3-substituted 2-phenylimidazo[2,1-b]benzothiazoles: synthesis, anticancer activity, and inhibition of tubulin polymerization

A new series of 3‐substituted 2‐phenylimidazo[2,1‐b]benzothiazoles ( 3 a – h ) were synthesized by C‐arylation of 2‐arylimidazo[2,1‐b]benzothiazoles using palladium acetate as catalyst, and the resulting compounds were evaluated for their anticancer activity. Compounds 3 a , 3 e , and 3 h exhibited good antiproliferative activity, with GI₅₀ values in the range of 0.19–83.1 μM . Compound 3 h showed potent anticancer efficacy against 60 human cancer cell lines, with a mean GI₅₀ value of 0.88 μM . This compound also induced cell‐cycle arrest in the G₂/M phase and inhibited tubulin polymerization followed by activation of caspase‐3 and apoptosis. A high‐throughput tubulin polymerization assay showed that the level of inhibition for compound 3 h is similar to that of combretastatin A‐4. Molecular modeling studies provided a molecular basis for the favorable binding of compounds 3 a , 3 e , and 3 h to the colchicine binding pocket of tubulin.     

Lowering of thickness of boron-doped microcrystalline hydrogenated silicon film by seeding technique

By using a seeding technique it has been possible to reduce the thickness of p-μc-Si:H film to 230 Å, with an improved electrical conductivity (0.93 S cm⁻¹) and lower optical absorption compared to those of conventional p-μc-Si:H layers without a seed layer, for use at the tunnel junction and as the top layer of a double junction n–i–p structured a-Si solar cell. Undoped-μc-Si:H has been used as the seed layer. The layers were prepared by the radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) method (13.56 MHz) at 40 mW/cm² rf power density and low substrate temperature (200 °C). The ultrathin seed layer (30 Å) enhances the growth of microcrystallinity of the p-type μc-Si:H film as confirmed by the results of transmission electron microscopy (TEM) analysis and Raman spectroscopy.     

Storage and affinity properties of Murraya koenigii trypsin inhibitor

The Murraya Koenigii trypsin inhibitor was found to be the major protein component of the seed extract. The quantity of protein was determined to be approximately 20% of total protein extracted by simple buffer extraction. During different stages of seed development after flowering, the protein concentrations were found to be 5.27, 5.5, 8.5, 18.8 and 20% in 7, 19, 25, 37 and 55 days, respectively. During seed germination, protein degradations were observed from 20% to 12, 7 and 2% in 13, 16 and 22 days, respectively. This inhibitor, earlier purified using ion-exchange and gel filtration chromatography, was purified in single step by affinity column, using Cibacron blue 3GA, with substantial increase in yield. In partial internal sequencing by MALDI-TOF-TOF, six peptides of varying length, totalling 98 amino acid residues, exhibited similarities to the sequences from protease inhibitors, storage proteins and homeodomain-like proteins.     

Implicit Spatial Contextual Learning in Healthy Aging.

Three experiments investigated the aging of implicit spatial and spatiotemporal context learning in 2 tasks. In contextual cuing, people learn to use repeated spatial configurations to facilitate search for a target, whereas in higher order serial learning, they learn to use subtle sequence regularities to respond more quickly and accurately to a series of events. Results reveal a dissociation; overall contextual cuing is spared in healthy aging, whereas higher order sequence learning is impaired in the same individuals. This finding suggests that these 2 forms of implicit learning rely on different neural substrates that age differently; the results are also consistent with recent evidence that fronto-striatal circuits are particularly susceptible to decline in health aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced Biocompatibility of Porous Nitinol

Porous Nitinol (PNT) has found vast applications in the medical industry as interbody fusion devices, synthetic bone grafts, etc. However, the tendency of the PNT to corrode is anticipated to be greater as compared to solid nitinol since there is a larger surface area in contact with body fluids. In such cases, surface preparation is known to play a major role in a material’s biocompatibility. In an effort to check the effect of surface treatments on the in vitro corrosion properties of PNT, in this investigation, they were subjected to different surface treatments such as boiling in water, dry heating, and passivation. The localized corrosion resistance of alloys before and after each treatment was evaluated in phosphate buffer saline solution (PBS) using cyclic polarization tests in accordance with ASTM F 2129-08.     

