230 research outputs found
Test di laboratorio di iniezione per l’impermeabilizzazione e consolidamento di terreni granulari per mezzo di materiali innovativi
La possibilità di iniettare un terreno, mediante una miscela in grado di modificarne le caratteristiche geotecniche, rimane oggi una delle tecniche di miglioramento dei terreni più efficace nell’ottica dello scavo di gallerie. I campi di applicabilità di queste miscele dipendono da numerosi parametri esterni, legati sia alle caratteristiche dei terreni da permeare, sia alle tecniche d’iniezione. Le prove di laboratorio non sono codificate e spesso sono basate su procedimenti concepiti ex novo dai vari sperimentatori. In linea generale si può dire che le prove di laboratorio sono prevalentemente focalizzate sulla caratterizzazione reologica delle miscele utilizzate, sulla loro effettiva capacità di penetrazione in terreni granulari campione e sui parametri di resistenza ottenibili sui terreni iniettati.
Il principale obiettivo della ricerca è quello di analizzare le proprietà di due nuovi materiali per l’iniezione, il microcemento e la nanosilice colloidale, attraverso la caratterizzazione della miscela e lo studio della sua capacità di penetrazione in vari terreni granulari.
Le prove effettuate in questa sperimentazione hanno dimostrato le effettive capacità di questi nuovi materiali nel conseguire un’eccellente penetrazione e un ottimo consolidamento dei terreni granulari, anche con percentuali di grani fini nel terreno
Procalcitonin-guided antibiotic therapy: An expert consensus
Procalcitonin (PCT) is a useful biomarker of bacterial infection and its use is associated to reduced duration of antibiotic therapy in the setting of intensive care medicine. To address the need of practical guidance for the use of PCT in various clinical settings, a group of experts was invited to participate at a consensus process with the aims of defining the rationale for appropriate use of PCT and for improving the management of critically ill patients with sepsis. A group of 14 experts from anesthesiology and critical care, infectious diseases, internal medicine, pulmonology, clinical microbiology, laboratory medicine, clinical pharmacology and methodology provided expert opinion through a modified Delphi process, after a comprehensive literature review. The appropriateness of use of PCT in terms of diagnosis, prognosis and antimicrobial stewardship was assessed for different scenarios or settings such us management of infection in the emergency department, regular wards, surgical wards or in the intensive care unit. Similarly, appropriateness and timing of PCT measurement were evaluated. All the process consisted in three Delphi rounds. PCT use is appropriate in algorithms for antibiotic de-escalation and discontinuation. In this case, reproducible, high sensitive assays should be used. However, initiation or escalation of antibiotic therapy in specific scenarios, including acute respiratory infections, should not be based solely on PCT serum levels. Clinical and radiological findings, evaluation of severity of illness and of patient's characteristics should be taken into proper account in order to correctly interpret PCT results
The Magnificent Seven: Magnetic fields and surface temperature distributions
Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT
data and characterized by thermal X-ray spectra are known. They exhibit very
similar properties and despite intensive searches their number remained
constant since 2001 which led to their name ``The Magnificent Seven''. Five of
the stars exhibit pulsations in their X-ray flux with periods in the range of
3.4 s to 11.4 s. XMM-Newton observations revealed broad absorption lines in the
X-ray spectra which are interpreted as cyclotron resonance absorption lines by
protons or heavy ions and / or atomic transitions shifted to X-ray energies by
strong magnetic fields of the order of 10^13 G. New XMM-Newton observations
indicate more complex X-ray spectra with multiple absorption lines. Pulse-phase
spectroscopy of the best studied pulsars RX J0720.4-3125 and RBS 1223 reveals
variations in derived emission temperature and absorption line depth with pulse
phase. Moreover, RX J0720.4-3125 shows long-term spectral changes which are
interpreted as due to free precession of the neutron star. Modeling of the
pulse profiles of RX J0720.4-3125 and RBS 1223 provides information about the
surface temperature distribution of the neutron stars indicating hot polar caps
which have different temperatures, different sizes and are probably not located
in antipodal positions.Comment: 10 pages, 8 figures, to appear in Astrophysics and Space Science, in
the proceedings of "Isolated Neutron Stars: from the Interior to the
Surface", edited by D. Page, R. Turolla and S. Zan
Alzheimer’s disease marker phospho-tau181 is not elevated in the first year after moderate-severe TBI
Background: Traumatic brain injury (TBI) is associated with the tauopathies Alzheimer’s disease and chronic traumatic encephalopathy. Advanced immunoassays show significant elevations in plasma total tau (t-tau) early post-TBI, but concentrations subsequently normalise rapidly. Tau phosphorylated at serine-181 (p-tau181) is a well-validated Alzheimer’s disease marker that could potentially seed progressive neurodegeneration. We tested whether post-traumatic p-tau181 concentrations are elevated and relate to progressive brain atrophy. Methods: Plasma p-tau181 and other post-traumatic biomarkers, including total-tau (t-tau), neurofilament light (NfL), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP), were assessed after moderate-to-severe TBI in the BIO-AX-TBI cohort (first sample mean 2.7 days, second sample within 10 days, then 6 weeks, 6 months and 12 months, n=42). Brain atrophy rates were assessed in aligned serial MRI (n=40). Concentrations were compared patients with and without Alzheimer’s disease, with healthy controls. Results: Plasma p-tau181 concentrations were significantly raised in patients with Alzheimer’s disease but not after TBI, where concentrations were non-elevated, and remained stable over one year. P-tau181 after TBI was not predictive of brain atrophy rates in either grey or white matter. In contrast, substantial trauma-associated elevations in t-tau, NfL, GFAP and UCH-L1 were seen, with concentrations of NfL and t-tau predictive of brain atrophy rates. Conclusions: Plasma p-tau181 is not significantly elevated during the first year after moderate-to-severe TBI and levels do not relate to neuroimaging measures of neurodegeneration
Órteses para o paciente com osteoartrite do polegar: o que os terapeutas ocupacionais no Brasil indicam?
