Simple and easy to implement testbeds are needed to further advance molecular communication research. To this end, this paper presents an in-vessel molecular communication testbed using magnetic nanoparticles dispersed in an aqueous suspension as they are also used for drug targeting in biotechnology. The transmitter is realized by an electronic pump for injection via a Yconnector. A second pump provides a background flow for signal propagation. For signal reception, we employ a susceptometer, an electronic device including a coil, where the magnetic particles move through and generate an electrical signal. We present experimental results for the transmission of a binary sequence and the system response following a single injection. For this flowdriven particle transport, we propose a simple parameterized mathematical model for evaluating the system response.

Background. The wide range of restorative materials available for use in the computer-aided design/ computer-aided manufacturing (CAD/CAM) technology requires a better understanding of their esthetic properties.Objectives. The aim of the study was to assess the stability of the color and translucency of different CAD/ CAM restorative materials before and after being subjected to different staining solutions. Material and methods.A total of 160 disc-shaped specimens were prepared from glass ceramic (IPS-e.max ® -CAD and Celtra Duo ® ), high-translucency zirconia (Lava TM Plus), resin nanoceramic (Lava TM Ultimate), and hybrid ceramic (VITA ENAMIC ® ) CAD/CAM blocks (5 groups, n = 32). The specimen color and translucency parameter (TP) were assessed using a spectrophotometer at baseline and after subjecting the specimens to different staining solutions (coffee, cola, ginger, and water). Changes in color (ΔE) and TP (ΔTP) were calculated. The data was analyzed using the analysis of variance (ANOVA) and Tukey' s post hoc test (p < 0.05). The correlation between ΔE and ΔTP was investigated using Pearson' s correlation coefficient.Results. Staining significantly affected the baseline color of all specimens. Ginger had the most significant effect on Lava Plus (ΔE = 4.01 ±1.2), cola on Celtra Duo (ΔE = 2.29 ±0.25) and coffee on Lava Ultimate (ΔE = 2.59 ±0.17). Generally, IPS-e.max-CAD showed the smallest ΔE. No significant differences in ΔTP were found between different staining solutions. Increased ΔE correlated with decreased translucency for all the tested materials and staining solutions. Conclusions.Staining had a marked effect on the color and translucency of the tested CAD/CAM materials. The color change was staining solution-and material-dependent, with IPS-e.max-CAD showing the greatest color stability.

Superparamagnetic iron oxide nanoparticles (SPIONs) have recently been introduced as information carriers in a testbed for molecular communication (MC) in duct flow. Here, a new receiver for this testbed is presented, based on the concept of a bridge circuit. The capability for a reliable transmission using the testbed and detection of the proposed receiver was evaluated by sending a text message and a 80 bit random sequence at a bit rate of 1/s, which resulted in a bit error rate of 0 %. Furthermore, the sensitivity of the device was assessed by a dilution series, which gave a limit for the detectability of peaks between 0.1 to 0.5 mg/mL. Compared to the commercial susceptometer that was previously used as receiver, the new detector provides an increased sampling rate of 100 samples/s and flexibility in the dimensions of the propagation channel. Furthermore, it allows to implement both single-ended and differential signaling in SPION-bases MC testbeds.

Introduction Dental ergonomics aim to improve the safety and efficiency of dentists, reducing possible occurrence of musculoskeletal disorders (MSDs). Factors affecting dental ergonomics include gender, tooth position, and use of equipment such as magnifying loupes. Since work habits are acquired early during undergraduate dental training, it is essential to assess the ergonomics of students at the preclinical training level. Objectives The present study aimed to assess the ergonomics of preclinical dental students in different clinical settings and their correlation to potential MSDs. Methods Student posture was assessed during preclinical restorative training using the Dental Ergonomics Assessment rubrics visual scale. The variables tested were use of magnification, gender, and tooth position. Musculoskeletal (MS) pain was reported using a questionnaire. Results were analyzed statistically using Mann‐Whitney U test and Wilcoxon t‐test (P < 0.05). Spearman test was used to determine the correlation between posture and pain. Results Use of magnification and tooth position significantly affected student posture. Female students had worse posture in certain clinical situations. Reported MS pain positively correlated with poor posture. Conclusion The use of magnifying loupes could have a positive impact on the ergonomics of dental students during their preclinical training, possibly decreasing the risk of developing MSDs.