56 research outputs found

    Molecular Farming in Plants

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    Plant molecular farming describes the production of recombinant proteins and other secondary metabolites in plants. This technology depends on a genetic transformation of plants that can be accomplished by the methods of stable gene transfer, such as gene transfer to nuclei and chloroplasts, and unstable transfer methods like viral vectors. An increasing quest for biomedicines has coincided with the high costs and inefficient production systems (bacterial, microbial eukaryotes, mammalian cells, insect cells, and transgenic animals). Therefore, transgenic plants as the bioreactors of a new generation have been the subject of considerable attention with respect to their advantages, such as the safety of recombinant proteins (antibodies, enzymes, vaccines, growth factors, etc.), and their potential for the large-scale and low-cost production. However, the application of transgenic plants can entail some worrying concerns, namely the amplification and diffusion of transgene, accumulation of recombinant protein toxicity in the environment, contamination of food chain, and costs of subsequent processing. The given threats need to be the subject of further caution and investigation to generate valuable products, such as enzymes, pharmaceutical proteins, and biomedicines by the safest, cheapest, and most efficient methods

    Development Cabinet Formalized

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    Alzheimer's disease (AD) is a kind of brain disease that arises due to the aggregation and fibrillation of amyloid β-peptides (Aβ). The peptide Aβ17-42 forms U-shape protofilaments of amyloid mature fibrils by cross-β strands, detected in brain cells of individuals with AD. Targeting the structure of Aβ17-42 and destabilizing its β-strands by natural compounds could be effective in the treatment of AD patients. Therefore, the interaction features of monomeric U-shape Aβ17-42 with natural flavonoids including myricetin, morin and flavone at different mole ratios were comprehensively studied to recognize the mechanism of Aβ monomer instability using molecular dynamics (MD) simulations. We found that all flavonoids have tendency to interact and destabilize Aβ peptide structure with mole ratio-dependent effects. The interaction free energies of myricetin (with 6 OHs) and morin (with 5 OHs) were more negative compared to flavone, although the total binding energies of all flavonoids are favorable and negative. Myricetin, morin and flavone penetrated into the core of the Aβ17-42 and formed self-clusters of Aβ17-42-flavonoid complexes. Analysis of Aβ17-42-flavonoids interactions identified that the hydrophobic interactions related to SASA-dependent energy are weak in all complexes. However, the intermolecular H-bonds are a main binding factor for shifting U-shape rod-like state of Aβ17-42 to globular-like disordered state. Myricetin and morin polyphenols form H-bonds with both peptide's carbonyl and amine groups whereas flavone makes H-bonds only with amine substitution. As a result, polyphenols are more efficient in destabilizing β-sheet structures of peptide. Accordingly, the natural polyphenolic flavonoids are useful in forming stable Aβ17-42-flavonoid clusters to inhibit Aβ17-42 aggregation and these compounds could be an effective candidate for therapeutically targeting U-shape protofilaments' monomer in amyloid mature fibrils

    Response of an Arch Dam to Non-Uniform Excitation Generated by a Seismic Wave Scattering Model

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    Non-uniform ground motions are generated based on a single record available at a site and seismic wave scattering analysis. The Chino Hills 2008 earthquake records at the Pacoima Dam site are used to indicate the accuracy of the method. Dynamic analysis of the Pacoima dam-reservoir-foundation under uniform and non-uniform ground motions is carried out using the EACD-3D2008 software, and the results are compared to recorded responses at different locations on the dam. There is good agreement between computed and recorded displacements of the dam for non-uniform excitation. For uniform excitation, the displacements are underestimated in comparison with those obtained from recorded excitation. Significant intensification of stresses, especially near the foundation, and different patterns of stress distribution are observed for non-uniform excitation in comparison with uniform excitation. For uniform excitation maximum stresses occur in the crown cantilever near the crest, but for non-uniform excitation the maximum stresses occur along the sides and near the foundation

