Abstract Objective The objective of this project, which was initiated from the Academy of Dental Materials, was to review and critically appraise methods to determine fracture, deformation and wear ...resistance of dental resin composites, in an attempt to provide guidance for investigators endeavoring to study these properties for these materials. Methods Test methods have been ranked in the priority of the specific property being tested, as well as of the specific test methods for evaluating that property. Focus was placed on the tests that are considered to be of the highest priority in terms of being the most useful, applicable, supported by the literature, and which show a correlation with clinical findings. Others are mentioned briefly for the purpose of being inclusive. When a standard test method exists, including those used in other fields, these have been identified in the beginning of each section. Also, some examples from the resin composite literature are included for each test method. Results The properties for evaluating resin composites were ranked in the priority of measurement as following: (1) Strength, Elastic Modulus, Fracture toughness, Fatigue, Indentation Hardness, Wear—abrasion (third body) and Wear—attrition (contact/two body), (2) Toughness, Edge strength (chipping) and (3) Wear determined by toothbrush. Significance The following guidance is meant to aid the researcher in choosing the proper method to assess key properties of dental resin composites with regard to their fracture, deformation and wear resistance.
The aim of this study was to compare the approach of general practitioners (GP) and outpatient specialists for psychiatry, neurology or psychosomatic medicine to patients with somatically unexplained ...complaints.
Qualitative interviews were conducted with general practitioners in Berlin and with outpatient specialists. Interviews were analyzed by qualitative content analysis.
Both GPs and specialists rarely used structured diagnostic instruments. Guidelines are seen and used with reservation throughout the different specialties. Similar to the GPs, most of the specialists surveyed in this study had reservations against the necessity of a precise coding according to the International Classification of Diseases (ICD).
In outpatient care the concern for the individual patient is the connecting element between different medical specialties. This results in a differential diagnostic and therapeutic approach that is not automatically in line with guidelines. The development of common concepts in ambulatory care might help to meet the demands of this complex group of patients with somatically unexplained complaints.
An attempt is made to quantify the contributions of different types of defect-solute clusters to the total irradiation-induced yield stress increase in neutron-irradiated (300°C, 0.6dpa), ...industrial-purity Fe–Cr model alloys (target Cr contents of 2.5, 5, 9 and 12at.% Cr). Former work based on the application of transmission electron microscopy, atom probe tomography, and small-angle neutron scattering revealed the formation of dislocation loops, NiSiPCr-enriched clusters and α′-phase particles, which act as obstacles to dislocation glide. The values of the dimensionless obstacle strength are estimated in the framework of a three-feature dispersed-barrier hardening model. Special attention is paid to the effect of measuring errors, experimental details and model details on the estimates. The three families of obstacles and the hardening model are well capable of reproducing the observed yield stress increase as a function of Cr content, suggesting that the nanostructural features identified experimentally are the main, if not the only, causes of irradiation hardening in these model alloys.
The objective of this work, commissioned by the Academy of Dental Materials, was to review and critically appraise test methods to characterize properties related to critical issues for dental resin ...composites, including technique sensitivity and handling, polymerization, and dimensional stability, in order to provide specific guidance to investigators planning studies of these properties.
The properties that relate to each of the main clinical issues identified were ranked in terms of their priority for testing, and the specific test methods within each property were ranked. An attempt was made to focus on the tests and methods likely to be the most useful, applicable, and supported by the literature, and where possible, those showing a correlation with clinical outcomes. Certain methods are only briefly mentioned to be all-inclusive. When a standard test method exists, whether from dentistry or another field, this test has been identified. Specific examples from the literature are included for each test method.
The properties for evaluating resin composites were ranked in the priority of measurement as follows: (1) porosity, radiopacity, sensitivity to ambient light, degree of conversion, polymerization kinetics, depth of cure, polymerization shrinkage and rate, polymerization stress, and hygroscopic expansion; (2) stickiness, slump resistance, and viscosity; and (3) thermal expansion.
The following guidance is meant to aid the researcher in choosing the most appropriate test methods when planning studies designed to assess certain key properties and characteristics of dental resin composites, specifically technique sensitivity and handling during placement, polymerization, and dimensional stability.
Interferometric gravitational-wave detectors are complex instruments comprised of a Michelson interferometer enhanced by multiple coupled cavities. Active feedback control is required to operate ...these instruments and keep the cavities locked on resonance. The optical response is highly nonlinear until a good operating point is reached. The linear operating range is between and 1% of a fringe for each degree of freedom. The resonance lock has to be achieved in all five degrees of freedom simultaneously, making the acquisition difficult. Furthermore, the cavity linewidth seen by the laser is only Hz, which is four orders of magnitude smaller than the linewidth of the free running laser. The arm length stabilization system is a new technique used for arm cavity locking in Advanced LIGO. Together with a modulation technique utilizing third harmonics to lock the central Michelson interferometer, the Advanced LIGO detector has been successfully locked and brought to an operating point where detecting gravitational-waves becomes feasible.
