Single-domain antibody bioconjugated near-IR quantum dots for targeted cellular imaging of pancreatic cancer

Successful targeted imaging of BxPC3 human pancreatic cancer cells is feasible with near-IR CdTeSe/CdS quantum dots (QDs) functionalized with single-domain antibody (sdAb) 2A3. For specific targeting, sdAbs are superior to conventional antibodies, especially in terms of stability, aggregation, and production cost. The bright CdTeSe/CdS QDs were synthesized to emit in the diagnostic window of 650-900 nm with a narrow emission band. 2A3 was derived from llama and is small in size of 13 kDa, but with fully-functional recognition to the target carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a possible biomarker as a therapeutic target of pancreatic cancer. For compelling imaging, optical may be the most sensible among the various imaging modalities, regarding the sensitivity and cost. This first report on sdAb-conjugated near-IR QDs with high signal to background sensitivity for targeted cellular imaging brings insights into the development of optical molecular imaging for early stage cancer diagnosis.     

Comparative life cycle assessment of beneficial applications for scrap tires

Life cycle assessment is used to determine the most environmentally beneficial alternatives for reuse of scrap tires, based on the concept of industrial ecology. Unutilized scrap tires can be a major source of pollution, and in the past decade Federal and state governments in the United States have encouraged the recycling and reuse of scrap tires in a number of applications, ranging from energy recovery to civil engineering materials to utilization of ground rubber in manufacturing. Life cycle inventory data are collected from primary industry sources as well as published literature, and life cycle impact analysis is performed using the TRACI tool. The results indicate that beneficial reuse of scrap tires, particularly in cement plants and artificial turf, provides reductions in greenhouse gas (GHG) emissions, air toxics, and water consumption. For example, every metric ton of tire-derived fuel substituted for coal in cement kilns avoids an estimated 543 kg (CO₂ equivalent) of direct and indirect GHG emissions. Taking into account the deductible CO₂ from natural rubber, the avoided GHG emissions would be 613 CO₂ kg eq. per metric ton. The use of scrap tires for fuel in cement plants provides more reductions in most environmental impact categories compared to other scrap tire applications, excluding application in artificial turf. Although the use of ground rubber for artificial turf offers the greatest environmental emission reductions, it has limited potential for large-scale utilization due to the saturated market for artificial turf. Therefore, the use of fuel derived from scrap tires in cement production appears to be an attractive option in view of its large market capacity and significant potential for environmental impact reductions.     

Removal of Cr(VI) by thermally activated weed Salvinia cucullata in a fixed-bed column

The present study evaluates the feasibility of using a thermally activated fresh water weed in removing Cr(VI) from wastewater through column studies. The effect of flow rate, bed height and Cr(VI) concentration of the feed solution on the adsorption capacity of the activated weed was investigated. The adsorption capacity increased with decrease in both flow rate and bed height but increased with an increase in initial adsorbate concentration. Four different kinetic models, such as. Adams-Bohart, Bed Depth Service Time (BDST), Thomas and Yoon-Nelson models were first applied to the experimental data to predict the breakthrough curve and to determine the characteristic parameters of the column useful for designing large-scale column studies. Different statistical methods such as Sum of the Square of the Error (SSE), Sum of the Absolute Error (SAE), Average Relative Error (ARE), Average Relative Standard Error (ARS) and regression coefficient, were applied to evaluate the prominent and unique characteristic features of the experimental and predicted parameters under the respective models to find out the best fit. The performance stability of the adsorbent was tested by continuous adsorption-desorption studies.     

Biogas generation potential by anaerobic digestion for sustainable energy development in India

The potential of biogas generation from anaerobic digestion of different waste biomass in India has been studied. Renewable energy from biomass is one of the most efficient and effective options among the various other alternative sources of energy currently available. The anaerobic digestion of biomass requires less capital investment and per unit production cost as compared to other renewable energy sources such as hydro, solar and wind. Further, renewable energy from biomass is available as a domestic resource in the rural areas, which is not subject to world price fluctuations or the supply uncertainties as of imported and conventional fuels. In India, energy demand from various sectors is increased substantially and the energy supply is not in pace with the demand which resulted in a deficit of 11,436 MW which is equivalent to 12.6% of peak demand in 2006. The total installed capacity of bioenergy generation till 2007 from solid biomass and waste to energy is about 1227 MW against a potential of 25,700 MW. The bioenergy potential from municipal solid waste, crop residue and agricultural waste, wastewater sludge, animal manure, industrial waste which includes distilleries, dairy plants, pulp and paper, poultry, slaughter houses, sugar industries is estimated. The total potential of biogas from all the above sources excluding wastewater has been estimated to be 40,734 Mm³/year.     

