Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 241
Filtrar
1.
J Synchrotron Radiat ; 30(Pt 1): 235-241, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36601942

RESUMO

The CLEAR X-ray emission spectrometer installed at the CLAESS beamline of the ALBA synchrotron is described. It is an energy-dispersive spectrometer based on Rowland circle geometry with 1 m-diameter circle. The energy dispersion is achieved by the combination of a diced analyzer crystal and a unidimensional detector. A single unconventional dynamically bent analyzer crystal (Si 111) permits a wide energy range to be covered, just by exploiting its different reflections (333, 444, 555, 777, 888): 6-22 keV, with a spectrometer efficiency that decreases above 11 keV because of the Si detector thickness (Mythen, 350 µm), while the relative scattering intensities for the Si 333, 444, 555, 777 and 888 reflections correspond to 36, 40, 21, 13 and 15, respectively. The provided energy resolution is typically below 1-2 eV and depends on the beam size, working Bragg angle and reflection exploited. In most cases the energy dispersion ranges from 10 to 20 eV and can be enlarged by working in the out-of-Rowland geometry up to 40 eV. The spectrometer works in full backscattering geometry with the beam passing through the two halves of the analyzer. The vacuum beam path and the particular geometry allow a typical average noise of only 0.5 counts per second per pixel. The spectrometer is mainly used for measuring emission lines and high-resolution absorption spectra, with a typical scanning time for highly concentrated systems of around half an hour, including several repeats. The intrinsic energy dispersion allows systematic collection of resonant X-ray emission maps by measuring high-resolution absorption spectra. Moreover, it allows spectra to be measured on a single-shot basis. Resonant inelastic X-ray scattering experiments to probe electronic excitations are feasible, although the spectrometer is not optimized for this purpose due to the limited energy resolution and scattering geometry provided. In that case, to minimize the quasi-elastic line, the spectrometer is able to rotate along the beam path. Advantages and disadvantages with respect to other existing spectrometers are highlighted.

2.
Phys Chem Chem Phys ; 25(9): 6684-6692, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36806473

RESUMO

We have combined the extended X-ray absorption fine structure (EXAFS) and X-ray emission spectroscopy (XES) to investigate the local structure and the local iron magnetic moments of (Li1-xFex)OHFeSe (x∼0.2) superconductors. The local structure, studied by Fe K-edge EXAFS measurements, is found to be inhomogeneous that is characterized by different Fe-Se bond lengths. The inhomogeneous phase exhibits a peculiar temperature dependence with lattice anomalies in the local structural parameters at the critical temperature Tc (36 K) and at the spin density wave (SDW) transition temperature TN (130 K). Fe Kß XES shows iron to be in a low spin state with the local Fe magnetic moment evolving anomalously as a function of temperature. Apart from a quantitative measurement of the local structure of (Li1-xFex)OHFeSe, providing direct evidence of nanoscale inhomogeneity, the results provide further evidence of the vital role that the coupled electronic, lattice and magnetic degrees of freedom play in the iron-based superconductors.

3.
Acta Neurochir (Wien) ; 165(3): 727-733, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36763132

RESUMO

BACKGROUND: MRgFUS Vim ablation is increasingly used for the treatment of tremor in ET e PD patients but there is little published research on the importance of operator experience in this procedure. This study aims to evaluate the learning curve and the influence of the operator experience on the procedural and clinical outcomes. METHODS: We retrospectively evaluated 90 patients (38 ET, 52 PD) submitted to MRgFUS unilateral thalamotomy in the period between February 2018 and July 2020. Clinical endpoints, procedural times, and technical parameters were recorded in all procedures. Based on the time of treatment, patients were divided into three groups of 30 units each, comparing all variables between each time period group. RESULTS: In Group A, the average patient preparation time was 120.6 min, the treatment time was 105.2 min, the number of was sonications 14.1, and the mean target shifts 3.1. In Group B, the mean preparation time was 105.5 min, the treatment time was 89.5 min, the number of sonications was 13.2, and the target shifts 3.0. Group C showed inferior values of preparation time (101.9 min), treatment time (71.7 min), numbers of sonications (10.6), and shifts (1.7). Thalamotomy-related complications occurred in 9 patients of Group A, 2 of Group B, and 5 of Group C. Tremor relapse occurred in 7 patients of Group A, 3 of Group B, and 2 of Group C. The days of hospitalization were comparable in the three groups. CONCLUSIONS: The operators experience is associated with the improvement of clinical and procedural outcome in MRgFUS thalatomy for the treatment of ET and PD tremor.


