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Add–drop filter (ADF) is a key component in optical integrated circuits that can be used in all-optical communication networks and wavelength division multiplexing (WDM) systems. The quality factor, coupling efficiency, transmission efficiency and coupling length are important parameters in add–drop filters. Photonic crystal (PC) optical devices have become popular among researchers because their structure is suitable to embed into optical circuits. This paper covers a comprehensive review of the principle structure of ADF, coupled mode theory (CMT), types and recent applications in WDMs, accelerometer and bio/chemical sensors. Although there are some different categories of photonic crystal ring resonator-based ADF in general, all of them can be divided into photonic to two class of non-circular and circular. This article is reported a comprehensive study about ADF and improvement of these ADF.

Photodynamic therapy (PDT) utilizes photosensitizers (PSs) to produce reactive oxygen species (ROSs) upon irradiation, which causes the shutdown of vessels and deprives the tumor of nutrients and oxygen, and in turn induces adverse effects on the immune system. However, significant efforts are needed to increase the efficiency in PDT in terms of light delivery to specific PSs for the clinical treatment of tumors located deep under the skin. Even though PDT offers a disease site-specific treatment modality, current efforts are directed to improve the solubility (in body fluids and injectable solvents), photostability, amphiphilicity (for tissue penetration), elimination, and systemic toxicity of traditional PSs based on porphyrin derivatives. Nanostructured materials show promising features to achieve most of such combined efforts. They can be artificially engineered to carry multiple theranostic agents onto targeted tumor sites. However, recent studies on photosensitive Cd-based nanostructures, mostly used in PDT, indicate that leeching of Cd2+ ions is stimulated when they are exposed to harsh biological conditions for continuous periods of time, thus making them acutely toxic and hindering their applications in in vivo settings. Since nanostructured materials are not completely immune to degradation, great strides have been made to seek new alternatives. In this review, we focus on the latest advances of Cd-free nanostructured metal transition sulfides (MTSs) as alternative PSs and study their high-energy transfer efficiency, rational designs, and potential applications in cancer-targeted PDT. Nanostructured MTSs are discussed in the context of their versatility to serve as phototherapy agents and superior properties, including their strong absorption in the NIR region, excellent photothermal conversion efficiency, controlled reactive oxygen species (ROS) production, versatile surface chemistry, high fluorescence, and structural and thermal stability. We discuss the latest advancements in correlating the self-aggregation of MTSs with their passive tumor cell targeting, highlighting their ability to efficiently produce ROSs, and mitigating their dark toxicity through polymeric functionalization. Treatment of deep-seated tumors by using these PSs upon preferential uptake by tumor tissues (due to the enhanced permeability and retention effect) is also reviewed. We finally summarize the main future perspectives of MTSs as next-generation PSs within the context of cancer theranostics. Graphical Abstract

The mechanism and regioselectivity of the Diels–Alder cycloaddition reaction between 9- (methoxymethyl)anthracene and citraconic anhydride are explored using the valuable density functional theory (DFT) methods. The solvent effects are considered using the polarizable continuum model in the toluene solution. Due to a small electrophilicity difference of the reactants, the reaction has a low polar character. The investigated Diels–Alder reaction has a normal electron demand character. Depending on the respective position of substituents in the cycloadducts (head-to-head (ortho) or head-to-tail (meta)) the reaction can be progressed via two different pathways: ortho and meta. Due to a very high activation energy, the meta pathway is rejected. The product of the ortho pathway is demonstrated to be the final product of the reaction in the toluene solution. The obtained DFT results are in good agreement with the experimental results.

Two Schiff bases are newly prepared by the condensation of 2-chloro-3-quinolinecarboxaldehyde with ethylenediamine and 1,4-butanediamine. The Schiff bases are characterized by the elemental analysis, IR, 1H and 13CNMR, UV-Vis, and fluorescence spectroscopies. Structural parameters together with the theoretical assignment of their vibrational frequencies and NMR chemical shifts are determined using density functional theory (DFT) approaches. There is good consistency between the DFT-calculated results and the experimental data, confirming the validity of the optimized geometries for the investigated Schiff bases. Optimized geometries of two Schiff bases are not planar, however, the substitutions are essentially in the same plane with the pyridine rings. Shapes of the frontier orbitals are determined using the natural bond orbital (NBO) analysis. Due to a high energy gap between the frontier orbitals, both Schiff bases are stable. Based on the Fukui function analysis, two Cl atoms and two azomethine nitrogen atoms are four suitable donor atoms for coordination to metal ions. Effects of the temperature and pH on the UV-Vis absorbance and fluorescence intensity of the Schiff bases are studied in a DMSO solution.

