Novel solvothermal approach to hydrophilic nanoparticles of late transition elements and its evaluation by nanoparticle tracking analysis

Solvothermal treatment of late transition metal acetylacetonates in a novel medium composed either of pure acetophenone or acetophenone mixtures with amino alcohols offers a general approach to uniform hydrophilic metal nanoparticles with high crystallinity and low degree of aggregation. Both pure metal and mixed-metal particles can be accesses by this approach. The produced materials have been characterized by SEM-EDS, TEM, FTIR in the solid state and by Nanoparticle Tracking Analysis in solutions. The chemical mechanisms of the reactions producing nanoparticles has been followed by NMR. Carrying out the process in pure acetophenone produces palladium metal, copper metal with minor impurity of Cu2O, and NiO. The synthesis starting from the mixtures of Pd and Ni acetylacetonates with up to 20 mol% of Pd, renders in minor yield the palladium-based metal alloy along with nickel oxide as the major phase. Even the synthesis starting from a mixed solution of Cu(acac)2 and Ni(acac)2 produces oxides as major products. The situation is improved when aminoalcohols such as 2-aminoethanol or 2-dimethylamino propanol are added to the synthesis medium. The particles in this case contain metallic elements and pairs of individual metals (not metal alloys) when produced from mixed precursor solutions

Plastid lipid droplets at the crossroads of prenylquinone metabolism

Lipid droplets called plastoglobules (PGs) exist in most plant tissues and plastid types. In chloroplasts, the polar lipid monolayer surrounding these low-density lipoprotein particles is continuous with the outer lipid leaflet of the thylakoid membrane. Often small clusters of two or three PGs, only one of them directly connected to thylakoids, are present. Structural proteins (known as plastid-lipid associated proteins/fibrillins or plastoglobulins) together with lipid metabolic enzymes coat the PGs. The hydrophobic core of PGs contains a range of neutral lipids including the prenylquinones [tocopherols (vitamin E), phylloquinone (vitamin K1), and plastoquinone (PQ-9)]. In this review the function of PGs and their associated enzymes in prenylquinone metabolism will be discusse

The Prevalence and Volumetry of Pituitary Cysts in Children with Growth Hormone Deficiency and Idiopathic Short Stature

Background Pituitary cysts have been speculated to cause endocrinopathies. We sought to describe the prevalence and volumetry of pituitary cysts in patients with growth hormone deficiency (GHD) and idiopathic short stature (ISS). Methods Six hundred and eighteen children evaluated for growth failure at the Division of Pediatric Endocrinology at New York Medical College between the years 2002 and 2012, who underwent GH stimulation testing and had a brain magnetic resonance imaging (MRI) prior to initiating GH treatment were randomly selected to be a part of this study. High resolution MRI was used to evaluate the pituitary gland for size and the presence of a cyst. Cyst prevalence, cyst volume and percentage of the gland occupied by the cyst (POGO) were documented. Results Fifty-six patients had a cyst, giving an overall prevalence of 9.1%. The prevalence of cysts in GHD patients compared to ISS patients was not significant (13.5% vs. 5.7%, p=0.46). Mean cyst volume was greater in GHD patients than ISS patients (62.0 mm3 vs. 29.4 mm3, p=0.01). POGO for GHD patients was significantly greater (p=0.003) than for ISS patients (15.3%+/-12.8 vs. 7.1%+/-8.0). Observers were blinded to patient groups. Conclusions GHD patients had a significantly greater volume and POGO compared to ISS patients. This raises the question of whether cysts are implicated in the pathology of growth failure

Transition Phenomena Induced by Internal Noise and Quasi-absorbing State

We study a simple chemical reaction system and effects of the internal noise. The chemical reaction system causes the same transition phenomenon discussed by Togashi and Kaneko [Phys. Rev. Lett. 86 (2001) 2459; J. Phys. Soc. Jpn. 72 (2003) 62]. By using the simpler model than Togashi-Kaneko's one, we discuss the transition phenomenon by means of a random walk model and an effective model. The discussion makes it clear that quasi-absorbing states, which are produced by the change of the strength of the internal noise, play an important role in the transition phenomenon. Stabilizing the quasi-absorbing states causes bifurcation of the peaks in the stationary probability distribution discontinuously.Comment: 6 pages, 5 figure

Fundamental Physical Constants: Looking from Different Angles

We consider fundamental physical constants which are among a few of the most important pieces of information we have learned about Nature after its intensive centuries-long studies. We discuss their multifunctional role in modern physics including problems related to the art of measurement, natural and practical units, origin of the constants, their possible calculability and variability etc

Testing SNe Ia distance measurement methods with SN 2011fe

The nearby, bright, almost completely unreddened Type Ia supernova 2011fe in M101 provides a unique opportunity to test both the precision and the accuracy of the extragalactic distances derived from SNe Ia light curve fitters. We apply the current, public versions of the independent light curve fitting codes MLCS2k2 and SALT2 to compute the distance modulus of SN 2011fe from high-precision, multi-color (BVRI) light curves. The results from the two fitting codes confirm that 2011fe is a "normal" (not peculiar) and only slightly reddened SN Ia. New unreddened distance moduli are derived as 29.21 +/- 0.07 mag (D ~ 6.95 +/- 0.23$ Mpc, MLCS2k2), and 29.05 +/- 0.07 mag (6.46 +/- 0.21 Mpc, SALT2). Despite the very good fitting quality achieved with both light curve fitters, the resulting distance moduli are inconsistent by 2 sigma. Both are marginally consistent (at ~1 sigma) with the HST Key Project distance modulus for M101. The SALT2 distance is in good agreement with the recently revised Cepheid- and TRGB-distance to M101. Averaging all SN- and Cepheid-based estimates, the absolute distance to M101 is ~6.6 +/- 0.5 Mpc.Comment: 8 pages, 7 figures, accepted for publication in A&

