Valency Effects In The Formation Of Supramolecular Nanoparticles

Supramolecular materials hold great promise as they allow the development of a versatile toolbox combined with properties such as responsiveness, exchange, uptake and delivery, size control, and many others. Supramolecular nanoparticles (SNPs) are of huge interest because of their high potential for biomedical applications, for example as in-vivo imaging and drug delivery vehicles. Here, SNPs based on the ternary-complex formation among cucurbit[8]uril (CB[8]), a methyl viologen polyethylene imine (MV-PEI) and novel multivalent naphthol-functionalized moieties, were assembled and the influence of the multivalency over the size-tunability was studied. A bivalent PEG-based stopper and a more intense grafted PAMAM dendrimer, named Np2-PEG and Np16-PAMAM, were synthesized, functionalized with the naphthol moieties and then separately employed as recognition units in the nanoparticles self-assembling. The effects of their greater valency over the SNPs size-tunability were investigated through Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). Particles assembled with the bivalent stopper revealed that the increased valency of the stopper induces the formation of more stable ternary complexes. Hence, the dynamic disassembly and reassembly processes, required for the formation of well-defined and size-tunable SNPs, are disfavored unless the temperature increases and well-defined nanoparticles are shaped. In contrast, the studies about the increased valency in the core of the nanoparticles showed that by respecting the 1:1:1 ratio among MV2+:CB[8]:Np-PEG/Np16-PAMAM, required for the formation of the ternary complex, the amount of the stopper is not enough to control the intermolecular network formation caused by the more intense grafted dendrimer. However, a control over the size of the SNPs was possible when the ratio among the supramolecular recognition units was changed from the traditional 1:1:1 to the newly 1:1:1:X, where X represents the amount of Np16-PAMAM

A case of dyspnea: respiratory failure due to pulmonary arteriovenous malformation

Pulmonary arteriovenous malformations (PAVMs) are abnormal communications between pulmonary arteries and veins. The clinical features suggestive of PAVMs are stigmata of right-to-left shunting (dyspnea, hypoxemia, cyanosis, cerebral embolism, brain abscess), unexplained hemoptysis, or hemothorax. We present a case of a young man who presented to the Emergency Department complaining of dyspnea, polycythemia, and persistent hypoxemia. Angio-computed tomographic scan of the chest detected multiple PAVMs. PAVMs are uncommon in the general population, but they represent an important consideration in the differential diagnosis of common pulmonary problems, including hypoxemia, pulmonary nodules, and hemoptysis

Donne uccise e donne maltrattate. Stesso passato ma anche stesso destino?

“Femicide” is an overspread phenomenon: in Italy every three days a woman is killed by her partner or ex partner. Trying to understand what underlies such crimes is so of great interest for criminologists. Femicide is very often preceded by domestic violence. In this study we considered a sample of women killed by their partner or ex partner and a sample of women ‘only’ abused and we compared the specific risk factors of femicide and of abuse. The results show that the most common risk factor is the presence of physical violence and threats, which are more severe in femicide. We discussed the possibility of preventive measures and action strategies (to be carried out by the police too) against the so-called “family disputes”.L’uccisione delle donne da parte di partner o ex partner (il c.d. femminicidio) assume dimensioni spropositate. In Italia, una donna viene uccisa ogni tre giorni, ed è interesse sempre maggiore da parte dei criminologi e degli studiosi del comportamento umano comprendere cosa sottende questi reati e come poterli prevenire. La letteratura scientifica e le indagini investigative e gli esiti giudiziari hanno messo in relazione il maltrattamento all’interno della coppia e il successivo omicidio. Con il presente studio condotto con un campione di donne uccise e donne ‘solo’ maltrattate si è voluto confrontare i così detti fattori di rischio del maltrattamento con i fattori di rischio del femminicidio. I risultati hanno dimostrato che le caratteristiche delle vittime, dell’autore sono simili, ma nei casi in cui c’è stato l’omicidio, esiste una quantità maggiore di violenza fisica, di minacce e di escalation della violenza. La prevenzione anche dell’attività da parte delle forze dell’ordine è nella direzione di mettere a punto strategie di intervento più mirate ed efficaci per contrastare le così dette ‘liti in famiglia’

Results of a Gene Panel Approach in a Cohort of Patients with Incomplete Distal Renal Tubular Acidosis and Nephrolithiasis.

