Fuzzy Based Hybrid Focus Value Estimation for Multi Focus Image Fusion

Due to limited depth-of-field of digital single-lens reflex cameras, the scene content within a limited distance from the imaging plane remains in focus while other objects closer to or further away from the point of focus appear as blurred (out-of-focus) in the image. Multi-Focus Image Fusion can be used to reconstruct a fully focused image from two or more partially focused images of the same scene. In this paper, a new Fuzzy Based Hybrid Focus Measure (FBHFM) for multi-focus image fusion has been proposed. Optimal block size is very critical step for multi-focus image fusion. Particle Swarm Optimization (PSO) algorithm has been used to find optimal size of the block of the images for extraction of focus measure features. After finding optimal blocks, three focus measures Sum of Modified Laplacian, Gray Level Variance and Contrast Visibility has been extracted and combined these focus measures by using intelligent fuzzy technique. Fuzzy based hybrid intelligent focus values were estimated using contrast visibility measure to generate focused image. Different sets of multi-focus images have been used in detailed experimentation and compared the results with state-of-the-art existing techniques such as Genetic Algorithm (GA), Principal Component Analysis (PCA), Laplacian Pyramid discrete wavelet transform (DWT), and aDWT for image fusion. It has been found that proposed method performs well as compare to existing methods.

     

Creep and Fatigue Failure in Single- and Double Hot Arm MEMS Thermal Actuators

Determination of the failure mechanisms of mechanical devices is the key to the design of reliable products. This paper reports an investigation on creep and fatigue failure of microelectromechanical (MEMS) thermal actuators. Finite element modeling is used to predict thermomechanical behavior of actuators under low to moderate voltage differences. The modeling results are compared with experimental results to evaluate the models. Two probable failure modes associated with thermal actuators, that is, fatigue and creep, are investigated, and it is found that creep is the dominant failure mechanism. The creep behaviors of several U-shape and double hot arm thermal MEMS actuators are examined, and their deformation-time curves are obtained numerically and experimentally. The curves follow a typical three-stage creep curve usually observed in metals. The creep life cycles of the devices are compared on the basis of their stress and temperature distributions. This study shows that actuators with the maximum temperature occurring at the location where the high stress is induced have shorter life spans than those experiencing the high stress away from the maximum temperature location. It is concluded that the double hot arm actuators with equal length have longer creep life than the U-shape (single hot arm) actuators.     

Radiological hazards of TENORM in precipitated calcium carbonate generated as waste at nitrophosphate fertilizer plant in Pakistan

The NORM (naturally occurring radioactive material) in phosphate rock is transferred as TENORM (technologically enhanced naturally occurring radioactive material) to phosphatic fertilizers and to the waste generated by the chemical processes. The waste generated at the NP (nitrophosphate) fertilizer plant at Multan in Pakistan is PCC (precipitated calcium carbonate). Thirty samples of the PCC were collected from the heaps of the waste near the fertilizer plant. Activity concentrations of radionuclides in the waste samples were measured by using the technique of gamma ray spectrometry consisting of coaxial type HPGe (high purity germanium) detector coupled with a PC (personal computer) based MCA (multichannel analyzer) through a spectroscopy amplifier. Activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the waste samples were determined to be 273 ± 23 (173-398), 32 ± 4 (26-39) and 56 ± 5 (46-66) Bq kg⁻¹ respectively. The activity concentration of ²²⁶Ra in the PCC waste was found to be higher than that in naturally occurring calcium carbonate (limestone and marble) and in worldwide soil. Radiological hazard was estimated from indoor and outdoor exposure to gamma rays from the PCC. Indoor annual effective dose was higher than 1 m Sv. Potential radiological pollution in the environment from TENORM in the PCC has also been addressed.     

Global buckling of composite structural insulated wall panels

This paper presents a new type of composites structural insulated panels (CSIPs) for structural wall applications. The proposed composite panel is made of low-cost thermoplastic orthotropic glass/poly-propylene (glass–PP) laminate as a facesheet and expanded polystyrene foam (EPS) as a core with very high facesheet/core moduli ratio. The proposed CSIP walls are intended to overcome problems of traditional Structural Insulated Panels (SIPs) such as termite attack, mold buildups and poor penetration resistance against wind borne debris. This paper investigates the behavior of CSIPs under concentric and eccentric loading. CSIPs specimens failed by global buckling mode in which no debonding was observed. The eccentric specimens failed at load 35% lower than that of the concentric ones. Global buckling formulas for concentric and eccentric loading were presented and validated using the experimental results and were in a good agreement. An equivalent stiffness formula was also developed for sandwich wall under in-plane loading considering the shear deformations effect of the core. Design study for CSIP walls is also presented to help in designing this new type of composite panels.     

Microfabricated Biomaterials for Engineering 3D Tissues

Mimicking natural tissue structure is crucial for engineered tissues with intended applications ranging from regenerative medicine to biorobotics. Native tissues are highly organized at the microscale, thus making these natural characteristics an integral part of creating effective biomimetic tissue structures. There exists a growing appreciation that the incorporation of similar highly organized microscale structures in tissue engineering may yield a remedy for problems ranging from vascularization to cell function control/determination. In this review, we highlight the recent progress in the field of microscale tissue engineering and discuss the use of various biomaterials for generating engineered tissue structures with microscale features. In particular, we will discuss the use of microscale approaches to engineer the architecture of scaffolds, generate artificial vasculature, and control cellular orientation and differentiation. In addition, the emergence of microfabricated tissue units and the modular assembly to emulate hierarchical tissues will be discussed.     

