Design and motion analysis of vibration-driven small robot Rizeh

Vibration mechanism is good candidates to be used as actuation system in small robots. However, mini fabrication of small electrical and mechanical drives is a challenging issue. Moreover, no analytical model for motion analysis of vibration driven robots is devised. In this paper, a small robot is developed. To setup a low-cost robot, cell phone vibrators are employed as actuation mechanism. Motion principle of the robot is analytically obtained and appropriate mechanical and electronic derives are designed. Some technical tips are employed to reduce the size of the robot. The obtained model was evaluated by simulations in MSC.ADAMS as well as some standard experiments on a real robot named Rizeh. Moreover, the robot is tested in a line following task, as a typical task for mobile robots.     

TP53 Targeted Deep Sequencing of Cell-Free DNA in Esophageal Squamous Cell Carcinoma Using Low-Quality Serum: Concordance with Tumor Mutation

Circulating cell-free DNA (cfDNA) is emerging as a potential tumor biomarker. CfDNA-based biomarkers may be applicable in tumors without an available non-invasive screening method among at-risk populations. Esophageal squamous cell carcinoma (ESCC) and residents of the Asian cancer belt are examples of those malignancies and populations. Previous epidemiological studies using cfDNA have pointed to the need for high volumes of good quality plasma (i.e., >1 mL plasma with 0 or 1 cycles of freeze-thaw) rather than archival serum, which is often the main available source of cfDNA in retrospective studies. Here, we have investigated the concordance of TP53 mutations in tumor tissue and cfDNA extracted from archival serum left-over from 42 cases and 39 matched controls (age, gender, residence) in a high-risk area of Northern Iran (Golestan). Deep sequencing of TP53 coding regions was complemented with a specialized variant caller (Needlestack). Overall, 23% to 31% of mutations were concordantly detected in tumor and serum cfDNA (based on two false discovery rate thresholds). Concordance was positively correlated with high cfDNA concentration, smoking history (p-value = 0.02) and mutations with a high potential of neoantigen formation (OR; 95%CI = 1.9 (1.11–3.29)), suggesting that tumor DNA release in the bloodstream might reflect the effects of immune and inflammatory context on tumor cell turnover. We identified TP53 mutations in five controls, one of whom was subsequently diagnosed with ESCC. Overall, the results showed that cfDNA mutations can be reliably identified by deep sequencing of archival serum, with a rate of success comparable to plasma. Nonetheless, 70% non-identifiable mutations among cancer patients and 12% mutation detection in controls are the main challenges in applying cfDNA to detect tumor-related variants when blindly targeting whole coding regions of the TP53 gene in ESCC.     

Links between sustainability and technology development

This article presents important official statements on the role of technology in sustainable development, such as some supporting cleaner production, sustainable development strategy, and the Environmental Technologies Action Plan (ETAP) of the European Union (EU). The author shows that sustainability entails more than using environmentally friendly technologies and products to achieve economic growth. The framework of sustainability implies that the impacts of a technology should be assessed using methods such as Constructive Technology Assessment (CTA) at the global and local levels to improve positive effects. The author refers to the case of pervasive computing as an area requiring such assessment.     

Evaluation of fitness of design in urban historical context: From the perspectives of residents

Historic city cores in many countries either fell into neglect or suffered from harmful developments. Due to a variety of reasons, conservation projects failed to preserve socio– cultural assets of historic environments. One of these reasons is that experts who involve in the development of historical context completely disregard the communities in such historic areas or their inhabitants. This paper looks into residents’ preferences on infill design projects as part of urban development in historical contexts. It aims to investigate preference ratings of those residents who live in urban historical context in terms of the quality of new infill design and its relationship to the historical surroundings. This research attempts to evaluate the best design strategies from the point view of the residents as well as the effects of cognitive properties on their preferences. Methodologically, a case study approach was adopted with 204 residents as participants in this survey. The contributive elements that are essential to the quality of fitness are identified through quantitative analysis. The findings of this research indicate that the most preferred design strategies are “Literal Replication” and “Invention within Style” from the perspective of the residents, who prefer, to a greater degree, new buildings in historical context replicating something from their surroundings. These findings are useful to experts and major organisations to conduct successful infill development, with consideration of the perceptions of the residents on the changes in their historical context.     

