No abstract

Invasion of crops with Aspergillus flavus may result in contamination of food and feed with carcinogenic mycotoxins such as aflatoxins (AF) and cyclopiazonic acid (CPA). In the present study, distribution and toxigenicity of Aspergillus flavus and A. parasiticus in soils of five peanut fields located in Guilan province, Northern Iran was investigated. From a total of 30 soil samples, 53 strains were isolated which all of them were finally identified as A. flavus by a combination of colony morphology, microscopic criteria and mycotoxin profiles. Chromatographic analysis of fungal cultures on yeast extract sucrose broth by tip culture method showed that 45 of the 53 A. flavus isolates (84.9 %) were able to produce either CPA or AFB 1 , while eight of the isolates (15.1 %) were non-toxigenic. The amounts of CPA and AFB 1 produced by the isolates were reported in the range of 18.2-403.8 lg/g and 53.3-7446.3 lg/g fungal dry weights, respectively. Chemotype classification of A. flavus isolates based on the ability for producing mycotoxins and sclerotia showed that 43.4 % were producers of CPA, AFB 1 and sclerotia (group I), 13.2 % of CPA and AFB 1 (group II), 9.4 % of AFB 1 and sclerotia (group III), 13.2 % of AFB 1 (group IV), 5.7 % of CPA and sclerotia (group V) and 15.1 % were non-toxigenic with no sclerotia (group VI). No strain was found as producer of only CPA or sclerotia. These results indicate different populations of mycotoxigenic A. flavus strains enable to produce hazardous amounts of AFB 1 and CPA are present in peanuts field soils which can be quite important regard to their potential to contaminate peanuts as a main crop consumed in human and animal nutrition.

Conventional drug delivery systems are challenged by concerns related to systemic toxicity, repetitive doses, drug concentrations fluctuation, and adverse effects. Various drug delivery systems are developed to overcome these limitations. Nanomaterials are employed in a variety of biomedical applications such as therapeutics delivery, cancer therapy, and tissue engineering. Physiochemical nanoparticle assembly techniques involve the application of solvents and potentially harmful chemicals, commonly at high temperatures. Genetically engineered organisms have the potential to be used as promising candidates for greener, efficient, and more adaptable platforms for the synthesis and assembly of nanomaterials. Genetically engineered carriers are precisely designed and constructed in shape and size, enabling precise control over drug attachment sites. The high accuracy of these novel advanced materials, biocompatibility, and stimuli‐responsiveness, elucidate their emerging application in controlled drug delivery. The current article represents the research progress in developing various genetically engineered carriers. Organic‐based nanoparticles including cellulose, collagen, silk‐like polymers, elastin‐like protein, silk‐elastin‐like protein, and inorganic‐based nanoparticles are discussed in detail. Afterward, viral‐based carriers are classified, and their potential for targeted therapeutics delivery is highlighted. Finally, the challenges and prospects of these delivery systems are concluded.

In this research using properties of Chebyshev polynomialswe explicitly determine the best uniform polynomial approximation of some classes of functions. In this way we present some new theorems about the best approximation of these classes.

No abstract