Evidence-based medicine curricula and barriers for physicians in training: a scoping review.

OBJECTIVES: To describe the published literature on EBM curricula for physicians in training and barriers during curriculum implementation. METHODS: We performed a systematic search and review of the medical literature on PubMed, Embase, ERIC, Scopus and Web of Science from the earliest available date until September 4, 2019. RESULTS: We screened 9,042 references and included 29 full-text studies and 14 meeting abstracts. Eighteen studies had moderate validity, and 6 had high validity. The EBM curricular structure proved highly variable in between studies. The majority of the EBM curricula was longitudinal with different lengths. Only five studies reported using Kern's six-step approach for curriculum development. Twenty-one articles reported on EBM skills and knowledge, and only 5/29 full-text articles used a validated assessment tool. Time was the main barrier to EBM curriculum implementation. All the included studies and abstracts, independent of the EBM curriculum structure or evaluation method used, found an improvement in the residents' attitudes and/or EBM skills and knowledge. CONCLUSIONS: The current body of literature available to guide educators in EBM curriculum development is enough to constitute a strong scaffold for developing any EBM curriculum. Given the amount of time and resources needed to develop and implement an EBM curriculum, it is very important to follow the curriculum development steps and use validated assessment tools.

Mobilization of metals and phosphorus from intact forest soil cores by dissolved inorganic carbon.

Increased dissolved inorganic carbon (DIC) enhances the mobilization of metals and nutrients in soil solutions. Our objective was to investigate the mobilization of Al, Ca, Fe, and P in forest soils due to fluctuating DIC concentrations. Intact soil cores were taken from the O and B horizons at the Bear Brook Watershed in Maine (BBWM) to conduct soil column transport experiments. Solutions with DIC concentrations (∼20-600 ppm) were introduced into the columns. DIC was reversibly sorbed and its migration was retarded by a factor of 1.2 to 2.1 compared to the conservative sodium bromide tracer, corresponding to a log K (D) = -0.82 to -0.07. Elevated DIC significantly enhanced the mobilization of all Al, Fe, Ca, and P. Particulate (>0.4 µm) Al and Fe were mobilized during chemical and flow transitions, such as increasing DIC and dissolved organic carbon (DOC), and resumption of flow after draining the columns. Calcium and P were primarily in dissolved forms. Mechanisms such as ion exchange (Al, Fe, Ca), ligand- and proton-promoted dissolution (Al and Fe), and ligand exchange (P) were the likely chemical mechanisms for the mobilization of these species. One column was packed with dried and sieved B-horizon soil. The effluent from this column had DOC, Al, and Fe concentrations considerably higher than those in the intact columns, suggesting that these species were mobilized from soil's microporous structure that was otherwise not exposed to the advective flow. Calcium and P concentrations, however, were similar to those in the intact columns, suggesting that these elements were less occluded in soil particles.

Investigating sorption-driven dissolved organic matter fractionation by multidimensional fluorescence spectroscopy and PARAFAC.

Soil organic matter is involved in many ecosystem processes, such as nutrient supply, metal solubilization, and carbon sequestration. This study examined the ability of multidimensional fluorescence spectroscopy and parallel factor analysis (PARAFAC) to provide detailed chemical information on the preferential sorption of higher-molecular-weight components of natural organic matter onto mineral surfaces. Dissolved organic matter (DOM) from soil organic horizons and tree leaf tissues was obtained using water extracts. The suite of fluorescence spectra was modeled with PARAFAC and it was revealed that the DOM extracts contained five fluorescing components: tryptophan-like (peak location at excitation <255 nm:emission 342 nm), tyrosine-like (276 nm:312 nm), and three humic-substance-like components (<255 nm:456 nm, 309 nm:426 nm, <255 nm:401 nm). In general, adsorption onto goethite and gibbsite increased with increasing DOM molecular weight and humification. PARAFAC analysis of the pre- and post-sorption DOM indicated that the ordering of sorption extent was humic-like components (average 91% sorption) > tryptophan-like components (52% sorption) > tyrosine-like components (29% sorption). This differential sorption of the modeled DOM components in both the soil organic horizon and leaf tissue extracts led to the fractionation of DOM. The results of this study demonstrate that multidimensional fluorescence spectroscopy combined with PARAFAC can quantitatively describe the chemical fractionation process due to the interaction of DOM with mineral surfaces.