Effects of spatial,temporal, and spectral resolutions on the estimation of wheat and barley leaf area index using multi- and hyper-spectral data (case study: Karaj,Iran)

Precision Agriculture - Leaf area index (LAI) is a key parameter for the calculation of crop biophysical and biochemical processes. Therefore, the accurate estimates of LAI has been always of great...     

Laser induced surface modification of clay-PAN composite nanofibers

In this study a newly laser treatment method for surface modification of nanofibers is introduced. The new method is based on different infrared absorption of materials. Surface modification of Clay-PAN composite nanofibers was performed using selective laser etching approach with CO₂ pulsed laser in order to increase surface area of nanofibers. The surface structure of resulted nanofibers is characterized using field emission scanning electron microscope and the results show characteristic modification of the surface topography of laser treated nanofibers. The modified surface structure of nanofibers was studied and analyzed for different laser pulse numbers and laser fluence. The results show that nanofiber surface modification strongly depends on the number of CO₂ laser pulses and frequency of modified sites on the surface of nanofibers increasing with increasing the pulse fluence. This new technique is highly selective and can also compete with conventional techniques for nanofibers surface modification.     

Evaluation of spatial variability of the integral energy of plant available water and its influential properties in paddy soil

Paddy and Water Environment - Plant Available Water is the main concept for describing the existing water content in a soil profile. Along with this concept, Integral Energy shows the energy...     

Radiosensitivity and repair kinetics of gamma-irradiated leukocytes from sporadic prostate cancer patients and healthy individuals assessed by alkaline comet assay

Background: Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition. Methods: Initial radiation-induced DNA damage (ratio of Tail DNA/Head DNA), dose-response curves and kinetics of DNA repair in leukocytes from healthy volunteers and prostate cancer patients were assessed using alkaline comet assay after exposure to ⁶⁰Co gamma rays. Results: Results showed that higher levels of baseline and gamma rays induced DNA damage in leukocytes of prostate cancer cases than in controls. A similar dose response was obtained for both groups. After a repair time of 24 h following in vitro irradiation, samples from the healthy individuals showed no residual DNA damage in their leukocytes, whereas prostate cancer patients revealed more than 20%. Although similar initial radiosensitivity was observed for both groups, the repair kinetics of radiation induced DNA damage of leukocytes from prostate cancer cases and healthy subjects were statistically different. Conclusion: These results support the hypothesis that men affected by prostate cancer may have a constitutional genomic instability. Key Words: Leukocytes, DNA damage, Radiosensitivity, Prostate cancer, Comet assay     

Extracellular production of silver nanoparticles by using three common species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis

Background: To develop a new green approach for biosynthesis of silver nanoparticles, myconanotechnology has been represented as a novel field of study in nanotechnology. In this study, we have reported the extracellular synthesis of highly stable silver nanoparticles using three species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. Methods: Clinical strains of these species were grown in a liquid medium containing mineral salt and incubated at 25°C for 5-7 days. The cell-free filtrate of each culture was obtained and subjected to synthesize silver nanoparticles in the presence of 1 mM AgNO₃. Results: The reduction of Ag+ ions in metal nanoparticles was investigated virtually by tracing the solution color which was switched into reddish-light brown after 72 h. For T. mentagrophytes, a UV-visible spectra demonstrating a strong, quite narrow peak located between 422 and 425 nm was obtained. For M. canis, a fairly wide peak centering at 441 nm and for T. rubrum, a weak spectrum to decipher were observed. According to transmission electron microscopy (TEM) results, fairly uniform, spherical, and small in size with almost less than 50 nm particles were forms in case of T. mentagrophytes. For the other two species, TEM images showed existence of small spherical nanosilvers but not as small as nanoparticles synthesized by T. mentagrophytes. Conclusion: We observed that species belong to a single genus of the fungi have variable ability to synthesize silver nanoparticles extracellulary with different efficiency. Furthermore, the extracellular synthesis may make the process simpler and easier for following processes.Key Words: Nanoparticles, Dermatophytes, Extracellular biosynthesis     

The role of Ile3434Thr XRCC7 gene polymorphism in Differentiated Thyroid Cancer risk in an Iranian population

Background

The aim of this study was to understand any association between differentiated thyroid carcinoma (DTC) and Ile3434Thr XRCC7 gene polymorphism (GenBank accession number: rs7830743). DTC is the most prevalent thyroid neoplasm, which includes papillary and follicular cell carcinoma. XRCC7 gene encodes a protein that functions in non-homologous end joining DNA repair pathway. Non-synonymous polymorphisms in this gene may alter DNA repair capacity of the cell and change the risk of developing cancers.

Methods

DTC patients (n = 173) and cancer free individuals (n = 204) were enrolled in a case-control study. The Ile3434Thr polymorphic alleles were discriminated by using amplification refractory mutation system-PCR method. The frequencies of this single nucleotide polymorphism in case and control groups were compared. Also, risk ratio for developing DTC in dichotomized genotypes was estimated by multivariate logistic regression analysis.

Results

Dichotomized genotypes into those with and without the 3434Thr allele showed that this allele was associated with DTC (OR [odd ratio]: 1.89, 95% confidence interval (CI) = 1.29-2.79, P<0.001). Also, TC genotype was significantly associated with increased risk of DTC (OR: 2.42, 95% CI = 1.55-3.81, P = 0.0001) in individuals carrying this genotype.

