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Triboelectric nanogenerator (TENG) development is undergoing rapid progress utilizing the state‐of‐the‐art 3D‐printing technologies. Herein a critical analysis of the latest developments in 3D‐printed wearable and implantable TENGs that can be used to energize small portable electronic and biomedical devices is presented. Recent progress in 3D‐printed triboelectric nanogenerator (3DP‐TENG) materials and architectural formations, as well as their performance, is evaluated for powering systems that implement physiological monitoring, multifunctional sensing, electronic energizing, noise canceling, dust filtering, and self‐healing. Furthermore, the review explicitly focuses on the 3D‐printing approaches used to form stable and robust 3DP‐TENGs. In addition, the key challenges to improving the performance of 3DP‐TENGs for optimal energy harvesting are discussed, and a roadmap is given for research and translation to commercial markets in the next decade.

Soft robotics is a recent and rapidly growing field of research that encompasses emerging advances in functional materials, fabrication, modelling, and performance control with important applications in the manipulation of fragile objects. The incorporation of three-dimensional (3D) printing into the fabrication of soft robots facilitates the customisation of their functions by the strategic placement of functional materials into locations that may be inaccessible by conventional manufacturing methods. Most current 3D-printed soft robots, however, are fabricated without considering their autonomy. In four-dimensional (4D) printing, the functionality of a soft robot is introduced during the printing process. To control this functionality, specific functional materials are embedded in desired locations. Four-dimensional printing and machine learning techniques provide new possibilities for developing stand-alone closed-loop 4D-printed soft robots. This review paper presents the current approaches employed to design and construct 4D-printed soft robots with customised geometrical, functional, and control properties. Keywords: Closed-loop, 4D printing, Soft robot, Machine learning, Control

Tremors are the most common type of movement disorder and affect the lives of those experiencing them. The efficacy of tremor therapies varies according to the aetiology of the tremor and its correct diagnosis. This study develops a portable measurement device capable of non-contact measurement of the tremor, which could assist in tremor diagnosis and classification. The performance of this device was assessed through a validation process using a shaker at a controlled frequency to measure human tremors, and the device was able to measure vibrations of 50 Hz accurately, which is more than twice the frequency of tremors produced by humans. Then, the device is tested to measure the tremors for two different activation conditions: rest and postural, for both hand and leg. The measured non-contact tremor vibration data successfully led to tremor classification in the subjects already diagnosed using a contact accelerometer.

Background and PurposePercutaneous nephrolithotomy (PCNL) can be done in patients who have previously had open nephrolithotomy. Currently, dilatation of the nephrostomy tract is achieved using an Amplatz renal dilator or telescopic metal dilators in these patients. The aim of this study was to compare the safety and efficacy of the one-shot procedure in patients with previous open nephrolithotomy with those of the current telescopic technique.Patients and MethodsThirty-one patients with past history of open surgery for kidney stone disease underwent PCNL at our institution from February 2006 to March 2007. Patients were randomly divided into two groups according to dilation technique used group A (telescopic procedure) and group B (one-shot procedure). X-ray exposure, blood loss, and complications were evaluated.ResultsNo significant difference in hemoglobin decrease was seen in the two groups. The stone-free and complication rates were the same in the two groups. Fluoroscopy time during the one-shot procedure was significantly shorter than that of the telescopic procedure (P< 0.000).ConclusionOur experience indicated that the one-shot procedure is feasible in patients with previous open nephrolithotomy. It is as safe and effective as the telescopic procedure, with significant reduction in x-ray exposure. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) is a capable technology based on a wide range of parameters. The goal of this study is to make a comparison between infill pattern and infill density generated by computer-aided design (CAD) and FDM. Grid, triangle, zigzag, and concentric patterns with various densities following the same structure of the FDM machine were designed by CAD software (CATIA V5®). Polylactic acid (PLA) material was assigned for both procedures. Surface roughness (SR) and tensile strength analysis were conducted to examine their effects on dog-bone samples. Also, a finite element analysis (FEA) was done on CAD specimens to find out the differences between printing and simulation processes. Results illustrated that CAD specimens had a better surface texture compared to the FDM machine while tensile tests showed patterns generated by FDM were stronger in terms of strength and stiffness. In this study, samples with concentric patterns had the lowest average SR (Ra) while zigzag was the worst with the value of 6.27 µm. Also, the highest strength was obtained for concentric and grid samples in both CAD and FDM procedures. These techniques can be useful in producing highly complex sandwich structures, bone scaffolds, and various combined patterns to achieve an optimal condition.

