Phosphotungstic Acid: An Efficient Catalyst for the Aqueous Phase Synthesis of Bis-(4-hydroxycoumarin-3-yl)methanes

In this present work, we report that phosphotungstic acid provides a simple, efficient and environmentally benign route is a two-component one-pot domino Knoevenagel-type condensation/Michael reaction between 4-coumarin derivative and an aldehyde in water as a solvent in shorter duration with high yields.      

Relationship between physicochemical and rheological properties of starches from Indian wheat lines

Starches from nine Indian wheat lines were evaluated to study the relationships between physicochemical and rheological properties. Large granules (>15 μm) were present in the highest proportion followed by medium (5–15 μm) and small granules (<5 μm). Amylose content ranged between 27.4 and 37.2%. Starch with the highest proportion of large granules (68.9%) showed higher values of G′_peak (576 Pa) and G′_final (432 Pa). Amylose content showed positive relationships with retrogradation, gel firmness, gumminess and adhesiveness while negative with springiness. Cooked starch pastes with the highest amylose content (37.2%) had higher ΔH_ret (0.88 J g^?1), G′_ret (361 Pa), adhesiveness (1.48 Ns), firmness (0.45 N) gumminess (0.22 N) and the lowest springiness (0.88). Amylose–lipid complex (AML) dissociation showed negative relations with swelling power, G′_peak, G′_breakdown and breakdown viscosity (r = ?0.779, ?0.66, ?0.771 & ?0.775, respectively, P < 0.05) while positive relationship with pasting temperature (r = 0.775, P < 0.05).     

Synthesis and characterization of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery

In the present work biodegradable pH-sensitive polycaprolactone/acrylic acid (PCL/AA) hydrogels have been developed using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and benzoyl peroxide as initiator. For these prepared hydrogels swelling studies, sol-gel fraction analysis and porosity measurements were performed. Results show that swelling of the hydrogels decreases on increasing the concentration of PCL and EGDMA, however swelling of hydrogels increases on increasing the concentration of AA. Results of sol-gel fraction analysis show that gel fraction increases on increasing concentration of monomer AA, polymer PCL as well as cross-linker EGDMA. As far as porosity is concerned, it increases on increasing the concentration of AA and PCL while porosity decreases on increasing the concentration of EGDMA. Hydrogels were characterized by measuring diffusion coefficient (D) and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were investigated using FTIR, SEM and XRD, respectively. Tramadol hydrochloride was loaded as model drug and its release pattern was analysed using various kinetic models like zero order, first order, Higuchi and Peppas. Results indicated that most of the samples followed non-Fickian release mechanism.     

Impact of follow up letters on non-attenders for breast screening: a general practice based study

Twelve cases of tumours of the nose and sinuses misdiagnosed at the first time as nasal polyp are reported. Of them, 4 were benign and 8 malignant. The endoscopic technique is helpful to differential diagnosis of benign or malignant lesions and polyps in these areas.     

Survey of spontaneous dystrophic mineralisation of pineal gland in ageing rats

The survey included 151 rats from several carcinogenicity studies up to 104 weeks and 260 rats from short-term studies up to 52 weeks. All studies were performed during the period 1990-1996. Young rats up to 52 weeks of age showed normal structural appearance, in 134 male rats the incidence of mineralisation was 6.3% and in 126 females the incidence was only slightly less at 5.6%. In ageing rats, 70-104 weeks, 88 males and 63 females showed far higher incidence of mineralisation, 83% and 57% respectively, showing that the incidence of mineralisation in ageing rats was higher in males than females. The focal mineralisation occurred mainly at the margin of the gland in the subcapsular region mostly adjacent to small blood vessels. On occasions these involved the parenchymal cells in the middle part of the gland. The focal mineralisation stained positive with von Kossa indicating presence of calcium and also with PAS (Pariodic Acid-Schiff method), indicating presence of neutral mucopolysaccharide. There was no evidence of positivity with Perl's stain (for ferric salts), Toluidine blue (for protein) or Alcian blue (for acid mucopolysaccharides). With Oil Red O there was evidence of presence of fat or lipid in pinealocytes.     