At zero temperature, a Galilean-invariant Bose fluid is expected to be fully superfluid. Here we investigate theoretically and experimentally the quenching of the superfluid density of a dilute ...Bose-Einstein condensate due to the breaking of translational (and thus Galilean) invariance by an external 1D periodic potential. Both Leggett's bound fixed by the knowledge of the total density and the anisotropy of the sound velocity provide a consistent determination of the superfluid fraction. The use of a large-period lattice emphasizes the important role of two-body interactions on superfluidity.
Zusammenfassung
Hintergrund
Ziel der Studie ist die Untersuchung des Vorgehens von Hausärzten und von Fachärzten für Psychiatrie, Nervenheilkunde oder Psychosomatik bei Patienten mit Beschwerden, die ...nicht sicher somatisch zugeordnet werden können.
Methode
Die Ergebnisse basieren auf zwei qualitativen Teilstudien, in denen Leitfadeninterviews inhaltsanalytisch ausgewertet wurden.
Ergebnisse
Sowohl Hausärzte als auch Fachärzte für Psychiatrie oder für Psychosomatik verwenden eher selten strukturierte diagnostische Instrumente. Die befragten Ärzte zeigten fachübergreifend Zurückhaltung bei der Einschätzung von Leitlinien. Ähnlich wie die befragten Hausärzte schätzten in unserer Studie viele der Spezialisten die Notwendigkeit einer präzisen ICD-Kodierung als eher gering ein.
Diskussion
Die Entwicklung gemeinsam entwickelter Konzepte könnte helfen, der komplexen Erkrankungsgruppe noch besser gerecht zu werden.
Sepsis survivors face mental and physical sequelae even years after discharge from the intensive care unit. The aim of this study was to evaluate the long-term courses of sepsis survivors and the ...effects of a primary care management intervention in sepsis aftercare.
This study presents a 24-month follow-up of a randomized controlled trial that recruited 291 patients who survived sepsis (including septic shock) from nine German intensive care units. Participants were randomized to usual care (n=143) or to a 12-month-intervention (n=148). The intervention included training of patients and their primary care physicians (PCP) in evidence-based post-sepsis care, case management provided by trained nurses, and clinical decision support for PCPs by consulting physicians. Usual care was provided by PCPs in the control group.
At the 24-month follow-up, 12 months after the 1-year-intervention, survival and measures of mental and physical health were collected by telephone interviews.
One hundred eighty-six (63.9%, 98 intervention, 88 control) of 291 patients completed the 24-month follow-up, showing both increased mortality and recovery from functional impairment. Unlike the intervention group, the control group showed a significant increase of posttraumatic stress symptoms according to the Posttraumatic Symptom Scale (difference between baseline and 24-months follow-up values, mean standard deviation 3.7 11.8 control vs -0.7 12.1 intervention; P = .016). There were no significant differences in all other outcomes between the intervention and control groups.
Twelve months after completion, a primary care management intervention among survivors of sepsis did not improve mental health-related quality of life. Patients in the intervention group showed less posttraumatic stress symptoms.
Four Fe–Cr binary alloys, with Cr content from 2.5 up to 12wt%, were neutron or ion irradiated up to a dose of 0.6 dpa at 300 °C. The microstructural response to irradiation has been characterised ...using Transmission Electron Microscopy (TEM). Both, neutrons and ions, gave rise to the formation of dislocation loops. The most striking difference between ion and neutron irradiation is the distribution of these loops in the sample. Except for the lowest Cr content, loops are distributed mainly along grain boundaries and dislocations in the neutron irradiated samples. The inhomogeneous distribution of dislocation loops could be related to the presence of α′ precipitates in the matrix. In contrast, a homogeneous distribution is observed in all ion irradiated samples. This important difference is attributed to the orders of magnitude difference in dose rate between these two irradiation conditions. Moreover, the density of loops depends non-monotonically on Cr content in case of neutron irradiation, while it seems to increase with Cr content for ion implantation. Differences are also observed in terms of cluster size, with larger sizes for neutron irradiation than for ion implantation, again pointing towards an effect of the dose rate.
•Fe–Cr binary alloys were irradiated with neutrons and ions at 300 °C, to 0.6 and 0.5 dpa, respectively. Both, neutrons and ions, gave rise to the formation of dislocation loops.•An effect of Cr is observed in the microstructural response to neutron irradiation and the main difference between alloys consists in the distribution of the dislocation loops throughout the material. While loops appeared homogeneously distributed in Fe–2.5Cr, loops appeared preferentially close to grain boundaries and dislocation lines in the alloys with higher Cr content.•Ion irradiation in similar conditions in terms of dpa resulted in a different damaged microstructure, mainly characterized by a spatially homogeneous distribution of loops for all Cr contents, with no development of high or low damaged regions as in the case of neutrons.•The differences are attributed to the difference in dose rate, affecting the initial distribution of defects and their subsequent development.
The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of ...the existing LIGO observatory facilities, we have designed a new instrument able to detect gravitational waves at distances 5 times further away than possible with Advanced LIGO, or at greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby Universe, as well as observing the Universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor.
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