N,N'-methylenediimidazolium salts: from self-assembly to an efficient DNAse protection system.

We have developed N,N'-dialkylmethylenediimidazolium salts ([C(n)C(n)DIM][X]2) that self-organize into multilayered cationic vesicles and can interact with DNA. These preorganized systems form complexes with linear DNA and protect it from DNase I cleavage.

Contribution of the central dopaminergic system in the anti-hypertensive effect of kinin B1 receptor antagonists in two rat models of hypertension.

Kinins are neuroactive peptides that could play a role in central autonomic control of blood pressure. Whereas kinin B1R binding sites were increased in specific brain areas of spontaneously hypertensive rats (SHR) and Angiotensin II (AngII)-hypertensive rats, the contribution of kinin B1R in hypertension remains controversial. The aims of the study were to determine: (a) the effects on mean arterial blood pressure (MAP) of centrally and peripherally administered B1R antagonists in SHR (16weeks) and AngII-hypertensive rats (200ng/kg/minx2weeks, s.

Roughness of simulated surfaces examined with a haptic tool: effects of spatial period, friction, and resistance amplitude.

A specifically designed force-feedback device accurately simulated textures consisting of lateral forces opposing motion, simulating friction. The textures were either periodic trapezoidal forces, or sinusoidal forces spaced at various intervals from 1.5 mm to 8.

Blood lead levels and major depressive disorder, panic disorder, and generalized anxiety disorder in US young adults.

Context: Lead is a ubiquitous neurotoxicant, and adverse cognitive and behavioral effects are well-documented in children and occupationally exposed adults but not in adults with low environmental exposure.

Objective: To investigate the association of current blood lead levels with 3 common psychiatric disorders-major depression, panic, and generalized anxiety-in young adults.

Design: Cross-sectional epidemiologic survey.

Formation of inclusion complexes between 1,1'-dialkyl-3,3'-(1,4-phenylene)bisimidazolium dibromide salts and cucurbit[7]uril.

N,N'-Dialkyl-(1,4-phenylene)bisimidazolium salts form inclusion complexes with cucurbit[7]uril (CB[7]) with high association constants. The stoichiometry of the complexes depends on the alkyl chains and on the relative concentration of the imidazolium salt and CB[7]. The binding interactions of CB[7] with these bisimidazolium salts were studied experimentally by (1)H NMR, high resolution mass spectroscopy, and UV spectroscopy, and theoretically by semiempirical molecular modeling.

Exploring side-chain diversity by submonomer solid-phase aza-peptide synthesis.

Submonomer synthesis of aza-peptides featuring regioselective alkylation of peptide-bound aza-Gly residues provided ten aza-analogues of the Growth Hormone Releasing Peptide-6 (GHRP-6) in 15-42% yield and purity generally >or=90%. Circular dichroism demonstrated that azaPhe-peptide 7a induced a beta-turn conformation which may be responsible for its 1000-fold improvement in GHRP-6 selectivity for the CD36 receptor. This versatile method for making aza-peptides avoids solution-phase hydrazine synthesis and is well suited for studying side-chain-activity relationships of biologically active peptides.

Using electronic polarization from the internal continuum (EPIC) for intermolecular interactions.

Recently, the vacuum-phase molecular polarizability tensor of various molecules has been accurately modeled (Truchon et al., J Chem Theory Comput 2008, 4, 1480) with an intramolecular continuum dielectric model. This preliminary study showed that electronic polarization can be accurately modeled when combined with appropriate dielectric constants and atomic radii.

Recognition of 1,4-Xylylene binding sites in polyimidazolium cations by cucurbit[7]uril: toward pseudorotaxane assembly.

The binding interactions between cucurbit[7]uril (CB[7]) and different polyimidazolium cations containing aromatic binding sites (1,4-xylylene units) were studied experimentally by 1D and 2D NMR, high-resolution mass spectrometry (HRMS), and fluorimetry, and, theoretically, by computed geometries and enthalpy changes. CB[7] was found to form [2]- and [3]-pseudorotaxanes with these cations by the inclusion of the internal 1,4-xylylene units.

Thermoregulated microemulsions by cyclodextrin sequestration: a new approach to efficient catalyst recovery.

The combination of imidazolium surfactants with alpha-cyclodextrins (CDs, in green) was used as a control element in the thermoregulated aqueous olefin hydroformylation. The self-assembly of the imidazolium surfactants (red) favors the micellization process at high temperatures, whereas at lower temperatures the complexation of the surfactant monomers into the alpha-CDs is favored.

RNA-Seq-quantitative measurement of expression through massively parallel RNA-sequencing.

The ability to quantitatively survey the global behavior of transcriptomes has been a key milestone in the field of systems biology, enabled by the advent of DNA microarrays. While this approach has literally transformed our vision and approach to cellular physiology, microarray technology has always been limited by the requirement to decide, a priori, what regions of the genome to examine. While very high density tiling arrays have reduced this limitation for simpler organisms, it remains an obstacle for larger, more complex, eukaryotic genomes.

Parental experience of home adaptation for children with motor disabilities.

Home adaptation is essential in increasing independence of children with disabilities and reducing the burden of care for parents. Physical and occupational therapists involved in home adaptations are faced with various challenges in meeting the needs and expectations of parents. This study aimed at exploring the experience of parents throughout the home adaptation process.

Killer granzyme B linked to N-myc- and c-myc-dependent HSC survival: isn't that comyc?

c-myc is a key regulator of hemopoietic stem cell (HSC) activity. In this issue of Cell Stem Cell, Laurenti et al. (2008) show that c-myc and N-myc control HSC survival and link this finding to the regulation of granzyme B expression.

