768 research outputs found
Fatigue properties of nanocrystallized surfaces obtained by high energy shot peening
AbstractAn unconventional method of shot peening aimed to generation of a nanograined layer over the surface of specimens has been applied by means of the standard air blast equipment but using peening parameters essentially different from typical ones. Surface nanocrystallization is verified and affirmed through different experimental procedures. Rotating bending fatigue tests are performed to evaluate the effect of this high energy shot peening and the nanocrystallized layer on fatigue life. First series results are available and the other tests are still in progress
Liver Resection after Downstaging Hepatocellular Carcinoma with Sorafenib
Background. Sorafenib is a molecular-targeted therapy used in palliative treatment of advanced hepatocellular carcinoma in Child A patients. Aims. To address the question of sorafenib as neoadjuvant treatment. Methods. We describe the cases of 2 patients who had surgery after sorafenib.
Results. The patients had a large hepatocellular carcinoma in the right liver with venous neoplastic thrombi (1 in the right portal branch, 1 in the right hepatic vein). After 9 months of sorafenib, reassessment showed that tumours had decreased in size with a necrotic component. A right hepatectomy with thrombectomy was performed, and histopathology showed 35% to 60% necrosis. One patient had a recurrence after 6 months and had another liver resection; they are both recurrence-free since then. Conclusion. Sorafenib can downstage hepatocellular carcinoma and thus could represent a bridge to surgery. It may be possible to select patients in good general condition with partial regression of the tumour with sorafenib for a treatment in a curative intent
Effect of Shot Peening on Oxidation and Precipitation in Inconel 718
In this study, the effect of the surface state on the behaviour of Inconel 718 alloy exposed to 640 ∘ C and 700 ∘ C environments for times varying between one and one hundred hours was investigated. In particular, the focus was set on the evolution of oxidation and precipitation phenomena during thermal exposure. Three surface states were considered: two generated through shot peening treatments featuring different coverage levels, while the third condition is a non-peened one. Shot peening treatments modify the surface condition and introduce higher residual stresses and microhardness values than in the non-treated condition. The morphology of the oxides appears to be different depending on the condition observed. Regarding the kinetics, over time the oxidation process follows a parabolic trend and appears to be influenced by the surface state; in particular, severe shot peening treatment is characterized by the highest intensity of the phenomenon. However, the order of magnitude of the weight gains measured suggests that the observed variations can be neglected, and that the positive effect of shot peening can be exploited without introducing oxidation problems. From the point of view of the microstructural evolution, an increase in the coarsening kinetics of γ ” phase was observed in the shot peened layer
ANTICUERPOS CONTRA EL VIRUS CAUSANTE DE LA RINOTRAQUEITIS INFECCIOSA EN VACUNOSDE LA PROVINCIA DE MELGAR, PUNO
El presente estudio tuvo por objetivo determinar la prevalencia del virus herpes bovino tipo 1 (VHB-1), agente causal de la rinotraqueitis infecciosa bovina, en animales de la provincia deMelgar, Puno. Se recolectaron muestras de sangre de bovinos mayores a 6 meses de edad (n = 382) provenientes de nueve distritos de la provincia de Melgar, para la detección de anticuerpos contra el VHB-1 mediante la prueba de neutralización viral. La prevalencia del VHB-1 fue de 29.0 ± 0.1%(110/382), sin que hubiese diferencias entre animales jóvenes (<2 años) y adultos (³2 años). Los títulos de anticuerpos variaron entre 2 a 128. Los resultados indican que el VHB-1 está difundido en los bovinos de la provincia de Melgar y, posiblemente, esté contribuyendo en la presentación de problemas respiratorios en animales jóvenes.The prevalence of bovine herpesvirus type 1 (BHV-1) was determined in 382 bovine older than 6months of age in herds of the province ofMelgar, Puno, Peru. Serum samples were tested for antibodies against BHV-1 using the viral neutralization test. The 29.0 ± 0.1%(110/382) of the samples had antibodies against BHV-1, without differences between young (2 years old) and mature (³2 years old) animals.Antibody titers varied between 2 to 128. The results indicated that BHV-1 infection is widespread in cattle population of the province ofMelgar, Puno, and it is possibly contributing to cause respiratory disease problems in young animals
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Polyornithine-based polyplexes to boost effective gene silencing in CNS disorders.
