9 research outputs found
Li4-xGe1-xPxO4 a potential solid-state electrolyte for all-oxide microbatteries
Solid-state electrolytes for Li-ion batteries are attracting growing interest
as they allow building safer batteries, also using lithium metal anodes. Here
we studied a compound in the lithium superionic conductor (LISICON) family,
i.e. Li4-xGe1-xPxO4 (LGPO). Thin films were deposited via pulsed laser
deposition and their electrical properties were compared with ceramic pellets.
A detailed characterization of the micro structure shows that thin films can be
deposited fully crystalline at higher temperatures but also partially amorphous
at room temperature. The conductivity is not strongly influenced by the
presence of grain boundaries, exposure to air or lithium deficiencies.
First-principles molecular dynamics simulations were employed to calculate the
lithium ion diffusion profile and the conductivity at various temperatures of
the ideal LGPO crystal. Simulations gives the upper limit of conductivity for a
defect free crystal, which is in the range of 10-2 S cm-1 at 300 deg. The ease
of thin film fabrication, the room-temperature Li-ion conductivity in the range
of a few microS cm-1 make LGPO a very appealing electrolyte material for thin
film all-solid-state all-oxide microbatteries
Quantum size effects in Pb islands on Cu(111): Electronic-structure calculations
The appearance of "magic" heights of Pb islands grown on Cu(111) is studied
by self-consistent electronic structure calculations. The Cu(111) substrate is
modeled with a one-dimensional pseudopotential reproducing the essential
features, i.e. the band gap and the work function, of the Cu band structure in
the [111] direction. Pb islands are presented as stabilized jellium overlayers.
The experimental eigenenergies of the quantum well states confined in the Pb
overlayer are well reproduced. The total energy oscillates as a continuous
function of the overlayer thickness reflecting the electronic shell structure.
The energies for completed Pb monolayers show a modulated oscillatory pattern
reminiscent of the super-shell structure of clusters and nanowires. The energy
minima correlate remarkably well with the measured most probable heights of Pb
islands. The proper modeling of the substrate is crucial to set the
quantitative agreement.Comment: 4 pages, 4 figures. Submitte
Main clinical features in patients at their first psychiatric admission to Italian acute hospital psychiatric wards. The PERSEO study
BACKGROUND: Few data are available on subjects presenting to acute wards for the first time with psychotic symptoms. The aims of this paper are (i) to describe the epidemiological and clinical characteristics of patients at their first psychiatric admission (FPA), including socio-demographic features, risk factors, life habits, modalities of onset, psychiatric diagnoses and treatments before admission; (ii) to assess the aggressive behavior and the clinical management of FPA patients in Italian acute hospital psychiatric wards, called SPDCs (Servizio Psichiatrico Diagnosi e Cura = psychiatric service for diagnosis and management). METHOD: Cross-sectional observational multi-center study involving 62 Italian SPDCs (PERSEO â Psychiatric EmeRgency Study and EpidemiOlogy). RESULTS: 253 FPA aged <= 40 were identified among 2521 patients admitted to Italian SPDCs over the 5-month study period. About half of FPA patients showed an aggressive behavior as defined by a Modified Overt Aggression Scale (MOAS) score greater than 0 Vs 46% of non-FPA patients (p = 0.3651). The most common was verbal aggression, while about 20% of FPA patients actually engaged in physical aggression against other people. 74% of FPA patients had no diagnosis at admission, while 40% had received a previous psychopharmacological treatment, mainly benzodiazepines and antidepressants. During SPDC stay, diagnosis was established in 96% of FPA patients and a pharmacological therapy was prescribed to 95% of them, mainly benzodiazepines, antipsychotics and mood stabilizers. CONCLUSION: Subjects presenting at their first psychiatric ward admission have often not undergone previous adequate psychiatric assessment and diagnostic procedures. The first hospital admission allows diagnosis and psychopharmacological treatment to be established. In our population, aggressive behaviors were rather frequent, although most commonly verbal. Psychiatric symptoms, as evaluated by psychiatrists and patients, improved significantly from admission to discharge both for FPA and non-FPA patients
