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The anomaly in lithium abundance is a well-known unresolved problem in nuclear astrophysics. A recent revisit to the problem tried the avenue of resonance enhancement to account for the primordial ^{7}Li abundance in standard big-bang nucleosynthesis. Prior measurements of the ^{7}Be(d,p)^{8}Be^{*} reaction could not account for the individual contributions of the different excited states involved, particularly at higher energies close to the Q value of the reaction. We carried out an experiment at HIE-ISOLDE, CERN to study this reaction at E_{c.m.}=7.8 MeV, populating excitations up to 22 MeV in ^{8}Be for the first time. The angular distributions of the several excited states have been measured and the contributions of the higher excited states in the total cross section at the relevant big-bang energies were obtained by extrapolation to the Gamow window using the talys code. The results show that by including the contribution of the 16.63 MeV state, the maximum value of the total S factor inside the Gamow window comes out to be 167 MeV b as compared to earlier estimate of 100 MeV b. However, this still does not account for the lithium discrepancy.

Unfolding of Tryptophanoctyl Ester and Elastic Deformation of Host Micelles via RR'3 N+ ⋠⋠⋠π Interaction: Conceivable Relevance to Wrapping Process of Receptor Mediated Endocytosis.

The interfacial properties of the mixed amphiphiles are modified by a stronger cation-π interaction between the quaternary ammonium head group of CTAB and the π-face of TROE, compared to the tyrosine analogue (TYOE). This eventually triggers a morphology transition through elastic deformation of the spherical micelles of CTAB to cylindrical/wormlike micelles. The unfolding of TROE and the molecular interactions in the nanoenvironment have been recognized by NMR spectroscopy and the physical characteristics of the entangled wormlike micelles are investigated by high resolution transmission electron microscopy (HRTEM), whereas the complex fluidic feature is examined by dynamic rheological measurements. Morphology tuning of the soft nanoaggregates of zwitterionic dodecylphosphocholine by the tryptophan analogue via choline-π interaction has unique biological consequences and we consider the significance of such interactions in facilitating endocytosis of a virion/nano particle(NP) in terms of a quantitative model. The implication in future research on drug development strategies is discussed.

Antidepressant-like effect of anacardic acid in mice via the L-arginine-nitric oxide-serotonergic system.

Depression, a multifactorial neuronal disorder with high morbidity/mortality, is associated with psychological, psychosocial, hereditary, and environmental etiologies, where reactive species exert pathophysiological functions. Anacardic acid (AA), a natural compound obtained from cashew nut liquid, has several pharmacological activities, including antioxidant and anticonvulsant. The aim of the present study was to evaluate the antidepressant-like effect of AA and the involvement of serotonergic, noradrenergic, and L-arginine-nitric oxide (NO) in tail suspension and forced swim tests and, more so, to investigate its antioxidant effect in Saccharomyces cerevisiae and in male Swiss mice (n = 8). In order to identify the antidepressant mechanisms, AA (10, 25, or 50 mg/kg, p.o.) was given 30 min before clonidine (2-adrenergic receptor agonist), L-arginine (NO precursor), propranolol (ß-adrenergic receptor antagonist), and several other agonists or antagonists used. On the other hand, clonidine, noradrenoreceptor, noradrenaline, and L-arginine were used to identify the antidepressant mechanisms. Results suggest that AA exerts antidepressant-like activity, especially at higher doses, possibly by inhibiting serotonin and 5HT-1A reuptake receptors and by inhibiting NO synthetase and guanylyl cyclase enzymes. Additionally, AA exhibited antioxidant effect in S. cerevisiae. This antioxidant capacity may be linked to its antidepressant-like effect but does not interact with α- and ß-adrenoceptor receptors. In conclusion, AA may be used as a promising agent to treat depression, especially which arises from oxidative stress.

Interaction of Tyrosine Analogues with Quaternary Ammonium Head Groups at the Micelle/Water Interface and Contrasting Effect of Molecular Folding on the Hydrophobic Outcome and End-Cap Geometry.