Assuntos
Tremor Essencial , Tremor , Humanos , Tremor/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , Curva de Aprendizado , Tremor Essencial/cirurgia , Tálamo/cirurgia , Imageamento por Ressonância Magnética/métodos
4.
J Thromb Thrombolysis ; 47(4): 527-532, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30877617

RESUMO

We evaluated the predictive value of several clinical, radiological and laboratory parameters on the risk of predict intracranial hemorrhage (ICH) in patients with atrial fibrillation (AF). We conducted a case-control study on a consecutive hospital based series of patients with AF and ICH. A random sample of subjects with AF without ischemic or hemorrhagic stroke was selected from the same hospital in the same period to perform as the control group, with a ratio of two controls per case. All patients underwent the same evaluation protocol. Patients without neuroimaging exams were excluded. During the study period we identified 37 subjects with AF and ICH. 74 subjects without stroke events were randomly chosen among subjects with AF. Among cases 56.8% were female; mean age was 83.1 years. Patients with ICH were more often on anticoagulant therapy (75.7%), compared with controls (45.9%; p = 0.0002). On CT scans, cases had a greater severity of leukoaraiosis at the Blennow scale (p < 0.0001) and a higher frequency of lacunar infarcts (p = 0.006). No significant association was found between MRI parameters or the HAS-BLED score and the occurrence of ICH. CT scan is more useful than MRI and HAS-BLED score to predict ICH in patients with AF on antithrombotic therapy.


Assuntos
Anticoagulantes , Fibrilação Atrial , Hemorragias Intracranianas , Leucoaraiose , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Fibrilação Atrial/sangue , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Hemorragias Intracranianas/sangue , Hemorragias Intracranianas/diagnóstico por imagem , Hemorragias Intracranianas/epidemiologia , Hemorragias Intracranianas/etiologia , Leucoaraiose/sangue , Leucoaraiose/diagnóstico por imagem , Leucoaraiose/epidemiologia , Leucoaraiose/etiologia , Masculino , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia
5.
Eur J Neurol ; 23(10): 1580-7, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27444738

RESUMO

BACKGROUND AND PURPOSE: The term hereditary spastic paraplegia (HSP) covers a spectrum of genetically heterogeneous disorders in which lower limb spasticity is the common clinical feature. Many patients with childhood-onset HSP are mistakenly diagnosed with cerebral palsy (CP). METHODS: A group of as yet molecularly undiagnosed HSP patients were analyzed using SpastoPlex, a customized target re-sequencing panel able to investigate the coding regions of 72 genes linked to HSP, spastic ataxias or related motor diseases. RESULTS: Our investigations identified loss-of-function mutations in AP4S1/SPG52 in four children (three families) who had previously received a diagnosis of diplegic/quadriplegic CP. The patients presented spastic paraparesis, mild facial dysmorphisms, moderate-to-severe intellectual disability and severe speech delay. Two patients manifested febrile seizures and childhood-onset focal seizures. In all the patients, brain magnetic resonance imaging (MRI) showed a peculiar hypoplastic posterior corpus callosum, often associated with ventriculomegaly, white matter loss and cerebral atrophy. CONCLUSION: Adaptor protein 4 (AP-4) deficiency disorders should be suspected in children with spastic paraparesis, cognitive deficit and absent speech accompanied by suggestive MRI features. Seizures might be amongst the clinical manifestations of the syndrome.


