Dark Left-Right Gauge Model: SU(2)_R Phenomenology

In the recently proposed dark left-right gauge model of particle interactions, the left-handed fermion doublet $(\nu,e)_L$ is connected to its right-handed counterpart $(n,e)_R$ through a scalar bidoublet, but $\nu_L$ couples to $n_R$ only through $\phi_1^0$ which has no vacuum expectation value. The usual R parity, i.e. $R = (-)^{3B+L+2j}$, can be defined for this nonsupersymmetric model so that both $n$ and $\Phi_1$ are odd together with $W_R^\pm$. The lightest $n$ is thus a viable dark-matter candidate (scotino). Here we explore the phenomenology associated with the $SU(2)_R$ gauge group of this model, which allows it to appear at the TeV energy scale. The exciting possibility of $Z' \to 8$ charged leptons is discussed.Comment: 12 pages, 2 figure

Regulation of Caenorhabditis elegans degenerin proteins by a putative extracellular domain

AbstractBackground: Rare, dominant mutations in the degenerin genes of Caenorhabditis elegans (deg-1, mec-4 and mec-10) cause neuronal degeneration. The extensive sequence similarity between degenerins and mammalian genes that encode subunits of the amiloride-sensitive sodium channel from kidney, colon and lung suggests that the C. elegans degenerins form ion channels. As mec-4 and mec-10 are needed for the reception of gentle touch stimuli, they may contribute to a mechanosensory ion channel. All the dominant degeneration-causing mutations in the C. elegans degenerin genes affect equivalent residues in a hydrophobic region that is structurally similar to the H5 domain of several ion channels, and so could form the channel lining. Increased channel activity may underlie the resulting degeneration, in which the affected cells vacuolate and swell.Results We now demonstrate that a missense change in a predicted extracellular region of the proteins encoded by deg-1 and mec-4 causes cell death similar to that caused by the dominant mutations. The missense mutation lies within a 22 amino-acid region found in all the C. elegans degenerins for which the sequences have been published, but not in the similar mammalian proteins. Deletion of nine amino acids surrounding the mutation site in mec-4 also causes neuronal degeneration. The degeneration-causing mutations in either the predicted pore-lining or the predicted extracellular regions of deg-1 are suppressed by additional, dominantly acting mutations that substitute larger for smaller residues within the channel lining.Conclusion Our data suggest that the putative extracellular domain negatively regulates degenerin activity, perhaps by gating the channel. As this region is only found in the C. elegans proteins, it may allow more rapid regulation of the nematode channels, which may be needed for them to function in mechanosensation. The suppressor mutations, by adding larger amino acids to the putative pore lining, could prevent degeneration by blocking the pore of a multisubunit channel

Pressure Driven Flow of Polymer Solutions in Nanoscale Slit Pores

Polymer solutions subject to pressure driven flow and in nanoscale slit pores are systematically investigated using the dissipative particle dynamics approach. We investigated the effect of molecular weight, polymer concentration and flow rate on the profiles across the channel of the fluid and polymer velocities, polymers density, and the three components of the polymers radius of gyration. We found that the mean streaming fluid velocity decreases as the polymer molecular weight or/and polymer concentration is increased, and that the deviation of the velocity profile from the parabolic profile is accentuated with increase in polymer molecular weight or concentration. We also found that the distribution of polymers conformation is highly anisotropic and non-uniform across the channel. The polymer density profile is also found to be non-uniform, exhibiting a local minimum in the center-plane followed by two symmetric peaks. We found a migration of the polymer chains either from or towards the walls. For relatively long chains, as compared to the thickness of the slit, a migration towards the walls is observed. However, for relatively short chains, a migration away from the walls is observed.Comment: 11 pages, 13 figure

Cyclometallated ruthenium complexes with P-stereogenic monophosphines containing a polycyclic aromatic substituent

Reactions of optically pure P-stereogenic ortho-tolyl substituted phosphines with [RuCl2(p-cymene)]2 afforded the corresponding kP-coordinated ruthenium(II) dichlorides (C1′, C2') even in the presence of sodium acetate. In contrast, the ruthenium cyclometallated (k2-C,P) complexes (C3eC9) were obtained with phosphines containing a polycyclic aromatic substituent (L3-L9), namely 1-naphthyl, 9-phenanthryl or 1-pyrenyl. Some diastereoselectivity in the cyclometallation process has been observed for the most bulky ligands. The new compounds have been used as catalytic precursors in the reduction of acetophenone to 1-phenylethanol by transfer hydrogenation

Síntesis y caracterización de un biomaterial para su uso en ingeniería de tejidos de piel

