145 research outputs found

    Professional Decisions and Ethical Values in Medical and Law Students

    Get PDF
    The purpose of this project is to evaluate and compare the values used by medical and law students when dealing with ethical dilemmas in the professional practice of law and medicine. It is assumed that conflict between doctors and lawyers often arises out of the different values that members of each profession apply to similar dilemmas

    Measurement report: Receptor modeling for source identification of urban fine and coarse particulate matter using hourly elemental composition

    Get PDF
    The elemental composition of the fine (PM2.5) and coarse (PM2.5−10) fraction of atmospheric particulate matter was measured at an hourly time resolution by the use of a streaker sampler during a winter period at a Central European urban background site in Warsaw, Poland. A combination of multivariate (Positive Matrix Factorization) and wind- (Conditional Probability Function) and trajectory-based (Cluster Analysis) receptor models was applied for source apportionment. It allowed for the identification of five similar sources in both fractions, including sulfates, soil dust, road salt, and traffic- and industry-related sources. Another two sources, i.e., Cl-rich and wood and coal combustion, were solely identified in the fine fraction. In the fine fraction, aged sulfate aerosol related to emissions from domestic solid fuel combustion in the outskirts of the city was the largest contributing source to fine elemental mass (44 %), while traffic-related sources, including soil dust mixed with road dust, road dust, and traffic emissions, had the biggest contribution to the coarse elemental mass (together accounting for 83 %). Regional transport of aged aerosols and more local impact of the rest of the identified sources played a crucial role in aerosol formation over the city. In addition, two intensive Saharan dust outbreaks were registered on 18 February and 8 March 2016. Both episodes were characterized by the long-range transport of dust at 1500 and 3000 m over Warsaw and the concentrations of the soil component being 7 (up to 3.5 µg m−3) and 6 (up to 6.1 µg m−3) times higher than the mean concentrations observed during non-episodes days (0.5 and 1.1 µg m−3) in the fine and coarse fractions, respectively. The set of receptor models applied to the high time resolution data allowed us to follow, in detail, the daily evolution of the aerosol elemental composition and to identify distinct sources contributing to the concentrations of the different PM fractions, and it revealed the multi-faceted nature of some elements with diverse origins in the fine and coarse fractions. The hourly resolution of meteorological conditions and air mass back trajectories allowed us to follow the transport pathways of the aerosol as well.</p

    Personality preference influences medical student use of specific computer-aided instruction (CAI)

    Get PDF
    BACKGROUND: The objective of this study was to test the hypothesis that personality preference, which can be related to learning style, influences individual utilization of CAI applications developed specifically for the undergraduate medical curriculum. METHODS: Personality preferences of students were obtained using the Myers-Briggs Type Indicator (MBTI) test. CAI utilization for individual students was collected from entry logs for two different web-based applications (a discussion forum and a tutorial) used in the basic science course on human anatomy. Individual login data were sorted by personality preference and the data statistically analyzed by 2-way mixed ANOVA and correlation. RESULTS: There was a wide discrepancy in the level and pattern of student use of both CAI. Although individual use of both CAI was positively correlated irrespective of MBTI preference, students with a "Sensing" preference tended to use both CAI applications more than the "iNtuitives". Differences in the level of use of these CAI applications (i.e., higher use of discussion forum vs. a tutorial) were also found for the "Perceiving/Judging" dimension. CONCLUSION: We conclude that personality/learning preferences of individual students influence their use of CAI in the medical curriculum

    Structure of the intramolecular human telomeric G-quadruplex in potassium solution: a novel adenine triple formation

    Get PDF
    We report the NMR solution structure of the intramolecular G-quadruplex formed in human telomeric DNA in K+. The hybrid-type telomeric G-quadruplex consists of three G-tetrads linked with mixed parallel–antiparallel G-strands, with the bottom two G-tetrads having the same G-arrangement (anti:anti:syn:anti) and the top G-tetrad having the reversed G-arrangement (syn:syn:anti:syn). The three TTA loop segments adopt different conformations, with the first TTA assuming a double-chain-reversal loop conformation, and the second and third TTA assuming lateral loop conformations. The NMR structure is very well defined, including the three TTA loops and the two flanking sequences at 5′- and 3′-ends. Our study indicates that the three loop regions interact with the core G-tetrads in a specific way that defines and stabilizes the unique human telomeric G-quadruplex structure in K+. Significantly, a novel adenine triple platform is formed with three naturally occurring adenine residues, A21, A3 and A9, capping the top tetrad of the hybrid-type telomeric G-quadruplex. This adenine triple is likely to play an important role in the formation of a stable human telomeric G-quadruplex structure in K+. The unique human telomeric G-quadruplex structure formed in K+ suggests that it can be specifically targeted for anticancer drug design

    Interaction of Pyrrolobenzodiazepine (PBD) Ligands with Parallel Intermolecular G-Quadruplex Complex Using Spectroscopy and ESI-MS