Clinical features and therapeutic management of patients admitted to Italian acute hospital psychiatric units: the PERSEO (psychiatric emergency study and epidemiology) survey
<p>Abstract</p> <p>Background</p> <p>The PERSEO study (psychiatric emergency study and epidemiology) is a naturalistic, observational clinical survey in Italian acute hospital psychiatric units, called SPDCs (Servizio Psichiatrico Diagnosi e Cura; in English, the psychiatric service for diagnosis and management). The aims of this paper are: (i) to describe the epidemiological and clinical characteristics of patients, including sociodemographic features, risk factors, life habits and psychiatric diagnoses; and (ii) to assess the clinical management, subjective wellbeing and attitudes toward medications.</p> <p>Methods</p> <p>A total of 62 SPDCs distributed throughout Italy participated in the study and 2521 patients were enrolled over the 5-month study period.</p> <p>Results</p> <p>Almost half of patients (46%) showed an aggressive behaviour at admission to ward, but they engaged more commonly in verbal aggression (38%), than in aggression toward other people (20%). A total of 78% of patients had a psychiatric diagnosis at admission, most frequently schizophrenia (36%), followed by depression (16%) and personality disorders (14%), and no relevant changes in the diagnoses pattern were observed during hospital stay. Benzodiazepines were the most commonly prescribed drugs, regardless of diagnosis, at all time points. Overall, up to 83% of patients were treated with neuroleptic drugs and up to 27% received more than one neuroleptic either during hospital stay or at discharge. Atypical and conventional antipsychotics were equally prescribed for schizophrenia (59 vs 65% during stay and 59 vs 60% at discharge), while atypical drugs were preferred in schizoaffective psychoses (72 vs 49% during stay and 70 vs 46% at discharge) and depression (41 vs 32% during stay and 44 vs 25% at discharge). Atypical neuroleptics were slightly preferred to conventional ones at hospital discharge (52 vs 44%). Polypharmacy was in general widely used. Patient attitudes toward medications were on average positive and self-reported compliance increased during hospital stay.</p> <p>Conclusion</p> <p>Results confirm the widespread use of antipsychotics and the increasing trend in atypical drugs prescription, in both psychiatric in- and outpatients.</p
Nonadiabatic fragmentation of excited molecular ions: An exploratory study for N
The photodissociation of
was studied in a one-dimensional approximation, with the
aim of understanding the nonadiabatic
features of the fragmentation dynamics.
In the collinear arrangement of the system,
the three lowest excited surfaces (
states) interact via two avoided crossings
outside the Franck-Condon region, and they are strongly coupled
radially by nonadiabatic terms.
Electronic transition probabilities
for the process , with in one of the three
lowest electronic states involved in the fragmentation,
were calculated using the semiclassical multichannel S-matrix
within the half-collision approach
to photodissociation.
The reliability of the
semiclassical theory,
for treating
multichannel nonadiabatic processes
was analyzed, and inelastic
cross-sections for the three processes
of electronically selected
fragmentations were calculated.
The structure found in the
calculated absorption lineshapes
reveals the marked influence of the nonadiabatic couplings
between excited
states in the fragmentation dynamics
of this molecular ion
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A stable pure hydroxyl layer on Pt{110}-(1x2)
The adsorption of water and coadsorption with oxygen on the missing-row reconstructed Pt{110}-(1x2) surface was studied by using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy. Coadsorbed oxygen below saturation (<0.65 +/- 0.05 ML) leads to the formation of 014, which occupies sites near the ridge Pt atoms, In contrast to the more closely packed Pt{111} Surface, OH appears not to form hydrogen bonds with coadsorbed water molecules and is stable after the desorption of water tip to about 205 K (as determined by TPD). Because OH and atomic oxygen compete for adsorption sites, water dissociation is only observed for oxygen coverages below saturation. In the absence of coadsorbed oxygen, water stays intact at all temperatures and forms a strongly bound layer of 2 ML coverage oil the clean Pt{110}-(1x2) surface at temperatures between 140 and 175 K