Effects of Model Protein Environments on the Dynamics of Proton Wires

The multiconfigurational molecular dynamics with quantum transitions (MC-MDQT) method is utilized to study the impact of model protein environments on the dynamics of proton wires. The MC-MDQT method allows the realtime nonequilibrium quantum dynamical simulation of proton transport along water chains and provides a framework for analyzing the detailed dynamical mechanisms of these multiple proton transfer reactions. In this paper, the protein environment is modeled by applying structural restraints to the oxygen atoms of the chain, by applying external electric fields, and by including solvating water molecules hydrogen-bonded to the ends of the water chain. Our simulations illustrate that the protein environment could strongly impact the dynamics of proton wires through a combination of structural restraints, fluctuating electric fields, solvation, and hydrogen bonding. Our simulations also indicate that quantum effects such as hydrogen tunneling and nonadiabatic transitions play a significant role under certain nonequilibrium conditions.     

NSOM the fourth dimension: Integrating nanometric spatial and femtosecond time resolution

Photonic devices are becoming the cornerstone of next generation systems for computing and information processing. This paper reports on the first steps in the development of methods to understand these devices with nanometric (10^?7 cm) spatial and femtosecond (10^?15 s) time resolution. The basis of this achievement is the dramatic developments that have occurred in the past few years in a new area of optics called near-field optics. Near-field optics is a form of lensless optics with a resolution that is subwavelength and which is independent of the wavelength of the light being employed. We report in this paper the transmission of pulses with tens of femtosecond duration through subwavelength, near-field optical elements. We also report on a femtosecond near-field optical light source with cross-correlating capabilities and on the growth of GaAs in the tip of micropipettes for use as an ultra-fast electro-optical switch which can cross-correlate optical, electrical, and electro-optical effects. These developments are especially relevant in the investigation of photonic devices since such devices can alter their characteristics as a function of size in the mesoscopic regime from just below lens-based optical resolutions to dimensions that approach atomic scales of ～1 nm (10^?7 cm). In view of the fact that these devices and the processes that govern them also exhibit ultrafast speeds, the combination of state of the art femtosecond laser spectroscopy with the unique features of near-field optics is a critical step in advancing our next generation understandings of such materials and structures so that their full potential in information processing can be achieved.     

Systems analysis utilising pathway interactions identifies sonic hedgehog pathway as a primary biomarker and oncogenic target in hepatocellular carcinoma

The development and progression of cancer is associated with disruption of biological networks. Historically studies have identified sets of signature genes involved in events ultimately leading to the development of cancer. Identification of such sets does not indicate which biologic processes are oncogenic drivers and makes it difficult to identify key networks to target for interventions. Using a comprehensive, integrated computational approach, the authors identify the sonic hedgehog (SHH) pathway as the gene network that most significantly distinguishes tumour and tumour‐adjacent samples in human hepatocellular carcinoma (HCC). The analysis reveals that the SHH pathway is commonly activated in the tumour samples and its activity most significantly differentiates tumour from the non‐tumour samples. The authors experimentally validate these in silico findings in the same biologic material using Western blot analysis. This analysis reveals that the expression levels of SHH, phosphorylated cyclin B1, and CDK7 levels are much higher in most tumour tissues as compared to normal tissue. It is also shown that siRNA‐mediated silencing of SHH gene expression resulted in a significant reduction of cell proliferation in a liver cancer cell line, SNU449 indicating that SHH plays a major role in promoting cell proliferation in liver cancer. The SHH pathway is a key network underpinning HCC aetiology which may guide the development of interventions for this most common form of human liver cancer.Inspec keywords: bioinformatics, cancer, cellular biophysics, genetics, liver, molecular biophysics, RNA, systems analysis, tumoursOther keywords: biomedical informatics, human liver cancer, network underpinning HCC aetiology, liver cancer cell line, cell proliferation, SHH gene expression, siRNA‐mediated silencing, CDK7 levels, phosphorylated cyclin B1, Western blot analysis, in silico findings, SHH pathway, human hepatocellular carcinoma, tumour‐adjacent samples, gene network, integrated computational approach, oncogenic drivers, biologic processes, cancer development, biological networks, cancer progression, oncogenic target, primary biomarker, sonic hedgehog pathway, pathway interactions, systems analysis     

