188 research outputs found
Public Concern About Monitoring Twitter Users and Their Conversations to Recruit for Clinical Trials: Survey Study
Background:
Social networks such as Twitter offer the clinical research community a novel opportunity for engaging potential study participants based on user activity data. However, the availability of public social media data has led to new ethical challenges about respecting user privacy and the appropriateness of monitoring social media for clinical trial recruitment. Researchers have voiced the need for involving users’ perspectives in the development of ethical norms and regulations. Objective:
This study examined the attitudes and level of concern among Twitter users and nonusers about using Twitter for monitoring social media users and their conversations to recruit potential clinical trial participants. Methods:
We used two online methods for recruiting study participants: the open survey was (1) advertised on Twitter between May 23 and June 8, 2017, and (2) deployed on TurkPrime, a crowdsourcing data acquisition platform, between May 23 and June 8, 2017. Eligible participants were adults, 18 years of age or older, who lived in the United States. People with and without Twitter accounts were included in the study. Results:
While nearly half the respondents—on Twitter (94/603, 15.6%) and on TurkPrime (509/603, 84.4%)—indicated agreement that social media monitoring constitutes a form of eavesdropping that invades their privacy, over one-third disagreed and nearly 1 in 5 had no opinion. A chi-square test revealed a positive relationship between respondents’ general privacy concern and their average concern about Internet research (PP=.001) and whether they consider Twitter monitoring for clinical trial recruitment as eavesdropping (PP=.003). As Twitter literacy increased, so did people’s concerns about researchers monitoring Twitter activity. Our data support the previously suggested use of the nonexceptionalist methodology for assessing social media in research, insofar as social media-based recruitment does not need to be considered exceptional and, for most, it is considered preferable to traditional in-person interventions at physical clinics. The expressed attitudes were highly contextual, depending on factors such as the type of disease or health topic (eg, HIV/AIDS vs obesity vs smoking), the entity or person monitoring users on Twitter, and the monitored information. Conclusions:
The data and findings from this study contribute to the critical dialogue with the public about the use of social media in clinical research. The findings suggest that most users do not think that monitoring Twitter for clinical trial recruitment constitutes inappropriate surveillance or a violation of privacy. However, researchers should remain mindful that some participants might find social media monitoring problematic when connected with certain conditions or health topics. Further research should isolate factors that influence the level of concern among social media users across platforms and populations and inform the development of more clear and consistent guidelines
Chiroptical Properties and Conformation of 4,5-Saturated Derivatives of 5-Aryl-1,4-benzodiazepin-2-ones
CD spectra of a series of 5-aryl-7-chloro-l,3,4,5-tetrahydro-
2H-l,4-benzodiazepin-2-one derivatives having different substituents
at positions 1, 3, 4, and 5 were studied. The absolute configuration
at C-5 of two homochiral analogues, 1 and 2, having
enantiomorphous ring conformations was determined on the basis
of chiroptical correlations and theoretical calculations. The latter
have shown that the optical activity mainly originates from the
one-electron mechanism and is determined by the helicity of the
diazepine ring, i. e. by the inherent chirality of the partial chromophore 4-chloro-N,2-dimethyl-formanilide. Exciton inter action s
between transitions of the two arornatic chromophores A and C
also give a significant contribution to chiroptical properties. By applying simple chiroptical rules dedueed from experimental
spectra and supported by calculations, the stereochemistry (absolute
conformation and configuration), of 3,5-disubstituted cis and
trans epimeric pairs (7-17) was revealed
Stereoelectronic properties of five anti-HSV-1 2′-deoxynucleosides analogues with heterocyclic substituents in the 5-position: A comparison with BVDU
Structural and electronic characteristics of 5-(5-chlorothien-2-yl)-2′-deoxyuridine (I), 5-(furan-2-yl)-2′-deoxyuridine (II), 5-(5-bromofuran-2-yl)-2′-deoxyuridine (III), 5-(3-bromoisoxazol-5-yl)-2′-deoxyuridine (V) and 5-(isoxazol-5-yl)-2′-deoxyuridine (IV) have been determined and compared to the BVDU (VI) characteristics in order to explain their respective affinity for the herpes simplex virus type 1 thymidine kinase (TK). Molecular structure of 5-(5-chlorothien-2-yl)-2′-deoxyuridine has been obtained using single crystal X-ray crystallography. Electrostatic potential maps, energy and topology of frontier orbitals were computed at the ab initio MO STO-3G and STO-3G* level. These studies reveal that the electrostatic potential energy maps are clearly dependent on the affinity of the compound for the enzyme.Peer reviewe
Blind test of density-functional-based methods on intermolecular interaction energies
In the past decade, a number of approaches have been developed to fix the failure of (semi) local density-functional theory (DFT) in describing intermolecular interactions. The performance of several such approaches with respect to highly accurate benchmarks is compared here on a set of separation-dependent interaction energies for ten dimers. Since the benchmarks were unknown before the DFT-based results were collected, this comparison constitutes a blind test of these methods
Methionine regulates copper/hydrogen peroxide oxidation products of Aβ
Metal-catalysed oxidation (MCO) may play a causative role in the pathogenesis of Alzheimer\u27s disease (AD). Amyloid peptide (A), the major biomarker of AD, in the presence of copper ions reduces Cu2+ to Cu+ and catalyses the formation of H2O2 that subsequently induces radicals through Fenton chemistry. A is also subject to attack by free radicals, where the presence of Cu2+ in conjunction with H2O2 catalyses oxygenation, primarily at the methionine sulfur atom. This work investigates MCO of A, to gain further insight into the role of oxidative stress in AD. By combining a fluorescence assay with gel electrophoresis to monitor MCO reactions of A (1-28) in the presence and absence of methionine it was determined that methionine can both protect some residues against MCO and promote the oxidation of Tyr(10) specifically. Electrospray ionization mass spectrometric analysis of methionine MCO products indicated the formation of methionine sulfoxide, methionine sulfone and related hydroxylated products. Similar products could be formed from the oxidation of Met(35) of A and may relate to changes in properties of the peptide following MCO. <br /
Correlation Analysis of Chemical Bonds (CACB) II: Quantum Mechanical Operators for Classical Chemical Concepts
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