Assuntos
Complexo 4 de Proteínas Adaptadoras/genética , Paraplegia Espástica Hereditária/diagnóstico , Paraplegia Espástica Hereditária/genética , Adolescente , Paralisia Cerebral/diagnóstico , Pré-Escolar , Erros de Diagnóstico , Feminino , Humanos , Masculino , Mutação , Linhagem
6.
Neurol Sci ; 37(7): 1113-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27083895

RESUMO

Although tumefactive multiple sclerosis is a well recognized variant of multiple sclerosis, prognostic uncertainty still exists about long term prognosis. The aim of this study was to estimate the occurrence and long term outcome of tumefactive demyelinating lesions (TDLs) in a cohort of multiple sclerosis patients. We reviewed brain MRI of 443 patients referred to our MS clinic. All patients meeting the McDonald criteria for multiple sclerosis and showing at least one TDL were included. Kaplan-Meier estimates of disease-free survival in patient cohort were compared with control group without TDLs using a log-rank test. Seven cases with TDLs were identified (occurrence 1.58 %). Tumefactive demyelinating lesion recurrence was 16.6 %. Cumulative proportion of patients free from clinical relapse and from new T2 lesions was lower in the control group although not reaching statistical significance (30 vs 50 %; P = 0.666 and 21.7 vs 33.3 %; P = 0.761, respectively). Disability progression analysis showed a not significant trend towards lower probability of remaining progression free for TDL patients (50 vs 61 %; P = 0.295). Occurrence of tumefactive demyelinating lesions in our cohort was higher than those reported in other studies. Overall, TDLs were not predictive of poor outcome in terms of disability progression.


Assuntos
Doenças Desmielinizantes/diagnóstico por imagem , Doenças Desmielinizantes/etiologia , Esclerose Múltipla/complicações , Adulto , Estudos de Coortes , Avaliação da Deficiência , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Esclerose Múltipla/diagnóstico por imagem , Modelos de Riscos Proporcionais , Análise de Sobrevida , Adulto Jovem
7.
J Environ Manage ; 150: 9-20, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25460419

RESUMO

Habitat modeling is an important tool to investigate the quality of the habitat for a species within a certain area, to predict species distribution and to understand the ecological processes behind it. Many species have been investigated by means of habitat modeling techniques mainly to address effective management and protection policies and cetaceans play an important role in this context. The bottlenose dolphin (Tursiops truncatus) has been investigated with habitat modeling techniques since 1997. The objectives of this work were to predict the distribution of bottlenose dolphin in a coastal area through the use of static morphological features and to compare the prediction performances of three different modeling techniques: Generalized Linear Model (GLM), Generalized Additive Model (GAM) and Random Forest (RF). Four static variables were tested: depth, bottom slope, distance from 100 m bathymetric contour and distance from coast. RF revealed itself both the most accurate and the most precise modeling technique with very high distribution probabilities predicted in presence cells (90.4% of mean predicted probabilities) and with 66.7% of presence cells with a predicted probability comprised between 90% and 100%. The bottlenose distribution obtained with RF allowed the identification of specific areas with particularly high presence probability along the coastal zone; the recognition of these core areas may be the starting point to develop effective management practices to improve T. truncatus protection.


Assuntos
Golfinho Nariz-de-Garrafa/fisiologia , Ecossistema , Animais , Sistemas de Informação Geográfica , Mar Mediterrâneo , Densidade Demográfica , Probabilidade
8.
J Vet Pharmacol Ther ; 37(6): 603-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24806910

