Implementation of problem-based learning modules in an introduction to public health course.

Introduction: With traditional lecture-based learning methods often criticized for their limited ability to foster critical thinking and cognitive engagement, problem-based learning (PBL) has emerged as a promising alternative. This research investigates the impact of PBL on student learning outcomes, specifically focusing on the development of higher-order thinking skills, communication, growth mindset, and metacognitive abilities. Methods: PBL was implemented in an undergraduate public health course at a private university in the southeast US. The study was conducted in the Spring of 2022 using a convergent mixed-methods approach. Quantitative data were derived from university-wide Quality Enhancement Plan surveys and a course-specific PBL survey, which were analyzed using Repeated Measures ANOVA to assess changes in student perceptions over time. Additionally, qualitative data from open-ended survey questions were analyzed through thematic analysis, providing deeper insights into the students' experiences and perceptions of PBL. Results: Results indicated significant improvements in student communication skills, growth mindset, and metacognitive abilities across the semester. The thematic analysis of qualitative responses corroborated these findings, revealing enhanced team collaboration, active engagement in problem-solving, and increased comfort with complex real-world issues. Discussion: The findings contribute to the growing body of evidence supporting PBL and offer practical insights for implementing PBL in public health education. The study also highlights the need for institutional support in adopting innovative teaching methods like PBL, emphasizing faculty development, resource allocation, and curriculum design.

Iron acyl thiolato carbonyls: structural models for the active site of the [Fe]-hydrogenase (Hmd).

Phosphine-modified thioester derivatives are shown to serve as efficient precursors to phosphine-stabilized ferrous acyl thiolato carbonyls, which replicate key structural features of the active site of the hydrogenase Hmd. The reaction of Ph(2)PC(6)H(4)C(O)SPh and sources of Fe(0) generates both Fe(SPh)(Ph(2)PC(6)H(4)CO)(CO)(3) (1) and the diferrous diacyl Fe(2)(SPh)(2)(CO)(3)(Ph(2)PC(6)H(4)CO)(2), which carbonylates to give 1. For the extremely bulky arylthioester Ph(2)PC(6)H(4)C(O)SC(6)H(3)-2,6-(2,4,6-trimethylphenyl)(2), oxidative addition is arrested and the Fe(0) adduct of the phosphine is obtained. Complex 1 reacts with cyanide to give Et(4)N[Fe(SPh)(Ph(2)PC(6)H(4)CO)(CN)(CO)(2)] (Et(4)N[2]). (13)C and (31)P NMR spectra indicate that substitution is stereospecific and cis to P. The IR spectrum of [2](-) in ν(CN) and ν(CO) regions very closely matches that for Hmd(CN). XANES and EXAFS measurements also indicate close structural and electronic similarity of Et(4)N[2] to the active site of wild-type Hmd. Complex 1 also stereospecifically forms a derivative with TsCH(2)NC, but the adduct is more labile than Et(4)N[2]. Tricarbonyl 1 was found to reversibly protonate to give a thermally labile derivative, IR measurements of which indicate that the acyl and thiolate ligands are probably not protonated in Hmd.

Coordination chemistry of a model for the GP cofactor in the Hmd hydrogenase: hydrogen-bonding and hydrogen-transfer catalysis.

Cp(*)M(2+) complexes (M = Rh, Ir; Cp(*) = C(5)Me(5)) are described for 6-(carboxymethyl)-4-methyl-2-hydroxypyridine (cmhpH(2)), an analogue of the guanylylpyridone cofactor in the hydrogenase Hmd. Three findings indicate that Cp(*)M(Hcmhp)(+) stabilizes the binding of hydrogen-bond acceptors to the sixth coordination site: (i) water binds in preference to Cl-, (ii) the adduct Cp(*)Rh(cmhp)(2-hydroxypyridine) exhibits a very short intramolecular hydrogen bond (r(o-o) = 2.38 A; (1)H NMR delta(H) 17.2), and (iii) Cp(*)Ir(cmhpH)Cl efficiently catalyzes the dehydrogenation of PhCH(OH)Me to PhC(O)Me.