Carbon Detection in Early-Time Optical Spectra of Type Ia Supernovae

While O is often seen in spectra of Type Ia supernovae (SNe Ia) as both unburned fuel and a product of C burning, C is only occasionally seen at the earliest times, and it represents the most direct way of investigating primordial white dwarf material and its relation to SN Ia explosion scenarios and mechanisms. In this paper, we search for C absorption features in 188 optical spectra of 144 low-redshift (z < 0.1) SNe Ia with ages <3.6 d after maximum brightness. These data were obtained as part of the Berkeley SN Ia Program (BSNIP; Silverman et al. 2012) and represent the largest set of SNe Ia in which C has ever been searched. We find that ~11 per cent of the SNe studied show definite C absorption features while ~25 per cent show some evidence for C II in their spectra. Also, if one obtains a spectrum at t < -5 d, then there is a better than 30 per cent chance of detecting a distinct absorption feature from C II. SNe Ia that show C are found to resemble those without C in many respects, but objects with C tend to have bluer optical colours than those without C. The typical expansion velocity of the C II {\lambda}6580 feature is measured to be 12,000-13,000 km/s, and the ratio of the C II {\lambda}6580 to Si II {\lambda}6355 velocities is remarkably constant with time and among different objects with a median value of ~1.05. While the pseudo-equivalent widths (pEWs) of the C II {\lambda}6580 and C II {\lambda}7234 features are found mostly to decrease with time, we see evidence of a significant increase in pEW between ~12 and 11 d before maximum brightness, which is actually predicted by some theoretical models. The range of pEWs measured from the BSNIP data implies a range of C mass in SN Ia ejecta of about (2-30) * 10^-3 M_Sun.Comment: 20 pages, 11 figures, 4 tables, revised version re-submitted to MNRA

Fourteen Months of Observations of the Possible Super-Chandrasekhar Mass Type Ia Supernova 2009dc

In this paper, we present and analyse optical photometry and spectra of the extremely luminous and slowly evolving Type Ia supernova (SN Ia) 2009dc, and offer evidence that it is a super-Chandrasekhar mass (SC) SN Ia and thus had a SC white dwarf (WD) progenitor. Optical spectra of SN 2007if, a similar object, are also shown. SN 2009dc had one of the most slowly evolving light curves ever observed for a SN Ia, with a rise time of ~23 days and Delta m_15(B) = 0.72 mag. We calculate a lower limit to the peak bolometric luminosity of ~2.4e43 erg/s, though the actual value is likely almost 40% larger. Optical spectra of SN 2009dc and SN 2007if obtained near maximum brightness exhibit strong C II features (indicative of a significant amount of unburned material), and the post-maximum spectra are dominated by iron-group elements. All of our spectra of SN 2009dc and SN 2007if also show low expansion velocities. However, we see no strong evidence in SN 2009dc for a velocity "plateau" near maximum light like the one seen in SN 2007if (Scalzo et al. 2010). The high luminosity and low expansion velocities of SN 2009dc lead us to derive a possible WD progenitor mass of more than 2 M_Sun and a Ni-56 mass of about 1.4-1.7 M_Sun. We propose that the host galaxy of SN 2009dc underwent a gravitational interaction with a neighboring galaxy in the relatively recent past. This may have led to a sudden burst of star formation which could have produced the SC WD progenitor of SN 2009dc and likely turned the neighboring galaxy into a "post-starburst galaxy." No published model seems to match the extreme values observed in SN 2009dc, but simulations do show that such massive progenitors can exist (likely as a result of the merger of two WDs) and can possibly explode as SC SNe Ia.Comment: 30 pages, 16 figures, 8 tables, re-submitted to MNRA

Improving mental health literacy in year 9 high school children across Wales: a protocol for a randomised control treatment trial (RCT) of a mental health literacy programme across an entire country

Background: Adolescence is a crucial period for developing and maintaining good habits for mental health and well-being. This is important for future mental health, as most mental health problems manifest during adolescence. Mental health literacy is the foundation for mental health prevention, stigma reduction, and increased help-seeking efficacy particularly among adolescents. The mental health literacy programme “The Guide”, which was developed in Canada, has shown success in increasing mental health literacy in North American 16-17 year olds. “The Guide Cymru” is an adaptation of The Guide designed for a younger age group (13-14 year olds) and for the Welsh culture and context and is being offered to all state schools in Wales. Methods: This two-armed cluster randomised control trial (RCT) will evaluate the effectiveness of The Guide Cymru. All 205 secondary schools in Wales will be invited to take part, involving up to 30,000 year 9 pupils. Schools will be randomised to either the immediate implementation of The Guide Cymru or to a wait-list control. The wait-list control will receive The Guide Cymru around 12 weeks later. Measures of mental health literacy (assessed via the Knowledge and Attitudes to Mental Health scale) and mental health problems (via the PedsQL and Strengths and Difficulties Questionnaire) will be taken at baseline (pre-intervention), 12 weeks later (after the active group has received The Guide Cymru), and 24 weeks later (after the wait-list control has received The Guide Cymru).Discussion: The trial aims to evaluate if The Guide Cymru increases mental health literacy, including reduced stigma to others and to the self, and increased levels of good mental health behaviours and help-seeking for mental health problems. Trial Registration: ISRCTN15462041. Registered 03/10/2019. https://doi.org/10.1186/ISRCTN15462041Keywords: Mental health literacy, Randomised Control Trial, Early intervention, Self-stigma, Stigma, Education, Adolescence, Help-seeking efficacy, School-based intervention