In situ scanning electron microscopy indentation studies on multilayer nitride films: Methodology and deformation mechanisms

Systematic studies of the deformation mechanisms of multilayer transition metal nitride coatings TiN/CrN, TiN/NbN, and NbN/CrN, and corresponding reference coatings of TiN, NbN, and CrN deposited by a direct current (dc) magnetron sputtering process onto silicon 〈100〉 have been performed. Mechanical characterization was conducted using a combination of microindentation and nanoindentation in the load range 30 to 150 mN and 0.5 to 3.5 mN, respectively. For both load ranges, scanning electron microscopy (SEM) in situ indentation was used to observe the indentation process including any pileup, sink-in, and fracture mechanisms specific to each coating. The coatings' microstructure, both before and after indentation, was analyzed using transmission electron microscopy (TEM). It was possible to both correlate the indentation load-displacement response to surface roughness effects and fracture modes (substrate and film cracking) and observe deformation mechanisms within the coating

Scale effects for strength, ductility, and toughness in "brittle” materials

Decreasing scales effectively increase nearly all important mechanical properties of at least some "brittle” materials below 100 nm. With an emphasis on silicon nanopillars, nanowires, and nanospheres, it is shown that strength, ductility, and toughness all increase roughly with the inverse radius of the appropriate dimension. This is shown experimentally as well as on a mechanistic basis using a proposed dislocation shielding model. Theoretically, this collects a reasonable array of semiconductors and ceramics onto the same field using fundamental physical parameters. This gives proportionality between fracture toughness and the other mechanical properties. Additionally, this leads to a fundamental concept of work per unit fracture area, which predicts the critical event for brittle fracture. In semibrittle materials such as silicon, this can occur at room temperature when the scale is sufficiently small. When the local stress associated with dislocation nucleation increases to that sufficient to break bonds, an instability occurs resulting in fractur

SUM_M(2)×\timesUC_C(1) Gauge Symmetry in High TcT_c Superconductivity

The square lattice structure of $CuO_2$ layers and the strongly correlated property of electrons indicate that the high $T_c$ superconductivity in cuprates can be described by a SO$_M$(5) coherent pairing state in which a SU$_M$(2)$\times$U$_C$(1) gauge symmetry is embedded. The spin and charge fluctuations that characterize the low energy magnetic excitations in cuprates are controlled by this intrinsic SU$_M$(2)$\times$U$_C$(1) gauge symmetry.Comment: 4 pages Revtex fil

The association between hospital variation in curative treatment for esophagogastric cancer and health-related quality of life and survival

Background: As previous studies showed significant hospital variation in curative treatment of esophagogastric cancer, this study assesses the association between this variation and overall, cancer-specific and recurrence-free survival, and Health-Related Quality of Life (HRQoL). Methods: Patients diagnosed with potentially curable esophageal or gastric cancer between 2015 and 2018 as registered in the Netherlands Cancer Registry were included. Data on overall survival was available for all patients, data on cancer-specific and recurrence-free survival and HRQoL was available for subgroups. Patients were classified according to diagnosis in hospitals with low, medium or high probability of treatment with curative intent (LP, MP or HP). Multivariable models were used to assess the association between LP, MP and HP hospitals and HRQoL and survival. Results: This study includes 7,199 patients with esophageal, and 2,407 with gastric cancer. Overall and cancer-specific survival was better for patients diagnosed in HP versus LP hospitals for both esophageal (HR = 0.82, 95%CI:0.77–0.88 and HR = 0.82, 95%CI:0.75–0.91, respectively), and gastric cancer (HR = 0.82, 95%CI:0.73–0.92 and HR = 0.74, 95%CI:0.64–0.87, respectively). These differences disappeared after adjustments for treatment. Recurrence-free survival was worse for gastric cancer patients diagnosed in HP hospitals (HR = 1.50, 95%CI:1.14–1.96), which disappeared after adjustment for radicality of surgery. Minor, but no clinically relevant, differences in HRQoL were observed.Conclusions: Patients diagnosed in hospitals with a high probability of treatment with curative intent have a better overall and cancer-specific but not recurrence-free survival, while minor differences in HRQoL were observed.</p

Long-Term Outcome of Patients With a Hematologic Malignancy and Multiple Organ Failure Admitted at the Intensive Care

