Wearable electrochemical glucose sensor of high flexibility and sensitivity using novel mushroom-like gold nanowires decorated bendable stainless steel wire sieve.

Long-term high blood glucose levels brings extremely detrimental effect on diabetic patients, such as blindness, renal failure, and cardiovascular diseases. Therefore, there is an urgent need to develop highly flexible and sensitive sensors for precisely non-invasive and continuous monitoring glucose levels. Herein, we present a highly flexible and sensitive wearable sensor for non-enzymatic electrochemical glucose analysis with vertically aligned mushroom-like gold nanowires (v-AuNWs) chemically grown on stainless steel wire sieve (SSWS) as integrated electrode. Owing to the unique nanostructures and excellent catalysis of the v-AuNWs, the as-fabricated glucose sensors exhibit superior flexibility and excellent electro-catalytic capability. In detail, these sensors display rapid response towards glucose within 5 s, and the sensor constructed with v-AuNWs for growth time of 15 min shows the highest sensitivity of 180.1 µA mM-1 cm-2 within a wide linear range of 6.5 × 10-4 mM-12.0 mM and the lowest detection limit of 0.65 µM (S/N = 3). It is noteworthy that due to the good ductility of the v-AuNWs and their strong contact with the SSWS substrate, these glucose sensors exhibit no obvious response variation after repeated bending for 100 times at bending angle of 180°. Additionally, the glucose sensors display superior anti-interfering capability as well as desirable repeatability. More importantly, these glucose sensors can be attached on human skin to determine sweat glucose reliably and analyze glucose concentration in human serum in vitro.

Evaluating the effectiveness of a novel digital evaluation technology on dental preclinical crown preparation training.

OBJECTIVES: To evaluate the assessment scores of a novel digital training program versus traditional training in dental preclinical crown preparation. METHODS: Crown preparations in two consecutive preclinical training sessions were retrospectively collected and assigned to three groups: traditional group (TG), scanning group (SG), and digital evaluation group (DG). Students in the TG (n = 20) were taught by conventional visual grading, while students in the SG (n = 25) received three-dimensional feedback from digitally scanned preparations. All the SG students continued with supplementary digital evaluation and preparations were allocated into the DG (n = 25). Comparison of total scores between groups was investigated using independent samples t-test and paired samples t-test. Mann‒Whitney U-test and Wilcoxon signed-rank test were used to statistically analyze the differences in subdividing categories. The level of significance was p < 0.05. Questionnaires on the digital evaluation procedure were answered by students in DG. RESULTS: The results showed a significant improvement (p < 0.01) in the total scores of DG than those of TG and SG, while there were no statistically significant differences between TG and SG. Scores of surface finish and undercut improved significantly in DG compared to TG and SG. The reduction scores of DG were significantly higher than those of SG. Students' feedback indicated a positive perspective on the implementation of the novel digital evaluation technology. CONCLUSIONS: These findings suggest that digital evaluation technology is useful for preclinical crown preparation training. Attention should also be paid to studying the optimal integration of digital dentistry into traditional dental curricula and its effects on students' learning curves.

Polyethylenimine-grafted nitrogen-doping magnetic biochar for efficient Cr(VI) decontamination: Insights into synthesis and adsorption mechanisms.

Herein, polyethylenimine (PEI)-grafted nitrogen (N)-doping magnetic biochar (PEIMW@MNBCBM) was synthesized, and characterization results showed that the microwave-assisted PEI grafting and ball milling-assisted N doping introduced abundant amino, pyridine N and pyrrole N structures onto biochar, which possessed high affinity to Cr(VI) in the anion form. The as-prepared PEIMW@MNBCBM displayed pH-dependence adsorption performance and high tolerance to co-existing ions with maximum uptake capacity of Cr(VI) identified as 183.02 mg/g. Furthermore, PEIMW@MNBCBM could bind Cr(VI) through electrostatic attraction, complexion, precipitation, reduction and pore filling. Especially, effective reduction of Cr(VI) was ascribed to cooperative electron transfer of partial oxygen-containing functional groups, intramolecular pyridine/pyrrole N, protonated amino and Fe2+ on the adsorbent, while oxygen-containing and amino functional groups from N-doping biochar and PEI synergistically complexed Cr(III) via providing lone pair electrons to form coordinate bonds. Furthermore, the stable precipitation was formed between Fe3+ and Cr(III). Additionally, the Cr(VI) elimination efficiency could maintain 95.83% even after four adsorption-desorption cycles, suggesting PEIMW@MNBCBM as a high-performance adsorbent for Cr(VI) contaminated water remediation.