Impaired follicular development and endocrine disorders in female rats by prepubertal exposure to toxic doses of cadmium.

Cadmium (Cd) has been associated with several physiological problems including reproductive and endocrine system dysfunction resulting in temporary infertility. The principal objective of this project was to investigate the effects of prepubertal exposure to toxic doses of Cd on puberty onset, the endocrine system, and follicular development. For this purpose, 16 female Sprague-Dawley rats weaned on postnatal day (PND) 21 were randomly divided into 4 groups (n = 4 per group). The treatments were as follows: 0, 25, 50, and 75 mg/kg/day of cadmium chloride (CdCl2) by oral gavage from PND 21 to observation of first vaginal opening (VO). The results demonstrated that prepubertal exposure to different doses of CdCl2 delays the age of VO, first diestrus, and first proestrus via altering the concentrations of estradiol and progesterone. The low level of these steroid hormones contributed to lower differentiation and maturation of follicles and it finally led to reduced ovarian reservoir of follicles and impaired follicular development. The number of atretic follicles and secondary follicles with premature cavity increased in rats that received a high dose of CdCl2, whereas the number of secondary follicles and corpora luteum decreased in the same circumstances. Taken together, these data suggest that prepubertal exposure to toxic doses of Cd delays the onset of puberty via disorderliness in the concentration of steroid hormones and reduces the ovarian reservoir of follicles, as well as folliculogenesis.

Low-temperature phyto-synthesis of copper oxide nanosheets: Its catalytic effect and application for colorimetric sensing.

The last decade has seen a remarkable detonation in modifying chemical processes for nanomaterial synthesis to make them 'green'. Owing to the unique properties of nanomaterial and with regard to environmental issues, in this study, a new alternative and fast eco-friendly approach for the synthesis of copper oxide nanosheets (CuO-NSs) using Terminalia catappa (Indian almond) leaf extract as a renewable and non-toxic reducing agent and efficient stabilizer was reported. It is noteworthy to mention that the present fabrication process can open up the possibility of fast, low cost and high efficiency synthesis of CuO nanostructures with an interesting morphology of nanosheets at ambient temperature and pressure. Optimization of important factors such as pH, the quantity of leaf extract, copper precursor concentration, incubation time and temperature on the formation of CuO-NSs were investigated. The formation of bioreduced CuO-NSs was certified by UV-Vis spectroscopy, XRD, TEM analysis and FT-IR spectroscopy. Due to good stability, and excellent catalytic activity of the synthesized CuO-NSs, they are exerted to degrade of MB dye in water as a model color pollutant in the presence of NaBH4 at room temperature. Furthermore, color properties of CuO nanostructures aid us to apply these biosynthesized nanomaterials in the design of optical sensors for detection of Fe2+ and Fe3+ ions. In view of many advantages of the current optical sensors based on CuO-NSs, such as eco-friendly, cost-effective, and straightforward design, the sensing system presents a potential application in environmental science.

Knowledge, attitude, and practices among Iranian neurologists toward evidence-based medicine.

Background: Evidence-based medicine (EBM) is a current practice in medicine to produce clinical practice guidelines from well-designed, randomized, controlled trials. We studied knowledge, attitude, and practice of EBM of neurologists who participated in the Iranian congress of neurology. Methods: A self-administered anonymous questionnaire was distributed and filled by neurologists. Results: A total of 200 neurologists were randomly sampled and with response rate of 56%. 33.9% of responder had previously participated in EBM courses. The average total knowledge score was 4.05 ± 0.80 out of a maximum possible score of 5.0. Textbooks were still the most favorite source of knowledge for our neurologists. A lack of time was the highest, and motivation the least mentioned barrier in using EBM. Conclusion: Overall, the Iranian neurologist had acceptable knowledge and attitude toward EBM and had same similar as found in other studies.

Synthesis of palladium nanoparticles on organically modified silica: application to design of a solid-state electrochemiluminescence sensor for highly sensitive determination of imipramine.

Organically modified silica substrate containing amine and vinyl functional groups were used for reduction and stabilization of palladium nanoparticles. Uniform spherical nanoparticles of palladium with average diameter of 10 nm were formed on silica substrate by direct contact of the substrate with an aqueous solution of palladium precursor, without the addition of any chemical reducer. Moreover, a sensitive and selective solid state electrochemiluminescence sensor was fabricated for the determination of imipramine, based on Ru(bpy)3(2+)-palladium nanoparticles doped carbon ionic liquid electrode. In this process, imipramine acts as a co-reactant for Ru(bpy)3(2+). It is believed that the enhancement of the electrochemiluminescence signal in the presence of palladium nanoparticles in the composite is due to palladium catalytic effect on electrochemical and also chemical process involved in formation of Ru(byp)3(2+)*. In addition, the results confirmed that, the rigid composite electrode shows the characteristic of microelectrode arrays. The proposed method was applied to the determination of imipramine in tablets and urine samples. The electrochemiluminescence intensity showed good linearity with the imipramine concentration from 1-100 pM, with a detection limit of 0.1 pM.

Highly efficient and stable palladium nanocatalysts supported on an ionic liquid-modified xerogel.

Incorporation of a phosphorylated ionic liquid as both a complexing and reducing agent for Pd(II) in a xerogel results in the formation of highly dispersed, uniformly sized Pd nanocatalysts, tightly supported on the surface of the silica and not embedded in the bulk of the xerogel.