Conclusion

Allele 3434Thr in XRCC7 gene might be associated with differentiated thyroid cancer risk. Further studies with larger samples are needed to verify these initial findings. Key Words: DNA repair enzymes, Thyroid neoplasms, Genetic polymorphism     

Role of mitotic inhibitors and genotype on chromosome doubling of <Emphasis Type="Italic">Rosa</Emphasis>

Dinitroanilines represent a class of compounds that are widely used in herbicide formulations as they depolymerise plant microtubles, causing chromosome doubling. The potential of microtubule depolymerising herbicides trifluralin, oryzalin, and amiprophosmethyl (APM) for in vitro chromosome doubling of Rosa was studied. Five concentrations (0, 3, 6, 12 and 24 μM) and three exposure periods (12, 24 and 48 h) for each of the compounds were compared. Oryzalin, trifluralin and APM were not significantly different in their ability to induce chromosome doubling of R. hybrida cv Iceberg. At concentration of 6 μM and exposure period of 24 h, chromosome doubling of R. hybrida cv Iceberg was not significantly different with each of the polyplodising agents. At higher concentration (24 μM) and longer exposure period (48 h), 66.7% and 62.5% chromosome doubling was achieved with APM and trifluralin, respectively. However, the application of 6 μM oryzalin to R. persica (2n = 2x), R. hybrida cv Iceberg (2n = 3x) and R. hybrida cv Akito (2n = 4x), resulted in 60.0%, 6.3% and 0% chromosome doubling, respectively, which suggest that chromosome doubling is genotype dependent and plants with lower ploidy level have a higher propensity for chromosome doubling. Flow cytometry results at 18 and 24 weeks after herbicide treatment, indicated that the best time to test the treated plants was after 24 weeks.     

Effects of mycorrhiza inoculation on cucumber growth irrigated with saline water

This experiment was conducted as a factorial based on complete randomized design (CRD) to study the effects of mycorrhiza inoculation density on cucumber cv. Super N3 irrigated with different salinity sodium chloride (NaCl) levels. Treatments were mycorrhiza inoculations; M1 (non mycorrhizal plant), M2 and M3 (mycorrhiza inoculations with 1000 and 2000 spores) and saline water was provided by S1, S2, S3, and S4 (control, 50, 75, and 100 mM NaCl) with 4 replications. The results showed that saline water reduced root, shoot, and fruit weights, and increased proline and electrolyte leakage. Photosynthesis rate, stomata and mesophyll conductance significantly decreased with increased NaCl concentrations. Mycorrhiza inoculation with 2000 spores increased fruit fresh and dry weights, proline and electrolyte leakage, and both mycorrhiza inoculations increased root and shoot dry weights, photosynthesis and stomata conductance. Root volume increased by mycorrhiza inoculation with 2000 spores under non-stress condition, and root length was stimulated by both mycorrhiza inoculations at all saline water levels. Fruit fresh and dry weights were enhanced by mycorrhiza inoculation with 1000 spores at all saline water levels. Photosynthesis rate was reduced by saline water stress and mycorrhiza inoculation stimulated photosynthesis rate. Mycorrhiza inoculation with 2000 spores increased transpiration under saline and non-saline conditions. Proline content of cucumber leaves increased under saline water application. Electrolyte leakage increased by saline water and mycorrhiza inoculation could not improve it. Both mycorrhiza inoculations (1000 and 2000 spores) at all salinity levels, and mycorrhiza inoculation with 1000 spores at 100 mM NaCl enhanced fruit weight, photosynthesis, and proline content of the cucumber leaves.     

Pomegranate ellagitannin-derived metabolites inhibit prostate cancer growth and localize to the mouse prostate gland

Our group has shown in a phase II clinical trial that pomegranate juice (PJ) increases prostate specific antigen (PSA) doubling time in prostate cancer (CaP) patients with a rising PSA. Ellagitannins (ETs) are the most abundant polyphenols present in PJ and contribute greatly towards its reported biological properties. On consumption, ETs hydrolyze to release ellagic acid (EA), which is then converted by gut microflora to 3,8-dihydroxy-6H-dibenzo[b, d]pyran-6-one (urolithin A, UA) derivatives. Despite the accumulating knowledge of ET metabolism in animals and humans, there is no available data on the pharmacokinetics and tissue disposition of urolithins. Using a standardized ET-enriched pomegranate extract (PE), we sought to further define the metabolism and tissue distribution of ET metabolites. PE and UA (synthesized in our laboratory) were administered to C57BL/6 wild-type male mice, and metabolite levels in plasma and tissues were determined over 24 h. ET metabolites were concentrated at higher levels in mouse prostate, colon, and intestinal tissues as compared to other tissues after administration of PE or UA. We also evaluated the effects of PE on CaP growth in severe combined immunodeficient (SCID) mice injected subcutaneously with human CaP cells (LAPC-4). PE significantly inhibited LAPC-4 xenograft growth in SCID mice as compared to vehicle control. Finally, EA and several synthesized urolithins were shown to inhibit the growth of human CaP cells in vitro. The chemopreventive potential of pomegranate ETs and localization of their bioactive metabolites in mouse prostate tissue suggest that pomegranate may play a role in CaP treatment and chemoprevention. This warrants future human tissue bioavailability studies and further clinical studies in men with CaP.