    Tecnología de semillas sintéticas para la encapsulación y el recrecimiento de puntas de brotes y embriones somáticos de Espárrago officinalis L

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    Apical buds obtained from Asparagus plant vitro culture and somatic embryos obtained from stem cultivation, explants in MS medium supplemented with mg¹ᶫ 1, 2, 4-D and mg¹ᶫ 1 and Kinetin have been used in this research to produce artificial seeds. We encapsulated apical buds and somatic embryo using 2% sodium alginate and calcium chloride to prepare the artificial seeds. We placed artificial seeds at room temperature (about 25 ° C), in the cold, the temperature of 4 ° C and -18 ° C for different times (15,30,60,90 days) and evaluated the growing power of these seeds in MS and ½MS mediums for further investigations about the viability of seeds. The highest conversion percentage of seedlings in encapsulated embryos (70.01) was related to seed harvested from embryos treated with BA and the highest conversion percentage of seedlings in apical buds (96.54) was obtained from cultivated untreated seeds in MS medium. Encapsulated arteries and buds maintained germination energy and viability with increasing storage time after 90 days of storage at 4 and 25 ° C despite viability reduction while un-capsulated embryos and buds completely lost viability after 60 days of storage at 4 and 25 ° C and seeds stored at -18 ° C completely lost viability after 15 days of storage. In general, the percentage of seed germination and conversion to seedling is higher in seeds cultivated in MS medium compared to seeds cultivated in ½MS medium.En esta investigación se han utilizado yemas apicales obtenidas de cultivo vitro vegetal de espárragos y embriones somáticos obtenidos del cultivo de tallos, explantes en medio MS suplementado con mg¹ᶫ 1, 2, 4-D y mg¹ᶫ 1 y Kinetin para producir semillas artificiales. Encapsulamos yemas apicales y embriones somáticos utilizando alginato de sodio al 2% y cloruro de calcio para preparar las semillas artificiales. Colocamos semillas artificiales a temperatura ambiente (alrededor de 25 ° C), en el frío, la temperatura de 4 ° C y -18 ° C para diferentes tiempos (15,30,60,90 días) y evaluamos el poder de crecimiento de estas semillas. en medios MS y ½MS para futuras investigaciones sobre la viabilidad de las semillas. El mayor porcentaje de conversión de plántulas en embriones encapsulados (70.01) se relacionó con la semilla recolectada de embriones tratados con BA y el mayor porcentaje de conversión de plántulas en yemas apicales (96.54) se obtuvo de semillas cultivadas sin tratar en medio MS. Las arterias y las yemas encapsuladas mantuvieron la energía de germinación y la viabilidad con un mayor tiempo de almacenamiento después de 90 días de almacenamiento a 4 y 25 ° C a pesar de la reducción de la viabilidad, mientras que los embriones y las yemas no encapsulados perdieron completamente la viabilidad después de 60 días de almacenamiento a 4 y 25 ° C y las semillas almacenado a -18 ° C perdió completamente la viabilidad después de 15 días de almacenamiento. En general, el porcentaje de germinación de semillas y conversión a plántula es mayor en semillas cultivadas en medio MS en comparación con semillas cultivadas en medio ½MS

    Full-scale Experimental Modal Analysis of an Arch Dam: The First Experience in Iran

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    Forced vibration field tests and finite-element studies were conducted on the Shahid Rajaee concrete arch dam in Northern Iran to determine the dynamic properties of the dam–reservoir–foundation system. The first forced vibration tests on the dam were performed with two different types of exciter units, with a limited maximum force, bolted on the dam crest for alternative in-phase and out-of-phase sequencing. Because of an insufficient number of recording sensors, two arrangements of sensors were used to cover sufficient points on the dam crest and one gallery during tests. Two kinds of vibration tests, on–off and frequency sweeping, were carried out on the dam. The primary natural frequencies of the coupled system for both symmetric and anti-symmetric vibration modes were approximated during on–off tests in two types of sequencing of exciters, in phase and out-of-phase, with a maximum frequency of 14 Hz. The principal forced vibration tests were performed at precise resonant frequencies based on the results of the on–off tests in which sweeping around the approximated frequencies at 0.1 Hz increments was performed. Baseline correction and suitable bandpass filtering were applied to the test records and then signal processing was carried out to compute the auto power, cross power and coherence spectra. Nine middle modes of vibration of the coupled system and corresponding damping ratios were estimated. The empirical results are compared against the results from calibrated finite-element modeling of the system using former ambient vibration tests, considering the dam–reservoir–foundation interaction effects. Good agreement is obtained between experimental and numerical results for eight middle modes of the dam–reservoir–foundation system

