1,205 research outputs found

    Charge Delocalization in Self-Assembled Mixed-Valence Aromatic Cation Radicals

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    The spontaneous assembly of aromatic cation radicals (D+•) with their neutral counterpart (D) affords dimer cation radicals (D2+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation of dimer cation radicals is deliberated with the aid of a series of cyclophane-like bichromophoric donors with drastically varied interplanar angles between the cofacially arranged aryl moieties. X-ray crystallography of a number of mixed-valence cation radicals derived from monochromophoric benzenoid donors established that they generally assemble in 1D stacks in the solid state. However, the use of polychromophoric intervalence cation radicals, where a single charge is effectively delocalized among all of the chromophores, can lead to higher-order assemblies with potential applications in long-range charge transport. As a proof of concept, we show that a single charge in the cation radical of a triptycene derivative is evenly distributed on all three benzenoid rings and this triptycene cation radical forms a 2D electronically coupled assembly, as established by X-ray crystallography

    (3E,5E)-1-Benzyl-3,5-dibenzyl­idenepiperidin-4-one

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    In the title compound, C26H23NO, C—H⋯O hydrogen bonds generate a ribbon structure along the a axis. These ribbons further assemble into a one-dimensional sheet parallel to the ac plane via C—H⋯π inter­actions. The piperidin-4-one ring adopts a sofa conformation with the 1-benzyl group in the equatorial position, and the 3- and 5-phenyl substituents stretched out on either side. The benzyl­idene units adopt E configurations and the 1-benzyl group is disposed towards the 3- substituent of the piperidin-4-one ring

    Enhanced oral bioavailability and hepatoprotective activity of thymoquinone in the form of phospholipidic nano-constructs

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    Background: The poor biopharmaceutical properties of thymoquinone (TQ) obstruct its development as a hepatoprotective agent. To surmount the delivery challenges of TQ, phospholipid nanoconstructs (PNCs) were constructed. Method: PNCs were constructed employing microemulsification technique and systematic optimization by three-factor three level Box-Behnken design. Result: Optimized PNC composition exhibited nano size (90%), controlled drug release pattern, and neutral surface charge (zeta potential of −0.65 mV). After oral administration of a single dose of PNC, it showed a relative bioavailability of 386.03% vis-à-vis plain TQ suspension. Further, TQ-loaded PNC demonstrated significant enhanced hepato-protective effect vis-à-vis pure TQ suspension and silymarin, as evidenced by reduction in the ALP, ALT, AST, bilirubin, and albumin level and ratified by histopathological analysis. Conclusion: TQ-loaded PNCs can be efficient nano-platforms for the management of hepatic disorders and promising drug delivery systems to enhance oral bioavailability of this hydrophobic molecule

    Genotyping-by-sequencing and multilocation evaluation of two interspecific backcross populations identify QTLs for yield-related traits in pigeonpea

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    This study has identified single-nucleotide polymorphism (SNP) markers associated with nine yield-related traits in pigeonpea by using two backcross populations (BP) developed through interspecific crosses and evaluating them at two locations and 3 years. In both the populations, markers have shown strong segregation distortion; therefore, a quantitative trait locus (QTL) mapping mixed model was used. A total of 86 QTLs explaining 12–21% phenotypic variation were detected in BP-1. On the other hand, 107 QTLs explaining 11–29% phenotypic variation were detected in BP-2. Although most QTLs were environment and trait specific, few stable and consistent QTLs were also detected. Interestingly, 11 QTLs in BP-2 were associated with more than one trait. Among these QTLs, eight QTLs associated with days to 50% flowering and days to 75% maturity were located on CcLG07. One SNP “S7_14185076” marker in BP-2 population has been found associated with four traits, namely days to 50% flowering, days to 75% maturity, primary branches per plant and secondary branches per plant with positive additive effect. Hence, the present study has not only identified QTLs for yield-related traits, but also discovered novel alleles from wild species, which can be used for improvement of traits through genomics-assisted breeding

