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Additive manufacturing (AM) or solid freeform fabrication (SFF) technique is extensively used to produce intrinsic 3D structures with high accuracy. Its significant contributions in the field of tissue engineering (TE) have significantly increased in the recent years. TE is used to regenerate or repair impaired tissues which are caused by trauma, disease and injury in human body. There are a number of novel materials such as polymers, ceramics and composites, which possess immense potential for production of scaffolds. However, the major challenge is in developing those bioactive and patient-specific scaffolds, which have a required controlled design like pore architecture with good interconnectivity, optimized porosity and microstructure. Such design not only supports cell proliferation but also promotes good adhesion and differentiation. However, the traditional techniques fail to fulfill all the required specific properties in tissue scaffold. The purpose of this study is to report the review on AM techniques for the fabrication of TE scaffolds.

The present review paper provides a detailed analysis of the widely used AM techniques to construct tissue scaffolds using stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), binder jetting (BJ) and advanced or hybrid additive manufacturing methods.

Subsequently, this study also focuses on understanding the concepts of TE scaffolds and their characteristics, working principle of scaffolds fabrication process. Besides this, mechanical properties, characteristics of microstructure, in vitro and in vivo analysis of the fabricated scaffolds have also been discussed in detail.

The review paper highlights the way forward in the area of additive manufacturing applications in TE field by following a systematic review methodology.

The purpose of this paper is to introduce a new tactile array sensor into the medical field to enhance current robotic minimally invasive surgery (RMIS) procedures that are still limited in scope and versatility. In this paper, a novel idea is proposed in which a tactile sensor array can measure rate of displacement in addition to force and displacement of any viscoelastic material during the course of a single touch. To verify this new array sensor, several experiments were conducted on a diversity of tissues from which it was concluded that this newly developed sensory offers definite and significant enhancements.

The proposed array sensor is capable of extracting force, displacement and displacement rate in the course of a single touch on tissues. Several experiments have been conducted on different tissues and the array sensor to verify the concept and to verify the output of the sensor.

It is shown that this new generation of sensors are required to distinguish the difference in hardness degrees of materials with viscoelastic behavior.

In this paper, a new generation of tactile sensors is proposed that is capable of measuring indentation time in addition to force and displacement. This idea is completely unique and has not been submitted to any conference or journal.

The large blood vessels (LBV) would act as a heat sink and hence play a significant role during photo-thermal therapy. Gold nanoshell was considered as a high-heat absorbing agent in photo-thermal heating to reduce the cooling effect of LBV. The heat sink effect of LBV results in insignificant irreversible tissue thermal damage. The paper aims to discuss these issues.

In this paper, the thermal history of tissue embedded with LBV during photo-thermal heating were calculated using finite element-based simulation technique. A volumetric laser source term based on modified Beer-Lambert law was introduced to model laser heating. The numerically predicted temperature drop was validated against that of previously performed experiments by the authors on tissue mimic embedded with simulated blood vessels. In the later part of the study, Arrhenius equation was coupled with the energy equation to investigate and report the irreversible thermal damage to the bio-tissues.

The results obtained conclude that tissue with different orientation of blood vessels results in different thermal response at the tissue surface. Gold nanoshells were introduced into the laser irradiated tissue to overcome the cooling effect of LBV during plasmonic photo-thermal heating. The effect of size and concentration of nanoparticles on tissue heating were analyzed. The predicted damage parameter was much lower in case of tissue embedded with blood vessel than that predicted in case of bare tissue, which results in incomplete tissue necrosis. Finally, the effects of laser specification, blood vessel specification and blood perfusion on the tissue thermal damage were examined.

The conjugate energy equations in conjunction with Arrhenius equation were solved numerically to predict the tissue irreversible damage embedded with LBV.

At present, electrical heating clothing is widely used to keep ourselves warm at low temperature. The purpose of this paper is to explore the heat transfer performance of electrical heating fabric and the thermal comfort of human skin at low temperature.

The combined model of skin-electrical heating fabric system was established to simulate human skin tissue wearing electrical heating clothing. A series of simulation experiments are designed on the basis of verifying the effectiveness of the combined model. The temperature distribution inside the combined model and on the skin surface under different heating powers is simulated and analyzed. At the same time, the influence of ambient temperature on the thermal performance of electrical heating fabric was explored.

