366 research outputs found
Spatial and seasonal distribution of invertebrates in Northern Apennine rheocrene springs
Four perennial rheocrene springs located between 919 and 1252 m a.s.l. on substrata characterized by different lithologies were studied. Water samples and invertebrates were collected seasonally for one year. The crenic fauna was collected using three sampling techniques: moss washing, drift tubes and benthic traps. Each sampling technique was particularly efficient for collecting specific taxa typical of the different habitats (crenophilous crustaceans and crenoxenic benthic insects were dominant in benthic traps and moss; crenophilic, stygophilic and stygobiotic crustaceans in drift tubes). A total of 3,284 invertebrates belonging to 54 taxa were collected. Ostracoda, Harpacticoida, and Diptera were the most abundant taxa. Species assemblages collected at each spring, in each season, in traps and mosses, differed among springs, and, based on invertebrate assemblages, the ordination of the investigated springs did not correspond to that based on environmental parameters. Of the environmental variables only pH and temperature explained the diversity pattern. Assemblages collected from different habitats also differed: benthic traps collected mainly Chironomidae, Ostracoda, other Diptera, crenophilous Harpacticoida, and Gastropoda; in moss assemblages, the fauna was mostly represented by crenophilic Harpacticoida, Ostracoda, Plecoptera, Chironomidae. Finally, the groundwater assemblages, collected with drift tubes, were dominated by crenophilous Harpacticoida, Chironomidae and Plecoptera. Variation in number of taxa over time was observed in traps and moss samples, whereas drift tubes showed no seasonality. Meiofauna (i.e., permanent meiofauna, represented by Nematoda, Copepoda, Ostracoda, and Hydrachnidia, and temporary meiofauna, represented by early instars of insect larvae) dominated all habitats, probably because of constant flow and favourable habitats such as moss. The presence of mosses was a factor that increased the species diversity of the investigated springs; drift tubes allowed most of the stygobiotic taxa to be collected, although this technique did not necessarily increase the total number of taxa collected. In addition to the array of habitats, other factors, such as geology, might influence the structure of invertebrate communities. The diversity of the investigated springs was strictly dependent on the presence of different microhabitats and local environmental conditions
Gitelman syndrome associated with chondrocalcinosis: description of two cases
Gitelman syndrome is a rare inherited tubulopathy, characterized by hypomagnesemia, hypokalemia, metabolic alkalosis, hypocalciuria and hyperreninemic hyperaldosteronism. The clinical spectrum is wide and includes: cramps, myalgies, muscle weakness, until episodes of carpo-podalic spasm, tetania, rabdomyolisis and paralysis. Some cases have been described in literature underlining the association of this condition with chondrocalcinosis, as a typical example of hypomagnesemia-induced crystal deposition disease. The therapy of Gitelman syndrome consists on the administration of defective electrolytes, althought not always effective. We describe two cases of Gitelman syndrome associated with chondrocalcinosis showing the wide range of presentation of this clinical condition
Catalytic Reduction of Carbon Dioxide on the (001), (011), and (111) Surfaces of TiC and ZrC: A Computational Study
We present a computational study of the activity and selectivity of early transition-metal carbides as carbon dioxide reduction catalysts. We analyze the effects of the adsorption of CO_{2} and H_{2} on the (001), (011), and metal-terminated (111) surfaces of TiC and ZrC, as carbon dioxide undergoes either dissociation to CO or hydrogenation to COOH or HCOO. The relative stabilities of the three reduction intermediates and the activation energies for their formation allow the identification of favored pathways on each surface, which are examined as they lead to the release of CO, HCOOH, CH_{3}OH, and CH_{4}, thereby also characterizing the activity and selectivity of the two materials. Reaction energetics implicate HCO as the key common intermediate on all surfaces studied and rule out the release of formaldehyde. Surface hydroxylation is shown to be highly selective toward methane production as the formation of methanol is hindered on all surfaces by its barrierless conversion to CO
Imaging activated-T-lymphocytes in the salivary glands of patients with sjögren’s syndrome by 99mTc-interleukin-2. diagnostic and therapeutic implications
Background: Sjögren’s syndrome (SS) is a progressive autoimmune disease characterized by local mononuclear cell infiltration of the salivary and lachrymal glands. Labial biopsy demonstrates local infiltration by Th1 cells that produce pro-inflammatory cytokines, such as interleukin-2 (IL2). The aim of this study was to assess the utility of 99mTc-labelled-IL2 (99mTc-IL2) in evaluating in vivo the extent and severity of lympho-mononuclear cell infiltration in the salivary glands of patients with SS. Methods: We investigated 48 patients with primary SS and 27 control subjects using 99mTc-IL2 scintigraphy. Furthermore, in a subgroup of 30 patients, we also performed 99mTc-pertechnetate scintigraphy (99mTcO4−) for evaluation of the salivary gland function. Results: 99mTc-IL2 uptake in the salivary glands of SS patients was higher than in the control subjects (1.30 ± 0.16 vs. 0.83 ± 0.08 for parotids and 1.36 ± 0.15 vs. 1.16 ± 0.07 for submandibular glands; p < 0.0001). The salivary gland uptake of 99mTc-IL2 in patients with a longer history of disease was lower compared with the recently diagnosed patients. A significant direct correlation was found between the uptake of 99mTc-IL2 and histology. Conclusions: 99mTc-IL2 scintigraphy showed that the degree of lymphocytic infiltration of major salivary glands is variable in patients with different disease durations. Patients with a high 99mTc-IL2 uptake could be efficiently treated with immuno-modulatory drugs and the efficacy of treatment could be followed-up by 99mTc-IL2 scintigraphy
Single Nucleotide Polymorphisms in collagen genes and association with skin quality trait
AbstractLivestock skin is largely employed in the manufacturing of clothing and shoes, sector in which Italy is a world leader. To sustain Italian products against foreign competition in the globalization era particular attention is to be focus on product quality. Here we investigate the association of SNP mutations in genes coding for collagen proteins present in animal skin with a number of phisico-chemical parameters influencing skin quality for the tanning industry.Skin and blood were sampled from 73 Italian Friesian and Italian Brown bovines and from 43 Bergamasca and Sarda ovines, classified by sex and age. Skins were characterised for a set of chemico-physical parameters (thickness, density, humidity, protein content, ashes, lipid content, hydrossi-proline and DNA content).Regions of the collagen type I, III and IV were screened for SNP discovery in the two species by sequencing a set of reference animals. In bovine 15 polymorphisms were identified: (2 in collagen type I, 9 in collagen type III alp..
