Charge Delocalization in Self-Assembled Mixed-Valence Aromatic Cation Radicals

The spontaneous assembly of aromatic cation radicals (D+•) with their neutral counterpart (D) affords dimer cation radicals (D2+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation of dimer cation radicals is deliberated with the aid of a series of cyclophane-like bichromophoric donors with drastically varied interplanar angles between the cofacially arranged aryl moieties. X-ray crystallography of a number of mixed-valence cation radicals derived from monochromophoric benzenoid donors established that they generally assemble in 1D stacks in the solid state. However, the use of polychromophoric intervalence cation radicals, where a single charge is effectively delocalized among all of the chromophores, can lead to higher-order assemblies with potential applications in long-range charge transport. As a proof of concept, we show that a single charge in the cation radical of a triptycene derivative is evenly distributed on all three benzenoid rings and this triptycene cation radical forms a 2D electronically coupled assembly, as established by X-ray crystallography

3-(7,8,13,14-Tetra­hydrodi­benzo­[a,i]phen­an­thridin-5-yl)benzene-1,2-diol

In the title compound, C27H21NO2, the half-chair conformation of the alicyclic rings gives rise to a slightly folded structure of the central tricyclic tetra­hydrophenanthridine unit. Tandem intra­molecular O—H⋯N and O—H⋯O hydrogen bonds give rise to adjacent S(6) and S(5) rings, respectively, which dictate the conformation of the 5-aryl substituent. In the crystal structure, an inter­molecular C—H⋯O contact generates chains parallel to [101]. Short O—H⋯π and C—H⋯π contacts are also observed

Antimicrobial Effect of Mouthwashes in Patients Undergoing Orthodontic Treatment

Objective: The purpose of the study was to determine the efficacy of three different mouthwashes in patients undergoing fixed orthodontic treatment for prevention of white spot lesions Methods: The study was conducted on 30 patients undergoing fixed orthodontic treatment between the ages of 15-25years. Patients were divided into 3groups - Group 1 control group, Group 2 using freshclor for 30 sec twice daily and group 3 using HiOra mouth wash for 30sec twice daily. Samples from tooth surfaces were collected at 1st day, 30th day and 90th day interval and were incubated for 48 hours. Colonies were counted using digital colony counter. Results: Freshclor and HiOra mouthwashes showed the maximum potential for the control of pathogenic organisms, and prevention of gingivitis and bacterial plaque inhibition than patients those were not using mouthwash

Disruption of cellular homeostasis induces organelle stress and triggers apoptosis like cell-death pathways in malaria parasite

A regulated protein turnover machinery in the cell is essential for effective cellular homeostasis; any interference with this system induces cellular stress and alters the normal functioning of proteins important for cell survival. In this study, we show that persistent cellular stress and organelle dysfunction because of disruption of cellular homeostasis in human malaria parasite Plasmodium falciparum, leads to apoptosis-like cell death. Quantitative global proteomic analysis of the stressed parasites before onset of cell death, showed upregulation of a number of proteins involved in cellular homeostasis; protein network analyses identified upregulated metabolic pathways that may be associated with stress tolerance and pro-survival mechanism. However, persistent stress on parasites cause structural abnormalities in endoplasmic reticulum and mitochondria, subsequently a cascade of reactions are initiated in parasites including rise in cytosolic calcium levels, loss of mitochondrial membrane potential and activation of VAD-FMK-binding proteases. We further show that activation of VAD-FMK-binding proteases in the parasites leads to degradation of phylogenetically conserved protein, TSN (Tudor staphylococcal nuclease), a known target of metacaspases, as well as degradation of other components of spliceosomal complex. Loss of spliceosomal machinery impairs the mRNA splicing, leading to accumulation of unprocessed RNAs in the parasite and thus dysregulate vital cellular functions, which in turn leads to execution of apoptosis-like cell death. Our results establish one of the possible mechanisms of instigation of cell death by organelle stress in Plasmodium

1-Meth­oxy-4-({[(4-meth­oxy­phen­yl)­sulfan­yl](phen­yl)meth­yl}sulfan­yl)benzene

The title compound, C21H20O2S2, forms a propeller-shaped structure with the tetra­hedral C atom as the central hub and meth­oxy­benzene and phenyl residues as radiating blades. Short C—H⋯π contacts are observed