Órteses são consideradas a primeira linha de atuação para o tratamento de disfunções causadas pela osteoartrite (OA) da articulação carpometacárpica do polegar. Entretanto, não existem estudos que investiguem as preferências e indicações de órteses por profissionais brasileiros. Objetivo: Identificar os modelos de órteses indicados por terapeutas ocupacionais para pacientes com OA do polegar, bem como as barreiras encontradas para o uso deste recurso. Métodos: Estudo exploratório transversal, realizado através de questionário eletrônico com terapeutas ocupacionais brasileiros. Os dados obtidos foram analisados por meio da distribuição, frequência e porcentagem das respostas. Resultados: Participaram da pesquisa 52 terapeutas ocupacionais de todo o Brasil, atuando junto a pacientes reumáticos. A maioria das indicações foi de órteses sob medida (81%), envolvendo mais de uma articulação (83,7%). PolÃticas institucionais e ausência de materiais foram as principais dificuldades para 48,1% dos participantes. Conclusão: A indicação de órteses para pacientes com OA se faz presente na prática clÃnica de terapeutas ocupacionais e torna-se importante o incentivo a estratégias que permitam o aperfeiçoamento e difusão de ações de reabilitação junto a esta população.Orthoses are the first line of action for the treatment of dysfunctions caused by osteoarthritis (OA) of the carpometacarpal joint of the thumb. However, there are no studies that investigate the preferences and orthotics prescriptions made by Brazilian health professionals. Objective: To identify orthotic designs indicated by occupational therapists for patients with thumb OA and the barriers encountered to use these devices. Methods: Cross-sectional, exploratory study conducted by electronic questionnaire with Brazilian occupational therapists. Data were analyzed using the distribution, frequency and percentage of responses. Results: 52 Brazilian occupational therapists who treated patients with rheumatic diseases participated in this study. Most of the participants indicated custom-made models (81%), involving more than one joint (83.7%). Institutional policies and lack of materials were the main barriers for 48.1% of the participants. Conclusion: The prescription of orthoses for patients with OA is present in the clinical practice of occupational therapists, and it is important to encourage strategies to the development and dissemination of rehabilitation actions for this population
Impact of the COVID-19 outbreak on severe trauma trends and healthcare system reassessment in Lombardia, Italy: an analysis from the regional trauma registry
Backgrounds: The COVID-19 pandemic drastically strained the health systems worldwide, obligating the reassessment of how healthcare is delivered. In Lombardia, Italy, a Regional Emergency Committee (REC) was established and the regional health system reorganized, with only three hospitals designated as hubs for trauma care. The aim of this study was to evaluate the effects of this reorganization of regional care, comparing the distribution of patients before and during the COVID-19 outbreak and to describe changes in the epidemiology of severe trauma among the two periods. Methods: A cohort study was conducted using retrospectively collected data from the Regional Trauma Registry of Lombardia (LTR). We compared the data of trauma patients admitted to three hub hospitals before the COVID-19 outbreak (September 1 to November 19, 2019) with those recorded during the pandemic (February 21 to May 10, 2020) in the same hospitals. Demographic data, level of pre-hospital care (Advanced Life Support-ALS, Basic Life Support-BLS), type of transportation, mechanism of injury (MOI), abbreviated injury score (AIS, 1998 version), injury severity score (ISS), revised trauma score (RTS), and ICU admission and survival outcome of all the patients admitted to the three trauma centers designed as hubs, were reviewed. Screening for COVID-19 was performed with nasopharyngeal swabs, chest ultrasound, and/or computed tomography. Results: During the COVID-19 pandemic, trauma patients admitted to the hubs increased (46.4% vs 28.3%, p < 0.001) with an increase in pre-hospital time (71.8 vs 61.3 min, p < 0.01), while observed in hospital mortality was unaffected. TRISS, ISS, AIS, and ICU admission were similar in both periods. During the COVID-19 outbreak, we observed substantial changes in MOI of severe trauma patients admitted to three hubs, with increases of unintentional (31.9% vs 18.5%, p < 0.05) and intentional falls (8.4% vs 1.2%, p < 0.05), whereas the pandemic restrictions reduced road- related injuries (35.6% vs 60%, p < 0.05). Deaths on scene were significantly increased (17.7% vs 6.8%, p < 0.001). Conclusions: The COVID-19 outbreak affected the epidemiology of severe trauma patients. An increase in trauma patient admissions to a few designated facilities with high level of care obtained satisfactory results, while COVID-19 patients overwhelmed resources of most other hospitals
Blood component therapy and coagulopathy in trauma: A systematic review of the literature from the trauma update group