In the current study, we synthesized new vanadyl complexes of the N,N′-dipyridoxyl(1,2-propanediamine) Schiff bases and characterized them by experimental and theoretical methods. Also, the antibacterial (against strains of S. aureus, P.aeruginosa and E. coli) and cytotoxicity activities of three V(IV) complexes including VO-EN, VO-13 and VO-12 of the pyridoxal SBs were evaluated against human prostate tumor cells (PC3 cell line), where the VO-EN, VO-13 and VO-12 species are V(IV) complexes of the N,N′-dipyridoxyl(ethylenediamine), N,N′-dipyridoxyl(1,3-propanediamine) and N,N′-dipyridoxyl(1,2-propanediamine) Schiff bases, respectively. Deprotonated form of the N,N′-dipyridoxyl(1,2-propanediamine) Schiff base acts as a tetradentate N2O2 ligand, which coordinates to the V(IV) via two phenolate oxygens and two azomethine nitrogens. In the square-pyramidal geometry of the synthesized complex (VO-12), an oxo ligand occupies the apical position. The analyzed results for the VO-12 complex were in agreement with the experimental tests, confirming the suitability of its optimized geometry. The synthesized VO-12 complex displays significant and reusable catalytic activities in synthesis of the tetrahydrobenzo[b]pyrans, where the V4+ central ion is the active site of the catalyst. All investigated SB complexes were active against P.aeruginosa, while VO-13, VO-12 and VO-EN complexes revealed no activity against E. coli and S. aureus, respectively. All complexes showed considerable cytotoxic against PC3 cells. Our results suggested that these complexes decreased the cell viability after 48 h and the VO-12 complex showed the highest cytotoxicity. These observations suggested that the VO-EN, VO-13 and VO-12 species can be cytotoxic materials for pharmaceutical applications. In addition, in a dose-dependent manner, these compounds can be consider as potent antimicrobial agents.

The 1,3-dipolar cycloadditions are extensively used for the preparation of five-membered heterocycles. A mechanism consisting of two pathways was proposed for production of two regioisomers of the 1,3-dipolar cycloaddition of the nitrilimine and a thione-containing dipolarophile. Here, we have investigated the kinetics and mechanism of this reaction using density functional theory. Two possible mechanisms of A and B have been investigated in which Cl− is present in the structure of the nitrilimine reactant in the case of mechanism A, while it is absent in the case of mechanism B. Mechanism A, involving Cl−, has higher barrier energy than mechanism B, and so is rejected. Mechanism B involves two pathways, I and II, which lead to two regioisomers with different percentages in the products. Both of the pathways are one-step. Pathway II involves the attack of the nitrogen atom of the nitrilimine on the carbon atom of the C=S group of the dipolarophile. The product of pathway II is kinetically and thermodynamically a more favorable product than its regioisomer produced in the other pathway. The obtained results are in agreement with the experimental results.

The Islamophobia Studies field, a new and emerging academic area of research and scholarly engagement, is currently witnessing contributions from a diverse set of scholars with more entering the fray daily. Initially, writings in the field were focused on problems and challenges facing Muslim assimilation and integration, primarily in the British context and secondarily on the larger European continent. Moreover, much of the early work on Islamophobia primarily delved into media representation and stereotypes without further theorizing or interrogating structural aspects that informed or framed the publicly constructed image of Islam and Muslims. Furthermore, and up to the most recent past, the existing methodological approaches of race, gender, culture and ethnic studies, and postcolonial studies (leaving aside other traditional departments within humanities and social science fields) remained distant from Islam and Islamophobia as a subject of scholarly investigation that does not originate in an orientalist and problematizing approach, even when it is attempting to be “objective” in the research. The focus of this chapter is introducing and tracing the development of the emerging field of Islamophobia Studies.

Research on Islamophobia has, at least up to this point, predominantly focused on the rising tide of racism and discrimination effecting Muslims in Europe, North America and Australia, with limited works covering Russia, Eastern Europe and New Zealand. Published works covering these regions are extensive, increasing daily and multidisciplinary in nature, which is understandable considering the intensity of hostility including direct violence and the impact of the rising tide of bigotry and xenophobia in the Global North. Furthermore, the bibliographical entries of scholarly works on the above regions are extensive and publications are beginning to take a more specialized trajectory to address specific areas within the emerging Islamophobia Studies field. A gap, or more accurately a major blind spot, in the scholarly research, is the existence of an Islamophobic phenomena in Muslim majority states that has historical roots but is rapidly intensifying and structurally being linked to the global Islamophobia industry. Theorizing and understanding the Islamophobia phenomena in Muslim majority states is urgently needed; how it developed, what are its distinctive features and how it differs from anti-Muslim discourses manifested in the Global North. I use Talal Asad’s work on secularism to help provide an approach to understanding the distinctive nature of Islamophobia in Muslim majority countries and how it is utilized in internal political, social, economic and religious contestations.

In this work, the kinetics and mechanism of the Diels-Alder cycloaddition reaction between the 9-bromomethyl antracene and Citraconic anhydride dienophile have been investigated theoretically in the toluene solution. All of the calculations have been performed by using the valuable DFT methods and PCM model.The reaction can be progressed via two different pathways, I and II. In the structure of the reactants of the pathways I and II, the 9-bromomethyl antracene and Citraconic anhydride species have different orientations. Both of the pathways have been investigated in details. The obtained DFT-resultssuch as prediction of the major product of the reaction are in agreement with the experimental results, confirming validity of the DFT-proposed mechanism.

I have been engaged in a constant writing project that intends to highlight Palestinian narratives since 1948 up to the present. The dispossession narrative touches every Palestinian family including my own. During the 1948 Nakba and the war period, two family members on my father side were martyred, Jawdat Ali Rida Muhammad Bazian and Imran Ali Rida Muhammad Bazian, while another relative, Rida Ali Muhammad Bazian, was tortured by the British and released to the family bleeding and unconscious in a coma and died at home after a few days, in 1946. The Bazian’s narrative is but a small part in a large picture that includes FaouziAs’adBazian and 14-year-old Khalid Bazian who were martyred in 1967 and 2000, respectively. The Bazian family narrative includes the dean of prisoners, ‘Alaa Bazian, a blind man but endowed with piercing vision for freedom, resistance and a towering figure in the prisoners’ movement.