The skin model with blood vessels reflected the temperature change of human skin wearing electrical heating clothing. The higher the heating power of the electrical heating fabric was, the greater the temperature of the skin surface changed, the faster the temperature rose and the longer the time required to reach the stable state would be. After the heating element was electrified, it had the greatest effect on the average temperature of the epidermis and dermis, had smaller effect on the average temperature of subcutaneous layer and had little effect on the temperature of blood vessels. When the heating power was the same, the higher the ambient temperature was, the more obvious the heating effect of electrical heating fabric was. Electrical heating fabrics with different heating powers were suitable for different ambient temperature ranges.

A reasonable and effective evaluation method for the thermal comfort of electrical heating fabric was provided by establishing the skin model and combined model of the skin-electrical heating fabric system. It provides a reference for the design and application of electrical heating clothing.

The purpose of this paper is to investigate the blood flow and temperature distribution in human extremities.

The simulation is carried out from three aspects. Firstly, the hemodynamics in the human upper limb is analyzed by one‐dimensional model for pulsalite flow in an elastic tube. Secondly, the blood flow and heat transfer through living tissues are described basing on porous media theory, and the tissue model is coupled with the one‐dimensional blood flow model. With respect to geometric modeling, MR‐image‐based modeling method is employed to construct a realistic model of the human finger.

It is found that the temperature variation is closely related to the blood flow variation in the fingertip and the blood flow distribution in the tissue is dependent on the locations of large arteries and veins.

Blood flow and temperature distribution in a 3D realistic human finger are firstly obtained by coupling the blood circulation and porous media model.

The purpose of this paper is to provide a method for determining the numerical solutions of the thermal damage of cylindrical living tissues using hyperbolic bioheat model. Due to the complex governing equation, the finite element approach has been adopted to solve these problems. To approve the accuracy of the numerical solution, the numerical outcomes obtained by the finite element approach are compared with the existing experimental study. In addition, the comparisons between the numerical outcomes and the existing experimental data displays that the present mathematical models are efficient tools to evaluate the bioheat transfer in the cylindrical living tissue. Numerical computations for temperatures and thermal damage are presented graphically.

In this section, the complex equation of bioheat transfer based upon one relaxation time in cylindrical living tissue is summarized by using the finite element method. This method has been used here to get the solution of equation (8) with initial conditions (9) and boundary conditions (10). The finite element technique is a strong method originally advanced for numerical solutions of complex problems in many fields, and it is the approach of choice for complex systems. Another advantage of this method is that it makes it possible to visualize and quantify the physical effects independently of the experimental limits. Abbas and his colleagues [26-34] have solved several problems under generalized thermoelastic theories.

In this study, the different values of blood perfusion and thermal relaxation time of the dermal part of cylindrical living tissue are used. To verify the accuracy of the numerical solutions, the numerical outcomes obtained by the finite element procedure and the existing experimental study have been compared. This comparison displays that the present mathematical model is an effective tool to evaluate the bioheat transfer in the living tissue.

The validation of the obtained results by using experimental data the numerical solution of hyperbolic bioheat equation is presented. Due to the nonlinearity of the basic equation, the finite element approach is adopted. The effects of thermal relaxation times on the thermal damage and temperature are studied.

The purpose of this paper is to determine the impact of human age on the distribution of electric field and absorbed energy that originates from a mobile phone.

This research was performed for frequencies of 900, 1800 and 2100 MHz, which are used in a mobile communication system. To obtain the most accurate results, 3 D realistic model of the child’s head has been created whereby the dimensions of this model correspond to the dimensions of a seven-year-old child. Distribution of the electric field and specific absorption rate (SAR) through the child’s head was obtained by numerical analysis based on the finite integration technique.

The results discover that amount of absorbed energy is greater in the surface layers of the child’s head model when the electromagnetic (EM) characteristics of tissues are adjusted for the child. This deviation corresponds to different EM characteristics of biological tissues and organs of an adult person compared to a child.

The study deals with penetrated electrical field and absorbed EM field energy. There is space for further studies of other EM field effects (e.g. thermal effects).

The analysis of obtained results leads to idea that mobile phones and devices aimed for children using should be modified to provide SAR values inside prescribed standards.

The obtained results are foundation for future research on influence of EM fields of mobile devices on human health.

The proposed procedure offers the model for accurate estimation and quality analysis of SAR and EM field distribution inside child head tissue.

