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

Nanofiber fabrication in a temperature and humidity controlled environment for improved fibre consistency

To fabricate nanofibers with reproducible characteristics, an important demand for many applications, the effect of controlled atmospheric conditions on resulting electrospun cellulose acetate (CA) nanofibers was evaluated for temperature ranging 17.5 - 35°C and relative humidity ranging 20% - 70%. With the potential application of nanofibers in many industries, especially membrane and filter fabrication, their reproducible production must be established to ensure commercially viability.
Cellulose acetate (CA) solution (0.2 g/ml) in a solvent mixture of acetone/DMF/ethanol (2:2:1) was electrospun into nonwoven fibre mesh with the fibre diameter ranging from 150nm to 1µm.
The resulting nanofibers were observed and analyzed by scanning electron microscopy (SEM), showing a correlation of reducing average fibre diameter with increasing atmospheric temperature. A less pronounced correlation was seen with changes in relative humidity regarding fibre diameter, though it was shown that increased humidity reduced the effect of fibre beading yielding a more consistent, and therefore better quality of fibre fabrication.
Differential scanning calorimetry (DSC) studies observed lower melt enthalpies for finer CA nanofibers in the first heating cycle confirming the results gained from SEM analysis. From the conditions that were explored in this study the temperature and humidity that gave the most suitable fibre mats for a membrane purpose were 25.0°C and 50%RH due to the highest level of fibre diameter uniformity, the lowest level of beading while maintaining a low fibre diameter for increased surface area and increased pore size homogeneity. This study has highlighted the requirement to control the atmospheric conditions during the electrospinning process in order to fabricate reproducible fibre mats

Role of Shrubs in Rangeland Based Livestock Production System in Western Rajasthan, India

Rangeland covers ~ 51% of the terrestrial surface of the Earth, and supports half of the world‟s livestock. More than 80 % of forage consumed by domestic livestock is supplied by rangelands in Africa and Asia. Hot arid regions of India cover an area of 31.7 million hectares and out of which Rajasthan state constitutes ~ 61.8 % of the entire area. The crop production in this area is low, unstable and risky. Livestock sustains arid farming systems by virtue of their potential to reduce risk, alleviate poverty, important providers of nutrients and traction for growing crops in smallholder systems and the imparting sustainability of household. The hot arid region of Rajasthan has about 29.08 million livestock. Pastures and grazing lands, residential area and wayside grazing lands, crop by-products and residues, fodder crops etc. are the major feed resources. For the small ruminants and camels, the rangelands are the major source of feed supply. Shrubs are vital component of rangeland vegetation and cover \u3e 70 % of desert landscapes from Aravalli to the international border of the Indian part of Thar desert. They are an important source of feed and assure feed availability in a drought situation. They have remarkable morpho-physiological adaptations to different land forms and survive under harsh edapho-climatic conditions. During recent past, a rapid decline population of browse shrubs is noticed due to their over exploitation, destruction of natural habitat, expending irrigation facilities, increasing agricultural mechanization and changes in land use pattern. In the present paper key species, fodder production and nutritive value of shrubs of hot arid rangelands are discussed

Prevalence and epidemiological aspect of dengue fever in western Rajasthan in year 2018

Background: Dengue fever (DF) is a common mosquito borne disease caused by dengue virus and is transmitted by Aedes mosquito. It is one of the major public health problems in India which affects all levels of society, but the burden of disease is a higher in poor people who live together in communities.  Aim of present study is aimed to assess the prevalence and epidemiological characteristics of cases of DF in  Tertiary Care Hospitals in Jodhpur, Rajasthan.Methods: A cross-sectional study was conducted in all cases of DF registered in the associated group of Hospitals of Dr. S.N. Medical College, Jodhpur from 1st January 2018 to 31st December 2018. Rapid immune-chromatographic card test and MAC ELISA test method was used to detect dengue non-structural protein 1 (NS1) antigen and dengue immunoglobulin M (IgM) antibodies in the Viral Research Diagnostic Laboratory (VRDL) of Department of Microbiology, Dr. S.N. Medical College to confirm the diagnosis. Results: Out of 2701 patients, 541 patients were tested serologically positive for DF (NS1, IgM). The highest number of suspected cases (1061) was reported in the month of October, 2018 out of whom 228 were positive. Maximum number of dengue cases reported were males belonging to 31-40 years age group from urban area. Fever was the main complaint in all the cases followed by vomiting, headache, and abdominal pain.Conclusion: Dengue is one of the major public health problems in India. A large number of cases are reported in the monsoon and post-monsoon period in the months from  September to December. Measures can be taken both at personal and government level to reduce morbidity and mortality from dengue

