Role of defects in transport through a quantum dot single electron transistor

The effect of a single dotlike defect on the transport through a quantum dot single electron transistor weakly coupled to external leads is studied. It is found that the conductance profile is changed significantly by the quantum mechanical tunneling between the dot and the defect and the interactions between them, both of which are dependent on the distance between the dot and the defect, as also by the morphology of the defect. In particular, we find that even a very small strength of interdot interaction has a major influence on the transport and must be taken into account in device fabrication

Dopamine Regulates Angiogenesis in Normal Dermal Wound Tissues

Cutaneous wound healing is a normal physiological process and comprises different phases. Among these phases, angiogenesis or new blood vessel formation in wound tissue plays an important role. Skin is richly supplied by sympathetic nerves and evidences indicate the significant role of the sympathetic nervous system in cutaneous wound healing. Dopamine (DA) is an important catecholamine neurotransmitter released by the sympathetic nerve endings and recent studies have demonstrated the potent anti-angiogenic action of DA, which is mediated through its D2 DA receptors. We therefore postulate that this endogenous catecholamine neurotransmitter may have a role in the neovascularization of dermal wound tissues and subsequently in the process of wound healing. In the present study, the therapeutic efficacy of D2 DA receptor antagonist has been investigated for faster wound healing in a murine model of full thickness dermal wound. Our results indicate that treatment with specific D2 DA receptor antagonist significantly expedites the process of full thickness normal dermal wound healing in mice by inducing angiogenesis in wound tissues. The underlined mechanisms have been attributed to the up-regulation of homeobox transcription factor HoxD3 and its target α5β1 integrin, which play a pivotal role in wound angiogenesis. Since D2 DA receptor antagonists are already in clinical use for other disorders, these results have significant translational value from the bench to the bedside for efficient wound management along with other conventional treatment modalities

Temperature dependent photoluminescence in self assembled InAs quantum dot arrays

In this paper we investigate the competing effects of thermally assisted hopping and radiative recombination of disorder induced spatially localized excitons on the temperature dependent PL spectrum of a self assembled InAs quantum dot array on GaAs. The stationary photoluminescence spectrum due to the lowest exciton state is calculated from a Monte Carlo simulation. We have also included the effect of the narrowing of the band gap with the increase of temperature. Our results on variation of the peak position and linewidth of the PL spectrum with temperature are in agreement with existing experimental results on InAs/GaAs dot arrays

Trichoderma: A Beneficial Organism for Agriculture

Trichoderma spp. are the most commonly used and widely applied biocontrol agents which is known for its antagonistic activities against plant pathogens especially soil borne pathogens such as Fusarium spp. (Fusarium wilt), Rhizoctonia, Pythium (Damping off), Sclerotium rolfsii (Sclerotinia rot), etc. Trichoderma exhibit diverse array of activities viz. plant growth promotion, biofertilizer, bioagents through the production of different biocontrol mechanisms (enzymes) such as chitinase, protease, glucanase, etc. Their mode of action is either by parasitizing the plant pathogens, secreting antibiotics or by competing for space and nutrients. Nutrient uptake is also enhanced as it regulates the root architecture promoting better root growth. Recently studies have found that it can also be utilized for bioremediation which will play a pivotal role in rejuvenating the environment from toxic substances. Heavy metal contaminants like Ni, Cd, Zn, Pb, As has been tolerated and accumulated by Trichoderma sp. Decomposition rate was fastened when Trichoderma was inoculated in agricultural waste substrate. It can detoxify toxic pesticides and fungicides which will be of great help in solving the environment pollutants besides increasing the soil fertility. Its role as biocontrol and as bioremediation can be of great advantage to the agriculture sector in solving disease problems and providing safe environment.</jats:p