The purpose of this paper is to present the design, analysis, fabrication, and assembly of four tooth annular microfabricated tactile sensors integrated with the upper and lower jaws of an endoscopic surgical grasper tool, in order to determine the properties and particularly the compliance of the biological tissues during minimally invasive surgery.

A viscoelastic Kelvin model is employed for tissue characterization. A comprehensive closed form and finite element analysis has been carried out to express the relationship between the force ratio, compliance, and the equivalent viscous damping of the tissue. The designed sensor uses a polyvinyledene fluoride film as its sensing element. The sensor consists of arrays of rigid and compliant elements which are mounted on the tip of an endoscopic surgical grasper tool. Relative force between adjacent parts of the contact object is used to measure the viscoelastic properties.

The tactile sensor is able to characterize different viscoelastic properties of tissues. The experiments validate analytical and finite elements results.

The sensor is designed to integrate with the actual endoscopic tools to measure the softness of tissues.

A novel sensor‐tissue model is presented to characterize the variety of biological tissues.

The purpose of this study was designed to investigate anise oil and geranium oil to amend body weight, serum bile acid and vitamin D, and liver histology in depressed rats.

Eighty male albino rats were divided into normal and depressed rats. Normal rats (40 rats) were divided into four equal groups: control, venlafaxine drug, anise oil and geranium oil groups. Depressed rats (40 rats) were divided into four equal groups: depressed rats, depressed rats + venlafaxine drug, depressed rats + anise oil and depressed rats + geranium oil groups. Body weight, food consumption and water intake were detected. Animal behavior, cerebral cortex and hippocampus neurotransmitters, serum bile acid and vitamin D and liver histology were also investigated in this study.

Body weight (117 ± 7.6 g), food consumption (5.6 ± 1.4 g/day) and water intake (8.7 ± 1.2 ml/day) were significantly decreased (p < 0.001) in depression compared to body weight (153 ± 7.6 g), food consumption (12.7 ± 1.6 g/day) and water intake (15.3 ± 1.6 ml/day) in control. Animal behavioral tests, e.g. sucrose preference (48.8 ± 1.5) test, distance traveled (70.0 ± 16.3), center square entries (0.20 ± 0.10), center square duration (52.18 ± 11.9), tail suspension (54.70 ± 2.9 s) test and forced swimming (134.4 ± 5.5 s) test were significantly decreased (p < 0.001) in depression compared to sucrose preference (89.2 ± 1.7) test, distance traveled (226 ± 90.1), center square entries (1.4 ± 1.8), center square duration (3.6 ± 2.0), tail suspension (19.3 ± 2.1 s) test and forced swimming (83.7 ± 3.6 s) test in control. Cerebral cortex and hippocampus areas neurotransmitters such as serotonin (7.4 ± 1.7 and 1.2 ± 0.54 pg/g tissue), dopamine (6.3 ± 1.5 and 0.86 ± 0.07 pg/g tissue), norepinephrine (8.1 ± 1.7 and 1.4 ± 0.41 pg/g tissue) and gamma aminobutyric acid (GABA) (1.3 ± 0.41 and 0.08 ± 0.04 µmole/g tissue), serum bile acid (46.8 ± 3.5 µmole/L) and vitamin D (1.3 ± 0.37 ng/ml) were significantly decreased (p?0.001) in depression compared to cerebral cortex and hippocampus areas neurotransmitters such as serotonin (16.8 ± 2.1 and 4.0 ± 1.4 pg/g tissue), dopamine (15.7 ± 2.0 and 1.8 ± 0.49 pg/g tissue) norepinephrine (18.2 ± 2.3 and 3.8 ± 1.3 pg/g tissue) and GABA (2.7 ± 0.62 and 0.16 ± 0.06 µmole/g tissue), serum bile acid (90.5 ± 4.3 µmole/L) and vitamin D (2.7 ± 0.58 ng/ml) in control. Depression induced injury to hepatic tissues. Oral supplementation with anise oil and geranium oil ameliorated body weight, serum bile acid and vitamin D and liver histology in depressed rats.

Depression treatment persists for a long time, so the search for a new herbal treatment is of concern due to available sources, cheap and no side effects of herbal plants. Anise oil and geranium oil improved body weight, food consumption, water intake, animal behavioral tests, cerebral cortex and hippocampus areas neurotransmitters, serum bile acid and vitamin D and liver histology in depression.