Antifungal activity of rice straw extract on some phytopathogenic fungi

The antifungal activity of allelochemicals extracted from rice straw on the radial growth rate and the activity of some hydrolyzing enzymes of Aspergillus flavus, Alternaria alternata and Botrytis cinerea were studied in vitro. Five different concentrations (2, 4, 6, 8 and 10%, w/v) of water, methanol and acetone extracts of rice straw were tested. All extracts significantly (P<0.05) inhibited the radial growth rate and protease, carboxymethyl cellulase (CMCase) and amylase activities of the tested fungal species. The most potent solvent was methanol. The present study suggests that rice straw extract had antifungal properties, thus it can be used as a natural alternative approach to synthetic fungicide.Key words: Rice straw, allelochemicals, antifungal, Aspergillus flavus, Alternaria alternata, Botrytis cinerea, amylase, protease, carboxymethyl cellulase

Antigen-Presenting Cell/Tumour Cell Hybrid Vaccines in Cancer Immunotherapy

In recent years, there has been a considerable interest in the development of immunotherapeutic approaches for treating cancers, including strategies for inducing antigen-specific cytotoxic T cells (CTLs) capable of killing tumour cells in situ. These approaches include both the active induction of CTLs by vaccination of tumour bearing patients, and the ex vivo expansion of tumour-specific CTLs for adoptive cellular transfer. One promising approach has been through the generation of hybrid cells, formed by fusion of professional antigen presenting cells (pAPCs) with tumour cells expressing relevant tumour associated antigens. Dendritic cells (DCs) represent the most potent form of pAPCs, and have been widely used in the generation of APC/tumour cell hybrid vaccines, in the context of a range of tumour types. Studies of fusion cell vaccines in animals have demonstrated not only the induction of tumour-specific CTLs, but also protection against subsequent tumour challenge and regression of established tumours. Results of clinical trials in patients have been less dramatic, but have shown the ability of hybrid vaccines to induce tumour-specific T cell responses, in some instances associated with disease stabilization or tumour regression. In addition to dendritic cell fusion vaccines, a number of non-DC fusion vaccines have been described

Kinetics of dissolution of calcium oxalate monohydrate in the presence of Hydrothiazide and Furosemide

Dissolution rates of calcium oxalate monohydrate (COM) were studied in the presence of Furosemide (Fm) and Hydrothiazide (Hz). Experiments were carried out at pH=6.5, t= 37 ºC, ionic strength =0.15 mol.dm-1 and degree of under-saturation (?) = 0.09. The results revealed that the inhibition followed surface controlled mechanism. The retardation effect followed the sequence Fm? Hz. Keywords: Human stones, COM, Hydrothiazide, Furosemide, Kinetic

Controlled Noncontact Manipulation of Nonmagnetic Untethered Microbeads Orbiting Two-Tailed Soft Microrobot

A rotating two-tailed soft microrobot induces a frequency dependent flow-field in low Reynolds number fluids. We use this flow-field to achieve noncontact manipulation of nonmagnetic microbeads with average diameter of 30 μ m in 2-D space. Our noncontact manipulation strategy capitalizes on exerting a rotational magnetic torque on the magnetic dipole of the microrobot. The induced flow-field enables microbeads in the surrounding fluid to orbit the microrobot along a sprocketlike trajectory due to a periodic and asymmetric flow-field caused by the two tails. A hydrodynamic model of the two-tailed microrobot and the orbiting microbeads is developed based on the method of regularized Stokeslets for computing Stokes flows. The relations between the angular velocity of the orbiting microbeads and the rotation frequency of the microrobot, their proximity (p), and tail length ratio of the microrobots are studied theoretically and experimentally. Our simulations and experimental results show that the angular velocity of the orbiting microbeads decreases nearly as |p|-2 with the distance to the microrobot and its tail length ratio. We also demonstrate closed-loop control of the microbeads toward target positions along sprocketlike trajectories with an average position error of 23.1 ± 9.1 μ m (n=10), and show the ability to swim away without affecting the positioning accuracy after manipulation

Damping device for a stationary labyrinth seal

A stationary labyrinth seal system includes a seal housing having an annular cavity, a plurality of damping devices, and a retaining ring. The damping devices are positioned within the annular cavity and are maintained within the annular cavity by the retaining ring