Regional differences of vitamin D deficiency in rheumatoid arthritis patients in Italy
Vitamin D deficiency is very common in patients with rheumatoid arthritis (RA). Aim of this study was to evaluate the prevalence of vitamin D deficiency among the different Italian regions and whether these variations are associated with different severity of the disease. The study includes 581 consecutive RA patients (464 women), not taking vitamin D supplements, from 22 Italian rheumatology centres uniformly distributed across Italy. Together with parameters of disease activity (disease activity score 28), functional impairment (activities of daily living and health assessment questionnaire disability index) and mean sun exposure time, all patients had serum 25-hydroxyvitamin D (25OHD) measured in a centralized laboratory. Vitamin D deficiency (25OHD level <20 ng/mL) was very frequent among RA patients; its prevalence was 60%, 52% and 38% in southern, central and northern Italy, respectively. Mean disease activity and disability scores were worse in southern regions of Italy. These scores were inversely related to 25OHD levels and this correlation remained statistically significant after adjusting for both body mass index (BMI) and sun exposure time. However, disease severity remained significantly higher in southern regions versus central-northern Italy after adjustment also for serum 25OHD levels, age and BMI. In RA Italian patients there are significant regional differences in the prevalence of vitamin D deficiency explained by different BMI, and sun exposure time, and inversely associated with disease activity and disability scores
Catalytic reduction of carbon dioxide on the (001), (011), and (111) surfaces of TiC and ZrC: a computational study
We present a computational study of the activity and selectivity of early transition-metal carbides as carbon dioxide reduction catalysts. We analyze the effects of the adsorption of CO2 and H2 on the (001), (011), and metal-terminated (111) surfaces of TiC and ZrC, as carbon dioxide undergoes either dissociation to CO or hydrogenation to COOH or HCOO. The relative stabilities of the three reduction intermediates and the activation energies for their formation allow the identification of favored pathways on each surface, which are examined as they lead to the release of CO, HCOOH, CH3OH, and CH4, thereby also characterizing the activity and selectivity of the two materials. Reaction energetics implicate HCO as the key common intermediate on all surfaces studied and rule out the release of formaldehyde. Surface hydroxylation is shown to be highly selective toward methane production as the formation of methanol is hindered on all surfaces by its barrierless conversion to CO
Strong mechanical driving of a single electron spin
Quantum devices for sensing and computing applications require coherent
quantum systems which can be manipulated in a fast and robust way. Such quantum
control is typically achieved using external electric or magnetic fields which
drive the system's orbital or spin degrees of freedom. However, most of these
approaches require complex and unwieldy antenna or gate structures, and with
few exceptions are limited to the regime of weak driving. Here, we present a
novel approach to strongly and coherently drive a single electron spin in the
solid state using internal strain fields in an integrated quantum device.
Specifically, we study individual Nitrogen-Vacancy (NV) spins embedded in
diamond mechanical oscillators and exploit the intrinsic strain coupling
between spin and oscillator to strongly drive the spins. As hallmarks of the
strong driving regime, we directly observe the energy spectrum of the emerging
phonon-dressed states and employ our strong, continuous driving for enhancement
of the NV spin coherence time. Our results constitute a first step towards
strain-driven, integrated quantum devices and open new perspectives to
investigate unexplored regimes of strongly driven multi-level systems and to
study exotic spin dynamics in hybrid spin-oscillator devices.We gratefully acknowledge financial support from SNI; NCCR QSIT; SNF grants 200021_143697; and EU FP7 grant 611143 (DIADEMS). AN holds a University Research Fellowship from the Royal Society and acknowledges support from the Winton Programme for the Physics of Sustainability.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nphys341
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