Nano-octopus: a new form of branching carbon nanofiber

A new multibranched octopus-type structure of carbon nanofibers is synthesized from a natural precursor, camphor, by a thermal chemical vapor deposition technique. An alloy of Cu:Ni catalyst is prepared by electrochemically coating nickel on a copper sheet, with nickel sulfate as an electrolyte, and heating that nickel-coated copper sheet to a higher temperature. Deposition of carbon on these substrates leads to the formation of a branched nanostructure in the temperature range of 923 K to 1023 K. The fiber diameter increases from 30 nm to 250 nm with increasing pyrolysis temperature. Detailed morphology and the internal structure of these fibers are studied by scanning and transmission electron microscopy.     

Coping through emotional approach: Scale construction and validation.

Four studies demonstrate the psychometric adequacy and validity of scales designed to assess coping through emotional approach. In separate undergraduate samples, exploratory and confirmatory factor analyses of dispositional (Study 1) and situational (Study 3) coping item sets yielded 2 distinct emotional approach coping factors: emotional processing (i.e., active attempts to acknowledge and understand emotions) and emotional expression. The 2 scales yielded high internal consistency and test-retest reliability, as well as convergent and discriminant validity. A study (Study 2) of young adults and their parents established the scales' interjudge reliabilities. Longitudinal (Study 3) and experimental (Study 4) research supported the predictive validity of the emotional approach coping scales with regard to adjustment to stressful encounters. Findings highlight the utility of functionalist theories of emotion as applied to coping theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective predictors of preschoolers' aggression and peer acceptance: Direct and indirect effects.

Observational assessments were made of 51 preschoolers' (mean age?=?53.25 months) peer aggression and emotional displays outside of (baseline) and during aggressive interactions, and their emotion knowledge and peer acceptance were also assessed. Results indicated that the connections between children's affective dispositions and their aggression and peer acceptance varied as a function of both the emotion context (baseline vs. aggression related) and the particular emotion involved (happiness vs anger). Emotion knowledge and affective dispositions overlapped little with each other, and both made independent contributions to peer acceptance and aggression. Mediation analyses revealed, however, that the significant connections between children's emotional dispositions and knowledge and their peer acceptance were mostly mediated by aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of punishment on response latency in extraverts.

Previous findings indicate that in comparison to introverts, extraverts are prone to form responses that are resistant to interruption by punishment. Because the tendency to stop and reflect following punishment may be crucial for subsequent learning, the present study examined differences between introverts' and extraverts' reactions to punishment using response latency on the trial following punishment as the dependent variable. 66 extraverted and 66 introverted male undergraduates, selected on the basis of Eysenck Personality Questionnaire scores, performed a pattern-matching task in which they received noncontingent 50% success and 50% failure feedback under 3 incentive conditions: reward only, punishment only, or both. As predicted, a significant interaction was found in the both incentive condition, reflecting the tendency of extraverts to respond more quickly and introverts more slowly following punishment than reward. No significant effects were found in the other 2 conditions, although extraverts tended to respond more quickly overall when only reward was given. A 2nd experiment, with 101 male undergraduates, that used reward-only and punishment-only feedback replicated this finding and yielded a significant group?×?condition interaction. Results indicate that in contrast to introverts, extraverts are activated by the availability of reward and, paradoxically, that punishment may facilitate rather than interrupt extraverts' reward-seeking behavior. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychosocial aspects of selected issues in women's reproductive health: Current status and future directions.

Emphasizing research published in the past decade, this article presents a summary and evaluation of psychosocial investigations of women's reproductive health, with a focus on selected aspects of menstruation, pregnancy and birth, infertility, and menopause. In some areas, studies have focused on negative physical and psychological concomitants of these health issues. However, research reveals substantial individual variability, with most women adapting well to reproductive health changes. Although methodological and conceptual shortcomings have limited firm conclusions, research has advanced our understanding of the multivariate biological, psychological, and social influences on women's reproductive health and associated outcomes. Understanding and promoting women's reproductive health across the lifespan requires biopsychosocial approaches to research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)