Non-equilibrium electrokinetic micro/nano fluidic mixer

We propose a new type of micro/nano fluidic mixer based on non-equilibrium electrokinetics and demonstrate its mixing performance. We fabricate the device with two-step reactive ion etching, one for nanochannels and one for microchannels. Mixing is achieved by strong vortex structures formed near the micro/nano channel interface. We expect the proposed device to be beneficial in the development of micro total analysis systems, since it is simple in its design with minimal fabrication complications.     

Design and Synthesis of Non-Covalent Imidazo[1,2-a]quinoxaline-Based Inhibitors of EGFR and Their Anti-Cancer Assessment

A series of 30 non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of epidermal growth factor receptor (EGFR) were designed and synthesized. EGFR inhibitory assessment (against wild type) data of compounds revealed 6b, 7h, 7j, 9a and 9c as potent EGFR^WT inhibitors with IC₅₀ values of 211.22, 222.21, 193.18, 223.32 and 221.53 nM, respectively, which were comparable to erlotinib (221.03 nM), a positive control. Furthermore, compounds exhibited excellent antiproliferative activity when tested against cancer cell lines harboring EGFR^WT; A549, a non-small cell lung cancer (NSCLC), HCT-116 (colon), MDA-MB-231 (breast) and gefitinib-resistant NSCLC cell line H1975 harboring EGFR^L858R/T790M. In particular, compound 6b demonstrated significant inhibitory potential against gefitinib-resistant H1975 cells (IC₅₀ = 3.65 μM) as compared to gefitinib (IC₅₀ > 20 μM). Moreover, molecular docking disclosed the binding mode of the 6b to the domain of EGFR (wild type and mutant type), indicating the basis of inhibition. Furthermore, its effects on redox modulation, mitochondrial membrane potential, cell cycle analysis and cell death mode in A549 lung cancer cells were also reported.     

Electrochemically Surface-modified Aluminum Electrode Enabling High Performance and Ultra-long Cycling Life Al-ion Batteries

Innovation in electronic devices has created a demand for energy storage systems. Recently, rechargeable Al-ion batteries (AIBs) have received significant attention owing to their high gravimetric capacity and low cost. In this study, the electrochemical performances of pristine, etched, and electropolished Al negative electrodes via surface modification were investigated to determine their efficiency in AIBs. Herein, pristine, etched, and electropolished Al acted as the negative electrodes (anodes), and pure graphite and aluminum chloride (AlCl₃)/1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) were used as the positive electrode (cathode) and ionic liquid electrolyte, respectively. This new type of electropolished Al-based battery cell shows good cyclability and high performance compared to pristine and etched Al electrodes. The electropolished Al electrode stabilized at an average capacity of 50 mAh g⁻¹ over 10,000 cycles at an ultrafast current rate of 5,000 mA g⁻¹.     

Influence of Ag Doped MoO3 Nanoparticles in the Seedling Growth and Inhibitory Action Against Microbial Organisms

Journal of Cluster Science - Herein we report the hydrothermal synthesis, characterization and biological applications of h-MoO3 and silver doped MoO3 nanoparticles (NPs). The phase formations of...     

Method for measuring the self-assembly of alkanethiols on gold at femtomolar concentrations

We describe a cantilever-based method for measuring the self-assembly of alkanethiols on a gold surface in a flow system that permits easy step changes in concentration and acquire a continuous in situ measure of the resulting chemisorption through the change in resonance frequency. A gold-coated (2.2 mm2), piezoelectric-excited, millimeter-sized cantilever (PEMC) sensor was exposed to 1-hexadecanethiol (HDT) in ethanol at concentrations ranging from 1 fM to 1 mM, sequentially and separately. A high-order flexural mode at approximately 850 kHz was monitored during the self-assembly. The resonance frequency decreases as a result of increased mass as chemisorption occurs on the surface. We show for the first time that the chemisorption of HDT at 1 fM is readily measurable and gave a response of 220 +/- 13 Hz (n = 4). At higher concentrations (10 and 100 fM; 1, 10, and 100 pM; 1, 10, and 100 nM; 1 microM; and 1 mM), the responses were proportionately, but nonlinearly, higher. At high concentrations (1 mM), the responses to C4, C8, C11, C16, and C18 alkanethiols were linearly proportional and were complete in approximately 25 min. We report for the first time that, once the Au surface is equilibrated at 1 pM, further chemisorption at a lower HDT concentration does not take place, even though over 99% of surface adsorption sites are available. At 1 fM, the overall chemisorption rate did not increase with a 2-fold increase in the HDT flow rate, suggesting that chemisorption at 1 fM is not transport-limited. The measured overall chemisorption rate constant at 1 fM was more rapid than 0.1 min-1.     

Integrated microelectronic device for label-free nucleic acid amplification and detection

We present an integrated microelectronic device for amplification and label-free detection of nucleic acids. Amplification by polymerase chain reaction (PCR) is achieved with on-chip metal resistive heaters, temperature sensors, and microfluidic valves. We demonstrate a rapid thermocycling with rates of up to 50 degrees C s(-1) and a PCR product yield equivalent to that of a bench-top system. Amplicons within the PCR product are detected by their intrinsic charge with a silicon field-effect sensor. Similar to existing optical approaches with intercalators such as SYBR Green, our sensing approach can directly detect standard double-stranded PCR product, while in contrast, our sensor does not require labeling reagents. By combining amplification and detection on the same device, we show that the presence or absence of a particular DNA sequence can be determined by converting the analog surface potential output of the field-effect sensor to a simple digital true/false readout.     

C-field Cosmology with Variable G in the Flat Friedmann--Robertson--Walker Model

The C-field cosmological model based on the Hoyle-Narlikar theory with variable gravitational constant G is investigated. To obtain the deterministic value of C=dC/dt we present certain constant values for integration constants. The creation field is proportional to time. G and p （density） decrease with time and the universe represents an expanding universe. The creation field increases as time increases. We find C=√1/2πf t where f〉0,Thus C=1 when f=1/2π〉0.     

Diastereo- and regioselective Diels-Alder reactions of 2-phosphaindolizines

1,3-Bis(alkoxycarbonyl)-2-phosphaindolizines undergo Diels-Alder reactions at the CP- functionality with 2,3-dimethylbutadiene and with isoprene in the presence of sulfur with complete diastereoselectivity. The reaction with isoprene occurs with 100% regioselectivity as well. 3-Ethoxycarbonyl-1-methyl-2-phosphaindolizine, however, fails to undergo Diels-Alder reaction under these conditions. Difference in the dienophilic reactivities of mono- and bis(alkoxycarbonyl) substituted 2-phosphaindolizines and the observed regioselectivity in the Diels-Alder reaction has been rationalized on the basis of DFT calculations. The relative stabilities of the transition structures have been explained on the basis of the NBO analysis.     

Stereoconvergent synthesis of the C1-C11 and C12-C24 fragments of (−)-macrolactin-A

Stereoconvergent syntheses of the C1-C11 and C12-C24 fragments of (−)-macrolactin-A are reported.