جستجوی مقالات مرتبط با کلیدواژه « زیست فراهمی » در نشریات گروه « پزشکی »

Increasing agricultural activities and subsequently releasing pollutants from agricultural systems as well as expanding industries cause heavy metals (lead and cadmium) to enter the environment. Application of amendments are suitable methods for the inactivation of heavy metals in contaminated soils.

In order to study the effect of organic amendments (bichar 640 and 420) and inorganic amendments (zeolite, bentonite, leca and pumice) on bioavailability of Pb and Cd during incubation time in a calcareous soil, a factorial experiment was conducted in a completely randomized design with 3 levels of amendments application in soil (0, 1 and 5 %) in three replications. Bioavailability of Pb and Cd in soil was determined using DTPA and EDTA- extractable during 90- and 180-days incubation time.

Results showed that concentration of DTPA-extractable Pb and Cd increased during the time. Application of biochar 640, bentonite and zeolite (5%) decreased concentration of EDTA-extractable Pb during the incubation time. Application of biochar (1%) were the most effective treatment in decreasing Pb concentration EDTA-exchangeable. Application of the organic amendments (biochar 640 and biochar 420) and inorganic amendments (pumice, leca bentonite, and zeolite) increased concentration of EDTA-extractable Cd during the incubation time. Application of 5% of zeolite showed the lowest increasing concentration of EDTA-extractable Cd during the incubation time.

Organic amendments were more efficient in immobilization of Cd and Pb than the inorganic amendments. These results might due to the high amount of organic carbon and cation exchange capacity of the organic amendments than the inorganic amendments.

Adequate dietary intake of Selenium (Se) with regard to crucial role in the body functions and prevention of risk of cancers is more important. According to growth of world populations and soil erode inadequate daily intake of Se is an noticeable man concerns. Selenium enriched yeast (Se-yeast) as a good food supplements of Se with high organic and bio-available form of Se which imitate the dietary form of it (selenomethionine) has been mentioned nowadays. This paper has been reviewed the beneficial health effects of Se-yeast in food enrichment in order to compensate inadequate dietary intake of Se, production process and its effective variables, Se-yeast specification, bioavailability, stability and safety.
Material and This review article has been prepared with electronic searching keywords of Se, Se-yeast, production process, food enrichment, bioavailability, stability, safety, also cellular, animal, human as well as biotechnological studies between 97 full text of English ISI articles from 1983 till 2014. The Selection of articles were conducted according to the relevance with the aim of this paper. Moreover., the methodology and findings of all eligible articles were used.
According to the applicable potential of Se-yeast in food fortification, it could be act as a precursor in synthesis of selenoproteins and anti-cancer antigens in body. Hense, Se-yeast has been authorized as an additive for enrichment of different food categories to improve Se content of foods by FAD. Therefore, According to GRAS approval intake of 100µg/d Se-yeast is completely safe. Generally, due to lack of Se in different parts of Iran, Se-yeast could be used in food-chain fortification to compensate lack of dietary intake of Se.

A large number of new development drugs are soluble poorly in both organic and aqueous media which shows a low bioavailability using formulation traditional methods. A promising approach to solve this problem is the formation of nanosuspensions. Various articles about the increasing solubility and bioavailability of poorly soluble or insoluble drugs by nanosuspension were evaluated. In formulation of nanosuspensions, submicron-sized drug particles are dispersed in a liquid phase then they stabilize using surfactants. With respect to the studies in the subject, in order to eliminate the toxicity or to increase efficiency of drugs, nanosuspension formulation was used to formulate drug components. The main advantages of this approach are its application for the most drugs and doing it simply. In this work, common approaches of the preparation of nanosuspensions, its unique properties, advantages, potential applications and stability evaluation techniques, is mentioned. Considering the specific features of nanosuspensions such as, increasing saturation solubility and dissolution rate, increased adhesion, ease of manufacturing process and scale-up and versatility (flexibility offered in the modification of surface properties and particle size), there will be many applications for this formulation in different routes of drug delivery.