Electronic Band Structure of the Two-Dimensional Surface-State Bands of the (1×1) and (1×2) Phases of Bi/GaSb(110)

The surface-state bands of the (1×1) and (1×2) phases of Bi/GaSb(110) have been probed using angle-resolved ultraviolet photoemission spectroscopy with synchrotron radiation. Four Bi-induced surface-state bands have been identified for both the (1×1) and the (1×2) phases. The bands with the lowest binding energies (SI and SII) have been attributed to intrachain bonding in the Bi overlayer and the higher-binding-energy bands (SIII and SIV) to overlayer states involved in the back bonding of the overlayer to the substrate. Based on initial-state dispersion measurements, we conclude that the Bi chains in the epitaxial overlayer remain intact throughout the phase transition. We propose a model for the overlayer structure of the (1×2) phase of Bi/GaSb(110)

Effect of integrated care for sick listed patients with chronic low back pain: economic evaluation alongside a randomised controlled trial

Objective To evaluate the cost effectiveness, cost utility, and cost-benefit of an integrated care programme compared with usual care for sick listed patients with chronic low back pain

The Generalizability of Personality Effects in Politics

A burgeoning line of research examining the relation between personality traits and political variables relies extensively on convenience samples. However, our understanding of the extent to which using convenience samples challenges the generalizability of these findings to target populations remains limited. We address this question by testing whether associations between personality and political characteristics observed in representative samples diverged from those observed in the sub-populations most commonly studied in convenience samples, namely students and internet users. We leverage ten high-quality representative datasets to compare the representative samples with the two sub- samples. We did not find any systematic differences in the relationship between personality traits and a broad range of political variables. Instead, results from the sub-samples generalized well to those observed in the broader and more diverse representative sample

An integrated care program to prevent work disability due to chronic low back pain: a process evaluation within a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>In the past decade, a considerable amount of research has been carried out to evaluate the effectiveness of innovative low back pain (LBP) interventions. Although some interventions proved to be effective, they are not always applied in daily practice. To successfully implement an innovative program it is important to identify barriers and facilitators in order to change practice routine. Because usual care is not directly aimed at return to work (RTW), we evaluated an integrated care program, combining a patient-directed and a workplace-directed intervention provided by a multidisciplinary team, including a clinical occupational physician to reduce occupational disability in chronic LBP patients. The aims of this study were to describe the feasibility of the implementation of the integrated care program, to assess the satisfaction and expectations of the involved stakeholders and to describe the needs for improvement of the program.</p> <p>Methods</p> <p>Eligible for this study were patients who had been on sick leave due to chronic LBP. Data were collected from the patients, their supervisors and the involved health care professionals, by means of questionnaires and structured charts, during 3-month follow-up. Implementation, satisfaction and expectations were investigated.</p> <p>Results</p> <p>Of the 40 patients who were eligible to participate in the integrated care program, 37 patients, their supervisors and the health care professionals actually participated in the intervention. Adherence to the integrated care program was in accordance with the protocol, and the patients, their supervisors and the health care professionals were (very) satisfied with the program. The role of the clinical occupational physician was of additional value in the RTW process. Time-investment was the only barrier for implementation reported by the multidisciplinary team.</p> <p>Conclusion</p> <p>The implementation of this program will not be influenced by any flaws in its application that are related to the program itself, or to the adherence of patients with chronic LBP and their health care professionals.</p> <p>This program is promising in terms of feasibility, satisfaction and compliance of the patients, their supervisors and the health care professionals. Before implementation on a wider scale, the communication and the information technology of the program should be improved.</p> <p>Trials Registration</p> <p>[ISRCTN28478651]</p

Passive and Active Oxidation of Si(100) by Atomic Oxygen: A Theoretical Study of Possible Reaction Mechanisms

Reaction mechanisms for oxidation of the Si(100) surface by atomic oxygen were studied with high-level quantum mechanical methods in combination with a hybrid QM/MM (Quantum mechanics/Molecular Mechanics) method. Consistent with previous experimental and theoretical results, three structures, “back-bond”, “on-dimer”, and “dimer-bridge”, are found to be the most stable initial surface products for O adsorption (and in the formation of SiO2 films, i.e., passive oxidation). All of these structures have significant diradical character. In particular, the “dimer-bridge” is a singlet diradical. Although the ground state of the separated reactants, O+Si(100), is a triplet, once the O atom makes a chemical bond with the surface, the singlet potential energy surface is the ground state. With mild activation energy, these three surface products can be interconverted, illustrating the possibility of the thermal redistribution among the initial surface products. Two channels for SiO desorption (leading to etching, i.e., active oxidation) have been found, both of which start from the back-bond structure. These are referred to as the silicon-first (SF) and oxygen-first (OF) mechanisms. Both mechanisms require an 89.8 kcal/mol desorption barrier, in good agreement with the experimental estimates of 80−90 kcal/mol. “Secondary etching” channels occurring after initial etching may account for other lower experimental desorption barriers. The calculated 52.2 kcal/mol desorption barrier for one such secondary etching channel suggests that the great variation in reported experimental barriers for active oxidation may be due to these different active oxidation channels

Multidisciplinary outpatient care program for patients with chronic low back pain: design of a randomized controlled trial and cost-effectiveness study [ISRCTN28478651]

<p>Abstract</p> <p>Background</p> <p>Chronic low back pain (LBP) is a major public and occupational health problem, which is associated with very high costs. Although medical costs for chronic LBP are high, most costs are related to productivity losses due to sick leave. In general, the prognosis for return to work (RTW) is good but a minority of patients will be absent long-term from work. Research shows that work related problems are associated with an increase in seeking medical care and sick leave. Usual medical care of patients is however, not specifically aimed at RTW.</p> <p>The objective is to present the design of a randomized controlled trial, i.e. the BRIDGE-study, evaluating the effectiveness in improving RTW and cost-effectiveness of a multidisciplinary outpatient care program situated in both primary and outpatient care setting compared with usual clinical medical care for patients with chronic LBP.</p> <p>Methods/Design</p> <p>The design is a randomized controlled trial with an economic evaluation alongside. The study population consists of patients with chronic LBP who are completely or partially sick listed and visit an outpatient clinic of one of the participating hospitals in Amsterdam (the Netherlands). Two interventions will be compared. 1. a multidisciplinary outpatient care program consisting of a workplace intervention based on participatory ergonomics, and a graded activity program using cognitive behavioural principles. 2. usual care provided by the medical specialist, the occupational physician, the patient's general practitioner and allied health professionals. The primary outcome measure is sick leave duration until full RTW. Sick leave duration is measured monthly by self-report during one year. Data on sick leave during one-year follow-up are also requested form the employers. Secondary outcome measures are pain intensity, functional status, pain coping, patient satisfaction and quality of life. Outcome measures are assessed before randomization and 3, 6, and 12 months later. All statistical analysis will be performed according to the intension-to-treat principle.</p> <p>Discussion</p> <p>Usual care of primary and outpatient health services isn't directly aimed at RTW, therefor it is desirable to look for care which is aimed at RTW. Research shows that several occupational interventions in primary care are aimed at RTW. They have shown a significant reduction of sick leave for employee with LBP. If a comparable reduction of sick leave duration of patients with chronic LBP of who attend an outpatient clinic can be achieved, such reductions will be obviously substantial for the Netherlands and will have a considerable impact.</p> <p>Trial registration</p> <p>ISRCTN28478651</p