Is endoluminal abdominal aortic aneurysm repair using an aortoaortic (tube) device a durable procedure?

BACKGROUND: Controversies over the frequency and intensity of the follow-up care of breast cancer patients exist. Some physicians have adopted an intensive approach to follow-up care that consists of frequent laboratory tests and routine imaging studies, including chest radiographs, bone scans, and CT scans, whereas others have established a minimalist approach consisting of only history, physical examinations, and mammograms. OBJECTIVES: Our objective was to evaluate the role of intensive follow-up on detection of breast cancer recurrence and to examine the impact of follow-up on overall survival. METHODS: During a 10-year period (1986-1996), 129 patients with recurrent disease were identified from a prospective database of 1898 breast cancer patients. The patients with recurrent disease were divided into minimalist or intensive groups according to method of detection. RESULTS: Twenty-seven of 126 (21%) patients were assigned to the intensive method of detection group (LFT, CEA, CA 15-3, chest radiograph, CT scan, and bone scan); 99 of 126 (79%) patients were assigned to the minimal detection group (history, physical examination, and mammography). Distant disease to the bone was the most common initial tumor recurrence, at 27%. History, physical examination, and mammography detected recurrent cancer in approximately the same amount of time as LFTs, tumor markers, CT scans, and chest radiographs (P = .960). When the recurrent patients were divided into intensive and minimalist groups and analyzed by time to detection of recurrence, there was no significant difference between the time to detection in those recurrences detected by intensive methods and those recurrences detected by minimalist methods (P = .95). The independent variables age, tumor size, type of surgery, number of positive nodes, time to recurrence, method of detection, and site of recurrence (regional or distant) were subject to univariate and multivariate analysis by the Cox proportional hazards model. Only two variables had an impact on survival by multivariate analysis: early timing of the recurrence (P = .0011) and the site of the recurrence (P = .02). Timing was defined as early (< or =365 days from the time of diagnosis to recurrence) or late (> or =365 days from the time of diagnosis to recurrence). Early recurrence was the first variable found to be significant on stepwise forward regression analysis. The primary site of recurrence was significant at step two. The method of detection--intensive or minimal--did not significantly affect survival (P = .18). CONCLUSIONS: There is no survival benefit to routine intensive follow-up regimens in detecting recurrent breast cancer. Expensive diagnostic tests such as bone scans, CT scans, and serial tumor markers are best used for detection of metastasis in symptomatic patients.     

Autophagy,Unfolded Protein Response,and Neuropilin-1 Cross-Talk in SARS-CoV-2 Infection: What Can Be Learned from Other Coronaviruses

The COVID-19 pandemic is caused by the 2019–nCoV/SARS-CoV-2 virus. This severe acute respiratory syndrome is currently a global health emergency and needs much effort to generate an urgent practical treatment to reduce COVID-19 complications and mortality in humans. Viral infection activates various cellular responses in infected cells, including cellular stress responses such as unfolded protein response (UPR) and autophagy, following the inhibition of mTOR. Both UPR and autophagy mechanisms are involved in cellular and tissue homeostasis, apoptosis, innate immunity modulation, and clearance of pathogens such as viral particles. However, during an evolutionary arms race, viruses gain the ability to subvert autophagy and UPR for their benefit. SARS-CoV-2 can enter host cells through binding to cell surface receptors, including angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP1). ACE2 blockage increases autophagy through mTOR inhibition, leading to gastrointestinal complications during SARS-CoV-2 virus infection. NRP1 is also regulated by the mTOR pathway. An increased NRP1 can enhance the susceptibility of immune system dendritic cells (DCs) to SARS-CoV-2 and induce cytokine storm, which is related to high COVID-19 mortality. Therefore, signaling pathways such as mTOR, UPR, and autophagy may be potential therapeutic targets for COVID-19. Hence, extensive investigations are required to confirm these potentials. Since there is currently no specific treatment for COVID-19 infection, we sought to review and discuss the important roles of autophagy, UPR, and mTOR mechanisms in the regulation of cellular responses to coronavirus infection to help identify new antiviral modalities against SARS-CoV-2 virus.     

Imprinted microspheres and nanoparticles with diclofenac sodium: effect of solvent on the morphology and recognition properties

To achieve suitable properties for specific applications, we synthesized diclofenac sodium (Ds) imprinted polymer beads with controllable size in the range of around 145 nm to 3 µm in diameter by the precipitation polymerization method using methacrylic acid as functional monomer, trimethylolpropane trimethacrylate as crosslinker and azobisisobutyronitrile as initiator. We analyzed the effect of the porogenic solvent on the morphology and recognition of particles. SEM analysis showed some dissimilarity in appearance of the imprinted polymers. The specific surface areas were 246 m² g^–1 and 260 m² g^–1 for imprinted polymers prepared in a mixture of tetrahydrofuran/acetonitrile (MIP1) and tetrahydrofuran/toluene (MIP2) respectively, which were in good agreement with the binding capacities of 150.4 mg g^–1 for MIP1 and 280.4 mg g^–1 for MIP2, but the imprinted nanoparticles with a specific selectivity factor of 1.5 had a better recognition property to Ds than the analog template meclofenamate sodium monohydrate (Ms) and also faster rebinding kinetics or greater accessibility of Ds. Finally the imprinted microspheres were successfully applied as a solid phase extraction sorbent for the extraction of Ds from human urine with limits of detection and quantification of 0.085 mg L^–1 and 0.227 mg L^–1, respectively. © 2013 Society of Chemical Industry