This paper presents nonlinear finite element (FE) models to predict time- and temperature-dependent responses of shape memory polymer (SMP) foams in the large deformation regime. For the first time, an A SMP foam constitutive model is implemented in the ABAQUS FE package with the aid of a VUMAT subroutine to predict thermo-visco-plastic behaviors. A phenomenological constitutive model is reformulated adopting a multiplicative decomposition of the deformation gradient into thermal and mechanical parts considering visco-plastic SMP matrix and glass microsphere inclusions. The stress split scheme is considered by a Maxwell element in parallel with a hyper-elastic rubbery spring. The Eyring dashpot is used for modelling the isotropic resistance to the local molecular rearrangement such as chain rotation. A viscous flow rule is adopted to prescribe shear viscosity and stress. An evolution rule is also considered for the athermal shear strengths to simulate macroscopic post-yield strain-softening behavior. In order to validate the accuracy of the model as well as the solution procedure, the numerical results are compared to experimental responses of Styrene and Polyurethane SMP foams at different temperatures and under different strain rates. The results show that the introduced FE modelling procedure is capable of capturing the major phenomena observed in experiments such as elastic and elastic-plastic behaviors, softening plateau regime, and densification.

Advancements in materials science and fabrication techniques have contributed to the significant growing attention to a wide variety of sensors for digital healthcare. While the progress in this area is tremendously impressive, few wearable sensors with the capability of real-time blood pressure monitoring are approved for clinical use. One of the key obstacles in the further development of wearable sensors for medical applications is the lack of comprehensive technical evaluation of sensor materials against the expected clinical performance. Here, we present an extensive review and critical analysis of various materials applied in the design and fabrication of wearable sensors. In our unique transdisciplinary approach, we studied the fundamentals of blood pressure and examined its measuring modalities while focusing on their clinical use and sensing principles to identify material functionalities. Then, we carefully reviewed various categories of functional materials utilized in sensor building blocks allowing for comparative analysis of the performance of a wide range of materials throughout the sensor operational-life cycle. Not only this provides essential data to enhance the materials’ properties and optimize their performance, but also, it highlights new perspectives and provides suggestions to develop the next generation pressure sensors for clinical use.

Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analysed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.

In this paper motion of rigid rod on a circular surface is studied analytically. A new analytical method called modified homotopy perturbation method (MHPM) is applied for solving this problem in different initial conditions to show capability of this method. The governing equation for motion of a rigid rod on the circular surface without slipping have been solved using MHPM. The efficacy of MHPM for handling nonlinear oscillation systems with various small and large oscillation amplitudes are presented in comparison with numerical benchmarks. Outcomes reveal that MHPM has an excellent agreement with numerical solution. The results show that by decreasing the oscillation amplitude, the velocity of rigid rod decreases and for A=π/3 the velocity profile is maximum.

Chaotic vibration has been identified in the flexible automotive wiper blade at certain wiping speeds. This irregular vibration not only decreases the wiping efficiency, but also degrades the driving comfort. A reliable nonlinear system identification namely nonlinear auto regressive exogenous Elman neural network (NARXENN) was adopted in first stage of this survey to model the flexible dynamics of wiper blade with acquired experimental data. In controller design part, taking into account environmental and external disturbances that cause changes in the dynamic characteristics of the system demanded a robust controller to make a trade off between the worst and best scenario. An active fuzzy force controller (AFLC) supervised by multi objective genetic algorithm (MOGA) is developed to keep both interests of noise and vibration redaction of automobile wiper blade at the reasonable rise time.