Background Traumatic coagulopathy is thought to increase mortality and its treatment to reduce preventable deaths. However, there is still uncertainty in this field, and available literature results may have been overestimated. Methods We searched the MEDLINE database using the PubMed platform. We formulated four queries investigating the prognostic weight of traumatic coagulopathy defined according to conventional laboratory testing, and the effectiveness in reducing mortality of three different treatments aimed at contrasting coagulopathy (high fresh frozen plasma/packed red blood cells ratios, fibrinogen, and tranexamic acid administration). Randomized controlled trials were selected along with observational studies that used a multivariable approach to adjust for confounding. Strict criteria were adopted for quality assessment based on a two-step approach. First, we rated quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Then, this rating was downgraded if other three criteria were not met: high reporting quality according to shared standards, absence of internal methodological and statistical issues not detailed by the GRADE system, and absence of external validity issues. Results With few exceptions, the GRADE rating, reporting and methodological quality of observational studies was "very low", with frequent external validity issues. The only two randomized trials retrieved were, instead, of high quality. Only weak evidence was found for a relation between coagulopathy and mortality. Very weak evidence was found supporting the use of fibrinogen administration to reduce mortality in trauma. On the other hand, we found high evidence that the use of 1:1 vs. 1:2 high fresh frozen plasma/packed red blood cells ratios failed to obtain a 12% mortality reduction. This does not exclude lower mortality rates, which have not been investigated. The use of tranexamic acid in trauma was supported by "high" quality evidence according to the GRADE classification but was downgraded to "moderate" for external validity issues. Conclusions Tranexamic acid is effective in reducing mortality in trauma. The other transfusion practices we investigated have been inadequately studied in the literature, as well as the independent association between mortality and coagulopathy measured with traditional laboratory testing. Overall, in this field of research literature quality is poor
Axonal marker neurofilament light predicts long-term outcomes and progressive neurodegeneration after traumatic brain injury
Axonal injury is a key determinant of long-term outcomes after traumatic brain injury (TBI) but has been difficult to measure clinically. Fluid biomarker assays can now sensitively quantify neuronal proteins in blood. Axonal components such as neurofilament light (NfL) potentially provide a diagnostic measure of injury. In the multicenter BIO-AX-TBI study of moderate-severe TBI, we investigated relationships between fluid biomarkers, advanced neuroimaging, and clinical outcomes. Cerebral microdialysis was used to assess biomarker concentrations in brain extracellular fluid aligned with plasma measurement. An experimental injury model was used to validate biomarkers against histopathology. Plasma NfL increased after TBI, peaking at 10 days to 6 weeks but remaining abnormal at 1 year. Concentrations were around 10 times higher early after TBI than in controls (patients with extracranial injuries). NfL concentrations correlated with diffusion MRI measures of axonal injury and predicted white matter neurodegeneration. Plasma TAU predicted early gray matter atrophy. NfL was the strongest predictor of functional outcomes at 1 year. Cerebral microdialysis showed that NfL concentrations in plasma and brain extracellular fluid were highly correlated. An experimental injury model confirmed a dose-response relationship of histopathologically defined axonal injury to plasma NfL. In conclusion, plasma NfL provides a sensitive and clinically meaningful measure of axonal injury produced by TBI. This reflects the extent of underlying damage, validated using advanced MRI, cerebral microdialysis, and an experimental model. The results support the incorporation of NfL sampling subacutely after injury into clinical practice to assist with the diagnosis of axonal injury and to improve prognostication
Systematic review of the literature and evidence-based recommendations for antibiotic prophylaxis in trauma : results from an italian consensus of experts
Antibiotic prophylaxis is frequently administered in severe trauma. However, the risk of selecting resistant bacteria, a major issue especially in critical care environments, has not been sufficiently investigated. The aim of the present study was to provide guidelines for antibiotic prophylaxis for four different trauma-related clinical conditions, taking into account the risks of antibiotic-resistant bacteria selection, thus innovating previous guidelines in the field
MHC-class-II are expressed in a subpopulation of human neural stem cells in vitro in an IFN gamma-independent fashion and during development
This work was supported by grants from Great Ormond Street Hospital Children’s Charity, Newlife Foundation,
the Antony Nolan Trust, a studentship to CAG from Consejo Nacional de Ciencia y Tecnologia (CONACyT)
and Instituto Jaliscience de la Juventud (IJJ), Mexico and GOSH NIHR Biomedical Research Centre. The human
embryonic and fetal material was provided by the Human Developmental Biology Resource (http://hdbr.org)
jointly funded by the Medical Research Council (grant G070089) and The Wellcome Trust (grant GR082557)
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