Objectives: Historically, patients with a hematologic malignancy have one of the highest mortality rates among cancer patients admitted to the ICU. Therefore, physicians are often reluctant to admit these patients to the ICU. The aim of our study was to examine the survival of patients who have a hematologic malignancy and multiple organ failure admitted to the ICU. Design: This retrospective cohort study, part of the HEMA-ICU study group, was designed to study the survival of patients with a hematologic malignancy and organ failure after admission to the ICU. Patients were followed for at least 1 year. Setting: Five university hospitals in the Netherlands. Patients: One-thousand ninety-seven patients with a hematologic malignancy who were admitted at the ICU. Interventions: None. Measurements and Main Results: Primary outcome was 1-year survival. Organ failure was categorized as acute kidney injury, respiratory failure, hepatic failure, and hemodynamic failure; multiple organ failure was defined as failure of two or more organs. The World Health Organization performance score measured 3 months after discharge from the ICU was used as a measure of functional outcome. The 1-year survival rate among these patients was 38%. Multiple organ failure was inversely associated with long-term survival, and an absence of respiratory failure was the strongest predictor of 1-year survival. The survival rate among patients with 2, 3, and 4 failing organs was 27%, 22%, and 8%, respectively. Among all surviving patients for which World Health Organization scores were available, 39% had a World Health Organization performance score of 0–1 3 months after ICU discharge. Functional outcome was not associated with the number of failing organs. Conclusions: Our results suggest that multiple organ failure should not be used as a criterion for excluding a patient with a hematologic malignancy from admission to the ICU

Myoclonus in comatose patients with electrographic status epilepticus after cardiac arrest: corresponding EEG patterns, effects of treatment and outcomes

Objective: To clarify the significance of any form of myoclonus in comatose patients after cardiac arrest with rhythmic and periodic EEG patterns (RPPs) by analyzing associations between myoclonus and EEG pattern, response to anti-seizure medication and neurological outcome.Design: Post hoc analysis of the prospective randomized Treatment of ELectroencephalographic STatus Epilepticus After Cardiopulmonary Resus-citation (TELSTAR) trial.Setting: Eleven ICUs in the Netherlands and Belgium.Patients: One hundred and fifty-seven adult comatose post-cardiac arrest patients with RPPs on continuous EEG monitoring. Interventions: Anti-seizure medication vs no anti-seizure medication in addition to standard care.Measurements and Main Results: Of 157 patients, 98 (63%) had myoclonus at inclusion. Myoclonus was not associated with one specific RPP type. However, myoclonus was associated with a smaller probability of a continuous EEG background pattern (48% in patients with vs 75% without myoclonus, odds ratio (OR) 0.31; 95% confidence interval (CI) 0.16-0.64) and earlier onset of RPPs (24% vs 9% within 24 hours after cardiac arrest, OR 3.86;95% CI 1.64-9.11). Myoclonus was associated with poor outcome at three months, but not invariably so (poor neurological outcome in 96% vs 82%, p = 0.004). Anti-seizure medication did not improve outcome, regardless of myoclonus presence (6% good outcome in the intervention group vs 2% in the control group, OR 0.33; 95% CI 0.03-3.32).Conclusions: Myoclonus in comatose patients after cardiac arrest with RPPs is associated with poor outcome and discontinuous or suppressed EEG. However, presence of myoclonus does not interact with the effects of anti-seizure medication and cannot predict a poor outcome without false positives.Neurological Motor Disorder

Nanostructured partially stabilized zirconia as an interlayer in a multi layered thermal barrier coating

Stresses developed within a thermal barrier coating (TBC) due to the mismatch in thermal expansion of different coating components causes coating failure. Nanostructured materials have an increased volume fraction of grain boundaries and this microstructural attribute may allow coatings to relieve the strain in the coating structure; thereby improving the effectiveness and the lifetime of the TBC. Multi – layered TBCs were prepared using two techniques; atmospheric pressure plasma spray using a commercial system, and reduced pressure plasma spray using the Triple Torch Plasma Reactor. The coatings were deposited on mullite and on NiCrAlY-coated steel substrates, and consisted of an inter layer of nano-phase partially stabilized zirconia (n-PSZ) and a layer of yttria stabilized zirconia coating (YSZ) as the top thermal barrier coat. The coatings were heat treated at various temperatures and the microstructural changes analyzed using scanning electron microscopy (SEM) images. It was observed that the changes in porosity, a critical microstructural feature that is necessary for the coatings to perform under operational conditions were not altered significantly - the data lay within the estimated deviations of the image analysis measurements. Mechanical properties of the coating were studied using micro-indentation and four point bend testing to better understand the effect of the n-PSZ inter-layer on the strain relief mechanisms that may be operative within the TBC

Extended domains of organized nanostructures and study of their physical properties

International audienc

Extended domains of organised metallic nanodots and study of their physical properties

International audienc