    Operation of Circuit Breaker with the help of Password

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    A circuit breaker is an electrical switch use to protect an electrical circuit from damage caused by faults. Its basic function is to detect a fault condition and protect from it. Fuse operates once after that it must be replaced but a circuit breaker can be reset to resume normal condition. During the manual operation, we see inoperable electrical accidents to the line man are rises during maintenance due to improper communication between the maintenance staff and the substation staff. In order to prevent such accidents, password based circuit breaker is design so that only authentic person can operate it with a password. There is also a facility of changing the password. The system is fully controlled by the microcontroller. The password is saved in an EEPROM, interfaced to the microcontroller and the password can be changed any time. A keypad is used to submit the password and a relay to operate circuit breaker, which is indicated by a bulb. Any wrong attempt to open the circuit breaker by entering the wrong password an alert will be shown in the LCD

    Impact of developmental project for sustainable pigeonpea livelihood system of rural poor households of Odisha

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    Farmers of Odisha’s rainfed areas have poor access to quality pigeonpea materials. In 2011, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) implemented a project ‘Introduction and Expansion of Improved Pigeonpea (Arhar) Production Technology in Rainfed Upland Ecosystems of Odisha’forfouryears (2011-2015) covering five districts. Two years after, a survey was conducted to study the adoption and effects of the interventions that revealed insights on yield, income and ways for sustaining and upscaling. The assessment showed that improved cultivars and improved agronomic practices resulted in significant increase in yield and income. ‘One village-One variety’ seed system led to quality seed supply not only in the project sites but also in adjacent villages. Innovative capacity development and commitments of stakeholders enriched knowledge and skills of pigeonpea’s cultivation that helped farmers in making appropriate choices. The result of the investment in two major pigeonpea activities namely improve pigeonpea production technology (IPPT) and seed production (SP) showed a robust investment gain computed at 308% or about four times increased from the ? 45 million ($900,000) invested in the project for two years

    Patterns of Molecular Diversity in Current and Previously Developed Hybrid Parents of Pearl Millet [Pennisetum glaucum (L.) R. Br.]

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    ICRISAT’s pearl millet (Pennisetum glaucum (L.) R. Br.) breeding program at Patancheru, India, has developed genetically diverse hybrid parents since 1980s. The present study investigated genetic diversity pattern between two groups of parents in this program, bred till 2004 and developed during 2004-2010. Combined analysis of 379 hybrid parents (current 166 parents and 213 previously developed hybrid parents) carried out using a set of highly polymorphic 28 SSRs detected 12.7 alleles per locus. An average of 8.5 and 8.7 SSR alleles per locus were found in previously developed and current parents, respectively, indicating marginal improvement in the levels of genetic diversity of hybrid parents in this program. Distance matrix differentiated these current and previously developed hybrid parents into 2 separate clusters, indicating infusion of new genetic variability over time as reflected by development of more genotype-specific alleles. Also, the seed and restorer parents were found clearly separated from each other in both the sets with few crossovers, indicating existence of two diverse and broad-based pools in hybrid parents of pearl millet. Restorer parents (R-lines) were found more diverse than seed parents (B-lines), as higher average gene diversity was detected among R-lines (0.70) than B-lines (0.56), though variation between B- and R-lines was found reduced in newly developed lines to 9.22% from 16.98% in previously developed lines. Results suggested that newly developed lines were as much divergent when compared with previously developed lines, indicating that current ICRISAT pearl millet breeding program was moving towards development of diverse new hybrid parental lines. The study suggested use of trait-specific donors in B- and R-lines separately to maintain sufficient genetic distance between seed and restorer breeding lines. It was pointed out to cross parents having higher genetic distance within the seed (B-lines) and restorer (R-lines) breeding programs to derive diverse and productive hybrid parental lines in future

    Phenotypic and molecular diversity-based prediction of heterosis in pearl millet ( Pennisetum glaucum L. (R.) Br.)