Differential roles of T cell receptor alpha and beta chains in ligand binding among H-2Kd-restricted cytolytic T lymphocyte clones specific for a photoreactive Plasmodium berghei circumsporozoite peptide derivative

To study the interaction of T cell receptor with its ligand, a complex of a major histocompatibility complex molecule and a peptide, we derived H-2Kd-restricted cytolytic T lymphocyte clones from mice immunized with a Plasmodium berghei circumsporozoite peptide (PbCS) 252-260 (SYIPSAEKI) derivative containing photoreactive Nepsilon-[4-azidobenzoyl] lysine in place of Pro-255. This residue and Lys-259 were essential parts of the epitope recognized by these clones. Most of the clones expressed BV1S1A1 encoded beta chains along with specific complementary determining region (CDR) 3beta regions but diverse alpha chain sequences. Surprisingly, all T cell receptors were preferentially photoaffinity labeled on the alpha chain. For a representative T cell receptor, the photoaffinity labeled site was located in the Valpha C-strand. Computer modeling suggested the presence of a hydrophobic pocket, which is formed by parts of the Valpha/Jalpha C-, F-, and G-strands and adjacent CDR3alpha residues and structured to be able to avidly bind the photoreactive ligand side chain. We previously found that a T cell receptor specific for a PbCS peptide derivative containing this photoreactive side chain in position 259 similarly used a hydrophobic pocket located between the junctional CDR3 loops. We propose that this nonpolar domain in these locations allow T cell receptors to avidly and specifically bind epitopes containing non-peptidic side chains.     

Electromagnetic interference shielding behavior of poly(trimethylene terephthalate)/multi-walled carbon nanotube composites

Poly(trimethylene terephthalate) [PTT]/multiwalled carbon nanotube [MWCNT] composites having varying amounts of MWCNTs were fabricated with an aim to investigate the potential of such composites as an effective light weight electromagnetic interference (EMI) shielding material in the frequency range of 12.4-18 GHz (Ku-band). PTT/MWCNT composite with shielding effectiveness (SE) of 36-42 dB was obtained at 10% (w/w) MWCNT loading. Shielding mechanism was studied by resolving the total SE into absorption (SE_A) and reflection loss (SE_R). PTT/MWCNT composite showed absorption dominated shielding; thus it can be used as microwave, radar absorbing and stealth material. The effect of MWCNT loadings on electrical conductivity (σ) and dielectric properties of PTT and the correlation among conductivity, tan δ, absorption loss and reflection loss were also studied.     

The Use of Ecological Momentary Assessment to Test Appraisal Theories of Emotion.

Although appraisal theories have received strong empirical support, there are methodological concerns about the research, including biased recall, heuristic responding, ethical issues, and weak and unrealistic induction of emotions in laboratories. To provide a more ecologically valid test of appraisal theories, the authors used ecological momentary assessment, in which the emotions and appraisals of Singaporean police officers were measured online over the course of an ordinary workday. The research focused on happiness. Support was obtained for predictions, demonstrating the generalizability of appraisal theories to a nonlaboratory setting and circumventing the shortcomings of previously used methodologies. Also, evidence was obtained that happiness was reported primarily in association with a specific combination of 3 relevant appraisals: high pleasantness, high perceived control, and low moral violation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of calcination temperature and heating rate on the optical properties and reactivity of rice husk ash

Rice husk is an agricultural waste and its conversion to value added products makes it a secondary resource material. On heating, rice husk gives ash with >90% by weight of silica with some carbon and other nonmetallic and metallic impurities. Silica of high purity, chemical reactivity and white color can be produced from rice husk by controlling the heating conditions and this material finds wide industrial applications. Properties of the ash depend upon various pretreatments and calcination conditions. The present work deals with the investigation on a rice husk sample from the state of Andhra Pradesh in India. The raw husk and its acid treated form were calcined at different conditions such as temperatures, soaking periods and heating rates. Lime reactivity, surface area, brightness and color values of the ash samples were measured. The high potassium content in the husk has been found to inhibit the carbon removal during ashing which affected the color as well as reactivity of the ash. Properties of the ash samples from the untreated and acid treated husk have been compared and correlated with the formation conditions.