Studies on interstitial carbon doping from a Ti precursor in a hierarchical TiO2 nanostructured photoanode by a single step hydrothermal route.

Carbon doping from a Ti precursor in TiO2 synthesized by a hydrothermal method was studied. The structural, optical and morphological study of the deposited material was carried out using X-ray diffraction, UV-vis spectroscopy and scanning electron microscopy characterization techniques. The elemental composition of the TiO2 deposited with different precursor concentrations was studied using X-ray photoelectron spectroscopy and electron dispersive X-ray spectroscopy. The amount of elemental carbon in the TiO2 matrix is found to be increased as the Ti precursor concentration is increased, which strengthens the proposed idea of carbon doping via a Ti precursor.

X-Rays from the Location of the Double-humped Transient ASASSN-15lh.

We present the detection of persistent soft X-ray radiation with Lx ~ 1041-1042 erg s-1 at the location of the extremely luminous, double-humped transient ASASSN-15lh as revealed by Chandra and Swift. We interpret this finding in the context of observations from our multiwavelength campaign, which revealed the presence of weak narrow nebular emission features from the host-galaxy nucleus and clear differences with respect to superluminous supernova optical spectra. Significant UV flux variability on short timescales detected at the time of the rebrightening disfavors the shock interaction scenario as the source of energy powering the long-lived UV emission, while deep radio limits exclude the presence of relativistic jets propagating into a low-density environment. We propose a model where the extreme luminosity and double-peaked temporal structure of ASASSN-15lh is powered by a central source of ionizing radiation that produces a sudden change in the ejecta opacity at later times. As a result, UV radiation can more easily escape, producing the second bump in the light curve. We discuss different interpretations for the intrinsic nature of the ionizing source. We conclude that, if the X-ray source is physically associated with the optical-UV transient, then ASASSN-15lh most likely represents the tidal disruption of a main-sequence star by the most massive spinning black hole detected to date. In this case, ASASSN-15lh and similar events discovered in the future would constitute the most direct probes of very massive, dormant, spinning, supermassive black holes in galaxies. Future monitoring of the X-rays may allow us to distinguish between the supernova hypothesis and the hypothesis of a tidal disruption event.

Ejection of the Massive Hydrogen-rich Envelope Timed with the Collapse of the Stripped SN 2014C.

We present multi-wavelength observations of SN 2014C during the first 500 days. These observations represent the first solid detection of a young extragalactic stripped-envelope SN out to high-energy X-rays ~40 keV. SN 2014C shows ordinary explosion parameters (Ek ~ 1.8 × 1051 erg and Mej ~ 1.7 M⊙). However, over an ~1 year timescale, SN 2014C evolved from an ordinary hydrogen-poor supernova into a strongly interacting, hydrogen-rich supernova, violating the traditional classification scheme of type-I versus type-II SNe. Signatures of the SN shock interaction with a dense medium are observed across the spectrum, from radio to hard X-rays, and revealed the presence of a massive shell of ~1 M⊙of hydrogen-rich material at ~6 × 1016 cm. The shell was ejected by the progenitor star in the decades to centuries before collapse. This result challenges current theories of massive star evolution, as it requires a physical mechanism responsible for the ejection of the deepest hydrogen layer of H-poor SN progenitors synchronized with the onset of stellar collapse. Theoretical investigations point at binary interactions and/or instabilities during the last nuclear burning stages as potential triggers of the highly time-dependent mass loss. We constrain these scenarios utilizing the sample of 183 SNe Ib/c with public radio observations. Our analysis identifies SN 2014C-like signatures in ~10% of SNe. This fraction is reasonably consistent with the expectation from the theory of recent envelope ejection due to binary evolution if the ejected material can survive in the close environment for 103-104 years. Alternatively, nuclear burning instabilities extending to core C-burning might play a critical role.

Studies on effect of temperature on synthesis of hierarchical TiO2 nanostructures by surfactant free single step hydrothermal route and its photoelectrochemical characterizations.