Gene silencing therapies have successfully suppressed the translation of target proteins, a strategy that holds great promise for the treatment of central nervous system (CNS) disorders. Advances in the current knowledge on multimolecular delivery vehicles are concentrated on overcoming the difficulties in delivery of small interfering (si)RNA to target tissues, which include anatomical accessibility, slow diffusion, safety concerns, and the requirement for specific cell uptake within the unique environment of the CNS. The present work addressed these challenges through the implementation of polyornithine derivatives in the construction of polyplexes used as non-viral siRNA delivery vectors. Physicochemical and biological characterization revealed biodegradability and biocompatibility of our polyornithine-based system and the ability to silence gene expression in primary oligodendrocyte progenitor cells (OPCs) effectively. In summary, the well-defined properties and neurological compatibility of this polypeptide-based platform highlight its potential utility in the treatment of CNS disorders
Stroke risk and NSAIDs: A systematic review of observational studies
Aims: To perform a quantitative systematic review of observational studies on the risk of stroke associated with the use of individual NSAIDs. Methods and results: Searches were conducted using the Medline database within PubMed (1990-2008). Observational cohort or case-control studies were eligible if reported on the risk of cardiovascular events associated with individual NSAIDs versus the nonuse of NSAIDs. We found 3193 articles, in which 75 were eligible for review and abstraction. Of the 75 articles, 6 reported relative risk (RR) of stroke. Data were abstracted into a database using a standardized entry form. Two authors assessed study quality, and discrepancies were resolved by consensus. The pooled RR of all subtypes of incident stroke was increased with the current use of rofecoxib (RR=1.64, 95% CI=1.15-2.33) and diclofenac (RR=1.27, 95% CI=1.08-1.48). The pooled estimates for naproxen, ibuprofen, and celecoxib were close to unity. The risk of ischemic stroke was also increased with rofecoxib (RR=1.82, 95% CI=1.09-3.04) and diclofenac (RR=1.20, 95% CI=0.99-1.45). Data were inadequate to estimate the pooled RR by dose and duration, for other individual NSAIDs or nonischemic stroke subtypes. Conclusion: This meta-analysis supports an increased risk of ischemic stroke with the current use of rofecoxib and diclofenac. Additional studies are required to evaluate most individual NSAIDS, the effect of dose and duration, and the subtypes of stroke
Antipsychotics and Torsadogenic Risk: Signals Emerging from the US FDA Adverse Event Reporting System Database
Background: Drug-induced torsades de pointes (TdP) and related clinical entities represent a current regulatory and clinical burden. Objective: As part of the FP7 ARITMO (Arrhythmogenic Potential of Drugs) project, we explored the publicly available US FDA Adverse Event Reporting System (FAERS) database to detect signals of torsadogenicity for antipsychotics (APs). Methods: Four groups of events in decreasing order of drug-attributable risk were identified: (1) TdP, (2) QT-interval abnormalities, (3) ventricular fibrillation/tachycardia, and (4) sudden cardiac death. The reporting odds ratio (ROR) with 95 % confidence interval (CI) was calculated through a cumulative analysis from group 1 to 4. For groups 1+2, ROR was adjusted for age, gender, and concomitant drugs (e.g., antiarrhythmics) and stratified for AZCERT drugs, lists I and II (http://www.azcert.org, as of June 2011). A potential signal of torsadogenicity was defined if a drug met all the following criteria: (a) four or more cases in group 1+2; (b) significant ROR in group 1+2 that persists through the cumulative approach; (c) significant adjusted ROR for group 1+2 in the stratum without AZCERT drugs; (d) not included in AZCERT lists (as of June 2011). Results: Over the 7-year period, 37 APs were reported in 4,794 cases of arrhythmia: 140 (group 1), 883 (group 2), 1,651 (group 3), and 2,120 (group 4). Based on our criteria, the following potential signals of torsadogenicity were found: amisulpride (25 cases; adjusted ROR in the stratum without AZCERT drugs = 43.94, 95 % CI 22.82-84.60), cyamemazine (11; 15.48, 6.87-34.91), and olanzapine (189; 7.74, 6.45-9.30). Conclusions: This pharmacovigilance analysis on the FAERS found 3 potential signals of torsadogenicity for drugs previously unknown for this risk