    Tecnología de semillas sintéticas para la encapsulación y el recrecimiento de puntas de brotes y embriones somáticos de Espárrago officinalis L

    Get PDF
    Apical buds obtained from Asparagus plant vitro culture and somatic embryos obtained from stem cultivation, explants in MS medium supplemented with mg¹ᶫ 1, 2, 4-D and mg¹ᶫ 1 and Kinetin have been used in this research to produce artificial seeds. We encapsulated apical buds and somatic embryo using 2% sodium alginate and calcium chloride to prepare the artificial seeds. We placed artificial seeds at room temperature (about 25 ° C), in the cold, the temperature of 4 ° C and -18 ° C for different times (15,30,60,90 days) and evaluated the growing power of these seeds in MS and ½MS mediums for further investigations about the viability of seeds. The highest conversion percentage of seedlings in encapsulated embryos (70.01) was related to seed harvested from embryos treated with BA and the highest conversion percentage of seedlings in apical buds (96.54) was obtained from cultivated untreated seeds in MS medium. Encapsulated arteries and buds maintained germination energy and viability with increasing storage time after 90 days of storage at 4 and 25 ° C despite viability reduction while un-capsulated embryos and buds completely lost viability after 60 days of storage at 4 and 25 ° C and seeds stored at -18 ° C completely lost viability after 15 days of storage. In general, the percentage of seed germination and conversion to seedling is higher in seeds cultivated in MS medium compared to seeds cultivated in ½MS medium.En esta investigación se han utilizado yemas apicales obtenidas de cultivo vitro vegetal de espárragos y embriones somáticos obtenidos del cultivo de tallos, explantes en medio MS suplementado con mg¹ᶫ 1, 2, 4-D y mg¹ᶫ 1 y Kinetin para producir semillas artificiales. Encapsulamos yemas apicales y embriones somáticos utilizando alginato de sodio al 2% y cloruro de calcio para preparar las semillas artificiales. Colocamos semillas artificiales a temperatura ambiente (alrededor de 25 ° C), en el frío, la temperatura de 4 ° C y -18 ° C para diferentes tiempos (15,30,60,90 días) y evaluamos el poder de crecimiento de estas semillas. en medios MS y ½MS para futuras investigaciones sobre la viabilidad de las semillas. El mayor porcentaje de conversión de plántulas en embriones encapsulados (70.01) se relacionó con la semilla recolectada de embriones tratados con BA y el mayor porcentaje de conversión de plántulas en yemas apicales (96.54) se obtuvo de semillas cultivadas sin tratar en medio MS. Las arterias y las yemas encapsuladas mantuvieron la energía de germinación y la viabilidad con un mayor tiempo de almacenamiento después de 90 días de almacenamiento a 4 y 25 ° C a pesar de la reducción de la viabilidad, mientras que los embriones y las yemas no encapsulados perdieron completamente la viabilidad después de 60 días de almacenamiento a 4 y 25 ° C y las semillas almacenado a -18 ° C perdió completamente la viabilidad después de 15 días de almacenamiento. En general, el porcentaje de germinación de semillas y conversión a plántula es mayor en semillas cultivadas en medio MS en comparación con semillas cultivadas en medio ½MS

    Path analysis of grain yield with ıts components in durum wheat under drought stress

