The Use of Retinoids for the Prevention and Treatment of Skin Cancers: An Updated Review

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.     

SoTCM: a scene-oriented task complexity metric for gaze-supported teleoperation tasks

Recent developments in human–robot interaction (HRI) research have heightened the need to incorporate indirect human signals to implicitly facilitate intuitive human–guided interactions. Eye-gaze has been widely used nowadays as an input interface in multi-modal teleoperation scenarios due to their advantage in revealing human intentions and forthcoming actions. However, to date, there has been no discussion about how the structure of the environment, that the human is interacting with, could affect the complexity of the teleoperation task. In this paper, a new metric named “Scene-oriented Task Complexity Metric” (SoTCM) is proposed to estimate the complexity of a certain scene that is involved in eye-gaze-supported teleoperation tasks. The proposed SoTCM objectively estimates the effort that could be exerted by the human operator in terms of the expected time required to point at all the informative locations retrieved from the scene under discussion. The developed SoTCM depends on both the density and distribution of the informative locations in the scene, while incorporates the eye movement behavior found in the psychology literature. The proposed SoTCM is subjectively validated by using the time-to-complete index in addition to the standard (NASA-TLX) workload measure in eight varying structure scenes. Results confirmed a significant relation between SoTCM and the measured task workload which endorses the applicability of using SoTCM in predicting scene complexities and subsequently the task workload in advance.     

Effect of Sm substitution on the magnetic and electrical properties of Cu-Zn ferrite

Samples of the chemical formula Cu_0.5Zn_0.5Fe_2–x Sm _x O₄ where x = 0.0, 0.02, 0.04, 0.06, 0.08 and 0.1 are studied. X-rays analysis indicated that all investigated samples are formed in a single cubic phase. The lattice parameter is found to increase relative to x = 0.0 except x = 0.02. The grain size is decreased for all samples relative to unsubstituted one except that with x = 0.02. It is noticed that the sample with x = 0.02 has the highest values of initial permeability, magnetization and Curie temperature, T _c. The homogeneity of the samples, the coercive field as well as T _c are found to decrease while the electrical resistivity increases with increasing Sm content.     

Use of three-dimensional dynamic analysis to interpret earthquake damage

A comparison is made for several major items of electrical equipment between observed behavior and response predicted using a general three-dimensional dynamic analysis. This was done as part of a major study for the Bonneville Power Administration. The items of equipment were subjected to ground motions from the 9 February 1971, San Fernando Earthquake which resulted in major damage. The correlation between analyses and observed behavior provided a general verification of the analysis procedures used.     

Learning from hint for the conservative motion of the constrained industrial redundant manipulators

A neural network (NN)-based kinematic inversion of industrial redundant arms is developed in this paper to conserve the joint configuration in cyclic trajectories. In the developed approach, the Widrow–Hoff NN with an online adaptive learning algorithm derived by applying Lyapunov approach is introduced. Since this kinematic inversion has an infinite number of joint angle vectors, a fuzzy neural network system is designed to provide an approximate value for that vector. Feeding this vector as an additional hint input vector to the NN limits and guides the output of the NN within the self-motion of the manipulator. The derivation of the candidate Lyapunov function, which is designed to achieve the joint configurations conservation in addition to the joint limits avoidance, leads to a computationally efficient online learning algorithm of the NN. Simulations are conducted for the PA-10 redundant manipulator to bear out the efficacy of the developed approach for tracking closed trajectories.     

A comparative study of NN- and EKF-based SFDA schemes with application to a nonlinear UAV model

In this article, we propose two schemes for sensor fault detection and accommodation (SFDA): one based on a neural network (NN) and the other on an extended Kalman filter (EKF). The objective of this article is to compare both approaches in terms of execution time, robustness to poorly modelled dynamics and sensitivity to different fault types. The schemes are tested on an unmanned air vehicle (UAV) application where traditional sensor redundancy methods can be too heavy and/or costly. In an attempt to reduce the false alarm rates and the number of undetected faults, a modified residual generator, originally proposed in Samy, Postlethwaite, and Gu in 2008 (Samy, I., Postlethwaite, I., and Gu, D.-W. (2008a). Neural Network Sensor Validation Scheme Demonstrated on a UAV Model, in IEEE Proceedings of CDC, Cancun, Mexico, pp. 1237–1242) is implemented. Simulation work is presented for use on a UAV demonstrator under construction with support from BAE systems and EPSRC. Results have shown that the NN-SFDA scheme outperforms the EKF-SFDA scheme with only one missed fault, zero false alarms and an average estimation error of 0.31°/s for 112 different test conditions.     

Integration of dialysis membranes into a poly(dimethylsiloxane) microfluidic chip for isoelectric focusing of proteins using whole-channel imaging detection

A poly(dimethylsiloxane) microfluidic chip-based cartridge is developed and reported here for protein analysis using isoelectic focusing (IEF)-whole-channel imaging detection (WCID) technology. In this design, commercial dialysis membranes are integrated to separate electrolytes and samples and to reduce undesired pressure-driven flow. Fused-silica capillaries are also incorporated in this design for sample injection and channel surface preconditioning. This structure is equivalent to that of a commercial fused-silica capillary-based cartridge for adapting to an IEF analyzer (iCE280 analyzer) to perform IEF-WCID. The successful integration of dialysis membranes into a microfluidic chip significantly improves IEF repeatability by eliminating undesired pressure-driven hydrodynamics and also makes sample injection much easier than that using the first-generation chip as reported recently. In this study, two microfluidic chips with a 100-microm-high, 100-microm-wide and a 200-microm-high, 50-microm-wide microchannel, respectively, were applied for qualitative and quantitative analysis of proteins. The mixture containing six pI markers with a pH range of 3-10 was successfully separated using IEF-WCID. The pH gradient exhibited a good linearity by plotting the pI value versus peak position, and the correlation coefficient reached 0.9994 and 0.9995 separately for the two chips. The separation of more complicated human hemoglobin control sample containing HbA, HbF, HbS, and HbC was also achieved. Additionally, for the quantitative analysis, a good linearity of IEF peak value versus myoglobin concentration in the range of 20-100 microg/mL was obtained.