Experimental study of end-capped acceptors influencing the photo-physical, electrochemical and thermal parameters of A-D-π-D-A type small molecular electron donors

385-392We have designed A-D-π-D-A type three new small molecular donor materials denoted as FD-IND, FD-DCV and FD-NBR, which have been synthesised and their photo-physical, electrochemical and thermal properties explored. The synthesised materials have fluorene as “π-spacer,” dithieonopyrrole as “Donor” (D) and various “Acceptor” (A) units are 1,3-indanedione (IND), dicyanovinylene (DCV) and N-butyl rhodanine (NBR). All these three materials have good solubility (~30 mg/mL) in most common organic solvents and have relatively broad absorption in the visible region covering the range of 300-650 nm with two primary absorption bands. The absorption bands located at shorter wavelength region are ascribed to a localized aromatic π-π* transition of the A-D-π-D-A system, while the bands at longer wavelength are mainly attributed to an ICT transition. All the compounds exhibit excellent thermal stabilities in the range of 260-373°C. Cyclic voltammetry data provided HOMO values as −5.26, −5.32 and −5.32 eV for FD-NBR, FD-DCV and FD-IND respectively. LUMO values estimated from HOMO values and optical band gap are −3.27, −3.22 and −3.37 eV for FD-NBR, FD-DCV and FD-IND respectively. Therefore, these are potential molecules for organic solar cells

Experimental study of end-capped acceptors influencing the photo-physical,electrochemical and thermal parameters of A-D-π-D-A type small molecularelectron donors

We have designed A-D-π-D-A type three new small molecular donor materials denoted as FD-IND, FD-DCV andFD-NBR, which have been synthesised and their photo-physical, electrochemical and thermal properties explored.The synthesised materials have fluorene as “π-spacer,” dithieonopyrrole as “Donor” (D) and various “Acceptor” (A) unitsare 1,3-indanedione (IND), dicyanovinylene (DCV) and N-butyl rhodanine (NBR). All these three materials have goodsolubility (~30 mg/mL) in most common organic solvents and have relatively broad absorption in the visible regioncovering the range of 300-650 nm with two primary absorption bands. The absorption bands located at shorter wavelengthregion are ascribed to a localized aromatic π-π* transition of the A-D-π-D-A system, while the bands at longer wavelengthare mainly attributed to an ICT transition. All the compounds exhibit excellent thermal stabilities in the range of 260-373°C.Cyclic voltammetry data provided HOMO values as −5.26, −5.32 and −5.32 eV for FD-NBR, FD-DCV and FD-INDrespectively. LUMO values estimated from HOMO values and optical band gap are −3.27, −3.22 and −3.37 eV forFD-NBR, FD-DCV and FD-IND respectively. Therefore, these are potential molecules for organic solar cells

Identification of a virus naturally infecting sorghum in India as Sugarcane streak mosaic virus

The virus associated with mosaic disease of sorghum growing around the sugarcane fields in Andhra Pradesh state, India was found to be serologically related to the Sugarcane streak mosaic virus (SStMV) and Sorghum mosaic Parbhani virus (SMPV). The reverse transcription-polymerase chain reaction (RT-PCR) of the total RNA from the enzyme-linked immunosorbent assay positive sorghum samples with the potyvirus specific degenerate primers yielded an amplicon of ∼500 bp. This amplicon sequence had a 95% identity to the SStMV-Andhra Pradesh (SStMV-AP) and SStMV-Coimbatore isolates reported to naturally infect sugarcane in India. Further confirmation was made by RT-PCR of these samples with the SStMV-AP sequence specific primers that yielded ∼1,000 bp amplicon comprising the entire coat protein and 3′ UTR of the viral genome. This amplicon sequence also had a identity of 95% at nucleotide level with the SStMV-AP sugarcane isolate, but at the CP amino acid level it had 97.8% identity. This partial sequence data confirmed the association of SStMV with the mosaic disease of sorghum in Andhra Pradesh state, India. To our knowledge, this is the first report on association of SStMV with mosaic disease of sorghum and designated as SStMV-sorghum isolat

Concomitant mandibular hypo-hyperdontia: Report of two rarest cases with the literature review

Concomitant occurrence of both hypodontia (congenital tooth agenesis) and hyperdontia (supernumerary tooth) in the same dental arch is an extremely rare dental anomaly. Literature search shows very few cases of this anomalous condition with all cases depicting the unilateral presence of supernumerary tooth. Therefore, the intention of the current article is to report two cases of concomitant occurrence of mandibular both hypo-hyperdontia. In that one case exhibited bilateral occurrence of mesiodens teeth in the midline of mandible with associated agenesis of permanent both central incisors and taurodontism in permanent molars, which is not published so far. The article also provides comprehensive literature review on this rarest clinical entity

Save cells before tooth replantation: A review

Avulsion is one of the most complex traumatic injury affecting both teeth and children. Avulsed teeth can be replanted. Treatment for avulsed teeth should include, pulp and periodontal ligament (PDL) cell management to increase the survival rate of these teeth. If immediate replantation is not possible, the clonicity and progenicity of the viable PDL cells can be maintained with the aid of suitable storage medium at the place of trauma. The incorrect use of a storage medium leads to PDL cell necrosis eventually resulting in ankylosis and replacement resorption of the tooth root. Due to the importance of the storage media in long-term prognosis of the avulsed teeth, an informed choice of a media is essential for a favorable outcome. This review discusses available storage media and their unique features along with pros and cons of each medium

