. The effect of solvent on the absorption spectrum indicates aggregation, either through intermolecular π-σ interaction among the main chromophore or through intermolecular hydrogen bonding between adenine and adenine group. Addition of water does not assist hydrogen bond formation between thymine-thymine, rather increasing the polarity of the solvent encourages π-σ interaction among NDI-TTs. No spectral change for NDI-TT with increasing temperature confirms hydrogen bonding is not playing a crucial role in NDI-TT. A fluorescence study on NDI-AA also establishes excimer formation along with ground state aggregation. As the water content in the solvent mixture increases, aggregation of NDI-AA is discouraged due to adenine-adenine hydrogen bonding in accordance with earlier results. At the same time, the NDI-TT emission spectrum does not shift to the blue region and the intensity of the peak around 535 nm increases at the expense of fluorescence in 411 nm. Thus, increasing water content in the solvent mixture facilitates aggregation through π-σ interaction in NDI-TT as thymine-thymine hydrogen bonding is less pronounced.

Factors associated with the public's trust in physicians in the context of the Lebanese healthcare system: a qualitative study.

BACKGROUND: The Lebanese public perceives the physician-patient relationship as flawed. The objectives of this study are to assess factors associated with the public's trust in physicians in the context of the Lebanese healthcare system and to explore potential ways to enhance it. METHODS: We conducted a qualitative study based on a grounded theory methodology using semi-structured interviews with members of the Lebanese public (not restricted to patients). We selected participants through convenience and maximum variation sampling approaches. The constant comparative analysis resulted in a theoretical framework that describes the factors influencing trust in physicians. RESULTS: Participants trusted an experienced, up-to-date, graduate of a North American or Western European school, working in a reputable hospital, with a high level of diagnostic skills. The personal characteristics that improved trust were physicians who are 'non-materialistic', have a good rapport, and have sufficient encounter time with patients. Social factors that enhance trust in the physician include: being a family member, recommended by a family member, featured in mainstream media, and/or having a good reputation. Trust increased compliance, loyalty despite occasional mistakes committed, high consultation fees, and negative attitudes towards the physician's institution. Conversely, no trust led to severed therapeutic relationship and seeking second opinions. CONCLUSION: The level of trust of members of the Lebanese public in physicians was affected by the personal characteristics of physicians, their practice or clinical skills, their interactions with the patient, finances, in addition to a number of social factors. Moreover, the level of trust had major implications on patients' interactions with their physicians.