Finite-Size Effects in Graphene Nanostructures

Finite-Size Effects in Graphene Nanostructure

The Jurassic pleurotomarioidean gastropod Laevitomaria and its palaeobiogeographical history

The genus Laevitomaria is reviewed and its palaeobiogeographical history is reconstructed based on the re-examination of its type species L. problematica, the study of material stored at the National Natural History Museum of Luxembourg, and an extensive review of the literature. The systematic study allows ascribing to Laevitomaria a number of Jurassic species from the western European region formerly included in other pleurotomariid genera. The following new combinations are proposed: Laevitomaria allionta, Laevitomaria amyntas, Laevitomaria angulba, Laevitomaria asurai, Laevitomaria daityai, Laevitomaria fasciata, Laevitomaria gyroplata, Laevitomaria isarensis, Laevitomaria joannis, Laevitomaria repeliniana, Laevitomaria stoddarti, Laevitomaria subplatyspira, and Laevitomaria zonata. The genus, which was once considered as endemic of the central part of the western Tethys, shows an evolutionary and palaeogeographical history considerably more complex than previously assumed. It first appeared in the Late Sinemurian in the northern belt of the central western Tethys involved in the Neotethyan rifting, where it experienced a first radiation followed by an abrupt decline of diversity in the Toarcian. Species diversity increased again during Toarcian\u2013Aalenian times in the southernmost part of western European shelf and a major radiation occurred during the Middle Aalenian to Early Bajocian in the northern Paris Basin and southern England. After a latest Bajocian collapse of diversity, Laevitomaria disappeared from both the central part of western Tethys and the European shelf. In the Bathonian, the genus appeared in the south-eastern margin of the Tethys where it lasted until the Oxfordian

Vetigastropoda and Neritimorpha from the Lower Bajocian of Luxembourg and palaeobiogeography of Aalenian\u2013Bajocian (Middle Jurassic) gastropods of western Europe

Vetigastropod and neritimorph species from Lower Bajocian (Middle Jurassic) sediments of south-western Luxembourg are described. Eighteen species are recognized. Two new genera \u2013 Szabotomaria gen. nov. and Fabercapulus gen. nov. \u2013 and four new species \u2013 Szabotomaria ziqquratiformis sp. nov., Colpomphalus thuyi sp. nov., Colpomphalus tigratus sp. nov. and Fabercapulus semisculptus sp. nov. \u2013 are erected. These species, together with other species recently described from the same strata, are part of a diverse assemblage consisting of 32 species belonging to 14 genera in six families and five superfamilies, representing the richest vetigastropod-neritimorph fauna currently known from Bajocian and sub-coeval deposits of western Europe. An analysis of the palaeoecological and palaeobiogeographical relationships of this fauna and those from other areas of the western European shelf was performed using cluster analysis and by comparison of the respective taxonomic structures. The former detected a major cluster composed of two distinct branches: the faunas of the northern Paris-Wessex Basin, including Luxembourg, and those of the southern Germany basin. These faunas have similar taxonomic structures and occur mainly in facies represented by condensed iron ooid-rich marls and limestones deposited in lower offshore to upper offshore-shoreface settings. The close relationship between the Luxembourg and other faunas of the Paris-Wessex Basin reflects free faunal exchange and facies similarities. Slight differences in the sedimentary context could explain the separation of the southern German from the Anglo-Paris branch, whereas similarities between Swabian and Franconian faunas most probably reflect the geographical continuity of these areas. The Early Bajocian fauna of the East Midlands Shelf comes from sediments deposited in a shallow-water, oolitic barrier complex and is different from other western European faunas in both species composition and taxonomic structure

AN OVERVIEW OF THE JURASSIC GASTROPODS FROM ROCCA BUSAMBRA (NORTH-WESTERN SICILY, ITALY)

This paper is an overview of the gastropods from the Toarcian to Lower Kimmeridgian fissure fillings of Rocca Busambra. They are the most diverse and richest Jurassic faunas known from the pelagic sediments of the western Tethys. 224 species, 137 of them new, were recognized. The main feature of the structure of these assemblages is the high number of new taxa and the concomitant presence of an archaic stock with Triassic affinities, and a group advancing the appearance of the modern caenogastropod taxa. These features give these assemblages an important place in the reconstruction of the evolution of the whole class

A theoretical study of linear beryllium chains: full configuration interaction.

