We predict by first-principles calculations that p-doped graphane is an electron-phonon superconductor with a critical temperature above the boiling point of liquid nitrogen. The unique strength of ...the chemical bonds between carbon atoms and the large density of electronic states at the Fermi energy arising from the reduced dimensionality give rise to a giant Kohn anomaly in the optical phonon dispersions and push the superconducting critical temperature above 90 K. As evidence of graphane was recently reported, and doping of related materials such as graphene, diamond, and carbon nanostructures is well established, superconducting graphane may be feasible.
The quest for materials capable of realizing the next generation of electronic and photonic devices continues to fuel research on the electronic, optical and vibrational properties of graphene. ...Few-layer graphene (FLG) flakes with less than ten layers each show a distinctive band structure. Thus, there is an increasing interest in the physics and applications of FLGs. Raman spectroscopy is one of the most useful and versatile tools to probe graphene samples. Here, we uncover the interlayer shear mode of FLGs, ranging from bilayer graphene (BLG) to bulk graphite, and suggest that the corresponding Raman peak measures the interlayer coupling. This peak scales from ~43 cm(-1) in bulk graphite to ~31 cm(-1) in BLG. Its low energy makes it sensitive to near-Dirac point quasiparticles. Similar shear modes are expected in all layered materials, providing a direct probe of interlayer interactions.
To monitor the spread and to evaluate the role for public health of Usutu virus (USUV) in an endemic area of Italy.
The survey was retrospectively conducted by detecting USUV RNA and USUV antibodies ...in cerebrospinal fluid and serum samples collected between 2008 and 2011 from 915 patients with or without neurologic impairments in the area of the municipality of Modena, Italy. Organs of birds and pools of mosquitoes were also tested for USUV RNA. Positive samples were partially sequenced and used for phylogenetic analysis.
The presence of USUV RNA (1.1%; 95% confidence interval (CI) 0.6–2.0) was significantly (p <0.05) higher than that of West Nile virus (0%; 95% CI 0–0.33). USUV antibody level was 6.57% (95% CI 4.87–8.82), and it was significantly higher (p <0.05) compared to that of West Nile virus (p 2.96, 95% CI 1.89–4.62). Partial genome sequencing of USUV strains detected in humans, birds and mosquitoes revealed high nucleotide sequence identity within them and with the USUV strains isolated in Central Europe.
USUV infection in humans is not a sporadic event in the studied area, and USUV neuroinvasiveness has been confirmed.
We statistically evaluated the relative orientation between gas column density structures, inferred from Herschel submillimetre observations, and the magnetic field projected on the plane of sky, ...inferred from polarized thermal emission of Galactic dust observed by the Balloon-borne Large-Aperture Submillimetre Telescope for Polarimetry (BLASTPol) at 250, 350, and 500 μm, towards the Vela C molecular complex. First, we find very good agreement between the polarization orientations in the three wavelength-bands, suggesting that, at the considered common angular resolution of 3.́0 that corresponds to a physical scale of approximately 0.61 pc, the inferred magnetic field orientation is not significantly affected by temperature or dust grain alignment effects. Second, we find that the relative orientation between gas column density structures and the magnetic field changes progressively with increasing gas column density, from mostly parallel or having no preferred orientation at low column densities to mostly perpendicular at the highest column densities. This observation is in agreement with previous studies by the Planck collaboration towards more nearby molecular clouds. Finally, we find a correspondencebetween (a) the trends in relative orientation between the column density structures and the projected magnetic field; and (b) the shape of the column density probability distribution functions (PDFs). In the sub-regions of Vela C dominated by one clear filamentary structure, or “ridges”, where the high-column density tails of the PDFs are flatter, we find a sharp transition from preferentially parallel or having no preferred relative orientation at low column densities to preferentially perpendicular at highest column densities. In the sub-regions of Vela C dominated by several filamentary structures with multiple orientations, or “nests”, where the maximum values of the column density are smaller than in the ridge-like sub-regions and the high-column density tails of the PDFs are steeper, such a transition is also present, but it is clearly less sharp than in the ridge-like sub-regions. Both of these results suggest that the magnetic field is dynamically important for the formation of density structures in this region.