Abstract Background Skin cancer is the most common cancer worldwide and commonly classified into malignant melanoma (MM) and Nonmelanoma skin cancers (NMSCs), which mainly include basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The extent to which Long Interspersed Element-1 (LINE-1, L1) ORF1p is expressed in cutaneous malignancies remains to be evaluated. This study aimed to assess LINE-1 ORF1p immunoreactivity in various skin cancer subtypes. Method The expression level of LINE-1 ORF1p was evaluated in 95 skin cancer specimens comprising 36 (37.9%) BCC, 28 (29.5%) SCC, and 31 (32.6%) melanoma using the tissue microarray (TMA) technique. Then the association between expression of LINE-1 encoded protein and clinicopathological parameters was analyzed. Results We showed that LINE-1 ORF1p expression level was substantially higher in BCC and SCC patients compared with melanoma samples (p 0.05). Conclusions According to our observation, LINE-1 ORF1p immunoreactivity in various skin tumor subtypes extends previous studies of LINE-1 expression in different cancers. LINE-1ORF1p overexpression in NMSCs compared with MM can be considered with caution as a tumor-specific antigen for NMSCs.

Today, entrepreneurship is one of the most important strategies for the development of local communities that in order to develop it, basic studies in this field are essential. Given the importance of entrepreneurship in the economic and social development of todaychr('39')s societies, it is important to explain the status of entrepreneurial indicators among villagers, as well as identify factors that can be effective in strengthening entrepreneurial indices. The present quantitative study, conducted via descriptive-analytical method, is aimed at investigating and assessing the state of entrepreneurship indicators and identifying factors affecting those indicators in rural residences of Ravansar Township. The data gathering tool was a questionnaire. The statistical population of the study consists of all heads of rural households in Ravansar Township as 5668 individuals. To achieve the research objectives, comparison tests, frequency distribution table, Pearson correlation coefficient and Spearman and multivariate regression were used in SPSS software. The results regarding enjoyment of heads of households from the entrepreneurship indicators indicated that the degree of enjoyment of 39.2% of the participants were at low and very low levels, 45.5% of them were at the moderate level, and about 15.3% of them were at high and very high levels. All in all, the mean calculated for villagers’ enjoyment of entrepreneurship indicators was about 2.74% which is a level lower than the moderate one. The results of multivariate regression indicated that five identified variables could explain about 70% of the variance of entrepreneurship indicators in the studied area. The identified variables and the explained percentage of each of them are as follows: socioeconomic status (0.391), access to facilities and equipment (0.315), social capital (0.244), performance of management institutions (0.240), and ownership of capital resources (0.191) respective to their significance. Results the relationship between entrepreneurship indices and the variables studied showed in among the 11 variables studied, the relationship between entrepreneurship and gender variables; Internet access, age, household size, and distance to essential centers were not statistically significant and the mentioned variables have not related to entrepreneurship. © 2018 Geographical Researches

Background: The promoter methylation and single nucleotide polymorphisms (SNPs) affect the transcription activity of cancer-related genes in several cancers including diffuse gastric cancer (DGC). Here we aimed to evaluate the promoter methylation status and the rs16260 at the promoter region of the CDH1 gene in DGC. Methods: This case-control study was performed of 48 formalin-fixed paraffin-embedded (FFPE) blocks of DGC patients and 41 fresh frozen tissue samples of healthy individuals. Methylation status was evaluated using methylation-specific polymerase chain reaction (PCR) and the rs16260 at the promoter region of the CDH1 gene was assessed using PCR and sequencing method. Results: The occurrence of methylation at the promoter region of the CDH1 gene in DGC patients was significantly higher than control samples (P < 0.0001). The methylated status was significantly associated with the poor differentiated histological type of DGC (P = 0.0428). The frequency of AC genotype and the A allele in DGC patients was significantly higher than the control subjects (P = 0.006 and 0.003, respectively). Conclusions: Here we showed that methylation at the CDH1 promoter may contribute to the DGC development, and also the AC genotype was associated with the risk of DGC.