International audienceWe present a full configuration interaction study of Be(N) (N=2,3,4,5) linear chains. A comparative study of the basis-set effect on the reproduction of the energy profile has been reported. In particular, the 3s1p, 4s2p, 4s2p1d, 5s3p2d, and 5s3p2d1f bases were selected. For the smallest chains (i.e., Be(2) and Be(3)), smaller basis sets give dissociative energy profiles, so large basis set is demanded for the reproduction of equilibrium minima in the structures. For Be(4) and Be(5) linear chains, the energy profiles show a minimum also by using the smallest basis sets, but the largest ones give a much stronger stabilization energy. For all the structures, two spin states have been studied: the singlet and the triplet. It is shown that the energy separation of the two states, in the equilibrium region, is small and decays exponentially with respect to the number of atoms in the chain. Finally an interpolative technique allowing for the estimation of the long-chain parameters from shorter ones is presented

In vitro antibacterial activity of ceftazidime/avibactam in combination against planktonic and biofilm carbapenemase-producing Klebsiella pneumoniae isolated from blood

Abstract Objectives The aim of this study was to report on in vitro tests of antibacterial activity of ceftazidime/avibactam in combination against planktonic or biofilm KPC carbapenemase-producing Klebsiella pneumoniae (KPC-Kp), the rate of KPC-Kp blood isolates in University of Perugia Hospital over a 5-year period, and their antimicrobial susceptibility patterns. Methods The antibacterial activity of ceftazidime/avibactam in combination with other antimicrobials was assessed against planktonic and biofilm bacteria by Etest and checkerboard assay. A retrospective review of laboratory data was performed to evaluate the rate of KPC-Kp from blood samples and their antimicrobial susceptibility patterns. Results Between 2014 and 2019, 130/4241 (3.1%) KPC-Kp were identified from blood cultures. Their rate increased from 2.3% in 2014–2015 to 4.5% over the last 3 years. Overall, 4.6% (6/130) of KPC-Kp isolates were susceptible to meropenem, 65.4% (85/130) to colistin, 65.1% (84/129) to tigecycline, 34.6% (45/130) to amikacin, 36.2% (42/116) to gentamicin, 40.2% (39/97) to fosfomycin and 91.5% (65/71) to ceftazidime/avibactam. Five of six ceftazidime/avibactam-resistant KPC-Kp were isolated from patients not treated with ceftazidime/avibactam. Synergism was detected both by Etest and checkerboard assay for the combination of ceftazidime/avibactam plus meropenem against planktonic isolates, whilst lower bactericidal activity was observed in biofilm KPC-Kp isolates. Conclusions Our in vitro data suggest that the combination of ceftazidime/avibactam plus meropenem has a synergistic antibacterial activity against planktonic bacteria, whilst a lower activity was detected against biofilm, suggesting worse clinical outcomes whenever biofilm infections are present. Further analyses are required to confirm these results before extending them to clinical practice

The Electronic Structure of Short Carbon Nanotubes: The Effects of Correlation

This paper presents a tight binding and ab initio study of finite zig-zag nanotubes of various diameters and lengths. The vertical energy spectra of such nanotubes are presented, as well as their spin multiplicities. The calculations performed using the tight binding approach show the existence of quasi-degenerate orbitals located around the Fermi level, thus suggesting the importance of high-quality ab initio methods, capable of a correct description of the nondynamical correlation. Such approaches (Complete Active Space SCF and Multireference Perturbation Theory calculations) were used in order to get accurate ground and nearest excited-state energies, along with the corresponding spin multiplicities

Use of Radium-223 Dichloride in Patients With Osteonecrosis of the Jaw Induced by Zoledronic Acid: Report of 2 Cases.

