Nanoparticles used as an ingredient in different types of concrete

Attempts to modify cement-based mixtures and to improve their properties have always attracted the attention of researchers. Favorable effects of nanoparticles, such as small particle size, high reactivity, and great surface area, have made them be used as one of the best replacements of cement. This paper aims to review the previous researches conducted regarding the effects of nanoparticles on the properties of concretes. Influence of various types of nanoparticles on the workability of fresh composite, mechanical properties such as compressive strength, flexural strength, splitting tensile strength, modulus of elasticity, and abrasion resistance, and durability-related properties such as water absorption, chloride ion penetration, resistance to frost, shrinkage, and carbonation of concrete is discussed.

Polyphenol oxidase/gold nanoparticles/mesoporous carbon-modified electrode as an electrochemical sensing platform for rutin in dark teas

By virtue of great surface area of mesoporous carbon, enhanced conductivity of AuNPs, and good electrochemical response of polyphenol oxidase to rutin, a PPO/AuNPs/FDU-15-modified electrode was used for the determination of rutin in dark teas.

Mesoporous Silica Materials as Drug Delivery: “The Nightmare” of Bacterial Infection

Mesoporous silica materials (MSM) have a great surface area and a high pore volume, meaning that they consequently have a large loading capacity, and have been demonstrated to be unique candidates for the treatment of different pathologies, including bacterial infection. In this text, we review the multiple ways of action in which MSM can be used to fight bacterial infection, including early detection, drug release, targeting bacteria or biofilm, antifouling surfaces, and adjuvant capacity. This review focus mainly on those that act as a drug delivery system, and therefore that have an essential characteristic, which is their great loading capacity. Since MSM have advantages in all stages of combatting bacterial infection; its prevention, detection and finally in its treatment, we can venture to talk about them as the “nightmare of bacteria”.

Green synthesis of gold nanoparticles and its diverse applications in various fields

Nanobiotechnology is a growing field due to its wide variety of applications in many fields of science and technology. Use of Nanoparticles in biomedical and biotechnology is due to its great surface area, improved permeability, retention effect etc. Green synthesized gold nanoparticles are very much useful for different applications in nanobiotechnology because of its properties and ecofriendly nature. Because of its chemical and physical properties, Colloidal gold has different uses in biotechnology. There are many ways to synthesize gold nanoparticles but green synthesis method is more appropriate as compared to others. This review addressed basically on the different methods of synthesis of gold nanoparticles but is also focused on its green synthesis, different shapes, sizes and various applications in each and every field of life. To be concise, AuNPs are potent tool in targeting drug delivery and biomedical application.

A new achievement in green degradation of aqueous organic pollutants under visible-light irradiation

The global attention has been focused on degradation of the environmental organic pollutants through green methods such as advanced oxidation processes (AOPs) under sunlight. However, AOPs have not yet been efficient in function of the photocatalyst that has been used. In this work, firstly, CaCu3Ti4O12 nanocomposite was simultaneously synthesized and decorated in different amounts of graphene oxide to enhance photodegradation of the organics. The result of the photocatalyst characterization showed that the sample with 8% graphene presented optimum photo-electrical properties such as low band gap energy and a great surface area. Secondly, the photocatalyst was applied for photodegradation of an organic model in a batch photoreactor. Thirdly, to scale up the process and optimize the efficiency, the photodegradation was modeled by multivariate semi-empirical methods. As the optimized condition showed, 45 mg/L of the methyl-orange has been removed at pH 5.8 by 0.96 g/L of the photocatalyst during 288 min of the light irradiation. Moreover, the photodegradation has been scaled up for industrial applications by determining the importance of the input effective variables according to the following organics order > photocatalyst > pH > irradiation time.

ANTIGENS IN IMMUNITY

The localization of antigen in primary follicles and germinal centers of rat popliteal lymph nodes described previously using I125- and I125-labeled antigen has been confirmed by direct staining with fluorescent antibodies. A fine web of phagocytic reticulum in primary follicles was found to be responsible for antigen localization in this area. The nature of this web was confirmed by studies of the localization of colloidal carbon. This unique feature of primary follicles is discussed in relation to its importance in the induction of immune responses, our belief being that the great surface area of antigen retaining cytoplasm in primary follicles is responsible for the appearance of germinal centers in these particular parts of the node.