50 research outputs found
Intergrowth texture in Au-Ag-Te minerals from Sandaowanzi gold deposit, Heilongjiang Province: Implications for ore-forming environment
A brief review of graphene-based material synthesis and its application in environmental pollution management
Feasibility of an innovative third-year chief resident system: an internal medicine residency leadership study
Introduction: The role of the internal medicine chief resident includes various administrative, academic, social, and educational responsibilities, fulfillment of which prepares residents for further leadership tasks. However, the chief resident position has historically only been held by a few residents. As fourth-year chief residents are becoming less common, we considered a new model for rotating third-year residents as the chief resident. Methods: Online surveys were given to all 29 internal medicine residents in a single university-based program after implementation of a leadership curriculum and specific job description for the third-year chief resident. Chief residents evaluated themselves on various aspects of leadership. Participation was voluntary. Descriptive statistics were generated using SPSS version 21. Results: Thirteen junior (first- or second-year) resident responses reported that the chief residents elicited input from others (mean rating 6.8), were committed to the team (6.8), resolved conflict (6.7), ensured efficiency, organization and productivity of the team (6.7), participated actively (7.0), and managed resources (6.6). Responses from senior residents averaged 1 point higher for each item; this pattern repeated itself in teaching evaluations. Chief resident self-evaluators were more comfortable running a morning report (8.4) than with being chief resident (5.8). Conclusion: The feasibility of preparing internal medicine residents for leadership roles through a rotating PGY-3 (postgraduate year) chief residency curriculum was explored at a small internal medicine residency, and we suggest extending the study to include other programs
Biological Uptake and Depuration of Radio-labeled Graphene by <i>Daphnia magna</i>
Graphene
layers are potential candidates in a large number of applications.
However, little is known about their ecotoxicological risks largely
as a result of a lack of quantification techniques in complex environmental
matrices. In this study, graphene was synthesized by means of graphitization
and exfoliation of sandwich-like FePO<sub>4</sub>/dodecylamine hybrid
nanosheets, and <sup>14</sup>C was incorporated in the synthesis. <sup>14</sup>C-labeled graphene was spiked to artificial freshwater and
the uptake and depuration of graphene by <i>Daphnia magna</i> were assessed. After exposure for 24 h to a 250 μg/L solution
of graphene, the graphene concentration in the organism was nearly
1% of the organism dry mass. These organisms excreted the graphene
to clean artificial freshwater and achieved roughly constant body
burdens after 24 h depuration periods regardless of the initial graphene
exposure concentration. Addition of algae and humic acid to water
during the depuration period resulted in release of a significant
fraction (>90%) of the accumulated graphene, but some still remained
in the organism. Accumulated graphene in adult <i>Daphnia</i> was likely transferred to the neonates. The uptake and elimination
results provided here support the environmental risk assessment of
graphene and the graphene quantification method is a powerful tool
for additional studies