La ingeniería de tejidos constituye una disciplina relativamente nueva y un campo de investigación y desarrollo interdisciplinario que aplica los conocimientos de la bioingeniería, química, física, biología etc. para resolver problemas químicos y quirúrgicos asociados a la pérdida de tejido o al fallo funcional de órganos (San Román et al., 2000; Naderi et al., 2011). Esta área de conocimiento busca proporcionar una nueva solución a los problemas de daño o pérdida tisular, mediante el reemplazo o restauración de tejido. Más aún se aspira a recobrar la función de un órgano y en algunos casos su reconstrucción parcial o total, con estructuras que contengan poblaciones específicas de células. La meta fundamental de la ingeniería de tejidos es desarrollar sustitutos (biológicos o sintéticos) que restauren, mantengan o mejoren la función del tejido perdido o lesionado por trauma o enfermedad. (Marler et al., 1998; Landínez et al., 2010). Esta nueva área de estudio permitirá crear estrategias que permitan la sustitución del tejido dañado, por un tejido diseñado y construido para satisfacer las funciones y las necesidades de cada paciente

Dietary AGEs as Exogenous Boosters of Inflammation

Most chronic modern non-transmissible diseases seem to begin as the result of low-grade inflammation extending over prolonged periods of time. The importance of diet as a source of many pro-inflammatory compounds that could create and sustain such a low-grade inflammatory state cannot be ignored, particularly since we are constantly exposed to them during the day. The focus of this review is on specific components of the diet associated with inflammation, specifically advanced glycation end products (AGEs) that form during thermal processing of food. AGEs are also generated in the body in normal physiology and are widely recognized as increased in diabetes, but many people are unaware of the potential importance of exogenous AGEs ingested in food. We review experimental models, epidemiologic data, and small clinical trials that suggest an important association between dietary intake of these compounds and development of an inflammatory and pro-oxidative state that is conducive to chronic diseases. We compare dietary intake of AGEs with other widely known dietary patterns, such as the Mediterranean and the Dietary Approaches to Stop Hypertension (DASH) diets, as well as the Dietary Inflammation Index (DII). Finally, we delineate in detail the pathophysiological mechanisms induced by dietary AGEs, both direct (i.e., non-receptor-mediated) and indirect (receptor-mediated

ARC Newsletter Volume 1, Issue 2

https://digitalcommons.lasalle.edu/arc_newsletter/1001/thumbnail.jp

Effect of Thevetia peruviana on murine-induced obesity

Background: Obesity is considered a multifactorial disease that has importantly increased the development of chronic degenerative diseases. Drugs available for treating obesity have the inconvenience of producing side effects of importance. In Mexican traditional medicine, the seeds of Thevetia peruviana have been widely employed for weight reduction.Materials and Methods: The effect produced by different extracts of T. peruviana on MonoSodium Glutamate (MSG)-induced obesity in mice was evaluated. A chemical analysis oriented toward the identification of the chemical compounds contained in the active extract was carried out.Results: Oral administration of the hexanic extract of T. peruviana (for 7 weeks) was capable of diminishing weight gain by up to 24.1% in the mice without observing the development of resistance to insulin. Median lethal dose of the hexanic and Ethyl Acetate (EtOAc) extracts was >2 g/kg. By utilizing bio-assay guided fractionation, eight secondary metabolites were purified and characterized.Conclusion: The hexanic extract obtained from Thevetia peruviana seeds was capable of reducing weight gain in mice with induced obesity. In addition, this extract showed good response to the glucose tolerance test, was able to avoid the development of insulin resistance, and also substantially increased serum adiponectin levels. Eight low-polarity compounds were identified in the active fraction. This species could be considered for ongoing investigation as a potential option to reduce obesityKeywords: Obesity, Thevetia peruviana, medicinal plants, body weight, adiponectin, monosodium glutamate, sterol

Connecting to nature through 360° videos during COVID-19 confinement: a pilot study of a brief psychological intervention

Psychological interventions have been shown to be beneficial in mitigating stress related to COVID-19 confinement. According to theories of restorative environments, exposure to natural surroundings has positive effects on well-being and stress through its restorative qualities. With 360° video-based Virtual Reality (VR), people can be exposed to nature and so better manage the consequences associated with mobility restrictions during confinement. The main aim of this pilot study was to examine whether a 360° video-based VR intervention composed of five 13-minute sessions (once a day) has positive effects on affect, well-being, and stress. The sample was made up of 10 participants (4 men and 6 women; age : M = 46.5, SD = 11.7) who were confined at home (voluntarily or not) during the COVID-19 pandemic. Participants were instructed to watch a 360° video each day (of a “beach” or “lake” environment) using their smartphone and VR glasses sent to them by mail. Participants responded with several self-reports before and/or after each session (emotions and sense of presence) and before and/or after the intervention (affect, well-being, perceived stress, perceived restorativeness of nature, and the usefulness and acceptability of the intervention). Results showed a tendency to improve positive (e.g., happiness) and negative (e.g., anxiousness) emotions and experience a high sense of presence after each session. Moreover, perceived restorative qualities of the environment and their cognitive and behavioral effects were high. A significant decrease in negative affect was found after the intervention. Usefulness and acceptability were also high. This is the first study to show that an affordable and accessible technology can be used to overcome the negative consequences of confinement and counteract its harmful psychological effects