RESUMO

Tramadol (T) is a centrally acting atypical opioid used for treatment of dogs. Piglets might experience pain following castration, tooth clipping and tail docking and experimental procedures. The aim of this study was to assess the pharmacokinetics of T and its active metabolite M1 in male piglets after a single intramuscular injection. Six healthy male piglets were administered T (5 mg/kg) intramuscularly. Blood was sampled at scheduled time intervals and drug plasma concentrations evaluated by a validated HPLC method. T plasma concentration was quantitatively detectable from 0.083 to 8 h. M1 was quantified over a shorter time period (0.083-6 h) with a Tmax at 0.821 h. The study demonstrated that piglets produce a larger amount of M1 compared with dogs, horses and goats. The human minimum effective concentration of M1 (40 ng/mL) was exceeded for over 3 h in piglets. If it is assumed to also apply to piglets, it could be speculated that the drug efficacy might exert its action over 3 h or longer. This assumption has to be confirmed by further specific pharmacokinetic/pharmacodynamic studies.


Assuntos
Analgésicos Opioides/farmacocinética , Suínos/metabolismo , Tramadol/farmacocinética , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/sangue , Animais , Animais Recém-Nascidos/sangue , Animais Recém-Nascidos/metabolismo , Injeções Intramusculares/veterinária , Masculino , Suínos/sangue , Tramadol/administração & dosagem , Tramadol/análogos & derivados , Tramadol/sangue
9.
Phys Rev Lett ; 110(3): 037401, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23373949

RESUMO

The optical properties of a GaTa(4)Se(8) single crystal are investigated under high pressure. At ambient pressure, the optical conductivity exhibits a charge gap of ≈0.12 eV and a broad midinfrared band at ≈0.55 eV. As pressure is increased, the low energy spectral weight is strongly enhanced and the optical gap is rapidly filled, pointing to an insulator to metal transition around 6 GPa. The overall evolution of the optical conductivity demonstrates that GaTa(4)Se(8) is a Mott insulator which undergoes a bandwidth-controlled Mott metal-insulator transition under pressure, in remarkably good agreement with theory. With the use of our optical data and ab initio band structure calculations, our results were successfully compared to the (U/D, T/D) phase diagram predicted by dynamical mean field theory for strongly correlated systems.

10.
Nat Genet ; 28(1): 49-52, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11326275

RESUMO

Epilepsies affect at least 2% of the population at some time in life, and many forms have genetic determinants. We have found a mutation in a gene encoding a GABA(A) receptor subunit in a large family with epilepsy. The two main phenotypes were childhood absence epilepsy (CAE) and febrile seizures (FS). There is a recognized genetic relationship between FS and CAE, yet the two syndromes have different ages of onset, and the physiology of absences and convulsions is distinct. This suggests the mutation has age-dependent effects on different neuronal networks that influence the expression of these clinically distinct, but genetically related, epilepsy phenotypes. We found that the mutation in GABRG2 (encoding the gamma2-subunit) abolished in vitro sensitivity to diazepam, raising the possibility that endozepines do in fact exist and have a physiological role in preventing seizures.


Assuntos
Epilepsia Tipo Ausência/genética , Receptores de GABA-A/genética , Convulsões Febris/genética , Idade de Início , Anticonvulsivantes/farmacologia , Criança , Segregação de Cromossomos , Diazepam/farmacologia , Eletrofisiologia , Éxons , Feminino , Moduladores GABAérgicos/farmacologia , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Subunidades Proteicas
11.
Rev Sci Instrum ; 94(5)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37232938

RESUMO

Two camera systems are installed on the DIII-D tokamak at the toroidal positions of 90° (90° system) and 225° (225° system), respectively. The cameras have two types of relay optics, namely, a coherent optical fiber bundle and a periscope system. The periscope system provides absolute intensity calibration stability while sacrificing resolution (10 lp/mm), while the fiber system provides high resolution (16 lp/mm) while sacrificing calibration stability. The periscope is available only for the 90° system. The optics of the 225° system were designed for view stability, repeatability, and easy maintenance. The cameras are located inside optimized neutron, x ray and magnetic shielding in order to reduce electronics damage, reboots, and magnetic and neutron interference, increasing the overall system reliability. An automated filter wheel, providing remote filter change, allows for remote wavelength selection. A software suite automates camera acquisition and data storage, allowing for remote operation and reduced operator involvement. System metadata is used to streamline the data analysis workflow, particularly for intensity calibration. The spatial calibration uses multiple observable wall features, resulting in a reconstruction accuracy ≤2 cm.