The surface property of the cationic micelles of cetyltrimethylammonium bromide (CTAB) in an aqueous medium is highly modified in the presence of tyrosineoctyl ester (TYOE) and tyrosinedodecyl ester (TYDE), the models for aromatic amino acid side chains of transmembrane proteins. While the synergistic interaction between the quaternary ammonium head group of CTAB and the π-electron cloud of aromatic amino acid ester is influenced by the relative orientation and the unusual molecular geometry of the latter, this eventually triggers a morphology transition of the spherical micelle to cylindrical/wormlike micelles and imparts a strong viscoelasticity in the medium. Physical characteristics of the elongated micelles have been investigated by high resolution transmission electron microscopy (HRTEM) and the small angle neutron scattering (SANS) technique; the complex fluidic nature of the system is investigated by a dynamic rheological measurement. The intermolecular interactions have been recognized via 1H NMR and 2D nuclear Overhauser effect spectroscopy (NOESY), and the unambiguous geometry of the end-caps of the rods has been ascertained for the first time. While the interplay between lipids and transmembrane proteins is thought to be crucial in controlling the membrane shape of the cells during many vital events such as cellular fission, fusion, and virus entry, the observed tuning of the micellar surface curvature via the cation-π interaction involving tyrosine analogues is thought provoking and opens up an avenue for new physical chemistry research on a vital biological phenomena.

Microalbuminuria: Correlation With Prevalence and Severity of Coronary Artery Disease in Non-Diabetics.

BACKGROUND: Previous studies have shown that microalbuminuria (MAU) is an independent risk factor for cardiovascular diseases in diabetics, hypertensive patients and in the general population. However, the correlation of MAU with the severity of coronary artery disease (CAD) in non-diabetic patients has not been addressed in detail. This study aimed to investigate the relationship between MAU and severity of angiographically confirmed CAD in non-diabetic patients. METHODS: This was a cross-sectional study, which included 90 non-diabetic patients with documented CAD by coronary angiography. The ratio of urine albumin to creatinine was used to define MAU and severity of CAD was estimated using SYNTAX score. Patients were divided into two groups: group I that included patients without MAU and group II that included patients with MAU. RESULTS: Out of 90 non-diabetic CAD patients, 62 (68.9%) were in group I (MAU negative) and 28 (31.1%) were in group II (MAU positive). There was statistically significant difference in the median SYNTAX score between the groups (21 vs. 28, P < 0.001). The prevalences of double vessel CAD and triple vessel CAD were significantly higher in MAU positive group. There was a strong relationship between the presence of MAU and the extent and complexity of CAD (r = 0.094; P < 0.001). CONCLUSION: Thus, we conclude that patients with MAU have more severe angiographically detected CAD than those without MAU, and MAU exhibits a significant association with the presence and severity of CAD.

Solvent-Induced Molecular Folding and Self-Assembled Nanostructures of Tyrosine and Tryptophan Analogues in Aqueous Solution: Fascinating Morphology of High Order.

Hydrophobic derivatives of tyrosine and tryptophan, viz. octyl and dodecyl esters of tyrosine and octyl ester of tryptophan, are synthesized, and the interfacial and bulk properties in aqueous media are investigated as models for the membrane proteins. Molecular modeling by the density functional theory method is carried out to understand the molecular conformation and geometry for the purpose of determining the packing parameters. Water-induced molecular folding of the esters of both tyrosine and tryptophan, as observed using rotating frame nuclear Overhauser effect spectroscopy, indicates that the segregation of the hydrophobic and hydrophilic blocks in water is the key to the development of fascinating interfacial property displayed by the aromatic amino acid esters. The unusually high-order morphology of the aggregates, as observed using high-resolution transmission electron microscopy, is highly uncommon for single-chain amphiphiles and points to the fact that the self-assembly behavior of the present systems resembles that of block copolymers. The study of the growth of mesosized hollow aggregates with internal bilayer structures from tyrosine and tryptophan-based model systems would add to the understanding of biochemistry and biotechnology relevant to the cell membrane. The potential of biocompatible nanostructured motifs as the drug carriers is discussed. The highly functional role played by the aromatic amino acids at the membrane-water interface will be considered with the present amphiphilic models for future perspective.

Effect of Ranolazine in Patients with Chest Pain and Normal Coronaries- A Hospital Based Study.