West Nile virus (WNV) is a global important mosquito-borne flavivirus causing West Nile disease (WND) with morbidity and mortality in humans and animals. It is endemic in many North African ...countries, however, in Libya, WND was reported in humans by serology but never been reported in animals.
A total of 578 and 63 serum samples from horses and dogs, respectively, were collected from healthy unvaccinated animals between 2016 - 2019. A commercially available competitive ELISA (c-ELISA) kit was initially used to test samples. Positive and doubtful sera for anti‐WNV IgG antibodies using the c-ELISA were confirmed and also screened for WNV and Usutu virus (USUV) antibodies using virus neutralization test (VNT).
The results of anti‐WNV antibodies using c-ELISA showed that 13.1% (76 out of 578) of horses samples and 30.1% (19 out of 63) of dogs samples were positive. A confirmation of ELISA equine and canine positive and doubtful samples using VNT was done. VNT showed that 68.4% (52 out of 76) of serum horses samples were positive and had an overall titration from 1:10 to 1:80. Among the ELISA dogs positive and doubtful samples, VNT showed that 78.9% (15 out of 19) were positive and had an overall titration from 1:10 to 1:80.
There is lack of information from many African countries and the real burden of WNV infections in Africa is not well known, however, strong evidence on the circulation of WNV in the continent. Horse remains the most relevant species to monitor the circulation of WNV but seroprevalence studies carried out on different animals reported WNV infection in different African countries, however, their role in the transmission cycle is not well understood. Only few countries have reported WNV from dogs in Africa with very scarce information from North Africa.
Future research on WND is urgently needed in Libya.
Bluetongue Maclachlan, N J; Mayo, C E; Daniels, P W ...
Revue scientifique et technique (International Office of Epizootics)
34, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that of human haemorrhagic viral ...fevers, with characteristic tissue infarction, haemorrhage, vascular leakage, oedema, and hypovolaemic shock. Importantly, BT is not zoonotic. Bluetongue virus (BTV) infection of ruminants and vector Culicoides midges is endemic throughout many tropical and temperate regions of the world; however, within this global range the virus exists within relatively discrete ecosystems (syn. episystems) where specific constellations of BTV serotypes are spread by different species of biting Culicoides midges. Recently discovered goat-associated BTVs, notably BTV serotype 25 (BTV-25) in central Europe, appear to have distinctive biological properties and an epidemiology that is not reliant on Culicoides midges as vectors for virus transmission. Bluetongue virus infection of ruminants is often subclinical, but outbreaks of severe disease occur regularly at the upper and lower limits of the virus's global range, where infection is distinctly seasonal. There have been recent regional alterations in the global distribution of BTV infection, particularly in Europe. It is proposed that climate change is responsible for these events through its impact on vector midges. However, the role of anthropogenic factors in mediating emergence of BTV into new areas remains poorly defined; for example, it is not clear to what extent anthropogenic factors were responsible for the recent translocation to northern and eastern Europe of live attenuated vaccine viruses and an especially virulent strain of BTV-8 with distinctive properties. Without thorough characterisation of all environmental and anthropogenic drivers of the recent emergence of BT in northern Europe and elsewhere, it is difficult to predict what the future holds in terms of global emergence of BTV infection. Accurate and convenient laboratory tests are available for the sensitive and specific serological and virological diagnosis of BTV infection and confirmation of BT in animals. Prevention and control strategies for BT are largely reactive in nature, and typically are reliant on vaccination of susceptible livestock and restrictions on animal trade and movement.
Epizootic haemorrhagic disease Maclachlan, N J; Zientara, S; Savini, G ...