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    This experiment was conducted in order to study the path analysis of grain yield with its components in durum wheat under potential and drought stress condition during 2005-2006 cropping season in Agriculture Research Station of Tabriz Islamic Azad University. 49 durum wheat line (6 line from Iran and 43line from other fount) was used for this purpose. Two separate simple lattic design (7 7) with two replications was conducted . In one experiment, the plants were commonly irrigated until physiological but in another experiment drought stress imposed in four different stages including; tillering, stem elongation, anthesis and grain filling. Correlations among traits after combining two experiments was calculated by SPSS software . Harvest index(r =0.849**), plant height(r =0.695**), and number of tiller (r =0.689**) had high correlation with grain yield. Back ward regressions was used for regressing grain yield on its components. Number of seeds per spike (0.432) , length of spike(0.407) and 1000 seed weight (0.385) had the highest direct positive effects on grain yield. Path analysis for 1000 seed weight, number of tillers per plant and number of seeds per spike showed that plant height (0.452), length of spike (0.857), days to flowering (0.345) were the most effective components of traits, respectively. Therefore, traits such as number of seeds per spike, spike length and 1000 seed weight could be used as a suitable indices in irrigated and dry farming conditions for obtaining durum wheat genotypes with high yield

    Discharge coefficient of combined rectangular-triangular weirs using soft computing models

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    This study investigates the potential of Adaptive Neuro-fuzzy inference system (ANFIS), M5P, and Gaussian Process regression (GP) approaches to predict discharge coefficient (Cd) of chimney weir with different apex angles. Out of 110 data points, 77 arbitrarily selected observations were used for training, whereas the remaining 77 data points were used for testing. Input data consisted of h/p, y/p, L/p, and w/z, whereas Cd was an output. Four shapes of membership functions, i.e., triangular, trapezoidal, generalized bell-shaped, and Gaussian, were used for the ANFIS-based model development. Five different goodness-of-fit parameters and various graphical presentations were used to evaluate the performance of the machine-learning models. It was found that the M5P-based model was superior to other implemented models in predicting the Cd with Correlation Coefficient (CC) (0.9532 and 0.9472), Mean Absolute Error (MAE) (0.0024 and 0.0026), (Root Mean Square Error) RMSE (0.0032 and 0.0033), Scattering Index (SI) (0.0048 and 0.0050), and Nash Sutcliffe Efficiency (NSE) (0.9085 and 0.9925) values in the training and testing stages, respectively. Another major outcome of this study was that the ANFIS model was better than GP and other MFs-based ANFIS-ti models. The sensitivity of the Cd variables is also investigated, which showed h/p and L/p as major influencing factors in the Cd

    Modal identification of Karun IV arch dam based on ambient vibration tests and seismic responses

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    This paper focuses on the operational modal analysis of the Karun IV dam, the highest concrete arch dam in Iran, based on the responses obtained from ambient vibration tests, which are carried out on the dam during 19 March 2014, and 3 March 2015 earthquake with an epicenter about 133 km northeast of the dam. The non-parametric FDD-Wavelet method is used for identification and extraction of modal parameters including natural frequencies, mode shapes and damping ratios. Nine and four natural frequencies are identified from ambient and seismic responses, respectively. Stabilization diagram and averaged coherence spectrum (ACS) are used to detect and eliminate spurious form true modes. Comparison of the results indicates that identification is performed properly and reliably

    Molecular insights into the regulation of rice kernel elongation

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    A large number of rice agronomic traits are complex, multi factorial and polygenic. As the mechanisms and genes determining grain size and yield are largely unknown, the identification of regulatory genes related to grain development remains a preeminent approach in rice genetic studies and breeding programs. Genes regulating cell proliferation and expansion in spikelet hulls and participating in endosperm development are the main controllers of rice kernel elongation and grain size. We review here and discuss recent findings on genes controlling rice grain size and the mechanisms, epialleles, epigenomic variation, and assessment of controlling genes using genome-editing tools relating to kernel elongation
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