Development of catalytic activity protocol for electrochemical reduction of carbon dioxide to value added products

Utilization of carbon dioxide for the production of value added products is a challenging task. Electrochemical reduction of carbon dioxide is one of the most promising techniques to convert the carbon dioxide into value added products. However, the development and selection of a suitable electrocatalyst is not so straightforward. The main problems are non-selectivity of the electrocatalyst toward CO₂ reduction, simultaneous hydrogen evolution reaction, and low efficiency of the process. To overcome these problems, many electrocatalysts have been studied and reported in the literature. However, there is no effective guideline to screen the electrocatalysts in a quick and simple way. Moreover, it is found that the method used for the screening of electrocatalyst is not accurate and has anomalies. Therefore, in this paper, a simple and quick protocol based on half-cell tests is proposed. The method provides a first-hand prediction about the electrochemical activity of an electrocatalyst toward electrochemical reduction of carbon dioxide. The protocol was validated and compared along with confirming the results by product analysis of the electrochemical reduction of CO₂ using full electrochemical reactor. The method was found satisfactory for the preliminary screening of electrocatalyst to reduce carbon dioxide electrochemically.     

Performance of superstrate multijunction amorphous silicon-based solar cells using optical layers for current management

The performance of multijunction amorphous silicon-based thin film solar cells has been reported using thin layers of TiO₂ and SiO_x acting as refractive index matching optical layers for different interfaces of the superstrate device structure. Improvement of short-circuit current from the sub-cells of a-Si/μc-Si cells is demonstrated with TiO₂ as anti-reflection layer at TCO/Si interface and SiO_x as intermediate-reflector layer between two sub-cells. An initial efficiency of 11.8% is achieved by applying both the TiO₂ and SiO_x optical layers in a-Si/μc-Si solar cell.     

Inhibition of angiogenesis and growth of human nerve-sheath tumors by AGM-1470

The effectiveness of AGM-1470, a potent, fungal-derived inhibitor of angiogenesis, in suppressing the neovascularization and growth of human Schwann cell tumors was tested in six schwannomas, seven neurofibromas, and one neurofibrosarcoma. Tumor fragments from surgical specimens were implanted into the subrenal capsule of 348 nude mice (nu/nu). Seven days after implantation, the tumors were measured and vascularity was graded. The animals were then randomly assigned to one of two groups, to receive either saline (control group) or systemic AGM-1470 treatment. After 2 to 6 weeks of treatment, tumor size and degree of vascularity were recorded. In the six different schwannomas implanted into 138 mice, the average vascular grade in the control group after 2 weeks of treatment increased from 2.2 to 3.2 (+1.0), while in the AGM-1470-treated group it decreased from 2.2 to 1.7 (-0.5) (p < 0.01). In the seven different neurofibromas implanted into 158 mice, the change in the average vascular grade in control and AGM-1470-treated animals was +0.5 and -1.0, respectively (p < 0.01). In the one neurofibrosarcoma implanted into 52 mice, the change in average vascular grade in each group during the 6-week treatment period was +1.9 and -1.0, respectively (p < 0.01). Neurofibrosarcoma growth after 6 weeks of AGM-1470 treatment was only 8.5% of the growth found in the control animals (p < 0.01). This study determined that AGM-1470 is effective in inhibiting angiogenesis and the growth of human nerve-sheath tumors.     

Controlled drug delivery by biodegradable poly(ester) devices: different preparative approaches

There has been extensive research on drug delivery by biodegradable polymeric devices since bioresorbable surgical sutures entered the market two decades ago. Among the different classes of biodegradable polymers, the thermoplastic aliphatic poly(esters) such as poly(lactide) (PLA), poly(glycolide) (PGA), and especially the copolymer of lactide and glycolide referred to as poly(lactide-co-glycolide) (PLGA) have generated tremendous interest because of their excellent biocompatibility, biodegradability, and mechanical strength. They are easy to formulate into various devices for carrying a variety of drug classes such as vaccines, peptides, proteins, and micromolecules. Most importantly, they have been approved by the United States Food and Drug Administration (FDA) for drug delivery. This review presents different preparation techniques of various drug-loaded PLGA devices, with special emphasis on preparing microparticles. Certain issues about other related biodegradable polyesters are discussed.     

Perceptual and conceptual memory processes in global amnesia.

To determine whether global amnesia reflects a selective deficit in conceptual processing, amnesic and control Ss performed 4 memory tasks that varied processing and retrieval requirements. A study-phase modality (auditory/visual) manipulation validated the nature of processing (perceptual and conceptual) engaged by each task. Amnesic patients were impaired on perceptual and conceptual explicit memory tasks (word-fragment and word-associate cued recall) and were intact on perceptual and conceptual implicit memory tasks (word-fragment completion and word association). These results are consistent with the view that limbic-diencephalic structures damaged in amnesia mediate, in part, processes typically engaged during explicit retrieval. The results are inconsistent, however, with the characterization of that deficit as being one of conceptual processing per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)