INTRODUCTION: There is an important role of coronary microcirculation in the clinical presentation and prognosis of patients who have typical chest pain despite normal epicardial coronary arteries (microvascular angina). Treatment of these patients is empirical because of the incomplete knowledge of its cause. Limited data has shown that ranolazine reduces angina and improves exercise performance in such patients with frequent angina. AIM: To evaluate the effect of ranolazine in patients with chest pain and normal epicardial coronaries (micro-vascular angina). MATERIALS AND METHODS: Sixty-five patients with anginal symptoms with abnormal exercise stress test and normal epicardial coronaries were enrolled for the study. All participants had baseline demographic and health history questionnaires, including Seattle Angina Questionnaire (SAQ) and Duke Activity Status Index (DASI). After enrolment, patients were randomly divided into two groups. One group (group 1) was assigned to ranolazine for six weeks along with other indicated anti-anginal drugs. The other group (group 2) was assigned to anti-anginal drugs other than ranolazine. Patients were reassessed for symptomatic and functional improvement (SAQ, DASI) at six weeks. RESULTS: Mean age of patients examined were 49.03 years in group 1 and 49.77 years in group 2. Approximately 42.9% of patients in group 1 and 40% in group 2 were male. Despite current anti-anginal therapy, patients in both the groups were symptomatic. At six weeks, 60% of patients in group 1 had angina as compared to 88.6% at baseline (p<0.05). Similarly, scores of domains of SAQ were higher at six weeks as compared to baseline (p<0.05) except for treatment satisfaction. No improvement of DASI score and functional capacity were seen in either group at six weeks as compared to baseline (p>0.05). At six weeks, angina was significantly lower in group 1 as compared to group 2 (60 % vs 86.7%; p<0.05). Four out of five SAQ subscale score were higher in ranolazine group as compared to the other group (p<0.05). Treatment satisfaction trended lower on ranolazine group (p<0.05). There was no significant differences in DASI in the two groups (DASI score 30.59 vs 29.85, p>0.05). CONCLUSION: Ranolazine is safe and improves symptoms significantly in patients with micro-vascular angina.

Formation, thermodynamic properties, microstructures and antimicrobial activity of mixed cationic/non-ionic surfactant microemulsions with isopropyl myristate as oil.

HYPOTHESIS: Modification of the interface by blending of surfactants produces considerable changes in the elastic rigidity of the interface, which in turn affects the physicochemical properties of w/o microemulsions. Hence, it could be possible to tune the thermodynamic properties, microstructures and antimicrobial activity of microemulsions by using ionic/non-ionic mixed surfactants and polar lipophilic oil, which are widely used in biologically relevant systems. EXPERIMENTS: The present report was aimed at precise characterization of mixed cetyltrimethylammonium bromide and polyoxyethylene (23) lauryl ether microemulsions stabilized in 1-pentanol (Pn) and isopropyl myristate at different physicochemical conditions by employing phase studies, the dilution method, conductivity, DLS, FTIR (with HOD probing) and (1)H NMR measurements. Further, microbiological activities at different compositions were examined against two bacterial strains Bacillus subtilis and Escherichia coli at 303 K. FINDINGS: The formation of mixed surfactant microemulsions was found to be spontaneous at all compositions, whereas it was endothermic at equimolar composition. FTIR and (1)H NMR measurements showed the existence of bulk-like, bound and trapped water molecules in confined environments. Interestingly, composition dependence of both highest and lowest inhibitory effects was observed against the bacterial strains, whereas similar features in spontaneity of microemulsion formation were also evidenced. These results suggested a close relationship between thermodynamic stability and antimicrobial activities. Such studies on polar lipophilic oil derived mixed surfactant microemulsions have not been reported earlier.

Physicochemical investigation of mixed surfactant microemulsions: water solubilization, thermodynamic properties, microstructure, and dynamics.