    Get PDF
    Studies on ligand interaction with quadruplex DNA, and their role in stabilizing the complex at concentration prevailing under physiological condition, has attained high interest. Electrospray ionization mass spectrometry (ESI-MS) and spectroscopic studies in solution were used to evaluate the interaction of PBD and TMPyP4 ligands, stoichiometry and selectivity to G-quadruplex DNA. Two synthetic ligands from PBD family, namely pyrene-linked pyrrolo[2,1-c][1,4]benzodiazepine hybrid (PBD1), mixed imine-amide pyrrolobenzodiazepine dimer (PBD2) and 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) were studied. G-rich single-stranded oligonucleotide d(5′GGGGTTGGGG3′) designated as d(T2G8), from the telomeric region of Tetrahymena Glaucoma, was considered for the interaction with ligands. ESI-MS and spectroscopic methods viz., circular dichroism (CD), UV-Visible, and fluorescence were employed to investigate the G-quadruplex structures formed by d(T2G8) sequence and its interaction with PBD and TMPyP4 ligands. From ESI-MS spectra, it is evident that the majority of quadruplexes exist as d(T2G8)2 and d(T2G8)4 forms possessing two to ten cations in the centre, thereby stabilizing the complex. CD band of PBD1 and PBD2 showed hypo and hyperchromicity, on interaction with quadruplex DNA, indicating unfolding and stabilization of quadruplex DNA complex, respectively. UV-Visible and fluorescence experiments suggest that PBD1 bind externally where as PBD2 intercalate moderately and bind externally to G-quadruplex DNA. Further, melting experiments using SYBR Green indicate that PBD1 unfolds and PBD2 stabilizes the G-quadruplex complex. ITC experiments using d(T2G8) quadruplex with PBD ligands reveal that PBD1 and PBD2 prefer external/loop binding and external/intercalative binding to quadruplex DNA, respectively. From experimental results it is clear that the interaction of PBD2 and TMPyP4 impart higher stability to the quadruplex complex

    Stabilization of G-quadruplex in the BCL2 promoter region in double-stranded DNA by invading short PNAs

    Get PDF
    Numerous regulatory genes have G-rich regions that can potentially form quadruplex structures, possibly playing a role in transcription regulation. We studied a G-rich sequence in the BCL2 gene 176-bp upstream of the P1 promoter for G-quadruplex formation. Using circular dichroism (CD), thermal denaturation and dimethyl sulfate (DMS) footprinting, we found that a single-stranded oligonucleotide with the sequence of the BCL2 G-rich region forms a potassium-stabilized G-quadruplex. To study G-quadruplex formation in double-stranded DNA, the G-rich sequence of the BCL2 gene was inserted into plasmid DNA. We found that a G-quadruplex did not form in the insert at physiological conditions. To induce G-quadruplex formation, we used short peptide nucleic acids (PNAs) that bind to the complementary C-rich strand. We examined both short duplex-forming PNAs, complementary to the central part of the BCL2 gene, and triplex-forming bis-PNAs, complementary to sequences adjacent to the G-rich BCL2 region. Using a DMS protection assay, we demonstrated G-quadruplex formation within the G-rich sequence from the promoter region of the human BCL2 gene in plasmid DNA. Our results show that molecules binding the complementary C-strand facilitate G-quadruplex formation and introduce a new mode of PNA-mediated sequence-specific targeting

    Metodologias utilizadas para detectar distúrbios emocionais em clínicas de assistência primária à saúde: revisão de literatura

    Get PDF
    A series of studies in the field of Epidemiological Psychiatry have been performed over the last two decades, and these have focused on the ability of primary care physicians to detect emotional disorders in the patients that attend their practices. The scientific methodology utilized in these studies is the subject of this review, which contains a discussion concerning: a) interviewer awareness bias; b) accuracy of the instruments and c) medical and psychological concepts involved in defining minor emotional disorders. Suggestions for change in the methodology are made in each of the sections of the review.Na área de epidemiologia psiquiátrica vêm sendo realizados, nos últimos vinte anos, estudos que têm como finalidade medir a habilidade que clínicos gerais possuem em detectar distúrbios emocionais nos pacientes que procuram atendimento na rede básica de saúde. A metodologia utilizada nesses estudos é o tema central da atual revisão, que contém a) viés do entrevistador; b) acuidade dos instrumentos; e c) conceitos médicos e psicológicos envolvidos na definição de distúrbio psiquiátrico menor. São também apresentadas sugestões para mudanças de metodologia

    Structure of the Hybrid-2 type intramolecular human telomeric G-quadruplex in K+ solution: insights into structure polymorphism of the human telomeric sequence

    Get PDF
    Formation of the G-quadruplex in the human telomeric sequence can inhibit the activity of telomerase, thus the intramolecular telomeric G-quadruplexes have been considered as an attractive anticancer target. Information of intramolecular telomeric G-quadruplex structures formed under physiological conditions is important for structure-based drug design. Here, we report the first structure of the major intramolecular G-quadruplex formed in a native, non-modified human telomeric sequence in K+ solution. This is a hybrid-type mixed parallel/antiparallel-G-stranded G-quadruplex, one end of which is covered by a novel T:A:T triple capping structure. This structure (Hybrid-2) and the previously reported Hybrid-1 structure differ in their loop arrangements, strand orientations and capping structures. The distinct capping structures appear to be crucial for the favored formation of the specific hybrid-type intramolecular telomeric G-quadruplexes, and may provide specific binding sites for drug targeting. Our study also shows that while the hybrid-type G-quadruplexes appear to be the major conformations in K+ solution, human telomeric sequences are always in equilibrium between Hybrid-1 and Hybrid-2 structures, which is largely determined by the 3′-flanking sequence. Furthermore, both hybrid-type G-quadruplexes suggest a straightforward means for multimer formation with effective packing in the human telomeric sequence and provide important implications for drug targeting of G-quadruplexes in human telomeres
    corecore