Exotic hierarchical rutile TiO2 nanostructures are synthesized by surfactant free single step hydrothermal route. The effect of reaction temperature, ranging from 140°C to 200°C on the properties of the synthesized rutile-TiO2 is investigated. The synthesized rutile-TiO2 nanostructures are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, UV-vis spectroscopy and scanning electron microscopy techniques. The deposited TiO2 samples are found to be photoelectrochemically active and the best photoelectrochemical performance (0.95±0.05%) is obtained for the sample deposited at 180°C. A possible temperature dependent growth mechanism resulting in photochemically active TiO2 nanostructure thin films is proposed.

An extremely luminous panchromatic outburst from the nucleus of a distant galaxy.

Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ∼100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy.

Effect of agitation and aeration on the production of nitrile hydratase by Rhodococcus erythropolis MTCC 1526 in a stirred tank reactor.

AIMS: To evaluate the effect of different physicochemical parameters such as agitation, aeration and pH on the growth and nitrile hydratase production by Rhodococcus erythropolis MTCC 1526 in a stirred tank reactor. METHODS AND RESULTS: Rhodococcus erythropolis MTCC 1526 was grown in 7-l reactor at different agitation, aeration and controlled pH. The optimum conditions for batch cultivation in the reactor were an agitation rate of 200 rev min(-1) , aeration 0.5 v/v/m at controlled pH 8. In this condition, the increase in nitrile hydratase activity was almost threefold compared to that in the shake flask. CONCLUSION: Agitation and aeration rate affected the dissolved-oxygen concentration in the reactor which in turn affected the growth and enzyme production. SIGNIFICANCE AND IMPACT OF THE STUDY: Cultivation of R. erythropolis MTCC 1526 in the reactor was found to have significant effect on the growth and nitrile hydratase production when compared to the shake flask.

Extraction and detection of Mycobacterium leprae DNA from ZNCF-stained skin smear slides for better identification of negative skin smears.

Abstract Identification of Mycobacterium leprae, which causes leprosy, is done by Ziehl Neelsen Carbol Fuchsin (ZNCF) stained slit skin smear microscopy that aids in the diagnosis and quantification of approximate bacterial load carried by the patient. We attempted M. leprae DNA extraction from 46 stained slit skin smear negative slides, using Proteinase K and SDS lysis, followed by ethanol precipitation. M. leprae specific primers (16SrRNA) were used for PCR-based amplification of DNA. We could detect M. leprae DNA in 15 (32.6%) samples. The method can be useful in the diagnosis of apparently slit skin smear negative leprosy cases.

Broadband observations of the naked-eye gamma-ray burst GRB 080319B.

Long-duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet.

GRB 030329: 3 years of radio afterglow monitoring.

Radio observations of gamma-ray burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other wave band. We have performed a 3-year monitoring campaign of GRB 030329 with the Westerbork Synthesis Radio Telescopes and the Giant Metrewave Radio Telescope. Our observations, combined with observations at other wavelengths, have allowed us to determine the GRB blast wave physical parameters, such as the total burst energy and the ambient medium density, as well as to investigate the jet nature of the relativistic outflow. Further, by modelling the late-time radio light curve of GRB 030329, we predict that the Low-Frequency Array (30-240 MHz) will be able to observe afterglows of similar GRBs, and constrain the physics of the blast wave during its non-relativistic phase.

Clinical profile of non-O1 strain-O139 of Vibrio cholerae in the region of Ambajogai, Maharashtra.