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    Genetic distances between hybrid parents based on phenotypic traits and molecular markers were investigated to assess their relationship with heterosis for grain and stover yield and other traits in pearl millet (Pennisetum glaucum [L.] R. Br.). Fifty-one hybrids developed using 101 hybrid parents (B and R lines) and showing a wide range of genetic distance between their parents based on eight phenotypic traits and 28–38 SSRs were evaluated in two sets for two seasons. The correlation between Euclidean distance (phenotypic distance, ED) and simple matching distance (molecular distance, SM) for parents of both sets was low but positive and significant (r = 0.2, P < 0.001).The correlation of ED in parents with better-parent heterosis for grain yield was similar in both sets (r = 0.38, P < 0.05). SM was not correlated with heterosis for grain yield in either set of hybrids. The results showed that phenotypic distance could be a better predictor of heterosis than molecular distance. The correlation between phenotypic distance and heterosis was not strong enough to permit the use of phenotypic diversity among parents as a major selection criterion for selection of parental lines displaying high levels of heterosis for grain and stover yield in pearl millet

    Smallholder farmers involvement in seed production of pigeonpea : An assessment in Odisha, India

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    Smallholder pigeonpea farmers in Odisha always rely on self-saved seeds of preferred landrace with long maturity period of 7 months and exploiting this for a period of 2-4 years or more. These model of seed system continuously resulted in low yield (250-500 kg/ha) due to seed deterioration. Seed production at farmers’ level with the provision of new package of technology such as providing farmers preferred high yielding disease resistant varieties and hybrids, on the ground training on improved crop management technologies, and integrated pest and disease management has contributed in increase in productivity (780 kg/ha), improving livelihood, and income of farmers in the project sites (Rayagada, Kalahandi, and Nauparha). Institutionalizing the seed system model through the ‘one village one variety’ concept has brought about the production of 1610 tons of various certified seeds. The assessment also revealed that higher investment in seed production resulted in higher seed yield and income. Likewise, farmers seed growers with medium land classification showed the best B:C ratio with ` 3.38 per ` 1 invested. Moreover, it can be deduced from the B:C ratio of all land classification that seed production is economically viable for smallholder farmers to venture in improving their livelihoods. However, there are still limitations that need to be addressed to ensure the sustainability of the seed delivery system of the project. The most pressing constraint of pigeonpea production is the damage caused by pests and the lack of farm inputs; trainings/awareness meetings/exposures are required to educate farmers on new pigeonpea technologies; and the need to regulate prices of pigeonpea seeds is a major concern for smallholder farmers to obtain benefit from their pigeonpea cultivation

    Nanofiber fabrication in a temperature and humidity controlled environment for improved fibre consistency

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    To fabricate nanofibers with reproducible characteristics, an important demand for many applications, the effect of controlled atmospheric conditions on resulting electrospun cellulose acetate (CA) nanofibers was evaluated for temperature ranging 17.5 - 35&#xb0;C and relative humidity ranging 20% - 70%. With the potential application of nanofibers in many industries, especially membrane and filter fabrication, their reproducible production must be established to ensure commercially viability.&#xd;&#xa;Cellulose acetate (CA) solution (0.2 g/ml) in a solvent mixture of acetone/DMF/ethanol (2:2:1) was electrospun into nonwoven fibre mesh with the fibre diameter ranging from 150nm to 1&#xb5;m.&#xd;&#xa;The resulting nanofibers were observed and analyzed by scanning electron microscopy (SEM), showing a correlation of reducing average fibre diameter with increasing atmospheric temperature. A less pronounced correlation was seen with changes in relative humidity regarding fibre diameter, though it was shown that increased humidity reduced the effect of fibre beading yielding a more consistent, and therefore better quality of fibre fabrication.&#xd;&#xa;Differential scanning calorimetry (DSC) studies observed lower melt enthalpies for finer CA nanofibers in the first heating cycle confirming the results gained from SEM analysis. From the conditions that were explored in this study the temperature and humidity that gave the most suitable fibre mats for a membrane purpose were 25.0&#xb0;C and 50%RH due to the highest level of fibre diameter uniformity, the lowest level of beading while maintaining a low fibre diameter for increased surface area and increased pore size homogeneity. This study has highlighted the requirement to control the atmospheric conditions during the electrospinning process in order to fabricate reproducible fibre mats
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