Bisphosphonates, a group of inorganic pyrophosphate analogues that prevent the loss of bone density, are commonly used in patients with bone metastases; the calcium-mimetic a-emitter radium-223 dichloride (Ra223) is a bone-targeting therapy used in patients with metastatic castration-resistant prostate cancer (mCRPC)-related bone metastases. Both treatments reduce pain and disability; Ra223 is associated with significantly improved overall survival in mCRPC. Patients who receive bisphosphonate therapy are at risk of developing osteonecrosis of the jaw, especially in those who do not undergo an accurate oral evaluation and sanitation before the beginning of therapy, and in patients who present with conditions that facilitate the development of this problem, such as inadequate oral and dental care, lack of prophylactic antimicrobial mouth rinsing, patient comorbidity, or suboptimal suturing after tooth extraction. Although there is possible synergism between bisphosphonates and Ra223 therapy, there is no consensus about the use of Ra223 in patients with previous/current osteonecrosis of the jaw induced by zoledronic acid. However, our experience suggests that Ra223 therapy might not be contraindicated in patients with osteonecrosis of the jaw induced by zoledronic acid if an appropriate multidisciplinary approach is followed, and we report 2 cases of patients with current or previous osteonecrosis of the jaw induced by zoledronic acid, who were treated with Ra223 for mCRPCrelated bone metastases. Multidisciplinary management, including accurate clinical and radiological evaluation before beginning therapy with Ra223, together with oral sanitation and periodic controls during treatment, allowed successful administration of Ra223 while reducing side effects, with absent or minimal worsening of osteonecrosis

Real-life comparison of Pirfenidone and Nintedanib in patients with Idiopathic Pulmonary Fibrosis: a 24-month assessment.

Background: Real-life data on the use of pirfenidone and nintedanib to treat patients with idiopathic pulmonary fibrosis (IPF) are still scarce. Methods: We compared the efficacy of either pirfenidone (n=78) or nintedanib (n=28) delivered over a 24-month period in patients with IPF, followed at two regional clinic centers in Italy, with a group of patients who refused the treatment (n=36), and who were considered to be controls. All patients completed regular visits at 1- to 3-month intervals, where primary [forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO)] and secondary outcomes (side effects, treatment compliance, and mortality) were recorded. Results: Over time, the decline in FVC and DLCO was significantly higher (p=0.0053 and p=0.037, respectively) in controls when compared with the combined treated group, with no significant difference between the two treated groups. Compared to patients with less advanced disease (GAP (Gender, Age, Physiology) stage I), those in GAP stages II and III showed a significantly higher decline in both FVC and DLCO irrespective of the drug taken. Side effects were similarly reported in patients receiving pirfenidone and nintedanib (5% and 7%, respectively), whereas mortality did not differ among the three groups. Conclusion: This real-life study demonstrated that both pirfenidone and nintedanib were equally effective in reducing the decline of FVC and DLCO versus non-treated patients after 24 months of treatment; however, patients with more advanced disease were likely to show a more rapid decline in respiratory function

Моделирование магнетронной распылительной системы методом конечных элементов

В работе проведено моделирование магнетронной распылительной системы методом конечных элементов и методом Галеркина. Получены распределения концентрации и скоростей носителей заряда, распределение электрического потенциала и магнитного поля, рассмотрены временные зависимости физических величин. Разработано программное обеспечение для моделирования сложных физических задач. Проведена верификация расчетного алгоритма на примере решения модельных задач. Отличительной особенностью исследуемой модели от существующих является учет нестационарного и конвективного слагаемых в уравнении для переноса скорости электрона и максимально точная реализация всех слагаемых в дифференциальном уравнении (в рамках метода Галеркина).The dissertation examines the modeling of a magnetron sputtering system by finite element analysis and Galerkin method. The model makes it possible to calculate the concentration, velocity, temperature, electrical potential and magnetic field. The methods and the code developed according to the model are usable for modeling complex physical tasks. The work also includes analysis and verification of results