Immunological responses in C3H/HeJ mice following nose-only inhalation exposure to different sizes of beryllium metal particles.

Beryllium is used in a wide variety of industries. Chronic beryllium disease is the most common occupational disease among workers following exposure to Be. The objective of this study was to determine the immunologic effects of two different particle sizes of Be metal, <2.

Study of the supramolecular cooperativity in the multirecognition mechanism of cyclodextrins/cucurbituril/disubstituted diimidazolium bromides.

N, N'-Disubstituted methylenediimidazolium bromide salts substituted with two aromatic groups present two different binding sites. In the binary complexes with cyclodextrins (CDs) or cucurbit[7]uril (CB[7]), the macrocycle is always positioned on the external aromatic residues. In the ternary complexes, CB[7] is positioned around the diimidazolium cation, where the external aromatic residue is included in the CD's cavity.

Benzophenone semicarbazone protection strategy for synthesis of aza-glycine containing aza-peptides.

Aza-glycine has been incorporated into peptide mimics as a tool for studying the active conformation and characterizing structure-function relationships for activity. Side reactions, such as intramolecular cyclizations to form hydantoins and oxadiazalones, have, however, inhibited efforts to make activated aza-Gly residues in solution using carbamate protection. Herein, we describe efficient incorporation of aza-glycine into aza-peptides using diphenyl hydrazone protection.

Accurate Molecular Polarizabilities Based on Continuum Electrostatics.

A novel approach for representing the intramolecular polarizability as a continuum dielectric is introduced to account for molecular electronic polarization. It is shown, using a finite-difference solution to the Poisson equation, that the Electronic Polarization from Internal Continuum (EPIC) model yields accurate gas-phase molecular polarizability tensors for a test set of 98 challenging molecules composed of heteroaromatics, alkanes and diatomics. The electronic polarization originates from a high intramolecular dielectric that produces polarizabilities consistent with B3LYP/aug-cc-pVTZ and experimental values when surrounded by vacuum dielectric.

Escherichia coli O157:H7 survives within human macrophages: global gene expression profile and involvement of the Shiga toxins.

Escherichia coli O157:H7 is an important food-borne pathogen that specifically binds to the follicle-associated epithelium in the intestine, which rapidly brings this bacterial pathogen in contact with underlying human macrophages. Very little information is available about the interaction between E. coli O157:H7 and human macrophages.

NMR structure of the complex between the Tfb1 subunit of TFIIH and the activation domain of VP16: structural similarities between VP16 and p53.

The Herpes Simplex Virion Protein 16 (VP16) activates transcription through a series of protein/protein interactions involving its highly acidic transactivation domain (TAD). The acidic TAD of VP16 (VP16TAD) has been shown to interact with several partner proteins both in vitro and in vivo, and many of these VP16 partners also bind the acidic TAD of the mammalian tumor suppressor protein p53. For example, the TADs of VP16 and p53 (p53TAD) both interact directly with the p62/Tfb1 (human/yeast) subunit of TFIIH, and this interaction correlates with their ability to activate both the initiation and elongation phase of transcription.

Dibenzylimidazolium halides: from complex molecular network in solid state to simple dimer in solution and in gas phase.

1,3-Dibenzylimidazolium bromide has been synthesized and the nature of the interactions between cations and anions has been studied in the solid state, in solution and in the gas phase. The cohesion of the crystal is ensured by a combination of hydrogen bonds, and aromatic stacking interactions. In solution and in the gas phase, the supramolecular structural organization due to T-stacking is maintained to a great extent.

Neural substrates of cognitive skill learning in Parkinson's disease.

While cognitive skill learning is normally acquired implicitly through frontostriatal circuitry in healthy individuals, neuroimaging studies suggest that patients with Parkinson's disease (PD) do so by activating alternate, intact brain areas associated with explicit memory processing. To further test this hypothesis, 10 patients with PD and 12 healthy controls were tested on a modified, learning version of the Tower of London task while undergoing positron emission tomography at four different time points over the course of learning. Despite having less accurate problem solving abilities than controls, PD patients were able to acquire the skill learning task.

2-vinylpyrroles and pyrrolo[3,2-d]pyrimidines from direct addition of aldehydes to 4-amino-pyrrole-2-carboxylate derivatives.

A new methodology for the direct preparation of 2-vinylpyrroles is presented. Treatment of 4-amino-pyrrole-2-carboxylates 5a-c and 6a-d with aliphatic aldehydes and TFA furnished 2-vinylpyrroles 2a-k in 9-87% yields. Under similar conditions ureidopyrroles 5a-c reacted with aryl aldehydes to provide pyrrolo[3,2-d]pyrimidines 1a-d in 28-63% yields.

Spatial variation in the molecular tilt orientational order within the solid domains of phase-separated, mixed dialkylphosphatidylcholine monolayers.

The miscibility of the solid-phase-forming distearoylphosphatidylcholine (DSPC) and the fluid-phase-forming dilauroylphosphatidylcholine (DLPC) at the air/water interface was investigated by the Langmuir film balance. Surface pressure-area isotherms suggest that mixtures containing 25.0-62.

Typhi genes expressed during infection or involved in pathogenesis.

Salmonella enterica serovar Typhi (Typhi), the aetiologic agent of typhoid fever, is a human restricted pathogen. Elucidation of the interactions between the infected host and this pathogen is critical to understand infectious diseases but is deterred by a lack of in vivo infection assays, since Typhi uniquely infects humans and there is no suitable animal model. Macrophages can be used as an alternative model, as the ability to survive and replicate within these cells is thought to be one of the major pathogenesis determinants for Salmonella.