12.
Sci Total Environ ; 882: 163649, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37094676

RESUMO

The dumping of an estimated amount of 57 million tons of hazardous sulfide mine waste from 1957 to 1990 into Portmán's Bay (SE Spain) caused one of the most severe cases of persistent anthropogenic impact in Europe's costal and marine environments. The resulting mine tailings deposit completely infilled Portmán's Bay and extended seawards on the continental shelf, bearing high levels of metals and As. The present work, where Synchrotron XAS, XRF core scanner and other data are combined, reveals the simultaneous presence of arsenopyrite (FeAsS), scorodite (FeAsO4·2H2O), orpiment (As2S3) and realgar (AsS) in the submarine extension of the mine tailings deposit. In addition to arsenopyrite weathering and scorodite formation, the, the presence of realgar and orpiment is discussed, considering both potential sourcing from the exploited ores and in situ precipitation from a combination of inorganic and biologically mediated geochemical processes. Whereas the formation of scorodite relates to the oxidation of arsenopyrite, we hypothesize that the presence of orpiment and realgar is associated to scorodite dissolution and subsequent precipitation of these two minerals within the mine tailings deposit under moderately reducing conditions. The occurrence of organic debris and reduced organic sulfur compounds evidences the activity of sulfate-reducing bacteria (SRB) and provides a plausible explanation to the reactions leading to the formation of authigenic realgar and orpiment. The precipitation of these two minerals in the mine tailings, according to our hypothesis, has important consequences for As mobility since this process would reduce the release of As into the surrounding environment. Our work provides for the first time valuable hints on As speciation in a massive submarine sulfide mine tailings deposit, which is highly relevant for similar situations worldwide.

13.
Spinal Cord ; 50(3): 238-42, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22124342

RESUMO

STUDY DESIGN: Multicenter, prospective study. OBJECTIVES: To assess the occurrence and predictors of return to work after traumatic spinal cord injury (SCI). SETTING: Italian rehabilitation centers. METHODS: We evaluated patients previously included in the Italian Group for the Epidemiological Study of Spinal Cord Injuries study. A standardised telephone interview was used to collect data after a mean follow-up of 3.8 years. The main outcome measure was employment at the end of follow-up. RESULTS: A total of 403 patients, 336 men and 67 women, with a mean age of 41.8±16.3 years, were included in the follow-up. In all, 42.1% of patients were employed at the moment of the interview, though 62% reported a worsening in their employment level. Predictors of employment were education (P<0.0001), bowel continence (P=0.02), independence in mobility (P=0.0004), ability to drive (P<0.0001), participating in the community (P=0.0001) and ability to live alone (P<0.0001) while age (P<0.0001), being married (P<0.0001), tetraplegia (P=0.03), occurrence of recent medical problems (P=0.002), re-hospitalization (P=0.02), presence of architectonic barriers (P=0.009) and having a public welfare subsidy (P<0.0001), predicted unemployment. On the basis of multivariate analysis, younger age, education, absence of tetraplegia, ability to drive, ability to live alone, previous employment were independent predictors of employment after SCI. Employment at follow-up was related to several indicators of quality of life. CONCLUSION: Employment after SCI was rather frequent and was related to several patient characteristics and social factors. Specific interventions on the patient and on the social environment may favor employment after SCI and improve quality of life.