Epidemiology of carbapenem-resistant Enterobacteriaceae colonization in ICU: a pilot study from a tertiary care hospital in Western Rajasthan, India

Background: Carbapenem-resistant Enterobacteriaceae (CRE) is a serious global public health threat. Antibiotic overuse, improper sanitation and unhygienic practices lead to large scale carriage and rapid spread.Methods: This is a prospective hospital based study planned for a period of 3 months including all patients admitted to 14 bedded Trauma ICU of a tertiary care hospital in Rajasthan. Rectal swabs were collected from admitted patients and carriage of carbapenem resistant Enterobacteriaceae looked for as per CDC guidelines. Screening of the Enterobacteriaceae colonies for carbapenemase production was done by Modified Hodge test. Carbapenem-resistant isolates were also tested for Metallo beta lactamase production by phenotypic disc confirmatory test.Results: A total of 73 patients were screened and 27 CRE isolates were obtained, carriage rate being 37%. A high level of resistance was seen to aminoglycosides, fluoroquinolones and cephalosporins. 100% sensitivity was however seen to Colistin, Tigecycline and Fosfomycin. 5 out of 27 strains showed a positive MHT test. Metallo beta lactamase (MBL) production was seen in 21/25 strains as tested by meropenem and Meropenem-EDTA discs.Conclusions: The current pilot study finds out the prevalence of CRE carriage among critically ill patients and stresses upon strong need for stringent infection control measures

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

(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

In Vitro Cell Models for Ophthalmic Drug Development Applications

© Sara Shafaie et al. 2016; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Tissue engineering is a rapidly expanding field that aims to establish feasible techniques to fabricate biologically equivalent replacements for diseased and damaged tissues/organs. Emerging from this prospect is the development of in vitro representations of organs for drug toxicity assessment. Due to the ever-increasing interest in ocular drug delivery as a route for administration as well as the rise of new ophthalmic therapeutics, there is a demand for physiologically accurate in vitro models of the eye to assess drug delivery and safety of new ocular medicines. This review summarizes current existing ocular models and highlights the important factors and limitations that need to be considered during their use.Peer reviewe

Crystal Structure of 2′,3′-Di-O-Acetyl-5′-Deoxy-5-Fluorocytidine with N–H···(O,F) Proton Donor Bifurcated and (C,N)–H···O Bifurcated Acceptor Dual Three-Center Hydrogen Bond Configurations

The title compound, C13H16O6N3F, features a central furan ring containing four carbon atom chiral centers with a 4-amino-5-fluoro-2-oxopyrimidine group, two acetyl groups and a methyl group bonded at the 2,3,4,5 positions, each in an absolute R configuration (2R,3R,4R,5R). It crystallizes in the monoclinic space group C2 with unit cell parameters a = 14.5341(3), b = 7.26230(10), c = 16.2197(3) Å, β = 116.607(2)°, Z = 4. An extensive array of intra and inter molecular hydrogen bond interactions dominate crystal packing in the unit cell highlighted by a relatively rare three-center proton-bifurcated donor N–H···(O,F) hydrogen bond interaction in cooperation with a second, (C,N)–H···O bifurcated acceptor three-center hydrogen bond in a supportive fashion. Additional weak Cg π-ring inter molecular interactions between a fluorine atom and the 4-amino-5-fluoro-2-oxopyrimidine ring in concert with multiple donor and acceptor hydrogen bonds significantly influence the bond distances, bond angles and torsion angles of the deoxy-5-fluorocytidine group. Comparison to a MOPAC computational calculation provides support to these observations