Background: Distal renal tubular acidosis (dRTA) is characterized by an impairment of urinary acidification resulting in metabolic acidosis, hypokalemia, and inappropriately elevated urine pH. If not treated, this chronic condition eventually leads to nephrocalcinosis, nephrolithiasis, impaired renal function, and bone demineralization. dRTA is a well-defined entity that can be diagnosed by genetic testing of 5 genes known to be disease-causative. Incomplete dRTA (idRTA) is defined as impaired urinary acidification that does not lead to overt metabolic acidosis and therefore can be diagnosed if patients fail to adequately acidify urine after an ammonium chloride (NH4Cl) challenge or furosemide and fludrocortisone test. It is still uncertain whether idRTA represents a distinct entity or is part of the dRTA spectrum and whether it is caused by mutations in the same genes of overt dRTA. Methods: In this cross-sectional study, we investigated a group of 22 stone formers whose clinical features were suspicious of idRTA. They underwent an NH4Cl challenge and were found to have impaired urinary acidification ability. These patients were then analyzed by genetic testing with sequencing of 5 genes: SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72. Results: Two unrelated individuals were found to have two different variants in SLC4A1 that had never been described before. Conclusions: Our results suggest the involvement of other genes or nongenetic tubular dysfunction in the pathogenesis of idRTA in stone formers. However, genetic testing may represent a cost-effective tool to recognize, treat, and prevent complications in these patients

On the Iron content of NGC 1978 in the LMC: a metal rich, chemically homogeneous cluster

We present a detailed abundance analysis of giant stars in NGC 1978, a massive, intermediate-age stellar cluster in the Large Magellanic Cloud, characterized by a high ellipticity and suspected to have a metallicity spread. We analyzed 11 giants, all cluster members, by using high resolution spectra acquired with the UVES/FLAMES spectrograph at the ESO-Very Large Telescope. We find an iron content of [Fe/H]=-0.38 dex with very low (0.07 dex) dispersion, and a mean heliocentric radial velocity Vr=293.1 (with an error of 0.9 km/s) and a velocity dispersion (3.1 km/s), thus excluding the presence of a significant metallicity, as well as velocity, spread within the cluster.Comment: 14 pages, 4 figures, accepted for publication by Apj

Super-crystals in composite ferroelectrics

As atoms and molecules condense to form solids, a crystalline state can emerge with its highly ordered geometry and subnanometric lattice constant. In some physical systems, such as ferroelectric perovskites, a perfect crystalline structure forms even when the condensing substances are non-stoichiometric. The resulting solids have compositional disorder and complex macroscopic properties, such as giant susceptibilities and non-ergodicity. Here, we observe the spontaneous formation of a cubic structure in composite ferroelectric potassium– lithium–tantalate–niobate with micrometric lattice constant, 104 times larger than that of the underlying perovskite lattice. The 3D effect is observed in specifically designed samples in which the substitutional mixture varies periodically along one specific crystal axis. Laser propagation indicates a coherent polarization super-crystal that produces an optical X-ray diffractometry, an ordered mesoscopic state of matter with important implications for critical phenomena and applications in miniaturized 3D optical technologies

The chemical composition of red giant stars in four intermediate-age clusters of the Large Magellanic Cloud

This paper presents the chemical abundance analysis of a sample of 27 red giant stars located in 4 popolous intermediate-age globular clusters in the Large Magellanic Cloud, namely NGC 1651, 1783, 1978 and 2173. This analysis is based on high-resolution (R ~ 47000) spectra obtained with the UVES@VLT spectrograph. For each cluster we derived up to 20 abundance ratios sampling the main chemical elemental groups, namely light odd-Z, alpha, iron-peak and neutron-capture elements. All the analysed abundance patterns behave similarly in the 4 clusters and also show negligible star-to-star scatter within each cluster. We find [Fe/H]=-0.30+-0.03, -0.35+-0.02, -0.38+-0.02 and -0.51+-0.03 dex for NGC 1651, 1783, 1978 and 2173, respectively. The measurement of light odd-Z nuclei gives slightly subsolar [Na/Fe] and a more significant [Al/Fe] depletion (~ -0.50 dex). The [alpha / Fe] abundance ratios are nearly solar, while the iron-peak elements well trace that one of the iron. s-process elements behave in a peculiar way: light s-elements give subsolar [Y/Fe] and [Zr/Fe] abundance ratios, while heavy s-elements give enhanced [Ba/Fe], [La/Fe] and [Nd/Fe] with respect to the solar values. Also, the [Eu/Fe] abundance ratio turns out to be enhanced (~ 0.4 dex).Comment: Accepted for publication on A

