Ion implantation and thermal annealing effects on composition and structure of Ni/Ti multilayer have been studied and reported in this paper. The thin films composed of five (Ni/Ti) bilayers were ...deposited by d.c. ion sputtering on (100) Si wafers to a total thickness of ∼180 nm. Ion irradiations were performed by 180 keV Ar+ ions with fluence of 6 × 1016 ions cm−2. After deposition and implantation, the samples were annealed at 400 °C for 30 min in an inert ambient. Composition and structural characterizations were performed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Annealing of as-deposited samples at 400 °C induces a progressed interaction between Ni and Ti layers with the initial formation of NiTi alloy phase. Progressed alloying was achieved for the ion fluence of 6 × 1016 ions cm−2 and the formed structure is composed of NiTi compound, only at depth around the projected ion range. In the deeper layers, beyond the projected range of implanted ions, the diffusion of Ni atoms can lead to solid state amorphization. Subsequent annealing at 400 °C for 30 min enabled enhanced interaction between intermixed Ni and Ti layers, and in the layers close to the Si substrate the conditions for the formation of intermetallic compound are created.
► Ni/Ti multilayer system is modified by ion implantation and thermal annealing. ► Thermal annealing is induced initial formatiom of NiTi intermetallic compound. ► NiTi nanoalloy phase is formed at room temperature after Ar ion implantation. ► Subsequent annealing of implanted Ni/Ti multilayer is enhanced formation of NiTi nanoalloy.
The increasing success of intensive consolidation chemotherapy (CCT) as an alternative to bone marrow transplant (BMT) in acute myeloid leukaemia (AML) necessitates comparison of the impact on ...quality of life (QoL) of these two treatment modalities. Most QoL studies following BMT involve small patient numbers and provide ambivalent results. The present study examines QoL in a large number of patients 1 year from the end of treatment within the United Kingdom Medical Research Council (UK MRC) AML10 trial of BMT versus CCT. Allogeneic-BMT (Allo-BMT) was observed to have an adverse impact on most QoL dimensions compared with Autologous-BMT (A-BMT) and CCT. More patients receiving BMT had mouth dryness problems and worse sexual and social relationships, professional and leisure activities than CCT patients. QoL in A-BMT patients was less impacted than Allo-BMT. Intention-to-treat analysis showed similar results. These results indicate that a reconsideration of treatment strategies is warranted, and that further, good prospective studies are needed to evaluate more clearly the effects of these treatments in long-term survivors.
We review progress in silicon LEDs using dislocation engineering to achieve high temperature operation, a process that is fully CMOS (Complementary Metal Oxide Semiconductor) compatible. We ...concentrate on devices operating in the near infra-red where high value applications are. The need for silicon emitters, lasers and optical amplifiers is discussed followed by an outline of previous approaches and possible future routes explored. Results on gain in silicon are reported and routes to electrically pumped injection lasers and optical amplifiers considered. Extension of 1.1 and 1.5
μm devices to other wavelengths is discussed.
To identify preoperative and intraoperative risk factors for adnexal torsion after hysterectomy, and to estimate the incidence of the disease in the modern-day era of laparoscopic surgery.
...Retrospective nested case-control study.
Large urban medical system.
Eighty-nine female patients ages 17 to 51.
Patients underwent ovarian-sparing hysterectomy.
The estimated incidence of ovarian torsion after hysterectomy was 0.5% (46/8538 ovarian-sparing hysterectomies). The following variables were found to be associated with adnexal torsion after hysterectomy in an adjusted logistic regression: laparoscopic or laparoscopic-assisted approach to hysterectomy vs any other approach (odds ratio OR, 3.36; 95% confidence interval CI, 0.86-13.23); younger age at the time of hysterectomy (17-40 years) vs older age (41-51 years) (OR, 3.45; 95% CI, 1.33-8.97); and a gynecologic history significant for endometriosis (OR, 4.07; 95% CI, 1.04-15.88).
There is an association between laparoscopic approach to hysterectomy, younger age at time of hysterectomy, and a history of endometriosis with subsequent risk of adnexal torsion. Providers should have a heightened index of suspicion for adnexal torsion after hysterectomy in patients presenting with acute-onset abdominal pain who underwent laparoscopic hysterectomy at a younger age.
Declines in habitat and wildlife in semiarid African savannas are widely reported and commonly attributed to agropastoral population growth, livestock impacts, and subsistence cultivation. However, ...extreme annual and shorter-term variability of rainfall, primary production, vegetation, and populations of grazers make directional trends and causal chains hard to establish in these ecosystems. Here two decades of changes in land cover and wildebeest in the Serengeti-Mara region of East Africa are analyzed in terms of potential drivers (rainfall, human and livestock population growth, socio-economic trends, land tenure, agricultural policies, and markets). The natural experiment research design controls for confounding variables, and our conceptual model and statistical approach integrate natural and social sciences data. The Kenyan part of the ecosystem shows rapid land-cover change and drastic decline for a wide range of wildlife species, but these changes are absent on the Tanzanian side. Temporal climate trends, human population density and growth rates, uptake of small-holder agriculture, and livestock population trends do not differ between the Kenyan and Tanzanian parts of the ecosystem and cannot account for observed changes. Differences in private versus state/communal land tenure, agricultural policy, and market conditions suggest, and spatial correlations confirm, that the major changes in land cover and dominant grazer species numbers are driven primarily by private landowners responding to market opportunities for mechanized agriculture, less by agropastoral population growth, cattle numbers, or small-holder land use.
Common understanding of the causes of land-use and land-cover change is dominated by simplifications which, in turn, underlie many environment-development policies. This article tracks some of the ...major myths on driving forces of land-cover change and proposes alternative pathways of change that are better supported by case study evidence. Cases reviewed support the conclusion that neither population nor poverty alone constitute the sole and major underlying causes of land-cover change worldwide. Rather, peoples’ responses to economic opportunities, as mediated by institutional factors, drive land-cover changes. Opportunities and constraints for new land uses are created by local as well as national markets and policies. Global forces become the main determinants of land-use change, as they amplify or attenuate local factors.
Within the field of environmental management and conservation, the concept of well-being is starting to gain traction in monitoring the socio-economic and cultural impact of interventions on local ...people. Here we consider the practical trade-offs policy makers and practitioners must navigate when utilizing the concept of well-being in environmental interventions. We first review current concepts of well-being before considering the need to balance the complexity and practical applicability of the definition used and to consider both positive and negative components of well-being. A key determinant of how well-being is operationalized is the identity of the organization wishing to monitor it. We describe the trade-offs around the external and internal validity of different approaches to measuring well-being and the relative contributions of qualitative and quantitative information to understanding well-being. We explore how these trade-offs may be decided as a result of a power struggle between stakeholders. Well-being is a complex, multi-dimensional, dynamic concept that cannot be easily defined and measured. Local perspectives are often missed during the project design process as a result of the more powerful voices of national governments and international NGOs, so for equity and local relevance it is important to ensure these perspectives are represented at a high level in project design and implementation.
PDF