In this contribution, we report on a systematic investigation of phase behavior and solubilization of water in water-in-heptane or decane aggregates stabilized by mixtures of polyoxyethylene (20) cetyl ether (Brij-58) and cetyltrimethylammonium bromide (CTAB) surfactants with varying compositions in conjugation with 1-pentanol (Pn) at fixed surfactant(s)/Pn ratio and temperature. Synergism in water solubilization was evidenced by the addition of CTAB to Brij-58 stabilized system in close proximity of equimolar composition in both oils. An attempt has been made to correlate composition dependent water solubilization and volume induced conductivity studies to provide insight into the solubilization mechanism of these mixed systems. Conductivity studies reveal the ascending curve in water solubilization capacity-(Brij-58:CTAB, w/w) profile as the interdroplet interaction branch indicating percolation of conductance and the descending curve is a curvature branch due to the rigidity of the interface in these systems. The microstructure of these systems as a function of surfactant composition has been determined by dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) measurements. FTIR study reveals increase and decrease in relative population of bound and bulk-like water, respectively, with increase in Brij-58:CTAB (w/w). DLS measurements showed that the droplet hydrodynamic diameter (Dh) decreases significantly with the increase in Brij-58:CTAB (w/w). Further, the interfacial composition and energetic parameters for the transfer of Pn from bulk oil to the interface were evaluated by the dilution method. Formation of temperature-insensitive microemulsions and temperature invariant droplet sizes are evidenced in the vicinity of the equimolar composition. The results are interpreted in terms of a proposed mechanism.

Physicochemical studies of mixed surfactant microemulsions with isopropyl myristate as oil.

The present study is focused on evaluation of interfacial compositions and thermodynamic properties of w/o mixed surfactant [(sodium dodecylsulfate, SDS/polyoxyethylene (23) lauryl ether, Brij-35)/1-pentanol (Pn)/isopropyl myristate (IPM)] microemulsions under various physicochemical conditions by the dilution method. The number of moles of Pn at the interface (n(a)(i)) and bulk oil (n(a)(o)), and various thermodynamic parameters [viz. standard Gibbs free energy (ΔG(o→i)(0)), standard enthalpy (ΔH(o→i)(0)), and standard entropy (ΔS(o→i)(0)) of the transfer of Pn from bulk oil to the interface] have been found to be dependent on the molar ratio of water to surfactant (ω), concentration of Brij-35 (X(Brij-35)), and temperature. Temperature-insensitive microemulsions with zero specific heat capacity (ΔC(p)(0))(o→i) have been formed at specific compositions. The intrinsic enthalpy change of the transfer process (ΔH(0))(o→i)* has been evaluated from linear correlation between ΔH(o→i)(0) and ΔS(o→i)(0) at different experimental temperatures. The present report also aims at a precise characterization on the basis of molecular interactions between the constituents and provides insight into the nature of the oil/water interfaces of these systems by conductivity and dynamic light scattering studies as a function of ω and X(Brij-35). Conductivity studies reveal that incorporation of Brij-35 in non-percolating water/SDS/Pn/IPM systems makes them favorable for ω-induced percolation behavior up to X(Brij-35) ≤ 0.5. But further addition of Brij-35 causes a decrease in conductivity with increasing ω. Furthermore, the hydrodynamic diameters of the microemulsion droplets increase with increase in both X(Brij-35) and ω. Correlations of the results in terms of the evaluated physicochemical parameters have been attempted.

Substantive treatment of Lutembacher's syndrome by the trans-septal puncture technique: a case report and review.

There are few reports on the primary percutaneous treatment of Lutembacher's syndrome for which surgery has been the traditionally accepted modality of treatment. Concerns for percutaneous treatment in this entity are: (1) it is technically demanding and the dual lesion renders negotiation of catheters and balloons difficult; (2) redo valvulotomy in the presence of an atrial septal device would be difficult; (3) it may not be suitable for all patients with the condition. We describe percutaneous treatment by a hitherto undescribed technique of separate low septal puncture and review the existing literature.

Effect of colloidal silica on the spectral behaviour of 7-hydroxycoumarin in aqueous medium.