OBJECTIVES: To study clinical profile of the newly emerged novel strain non-O1, O139 of Vibrio cholerae, in the region of Ambajogai, District Beed of Maharashtra. METHODS: Out of 208 patients of acute gastroenteritis, 41 revealed to be positive for Vibrio cholerae by recommended method of stool examination. All the strains were sent to National Institute of Cholera and Infectious Diseases, Calcutta for confirmation. RESULTS: Out of 41 cases, 12 were of Vibrio cholerae O1, 29 Non-O1, of which nine found to be O139 strain. All patients were from 2-80 years of age with low-socioeconomic status and maximum incidence was in August (64.70%), presented with severe rice watery loose motions. Vomiting was observed in 26 (63.41%), more so in patients of O139 infection (88.88%) than four (33.33%) of O1 infection. Sweating was observed in three patients (33.33%) of O139 infection, cramps in gastrocnemis muscles in three patients (33.33%) of O139 infection and two (16.66%) of O1 infection. Signs of dehydration were mild to moderate in four patients (33.33%) of O1 infection; severe dehydration in six (66.66%), moderate in two (22.22%) and mild in one patient (11.11%) of O139 infection. While dehydration was severe in four (20%), moderate in one (5%) and mild in three patients (15%) of Non-O1 infection (excluding O139 cases). Clinical features were more severe in patients of serotype O139 than the patients of O1 and Non-O1 (excluding O139 cases). However all patients responded to intravenous fluids, oral rehydration and antibiotics (tetracycline) within 24-48 hours without any mortality. CONCLUSIONS: This study reflects the first emergence of Non-O1, strain O139 during the year 1997 with severe and critical clinical features in Ambajogai region causing high morbidity in the form of severe dehydration and peripheral circulatory collapse which requires early and correct diagnosis and prompt treatment.

High intracellular calcium concentrations in transformed lymphoblasts from subjects with bipolar I disorder.

OBJECTIVE: Higher basal concentrations of intracellular calcium Ca2+ in platelets and lymphocytes from subjects with bipolar affective disorder than in unipolar depressed and healthy subjects implicate abnormal intracellular Ca2+ signaling in bipolar disorder. The purpose of this study was to clarify whether these intracellular Ca2+ abnormalities are trait related. METHOD: Basal Ca2+ concentration was measured by using ratiometric fluorescence assay with fura-2 for T lymphocytes and Epstein-Barr-virus-immortalized B lymphoblasts from physically healthy subjects with DSM-IV diagnoses of bipolar mood disorder (bipolar I, N = 28; bipolar II, N = 11) or major depressive disorder (N = 14), mixed psychiatric patients with non-mood disorders (N = 14), and health subjects (N = 20). Phytohemagglutinin-stimulated (10 micrograms/ml) intracellular Ca2+ levels were also determined in T lymphocytes. RESULTS: The basal Ca2+ concentration was significantly higher in the B lymphoblasts from patients with bipolar I disorder, but not bipolar II disorder or major depression, than in healthy subjects or psychiatric patients with nonmood disorders. There was a significant interaction between gender and diagnosis in the effect on basal Ca2+ levels in T lymphocytes. Contrasts of diagnoses within gender revealed significantly higher basal Ca2+ concentrations in T lymphocytes in male bipolar I patients, but not mean with bipolar II disorder or major depression, than in healthy male comparison subjects. Phytohemagglutinin-stimulated Ca2+ concentrations did not differ among groups, but the percent differences from basal Ca2+ levels were lower in bipolar I and depressed patients than in healthy subjects. CONCLUSIONS: These findings support the occurrence of abnormal calcium homeostasis in bipolar disorder and suggest that trait-dependent factors account, at least partly, for the higher basal lymphocyte Ca2+ concentration in bipolar I subjects.

Lack of effect of antidepressants on mononuclear leukocyte G-protein levels or function in depressed outpatients.

Evidence from studies in animal and cultured cell models suggests that antidepressants (ADs) may enhance postreceptor signalling through the G protein coupled adenylyl cyclase (AC) pathways. To test whether this also occurs in patients receiving AD treatment, G-protein-activated-AC activity and the levels of alpha s and alpha i were measured in mononuclear leukocytes (MNLs) from 12 subjects with major depressive disorder (MDD) at baseline and after a 5 week trial of AD treatment. Although no differences were found in GTP gamma S-and forskolin-stimulated AC activity or the levels of alpha s and alpha i in MDD subjects compared with age- and sex-matched healthy subjects, pretreatment basal AC activity was significantly lower in treatment responders compared with healthy subjects. No significant changes were evident in any of these biochemical measures following 5 weeks of AD treatment in the patient group as a whole or stratified by response. These findings do not support an effect of ADs on the G-protein AC pathway, at least in MNLs. Lower pretreatment basal AC activity in responders suggests some change(s) in post-receptor signalling processes may be associated with an increased likelihood of therapeutic response to ADs.

