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Full-Text Articles in Physical Sciences and Mathematics
Dual Inhibition Of Sodium-Mediated Proton And Calcium Efflux Triggers Non-Apoptotic Cell Death In Malignant Gliomas, William Harley, Candace Floyd, Tamara Dunn, Xiao-Dong Zhang, Tsung-Yu Chen, Manu Hegde, Hasan Palandoken, Michael H. Nantz, Leonardo Leon, K.L. Carraway Iii, Bruce Lyeth, Fredric A. Gorin
Dual Inhibition Of Sodium-Mediated Proton And Calcium Efflux Triggers Non-Apoptotic Cell Death In Malignant Gliomas, William Harley, Candace Floyd, Tamara Dunn, Xiao-Dong Zhang, Tsung-Yu Chen, Manu Hegde, Hasan Palandoken, Michael H. Nantz, Leonardo Leon, K.L. Carraway Iii, Bruce Lyeth, Fredric A. Gorin
Chemistry and Biochemistry
Malignant glioma cells maintain an elevated intracellular pH (pHi) within hypoxic–ischemic tumormicroenvironments through persistent activation of sodium–proton transport (McLean et al., 2000). Amiloride has been reported to selectively kill human malignant glioma cell lines but not primary astrocytes (Hegde et al., 2004). While amiloride reduces pHi of malignant gliomas by inhibiting isoform 1 of sodium–proton exchange (NHE1), direct acidification was shown to be cytostatic rather than cytotoxic. At cytotoxic concentrations, amiloride has multiple drug targets including inhibition of NHE1 and sodium–calciumexchange. Amiloride's glioma cytotoxicity can be explained, at least in part, by dual inhibition of NHE1 and …
Solving The Low Dimensional Smoluchowski Equation With A Singular Value Basis Set, Gregory E. Scott, Martin Gruebele
Solving The Low Dimensional Smoluchowski Equation With A Singular Value Basis Set, Gregory E. Scott, Martin Gruebele
Chemistry and Biochemistry
Reaction kinetics on free energy surfaces with small activation barriers can be computed directly with the Smoluchowski equation. The procedure is computationally expensive even in a few dimensions. We present a propagation method that considerably reduces computational time for a particular class of problems: when the free energy surface suddenly switches by a small amount, and the probability distribution relaxes to a new equilibrium value. This case describes relaxation experiments. To achieve efficient solution, we expand the density matrix in a basis set obtained by singular value decomposition of equilibrium density matrices. Grid size during propagation is reduced from (100–1000) …
Novel Polymer Coupling Chemistry Based Upon Latent Cysteine-Like Residues And Thiazolidine Chemistry, Jospeh S. Carlson, Megan R. Hill, Taiga Young, Philip Costanzo
Novel Polymer Coupling Chemistry Based Upon Latent Cysteine-Like Residues And Thiazolidine Chemistry, Jospeh S. Carlson, Megan R. Hill, Taiga Young, Philip Costanzo
Chemistry and Biochemistry
Chain end functional polymers were prepared via reversible addition–fragmentation transfer (RAFT) polymerization techniques that were further chain extended with acrylonitrile. Under reducing conditions, latent cysteine-like residues were exposed at the chain ends. A variety of reduction conditions were explored and base polymers were then tethered together via thiazolidine chemistry.
A Natural Missing Link Between Activated And Downhill Protein Folding Scenarios, Feng Liu, Caroline Maynard, Gregory E. Scott, Artem Melnykov, Kathleen B. Hall, Martin Gruebele
A Natural Missing Link Between Activated And Downhill Protein Folding Scenarios, Feng Liu, Caroline Maynard, Gregory E. Scott, Artem Melnykov, Kathleen B. Hall, Martin Gruebele
Chemistry and Biochemistry
We propose protein PTB1:4W as a good candidate for engineering into a downhill folder. PTB1:4W has a probe-dependent thermal unfolding curve and sub-millisecond T-jump relaxation kinetics on more than one time scale. Its refolding rate in denaturant is a non-linear function of denaturant concentration (curved chevron plot). Yet at high denaturant concentration its unfolding is probe-independent, and the folding kinetics can be fitted to a single exponential decay. The domain appears to fold via a mechanism between downhill folding and activated folding over several small barriers, and when denaturant is added, one of these barriers greatly increases and simplifies the …
Millimeter-Scale Contact Printing Of Aqueous Solutions Using A Stamp Made Out Of Paper And Tape, Chao-Min Cheng, Aaron D. Mazzeo, Jinlong Gong, Andres W. Martinez, Scott T. Phillips, Nina Jain, George M. Whitesides
Millimeter-Scale Contact Printing Of Aqueous Solutions Using A Stamp Made Out Of Paper And Tape, Chao-Min Cheng, Aaron D. Mazzeo, Jinlong Gong, Andres W. Martinez, Scott T. Phillips, Nina Jain, George M. Whitesides
Chemistry and Biochemistry
This communication describes a simple method for printing aqueous solutions with millimeter-scale patterns on a variety of substrates using an easily fabricated, paper-based microfluidic device (a paper-based ―stamp‖) as a contact printing device. The device is made from inexpensive materials, and it is easily assembled by hand; this method is thus accessible to a wide range of laboratories and budgets. A single device was used to print over 2500 spots in less than three minutes at a density of 16 spots per square centimetre. This method provides a new tool to pattern biochemicals—reagents, antigens, proteins, and DNA—on planar substrates. The …
Electrochemical Sensing In Paper-Based Microfluidic Devices, Zhihong Nie, Christian A. Nijhuis, Jinlong Gong, Xin Chen, Alexander Kumachev, Andres W. Martinez, Max Narovlyansky, George M. Whitesides
Electrochemical Sensing In Paper-Based Microfluidic Devices, Zhihong Nie, Christian A. Nijhuis, Jinlong Gong, Xin Chen, Alexander Kumachev, Andres W. Martinez, Max Narovlyansky, George M. Whitesides
Chemistry and Biochemistry
This paper describes the fabrication and the performance of microfluidic paper-based electrochemical sensing devices (we call the microfluidic paper-based electrochemical devices, μPEDs). The μPEDs comprise paper-based microfluidic channels patterned by photolithography or wax printing, and electrodes screen-printed from conducting inks (e.g., carbon or Ag/AgCl). We demonstrated that the μPEDs are capable of quantifying the concentrations of various analytes (e.g., heavy-metal ions and glucose) in aqueous solutions. This low-cost analytical device should be useful for applications in public health, environmental monitoring, and the developing world.
Programmable Diagnostic Devices Made From Paper And Tape, Andres W. Martinez, Scott T. Phillips, Zhihong Nie, Chao-Min Cheng, Emanuel Carrilho, Benjamin J. Wiley, George M. Whitesides
Programmable Diagnostic Devices Made From Paper And Tape, Andres W. Martinez, Scott T. Phillips, Zhihong Nie, Chao-Min Cheng, Emanuel Carrilho, Benjamin J. Wiley, George M. Whitesides
Chemistry and Biochemistry
This paper describes three-dimensional microfluidic paper-based analytical devices (3-D μPADs) that can be programmed (postfabrication) by the user to generate multiple patterns of flow through them. These devices are programmed by pressing single-use ‘on’ buttons, using a stylus or a ballpoint pen. Pressing a button closes a small space (gap) between two vertically aligned microfluidic channels, and allows fluids to wick from one channel to the other. These devices are simple to fabricate, and are made entirely out of paper and double-sided adhesive tape. Programmable devices expand the capabilities of μPADs and provide a simple method for controlling the movement …