1,3,4-Oxadiazole as a Potential Anti-Cancer Scaffold: A Review

1,3,4-oxadiazole is an aromatic heterocycle with –N=C=O- linkage. 1,3,4-oxadiazole derivatives possess remarkable biological properties; antimicrobial anti-inflammatory, anti-cancer, antitubercular, antioxidant, antiviral, and anti-diabetic. This scaffold is present in many marketed drugs, such as Raltegravir, Tiodazosin, Nesapidil, and Zibotentan. 1,3,4-oxadiazole derivatives have displayed significant anti-cancer potential with a diverse mode of actions viz. growth factors, enzymes, kinases, etc. The present review gives an overview of the anti-cancer potential of 1,3,4-oxadiazoles derivatives in cancer drug discovery and development from the last ten years.

Integrated silicon photonic filters based on nanowire cascaded Sagnac loop resonators

We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI) nanowires implemented by cascaded Sagnac loop reflector (CSLR) resonators. We investigate mode splitting in these standing-wave (SW) resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs) and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.

Advantages and limitations of microtiter biofilm assays in the model of antibiofilm activity of Klebsiella phage KP34 and its depolymerase

One of the potential antibiofilm strategies is to use lytic phages and phage-derived polysaccharide depolymerases. The idea is to uncover bacteria embedded in the biofilm matrix making them accessible and vulnerable to antibacterials and the immune system. Here we present the antibiofilm efficiency of lytic phage KP34 equipped with virion-associated capsule degrading enzyme (depolymerase) and its recombinant depolymerase KP34p57, depolymerase-non-bearing phage KP15, and ciprofloxacin, separately and in combination, using a multidrug-resistant K. pneumoniae biofilm model. The most effective antibiofilm agents were (1) phage KP34 alone or in combination with ciprofloxacin/phage KP15, and (2) depolymerase KP34p57 with phage KP15 and ciprofloxacin. Secondly, applying the commonly used biofilm microtiter assays: (1) colony count, (2) LIVE/DEAD BacLight Bacterial Viability Kit, and (3) crystal violet (CV) biofilm staining, we unravelled the main advantages and limitations of the above methods in antibiofilm testing. The diverse mode of action of selected antimicrobials strongly influenced obtained results, including a false positive enlargement of biofilm mass (CV staining) while applying polysaccharide degrading agents. We suggest that to get a proper picture of antimicrobials’ effectiveness, multiple examination methods should be used and the results must be read considering the principle of each technique and the antibacterial mechanism.

Recent advances in mode-locked fiber lasers based on two-dimensional materials

Due to the unique properties of two-dimensional (2D) materials, much attention has been paid to the exploration and application of 2D materials. In this review, we focus on the application of 2D materials in mode-locked fiber lasers. We summarize the synthesis methods for 2D materials, fiber integration with 2D materials and 2D materials based saturable absorbers. We discuss the performance of the diverse mode-locked fiber lasers in the typical operating wavelength such as 1, 1.5, 2 and 3 μm. Finally, a summary and outlook of the further applications of the new materials in mode-locked fiber lasers are presented.

Coumarin Hybrids: Promising Scaffolds in the Treatment of Breast Cancer

: Breast cancer is the most common invasive cancer in women, and the second main cause of deaths in women, after lung cancer. There is continuous advancement in the development of therapeutic agents against breast cancer in recent years and it is still in progress. Development of hybrid molecules by combining different pharmacophores to obtain significant biological activity is an excellent approach. Coupling of coumarin scaffold with other distinct motifs has led to the design of newer compounds against breast cancer. These distinct pharmacophores possess a diverse mode of action as well as selectivity. It has been reported in the literature that coumarin hybrids possess significant potency against breast cancer by binding to various biological targets which are associated with breast cancer. Due to low toxicity profile on various organ systems, coumarin hybrids have nowadays attracted the keen attention of researchers to explore their therapeutic ability against breast cancer. Reported coumarin hybrids include coupling with isoxazole, thiazole, monastrol, chalcone, triazole, sulphonamide, triphenylethylene, benzimidazole, pyran, imidazole, stilbene, oestrogen, phenylsulphonylfuroxan, etc. In the present review, a description of various coumarin hybrid molecules has been presented along with their structural-activity relationships.