Synergy Effect of Ultrasonic Nanocrystalline Surface Modification and Laser Surface Texturing on Friction and Wear Behavior of Graphite Cast Iron

Laser surface texturing (LST) followed by an ultrasonic nanocrystalline surface modification (UNSM) process was applied to graphite cast iron to improve the friction and wear behavior. The surface hardness of the UNSM-treated and UNSM + LST-treated specimens was increased significantly compared to the polished and LST-treated specimens. The friction and wear behavior of the specimens was assessed using a ball-on-disk friction tester at an applied load of 10 N and a speed of 5 cm/s in both dry and lubrication conditions. The friction coefficient of the UNSM-, LST-, and UNSM + LST-treated specimens reduced in both dry and lubrication conditions compared to the polished specimen by 64, 30, and 64% and 63, 67, and 75%, respectively. In lubrication condition, the friction coefficient of the UNSM- and LST-treated specimens was further reduced by about 30 and 25% by UNSM + LST processes. In dry condition, the UNSM + LST-treated specimen exhibited a reduction in the friction coefficient of 46% compared to the LST-treated specimen, whereas no reduction in friction coefficient was found compared to the UNSM-treated specimen. The wear resistance of the UNSM-, LST-, and the UNSM + LST-treated specimens was enhanced by 22, 11, and 37% in the dry condition, respectively, whereas minuscule wear was observed in the lubrication condition that was difficult to quantify in our experiment. UNSM and LST processes were effectively combined to improve the friction and wear behavior of graphite cast iron.     

Probabilistic modeling of the states of a buffer in a productionflow system

Assembly line manufacturing systems and materials handling systems usually operate through a system of serially linked stages. In a serially dependent system of this type, the failure of any stage either causes a reduction or causes the complete shutdown of the system. The provision of buffers between stages can result in operation of the nonfailed stages even in the event of failure of a stage. The author presents a stochastic analysis of a buffered production system. The probability of the buffer being full is determined as a function of buffer capacity. This, in turn is used to make the decision on buffer size. Results of the analysis indicate that, over the range of buffer capacity from zero to infinity, the probability of the buffer-full-state exhibits monotonically decreasing behavior that approaches zero asymptotically as buffer size approaches infinity. This finding can be used to detect the range over which the probability of the buffer-full-state asymptotically approaches zero, and appropriately select a buffer size beyond which there is no significant gain in system availability to justify the incremental cost of the additional buffer capacity     

Neuroimmunoregulation and cancer (review)

It is certain that neuroimmune mechanisms play a role in host defence against cancer. However, this interaction is highly complex and many variations are possible according to the nature of the neoplasms involved. There are indications that adaptive immunity is present in a significant proportion of tumor bearing hosts, and this defence may be boosted by specially designed vaccines and cytokines. Natural immune mediators are also implicated in resistance against tumor development. Here we review the evidence suggesting that hormonal manipulation of the host can result in the elevation of immune defences against cancer. Such manipulation strengthens both the adaptive and natural immune defences of the host, both of which play significant roles. Natural defence mechanisms are boosted by cytokines and hormones during febrile reactions which are now known as the acute phase response. It is suggested that hormonal stimulation of immune mechanisms coupled with the usual immunostimulants already in use may be employed to good advantage for the combination immunotherapy of cancer. Modern molecular biology approaches permit the development of laboratory monitoring procedures which may be used for the prediction and follow-up of therapeutic success.     

New theory of delays in semiconductor lasers

A simple model which can explain practically all important features of time delays in GaAs lasers is presented. It assumes only the presence of traps within the forbidden band and considers that the relative movement of quasi-Fermi levels of traps with temperature controls the population of the empty traps which act as saturable absorbers and thereby produce delays.     

Memory effect in an ionic liquid matrix containing single-walled carbon nanotubes and polystyrene

We report the use of an ionic liquid (IL) gel matrix containing a blend of single-walled carbon nanotubes (SWNTs) and polystyrene (PS) as a memory device. SWNTs and PS beads were mixed in a room-temperature IL, 1-butyl-3-methyl-hexafluorophosphate ([BMIM][PF(6)]). The composite gel was sandwiched between a bottom ITO glass and a top aluminium electrode. By merely changing the concentrations of SWNTs in the inert insulating PS matrix, we observed several distinct electrical properties of the device, such as an insulator, a memory in terms of switching and negative differential resistance (NDR), and a conductor. The electric bistable switching hops between a higher impedance (OFF) state and a lower impedance (ON) state which is approximately equal to five orders of current decays.     

Organic memory using [6,6]-phenyl-C(61) butyric acid methyl ester: morphology, thickness and concentration dependence studies

We report a simple memory device in which the fullerene-derivative [6,6]-phenyl-C(61) butyric acid methyl ester (PCBM) mixed with inert polystyrene (PS) matrix is sandwiched between two aluminum (Al) electrodes. Transmission electron microscopy (TEM) images of PCBM:PS films showed well controlled morphology without forming any aggregates at low weight percentages (<10?wt%) of PCBM in PS. Energy dispersive x-ray spectroscopy (EDX) analysis of the device cross-sections indicated that the thermal evaporation of the Al electrodes did not lead to the inclusion of Al metal nanoparticles into the active PCBM:PS film. Above a threshold voltage of <3?V, independent of thickness, a consistent negative differential resistance (NDR) is observed in devices in the thickness range from 200 to 350?nm made from solutions with 4-10?wt% of PCBM in PS. We found that the threshold voltage (V(th)) for switching from the high-impedance state to the low-impedance state, the voltage at maximum current density (V(max)) and the voltage at minimum current density (V(min)) in the NDR regime are constant within this thickness range. The current density ratio at V(max) and V(min) is more than or equal to 10, increasing with thickness. Furthermore, the current density is exponentially dependent on the longest tunneling jump between two PCBM molecules, suggesting a tunneling mechanism between individual PCBM molecules. This is further supported with temperature independent NDR down to 240?K.