Revue scientifique et technique (International Office of Epizootics),
08/2015, Letnik:
34, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Summary Epizootic haemorrhagic disease (EHD) is an arthropod-transmitted viral disease of certain wild ungulates, notably North American white-tailed deer and, more rarely, cattle. The disease in ...white-tailed deer results from vascular injury analogous to that caused by bluetongue virus (BTV), to which EHD virus (EHDV) is closely related. There are seven serotypes of EHDV recognised, and Ibaraki virus, which is the cause of sporadic disease outbreaks in cattle in Asia, is included in EHDV serotype 2. The global distribution and epidemiology of BTV and EHDV infections are also similar, as both viruses occur throughout temperate and tropical regions of the world where they are transmitted by biting Culicoides midges and infect a wide variety of domestic and wild ungulates. However, the global distribution and epidemiology of EHDV infection are less well characterised than they are for BTV. Whereas most natural and experimental EHDV infections (other than Ibaraki virus infection) of livestock are subclinical or asymptomatic, outbreaks of EHD have recently been reported among cattle in the Mediterranean Basin, Reunion Island, South Africa, and the United States. Accurate and convenient laboratory tests are increasingly available for the sensitive and specific serological and virological diagnosis of EHDV infection and confirmation of EHD in animals, but commercial vaccines are available only for prevention of Ibaraki disease and not for protection against other strains and serotypes of EHDV.
Using
ab initio method, which includes van der Waals interactions, we show that turbostratic stacking lowers the corrugation and exfoliation energies. The lower corrugation energy decreases
C
44 and ...gives rise to ultralow friction behaviour in turbostratic graphitic systems. Our results indicate that flakes with turbostratic stacking are easier to exfoliate.
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► Turbostratic stacking lowers the corrugation and exfoliation energies. ► The lower corrugation energy decreases C
44 and more bending modes are excited. ► Flakes with turbostratic stacking are easier to exfoliate. ► Ultralow friction behaviour is predicted in turbostratic graphitic systems.
The thermodynamic and mechanical properties of graphitic systems are strongly dependent on the shear elastic constant
C
44. Using state-of-the-art density functional calculations, we provide the first complete determination of their elastic constants and exfoliation energies. We show that stacking misorientations lead to a severe lowering of
C
44 of at least one order of magnitude. The lower exfoliation energy and the lower
C
44 (more bending modes) suggest that flakes with random stacking should be easier to exfoliate than the ones with perfect or rhombohedral stacking. We also predict ultralow friction behaviour in turbostratic graphitic systems.
Epizootic heamorragic disease Savini, G; Afonso, A; Mellor, P ...
Research in veterinary science,
08/2011, Letnik:
91, Številka:
1
Journal Article
Recenzirano
Epizootic haemorrhagic disease (EHD) is an infectious non-contagious viral disease transmitted by insects of the genus Culicoides which affects wild and domestic ruminants. The causative agent, the ...epizootic haemorrhagic disease virus (EHDV), belongs to the family Reoviridae, genus Orbivirus and shares many morphological and structural characteristics with the other members of the genus such as bluetongue, African horse sickness and equine encephalosis viruses. In recent years EHD outbreaks have been reported in countries bordering the European Union. They caused disease in cattle and severe repercussion on the livestock industry of the affected countries. In the light of recent European bluetongue epizootic these events pose an increasing threat to the European Union. This review includes the most recent information regarding the virus and the disease as well as tools for its diagnosis and control. It is our conviction that more attention should be drawn to both EHDV and the disease itself in order to fulfil all these gaps and not to be unprepared in case future possible incursions.
Background and purpose: Optic nerve involvement is frequent in mitochondrial disease, and retinal abnormalities are described in Parkinson’s disease (PD).
Methods: We evaluated retinal nerve fiber ...layer (RNFL) thickness by optical coherence tomography in 43 patients with PD and in 86 age‐matched controls. We considered separately the eyes ipsilateral and contralateral to the most affected body side in patients with PD. ancova analysis, Pearson test, and multiple regression analysis were used (P < 0.05).
Results: Patients with PD showed significantly thinner temporal RNFL thickness compared to controls (P = 0.004), more evident in the eye contralateral to the most affected body side. Average RNFL thickness significantly correlated with age in both controls and patients with PD (P‐values ranging from 0.001 to 0.019), whereas in patients with PD RNFL thickness did not correlate with clinical variables.
Conclusions: Our study reveals a loss of retinal nerve fibers in the temporal quadrant in PD, which is typically susceptible in mitochondrial optic neuropathies.
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