Assuntos
Emprego/estatística & dados numéricos , Qualidade de Vida , Traumatismos da Medula Espinal , Adulto , Feminino , Seguimentos , Previsões , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Características de Residência , Traumatismos da Medula Espinal/economia , Traumatismos da Medula Espinal/psicologia , Traumatismos da Medula Espinal/reabilitação , Adulto Jovem
14.
Materials (Basel) ; 15(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35806527

RESUMO

The local structure of the filled tetragonal tungsten bronze (TTB) niobate Ba3Nb5-xTixO15 (x = 0, 0.1, 0.7, 1.0), showing a metal-insulator transition with Ti substitution, has been studied by Nb K-edge extended X-ray absorption fine structure (EXAFS) measurements as a function of temperature. The Ti substitution has been found to have a substantial effect on the local structure, that remains largely temperature independent in the studied temperature range of 80-400 K. The Nb-O bonds distribution shows an increased octahedral distortion induced by Ti substitution, while Nb-Ba distances are marginally affected. The Nb-O bonds are stiffer in the Ti substituted samples, which is revealed by the temperature dependent mean square relative displacements (MSRDs). Furthermore, there is an overall increase in the configurational disorder while the system with Nb 4d electrons turns insulating. The results underline a clear relationship between the local structure and the electronic transport properties suggesting that the metal-insulator transition and possible thermoelectric properties of TTB structured niobates can be tuned by disorder.

15.
Phys Rev Lett ; 107(23): 237202, 2011 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-22182121

RESUMO

The structural stability of fcc Ni over a very large pressure range offers a unique opportunity to experimentally investigate how magnetism is modified by simple compression. K-edge x-ray magnetic circular dichroism (XMCD) shows that fcc Ni is ferromagnetic up to 200 GPa, contradicting recent predictions of an abrupt transition to a paramagnetic state at 160 GPa. Density functional theory calculations point out that the pressure evolution of the K-edge XMCD closely follows that of the p projected orbital moment rather than that of the total spin moment. The disappearance of magnetism in Ni is predicted to occur above 400 GPa.

16.
Rev Sci Instrum ; 92(3): 033533, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33819993

RESUMO

An Imaging Fast Ion D-alpha (IFIDA) diagnostic, characterized by a high optical spatial resolution of ≤2 mm for accurate validation of energetic particle (EP) transport models, has been developed on DIII-D. The diagnostic provides a 2D image in the radial-poloidal plane of the FIDA signal generated by EP emission after charge exchange with an injected neutral beam. A narrow passband filter integrates the FIDA signal in the spectral region of 650-652 nm (blue-shifted FIDA tail), which is mostly generated by co-passing EPs of energies E ≃ 40-80 keV. A beam modulation technique is employed to estimate the active component of the signal, which is then used to compute EP profiles and gradients with a higher accuracy than the standard spectroscopic FIDA diagnostic. The current diagnostic time resolution is ≃3 ms. In this work, the IFIDA diagnostic design is explained and data are compared with the spectroscopic FIDA diagnostic, which shares the same viewing geometry, to assess the improvements in EP profile reconstruction.

17.
Sci Rep ; 11(1): 17763, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493767

RESUMO

The elusive crystal structure of the so-called 'antimonic acid' has been investigated by means of robust and state-of-the-art techniques. The synergic results of solid-state magic-angle spinning nuclear magnetic resonance spectroscopy and a combined Rietveld refinement from synchrotron X-ray and neutron powder diffraction data reveal that this compound contains two types of protons, in a pyrochlore-type structure of stoichiometric formula (H3O)1.20(7)H0.77(9)Sb2O6. Some protons belong to heavily delocalized H3O+ subunits, while some H+ are directly bonded to the oxygen atoms of the covalent framework of the pyrochlore structure, with O-H distances close to 1 Å. A proton diffusion mechanism is proposed relying on percolation pathways determined by bond-valence energy landscape analysis. X-ray absorption spectroscopy results corroborate the structural data around Sb5+ ions at short-range order. Thermogravimetric analysis and differential scanning calorimetry endorsed the conclusions on the water content within antimonic acid. Additional 0.7 water molecules per formula were assessed as moisture water by thermal analysis.