Absorption and emission spectroscopic studies, in combination with FTIR measurements, were carried out for 7-hydroxycoumarin (7HC) and nanocolloidal dispersion of silica. Attempt has been made to identify the characteristics of excited state H-bond formed between colloidal silica and 7HC in aqueous medium. Both the absorption and emission spectra of 7HC was found to be dependent on the concentration of silica. At lower silica concentrations, the absorption spectra decreases with increasing silica concentration, on the other hand, at higher concentration a bathochromic shift occurs in the absorption spectra of 7HC. Fluorescence behaviour followed the opposite trend in comparison to the absorption spectra. It is proposed that at lower silica concentration, excited state H-bond was formed between 7HC and silica dispersions. At higher concentration, the decrease in fluorescence intensity is attributed to the self quenching of adsorbed dye molecules over silica surface following the mechanism of Homo Förster resonance energy transfer (HFRET). Results were correlated with the size and surface charge of colloidal silica as measured by dynamic light scattering and zeta potential studies.

Molecular interaction of organic dyes in bulk and confined media.

Molecular interactions of five thiazine dyes with increasing alkyl substitution have been studied in aqueous and microemulsion media at 303K within a concentration range of (1.35-7.00)x10(-4)M. The dimerization constant (K(d)) values for the five dyes are ranged between 1.761 and 6.258x10(3)lmol(-1) in bulk water media, where as in microemulsion media, K(d)'s are ranged between 1.760 and 4.110x10(3)lmol(-1). Thionine (with no methyl substitution) and azure A (with two methyl substitution) displayed slightly larger K(d) values in microemulsion water pools compared to bulk water while other dyes recorded significant drop in K(d) values. The influence of microemulsion media on the molecular interaction of dyes has been explained in terms of electrostatic and hydrophobic factors. The monomer and the dimer spectra are explained in terms of molecular exciton model and the optical absorption parameters of both the species are reported in bulk and confined media.

Hydrogen-bond-induced microstructural transition of ionic micelles in the presence of neutral naphthols: pH dependent morphology and location of surface activity.

The effect of naphthols and methoxynaphthalenes on the microstructure transition of cetyltrimethylammonium bromide (CTAB) micelles is studied. Although the surface activities of these two types of organic dopants are strong, methoxynaphthalenes failed to promote spherical to worm-like micellar transition and to impart viscoelasticity to the aqueous CTAB solution, presumably due to their inability to form unique H-bonds with interfacial water. The micropolarity of OH sites of micelle-embedded naphthols is measured by observing the pK(a) shift at the micellar surface relative to bulk water. On the basis of spectroscopic and other data, the microstructures formed by both classes of dopants at the micellar surface are predicted. On the basis of hydroxyaromatic dopants, a simple and effective route to design pH-responsive viscoelastic worm-like micelles and the vesicles of single tail cationic surfactant (CTAB) is reported. Results are confirmed by observing cryogenic transmission electron microscopy (cryo-TEM) images.

Micellar shape transition under dilute salt-free conditions: promotion and self-fluorescence monitoring of stimuli-responsive viscoelasticity by 1- and 2-naphthols.

Effect of 1 and 2-naphthols on the shape transition of cetyl trimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) micelles are studied. Stimuli-responsive viscoelastic gels of long wormlike micelles are formed at low surfactant concentrations in the presence of neutral naphthols, where H-bonding plays a key role in micellar shape transition in the absence of any charge screening. Micelle-embedded naphthols also act as novel self-fluorescence probes for monitoring viscoelasticity of the system as a function of applied shear. 1H NMR study shows that the solubilization sites of naphthols in the micelle are located near the surface. While UV absorption and Fourier transform infrared studies confirm the presence of intermolecular H-bonds in micelle embedded naphthols, transmission electron micrographs of vacuum-dried samples at room temperature demonstrate the transition in shape from sphere to rodlike micelles.

Enzymatic, alkaline, and autocatalytic degradation of poly(L-lactic acid): effects of biaxial orientation.

