Mesoporous carbon for capacitive deionization of saline water

Self-assembled mesoporous carbon (MC) materials have been synthesized and tested for application in capacitive deionization (CDI) of saline water. MC was prepared by self-assembly of a triblock copolymer with hydrogen-bonded chains via a phenolic resin, such as resorcinol or phloroglucinol in acidic conditions, followed by carbonization and, in some cases, activation by KOH. Carbon synthesized in this way was ground into powder, from which activated MC sheets were produced. In a variation of this process, after the reaction of triblock copolymer with resorcinol or phloroglucinol, the gel that was formed was used to coat a graphite plate and then carbonized. The coated graphite plate in this case was not activated and was tested to serve as current collector during the CDI process. The performance of these MC materials was compared to that of carbon aerogel for salt concentrations ranging between 1000 ppm and 35,000 ppm. Resorcinol-based MC removed up to 15.2 mg salt per gram of carbon, while carbon aerogel removed 5.8 mg salt per gram of carbon. Phloroglucinol-based MC-coated graphite exhibited the highest ion removal capacity at 21 mg of salt per gram of carbon for 35,000 ppm salt concentration.

Evidence that the kinase-truncated c-Src regulates NF-κB signaling by targeting NEMO

The tyrosine kinase c-Src and transcription factor NF-κB are considered crucial components required for normal osteoclastogenesis. Genetic ablation of either pathway leads to detrimental osteopetrotic phenotypes in mice. Similarly, obstruction of either pathway halts osteoclastogenesis and lessens various forms of bone loss. It has been shown previously that mice expressing a kinase domain-truncated c-Src, termed Src251, develop severe osteopetrosis owing to increased osteoclast apoptosis. It was further suggested that this phenomenon is associated with reduced Akt kinase activity. However, the precise mechanism underlying the osteoclast inhibitory effect of Src251 remains obscure. C-Src associates with TRAF6-p62 interacting with receptor activator of NF-κB (RANK) distal region and the complex facilitate activation of RANK down stream signal transduction cascades including NF-κB. Given this proximity between c-Src and NF-κB signaling in osteoclasts, we surmised that inhibition of osteoclastogenesis by Src251 may be achieved through inhibition of NF-κB signaling. We have demonstrated recently that NEMO, the regulatory subunit of the IKK complex, is crucial for osteoclastogenesis and interacts with c-Src in osteoclast progenitors. Transfection studies, in which we employed various forms of c-Src and NEMO, revealed that the dominant negative form of c-Src, namely Src251, mediates degradation of NEMO thus halting NF-κB signaling. Furthermore, degradation of NEMO requires its intact zinc finger domain which is located at the ubiquitination domain. This process also requires appropriate cellular localization of Src251, since deletion of its myristoylation domain ablates its degradation capacity. Buttressing these findings, the expression of NEMO and NF-κB signaling were significantly reduced in monocytes collected from Src251 transgenic mice.

Design and Evaluation of Identifiable Key-Click Signals for Mobile Devices

As touch based input becomes more popular in mobile devices, there is an increasing need for haptic feedback on key-less input surface. Four experiments were conducted to design and evaluate identifiable emulated key-click signals using a piezoelectric actuator. Experiments I and II assessed the information transmission capacity for the amplitude, frequency, and number of cycles of raised cosine waveforms used to drive the piezo actuators under fixed- and roving-background conditions, respectively. Experiment III estimated the total information transfer for all three parameters. The results were used to reduce the number of stimulus alternatives in the key-click signal set with the goal to achieve perfect identification performance. Experiment IV verified that up to 5 to 6 identifiable key-click signals could be achieved with the experimental setup. The present study outlines an information theoretic approach to conducting identification experiments to guide the design of and to evaluate a perfectly identifiable stimulus set. The methodology can be applied to other applications in need of perceptually identifiable stimulation patterns.

Direct-Write Precision Resistors for Ceramic Packages

A direct-write approach to fabricate high precision resistors is reported. Special attention is paid to the effect of print thickness on the resistance value of buried resistors after a low temperature co-firing process. The results show that the direct-write approach provides a superior line definition and thickness control over a traditional screen printing process. Microstructural analysis indicates that there is an interdiffused layer developed between the resistor material and the low temperature co-fired ceramic substrate. These observations are consistent with electrical measurements which show that resistance increases as the effective cross-sectional area is reduced. The resistance data show that the standard deviations for resistors printed on a 6” × 6” area are 5% and 15% for the direct-write and the screen-printed patterns, respectively.

Perception of uncontrolled blood pressure and behaviours to improve blood pressure: findings from the 2009 Survey on Living with Chronic Diseases in Canada

Individuals with hypertension should lower and maintain their blood pressure levels through lifestyle modification and/or pharmacotherapy. To determine whether perception of blood pressure control is related to behaviours and intentions for improving blood pressure, data from 6142 Canadians age 20+ years with self-reported hypertension were analysed. Relationships between perception of control, current behaviours for blood pressure control and intentions to improve these behaviours were examined. Although individuals who reported uncontrolled blood pressure were equally likely to report engaging in lifestyle behaviours for blood pressure control, they were more likely to indicate an intention to improve their health, compared with those who reported well-controlled/low blood pressure. These individuals were also less likely to report having enough information to control their blood pressure. In addition, they were less likely to report having been advised to take antihypertensive medication, and to be taking and adhering to medications. Individuals who perceive their blood pressure as uncontrolled have intentions to make health-enhancing changes but may lack the information to do so. The study highlights the potential need for programmes/services to help those with uncontrolled blood pressure make lifestyle changes and/or take appropriate medication.