Calculated and measured absorption cross sections of lossy objects in reverberation chamber

Reverberation chambers can be used to measure radiation efficiency of small antennas when these are located close to lossy objects. The lossy objects represent a heavy loading of the chamber. This loading is characterized by the mean absorption cross section of the lossy objects. This paper describes how this mean absorption cross section can be calculated from the scattered far field of an object by using the forward scattering theorem, or from a more laborious near-field evaluation. Results for lossy spheres and cylinders are calculated by using three different codes, based on spherical mode expansion, finite difference time domain techniques, and moment methods, respectively. The results for the cylinder are compared with measured levels in a reverberation chamber.     

Evaluation of bonding effectiveness of a self-etch and an etch-and-rinse adhesive resin to un-treated and Er:Yag laser treated dentin using mini-interfacial fracture toughness test

The aim of current study was to assess interfacial bonding effectiveness of self-etch and etch-and-rinse dental adhesives to untreated and Er:YAG laser-treated dentine using mini-interfacial fracture toughness (mini-iFT) test. 32 selected non-carious third molars were divided into two groups: untreated and Er:YAG laser treated. The laser-treated specimens were subjected to Er:YAG laser with energy density of 25.82?J/cm². Both groups were further assigned to two groups based on adhesive systems: self-etch and etch-and-rinse. The teeth were sectioned perpendicular to the adhesive/dentine interface to obtain 1.5?×?2?mm wide longitudinal rectangular sections. A single notch then was prepared at the adhesive-dentine interface. The mini-iFT test was done via a 4-point bend testing until failure and the KIC was calculated. All specimens were observed using a, scanning electron microscope (SEM). The data were analysed using two-way analysis of variance (ANOVA) at a significant level of 0.05. Weibull parameters including Weibull modulus and characteristic strength also were calculated for each experimental group. Two-way ANOVA showed both variables (the type of adhesive system and laser treatment) significantly influenced the mini-iFT values of specimens (p?≤?0.001). The self-etch and laser-treated group showed lower mini-iFT than the etch-and-rinse and untreated samples. SEM observations revealed that the fracture region was located at the adhesive-dentine interface in most of the specimens. The Er:YAG laser treatment may adversely affects the bonding effectiveness of the dentine/adhesive interface. The mini-iFT method can be used as a discriminative and valid method for the evaluation of bonding effectiveness at the adhesive-dentine interface.     

Diffusion creep and superplasticity in aluminium alloys

The plastic deformation of two classes of fine-grained aluminium alloys at elevated temperatures and slow strain rates have been investigated. One class of material, Al–Cu–Zr, was processed to develop banded microstructures; the other class, based on Al–(Mg)–Mn, had near-equiaxed microstructures. In both classes, superplastic behaviour was found in the variants with the higher solute content. The evolution of the banded microstructures and the results from surface grid measurement in the Al–(Mg)–Mn alloys give results which indicate that the superplasticity is primarily a result of diffusion creep, and the effect of solute is proposed to be via an enhancement of solvent self-diffusion.     

Different types of bioceramics as dental pulp capping materials: A systematic review

The aim of this study was to summarize and systemically review the different types of bioceramics that have been proposed to be used as direct dental pulp capping materials for dentin regeneration in permanent teeth. This article reviewed the studies carried out on the bioceramic materials as dental pulp capping agents. PubMed, Embase, Cochrane Central Register of Controlled Trials, and Scopus electronic databases were searched with the selected keywords. The retrieved articles were evaluated by 2 reviewers according to the inclusion and exclusion criteria and the extracted data were arranged in Tables. After removing duplicate articles and further screening, 3126 articles were retrieved in this review. Following discussing the composition and characteristics of different types of bioceramics reported in the literature, 47 articles that met the inclusion criteria were included in this systematic review. The results of this review showed that certain types of calcium silicate-based materials, mineral trioxide aggregate (MTA), and Biodentine seem to be the most effective bioceramics currently used for direct pulp capping in permanent teeth compared with that of other types of bioceramics. In addition, different types of calcium phosphate materials like tricalcium phosphates and bioactive glasses have been recently introduced as alternative bioceramics for dental pulp capping. Calcium phosphates might be considered as more appropriate pulp capping materials in future because of their unique characteristics. However, because of lack of promising information, only further well-designed in vitro and long term clinical studies are required to confirm the most appropriate type of bioceramics for direct dental pulp capping procedures.