Genetic linkage evaluation of twenty-four loci in an eastern Canadian family segregating Darier's disease (keratosis follicularis).

BACKGROUND: Darier's disease (keratosis follicularis) is known to have a genetic cause as evidenced by its autosomal dominant transmission in families. The gene causing this disease has not been discovered. OBJECTIVE: During an ongoing linkage study of schizophrenia, a family segregating Darier's disease was found. This family is being studied in an attempt to locate prospective regions that may contain the Darier's disease gene. METHODS: Two genetic strategies are being employed: (1) testing candidate genes for the disorder and (2) scanning the entire genome with polymerase chain reaction-based microsatellite markers. RESULTS: Thirty-nine marker systems located on chromosomes 1, 2, 4, 5, 6, 9, 11, 12, 16, 17, 22, X, and Y have been genotyped. Slightly positive lod scores were achieved between six markers and Darier's disease. The remaining 33 markers were nonsegregating or indeterminate, or revealed an obligate recombinant. CONCLUSION: Linkage analysis can lead to localization of the gene causing Darier's disease. In these preliminary studies low positive lod scores were obtained, potentially pointing to the chromosomal location of the Darier's disease gene.

Mononuclear leukocyte levels of G proteins in depressed patients with bipolar disorder or major depressive disorder.

Stimulatory (Gs) and inhibitory (G(i)) guanine nucleotide binding protein alpha subunit levels were measured in mononuclear leukocytes from 22 drug-free depressed patients (eight with bipolar disorder, 14 with major depressive disorder) and a comparison group of 17 age- and sex-matched healthy subjects. The levels of Gs alpha and G(i) alpha were significantly higher (160% and 114%, respectively) in the bipolar patients, but not the patients with major depressive disorder, than in the healthy subjects. These data add to the evidence for abnormalities in G protein levels and function in the pathophysiology of bipolar disorder.

Cerebral cortex Gs alpha protein levels and forskolin-stimulated cyclic AMP formation are increased in bipolar affective disorder.

Experimental animal and peripheral blood cell studies point to guanine nucleotide regulatory (G) protein disturbances in bipolar affective disorder. We have previously reported elevated prefrontal cortex Gs alpha protein in bipolar affective disorder and have now extended these preliminary observations in a larger number of subjects, assessing the brain regional specificity of these changes in greater detail, determining the functional biochemical correlates of such changes, and evaluating their diagnostic specificity. Membrane G protein (Gs alpha, Gi alpha, Go alpha, and G beta) immunoreactivities were estimated by western blotting in postmortem brain regions obtained from 10 patients with a DSMIII-R diagnosis of bipolar affective disorder and 10 nonpsychiatric controls matched on the basis of age, postmortem delay, and brain pH. To examine whether there were functional correlates to the observed elevated Gs alpha levels, basal and GTP gamma S- and forskolin-stimulated cyclic AMP production was determined in the same brain regions. Compared with controls, Gs alpha (52-kDa species) immunoreactivity was significantly (p < 0.05) elevated in prefrontal (+36%), temporal (+65%), and occipital (+96%) cortex but not in hippocampus (+28%), thalamus (-23%), or cerebellum (+21%). In contrast, no significant differences were found in the other G protein subunits (Gi alpha, Go alpha, G beta) measured in these regions. Forskolin-stimulated cyclic AMP production was significantly increased in temporal (+31%) and occipital (+96%) cortex but not in other regions. No significant differences were apparent in basal or GTP gamma S-stimulated cyclic AMP production.(ABSTRACT TRUNCATED AT 250 WORDS)

New polymorphism for the human serotonin 1D receptor variant (5-HT1D beta) not linked to schizophrenia in five Canadian pedigrees.