Distances, ages, and epoch of formation of globular clusters

We review the results on distances and absolute ages of galactic globular clusters (GCs) obtained after the release of the Hipparcos catalogue. Several methods for the Population II local distance scale are discussed, exploiting NEW RESULTS for RR Lyraes in the Large Magellanic Cloud (LMC). We find that the so-called Short and Long Distance Scales may be reconciled whether a consistent reddening scale is adopted for Cepheids and RR Lyrae variables in the LMC. Distances and ages for the 9 clusters discussed in Paper I are re-derived using an enlarged sample of local subdwarfs, which includes about 90% of the metal-poor dwarfs with accurate parallaxes (Delta p/p < 0.12) in the whole Hipparcos catalogue. On average, our revised distance moduli are decreased by 0.04 mag with respect to Paper I. The corresponding age of the GCs is t=11.5+-2.6 Gyr (95% confidence range). The relation between Mv(ZAHB) and metallicity for the nine programme clusters turns out to be Mv(ZAHB)=(0.18+-0.09)([Fe/H]+1.5)+(0.53+-0.12).Thanks to Hipparcos the major contribution to the total error budget associated with the subdwarf fitting technique has been moved from parallaxes to photometric calibrations, reddening and metallicity scale. This total uncertainty still amounts to about +-0.12 mag. Comparing the corresponding (true) LMC distance modulus 18.64+-0.12 mag with other existing determinations, we conclude that at present the best estimate for the distance of the LMC is: 18.54+-0.03+-0.06, suggesting that distances from the subdwarf fitting method are 1 sigma too long. Consequently, our best estimate for the age of the GCs is revised to: Age = 12.9+-2.9 Gyr (95% confidence range). The best relation between Mv(ZAHB) and [Fe/H] is: Mv(ZAHB) =(0.18+-0.09)([Fe/H]+1.5)+(0.63+-0.07).Comment: 76 pages, 6 encapsulated figures and 6 tables. Latex, uses aasms4.sty. Revised and improved version, with new data on field RR Lyraes in LMC. Accepted in the Astrophysical Journa

Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters

Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the formation of massive star clusters, which includes several episodes of star formation. While this provides an explanation for several features of globular clusters, including the second parameter problem, it also opens new perspectives about the relation between globular clusters and the halo of our Galaxy, and by extension of all populations with a high specific frequency of globular clusters, such as, e.g., giant elliptical galaxies. We review progress in this area, focusing on the most recent studies. Several points remain to be properly understood, in particular those concerning the nature of the polluters producing the abundance pattern in the clusters and the typical timescale, the range of cluster masses where this phenomenon is active, and the relation between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review

Conversion to secondary progressive multiple sclerosis: patient awareness and needs. results from an online survey in Italy and Germany

Background: Few studies have investigated the experiences of patients around the conversion to secondary progressive multiple sclerosis (SPMS). ManTra is a mixed-method, co-production research project conducted in Italy and Germany to develop an intervention for newly-diagnosed SPMS patients. In previous project actions, we identified the needs and experiences of patients converting to SPMS via literature review and qualitative research which involved key stakeholders.Aims: The online patient survey aimed to assess, on a larger and independent sample of recently-diagnosed SPMS patients: (a) the characteristics associated to patient awareness of SPMS conversion; (b) the experience of conversion; (c) importance and prioritization of the needs previously identified.Methods: Participants were consenting adults with SPMS since &lt;= 5 years. The survey consisted of three sections: on general and clinical characteristics; on experience of SPMS diagnosis disclosure (aware participants only); and on importance and prioritization of 33 pre-specified needs.Results: Of 215 participants, those aware of their SPMS diagnosis were 57% in Italy vs. 77% in Germany (p = 0.004). In both countries, over 80% of aware participants received a SPMS diagnosis from the neurologist; satisfaction with SPMS disclosure was moderate to high. Nevertheless, 28-35% obtained second opinions, and 48-56% reported they did not receive any information on SPMS. Participants actively seeking further information were 63% in Germany vs. 31% in Italy (p &lt; 0.001).Variables independently associated to patient awareness were geographic area (odds ratio, OR 0.32, 95% CI 0.13-0.78 for Central Italy; OR 0.21, 95% CI 0.08-0.58 for Southern Italy [vs. Germany]) and activity limitations (OR 7.80, 95% CI 1.47-41.37 for dependent vs. autonomous patients).All pre-specified needs were scored a lot or extremely important, and two prioritized needs were shared by Italian and German patients: "physiotherapy" and "active patient care involvement." The other two differed across countries: "an individualized health care plan" and "information on social rights and policies" in Italy, and "psychological support" and "cognitive rehabilitation" in Germany.Conclusions: Around 40% of SPMS patients were not aware of their disease form indicating a need to improve patient-physician communication. Physiotherapy and active patient care involvement were prioritized in both countries