(3E,5E)-1-Benzyl-3,5-bis­(2-fluoro­benzyl­idene)piperidin-4-one

The inversion-related mol­ecules of the title compound, C26H21F2NO, associate into closed dimeric subunits via co-operative C—H⋯π inter­actions. Two non-classical C—H⋯O and one C—H⋯N intra­molecular hydrogen bonds are also found in the crystal structure. The piperidin-4-one ring adopts a sofa conforamtion with the 1-benzyl group in the equatorial position, and the equiplanar fluoro­phenyl substituents in the 3- and 5-positions stretched out on either side. The 1-benzyl group is disposed towards the substituent in the 6th position of the piperidin-4-one ring. The 3,5-diene units possess E configurations

Purification and characterisation of immunoglobulins from the serum of a catfish, Clarias gariepinus (Burchell, 1822)

Attempts have been made to characterize and purify immunoglobulins from the serum of Clarias gariepinus, which has been immunized with bovine serum albumen. Initially, the proteins in the serum were chromatographed successively by affinity chromatography column. The affinity-purified fraction was concentrated and checked in SDS-PAGE, two bands of heavy chain and two bands of light chain were observed. Since teleost immunoglobulins have been shown to belong to a single class, the extra bands in light and heavy chains in the present study might be the breakdown of immunoglobulin or some unpurified contaminants. The affinity-purified fraction was also subjected to gel filtration chromatography column

1,1′-[(2-Bromo­phen­yl)­methyl­ene]­dipyrrolidin-2-one

In the title compound, C15H17BrN2O2, both pyrrolidinone rings adopt envelope conformations. The crystal packing is characterized by short C—Br⋯O=C inter­actions [Br⋯O = 3.1730 (13) Å], leading to supra­molecular dimers. Inter­molecular C—H⋯O and C—H⋯π inter­actions are also observed

Prevalence of anemia among school going adolescent girls in rural area of Pune, Maharashtra, India

Background: Anemia is like the tip of an iceberg, as majority of anemic subjects are asymptomatic. Low iron diet for longer period perpetuates an inter-generational cycle of anemia, anemic women giving birth to anemic children. This situation is more acute in rural area due to their dietary habits, illiterate parents, socio-economic status, misconception about food, religions belief, menstruation and physical activity.Methods: This descriptive cross-sectional study was conducted in rural field practice area of Rural Heath Training Centre (RHTC) under department of community medicine, Bharati Vidyapeeth Medical college Pune, Maharashtra, India. There are 11 villages under RHTC Lavale: Out of them one village viz. Pirangut village was randomly selected. (by using random sampling method). This study was conducted in 2013. Total 740 senior secondary school girls studying in class 6th to 12th (10-19 age group) were included. Hb level was measured by Sahli′s hemoglobinometer. Chi square was used to test for association between qualitative variables, and p-value less than 0.05 was considered significant.Results: The Hb level of girls reveal that majority 648 (87.6%) of them were anemic. It was found that 305 (47.06%) and 340 (52.48%) were suffering from mild and moderate anemia while 3 (0.46%) had severe anemia. The significant association was found with BMI for age.Conclusions: Active measures to decrease the prevalence of anemia through educating these girls and their mothers, school diet supplementation, providing low cost diet

On the Wang-Landau Method for Off-Lattice Simulations in the "Uniform" Ensemble

We present a rigorous derivation for off-lattice implementations of the so-called "random-walk" algorithm recently introduced by Wang and Landau [PRL 86, 2050 (2001)]. Originally developed for discrete systems, the algorithm samples configurations according to their inverse density of states using Monte-Carlo moves; the estimate for the density of states is refined at each simulation step and is ultimately used to calculate thermodynamic properties. We present an implementation for atomic systems based on a rigorous separation of kinetic and configurational contributions to the density of states. By constructing a "uniform" ensemble for configurational degrees of freedom--in which all potential energies, volumes, and numbers of particles are equally probable--we establish a framework for the correct implementation of simulation acceptance criteria and calculation of thermodynamic averages in the continuum case. To demonstrate the generality of our approach, we perform sample calculations for the Lennard-Jones fluid using two implementation variants and in both cases find good agreement with established literature values for the vapor-liquid coexistence locus.Comment: 21 pages, 4 figure