The hydrolytic degradation of biaxially oriented and de-oriented (melt-crystallized) poly(l-lactic acid) (PLLA) films was investigated in Tris-HCl-buffered solution (pH 8.6) with proteinase K, alkaline solution, and phosphate-buffered solution (pH 7.4) by the use of gravimetry, gel permeation chromatography, differential scanning calorimetry, and scanning electron microscopy. Biaxial orientation disturbed the proteinase K-catalyzed enzymatic degradation of PLLA films and the effects of biaxial orientation overcame those of crystallinity. The former may be due to the fact the enzyme cannot attach to the extended (strained) chains in the amorphous regions of the biaxially oriented PLLA film or cannot catalyze the cleavage of the strained chains. Another probable cause is that the enzyme can act only at the film surface of the biaxially oriented PLLA film, in marked contrast with the case of the de-oriented PLLA films where enzymatic degradation can proceed beneath the spherulitic crystalline residues. The effects of biaxial orientation on the alkaline and autocatalytic degradation of the PLLA films were insignificant for the periods studied here. The crystallinity rather than the biaxial orientation seems to determine the alkaline and autocatalytic degradation rates of the PLLA films. The accumulation of crystalline residues formed as a result of selective cleavage and removal of the amorphous chains was observed for the de-oriented PLLA films, but not for the biaxially oriented PLLA film, when degraded in the presence of proteinase K. This means the facile release of formed crystalline residues from the surface of the biaxially oriented PLLA film during enzymatic degradation, due to the fact that the crystalline regions of the biaxially oriented PLLA film were oriented with their c axis parallel to the film surface.

Physical properties, crystallization, and spherulite growth of linear and 3-arm poly(L-lactide)s.

The physical properties, crystallization, and spherulite growth behavior and mechanism of linear and 3-arm poly(L-lactide) [i.e., poly(L-lactic acid) (PLLA)] have been investigated using absolute molecular weight as a molecular index. The branching reduces the chain mobility of PLLA and must be excluded from the crystalline regions. The former factor gives the higher glass transition temperature (T(g)) and starting temperature for thermal degradation (T(d,S)) of 3-arm PLLA compared with those of linear PLLA. On the other hand, both the former and the latter factors lead to the higher cold crystallization temperature (T(cc)), the longer induction period for spherulite growth (t(i)), the lower melting temperature (T(m)), crystallinitiy (X(c)), and radius growth rate of the spherulties (G) for the 3-arm PLLA compared with those for the linear PLLA. The G of 3-arm PLLA showed the vague dependence on number-average molecular weight (M(n)), probably because the branching effect was balanced with the molecular weight effect. At the M(n) exceeding critical values, the linear and 3-arm PLLA crystallize in regime II or regime III kinetics, depending on crystallization temperature (T(c)). In contrast, at the M(n) below critical values, the linear and 3-arm PLLA crystallize according solely to regime III and regime II kinetics, respectively, for all the T(c).

Detection of multiple active site domain motions in transient-state component time courses of the Clostridium symbiosum L-glutamate dehydrogenase-catalyzed oxidative deamination reaction.

We present a multiwavelength, transient-state kinetic study of the oxidative deamination reaction catalyzed by Clostridium symbiosum glutamate dehydrogenase (csGDH) producing the real-time reaction courses of spectroscopically resolved kinetically competent intermediate complexes. The results show striking differences from a corresponding transient-state study of the same reaction by the structurally homologous enzyme from beef liver (blGDH). In addition to the highly blue-shifted alpha-iminoglutarate and highly red-shifted carbinolamine complexes observed in both reactions, the csGDH reaction appeared to show the release of free NADH at a very early and mechanistically unlikely point in the reaction. Using lactic acid dehydrogenase as a "reporter" for free NADH, we show that the early portion of this signal reflects previously unobserved spectrally unshifted enzyme-bound NADH complexes. We provide experimental evidence to show that such spectrally anomalous complexes must represent forms of the known alpha-imino and alpha-carbinolamine complexes in which the active site cleft is open. This evidence includes isothermal calorimetric measurements and pH-jump experiments that show the existence of differing two-state transitions in blGDH and csGDH and locate active site domain motions at differing points in the transient-state time courses of the two enzyme reactions. We prove the kinetic competence of a new and more highly detailed mechanism for the csGDH reaction that involves the alternation of open and closed enzyme complexes as integral steps. These findings, supported by the available X-ray crystal structure data, suggest the existence of a programmed time course of protein domain motions coordinated with the classically considered chemical time course. This new viewpoint may be presumed to be applicable to enzyme reactions other than those of the alpha-amino acid dehydrogenases.