Silicon Nanowire Sensors Enable Diagnosis of Patients via Exhaled Breath
Two of the biggest challenges in medicine today are the need to detect diseases in a noninvasive manner and to differentiate between patients using a single diagnostic tool. The current study targets these two challenges by developing a molecularly modified silicon nanowire field effect transistor (SiNW FET) and showing its use in the detection and classification of many disease breathprints (lung cancer, gastric cancer, asthma, and chronic obstructive pulmonary disease). The fabricated SiNW FETs are characterized and optimized based on a training set that correlate their sensitivity and selectivity toward volatile organic compounds (VOCs) linked with the various disease breathprints. The best sensors obtained in the training set are then examined under real-world clinical conditions, using breath samples from 374 subjects. Analysis of the clinical samples show that the optimized SiNW FETs can detect and discriminate between almost all binary comparisons of the diseases under examination with >80% accuracy. Overall, this approach has the potential to support detection of many diseases in a direct harmless way, which can reassure patients and prevent numerous unpleasant investigations
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Being Surveyed Can Change Later Behavior and Related Parameter Estimates
Does completing a household survey change the later behavior of those surveyed? In three field studies of health and two of microlending, we randomly assigned subjects to be surveyed about health and/or household finances and then measured subsequent use of a related product with data that does not rely on subjects' self-reports. In the three health experiments, we find that being surveyed increases use of water treatment products and take-up of medical insurance. Frequent surveys on reported diarrhea also led to biased estimates of the impact of improved source water quality. In two microlending studies, we do not find an effect of being surveyed on borrowing behavior. The results suggest that limited attention could play an important but context-dependent role in consumer choice, with the implication that researchers should reconsider whether, how, and how much to survey their subjectsEconomic
Comparison of Pittsburgh compound B and florbetapir in cross-sectional and longitudinal studies.
IntroductionQuantitative in vivo measurement of brain amyloid burden is important for both research and clinical purposes. However, the existence of multiple imaging tracers presents challenges to the interpretation of such measurements. This study presents a direct comparison of Pittsburgh compound B-based and florbetapir-based amyloid imaging in the same participants from two independent cohorts using a crossover design.MethodsPittsburgh compound B and florbetapir amyloid PET imaging data from three different cohorts were analyzed using previously established pipelines to obtain global amyloid burden measurements. These measurements were converted to the Centiloid scale to allow fair comparison between the two tracers. The mean and inter-individual variability of the two tracers were compared using multivariate linear models both cross-sectionally and longitudinally.ResultsGlobal amyloid burden measured using the two tracers were strongly correlated in both cohorts. However, higher variability was observed when florbetapir was used as the imaging tracer. The variability may be partially caused by white matter signal as partial volume correction reduces the variability and improves the correlations between the two tracers. Amyloid burden measured using both tracers was found to be in association with clinical and psychometric measurements. Longitudinal comparison of the two tracers was also performed in similar but separate cohorts whose baseline amyloid load was considered elevated (i.e., amyloid positive). No significant difference was detected in the average annualized rate of change measurements made with these two tracers.DiscussionAlthough the amyloid burden measurements were quite similar using these two tracers as expected, difference was observable even after conversion into the Centiloid scale. Further investigation is warranted to identify optimal strategies to harmonize amyloid imaging data acquired using different tracers
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