Silicon nanopillar substrates for enhancing signal intensity in DNA microarrays

The use of ordered, high-aspect ratio nanopillar arrays on the surface of silicon-based chips to enhance signal intensity in DNA microarrays is reported. These nanopillars consisting either of a single silicon dioxide substrate or a dual silicon/silicon dioxide substrate are fabricated using deep-UV lithography followed by reactive ion etching. These pillar type arrays provide a three-dimensional high surface-density platform that increases the immobilization capacity of captured probes, enhances target accessibility and reduces background noise interference in DNA microarrays, leading to improved signal-to-noise ratios, sensitivity and specificity. Consequently, it was found that the use of such nanopillars enhanced the hybridization signals by up to seven times as compared to silicon dioxide thin film substrates. In addition, hybridization of synthetic targets to capture probes that contained a single-base variation showed that the perfect matched duplex signals on dual-substrate nanopillars can be up to 23 times higher than the mismatched duplex signals, allowing the targets to be unambiguously identified. These results suggest that the nanopillars, particularly the dual-substrate pillars, are able to enhance the hybridization signals and discrimination power in nucleic acids-based detection, providing an alternative platform for improving the performance of DNA microarrays.     

Lactase activity of microorganisms

Sixty-two strains of yeasts, molds and bacteria were screened for lactase (β-D-galactosidase) activity. Strains exhibiting the enzyme activity were evaluated for cell yield as well as enzyme units available per litre of the medium, per g cell dry weight and per mg protein of their cell-free extracts. The molds exhibited lowest enzyme activity but highest cell yields, bacteria produced lowest cell yield and maximum enzyme activity. Cultures exhibiting very high activity among yeasts wereSaccharomyces fragilis (strain 3217) and among bacteriaStreptococcus cremoris (strain H),Lactobacillus bulgaricus (strain RTS and 1373) andLeuconostoc citrovorum (strain 8081).     

Artabotrys manoranjanii sp. nov. (Annonaceae) from the Andaman Islands,India

Artabotrys manoranjanii M. V. Ramana, J. Swamy & K. C. Mohan (Annonaceae), a new species from the foot hills of Saddle Peak National Park, north Andaman Islands, is described and illustrated. Its fleshy petals and prominent stigmas, distinguish it from all previously known species. Its affinity with A. parkinsonii Chatterjee, a Myanmar species, and A. grandiflorus King, a species from Malayan peninsula, is deliberated.     

Fungal cell membrane—promising drug target for antifungal therapy

Increase in invasive fungal infections over the past few years especially in immunocompromised patients prompted the search for new antifungal agents with improved efficacy. Current antifungal armoury includes very few effective drugs like Amphotericin B; new generation azoles, including voriconazole and posaconazole; echinocandins like caspofungin and micafungin to name a few. Azole class of antifungals which target the fungal cell membrane are the first choice of treatment for many years because of their effectiveness. As the fungal cell membrane is predominantly made up of sterols, glycerophospholipids and sphingolipids, the role of lipids in pathogenesis and target identification for improved therapeutics were largely pursued by researchers during the last few years. Present review focuses on cell membrane as an antifungal target with emphasis on membrane biogenesis, structure and function of cell membrane, cell membrane inhibitors, screening assays, recent advances and future prospects.     

Strain-induced inflammation in pulmonary alveolar tissue due to mechanical ventilation

Inflammation is the body’s attempt at self-protection to remove harmful stimuli, including damaged cells, irritants, or pathogens and begin the healing process. In this study, strain-induced inflammation in pulmonary alveolar tissue under high tidal volume is investigated through a combination of an inflammation model and fluid structure interaction (FSI) analysis. A realistic three-dimensional organ model for alveolar sacs is built, and FSI is employed to evaluate strain distribution in alveolar tissue for different tidal volume (TV) values under the mechanical ventilation (MV) condition. The alveolar tissue is treated as a hyperelastic solid and provides the environment for the tissue constituents. The influence of different strain distributions resulting from different tidal volumes is investigated. It is observed that strain is highly distributed in the inlet area. In addition, strain versus time curves in different locations through the alveolar model reveals that middle layers in the alveolar region would undergo higher levels of strain during breathing under the MV condition. Three different types of strain distributions in the alveolar region from the FSI simulation are transferred to the CA model to study population dynamics of cell constituents under MV for different TVs; 200, 500 and 1000 mL, respectively. The CA model results suggests that strain distribution plays a significant role in population dynamics. An interplay between strain magnitude and distribution appears to influence healing capability. Results suggest that increasing TV leads to an exponential rise in tissue damage by inflammation.     

Design, synthesis, and biological evaluation of 1-(4-sulfamylphenyl)-3-trifluoromethyl-5-indolyl pyrazolines as cyclooxygenase-2 (COX-2) and lipoxygenase (LOX) inhibitors

A series of 20 novel 1-(4-sulfamylphenyl)-3-trifluoromethyl-5-indolyl pyrazolines were designed, synthesized, and screened in vitro for anti-inflammatory activity. These compounds were designed for evaluation as dual inhibitors of cyclooxygenases (COX-1 and COX-2) and lipoxygenases (LOX-5, LOX-12, and LOX-15) that are responsible for inflammation and pain. All pyrazoline molecules prepared are optically active and compounds that are more potent in COX-2 inhibitory activity (5a and 5f) were resolved by chiral column and each enantiomer was tested for cyclooxygenase inhibitory activity. Molecular modeling and comparison of molecular models of 5a enantiomers with that of celecoxib model shows that 5a (enantiomer-1) and 5a (enantiomer-2) have more hydrogen bonding interactions in the catalytic domain of COX-2 enzyme than celecoxib. Compounds 5a, 5e, and 5f showed moderate to good LOX-5 and LOX-15 inhibitory activity and this is comparable to that of celecoxib and more potent than rofecoxib.