18.
J Clin Neurosci ; 92: 33-38, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34509258

RESUMO

MRgFUS Vim thalamotomy is a novel, effective, minimally invasive therapeutic option for patients with essential tremor (ET). Among the selection criteria, some parameters related to the patient's anatomy, such as the skull density ratio (SDR), are well recognized. The role of brain tissue interposed between the target and the ultrasound transducers has never been explored. Therefore, the purpose of our study was to evaluate the correlation and the possible predictive value between brain tissue volumes (grey matter - GM, white matter - WM, and cerebrospinal fluid - CSF) and several treatment-related variables (periprocedural parameters, MRI imaging findings, and the clinical outcome). We analysed data from thirty ET patients previously submitted to MRgFUS thalamotomy. Pre-treatment images were automatically segmented in sopra-tentorial (ST) WM, GM, and CSF using SPM 12. The most significant findings were a positive correlation of the ST-GM with the Accumulated Thermal Dose (ATD) (p < 0,001) and a negative correlation of the ATD temperature with ST-CSF and ST-TIV (p < 0,001). Ultrasound propagation speed is lower in fluids than brain tissues. Also, WM has an attenuation rate of 1.5 higher than the GM. Therefore, the difference in the ATD may be explained by the different acoustic properties of normal brain tissues interposed between the transducers and the VIM.


Assuntos
Tremor Essencial , Tremor Essencial/diagnóstico por imagem , Tremor Essencial/cirurgia , Humanos , Imageamento por Ressonância Magnética , Prognóstico , Crânio , Tálamo/diagnóstico por imagem , Tálamo/cirurgia
19.
G Ital Med Lav Ergon ; 32(4 Suppl): 192-4, 2010.
Artigo em Italiano | MEDLINE | ID: mdl-21438259

RESUMO

The aim of this study was to evaluate the employment condition of persons with TSCI 4 years after discharge from rehabilitation facilities, as well as the factors related to better outcome. In the follow-up we interviewed 403 persons. We recorded the following variables: current employment status, causes of unemployment and their correlation with demographic status, clinical status and other information. In our results 51.4% of the interviewed persons were unemployed, 34.7% had a job and 7.2% were students. Among the unemployed persons 34% had suffered an accident at work, 31% had been unable to find suitable work and 31% were retired. Employment significantly correlated with younger age, single status, being paraplegic, being autonomous in bladder/bowel management, driving a car and a better quality of life. In the multivariate analysis the factors predicting better outcome were younger age, ability to drive and a better quality of life.


Assuntos
Terapia Ocupacional , Traumatismos da Medula Espinal/reabilitação , Trabalho , Adulto , Feminino , Humanos , Masculino
20.
J Phys Condens Matter ; 33(9): 095803, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331297

RESUMO

The local structure of La(Fe1-x Mn x )AsO has been investigated using temperature dependent Fe K-edge extended x-ray absorption fine structure (EXAFS) measurements. The EXAFS data reveal distinct behavior of Fe-As and Fe-Fe atomic displacements with a clear boundary between x ⩽ 0.02 and x > 0.02. The Fe-As bondlength shows a gradual thermal expansion while the Fe-Fe bond manifests a temperature dependent anomaly at ∼180 K for x > 0.02. It is interesting to find characteristically different nature of Fe-As and Fe-Fe bondlengths shown by the temperature dependent mean square relative displacements. Indeed, the Fe-As bond, stiffer than that of the Fe-Fe, gets softer for x ⩽ 0.02 and hardly shows any change for x > 0.02. On the other hand, Fe-Fe bond tends to be stiffer for x ⩽ 0.02 followed by a substantial softening for x > 0.02. Such a distinction has been seen also in the As K-edge x-ray absorption near edge structure, probing local geometry around As atom together with the valence electronic structure. The results suggest that local atomic displacements by Mn substitution inducing increased iron local magnetic moment that should be the main reason for its dramatic effect in iron-based superconductors.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA