Showing papers by "Islamic Azad University published in 2019"

A comprehensive review on tyrosinase inhibitors.

Abstract: Tyrosinase is a multi-copper enzyme which is widely distributed in different organisms and plays an important role in the melanogenesis and enzymatic browning. Therefore, its inhibitors can be attractive in cosmetics and medicinal industries as depigmentation agents and also in food and agriculture industries as antibrowning compounds. For this purpose, many natural, semi-synthetic and synthetic inhibitors have been developed by different screening methods to date. This review has focused on the tyrosinase inhibitors discovered from all sources and biochemically characterised in the last four decades.

Exploring Nature and Predicting Strength of Hydrogen Bonds: A Correlation Analysis Between Atoms-in-Molecules Descriptors, Binding Energies, and Energy Components of Symmetry-Adapted Perturbation Theory.

Abstract: This work studies the underlying nature of H-bonds (HBs) of different types and strengths and tries to predict binding energies (BEs) based on the properties derived from wave function analysis. A total of 42 HB complexes constructed from 28 neutral and 14 charged monomers were considered. This set was designed to sample a wide range of HB strengths to obtain a complete view about HBs. BEs were derived with the accurate coupled cluster singles and doubles with perturbative triples correction (CCSD(T))(T) method and the physical components of the BE were investigated by symmetry-adapted perturbation theory (SAPT). Quantum theory of atoms-in-molecules (QTAIM) descriptors and other HB indices were calculated based on high-quality density functional theory wave functions. We propose a new and rigorous classification of H-bonds (HBs) based on the SAPT decomposition. Neutral complexes are either classified as "very weak" HBs with a BE ≥ -2.5 kcal/mol that are mainly dominated by both dispersion and electrostatic interactions or as "weak-to-medium" HBs with a BE varying between -2.5 and -14.0 kcal/mol that are only dominated by electrostatic interactions. On the other hand, charged complexes are divided into "medium" HBs with a BE in the range of -11.0 to -15.0 kcal/mol, which are mainly dominated by electrostatic interactions, or into "strong" HBs whose BE is more negative than -15.0 kcal/mol, which are mainly dominated by electrostatic together with induction interactions. Among various explored correlations between BEs and wave function-based HB descriptors, a fairly satisfactory correlation was found for the electron density at the bond critical point (BCP; ρBCP ) of HBs. The fitted equation for neutral complexes is BE/kcal/mol = - 223.08 × ρBCP /a. u. + 0.7423 with a mean absolute percentage error (MAPE) of 14.7%, while that for charged complexes is BE/kcal/mol = - 332.34 × ρBCP /a. u. - 1.0661 with a MAPE of 10.0%. In practice, these equations may be used for a quick estimation of HB BEs, for example, for intramolecular HBs or large HB networks in biomolecules. © 2019 Wiley Periodicals, Inc.

Global, regional, and national burden of suicide mortality 1990 to 2016: systematic analysis for the Global Burden of Disease Study 2016

Abstract: Objectives To use the estimates from the Global Burden of Disease Study 2016 to describe patterns of suicide mortality globally, regionally, and for 195 countries and territories by age, sex, and Socio-demographic index, and to describe temporal trends between 1990 and 2016. Design Systematic analysis. Main outcome measures Crude and age standardised rates from suicide mortality and years of life lost were compared across regions and countries, and by age, sex, and Socio-demographic index (a composite measure of fertility, income, and education). Results The total number of deaths from suicide increased by 6.7% (95% uncertainty interval 0.4% to 15.6%) globally over the 27 year study period to 817 000 (762 000 to 884 000) deaths in 2016. However, the age standardised mortality rate for suicide decreased by 32.7% (27.2% to 36.6%) worldwide between 1990 and 2016, similar to the decline in the global age standardised mortality rate of 30.6%. Suicide was the leading cause of age standardised years of life lost in the Global Burden of Disease region of high income Asia Pacific and was among the top 10 leading causes in eastern Europe, central Europe, western Europe, central Asia, Australasia, southern Latin America, and high income North America. Rates for men were higher than for women across regions, countries, and age groups, except for the 15 to 19 age group. There was variation in the female to male ratio, with higher ratios at lower levels of Socio-demographic index. Women experienced greater decreases in mortality rates (49.0%, 95% uncertainty interval 42.6% to 54.6%) than men (23.8%, 15.6% to 32.7%). Conclusions Age standardised mortality rates for suicide have greatly reduced since 1990, but suicide remains an important contributor to mortality worldwide. Suicide mortality was variable across locations, between sexes, and between age groups. Suicide prevention strategies can be targeted towards vulnerable populations if they are informed by variations in mortality rates.

A review on metal-organic frameworks: Synthesis and applications

Abstract: Metal organic frameworks (MOFs) are considered as a group of compounds, either metal ions or clusters, harmonized with organic ligands to form one or some dimensional structures. In addition to resilient bonds between inorganic and organic units, reticular synthesis creates MOFs, accurate selection of constituents of which can produce high thermal and chemical stability and crystals of ultrahigh porosity. Other solids have not shown the same accuracy normally used in chemical modification and even the capability of increasing their metrics with no modification of the underlying topology. With shape of building units and chemical compositions multiplying based on specific structures, MOFs might result in compounds that propose a synergistic mixture of features. This study presents up to date advances in both synthesis methods of MOFs and structural characteristics. Furthermore, the use of MOFs in different fields such as the removal of absorption and separation of toxic substances from gas and liquid, catalysts, a variety of sensors, storage of clean energies and environmental applications, medical and biological applications, and optoelectronic equipment is included.

A comprehensive survey: Whale Optimization Algorithm and its applications

Abstract: Whale Optimization Algorithm (WOA) is an optimization algorithm developed by Mirjalili and Lewis in 2016. An overview of WOA is described in this paper, rooted from the bubble-net hunting strategy, besides an overview of WOA applications that are used to solve optimization problems in various categories. The best solution has been determined to make something as functional and effective as possible through the optimization process by minimizing or maximizing the parameters involved in the problems. Research and engineering attention have been paid to Meta-heuristics for purposes of decision-making given the growing complexity of models and the needs for quick decision making in the engineering. An updated review of research of WOA is provided in this paper for hybridization, improved, and variants. The categories included in the reviews are Engineering, Clustering, Classification, Robot Path, Image Processing, Networks, Task Scheduling, and other engineering applications. According to the reviewed literature, WOA is mostly used in the engineering area to solve optimization problems. Providing an overview and summarizing the review of WOA applications are the aims of this paper.

Two-dimensional materials in semiconductor photoelectrocatalytic systems for water splitting

Abstract: Hydrogen (H2) production via solar water splitting is one of the most ideal strategies for providing sustainable fuel because this requires only water and sunlight. In achieving high-yield production of hydrogen as a recyclable energy carrier, the nanoscale design of semiconductor (SC) materials plays a pivotal role in both photoelectrochemical (PEC) and photocatalytic (PC) water splitting reactions. In this context, the advent of two-dimensional (2D) materials with remarkable electronic and optical characteristics has attracted great attention for their application to PEC/PC systems. The elaborate design of combined 2D layered materials interfaced with other SCs can markedly enhance the PEC/PC efficiencies via bandgap alteration and heterojunction formation. Three classes of 2D materials including graphene, transition metal dichalcogenides (TMDs), and graphitic carbon nitride (g-C3N4), and their main roles in the photoelectrocatalytic production of H2, are discussed in detail herein. We highlight the various roles of these 2D materials, such as enhanced light harvesting, suitable band edge alignment, facilitated charge separation, and stability during the water splitting reaction, in various SC/2D photoelectrode and photocatalytic systems. The roles of emerging 2D nanomaterials, such as 2D metal oxyhalides, 2D metal oxides, and layered double hydroxides, in PEC H2 production are also discussed.

A new prediction model of battery and wind-solar output in hybrid power system

Abstract: In this paper short term power forecast of wind and solar power is proposed to evaluate the available output power of each production component. In this model, lead acid batteries used in proposed hybrid power system based on wind-solar power system. So, before the predicting of power output, a simple mathematical approach to simulate the lead–acid battery behaviors in stand-alone hybrid wind-solar power generation systems will be introduced. Then, the proposed forecast problem will be evaluated which is taken as constraint status through state of charge (SOC) of the batteries. The proposed forecast model includes a feature selection filter and hybrid forecast engine based on neural network (NN) and an intelligent evolutionary algorithm. This method not only could maintain the SOC of batteries in suitable range, but also could decrease the on-or-off switching number of wind turbines and PV modules. Effectiveness of the proposed method has been applied over real world engineering data. Obtained numerical analysis, demonstrate the validity of proposed method.

Optimisation of demand response in electric power systems, a review

Abstract: Demand response programs offer efficient solutions for many power system problems, such as high generation cost, high demand’s peak to average ratio, high emissions, reliability issues and congestion in generation, transmission and distribution systems. Their main function is to assist power systems during peak demand hours and also during contingencies. They are a subcategory of the family of demand side management (DSM) strategies. DR programs are classified into two broad categories; price-based DR programs and incentive-based DR programs. In order to exploit their full potential, DR programs must be implemented optimally. Such a problem, which here is referred to as “DR optimisation problem”, is a hot research topic and has been frequently researched in the literature. This paper aims to review different research works on DR optimisation problems. Based on the conducted review, some directions for future research are proposed.

Fourth generation biofuel: a review on risks and mitigation strategies

Abstract: Fourth generation biofuel (FGB) uses genetically modified (GM) algae to enhance biofuel production. Although GM algae biofuel is a well-known alternative to fossil fuels, the potential environmental and health-related risks are still of great concern. An evaluation of these concerns and accordingly devising appropriate mitigation strategies to deal with them are important to a successful commercialized production of FGB. While extensive research has been carried out on genetic modification and other technologies that aim to increase the productivity of algae strains, only a handful of them deal with the legislative limitations imposed on exploiting and processing GM algae. This paper examines this legislation and the mitigation strategies to meet potential risks associated with the exploitation and processing of FGB. Open-pond system is an economic solution for large-scale cultivation of microalgae; however, the concern regarding the health and environmental risk of cultivating GM algae and the associated stringent regulations is considered as the main barrier of FGB production. Disposal of the residue is another important issue that should be considered in FGB production. The byproducts obtained from energy extraction step and residual water from the harvesting process may contain plasmid or chromosomal DNA that may cause the risk of lateral gene transfer. Hence an appropriate mitigation practices should be used for replacement of the hazardous water residue and by-products with more environmentally friendly alternatives. The results obtained from several field testing projects for open-environment exploitation of GM algae show that under the various conditions used, there was no apparent proof to support possible horizontal gene transfer in release of GM algae.

A green ideology in Asian emerging economies: From environmental policy and sustainable development

Abstract: This panel study investigates the relationship between green logistics indices, economic, environmental, and social factors in the perspective of Asian emerging economies. This study adopted Fully Modified OLS (FMOLS) Model and Dynamic OLS (DOLS) Model methods to test the research hypothesis, catering the problem of endogeneity and serial correlation. The results suggest that logistics operations, particularly LPI2 (efficiency of customs clearance processes), LPI4 (quality of logistics services), and LPI5 (trade and transport‐related infrastructure), are positively and significantly correlated with per capita income, manufacturing value added and trade openness, whereas greater logistics operations are negatively associated with social and environmental problems including, climate change, global warming, carbon emissions, and poisoning atmosphere. In addition, human health is badly affected by heavy smog, acid rainfall, and water pollution. The findings further extend and reveal that political instability, natural disaster, and terrorism are also a primary cause of poor economic growth and environmental sustainability with poor trade and logistics infrastructure. There is very limited empirical work presented in the literature using renewable energy and green ideology to solve macro‐level social and environmental problems, and this study will assist the policy makers and researchers to understand the importance of the green concept in improving countries' social, economic, and environmental performance.

Extracting Appropriate Nodal Marginal Prices for All Types of Committed Reserve

Abstract: This paper proposes a framework to extract appropriate locational marginal prices for each type of reserve (up-/down-going reserves at both generation- and demand-sides). The proposed reserve pricing scheme accounts for the lost opportunity of selling the convertible products (energy and reserve). The fair prices can be obtained for capacity reserves applying this framework, since this framework assigns the same prices to the same services provided at the same location. The proposed reserve pricing scheme provides all the market participants with the appropriate signals to modify their offers according to the system operator requirements. The pricing problem is decomposed to different hourly sub-problems considering the bounding constraints. To show the effectiveness of the proposed algorithm, it is applied to the IEEE reliability test system and the results are discussed.

Green synthesis of zinc oxide nanoparticles: a comparison

Abstract: Green synthesis of nanoparticles by biological systems especially plant extracts has become an emerging field in nanotechnology. In this study, zinc oxide nanoparticles were synthesized using Lauru...

Skin tissue engineering: wound healing based on stem-cell-based therapeutic strategies

Abstract: Normal wound healing is a dynamic and complex multiple phase process involving coordinated interactions between growth factors, cytokines, chemokines, and various cells. Any failure in these phases may lead wounds to become chronic and have abnormal scar formation. Chronic wounds affect patients’ quality of life, since they require repetitive treatments and incur considerable medical costs. Thus, much effort has been focused on developing novel therapeutic approaches for wound treatment. Stem-cell-based therapeutic strategies have been proposed to treat these wounds. They have shown considerable potential for improving the rate and quality of wound healing and regenerating the skin. However, there are many challenges for using stem cells in skin regeneration. In this review, we present some sets of the data published on using embryonic stem cells, induced pluripotent stem cells, and adult stem cells in healing wounds. Additionally, we will discuss the different angles whereby these cells can contribute to their unique features and show the current drawbacks.

Transformative effects of IoT, Blockchain and Artificial Intelligence on cloud computing: Evolution, vision, trends and open challenges

Abstract: Cloud computing plays a critical role in modern society and enables a range of applications from infrastructure to social media. Such system must cope with varying load and evolving usage reflecting societies’ interaction and dependency on automated computing systems whilst satisfying Quality of Service (QoS) guarantees. Enabling these systems are a cohort of conceptual technologies, synthesized to meet demand of evolving computing applications. In order to understand current and future challenges of such system, there is a need to identify key technologies enabling future applications. In this study, we aim to explore how three emerging paradigms (Blockchain, IoT and Artificial Intelligence) will influence future cloud computing systems. Further, we identify several technologies driving these paradigms and invite international experts to discuss the current status and future directions of cloud computing. Finally, we proposed a conceptual model for cloud futurology to explore the influence of emerging paradigms and technologies on evolution of cloud computing.

Controlling Cell Behavior through the Design of Biomaterial Surfaces: A Focus on Surface Modification Techniques

Abstract: Surface interaction at the biomaterial–cell interface is essential for a variety of cellular functions, such as adhesion, proliferation, and differentiation. Nevertheless, changes in the biointerface enable to trigger specific cell signaling and result in different cellular responses. In order to manufacture biomaterials with higher functionality, biomaterials containing immobilized bioactive ligands have been widely introduced and employed for tissue engineering and regenerative medicine applications. Moreover, a number of physical and chemical strategies have been used to improve the functionality of biomaterials and specifically at the material interface. Here, the interactions between materials and cells at the interface levels are described. Then, the importance of surface properties in cell function is discussed and recent methods for surface modifications are systematically highlighted. Additionally, the impact of bulk material properties on the cellular responses is briefly reviewed.

A survey on classification techniques for opinion mining and sentiment analysis

Abstract: Opinion mining is considered as a subfield of natural language processing, information retrieval and text mining. Opinion mining is the process of extracting human thoughts and perceptions from unstructured texts, which with regard to the emergence of online social media and mass volume of users’ comments, has become to a useful, attractive and also challenging issue. There are varieties of researches with different trends and approaches in this area, but the lack of a comprehensive study to investigate them from all aspects is tangible. In this paper we represent a complete, multilateral and systematic review of opinion mining and sentiment analysis to classify available methods and compare their advantages and drawbacks, in order to have better understanding of available challenges and solutions to clarify the future direction. For this purpose, we present a proper framework of opinion mining accompanying with its steps and levels and then we completely monitor, classify, summarize and compare proposed techniques for aspect extraction, opinion classification, summary production and evaluation, based on the major validated scientific works. In order to have a better comparison, we also propose some factors in each category, which help to have a better understanding of advantages and disadvantages of different methods.

Strategies toward rheumatoid arthritis therapy; the old and the new.

Abstract: Currently, medications used to treat rheumatoid arthritis (RA) are glucocorticoids (GCs) and nonsteroidal anti-inflammatory drugs (NSAIDs), predominantly used for controlling the pain and inflammation, disease-modifying antirheumatic drugs (DMARDs), administered as first-line medication for newly diagnosed RA cases, and biological therapies, used to target and inhibit specific molecules of the immune and inflammatory responses. NSAIDs and other GCs are effective in alleviating the pain, inflammation, and stiffness due to RA. DMARDs that are used for RA therapy are hydroxychloroquine, methotrexate, leflunomide, and sulfasalazine. The biological therapies, on the contrary, are chimeric anti-CD20 monoclonal antibody, rituximab, inhibitors of tumor necrosis factor-α (TNF-α) like etanercept, infliximab, and adalimumab, a recombinant inhibitor of interleukin-1 (IL-1), anakinra, and costimulation blocker, abatacept. Moreover, newly under evaluation biological therapies include new TNF-α inhibitors, JAK inhibitors, anti-interleukin-6-receptor monoclonal antibodies (mABs), and antibodies against vital molecules involved in the survival and development of functional B cells. The new strategies to treat RA has improved the course of the disease and most of the patients are successful in remission of the clinical manifestations if the diagnosis of the disease occur early. The probability of remission increase if the diagnosis happens rapidly and treat-to-target approach are implemented. In this review article, we have attempted to go through the treatment strategies for RA therapy both the routine ones and those which have been developed over the past few years and currently under investigation.