A new HincII polymorphism for the human serotonin 1D receptor variant (5-HT1D beta) is reported. In light of evidence indicating possible dysfunction of the 5-HT neurotransmitter system in schizophrenia, this new 5-HT receptor polymorphism was tested for linkage to schizophrenia in 5 Canadian pedigrees. Although 1 of the 5 pedigrees tested had a slightly positive lod score, there was no evidence overall for linkage to schizophrenia under dominant, recessive, or two locus models.

Left ventricular M-mode echocardiographic measurements of Indian population.

The left ventricular dimensions of 506 normal healthy subjects (men = 317, women = 189) in the age group of 17 to 80 years were measured echocardiographically. The measurements were found to differ significantly from the western data. A separate limit for left ventricular echocardiographic parameter for the normal Indian population was established.

Left ventricular mass in normal Indian population.

A prospective study was conducted to ascertain the distribution of the left ventricular mass in normal adult Indian population and to establish the upper limit of the same. Four hundred and eighty normal subjects (men = 310; women = 170), in the age group of 18 to 60 years were screened echocardiographically, to estimate the left ventricular mass. The left ventricular mass in men was found to be 124 +/- 32 gm whereas in women it was 93 +/- 37 gm. The upper limit of the left ventricular mass (mean +/- 2 SD) was found to be 189 gm and 167 gm, for men and women respectively. The left ventricular mass in both men and women correlated with the body weight (r = 0.51, p less than 0.001; r = 0.22, p less than 0.001), height (r = 0.27, p less than 0.001; r = 0.22, p less than 0.01), and the body surface area (r = 0.49, p less than 0.001; r = 0.27, p less than 0.001), whereas it was found to be independent of age (r = 0.01, p = NS; r = 0.10, p = NS). In men alone the diastolic blood pressure influenced the left ventricular mass (r = 0.27, p less than 0.001), otherwise the left ventricular mass was independent of systemic blood pressure variations within the normal range. The left ventricular mass in the present study differs significantly from the Western population.

A possible change in the rate-limiting step for cardiac norepinephrine synthesis in the cardiomyopathic Syrian hamster.

The development of heart failure in the cardiomyopathic hamster is associated with a decrease in norepinephrine stores and parallel increases in cardiac sympathetic tone and tyrosine hydroxylase activity. Despite the increase in tyrosine hydroxylase, cardiac norepinephrine synthesis does not increase in heart failure. In this study, we have shown that an accumulation of cardiac dopamine accompanies the decline of cardiac norepinephrine. The abnormal content of norepinephrine and of dopamine in the decompensating hamster heart is restored to normal by peripheral ganglionic blockade. The acute increase in cardiac sympathetic tone induced by immobilization stress in control hamsters mimics the alterations in cardiac catecholamine distribution found in heart failure. Other investigators have demonstrated similar alterations in the catecholamine content of the rat submaxillary gland and adrenal medulla following an increase in sympathetic input to these organs. We conclude that the increase in cardiac sympathetic tone in the late stages of hamster cardiomyopathy appears to lead to a shift in the rate-limiting step for norepinephrine synthesis from the hydroxylation of tyrosine to the hydroxylation of dopamine. There is evidence that this shift which results in an accumulation of dopamine in the noradrenergic nerve terminals of the heart is a general manifestaion of augmented sympathetic nerve traffic rather than a peculiarity of hamster cardiomyopathy.

Differential responsiveness of central noradrenergic and dopaminergic neuron tyrosine hydroxylase to hypophysectomy, ACTH and glucocorticoid administration.

Hypophysectomy leads to a small increase in tyrosine hydroxylase activity of all brain areas containing noradrenergic neurons or tuberoinfundibular dopamine neurons, but nigroneostriatal dopamine neurons are not so affected. ACTH or corticosterone treatment inhibited this effect of hypophysectomy in some noradrenergic neurons and in tuberoinfundibular dopamine neurons. These data showing differential responsiveness of tyrosine hydroxylase in different brain areas are compatible with differences in regulation or molecular form of tyrosine hydroxylase in central noradrenergic and dopaminergic neurons. The disparity between increased hypothalamic tyrosine hydroxylase activity and decreased norepinephrine turnover following hypophysectomy may result from a change in the rate-limiting step to the hydroxylation of dopamine.