Unsteady flow of a nanofluid over a sphere with nonlinear Boussinesq approximation

A theoretical study is presented of transient mixed convection boundary layer flow of a nanofluid in the forward stagnation region of a heated sphere which is rotating with time dependent angular velocity. The effect of the non-linear Boussinesq approximation is taken into account. The nanofluid is treated as a two-component mixture i.e. nano-particles distributed homogenously in a base fluid (water or gas). The effects of the Brownian motion and thermophoresis are included for the nanofluid and constant wall temperature is imposed at the sphere surface. The first and second laws of thermodynamics are employed in order to study thermophysics as well as heat and mass transfer phenomena. By introducing appropriate similarity variables the governing equations are transformed into a system of dimensionless, nonlinear, coupled, ordinary differential equations which are solved numerically by applying the second-order accurate implicit finite difference Keller box method. The reliability and efficiency of the obtained numerical results are validated via comparison with the previously published results for special cases. The effects of various parameters on primary and secondary velocities, temperature, nanofluid volume fraction (concentration), primary and secondary shear stress functions, Nusselt number function (wall heat transfer rate) and Sherwood number function (wall nanoparticle mass transfer rate) are visualized. Furthermore the influence of non-linear temperature parameter, Brinkman parameter (ratio of Brinkman number to dimensionless temperature ratio), local Reynolds number and unsteadiness parameter on entropy generation number is computed. A strong elevation in entropy generation number is computed with both increasing Brinkman parameter and unsteadiness parameter. Primary and secondary surface shear stresses, Nusselt number and Sherwood number also increase with unsteadiness and rotation parameters. Primary shear stress is boosted with increasing mixed convection parameter and Brownian motion effect whereas secondary shear stress is depressed. Temperatures are suppressed with increasing nonlinear temperature parameter whereas nano-particle concentrations are elevated. Increasing thermophoresis parameter enhances both temperatures and nano-particle concentration values. The simulations find applications in rotating chemical engineering mixing systems and nano-coating transport phenomena

A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

Molecular Evidence for a Functional Ecdysone Signaling System in Brugia malayi

Filarial parasites such as Brugia malayi and Onchocerca volvulus are the causative agents of the tropical diseases lymphatic filariasis and onchocerciasis, which infect 150 million people, mainly in Africa and Southeast Asia. Filarial nematodes have a complex life cycle that involves transmission and development within both mammalian and insect hosts. The successful completion of the life cycle includes four molts, two of which are triggered upon transmission from one host to the other, human and mosquito, respectively. Elucidation of the molecular mechanisms involved in the molting processes in filarial nematodes may yield a new set of targets for drug intervention. In insects and other arthropods molting transitions are regulated by the steroid hormone ecdysone that interacts with a specialized hormone receptor composed of two different proteins belonging to the family of nuclear receptors. We have cloned from B. malayi two members of the nuclear receptor family that show many sequence and biochemical properties consistent with the ecdysone receptor of insects. This finding represents the first report of a functional ecdysone receptor homolog in nematodes. We have also established a transgenic hormone induction assay in B. malayi that can be used to discover ecdysone responsive genes and potentially lead to screening assays for active compounds for pharmaceutical development

Imidacloprid-Induced Impairment of Mushroom Bodies and Behavior of the Native Stingless Bee Melipona quadrifasciata anthidioides

Declines in pollinator colonies represent a worldwide concern. The widespread use of agricultural pesticides is recognized as a potential cause of these declines. Previous studies have examined the effects of neonicotinoid insecticides such as imidacloprid on pollinator colonies, but these investigations have mainly focused on adult honey bees. Native stingless bees (Hymenoptera: Apidae: Meliponinae) are key pollinators in neotropical areas and are threatened with extinction due to deforestation and pesticide use. Few studies have directly investigated the effects of pesticides on these pollinators. Furthermore, the existing impact studies did not address the issue of larval ingestion of contaminated pollen and nectar, which could potentially have dire consequences for the colony. Here, we assessed the effects of imidacloprid ingestion by stingless bee larvae on their survival, development, neuromorphology and adult walking behavior. Increasing doses of imidacloprid were added to the diet provided to individual worker larvae of the stingless bee Melipona quadrifasciata anthidioides throughout their development. Survival rates above 50% were only observed at insecticide doses lower than 0.0056 µg active ingredient (a.i.)/bee. No sublethal effect on body mass or developmental time was observed in the surviving insects, but the pesticide treatment negatively affected the development of mushroom bodies in the brain and impaired the walking behavior of newly emerged adult workers. Therefore, stingless bee larvae are particularly susceptible to imidacloprid, as it caused both high mortality and sublethal effects that impaired brain development and compromised mobility at the young adult stage. These findings demonstrate the lethal effects of imidacloprid on native stingless bees and provide evidence of novel serious sublethal effects that may compromise colony survival. The ecological and economic importance of neotropical stingless bees as pollinators, their susceptibility to insecticides and the vulnerability of their larvae to insecticide exposure emphasize the importance of studying these species