Chronic but not acute treatment with caffeine attenuates traumatic brain injury in the mouse cortical impact model

Caffeine, the most consumed psychoactive drug and non-specific adenosine receptor antagonist, has recently been shown to exert a neuroprotective effect against brain injury in animal models of Parkinson's disease (PD) and stroke. However, the effects of caffeine on traumatic brain injury (TBI) are not known. In this study, we investigated the effects of acute and chronic caffeine treatment on brain injury in a cortical-impact model of TBI in mice. Following TBI, neurological deficits, cerebral edema, as well as inflammatory cell infiltration were all significantly attenuated in mice pretreated chronically (for 3 weeks) with caffeine in drinking water compared with the mice pretreated with saline. Furthermore, we found that chronic caffeine treatment attenuated glutamate release and inflammatory cytokine production, effects that were correlated with an upregulation of brain A1 receptor mRNA. By contrast, acute treatment with caffeine (i.p. injection, 30 min before TBI) was not effective in protecting against TBI-induced brain injury. These results suggest that chronic (but not acute) caffeine treatment attenuates brain injury, possibly by A1 receptor-mediated suppression of glutamate release and inhibition of excessive inflammatory cytokine production. These results highlight the potential benefit of chronic caffeine intake for preventing TBI and provide a rationale for the epidemiological investigation of the potential association between TBI and human caffeine intake.

Synthesis and self-assembly of [60]fullerene containing sulfobetaine polymer in aqueous solution

A well-defined poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA-b-C60) was synthesized using the atom transfer radical polymerization (ATRP) technique and betainized with 1,3-sulfobetaine to yield a Bet-PDMAEMA-b-C60. The solution properties were then studied by light transmittance, viscometric, 1H NMR laser light scattering, and transmission electron macroscopic techniques. It was found that Bet-PDMAEMA-b-C60 exhibits an upper critical solution temperature (USCT) similar to that observed for Bet-PDMAEMA in aqueous solution. However, the modification of Bet-PDMAEMA with a C60 molecule increases the UCST of Bet-PDMAEMA in solution, which is a function of the solution ionic strength. Addition of a small amount of salt increases the UCST, similar to polyelectrolyte systems, while the presence of an excess amount of salt leads to a decrease in the UCST, attributed to the antipolyelectrolyte effect of polyampholytes. In aqueous salt solution, Bet-PDMAEMA-b-C60 chains self-assemble into micelles that coexist with unimeric Bet-PDMAEMA-b-C60 chains. TEM studies revealed that the system agglomerates when the temperature exceeds the UCST.

Elucidation of some Bax conformational changes through crystallization of an antibody–peptide complex

The Bcl-2 family member Bax plays a critical role in apoptosis. In healthy resting cells, Bax resides in the cytoplasm and loosely attached to the mitochondrial membrane. Apoptotic stimuli induce Bax activation, which is characterized by translocation and multimerization on the mitochondrial membrane surface resulting in exposure of an amino terminal epitope recognized by the monoclonal antibody 6A7. To understand the structural changes that occur during Bax activation, we determined the crystal structure of a Bax peptide bound to the 6A7 Fab fragment to a resolution of 2.3 A. The structure reveals the conformation of the 6A7 peptide epitope on Bax in the activated form and elucidates the extensive structural changes that Bax must undergo during the conversion from its native to its activated conformation.

Self-assembly of well-defined mono and dual end-capped C(60) containing polyacrylic acids in aqueous solution

Well-defined stimuli-responsive mono and dual fullerene (C(60)) end-capped poly(acrylic acid)s (PAA-C(60) and C(60)-PAA-C(60)) were synthesized by reacting C(60) with well-defined mono and dual azide end-functionalized poly(tert-butyl acrylate)s, followed by hydrolysis. The aggregation behaviors of these C(60) end-capped polymers in aqueous solution were examined using potentiometric and conductometric titrations and static and dynamic light scattering as well as transmission electron microscopy (TEM). Both PAA-C(60) and C(60)-PAA-C(60) show pH-responsive and water-soluble properties at high pH. Both polymers self-assemble to form large compound micelles (LCMs) in aqueous solutions. The LCMs of PAA-C(60) exist as "compact aggregates", whereas the LCMs of C(60)-PAA-C(60) possess a "core-shell" structure with a larger size and aggregation number. The micelles for both polymers swell upon neutralization, where the R(h) of PAA-C(60) micelles increases from approximately 44 to approximately 102 nm and the R(h) of C(60)-PAA-C(60) aggregates varies from approximately 89 to approximately 128 nm with increasing degree of neutralization. The lower swelling of the dual end-capped C(60)-PAA-C(60) system is related to its higher C(60) content, which enhances the interpolymer chain hydrophobic association that restrains the swelling of micellar aggregates.